cryptoBoxBeforeNm method

Uint8List cryptoBoxBeforeNm(KeyPair keyPair)

Implementation

Uint8List cryptoBoxBeforeNm(KeyPair keyPair) {
  // Allocate memory for the shared secret key (k), public key (pk), and secret key (sk)
  final sharedSecretKey = calloc<ffi.Uint8>(crypto_box_BEFORENMBYTES);
  final publicKey = calloc<ffi.Uint8>(crypto_box_PUBLICKEYBYTES);
  final secretKey = calloc<ffi.Uint8>(crypto_box_SECRETKEYBYTES);

  try {
    // Fill publicKey and secretKey with your values
    for (var i = 0; i < crypto_box_PUBLICKEYBYTES; i++) {
      publicKey.elementAt(i).value = keyPair.pk[i];
    }
    for (var i = 0; i < crypto_box_SECRETKEYBYTES; i++) {
      secretKey.elementAt(i).value = keyPair.sk[i];
    }

    // Call crypto_box_beforenm to compute the shared secret key
    final result = crypto_box_beforenm(
      sharedSecretKey.cast<ffi.UnsignedChar>(),
      publicKey.cast<ffi.UnsignedChar>(),
      secretKey.cast<ffi.UnsignedChar>(),
    );

    if (result == 0) {
      // Print the computed shared secret key
      final sharedSecretKeyList =
          sharedSecretKey.asTypedList(crypto_box_BEFORENMBYTES);
      // Clone the original list
      return Uint8List.fromList(List.from(sharedSecretKeyList));
    } else {
      debugPrint('[Lazysodium] Crypto box before nm failed.');
      return Uint8List(0);
    }
  } finally {
    // Free allocated memory
    calloc.free(sharedSecretKey);
    calloc.free(publicKey);
    calloc.free(secretKey);
  }
}