We are integrating with a partner vendor and we need to be able to redirect authenticated members to a different website with an authorization code based on the member clicking a link within our Umbraco site. That link points the current member to the IdentityServer authorization endpoint which is part of same Umbraco website. The call to the authorization endpoint would then redirect the member to the partner website with authorization code as part of the querystring.

That other website can then use that authorization code to obtain a token containing the claims to identify the member.

I've implemented a custom IdentityServer user service. However, when the authorization endpoint is called and the user service's PreAuthenticateAsync method is called Umbraco doesn't recognize the member as being logged in even though they are. I'm instantiating an instance of the MembershipHelper by passing in the UmbracoContext.Current in the constructor and the CurrentUserName property is null and the GetCurrentMember() method returns null.

I'm not sure why I'm experiencing this behavior. Does anyone have any experience with IdentityServer3 and Umbraco 7?