Date: Thu, 03 Mar 2022 15:15:24 +0900 (JST)
Message-Id: <20220303.151524.1159715505705492773.t-ishii@sranhm.sra.co.jp>
To: sfrost@snowman.net
Cc: tgl@sss.pgh.pa.us, pgsql@j-davis.com, smilingsamay@gmail.com,
        pgsql-hackers@lists.postgresql.org
Subject: Re: Proposal: Support custom authentication methods using hooks
From: Tatsuo Ishii <ishii@sraoss.co.jp>
In-Reply-To: <20220228214255.GO10577@tamriel.snowman.net>
References: <20220228204634.GM10577@tamriel.snowman.net>
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> Yes, really, it's a known-broken system which suffers from such an old
> and well known attack that it's been given a name: pass-the-hash.  As
> was discussed on this thread even, just the fact that it's not trivial
> to break on the wire doesn't make it not-broken, particularly when we
> use the username (which is rather commonly the same one used across
> multiple systems..) as the salt.  Worse, md5 isn't exactly the pinnacle

I am not a big fan of md5 auth but saying that md5 auth uses username
as the salt is oversimplified. The md5 hashed password shored in
pg_shadow is created as md5(password + username).  But the md5 hashed
password flying over wire is using a random salt like md5(md5(password
+ username) + random_salt).

Best reagards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp