PKCE - Code Challenge Method not supported

API and Webhooks
1

Description
I’m attempting to add PKCE to an OAuth flow that previously worked.
Setting code_challenge_method=S256 looks like it should work, according to the RFC and Zoom’s documentation, so what am I missing here?

Error
Web browser displays an error “Code Challenge Method not supported. (4,715)”

Which App Type (OAuth / Chatbot / JWT / Webhook)?
OAuth

Which Endpoint/s?

https://zoom.us/oauth/

How To Reproduce (If applicable)
Steps to reproduce the behavior:

  1. Submit a URL like
    https://zoom.us/oauth2/login?client_id={_}&response_type=code&redirect_uri={_}&state={_}&code_challenge={_}&code_challenge_method=S256&_x_zm_rtaid={_}&_x_zm_rhtaid={_}

where {_} represents the redacted parts.

  1. Error messages appears “Code Challenge Method not supported. (4,715)”
2

Hey @AJW,

Thank you for reaching out to the Zoom Developer Forum. I’ve been investigating a similar issue and have added your case to the open issue with our engineering team. I’ll be sure to keep you updated. (ZOOM-276777)

Thanks,
Max

3

Hey @MaxM ,

Same issue here (4.715). I am implementing Zoom OAuth2 for a Flutter desktop app using the oauth2 package. I actually had to modify the package and remove PKCE in order to get the authentication to work.

I appreciate your support,
Jonas

4

@Jonas @AJW

Try using the value sha256 for the code_challenge_method parameter and let us know if that resolves your issues. We’ll update our documentation around this.

Thanks,
Max

5

As an update, you will want to make sure that you are using lowercase letters: sha256

Max

6

This resolves the issue, thank you for the updated information.

1 Like
7

Hey @AJW,

I’m glad that helped! We’ll make sure to update our documentation and will support different cases in the future.

Thanks,
Max