MD5

Started by Jamie Deppelerover 21 years ago8 messagesgeneral
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#1Jamie Deppeler
jamie@doitonce.net.au

Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

#2Michael Fuhr
mike@fuhr.org
In reply to: Jamie Deppeler (#1)
Re: MD5

On Fri, Dec 17, 2004 at 09:41:22AM +1100, Jamie Deppeler wrote:

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

MD5 returns a hash, not an encrypted string that could later be
decrypted. For an encryption mechanism see contrib/pgcrypto.

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

#3Tino Wildenhain
tino@wildenhain.de
In reply to: Jamie Deppeler (#1)
Re: MD5

Hi,

Am Freitag, den 17.12.2004, 09:41 +1100 schrieb Jamie Deppeler:

Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

No. You cannot encrypt with md5 because you cant decrypt.
md5 is a hash function. But you can use it any time to
hash values you insert.

Regards
Tino

#4Jamie Deppeler
jamie@doitonce.net.au
In reply to: Tino Wildenhain (#3)
Re: MD5

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Tino Wildenhain wrote:
<blockquote cite="mid1103240237.5337.159.camel@Andrea.peacock.de"
type="cite">
<pre wrap="">Hi,

Am Freitag, den 17.12.2004, 09:41 +1100 schrieb Jamie Deppeler:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users
</pre>
</blockquote>
<pre wrap=""><!---->
No. You cannot encrypt with md5 because you cant decrypt.
md5 is a hash function. But you can use it any time to
hash values you insert.

Regards
Tino

</pre>
</blockquote>
Well basically i want to store and hashed value that will never be
changed just compaired too hashed values<br>
<br>
also when i try to encrpyt a field i get this error
encypt(text,"unknown","unknown")<br>
</body>
</html>

#5Chris Smith
chris@interspire.com
In reply to: Jamie Deppeler (#4)
Re: MD5

Use the md5 function:

select md5('welcome');
md5
----------------------------------
40be4e59b9a2a2b5dffb918c0e86b3d7
(1 row)

Regards,

Chris Smith

Suite 30, 45-51 Huntley St, Alexandria, NSW 2015 Australia

Ph: +61 2 9517 2505
Fx: +61 2 9517 1915

email: info@interspire.com
web: www.interspire.com

Jamie Deppeler wrote:

Tino Wildenhain wrote:

Hi,

Am Freitag, den 17.12.2004, 09:41 +1100 schrieb Jamie Deppeler:

Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

No. You cannot encrypt with md5 because you cant decrypt.
md5 is a hash function. But you can use it any time to
hash values you insert.

Regards
Tino

Well basically i want to store and hashed value that will never be
changed just compaired too hashed values

also when i try to encrpyt a field i get this error
encypt(text,"unknown","unknown")

------------------------------------------------------------------------

No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.296 / Virus Database: 265.5.4 - Release Date: 12/15/2004

--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.296 / Virus Database: 265.5.4 - Release Date: 12/15/2004

#6Chris Smith
chris@interspire.com
In reply to: Jamie Deppeler (#4)
Re: MD5

(Ignore my other reply.. ;P)

You'll need to import the pgcrypto.sql file (this creates the functions
for you).

Read the doco on how to install the extension, it should tell you where
the sql file is.

Regards,

Chris Smith

Suite 30, 45-51 Huntley St, Alexandria, NSW 2015 Australia

Ph: +61 2 9517 2505
Fx: +61 2 9517 1915

email: info@interspire.com
web: www.interspire.com

Jamie Deppeler wrote:

Tino Wildenhain wrote:

Hi,

Am Freitag, den 17.12.2004, 09:41 +1100 schrieb Jamie Deppeler:

Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

No. You cannot encrypt with md5 because you cant decrypt.
md5 is a hash function. But you can use it any time to
hash values you insert.

Regards
Tino

Well basically i want to store and hashed value that will never be
changed just compaired too hashed values

also when i try to encrpyt a field i get this error
encypt(text,"unknown","unknown")

------------------------------------------------------------------------

No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.296 / Virus Database: 265.5.4 - Release Date: 12/15/2004

--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.296 / Virus Database: 265.5.4 - Release Date: 12/15/2004

#7Michael Fuhr
mike@fuhr.org
In reply to: Jamie Deppeler (#4)
Re: MD5

[Please don't post in HTML]

On Fri, Dec 17, 2004 at 10:55:47AM +1100, Jamie Deppeler wrote:

Well basically i want to store and hashed value that will never be
changed just compaired too hashed values

In that case MD5 should suffice, although recently-discovered
weaknesses have led some people to prefer SHA-1 or RIPEMD-160,
which are available through contrib/pgcrypto.

http://en.wikipedia.org/wiki/Md5

Your original question asked about encryption, so we gave answers
based on that requirement.

also when i try to encrpyt a field i get this error
encypt(text,"unknown","unknown")

Please show the SQL statement you executed and the complete, exact
error message.

Did you build and install pgcrypto? It's likely not installed on
your system by default.

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

#8Tino Wildenhain
tino@wildenhain.de
In reply to: Jamie Deppeler (#4)
Re: MD5

Am Freitag, den 17.12.2004, 10:55 +1100 schrieb Jamie Deppeler:

Tino Wildenhain wrote:

Hi,

Am Freitag, den 17.12.2004, 09:41 +1100 schrieb Jamie Deppeler:

Hi,

I was just wondering is it possible to encrypt a filed in the database
with md5? i know it is possible to do it with DB users

No. You cannot encrypt with md5 because you cant decrypt.
md5 is a hash function. But you can use it any time to
hash values you insert.

Regards
Tino

Well basically i want to store and hashed value that will never be
changed just compaired too hashed values

also when i try to encrpyt a field i get this error
encypt(text,"unknown","unknown")

No, encrypt would not be md5. md5 hash is calculated
via md5() which is built in on and above 7.3 I believe.
If you need more/other functions, try contrib/pgcrypt
or so - this is a couple of functions to implement encryption.
(Depending on your installation, postgres-contrib might be
a seperate package)

Regards
Tino