Re: [PATCH] Support pg_ident mapping for LDAP

On Tue, 2021-09-28 at 15:38 +0200, Magnus Hagander wrote:
> I'm a bit hesitant about the ldapuser libpq parameter. Do we really
> want to limit ourselves to just ldap, if we allow this? I mean, why
> not allow say radius or pam to also specify a different username for
> the external system? If we want to do that, now or in the future, we
> should have a much more generic parameter name, something like
> authuser?

I'd be on board with a more general option name.

So from the perspective of a SASL exchange, PGUSER would be the
authorization identity, and PGAUTHUSER, say, would be the
authentication identity. Is "auth" a clear enough prefix that users and
devs will understand what the difference is between the two?

         | authn             authz
---------+-----------------------------------
  envvar | PGAUTHUSER        PGUSER
conninfo | authuser          user
frontend | conn->pgauthuser  conn->pguser backend | port->auth_user   port->user_name

> Why do we actually need ldap_map_dn? Shouldn't this just be what
> happens if you specify map= on an ldap connection?

For simple-bind setups, I think requiring users to match an entire DN
is probably unnecessary (and/or dangerous once you start getting into
regex mapping), so the map uses the bare username by default. My intent
was for that to have the same default behavior as cert maps.

Thanks,
--Jacob