jc_crypto_hashing

A Flutter plugin providing Android JCA (Java Cryptography Architecture) backend for cryptographic operations.

This package uses package:jnigen to call native Android Java APIs directly from Dart, avoiding the need for bundling external native binaries like BoringSSL for basic cryptographic tasks on Android.

Features

• Hashing: SHA-256, SHA-512
• HMAC: HMAC-SHA256
• AES-GCM: Encryption, Decryption, and Key Generation
• Additional Authenticated Data (AAD): Supported for AES-GCM
• Hardware-Backed Keys: Support for Android Keystore (KeyStore aliases)
• Performance: Optimized using ThreadLocal Cipher reuse

Usage

import 'package:jc_crypto_hashing/jc_crypto_hashing.dart';
import 'dart:typed_data';

void main() async {
  final crypto = CryptoJCA();
  
  // 1. Generation of a secure Software Key
  final key = await crypto.generateSoftwareKey(bits: 256);
  
  // 2. Prepare data, IV and AAD
  final data = Uint8List.fromList("Sensitive Content".codeUnits);
  final iv = CryptoJCA.generateIv();
  final aad = Uint8List.fromList("AAD-String".codeUnits);

  // 3. Encrypt using the CryptoKey object
  final encrypted = await crypto.aesGcmEncrypt(
    data, 
    iv, 
    cryptoKey: key, 
    additionalData: aad
  );
  
  // 4. Decrypt 
  final decrypted = await crypto.aesGcmDecrypt(
    encrypted, 
    iv, 
    cryptoKey: key, 
    additionalData: aad
  );
  
  print(String.fromCharCodes(decrypted)); // "Sensitive Content"
}

Using Android Keystore (Hardware Backed)

// Generate a key that stays in the security hardware
final keystoreKey = await crypto.generateKeystoreKey("my_identifier");

// Encrypt - the raw key never enters Dart/user memory
final encrypted = await crypto.aesGcmEncrypt(data, iv, cryptoKey: keystoreKey);

Platform Support

This package is specifically designed for Android. It is intended as a high-performance, system-native alternative for package:webcrypto and other cryptographic needs.

Setup

No special setup is required. The package automatically handles the JNI bindings and Java code and bundles them into your Android APK/AAB.