Use same key for encryption purposes

uni/lib/controller/background_workers/notifications.dart

@@ -71,6 +71,10 @@ class NotificationManager {
     final userInfo = await AppSharedPreferences.getPersistentUserInfo();
     final faculties = await AppSharedPreferences.getUserFaculties();
 
+    if (userInfo == null || faculties.isEmpty) {
+      return;
+    }
+
     final session = await NetworkRouter.login(
       userInfo.item1,
       userInfo.item2,

uni/lib/controller/local_storage/app_shared_preferences.dart

@@ -14,6 +14,10 @@ import 'package:uni/utils/favorite_widget_type.dart';
 /// This database stores the user's student number, password and favorite
 /// widgets.
 class AppSharedPreferences {
+  static final iv = encrypt.IV.fromLength(16);
+  static final key =
+      encrypt.Key.fromBase64('DT3/GTNYldhwOD3ZbpVLoAwA/mncsN7U7sJxfFn3y0A=');
+
   static const lastUpdateTimeKeySuffix = '_last_update_time';
   static const String userNumber = 'user_number';
   static const String userPw = 'user_password';
@@ -24,10 +28,6 @@ class AppSharedPreferences {
       'tuition_notification_toogle';
   static const String themeMode = 'theme_mode';
   static const String locale = 'app_locale';
-  static const int keyLength = 32;
-  static const int ivLength = 16;
-  static final iv = encrypt.IV.fromLength(ivLength);
-
   static const String favoriteCards = 'favorite_cards';
   static final List<FavoriteWidgetType> defaultFavoriteCards = [
     FavoriteWidgetType.schedule,
@@ -149,9 +149,12 @@ class AppSharedPreferences {
   /// * the first element in the tuple is the user's student number.
   /// * the second element in the tuple is the user's password, in plain text
   /// format.
-  static Future<Tuple2<String, String>> getPersistentUserInfo() async {
+  static Future<Tuple2<String, String>?> getPersistentUserInfo() async {
     final userNum = await getUserNumber();
     final userPass = await getUserPassword();
+    if (userNum == null || userPass == null) {
+      return null;
+    }
     return Tuple2(userNum, userPass);
   }
 
@@ -164,22 +167,16 @@ class AppSharedPreferences {
   }
 
   /// Returns the user's student number.
-  static Future<String> getUserNumber() async {
+  static Future<String?> getUserNumber() async {
     final prefs = await SharedPreferences.getInstance();
-    return prefs.getString(userNumber) ??
-        ''; // empty string for the case it does not exist
+    return prefs.getString(userNumber);
   }
 
   /// Returns the user's password, in plain text format.
-  static Future<String> getUserPassword() async {
+  static Future<String?> getUserPassword() async {
     final prefs = await SharedPreferences.getInstance();
-    var pass = prefs.getString(userPw) ?? '';
-
-    if (pass != '') {
-      pass = decode(pass);
-    }
-
-    return pass;
+    final password = prefs.getString(userPw);
+    return password != null ? decode(password) : null;
   }
 
   /// Replaces the user's favorite widgets with [newFavorites].
@@ -270,15 +267,18 @@ class AppSharedPreferences {
   }
 
   /// Decrypts [base64Text].
-  static String decode(String base64Text) {
+  static String? decode(String base64Text) {
     final encrypter = _createEncrypter();
-    return encrypter.decrypt64(base64Text, iv: iv);
+    try {
+      return encrypter.decrypt64(base64Text, iv: iv);
+    } catch (e) {
+      return null;
+    }
   }
 
   /// Creates an [encrypt.Encrypter] for encrypting and decrypting the user's
   /// password.
   static encrypt.Encrypter _createEncrypter() {
-    final key = encrypt.Key.fromLength(keyLength);
     return encrypt.Encrypter(encrypt.AES(key));
   }
 

uni/lib/controller/networking/network_router.dart

@@ -71,6 +71,7 @@ class NetworkRouter {
         faculties,
         persistentSession: persistentSession,
       );
+
       if (session == null) {
         Logger().e('Login failed: user not authenticated');
         return null;
@@ -90,6 +91,12 @@ class NetworkRouter {
   static Future<Session?> reLoginFromSession(Session session) async {
     final username = session.username;
     final password = await AppSharedPreferences.getUserPassword();
+
+    if (password == null) {
+      Logger().e('Re-login failed: password not found');
+      return null;
+    }
+
     final faculties = session.faculties;
     final persistentSession = session.persistentSession;
 

uni/lib/main.dart

@@ -52,10 +52,8 @@ SentryEvent? beforeSend(SentryEvent event) {
 
 Future<String> firstRoute() async {
   final userPersistentInfo = await AppSharedPreferences.getPersistentUserInfo();
-  final userName = userPersistentInfo.item1;
-  final password = userPersistentInfo.item2;
 
-  if (userName != '' && password != '') {
+  if (userPersistentInfo != null) {
     return '/${DrawerItem.navPersonalArea.title}';
   }
 

uni/lib/model/providers/lazy/exam_provider.dart

@@ -1,7 +1,6 @@
 import 'dart:async';
 import 'dart:collection';
 
-import 'package:tuple/tuple.dart';
 import 'package:uni/controller/fetchers/exam_fetcher.dart';
 import 'package:uni/controller/local_storage/app_exams_database.dart';
 import 'package:uni/controller/local_storage/app_shared_preferences.dart';
@@ -42,27 +41,28 @@ class ExamProvider extends StateProviderNotifier {
   Future<void> loadFromRemote(Session session, Profile profile) async {
     await fetchUserExams(
       ParserExams(),
-      await AppSharedPreferences.getPersistentUserInfo(),
       profile,
       session,
       profile.courseUnits,
+      persistentSession:
+          (await AppSharedPreferences.getPersistentUserInfo()) != null,
     );
   }
 
   Future<void> fetchUserExams(
     ParserExams parserExams,
-    Tuple2<String, String> userPersistentInfo,
     Profile profile,
     Session session,
-    List<CourseUnit> userUcs,
-  ) async {
+    List<CourseUnit> userUcs, {
+    required bool persistentSession,
+  }) async {
     try {
       final exams = await ExamFetcher(profile.courses, userUcs)
           .extractExams(session, parserExams);
 
       exams.sort((exam1, exam2) => exam1.begin.compareTo(exam2.begin));
 
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (persistentSession) {
         await AppExamsDatabase().saveNewExams(exams);
       }
 

uni/lib/model/providers/lazy/lecture_provider.dart

@@ -1,7 +1,6 @@
 import 'dart:async';
 import 'dart:collection';
 
-import 'package:tuple/tuple.dart';
 import 'package:uni/controller/fetchers/schedule_fetcher/schedule_fetcher.dart';
 import 'package:uni/controller/fetchers/schedule_fetcher/schedule_fetcher_api.dart';
 import 'package:uni/controller/fetchers/schedule_fetcher/schedule_fetcher_html.dart';
@@ -30,23 +29,24 @@ class LectureProvider extends StateProviderNotifier {
   @override
   Future<void> loadFromRemote(Session session, Profile profile) async {
     await fetchUserLectures(
-      await AppSharedPreferences.getPersistentUserInfo(),
       session,
       profile,
+      persistentSession:
+          (await AppSharedPreferences.getPersistentUserInfo()) != null,
     );
   }
 
   Future<void> fetchUserLectures(
-    Tuple2<String, String> userPersistentInfo,
     Session session,
     Profile profile, {
+    required bool persistentSession,
     ScheduleFetcher? fetcher,
   }) async {
     try {
       final lectures =
           await getLecturesFromFetcherOrElse(fetcher, session, profile);
 
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (persistentSession) {
         final db = AppLecturesDatabase();
         await db.saveNewLectures(lectures);
       }

uni/lib/model/providers/startup/profile_provider.dart

@@ -75,7 +75,7 @@ class ProfileProvider extends StateProviderNotifier {
       final userPersistentInfo =
           await AppSharedPreferences.getPersistentUserInfo();
 
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (userPersistentInfo != null) {
         final profileDb = AppUserDataDatabase();
         await profileDb.saveUserFees(feesBalance, feesLimit);
       }
@@ -95,7 +95,7 @@ class ProfileProvider extends StateProviderNotifier {
 
       final userPersistentInfo =
           await AppSharedPreferences.getPersistentUserInfo();
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (userPersistentInfo != null) {
         final profileDb = AppUserDataDatabase();
         await profileDb.saveUserPrintBalance(printBalance);
       }
@@ -119,7 +119,7 @@ class ProfileProvider extends StateProviderNotifier {
 
       final userPersistentInfo =
           await AppSharedPreferences.getPersistentUserInfo();
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (userPersistentInfo != null) {
         // Course units are saved later, so we don't it here
         final profileDb = AppUserDataDatabase();
         await profileDb.insertUserData(_profile);
@@ -144,7 +144,7 @@ class ProfileProvider extends StateProviderNotifier {
 
       final userPersistentInfo =
           await AppSharedPreferences.getPersistentUserInfo();
-      if (userPersistentInfo.item1 != '' && userPersistentInfo.item2 != '') {
+      if (userPersistentInfo != null) {
         final coursesDb = AppCoursesDatabase();
         await coursesDb.saveNewCourses(courses);
 

uni/lib/model/providers/startup/session_provider.dart

@@ -35,6 +35,11 @@ class SessionProvider extends StateProviderNotifier {
   Future<void> loadFromStorage() async {
     final userPersistentInfo =
         await AppSharedPreferences.getPersistentUserInfo();
+
+    if (userPersistentInfo == null) {
+      return;
+    }
+
     final userName = userPersistentInfo.item1;
     final password = userPersistentInfo.item2;
 

uni/lib/view/common_widgets/page_transition.dart

@@ -1,6 +1,4 @@
 import 'package:flutter/material.dart';
-
-import 'package:uni/controller/local_storage/app_shared_preferences.dart';
 import 'package:uni/view/navigation_service.dart';
 import 'package:uni/view/terms_and_condition_dialog.dart';
 
@@ -49,16 +47,9 @@ class PageTransition {
   static Future<void> requestTermsAndConditionsAcceptanceIfNeeded(
     BuildContext context,
   ) async {
-    final userPersistentInfo =
-        await AppSharedPreferences.getPersistentUserInfo();
-    final userName = userPersistentInfo.item1;
-    final password = userPersistentInfo.item2;
-
     if (context.mounted) {
       final termsAcceptance = await TermsAndConditionDialog.buildIfTermsChanged(
         context,
-        userName,
-        password,
       );
 
       switch (termsAcceptance) {

uni/lib/view/login/login.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_svg/svg.dart';
+import 'package:logger/logger.dart';
 import 'package:provider/provider.dart';
 import 'package:uni/generated/l10n.dart';
 import 'package:uni/model/entities/login_exceptions.dart';
@@ -67,6 +68,7 @@ class LoginPageViewState extends State<LoginPageView> {
         } else if (error is WrongCredentialsException) {
           unawaited(ToastMessage.error(context, error.message));
         } else {
+          Logger().e(error);
           unawaited(ToastMessage.error(context, S.of(context).failed_login));
         }
       }

uni/lib/view/terms_and_condition_dialog.dart

@@ -13,17 +13,14 @@ class TermsAndConditionDialog {
 
   static Future<TermsAndConditionsState> buildIfTermsChanged(
     BuildContext context,
-    String userName,
-    String password,
   ) async {
     final termsAreAccepted =
         await updateTermsAndConditionsAcceptancePreference();
 
     if (!termsAreAccepted) {
       final routeCompleter = Completer<TermsAndConditionsState>();
       SchedulerBinding.instance.addPostFrameCallback(
-        (timestamp) =>
-            _buildShowDialog(context, routeCompleter, userName, password),
+        (timestamp) => _buildShowDialog(context, routeCompleter),
       );
       return routeCompleter.future;
     }
@@ -34,8 +31,6 @@ class TermsAndConditionDialog {
   static Future<void> _buildShowDialog(
     BuildContext context,
     Completer<TermsAndConditionsState> userTermsDecision,
-    String userName,
-    String password,
   ) {
     return showDialog(
       context: context,

uni/test/integration/src/exams_page_test.dart

@@ -6,7 +6,6 @@ import 'package:http/http.dart' as http;
 import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
 import 'package:provider/provider.dart';
-import 'package:tuple/tuple.dart';
 import 'package:uni/controller/networking/network_router.dart';
 import 'package:uni/controller/parsers/parser_exams.dart';
 import 'package:uni/model/entities/course.dart';
@@ -82,10 +81,10 @@ void main() {
 
       await examProvider.fetchUserExams(
         ParserExams(),
-        const Tuple2('', ''),
         profile,
         Session(username: '', cookies: '', faculties: ['feup']),
         [sopeCourseUnit, sdisCourseUnit],
+        persistentSession: false,
       );
 
       await tester.pumpAndSettle();
@@ -118,10 +117,10 @@ void main() {
 
       await examProvider.fetchUserExams(
         ParserExams(),
-        const Tuple2('', ''),
         profile,
         Session(username: '', cookies: '', faculties: ['feup']),
         [sopeCourseUnit, sdisCourseUnit],
+        persistentSession: false,
       );
 
       await tester.pumpAndSettle();

uni/test/integration/src/schedule_page_test.dart

@@ -7,7 +7,6 @@ import 'package:http/http.dart' as http;
 import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
 import 'package:provider/provider.dart';
-import 'package:tuple/tuple.dart';
 import 'package:uni/controller/networking/network_router.dart';
 import 'package:uni/model/entities/course.dart';
 import 'package:uni/model/entities/profile.dart';
@@ -71,9 +70,9 @@ void main() {
       expect(find.byKey(const Key(scheduleSlotTimeKey2)), findsNothing);
 
       await scheduleProvider.fetchUserLectures(
-        const Tuple2('', ''),
         Session(username: '', cookies: '', faculties: ['feup']),
         profile,
+        persistentSession: false,
       );
 
       await tester.tap(find.byKey(const Key('schedule-page-tab-2')));