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: David Fetter <david@fetter.org>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Magnus Hagander <magnus@hagander.net>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Robert Haas <robertmhaas@gmail.com>, Julian Markwort <julian.markwort@uni-muenster.de>, Stephen Frost <sfrost@snowman.net>, David Steele <david@pgmasters.net>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>, Valery Popov <v.popov@postgrespro.ru>
Date: 2016-07-20T23:42:51Z
Lists: pgsql-hackers 
On Thu, Jul 21, 2016 at 5:25 AM, David Fetter <david@fetter.org> wrote:
> On Wed, Jul 20, 2016 at 02:12:57PM -0400, Alvaro Herrera wrote:
>> Michael Paquier wrote:
>> > On Wed, Jul 6, 2016 at 4:18 PM, Michael Paquier
>> > <michael.paquier@gmail.com> wrote:
>> > > OK, after hacking that for a bit I have finished with option 2 and the
>> > > set of PG-like set of routines, the use of USE_SSL in the file
>> > > containing all the SHA functions of OpenBSD has proved to be really
>> > > ugly, but with a split things are really clear to the eye. The stuff I
>> > > got builds on OSX, Linux and MSVC. pgcrypto cannot link directly to
>> > > libpgcommon.a, so I am making it compile directly with the source
>> > > files, as it is doing on HEAD.
>> >
>> > Btw, attached is the patch I did for this part if there is any interest in it.
>>
>> After quickly eyeballing your patch, I agree with the decision of going
>> with (2), even if my gut initially told me that (1) would be better
>> because it'd require less makefile trickery.

Yeah, I thought the same thing as well when putting my hands in the
dirt... But the in the end (2) is really less ugly.

>> I'm surprised that you say pgcrypto cannot link libpgcommon directly.
>> Is there some insurmountable problem there?  I notice your MSVC patch
>> uses libpgcommon while the Makefile symlinks the files.

I am running into some weird things when linking both on OSX... But I
am not done with it completely yet. I'll adjust that a bit more when
producing the set of patches that will be published. So let's see.

> People have, in the past, expressed concerns about linking in
> pgcrypto.  Apparently, in some countries, it's a legal problem.

Do you have any references? I don't see that as a problem.
-- 
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.