Why New Fb API 2.4 Returns Null Email on MVC 5 with Identity and Oauth 2

Access email address in the OAuth ExternalLoginCallback from Facebook v2.4 API in ASP.NET MVC 5

To resolve this I had to install the Facebook SDK for .NET from nuget and query the email address separately.

In the ExternalLoginCallback method, I added a conditional to populate the email address from the Facebook Graph API;

var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();

if (loginInfo == null)
{
    return RedirectToAction("Login");
}

// added the following lines
if (loginInfo.Login.LoginProvider == "Facebook")
{
    var identity = AuthenticationManager.GetExternalIdentity(DefaultAuthenticationTypes.ExternalCookie);
    var access_token = identity.FindFirstValue("FacebookAccessToken");
    var fb = new FacebookClient(access_token);
    dynamic myInfo = fb.Get("/me?fields=email"); // specify the email field
    loginInfo.Email = myInfo.email;
}

And to get the FacebookAccessToken I extended ConfigureAuth;

app.UseFacebookAuthentication(new FacebookAuthenticationOptions
{
    AppId = "XXX",
    AppSecret = "XXX",
    Scope = { "email" },
    Provider = new FacebookAuthenticationProvider
    {
        OnAuthenticated = context =>
        {
            context.Identity.AddClaim(new System.Security.Claims.Claim("FacebookAccessToken", context.AccessToken));
            return Task.FromResult(true);
        }
    }
});

facebook api version 2.4 not returning email from owin facebookauthentication options?

I would imagine that the Owin Facebook authentication needs an update. The current version was updated in Feb 2015, prior to v2.4 of the Graph API.

With v2.3 and below calling https://graph.facebook.com/v2.3/me would have returned email, name, id, gender etc. In v2.4 this will just return name and in v2.4 this will just return name and id.

https://graph.facebook.com/v2.4/me

{
"name": "Name Returned",
"id": "1343143144321"
}

Therefore If you require the email address you will need to implement your own fix in your code.

In your server side implementation request the email address to be specifically returned
https://graph.facebook.com/v2.4/me?fields=email&access_token=

Retrieving users Facebook email on OWIN login

Turns out there has been a breaking change in Facebook API v 2.4 where you have to specify fields you want to retrieve. The graph request used to be:

https://graph.facebook.com/v2.3/me?access_token=XXXXX

but for performance reasons as of FB API v2.4 you also have to specify fileds you want to retrieve within the scope:

https://graph.facebook.com/v2.4/me?fields=id,name,email&access_token=XXXXX

Microsoft FB client implementation by default attaches access_token to the query string as "?access_token" which leads to the broken request (extra question mark ):

https://graph.facebook.com/v2.4/me?fields=id,name,email?access_token=XXXXX

So, to remedy that we need to use a custom BackchannelHttpHandler. First, we create the endpoint class:

    public class FacebookBackChannelHandler : HttpClientHandler
    {
        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            if (!request.RequestUri.AbsolutePath.Contains("/oauth"))
            {
                request.RequestUri = new Uri(request.RequestUri.AbsoluteUri.Replace("?access_token", "&access_token"));
            }

            return await base.SendAsync(request, cancellationToken);
        }
    }

And then we provide it in facebook auth options along with explicitly specifying UserInformationEndpoint:

var facebookAuthOptions = new FacebookAuthenticationOptions
        {
            AppId = ConfigurationManager.AppSettings["FacebookAppId"],
            AppSecret = ConfigurationManager.AppSettings["FacebookAppSecret"],
            BackchannelHttpHandler = new FacebookBackChannelHandler(),
            UserInformationEndpoint = "https://graph.facebook.com/v2.4/me?fields=id,name,email",
            Scope = { "email" }
            <.....>
        };

From: https://stackoverflow.com/a/32636149/3130094

Version Deprecation Facebook Graph API v2.2

I had the same problem and here is how I managed to fix it and get the email from Facebook.

• Update following NuGet Pacakges
  
  
  • Microsoft.Owin to version 3.1.0-rc1
  • Microsoft.Owin.Security to version 3.1.0-rc1
  • Microsoft.Owin.Security.Cookies to version 3.1.0-rc1
  • Microsoft.Owin.Security.OAuth to version 3.1.0-rc1
  • Microsoft.Owin.Security.Facebook to version 3.1.0-rc1

Then add the following code to the Identity Startup class

var facebookOptions = new FacebookAuthenticationOptions()
        {
            AppId = "your app id",
            AppSecret = "your app secret",
            BackchannelHttpHandler = new FacebookBackChannelHandler(),
            UserInformationEndpoint = "https://graph.facebook.com/v2.8/me?fields=id,name,email,first_name,last_name",
            Scope = { "email" }
        };

        app.UseFacebookAuthentication(facebookOptions);

This is the definition class for FacebookBackChannelHandler():

using System;
using System.Net.Http;

public class FacebookBackChannelHandler : HttpClientHandler
{
    protected override async System.Threading.Tasks.Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request,
        System.Threading.CancellationToken cancellationToken)
    {
        // Replace the RequestUri so it's not malformed
        if (!request.RequestUri.AbsolutePath.Contains("/oauth"))
        {
            request.RequestUri = new Uri(request.RequestUri.AbsoluteUri.Replace("?access_token", "&access_token"));
        }

        return await base.SendAsync(request, cancellationToken);
    }
}

ASP.NET MVC5 OWIN Facebook authentication suddenly not working

Ok I've got a solution to the problem.

This is the code I had previously in my Startup.Auth.cs file:

var x = new FacebookAuthenticationOptions();
            //x.Scope.Add("email");
            x.AppId = "1442725269277224";
            x.AppSecret = "<secret>";
            x.Provider = new FacebookAuthenticationProvider()
            {
                OnAuthenticated = async context =>
                {
                        //Get the access token from FB and store it in the database and
                    //use FacebookC# SDK to get more information about the user
                    context.Identity.AddClaim(new System.Security.Claims.Claim("FacebookAccessToken",context.AccessToken));
                    context.Identity.AddClaim(new System.Security.Claims.Claim("urn:facebook:name", context.Name));
                    context.Identity.AddClaim(new System.Security.Claims.Claim("urn:facebook:email", context.Email));
                }
            };
            x.SignInAsAuthenticationType = DefaultAuthenticationTypes.ExternalCookie;
            app.UseFacebookAuthentication(x);

Notice how the

x.Scope.Add("email")

line has been commented out, but still I'm query-ing for the e-mail later in the OnAuthenticated handler? Yup, that's right. For some reason this worked flawlessly for a few weeks.

My solution was to simply uncomment the x.Scope.Add("email"); line to make sure that the scope=email variable was present in the initial request to Facebook.

Now everything works like it did!

I cannot understand why this worked before like it was. The only explanation I can come up with is that Facebook changed something on their end.

Getting the email from external providers Google and Facebook during account association step in a default MVC5 app

PLEASE SEE UPDATES AT THE BOTTOM OF THIS POST!

The following works for me for Facebook:

StartupAuth.cs:

var facebookAuthenticationOptions = new FacebookAuthenticationOptions()
{
    AppId = "x",
    AppSecret = "y"
};
facebookAuthenticationOptions.Scope.Add("email");
app.UseFacebookAuthentication(facebookAuthenticationOptions);

ExternalLoginCallback method:

var externalIdentity = HttpContext.GetOwinContext().Authentication.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);
var emailClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Email);
var email = emailClaim.Value;

And for Google:

StartupAuth.cs

app.UseGoogleAuthentication();

ExternalLoginCallback method (same as for facebook):

var externalIdentity = HttpContext.GetOwinContext().Authentication.GetExternalIdentityAsync(DefaultAuthenticationTypes.ExternalCookie);
var emailClaim = externalIdentity.Result.Claims.FirstOrDefault(c => c.Type == ClaimTypes.Email);
var email = emailClaim.Value;

If I set a breakpoint here:

var email = emailClaim.Value;

I see the email address for both Facebook and Google in the debugger.

Update 1: The old answer had me confused so I updated it with the code I have in my own project that I just debugged and I know works.

Update 2: With the new ASP.NET Identity 2.0 RTM version you no longer need any of the code in this post. The proper way to get the email is by simply doing the following:

1. Startup.Auth.cs

       app.UseFacebookAuthentication(
          appId: "x",
          appSecret: "y");
   
       app.UseGoogleAuthentication();
   

2. AccountController.cs

   //
   // GET: /Account/ExternalLoginCallback
   [AllowAnonymous]
   public async Task<ActionResult> ExternalLoginCallback(string returnUrl)
   {
       var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();
       if (loginInfo == null)
       {
           return RedirectToAction("Login");
       }
   
       // Sign in the user with this external login provider if the user already has a login
       var result = await SignInHelper.ExternalSignIn(loginInfo, isPersistent: false);
       switch (result)
       {
           case SignInStatus.Success:
               return RedirectToLocal(returnUrl);
           case SignInStatus.LockedOut:
               return View("Lockout");
           case SignInStatus.RequiresTwoFactorAuthentication:
               return RedirectToAction("SendCode", new { ReturnUrl = returnUrl });
           case SignInStatus.Failure:
           default:
               // If the user does not have an account, then prompt the user to create an account
               ViewBag.ReturnUrl = returnUrl;
               ViewBag.LoginProvider = loginInfo.Login.LoginProvider;
               return View("ExternalLoginConfirmation", new ExternalLoginConfirmationViewModel { Email = loginInfo.Email });
       }
   }
   

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