appauth: support SFSafariController

flutter_appauth/example/lib/main.dart

@@ -1,9 +1,11 @@
 import 'dart:convert';
 import 'dart:io' show Platform;
 import 'dart:math';
+
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_appauth/flutter_appauth.dart';
+import 'package:flutter_appauth_platform_interface/flutter_appauth_platform_interface.dart';
 import 'package:http/http.dart' as http;
 
 void main() => runApp(const MyApp());
@@ -106,8 +108,7 @@ class _MyAppState extends State<MyApp> {
                         'session',
                         textAlign: TextAlign.center,
                       ),
-                      onPressed: () => _signInWithAutoCodeExchange(
-                          preferEphemeralSession: true),
+                      onPressed: () => _signInWithAutoCodeExchange(),
                     ),
                   ),
                 ElevatedButton(
@@ -284,8 +285,7 @@ class _MyAppState extends State<MyApp> {
     }
   }
 
-  Future<void> _signInWithAutoCodeExchange(
-      {bool preferEphemeralSession = false}) async {
+  Future<void> _signInWithAutoCodeExchange() async {
     try {
       _setBusyState();
 
@@ -295,13 +295,11 @@ class _MyAppState extends State<MyApp> {
       */
       final AuthorizationTokenResponse result =
           await _appAuth.authorizeAndExchangeCode(
-        AuthorizationTokenRequest(
-          _clientId,
-          _redirectUrl,
-          serviceConfiguration: _serviceConfiguration,
-          scopes: _scopes,
-          preferEphemeralSession: preferEphemeralSession,
-        ),
+        AuthorizationTokenRequest(_clientId, _redirectUrl,
+            serviceConfiguration: _serviceConfiguration,
+            scopes: _scopes,
+            preferredExternalAgent:
+                ExternalAgentType.ASWebAuthenticationSession),
       );
 
       /* 

flutter_appauth/ios/Classes/AppAuthIOSAuthorization.h

@@ -1,6 +1,7 @@
 #import <AppAuth/AppAuth.h>
 #import <Flutter/Flutter.h>
 #import "OIDExternalUserAgentIOSNoSSO.h"
+#import "OIDExternalUserAgentIOSSafariViewController.h"
 #import "FlutterAppAuth.h"
 
 NS_ASSUME_NONNULL_BEGIN

flutter_appauth/ios/Classes/AppAuthIOSAuthorization.m

@@ -2,7 +2,7 @@
 
 @implementation AppAuthIOSAuthorization
 
-- (id<OIDExternalUserAgentSession>) performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferEphemeralSession:(BOOL)preferEphemeralSession result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce{
+- (id<OIDExternalUserAgentSession>) performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferredExternalAgent:(NSString*)preferredExternalAgent result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce{
   NSString *codeVerifier = [OIDAuthorizationRequest generateCodeVerifier];
   NSString *codeChallenge = [OIDAuthorizationRequest codeChallengeS256ForVerifier:codeVerifier];
 
@@ -21,7 +21,7 @@ @implementation AppAuthIOSAuthorization
                                     additionalParameters:additionalParameters];
   UIViewController *rootViewController = [self rootViewController];
   if(exchangeCode) {
-      id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController useEphemeralSession:preferEphemeralSession];
+      id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController preferredExternalAgent:preferredExternalAgent];
       return [OIDAuthState authStateByPresentingAuthorizationRequest:request externalUserAgent:externalUserAgent callback:^(OIDAuthState *_Nullable authState,
                                                                                                                                                   NSError *_Nullable error) {
           if(authState) {
@@ -32,7 +32,7 @@ @implementation AppAuthIOSAuthorization
           }
       }];
   } else {
-      id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController useEphemeralSession:preferEphemeralSession];
+      id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController preferredExternalAgent:preferredExternalAgent];
       return [OIDAuthorizationService presentAuthorizationRequest:request externalUserAgent:externalUserAgent callback:^(OIDAuthorizationResponse *_Nullable authorizationResponse, NSError *_Nullable error) {
           if(authorizationResponse) {
               NSMutableDictionary *processedResponse = [[NSMutableDictionary alloc] init];
@@ -56,7 +56,7 @@ @implementation AppAuthIOSAuthorization
                                                                                                                                                                                                                                                additionalParameters:requestParameters.additionalParameters];
 
   UIViewController *rootViewController = [self rootViewController];
-  id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController useEphemeralSession:requestParameters.preferEphemeralSession];
+  id<OIDExternalUserAgent> externalUserAgent = [self userAgentWithViewController:rootViewController preferredExternalAgent:requestParameters.preferredExternalAgent];
 
 
   return [OIDAuthorizationService presentEndSessionRequest:endSessionRequest externalUserAgent:externalUserAgent callback:^(OIDEndSessionResponse * _Nullable endSessionResponse, NSError * _Nullable error) {
@@ -71,13 +71,17 @@ @implementation AppAuthIOSAuthorization
   }];
 }
 
-- (id<OIDExternalUserAgent>)userAgentWithViewController:(UIViewController *)rootViewController useEphemeralSession:(BOOL)useEphemeralSession {
-    if (useEphemeralSession) {
+- (id<OIDExternalUserAgent>)userAgentWithViewController:(UIViewController *)rootViewController preferredExternalAgent:(NSString*)preferredExternalAgent {
+    if ([preferredExternalAgent isEqual:@"ExternalAgentType.EphemeralSession"]) {
         return [[OIDExternalUserAgentIOSNoSSO alloc]
                 initWithPresentingViewController:rootViewController];
+    } else if ([preferredExternalAgent isEqual:@"ExternalAgentType.SFSafariViewController"]) {
+        return [[OIDExternalUserAgentIOSSafariViewController alloc]
+                initWithPresentingViewController:rootViewController];
+    } else {
+        return [[OIDExternalUserAgentIOS alloc]
+                initWithPresentingViewController:rootViewController];
     }
-    return [[OIDExternalUserAgentIOS alloc]
-            initWithPresentingViewController:rootViewController];
 }
 
 - (UIViewController *)rootViewController {

flutter_appauth/ios/Classes/FlutterAppAuth.h

@@ -39,12 +39,12 @@ static NSString *const END_SESSION_ERROR_MESSAGE_FORMAT = @"Failed to end sessio
 @property(nonatomic, strong) NSString *discoveryUrl;
 @property(nonatomic, strong) NSDictionary *serviceConfigurationParameters;
 @property(nonatomic, strong) NSDictionary *additionalParameters;
-@property(nonatomic, readwrite) BOOL preferEphemeralSession;
+@property(nonatomic, strong) NSString *preferredExternalAgent;
 @end
 
 @interface AppAuthAuthorization : NSObject
 
-- (id<OIDExternalUserAgentSession>)performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferEphemeralSession:(BOOL)preferEphemeralSession result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce;
+- (id<OIDExternalUserAgentSession>)performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferredExternalAgent:(NSString*)preferredExternalAgent result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce;
 
 - (id<OIDExternalUserAgentSession>)performEndSessionRequest:(OIDServiceConfiguration *)serviceConfiguration requestParameters:(EndSessionRequestParameters *)requestParameters result:(FlutterResult)result;
 

flutter_appauth/ios/Classes/FlutterAppAuth.m

@@ -96,7 +96,7 @@ + (NSString *) formatMessageWithError:(NSString *)messageFormat error:(NSError *
 
 @implementation AppAuthAuthorization
 
-- (id<OIDExternalUserAgentSession>)performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferEphemeralSession:(BOOL)preferEphemeralSession result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce {
+- (id<OIDExternalUserAgentSession>)performAuthorization:(OIDServiceConfiguration *)serviceConfiguration clientId:(NSString*)clientId clientSecret:(NSString*)clientSecret scopes:(NSArray *)scopes redirectUrl:(NSString*)redirectUrl additionalParameters:(NSDictionary *)additionalParameters preferredExternalAgent:(NSString*)preferredExternalAgent result:(FlutterResult)result exchangeCode:(BOOL)exchangeCode nonce:(NSString*)nonce {
     return nil;
 }
 

flutter_appauth/ios/Classes/FlutterAppauthPlugin.m

@@ -28,7 +28,7 @@ @interface TokenRequestParameters : NSObject
 @property(nonatomic, strong) NSArray *scopes;
 @property(nonatomic, strong) NSDictionary *serviceConfigurationParameters;
 @property(nonatomic, strong) NSDictionary *additionalParameters;
-@property(nonatomic, readwrite) BOOL preferEphemeralSession;
+@property(nonatomic, strong) NSString *preferredExternalAgent;
 
 @end
 
@@ -47,7 +47,7 @@ - (void)processArguments:(NSDictionary *)arguments {
     _scopes = [ArgumentProcessor processArgumentValue:arguments withKey:@"scopes"];
     _serviceConfigurationParameters = [ArgumentProcessor processArgumentValue:arguments withKey:@"serviceConfiguration"];
     _additionalParameters = [ArgumentProcessor processArgumentValue:arguments withKey:@"additionalParameters"];
-    _preferEphemeralSession = [[ArgumentProcessor processArgumentValue:arguments withKey:@"preferEphemeralSession"] isEqual:@YES];
+    _preferredExternalAgent = [ArgumentProcessor processArgumentValue:arguments withKey:@"preferredExternalAgent"];
 }
 
 - (id)initWithArguments:(NSDictionary *)arguments {
@@ -82,7 +82,7 @@ - (id)initWithArguments:(NSDictionary *)arguments {
     _discoveryUrl = [ArgumentProcessor processArgumentValue:arguments withKey:@"discoveryUrl"];
     _serviceConfigurationParameters = [ArgumentProcessor processArgumentValue:arguments withKey:@"serviceConfiguration"];
     _additionalParameters = [ArgumentProcessor processArgumentValue:arguments withKey:@"additionalParameters"];
-    _preferEphemeralSession = [[ArgumentProcessor processArgumentValue:arguments withKey:@"preferEphemeralSession"] isEqual:@YES];
+    _preferredExternalAgent = [ArgumentProcessor processArgumentValue:arguments withKey:@"preferredExternalAgent"];
     return self;
 }
 @end
@@ -149,7 +149,7 @@ -(void)handleAuthorizeMethodCall:(NSDictionary*)arguments result:(FlutterResult)
 
     if(requestParameters.serviceConfigurationParameters != nil) {
         OIDServiceConfiguration *serviceConfiguration = [self processServiceConfigurationParameters:requestParameters.serviceConfigurationParameters];
-        _currentAuthorizationFlow = [authorization performAuthorization:serviceConfiguration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferEphemeralSession:requestParameters.preferEphemeralSession result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
+        _currentAuthorizationFlow = [authorization performAuthorization:serviceConfiguration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferredExternalAgent:requestParameters.preferredExternalAgent result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
     } else if (requestParameters.discoveryUrl) {
         NSURL *discoveryUrl = [NSURL URLWithString:requestParameters.discoveryUrl];
         [OIDAuthorizationService discoverServiceConfigurationForDiscoveryURL:discoveryUrl
@@ -161,7 +161,7 @@ -(void)handleAuthorizeMethodCall:(NSDictionary*)arguments result:(FlutterResult)
                 return;
             }
 
-            self->_currentAuthorizationFlow = [authorization performAuthorization:configuration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferEphemeralSession:requestParameters.preferEphemeralSession result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
+            self->_currentAuthorizationFlow = [authorization performAuthorization:configuration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferredExternalAgent:requestParameters.preferredExternalAgent result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
         }];
     } else {
         NSURL *issuerUrl = [NSURL URLWithString:requestParameters.issuer];
@@ -174,7 +174,7 @@ -(void)handleAuthorizeMethodCall:(NSDictionary*)arguments result:(FlutterResult)
                 return;
             }
 
-            self->_currentAuthorizationFlow = [authorization performAuthorization:configuration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferEphemeralSession:requestParameters.preferEphemeralSession result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
+            self->_currentAuthorizationFlow = [authorization performAuthorization:configuration clientId:requestParameters.clientId clientSecret:requestParameters.clientSecret scopes:requestParameters.scopes redirectUrl:requestParameters.redirectUrl additionalParameters:requestParameters.additionalParameters preferredExternalAgent:requestParameters.preferredExternalAgent result:result exchangeCode:exchangeCode nonce:requestParameters.nonce];
         }];
     }
 }

flutter_appauth/ios/Classes/OIDExternalUserAgentIOSSafariViewController.h

@@ -0,0 +1,68 @@
+/*! @file OIDExternalUserAgentIOSSafariViewController.h
+    @brief AppAuth iOS SDK
+    @copyright
+        Copyright 2018 Google Inc. All Rights Reserved.
+    @copydetails
+        Licensed under the Apache License, Version 2.0 (the "License");
+        you may not use this file except in compliance with the License.
+        You may obtain a copy of the License at
+        http://www.apache.org/licenses/LICENSE-2.0
+        Unless required by applicable law or agreed to in writing, software
+        distributed under the License is distributed on an "AS IS" BASIS,
+        WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+        See the License for the specific language governing permissions and
+        limitations under the License.
+ */
+
+#import <UIKit/UIKit.h>
+
+#import "OIDExternalUserAgentIOSSafariViewController.h"
+#import "OIDExternalUserAgent.h"
+#import "OIDExternalUserAgentIOS.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/*! @brief Allows library consumers to bootstrap an @c SFSafariViewController as they see fit.
+    @remarks Useful for customizing tint colors and presentation styles.
+ */
+@protocol OIDSafariViewControllerFactory
+
+/*! @brief Creates and returns a new @c SFSafariViewController.
+    @param URL The URL which the @c SFSafariViewController should load initially.
+ */
+- (SFSafariViewController *)safariViewControllerWithURL:(NSURL *)URL;
+
+@end
+
+/*! @brief A special-case iOS external user-agent that always uses
+        \SFSafariViewController (on iOS 9+). Most applications should use
+        the more generic @c OIDExternalUserAgentIOS to get the default
+        AppAuth user-agent handling with the benefits of Single Sign-on (SSO)
+        for all supported versions of iOS.
+ */
+@interface OIDExternalUserAgentIOSSafariViewController : NSObject<OIDExternalUserAgent>
+
+/*! @brief Allows library consumers to change the @c OIDSafariViewControllerFactory used to create
+        new instances of @c SFSafariViewController.
+    @remarks Useful for customizing tint colors and presentation styles.
+    @param factory The @c OIDSafariViewControllerFactory to use for creating new instances of
+        @c SFSafariViewController.
+ */
++ (void)setSafariViewControllerFactory:(id<OIDSafariViewControllerFactory>)factory;
+
+/*! @internal
+    @brief Unavailable. Please use @c initWithPresentingViewController:
+ */
+- (nonnull instancetype)init NS_UNAVAILABLE;
+
+/*! @brief The designated initializer.
+    @param presentingViewController The view controller from which to present the
+        \SFSafariViewController.
+ */
+- (nullable instancetype)initWithPresentingViewController:
+    (UIViewController *)presentingViewController
+            NS_DESIGNATED_INITIALIZER;
+
+@end
+
+NS_ASSUME_NONNULL_END