MIME-Version: 1.0
References: <ZiH7vHwEJeRKHlST@paquier.xyz> <c786e226-4039-4522-ba07-92501fce9b6a@iki.fi>
 <CAOYmi+kbYPX78nu0k7OODxUhoD6H1OXdugiMK1z9Nn33G-qdcQ@mail.gmail.com>
 <a0983295-67ae-487e-84e3-6e1148af3a25@iki.fi> <ZiYPmUZjcQtPz2j7@paquier.xyz>
 <feebbeee-df5f-484f-b07e-062bd0230bd2@iki.fi> <ZidKMB1tcgM3bzFZ@paquier.xyz>
 <CAOYmi+n57x+8DVi9J+dGmFQo+2Eb+bg_+geH=jqfh3E=NWHfOA@mail.gmail.com> <CA+TgmoaLpDVY2ywqQUfxvKEQZ+nwkabcw_f=i4Zyivt9CLjcmA@mail.gmail.com>
In-Reply-To: <CA+TgmoaLpDVY2ywqQUfxvKEQZ+nwkabcw_f=i4Zyivt9CLjcmA@mail.gmail.com>
From: Jacob Champion <jacob.champion@enterprisedb.com>
Date: Tue, 23 Apr 2024 12:33:58 -0700
Message-ID: <CAOYmi+=sj+1uydS0NR4nYzw-LRWp3Q-s5speBug5UCLSPMbvGA@mail.gmail.com>
Subject: Re: Direct SSL connection with ALPN and HBA rules
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Heikki Linnakangas <hlinnaka@iki.fi>, 
	Postgres hackers <pgsql-hackers@lists.postgresql.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://www.postgresql.org/message-id/CAOYmi%2B%3Dsj%2B1uydS0NR4nYzw-LRWp3Q-s5speBug5UCLSPMbvGA%40mail.gmail.com>
Precedence: bulk

On Tue, Apr 23, 2024 at 10:43=E2=80=AFAM Robert Haas <robertmhaas@gmail.com=
> wrote:
> I've not followed this thread closely enough to understand the comment
> about requiredirect maybe not actually requiring direct, but if that
> were true it seems like it might be concerning.

It may be my misunderstanding. This seems to imply bad behavior:

> If the server rejects GSS encryption, SSL is
> negotiated over the same TCP connection using the traditional postgres
> protocol, regardless of <literal>sslnegotiation</literal>.

As does this comment:

> +   /*
> +    * If enabled, try direct SSL. Unless we have a valid TCP connection =
that
> +    * failed negotiating GSSAPI encryption or a plaintext connection in =
case
> +    * of sslmode=3D'allow'; in that case we prefer to reuse the connecti=
on with
> +    * negotiated SSL, instead of reconnecting to do direct SSL. The poin=
t of
> +    * direct SSL is to avoid the roundtrip from the negotiation, but
> +    * reconnecting would also incur a roundtrip.
> +    */

but when I actually try those cases, I see that requiredirect does
actually cause a direct SSL connection to be done, even with
sslmode=3Dallow. So maybe it's just misleading documentation (or my
misreading of it) that needs to be expanded? Am I missing a different
corner case where requiredirect is ignored, Heikki?

I still question the utility of allowing sslmode=3Dallow with
sslnegotiation=3Drequiredirect, because it seems like you've made both
the performance and security characteristics actively worse if you
choose that combination. But I want to make sure I understand the
current behavior correctly before I derail the discussion too much...

Thanks,
--Jacob