public void run() {
try {
ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
BigInteger bg = dhSpec.getG();
BigInteger bp = dhSpec.getP();
oos.writeObject(bg);
oos.writeObject(bp);
KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
kpg.initialize(1024);
KeyPair kpa = (KeyPair) ois.readObject();
KeyAgreement dh = KeyAgreement.getInstance("DH");
KeyPair kp = kpg.generateKeyPair();
oos.writeObject(kp);
dh.init(kp.getPrivate());
Key pk = dh.doPhase(kpa.getPublic(), true);
MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
byte[] rawbits = sha256.digest(dh.generateSecret());
Cipher c = Cipher.getInstance(CIPHER_MODE);
SecretKey key = new SecretKeySpec(rawbits, 0, 16, "AES");
byte ivbits[] = (byte[]) ois.readObject();
IvParameterSpec iv = new IvParameterSpec(ivbits);
c.init(Cipher.DECRYPT_MODE, key, iv);
Mac m = Mac.getInstance("HmacSHA1");
SecretKey mackey = new SecretKeySpec(rawbits, 16, 16, "HmacSHA1");
m.init(mackey);
byte ciphertext[], cleartext[], mac[];
try {
while (true) {
ciphertext = (byte[]) ois.readObject();
mac = (byte[]) ois.readObject();
if (Arrays.equals(mac, m.doFinal(ciphertext))) {
cleartext = c.update(ciphertext);
System.out.println(ct + " : " + new String(cleartext, "UTF-8"));
} else {
// System.exit(1);
System.out.println(ct + "error");
}
}
} catch (EOFException e) {
cleartext = c.doFinal();
System.out.println(ct + " : " + new String(cleartext, "UTF-8"));
System.out.println("[" + ct + "]");
} finally {
if (ois != null) ois.close();
if (oos != null) oos.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
Provider p = new SampleProvider();
// Serialize and deserialize the above Provider object
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(p);
oos.close();
ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
ObjectInputStream ois = new ObjectInputStream(bais);
Provider p2 = (Provider) ois.readObject();
ois.close();
checkProviderInfoEntries(p2);
}
public static void main(String[] args) {
try {
if (args[0].equals("-genkey")) {
KeyPairGenerator pairgen = KeyPairGenerator.getInstance("RSA");
SecureRandom random = new SecureRandom();
pairgen.initialize(KEYSIZE, random);
KeyPair keyPair = pairgen.generateKeyPair();
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(args[1]));
out.writeObject(keyPair.getPublic());
out.close();
out = new ObjectOutputStream(new FileOutputStream(args[2]));
out.writeObject(keyPair.getPrivate());
out.close();
} else if (args[0].equals("-encrypt")) {
KeyGenerator keygen = KeyGenerator.getInstance("AES");
SecureRandom random = new SecureRandom();
keygen.init(random);
SecretKey key = keygen.generateKey();
// wrap with RSA public key
ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(args[3]));
Key publicKey = (Key) keyIn.readObject();
keyIn.close();
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.WRAP_MODE, publicKey);
byte[] wrappedKey = cipher.wrap(key);
DataOutputStream out = new DataOutputStream(new FileOutputStream(args[2]));
out.writeInt(wrappedKey.length);
out.write(wrappedKey);
InputStream in = new FileInputStream(args[1]);
cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, key);
crypt(in, out, cipher);
in.close();
out.close();
} else {
DataInputStream in = new DataInputStream(new FileInputStream(args[1]));
int length = in.readInt();
byte[] wrappedKey = new byte[length];
in.read(wrappedKey, 0, length);
// unwrap with RSA private key
ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(args[3]));
Key privateKey = (Key) keyIn.readObject();
keyIn.close();
Cipher cipher = Cipher.getInstance("RSA");
cipher.init(Cipher.UNWRAP_MODE, privateKey);
Key key = cipher.unwrap(wrappedKey, "AES", Cipher.SECRET_KEY);
OutputStream out = new FileOutputStream(args[2]);
cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, key);
crypt(in, out, cipher);
in.close();
out.close();
}
} catch (IOException e) {
e.printStackTrace();
} catch (GeneralSecurityException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public boolean connect(String username, String weakSecret, final String server, final int port) {
System.out.println("attempting to connect");
try {
sock = new Socket();
sock.connect(new InetSocketAddress(server, port));
output = new ObjectOutputStream(sock.getOutputStream());
input = new ObjectInputStream(sock.getInputStream());
output.writeObject(username);
// do DH exchange and agree on starting message index
try {
if (weakSecret != null) // group server connect
{
HashMap<String, SecretKey> secretKeys =
DHKeyExchange.generateSecretKeyWithWeakSecret(username, weakSecret, input, output);
if (secretKeys == null) throw new Exception("Unable to verify server");
encryptionKey = secretKeys.get("encryptionKey");
signingKey = secretKeys.get("signingKey");
} else // file server connect
{
PublicKey fileServerPublicKey = (PublicKey) input.readObject(); // read in public key
File savedKeys = new File("savedkeys.bin");
ArrayList<PublicKey> knownKeys = new ArrayList<PublicKey>();
if (savedKeys.exists()) {
ObjectInputStream in = new ObjectInputStream(new FileInputStream(savedKeys));
knownKeys = (ArrayList<PublicKey>) in.readObject();
}
if (!knownKeys.contains(fileServerPublicKey)) // prompt the user to verify the key
{
MessageDigest sha = MessageDigest.getInstance("SHA-1");
byte[] digest = sha.digest(fileServerPublicKey.getEncoded());
System.out.println("RSA key fingerprint is " + getFingerprint(digest));
System.out.println(
"Please verify this is correct by contacting the file server owner.");
System.out.println(
"Do you want to add this key to your list of saved servers? (yes/no)");
Scanner scanner = new Scanner(System.in);
String answer = scanner.nextLine();
if (answer.toLowerCase().equals("yes")) {
knownKeys.add(fileServerPublicKey);
savedKeys.delete();
savedKeys.createNewFile();
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(savedKeys));
out.writeObject(knownKeys);
out.flush();
out.close();
output.writeObject("yes");
} else {
output.writeObject("no");
System.out.println("Exiting");
System.exit(0);
}
} else // accpet the key without prompt
output.writeObject("yes");
generateRSAKeypair();
output.writeObject(publicKey);
HashMap<String, SecretKey> secretKeys =
DHKeyExchange.generateSecretKeySignedExchange(
input, output, privateKey, fileServerPublicKey);
if (secretKeys == null) throw new Exception("Unable to verify server");
encryptionKey = secretKeys.get("encryptionKey");
signingKey = secretKeys.get("signingKey");
}
encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
MessageDigest sha = MessageDigest.getInstance("SHA-1");
byte[] key = sha.digest(encryptionKey.getEncoded());
key = Arrays.copyOf(key, 16); // use only first 128 bit
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
encryptCipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, new IvParameterSpec(ivBytes));
decryptCipher.init(Cipher.DECRYPT_MODE, secretKeySpec, new IvParameterSpec(ivBytes));
BigInteger R = new BigInteger(128, new SecureRandom());
output.writeObject(encryptCipher.doFinal(R.toByteArray()));
BigInteger start = new BigInteger(decryptCipher.doFinal((byte[]) input.readObject()));
if (start.compareTo(R) < 0) throw new Exception("Invalid message index from server");
else messageIndex = start.add(BigInteger.ONE);
} catch (Exception ex) {
System.out.println("Failed to connect: " + ex.getMessage());
// if anything fails, we are not connected
sock = null;
return false;
}
} catch (IOException ex) {
return false;
}
return true;
}