Best way for login authentication

[James Hambrick]

I'm making a chat program and I want the user to have to login. I figure the username/password would be sent to the server where it will check a file to see if that username/password is in the file. If so let them login. I differentiated a login with username/password from a message being sent by the first couple letters of the string being something like 'login1234' or something. The obvious downside is if a user sends a message that begins with 'login1234'

How do you guys take care of this?

[David Newton]

The way some chat clients handle something like this is to have commands, prefixed by a "/" or ":" or whatever.

[James Hambrick]

thanks

[James Hambrick]

Okay I am still working on this login thing for the chatsoftware. I have the client sending the login reguest, the server authenticating it, but I cannot seem to figure out how to get the server to send an "accpeted" response. Here my fill code.

Client

import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class SimpleChatClient{

	String username;
	String password;
	JTextArea incoming;
	JTextField outgoing;
	JTextField usernameText;
	JPasswordField passwordText;
	BufferedReader reader;
	PrintWriter writer;
	Socket sock;
	JFrame frame;
	JFrame loginFrame;
	


		
	public static void main(String[] args){
		SimpleChatClient client = new SimpleChatClient();
		client.go();
	}	

	public void go(){
		//make gui and register listener with the send button
		//call the setUpnetworking() method
		
	
		loginFrame = new JFrame("Login");
		frame = new JFrame("Simple Chat Client");
		JPanel loginPanel = new JPanel();
		JPanel mainPanel = new JPanel();
		JLabel usernameLabel = new JLabel("Username:");
		JLabel passwordLabel = new JLabel("Password:");
		usernameText = new JTextField(25);
		passwordText = new JPasswordField(25);
		JButton loginButton = new JButton("Login");
		loginButton.addActionListener(new LoginListener());
		JButton cancelButton = new JButton("Cancel");
		cancelButton.addActionListener(new CancelListener());
		incoming = new JTextArea(15,50);
		incoming.setLineWrap(true);
		incoming.setWrapStyleWord(true);
		incoming.setEditable(false);
		JScrollPane qScroller = new JScrollPane(incoming);
		qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);		
		qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);		
		outgoing = new JTextField(50);
		JButton  sendButton = new JButton("Send");
		sendButton.addActionListener(new SendButtonListener());
		mainPanel.add(qScroller);
		mainPanel.add(outgoing);
		mainPanel.add(sendButton);
		loginPanel.add(usernameLabel);
		loginPanel.add(usernameText);
		loginPanel.add(passwordLabel);
		loginPanel.add(passwordText);
		loginPanel.add(loginButton);
		loginPanel.add(cancelButton);
		setUpNetworking();

		Thread readerThread = new Thread(new IncomingReader());
		readerThread.start();

		loginFrame.getContentPane().add(BorderLayout.CENTER,loginPanel);
		loginFrame.setSize(400,150);
		loginFrame.setDefaultCloseOperation(loginFrame.EXIT_ON_CLOSE);

		frame.getContentPane().add(BorderLayout.CENTER,mainPanel);
		frame.setSize(600,400);
		frame.setVisible(false);
		loginFrame.setVisible(true);
		frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
		

	}


	public class LoginListener implements ActionListener{
		public void actionPerformed(ActionEvent ev){
			username = usernameText.getText();
			password = passwordText.getText();
			passwordText.setText("");
			usernameText.setText("");
			//System.out.println(username + " " + password);
			try{
				writer.println("login1234" + username + password);
				writer.flush();
			}catch(Exception ex){ex.printStackTrace();}
		}


	}

	public class CancelListener implements ActionListener{
		public void actionPerformed(ActionEvent ev){
			System.exit(0);
		}
	}

	public void setUpNetworking(){
		//make a Socket, then make a PrintWriter
		//assign the PrintWriter to writer instance variable
		try{
			sock = new Socket("127.0.0.1",5000);
			InputStreamReader streamReader = new InputStreamReader(sock.getInputStream());
			reader = new BufferedReader(streamReader);
			writer = new PrintWriter(sock.getOutputStream());
			System.out.println("network established");
		}catch(IOException ex){
			ex.printStackTrace();
		}
	}
	
	public class SendButtonListener implements ActionListener{
		public void actionPerformed(ActionEvent ev){
			//get the text from the text field and 
			//send it to the server using the writer 
			try{
				writer.println(username +": " + outgoing.getText());
				writer.flush();
			}catch(Exception ex){
				ex.printStackTrace();
			}
			outgoing.setText("");
			outgoing.requestFocus();
		}
	}
	public class IncomingReader implements Runnable{
		public void run(){
			String message;
			try{
				while((message = reader.readLine()) != null){
					System.out.println(message);
					if(message.equals("login1234accepted")){
						loginFrame.setVisible(false);
						frame.setVisible(true);
					}else{
						System.out.println("read " + message);
						incoming.append(message + "\n");
					}
				}
			}catch(IOException ex){ex.printStackTrace();}
		}
	}


}
		

Server

import java.io.*;
import java.net.*;
import java.util.*;

public class SimpleChatServer{

	ArrayList clientOutputStream;
	PrintWriter writer;
		
	public class ClientHandler implements Runnable{
		BufferedReader reader;
		Socket sock;
		
		public ClientHandler(Socket clientSocket){
			try{
				sock = clientSocket;
				InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
				reader = new BufferedReader(isReader);
			}catch(Exception ex){ex.printStackTrace();}
		}
		
		public void run(){
			String message;
			try{
				while((message = reader.readLine()) != null){
                                                                               //authenticating like this now just to get it to work, then I will have it search through a file instead
					if(message.equals("login1234james3302pass")){
						loginAuthenticate();
					}else{
						System.out.println("read " + message);
						tellEveryone(message);
					}
					
				}
			}catch(Exception ex){ex.printStackTrace();}
	
		}

		public void loginAuthenticate(){
			try{
				//send "loginaccepted" to user
				
				System.out.println("login1234acceptedSent");
			}catch(Exception ex){ex.printStackTrace();}
		}
	}

	public static void main(String[] args){
		new SimpleChatServer().go();
	}

		

	public void go(){
		clientOutputStream = new ArrayList();
		try{
			ServerSocket serverSock = new ServerSocket(5000);
			
			while(true){
				Socket clientSocket = serverSock.accept();
				writer = new PrintWriter(clientSocket.getOutputStream());
				clientOutputStream.add(writer);
				
				Thread t = new Thread(new ClientHandler(clientSocket));
				t.start();
				System.out.println("got a connection");
			}
		}catch(Exception ex){ex.printStackTrace();}
	}

	public void tellEveryone(String message){
		Iterator it = clientOutputStream.iterator();
		while(it.hasNext()){
			try{
				PrintWriter writer = (PrintWriter) it.next();
				writer.println(message);
				writer.flush();
			}catch(Exception ex){ex.printStackTrace();}
		}
	}
 

}

[David Newton]

Is that thing you're printing to System.out supposed to go to the client instead?

[James Hambrick]

David Newton wrote:Is that thing you're printing to System.out supposed to go to the client instead?

public void loginAuthenticate(){   
            try{   
                //send "loginaccepted" to user   
                   
                System.out.println("login1234acceptedSent");   
            }catch(Exception ex){ex.printStackTrace();}   
        }   
    }   

No, "loginaccepted" is supposed to be sent to the client.

[James Hambrick]

got that part working. Now I'm going to have it search through a file to the username/password. Then send to everyone(all the clients) the new user that connected so it can be added to the JList.