import java.io.*;
import java.net.*;
import java.util.Random;
import java.math.BigInteger;

/*
* ## Authors
*
* Class to establish connection to server and call secureFile.java
*
*/

public class Client
{
private Socket sock; //Socket to communicate with.
private static boolean DEBUG = false;
private String KEY = "";

/**
* Main method, starts the client.
* @param args args[0] needs to be a hostname, args[1] a port number.
*/
public static void main (String [] args)
{
   if (args.length < 2) {
         System.out.println ("Usage: java Client hostname port#");
         System.out.println ("hostname is a string identifying your server");
         System.out.println ("port is a positive integer identifying the port to connect to the server");
         return;
   }

   if (args.length == 3 && args[2].toLowerCase().equals("debug"))
         DEBUG = true;

   if (DEBUG)
         System.out.println("DEBUG mode on");

   try {
         Client c = new Client (args[0], Integer.parseInt(args[1]));
   }
   catch (NumberFormatException e) {
         System.out.println ("Usage: java Client hostname port#");
         System.out.println ("Second argument was not a port number");
         return;
   }
}

/**
*
*/
private int getKey(BufferedReader in, PrintWriter out){

   BigInteger p, g, b, B, A, s;
   String incoming = null;

   /* Get p, g values from the server */
   try {
   incoming = in.readLine();
   }
   catch (IOException e) {
   System.out.println("Getting value of p failed.");
   return -1;
   }
   p = new BigInteger(incoming);

   if(DEBUG)
   System.out.println("Got value of p : " + p);

   try {
   incoming = in.readLine();
   }
   catch (IOException e) {
   System.out.println("Getting value of g failed.");
   return -1;
   }
   g = new BigInteger(incoming);

   if(DEBUG)
   System.out.println("Got value of g : " + g);

   /* Generating random number */
   b = new BigInteger(99, new Random());

   if(DEBUG)
   System.out.println("Generated value of b : " + b);

   B = g.modPow(b, p);

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