CWA-164 | added biometric authentication

lib/generated/i18n.dart

@@ -38,6 +38,7 @@ class S implements WidgetsLocalizations {
   String get authenticated => "Authenticated";
   String get authentication => "Authentication";
   String get available_balance => "Available Balance";
+  String get biometric_auth_reason => "Scan your fingerprint to authenticate";
   String get cancel => "Cancel";
   String get change => "Change";
   String get change_currency => "Change Currency";
@@ -315,6 +316,8 @@ class $de extends S {
   @override
   String get hidden_balance => "Verstecktes Gleichgewicht";
   @override
+  String get biometric_auth_reason => "Scannen Sie Ihren Fingerabdruck zur Authentifizierung";
+  @override
   String get transaction_sent => "Transaktion gesendet!";
   @override
   String get password => "Passwort";
@@ -861,6 +864,8 @@ class $hi extends S {
   @override
   String get hidden_balance => "छिपा हुआ संतुलन";
   @override
+  String get biometric_auth_reason => "प्रमाणित करने के लिए अपने फ़िंगरप्रिंट को स्कैन करें";
+  @override
   String get transaction_sent => "भेजा गया लेन-देन";
   @override
   String get password => "पारण शब्द";
@@ -1407,6 +1412,8 @@ class $ru extends S {
   @override
   String get hidden_balance => "Скрытый баланс";
   @override
+  String get biometric_auth_reason => "Отсканируйте свой отпечаток пальца для аутентификации";
+  @override
   String get transaction_sent => "Tранзакция отправлена!";
   @override
   String get password => "Password";
@@ -1953,6 +1960,8 @@ class $ko extends S {
   @override
   String get hidden_balance => "숨겨진 균형";
   @override
+  String get biometric_auth_reason => "지문을 스캔하여 인증";
+  @override
   String get transaction_sent => "거래가 전송되었습니다!";
   @override
   String get password => "암호";
@@ -2499,6 +2508,8 @@ class $pt extends S {
   @override
   String get hidden_balance => "Saldo escondido";
   @override
+  String get biometric_auth_reason => "Digitalize sua impressão digital para autenticar";
+  @override
   String get transaction_sent => "Transação enviada!";
   @override
   String get password => "Senha";
@@ -3045,6 +3056,8 @@ class $ja extends S {
   @override
   String get hidden_balance => "隠れたバランス";
   @override
+  String get biometric_auth_reason => "प指紋をスキャンして認証する";
+  @override
   String get transaction_sent => "トランザクションが送信されました！";
   @override
   String get password => "パスワード";
@@ -3595,6 +3608,8 @@ class $pl extends S {
   @override
   String get hidden_balance => "Ukryta równowaga";
   @override
+  String get biometric_auth_reason => "Zeskanuj swój odcisk palca, aby go uwierzytelnić";
+  @override
   String get transaction_sent => "Transakcja wysłana!";
   @override
   String get password => "Hasło";
@@ -4141,6 +4156,8 @@ class $es extends S {
   @override
   String get hidden_balance => "Balance oculto";
   @override
+  String get biometric_auth_reason => "Escanee su huella digital para autenticar";
+  @override
   String get transaction_sent => "Transacción enviada!";
   @override
   String get password => "Contraseña";
@@ -4687,6 +4704,8 @@ class $nl extends S {
   @override
   String get hidden_balance => "Verborgen balans";
   @override
+  String get biometric_auth_reason => "Scan uw vingerafdruk om te verifiëren";
+  @override
   String get transaction_sent => "Transactie verzonden!";
   @override
   String get password => "Wachtwoord";
@@ -5233,6 +5252,8 @@ class $zh extends S {
   @override
   String get hidden_balance => "隐藏余额";
   @override
+  String get biometric_auth_reason => "掃描指紋以進行身份驗證";
+  @override
   String get transaction_sent => "交易已发送";
   @override
   String get password => "密码";

lib/src/domain/common/biometric_auth.dart

@@ -0,0 +1,24 @@
+import 'package:local_auth/local_auth.dart';
+import 'package:flutter/services.dart';
+import 'package:cake_wallet/generated/i18n.dart';
+
+class BiometricAuth {
+
+  Future<bool> isAuthenticated() async {
+    final LocalAuthentication _localAuth = LocalAuthentication();
+
+    try {
+      return await _localAuth.authenticateWithBiometrics(
+          localizedReason: S.current.biometric_auth_reason,
+          useErrorDialogs: true,
+          stickyAuth: false
+      );
+    } on PlatformException
+    catch(e) {
+      print(e);
+    }
+
+    return false;
+  }
+
+}

lib/src/screens/auth/auth_page.dart

@@ -6,6 +6,8 @@ import 'package:cake_wallet/generated/i18n.dart';
 import 'package:cake_wallet/src/stores/auth/auth_state.dart';
 import 'package:cake_wallet/src/stores/auth/auth_store.dart';
 import 'package:cake_wallet/src/screens/pin_code/pin_code.dart';
+import 'package:cake_wallet/src/stores/settings/settings_store.dart';
+import 'package:cake_wallet/src/domain/common/biometric_auth.dart';
 
 typedef OnAuthenticationFinished = void Function(bool, AuthPageState);
 
@@ -33,6 +35,26 @@ class AuthPageState extends State<AuthPage> {
   @override
   Widget build(BuildContext context) {
     final authStore = Provider.of<AuthStore>(context);
+    final settingsStore = Provider.of<SettingsStore>(context);
+
+    if (settingsStore.allowBiometricalAuthentication) {
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        final biometricAuth = BiometricAuth();
+        biometricAuth.isAuthenticated().then(
+                (isAuth) {
+              if (isAuth) {
+                authStore.biometricAuth();
+                _key.currentState.showSnackBar(
+                  SnackBar(
+                    content: Text(S.of(context).authenticated),
+                    backgroundColor: Colors.green,
+                  ),
+                );
+              }
+            }
+        );
+      });
+    }
 
     reaction((_) => authStore.state, (AuthState state) {
       if (state is AuthenticatedSuccessfully) {

lib/src/stores/auth/auth_store.dart

@@ -91,4 +91,9 @@ abstract class AuthStoreBase with Store {
 
     return Duration(milliseconds: timeout);
   }
+
+  @action
+  void biometricAuth() {
+    state = AuthenticatedSuccessfully();
+  }
 }