Hello,

I have an external OIDC provider that uses multiple signing keys to sign the id_tokens it issues. 

According to the OIDC spec (https://openid.net/specs/openid-connect-discovery-1_0.html), "jwks_uri" is an "URL of the OP's JSON Web Key Set. The set contains the signing key(s) that RP uses to validate signature from the OP". 

Now, there is only a single validating public key  shown on the OIDC external provider configuration page. When importing OIDC provider configuration using OIDC provider metadata uri, keycloak picks the first JWK which "use" parameter value is set to "sig". In my case, all JWKs in the JWK Set have their "use" member set to "sig". I took a cursory look at the JWKS spec (https://tools.ietf.org/html/draft-ietf-jose-json-web-key-41#section-4.2) and based on what I've read it seems there could be more than one key with the same "use" parameter. Shouldn't keycloak store all signing keys instead of just one, and use the value of the "kid" parameter from the provider's auth response to choose a corresponding public key to do the validation?

Regards,

--Peter