Esempio n. 1
0
 public static void main(String[] args) throws IOException, NoSuchAlgorithmException {
   DataOutputStream output = new DataOutputStream(new BufferedOutputStream(System.out));
   LRC lrc = new LRC(output);
   DataInputStream input = new DataInputStream(new BufferedInputStream(System.in));
   lrc.writeStream(input);
   output.flush();
 }
Esempio n. 2
0
 public void run() // loop utama, utk nerima user input n kirim ke server&client laen
     {
   while (thread != null) {
     try {
       String a = console.readLine();
       String b = cryptor.encrypt(a);
       streamOut.writeUTF(cryptor.encrypt(a));
       streamOut.flush();
     } catch (IOException ioe) {
       System.out.println("Sending error: " + ioe.getMessage());
       stop();
     }
   }
 }
Esempio n. 3
0
  /**
   * Compute the hash an IP address. The hash is the first 8 bytes of the SHA digest of the IP
   * address.
   */
  private static byte[] computeAddressHash() {

    /*
     * Get the local host's IP address.
     */
    byte[] addr =
        (byte[])
            java.security.AccessController.doPrivileged(
                new PrivilegedAction() {
                  public Object run() {
                    try {
                      return InetAddress.getLocalHost().getAddress();
                    } catch (Exception e) {
                    }
                    return new byte[] {0, 0, 0, 0};
                  }
                });

    byte[] addrHash;
    final int ADDR_HASH_LENGTH = 8;

    try {
      /*
       * Calculate message digest of IP address using SHA.
       */
      MessageDigest md = MessageDigest.getInstance("SHA");
      ByteArrayOutputStream sink = new ByteArrayOutputStream(64);
      DataOutputStream out = new DataOutputStream(new DigestOutputStream(sink, md));
      out.write(addr, 0, addr.length);
      out.flush();

      byte digest[] = md.digest();
      int hashlength = Math.min(ADDR_HASH_LENGTH, digest.length);
      addrHash = new byte[hashlength];
      System.arraycopy(digest, 0, addrHash, 0, hashlength);

    } catch (IOException ignore) {
      /* can't happen, but be deterministic anyway. */
      addrHash = new byte[0];
    } catch (NoSuchAlgorithmException complain) {
      throw new InternalError(complain.toString());
    }
    return addrHash;
  }
Esempio n. 4
0
  public void actionPerformed(ActionEvent e) {
    Object source = e.getSource();
    // Client pressed enter in the message entry field-send it
    if (source == enterField) {
      // Get the message
      message = e.getActionCommand();
      try {
        // Encipher the message
        if (message.length() > plaintextBlockSize)
          message = message.substring(0, plaintextBlockSize);
        byte[] ciphertext =
            Ciphers.RSAEncipherWSalt(message.getBytes(), BigIntegerMath.THREE, recipModulus, sr);
        // Send to the server
        output.write(ciphertext);
        output.flush();
        // Display same message in client output area
        displayArea.append("\n" + message);
        enterField.setText("");
      } catch (IOException ioe) {
        displayArea.append("\nError writing message");
      }
    } else if (source == connectButton) {
      if (connection != null) { // Already connected-button press now means disconnect
        try {
          // Send final message of 0
          byte[] lastMsg = new byte[1];
          lastMsg[0] = 0;
          output.write(Ciphers.RSAEncipherWSalt(lastMsg, BigIntegerMath.THREE, recipModulus, sr));
          output.flush();
          // close connection and IO streams, change some components
          closeAll();
        } catch (IOException ioe) {
          displayArea.append("\nError closing connection");
        }
      } else { // Not connected-connect
        // Get name of server to connect to
        chatServer = serverField.getText();
        displayArea.setText("Attempting connection to " + chatServer);
        try {
          // Set up the socket
          connection = new Socket(chatServer, 55555);

          displayArea.append("\nConnected to: " + connection.getInetAddress().getHostName());

          // Set up the IO streams
          output = new DataOutputStream(connection.getOutputStream());
          output.flush();
          input = new DataInputStream(connection.getInputStream());

          // Exchange public keys with the server-send yours, get theirs
          exchangeKeys();

          // Change appearance/functionality of some components
          serverField.setEditable(false);
          connectButton.setLabel("Disconnect from server above");
          enterField.setEnabled(true);
          // Set up a thread to listen for the connection
          listener =
              new Thread(
                  new Runnable() {
                    public void run() {
                      go();
                    }
                  });
          listener.start();
        } catch (IOException ioe) {
          displayArea.append("\nError connecting to " + chatServer);
        }
      }
    }
  }