import java.awt.*;
import java.net.*;
import java.awt.event.*;
import java.util.Random;
import java.util.Vector;
import java.util.Enumeration;
import java.util.List;
import java.util.Arrays;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.text.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.*;
import javax.swing.text.html.*;

/** 
 * ParaDigEm chat client.
 * 
 * A broadcast-based chat client for meetings that are being held in
 * Places Of No Infrastructure (PONI).  If you are near
 * infrastructure, you should use Jabber instead.
 *
 * Requires swing and the JCE.
 *
 * crypto: 
 *
 * ParaDigEm can send and receive Blowfish in ECB mode.  We can't use
 * chaining because we're on udp, so we can't expect to get the
 * packets in order, or un-duplicated... or at all.
 *
 * There are three keys: null, default, and custom.  I'm not sure why
 * you'd want cleartext (null).  The default key is just there to
 * prevent casual packet snooping.  You should use a custom key, but
 * then you need a key exchange mechanism, so there you go.
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Copyright (C) 2002 Christpher R. Wren
 * 
 * @author Christopher R. Wren <c@drwren.com>
 * @version 1.0 
 *  
 */
class ParaDigEm extends JFrame implements ActionListener, 
                                          WindowListener,
                                          Runnable,
                                          ComponentListener
{
  /** 
   * The default key
   */
  static String keyString = "fKHbZnN$a";

  /** 
   * text stuff
   */
  Document log = null;
  Document input = null;
  JTextField textArea = null;
  SimpleAttributeSet bold = null;
  SimpleAttributeSet[] color = null;
  Font basefont = null;

  /** 
   * socket stuff
   */
  String address = "255.255.255.255";
  short port = 6789;
  InetAddress group = null;
  DatagramSocket s = null;
  //MulticastSocket s = null;

  /** 
   * receive thread and control
   */
  Thread thread = null;
  boolean done = false;
  
  /** 
   * ciphers
   */
  Cipher[] cipherEnc = null;
  Cipher[] cipherDec = null;
  Color[] highlight = null;
  boolean[] view = null;
  int currentCipher = 1;
  JRadioButtonMenuItem[] cipherMenu = null;
  Random shaker = null;

  String nickname;
  
  /** 
   * Make a chat window.
   *
   * @param nick the default nickname
   */
  ParaDigEm(String nick)
  {
    super("ParaDigEm (" + nick + ")");

    nickname = nick;

    bold = new SimpleAttributeSet();
    StyleConstants.setBold(bold, true);

    highlight = new Color[3];
    highlight[0] = Color.red;
    highlight[1] = new Color(0,128,0);
    highlight[2] = Color.blue;
    
    color = new SimpleAttributeSet[3];
    color[0] = new SimpleAttributeSet();
    StyleConstants.setForeground(color[0], highlight[0]);
    StyleConstants.setForeground(color[0], highlight[0]);
    color[1] = new SimpleAttributeSet();
    StyleConstants.setForeground(color[1], highlight[1]);
    color[2] = new SimpleAttributeSet();
    StyleConstants.setForeground(color[2], highlight[2]);

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Border blackline = BorderFactory.createLineBorder(Color.black);

    JTextPane textPane = new JTextPane();
    log = (Document) textPane.getDocument();
    textPane.setMaximumSize(new Dimension(300,200));        
    textPane.setBorder(blackline);
    textPane.setEditable(false);
    textPane.setFocusable(false);
    textPane.addComponentListener(this);
    JScrollPane scroller = new JScrollPane(textPane);
    getContentPane().add(scroller, BorderLayout.CENTER);

    textArea = new JTextField(80);
    textArea.setMaximumSize(new Dimension(300,100));        
    textArea.setBorder(blackline);
    textArea.addActionListener(this);
    basefont = textArea.getFont();
    input = textArea.getDocument();    
    getContentPane().add(textArea, BorderLayout.SOUTH);

    setFont(basefont.getSize());

    //Create the menu bar.
    JMenuBar menuBar = new JMenuBar();
    menuBar.setBackground(Color.white);
    setJMenuBar(menuBar);
    //Build the first menu.
    JMenu menu = new JMenu("Tools");
    menu.setBackground(Color.white);
    menuBar.add(menu);
    JMenuItem menuItem;
    menuItem = new JMenuItem("Send");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("Clear Log");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("Set Nick");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("Set Key");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("Help");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("About");
    menuItem.setBackground(Color.white);
    menuItem.addActionListener(this);
    menu.add(menuItem);

    //Build the second menu.
    menu = new JMenu("View");
    menu.setBackground(Color.white);
    menuBar.add(menu);
    menuItem = new JRadioButtonMenuItem("View Cleartext", true);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[0]);
    menu.add(menuItem);
    menuItem = new JRadioButtonMenuItem("View Default Key", true);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[1]);
    menu.add(menuItem);
    menuItem = new JRadioButtonMenuItem("View Custom Key", true);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[2]);
    menu.add(menuItem);
    addWindowListener(this);
    menuItem = new JRadioButtonMenuItem("View Decrypt Failures", true);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(Color.black);
    menu.add(menuItem);
    addWindowListener(this);
 
    //Build the third menu.
    ButtonGroup bgroup = new ButtonGroup();
    cipherMenu = new JRadioButtonMenuItem[3];
    menu = new JMenu("Cipher");
    menu.setBackground(Color.white);
    menuBar.add(menu);
    menuItem = cipherMenu[0] = new JRadioButtonMenuItem("Cleartext");
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[0]);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = cipherMenu[1] = new JRadioButtonMenuItem("Default Key");
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[1]);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = cipherMenu[2] = new JRadioButtonMenuItem("Custom Key");
    menuItem.addActionListener(this);
    menuItem.setEnabled(false);
    menuItem.setBackground(Color.white);
    menuItem.setForeground(highlight[2]);
    menu.add(menuItem);
    bgroup.add(menuItem);
    addWindowListener(this);

    //Build the fouth menu.
    bgroup = new ButtonGroup();
    menu = new JMenu("Font");
    menu.setBackground(Color.white);
    menuBar.add(menu);
    menuItem = new JRadioButtonMenuItem("8 point", basefont.getSize() == 8);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("10 point", basefont.getSize() == 10);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("12 point", basefont.getSize() == 12);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("14 point", basefont.getSize() == 14);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("16 point", basefont.getSize() == 16);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("18 point", basefont.getSize() == 18);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("20 point", basefont.getSize() == 20);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    menuItem = new JRadioButtonMenuItem("24 point", basefont.getSize() == 24);
    menuItem.addActionListener(this);
    menuItem.setBackground(Color.white);
    menu.add(menuItem);
    bgroup.add(menuItem);
    addWindowListener(this);

    setSize(300, 300);
    validate();
    setVisible(true);
    textArea.requestFocus();

    shaker = new Random();
    initCipher();
    
    try
      {
        //group = InetAddress.getByName("239.135.23.84");
        group = InetAddress.getByName(address);
        //s = new MulticastSocket(port);
        s = new DatagramSocket(port);
        s.setBroadcast(true);
        s.setSoTimeout(1000);
                            
        //          s.joinGroup(group);
        //          s.setTimeToLive(5);
        //          s.setLoopbackMode(true);
        //          if (s.getLoopbackMode())
        //            System.err.println("loopback enabled.");
        //          else
        //            System.err.println("loopback diabled.");
        
        thread = new Thread(this);
        thread.start();
      }
    catch (Exception e)
      {
        System.err.println("Couldn't join multicast group.");
      }
  }

  /** 
   * Mainloop for receive thread
   */
  public void run()
  {
    while(!done)
      {
        recv();
      }
  }

  void setFont(int size)
  {
    basefont = basefont.deriveFont((float) size);
    textArea.setFont(basefont);
    StyleConstants.setFontSize(bold, size);
    StyleConstants.setFontSize(color[0], size);
    StyleConstants.setFontSize(color[1], size);
    StyleConstants.setFontSize(color[2], size);
  }

  /** 
   * Setup the cleartext and internal key cipher
   */
  void initCipher()
  {
    try
      {
        SecretKeySpec key = new SecretKeySpec(keyString.getBytes(), 
                                              "Blowfish");
        cipherDec = new Cipher[3];
        cipherEnc = new Cipher[3];
        
        Cipher ciphertmp;
        cipherDec[0] = new NullCipher(); 
        cipherEnc[0] = new NullCipher();
        cipherDec[1] = Cipher.getInstance("Blowfish/ECB/PKCS5Padding");
        cipherDec[1].init(Cipher.DECRYPT_MODE, key);
        cipherEnc[1] = Cipher.getInstance("Blowfish/ECB/PKCS5Padding");
        cipherEnc[1].init(Cipher.ENCRYPT_MODE, key);
        setCurrentCipher(1);
        cipherDec[2] = null;
        cipherEnc[2] = null;
        
        view = new boolean[4];
        view[0] = view[1] = view[2] = view[3] = true;
      }
    catch (Exception e)
      {
        System.err.println("Couldn't initialize cipher:" + e);
      }
  }

  /** 
   * build the custom ciphers
   */
  void setCustomCipher(String keyString)
  {
    try
      {
        SecretKeySpec key = new SecretKeySpec(keyString.getBytes(), 
                                              "Blowfish");

        // 2
        cipherDec[2] = Cipher.getInstance("Blowfish/ECB/PKCS5Padding");
        cipherDec[2].init(Cipher.DECRYPT_MODE, key);
        cipherEnc[2] = Cipher.getInstance("Blowfish/ECB/PKCS5Padding");
        cipherEnc[2].init(Cipher.ENCRYPT_MODE, key);
        setCurrentCipher(2);

        cipherMenu[0].setSelected(false);
        cipherMenu[1].setSelected(false);
        cipherMenu[2].setSelected(true);
        cipherMenu[2].setEnabled(true);
      }
    catch (Exception e)
      {
        System.err.println("Couldn't initialize cipher:" + e);
      }
  }

  /** 
   * switch ciphers. make sure menu and textfield color are consistent 
   */
  void setCurrentCipher(int i)
  {
    cipherMenu[0].setSelected(false);
    cipherMenu[1].setSelected(false);
    cipherMenu[2].setSelected(false);

    currentCipher = i;
    textArea.setForeground(highlight[i]);    
    cipherMenu[i].setSelected(true);
  }

  /** 
   * is this a typable string?  null cipher always succeeds.
   */
  boolean isPrintable(byte[] probe)
  {
    boolean ret = true;
    for (int i = 4; i<probe.length; i++)
      ret &= !Character.isISOControl((char)probe[i]);
    return(ret);
  }

  /** 
   * decrypt a packet
   *
   * @param input the packet to decrypt
   * @param len the packet length given by the datagram (Note that
   *            input.length is not necessarily the same as len) 
   * @retrun a vector with the key that was used and the cleartext buffer
   */
  Vector decrypt(byte[] input, int len)
  {
    int keynum = -1;
    byte[] cipherbuf = null;

    for (int i=0; i<3; i++)
      {
        if (cipherDec[i] != null)
          try {
            byte[] tmp = cipherDec[i].doFinal(input, 
                                              0, len);
            cipherbuf = tmp;
            keynum=i;
          } catch (Exception e) {
          }
      }
    
    if ((keynum==0) && (!isPrintable(cipherbuf)))
      {
        keynum = -1;
        cipherbuf = null;
      }

    Vector ret = new Vector();
    ret.add(new Integer(keynum));
    ret.add(cipherbuf);
    return(ret);
  }

  /** 
   * encrypt a packet
   *
   * @param input the cleartext to encrypt
   * @return the encrypted bytes 
   */
  byte [] encrypt(byte[] input)
  {
    byte[] cipherbuf = null;

    try {
      cipherbuf = cipherEnc[currentCipher].doFinal(input);
    } catch (Exception e) {
      System.out.println("encryption failed with cipher " + currentCipher);
    }

    return(cipherbuf);
  }

  /** 
   * a static for recv
   */
  String lastSalt = null;

  /** 
   * get the next packet, decrypt it, and add it to the log
   */
  void recv()
  {
    byte[] buf = new byte[10000];
    DatagramPacket recv = new DatagramPacket(buf, buf.length);

    try
      {
        s.receive(recv);

        Vector payload = decrypt(recv.getData(),
                                 recv.getLength());
        int keynum = ((Integer)payload.get(0)).intValue();
        byte[] cipherbuf = (byte[])payload.get(1);
        
        if (keynum != -1)
          {
            String salt = new String(cipherbuf, 0, 4);
            if (! salt.equals(lastSalt))
              {
                lastSalt = salt;

                if (view[keynum])
                  {
                    String msg = new String (cipherbuf, 
                                             4, cipherbuf.length-4);
                    int delim = msg.indexOf(':', 0)+1;
                    log.insertString(log.getLength(), 
                                     msg.substring(0,delim),
                                     bold);
                    log.insertString(log.getLength(), 
                                     msg.substring(delim, msg.length()),
                                     color[keynum]);
                    log.insertString(log.getLength(), 
                                     "\n",
                                     null);
                  }
                else
                  {
                    if (view[3])
                      log.insertString(log.getLength(), 
                                       "--key rejected--\n",
                                       null);
                  }
              }
            else
              {
                // log.insertString(log.getLength(), 
                //                  "reject bounce\n",
                //                  null);
              }
          }
        else
          {
            if (view[3])
              log.insertString(log.getLength(), 
                               "--decrypt failure--\n",
                               null);
          }
      }
    catch (Exception e)
      {
      }
  }

  /** 
   * pull text from the input buffer, encrypt it, and send it.
   */
  void send()
  {
    try {      
      byte[] salt = new byte[4];
      shaker.nextBytes(salt);
      String msg = (new String(salt) + 
                    nickname + 
                    ": " + 
                    input.getText(0, input.getLength()));
      byte[] cipherbuf = encrypt(msg.getBytes());
      DatagramPacket hi = new DatagramPacket(cipherbuf,
                                             cipherbuf.length,
                                             group, port );
      s.send(hi);
      input.remove(0, input.getLength());
    } catch (Exception x) {
      System.err.println("Couldn't send new text:" + x);
    } 
  }

  /** 
   * pull the new nickanme from the input buffer.
   */
  void setNick()
  {
    try
      {
        if (input.getLength() > 0)
          {
            nickname = input.getText(0, input.getLength());
            input.remove(0, input.getLength());
            setTitle("ParaDigEm (" + nickname + ")");
          }
        else
          {
            input.remove(0, input.getLength());
            input.insertString(0,
                               "type new nickname here, and then 'Set Nick'",
                               null);
          }
      }
    catch (Exception c)
      {
        System.err.println("Couldn't set nickname from input:" + c);
      }
  }

  /** 
   * pull the new custom key string from the input buffer.
   */
  void setKey()
  {
    try
      {
        if (input.getLength() > 0)
          {
            String keyString = input.getText(0, input.getLength());
            if (keyString.length() > 9)
              keyString = keyString.substring(0,9);
            input.remove(0, input.getLength());
            setCustomCipher(keyString);
          }
        else
          {
            input.remove(0, input.getLength());
            input.insertString(0,
                               "type new custom key here, and then 'Set Key'",
                               null);
          }
      }
    catch (Exception c)
      {
        System.err.println("Couldn't set key from input:" + c);
      }
  }

  /** 
   * print the help banner to the log
   */
  void help()
  {
    try
      {
        log.insertString(log.getLength(), 
                         "help:\n",
                         bold);
        log.insertString(log.getLength(), 
                         "  /nick <nickname> to change nickname\n"+
                         "  /key <keystring> to change custom key\n"+
                         "  /help for this message\n",
                         null);
        log.insertString(log.getLength(), 
                         "  cleartext color\n",
                         color[0]);
        log.insertString(log.getLength(), 
                         "  default key color\n",
                         color[1]);
        log.insertString(log.getLength(), 
                         "  custom key color\n",
                         color[2]);
        input.remove(0, input.getLength());
      }
    catch (Exception c)
      {
        System.err.println("Couldn't set key from input:" + c);
      }
  }

  void about()
  {
    try
      {
        log.insertString(log.getLength(), 
                         "about:\n",
                         bold);

        log.insertString(log.getLength(), 
                         "ParaDigEm version 1.0 " +
                         "Copyright (C) 2002 christopher R. Wren\n" +
                         "ParaDigEm comes with ABSOLUTELY NO WARRANTY.\n"+
                         "This is free software, and you are "+
                         "welcome to redistribute it under certain "+
                         "conditions.\n"+
                         "See http://www.fsf.org/licenses/gpl.txt "+
                         "for more detals\n",
                         null);
        input.remove(0, input.getLength());
      }
    catch (Exception c)
      {
        System.err.println("Couldn't set key from input:" + c);
      }
  }

  /** 
   * dispatch actions form the menu and the input field 
   */
  public void actionPerformed(ActionEvent e) 
  {
    if (e.getSource() instanceof JMenuItem)
      {
        JMenuItem source = (JMenuItem)(e.getSource());
        if(source.getText().equals("Send"))
          {
            send();
          }
        if(source.getText().equals("Clear Log"))
          {
            try {
              log.remove(0, log.getLength());
            } catch (Exception x) {
            }
          }
        if(source.getText().equals("Help"))
          {
            help();
          }
        if(source.getText().equals("About"))
          {
            about();
          }
        if(source.getText().equals("Set Nick"))
          {
            setNick();
          }
        if(source.getText().equals("Set Key"))
          {
            setKey();
          }
        if(source.getText().equals("Cleartext"))
          {
            setCurrentCipher(0);
          }
        if(source.getText().equals("Default Key"))
          {
            setCurrentCipher(1);
          }        
        if(source.getText().equals("Custom Key"))
          {
            setCurrentCipher(2);
          }
        if(source.getText().equals("View Cleartext"))
          {
            view[0] = source.isSelected();
          }
        if(source.getText().equals("View Default Key"))
          {
            view[1] = source.isSelected();
          }        
        if(source.getText().equals("View Custom Key"))
          {
            view[2] = source.isSelected();
          }
        if(source.getText().equals("View Decrypt Failures"))
          {
            view[3] = source.isSelected();
          }
        if(source.getText().equals("8 point"))
          {
            setFont(8);
          }
        if(source.getText().equals("10 point"))
          {
            setFont(10);
          }
        if(source.getText().equals("12 point"))
          {
            setFont(12);
          }
        if(source.getText().equals("14 point"))
          {
            setFont(14);
          }
        if(source.getText().equals("16 point"))
          {
            setFont(16);
          }
        if(source.getText().equals("18 point"))
          {
            setFont(18);
          }
        if(source.getText().equals("20 point"))
          {
            setFont(20);
          }
        if(source.getText().equals("24 point"))
          {
            setFont(24);
          }
      }
    if (e.getSource() instanceof JTextField)
      {
        try{
          
          String command = input.getText(0, input.getLength());
          if (command.startsWith("/key"))
            {
              input.remove(0, 5);
              setKey();
            }
          else if (command.startsWith("/nick "))
            {
              input.remove(0, 6);
              setNick();
            }
          else if (command.startsWith("/help"))
            {
              help();
            }
          else
            {
              send();
            }
        } catch (Exception x) {
        }
      }

  }

  //implment WindowListener
  public void windowActivated(WindowEvent e) 
  {
  }
  public void windowClosed(WindowEvent e) 
  {
  }
  /** 
   * catch the window close event and tell the thread to die before we go 
   */
  public void windowClosing(WindowEvent e) 
  {
    done = true;
    dispose();
  }
  public   void windowDeactivated(WindowEvent e) 
  {
  }
  public void windowDeiconified(WindowEvent e) 
  {
  }
  public void windowIconified(WindowEvent e) 
  {
  }
  public void windowOpened(WindowEvent e) 
  {
  }

  //implment ComponentListener

  /** 
   * make sure we always scroll to the bottom on output
   */
  public void componentResized(ComponentEvent e) 
  {
    if (e.getComponent() instanceof JComponent)
      {
        JComponent c = (JComponent) e.getComponent();
          
        Rectangle view = new Rectangle(0,
                                       c.getHeight()-10,
                                       10,10);
        c.scrollRectToVisible(view);
      }
  }
  public void componentHidden(ComponentEvent e) 
  {}
  public void componentMoved(ComponentEvent e) 
  {}
  public void componentShown(ComponentEvent e)  
  {}

  public static void main(String args[]) 
  {
    if (args.length >= 1)
      {
        ParaDigEm PDE = new ParaDigEm(args[0]);
      }
    else
      {
        System.err.println("You might want to specify " +
                           "a nickanme o nthe command line.");
        try {
          ParaDigEm PDE = new ParaDigEm(InetAddress.getLocalHost().toString());
        } catch (Exception e) {
          ParaDigEm PDE = new ParaDigEm("Nobody");
        }
      }
  }

}