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JCODHKeyExchange.java

package edu.virtualschool.jco.unfinished;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.math.BigInteger;
import java.net.ServerSocket;
import java.net.Socket;
import java.security.SecureRandom;

import javax.crypto.spec.DHParameterSpec;

import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.agreement.DHAgreement;
import org.bouncycastle.crypto.generators.DHKeyPairGenerator;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.params.DHKeyGenerationParameters;
import org.bouncycastle.crypto.params.DHKeyParameters;
import org.bouncycastle.crypto.params.DHParameters;
import org.bouncycastle.crypto.params.DHPrivateKeyParameters;
import org.bouncycastle.crypto.params.DHPublicKeyParameters;

import edu.virtualschool.jco.JCOBase64;
import edu.virtualschool.jwaa.IntervalTimer;


public class JCODHKeyExchange
{
  private static final BigInteger skipP = new BigInteger(
    "f488fd584e49dbcd20b49d349107366b336c380d451d0f7c88b31c7c5b2d8ef6"+
    "f3c923c043f0a55b188d8ebb558cb85d38d334fd7c175743a31d186cde33212c"+
    "b52aff3ce1b1294018118d7c84a70a72d686c40319c807297aca950cd9968fab"+
    "d00a509b0246d3083d66a45d419f9c7cbd894b221926baaba25ec355e92f78c7", 16);

  private static final BigInteger skipG = BigInteger.valueOf(2);

  public static final DHParameterSpec skipParams = 
    new DHParameterSpec(skipP, skipG);
    
  public final static   int port = 8765;
  public static class Server
  {
    final DataOutputStream out;
    final DataInputStream in;
    final JCODHKeyPair serverKeyPair = new JCODHKeyPair(skipP, skipG);
    
    public static void main(String[] args) throws Exception
    {
      Server server = new Server(port);
      byte[] secret = server.getSessionKeyBytes();
      System.out.println("Server secret:"+JCOBase64.encode(secret));
    }
    public Server(int port) throws Exception
    {
      // Wait for network connection
      ServerSocket ss = new ServerSocket(port);
      System.out.println("Listening on port " + port);
      Socket s = ss.accept();
      this.out = new DataOutputStream(s.getOutputStream());
      this.in = new DataInputStream(s.getInputStream());
    }
    public final byte[] getSessionKeyBytes() throws Exception
    {
      // Receive client public key
      int clientKeyLength = in.readInt();
      byte[] clientBytes = new byte[clientKeyLength];
      in.readFully(clientBytes);
      JCODHPublicKey clientPublicKey = new JCODHPublicKey(clientBytes);
      
      // Respond with server public key
      JCODHPublicKey serverPublicKey = serverKeyPair.getPublic();
      byte[] serverBytes = serverPublicKey.getEncoded();
      out.writeInt(serverBytes.length);
      out.write(serverBytes);
      
      // Generate shared secret
      AsymmetricKeyParameter akp = clientPublicKey.getParameters();
      DHKeyParameters dkp = (DHKeyParameters)akp;
      DHParameters  p = dkp.getParameters();
      SecureRandom r = new SecureRandom();
      DHKeyGenerationParameters params = new DHKeyGenerationParameters(r, p);
      DHKeyPairGenerator kpGen = new DHKeyPairGenerator();
      kpGen.init(params);
      
      AsymmetricCipherKeyPair pair = kpGen.generateKeyPair();
      DHPublicKeyParameters pubP = (DHPublicKeyParameters)pair.getPublic();
      DHPrivateKeyParameters prvP = (DHPrivateKeyParameters)pair.getPrivate();
      
//    Listening on port 8765
//    Server calculateMessage:9408 msec
//    Server calculateAgreement:364 msec
//    Server secret:ANozRjQvpOiaTgEHS46yqrNJBMWk93F5EfS/Vw2UhAVUW/mUzKoMyX4kPd95g3vF3BwTkmMm5TspDN32YQP7/1p9lVvW4tuIadqpqvWO8z94EIRbkus8VyMZq21OwwgHOHYNiAR0oKY5AlxMTf2O+buWJGjIeMGZulgBhzQQzkej
      
      IntervalTimer t = new IntervalTimer();
      DHAgreement dha = new DHAgreement();
      System.err.println("Server dha=DHAgreement:"+t);
      dha.init(prvP);
      System.err.println("Server dha.init:"+t);
      BigInteger  message = dha.calculateMessage();
      System.err.println("Server dha.calculateMessage:"+t);
      BigInteger  agreement = dha.calculateAgreement(pubP, message);
      System.err.println("Server dha.calculateAgreement:"+t);
      byte[] secret = agreement.toByteArray();
      
      // Clean up
      out.close();
      in.close();
      return secret;
    }
  }
  public static class Client
  {
    final DataOutputStream out;
    final DataInputStream in;
    final JCODHKeyPair clientKeyPair = new JCODHKeyPair(skipP, skipG);

    
    public static void main(String[] args) throws Exception
    {
      String host = "localhost";
      Client client = new Client(host, port);
      byte[] secret = client.getSessionKeyBytes();
      System.out.println("Client secret: " + JCOBase64.encode(secret));
    }
    public Client(String host, int port)  throws Exception
    {
    // Open the network connection
      Socket s = new Socket(host, port);
      this.out = new DataOutputStream(s.getOutputStream());
      this.in = new DataInputStream(s.getInputStream());
    }
    public byte[] getSessionKeyBytes() throws Exception
    {
      // Send client public key
      JCODHPublicKey clientPublicKey = clientKeyPair.getPublic();
      byte[] myBytes = clientPublicKey.getEncoded();
      out.writeInt(myBytes.length);
      out.write(myBytes);
      
      // Receive their public key
      int serverLength = in.readInt();
      byte[] serverBytes = new byte[serverLength];
      in.readFully(serverBytes);
      JCODHPublicKey serverPublicKey = new JCODHPublicKey(serverBytes);
          
      // Generate the secret value
      AsymmetricKeyParameter akp = serverPublicKey.getParameters();
      DHKeyParameters dkp = (DHKeyParameters)akp;
      DHParameters  p = dkp.getParameters();
      SecureRandom r = new SecureRandom();
      
      DHKeyGenerationParameters params = new DHKeyGenerationParameters(r, p);
      DHKeyPairGenerator kpGen = new DHKeyPairGenerator();
      kpGen.init(params);
      AsymmetricCipherKeyPair pair = kpGen.generateKeyPair();
      DHPublicKeyParameters pubP = (DHPublicKeyParameters)pair.getPublic();
      DHPrivateKeyParameters prvP = (DHPrivateKeyParameters)pair.getPrivate();
      
//    Client calculateMessage:7512 msec
//    Client calculateAgreement:753 msec
//    Client secret: GksSntlQZSUn4HLbmLY3NV4CVO7txRaA2Iv+M7/oveW5GFzDkZYvyAcH46hpFHmbP9GwMGxj73HOFSUVW3oq9EcbObkRb++3RUW+amb9h+2t0vkggFLKc/SLik95RHwwu7Yx27sfKrHs5ivEWdkF+9tA+OUJ7RTPHsBmID/0zMg=

      IntervalTimer t = new IntervalTimer();
      DHAgreement dha = new DHAgreement();
      System.err.println("Client dha=DHAgreement msec:"+t);
      dha.init(prvP); 
      System.err.println("Client dha.init msec:"+t);
      BigInteger  message = dha.calculateMessage();
      System.err.println("Client dha.calculateMessage msec:"+t);
      BigInteger  agreement = dha.calculateAgreement(pubP, message);
      System.err.println("Client dha.calculateAgreement msec:"+t);
      byte[] secret = agreement.toByteArray();
      
      // Clean up
      out.close();
      in.close();
      return secret;
    }
  }
}
//Listening on port 8765
//Server dha=DHAgreement:22
//Server dha.init:28
//Server dha.calculateMessage:25052
//Server dha.calculateAgreement:747
//Server secret:AJvxbF2BZH+fgCxuOpixa6IQl7Mdr4qhsHJOXO+Mhffg31EAy0Hu9hUkY9uNgA6XBnXxBPs8BNjSYK/SlA2RvJL5L5PmHKWYqKuF9XQP4SbhbD98K2InOW8rs47i1LP3Oo0eVmG4HESuQDErGxUMrIFldRVy4TohGUSb0EVQHoiO

//Client dha=DHAgreement msec:7
//Client dha.init msec:39
//Client dha.calculateMessage msec:35524
//Client dha.calculateAgreement msec:370
//Client secret: ALj9pDOn1QLHsvork6Lg0jEt1xsLQc1w282HQc/ZvHI7ea4sJO/PSVqE9t6ipGfuSJJEAJ8jQfqAViGS0losaX+3Ik6L238trB9tOnWseWA8MYZezqZBfyB0Af+fdi7MOzAwsweKr2JarclfbcLIH0/asLSXu5NdPcNlOv6XAlZr