Java Mutual authentication- Client Server

Question

I'm writing a simple java client/server program in which just establishes a connection with the server sends it a sentence and the server sends the response for that. This is actually an example straight forward.

In above scenario, am looking for SSL based mutual authentication. I need to implement it in java.

Please suggest me if you have any example or how to implement same in Java.

Answer 1

When you say "client/server", does it means use Socket ? But SSL is usually used in HTTP connectons. I have not seen it used in socket connections. Here is sample for HTTP: You have to load you PKCS12 certificate into a keystore and provide that store to the SSLContext.

private SSLSocketFactory getFactory( File pKeyFile, String pKeyPassword ) throws ... {
      KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("SunX509);
      KeyStore keyStore = KeyStore.getInstance("PKCS12");

      InputStream keyInput = new FileInputStream(pKeyFile);
      keyStore.load(keyInput, pKeyPassword.toCharArray());
      keyInput.close();

      keyManagerFactory.init(keyStore, pKeyPassword.toCharArray());

      SSLContext context = SSLContext.getInstance("TLS");
      context.init(keyManagerFactory.getKeyManagers(), null, new SecureRandom());

      return context.getSocketFactory();
    }

    URL url = new URL("someurl");
    HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
    con.setSSLSocketFactory(getFactory(new File("file.p12"), "secret"));

Answer 2

Server code:

import java.io.*;
import java.net.*;
import java.util.*;
public class OTPServer {
 public static void main(String []args) throws IOException {
  ServerSocket ServerSocket= new ServerSocket(7777);
  System.out.println("Sever running and waiting for client");
  Socket ClientSocket=ServerSocket.accept();
  PrintWriter out=new PrintWriter(ClientSocket.getOutputStream(),true);
  Scanner sc=new Scanner(ClientSocket.getInputStream());
  String id=sc.nextLine();
  Random r=new Random();
  String otp=new String();
  for(int i=0;i<5;i++){
   otp+=r.nextInt(10);
  }
  System.out.print(otp);
  String newId=sc.nextLine();
  String newOtp=sc.nextLine();
  if(newId.equals(id)){
   if(!newOtp.equals(otp)){
    out.println("Incoreeect OTP!");    
   }
   else{
    out.println("Logged In!");
   }
  }
  System.exit(0);
 } 
}

Client code:

import java.io.*;
import java.net.*;
import java.util.*;
public class OTPServer {
 public static void main(String []args) throws IOException {
  ServerSocket ServerSocket= new ServerSocket(7777);
  System.out.println("Sever running and waiting for client");
  Socket ClientSocket=ServerSocket.accept();
  PrintWriter out=new PrintWriter(ClientSocket.getOutputStream(),true);
  Scanner sc=new Scanner(ClientSocket.getInputStream());
  String id=sc.nextLine();
  Random r=new Random();
  String otp=new String();
  for(int i=0;i<5;i++){
   otp+=r.nextInt(10);
  }
  System.out.print(otp);
  String newId=sc.nextLine();
  String newOtp=sc.nextLine();
  if(newId.equals(id)){
   if(!newOtp.equals(otp)){
    out.println("Incoreeect OTP!");    
   }
   else{
    out.println("Logged In!");
   }
  }
  System.exit(0);
 } 
}