Support for non-OIDC OAuth 2.0 upstreams

[matrixbot]

This issue was originally created by @colemickens at matrix-org/matrix-authentication-service#2080.

Is this project considering support for upstream OAuth2 providers, rather than just upstream OIDC providers?

For example, GitHub only provides OIDC for their Actions workloads/tokens, not for the general third party auth - they only offer OAuth2.

[matrixbot]

This comment was originally posted by @sandhose at matrix-org/matrix-authentication-service#2080 (comment).

We do plan to support non-OIDC OAuth 2.0 upstreams by specifying manually the authorization endpoint, token endpoint and userinfo endpoint. I've created all the relevant issues to support that:

• Allow overriding upstream OAuth 2.0 endpoints #2085
• Make the issuer on upstream OAuth 2.0 providers optional #2086
• Allow disabling OIDC discovery in upstream OAuth 2.0 providers #2087
• Allow fetching user claims through the userinfo_endpoint on upstream OAuth 2.0 logins #2088

[sandhose]

This is now the case! It's just missing documentation