Horton

Re: Password identifiers, protocol aging and SCRAM protocol

Heikki Linnakangas <hlinnaka@iki.fi>

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From: Heikki Linnakangas <hlinnaka@iki.fi>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: David Steele <david@pgmasters.net>, Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, David Fetter <david@fetter.org>, Alvaro Herrera <alvherre@2ndquadrant.com>, Magnus Hagander <magnus@hagander.net>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Julian Markwort <julian.markwort@uni-muenster.de>, Stephen Frost <sfrost@snowman.net>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>, Valery Popov <v.popov@postgrespro.ru>
Date: 2016-10-17T09:27:17Z
Lists: pgsql-hackers 
On 10/17/2016 12:18 PM, Michael Paquier wrote:
> You removed the part of pgcrypto in charge of randomness, nice move. I
> was wondering about how to do with the perfc and the unix_std at some
> point, and ripping them off as you did is fine for me.

Yeah. I didn't understand the need for the perfc stuff. Are there 
Windows systems that don't have the Crypto APIs? I doubt it, but the 
buildfarm will tell us in a moment if there are.

And if we don't have a good source of randomness like /dev/random, I 
think it's better to fail, than try to collect entropy ourselves (which 
is what unix_std did). If there's a platform where that doesn't work, 
someone will hopefully send us a patch, rather than silently fall back 
to an iffy implementation.

- Heikki

Commits

  1. Support SCRAM-SHA-256 authentication (RFC 5802 and 7677).

  2. Refactor SHA2 functions and move them to src/common/.

  3. Replace isMD5() with a more future-proof way to check if pw is encrypted.

  4. Remove bogus notice that older clients might not work with MD5 passwords.

  5. Refactor the code for verifying user's password.

  6. Replace PostmasterRandom() with a stronger source, second attempt.

  7. Remove support for (insecure) crypt authentication.