예제 #1
0
  /**
   * Starts the server listening. Creates a new server thread for each connecting client.
   *
   * @param args Any command line arguments passed to the software.
   */
  public static void main(String[] args) throws Exception {
    ServerSocket listenSocket = new ServerSocket(LISTENING_PORT);
    System.out.println("Super mega-awesome file server of awesome. Awaiting patrons...");
    System.out.println("Listening on port " + LISTENING_PORT);

    while (true) {
      new Thread(new FileServer(listenSocket.accept())).start();
    }
  }
예제 #2
0
 private void acceptConnections() {
   for (; ; ) {
     try {
       String handlerName = fullName + "-Handler-" + Thread.activeCount();
       new Thread(new ClientHandler(socket.accept()), handlerName).start();
     } catch (Exception ex) {
       Log.warn(fullName + ": exception accepting connection.", ex);
     }
   }
 }
예제 #3
0
  public static void main(String args[]) {

    int port = 6502;
    SSLServerSocket server;

    try {
      // get the keystore into memory
      KeyStore ks = KeyStore.getInstance("JKS");
      ks.load(new FileInputStream(keyStore), keyStorePass);

      // initialize the key manager factory with the keystore data
      KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
      kmf.init(ks, keyStorePass);

      // initialize the SSLContext engine
      // may throw NoSuchProvider or NoSuchAlgorithm exception
      // TLS - Transport Layer Security most generic

      SSLContext sslContext = SSLContext.getInstance("TLS");

      // Inititialize context with given KeyManagers, TrustManagers,
      // SecureRandom defaults taken if null

      sslContext.init(kmf.getKeyManagers(), null, null);

      // Get ServerSocketFactory from the context object
      ServerSocketFactory ssf = sslContext.getServerSocketFactory();
      //  Now like programming with normal server sockets
      ServerSocket serverSocket = ssf.createServerSocket(port);

      System.out.println("Accepting secure connections");

      Socket client = serverSocket.accept();
      System.out.println("Got connection");

      BufferedWriter out = new BufferedWriter(new OutputStreamWriter(client.getOutputStream()));
      BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
      String username = in.readLine();
      String password = in.readLine();

      if (username.equals("Josh") && password.equals("GoBucs")) {
        out.write("Greeting Client");
      } else {
        out.write("Sorry, you are not authorized");
      }
      out.flush();
      in.close();
      out.close();
    } catch (Exception e) {
      System.out.println("Exception thrown " + e);
    }
  }
예제 #4
0
 public void run() {
   try {
     while (true) {
       Socket nsk;
       try {
         nsk = sk.accept();
       } catch (IOException e) {
         break;
       }
       new Client(nsk);
     }
   } finally {
     try {
       sk.close();
     } catch (IOException e) {
       throw (new RuntimeException(e));
     }
   }
 }
예제 #5
0
  public static void main(String[] args) {
    tcount = 0;
    try {
      ServerSocket ss = new ServerSocket(4567);

      AlgorithmParameterGenerator gerador = AlgorithmParameterGenerator.getInstance("DH");
      gerador.init(1024);
      AlgorithmParameters parametros = gerador.generateParameters();
      DHParameterSpec dhSpec = (DHParameterSpec) parametros.getParameterSpec(DHParameterSpec.class);

      while (true) {
        Socket s = ss.accept();
        tcount++;
        TServidor ts = new TServidor(s, tcount, dhSpec);
        ts.start();
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public static void main(String[] args) throws Exception {
    // prompt user to enter a port number

    System.out.print("Enter the port number: ");
    Scanner scan = new Scanner(System.in);
    int port = scan.nextInt();
    scan.nextLine();
    System.out.print("Enter the host name: ");
    String hostName = scan.nextLine();

    // Initialize a key pair generator with the SKIP parameters we sepcified, and genrating a pair
    // This will take a while: 5...15 seconrds

    System.out.println("Generating a Diffie-Hellman keypair: ");
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("DH");
    kpg.initialize(PARAMETER_SPEC);
    KeyPair keyPair = kpg.genKeyPair();
    System.out.println("key pair has been made...");

    // one the key pair has been generated, we want to listen on
    // a given port for a connection to come in
    // once we get a connection, we will get two streams, One for input
    // and one for output
    // open a port and wait for a connection

    ServerSocket ss = new ServerSocket(port);
    System.out.println("Listeining on port " + port + " ...");
    Socket socket = ss.accept();

    // use to output and input primitive data type

    DataOutputStream out = new DataOutputStream(socket.getOutputStream());

    // next thing to do is send our public key and receive client's
    // this corresponds to server step 3 and step 4 in the diagram

    System.out.println("Sending my public key...");
    byte[] keyBytes = keyPair.getPublic().getEncoded();
    out.writeInt(keyBytes.length);
    out.write(keyBytes);
    System.out.println("Server public key bytes: " + CryptoUtils.toHex(keyBytes));

    // receive the client's public key

    System.out.println("Receiving client's public key...");
    DataInputStream in = new DataInputStream(socket.getInputStream());
    keyBytes = new byte[in.readInt()];
    in.readFully(keyBytes);

    // create client's public key

    KeyFactory kf = KeyFactory.getInstance("DH");
    X509EncodedKeySpec x509Spec = new X509EncodedKeySpec(keyBytes);
    PublicKey clientPublicKey = kf.generatePublic(x509Spec);

    // print out client's public key bytes

    System.out.println(
        "Client public key bytes: " + CryptoUtils.toHex(clientPublicKey.getEncoded()));

    // we can now use the client's public key and
    // our own private key to perform the key agreement

    System.out.println("Performing the key agreement ... ");
    KeyAgreement ka = KeyAgreement.getInstance("DH");
    ka.init(keyPair.getPrivate());
    ka.doPhase(clientPublicKey, true);

    // in a chat application, each character is sendt over the wire, separetly encrypted,
    // Instead of using ECB, we are goin to use CFB, with a block size of 8 bits(1byte)
    // to send each character. We will encrypt the same character in a different way
    // each time. But in order to use CFB8, we need an IVof 8 bytes. We will create
    // that IV randomly and and send it to the client. It doesn't matter if somoene
    // eavesdrops on the IV when it is sent over the wire. it's not sensitive info

    // creating the IV and sending it corresponds to step 6 and 7

    byte[] iv = new byte[8];
    SecureRandom sr = new SecureRandom();
    sr.nextBytes(iv);
    out.write(iv);

    // we generate the secret byte array we share with the client and use it
    // to create the session key (Step 8)

    byte[] sessionKeyBytes = ka.generateSecret();

    // create the session key

    SecretKeyFactory skf = SecretKeyFactory.getInstance("DESede");
    DESedeKeySpec DESedeSpec = new DESedeKeySpec(sessionKeyBytes);
    SecretKey sessionKey = skf.generateSecret(DESedeSpec);

    // printout session key bytes

    System.out.println("Session key bytes: " + CryptoUtils.toHex(sessionKey.getEncoded()));

    // now use tha that session key and IV to create a CipherInputStream. We will use them to read
    // all character
    // that are sent to us by the client

    System.out.println("Creating the cipher stream ...");
    Cipher decrypter = Cipher.getInstance("DESede/CFB8/NoPadding");
    IvParameterSpec spec = new IvParameterSpec(iv);
    decrypter.init(Cipher.DECRYPT_MODE, sessionKey, spec);
    CipherInputStream cipherIn = new CipherInputStream(socket.getInputStream(), decrypter);

    // we just keep reading the input and print int to the screen, until -1 sent over

    int theCharacter = 0;
    theCharacter = cipherIn.read();
    while (theCharacter != -1) {
      System.out.print((char) theCharacter);
      theCharacter = cipherIn.read();
    }
    // once -1 is received we want to close up our stream and exit

    cipherIn.close();
    in.close();
    out.close();
    socket.close();
  }