Re: Postgres: pg_hba.conf, md5, pg_shadow, encrypted passwords - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Postgres: pg_hba.conf, md5, pg_shadow, encrypted passwords
Date
Msg-id 11372.1114059278@sss.pgh.pa.us
Whole thread Raw
In response to Re: Postgres: pg_hba.conf, md5, pg_shadow, encrypted passwords  ("Jim C. Nasby" <decibel@decibel.org>)
List pgsql-hackers
"Jim C. Nasby" <decibel@decibel.org> writes:
> I would think it wouldn't be hard to change the protocol/code so that
> the response from providing an invalid user is the same as providing a
> valid one.

How would you do that?  The response for a valid user will (a) include
the same salt on repeated trials (so no generating a random one); (b)
usually be different from the salt given for other usernames (so no
using the same one every time, either) and (c) probably be provided in a
measurably different time from the time taken by any algorithm that
manages to work around (a) and (b).

You could maybe work around (c) by delaying *all* password challenges to
take, say, 100 msec ... but that's hardly what I call a cost-free
solution either.
        regards, tom lane


pgsql-hackers by date:

Previous
From: "Jim C. Nasby"
Date:
Subject: Re: Proposal for background vacuum full/cluster
Next
From: Tom Lane
Date:
Subject: Re: Proposal for background vacuum full/cluster