I have spent probably more than 10 hours in the last two days trying to understand how to implement user login with Google Hybrid OpenID+OAuth (Federated Login)

To trigger the authorization request I use:

InMemoryOAuthTokenManager tm = new InMemoryOAuthTokenManager( ConfigurationManager.AppSettings["googleConsumerKey"], ConfigurationManager.AppSettings["googleConsumerSecret"]);
using (OpenIdRelyingParty openid = new OpenIdRelyingParty())
{
  Realm realm = HttpContext.Current.Request.Url.Scheme + Uri.SchemeDelimiter + ConfigurationManager.AppSettings["googleConsumerKey"] + "/";
  IAuthenticationRequest request = openid.CreateRequest(identifier, Realm.AutoDetect, new Uri(HttpContext.Current.Request.Url.Scheme + "://" + HttpContext.Current.Request.Url.Authority + "/OAuth/google"));

  var authorizationRequest = new AuthorizationRequest
  {
    Consumer = ConfigurationManager.AppSettings["googleConsumerKey"],
    Scope = "https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/plus.me",
  };

  request.AddExtension(authorizationRequest);

  request.AddExtension(new ClaimsRequest
  {
    Email = DemandLevel.Request,
    Gender = DemandLevel.Require
  });

  request.RedirectToProvider();
}

To retrieve the accesstoken I use:

using (OpenIdRelyingParty openid = new OpenIdRelyingParty())
{
  IAuthenticationResponse authResponse = openid.GetResponse();
  if (authResponse != null)
  {
    switch (authResponse.Status)
    {
      case AuthenticationStatus.Authenticated:
        HttpContext.Current.Trace.Write("AuthenticationStatus", "Authenticated");
        FetchResponse fr = authResponse.GetExtension<FetchResponse>();

        InMemoryOAuthTokenManager tm = new InMemoryOAuthTokenManager(ConfigurationManager.AppSettings["googleConsumerKey"], ConfigurationManager.AppSettings["googleConsumerSecret"]);

        ServiceProviderDescription spd = new ServiceProviderDescription {
          spd.RequestTokenEndpoint = new DotNetOpenAuth.Messaging.MessageReceivingEndpoint("https://accounts.google.com/o/oauth2/token", HttpDeliveryMethods.AuthorizationHeaderRequest | HttpDeliveryMethods.GetRequest);
          spd.AccessTokenEndpoint = new DotNetOpenAuth.Messaging.MessageReceivingEndpoint("https://accounts.google.com/o/oauth2/token", HttpDeliveryMethods.AuthorizationHeaderRequest | HttpDeliveryMethods.GetRequest);
          spd.UserAuthorizationEndpoint = new DotNetOpenAuth.Messaging.MessageReceivingEndpoint("https://accounts.google.com/o/oauth2/auth?access_type=offline", HttpDeliveryMethods.AuthorizationHeaderRequest | HttpDeliveryMethods.GetRequest);
          spd.TamperProtectionElements = new ITamperProtectionChannelBindingElement[] { new HmacSha1SigningBindingElement() };

        WebConsumer wc = new WebConsumer(spd, tm);
        AuthorizedTokenResponse accessToken = wc.ProcessUserAuthorization();

        if (accessToken != null)
        {
          HttpContext.Current.Trace.Write("accessToken", accessToken.ToString());
        }
        else
        {
        }
        break;
      case AuthenticationStatus.Canceled:
        HttpContext.Current.Trace.Write("AuthenticationStatus", "Canceled");
        break;
      case AuthenticationStatus.Failed:
        HttpContext.Current.Trace.Write("AuthenticationStatus", "Failed");
        break;
      default:
        break;
    }
  }
}

Unfortunatelly I get AuthenticationStatus.Authenticated but wc.ProcessUserAuthorization() is null.

What am I doing wrong?

Thanks a lot for any help.