Re: [HACKERS] scram and \password - Mailing list pgsql-hackers

On 04/10/2017 08:42 AM, Michael Paquier wrote:
> As there have been some conflicts because of the commit of SASLprep,
> here is a rebased set of patches. A couple of things worth noting:
> - SASLprep does an allocation of the prepared password string. It is
> definitely better to do all the ground work in pg_saslprep but this
> costs a free() call with a #ifdef FRONTEND at the end of
> scram_build_verifier().
> - Patch 0005 does that:
> +           /*
> +            * Hash password using SCRAM-SHA-256 when connecting to servers
> +            * newer than Postgres 10, and hash with MD5 otherwise.
> +            */
> +           if (pset.sversion < 100000)
> +               encrypted_password = PQencryptPassword(pw1, user, "md5");
> +           else
> +               encrypted_password = PQencryptPassword(pw1, user, "scram");
> Actually I am thinking that guessing the hashing function according to
> the value of password_encryption would make the most sense. Thoughts?

Thanks! I've been busy on the other thread on future-proofing the 
protocol with negotiating the SASL mechanism, I'll come back to this 
once we get that settled. By the end of the week, I presume.

Not sure about the password-encryption thing, there are good arguments 
for either behavior..

- Heikki