decryptWithAgreement static method

String decryptWithAgreement(String message, ECDHBasicAgreement agreement, String publicKey)

Implementation

static String decryptWithAgreement(
    String message, ECDHBasicAgreement agreement, String publicKey) {
  var strs = message.split("?iv=");
  if (strs.length != 2) {
    return "";
  }
  message = strs[0];
  var iv = strs[1];
  var ivData = base64.decode(iv);

  var pubKey = getPubKey(publicKey);
  var agreementD0 = agreement.calculateAgreement(pubKey);
  var encryptKey = agreementD0.toRadixString(16).padLeft(64, "0");

  // var encrypter = Encrypter(AES(
  //     Key(Uint8List.fromList(hex.decode(encryptKey))),
  //     mode: AESMode.cbc));
  // return encrypter.decrypt(Encrypted.from64(message), iv: IV.fromBase64(iv));

  final cipherCbc =
      PaddedBlockCipherImpl(PKCS7Padding(), CBCBlockCipher(AESEngine()));
  final paramsCbc = PaddedBlockCipherParameters(
      ParametersWithIV(
          KeyParameter(Uint8List.fromList(hex.decode(encryptKey))), ivData),
      null);
  cipherCbc.init(false, paramsCbc);

  var result = cipherCbc.process(base64.decode(message));

  return utf8.decode(result);
}