Feedback-ID: i0fe9450f:Fastmail
Date: Sun, 11 Dec 2022 12:32:38 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Andres Freund <andres@anarazel.de>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Raising the SCRAM iteration count
Message-ID: <Y5VPVlwE/a+CzZCZ@paquier.xyz>
References: <F72E7BC7-189F-4B17-BF47-9735EB72C364@yesql.se>
 <20221210001538.czikyvk3xtkphxfu@awork3.anarazel.de>
 <4E147E88-76CF-4E54-B8CE-B4FE1AD40CF5@yesql.se>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="yZw5PXQ0FGPIA1v9"
Content-Disposition: inline
In-Reply-To: <4E147E88-76CF-4E54-B8CE-B4FE1AD40CF5@yesql.se>
Archived-At: 
 <https://www.postgresql.org/message-id/Y5VPVlwE/a%2BCzZCZ%40paquier.xyz>
Precedence: bulk


--yZw5PXQ0FGPIA1v9
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Sun, Dec 11, 2022 at 12:46:23AM +0100, Daniel Gustafsson wrote:
> SCRAM with an iteration count of 1 still provides a lot of benefits over =
md5,
> so if we can make those comparable in performance then that could be a way
> forward (with the tradeoffs properly documented).

Okay, it looks like there is a wish to make that configurable anyway,
and I have a few comments about that.

       {"scram_iteration_count", PGC_SUSET, CONN_AUTH_AUTH,
+           gettext_noop("Sets the iteration count for SCRAM secret generat=
ion."),
+           NULL,
+           GUC_NOT_IN_SAMPLE | GUC_SUPERUSER_ONLY
+       },

Shouldn't this be user-settable as a PGC_USERSET rather than
PGC_SUSET which would limit its updates to superusers?

As shaped, the GUC would not benefit to \password, and we should not
encourage users to give a raw password over the wire if possible if
they wish to compute a verifier with a given interation number.
Hence, wouldn't it be better to mark it as GUC_REPORT, and store its=20
status in pg_conn@libpq-int.h in the same fashion as
default_transaction_read_only and hot_standby?  This way,
PQencryptPasswordConn() would be able to feed on it automatically
rather than always assume the default implied by
pg_fe_scram_build_secret().
--
Michael

--yZw5PXQ0FGPIA1v9
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=QPEY
-----END PGP SIGNATURE-----

--yZw5PXQ0FGPIA1v9--