aesCbcEncrypt static method

Uint8List aesCbcEncrypt(
  1. Uint8List key,
  2. Uint8List iv,
  3. String text
)

Implementation

static Uint8List aesCbcEncrypt(
  Uint8List key,
  Uint8List iv,
  String text,
) {
  final paddedPlaintext = pad(utf8.encode(text) as Uint8List, 16);
  if (![128, 192, 256].contains(key.length * 8)) {
    throw ArgumentError.value(key, 'key', 'invalid key length for AES');
  }
  if (iv.length * 8 != 128) {
    throw ArgumentError.value(iv, 'iv', 'invalid IV length for AES');
  }
  if (paddedPlaintext.length * 8 % 128 != 0) {
    throw ArgumentError.value(
        paddedPlaintext, 'paddedPlaintext', 'invalid length for AES');
  }

  // Create a CBC block cipher with AES, and initialize with key and IV

  final cbc = BlockCipher('AES/CBC')
    ..init(true, ParametersWithIV(KeyParameter(key), iv)); // true=encrypt

  // Encrypt the plaintext block-by-block

  final cipherText = Uint8List(paddedPlaintext.length); // allocate space

  var offset = 0;
  while (offset < paddedPlaintext.length) {
    offset += cbc.processBlock(paddedPlaintext, offset, cipherText, offset);
  }
  assert(offset == paddedPlaintext.length);

  return cipherText;
}