How to use

ECIESTest

in

io.yggdrash.common.crypto

@Test
public void testRoundTrip() throws InvalidCipherTextException, IOException {
  ECPoint pub1 = pub(PRIVATE_KEY1);
  byte[] plaintext = "Hello world".getBytes();
  byte[] ciphertext = encrypt(pub1, plaintext);
  byte[] plaintext1 = decrypt(PRIVATE_KEY1, ciphertext);
  assertArrayEquals(plaintext, plaintext1);
}

private static byte[] decrypt(BigInteger prv, byte[] cipher) throws InvalidCipherTextException, IOException {
  ByteArrayInputStream is = new ByteArrayInputStream(cipher);
  byte[] ephemBytes = new byte[2 * ((curve.getCurve().getFieldSize() + 7) / 8) + 1];
  is.read(ephemBytes);
  ECPoint ephem = curve.getCurve().decodePoint(ephemBytes);
  byte[] IV = new byte[KEY_SIZE / 8];
  is.read(IV);
  byte[] cipherBody = new byte[is.available()];
  is.read(cipherBody);
  EthereumIESEngine iesEngine = makeIESEngine(false, ephem, prv, IV);
  return iesEngine.processBlock(cipherBody, 0, cipherBody.length);
}

@Test
public void testDecryptTestVector() throws IOException, InvalidCipherTextException {
  byte[] ciphertext = Hex.decode(CIPHERTEXT1);
  byte[] plaintext = decrypt(PRIVATE_KEY1, ciphertext);
  assertArrayEquals(new byte[] {1, 1, 1}, plaintext);
}

private static byte[] encrypt(ECPoint toPub, byte[] plaintext) throws InvalidCipherTextException, IOException {
  ECKeyPairGenerator eGen = new ECKeyPairGenerator();
  SecureRandom random = new SecureRandom();
  KeyGenerationParameters gParam = new ECKeyGenerationParameters(curve, random);
  eGen.init(gParam);
  byte[] IV = new byte[KEY_SIZE / 8];
  new SecureRandom().nextBytes(IV);
  AsymmetricCipherKeyPair ephemPair = eGen.generateKeyPair();
  BigInteger prv = ((ECPrivateKeyParameters) ephemPair.getPrivate()).getD();
  ECPoint pub = ((ECPublicKeyParameters) ephemPair.getPublic()).getQ();
  EthereumIESEngine iesEngine = makeIESEngine(true, toPub, prv, IV);
  ECKeyGenerationParameters keygenParams = new ECKeyGenerationParameters(curve, random);
  ECKeyPairGenerator generator = new ECKeyPairGenerator();
  generator.init(keygenParams);
  ECKeyPairGenerator gen = new ECKeyPairGenerator();
  gen.init(new ECKeyGenerationParameters(ECKey.CURVE, random));
  byte[] cipher = iesEngine.processBlock(plaintext, 0, plaintext.length);
  ByteArrayOutputStream bos = new ByteArrayOutputStream();
  bos.write(pub.getEncoded(false));
  bos.write(IV);
  bos.write(cipher);
  return bos.toByteArray();
}