programming encryption help

[shyguy]

as a project i am adding security to a chat room application all in java...

i already have the basic chat server and client, but i need to create a seperate java application to integrate with it to add security.

so i basically need to set it up so that all communications are encrypted, so outside eavesdroppers cant understand them. i have to implement authentication so that only verified users can access the chat service. the method used was going to be a based on a simplified version of the Kerberos protocol. was going to omit the Kerberos ticket server from this for the time being.

any help here would be muchly appreciated... source code of a working example would be great...

[PowerCum]

use ssl. a port of yassl (standalone ssl implementation) will do the work.

[shyguy]

hiya... i know a bit more about what i have to do for this now... its for an assignment and my programming isnt that great so i really need some example to checkout and get me started... need help PLEASE!!

i basically have to use the JCE DES method which i already have the basic code for, but i have to make it so that i create a second dummy server which authenticates the user/client and then also lets the real server know... i can just hard code the user names and keys... ive pasted the code for the client and the server below: (sorry for the huge post)...

client:
import java.io.*;
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;


public class ChatClient extends JFrame implements ActionListener
{
JTextField loginID = new JTextField(20);
JTextField messageLine = new JTextField(60);
JTextArea chatArea = new JTextArea("", 30,60);

JPanel loginPanel = new JPanel();
JPanel chatPanel = new JPanel();
JPanel messagePanel = new JPanel();
JScrollPane scp = new JScrollPane(chatArea);

JLabel loginLabel = new JLabel(" Login ID:");
JLabel messageLabel = new JLabel(" Message:");
JButton loginButton = new JButton("Login");
JButton sendButton = new JButton("Send");
JButton quitButton = new JButton("Quit");

ObjectInputStream dis;
ObjectOutputStream dos;
NetListener nl; // A thread that listens for incoming messages and passes them to the GUI, defined below

public ChatClient ()
{
//hahahahahahahaha= Set up GUI hahahahahahahaha=
Container f = getContentPane();
f.setLayout(new BorderLayout());

f.add(loginPanel,BorderLayout.NORTH);
loginPanel.setLayout(new FlowLayout());
loginPanel.add(loginLabel);
loginPanel.add(loginID);
loginPanel.add(loginButton);

f.add(chatPanel,BorderLayout.CENTER);
chatPanel.add(scp);

f.add(messagePanel,BorderLayout.SOUTH);
messagePanel.setLayout(new FlowLayout());
messagePanel.add(messageLabel);
messagePanel.add(messageLine);
messagePanel.add(sendButton);

loginButton.addActionListener(this);
sendButton.addActionListener(this);
quitButton.addActionListener(this);
//hahahahahahahaha= Open data streams hahahahahahahahahahahaha
try
{
Socket sk = new Socket("localhost",8000); //hahahaha= Server and Client on the same host hahahaha=
dis = new ObjectInputStream(sk.getInputStream());
dos = new ObjectOutputStream(sk.getOutputStream());
}
catch (Exception ex)
{System.out.println(ex);}

}

public static void main(String [] args)
{
ChatClient cc = new ChatClient();
cc.nl = new NetListener(cc.dis,cc); //hahahahahahahaha Create netListener object, pass InoutStream and GUI objects to it
cc.nl.start(); //hahahaha= Start listening hahahahahahahahahahahaha
cc.setDefaultCloseOperation(EXIT_ON_CLOSE);
cc.pack();
cc.setTitle("Insecure Chat Room, for Insecure people");
cc.setVisible(true);
}

public void actionPerformed(ActionEvent ev)
{
try
{
if (ev.getSource()hahahaha loginButton)
{
String id = loginID.getText();;
loginID.setText("");
dos.writeObject("Login:"+id);
dos.flush();
}

if (ev.getSource()hahahaha sendButton)
{
String line = messageLine.getText();
messageLine.setText("");
dos.writeObject(line);
dos.flush();
}
}

catch (Exception e)

{System.out.println(e);}

}
}


class NetListener extends Thread
{
ObjectInputStream ois;
ChatClient cli;
public NetListener(ObjectInputStream ois, ChatClient cli)
{
this.ois = ois;
this.cli = cli;
}
public void run()
{
while (true)
{
try
{
String s = (String) ois.readObject();
cli.chatArea.append("\n"+s);
}

catch (Exception ex)
{
System.out.println(ex);
}

}
}

}

server:
import java.io.*;
import java.net.*;
import java.util.*;
//hahahahahahahahahahahahahahahahahahahaha= Multi-Threaded Server hahahahahahahahahahahahahahahaha=
public class ChatServer
{
int client = 0;
Vector oosVect = new Vector();//hahahaha A collection of data streams, one for each client. Used for broadcasting

public static void main(String [] args)
{
ChatServer bs = new ChatServer();
System.out.println("ChatServer is running.");
try
{
ServerSocket ss = new ServerSocket(8000);

while(true)
{
Socket sk = ss.accept();
InetAddress ia = sk.getInetAddress();
String ha = ia.getHostName();

ChatThread bt = new ChatThread(sk, bs);
bt.start();
bs.client++;
System.out.println("Client " + bs.client + " connected.");
}
}
catch (Exception ed)
{}
}

public void broadcast(String message)
{
try
{
for (int n=0; n<oosVect.size();n++)
{
ObjectOutputStream oStream = (ObjectOutputStream) oosVect.elementAt(n);
oStream.writeObject(message);
System.out.println("Broadcasting.." +message);
oStream.flush();
}
}
catch (IOException io)
{
System.out.println(io);
}
}
}

class ChatThread extends Thread //hahahahahahahahahahahahahahahaha= Thread to communicate with each client hahahaha=
{
Socket sok;
ChatServer cs;
public ChatThread(Socket sok, ChatServer cs)
{
this.sok=sok;
this.cs = cs;
}

public void run()
{
String id="";
try
{

ObjectOutputStream dos = new ObjectOutputStream(sok.getOutputStream());
ObjectInputStream dis = new ObjectInputStream(sok.getInputStream());
cs.oosVect.addElement(dos);
while (true)
{
String message = (String)dis.readObject();
if (message.startsWith("Login"))
{
StringTokenizer st = new StringTokenizer(message,":");
id = st.nextToken();
id = st.nextToken();
message = id + " has joined.";
}
else
{
if (!id.equals("")) message = " "+id+"> " + message;
}
cs.broadcast(message);
dos.flush();
}

}
catch (Exception e)
{}
}
}

[PowerCum]

go to www.freshmeat.net and start searching. You will find lots of open source java stuff... included encryption stuff.

[shyguy]

i have had a good look through feshmeat but cant find anything that will help me with my situation...