Пример #1
0
  public static void main(String[] args) {

    if (args.length == 1) {
      if (args[0].equals("-genkey")) {
        try {
          CipherUtils.generateKey();
        } catch (KeyStoreException
            | CertificateException
            | NoSuchAlgorithmException
            | IOException e) {
          e.printStackTrace();
        }
        System.exit(0);
      } else {
        System.exit(-1);
      }
    }

    try {
      Socket s = new Socket("localhost", Servidor.PORT);

      ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
      ObjectInputStream ois = new ObjectInputStream(s.getInputStream());
      CipherUtils cipherUtils = new CipherUtils(ois, oos);
      String test;
      BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
      while ((test = stdIn.readLine()) != null) {
        cipherUtils.encrypt(test);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
Пример #2
0
  @Override
  public void run() {
    ObjectInputStream ois = null;
    ObjectOutputStream oos = null;
    try {
      oos = new ObjectOutputStream(mSocket.getOutputStream());
      ois = new ObjectInputStream(mSocket.getInputStream());

      // Enviar o nosso g^Y
      oos.writeUTF(mPrivateKey.toString());
      oos.flush();

      // Receber o g^X da Alice
      BigInteger gX = new BigInteger(ois.readUTF());

      // Calcular a chave
      mKey = mGpowModP.modPow(gX, mPrime);

      CipherUtils cipherUtils = new CipherUtils(ois, oos, mKey);
      String test;
      BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));

      while ((test = stdIn.readLine()) != null) {
        cipherUtils.encrypt(test);
      }

    } catch (Exception e) {
      e.printStackTrace();
    } finally {

      if (ois != null) {
        try {
          ois.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      if (oos != null) {
        try {
          oos.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
  }
  /*
   * Initial IV client to server: HASH (K || H || "A" || session_id) Initial
   * IV server to client: HASH (K || H || "B" || session_id) Encryption key
   * client to server: HASH (K || H || "C" || session_id) Encryption key
   * server to client: HASH (K || H || "D" || session_id) Integrity key client
   * to server: HASH (K || H || "E" || session_id) Integrity key server to
   * client: HASH (K || H || "F" || session_id)
   */
  public void init(
      String encryptionAlgorithm,
      String cipherAlgorithm,
      int keyLength,
      String macAlgorithm,
      byte[] K,
      byte[] H,
      byte[] sessionId)
      throws GeneralSecurityException {
    MessageDigest sha = MessageDigest.getInstance("SHA-1");

    sha.reset();
    sha.update(
        new SshPacketBuilder().writeMpInt(K).append(H).writeByte('A').append(sessionId).finish());
    byte[] iv = sha.digest();

    sha.reset();
    sha.update(
        new SshPacketBuilder().writeMpInt(K).append(H).writeByte('C').append(sessionId).finish());
    byte[] cipherKey = sha.digest();

    try {
      cipher = Cipher.getInstance(encryptionAlgorithm + "/" + cipherAlgorithm + "/NoPadding");

      iv = CipherUtils.expandKey(K, H, iv, sha, cipher.getBlockSize());
      cipherKey = CipherUtils.expandKey(K, H, cipherKey, sha, keyLength);

      iv = CipherUtils.shrinkKey(iv, cipher.getBlockSize());
      cipherKey = CipherUtils.shrinkKey(cipherKey, keyLength);

      cipher.init(
          Cipher.ENCRYPT_MODE,
          new SecretKeySpec(cipherKey, encryptionAlgorithm),
          new IvParameterSpec(iv));

      sha.reset();
      sha.update(
          new SshPacketBuilder().writeMpInt(K).append(H).writeByte('E').append(sessionId).finish());
      byte[] macKey = sha.digest();

      mac = Mac.getInstance(macAlgorithm);

      macKey = CipherUtils.expandKey(K, H, macKey, sha, mac.getMacLength());
      macKey = CipherUtils.shrinkKey(macKey, mac.getMacLength());

      mac.init(new SecretKeySpec(macKey, macAlgorithm));
    } catch (GeneralSecurityException e) {
      cipher = null;
      mac = null;
      throw e;
    }
  }