flutter_ever_crypto

A Flutter plugin that provides XChaCha20Poly1305 and Kyber1024 post-quantum cryptography through FFI bindings to the Rust ever-crypto library.

Features

  • XChaCha20Poly1305: Authenticated encryption with extended nonce
  • Kyber1024: Post-quantum key encapsulation mechanism
  • Cross-platform: Supports Android, iOS, Linux, macOS, and Windows
  • High performance: Native Rust implementation with FFI bindings
  • Memory safe: Proper memory management with automatic cleanup

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  flutter_ever_crypto: ^0.1.2

Usage

XChaCha20Poly1305 Encryption/Decryption

import 'package:flutter_ever_crypto/flutter_ever_crypto.dart';

// Generate a random key and nonce
final key = EverCrypto.generateXChaChaKey();
final nonce = EverCrypto.generateXChaChaNonce();

// Encrypt data
final plaintext = Uint8List.fromList(utf8.encode('Hello, World!'));
final ciphertext = EverCrypto.xchachaEncrypt(key, nonce, plaintext);

// Decrypt data
final decrypted = EverCrypto.xchachaDecrypt(key, nonce, ciphertext);
final decryptedText = utf8.decode(decrypted);
print(decryptedText); // Output: Hello, World!

Kyber1024 Key Exchange

import 'package:flutter_ever_crypto/flutter_ever_crypto.dart';

// Generate a key pair
final keyPair = EverCrypto.generateKyberKeyPair();

// Encapsulate a shared secret (Alice's side)
final encapsulateResult = EverCrypto.kyberEncapsulate(keyPair.publicKey);

// Decapsulate the shared secret (Bob's side)
final decapsulatedSecret = EverCrypto.kyberDecapsulate(
  encapsulateResult.ciphertext, 
  keyPair.secretKey
);

// Both sides now have the same shared secret
print(encapsulateResult.sharedSecret.toString() == decapsulatedSecret.toString()); // true

API Reference

EverCrypto Class

XChaCha20Poly1305 Methods

  • Uint8List generateXChaChaKey(): Generate a random 32-byte key
  • Uint8List generateXChaChaNonce(): Generate a random 24-byte nonce
  • Uint8List xchachaEncrypt(Uint8List key, Uint8List nonce, Uint8List plaintext, {Uint8List? aad}): Encrypt data
  • Uint8List xchachaDecrypt(Uint8List key, Uint8List nonce, Uint8List ciphertext, {Uint8List? aad}): Decrypt data

Kyber1024 Methods

  • KyberKeyPair generateKyberKeyPair(): Generate a new key pair
  • KyberEncapsulateResult kyberEncapsulate(Uint8List publicKey): Encapsulate a shared secret
  • Uint8List kyberDecapsulate(Uint8List ciphertext, Uint8List secretKey): Decapsulate a shared secret

Data Structures

  • KyberKeyPair: Contains public and secret keys
  • KyberEncapsulateResult: Contains shared secret and ciphertext

Error Handling

The plugin throws EverCryptoException when operations fail:

try {
  final key = EverCrypto.generateXChaChaKey();
  // ... use the key
} on EverCryptoException catch (e) {
  print('Crypto operation failed: ${e.message}');
}

Platform Support

  • ✅ Android
  • ✅ iOS
  • ✅ Linux
  • ✅ macOS
  • ✅ Windows

Dependencies

This plugin depends on the Rust ever-crypto library which provides:

  • chacha20poly1305: XChaCha20Poly1305 implementation
  • pqcrypto-kyber: Kyber1024 implementation
  • zeroize: Secure memory zeroing

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Libraries

flutter_ever_crypto