Use a generated password when creating wallet

diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index 2aaf3b0..58a2220 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -6,7 +6,9 @@
     <application
         android:label="monero_light_wallet"
         android:name="${applicationName}"
-        android:icon="@mipmap/ic_launcher">
+        android:icon="@mipmap/ic_launcher"
+        android:allowBackup="false">
+        
         
         <meta-data
             android:name="com.google.firebase.messaging.default_notification_channel_id"
diff --git a/lib/consts.dart b/lib/consts.dart
index 057a2d5..84d9338 100644
--- a/lib/consts.dart
+++ b/lib/consts.dart
@@ -3,3 +3,4 @@ const String torDataDirName = 'tor';
 const int txDirectionIncoming = 0;
 const int txDirectionOutgoing = 1;
 const supportedFiatCurrencies = ['USD', 'EUR'];
+const walletPasswordStorageKey = 'walletPassword';
diff --git a/lib/models/wallet_model.dart b/lib/models/wallet_model.dart
index e02b672..158ac79 100644
--- a/lib/models/wallet_model.dart
+++ b/lib/models/wallet_model.dart
@@ -21,6 +21,7 @@ import 'package:monero_light_wallet/util/formatting.dart';
 import 'package:monero_light_wallet/util/height.dart';
 import 'package:monero_light_wallet/util/logging.dart';
 import 'package:monero_light_wallet/util/wallet.dart';
+import 'package:monero_light_wallet/util/wallet_password.dart';
 
 String generateHexString(int length) {
   final Random random = Random.secure();
@@ -438,11 +439,16 @@ class WalletModel with ChangeNotifier {
     });
   }
 
-  Future<MoneroWallet> _getWalletFromLegacySeed(
-    String mnemonic,
-    int restoreHeight, {
+  Future<MoneroWallet> _getWalletFromLegacySeed({
+    required String mnemonic,
+    required int restoreHeight,
+    required String password,
     bool isDummy = false,
   }) async {
+    if (!isDummy && password == '') {
+      throw Exception('Password should not be empty.');
+    }
+
     final wmFfiAddr = _w2WalletManager.ffiAddress();
     final walletPath = await getWalletPath();
 
@@ -453,7 +459,7 @@ class WalletModel with ChangeNotifier {
         mnemonic: mnemonic,
         seedOffset: '',
         restoreHeight: restoreHeight,
-        password: 'pass',
+        password: password,
         path: isDummy ? '' : walletPath,
       ).address;
     });
@@ -461,11 +467,16 @@ class WalletModel with ChangeNotifier {
     return MoneroWallet(Pointer<Void>.fromAddress(walletFfiAddr));
   }
 
-  Future<MoneroWallet> _getWalletFromPolyseed(
-    String mnemonic,
-    int restoreHeight, {
+  Future<MoneroWallet> _getWalletFromPolyseed({
+    required String mnemonic,
+    required int restoreHeight,
+    required String password,
     bool isDummy = false,
   }) async {
+    if (!isDummy && password == '') {
+      throw Exception('Password should not be empty.');
+    }
+
     final wmFfiAddr = _w2WalletManager.ffiAddress();
     final walletPath = await getWalletPath();
 
@@ -477,7 +488,7 @@ class WalletModel with ChangeNotifier {
         seedOffset: '',
         restoreHeight: restoreHeight,
         path: isDummy ? '' : walletPath,
-        password: 'pass',
+        password: password,
         newWallet: true,
         kdfRounds: 1,
       ).address;
@@ -492,44 +503,69 @@ class WalletModel with ChangeNotifier {
     String passphrase = '',
   ]) async {
     final legacyWallet = await _getWalletFromLegacySeed(
-      mnemonic,
-      restoreHeight,
+      mnemonic: mnemonic,
+      restoreHeight: restoreHeight,
+      password: '',
       isDummy: true,
     );
 
     final polyseedWallet = await _getWalletFromPolyseed(
-      mnemonic,
-      restoreHeight,
+      mnemonic: mnemonic,
+      restoreHeight: restoreHeight,
+      password: '',
       isDummy: true,
     );
 
     final legacyError = legacyWallet.errorString();
     final polyseedError = polyseedWallet.errorString();
 
+    final walletPassword = genWalletPassword();
+
     if (!legacyError.contains('word list failed verification')) {
-      _w2Wallet = await _getWalletFromLegacySeed(mnemonic, restoreHeight);
+      _w2Wallet = await _getWalletFromLegacySeed(
+        mnemonic: mnemonic,
+        restoreHeight: restoreHeight,
+        password: walletPassword,
+      );
     } else if (polyseedError != 'Failed polyseed decode') {
-      _w2Wallet = await _getWalletFromPolyseed(mnemonic, restoreHeight);
+      _w2Wallet = await _getWalletFromPolyseed(
+        mnemonic: mnemonic,
+        restoreHeight: restoreHeight,
+        password: walletPassword,
+      );
     }
 
     if (_w2Wallet == null) {
       throw Exception("Something went wrong when generating seed");
     }
 
+    await storeWalletPassword(walletPassword);
+
     _w2TxHistory = _w2Wallet!.history();
 
-    store();
+    await store();
     notifyListeners();
   }
 
-  Future openExisting() async {
+  Future<void> openExisting() async {
     final path = await getWalletPath();
 
-    _w2Wallet = _w2WalletManager.openWallet(path: path, password: 'pass');
+    final password = await getWalletPassword();
+
+    if (password == null) {
+      final errorMsg =
+          'Failed to open existing wallet: could not get password.';
+      log(LogLevel.error, errorMsg);
+      throw Exception(errorMsg);
+    }
+
+    _w2Wallet = _w2WalletManager.openWallet(path: path, password: password);
     final errorString = _w2WalletManager.errorString();
 
     if (errorString != '') {
-      log(LogLevel.error, 'Failed to open existing wallet: $errorString');
+      final errorMsg = 'Failed to open existing wallet: $errorString';
+      log(LogLevel.error, errorMsg);
+      throw Exception(errorMsg);
     }
 
     _w2TxHistory = _w2Wallet!.history();
diff --git a/lib/util/wallet_password.dart b/lib/util/wallet_password.dart
new file mode 100644
index 0000000..f25442b
--- /dev/null
+++ b/lib/util/wallet_password.dart
@@ -0,0 +1,28 @@
+import 'dart:math';
+import 'dart:typed_data';
+
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import 'package:monero_light_wallet/consts.dart';
+
+String genWalletPassword() {
+  final byteLength = 16;
+  final rand = Random.secure();
+  final bytes = Uint8List.fromList(
+    List<int>.generate(byteLength, (_) => rand.nextInt(256)),
+  );
+  final sb = StringBuffer();
+  for (final b in bytes) {
+    sb.write(b.toRadixString(16).padLeft(2, '0'));
+  }
+  return sb.toString();
+}
+
+Future<void> storeWalletPassword(String password) async {
+  final storage = FlutterSecureStorage();
+  await storage.write(key: walletPasswordStorageKey, value: password);
+}
+
+Future<String?> getWalletPassword() async {
+  final storage = FlutterSecureStorage();
+  return storage.read(key: walletPasswordStorageKey);
+}
diff --git a/linux/flutter/generated_plugin_registrant.cc b/linux/flutter/generated_plugin_registrant.cc
index f6f23bf..38dd0bc 100644
--- a/linux/flutter/generated_plugin_registrant.cc
+++ b/linux/flutter/generated_plugin_registrant.cc
@@ -6,9 +6,13 @@
 
 #include "generated_plugin_registrant.h"
 
+#include <flutter_secure_storage_linux/flutter_secure_storage_linux_plugin.h>
 #include <url_launcher_linux/url_launcher_plugin.h>
 
 void fl_register_plugins(FlPluginRegistry* registry) {
+  g_autoptr(FlPluginRegistrar) flutter_secure_storage_linux_registrar =
+      fl_plugin_registry_get_registrar_for_plugin(registry, "FlutterSecureStorageLinuxPlugin");
+  flutter_secure_storage_linux_plugin_register_with_registrar(flutter_secure_storage_linux_registrar);
   g_autoptr(FlPluginRegistrar) url_launcher_linux_registrar =
       fl_plugin_registry_get_registrar_for_plugin(registry, "UrlLauncherPlugin");
   url_launcher_plugin_register_with_registrar(url_launcher_linux_registrar);
diff --git a/linux/flutter/generated_plugins.cmake b/linux/flutter/generated_plugins.cmake
index 1e0aea0..dc0bcf2 100644
--- a/linux/flutter/generated_plugins.cmake
+++ b/linux/flutter/generated_plugins.cmake
@@ -3,6 +3,7 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
+  flutter_secure_storage_linux
   url_launcher_linux
 )
 
diff --git a/macos/Flutter/GeneratedPluginRegistrant.swift b/macos/Flutter/GeneratedPluginRegistrant.swift
index 64d86c2..c2f0a8e 100644
--- a/macos/Flutter/GeneratedPluginRegistrant.swift
+++ b/macos/Flutter/GeneratedPluginRegistrant.swift
@@ -6,6 +6,7 @@ import FlutterMacOS
 import Foundation
 
 import flutter_local_notifications
+import flutter_secure_storage_macos
 import mobile_scanner
 import path_provider_foundation
 import screen_brightness_macos
@@ -14,6 +15,7 @@ import shared_preferences_foundation
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
+  FlutterSecureStoragePlugin.register(with: registry.registrar(forPlugin: "FlutterSecureStoragePlugin"))
   MobileScannerPlugin.register(with: registry.registrar(forPlugin: "MobileScannerPlugin"))
   PathProviderPlugin.register(with: registry.registrar(forPlugin: "PathProviderPlugin"))
   ScreenBrightnessMacosPlugin.register(with: registry.registrar(forPlugin: "ScreenBrightnessMacosPlugin"))
diff --git a/pubspec.lock b/pubspec.lock
index 6caf489..0fa8f4b 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -179,6 +179,54 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.6.1"
+  flutter_secure_storage:
+    dependency: "direct main"
+    description:
+      name: flutter_secure_storage
+      sha256: "9cad52d75ebc511adfae3d447d5d13da15a55a92c9410e50f67335b6d21d16ea"
+      url: "https://pub.dev"
+    source: hosted
+    version: "9.2.4"
+  flutter_secure_storage_linux:
+    dependency: transitive
+    description:
+      name: flutter_secure_storage_linux
+      sha256: be76c1d24a97d0b98f8b54bce6b481a380a6590df992d0098f868ad54dc8f688
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.3"
+  flutter_secure_storage_macos:
+    dependency: transitive
+    description:
+      name: flutter_secure_storage_macos
+      sha256: "6c0a2795a2d1de26ae202a0d78527d163f4acbb11cde4c75c670f3a0fc064247"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.3"
+  flutter_secure_storage_platform_interface:
+    dependency: transitive
+    description:
+      name: flutter_secure_storage_platform_interface
+      sha256: cf91ad32ce5adef6fba4d736a542baca9daf3beac4db2d04be350b87f69ac4a8
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.2"
+  flutter_secure_storage_web:
+    dependency: transitive
+    description:
+      name: flutter_secure_storage_web
+      sha256: f4ebff989b4f07b2656fb16b47852c0aab9fed9b4ec1c70103368337bc1886a9
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.2.1"
+  flutter_secure_storage_windows:
+    dependency: transitive
+    description:
+      name: flutter_secure_storage_windows
+      sha256: b20b07cb5ed4ed74fc567b78a72936203f587eba460af1df11281c9326cd3709
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.2"
   flutter_svg:
     dependency: "direct main"
     description:
@@ -221,6 +269,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.20.2"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      sha256: f2c445dce49627136094980615a031419f7f3eb393237e4ecd97ac15dea343f3
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.6.7"
   leak_tracker:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index 50099a2..2de61fb 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -64,6 +64,7 @@ dependencies:
   permission_handler: ^12.0.1
   flutter_svg: ^2.2.1
   skeletonizer: ^2.1.0+1
+  flutter_secure_storage: ^9.2.4
 
 dev_dependencies:
   flutter_test:
diff --git a/windows/flutter/generated_plugin_registrant.cc b/windows/flutter/generated_plugin_registrant.cc
index f0270da..89ba8c2 100644
--- a/windows/flutter/generated_plugin_registrant.cc
+++ b/windows/flutter/generated_plugin_registrant.cc
@@ -6,12 +6,15 @@
 
 #include "generated_plugin_registrant.h"
 
+#include <flutter_secure_storage_windows/flutter_secure_storage_windows_plugin.h>
 #include <permission_handler_windows/permission_handler_windows_plugin.h>
 #include <screen_brightness_windows/screen_brightness_windows_plugin.h>
 #include <share_plus/share_plus_windows_plugin_c_api.h>
 #include <url_launcher_windows/url_launcher_windows.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
+  FlutterSecureStorageWindowsPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("FlutterSecureStorageWindowsPlugin"));
   PermissionHandlerWindowsPluginRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("PermissionHandlerWindowsPlugin"));
   ScreenBrightnessWindowsPluginRegisterWithRegistrar(
diff --git a/windows/flutter/generated_plugins.cmake b/windows/flutter/generated_plugins.cmake
index 3b3429f..9a83522 100644
--- a/windows/flutter/generated_plugins.cmake
+++ b/windows/flutter/generated_plugins.cmake
@@ -3,6 +3,7 @@
 #
 
 list(APPEND FLUTTER_PLUGIN_LIST
+  flutter_secure_storage_windows
   permission_handler_windows
   screen_brightness_windows
   share_plus