Vfrdtyky

I went through many question asked here for socket programming but they are either connected to HTTP/URL . I just have two java class for server and client connected through port. The problem I face is that i have to let client1 read a file where as client2 is not allowed to read.I'm looking for any possible method to implement so that I will be able to allow or delete request based on the policy file.I tried to use the Security Manger method but failed to implement it properly. any suggest would be of great help

I will post the server class and the policy details below

Policy file

grant {



permission java.io.FilePermission "D:\Uni\System security\Client Server 

Example\ClientServerExample\src\javaapplication2\abc.txt", "read", 

signedBy "client1";



permission java.io.FilePermission "D:\Uni\System security\Client Server 

Example\ClientServerExample\src\javaapplication2\abc.txt", "write", 

signedBy "client2";



permission java.security.AllPermission, signedBy "client1";

permission javax.security.auth.kerberos.ServicePermission "285", "initiate, 

accept", signedBy "client1";



};

Server Class

package javaapplication2;



import java.io.*;

import java.net.*;

import java.security.*;

import java.util.Properties;

import java.util.logging.Level;

import java.util.logging.Logger;



class Multi extends Thread

{

    private Socket s = null;

    DataInputStream infromClient;



    Multi() throws IOException

    {

    }



    Multi( Socket s ) throws IOException

    {

        this.s = s;

        infromClient = new DataInputStream( s.getInputStream() );

    }



    public void run()

    {

        try

        {

            System.out.println( "Socket Closing" );

            s.close();

        }

        catch ( IOException ex )

        {

            Logger.getLogger( Multi.class.getName() ).log( Level.SEVERE, null, ex );

        }

    }

}



public class Server

{

    @SuppressWarnings("resource")

    public static void main( String args ) throws IOException, InterruptedException

    {

        System.setProperty( "java.security.policy", "file:/C:/Users/Ali/Desktop/java.policy" );



        SecurityManager client1 = new SecurityManager();

        System.setSecurityManager( client1 );



        ServerSocket socket = null;

        DataInputStream in;

        PrintStream out;

        Socket clientSocket1 = null;



        //try {



        //System.out.println("Allowed!");

        //} 



        while ( true )

        {

            socket = new ServerSocket( 200 );

            System.out.println( "Server is Awaiting" );

            clientSocket1 = socket.accept();



            in = new DataInputStream( ( clientSocket1 ).getInputStream() );//read from client1

            BufferedReader fileRead = new BufferedReader( new InputStreamReader( in ) );

            String fname = fileRead.readLine();



            FileInputStream propFile =

                    new FileInputStream( fname );

            Properties p = new Properties( System.getProperties() );

            p.load( propFile );

            System.setProperties( p );

            // display new properties

            System.getProperties().list( System.out );



            try

            {



                AccessController.checkPermission( new FilePermission( fname, "read" ) );



                BufferedReader contentRead = new BufferedReader( new FileReader( fname ) );

                out = new PrintStream( clientSocket1.getOutputStream() );//write to client1

                PrintWriter pwrite = new PrintWriter( out, true );



                String str;

                while ( ( str = contentRead.readLine() ) != null )

                {

                    pwrite.println( str );         // sending each line to client

                }



            }

            catch ( SecurityException e )

            {

            }

            Multi t = new Multi( clientSocket1 );

            t.start();

            Thread.sleep( 2000 );

            socket.close();

        }

    }

}