encrypt method

Uint8List encrypt(Uint8List key, Uint8List plaintext)

Encrypt: returns nonce(12) | ciphertext | tag(16).

Implementation

Uint8List encrypt(Uint8List key, Uint8List plaintext) {
  final nonce =
      Uint8List.fromList(List.generate(12, (_) => _rng.nextInt(256)));
  return using((a) {
    final hAlg = _openGcmAlg(a);
    final hKey = _genSymKey(a, hAlg, key);
    try {
      final nonceP = a<Uint8>(12)..asTypedList(12).setAll(0, nonce);
      final tagP = a<Uint8>(16);
      final inP = a<Uint8>(plaintext.isEmpty ? 1 : plaintext.length);
      if (plaintext.isNotEmpty) {
        inP.asTypedList(plaintext.length).setAll(0, plaintext);
      }
      final outP = a<Uint8>(plaintext.isEmpty ? 1 : plaintext.length);
      final info = _authInfo(a, nonceP, tagP);
      final cbResult = a<Uint32>();
      final st = _encryptFn(hKey, inP, plaintext.length, info.cast(), nullptr,
          0, outP, plaintext.length, cbResult, 0);
      if (st != _statusSuccess) {
        throw StateError('BCryptEncrypt failed (status=$st)');
      }
      final ctLen = cbResult.value;
      final out = Uint8List(12 + ctLen + 16);
      out.setRange(0, 12, nonce);
      if (ctLen > 0) out.setRange(12, 12 + ctLen, outP.asTypedList(ctLen));
      out.setRange(12 + ctLen, out.length, tagP.asTypedList(16));
      return out;
    } finally {
      _destroyKey(hKey);
      _closeAlg(hAlg, 0);
    }
  });
}