Re: Add "password_protocol" connection parameter to libpq

On Sun, 2019-08-11 at 19:00 +0200, Peter Eisentraut wrote:
> On 2019-08-09 23:56, Jeff Davis wrote:
> > 1. Hierarchical semantics, where you specify the least-secure
> > acceptable method:
> >
> > password_protocol = {any,md5,scram-sha-256,scram-sha-256-plus}
>
> What would the hierarchy be if scram-sha-512 and scram-sha-512-plus
> are
> added?

https://postgr.es/m/daf0017a1a5c2caabf88a4e00f66b4fcbdfeccad.camel%40j-davis.com

The weakness of proposal #1 is that it's not very "future-proof" and we
would likely need to change something about it later when we support
new methods. That wouldn't break clients, but it would be annoying to
need to support some old syntax and some new syntax for the connection
parameters.

Proposal #3 does not have this weakness. When we add sha-512, we could
also add a parameter to specify that the client requires a certain hash
algorithm for SCRAM.

Do you favor that existing proposal #3, or are you proposing a fourth
option?

Regards,
Jeff Davis