Re: Postgres: pg_hba.conf, md5, pg_shadow, encrypted passwords

On Wed, Apr 20, 2005 at 06:03:18PM -0400, Tom Lane wrote:
> Well, I have no particular problem with offering SHA1 as an alternative
> hash method for those who find MD5 too weak ... but I still question the
> value of putting any random salt in the table.  AFAICS you would have to
> send that salt as part of the initial password challenge, which means
> any potential attacker could find it out even before trying to
> compromise pg_shadow; so Stephen's argument that there is a useful
> improvement in protection against precomputation of password hashes
> still falls down.
> 
> BTW, one could also ask exactly what threat model Stephen is concerned
> about.  ISTM anyone who can obtain the contents of pg_shadow has
> *already* broken your database security.

FWIW, I do think there's some benefit to not being able to pre-compute
an entire hash table for accounts such as 'postgres' and 'www'. But I
agree it would be useful to know the actual threat model.
-- 
Jim C. Nasby, Database Consultant               decibel@decibel.org 
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