fix: BAD_DECRYPT Exception on invalid cipher

packages/smooth_app/lib/data_models/user_management_provider.dart

@@ -1,4 +1,5 @@
-import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:openfoodfacts/openfoodfacts.dart';
 import 'package:openfoodfacts/utils/OpenFoodAPIConfiguration.dart';
 import 'package:smooth_app/database/dao_secured_string.dart';
@@ -7,10 +8,6 @@ class UserManagementProvider with ChangeNotifier {
   static const String _USER_ID = 'user_id';
   static const String _PASSWORD = 'pasword';
 
-  bool _finishedLoading = false;
-
-  bool get isLoading => !_finishedLoading;
-
   /// Checks credentials and conditionally saves them
   Future<bool> login(User user) async {
     final bool rightCredentials;
@@ -22,6 +19,7 @@ class UserManagementProvider with ChangeNotifier {
 
     if (rightCredentials) {
       await putUser(user);
+      notifyListeners();
     }
 
     return rightCredentials && await credentialsInStorage();
@@ -38,20 +36,27 @@ class UserManagementProvider with ChangeNotifier {
   }
 
   /// Mounts already stored credentials, called at app startup
-  Future<void> mountCredentials() async {
-    final String? userId = await DaoSecuredString.get(_USER_ID);
-    final String? password = await DaoSecuredString.get(_PASSWORD);
+  static Future<void> mountCredentials() async {
+    String? userId;
+    String? password;
+
+    try {
+      userId = await DaoSecuredString.get(_USER_ID);
+      password = await DaoSecuredString.get(_PASSWORD);
+    } on PlatformException {
+      /// Decrypting the values can go wrong if, for example, the app was
+      /// manually overwritten from an external apk.
+      DaoSecuredString.remove(key: _USER_ID);
+      DaoSecuredString.remove(key: _PASSWORD);
+      debugPrint('Credentials query failed, you have been logged out');
+    }
 
     if (userId == null || password == null) {
-      _finishedLoading = true;
-      notifyListeners();
       return;
     }
 
     final User user = User(userId: userId, password: password);
     OpenFoodAPIConfiguration.globalUser = user;
-    _finishedLoading = true;
-    notifyListeners();
   }
 
   /// Checks if any credentials exist in storage

packages/smooth_app/lib/main.dart

@@ -82,6 +82,7 @@ Future<bool> _init1() async {
     system: Platform.operatingSystemVersion,
     url: 'https://world.openfoodfacts.org/',
   );
+  await UserManagementProvider.mountCredentials();
   _userPreferences = await UserPreferences.getUserPreferences();
   _localDatabase = await LocalDatabase.getLocalDatabase();
   _productPreferences = ProductPreferences(
@@ -178,6 +179,7 @@ class _SmoothAppState extends State<SmoothApp> {
     final ThemeProvider themeProvider = context.watch<ThemeProvider>();
     final Widget appWidget = OnboardingFlowNavigator(_userPreferences)
         .getPageWidget(context, _userPreferences.lastVisitedOnboardingPage);
+
     return MaterialApp(
       localizationsDelegates: AppLocalizations.localizationsDelegates,
       supportedLocales: AppLocalizations.supportedLocales,
@@ -227,8 +229,6 @@ class SmoothAppGetLanguage extends StatelessWidget {
     final LocalDatabase _localDatabase = context.read<LocalDatabase>();
     AnalyticsHelper.trackStart(_localDatabase, context);
 
-    context.read<UserManagementProvider>().mountCredentials();
-
     return appWidget;
   }
 }

packages/smooth_app/lib/pages/user_preferences_profile.dart

@@ -109,19 +109,17 @@ class _UserPreferencesPageState extends State<UserPreferencesSection> {
 
   @override
   Widget build(BuildContext context) {
-    final UserManagementProvider userManagementProvider =
-        context.watch<UserManagementProvider>();
+    // We need to listen to reflect login's from outside of the preferences page
+    // e.g. question card, ...
+    context.watch<UserManagementProvider>();
 
     final ThemeData theme = Theme.of(context);
     final AppLocalizations appLocalizations = AppLocalizations.of(context)!;
     final Size size = MediaQuery.of(context).size;
 
     final List<Widget> result = <Widget>[];
 
-    if (userManagementProvider.isLoading) {
-      //Loading
-      result.add(const Center(child: CircularProgressIndicator()));
-    } else if (OpenFoodAPIConfiguration.globalUser != null) {
+    if (OpenFoodAPIConfiguration.globalUser != null) {
       //Credentials
       final String userId = OpenFoodAPIConfiguration.globalUser!.userId;
       result.add(