Refactor SASL exchange in preparation for OAuth Bearer

On Fri, Feb 23, 2024 at 2:30 AM Daniel Gustafsson <daniel@yesql.se> wrote:

The attached two patches are smaller refactorings to the SASL exchange and init
codepaths which are required for the OAuthbearer work [0]. Regardless of the
future of that patchset, these refactorings are nice cleanups and can be
considered in isolation. Another goal is of course to reduce scope of the
OAuth patchset to make it easier to review.

Thanks for pulling these out! They look good overall, just a few notes below.

In 0001:

+ * SASL_FAILED: The exchance has failed and the connection should be

s/exchance/exchange/

- if (final && !done)
+ if (final && !(status == SASL_FAILED || status == SASL_COMPLETE))

Since there's not yet a SASL_ASYNC, I wonder if this would be more
readable if it were changed to
if (final && status == SASL_CONTINUE)
to match the if condition shortly after it.

In 0002, at the beginning of pg_SASL_init, the `password` variable now
has an uninitialized code path. The OAuth patchset initializes it to
NULL:

+++ b/src/interfaces/libpq/fe-auth.c
@@ -425,7 +425,7 @@ pg_SASL_init(PGconn *conn, int payloadlen)
int                     initialresponselen;
const char *selected_mechanism;
PQExpBufferData mechanism_buf;
-       char       *password;
+       char       *password = NULL;
SASLStatus      status;

initPQExpBuffer(&mechanism_buf);

I'll base the next version of the OAuth patchset on top of these.

Thanks!
--Jacob

On 26 Feb 2024, at 19:56, Jacob Champion <jacob.champion@enterprisedb.com> wrote:

+ * SASL_FAILED: The exchance has failed and the connection should be

s/exchance/exchange/

I rank that as one of my better typos actually. Fixed though.

- if (final && !done)
+ if (final && !(status == SASL_FAILED || status == SASL_COMPLETE))

Since there's not yet a SASL_ASYNC, I wonder if this would be more
readable if it were changed to
if (final && status == SASL_CONTINUE)
to match the if condition shortly after it.

Fair point, that's more readable in this commit.

In 0002, at the beginning of pg_SASL_init, the `password` variable now
has an uninitialized code path. The OAuth patchset initializes it to
NULL:

Nice catch, fixed.

--
Daniel Gustafsson

On Wed, Feb 28, 2024 at 2:54 PM Daniel Gustafsson <daniel@yesql.se> wrote:

I rank that as one of my better typos actually. Fixed though.

LGTM!

Thanks,
--Jacob

On 29 Feb 2024, at 20:58, Jacob Champion <jacob.champion@enterprisedb.com> wrote:

On Wed, Feb 28, 2024 at 2:54 PM Daniel Gustafsson <daniel@yesql.se> wrote:

I rank that as one of my better typos actually. Fixed though.

LGTM!

Thanks for review, and since Heikki marked it ready for committer I assume that
counting as a +1 as well. Attached is a rebase on top of HEAD to get a fresh
run from the CFBot before applying this.

--
Daniel Gustafsson

On 20 Mar 2024, at 15:28, Daniel Gustafsson <daniel@yesql.se> wrote:

On 29 Feb 2024, at 20:58, Jacob Champion <jacob.champion@enterprisedb.com> wrote:

On Wed, Feb 28, 2024 at 2:54 PM Daniel Gustafsson <daniel@yesql.se> wrote:

I rank that as one of my better typos actually. Fixed though.

LGTM!

Thanks for review, and since Heikki marked it ready for committer I assume that
counting as a +1 as well. Attached is a rebase on top of HEAD to get a fresh
run from the CFBot before applying this.

And after another pass over it I ended up pushing it today.

--
Daniel Gustafsson