Horton

Re: SCRAM with channel binding downgrade attack

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Postgres hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Magnus Hagander <magnus@hagander.net>, Stephen Frost <sfrost@snowman.net>, Bruce Momjian <bruce@momjian.us>
Date: 2018-06-06T22:04:17Z
Lists: pgsql-hackers 
On Wed, Jun 06, 2018 at 11:53:06PM +0300, Heikki Linnakangas wrote:
> That would certainly be good. We've always had that problem, even with md5
> -> plaintext password downgrade, and it would be nice to fix it. It's quite
> late in the release cycle already, do you think we should address that now?
> I could go either way..

I would be inclined to treat that as new development as this is no new
problem.  Still that's linked with what is discussed on this thread with
scram_channel_bindin_mode.

> What should the option look like? Perhaps something like:
> 
> allowed_authentication_methods=md5,SCRAM-SHA-256,SCRAM-SHA-256-PLUS

That's actually a discussion I had with somebody after my talk at
PGCon, and I suggested a comma-separate list of authorized protocols as
well, except that those could just map to the hba entries, and that each
entry could just be lower-case :)
--
Michael

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.