Re: Password identifiers, protocol aging and SCRAM protocol

On 09/26/2016 09:02 AM, Michael Paquier wrote:
> On Mon, Sep 26, 2016 at 2:15 AM, David Steele <david(at)pgmasters(dot)net> wrote:
>> * [PATCH 3/8] Switch password_encryption to a enum
>>
>> Does not apply on HEAD (98c2d3332):
>
> Interesting, it works for me on da6c4f6.
>
>> For here on I used 39b691f251 for review and testing.
>> I seems you are keeping on/off for backwards compatibility, shouldn't
>> the default now be "md5"?
>>
>> -#password_encryption = on
>> +#password_encryption = on # on, off, md5 or plain
>
> That sounds like a good idea, so switched this way.

Committed this patch in the series, to turn password_encryption GUC into
an enum.

There was one bug in the patch: if a plaintext password was given with
CREATE/ALTER USER foo PASSWORD 'bar', but password_encryption was 'md5',
it would incorrectly pass PASSWORD_TYPE_MD5 to the check-password hook.
That would limit the amount of checking that the hook can do. Fixed
that. Also edited the docs and comments a little bit, hopefully for the
better.

Once we get the main SCRAM patch in, we may want to remove the "on"
alias altogether. We don't promise backwards-compatibility of config
files or GUC values, and not many people set password_encryption=on
explicitly anyway, since it's the default. But I kept it now, as there's
no ambiguity on what "on" means, yet.

- Heikki