'(x >= 0) && (x <= _MASK_32)': is not true

[hsynksahin]

After updating Flutter version pointy castle started to give me errors with the same code.

I am using the encrypt package which uses this package. The same encryption code was working a few days ago, I have upgraded the flutter now its gives me 'package:pointycastle/src/ufixnum.dart': Failed assertion: line 198 pos 10: '(x >= 0) && (x <= _MASK_32)': is not true. error when I try to encrypt something with it. Can anyone explain why this could be happen?

When I downgraded the flutter to 3.19.0 and there is no problem, but after upgrading to 3.19.1 the exception occurs.

[hsynksahin]

Now it happens even in flutter 3.19.0. Can we at least have a error message for this one ?

Problem occurres when I encrypt a dummy password like 123456
Using version 3.7.4 (latest) // Also tested at 3.7.3
Encryption (5.0.3)

Here is my flutter doctor at any case:

[✓] Flutter (Channel stable, 3.19.0, on macOS 14.2.1 23C71 darwin-arm64, locale en-TR)
    • Flutter version 3.19.0 on channel stable at /Applications/Development/tools/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision bae5e49bc2 (13 days ago), 2024-02-13 17:46:18 -0800
    • Engine revision 04817c99c9
    • Dart version 3.3.0
    • DevTools version 2.31.1

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at /Applications/Development/tools/sdk
    • Platform android-34, build-tools 34.0.0
    • Java binary at: /Applications/Development/apps/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.7+0-17.0.7b1000.6-10550314)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 15.2)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 15C500b
    • CocoaPods version 1.15.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2023.1)
    • Android Studio at /Applications/Development/apps/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • android-studio-dir = /Applications/Development/apps/Android Studio.app
    • Java version OpenJDK Runtime Environment (build 17.0.7+0-17.0.7b1000.6-10550314)

[✓] VS Code (version 1.86.2)
    • VS Code at /Applications/Development/apps/Visual Studio Code.app/Contents
    • Flutter extension version 3.82.0

[✓] Connected device (3 available)
    • iPhone X (mobile) • DF1A73AF-23A9-40FE-B341-E23944D7524D • ios            • com.apple.CoreSimulator.SimRuntime.iOS-15-0 (simulator)
    • macOS (desktop)   • macos                                • darwin-arm64   • macOS 14.2.1 23C71 darwin-arm64
    • Chrome (web)      • chrome                               • web-javascript • Google Chrome 121.0.6167.184

[✓] Network resources
    • All expected network resources are available.

• No issues found!

[hsynksahin]

The code that trying to encrypt the data:

(IStorageRepository is basicly a SharedPrefferences)

class TwoWayAES extends ITwoWayEncryption {
  static const AESMode _mode = AESMode.ofb64Gctr;

  // secure storage
  final IStorageRepository secureStorage;

  const TwoWayAES({required this.secureStorage});

  @override
  Future<String> encrypt(String plainText) async {
    final key = Key.fromUtf8(EncryptionEnv.privateKey);
    final encrypter = Encrypter(AES(key, mode: _mode));

    final encrypted = encrypter.encrypt(plainText, iv: await getIv);

    return encrypted.base64;
  }

  @override
  Future<String> decrypt(String base64) async {
    final key = Key.fromUtf8(EncryptionEnv.privateKey);
    final encrypter = Encrypter(AES(key, mode: _mode));

    var encrypted = Encrypted.fromBase64(base64);
    final decrypted = encrypter.decrypt(encrypted, iv: await getIv);

    return decrypted;
  }

  @override
  Future<bool> isValid(String encryptedText, String test) async {
    final key = Key.fromUtf8(EncryptionEnv.privateKey);
    final encrypter = Encrypter(AES(key, mode: _mode));

    final encryptedTest = encrypter.encrypt(test, iv: await getIv);
    var result = encryptedText.compareTo(encryptedTest.base64) == 0;

    return result;
  }

  Future<IV> get getIv async {
    var iv = await secureStorage.read(EncryptionEnv.publicKey);

    if (iv == null) {
      var newIv = IV.fromSecureRandom(16);

      await secureStorage.write(EncryptionEnv.publicKey, newIv.base64);
      return newIv;
    } else {
      return IV.fromBase64(iv);
    }
  }
}

Note: It seems like problem is with the ofb64Gctr. I switched mode to ctr now I'm not taking any errors.

Also oppened an issue at encryption repository to direct here.

[dodatw]

Hi hsynksahin

Did you find solution? I face same issue when upgrade from 3.13.7 to 3.24.3.
I cannot reproduce this issue, but on firebase crashlytics:

Using pointycastle (3.7.4) / encrypt (5.0.3)

          Crashed: io.flutter.1.ui
0  App                            0x5e3254 pack32 + 197 (ufixnum.dart:197)
1  App                            0x5e3188 pack32 + 197 (ufixnum.dart:197)
2  App                            0xc70abc AESEngine._decryptBlock + 1548 (aes.dart:1548)
3  App                            0xc6ee68 AESEngine.processBlock + 1325 (aes.dart:1325)
4  App                            0xc73cac ECBBlockCipher.processBlock + 40 (ecb.dart:40)
5  App                            0xc83d94 PaddedBlockCipherImpl.processBlock + 79 (padded_block_cipher_impl.dart:79)
6  App                            0xc844a0 PaddedBlockCipherImpl.doFinal + 112 (padded_block_cipher_impl.dart:112)
7  App                            0xc84014 PaddedBlockCipherImpl.process + 74 (padded_block_cipher_impl.dart:74)
8  App                            0xb7dcf0 AES.decrypt + 49 (aes.dart:49)
9  App                            0x5b31d0 Encrypter.decryptBytes + 40 (encrypter.dart:40)
10 App                            0x5b3164 Encrypter.decrypt + 49 (encrypter.dart:49)
11 App                            0x5b308c FileEncryptUtils.decryptUrlFromServer + 25 (file_encrypt_utils.dart:25)
12 App                            0x5b2db4 UploadUtils.downloadVideo + 777 (upload_utils.dart:777)
13 App                            0xca785c SuspendState._createAsyncStarCallback.<anonymous closure> + 384 (async_patch.dart:384)
14 App                            0x23e04 FutureListener.handleValue + 1662 (zone.dart:1662)
15 App                            0x23ca0 Future._propagateToListeners.handleValueCallback + 863 (future_impl.dart:863)
16 App                            0x1480c Future._propagateToListeners + 894 (future_impl.dart:894)
17 App                            0x14490 Future._completeWithValue + 661 (future_impl.dart:661)
18 App                            0xca7c30 SuspendState._returnAsyncNotFuture + 359 (async_patch.dart:359)
19 App                            0x3dc38 stub _iso_stub_ReturnAsyncNotFutureStub + 193336
20 App                            0xca785c SuspendState._createAsyncStarCallback.<anonymous closure> + 384 (async_patch.dart:384)
21 App                            0x23e04 FutureListener.handleValue + 1662 (zone.dart:1662)
22 App                            0x23ca0 Future._propagateToListeners.handleValueCallback + 863 (future_impl.dart:863)
23 App                            0x1480c Future._propagateToListeners + 894 (future_impl.dart:894)
24 App                            0x14490 Future._completeWithValue + 661 (future_impl.dart:661)
25 App                            0xca7c30 SuspendState._returnAsyncNotFuture + 359 (async_patch.dart:359)
26 App                            0x3dc38 stub _iso_stub_ReturnAsyncNotFutureStub + 193336
27 App                            0xca785c SuspendState._createAsyncStarCallback.<anonymous closure> + 384 (async_patch.dart:384)
28 App                            0x23e04 FutureListener.handleValue + 1662 (zone.dart:1662)
29 App                            0x23ca0 Future._propagateToListeners.handleValueCallback + 863 (future_impl.dart:863)
30 App                            0x1480c Future._propagateToListeners + 894 (future_impl.dart:894)
31 App                            0x14490 Future._completeWithValue + 661 (future_impl.dart:661)
32 App                            0x14404 Future._asyncCompleteWithValue.<anonymous closure> + 735 (future_impl.dart:735)
33 App                            0x14290 microtaskLoop + 34 (schedule_microtask.dart:34)
34 App                            0x14190 startMicrotaskLoop (#2) + 54 (schedule_microtask.dart:54)
35 App                            0x14154 startMicrotaskLoop + 44 (schedule_microtask.dart:44)
36 App                            0xbbac stub InvokeDartCode + 31660
37 Flutter                        0x62b748 dart::DartEntry::InvokeFunction(dart::Function const&, dart::Array const&, dart::Array const&) + 33 (allocation.h:33)
38 Flutter                        0x732e9c Dart_InvokeClosure + 4671 (dart_api_impl.cc:4671)
39 Flutter                        0x59adb4 tonic::DartMicrotaskQueue::RunMicrotasks() + 77 (dart_microtask_queue.cc:77)
40 Flutter                        0x7eaec fml::MessageLoopImpl::FlushTasks(fml::FlushType) + 100 (wrap_iter.h:100)
41 Flutter                        0x81e5c fml::MessageLoopDarwin::OnTimerFire(__CFRunLoopTimer*, fml::MessageLoopDarwin*) + 86 (message_loop_darwin.mm:86)
42 CoreFoundation                 0xb7a2c __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 32
43 CoreFoundation                 0xb76d0 __CFRunLoopDoTimer + 1004
44 CoreFoundation                 0xb722c __CFRunLoopDoTimers + 288
45 CoreFoundation                 0x53888 __CFRunLoopRun + 1856
46 CoreFoundation                 0x52cd8 CFRunLoopRunSpecific + 608
47 Flutter                        0x81f48 fml::MessageLoopDarwin::Run() + 52 (message_loop_darwin.mm:52)
48 Flutter                        0x81b90 std::_fl::__function::__func<fml::Thread::Thread(std::_fl::function<void (fml::Thread::ThreadConfig const&)> const&, fml::Thread::ThreadConfig const&)::$_0, std::_fl::allocator<fml::Thread::Thread(std::_fl::function<void (fml::Thread::ThreadConfig const&)> const&, fml::Thread::ThreadConfig const&)::$_0>, void ()>::operator()() + 94 (message_loop_impl.cc:94)
49 Flutter                        0x81820 fml::ThreadHandle::ThreadHandle(std::_fl::function<void ()>&&)::$_0::__invoke(void*) + 470 (function.h:470)
50 libsystem_pthread.dylib        0x606c _pthread_start + 136
51 libsystem_pthread.dylib        0x10d8 thread_start + 8
        

code

  static String decryptUrlFromServer(String encUrl, String aesKey) {
    final encrypter = Encrypter(AES(Key.fromBase64(aesKey), mode: AESMode.ecb));
    final encrypted = Encrypted.fromBase64(encUrl);
    return encrypter.decrypt(encrypted, iv: IV.fromLength(16));
  }

Thanks.

[hsynksahin]

Unfortunately I did not! But staying in specific version does it. Just initialize a seperate package with seperate pubspec.yaml so the flutter pub upgrade wont update it. And for some reason if its gonna updated put some description. This is how I solved. Here is my versions:

encrypt: 5.0.3 # last working: 5.0.3
pointycastle: 3.9.1 # last working: 3.9.1

And Im using static const AESMode _mode = AESMode.ofb64; as mode now. (Dont really know what changes)

Hope this will work for you too.