Re: [GENERAL] SHA1 on postgres 8.3 - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [GENERAL] SHA1 on postgres 8.3
Date
Msg-id 200801281856.m0SIuUm05011@momjian.us
Whole thread Raw
In response to Re: [GENERAL] SHA1 on postgres 8.3  ("Marko Kreen" <markokr@gmail.com>)
Responses Re: [GENERAL] SHA1 on postgres 8.3  ("Greg Sabino Mullane" <greg@turnstep.com>)
Re: [GENERAL] SHA1 on postgres 8.3  (Florian Weimer <fweimer@bfk.de>)
Re: [GENERAL] SHA1 on postgres 8.3  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
I am not thrilled about moving _some_ of pgcrypto into the backend ---
pgcrypto right now seems well designed and if we pull part of it out it
seems it will be less clear than what we have now.  Perhaps we just need
to document that md5() isn't for general use and some function in
pgcrypto should be used instead?

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

Marko Kreen wrote:
> On 1/21/08, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > > MD5 is broken in the sense that you can create two or more meaningful
> > > documents with the same hash.
> >
> > Note that this isn't actually very interesting for the purpose for
> > which the md5() function was put into core: namely, hashing passwords
> > before they are stored in pg_authid.
> 
> Note: this was bad idea.  The function that should have been
> added to core would be pg_password_hash(username, password).
> 
> Adding md5() lessens incentive to install pgcrypto or push/accept
> digest() into core and gives impression there will be sha1(), etc
> in the future.
> 
> Now users who want to store passwords in database (the most
> popular usage) will probably go with md5() without bothering
> with pgcrypto.  They probably see "Postgres itself uses MD5 too",
> without realizing their situation is totally different from
> pg_authid one.
> 
> It's like we have solution that is ACID-compliant 99% of the time in core,
> so why bother with 100% one.
> 
> -- 
> marko
> 
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--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://postgres.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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