Feature - Check availability of protected data on iOS and macOS

README.md

@@ -44,14 +44,14 @@ _Note_ KeyStore was introduced in Android 4.3 (API level 18). The plugin wouldn'
 ## Platform Implementation
 Please note that this table represents the functions implemented in this repository and it is possible that changes haven't yet been released on pub.dev
 
-|         | read               | write              | delete             | containsKey        | readAll            | deleteAll          |
-|---------|--------------------|--------------------|--------------------|--------------------|--------------------|--------------------|
-| Android | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| iOS     | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| Windows | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| Linux   | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| macOS   | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
-| Web     | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |
+|         | read               | write              | delete             | containsKey        | readAll            | deleteAll          | isCupertinoProtectedDataAvailable | onCupertinoProtectedDataAvailabilityChanged |
+| ------- | ------------------ | ------------------ | ------------------ | ------------------ | ------------------ | ------------------ | --------------------------------- | ------------------------------------------- |
+| Android | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |                                   |
+| iOS     | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark:                | :white_check_mark:                          |
+| Windows | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |                                   |
+| Linux   | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |                                   |
+| macOS   | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark:                | :white_check_mark: (on macOS 12 and newer)  |
+| Web     | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: | :white_check_mark: |                                   |
 
 ## Getting Started
 

flutter_secure_storage/example/lib/main.dart

@@ -17,7 +17,7 @@ class ItemsWidget extends StatefulWidget {
   ItemsWidgetState createState() => ItemsWidgetState();
 }
 
-enum _Actions { deleteAll }
+enum _Actions { deleteAll, isProtectedDataAvailable }
 
 enum _ItemActions { delete, edit, containsKey, read }
 
@@ -56,6 +56,10 @@ class ItemsWidgetState extends State<ItemsWidget> {
     _readAll();
   }
 
+  Future<void> _isProtectedDataAvailable() async {
+    await _storage.isCupertinoProtectedDataAvailable();
+  }
+
   Future<void> _addNewItem() async {
     final String key = _randomValue();
     final String value = _randomValue();
@@ -99,6 +103,9 @@ class ItemsWidgetState extends State<ItemsWidget> {
                   case _Actions.deleteAll:
                     _deleteAll();
                     break;
+                  case _Actions.isProtectedDataAvailable:
+                    _isProtectedDataAvailable();
+                    break;
                 }
               },
               itemBuilder: (BuildContext context) => <PopupMenuEntry<_Actions>>[
@@ -107,6 +114,11 @@ class ItemsWidgetState extends State<ItemsWidget> {
                   value: _Actions.deleteAll,
                   child: Text('Delete all'),
                 ),
+                const PopupMenuItem(
+                  key: Key('is_protected_data_available'),
+                  value: _Actions.isProtectedDataAvailable,
+                  child: Text('IsProtectedDataAvailable'),
+                ),
               ],
             ),
           ],

flutter_secure_storage/example/test_driver/app_test.dart

@@ -48,6 +48,10 @@ void main() {
         await pageObject.rowHasTitle('Row 0', 0);
         await pageObject.deleteRow(0);
         await pageObject.hasNoRow(0);
+
+        await Future.delayed(const Duration(seconds: 1));
+
+        await pageObject.isProtectedDataAvailable();
       },
       timeout: const Timeout(Duration(seconds: 120)),
     );
@@ -61,6 +65,8 @@ class HomePageObject {
   final _addRandomButtonFinder = find.byValueKey('add_random');
   final _deleteAllButtonFinder = find.byValueKey('delete_all');
   final _popUpMenuButtonFinder = find.byValueKey('popup_menu');
+  final _isProtectedDataAvailableButtonFinder =
+      find.byValueKey('is_protected_data_available');
 
   Future deleteAll() async {
     await driver.tap(_popUpMenuButtonFinder);
@@ -96,4 +102,9 @@ class HomePageObject {
   Future hasNoRow(int index) async {
     await driver.waitForAbsent(find.byValueKey('title_row_$index'));
   }
+
+  Future<void> isProtectedDataAvailable() async {
+    await driver.tap(_popUpMenuButtonFinder);
+    await driver.tap(_isProtectedDataAvailableButtonFinder);
+  }
 }

flutter_secure_storage/ios/Classes/SwiftFlutterSecureStoragePlugin.swift

@@ -6,15 +6,20 @@
 //
 
 import Flutter
+import UIKit
 
-public class SwiftFlutterSecureStoragePlugin: NSObject, FlutterPlugin {
+public class SwiftFlutterSecureStoragePlugin: NSObject, FlutterPlugin, FlutterStreamHandler {
 
     private let flutterSecureStorageManager: FlutterSecureStorage = FlutterSecureStorage()
-
+    private var secStoreAvailabilitySink: FlutterEventSink?
+
     public static func register(with registrar: FlutterPluginRegistrar) {
         let channel = FlutterMethodChannel(name: "plugins.it_nomads.com/flutter_secure_storage", binaryMessenger: registrar.messenger())
+        let eventChannel = FlutterEventChannel(name: "plugins.it_nomads.com/flutter_secure_storage/events", binaryMessenger: registrar.messenger())
         let instance = SwiftFlutterSecureStoragePlugin()
         registrar.addMethodCallDelegate(instance, channel: channel)
+        registrar.addApplicationDelegate(instance)
+        eventChannel.setStreamHandler(instance)
     }
 
     public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
@@ -39,11 +44,43 @@ public class SwiftFlutterSecureStoragePlugin: NSObject, FlutterPlugin {
                 self.readAll(call, handleResult)
             case "containsKey":
                 self.containsKey(call, handleResult)
+            case "isProtectedDataAvailable":
+                // UIApplication is not thread safe
+                DispatchQueue.main.async {
+                    result(UIApplication.shared.isProtectedDataAvailable)
+                }
             default:
                 handleResult(FlutterMethodNotImplemented)
             }
         }
     }
+
+    public func applicationProtectedDataDidBecomeAvailable(_ application: UIApplication) {
+        guard let sink = secStoreAvailabilitySink else {
+            return
+        }
+
+        sink(true)
+    }
+
+    public func applicationProtectedDataWillBecomeUnavailable(_ application: UIApplication) {
+        guard let sink = secStoreAvailabilitySink else {
+            return
+        }
+
+        sink(false)
+    }
+
+    public func onListen(withArguments arguments: Any?,
+                         eventSink: @escaping FlutterEventSink) -> FlutterError? {
+        self.secStoreAvailabilitySink = eventSink
+        return nil
+    }
+
+    public func onCancel(withArguments arguments: Any?) -> FlutterError? {
+        self.secStoreAvailabilitySink = nil
+        return nil
+    }
 
     private func read(_ call: FlutterMethodCall, _ result: @escaping FlutterResult) {
         let values = parseCall(call)

flutter_secure_storage/lib/flutter_secure_storage.dart

@@ -261,6 +261,22 @@ class FlutterSecureStorage {
     }
   }
 
+  /// iOS only feature
+  ///
+  /// On all unsupported platforms returns an stream emitting `true` once
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+      _platform.onCupertinoProtectedDataAvailabilityChanged;
+
+  /// iOS and macOS only feature.
+  ///
+  /// On macOS this is only avaible on macOS 12 or newer. On older versions always returns true.
+  /// On all unsupported platforms returns true
+  ///
+  /// iOS: https://developer.apple.com/documentation/uikit/uiapplication/1622925-isprotecteddataavailable
+  /// macOS: https://developer.apple.com/documentation/appkit/nsapplication/3752992-isprotecteddataavailable
+  Future<bool> isCupertinoProtectedDataAvailable() =>
+      _platform.isCupertinoProtectedDataAvailable();
+
   /// Initializes the shared preferences with mock values for testing.
   @visibleForTesting
   static void setMockInitialValues(Map<String, String> values) {

flutter_secure_storage/lib/test/test_flutter_secure_storage_platform.dart

@@ -43,4 +43,11 @@ class TestFlutterSecureStoragePlatform extends FlutterSecureStoragePlatform {
     required Map<String, String> options,
   }) async =>
       data[key] = value;
+
+  @override
+  Future<bool> isCupertinoProtectedDataAvailable() => Future.value(true);
+
+  @override
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+      Stream.value(true);
 }

flutter_secure_storage_macos/macos/Classes/FlutterSecureStoragePlugin.swift

@@ -31,6 +31,15 @@ public class FlutterSecureStoragePlugin: NSObject, FlutterPlugin {
             readAll(call, result)
         case "containsKey":
             containsKey(call, result)
+        case "isProtectedDataAvailable":
+            // NSApplication is not thread safe
+            DispatchQueue.main.async {
+                if #available(macOS 12.0, *) {
+                    result(NSApplication.shared.isProtectedDataAvailable)
+                } else {
+                    result(true)
+                }
+            }
         default:
             result(FlutterMethodNotImplemented)
         }

flutter_secure_storage_platform_interface/lib/flutter_secure_storage_platform_interface.dart

@@ -1,5 +1,7 @@
 library flutter_secure_storage_platform_interface;
 
+import 'dart:io';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
@@ -29,6 +31,10 @@ abstract class FlutterSecureStoragePlatform extends PlatformInterface {
     _instance = instance;
   }
 
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged;
+
+  Future<bool> isCupertinoProtectedDataAvailable();
+
   Future<void> write({
     required String key,
     required String value,

flutter_secure_storage_platform_interface/lib/src/method_channel_flutter_secure_storage.dart

@@ -3,7 +3,25 @@ part of '../flutter_secure_storage_platform_interface.dart';
 const MethodChannel _channel =
     MethodChannel('plugins.it_nomads.com/flutter_secure_storage');
 
+const EventChannel _eventChannel =
+    EventChannel('plugins.it_nomads.com/flutter_secure_storage/events');
+
 class MethodChannelFlutterSecureStorage extends FlutterSecureStoragePlatform {
+  @override
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged => _eventChannel
+      .receiveBroadcastStream()
+      .where((event) => event is bool)
+      .map((event) => event as bool);
+
+  @override
+  Future<bool> isCupertinoProtectedDataAvailable() async {
+    if (!kIsWeb && Platform.isIOS) {
+      (await _channel.invokeMethod<bool>('isProtectedDataAvailable'))!;
+    }
+
+    return Future.value(true);
+  }
+
   @override
   Future<bool> containsKey({
     required String key,

flutter_secure_storage_platform_interface/test/flutter_secure_storage_platform_interface_mock.dart

@@ -50,4 +50,11 @@ class ExtendsFlutterSecureStoragePlatform extends FlutterSecureStoragePlatform {
     required Map<String, String> options,
   }) =>
       Future<void>.value();
+
+  @override
+  Future<bool> isCupertinoProtectedDataAvailable() => Future.value(true);
+
+  @override
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+      Stream.value(true);
 }

flutter_secure_storage_platform_interface/test/flutter_secure_storage_platform_interface_test.dart

@@ -47,6 +47,8 @@ void main() {
 
       if (methodCall.method == 'containsKey') {
         return true;
+      } else if (methodCall.method == 'isProtectedDataAvailable') {
+        return true;
       }
 
       return null;
@@ -170,5 +172,11 @@ void main() {
         ],
       );
     });
+
+    test('isProtectedDataAvailable', () async {
+      final result = await storage.isCupertinoProtectedDataAvailable();
+
+      expect(result, true);
+    });
   });
 }

flutter_secure_storage_windows/lib/src/flutter_secure_storage_windows_ffi.dart

@@ -150,6 +150,13 @@ class FlutterSecureStorageWindows extends FlutterSecureStoragePlatform {
       _backwardCompatible.delete(key: key, options: options);
     }
   }
+
+  @override
+  Future<bool> isCupertinoProtectedDataAvailable() => Future.value(true);
+
+  @override
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+      Stream.value(true);
 }
 
 @visibleForTesting

flutter_secure_storage_windows/lib/src/flutter_secure_storage_windows_stub.dart

@@ -13,32 +13,46 @@ class FlutterSecureStorageWindows extends FlutterSecureStoragePlatform {
   }
 
   @override
-  Future<bool> containsKey(
-          {required String key, required Map<String, String> options,}) =>
+  Future<bool> containsKey({
+    required String key,
+    required Map<String, String> options,
+  }) =>
       Future.value(false);
 
   @override
-  Future<void> delete(
-          {required String key, required Map<String, String> options,}) =>
+  Future<void> delete({
+    required String key,
+    required Map<String, String> options,
+  }) =>
       Future.value();
 
   @override
   Future<void> deleteAll({required Map<String, String> options}) =>
       Future.value();
 
   @override
-  Future<String?> read(
-          {required String key, required Map<String, String> options,}) =>
+  Future<String?> read({
+    required String key,
+    required Map<String, String> options,
+  }) =>
       Future.value();
 
   @override
   Future<Map<String, String>> readAll({required Map<String, String> options}) =>
       Future.value({});
 
   @override
-  Future<void> write(
-          {required String key,
-          required String value,
-          required Map<String, String> options,}) =>
+  Future<void> write({
+    required String key,
+    required String value,
+    required Map<String, String> options,
+  }) =>
       Future.value();
+
+  @override
+  Future<bool> isCupertinoProtectedDataAvailable() => Future.value(true);
+
+  @override
+  Stream<bool> get onCupertinoProtectedDataAvailabilityChanged =>
+      Stream.value(true);
 }