Horton

Re: [PoC] Federated Authn/z with OAUTHBEARER

Jacob Champion <jchampion@timescale.com>

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From: Jacob Champion <jchampion@timescale.com>
To: Andrey Chudnovsky <achudnovskij@gmail.com>
Cc: mahendrakar s <mahendrakarforpg@gmail.com>, hlinnaka@iki.fi, Michael Paquier <michael@paquier.xyz>, Pg Hackers <pgsql-hackers@postgresql.org>, smilingsamay@gmail.com
Date: 2023-01-17T22:43:59Z
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

On Sun, Jan 15, 2023 at 12:03 PM Andrey Chudnovsky
<achudnovskij@gmail.com> wrote:
> 2. Removed Device Code implementation in libpq. Several reasons:
>    - Reduce scope and focus on the protocol first.
>    - Device code implementation uses iddawc dependency. Taking this
> dependency is a controversial step which requires broader discussion.
>    - Device code implementation without iddaws would significantly
> increase the scope of the patch, as libpq needs to poll the token
> endpoint, setup different API calls, e.t.c.
>    - That flow should canonically only be used for clients which can't
> invoke browsers. If it is the only flow to be implemented, it can be
> used in the context when it's not expected by the OAUTH protocol.

I'm not understanding the concern in the final point -- providers
generally require you to opt into device authorization, at least as far
as I can tell. So if you decide that it's not appropriate for your use
case... don't enable it. (And I haven't seen any claims that opting into
device authorization weakens the other flows in any way. So if we're
going to implement a flow in libpq, I still think device authorization
is the best choice, since it works on headless machines as well as those
with browsers.)

All of this points at a bigger question to the community: if we choose
not to provide a flow implementation in libpq, is adding OAUTHBEARER
worth the additional maintenance cost?

My personal vote would be "no". I think the hook-only approach proposed
here would ensure that only larger providers would implement it in
practice, and in that case I'd rather spend cycles on generic SASL.

> 3. Temporarily removed test suite. We are actively working on aligning
> the tests with the latest changes. Will add a patch with tests soon.

Okay. Case in point, the following change to the patch appears to be
invalid JSON:

> +   appendStringInfo(&buf,
> +       "{ "
> +           "\"status\": \"invalid_token\", "
> +           "\"openid-configuration\": \"%s\","
> +           "\"scope\": \"%s\" ",
> +           "\"issuer\": \"%s\" ",
> +       "}",

Additionally, the "issuer" field added here is not part of the RFC. I've
written my thoughts about unofficial extensions upthread but haven't
received a response, so I'm going to start being more strident: Please,
for the sake of reviewers, call out changes you've made to the spec, and
why they're justified.

The patches seem to be out of order now (and the documentation in the
commit messages has been removed).

Thanks,
--Jacob