Horton

Re: SCRAM with channel binding downgrade attack

Bruce Momjian <bruce@momjian.us>

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From: Bruce Momjian <bruce@momjian.us>
To: Michael Paquier <michael@paquier.xyz>
Cc: Magnus Hagander <magnus@hagander.net>, Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Stephen Frost <sfrost@snowman.net>
Date: 2018-05-18T13:30:22Z
Lists: pgsql-hackers 
On Fri, May 18, 2018 at 12:03:49PM +0900, Michael Paquier wrote:
> On Fri, May 18, 2018 at 10:46:46AM +0900, Michael Paquier wrote:
> > From a security point of view, 1) is important for libpq, but I am not
> > much enthusiast about 2) as a whole.  The backend has proper support for
> > channel binding, hence other drivers speaking the protocol could have
> > their own restriction mechanisms.
> 
> So, I have been playing with libpq to address point 1), and added a new
> connection parameter called channel_binding_mode which can be set to
> 'prefer', which is what libpq uses now, and 'require'.  The patch has
> two important parts:

Good work, but I think the existance of both scram_channel_binding and
channel_binding_mode in libpq is confusing.  I am thinking we should
have one channel binding parameter that can take values "prefer",
"tls-unique", "tls-server-end-point", and "require".  I don't see the
point to having "none" and "allow" that sslmode supports.   "tls-unique"
and "tls-server-end-point" would _require_ those channel binding modes; 
the setting would never be ignored, e.g. if no SSL.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

Commits

  1. doc: update PG 11 release notes

  2. Fix misspelled pg_trgm contrib name in PostgreSQL 11 release notes

  3. Doc: clarify release note text about v11's new window function features.

  4. Improve wording of release notes item

  5. Fix typos in release notes

  6. Doc: preliminary list of PG11 major features.

  7. Make numeric power() handle NaNs according to the modern POSIX spec.

  8. Various improvements of skipping index scan during vacuum technics

  9. Revert back-branch changes in power()'s behavior for NaN inputs.

  10. Avoid wrong results for power() with NaN input on more platforms.

  11. Avoid wrong results for power() with NaN input on some platforms.

  12. Skip full index scan during cleanup of B-tree indexes when possible

  13. Rewrite the code that applies scan/join targets to paths.

  14. Postpone generate_gather_paths for topmost scan/join rel.

  15. Add casts from jsonb

  16. Make plpgsql use its DTYPE_REC code paths for composite-type variables.

  17. Don't allow VACUUM VERBOSE ANALYZE VERBOSE.

  18. Pass InitPlan values to workers via Gather (Merge).

  19. Account for the effect of lossy pages when costing bitmap scans.

  20. Allow no-op GiST support functions to be omitted.

  21. Rearm statement_timeout after each executed query.

  22. Push limit through subqueries to underlying sort, where possible.