Re: Raising the SCRAM iteration count

> On 15 Dec 2022, at 00:52, Michael Paquier <michael@paquier.xyz> wrote:

>    conn->in_hot_standby = PG_BOOL_UNKNOWN;
> +   conn->scram_iterations = SCRAM_DEFAULT_ITERATIONS;
> 
> s/SCRAM_DEFAULT_ITERATIONS/SCRAM_SHA_256_DEFAULT_ITERATIONS/ and
> s/scram_iterations/scram_sha_256_interations/ perhaps?  

Distinct members in the conn object is only of interest if there is a way for
the user to select a different password method in \password right?  I can
rename it now but I think doing too much here is premature, awaiting work on
\password (should that materialize) seems reasonable no?

> +#ifndef FRONTEND
> +/*
> + * Number of iterations when generating new secrets.
> + */
> +extern PGDLLIMPORT int scram_sha256_iterations;
> +#endif
> 
> It looks like libpq/scram.h, which is backend-only, would be a better
> location.

Fixed.

> @@ -692,7 +697,7 @@ mock_scram_secret(const char *username, int *iterations, char **salt,
>    encoded_salt[encoded_len] = '\0';
> 
>    *salt = encoded_salt;
> -   *iterations = SCRAM_DEFAULT_ITERATIONS;
> +   *iterations = scram_sha256_iterations;
> 
> This looks incorrect to me?  The mock authentication is here to
> produce a realistic verifier, still it will fail.  It seems to me that
> we'd better stick to the default in all the cases.

For avoiding revealing anything, I think a case can be argued for both.  I've
reverted back to the default though.

I also renamed the GUC sha_256 to match terminology we use.

--
Daniel Gustafsson		https://vmware.com/