Horton

Re: [PoC] Federated Authn/z with OAUTHBEARER

Jacob Champion <jacob.champion@enterprisedb.com>

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From: Jacob Champion <jacob.champion@enterprisedb.com>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Peter Eisentraut <peter@eisentraut.org>, Antonin Houska <ah@cybertec.at>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2024-12-05T18:29:52Z
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

Attachments

On Wed, Nov 27, 2024 at 9:27 AM Daniel Gustafsson <daniel@yesql.se> wrote:
> Thanks for the updated version, it's really starting to take good shape.  A few
> small comments on v37 from a a first quick skim-through:

Applied in v38, thanks!

> fail_validator.c seems to have the #include list copied from validator.c and
> pulls in unnecessarily many headers.

Oops, thanks for the cleanup.

> In validate() I wonder if we should doublecheck that have a a proper set of
> validator callbacks loaded just to make even more sure that we don't introduce
> anything terrible in this codepath.

Seems good. I think this part of the API is going to need an
ABI-compatibility pass, too. For example, do we want a module to
allocate the result struct itself (which locks in the struct length)?
And should we have a MAGIC_NUMBER of some sort in the static callback
list, maybe?

--

Now that our JSON API can be put into "leakproof" mode [1], I can fuzz
the parser implementations. libfuzzer has been able to find one known
issue, plus two more that I was unaware of:

1. Duplicate fields caused the previous field values to leak. (This
was the documented FIXME; we now error out in this case.)
2. The array-of-strings parsing had a subtle logic bug: if field "a"
was expected to be an array of strings, we would also accept the
construction `"a": "1"` as if it were equivalent to `"a": ["1"]`. This
messed up the internal tracking and tripped assertions.
3. handle_oauth_sasl_error() was leaking all of its parsed fields if
they didn't get hooked into the PGconn struct before a failure.

All three are fixed in v38; I will keep working on expanding the
amount of code covered by my fuzzers.

Additionally, the following pieces of feedback has been addressed:
- We now validate the incoming JSON as UTF-8 before lexing it, to
prevent invalid multibyte sequences from sneaking through in the
strings [2]. Still need to determine how \uXXXX sequences will
interact with the more punishing client encodings in error messages.
- --with-builtin-oauth/-Dwith_builtin_oauth has been renamed
--with-libcurl/-Dlibcurl, and the Autoconf side uses PKG_CHECK_MODULES
exclusively.
- markPQExpBufferBroken has been replaced with termPQExpBuffer in
append_urlencoded()
- the anonymous union has been named
- pg_be_oauth_mech uses a designated initializer

Next up, the many-many documentation requests, now that the fuzzers
can run while I write.

Thanks,
--Jacob

[1] https://postgr.es/c/5c32c21afe6
[2] https://postgr.es/m/ZjmjPyA29dIJjmjI%40paquier.xyz