Horton

Re: [REVIEW]: 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: Dmitry Dolgov <9erthalion6@gmail.com>
Cc: Valery Popov <v.popov@postgrespro.ru>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2016-03-02T06:52:20Z
Lists: pgsql-hackers 
On Wed, Mar 2, 2016 at 4:05 AM, Dmitry Dolgov <9erthalion6@gmail.com> wrote:
> [...]

Thanks for the review.

> The default value contains "scram". Shouldn't be here also:
>
>>        Specifies a comma-separated list of supported password formats by
>>        the server. Supported formats are currently <literal>plain</>,
>>        <literal>md5</> and <literal>scram</>.
>
> Or I missed something?

Ah, I see. That's in the documentation of password_protocols. Yes
scram should be listed there as well. That should be fixed in 0009.

>>       <para>
>>        <varname>db_user_namespace</> causes the client's and
>>        server's user name representation to differ.
>>        Authentication checks are always done with the server's user name
>>        so authentication methods must be configured for the
>>        server's user name, not the client's.  Because
>>        <literal>md5</> uses the user name as salt on both the
>>        client and server, <literal>md5</> cannot be used with
>>        <varname>db_user_namespace</>.
>>       </para>
>
> Looks like the same (pls, correct me if I'm wrong) is applicable for "scram"
> as I see from the code below. Shouldn't be "scram" mentioned here also?

Oops. Good catch. Yes it should be mentioned as part of the SCRAM patch (0009).
-- 
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.