Add support of multiple public keys to verify tokens with a set of keys

[alexandre-daubois]

It may be convenient to use multiple public keys to verify token signature when using RS algorithm. It would allow to verify tokens coming from different providers.

Somehow related to #707

[chalasr]

Thanks for the PR.
#707 is about allowing per-firewall configuration (including keys). Would that match your use case? Or do you need to support multiple keys for your entire application as this PR currently suggests?

[alexandre-daubois]

Thanks for your reply! I don't think this would match our use case. Indeed, we would need to support multiple public keys for a single firewall. Tokens are coming from many providers, each with their own key, passing to a single firewall on a common endpoint.

[HidouriAnis]

I currently have the same needs as you, what did you do as a solution?

[alexandre-daubois]

@HidouriAnis for now, we did it like as it's in #707, in this comment. Even if this works, this is not super convenient to redefine all services like this. It's also very verbose.

[chalasr]

Thank you @alexandre-daubois.