Auth Facebook does not work on Android

[petrdrabek]

Hi!
On Auth Facebook Android is not set muttability flag for pending intent. Handling activity result then ends up in exception.

Java.Lang.IllegalArgumentException: 'app.name: Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.

[TobiasBuchholz]

Hi,

for sign in with Facebook Plugin.Firebase.Auth.Facebook just calls the methods of FirebaseAuth:

Plugin.Firebase/src/Auth.Facebook/Platforms/Android/FirebaseAuthFacebookImplementation.cs

Line 30 in 34f6f5b

public async Task<IFirebaseUser> SignInWithFacebookAsync()

That means creating the PendingIntent happens inside the Xamarin.Facebook.Android sdk and there is no way for Plugin.Firebase to set FLAG_IMMUTABLE or FLAG_MUTABLE. Furhtermore the sdk was last updated at 19.10.2021...you could create an issue on their repo and cross fingers someone responses.

[petrdrabek]

@TobiasBuchholz It looks like, they dont have intention to fix it soon (xamarin/FacebookComponents#237 (comment)). Can we use fixed library for login like https://www.nuget.org/packages/Anjo.Android.Facebook/ in this plugin?

It would help a lot. Thanks.

[petrdrabek]

Any update on this? Or has someone workaround? This is still major issue for us.

[petrdrabek]

@TobiasBuchholz I'd like to revive this issue. Is this still a problem—does anyone here have a working Facebook login on Android? If so, I and other developers need a solution for this.

If not, and Facebook login simply doesn't work on Android, could I submit a PR to replace the current Facebook login NuGet package with one that works?

[AdamEssenmacher]

I would hesitate to switch over to the Anjo.* Facebook bindings because:

1. They don't seem to be open source.
2. We don't know how committed the maintainer is to keeping them updated.

That aside, you do not need direct support from this plugin to connect Facebook Auth with Firebase Login in your app.

Android Example:

var credential = Firebase.Auth.GetCredential(accessToken);
var authResult = await Firebase.Auth.FirebaseAuth.Instance.SignInWithCredentialAsync(credential);

[Salim-Farran]

Hello everyone, I'm still facing the same issue. Anyone found a solution to this problem?

[petrdrabek]

@Salim-Farran You can write your own facebook auth implementation for Android, there os no other way to make it works, at least that I know. There is my own implementation that works:

using Android.Content;
using Firebase.Auth;
using Microsoft.Maui.ApplicationModel;
using Plugin.Firebase.Core;
using Plugin.Firebase.Auth.Platforms.Android.Extensions;
using Plugin.Firebase.Core.Exceptions;
using Activity = Android.App.Activity;
using CrossFirebaseAuthException = Plugin.Firebase.Core.Exceptions.FirebaseAuthException;
using Apinote.Services.Auth;
using Android.App;
using Plugin.Firebase.Auth;

namespace your.namespace;

public sealed class FirebaseAuthFacebookImplementation : DisposableBase, IFirebaseAuthFacebook
{
    public static Task HandleActivityResultAsync(int requestCode, Result resultCode, Intent data)
    {
        _facebookAuth.Value.HandleActivityResult(requestCode, resultCode, data);
        return Task.CompletedTask;
    }

    private readonly FirebaseAuth _firebaseAuth;
    private static Lazy<FacebookAuth> _facebookAuth;

    public FirebaseAuthFacebookImplementation()
    {
        _firebaseAuth = FirebaseAuth.Instance;
        _facebookAuth = new Lazy<FacebookAuth>(() => new FacebookAuth());
    }

    public async Task<IFirebaseUser> SignInWithFacebookAsync()
    {
        try
        {
            var credential = await _facebookAuth.Value.GetCredentialAsync(Activity);
            return await SignInWithCredentialAsync(credential);
        }
        catch (Exception e)
        {
            throw GetFirebaseAuthException(e);
        }
    }

    private async Task<IFirebaseUser> SignInWithCredentialAsync(AuthCredential credential)
    {
        var authResult = await _firebaseAuth.SignInWithCredentialAsync(credential);
        return authResult.User.ToAbstract(authResult.AdditionalUserInfo);
    }

    private static CrossFirebaseAuthException GetFirebaseAuthException(Exception ex)
    {
        return ex switch
        {
            FirebaseAuthEmailException => new CrossFirebaseAuthException(FIRAuthError.InvalidEmail, ex.Message),
            FirebaseAuthInvalidUserException => new CrossFirebaseAuthException(FIRAuthError.UserNotFound, ex.Message),
            FirebaseAuthWeakPasswordException => new CrossFirebaseAuthException(FIRAuthError.WeakPassword, ex.Message),
            FirebaseAuthInvalidCredentialsException { ErrorCode: "ERROR_WRONG_PASSWORD" } => new CrossFirebaseAuthException(FIRAuthError.WrongPassword, ex.Message),
            FirebaseAuthInvalidCredentialsException => new CrossFirebaseAuthException(FIRAuthError.InvalidCredential, ex.Message),
            FirebaseAuthUserCollisionException { ErrorCode: "ERROR_EMAIL_ALREADY_IN_USE" } => new CrossFirebaseAuthException(FIRAuthError.EmailAlreadyInUse, ex.Message),
            FirebaseAuthUserCollisionException { ErrorCode: "ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL" } => new CrossFirebaseAuthException(FIRAuthError.AccountExistsWithDifferentCredential, ex.Message),
            _ => new CrossFirebaseAuthException(FIRAuthError.Undefined, ex.Message)
        };
    }

    public async Task<IFirebaseUser> LinkWithFacebookAsync()
    {
        try
        {
            var credential = await _facebookAuth.Value.GetCredentialAsync(Activity);
            return await LinkWithCredentialAsync(credential);
        }
        catch (Exception e)
        {
            _facebookAuth.Value.SignOut();
            throw GetFirebaseAuthException(e);
        }
    }

    private async Task<IFirebaseUser> LinkWithCredentialAsync(AuthCredential credential)
    {
        var authResult = await _firebaseAuth.CurrentUser.LinkWithCredentialAsync(credential);
        return authResult.User.ToAbstract(authResult.AdditionalUserInfo);
    }

    public Task SignOutAsync()
    {
        return Task.CompletedTask;
    }

    private static Activity Activity =>
        Platform.CurrentActivity ?? throw new NullReferenceException("Platform.CurrentActivity is null");
}


using Android.Runtime;
using Com.Facebook;

namespace your.namespace
{
    public sealed class FacebookCallback<TResult> : Java.Lang.Object, IFacebookCallback where TResult : Java.Lang.Object
    {
        private readonly Action _onCancel;
        private readonly Action<FacebookException> _onError;
        private readonly Action<TResult> _onSuccess;

        public FacebookCallback(
            Action onCancel = null,
            Action<FacebookException> onError = null,
            Action<TResult> onSuccess = null)
        {
            _onCancel = onCancel;
            _onError = onError;
            _onSuccess = onSuccess;
        }

        public void OnCancel()
        {
            _onCancel?.Invoke();
        }

        public void OnError(FacebookException error)
        {
            _onError?.Invoke(error);
        }

        public void OnSuccess(Java.Lang.Object result)
        {
            _onSuccess?.Invoke(result.JavaCast<TResult>());
        }
    }
}


using Firebase.Auth;
using Android.App;
using Android.Content;
using Com.Facebook;
using Com.Facebook.Login;
using Com.Facebook.Core;
using Com.Facebook.Share;
using Com.Facebook.Devicerequests;
using Com.Facebook.Internal;

namespace your.namespace

public sealed class FacebookAuth
{
    private readonly ICallbackManager _callbackManager;

    public FacebookAuth()
    {
        FacebookSdk.FullyInitialize();
        
        _callbackManager = new CallbackManagerImpl();

    }

    public Task<AuthCredential> GetCredentialAsync(Activity activity)
    {
        FacebookSdk.SdkInitialize(activity.ApplicationContext);
        var tcs = new TaskCompletionSource<AuthCredential>();
        var callback = new FacebookCallback<LoginResult>(
            onSuccess: x => tcs.SetResult(FacebookAuthProvider.GetCredential(x.AccessToken.Token)),
            onCancel: tcs.SetCanceled,
            onError: tcs.SetException);

        LoginManager.Instance.RegisterCallback(_callbackManager, callback);
        LoginManager.Instance.LogInWithReadPermissions(activity, new List<string> { "public_profile", "email" });
        return tcs.Task;
    }

    public void HandleActivityResult(int requestCode, Result resultCode, Intent data)
    {
        _callbackManager.OnActivityResult(requestCode, (int)resultCode, data);
    }

    public void SignOut()
    {
        LoginManager.Instance.LogOut();
    }
}

With help of nuget Anjo.Android.Facebook.Login

[Salim-Farran]

@petrdrabek Thank you so much. This is working perfectly also for me 😍. Just had to add the facebook client token in the AndroidManifest.xml and everything worked fine.

[AdamEssenmacher]

We're removing all provider-specific auth implementations from this plugin. Developers should access the native Firebase SDKs directly on a per-platform bases to implement the providers they need.