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 savePublicKeyInFile(String path, PublicKey key) {
try {
KeyFactory fac = KeyFactory.getInstance("RSA");
RSAPublicKeySpec RSAspec = fac.getKeySpec(key, RSAPublicKeySpec.class);
FileOutputStream file3 = new FileOutputStream(path);
ObjectOutputStream obj_stream = new ObjectOutputStream(file3);
obj_stream.writeObject(RSAspec.getModulus());
obj_stream.writeObject(RSAspec.getPublicExponent());
} catch (Exception ex) {
System.err.println("Probeleme de sauvegarde de la cle public dans un fichier: " + ex);
}
}
private static void saveKey(String fileName, Key key) {
try {
FileOutputStream fos = new FileOutputStream(new File(fileName));
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(key);
oos.flush();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Sends the specified file to the client. File must exist or client and server threads will hang
* indefinitely. Generates a session key to encrypt the file over transfer; session key is
* encrypted using the client's public (asymmetric) key.
*
* @param aFile The name or path of the file to send.
* @throws IOException Error reading from socket.
*/
private void sendFile(String aFile) throws IOException {
try {
// get client public key
ObjectInputStream clientPubIn = new ObjectInputStream(connectedSocket.getInputStream());
PublicKey clientPublicKey = (PublicKey) clientPubIn.readObject();
// generate key string and send to client using their public key encrypted with RSA
// (asymmetric)
String keyString = generateKeyString();
Cipher keyCipher = Cipher.getInstance("RSA");
keyCipher.init(Cipher.ENCRYPT_MODE, clientPublicKey);
SealedObject sealedKeyString = new SealedObject(keyString, keyCipher);
ObjectOutputStream testOut = new ObjectOutputStream(outToClient);
testOut.writeObject(sealedKeyString);
testOut.flush();
// generate key spec from keyString
SecretKeySpec keySpec = new SecretKeySpec(keyString.getBytes(), "DES");
// set up encryption
Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, keySpec);
CipherOutputStream cipherOut = new CipherOutputStream(outToClient, cipher);
// send file
byte[] fileBuffer = new byte[BUFFER_SIZE];
InputStream fileReader = new BufferedInputStream(new FileInputStream(aFile));
int bytesRead;
while ((bytesRead = fileReader.read(fileBuffer)) != EOF) {
cipherOut.write(fileBuffer, 0, bytesRead);
}
cipherOut.flush();
cipherOut.close();
disconnect();
} catch (NoSuchPaddingException nspe) {
System.out.println("No such padding.");
} catch (NoSuchAlgorithmException nsae) {
System.out.println("Invalid algorithm entered");
} catch (ClassNotFoundException cnfe) {
System.out.println("Class not found.");
} catch (InvalidKeyException ike) {
System.out.println("Invalid key used for file encryption.");
} catch (FileNotFoundException fnfe) {
System.out.println("Invalid file entered.");
return;
} catch (IllegalBlockSizeException ibse) {
System.out.println("Illegal block size used for encryption.");
}
}
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);
}
// Needed by NativeJavaObject serializer
public static void writeAdapterObject(Object javaObject, ObjectOutputStream out)
throws IOException {
Class<?> cl = javaObject.getClass();
out.writeObject(cl.getSuperclass().getName());
Class<?>[] interfaces = cl.getInterfaces();
String[] interfaceNames = new String[interfaces.length];
for (int i = 0; i < interfaces.length; i++) interfaceNames[i] = interfaces[i].getName();
out.writeObject(interfaceNames);
try {
Object delegee = cl.getField("delegee").get(javaObject);
out.writeObject(delegee);
return;
} catch (IllegalAccessException e) {
} catch (NoSuchFieldException e) {
}
throw new IOException();
}
public void disconnect() {
if (isConnected()) {
try {
Envelope message = new Envelope("DISCONNECT");
message.addObject(messageIndex);
output.writeObject(encryptCipher.doFinal(message.getBytes()));
sock.close();
sock = null;
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
e.printStackTrace(System.err);
}
}
}
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;
}
