Re: postgres_fdw, dblink, and CREATE SUBSCRIPTION security

On Wed, Mar 8, 2023 at 5:44 PM Jacob Champion <jchampion@timescale.com> wrote:
>
> On Wed, Mar 8, 2023 at 11:40 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > On Wed, Mar 8, 2023 at 2:30 PM Jacob Champion <jchampion@timescale.com> wrote:
> > > I don't think I necessarily like that option better than SASL-style,
> > > but hopefully that clarifies it somewhat?
> >
> > Hmm, yeah, I guess that's OK.
>
> Okay, cool.
>
> > I still don't love it, though. It feels
> > more solid to me if the proxy can actually block the connections
> > before they even happen, without having to rely on a server
> > interaction to figure out what is permissible.
>
> Sure. I don't see a way for the proxy to figure that out by itself,
> though, going back to my asymmetry argument from before. Only the
> server truly knows, at time of HBA processing, whether the proxy
> itself has authority. If the proxy knew, it wouldn't be confused.
>
> > I don't know what you mean by SASL-style, exactly.
>
> That's the one where the server explicitly names all forms of
> authentication, including the ambient ones (ANONYMOUS, EXTERNAL,
> etc.), and requires the client to choose one before running any
> actions on their behalf. That lets the require_auth machinery work for
> this case, too.
>
> --Jacob



--
Robert Haas
EDB: http://www.enterprisedb.com