Horton

Re: Password identifiers, protocol aging and SCRAM protocol

Michael Paquier <michael.paquier@gmail.com>

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From: Michael Paquier <michael.paquier@gmail.com>
To: Heikki Linnakangas <hlinnaka@iki.fi>
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: 2016-10-17T09:18:53Z
Lists: pgsql-hackers 
On Mon, Oct 17, 2016 at 5:55 PM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> 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.

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.
-- 
Michael

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.