Horton

Re: [PoC] Federated Authn/z with OAUTHBEARER

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Jacob Champion <jchampion@timescale.com>
Cc: "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, mahendrakar s <mahendrakarforpg@gmail.com>, Andrey Chudnovsky <achudnovskij@gmail.com>, "hlinnaka@iki.fi" <hlinnaka@iki.fi>, "michael@paquier.xyz" <michael@paquier.xyz>, "smilingsamay@gmail.com" <smilingsamay@gmail.com>, Stephen Frost <sfrost@snowman.net>
Date: 2023-07-01T04:28:52Z
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

On Sat, May 20, 2023 at 10:01 AM Jacob Champion <jchampion@timescale.com> wrote:
> - The client implementation is currently epoll-/Linux-specific. I think
> kqueue shouldn't be too much trouble for the BSDs, but it's even more
> code to maintain.

I guess you also need a fallback that uses plain old POSIX poll()?  I
see you're not just using epoll but also timerfd.  Could that be
converted to plain old timeout bookkeeping?  That should be enough to
get every other Unix and *possibly* also Windows to work with the same
code path.

> - Unless someone is aware of some amazing Winsock magic, I'm pretty sure
> the multiplexed-socket approach is dead in the water on Windows. I think
> the strategy there probably has to be a background thread plus a fake
> "self-pipe" (loopback socket) for polling... which may be controversial?

I am not a Windows user or hacker, but there are certainly several
ways to multiplex sockets.  First there is the WSAEventSelect() +
WaitForMultipleObjects() approach that latch.c uses.  It has the
advantage that it allows socket readiness to be multiplexed with
various other things that use Windows "events".  But if you don't need
that, ie you *only* need readiness-based wakeup for a bunch of sockets
and no other kinds of fd or object, you can use winsock's plain old
select() or its fairly faithful poll() clone called WSAPoll().  It
looks a bit like that'd be true here if you could kill the timerfd?

It's a shame to write modern code using select(), but you can find
lots of shouting all over the internet about WSAPoll()'s defects, most
famously the cURL guys[1] whose blog is widely cited, so people still
do it.  Possibly some good news on that front:  by my reading of the
docs, it looks like that problem was fixed in Windows 10 2004[2] which
itself is by now EOL, so all systems should have the fix?  I suspect
that means that, finally, you could probably just use the same poll()
code path for Unix (when epoll is not available) *and* Windows these
days, making porting a lot easier.  But I've never tried it, so I
don't know what other problems there might be.  Another thing people
complain about is the lack of socketpair() or similar in winsock which
means you unfortunately can't easily make anonymous
select/poll-compatible local sockets, but that doesn't seem to be
needed here.

[1] https://daniel.haxx.se/blog/2012/10/10/wsapoll-is-broken/
[2] https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsapoll