cleaner backup changes

lib/core/backup_service.dart

@@ -28,11 +28,10 @@ class BackupService {
       : _cipher = Cryptography.instance.chacha20Poly1305Aead(),
         _correctWallets = <WalletInfo>[];
 
-  static const currentVersion = _v3;
+  static const currentVersion = _v2;
 
   static const _v1 = 1;
   static const _v2 = 2;
-  static const _v3 = 3;
 
   final Cipher _cipher;
   final FlutterSecureStorage _flutterSecureStorage;
@@ -54,9 +53,6 @@ class BackupService {
       case _v2:
         await _importBackupV2(data, password);
         break;
-      case _v3:
-        await _importBackupV3(data, password);
-        break;
       default:
         break;
     }
@@ -69,8 +65,6 @@ class BackupService {
         return await _exportBackupV1(password, nonce: nonce);
       case _v2:
         return await _exportBackupV2(password);
-      case _v3:
-        return await _exportBackupV3(password);
       default:
         throw Exception('Incorrect version: $version for exportBackup');
     }
@@ -80,16 +74,14 @@ class BackupService {
   Future<Uint8List> _exportBackupV1(String password, {String nonce = secrets.backupSalt}) async =>
       throw Exception('Deprecated. Export for backups v1 is deprecated. Please use export v2.');
 
-  Future<Uint8List> _exportBackupV2(String password, {bool keychainV3 = false}) async {
+  Future<Uint8List> _exportBackupV2(String password) async {
     final zipEncoder = ZipFileEncoder();
     final appDir = await getApplicationDocumentsDirectory();
     final now = DateTime.now();
     final tmpDir = Directory('${appDir.path}/~_BACKUP_TMP');
     final archivePath = '${tmpDir.path}/backup_${now.toString()}.zip';
     final fileEntities = appDir.listSync(recursive: false);
-    final keychainDump = keychainV3
+    final keychainDump = await _exportKeychainDumpV2(password);
-        ? (await _exportKeychainDumpV2(password))
-        : (await _exportKeychainDumpV3(password));
     final preferencesDump = await _exportPreferencesJSON();
     final preferencesDumpFile = File('${tmpDir.path}/~_preferences_dump_TMP');
     final keychainDumpFile = File('${tmpDir.path}/~_keychain_dump_TMP');
@@ -123,10 +115,6 @@ class BackupService {
     return await _encryptV2(content, password);
   }
 
-  Future<Uint8List> _exportBackupV3(String password) async {
-    return await _exportBackupV2(password, keychainV3: true);
-  }
-
   Future<void> _importBackupV1(Uint8List data, String password, {required String nonce}) async {
     final appDir = await getApplicationDocumentsDirectory();
     final decryptedData = await _decryptV1(data, password, nonce);
@@ -150,7 +138,7 @@ class BackupService {
     await _importPreferencesDump();
   }
 
-  Future<void> _importBackupV2(Uint8List data, String password, {bool keychainV3 = false}) async {
+  Future<void> _importBackupV2(Uint8List data, String password) async {
     final appDir = await getApplicationDocumentsDirectory();
     final decryptedData = await _decryptV2(data, password);
     final zip = ZipDecoder().decodeBytes(decryptedData);
@@ -169,18 +157,10 @@ class BackupService {
     });
 
     await _verifyWallets();
-    if (keychainV3) {
-      await _importKeychainDumpV3(password);
-    } else {
     await _importKeychainDumpV2(password);
-    }
     await _importPreferencesDump();
   }
 
-  Future<void> _importBackupV3(Uint8List data, String password) async {
-    await _importBackupV2(data, password, keychainV3: true);
-  }
-
   Future<void> _verifyWallets() async {
     final walletInfoSource = await _reloadHiveWalletInfoBox();
     _correctWallets =
@@ -465,6 +445,7 @@ class BackupService {
     });
 
     await _flutterSecureStorage.delete(key: pinCodeKey);
+    // we know it's the old pin format since it's a v1 import:
     await _flutterSecureStorage.write(
         key: pinCodeKey, value: (await argon2Hash(password: decodedPin)));
 
@@ -480,7 +461,7 @@ class BackupService {
     final keychainJSON =
         json.decode(utf8.decode(decryptedKeychainDumpFileData)) as Map<String, dynamic>;
     final keychainWalletsInfo = keychainJSON['wallets'] as List;
-    final decodedPin = keychainJSON['pin'] as String;
+    final potentiallyDecodedPin = keychainJSON['pin'] as String;
     final pinCodeKey = generateStoreKeyFor(key: SecretStoreKey.pinCodePassword);
     final backupPasswordKey = generateStoreKeyFor(key: SecretStoreKey.backupPassword);
     final backupPassword = keychainJSON[backupPasswordKey] as String;
@@ -493,35 +474,14 @@ class BackupService {
       await importWalletKeychainInfo(info);
     });
 
-    await _flutterSecureStorage.delete(key: pinCodeKey);
+    late String encodedPin;
-    await _flutterSecureStorage.write(
+    // not a formal check but an argon2 hash is always going to be > 10 characters long (and decoded pins either 4 or 6)
-        key: pinCodeKey, value: (await argon2Hash(password: decodedPin)));
+    if (potentiallyDecodedPin.length < 10) {
-
+      encodedPin = await argon2Hash(password: potentiallyDecodedPin);
-    keychainDumpFile.deleteSync();
+    } else {
+      encodedPin = potentiallyDecodedPin;
     }
 
-  Future<void> _importKeychainDumpV3(String password,
-      {String keychainSalt = secrets.backupKeychainSalt}) async {
-    final appDir = await getApplicationDocumentsDirectory();
-    final keychainDumpFile = File('${appDir.path}/~_keychain_dump');
-    final decryptedKeychainDumpFileData =
-        await _decryptV3(keychainDumpFile.readAsBytesSync(), '$keychainSalt$password');
-    final keychainJSON =
-        json.decode(utf8.decode(decryptedKeychainDumpFileData)) as Map<String, dynamic>;
-    final keychainWalletsInfo = keychainJSON['wallets'] as List;
-    final encodedPin = keychainJSON['pin'] as String;
-    final pinCodeKey = generateStoreKeyFor(key: SecretStoreKey.pinCodePassword);
-    final backupPasswordKey = generateStoreKeyFor(key: SecretStoreKey.backupPassword);
-    final backupPassword = keychainJSON[backupPasswordKey] as String;
-
-    await _flutterSecureStorage.delete(key: backupPasswordKey);
-    await _flutterSecureStorage.write(key: backupPasswordKey, value: backupPassword);
-
-    keychainWalletsInfo.forEach((dynamic rawInfo) async {
-      final info = rawInfo as Map<String, dynamic>;
-      await importWalletKeychainInfo(info);
-    });
-
     await _flutterSecureStorage.delete(key: pinCodeKey);
     await _flutterSecureStorage.write(key: pinCodeKey, value: encodedPin);
 
@@ -561,26 +521,6 @@ class BackupService {
     return encrypted;
   }
 
-  Future<Uint8List> _exportKeychainDumpV3(String password,
-      {String keychainSalt = secrets.backupKeychainSalt}) async {
-    final key = generateStoreKeyFor(key: SecretStoreKey.pinCodePassword);
-    final encodedPin = await _flutterSecureStorage.read(key: key);
-    final wallets = await Future.wait(_walletInfoSource.values.map((walletInfo) async {
-      return {
-        'name': walletInfo.name,
-        'type': walletInfo.type.toString(),
-        'password': await _keyService.getWalletPassword(walletName: walletInfo.name)
-      };
-    }));
-    final backupPasswordKey = generateStoreKeyFor(key: SecretStoreKey.backupPassword);
-    final backupPassword = await _flutterSecureStorage.read(key: backupPasswordKey);
-    final data = utf8.encode(
-        json.encode({'pin': encodedPin, 'wallets': wallets, backupPasswordKey: backupPassword}));
-    final encrypted = await _encryptV3(Uint8List.fromList(data), '$keychainSalt$password');
-
-    return encrypted;
-  }
-
   Future<String> _exportPreferencesJSON() async {
     final preferences = <String, dynamic>{
       PreferencesKey.currentWalletName:
@@ -689,10 +629,4 @@ class BackupService {
 
   Future<Uint8List> _decryptV2(Uint8List data, String passphrase) async =>
       cake_backup.decrypt(passphrase, data);
-
-  Future<Uint8List> _encryptV3(Uint8List data, String passphrase) async =>
-      cake_backup.encrypt(passphrase, data, version: _v3);
-
-  Future<Uint8List> _decryptV3(Uint8List data, String passphrase) async =>
-      cake_backup.decrypt(passphrase, data);
 }