Horton

Re: Direct SSL connection with ALPN and HBA rules

Daniel Gustafsson <daniel@yesql.se>

View thread View on postgr.es
From: Daniel Gustafsson <daniel@yesql.se>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Jacob Champion <jacob.champion@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>, Michael Paquier <michael@paquier.xyz>, Postgres hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-04-30T10:10:38Z
Lists: pgsql-hackers 
> On 29 Apr 2024, at 21:06, Heikki Linnakangas <hlinnaka@iki.fi> wrote:

> Oh I was not aware sslrootcert=system works like that. That's a bit surprising, none of the other ssl-related settings imply or require that SSL is actually used. Did we intend to set a precedence for new settings with that?

It was very much intentional, and documented, an sslmode other than verify-full
makes little sense when combined with sslrootcert=system.  It wasn't intended
to set a precedence (though there is probably a fair bit of things we can do,
getting this right is hard enough as it is), rather it was footgun prevention.

--
Daniel Gustafsson

Commits

  1. Remove option to fall back from direct to postgres SSL negotiation

  2. Reject SSL connection if ALPN is used but there's no common protocol

  3. libpq: Enforce ALPN in direct SSL connections

  4. libpq: If ALPN is not used, make PQsslAttribute(conn, "alpn") == ""

  5. Fix documentation and comments on what happens after GSS rejection

  6. doc: Add note to prevent server spoofing with SCRAM