PKCE Support

[edhenry]

Hey there! First of all, thank you for the library! This has been incredibly useful and educational for me!

I have a question around the PKCE support that is outlined in the docs here. I noticed from the docs that the code_verifier is listed as an Optional[str] under the get_access_token method defined on the OAuth2AuthorizeCallback, but I don't see how one could populate this argument. Is there a way to do this or is the argument added for potential future use?

Apologies if this seems like a simple question. Security isn't my strong suit!

[frankie567]

So, it turns out that @king-jam is currently adding proper support to PKCE parameters in #321 😄 It means that we'll soon support to add PKCE parameters start to end.

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Regarding the values to set, I recommend you to read this documentation from one of my another projects which explains the basics of PKCE: https://docs.fief.dev/going-further/pkce/

You can check out this implementation to know how to generate code verifiers and hashes suitable for PKCE: https://github.com/fief-dev/fief-python/blob/main/fief_client/pkce.py

I'm wondering if this could be a good addition to HTTPX OAuth 🤔 Could be nice to have those helper functions built-in. What do you think?

[adrien-f]

Hello and greetings 👋

Following #321 being merged, the documentation mentions the new PKCE fields but it appears that a version containing them has not been released yet!

Would that be something possible?

Thank you in advance!