OWIN OpenID MVC5 - Dynamically Change the OpenID Service Provider URL...

Can you show me the code in Startup.Auth.cs for the provider please?

I am using this library:

https://github.com/owin-middleware/OwinOAuthProviders

one of the (many) sample implementations is this:

app.UseOpenIDAuthentication("https://www.google.com/accounts/o8/id", "Google");

If you are asking for a way to change the URL for OpenID authentication, it seems like it is right in front of me:

app.UseOpenIDAuthentication("https://www.google.com/accounts/o8/id", "Google");

That is set during Startup;

What i need to do is change that URL after they click login and are redirected to the ExternalLogin() action.

I would like to change that provider URL dynamically in ExternalLogin().

Part of the problem is having a valid instance of IAppBuilder.app in the controller.

Now that I understand your question, I would think that you could solve this problem by keeping an instance of the OAuth provider, but I am not sure if there is a property for the URL.

This command returns the list of providers:

"HttpContext.GetOwinContext().Authentication.GetExternalAuthenticationTypes()"

However, it only provides the Caption (i.e. "Google") and the AuthenticationType ("ExternalCookie").

If u have a code example of how u might proceed with keeping an instance of the provider around, that would be a big help!

thanks

I downloaded the provider source code, and when I use that code, I get this exception:

'Microsoft.Owin.Security.IAuthenticationManager' does not contain a definition for 'GetExternalAuthenticationTypes' and no extension method 'GetExternalAuthenticationTypes' accepting a first argument of type 'Microsoft.Owin.Security.IAuthenticationManager' could be found (are you missing a using directive or an assembly reference?


The version for Microsoft.Owin.Security is 2.1.0.0.

I did find GetAuthenticationTypes, which returns IEnumerable<AuthenticationDescription>.  That only provides a description, not an instance.  I am still looking for the magic for getting the instance of the provider.

I'm glad I'm not the only one who feels like magic is required!

Looking forward to hearing your findings...

I was able to get the OpenIDAuthenticationOptions instance, which has the discovery URI for Google.  When the AppBuilder.Use is called, it stores some information about the middleware element in the _middleware field:

  public IAppBuilder Use(object middleware, params object[] args)
        {
            this._middleware.Add(AppBuilder.ToMiddlewareFactory(middleware, args));
            return this;
        }

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This reflection code, sets up Google OAuth, which stores the URI in the OpenIDAuthenticationOptions, and then pulls the options back from the _middleware field.  I haven't found a property to access the options.  

Another possibility, though, might be to create your own class, which inherits from OpenIDAuthenticationMiddleware, and then extend the class to give you the functionality that you need.

  app.UseOpenIDAuthentication("https://www.google.com/accounts/o8/id", "Google");

            var field = app.GetType().GetField("_middleware", BindingFlags.NonPublic | BindingFlags.Instance);

            var middlewareList = (IList<Tuple<Type, Delegate, object[]>>)field.GetValue(app);

            var optionList = middlewareList
                .SelectMany(x => x.Item3)
                .ToList();

            var openIdOptions = optionList
                .OfType<OpenIDAuthenticationOptions>()
                .FirstOrDefault();

            if (openIdOptions != null)
            {
                var uri = openIdOptions.ProviderDiscoveryUri;
                Console.WriteLine(uri);
            }

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Using multiple OpenIDAuthenticationMiddleware instances is probably the better approach, but I want to explore the other possibility of getting an instance of the class, too.

This approach provided a simple but dynamic solution to the problem.

1. Create table that contains details required when calling UseOpenIDAuthentication().
2. Add method that retrieved table content.
3. Iterate over list and call UseOpenIDAuthentication(key, value);

Bob's answer could possibly work, however I didn't get a chance to test it.