Horton

Re: Direct SSL connection with ALPN and HBA rules

Jacob Champion <jacob.champion@enterprisedb.com>

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From: Jacob Champion <jacob.champion@enterprisedb.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Daniel Gustafsson <daniel@yesql.se>, Michael Paquier <michael@paquier.xyz>, Postgres hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-05-13T16:45:27Z
Lists: pgsql-hackers 
(There's, uh, a lot to respond to above and I'm trying to figure out
how best to type up all of it.)

On Mon, May 13, 2024 at 9:13 AM Robert Haas <robertmhaas@gmail.com> wrote:
> However,
> I disagree with Jacob's assertion that sslmode=require has no security
> benefits over sslmode=prefer.

For the record, I didn't say that... You mean Jelte's quote up above?:

> sslmode=prefer and sslmode=require
> are the same amount of insecure imho (i.e. extremely insecure).

I agree that requiring passive security is tangibly better than
allowing fallback to plaintext. I think Jelte's point might be better
stated as, =prefer and =require give the same amount of protection
against active attack (none).

--Jacob

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