OpenID connect authentication via back channel communication - Getting access token from a .Net WCF service

Question

I'm trying to get information how to authenticate and authorize a user from a backend WCF service using OpenID Connect configuration rather than using a client application (like Angular /.Net MVC web application).

Can this be achieved using "Authorization Code Flow"?

If yes, could one please guide me, how this can be achieved as we will not be able to configure the re-direction URL for a backend service to get the access token.

If not, could one please tell me how this can be achieved? I did read that this can be achieved by back channel communication (ie https://openid.net/specs/openid-connect-backchannel-1_0.html . If one can help me with the tutorial document that is available in internet that would be really helpful.

Answer 1

The link you mention is about back-channel logout: a communication from your OpenID provider toward your backend to notify your backend of a user ending her/his session at the OpenID provider. I do not see how this could be used to authenticate a user.

It feels somewhat odd that you are trying to authenticate a user from a backend service. The whole idea behind OAuth and OpenID is to pass a credential allow with your request to the backend. The backend must verify that credential but should not involve in gathering and issuing that credential, it should rely on a trusted party (the OpenID provider) to issue those credentials.