Where to set the OAuth redirect_uri in ASP.NET 4.5 webforms application

Question

I can't find anywhere how to set the OAuth2 redirect_uri in an ASP.NET 4.5 webforms application. By default it's set to localhost and of course I get this error from google:

The redirect URI in the request: http://localhost:3884/signin-google did not 
match a registered redirect URI

And this from Facebook:

Given URL is not allowed by the Application configuration.: One or more of the
given URLs is not allowed by the App's settings. It must match the Website URL
or Canvas URL, or the domain must be a subdomain of one of the App's domains.

And I get this error from my website domain (not from the localhost).

Answer 1

I was testing the built in external login logic for authentication, and I got this error even though my Google API credentials were correct. For example the redirect URI was set to:

http://localhost:29405/signin-google

The odd thing was that the default CallbackPath for the Google Authentication is "/signin-google" but I had to set this anyway in App_Start/Startup.Auth, so I added this line and it worked:

CallbackPath = new PathString("/signin-google")

so...

app.UseGoogleAuthentication(new GoogleOAuth2AuthenticationOptions()
        {
            ClientId = "YOUR CLIENT ID",
            ClientSecret = "YOUR CLIENT SECRET",
            CallbackPath = new PathString("/signin-google")
        });

Answer 2

After looking at a lot of answers this is what worked for me:

1. Enable Google + API

2. The default redirect URI is /signin-google, so add this to the Authorized redirect URI.

3. Add this to the RouteConfig File:

   routes.MapRoute(name: "signin-google", url: "signin-google", defaults: new { controller = "Account", action = "ExternalLoginCallback" });

Hope it helps anyone that cross by this problem.