Re: [PoC] Federated Authn/z with OAUTHBEARER

Stephen Frost <sfrost@snowman.net>

From: Stephen Frost <sfrost@snowman.net>
To: Andrey Chudnovsky <achudnovskij@gmail.com>
Cc: Jacob Champion <jchampion@timescale.com>, mahendrakar s <mahendrakarforpg@gmail.com>, hlinnaka@iki.fi, Michael Paquier <michael@paquier.xyz>, Pg Hackers <pgsql-hackers@postgresql.org>, smilingsamay@gmail.com
Date: 2023-02-27T20:31:04Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. meson: Fix install-quiet after clean

  2. oauth: Run Autoconf tests with correct compiler flags

  3. Link libpq with libdl if the platform needs that.

  4. Doc: correct spelling of meson switch.

  5. oauth: Correct SSL dependency for libpq-oauth.a

  6. oauth: Fix Autoconf build on macOS

  7. oauth: Move the builtin flow into a separate module

  8. Remove a stray "pgrminclude" annotation

  9. oauth: Simplify copy of PGoauthBearerRequest

  10. oauth: Improve validator docs on interruptibility

  11. oauth: Disallow synchronous DNS in libcurl

  12. oauth: Fix postcondition for set_timer on macOS

  13. oauth: Use IPv4-only issuer in oauth_validator tests

  14. Work around OAuth/EVFILT_TIMER quirk on NetBSD.

  15. oauth: Fix incorrect const markers in struct

  16. Add missing entry to oauth_validator test .gitignore

  17. cirrus: Temporarily fix libcurl link error

  18. Add support for OAUTHBEARER SASL mechanism

  19. libpq: Handle asynchronous actions during SASL

  20. require_auth: prepare for multiple SASL mechanisms

  21. Move PG_MAX_AUTH_TOKEN_LENGTH to libpq/auth.h

  22. Make SASL max message length configurable

  23. jsonapi: fully initialize dummy lexer

  24. common/jsonapi: support libpq as a client

  25. Remove fe_memutils from libpgcommon_shlib

  26. Revert ECPG's use of pnstrdup()

  27. Explicitly require password for SCRAM exchange

  28. Refactor SASL exchange to return tri-state status

Greetings,

* Andrey Chudnovsky (achudnovskij@gmail.com) wrote:
> > This really doesn't feel like a great area to try and do hooks or
> > similar in, not the least because that approach has been tried and tried
> > again (PAM, GSSAPI, SASL would all be examples..) and frankly none of
> > them has turned out great (which is why we can't just tell people "well,
> > install the pam_oauth2 and watch everything work!") and this strikes me
> > as trying to do that yet again but worse as it's not even a dedicated
> > project trying to solve the problem but more like a side project.
> 
> In this case it's not intended to be an open-ended hook, but rather an
> implementation of a specific rfc (rfc-7628) which defines a
> client-server communication for the authentication flow.
> The rfc itself does leave a lot of flexibility on specific parts of
> the implementation. Which do require hooks:

Color me skeptical on an RFC that requires hooks.

> (1.) Server side hook to validate the token, which is specific to the
> OAUTH provider.
> (2.) Client side hook to request the client to obtain the token.

Perhaps I'm missing it... but weren't these handled with what the
original patch that Jacob had was doing?

> On (1.), we would need a hook for the OAUTH provider extension to do
> validation. We can though do some basic check that the credential is
> indeed a JWT token signed by the requested issuer.
> 
> Specifically (2.) is where we can provide a layer in libpq to simplify
> the integration. i.e. implement some OAUTH flows.
> Though we would need some flexibility for the clients to bring their own token:
> For example there are cases where the credential to obtain the token
> is stored in a separate secure location and the token is returned from
> a separate service or pushed from a more secure environment.

In those cases... we could, if we wanted, simply implement the code to
actually pull the token, no?  We don't *have* to have a hook here for
this, we could just make it work.

> > another new "generic" set of hooks/APIs that will just cause DBAs and
> > our users headaches trying to make work.
> As I mentioned above, it's an rfc implementation, rather than our invention.

While I only took a quick look, I didn't see anything in that RFC that
explicitly says that hooks or a plugin or a library or such is required
to meet the RFC.  Sure, there are places which say that the
implementation is specific to a particular server or client but that's
not the same thing.

> When it comes to DBAs and the users.
> Builtin libpq implementations which allows psql and pgadmin to
> seamlessly connect should suffice those needs.
> While extensibility would allow the ecosystem to be open for OAUTH
> providers, SAAS developers, PAAS providers and other institutional
> players.

Each to end up writing their own code to do largely the same thing
without the benefit of the larger community to be able to review and
ensure that it's done properly?

That doesn't sound like a great approach to me.

Thanks,

Stephen