Cutting support for OpenSSL 1.0.1 and 1.0.2 in 17~?

From b59a9a192d88bfd6261a3559ace8caced2e25d9a Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Fri, 26 May 2023 10:45:35 +0900
Subject: [PATCH v2] Remove support for OpenSSL 1.0.1

A few notes about that:
- This simplifies a lot of code areas related to channel binding, as
X509_get_signature_nid() always exists.
- This removes the comments related to 1.0.1e introduced by 74242c2.
- Do we need to care about the case of building the Postgres code with
LibreSSL on Windows for the MSVC scripts, leading to the removal of the
check with HAVE_SSL_CTX_SET_CERT_CB?
---
 src/include/libpq/libpq-be.h             |  6 ----
 src/include/pg_config.h.in               |  3 --
 src/backend/libpq/auth-scram.c           | 20 ++++++------
 src/backend/libpq/be-secure-openssl.c    |  4 ---
 src/interfaces/libpq/fe-auth-scram.c     |  8 ++---
 src/interfaces/libpq/fe-auth.c           |  2 +-
 src/interfaces/libpq/fe-secure-openssl.c |  4 ---
 src/interfaces/libpq/libpq-int.h         |  6 ----
 src/test/ssl/t/002_scram.pl              | 41 ++++--------------------
 doc/src/sgml/installation.sgml           |  2 +-
 configure                                | 16 ++++-----
 configure.ac                             |  8 ++---
 meson.build                              |  7 ++--
 src/tools/msvc/Solution.pm               | 10 +-----
 14 files changed, 37 insertions(+), 100 deletions(-)

diff --git a/src/include/libpq/libpq-be.h b/src/include/libpq/libpq-be.h
index 3b2ce9908f..a0b74c8095 100644
--- a/src/include/libpq/libpq-be.h
+++ b/src/include/libpq/libpq-be.h
@@ -305,14 +305,8 @@ extern void be_tls_get_peer_serial(Port *port, char *ptr, size_t len);
  *
  * The result is a palloc'd hash of the server certificate with its
  * size, and NULL if there is no certificate available.
- *
- * This is not supported with old versions of OpenSSL that don't have
- * the X509_get_signature_nid() function.
  */
-#if defined(USE_OPENSSL) && (defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO))
-#define HAVE_BE_TLS_GET_CERTIFICATE_HASH
 extern char *be_tls_get_certificate_hash(Port *port, size_t *len);
-#endif
 
 /* init hook for SSL, the default sets the password callback if appropriate */
 #ifdef USE_OPENSSL
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6d572c3820..ca3a49c552 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -529,9 +529,6 @@
 /* Define to 1 if you have the `X509_get_signature_info' function. */
 #undef HAVE_X509_GET_SIGNATURE_INFO
 
-/* Define to 1 if you have the `X509_get_signature_nid' function. */
-#undef HAVE_X509_GET_SIGNATURE_NID
-
 /* Define to 1 if the assembler supports X86_64's POPCNTQ instruction. */
 #undef HAVE_X86_64_POPCNTQ
 
diff --git a/src/backend/libpq/auth-scram.c b/src/backend/libpq/auth-scram.c
index 9b286aa4d7..118d15b1a1 100644
--- a/src/backend/libpq/auth-scram.c
+++ b/src/backend/libpq/auth-scram.c
@@ -209,10 +209,9 @@ scram_get_mechanisms(Port *port, StringInfo buf)
 	/*
 	 * Advertise the mechanisms in decreasing order of importance.  So the
 	 * channel-binding variants go first, if they are supported.  Channel
-	 * binding is only supported with SSL, and only if the SSL implementation
-	 * has a function to get the certificate's hash.
+	 * binding is only supported with SSL.
 	 */
-#ifdef HAVE_BE_TLS_GET_CERTIFICATE_HASH
+#ifdef USE_SSL
 	if (port->ssl_in_use)
 	{
 		appendStringInfoString(buf, SCRAM_SHA_256_PLUS_NAME);
@@ -251,13 +250,12 @@ scram_init(Port *port, const char *selected_mech, const char *shadow_pass)
 	/*
 	 * Parse the selected mechanism.
 	 *
-	 * Note that if we don't support channel binding, either because the SSL
-	 * implementation doesn't support it or we're not using SSL at all, we
-	 * would not have advertised the PLUS variant in the first place.  If the
-	 * client nevertheless tries to select it, it's a protocol violation like
-	 * selecting any other SASL mechanism we don't support.
+	 * Note that if we don't support channel binding, or if we're not using
+	 * SSL at all, we would not have advertised the PLUS variant in the first
+	 * place.  If the client nevertheless tries to select it, it's a protocol
+	 * violation like selecting any other SASL mechanism we don't support.
 	 */
-#ifdef HAVE_BE_TLS_GET_CERTIFICATE_HASH
+#ifdef USE_SSL
 	if (strcmp(selected_mech, SCRAM_SHA_256_PLUS_NAME) == 0 && port->ssl_in_use)
 		state->channel_binding_in_use = true;
 	else
@@ -1010,7 +1008,7 @@ read_client_first_message(scram_state *state, const char *input)
 						 errmsg("malformed SCRAM message"),
 						 errdetail("The client selected SCRAM-SHA-256-PLUS, but the SCRAM message does not include channel binding data.")));
 
-#ifdef HAVE_BE_TLS_GET_CERTIFICATE_HASH
+#ifdef USE_SSL
 			if (state->port->ssl_in_use)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION),
@@ -1306,7 +1304,7 @@ read_client_final_message(scram_state *state, const char *input)
 	channel_binding = read_attr_value(&p, 'c');
 	if (state->channel_binding_in_use)
 	{
-#ifdef HAVE_BE_TLS_GET_CERTIFICATE_HASH
+#ifdef USE_SSL
 		const char *cbind_data = NULL;
 		size_t		cbind_data_len = 0;
 		size_t		cbind_header_len;
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 05276ab95c..658b09988d 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -831,8 +831,6 @@ be_tls_write(Port *port, void *ptr, size_t len, int *waitfor)
  *
  * These functions are closely modelled on the standard socket BIO in OpenSSL;
  * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c.
- * XXX OpenSSL 1.0.1e considers many more errcodes than just EINTR as reasons
- * to retry; do we need to adopt their logic for that?
  */
 
 #ifndef HAVE_BIO_GET_DATA
@@ -1429,7 +1427,6 @@ be_tls_get_peer_serial(Port *port, char *ptr, size_t len)
 		ptr[0] = '\0';
 }
 
-#if defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO)
 char *
 be_tls_get_certificate_hash(Port *port, size_t *len)
 {
@@ -1488,7 +1485,6 @@ be_tls_get_certificate_hash(Port *port, size_t *len)
 
 	return cert_hash;
 }
-#endif
 
 /*
  * Convert an X509 subject name to a cstring.
diff --git a/src/interfaces/libpq/fe-auth-scram.c b/src/interfaces/libpq/fe-auth-scram.c
index 6b779ec7ff..61e6cd84d2 100644
--- a/src/interfaces/libpq/fe-auth-scram.c
+++ b/src/interfaces/libpq/fe-auth-scram.c
@@ -401,7 +401,7 @@ build_client_first_message(fe_scram_state *state)
 		Assert(conn->ssl_in_use);
 		appendPQExpBufferStr(&buf, "p=tls-server-end-point");
 	}
-#ifdef HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
+#ifdef USE_SSL
 	else if (conn->channel_binding[0] != 'd' && /* disable */
 			 conn->ssl_in_use)
 	{
@@ -474,7 +474,7 @@ build_client_final_message(fe_scram_state *state)
 	 */
 	if (strcmp(state->sasl_mechanism, SCRAM_SHA_256_PLUS_NAME) == 0)
 	{
-#ifdef HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
+#ifdef USE_SSL
 		char	   *cbind_data = NULL;
 		size_t		cbind_data_len = 0;
 		size_t		cbind_header_len;
@@ -540,9 +540,9 @@ build_client_final_message(fe_scram_state *state)
 		appendPQExpBufferStr(&conn->errorMessage,
 							 "channel binding not supported by this build\n");
 		return NULL;
-#endif							/* HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH */
+#endif							/* USE_SSL */
 	}
-#ifdef HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
+#ifdef USE_SSL
 	else if (conn->channel_binding[0] != 'd' && /* disable */
 			 conn->ssl_in_use)
 		appendPQExpBufferStr(&buf, "c=eSws");	/* base64 of "y,," */
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 88fd0f3d80..f8e09d3b41 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -478,7 +478,7 @@ pg_SASL_init(PGconn *conn, int payloadlen)
 			{
 				/* The server has offered SCRAM-SHA-256-PLUS. */
 
-#ifdef HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
+#ifdef USE_SSL
 				/*
 				 * The client supports channel binding, which is chosen if
 				 * channel_binding is not disabled.
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 390c888c96..bea71660ab 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -364,7 +364,6 @@ pgtls_write(PGconn *conn, const void *ptr, size_t len)
 	return n;
 }
 
-#if defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO)
 char *
 pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 {
@@ -439,7 +438,6 @@ pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 
 	return cert_hash;
 }
-#endif							/* HAVE_X509_GET_SIGNATURE_NID */
 
 /* ------------------------------------------------------------ */
 /*						OpenSSL specific code					*/
@@ -1826,8 +1824,6 @@ PQsslAttribute(PGconn *conn, const char *attribute_name)
  *
  * These functions are closely modelled on the standard socket BIO in OpenSSL;
  * see sock_read() and sock_write() in OpenSSL's crypto/bio/bss_sock.c.
- * XXX OpenSSL 1.0.1e considers many more errcodes than just EINTR as reasons
- * to retry; do we need to adopt their logic for that?
  */
 
 #ifndef HAVE_BIO_GET_DATA
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 0045f83cbf..b70d4aee6a 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -833,14 +833,8 @@ extern ssize_t pgtls_write(PGconn *conn, const void *ptr, size_t len);
  *
  * NULL is sent back to the caller in the event of an error, with an
  * error message for the caller to consume.
- *
- * This is not supported with old versions of OpenSSL that don't have
- * the X509_get_signature_nid() function.
  */
-#if defined(USE_OPENSSL) && (defined(HAVE_X509_GET_SIGNATURE_NID) || defined(HAVE_X509_GET_SIGNATURE_INFO))
-#define HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH
 extern char *pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len);
-#endif
 
 /*
  * Verify that the server certificate matches the host name we connected to.
diff --git a/src/test/ssl/t/002_scram.pl b/src/test/ssl/t/002_scram.pl
index 28c54bdb09..3a798e1a56 100644
--- a/src/test/ssl/t/002_scram.pl
+++ b/src/test/ssl/t/002_scram.pl
@@ -44,9 +44,6 @@ my $SERVERHOSTADDR = '127.0.0.1';
 # This is the pattern to use in pg_hba.conf to match incoming connections.
 my $SERVERHOSTCIDR = '127.0.0.1/32';
 
-# Determine whether build supports tls-server-end-point.
-my $supports_tls_server_end_point =
-  check_pg_config("#define HAVE_X509_GET_SIGNATURE_NID 1");
 # Determine whether build supports detection of hash algorithms for
 # RSA-PSS certificates.
 my $supports_rsapss_certs =
@@ -90,21 +87,9 @@ $node->connect_fails(
 	expected_stderr => qr/invalid channel_binding value: "invalid_value"/);
 $node->connect_ok("$common_connstr user=ssltestuser channel_binding=disable",
 	"SCRAM with SSL and channel_binding=disable");
-if ($supports_tls_server_end_point)
-{
-	$node->connect_ok(
-		"$common_connstr user=ssltestuser channel_binding=require",
-		"SCRAM with SSL and channel_binding=require");
-}
-else
-{
-	$node->connect_fails(
-		"$common_connstr user=ssltestuser channel_binding=require",
-		"SCRAM with SSL and channel_binding=require",
-		expected_stderr =>
-		  qr/channel binding is required, but server did not offer an authentication method that supports channel binding/
-	);
-}
+$node->connect_ok(
+	"$common_connstr user=ssltestuser channel_binding=require",
+	"SCRAM with SSL and channel_binding=require");
 
 # Now test when the user has an MD5-encrypted password; should fail
 $node->connect_fails(
@@ -152,22 +137,10 @@ $node->connect_fails(
 	expected_stderr =>
 	  qr/channel binding required but not supported by server's authentication request/
 );
-if ($supports_tls_server_end_point)
-{
-	$node->connect_ok(
-		"$common_connstr user=ssltestuser channel_binding=require require_auth=scram-sha-256",
-		"SCRAM with SSL, channel_binding=require, and require_auth=scram-sha-256"
-	);
-}
-else
-{
-	$node->connect_fails(
-		"$common_connstr user=ssltestuser channel_binding=require require_auth=scram-sha-256",
-		"SCRAM with SSL, channel_binding=require, and require_auth=scram-sha-256",
-		expected_stderr =>
-		  qr/channel binding is required, but server did not offer an authentication method that supports channel binding/
-	);
-}
+$node->connect_ok(
+	"$common_connstr user=ssltestuser channel_binding=require require_auth=scram-sha-256",
+	"SCRAM with SSL, channel_binding=require, and require_auth=scram-sha-256"
+);
 
 # Now test with a server certificate that uses the RSA-PSS algorithm.
 # This checks that the certificate can be loaded and that channel binding
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 75dc81a0a9..e9d797417a 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -275,7 +275,7 @@ documentation.  See standalone-profile.xsl for details.
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.1.
+      required version is 1.0.2.
      </para>
     </listitem>
 
diff --git a/configure b/configure
index 1b415142d1..c25089f2c1 100755
--- a/configure
+++ b/configure
@@ -12744,9 +12744,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.1
+    # Minimum required OpenSSL version is 1.0.2
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10001000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12961,15 +12961,13 @@ else
 fi
 
   fi
-  # Functions introduced in OpenSSL 1.0.2. LibreSSL does not have
-  # SSL_CTX_set_cert_cb().
-  for ac_func in X509_get_signature_nid SSL_CTX_set_cert_cb
+  # LibreSSL does not have SSL_CTX_set_cert_cb().
+  for ac_func in SSL_CTX_set_cert_cb
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
+if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+#define HAVE_SSL_CTX_SET_CERT_CB 1
 _ACEOF
 
 fi
diff --git a/configure.ac b/configure.ac
index 09558ada0f..093bfad082 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1367,8 +1367,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.1
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10001000L],
+  # Minimum required OpenSSL version is 1.0.2
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1377,9 +1377,9 @@ if test "$with_ssl" = openssl ; then
      AC_SEARCH_LIBS(CRYPTO_new_ex_data, [eay32 crypto], [], [AC_MSG_ERROR([library 'eay32' or 'crypto' is required for OpenSSL])])
      AC_SEARCH_LIBS(SSL_new, [ssleay32 ssl], [], [AC_MSG_ERROR([library 'ssleay32' or 'ssl' is required for OpenSSL])])
   fi
-  # Functions introduced in OpenSSL 1.0.2. LibreSSL does not have
+  # Function introduced in OpenSSL 1.0.2. LibreSSL does not have
   # SSL_CTX_set_cert_cb().
-  AC_CHECK_FUNCS([X509_get_signature_nid SSL_CTX_set_cert_cb])
+  AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
   # Functions introduced in OpenSSL 1.1.0. We used to check for
   # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
diff --git a/meson.build b/meson.build
index 16b2e86646..7d0122ab32 100644
--- a/meson.build
+++ b/meson.build
@@ -1268,9 +1268,8 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Functions introduced in OpenSSL 1.0.2.
-      ['X509_get_signature_nid'],
-      ['SSL_CTX_set_cert_cb'], # not in LibreSSL
+      # Functions introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
 
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
@@ -1312,7 +1311,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10001000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
                 description: '''Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.''')
       ssl_library = 'openssl'
     else
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
index b6d31c3583..e6d8f9fedc 100644
--- a/src/tools/msvc/Solution.pm
+++ b/src/tools/msvc/Solution.pm
@@ -371,7 +371,6 @@ sub GenerateFiles
 		HAVE_UUID_UUID_H => undef,
 		HAVE_WCSTOMBS_L => 1,
 		HAVE_VISIBILITY_ATTRIBUTE => undef,
-		HAVE_X509_GET_SIGNATURE_NID => 1,
 		HAVE_X509_GET_SIGNATURE_INFO => undef,
 		HAVE_X86_64_POPCNTQ => undef,
 		HAVE__BOOL => undef,
@@ -488,6 +487,7 @@ sub GenerateFiles
 	if ($self->{options}->{openssl})
 	{
 		$define{USE_OPENSSL} = 1;
+		$define{HAVE_SSL_CTX_SET_CERT_CB} = 1;
 
 		my ($digit1, $digit2, $digit3) = $self->GetOpenSSLVersion();
 
@@ -509,14 +509,6 @@ sub GenerateFiles
 			$define{HAVE_HMAC_CTX_NEW} = 1;
 			$define{HAVE_OPENSSL_INIT_SSL} = 1;
 		}
-
-		# Symbols needed with OpenSSL 1.0.2 and above.
-		if (   ($digit1 >= '3' && $digit2 >= '0' && $digit3 >= '0')
-			|| ($digit1 >= '1' && $digit2 >= '1' && $digit3 >= '0')
-			|| ($digit1 >= '1' && $digit2 >= '0' && $digit3 >= '2'))
-		{
-			$define{HAVE_SSL_CTX_SET_CERT_CB} = 1;
-		}
 	}
 
 	$self->GenerateConfigHeader('src/include/pg_config.h', \%define, 1);
-- 
2.40.1

From 30ca8928a0a6bd901105529fe664e989122ed6ae Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Tue, 2 Apr 2024 20:46:41 +0200
Subject: [PATCH v1] Remove support for OpenSSL 1.0.2 and 1.1.0

This sets the required version of OpenSSL at 1.1.1.
---
 configure                                |  40 +----
 configure.ac                             |  19 +--
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   4 +-
 meson.build                              |  21 +--
 src/backend/libpq/be-secure-openssl.c    |  33 +---
 src/common/hmac_openssl.c                |  13 --
 src/include/pg_config.h.in               |  21 ---
 src/interfaces/libpq/fe-secure-openssl.c | 205 +----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 10 files changed, 20 insertions(+), 343 deletions(-)

diff --git a/configure b/configure
index 36feeafbb2..16b7b1fef9 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12556,36 +12557,8 @@ _ACEOF
 fi
 done
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
 
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
-_ACEOF
-
-fi
-done
+$as_echo "#define USE_OPENSSL 1" >>confdefs.h
 
   # Function introduced in OpenSSL 1.1.1.
   for ac_func in X509_get_signature_info
@@ -12596,12 +12569,11 @@ if test "x$ac_cv_func_X509_get_signature_info" = xyes; then :
 #define HAVE_X509_GET_SIGNATURE_INFO 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL, version 1.1.1 or newer, is required for SSL support" "$LINENO" 5
 fi
 done
 
-
-$as_echo "#define USE_OPENSSL 1" >>confdefs.h
-
 elif test "$with_ssl" != no ; then
   as_fn_error $? "--with-ssl must specify openssl" "$LINENO" 5
 fi
diff --git a/configure.ac b/configure.ac
index 57f734879e..9d9e976de5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1347,19 +1348,9 @@ if test "$with_ssl" = openssl ; then
   fi
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
-  AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
+  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([X509_get_signature_info], [], [AC_MSG_ERROR([OpenSSL, version 1.1.1 or newer, is required for SSL support])])
 elif test "$with_ssl" != no ; then
   AC_MSG_ERROR([--with-ssl must specify openssl])
 fi
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index d3e87056f2..e718d355bb 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1741,9 +1741,9 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
         <productname>PostgreSQL</productname> 14 disables compression
         completely in the backend.
diff --git a/meson.build b/meson.build
index 18b5be842e..119f9c9405 100644
--- a/meson.build
+++ b/meson.build
@@ -1274,25 +1274,8 @@ if sslopt in ['auto', 'openssl']
 
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
-
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
       # Function introduced in OpenSSL 1.1.1
-      ['X509_get_signature_info'],
+      ['X509_get_signature_info', {'required': true}]
     ]
 
     are_openssl_funcs_complete = true
@@ -1314,7 +1297,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..c0227f6239 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -98,13 +98,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -261,15 +255,11 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
 	 */
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
-#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
@@ -531,10 +521,8 @@ aloop:
 					case SSL_R_WRONG_SSL_VERSION:
 					case SSL_R_WRONG_VERSION_NUMBER:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
-#ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
 					case SSL_R_VERSION_TOO_LOW:
-#endif
 						give_proto_hint = true;
 						break;
 					default:
@@ -898,7 +886,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +908,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
@@ -1468,15 +1447,9 @@ be_tls_get_certificate_hash(Port *port, size_t *len)
 
 	/*
 	 * Get the signature algorithm of the certificate to determine the hash
-	 * algorithm to use for the result.  Prefer X509_get_signature_info(),
-	 * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
+	 * algorithm to use for the result.
 	 */
-#if HAVE_X509_GET_SIGNATURE_INFO
 	if (!X509_get_signature_info(server_cert, &algo_nid, NULL, NULL, NULL))
-#else
-	if (!OBJ_find_sigid_algs(X509_get_signature_nid(server_cert),
-							 &algo_nid, NULL))
-#endif
 		elog(ERROR, "could not determine server certificate signature algorithm");
 
 	/*
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index d10f7e5af7..89d71a819e 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -138,14 +138,10 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-#ifdef HAVE_HMAC_CTX_NEW
 #ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -159,14 +155,10 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifdef HAVE_HMAC_CTX_NEW
 #ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
-#else
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif							/* HAVE_HMAC_CTX_NEW */
 
 	return ctx;
 }
@@ -325,16 +317,11 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
 #ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
 
 	explicit_bzero(ctx, sizeof(pg_hmac_ctx));
 	FREE(ctx);
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..d2286e0b44 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
@@ -303,9 +288,6 @@
 /* Define to 1 if you have the `mkdtemp' function. */
 #undef HAVE_MKDTEMP
 
-/* Define to 1 if you have the `OPENSSL_init_ssl' function. */
-#undef HAVE_OPENSSL_INIT_SSL
-
 /* Define to 1 if you have the <ossp/uuid.h> header file. */
 #undef HAVE_OSSP_UUID_H
 
@@ -507,9 +489,6 @@
 /* Define to 1 if you have the `wcstombs_l' function. */
 #undef HAVE_WCSTOMBS_L
 
-/* Define to 1 if you have the `X509_get_signature_info' function. */
-#undef HAVE_X509_GET_SIGNATURE_INFO
-
 /* Define to 1 if the assembler supports X86_64's POPCNTQ instruction. */
 #undef HAVE_X86_64_POPCNTQ
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..dd9dfe963c 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -377,15 +376,9 @@ pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 
 	/*
 	 * Get the signature algorithm of the certificate to determine the hash
-	 * algorithm to use for the result.  Prefer X509_get_signature_info(),
-	 * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
+	 * algorithm to use for the result.
 	 */
-#if HAVE_X509_GET_SIGNATURE_INFO
 	if (!X509_get_signature_info(peer_cert, &algo_nid, NULL, NULL, NULL))
-#else
-	if (!OBJ_find_sigid_algs(X509_get_signature_nid(peer_cert),
-							 &algo_nid, NULL))
-#endif
 	{
 		libpq_append_conn_error(conn, "could not determine server certificate signature algorithm");
 		return NULL;
@@ -505,11 +498,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +529,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +697,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +713,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +724,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1435,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1449,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1466,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1706,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1731,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1738,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.32.1 (Apple Git-133)

From 1c9b9a13f8ae5fdab0d71d572eea6b572ba10751 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Tue, 2 Apr 2024 20:46:41 +0200
Subject: [PATCH v2] Remove support for OpenSSL 1.0.2 and 1.1.0

This sets the required version of OpenSSL at 1.1.1.
---
 configure                                |  40 +----
 configure.ac                             |  19 +--
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   4 +-
 meson.build                              |  21 +--
 src/backend/libpq/be-secure-openssl.c    |  33 +---
 src/common/hmac_openssl.c                |  34 +---
 src/include/pg_config.h.in               |  21 ---
 src/interfaces/libpq/fe-secure-openssl.c | 205 +----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 10 files changed, 27 insertions(+), 357 deletions(-)

diff --git a/configure b/configure
index 36feeafbb2..16b7b1fef9 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12556,36 +12557,8 @@ _ACEOF
 fi
 done
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
 
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
-_ACEOF
-
-fi
-done
+$as_echo "#define USE_OPENSSL 1" >>confdefs.h
 
   # Function introduced in OpenSSL 1.1.1.
   for ac_func in X509_get_signature_info
@@ -12596,12 +12569,11 @@ if test "x$ac_cv_func_X509_get_signature_info" = xyes; then :
 #define HAVE_X509_GET_SIGNATURE_INFO 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL, version 1.1.1 or newer, is required for SSL support" "$LINENO" 5
 fi
 done
 
-
-$as_echo "#define USE_OPENSSL 1" >>confdefs.h
-
 elif test "$with_ssl" != no ; then
   as_fn_error $? "--with-ssl must specify openssl" "$LINENO" 5
 fi
diff --git a/configure.ac b/configure.ac
index 57f734879e..9d9e976de5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1347,19 +1348,9 @@ if test "$with_ssl" = openssl ; then
   fi
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
-  AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
+  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([X509_get_signature_info], [], [AC_MSG_ERROR([OpenSSL, version 1.1.1 or newer, is required for SSL support])])
 elif test "$with_ssl" != no ; then
   AC_MSG_ERROR([--with-ssl must specify openssl])
 fi
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index e69feacfe6..c4a3804254 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1779,9 +1779,9 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
         <productname>PostgreSQL</productname> 14 disables compression
         completely in the backend.
diff --git a/meson.build b/meson.build
index 18b5be842e..119f9c9405 100644
--- a/meson.build
+++ b/meson.build
@@ -1274,25 +1274,8 @@ if sslopt in ['auto', 'openssl']
 
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
-
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
       # Function introduced in OpenSSL 1.1.1
-      ['X509_get_signature_info'],
+      ['X509_get_signature_info', {'required': true}]
     ]
 
     are_openssl_funcs_complete = true
@@ -1314,7 +1297,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..c0227f6239 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -98,13 +98,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -261,15 +255,11 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
 	 */
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
-#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
@@ -531,10 +521,8 @@ aloop:
 					case SSL_R_WRONG_SSL_VERSION:
 					case SSL_R_WRONG_VERSION_NUMBER:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
-#ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
 					case SSL_R_VERSION_TOO_LOW:
-#endif
 						give_proto_hint = true;
 						break;
 					default:
@@ -898,7 +886,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +908,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
@@ -1468,15 +1447,9 @@ be_tls_get_certificate_hash(Port *port, size_t *len)
 
 	/*
 	 * Get the signature algorithm of the certificate to determine the hash
-	 * algorithm to use for the result.  Prefer X509_get_signature_info(),
-	 * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
+	 * algorithm to use for the result.
 	 */
-#if HAVE_X509_GET_SIGNATURE_INFO
 	if (!X509_get_signature_info(server_cert, &algo_nid, NULL, NULL, NULL))
-#else
-	if (!OBJ_find_sigid_algs(X509_get_signature_nid(server_cert),
-							 &algo_nid, NULL))
-#endif
 		elog(ERROR, "could not determine server certificate signature algorithm");
 
 	/*
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..c2506de7c5 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,11 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
-#define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -68,13 +62,13 @@ struct pg_hmac_ctx
 	pg_hmac_errno error;
 	const char *errreason;
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwner resowner;
 #endif
 };
 
 /* ResourceOwner callbacks to hold HMAC contexts */
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void ResOwnerReleaseHMAC(Datum res);
 
 static const ResourceOwnerDesc hmac_resowner_desc =
@@ -139,16 +133,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,11 +151,8 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
@@ -328,14 +314,8 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
@@ -379,7 +359,7 @@ pg_hmac_error(pg_hmac_ctx *ctx)
 
 /* ResourceOwner callbacks */
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void
 ResOwnerReleaseHMAC(Datum res)
 {
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..d2286e0b44 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
@@ -303,9 +288,6 @@
 /* Define to 1 if you have the `mkdtemp' function. */
 #undef HAVE_MKDTEMP
 
-/* Define to 1 if you have the `OPENSSL_init_ssl' function. */
-#undef HAVE_OPENSSL_INIT_SSL
-
 /* Define to 1 if you have the <ossp/uuid.h> header file. */
 #undef HAVE_OSSP_UUID_H
 
@@ -507,9 +489,6 @@
 /* Define to 1 if you have the `wcstombs_l' function. */
 #undef HAVE_WCSTOMBS_L
 
-/* Define to 1 if you have the `X509_get_signature_info' function. */
-#undef HAVE_X509_GET_SIGNATURE_INFO
-
 /* Define to 1 if the assembler supports X86_64's POPCNTQ instruction. */
 #undef HAVE_X86_64_POPCNTQ
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..dd9dfe963c 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -377,15 +376,9 @@ pgtls_get_peer_certificate_hash(PGconn *conn, size_t *len)
 
 	/*
 	 * Get the signature algorithm of the certificate to determine the hash
-	 * algorithm to use for the result.  Prefer X509_get_signature_info(),
-	 * introduced in OpenSSL 1.1.1, which can handle RSA-PSS signatures.
+	 * algorithm to use for the result.
 	 */
-#if HAVE_X509_GET_SIGNATURE_INFO
 	if (!X509_get_signature_info(peer_cert, &algo_nid, NULL, NULL, NULL))
-#else
-	if (!OBJ_find_sigid_algs(X509_get_signature_nid(peer_cert),
-							 &algo_nid, NULL))
-#endif
 	{
 		libpq_append_conn_error(conn, "could not determine server certificate signature algorithm");
 		return NULL;
@@ -505,11 +498,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +529,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +697,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +713,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +724,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1435,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1449,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1466,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1706,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1731,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1738,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.32.1 (Apple Git-133)

From a8ae675062df2681fd31db093ef284edc5900b48 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Tue, 2 Apr 2024 20:46:41 +0200
Subject: [PATCH v3] Remove support for OpenSSL 1.0.2 and 1.1.0

This sets the required version of OpenSSL at 1.1.1.
---
 configure                                |  30 +---
 configure.ac                             |  20 +--
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   4 +-
 meson.build                              |  28 ++--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/common/hmac_openssl.c                |  34 +---
 src/include/pg_config.h.in               |   3 -
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 11 files changed, 36 insertions(+), 311 deletions(-)

diff --git a/configure b/configure
index 36feeafbb2..0411eaedd2 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12556,11 +12557,7 @@ _ACEOF
 fi
 done
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
+  # Functions introduced in OpenSSL 1.1.0/LibreSSL 2.7.0.
   for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
@@ -12570,24 +12567,13 @@ if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
 #define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL, version 1.1.1 or newer, is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
-_ACEOF
-
-fi
-done
-
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1. This is our minimum version, but we
+  # can't require it because it's not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 57f734879e..73a55bd3c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as he deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1347,17 +1348,10 @@ if test "$with_ssl" = openssl ; then
   fi
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  # Functions introduced in OpenSSL 1.1.0/LibreSSL 2.7.0.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free], [], [AC_MSG_ERROR([OpenSSL, version 1.1.1 or newer, is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1. This is our minimum version, but we
+  # can't require it because it's not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index e69feacfe6..c4a3804254 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1779,9 +1779,9 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
         <productname>PostgreSQL</productname> 14 disables compression
         completely in the backend.
diff --git a/meson.build b/meson.build
index 18b5be842e..3eeb5635c2 100644
--- a/meson.build
+++ b/meson.build
@@ -1275,23 +1275,15 @@ if sslopt in ['auto', 'openssl']
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
 
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      # Functions introduced in OpenSSL 1.1.0/LibreSSL 2.7.0.
+      ['OPENSSL_init_ssl', {'required': true}],
+      ['BIO_meth_new', {'required': true}],
+      ['ASN1_STRING_get0_data', {'required': true}],
+      ['HMAC_CTX_new', {'required': true}],
+      ['HMAC_CTX_free', {'required': true}],
+
+      # Function introduced in OpenSSL 1.1.1. This is our minimum version, but
+      # we can't require it because it's not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1306,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..769e9eb2b7 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -98,13 +99,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -898,7 +893,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +915,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..c2506de7c5 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,11 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
-#define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -68,13 +62,13 @@ struct pg_hmac_ctx
 	pg_hmac_errno error;
 	const char *errreason;
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwner resowner;
 #endif
 };
 
 /* ResourceOwner callbacks to hold HMAC contexts */
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void ResOwnerReleaseHMAC(Datum res);
 
 static const ResourceOwnerDesc hmac_resowner_desc =
@@ -139,16 +133,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,11 +151,8 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
@@ -328,14 +314,8 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
@@ -379,7 +359,7 @@ pg_hmac_error(pg_hmac_ctx *ctx)
 
 /* ResourceOwner callbacks */
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void
 ResOwnerReleaseHMAC(Datum res)
 {
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..27989dff25 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -84,9 +84,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..96f91938ef 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1441,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1455,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1472,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1712,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1737,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1744,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.34.1

From c288d560c5b24e021b7f313d61f258dba37dc04e Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 5 Apr 2024 14:43:09 +0200
Subject: [PATCH v4] Remove support for OpenSSL 1.0.2

This makes OpenSSL 1.1.1/LibreSSL 3.3.2 the minimally required
versions. Also adjust to past tense in documentation

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
---
 config/programs.m4                       |  25 +++
 configure                                |  75 +++++----
 configure.ac                             |  20 +--
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   6 +-
 meson.build                              |  45 +++---
 src/backend/libpq/be-secure-openssl.c    |  33 ++--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  34 +---
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |   3 -
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 src/port/pg_strong_random.c              |   6 +-
 17 files changed, 133 insertions(+), 461 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/config/programs.m4 b/config/programs.m4
index 490ec9fe9f..230ec21cd7 100644
--- a/config/programs.m4
+++ b/config/programs.m4
@@ -143,6 +143,31 @@ if test "$pgac_cv_ldap_safe" != yes; then
 fi])
 
 
+# PGAC_CHECK_OPENSSL
+# ------------------
+# Check for OpenSSL being at least version 1.1.1 and LibreSSL being at least
+# version 3.3.2 (which shipped in OpenBSD 6.9).  The actual version number
+# found is not recorded, instead we gate functionality based on capabilities to
+# avoid having to check multiple version numbers in the code.
+AC_DEFUN([PGAC_CHECK_OPENSSL],
+[AC_CACHE_CHECK([for compatible OpenSSL installation], [pgac_cv_openssl_safe],
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+[#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif], [])],
+[pgac_cv_openssl_safe=yes],
+[pgac_cv_openssl_safe=no])])
+
+if test "$pgac_cv_openssl_safe" != yes; then
+  AC_MSG_ERROR([OpenSSL 1.1.1 or later is required.])
+fi])
+
 
 # PGAC_CHECK_READLINE
 # -------------------
diff --git a/configure b/configure
index 36feeafbb2..32b0f1bc6d 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12544,50 +12545,58 @@ else
 fi
 
   fi
-  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-  for ac_func in SSL_CTX_set_cert_cb
-do :
-  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
-if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_SSL_CTX_SET_CERT_CB 1
-_ACEOF
 
-fi
-done
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for compatible OpenSSL installation" >&5
+$as_echo_n "checking for compatible OpenSSL installation... " >&6; }
+if ${pgac_cv_openssl_safe+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif
+int
+main ()
+{
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+  ;
+  return 0;
+}
 _ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_openssl_safe=yes
+else
+  pgac_cv_openssl_safe=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_openssl_safe" >&5
+$as_echo "$pgac_cv_openssl_safe" >&6; }
 
+if test "$pgac_cv_openssl_safe" != yes; then
+  as_fn_error $? "OpenSSL 1.1.1 or later is required." "$LINENO" 5
 fi
-done
 
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
+  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+  for ac_func in SSL_CTX_set_cert_cb
 do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
+if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_SSL_CTX_SET_CERT_CB 1
 _ACEOF
 
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 57f734879e..b1e8d7f696 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1345,19 +1346,12 @@ if test "$with_ssl" = openssl ; then
      AC_SEARCH_LIBS(CRYPTO_new_ex_data, [eay32 crypto], [], [AC_MSG_ERROR([library 'eay32' or 'crypto' is required for OpenSSL])])
      AC_SEARCH_LIBS(SSL_new, [ssleay32 ssl], [], [AC_MSG_ERROR([library 'ssleay32' or 'ssl' is required for OpenSSL])])
   fi
+
+  PGAC_CHECK_OPENSSL
+
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index e69feacfe6..8987ca5d65 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1779,11 +1779,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
diff --git a/meson.build b/meson.build
index 87437960bc..6fc1417bba 100644
--- a/meson.build
+++ b/meson.build
@@ -1268,6 +1268,28 @@ if sslopt in ['auto', 'openssl']
   endif
 
   if ssl.found()
+	  # Check for OpenSSL being at least version 1.1.1 and LibreSSL being at
+	  # least version 3.3.2 (which shipped in OpenBSD 6.9).  The actual version
+	  # number found is not recorded, instead we gate functionality based on
+	  # capabilities to avoid having to check multiple version numbers in the
+	  # code.
+      compat_test_code = '''
+#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif
+'''
+      if not cc.compiles(compat_test_code,
+          name: 'OpenSSL implementation compatible',
+          dependencies: ssl, args: test_c_args)
+        error('OpenSSL 1.1.1 or later is required')
+      endif
+
     check_funcs = [
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
@@ -1275,23 +1297,7 @@ if sslopt in ['auto', 'openssl']
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
 
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1320,10 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+	  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the
+	  # deprecation level since 1.1.1 wasn't defined as a deprecation point by
+	  # OpenSSL
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..0acf4758e4 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -98,13 +99,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -261,15 +256,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
@@ -533,6 +533,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
@@ -898,7 +900,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +922,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..c2506de7c5 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,11 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
-#define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -68,13 +62,13 @@ struct pg_hmac_ctx
 	pg_hmac_errno error;
 	const char *errreason;
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwner resowner;
 #endif
 };
 
 /* ResourceOwner callbacks to hold HMAC contexts */
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void ResOwnerReleaseHMAC(Datum res);
 
 static const ResourceOwnerDesc hmac_resowner_desc =
@@ -139,16 +133,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,11 +151,8 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
@@ -328,14 +314,8 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
@@ -379,7 +359,7 @@ pg_hmac_error(pg_hmac_ctx *ctx)
 
 /* ResourceOwner callbacks */
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void
 ResOwnerReleaseHMAC(Datum res)
 {
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..27989dff25 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -84,9 +84,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..96f91938ef 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1441,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1455,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1472,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1712,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1737,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1744,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..5df63f99e4 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -56,9 +56,9 @@ void
 pg_strong_random_init(void)
 {
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is in
+	 * theory no longer be required in OpenSSL 1.1.1 and later versions, but
+	 * there is no harm in taking extra precautions.
 	 */
 	RAND_poll();
 }
-- 
2.32.1 (Apple Git-133)

From 22bf945e105789767419efd6217e0e172f1a7e9c Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Sat, 6 Apr 2024 00:13:18 +0200
Subject: [PATCH v5] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL for quite some time, and is not the
base OpenSSL library in any distribution which will package 17.
This makes OpenSSL 1.1.1/LibreSSL 3.3.2 the minimum required
versions for compiling PostgreSQL with TLS support.

While updating the documentation, also adjust to past tense for
documenting SSL compression.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 config/programs.m4                       |  25 +++
 configure                                |  75 +++++----
 configure.ac                             |  20 +--
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   6 +-
 meson.build                              |  45 +++---
 src/backend/libpq/be-secure-openssl.c    |  33 ++--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  34 +---
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  18 ---
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 src/port/pg_strong_random.c              |   6 +-
 17 files changed, 133 insertions(+), 476 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/config/programs.m4 b/config/programs.m4
index 490ec9fe9f..230ec21cd7 100644
--- a/config/programs.m4
+++ b/config/programs.m4
@@ -143,6 +143,31 @@ if test "$pgac_cv_ldap_safe" != yes; then
 fi])
 
 
+# PGAC_CHECK_OPENSSL
+# ------------------
+# Check for OpenSSL being at least version 1.1.1 and LibreSSL being at least
+# version 3.3.2 (which shipped in OpenBSD 6.9).  The actual version number
+# found is not recorded, instead we gate functionality based on capabilities to
+# avoid having to check multiple version numbers in the code.
+AC_DEFUN([PGAC_CHECK_OPENSSL],
+[AC_CACHE_CHECK([for compatible OpenSSL installation], [pgac_cv_openssl_safe],
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
+[#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif], [])],
+[pgac_cv_openssl_safe=yes],
+[pgac_cv_openssl_safe=no])])
+
+if test "$pgac_cv_openssl_safe" != yes; then
+  AC_MSG_ERROR([OpenSSL 1.1.1 or later is required.])
+fi])
+
 
 # PGAC_CHECK_READLINE
 # -------------------
diff --git a/configure b/configure
index 36feeafbb2..32b0f1bc6d 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12544,50 +12545,58 @@ else
 fi
 
   fi
-  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-  for ac_func in SSL_CTX_set_cert_cb
-do :
-  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
-if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_SSL_CTX_SET_CERT_CB 1
-_ACEOF
 
-fi
-done
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for compatible OpenSSL installation" >&5
+$as_echo_n "checking for compatible OpenSSL installation... " >&6; }
+if ${pgac_cv_openssl_safe+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif
+int
+main ()
+{
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
-do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+  ;
+  return 0;
+}
 _ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  pgac_cv_openssl_safe=yes
+else
+  pgac_cv_openssl_safe=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_openssl_safe" >&5
+$as_echo "$pgac_cv_openssl_safe" >&6; }
 
+if test "$pgac_cv_openssl_safe" != yes; then
+  as_fn_error $? "OpenSSL 1.1.1 or later is required." "$LINENO" 5
 fi
-done
 
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
+  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+  for ac_func in SSL_CTX_set_cert_cb
 do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
+if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_SSL_CTX_SET_CERT_CB 1
 _ACEOF
 
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 57f734879e..b1e8d7f696 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1345,19 +1346,12 @@ if test "$with_ssl" = openssl ; then
      AC_SEARCH_LIBS(CRYPTO_new_ex_data, [eay32 crypto], [], [AC_MSG_ERROR([library 'eay32' or 'crypto' is required for OpenSSL])])
      AC_SEARCH_LIBS(SSL_new, [ssleay32 ssl], [], [AC_MSG_ERROR([library 'ssleay32' or 'ssl' is required for OpenSSL])])
   fi
+
+  PGAC_CHECK_OPENSSL
+
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index e69feacfe6..8987ca5d65 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1779,11 +1779,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
diff --git a/meson.build b/meson.build
index 87437960bc..720c144bf9 100644
--- a/meson.build
+++ b/meson.build
@@ -1268,6 +1268,28 @@ if sslopt in ['auto', 'openssl']
   endif
 
   if ssl.found()
+	  # Check for OpenSSL being at least version 1.1.1 and LibreSSL being at
+	  # least version 3.3.2 (which shipped in OpenBSD 6.9).  The actual version
+	  # number found is not recorded, instead we gate functionality based on
+	  # capabilities to avoid having to check multiple version numbers in the
+	  # code.
+      compat_test_code = '''
+#include <openssl/opensslv.h>
+#if ((OPENSSL_VERSION_NUMBER == 0x20000000) && \
+	(defined(LIBRESSL_VERSION_NUMBER) && \
+	LIBRESSL_VERSION_NUMBER < 0x3030200fL))
+choke me
+#endif
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+choke me
+#endif
+'''
+      if not cc.compiles(compat_test_code,
+          name: 'OpenSSL implementation compatible',
+          args: test_c_args, dependencies: ssl_int, include_directories: postgres_inc)
+        error('OpenSSL 1.1.1 or later is required')
+      endif
+
     check_funcs = [
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
@@ -1275,23 +1297,7 @@ if sslopt in ['auto', 'openssl']
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
 
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1320,10 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+	  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the
+	  # deprecation level since 1.1.1 wasn't defined as a deprecation point by
+	  # OpenSSL
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..0acf4758e4 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -98,13 +99,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -261,15 +256,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
@@ -533,6 +533,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
@@ -898,7 +900,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +922,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..c2506de7c5 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,11 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
-#define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -68,13 +62,13 @@ struct pg_hmac_ctx
 	pg_hmac_errno error;
 	const char *errreason;
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwner resowner;
 #endif
 };
 
 /* ResourceOwner callbacks to hold HMAC contexts */
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void ResOwnerReleaseHMAC(Datum res);
 
 static const ResourceOwnerDesc hmac_resowner_desc =
@@ -139,16 +133,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,11 +151,8 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
@@ -328,14 +314,8 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
@@ -379,7 +359,7 @@ pg_hmac_error(pg_hmac_ctx *ctx)
 
 /* ResourceOwner callbacks */
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void
 ResOwnerReleaseHMAC(Datum res)
 {
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..d7fa014c5a 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
@@ -303,9 +288,6 @@
 /* Define to 1 if you have the `mkdtemp' function. */
 #undef HAVE_MKDTEMP
 
-/* Define to 1 if you have the `OPENSSL_init_ssl' function. */
-#undef HAVE_OPENSSL_INIT_SSL
-
 /* Define to 1 if you have the <ossp/uuid.h> header file. */
 #undef HAVE_OSSP_UUID_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..96f91938ef 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1441,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1455,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1472,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1712,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1737,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1744,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..5df63f99e4 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -56,9 +56,9 @@ void
 pg_strong_random_init(void)
 {
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is in
+	 * theory no longer be required in OpenSSL 1.1.1 and later versions, but
+	 * there is no harm in taking extra precautions.
 	 */
 	RAND_poll();
 }
-- 
2.32.1 (Apple Git-133)

From 0910a7341207b5a7f62a81e439daa24876ad6380 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Sat, 6 Apr 2024 19:41:28 +0200
Subject: [PATCH v6] Remove support for OpenSSL 1.0.2 and 1.1.0

OpenSSL 1.0.2 has been EOL for quite some time, and is not the
base OpenSSL library in any distribution which will package 17.
Bumping the required version to 1.1.1 allows us to remove a lot
of special cased code, and moves us to an OpenSSL version which
has a fork-safe RNG by default.

This makes OpenSSL 1.1.1/LibreSSL 3.3.2 the minimum required
versions for compiling PostgreSQL with TLS support.

While updating the documentation, also adjust to past tense for
documenting SSL compression.

Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  47 ++----
 configure.ac                             |  20 +--
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |   6 +-
 meson.build                              |  27 ++--
 src/backend/libpq/be-secure-openssl.c    |  33 ++--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  34 +---
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  21 +--
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 src/port/pg_strong_random.c              |   6 +-
 16 files changed, 67 insertions(+), 474 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/configure b/configure
index 36feeafbb2..0ec63ab082 100755
--- a/configure
+++ b/configure
@@ -12327,9 +12327,10 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12544,50 +12545,34 @@ else
 fi
 
   fi
-  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-  for ac_func in SSL_CTX_set_cert_cb
-do :
-  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
-if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_SSL_CTX_SET_CERT_CB 1
-_ACEOF
-
-fi
-done
 
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  # Function introduced in OpenSSL 1.1.1 and LibreSSL 3.3.2
+  for ac_func in EVP_PKEY_new_CMAC_key
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  ac_fn_c_check_func "$LINENO" "EVP_PKEY_new_CMAC_key" "ac_cv_func_EVP_PKEY_new_CMAC_key"
+if test "x$ac_cv_func_EVP_PKEY_new_CMAC_key" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+#define HAVE_EVP_PKEY_NEW_CMAC_KEY 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL 1.1.1 or later is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
+  # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+  for ac_func in SSL_CTX_set_cert_cb
 do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "SSL_CTX_set_cert_cb" "ac_cv_func_SSL_CTX_set_cert_cb"
+if test "x$ac_cv_func_SSL_CTX_set_cert_cb" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_SSL_CTX_SET_CERT_CB 1
 _ACEOF
 
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 57f734879e..b19f4775ff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,9 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the deprecation
+  # level since 1.1.1 wasn't defined as a deprecation point by OpenSSL
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1345,19 +1346,12 @@ if test "$with_ssl" = openssl ; then
      AC_SEARCH_LIBS(CRYPTO_new_ex_data, [eay32 crypto], [], [AC_MSG_ERROR([library 'eay32' or 'crypto' is required for OpenSSL])])
      AC_SEARCH_LIBS(SSL_new, [ssleay32 ssl], [], [AC_MSG_ERROR([library 'ssleay32' or 'ssl' is required for OpenSSL])])
   fi
+
+  # Function introduced in OpenSSL 1.1.1 and LibreSSL 3.3.2
+  AC_CHECK_FUNCS([EVP_PKEY_new_CMAC_key], [], [AC_MSG_ERROR([OpenSSL 1.1.1 or later is required for SSL support])])
   # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
   AC_CHECK_FUNCS([SSL_CTX_set_cert_cb])
-  # Functions introduced in OpenSSL 1.1.0. We used to check for
-  # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-  # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-  # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-  # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..1d5578d935 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.1.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index e69feacfe6..8987ca5d65 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1779,11 +1779,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
diff --git a/meson.build b/meson.build
index 87437960bc..19b2efcd3f 100644
--- a/meson.build
+++ b/meson.build
@@ -1268,30 +1268,18 @@ if sslopt in ['auto', 'openssl']
   endif
 
   if ssl.found()
+
     check_funcs = [
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
+      # Function introduced in OpenSSL 1.1.1 and LibreSSL 3.3.2
+      ['EVP_PKEY_new_CMAC_key'],
+
       # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
       ['SSL_CTX_set_cert_cb'],
 
-      # Functions introduced in OpenSSL 1.1.0. We used to check for
-      # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
-      # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
-      # doesn't have these OpenSSL 1.1.0 functions. So check for individual
-      # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1302,10 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+	  # Minimum required OpenSSL version is 1.1.1, but we set 1.1.0 as the
+	  # deprecation level since 1.1.1 wasn't defined as a deprecation point by
+	  # OpenSSL
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 72e43af353..0acf4758e4 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -98,13 +99,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -261,15 +256,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
@@ -533,6 +533,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
@@ -898,7 +900,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -921,14 +922,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..c2506de7c5 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,11 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
-#define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -68,13 +62,13 @@ struct pg_hmac_ctx
 	pg_hmac_errno error;
 	const char *errreason;
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwner resowner;
 #endif
 };
 
 /* ResourceOwner callbacks to hold HMAC contexts */
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void ResOwnerReleaseHMAC(Datum res);
 
 static const ResourceOwnerDesc hmac_resowner_desc =
@@ -139,16 +133,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,11 +151,8 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	ctx->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberHMAC(CurrentResourceOwner, ctx);
 #endif
@@ -328,14 +314,8 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
 #endif
@@ -379,7 +359,7 @@ pg_hmac_error(pg_hmac_ctx *ctx)
 
 /* ResourceOwner callbacks */
 
-#ifdef USE_RESOWNER_FOR_HMAC
+#ifndef FRONTEND
 static void
 ResOwnerReleaseHMAC(Datum res)
 {
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 591e1ca3df..9237984e74 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -133,6 +124,9 @@
 /* Define to 1 if you have the <editline/readline.h> header file. */
 #undef HAVE_EDITLINE_READLINE_H
 
+/* Define to 1 if you have the `EVP_PKEY_new_CMAC_key' function. */
+#undef HAVE_EVP_PKEY_NEW_CMAC_KEY
+
 /* Define to 1 if you have the <execinfo.h> header file. */
 #undef HAVE_EXECINFO_H
 
@@ -198,12 +192,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
@@ -303,9 +291,6 @@
 /* Define to 1 if you have the `mkdtemp' function. */
 #undef HAVE_MKDTEMP
 
-/* Define to 1 if you have the `OPENSSL_init_ssl' function. */
-#undef HAVE_OPENSSL_INIT_SSL
-
 /* Define to 1 if you have the <ossp/uuid.h> header file. */
 #undef HAVE_OSSP_UUID_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 0c8c9f8dcb..96f91938ef 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /*
  *	Create per-connection SSL object, and load the client certificate,
  *	private key, and trusted CA certs.
@@ -1596,8 +1441,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1612,8 +1455,6 @@ pgtls_close(PGconn *conn)
 			SSL_free(conn->ssl);
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1631,30 +1472,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1895,7 +1712,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1921,14 +1737,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1936,13 +1744,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 9c05f11a6e..d049087301 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -565,11 +565,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..5df63f99e4 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -56,9 +56,9 @@ void
 pg_strong_random_init(void)
 {
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is in
+	 * theory no longer be required in OpenSSL 1.1.1 and later versions, but
+	 * there is no harm in taking extra precautions.
 	 */
 	RAND_poll();
 }
-- 
2.32.1 (Apple Git-133)

From 5cbbb027f0537dfb89fe6ac6024e831ca8dfc385 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:20:31 +0200
Subject: [PATCH v7 5/5] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.1 is being
increasingly phased out from production use, remove the initialization
and only do it explicitly for anyone running 1.1.0.  This will penalize
1.1.0 installations by doing it per call to pg_strong_random, but the
number of production environments running the latest PostgreSQL combined
with a very out of date OpenSSL (which never was available as LTS/ELS)
is believed to be low.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random which
for the vast majority of users is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/include/port.h          |  1 -
 src/port/pg_strong_random.c | 38 +++++++++++--------------------------
 2 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/src/include/port.h b/src/include/port.h
index ae115d2d97..2a363764f1 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -473,7 +473,6 @@ extern char *pg_inet_net_ntop(int af, const void *src, int bits,
 							  char *dst, size_t size);
 
 /* port/pg_strong_random.c */
-extern void pg_strong_random_init(void);
 extern bool pg_strong_random(void *buf, size_t len);
 
 /*
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..99e5e4b66a 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -25,14 +25,11 @@
 #include <sys/time.h>
 
 /*
- * pg_strong_random & pg_strong_random_init
+ * pg_strong_random
  *
  * Generate requested number of random bytes. The returned bytes are
  * cryptographically secure, suitable for use e.g. in authentication.
  *
- * Before pg_strong_random is called in any process, the generator must first
- * be initialized by calling pg_strong_random_init().
- *
  * We rely on system facilities for actually generating the numbers.
  * We support a number of sources:
  *
@@ -51,23 +48,22 @@
 #ifdef USE_OPENSSL
 
 #include <openssl/rand.h>
-
-void
-pg_strong_random_init(void)
-{
-	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
-	 */
-	RAND_poll();
-}
+#include <openssl/opensslv.h>
 
 bool
 pg_strong_random(void *buf, size_t len)
 {
 	int			i;
 
+#if (OPENSSL_VERSION_NUMBER <= 0x10100000L)
+	/*
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * requred on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
+	 */
+	RAND_poll();
+#endif
+
 	/*
 	 * Check that OpenSSL's CSPRNG has been sufficiently seeded, and if not
 	 * add more seed data using RAND_poll().  With some older versions of
@@ -104,12 +100,6 @@ pg_strong_random(void *buf, size_t len)
  */
 static HCRYPTPROV hProvider = 0;
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed on WIN32 */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
@@ -143,12 +133,6 @@ pg_strong_random(void *buf, size_t len)
  * Without OpenSSL or Win32 support, just read /dev/urandom ourselves.
  */
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
-- 
2.39.3 (Apple Git-146)

From 348e8294f73ede569a054c74c467bb492f689e96 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:12:17 +0200
Subject: [PATCH v7 4/5] Support SSL_R_VERSION_TOO_LOW on LibreSSL

The SSL_R_VERSION_TOO_LOW error reason is supported in LibreSSL since
LibreSSL 3.6.3, shipped in OpenSSL 7.2. Previously we only checked for
SSL_R_VERSION_TOO_HIGH and then applied both under that guard since
OpenSSL has only ever supported both at the same time. This breaks the
check into one per reason to allow SSL_R_VERSION_TOO_LOW to work when
using LibreSSL.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index efd49ffca8..59c71b15b5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -542,6 +542,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
-- 
2.39.3 (Apple Git-146)

From 8b93bf797cfab09e0f1713bbea9d97e2c2474de4 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 12:44:24 +0200
Subject: [PATCH v7 3/5] Support disallowing SSL renegotiation in LibreSSL

LibreSSL doesn't support the SSL_OP_NO_RENEGOTIATION macro which is
used by OpenSSL, instead it has invented a similar one for client-
side renegotiation: SSL_OP_NO_CLIENT_RENEGOTIATION. This has been
supported since LibreSSL 2.5.1 which by now can be considered well
below the minimum requirement.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 88153d4bda..efd49ffca8 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -262,15 +262,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
-- 
2.39.3 (Apple Git-146)

From da93e9b7fcc57ba39a3c9bd8bf405558eb5469ed Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:21:55 +0200
Subject: [PATCH v7 2/5] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 ++--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/backend/postmaster/fork_process.c    |   3 -
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +--
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 15 files changed, 28 insertions(+), 440 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/configure b/configure
index cfbd2a096f..73e76070b0 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 67e738d92b..cf85ad409e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index 5acf083ce3..02e914e123 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 29c9af1aab..88153d4bda 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -104,13 +105,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -933,7 +928,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -956,14 +950,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/backend/postmaster/fork_process.c b/src/backend/postmaster/fork_process.c
index 5e42a74ab5..bcff9ef661 100644
--- a/src/backend/postmaster/fork_process.c
+++ b/src/backend/postmaster/fork_process.c
@@ -110,9 +110,6 @@ fork_process(void)
 				close(fd);
 			}
 		}
-
-		/* do post-fork initialization for random number generation */
-		pg_strong_random_init();
 	}
 	else
 	{
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index c98cfa6084..640edebcfe 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1460,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1475,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1492,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1752,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1777,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1784,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..434d6c449f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.39.3 (Apple Git-146)

From e505ee12a13ee245a0d67708a35d43c9ced35c42 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:36:08 +0200
Subject: [PATCH v7 1/5] Doc: Use past tense for things which happened in the
 past

The paragraph on SSL compression is largely describing events which
took place many years ago, so reword with past tense.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 doc/src/sgml/libpq.sgml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 9199d0d2e5..0db3667fdf 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1840,11 +1840,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
-- 
2.39.3 (Apple Git-146)

From fb754690b98d87115de6c7c4e6952a67db547a4a Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:20:31 +0200
Subject: [PATCH v8 5/5] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.1 is being
increasingly phased out from production use, remove the initialization
and only do it explicitly for anyone running 1.1.0.  This will penalize
1.1.0 installations by doing it per call to pg_strong_random, but the
number of production environments running the latest PostgreSQL combined
with a very out of date OpenSSL (which never was available as LTS/ELS)
is believed to be low.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random which
for the vast majority of users is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/backend/postmaster/fork_process.c |  3 --
 src/include/port.h                    |  1 -
 src/port/pg_strong_random.c           | 43 ++++++++++-----------------
 3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/src/backend/postmaster/fork_process.c b/src/backend/postmaster/fork_process.c
index 5e42a74ab5..bcff9ef661 100644
--- a/src/backend/postmaster/fork_process.c
+++ b/src/backend/postmaster/fork_process.c
@@ -110,9 +110,6 @@ fork_process(void)
 				close(fd);
 			}
 		}
-
-		/* do post-fork initialization for random number generation */
-		pg_strong_random_init();
 	}
 	else
 	{
diff --git a/src/include/port.h b/src/include/port.h
index ae115d2d97..2a363764f1 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -473,7 +473,6 @@ extern char *pg_inet_net_ntop(int af, const void *src, int bits,
 							  char *dst, size_t size);
 
 /* port/pg_strong_random.c */
-extern void pg_strong_random_init(void);
 extern bool pg_strong_random(void *buf, size_t len);
 
 /*
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..ac78a93536 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -25,14 +25,11 @@
 #include <sys/time.h>
 
 /*
- * pg_strong_random & pg_strong_random_init
+ * pg_strong_random
  *
  * Generate requested number of random bytes. The returned bytes are
  * cryptographically secure, suitable for use e.g. in authentication.
  *
- * Before pg_strong_random is called in any process, the generator must first
- * be initialized by calling pg_strong_random_init().
- *
  * We rely on system facilities for actually generating the numbers.
  * We support a number of sources:
  *
@@ -51,22 +48,26 @@
 #ifdef USE_OPENSSL
 
 #include <openssl/rand.h>
-
-void
-pg_strong_random_init(void)
-{
-	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
-	 */
-	RAND_poll();
-}
+#include <openssl/opensslv.h>
 
 bool
 pg_strong_random(void *buf, size_t len)
 {
 	int			i;
+#if (OPENSSL_VERSION_NUMBER <= 0x10100000L)
+	static bool rand_initialized = false;
+
+	/*
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
+	 */
+	if (!rand_initialized)
+	{
+		RAND_poll();
+		rand_initialized = true;
+	}
+#endif
 
 	/*
 	 * Check that OpenSSL's CSPRNG has been sufficiently seeded, and if not
@@ -104,12 +105,6 @@ pg_strong_random(void *buf, size_t len)
  */
 static HCRYPTPROV hProvider = 0;
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed on WIN32 */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
@@ -143,12 +138,6 @@ pg_strong_random(void *buf, size_t len)
  * Without OpenSSL or Win32 support, just read /dev/urandom ourselves.
  */
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
-- 
2.39.3 (Apple Git-146)

From 9e09a62f552a15bc280cf88d3ffd880175f7bdf8 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:12:17 +0200
Subject: [PATCH v8 4/5] Support SSL_R_VERSION_TOO_LOW on LibreSSL

The SSL_R_VERSION_TOO_LOW error reason is supported in LibreSSL since
LibreSSL 3.6.3, shipped in OpenSSL 7.2. Previously we only checked for
SSL_R_VERSION_TOO_HIGH and then applied both under that guard since
OpenSSL has only ever supported both at the same time. This breaks the
check into one per reason to allow SSL_R_VERSION_TOO_LOW to work when
using LibreSSL.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index efd49ffca8..59c71b15b5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -542,6 +542,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
-- 
2.39.3 (Apple Git-146)

From 4c75bbe0fd09ba69b81db2d2270907f5c604ec24 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 12:44:24 +0200
Subject: [PATCH v8 3/5] Support disallowing SSL renegotiation in LibreSSL

LibreSSL doesn't support the SSL_OP_NO_RENEGOTIATION macro which is
used by OpenSSL, instead it has invented a similar one for client-
side renegotiation: SSL_OP_NO_CLIENT_RENEGOTIATION. This has been
supported since LibreSSL 2.5.1 which by now can be considered well
below the minimum requirement.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 88153d4bda..efd49ffca8 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -262,15 +262,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
-- 
2.39.3 (Apple Git-146)

From 09e807672fb9b8d3f70c522d2aaf616e2dc407d9 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:21:55 +0200
Subject: [PATCH v8 2/5] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 ++--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +--
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 14 files changed, 28 insertions(+), 437 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/configure b/configure
index cfbd2a096f..73e76070b0 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 67e738d92b..cf85ad409e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index 43fad5323c..b77dda7c2b 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 29c9af1aab..88153d4bda 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -104,13 +105,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -933,7 +928,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -956,14 +950,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index c98cfa6084..640edebcfe 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1460,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1475,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1492,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1752,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1777,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1784,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..434d6c449f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.39.3 (Apple Git-146)

From 5bba79f12b32b5b9840d16971056cdd3bb7c1ab0 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:36:08 +0200
Subject: [PATCH v8 1/5] Doc: Use past tense for things which happened in the
 past

The paragraph on SSL compression is largely describing events which
took place many years ago, so reword with past tense.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 doc/src/sgml/libpq.sgml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 9199d0d2e5..0db3667fdf 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1840,11 +1840,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
-- 
2.39.3 (Apple Git-146)

From 88396949018b1e66d94ec9d77f54086fb55fcaa6 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:20:31 +0200
Subject: [PATCH v9 5/5] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.1 is being
increasingly phased out from production use, remove the initialization
and only do it explicitly for anyone running 1.1.0.  This will penalize
1.1.0 installations by doing it per call to pg_strong_random, but the
number of production environments running the latest PostgreSQL combined
with a very out of date OpenSSL (which never was available as LTS/ELS)
is believed to be low.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random which
for the vast majority of users is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/backend/postmaster/fork_process.c |  3 --
 src/include/port.h                    |  1 -
 src/port/pg_strong_random.c           | 43 ++++++++++-----------------
 3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/src/backend/postmaster/fork_process.c b/src/backend/postmaster/fork_process.c
index 5e42a74ab5..bcff9ef661 100644
--- a/src/backend/postmaster/fork_process.c
+++ b/src/backend/postmaster/fork_process.c
@@ -110,9 +110,6 @@ fork_process(void)
 				close(fd);
 			}
 		}
-
-		/* do post-fork initialization for random number generation */
-		pg_strong_random_init();
 	}
 	else
 	{
diff --git a/src/include/port.h b/src/include/port.h
index ae115d2d97..2a363764f1 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -473,7 +473,6 @@ extern char *pg_inet_net_ntop(int af, const void *src, int bits,
 							  char *dst, size_t size);
 
 /* port/pg_strong_random.c */
-extern void pg_strong_random_init(void);
 extern bool pg_strong_random(void *buf, size_t len);
 
 /*
diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..48b8671e68 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -25,14 +25,11 @@
 #include <sys/time.h>
 
 /*
- * pg_strong_random & pg_strong_random_init
+ * pg_strong_random
  *
  * Generate requested number of random bytes. The returned bytes are
  * cryptographically secure, suitable for use e.g. in authentication.
  *
- * Before pg_strong_random is called in any process, the generator must first
- * be initialized by calling pg_strong_random_init().
- *
  * We rely on system facilities for actually generating the numbers.
  * We support a number of sources:
  *
@@ -51,22 +48,26 @@
 #ifdef USE_OPENSSL
 
 #include <openssl/rand.h>
-
-void
-pg_strong_random_init(void)
-{
-	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
-	 */
-	RAND_poll();
-}
+#include <openssl/opensslv.h>
 
 bool
 pg_strong_random(void *buf, size_t len)
 {
 	int			i;
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
+	static bool rand_initialized = false;
+
+	/*
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
+	 */
+	if (!rand_initialized)
+	{
+		RAND_poll();
+		rand_initialized = true;
+	}
+#endif
 
 	/*
 	 * Check that OpenSSL's CSPRNG has been sufficiently seeded, and if not
@@ -104,12 +105,6 @@ pg_strong_random(void *buf, size_t len)
  */
 static HCRYPTPROV hProvider = 0;
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed on WIN32 */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
@@ -143,12 +138,6 @@ pg_strong_random(void *buf, size_t len)
  * Without OpenSSL or Win32 support, just read /dev/urandom ourselves.
  */
 
-void
-pg_strong_random_init(void)
-{
-	/* No initialization needed */
-}
-
 bool
 pg_strong_random(void *buf, size_t len)
 {
-- 
2.39.3 (Apple Git-146)

From db84b48ed74770bf7f67ed44475f0f52939d772d Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 13:12:17 +0200
Subject: [PATCH v9 4/5] Support SSL_R_VERSION_TOO_LOW on LibreSSL

The SSL_R_VERSION_TOO_LOW error reason is supported in LibreSSL since
LibreSSL 3.6.3, shipped in OpenSSL 7.2. Previously we only checked for
SSL_R_VERSION_TOO_HIGH and then applied both under that guard since
OpenSSL has only ever supported both at the same time. This breaks the
check into one per reason to allow SSL_R_VERSION_TOO_LOW to work when
using LibreSSL.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index efd49ffca8..59c71b15b5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -542,6 +542,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
-- 
2.39.3 (Apple Git-146)

From bf0c8974bbb8ae31c1379b99e4cfc17cf357599c Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 12:44:24 +0200
Subject: [PATCH v9 3/5] Support disallowing SSL renegotiation in LibreSSL

LibreSSL doesn't support the SSL_OP_NO_RENEGOTIATION macro which is
used by OpenSSL, instead it has invented a similar one for client-
side renegotiation: SSL_OP_NO_CLIENT_RENEGOTIATION. This has been
supported since LibreSSL 2.5.1 which by now can be considered well
below the minimum requirement.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 88153d4bda..efd49ffca8 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -262,15 +262,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
-- 
2.39.3 (Apple Git-146)

From d68e4cab94e49e7567093b08ab3dc52f961ec76d Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:21:55 +0200
Subject: [PATCH v9 2/5] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 ++--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +--
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 14 files changed, 28 insertions(+), 437 deletions(-)
 delete mode 100644 src/common/protocol_openssl.c

diff --git a/configure b/configure
index cfbd2a096f..73e76070b0 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 67e738d92b..cf85ad409e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index 43fad5323c..b77dda7c2b 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 29c9af1aab..88153d4bda 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -104,13 +105,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -933,7 +928,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -956,14 +950,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
deleted file mode 100644
index ae378685e1..0000000000
--- a/src/common/protocol_openssl.c
+++ /dev/null
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index c98cfa6084..640edebcfe 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1460,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1475,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1492,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has then loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1752,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1777,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1784,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..434d6c449f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.39.3 (Apple Git-146)

From 9ad9e09523574bf33d8a832e03c31ea539cfe2dc Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Apr 2024 11:36:08 +0200
Subject: [PATCH v9 1/5] Doc: Use past tense for things which happened in the
 past

The paragraph on SSL compression is largely describing events which
took place many years ago, so reword with past tense.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 doc/src/sgml/libpq.sgml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 9199d0d2e5..0db3667fdf 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1840,11 +1840,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
-- 
2.39.3 (Apple Git-146)

From 82f8a165c651dcdf9b35e208c8aa00fba8696dfe Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:36:52 +0200
Subject: [PATCH v10 1/5] Doc: Use past tense for things which happened in the
 past

The paragraph on SSL compression is largely describing events which
took place many years ago, so reword with past tense.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 doc/src/sgml/libpq.sgml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 9199d0d2e5..0db3667fdf 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1840,11 +1840,11 @@ postgresql://%2Fvar%2Flib%2Fpostgresql/dbname
 
        <para>
         SSL compression is nowadays considered insecure and its use is no
-        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disables
+        longer recommended.  <productname>OpenSSL</productname> 1.1.0 disabled
         compression by default, and many operating system distributions
-        disable it in prior versions as well, so setting this parameter to on
+        disabled it in prior versions as well, so setting this parameter to on
         will not have any effect if the server does not accept compression.
-        <productname>PostgreSQL</productname> 14 disables compression
+        <productname>PostgreSQL</productname> 14 disabled compression
         completely in the backend.
        </para>
 
-- 
2.39.3 (Apple Git-146)

From 9f7aff6c60727ed431b638a4d0d4cde3994ae7c5 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:00 +0200
Subject: [PATCH v10 2/5] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 ++--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +--
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 14 files changed, 28 insertions(+), 437 deletions(-)

diff --git a/configure b/configure
index cfbd2a096f..73e76070b0 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 67e738d92b..cf85ad409e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index cdfd31377d..f9ec8b66a8 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 29c9af1aab..88153d4bda 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -104,13 +105,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -933,7 +928,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -956,14 +950,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index e7a4d006e1..640edebcfe 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1460,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1475,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1492,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1752,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1777,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1784,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..434d6c449f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.39.3 (Apple Git-146)

From 436f9bf6d4bf04eb8b47fea4fede6176be5e29e8 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:44 +0200
Subject: [PATCH v10 3/5] Support disallowing SSL renegotiation in LibreSSL

LibreSSL doesn't support the SSL_OP_NO_RENEGOTIATION macro which is
used by OpenSSL, instead it has invented a similar one for client-
side renegotiation: SSL_OP_NO_CLIENT_RENEGOTIATION. This has been
supported since LibreSSL 2.5.1 which by now can be considered well
below the minimum requirement.

Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 88153d4bda..efd49ffca8 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -262,15 +262,20 @@ be_tls_init(bool isServerStart)
 	/* disallow SSL compression */
 	SSL_CTX_set_options(context, SSL_OP_NO_COMPRESSION);
 
-#ifdef SSL_OP_NO_RENEGOTIATION
-
 	/*
-	 * Disallow SSL renegotiation, option available since 1.1.0h.  This
-	 * concerns only TLSv1.2 and older protocol versions, as TLSv1.3 has no
-	 * support for renegotiation.
+	 * Disallow SSL renegotiation.  This concerns only TLSv1.2 and older
+	 * protocol versions, as TLSv1.3 has no support for renegotiation.
+	 * SSL_OP_NO_RENEGOTIATION is available in OpenSSL since 1.1.0h (via a
+	 * backport from 1.1.1). SSL_OP_NO_CLIENT_RENEGOTIATION is available in
+	 * LibreSSL since 2.5.1 disallowing all client-initiated renegotiation
+	 * (this is usually on by default).
 	 */
+#ifdef SSL_OP_NO_RENEGOTIATION
 	SSL_CTX_set_options(context, SSL_OP_NO_RENEGOTIATION);
 #endif
+#ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
+	SSL_CTX_set_options(context, SSL_OP_NO_CLIENT_RENEGOTIATION);
+#endif
 
 	/* set up ephemeral DH and ECDH keys */
 	if (!initialize_dh(context, isServerStart))
-- 
2.39.3 (Apple Git-146)

From 909a6c2c9de701931488ab28cc9500ff2326e43e Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:57 +0200
Subject: [PATCH v10 4/5] Support SSL_R_VERSION_TOO_LOW on LibreSSL

The SSL_R_VERSION_TOO_LOW error reason is supported in LibreSSL since
LibreSSL 3.6.3, shipped in OpenBSD 7.2.  SSL_R_VERSION_TOO_HIGH is on
the other hand not supported in any version of LibreSSL.  Previously
we only checked for SSL_R_VERSION_TOO_HIGH and then applied both under
that guard since OpenSSL has only ever supported both at the same time.
This breaks the check into one per reason to allow SSL_R_VERSION_TOO_LOW
to work when using LibreSSL.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org
---
 src/backend/libpq/be-secure-openssl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index efd49ffca8..59c71b15b5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -542,6 +542,8 @@ aloop:
 					case SSL_R_TLSV1_ALERT_PROTOCOL_VERSION:
 #ifdef SSL_R_VERSION_TOO_HIGH
 					case SSL_R_VERSION_TOO_HIGH:
+#endif
+#ifdef SSL_R_VERSION_TOO_LOW
 					case SSL_R_VERSION_TOO_LOW:
 #endif
 						give_proto_hint = true;
-- 
2.39.3 (Apple Git-146)

From 0fc05de568f8699b6265efaf40aad9836b59166a Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v10 5/5] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checkig the OpenSSL
version number.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From 331207efef429954265bbb24687d71df91e2c9a9 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v11 2/2] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checkig the OpenSSL
version number.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From 626cdc6b1b6a1ed30b44b261c645c8a922360ba4 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:00 +0200
Subject: [PATCH v11 1/2] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 ++--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  16 +-
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +--
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 --------------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-secure-openssl.c | 197 -----------------------
 src/interfaces/libpq/libpq-int.h         |   5 -
 14 files changed, 28 insertions(+), 437 deletions(-)

diff --git a/configure b/configure
index cfbd2a096f..73e76070b0 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index 67e738d92b..cf85ad409e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index cdfd31377d..f9ec8b66a8 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index fc46a33539..59c71b15b5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -104,13 +105,7 @@ be_tls_init(bool isServerStart)
 	/* This stuff need be done only once. */
 	if (!SSL_initialized)
 	{
-#ifdef HAVE_OPENSSL_INIT_SSL
 		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
 		SSL_initialized = true;
 	}
 
@@ -940,7 +935,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -963,14 +957,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index e7a4d006e1..640edebcfe 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -505,11 +504,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +535,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,49 +703,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 /*
  * Initialize SSL library.
  *
@@ -771,67 +719,10 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	if (pthread_mutex_lock(&ssl_config_mutex))
 		return -1;
 
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
 	if (!ssl_lib_initialized && do_ssl)
 	{
 		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
 			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
 		ssl_lib_initialized = true;
 	}
 
@@ -839,52 +730,6 @@ pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
 	return 0;
 }
 
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1460,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1475,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1492,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1752,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1777,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1784,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..434d6c449f 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
-- 
2.39.3 (Apple Git-146)

From 8cdf1101c57917e425feb08f6c26fc35a6be9611 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v12 2/2] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checkig the OpenSSL
version number.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From a9f6a2a2db3c12665fb96d01ad22056c4342e604 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:00 +0200
Subject: [PATCH v12 1/2] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 +--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  24 +--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  21 +-
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 -----------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-connect.c        |  18 --
 src/interfaces/libpq/fe-secure-openssl.c | 246 -----------------------
 src/interfaces/libpq/fe-secure.c         |  35 +---
 src/interfaces/libpq/libpq-int.h         |  13 +-
 16 files changed, 41 insertions(+), 542 deletions(-)

diff --git a/configure b/configure
index 89644f2249..1181a7347f 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index c7322e292c..2d5e2c2c2c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index a453f804cd..e35f52a4d0 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/meson.build b/meson.build
index cdfd31377d..f9ec8b66a8 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index fc46a33539..3ba85490e5 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -80,7 +81,6 @@ static const char *SSLerrmessage(unsigned long ecode);
 static char *X509_NAME_to_cstring(X509_NAME *name);
 
 static SSL_CTX *SSL_context = NULL;
-static bool SSL_initialized = false;
 static bool dummy_ssl_passwd_cb_called = false;
 static bool ssl_is_server_start;
 
@@ -101,19 +101,6 @@ be_tls_init(bool isServerStart)
 	int			ssl_ver_min = -1;
 	int			ssl_ver_max = -1;
 
-	/* This stuff need be done only once. */
-	if (!SSL_initialized)
-	{
-#ifdef HAVE_OPENSSL_INIT_SSL
-		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
-		SSL_initialized = true;
-	}
-
 	/*
 	 * Create a new SSL context into which we'll load all the configuration
 	 * settings.  If we fail partway through, we can avoid memory leakage by
@@ -940,7 +927,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -963,14 +949,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..e55b024159 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -139,16 +134,11 @@ pg_hmac_create(pg_cryptohash_type type)
 	 * previous runs.
 	 */
 	ERR_clear_error();
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +152,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +315,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index ec20e3f3a9..f56c0712bb 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3327,16 +3327,6 @@ keep_going:						/* We will come back to here until there is
 
 #ifdef USE_SSL
 
-				/*
-				 * Enable the libcrypto callbacks before checking if SSL needs
-				 * to be done.  This is done before sending the startup packet
-				 * as depending on the type of authentication done, like MD5
-				 * or SCRAM that use cryptohashes, the callbacks would be
-				 * required even without a SSL connection
-				 */
-				if (pqsecure_initialize(conn, false, true) < 0)
-					goto error_return;
-
 				/*
 				 * If direct SSL is enabled, jump right into SSL handshake. We
 				 * will come back here after SSL encryption has been
@@ -3510,14 +3500,6 @@ keep_going:						/* We will come back to here until there is
 					}
 				}
 
-				/*
-				 * Set up global SSL state if required.  The crypto state has
-				 * already been set if libpq took care of doing that, so there
-				 * is no need to make that happen again.
-				 */
-				if (pqsecure_initialize(conn, true, false) != 0)
-					goto error_return;
-
 				/*
 				 * Begin or continue the SSL negotiation process.
 				 */
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index e7a4d006e1..8927571076 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -83,14 +82,6 @@ static int	my_sock_write(BIO *h, const char *buf, int size);
 static BIO_METHOD *my_BIO_s_socket(void);
 static int	my_SSL_set_fd(PGconn *conn, int fd);
 
-
-static bool pq_init_ssl_lib = true;
-static bool pq_init_crypto_lib = true;
-
-static bool ssl_lib_initialized = false;
-
-static long crypto_open_connections = 0;
-
 static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook = NULL;
@@ -100,20 +91,6 @@ static int	ssl_protocol_version_to_openssl(const char *protocol);
 /*			 Procedures common to all secure sessions			*/
 /* ------------------------------------------------------------ */
 
-void
-pgtls_init_library(bool do_ssl, int do_crypto)
-{
-	/*
-	 * Disallow changing the flags while we have open connections, else we'd
-	 * get completely confused.
-	 */
-	if (crypto_open_connections != 0)
-		return;
-
-	pq_init_ssl_lib = do_ssl;
-	pq_init_crypto_lib = do_crypto;
-}
-
 PostgresPollingStatusType
 pgtls_open_client(PGconn *conn)
 {
@@ -505,11 +482,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +513,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,179 +681,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-/*
- * Initialize SSL library.
- *
- * In threadsafe mode, this includes setting up libcrypto callback functions
- * to do thread locking.
- *
- * If the caller has told us (through PQinitOpenSSL) that he's taking care
- * of libcrypto, we expect that callbacks are already set, and won't try to
- * override it.
- */
-int
-pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return -1;
-
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-	if (!ssl_lib_initialized && do_ssl)
-	{
-		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
-			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
-		ssl_lib_initialized = true;
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-	return 0;
-}
-
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1615,8 +1411,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1632,8 +1426,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1651,30 +1443,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1935,7 +1703,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -1961,14 +1728,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -1976,13 +1735,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index f628082337..5567be9d39 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -108,42 +108,27 @@ PQsslInUse(PGconn *conn)
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitSSL(int do_init)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_init, do_init);
-#endif
+	/* no-op */
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL and/or libcrypto.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitOpenSSL(int do_ssl, int do_crypto)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_ssl, do_crypto);
-#endif
-}
-
-/*
- *	Initialize global SSL context
- */
-int
-pqsecure_initialize(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	int			r = 0;
-
-#ifdef USE_SSL
-	r = pgtls_init(conn, do_ssl, do_crypto);
-#endif
-
-	return r;
+	/* no-op */
 }
 
 /*
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..21df8623a7 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
@@ -763,7 +758,6 @@ extern int	pqWriteReady(PGconn *conn);
 
 /* === in fe-secure.c === */
 
-extern int	pqsecure_initialize(PGconn *, bool, bool);
 extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
 extern void pqsecure_close(PGconn *);
 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
@@ -786,19 +780,18 @@ extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
 /*
  *	Implementation of PQinitSSL().
  */
-extern void pgtls_init_library(bool do_ssl, int do_crypto);
+extern void pgtls_init_library(bool do_ssl);
 
 /*
  * Initialize SSL library.
  *
  * The conn parameter is only used to be able to pass back an error
  * message - no connection-local setup is made here.  do_ssl controls
- * if SSL is initialized, and do_crypto does the same for the crypto
- * part.
+ * if SSL is initialized.
  *
  * Returns 0 if OK, -1 on failure (adding a message to conn->errorMessage).
  */
-extern int	pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto);
+extern int	pgtls_init(PGconn *conn, bool do_ssl);
 
 /*
  *	Begin or continue negotiating a secure session.
-- 
2.39.3 (Apple Git-146)

From 07546ae71663b2be824b40f70d583195b10c9708 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v13 2/2] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checkig the OpenSSL
version number.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From 5fcf25d268a29022a8e4f1eea299cc01940fd96c Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:37:00 +0200
Subject: [PATCH v13 1/2] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from upstream for some time, and is no
longer the default OpenSSL version with any vendor which package
PostgreSQL.  By retiring support for 1.0.2 we can remove a lot of
complexity from the tree which is no longer required.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 +--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |  36 ++--
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  24 +--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  20 +-
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 -----------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-connect.c        |  18 --
 src/interfaces/libpq/fe-secure-openssl.c | 246 -----------------------
 src/interfaces/libpq/fe-secure.c         |  35 +---
 src/interfaces/libpq/libpq-int.h         |  13 +-
 src/test/ssl/t/001_ssltests.pl           |   3 +-
 18 files changed, 58 insertions(+), 563 deletions(-)

diff --git a/configure b/configure
index 89644f2249..1181a7347f 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index c7322e292c..2d5e2c2c2c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 1b32d5ca62..daa7d19b77 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 101c676e08..11c0ae0e3c 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -9830,9 +9830,11 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
   <title>SSL Library Initialization</title>
 
   <para>
-   If your application initializes <literal>libssl</literal> and/or
-   <literal>libcrypto</literal> libraries and <application>libpq</application>
-   is built with <acronym>SSL</acronym> support, you should call
+   Applications which need to be compatible with older versions of
+   <productname>PostgreSQL</productname>, using <productname>OpenSSL</productname>
+   version 1.0.2 or older, need to initialize the SSL library before using it.
+   Applications which initialize <literal>libssl</literal> and/or
+   <literal>libcrypto</literal> libraries should call
    <xref linkend="libpq-PQinitOpenSSL"/> to tell <application>libpq</application>
    that the <literal>libssl</literal> and/or <literal>libcrypto</literal> libraries
    have been initialized by your application, so that
@@ -9840,6 +9842,10 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
    However, this is unnecessary when using <productname>OpenSSL</productname>
    version 1.1.0 or later, as duplicate initializations are no longer problematic.
   </para>
+  <para>
+   Refer to the documentation for the version of <productname>PostgreSQL</productname>
+   that you are targeting for details on their use.
+  </para>
 
   <para>
    <variablelist>
@@ -9855,21 +9861,8 @@ void PQinitOpenSSL(int do_ssl, int do_crypto);
       </para>
 
       <para>
-       When <parameter>do_ssl</parameter> is non-zero, <application>libpq</application>
-       will initialize the <productname>OpenSSL</productname> library before first
-       opening a database connection.  When <parameter>do_crypto</parameter> is
-       non-zero, the <literal>libcrypto</literal> library will be initialized.  By
-       default (if <xref linkend="libpq-PQinitOpenSSL"/> is not called), both libraries
-       are initialized.  When SSL support is not compiled in, this function is
-       present but does nothing.
-      </para>
-
-      <para>
-       If your application uses and initializes either <productname>OpenSSL</productname>
-       or its underlying <literal>libcrypto</literal> library, you <emphasis>must</emphasis>
-       call this function with zeroes for the appropriate parameter(s)
-       before first opening a database connection.  Also be sure that you
-       have done that initialization before opening a database connection.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
      </listitem>
     </varlistentry>
@@ -9886,11 +9879,14 @@ void PQinitSSL(int do_ssl);
       <para>
        This function is equivalent to
        <literal>PQinitOpenSSL(do_ssl, do_ssl)</literal>.
-       It is sufficient for applications that initialize both or neither
-       of <productname>OpenSSL</productname> and <literal>libcrypto</literal>.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
 
       <para>
+       <xref linkend="libpq-PQinitSSL"/> and <xref linkend="libpq-PQinitOpenSSL"/>
+       are maintained for backwards compatibility, but are no longer required
+       since <productname>PostgreSQL</productname> 18.
        <xref linkend="libpq-PQinitSSL"/> has been present since
        <productname>PostgreSQL</productname> 8.0, while <xref linkend="libpq-PQinitOpenSSL"/>
        was added in <productname>PostgreSQL</productname> 8.4, so <xref linkend="libpq-PQinitSSL"/>
diff --git a/meson.build b/meson.build
index 1c0579d5a6..12508612a6 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 60cf68aac4..85c700cb05 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -80,7 +81,6 @@ static const char *SSLerrmessage(unsigned long ecode);
 static char *X509_NAME_to_cstring(X509_NAME *name);
 
 static SSL_CTX *SSL_context = NULL;
-static bool SSL_initialized = false;
 static bool dummy_ssl_passwd_cb_called = false;
 static bool ssl_is_server_start;
 
@@ -101,19 +101,6 @@ be_tls_init(bool isServerStart)
 	int			ssl_ver_min = -1;
 	int			ssl_ver_max = -1;
 
-	/* This stuff need be done only once. */
-	if (!SSL_initialized)
-	{
-#ifdef HAVE_OPENSSL_INIT_SSL
-		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
-		SSL_initialized = true;
-	}
-
 	/*
 	 * Create a new SSL context into which we'll load all the configuration
 	 * settings.  If we fail partway through, we can avoid memory leakage by
@@ -940,7 +927,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -963,14 +949,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..da2c93e32a 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -144,11 +139,7 @@ pg_hmac_create(pg_cryptohash_type type)
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +153,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +316,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 81d278c395..20f1960319 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3336,16 +3336,6 @@ keep_going:						/* We will come back to here until there is
 
 #ifdef USE_SSL
 
-				/*
-				 * Enable the libcrypto callbacks before checking if SSL needs
-				 * to be done.  This is done before sending the startup packet
-				 * as depending on the type of authentication done, like MD5
-				 * or SCRAM that use cryptohashes, the callbacks would be
-				 * required even without a SSL connection
-				 */
-				if (pqsecure_initialize(conn, false, true) < 0)
-					goto error_return;
-
 				/*
 				 * If direct SSL is enabled, jump right into SSL handshake. We
 				 * will come back here after SSL encryption has been
@@ -3523,14 +3513,6 @@ keep_going:						/* We will come back to here until there is
 					}
 				}
 
-				/*
-				 * Set up global SSL state if required.  The crypto state has
-				 * already been set if libpq took care of doing that, so there
-				 * is no need to make that happen again.
-				 */
-				if (pqsecure_initialize(conn, true, false) != 0)
-					goto error_return;
-
 				/*
 				 * Begin or continue the SSL negotiation process.
 				 */
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index fb6bb911f5..b9bfb8e37e 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -83,14 +82,6 @@ static int	my_sock_write(BIO *h, const char *buf, int size);
 static BIO_METHOD *my_BIO_s_socket(void);
 static int	my_SSL_set_fd(PGconn *conn, int fd);
 
-
-static bool pq_init_ssl_lib = true;
-static bool pq_init_crypto_lib = true;
-
-static bool ssl_lib_initialized = false;
-
-static long crypto_open_connections = 0;
-
 static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook = NULL;
@@ -100,20 +91,6 @@ static int	ssl_protocol_version_to_openssl(const char *protocol);
 /*			 Procedures common to all secure sessions			*/
 /* ------------------------------------------------------------ */
 
-void
-pgtls_init_library(bool do_ssl, int do_crypto)
-{
-	/*
-	 * Disallow changing the flags while we have open connections, else we'd
-	 * get completely confused.
-	 */
-	if (crypto_open_connections != 0)
-		return;
-
-	pq_init_ssl_lib = do_ssl;
-	pq_init_crypto_lib = do_crypto;
-}
-
 PostgresPollingStatusType
 pgtls_open_client(PGconn *conn)
 {
@@ -505,11 +482,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +513,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,179 +681,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-/*
- * Initialize SSL library.
- *
- * In threadsafe mode, this includes setting up libcrypto callback functions
- * to do thread locking.
- *
- * If the caller has told us (through PQinitOpenSSL) that he's taking care
- * of libcrypto, we expect that callbacks are already set, and won't try to
- * override it.
- */
-int
-pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return -1;
-
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-	if (!ssl_lib_initialized && do_ssl)
-	{
-		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
-			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
-		ssl_lib_initialized = true;
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-	return 0;
-}
-
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1643,8 +1439,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1660,8 +1454,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1679,30 +1471,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1980,7 +1748,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -2006,14 +1773,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -2021,13 +1780,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index f628082337..5567be9d39 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -108,42 +108,27 @@ PQsslInUse(PGconn *conn)
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitSSL(int do_init)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_init, do_init);
-#endif
+	/* no-op */
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL and/or libcrypto.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitOpenSSL(int do_ssl, int do_crypto)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_ssl, do_crypto);
-#endif
-}
-
-/*
- *	Initialize global SSL context
- */
-int
-pqsecure_initialize(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	int			r = 0;
-
-#ifdef USE_SSL
-	r = pgtls_init(conn, do_ssl, do_crypto);
-#endif
-
-	return r;
+	/* no-op */
 }
 
 /*
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 3691e5ee96..21df8623a7 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -580,11 +580,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
@@ -763,7 +758,6 @@ extern int	pqWriteReady(PGconn *conn);
 
 /* === in fe-secure.c === */
 
-extern int	pqsecure_initialize(PGconn *, bool, bool);
 extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
 extern void pqsecure_close(PGconn *);
 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
@@ -786,19 +780,18 @@ extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
 /*
  *	Implementation of PQinitSSL().
  */
-extern void pgtls_init_library(bool do_ssl, int do_crypto);
+extern void pgtls_init_library(bool do_ssl);
 
 /*
  * Initialize SSL library.
  *
  * The conn parameter is only used to be able to pass back an error
  * message - no connection-local setup is made here.  do_ssl controls
- * if SSL is initialized, and do_crypto does the same for the crypto
- * part.
+ * if SSL is initialized.
  *
  * Returns 0 if OK, -1 on failure (adding a message to conn->errorMessage).
  */
-extern int	pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto);
+extern int	pgtls_init(PGconn *conn, bool do_ssl);
 
 /*
  *	Begin or continue negotiating a secure session.
diff --git a/src/test/ssl/t/001_ssltests.pl b/src/test/ssl/t/001_ssltests.pl
index 94ff043c8e..c982aeb361 100644
--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -36,8 +36,7 @@ sub switch_server_cert
 }
 
 # Determine whether this build uses OpenSSL or LibreSSL. As a heuristic, the
-# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL. (Nor for OpenSSL
-# 1.0.1, but that's old enough that accommodating it isn't worth the cost.)
+# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL.
 my $libressl = not check_pg_config("#define HAVE_SSL_CTX_SET_CERT_CB 1");
 
 #### Some configuration
-- 
2.39.3 (Apple Git-146)

From b0b113cd3af897b0eb31de74100b14b4a04ca29c Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v14 2/2] Remove pg_strong_random initialization.

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checkig the OpenSSL
version number.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From ed61fbcc6f3a470ebacc4148b2a9e940e8df6ad1 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Fri, 12 Jul 2024 22:08:08 +0200
Subject: [PATCH v14 1/2] Remove support for OpenSSL 1.0.2

OpenSSL 1.0.2 has been EOL from the upstream OpenSSL project for
some time, and is no longer the default OpenSSL version with any
vendor which package PostgreSQL. By retiring support for OpenSSL
1.0.2 we can remove a lot of no longer required complexity for
managing state within libcrypto which is now handled by OpenSSL.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 +--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |  36 ++--
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  24 +--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  20 +-
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 -----------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-connect.c        |  18 --
 src/interfaces/libpq/fe-secure-openssl.c | 246 -----------------------
 src/interfaces/libpq/fe-secure.c         |  35 +---
 src/interfaces/libpq/libpq-int.h         |  23 ---
 src/test/ssl/t/001_ssltests.pl           |   3 +-
 18 files changed, 55 insertions(+), 576 deletions(-)

diff --git a/configure b/configure
index 76f06bd8fd..bea2e9f234 100755
--- a/configure
+++ b/configure
@@ -12330,9 +12330,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12564,33 +12564,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info
 do :
   ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
diff --git a/configure.ac b/configure.ac
index ab2d51c21c..818f7ee702 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1335,8 +1335,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1352,12 +1352,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 4784834ab9..5e0e163acb 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 068ee60771..f0e1681987 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -9863,9 +9863,11 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
   <title>SSL Library Initialization</title>
 
   <para>
-   If your application initializes <literal>libssl</literal> and/or
-   <literal>libcrypto</literal> libraries and <application>libpq</application>
-   is built with <acronym>SSL</acronym> support, you should call
+   Applications which need to be compatible with older versions of
+   <productname>PostgreSQL</productname>, using <productname>OpenSSL</productname>
+   version 1.0.2 or older, need to initialize the SSL library before using it.
+   Applications which initialize <literal>libssl</literal> and/or
+   <literal>libcrypto</literal> libraries should call
    <xref linkend="libpq-PQinitOpenSSL"/> to tell <application>libpq</application>
    that the <literal>libssl</literal> and/or <literal>libcrypto</literal> libraries
    have been initialized by your application, so that
@@ -9873,6 +9875,10 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
    However, this is unnecessary when using <productname>OpenSSL</productname>
    version 1.1.0 or later, as duplicate initializations are no longer problematic.
   </para>
+  <para>
+   Refer to the documentation for the version of <productname>PostgreSQL</productname>
+   that you are targeting for details on their use.
+  </para>
 
   <para>
    <variablelist>
@@ -9888,21 +9894,8 @@ void PQinitOpenSSL(int do_ssl, int do_crypto);
       </para>
 
       <para>
-       When <parameter>do_ssl</parameter> is non-zero, <application>libpq</application>
-       will initialize the <productname>OpenSSL</productname> library before first
-       opening a database connection.  When <parameter>do_crypto</parameter> is
-       non-zero, the <literal>libcrypto</literal> library will be initialized.  By
-       default (if <xref linkend="libpq-PQinitOpenSSL"/> is not called), both libraries
-       are initialized.  When SSL support is not compiled in, this function is
-       present but does nothing.
-      </para>
-
-      <para>
-       If your application uses and initializes either <productname>OpenSSL</productname>
-       or its underlying <literal>libcrypto</literal> library, you <emphasis>must</emphasis>
-       call this function with zeroes for the appropriate parameter(s)
-       before first opening a database connection.  Also be sure that you
-       have done that initialization before opening a database connection.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
      </listitem>
     </varlistentry>
@@ -9919,11 +9912,14 @@ void PQinitSSL(int do_ssl);
       <para>
        This function is equivalent to
        <literal>PQinitOpenSSL(do_ssl, do_ssl)</literal>.
-       It is sufficient for applications that initialize both or neither
-       of <productname>OpenSSL</productname> and <literal>libcrypto</literal>.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
 
       <para>
+       <xref linkend="libpq-PQinitSSL"/> and <xref linkend="libpq-PQinitOpenSSL"/>
+       are maintained for backwards compatibility, but are no longer required
+       since <productname>PostgreSQL</productname> 18.
        <xref linkend="libpq-PQinitSSL"/> has been present since
        <productname>PostgreSQL</productname> 8.0, while <xref linkend="libpq-PQinitOpenSSL"/>
        was added in <productname>PostgreSQL</productname> 8.4, so <xref linkend="libpq-PQinitSSL"/>
diff --git a/meson.build b/meson.build
index 5387bb6d5f..fd2e09a40e 100644
--- a/meson.build
+++ b/meson.build
@@ -1272,26 +1272,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
     ]
 
@@ -1314,7 +1305,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 387f30cdaa..2ca648fb45 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -80,7 +81,6 @@ static const char *SSLerrmessage(unsigned long ecode);
 static char *X509_NAME_to_cstring(X509_NAME *name);
 
 static SSL_CTX *SSL_context = NULL;
-static bool SSL_initialized = false;
 static bool dummy_ssl_passwd_cb_called = false;
 static bool ssl_is_server_start;
 
@@ -101,19 +101,6 @@ be_tls_init(bool isServerStart)
 	int			ssl_ver_min = -1;
 	int			ssl_ver_max = -1;
 
-	/* This stuff need be done only once. */
-	if (!SSL_initialized)
-	{
-#ifdef HAVE_OPENSSL_INIT_SSL
-		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
-		SSL_initialized = true;
-	}
-
 	/*
 	 * Create a new SSL context into which we'll load all the configuration
 	 * settings.  If we fail partway through, we can avoid memory leakage by
@@ -941,7 +928,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -964,14 +950,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 3d83299432..fdc33ed6d4 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..da2c93e32a 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -144,11 +139,7 @@ pg_hmac_create(pg_cryptohash_type type)
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +153,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +316,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index de68e408fa..8cbc46ab81 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index f8d3e3b6b8..2b5f5cafab 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,9 +54,6 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you want to use atomics if available. */
 #undef HAVE_ATOMICS
 
@@ -66,9 +63,6 @@
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -84,9 +78,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -198,12 +189,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index e003279fb6..01269a289c 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3341,16 +3341,6 @@ keep_going:						/* We will come back to here until there is
 
 #ifdef USE_SSL
 
-				/*
-				 * Enable the libcrypto callbacks before checking if SSL needs
-				 * to be done.  This is done before sending the startup packet
-				 * as depending on the type of authentication done, like MD5
-				 * or SCRAM that use cryptohashes, the callbacks would be
-				 * required even without a SSL connection
-				 */
-				if (pqsecure_initialize(conn, false, true) < 0)
-					goto error_return;
-
 				/*
 				 * If SSL is enabled, start the SSL negotiation. We will come
 				 * back here after SSL encryption has been established, with
@@ -3531,14 +3521,6 @@ keep_going:						/* We will come back to here until there is
 					}
 				}
 
-				/*
-				 * Set up global SSL state if required.  The crypto state has
-				 * already been set if libpq took care of doing that, so there
-				 * is no need to make that happen again.
-				 */
-				if (pqsecure_initialize(conn, true, false) != 0)
-					goto error_return;
-
 				/*
 				 * Begin or continue the SSL negotiation process.
 				 */
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index 5c867106fb..ec9fd91059 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -83,14 +82,6 @@ static int	my_sock_write(BIO *h, const char *buf, int size);
 static BIO_METHOD *my_BIO_s_socket(void);
 static int	my_SSL_set_fd(PGconn *conn, int fd);
 
-
-static bool pq_init_ssl_lib = true;
-static bool pq_init_crypto_lib = true;
-
-static bool ssl_lib_initialized = false;
-
-static long crypto_open_connections = 0;
-
 static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook = NULL;
@@ -100,20 +91,6 @@ static int	ssl_protocol_version_to_openssl(const char *protocol);
 /*			 Procedures common to all secure sessions			*/
 /* ------------------------------------------------------------ */
 
-void
-pgtls_init_library(bool do_ssl, int do_crypto)
-{
-	/*
-	 * Disallow changing the flags while we have open connections, else we'd
-	 * get completely confused.
-	 */
-	if (crypto_open_connections != 0)
-		return;
-
-	pq_init_ssl_lib = do_ssl;
-	pq_init_crypto_lib = do_crypto;
-}
-
 PostgresPollingStatusType
 pgtls_open_client(PGconn *conn)
 {
@@ -505,11 +482,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +513,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,179 +681,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-/*
- * Initialize SSL library.
- *
- * In threadsafe mode, this includes setting up libcrypto callback functions
- * to do thread locking.
- *
- * If the caller has told us (through PQinitOpenSSL) that he's taking care
- * of libcrypto, we expect that callbacks are already set, and won't try to
- * override it.
- */
-int
-pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return -1;
-
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-	if (!ssl_lib_initialized && do_ssl)
-	{
-		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
-			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
-		ssl_lib_initialized = true;
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-	return 0;
-}
-
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1643,8 +1439,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1660,8 +1454,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1679,30 +1471,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1980,7 +1748,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -2006,14 +1773,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -2021,13 +1780,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index f628082337..5567be9d39 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -108,42 +108,27 @@ PQsslInUse(PGconn *conn)
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitSSL(int do_init)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_init, do_init);
-#endif
+	/* no-op */
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL and/or libcrypto.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitOpenSSL(int do_ssl, int do_crypto)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_ssl, do_crypto);
-#endif
-}
-
-/*
- *	Initialize global SSL context
- */
-int
-pqsecure_initialize(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	int			r = 0;
-
-#ifdef USE_SSL
-	r = pgtls_init(conn, do_ssl, do_crypto);
-#endif
-
-	return r;
+	/* no-op */
 }
 
 /*
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index f36d76bf3f..e93962867b 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -578,11 +578,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
@@ -761,7 +756,6 @@ extern int	pqWriteReady(PGconn *conn);
 
 /* === in fe-secure.c === */
 
-extern int	pqsecure_initialize(PGconn *, bool, bool);
 extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
 extern void pqsecure_close(PGconn *);
 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
@@ -781,23 +775,6 @@ extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
  * The SSL implementation provides these functions.
  */
 
-/*
- *	Implementation of PQinitSSL().
- */
-extern void pgtls_init_library(bool do_ssl, int do_crypto);
-
-/*
- * Initialize SSL library.
- *
- * The conn parameter is only used to be able to pass back an error
- * message - no connection-local setup is made here.  do_ssl controls
- * if SSL is initialized, and do_crypto does the same for the crypto
- * part.
- *
- * Returns 0 if OK, -1 on failure (adding a message to conn->errorMessage).
- */
-extern int	pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto);
-
 /*
  *	Begin or continue negotiating a secure session.
  */
diff --git a/src/test/ssl/t/001_ssltests.pl b/src/test/ssl/t/001_ssltests.pl
index b877327023..4bd868ff65 100644
--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -36,8 +36,7 @@ sub switch_server_cert
 }
 
 # Determine whether this build uses OpenSSL or LibreSSL. As a heuristic, the
-# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL. (Nor for OpenSSL
-# 1.0.1, but that's old enough that accommodating it isn't worth the cost.)
+# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL.
 my $libressl = not check_pg_config("#define HAVE_SSL_CTX_SET_CERT_CB 1");
 
 #### Some configuration
-- 
2.39.3 (Apple Git-146)

From e73f3e7454ff516a12361346e04d3bcf8309ce4f Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 18 Apr 2024 21:39:33 +0200
Subject: [PATCH v15 2/2] Only perform pg_strong_random init when required

The random number generator in OpenSSL 1.1.1 was redesigned to provide
fork safety by default, thus removing the need for calling RAND_poll
after forking to ensure that two processes cannot share the same state.
Since we now support 1.1.0 as the minumum version, and 1.1.0 is being
increasingly phased out from production use, only perform the RAND_poll
initialization for installations running 1.1.0 by checking the OpenSSL
version number. This saves the vast majority of installations from the
init function call overhead.

LibreSSL changed random number generator when forking OpenSSL and has
provided fork safety since version 2.0.2.

This removes the overhead of initializing the RNG for strong random
for the vast majority of users for whom it is no longer required.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 src/port/pg_strong_random.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/port/pg_strong_random.c b/src/port/pg_strong_random.c
index 5f2b248425..a8efb2b188 100644
--- a/src/port/pg_strong_random.c
+++ b/src/port/pg_strong_random.c
@@ -50,17 +50,20 @@
 
 #ifdef USE_OPENSSL
 
+#include <openssl/opensslv.h>
 #include <openssl/rand.h>
 
 void
 pg_strong_random_init(void)
 {
+#if (OPENSSL_VERSION_NUMBER < 0x10101000L)
 	/*
-	 * Make sure processes do not share OpenSSL randomness state.  This is no
-	 * longer required in OpenSSL 1.1.1 and later versions, but until we drop
-	 * support for version < 1.1.1 we need to do this.
+	 * Make sure processes do not share OpenSSL randomness state.  This is not
+	 * required on LibreSSL and no longer required in OpenSSL 1.1.1 and later
+	 * versions.
 	 */
 	RAND_poll();
+#endif
 }
 
 bool
-- 
2.39.3 (Apple Git-146)

From 014ce6fd56a559d6eadc76260857b816b50a2ebd Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <daniel@yesql.se>
Date: Mon, 2 Sep 2024 09:28:07 +0200
Subject: [PATCH v15 1/2] Remove support for OpenSSL older than 1.1.0

OpenSSL 1.0.2 has been EOL from the upstream OpenSSL project for
some time, and is no longer the default OpenSSL version with any
vendor which package PostgreSQL. By retiring support for OpenSSL
1.0.2 we can remove a lot of no longer required complexity for
managing state within libcrypto which is now handled by OpenSSL.

Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/ZG3JNursG69dz1lr@paquier.xyz
Discussion: https://postgr.es/m/CA+hUKGKh7QrYzu=8yWEUJvXtMVm_CNWH1L_TLWCbZMwbi1XP2Q@mail.gmail.com
---
 configure                                |  31 +--
 configure.ac                             |  12 +-
 contrib/pgcrypto/openssl.c               |   8 -
 doc/src/sgml/installation.sgml           |   2 +-
 doc/src/sgml/libpq.sgml                  |  36 ++--
 meson.build                              |  23 +--
 src/backend/libpq/be-secure-openssl.c    |  24 +--
 src/common/Makefile                      |   3 +-
 src/common/hmac_openssl.c                |  20 +-
 src/common/meson.build                   |   1 -
 src/common/protocol_openssl.c            | 117 -----------
 src/include/common/openssl.h             |  14 +-
 src/include/pg_config.h.in               |  15 --
 src/interfaces/libpq/fe-connect.c        |  18 --
 src/interfaces/libpq/fe-secure-openssl.c | 246 -----------------------
 src/interfaces/libpq/fe-secure.c         |  35 +---
 src/interfaces/libpq/libpq-int.h         |  23 ---
 src/test/ssl/t/001_ssltests.pl           |   3 +-
 18 files changed, 55 insertions(+), 576 deletions(-)

diff --git a/configure b/configure
index 537366945c..53c8a1f2ba 100755
--- a/configure
+++ b/configure
@@ -12313,9 +12313,9 @@ if test "$with_openssl" = yes ; then
 fi
 
 if test "$with_ssl" = openssl ; then
-    # Minimum required OpenSSL version is 1.0.2
+    # Minimum required OpenSSL version is 1.1.0
 
-$as_echo "#define OPENSSL_API_COMPAT 0x10002000L" >>confdefs.h
+$as_echo "#define OPENSSL_API_COMPAT 0x10100000L" >>confdefs.h
 
   if test "$PORTNAME" != "win32"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for CRYPTO_new_ex_data in -lcrypto" >&5
@@ -12547,33 +12547,20 @@ done
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  for ac_func in OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free
+  for ac_func in OPENSSL_init_ssl
 do :
-  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
-ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
-if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
-  cat >>confdefs.h <<_ACEOF
-#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
-_ACEOF
-
-fi
-done
-
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  for ac_func in CRYPTO_lock
-do :
-  ac_fn_c_check_func "$LINENO" "CRYPTO_lock" "ac_cv_func_CRYPTO_lock"
-if test "x$ac_cv_func_CRYPTO_lock" = xyes; then :
+  ac_fn_c_check_func "$LINENO" "OPENSSL_init_ssl" "ac_cv_func_OPENSSL_init_ssl"
+if test "x$ac_cv_func_OPENSSL_init_ssl" = xyes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_CRYPTO_LOCK 1
+#define HAVE_OPENSSL_INIT_SSL 1
 _ACEOF
 
+else
+  as_fn_error $? "OpenSSL version >= 1.1.0 is required for SSL support" "$LINENO" 5
 fi
 done
 
-  # Function introduced in OpenSSL 1.1.1.
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   for ac_func in X509_get_signature_info SSL_CTX_set_num_tickets
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
diff --git a/configure.ac b/configure.ac
index 4e279c4bd6..6a35b2880b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1314,8 +1314,8 @@ fi
 
 if test "$with_ssl" = openssl ; then
   dnl Order matters!
-  # Minimum required OpenSSL version is 1.0.2
-  AC_DEFINE(OPENSSL_API_COMPAT, [0x10002000L],
+  # Minimum required OpenSSL version is 1.1.0
+  AC_DEFINE(OPENSSL_API_COMPAT, [0x10100000L],
             [Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.])
   if test "$PORTNAME" != "win32"; then
      AC_CHECK_LIB(crypto, CRYPTO_new_ex_data, [], [AC_MSG_ERROR([library 'crypto' is required for OpenSSL])])
@@ -1331,12 +1331,8 @@ if test "$with_ssl" = openssl ; then
   # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
   # doesn't have these OpenSSL 1.1.0 functions. So check for individual
   # functions.
-  AC_CHECK_FUNCS([OPENSSL_init_ssl BIO_meth_new ASN1_STRING_get0_data HMAC_CTX_new HMAC_CTX_free])
-  # OpenSSL versions before 1.1.0 required setting callback functions, for
-  # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-  # function was removed.
-  AC_CHECK_FUNCS([CRYPTO_lock])
-  # Function introduced in OpenSSL 1.1.1.
+  AC_CHECK_FUNCS([OPENSSL_init_ssl], [], [AC_MSG_ERROR([OpenSSL version >= 1.1.0 is required for SSL support])])
+  # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
   AC_CHECK_FUNCS([X509_get_signature_info SSL_CTX_set_num_tickets])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
diff --git a/contrib/pgcrypto/openssl.c b/contrib/pgcrypto/openssl.c
index 8259de5e39..26454bc3e2 100644
--- a/contrib/pgcrypto/openssl.c
+++ b/contrib/pgcrypto/openssl.c
@@ -154,8 +154,6 @@ digest_free(PX_MD *h)
 	pfree(h);
 }
 
-static int	px_openssl_initialized = 0;
-
 /* PUBLIC functions */
 
 int
@@ -166,12 +164,6 @@ px_find_digest(const char *name, PX_MD **res)
 	PX_MD	   *h;
 	OSSLDigest *digest;
 
-	if (!px_openssl_initialized)
-	{
-		px_openssl_initialized = 1;
-		OpenSSL_add_all_algorithms();
-	}
-
 	md = EVP_get_digestbyname(name);
 	if (md == NULL)
 		return PXE_NO_HASH;
diff --git a/doc/src/sgml/installation.sgml b/doc/src/sgml/installation.sgml
index 9e5a35ca3f..ff9abd4649 100644
--- a/doc/src/sgml/installation.sgml
+++ b/doc/src/sgml/installation.sgml
@@ -293,7 +293,7 @@
       encrypted client connections.  <productname>OpenSSL</productname> is
       also required for random number generation on platforms that do not
       have <filename>/dev/urandom</filename> (except Windows).  The minimum
-      required version is 1.0.2.
+      required version is 1.1.0.
      </para>
     </listitem>
 
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index f916fce414..25646f6f8e 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -9865,9 +9865,11 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
   <title>SSL Library Initialization</title>
 
   <para>
-   If your application initializes <literal>libssl</literal> and/or
-   <literal>libcrypto</literal> libraries and <application>libpq</application>
-   is built with <acronym>SSL</acronym> support, you should call
+   Applications which need to be compatible with older versions of
+   <productname>PostgreSQL</productname>, using <productname>OpenSSL</productname>
+   version 1.0.2 or older, need to initialize the SSL library before using it.
+   Applications which initialize <literal>libssl</literal> and/or
+   <literal>libcrypto</literal> libraries should call
    <xref linkend="libpq-PQinitOpenSSL"/> to tell <application>libpq</application>
    that the <literal>libssl</literal> and/or <literal>libcrypto</literal> libraries
    have been initialized by your application, so that
@@ -9875,6 +9877,10 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
    However, this is unnecessary when using <productname>OpenSSL</productname>
    version 1.1.0 or later, as duplicate initializations are no longer problematic.
   </para>
+  <para>
+   Refer to the documentation for the version of <productname>PostgreSQL</productname>
+   that you are targeting for details on their use.
+  </para>
 
   <para>
    <variablelist>
@@ -9890,21 +9896,8 @@ void PQinitOpenSSL(int do_ssl, int do_crypto);
       </para>
 
       <para>
-       When <parameter>do_ssl</parameter> is non-zero, <application>libpq</application>
-       will initialize the <productname>OpenSSL</productname> library before first
-       opening a database connection.  When <parameter>do_crypto</parameter> is
-       non-zero, the <literal>libcrypto</literal> library will be initialized.  By
-       default (if <xref linkend="libpq-PQinitOpenSSL"/> is not called), both libraries
-       are initialized.  When SSL support is not compiled in, this function is
-       present but does nothing.
-      </para>
-
-      <para>
-       If your application uses and initializes either <productname>OpenSSL</productname>
-       or its underlying <literal>libcrypto</literal> library, you <emphasis>must</emphasis>
-       call this function with zeroes for the appropriate parameter(s)
-       before first opening a database connection.  Also be sure that you
-       have done that initialization before opening a database connection.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
      </listitem>
     </varlistentry>
@@ -9921,11 +9914,14 @@ void PQinitSSL(int do_ssl);
       <para>
        This function is equivalent to
        <literal>PQinitOpenSSL(do_ssl, do_ssl)</literal>.
-       It is sufficient for applications that initialize both or neither
-       of <productname>OpenSSL</productname> and <literal>libcrypto</literal>.
+       This function is deprecated and only present for backwards compatibility,
+       it does nothing.
       </para>
 
       <para>
+       <xref linkend="libpq-PQinitSSL"/> and <xref linkend="libpq-PQinitOpenSSL"/>
+       are maintained for backwards compatibility, but are no longer required
+       since <productname>PostgreSQL</productname> 18.
        <xref linkend="libpq-PQinitSSL"/> has been present since
        <productname>PostgreSQL</productname> 8.0, while <xref linkend="libpq-PQinitOpenSSL"/>
        was added in <productname>PostgreSQL</productname> 8.4, so <xref linkend="libpq-PQinitSSL"/>
diff --git a/meson.build b/meson.build
index ea07126f78..4764b09266 100644
--- a/meson.build
+++ b/meson.build
@@ -1359,26 +1359,17 @@ if sslopt in ['auto', 'openssl']
       ['CRYPTO_new_ex_data', {'required': true}],
       ['SSL_new', {'required': true}],
 
-      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
-      ['SSL_CTX_set_cert_cb'],
-
       # Functions introduced in OpenSSL 1.1.0. We used to check for
       # OPENSSL_VERSION_NUMBER, but that didn't work with 1.1.0, because LibreSSL
       # defines OPENSSL_VERSION_NUMBER to claim version 2.0.0, even though it
       # doesn't have these OpenSSL 1.1.0 functions. So check for individual
       # functions.
-      ['OPENSSL_init_ssl'],
-      ['BIO_meth_new'],
-      ['ASN1_STRING_get0_data'],
-      ['HMAC_CTX_new'],
-      ['HMAC_CTX_free'],
-
-      # OpenSSL versions before 1.1.0 required setting callback functions, for
-      # thread-safety. In 1.1.0, it's no longer required, and CRYPTO_lock()
-      # function was removed.
-      ['CRYPTO_lock'],
-
-      # Function introduced in OpenSSL 1.1.1
+      ['OPENSSL_init_ssl', {'required': true}],
+
+      # Function introduced in OpenSSL 1.0.2, not in LibreSSL.
+      ['SSL_CTX_set_cert_cb'],
+
+      # Function introduced in OpenSSL 1.1.1, not in LibreSSL.
       ['X509_get_signature_info'],
       ['SSL_CTX_set_num_tickets'],
     ]
@@ -1402,7 +1393,7 @@ if sslopt in ['auto', 'openssl']
     if are_openssl_funcs_complete
       cdata.set('USE_OPENSSL', 1,
                 description: 'Define to 1 to build with OpenSSL support. (-Dssl=openssl)')
-      cdata.set('OPENSSL_API_COMPAT', '0x10002000L',
+      cdata.set('OPENSSL_API_COMPAT', '0x10100000L',
                 description: 'Define to the OpenSSL API version in use. This avoids deprecation warnings from newer OpenSSL versions.')
       ssl_library = 'openssl'
     else
diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 60cf5d16e7..1ebd3f2e6d 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -44,6 +44,7 @@
  * include <wincrypt.h>, but some other Windows headers do.)
  */
 #include "common/openssl.h"
+#include <openssl/bn.h>
 #include <openssl/conf.h>
 #include <openssl/dh.h>
 #ifndef OPENSSL_NO_ECDH
@@ -80,7 +81,6 @@ static const char *SSLerrmessage(unsigned long ecode);
 static char *X509_NAME_to_cstring(X509_NAME *name);
 
 static SSL_CTX *SSL_context = NULL;
-static bool SSL_initialized = false;
 static bool dummy_ssl_passwd_cb_called = false;
 static bool ssl_is_server_start;
 
@@ -101,19 +101,6 @@ be_tls_init(bool isServerStart)
 	int			ssl_ver_min = -1;
 	int			ssl_ver_max = -1;
 
-	/* This stuff need be done only once. */
-	if (!SSL_initialized)
-	{
-#ifdef HAVE_OPENSSL_INIT_SSL
-		OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-		OPENSSL_config(NULL);
-		SSL_library_init();
-		SSL_load_error_strings();
-#endif
-		SSL_initialized = true;
-	}
-
 	/*
 	 * Create a new SSL context into which we'll load all the configuration
 	 * settings.  If we fail partway through, we can avoid memory leakage by
@@ -952,7 +939,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -975,14 +961,6 @@ my_BIO_s_socket(void)
 			my_bio_methods = NULL;
 			return NULL;
 		}
-#else
-		my_bio_methods = malloc(sizeof(BIO_METHOD));
-		if (!my_bio_methods)
-			return NULL;
-		memcpy(my_bio_methods, biom, sizeof(BIO_METHOD));
-		my_bio_methods->bread = my_sock_read;
-		my_bio_methods->bwrite = my_sock_write;
-#endif
 	}
 	return my_bio_methods;
 }
diff --git a/src/common/Makefile b/src/common/Makefile
index 89ef61c52a..d4f4b573c0 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -88,8 +88,7 @@ OBJS_COMMON = \
 ifeq ($(with_ssl),openssl)
 OBJS_COMMON += \
 	cryptohash_openssl.o \
-	hmac_openssl.o \
-	protocol_openssl.o
+	hmac_openssl.o
 else
 OBJS_COMMON += \
 	cryptohash.o \
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
index 84fcf340d8..da2c93e32a 100644
--- a/src/common/hmac_openssl.c
+++ b/src/common/hmac_openssl.c
@@ -35,17 +35,12 @@
 
 /*
  * In backend, use an allocation in TopMemoryContext to count for resowner
- * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
- * known, just use palloc().  In frontend, use malloc to be able to return
+ * cleanup handling if necessary.  In frontend, use malloc to be able to return
  * a failure status back to the caller.
  */
 #ifndef FRONTEND
-#ifdef HAVE_HMAC_CTX_NEW
 #define USE_RESOWNER_FOR_HMAC
 #define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
-#else
-#define ALLOC(size) palloc(size)
-#endif
 #define FREE(ptr) pfree(ptr)
 #else							/* FRONTEND */
 #define ALLOC(size) malloc(size)
@@ -144,11 +139,7 @@ pg_hmac_create(pg_cryptohash_type type)
 	ResourceOwnerEnlarge(CurrentResourceOwner);
 #endif
 
-#ifdef HAVE_HMAC_CTX_NEW
 	ctx->hmacctx = HMAC_CTX_new();
-#else
-	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
-#endif
 
 	if (ctx->hmacctx == NULL)
 	{
@@ -162,9 +153,6 @@ pg_hmac_create(pg_cryptohash_type type)
 		return NULL;
 	}
 
-#ifndef HAVE_HMAC_CTX_NEW
-	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
-#endif
 
 #ifdef USE_RESOWNER_FOR_HMAC
 	ctx->resowner = CurrentResourceOwner;
@@ -328,13 +316,7 @@ pg_hmac_free(pg_hmac_ctx *ctx)
 	if (ctx == NULL)
 		return;
 
-#ifdef HAVE_HMAC_CTX_FREE
 	HMAC_CTX_free(ctx->hmacctx);
-#else
-	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
-	FREE(ctx->hmacctx);
-#endif
-
 #ifdef USE_RESOWNER_FOR_HMAC
 	if (ctx->resowner)
 		ResourceOwnerForgetHMAC(ctx->resowner, ctx);
diff --git a/src/common/meson.build b/src/common/meson.build
index 1a564e1dce..d396e11ce9 100644
--- a/src/common/meson.build
+++ b/src/common/meson.build
@@ -44,7 +44,6 @@ if ssl.found()
   common_sources += files(
     'cryptohash_openssl.c',
     'hmac_openssl.c',
-    'protocol_openssl.c',
   )
 else
   common_sources += files(
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
index ae378685e1..e69de29bb2 100644
--- a/src/common/protocol_openssl.c
+++ b/src/common/protocol_openssl.c
@@ -1,117 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * protocol_openssl.c
- *	  OpenSSL functionality shared between frontend and backend
- *
- * This should only be used if code is compiled with OpenSSL support.
- *
- * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * IDENTIFICATION
- *		  src/common/protocol_openssl.c
- *
- *-------------------------------------------------------------------------
- */
-
-#ifndef FRONTEND
-#include "postgres.h"
-#else
-#include "postgres_fe.h"
-#endif
-
-#include "common/openssl.h"
-
-/*
- * Replacements for APIs introduced in OpenSSL 1.1.0.
- */
-#ifndef SSL_CTX_set_min_proto_version
-
-/*
- * OpenSSL versions that support TLS 1.3 shouldn't get here because they
- * already have these functions.  So we don't have to keep updating the below
- * code for every new TLS version, and eventually it can go away.  But let's
- * just check this to make sure ...
- */
-#ifdef TLS1_3_VERSION
-#error OpenSSL version mismatch
-#endif
-
-int
-SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
-
-	if (version > TLS1_VERSION)
-		ssl_options |= SSL_OP_NO_TLSv1;
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version > TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version > TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-int
-SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
-{
-	int			ssl_options = 0;
-
-	Assert(version != 0);
-
-	/*
-	 * Some OpenSSL versions define TLS*_VERSION macros but not the
-	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
-	 * unsuccessfully here.
-	 */
-#ifdef TLS1_1_VERSION
-	if (version < TLS1_1_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_1
-		ssl_options |= SSL_OP_NO_TLSv1_1;
-#else
-		return 0;
-#endif
-	}
-#endif
-#ifdef TLS1_2_VERSION
-	if (version < TLS1_2_VERSION)
-	{
-#ifdef SSL_OP_NO_TLSv1_2
-		ssl_options |= SSL_OP_NO_TLSv1_2;
-#else
-		return 0;
-#endif
-	}
-#endif
-
-	SSL_CTX_set_options(ctx, ssl_options);
-
-	return 1;					/* success */
-}
-
-#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/include/common/openssl.h b/src/include/common/openssl.h
index 964d691d32..cc54604e6e 100644
--- a/src/include/common/openssl.h
+++ b/src/include/common/openssl.h
@@ -18,10 +18,10 @@
 #include <openssl/ssl.h>
 
 /*
- * OpenSSL doesn't provide any very nice way to identify the min/max
- * protocol versions the library supports, so we fake it as best we can.
- * Note in particular that this doesn't account for restrictions that
- * might be specified in the installation's openssl.cnf.
+ * LibreSSL doesn't provide any very nice way to identify the max protocol
+ * versions the library supports, analogous to TLS_MAX_VERSION in OpenSSL, so
+ * we define our own.  Note in particular that this doesn't account for
+ * restrictions that might be specified in the installation's openssl.cnf.
  *
  * We disable SSLv3 and older in library setup, so TLSv1 is the oldest
  * protocol version of interest.
@@ -38,12 +38,6 @@
 #define MAX_OPENSSL_TLS_VERSION  "TLSv1"
 #endif
 
-/* src/common/protocol_openssl.c */
-#ifndef SSL_CTX_set_min_proto_version
-extern int	SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);
-extern int	SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);
-#endif
-
 #endif							/* USE_OPENSSL */
 
 #endif							/* COMMON_OPENSSL_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 979925cc2e..38006367a4 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -54,18 +54,12 @@
 /* Define to 1 if you have the `append_history' function. */
 #undef HAVE_APPEND_HISTORY
 
-/* Define to 1 if you have the `ASN1_STRING_get0_data' function. */
-#undef HAVE_ASN1_STRING_GET0_DATA
-
 /* Define to 1 if you have the <atomic.h> header file. */
 #undef HAVE_ATOMIC_H
 
 /* Define to 1 if you have the `backtrace_symbols' function. */
 #undef HAVE_BACKTRACE_SYMBOLS
 
-/* Define to 1 if you have the `BIO_meth_new' function. */
-#undef HAVE_BIO_METH_NEW
-
 /* Define to 1 if your compiler handles computed gotos. */
 #undef HAVE_COMPUTED_GOTO
 
@@ -81,9 +75,6 @@
 /* Define to 1 if you have the <crtdefs.h> header file. */
 #undef HAVE_CRTDEFS_H
 
-/* Define to 1 if you have the `CRYPTO_lock' function. */
-#undef HAVE_CRYPTO_LOCK
-
 /* Define to 1 if you have the declaration of `fdatasync', and to 0 if you
    don't. */
 #undef HAVE_DECL_FDATASYNC
@@ -199,12 +190,6 @@
 /* Define to 1 if you have the `history_truncate_file' function. */
 #undef HAVE_HISTORY_TRUNCATE_FILE
 
-/* Define to 1 if you have the `HMAC_CTX_free' function. */
-#undef HAVE_HMAC_CTX_FREE
-
-/* Define to 1 if you have the `HMAC_CTX_new' function. */
-#undef HAVE_HMAC_CTX_NEW
-
 /* Define to 1 if you have the <ifaddrs.h> header file. */
 #undef HAVE_IFADDRS_H
 
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 4cd7281b6e..3fa2dd864f 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3342,16 +3342,6 @@ keep_going:						/* We will come back to here until there is
 
 #ifdef USE_SSL
 
-				/*
-				 * Enable the libcrypto callbacks before checking if SSL needs
-				 * to be done.  This is done before sending the startup packet
-				 * as depending on the type of authentication done, like MD5
-				 * or SCRAM that use cryptohashes, the callbacks would be
-				 * required even without a SSL connection
-				 */
-				if (pqsecure_initialize(conn, false, true) < 0)
-					goto error_return;
-
 				/*
 				 * If SSL is enabled, start the SSL negotiation. We will come
 				 * back here after SSL encryption has been established, with
@@ -3544,14 +3534,6 @@ keep_going:						/* We will come back to here until there is
 					}
 				}
 
-				/*
-				 * Set up global SSL state if required.  The crypto state has
-				 * already been set if libpq took care of doing that, so there
-				 * is no need to make that happen again.
-				 */
-				if (pqsecure_initialize(conn, true, false) != 0)
-					goto error_return;
-
 				/*
 				 * Begin or continue the SSL negotiation process.
 				 */
diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c
index b6fffd7b9b..b5749d0292 100644
--- a/src/interfaces/libpq/fe-secure-openssl.c
+++ b/src/interfaces/libpq/fe-secure-openssl.c
@@ -71,7 +71,6 @@ static int	openssl_verify_peer_name_matches_certificate_name(PGconn *conn,
 static int	openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 															ASN1_OCTET_STRING *addr_entry,
 															char **store_name);
-static void destroy_ssl_system(void);
 static int	initialize_SSL(PGconn *conn);
 static PostgresPollingStatusType open_client_SSL(PGconn *conn);
 static char *SSLerrmessage(unsigned long ecode);
@@ -83,14 +82,6 @@ static int	my_sock_write(BIO *h, const char *buf, int size);
 static BIO_METHOD *my_BIO_s_socket(void);
 static int	my_SSL_set_fd(PGconn *conn, int fd);
 
-
-static bool pq_init_ssl_lib = true;
-static bool pq_init_crypto_lib = true;
-
-static bool ssl_lib_initialized = false;
-
-static long crypto_open_connections = 0;
-
 static pthread_mutex_t ssl_config_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 static PQsslKeyPassHook_OpenSSL_type PQsslKeyPassHook = NULL;
@@ -100,20 +91,6 @@ static int	ssl_protocol_version_to_openssl(const char *protocol);
 /*			 Procedures common to all secure sessions			*/
 /* ------------------------------------------------------------ */
 
-void
-pgtls_init_library(bool do_ssl, int do_crypto)
-{
-	/*
-	 * Disallow changing the flags while we have open connections, else we'd
-	 * get completely confused.
-	 */
-	if (crypto_open_connections != 0)
-		return;
-
-	pq_init_ssl_lib = do_ssl;
-	pq_init_crypto_lib = do_crypto;
-}
-
 PostgresPollingStatusType
 pgtls_open_client(PGconn *conn)
 {
@@ -505,11 +482,7 @@ openssl_verify_peer_name_matches_certificate_name(PGconn *conn, ASN1_STRING *nam
 	/*
 	 * GEN_DNS can be only IA5String, equivalent to US ASCII.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	namedata = ASN1_STRING_get0_data(name_entry);
-#else
-	namedata = ASN1_STRING_data(name_entry);
-#endif
 	len = ASN1_STRING_length(name_entry);
 
 	/* OK to cast from unsigned to plain char, since it's all ASCII. */
@@ -540,11 +513,7 @@ openssl_verify_peer_name_matches_certificate_ip(PGconn *conn,
 	 * GEN_IPADD is an OCTET STRING containing an IP address in network byte
 	 * order.
 	 */
-#ifdef HAVE_ASN1_STRING_GET0_DATA
 	addrdata = ASN1_STRING_get0_data(addr_entry);
-#else
-	addrdata = ASN1_STRING_data(addr_entry);
-#endif
 	len = ASN1_STRING_length(addr_entry);
 
 	return pq_verify_peer_name_matches_certificate_ip(conn, addrdata, len, store_name);
@@ -712,179 +681,6 @@ pgtls_verify_peer_name_matches_certificate_guts(PGconn *conn,
 	return rc;
 }
 
-#if defined(HAVE_CRYPTO_LOCK)
-/*
- *	Callback functions for OpenSSL internal locking.  (OpenSSL 1.1.0
- *	does its own locking, and doesn't need these anymore.  The
- *	CRYPTO_lock() function was removed in 1.1.0, when the callbacks
- *	were made obsolete, so we assume that if CRYPTO_lock() exists,
- *	the callbacks are still required.)
- */
-
-static unsigned long
-pq_threadidcallback(void)
-{
-	/*
-	 * This is not standards-compliant.  pthread_self() returns pthread_t, and
-	 * shouldn't be cast to unsigned long, but CRYPTO_set_id_callback requires
-	 * it, so we have to do it.
-	 */
-	return (unsigned long) pthread_self();
-}
-
-static pthread_mutex_t *pq_lockarray;
-
-static void
-pq_lockingcallback(int mode, int n, const char *file, int line)
-{
-	/*
-	 * There's no way to report a mutex-primitive failure, so we just Assert
-	 * in development builds, and ignore any errors otherwise.  Fortunately
-	 * this is all obsolete in modern OpenSSL.
-	 */
-	if (mode & CRYPTO_LOCK)
-	{
-		if (pthread_mutex_lock(&pq_lockarray[n]))
-			Assert(false);
-	}
-	else
-	{
-		if (pthread_mutex_unlock(&pq_lockarray[n]))
-			Assert(false);
-	}
-}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-/*
- * Initialize SSL library.
- *
- * In threadsafe mode, this includes setting up libcrypto callback functions
- * to do thread locking.
- *
- * If the caller has told us (through PQinitOpenSSL) that he's taking care
- * of libcrypto, we expect that callbacks are already set, and won't try to
- * override it.
- */
-int
-pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return -1;
-
-#ifdef HAVE_CRYPTO_LOCK
-	if (pq_init_crypto_lib)
-	{
-		/*
-		 * If necessary, set up an array to hold locks for libcrypto.
-		 * libcrypto will tell us how big to make this array.
-		 */
-		if (pq_lockarray == NULL)
-		{
-			int			i;
-
-			pq_lockarray = malloc(sizeof(pthread_mutex_t) * CRYPTO_num_locks());
-			if (!pq_lockarray)
-			{
-				pthread_mutex_unlock(&ssl_config_mutex);
-				return -1;
-			}
-			for (i = 0; i < CRYPTO_num_locks(); i++)
-			{
-				if (pthread_mutex_init(&pq_lockarray[i], NULL))
-				{
-					free(pq_lockarray);
-					pq_lockarray = NULL;
-					pthread_mutex_unlock(&ssl_config_mutex);
-					return -1;
-				}
-			}
-		}
-
-		if (do_crypto && !conn->crypto_loaded)
-		{
-			if (crypto_open_connections++ == 0)
-			{
-				/*
-				 * These are only required for threaded libcrypto
-				 * applications, but make sure we don't stomp on them if
-				 * they're already set.
-				 */
-				if (CRYPTO_get_id_callback() == NULL)
-					CRYPTO_set_id_callback(pq_threadidcallback);
-				if (CRYPTO_get_locking_callback() == NULL)
-					CRYPTO_set_locking_callback(pq_lockingcallback);
-			}
-
-			conn->crypto_loaded = true;
-		}
-	}
-#endif							/* HAVE_CRYPTO_LOCK */
-
-	if (!ssl_lib_initialized && do_ssl)
-	{
-		if (pq_init_ssl_lib)
-		{
-#ifdef HAVE_OPENSSL_INIT_SSL
-			OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
-#else
-			OPENSSL_config(NULL);
-			SSL_library_init();
-			SSL_load_error_strings();
-#endif
-		}
-		ssl_lib_initialized = true;
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-	return 0;
-}
-
-/*
- *	This function is needed because if the libpq library is unloaded
- *	from the application, the callback functions will no longer exist when
- *	libcrypto is used by other parts of the system.  For this reason,
- *	we unregister the callback functions when the last libpq
- *	connection is closed.  (The same would apply for OpenSSL callbacks
- *	if we had any.)
- *
- *	Callbacks are only set when we're compiled in threadsafe mode, so
- *	we only need to remove them in this case. They are also not needed
- *	with OpenSSL 1.1.0 anymore.
- */
-static void
-destroy_ssl_system(void)
-{
-#if defined(HAVE_CRYPTO_LOCK)
-	if (pthread_mutex_lock(&ssl_config_mutex))
-		return;
-
-	if (pq_init_crypto_lib && crypto_open_connections > 0)
-		--crypto_open_connections;
-
-	if (pq_init_crypto_lib && crypto_open_connections == 0)
-	{
-		/*
-		 * No connections left, unregister libcrypto callbacks, if no one
-		 * registered different ones in the meantime.
-		 */
-		if (CRYPTO_get_locking_callback() == pq_lockingcallback)
-			CRYPTO_set_locking_callback(NULL);
-		if (CRYPTO_get_id_callback() == pq_threadidcallback)
-			CRYPTO_set_id_callback(NULL);
-
-		/*
-		 * We don't free the lock array. If we get another connection in this
-		 * process, we will just re-use them with the existing mutexes.
-		 *
-		 * This means we leak a little memory on repeated load/unload of the
-		 * library.
-		 */
-	}
-
-	pthread_mutex_unlock(&ssl_config_mutex);
-#endif
-}
-
 /* See pqcomm.h comments on OpenSSL implementation of ALPN (RFC 7301) */
 static unsigned char alpn_protos[] = PG_ALPN_PROTOCOL_VECTOR;
 
@@ -1643,8 +1439,6 @@ open_client_SSL(PGconn *conn)
 void
 pgtls_close(PGconn *conn)
 {
-	bool		destroy_needed = false;
-
 	if (conn->ssl_in_use)
 	{
 		if (conn->ssl)
@@ -1660,8 +1454,6 @@ pgtls_close(PGconn *conn)
 			conn->ssl = NULL;
 			conn->ssl_in_use = false;
 			conn->ssl_handshake_started = false;
-
-			destroy_needed = true;
 		}
 
 		if (conn->peer)
@@ -1679,30 +1471,6 @@ pgtls_close(PGconn *conn)
 		}
 #endif
 	}
-	else
-	{
-		/*
-		 * In the non-SSL case, just remove the crypto callbacks if the
-		 * connection has them loaded.  This code path has no dependency on
-		 * any pending SSL calls.
-		 */
-		if (conn->crypto_loaded)
-			destroy_needed = true;
-	}
-
-	/*
-	 * This will remove our crypto locking hooks if this is the last
-	 * connection using libcrypto which means we must wait to call it until
-	 * after all the potential SSL calls have been made, otherwise we can end
-	 * up with a race condition and possible deadlocks.
-	 *
-	 * See comments above destroy_ssl_system().
-	 */
-	if (destroy_needed)
-	{
-		destroy_ssl_system();
-		conn->crypto_loaded = false;
-	}
 }
 
 
@@ -1981,7 +1749,6 @@ my_BIO_s_socket(void)
 	if (!my_bio_methods)
 	{
 		BIO_METHOD *biom = (BIO_METHOD *) BIO_s_socket();
-#ifdef HAVE_BIO_METH_NEW
 		int			my_bio_index;
 
 		my_bio_index = BIO_get_new_index();
@@ -2007,14 +1774,6 @@ my_BIO_s_socket(void)
 		{
 			goto err;
 		}
-#else
-		res = malloc(sizeof(BIO_METHOD));
-		if (!res)
-			goto err;
-		memcpy(res, biom, sizeof(BIO_METHOD));
-		res->bread = my_sock_read;
-		res->bwrite = my_sock_write;
-#endif
 	}
 
 	my_bio_methods = res;
@@ -2022,13 +1781,8 @@ my_BIO_s_socket(void)
 	return res;
 
 err:
-#ifdef HAVE_BIO_METH_NEW
 	if (res)
 		BIO_meth_free(res);
-#else
-	if (res)
-		free(res);
-#endif
 	pthread_mutex_unlock(&ssl_config_mutex);
 	return NULL;
 }
diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c
index f628082337..5567be9d39 100644
--- a/src/interfaces/libpq/fe-secure.c
+++ b/src/interfaces/libpq/fe-secure.c
@@ -108,42 +108,27 @@ PQsslInUse(PGconn *conn)
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitSSL(int do_init)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_init, do_init);
-#endif
+	/* no-op */
 }
 
 /*
- *	Exported function to allow application to tell us it's already
- *	initialized OpenSSL and/or libcrypto.
+ *	Exported function to allow application to tell us it's already initialized
+ *	OpenSSL.  Since OpenSSL 1.1.0 it is no longer required to explicitly
+ *	initialize libssl and libcrypto, so this is a no-op.  This function remains
+ *	for backwards API compatibility.
  */
 void
 PQinitOpenSSL(int do_ssl, int do_crypto)
 {
-#ifdef USE_SSL
-	pgtls_init_library(do_ssl, do_crypto);
-#endif
-}
-
-/*
- *	Initialize global SSL context
- */
-int
-pqsecure_initialize(PGconn *conn, bool do_ssl, bool do_crypto)
-{
-	int			r = 0;
-
-#ifdef USE_SSL
-	r = pgtls_init(conn, do_ssl, do_crypto);
-#endif
-
-	return r;
+	/* no-op */
 }
 
 /*
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index 8ed1b28fcc..9579f80353 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -592,11 +592,6 @@ struct pg_conn
 	void	   *engine;			/* dummy field to keep struct the same if
 								 * OpenSSL version changes */
 #endif
-	bool		crypto_loaded;	/* Track if libcrypto locking callbacks have
-								 * been done for this connection. This can be
-								 * removed once support for OpenSSL 1.0.2 is
-								 * removed as this locking is handled
-								 * internally in OpenSSL >= 1.1.0. */
 #endif							/* USE_OPENSSL */
 #endif							/* USE_SSL */
 
@@ -776,7 +771,6 @@ extern int	pqWriteReady(PGconn *conn);
 
 /* === in fe-secure.c === */
 
-extern int	pqsecure_initialize(PGconn *, bool, bool);
 extern PostgresPollingStatusType pqsecure_open_client(PGconn *);
 extern void pqsecure_close(PGconn *);
 extern ssize_t pqsecure_read(PGconn *, void *ptr, size_t len);
@@ -796,23 +790,6 @@ extern void pq_reset_sigpipe(sigset_t *osigset, bool sigpipe_pending,
  * The SSL implementation provides these functions.
  */
 
-/*
- *	Implementation of PQinitSSL().
- */
-extern void pgtls_init_library(bool do_ssl, int do_crypto);
-
-/*
- * Initialize SSL library.
- *
- * The conn parameter is only used to be able to pass back an error
- * message - no connection-local setup is made here.  do_ssl controls
- * if SSL is initialized, and do_crypto does the same for the crypto
- * part.
- *
- * Returns 0 if OK, -1 on failure (adding a message to conn->errorMessage).
- */
-extern int	pgtls_init(PGconn *conn, bool do_ssl, bool do_crypto);
-
 /*
  *	Begin or continue negotiating a secure session.
  */
diff --git a/src/test/ssl/t/001_ssltests.pl b/src/test/ssl/t/001_ssltests.pl
index b877327023..4bd868ff65 100644
--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -36,8 +36,7 @@ sub switch_server_cert
 }
 
 # Determine whether this build uses OpenSSL or LibreSSL. As a heuristic, the
-# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL. (Nor for OpenSSL
-# 1.0.1, but that's old enough that accommodating it isn't worth the cost.)
+# HAVE_SSL_CTX_SET_CERT_CB macro isn't defined for LibreSSL.
 my $libressl = not check_pg_config("#define HAVE_SSL_CTX_SET_CERT_CB 1");
 
 #### Some configuration
-- 
2.39.3 (Apple Git-146)

From 91550eaac4883113b9e85361c5c049a6555cd2f3 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Tue, 10 Sep 2024 09:53:32 +0200
Subject: [PATCH] Remove obsolete unconstify()

This is no longer needed as of OpenSSL 1.1.0 (the current minimum
version).  LibreSSL made the same change around the same time as well.
---
 src/backend/libpq/be-secure-openssl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 1ebd3f2e6d3..8ec78c83304 100644
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -1075,7 +1075,7 @@ load_dh_buffer(const char *buffer, size_t len)
 	BIO		   *bio;
 	DH		   *dh = NULL;
 
-	bio = BIO_new_mem_buf(unconstify(char *, buffer), len);
+	bio = BIO_new_mem_buf(buffer, len);
 	if (bio == NULL)
 		return NULL;
 	dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
-- 
2.46.0