Passing parameters to Azure Active Directory authentication

Question

I have an ASP.Net MVC Application, Owin, and I\'m using Azure Active Directory authentication as well.

I want to pass a parameter when the user is redirected to the

Answer 1

Similar to what Gaurav is suggesting, but adding a few special considerations. Basically, the state is used by the Owin middleware, so while you can inject your own stuff, you need to make sure you revert it back before the Owin middleware tries to use it otherwise you'll get auth errors.

This is effectively what I replied to a very similar question:

Custom parameter with Microsoft.Owin.Security.OpenIdConnect and AzureAD v 2.0 endpoint

In Startup.Auth.cs, when you setup the OpenIdConnectAuthenticationOptions you'd add the following:

app.UseOpenIdConnectAuthentication(
  new OpenIdConnectAuthenticationOptions
  {
    //...
    Notifications = new OpenIdConnectAuthenticationNotifications
    {
      RedirectToIdentityProvider = OnRedirectToIdentityProvider,
      MessageReceived = OnMessageReceived
    },
  });

And use RedirectToIdentityProvider to inject your parameter, something along the lines of:

private static Task OnRedirectToIdentityProvider(RedirectToIdentityProviderNotification notification)
{
  var stateQueryString = notification.ProtocolMessage.State.Split('=');
  var protectedState = stateQueryString[1];
  var state = notification.Options.StateDataFormat.Unprotect(protectedState);
  state.Dictionary.Add("mycustomparameter", "myvalue");
  notification.ProtocolMessage.State = stateQueryString[0] + "=" + notification.Options.StateDataFormat.Protect(state);
  return Task.FromResult(0);
}

And then use MessageReceived to extract it, like so:

private static Task OnMessageReceived(MessageReceivedNotification notification)
{
  string mycustomparameter;
  var protectedState = notification.ProtocolMessage.State.Split('=')[1];
  var state = notification.Options.StateDataFormat.Unprotect(protectedState);
  state.Dictionary.TryGetValue("mycustomparameter", out mycustomparameter);
  return Task.FromResult(0);
}

You'd obviously need to improve/harden this but this should get you going.