private static PublicKey receivePublicKey(final DataInputStream in)
throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
final byte[] keyBytes = new byte[in.readInt()];
in.readFully(keyBytes);
final KeyFactory kf = KeyFactory.getInstance(KeyExchange.DH.value());
final X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(keyBytes);
final PublicKey theirPublicKey = kf.generatePublic(x509Spec);
return theirPublicKey;
}
private static void generateSecretValue(final PublicKey theirPublicKey)
throws NoSuchAlgorithmException, InvalidKeyException {
final KeyAgreement ka = KeyAgreement.getInstance(KeyExchange.DH.value());
ka.init(keyPair.getPrivate());
ka.doPhase(theirPublicKey, true);
secret = ka.generateSecret();
// LOG.info(MessageFormat.format("Secret value generated by SkipClient:{0}", new
// String(Base64.encodeBase64(secret)), "UTF-8"));
}
public static void start()
throws IOException, NoSuchAlgorithmException, InvalidAlgorithmParameterException,
InvalidKeySpecException, InvalidKeyException {
// Create a Diffie-Hellman Key pair
final KeyPairGen kpg = new KeyPairGen(KeyExchange.DH.value(), Skip.sDHParameterSpec);
keyPair = kpg.getKeyPair();
// Open the network connection
LOG.info("Connecting to Server:" + host + ":" + port);
final Socket s = new Socket(host, port);
LOG.info("Connected!");
final DataOutputStream out = new DataOutputStream(s.getOutputStream());
final DataInputStream in = new DataInputStream(s.getInputStream());
sendPublicKey(out);
LOG.info("Public key sent to server.");
final PublicKey theirPublicKey = receivePublicKey(in);
LOG.info("Public key received from server.");
generateSecretValue(theirPublicKey);
}