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: 2016-10-17T08:55:21Z
Lists: pgsql-hackers 
On 10/15/2016 04:26 PM, Michael Paquier wrote:
>> * Now that we don't call random() in postmaster anymore, is there any point
>> in calling srandom() there (i.e. where the above incorrect comment was)?
>> Should we remove it? random() might be used by pre-loaded extensions,
>> though. (Hopefully not for cryptographic purposes.)
>
> That's the business of the maintainers such modules, so my heart is
> telling me to rip it off, but my mind tells me that there is no point
> in making them unhappy either if they rely on it. I'd trust my mind on
> this one, other opinions are welcome.

I kept it for now. Doesn't do any harm either, even if it's unnecessary.

>> * Should we backport this? Sorry if we discussed that already, but I don't
>> remember.
>
> I think that we discussed quickly the point at last PGCon during the
> SCRAM-committee-unofficial meeting, and that we talked about doing
> that only for HEAD.

Ok, committed to HEAD.

Thanks!

- 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.