Re: scram and \password

On 03/14/2017 04:47 AM, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> I'm not talking about changing the default, just having it be possible
>> to use \password with the new system as it was with the old, whatever
>> exactly we think that means.
>
> Seems to me the intended behavior of \password is to use the best
> available practice.  So my guess is that it ought to use SCRAM when
> talking to a >= 10.0 server.  What the previous password was ought
> to be irrelevant, even if it could find that out which it shouldn't
> be able to IMO.

If the server isn't set up to do SCRAM authentication, i.e. there are no 
"scram" entries in pg_hba.conf, and you set yourself a SCRAM verifier, 
you have just locked yourself out of the system. I think that's a 
non-starter. There needs to be some more intelligence in the decision.

It would be a lot more sensible, if there was a way to specify in 
pg_hba.conf, "scram-or-md5". We punted on that for PostgreSQL 10, but 
perhaps we should try to cram that in, after all.

- Heikki