feat: Add Facebook access token authentication

auth0_flutter/android/src/main/kotlin/com/auth0/auth0_flutter/Auth0FlutterPlugin.kt

@@ -58,6 +58,7 @@ class Auth0FlutterPlugin: FlutterPlugin, MethodCallHandler, ActivityAware {
       listOf(
         LoginApiRequestHandler(),
         LoginWithOtpApiRequestHandler(),
+        LoginWithFacebookApiRequestHandler(),
         MultifactorChallengeApiRequestHandler(),
         EmailPasswordlessApiRequestHandler(),
         PhoneNumberPasswordlessApiRequestHandler(),

auth0_flutter/android/src/main/kotlin/com/auth0/auth0_flutter/request_handlers/api/LoginWithFacebookApiRequestHandler.kt

@@ -0,0 +1,52 @@
+package com.auth0.auth0_flutter.request_handlers.api
+
+import com.auth0.android.authentication.AuthenticationAPIClient
+import com.auth0.android.authentication.AuthenticationException
+import com.auth0.android.callback.Callback
+import com.auth0.android.result.Credentials
+import com.auth0.auth0_flutter.toMap
+import com.auth0.auth0_flutter.request_handlers.MethodCallRequest
+import com.auth0.auth0_flutter.utils.assertHasProperties
+import io.flutter.plugin.common.MethodChannel
+
+private const val AUTH_LOGIN_WITH_FACEBOOK_METHOD = "auth#loginWithFacebook"
+
+class LoginWithFacebookApiRequestHandler : ApiRequestHandler {
+    override val method: String = AUTH_LOGIN_WITH_FACEBOOK_METHOD
+
+    override fun handle(api: AuthenticationAPIClient, request: MethodCallRequest, result: MethodChannel.Result) {
+        assertHasProperties(listOf("accessToken"), request.data)
+
+        val accessToken = request.data["accessToken"] as String
+        val profile = request.data["profile"] as? Map<String, Any>
+        val builder = if (profile != null) {
+            api.loginWithNativeSocialToken(accessToken, "facebook", profile)
+        } else {
+            api.loginWithNativeSocialToken(accessToken, "facebook")
+        }
+
+        // Add optional parameters
+        (request.data["scopes"] as? List<*>)?.let { scopes ->
+            builder.setScope((scopes as List<String>).joinToString(" "))
+        }
+        (request.data["audience"] as? String)?.let { builder.setAudience(it) }
+
+        if (request.data["parameters"] is HashMap<*, *>) {
+            builder.addParameters(request.data["parameters"] as Map<String, String>)
+        }
+
+        builder.start(object : Callback<Credentials, AuthenticationException> {
+            override fun onFailure(exception: AuthenticationException) {
+                result.error(
+                    exception.getCode(),
+                    exception.getDescription(),
+                    exception.toMap()
+                )
+            }
+
+            override fun onSuccess(credentials: Credentials) {
+                result.success(credentials.toMap())
+            }
+        })
+    }
+}

auth0_flutter/darwin/Classes/AuthAPI/AuthAPIHandler.swift

@@ -17,6 +17,7 @@ public class AuthAPIHandler: NSObject, FlutterPlugin {
     enum Method: String, CaseIterable {
         case loginWithUsernameOrEmail = "auth#login"
         case loginWithOTP = "auth#loginOtp"
+        case loginWithFacebook = "auth#loginWithFacebook"
         case multifactorChallenge = "auth#multifactorChallenge"
         case signup = "auth#signUp"
         case userInfo = "auth#userInfo"
@@ -60,6 +61,7 @@ public class AuthAPIHandler: NSObject, FlutterPlugin {
         switch method {
         case .loginWithUsernameOrEmail: return AuthAPILoginUsernameOrEmailMethodHandler(client: client)
         case .loginWithOTP: return AuthAPILoginWithOTPMethodHandler(client: client)
+        case .loginWithFacebook: return AuthAPILoginWithFacebookMethodHandler(client: client)
         case .multifactorChallenge: return AuthAPIMultifactorChallengeMethodHandler(client: client)
         case .signup: return AuthAPISignupMethodHandler(client: client)
         case .userInfo: return AuthAPIUserInfoMethodHandler(client: client)

auth0_flutter/darwin/Classes/AuthAPI/AuthAPILoginWithFacebookMethodHandler.swift

@@ -0,0 +1,47 @@
+import Auth0
+
+#if os(iOS)
+import Flutter
+#else
+import FlutterMacOS
+#endif
+
+struct AuthAPILoginWithFacebookMethodHandler: MethodHandler {
+    enum Argument: String {
+        case accessToken
+        case scopes
+        case parameters
+        case audience
+        case profile
+    }
+
+    let client: Authentication
+
+    func handle(with arguments: [String: Any], callback: @escaping FlutterResult) {
+        guard let accessToken = arguments[Argument.accessToken] as? String else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.accessToken.rawValue)))
+        }
+        guard let scopes = arguments[Argument.scopes] as? [String] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.scopes.rawValue)))
+        }
+        guard let parameters = arguments[Argument.parameters] as? [String: Any] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.parameters.rawValue)))
+        }
+
+        let audience = arguments[Argument.audience] as? String
+        let profile = arguments[Argument.profile] as? [String: Any] ?? [:]
+
+        client
+            .login(facebookSessionAccessToken: accessToken,
+                   profile: profile,
+                   audience: audience,
+                   scope: scopes.asSpaceSeparatedString)
+            .parameters(parameters)
+            .start {
+                switch $0 {
+                case let .success(credentials): callback(result(from: credentials))
+                case let .failure(error): callback(FlutterError(from: error))
+                }
+            }
+    }
+}

auth0_flutter/example/ios/.symlinks/plugins/auth0_flutter/darwin/Classes/AuthAPI/AuthAPILoginWithFacebookMethodHandler.swift

@@ -0,0 +1,47 @@
+import Auth0
+
+#if os(iOS)
+import Flutter
+#else
+import FlutterMacOS
+#endif
+
+struct AuthAPILoginWithFacebookMethodHandler: MethodHandler {
+    enum Argument: String {
+        case accessToken
+        case scopes
+        case parameters
+        case audience
+        case profile
+    }
+
+    let client: Authentication
+
+    func handle(with arguments: [String: Any], callback: @escaping FlutterResult) {
+        guard let accessToken = arguments[Argument.accessToken] as? String else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.accessToken.rawValue)))
+        }
+        guard let scopes = arguments[Argument.scopes] as? [String] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.scopes.rawValue)))
+        }
+        guard let parameters = arguments[Argument.parameters] as? [String: Any] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.parameters.rawValue)))
+        }
+
+        let audience = arguments[Argument.audience] as? String
+        let profile = arguments[Argument.profile] as? [String: Any] ?? [:]
+
+        client
+            .login(facebookSessionAccessToken: accessToken,
+                   profile: profile,
+                   audience: audience,
+                   scope: scopes.asSpaceSeparatedString)
+            .parameters(parameters)
+            .start {
+                switch $0 {
+                case let .success(credentials): callback(result(from: credentials))
+                case let .failure(error): callback(FlutterError(from: error))
+                }
+            }
+    }
+}

auth0_flutter/ios/Classes/AuthAPI/AuthAPILoginWithFacebookMethodHandler.swift

@@ -0,0 +1,44 @@
+import Auth0
+
+#if os(iOS)
+import Flutter
+#else
+import FlutterMacOS
+#endif
+
+struct AuthAPILoginWithFacebookMethodHandler: MethodHandler {
+    enum Argument: String {
+        case accessToken
+        case scopes
+        case parameters
+        case audience
+    }
+
+    let client: Authentication
+
+    func handle(with arguments: [String: Any], callback: @escaping FlutterResult) {
+        guard let accessToken = arguments[Argument.accessToken] as? String else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.accessToken.rawValue)))
+        }
+        guard let scopes = arguments[Argument.scopes] as? [String] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.scopes.rawValue)))
+        }
+        guard let parameters = arguments[Argument.parameters] as? [String: Any] else {
+            return callback(FlutterError(from: .requiredArgumentMissing(Argument.parameters.rawValue)))
+        }
+
+        let audience = arguments[Argument.audience] as? String
+
+        client
+            .login(facebookSessionAccessToken: accessToken,
+                   audience: audience,
+                   scope: scopes.asSpaceSeparatedString)
+            .parameters(parameters)
+            .start {
+                switch $0 {
+                case let .success(credentials): callback(result(from: credentials))
+                case let .failure(error): callback(FlutterError(from: error))
+                }
+            }
+    }
+}

auth0_flutter/lib/src/mobile/authentication_api.dart

@@ -112,6 +112,67 @@ class AuthenticationApi {
         mfaToken: mfaToken,
       )));
 
+  /// Authenticates the user with a Facebook access token.
+  /// If successful, it returns a set of tokens, as well as the user's profile
+  /// (constructed from ID token claims).
+  ///
+  /// This method requires that you've already obtained a valid Facebook access
+  /// token from the Facebook SDK. The token will be exchanged for Auth0 tokens.
+  ///
+  /// ## Endpoint
+  /// https://auth0.com/docs/api/authentication#social-login-with-provider-s-access-token
+  ///
+  /// ## Notes
+  ///
+  /// * [audience] relates to the API Identifier you want to reference in your
+  /// access tokens. See [API settings](https://auth0.com/docs/get-started/apis/api-settings)
+  /// to learn more.
+  /// * [scopes] defaults to `openid profile email offline_access`. You can
+  /// override these scopes, but `openid` and `profile` are always requested 
+  /// regardless of this setting.
+  /// * [profile] contains user profile data from Facebook. This should be the
+  /// profile object obtained from the Facebook SDK.
+  /// * [parameters] can be used to send through custom parameters to the
+  /// endpoint to be picked up in a Rule or Action.
+  ///
+  /// ## Usage example
+  ///
+  /// ```dart
+  /// // First, get Facebook access token from Facebook SDK
+  /// final facebookToken = await getFacebookAccessToken();
+  /// final facebookProfile = await getFacebookProfile();
+  ///
+  /// // Then authenticate with Auth0
+  /// final result = await auth0.api.loginWithFacebook(
+  ///   accessToken: facebookToken,
+  ///   profile: facebookProfile
+  /// );
+  /// ```
+  Future<Credentials> loginWithFacebook({
+    required final String accessToken,
+    final String? audience,
+    final Set<String> scopes = const {
+      'openid',
+      'profile',
+      'email',
+      'offline_access'
+    },
+    final Map<String, String> parameters = const {},
+    final Map<String, dynamic>? profile,
+  }) {
+    // Ensure openid and profile are always included
+    final effectiveScopes = {...scopes, 'openid', 'profile'};
+
+    return Auth0FlutterAuthPlatform.instance
+        .loginWithFacebook(_createApiRequest(AuthLoginWithSocialTokenOptions(
+      accessToken: accessToken,
+      audience: audience,
+      scopes: effectiveScopes,
+      parameters: parameters,
+      profile: profile,
+    )));
+  }
+
   /// Requests a challenge for multi-factor authentication (MFA) based on the
   /// challenge types supported by the app and user.
   ///

auth0_flutter_platform_interface/lib/auth0_flutter_platform_interface.dart

@@ -4,6 +4,7 @@ export 'src/auth/auth_dpop_headers_options.dart';
 export 'src/auth/auth_login_code_options.dart';
 export 'src/auth/auth_login_options.dart';
 export 'src/auth/auth_login_with_otp_options.dart';
+export 'src/auth/auth_login_with_social_token_options.dart';
 export 'src/auth/auth_multifactor_challenge_options.dart';
 export 'src/auth/auth_passwordless_login_options.dart';
 export 'src/auth/auth_passwordless_type.dart';

auth0_flutter_platform_interface/lib/src/auth/auth_login_with_social_token_options.dart

@@ -0,0 +1,26 @@
+import '../request/request_options.dart';
+
+class AuthLoginWithSocialTokenOptions implements RequestOptions {
+  final String accessToken;
+  final String? audience;
+  final Set<String> scopes;
+  final Map<String, String> parameters;
+  final Map<String, dynamic>? profile;
+
+  AuthLoginWithSocialTokenOptions({
+    required this.accessToken,
+    this.audience,
+    this.scopes = const {},
+    this.parameters = const {},
+    this.profile,
+  });
+
+  @override
+  Map<String, dynamic> toMap() => {
+        'accessToken': accessToken,
+        'audience': audience,
+        'scopes': scopes.toList(),
+        'parameters': parameters,
+        'profile': profile
+      };
+}

auth0_flutter_platform_interface/lib/src/auth0_flutter_auth_platform.dart

@@ -4,6 +4,7 @@ import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 import 'auth/auth_login_code_options.dart';
 import 'auth/auth_login_options.dart';
 import 'auth/auth_login_with_otp_options.dart';
+import 'auth/auth_login_with_social_token_options.dart';
 import 'auth/auth_multifactor_challenge_options.dart';
 import 'auth/auth_passwordless_login_options.dart';
 import 'auth/auth_renew_access_token_options.dart';
@@ -37,6 +38,11 @@ abstract class Auth0FlutterAuthPlatform extends PlatformInterface {
     throw UnimplementedError('authLoginWithOtp() has not been implemented');
   }
 
+  Future<Credentials> loginWithFacebook(
+      final ApiRequest<AuthLoginWithSocialTokenOptions> request) {
+    throw UnimplementedError('loginWithFacebook() has not been implemented');
+  }
+
   Future<Challenge> multifactorChallenge(
       final ApiRequest<AuthMultifactorChallengeOptions> request) {
     throw UnimplementedError('multifactorChallenge() has not been implemented');

auth0_flutter_platform_interface/lib/src/method_channel_auth0_flutter_auth.dart

@@ -4,6 +4,7 @@ import 'auth/api_exception.dart';
 import 'auth/auth_login_code_options.dart';
 import 'auth/auth_login_options.dart';
 import 'auth/auth_login_with_otp_options.dart';
+import 'auth/auth_login_with_social_token_options.dart';
 import 'auth/auth_multifactor_challenge_options.dart';
 import 'auth/auth_passwordless_login_options.dart';
 import 'auth/auth_renew_access_token_options.dart';
@@ -22,6 +23,7 @@ const MethodChannel _channel = MethodChannel('auth0.com/auth0_flutter/auth');
 
 const String authLoginMethod = 'auth#login';
 const String authLoginWithOtpMethod = 'auth#loginOtp';
+const String authLoginWithFacebookMethod = 'auth#loginWithFacebook';
 const String authMultifactorChallengeMethod = 'auth#multifactorChallenge';
 const String authStartPasswordlessWithEmailMethod =
     'auth#passwordlessWithEmail';
@@ -52,6 +54,15 @@ class MethodChannelAuth0FlutterAuth extends Auth0FlutterAuthPlatform {
     return Credentials.fromMap(result);
   }
 
+  @override
+  Future<Credentials> loginWithFacebook(
+      final ApiRequest<AuthLoginWithSocialTokenOptions> request) async {
+    final Map<String, dynamic> result =
+        await invokeRequest(method: authLoginWithFacebookMethod, request: request);
+
+    return Credentials.fromMap(result);
+  }
+
   @override
   Future<Challenge> multifactorChallenge(
       final ApiRequest<AuthMultifactorChallengeOptions> request) async {