Re: Proposal: Support custom authentication methods using hooks

Greetings,

* Jonathan S. Katz (jkatz(at)postgresql(dot)org) wrote:
> On 2/25/22 12:39 PM, Tom Lane wrote:
> >Jeff Davis <pgsql(at)j-davis(dot)com> writes:
> >>On Thu, 2022-02-24 at 20:47 -0500, Tom Lane wrote:
> >>>... and, since we can't readily enforce that the client only sends
> >>>those cleartext passwords over suitably-encrypted connections, this
> >>>could easily be a net negative for security. Not sure that I think
> >>>it's a good idea.
> >
> >>I don't understand your point. Can't you just use "hostssl" rather than
> >>"host"?
> >
> >My point is that sending cleartext passwords over the wire is an
> >insecure-by-definition protocol that we shouldn't be encouraging
> >more use of.
>
> This is my general feeling as well. We just spent a bunch of effort adding,
> refining, and making SCRAM the default method. I think doing anything that
> would drive more use of sending plaintext passwords, even over TLS, is
> counter to that.

Agreed.

> I do understand arguments for (e.g. systems that require checking password
> complexity), but I wonder if it's better for us to delegate that to an
> external auth system. Regardless, I can get behind Andres' point to "check
> Port->ssl_in_use before sendAuthRequest(AUTH_REQ_PASSWORD)".

Password complexity is only needed to be checked at the time of password
change though, which is not on every login, and should be after a
confirmed mutual authentication between the client and the server.
That's a very different situation.

> I'm generally in favor of being able to support additional authentication
> methods, the first one coming to mind is supporting OIDC. Having a pluggable
> auth infrastructure could possibly make such efforts easier. I'm definitely
> intrigued.

I'm not thrilled with the idea, for my part.

Thanks,

Stephen