import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.IOException;

public class KeyTools
{
   public static void writeToFile(Key key, File file)
   throws IOException
   {
      FileOutputStream fileoutputstream = new FileOutputStream(file);
      ObjectOutputStream objectoutputstream = new ObjectOutputStream(fileoutputstream);
      //objectoutputstream.writeObject(key); // p*1
	  objectoutputstream.writeObject(key.getEncoded()); // p*2
	  //objectoutputstream.writeObject(new String(key.getEncoded())); //p*3
	  System.out.println("filename: " + file);
	  System.out.println("algorithm: " + key.getAlgorithm());
	  System.out.println("format: " + key.getFormat());
      objectoutputstream.close();
   }

   public static Key readFromFile(File file)
   throws ClassNotFoundException,
          IOException
   {
      FileInputStream fileinputstream = new FileInputStream(file);
      ObjectInputStream objectinputstream = new ObjectInputStream(fileinputstream);
      Key key = (Key)objectinputstream.readObject();
      objectinputstream.close();
      return key;
   }

   public static void writeToStream(Key key, OutputStream outputstream)
   throws IOException
   {
      new ObjectOutputStream(outputstream).writeObject(key);
   }

   public static Key readFromStream(InputStream inputstream)
   throws ClassNotFoundException,
          IOException
   {
      return (Key) new ObjectInputStream(inputstream).readObject();
   }

   public static KeyPair generateKeyPair()
   throws NoSuchAlgorithmException
   {
      KeyPairGenerator keypairgenerator = KeyPairGenerator.getInstance("DSA");
	  //KeyPairGenerator keypairgenerator = KeyPairGenerator.getInstance("DiffieHellman");

      keypairgenerator.initialize(1024, new SecureRandom());

      return keypairgenerator.generateKeyPair();
   }

   public static void main(String[] args)
   {
      try
      {
         File filePublic = new File(args[0]);
         File filePrivate = new File(args[1]);

         KeyPair keypair = generateKeyPair();

         writeToFile(keypair.getPublic(), filePublic);
         writeToFile(keypair.getPrivate(), filePrivate);
      }
      catch (Exception ex)
      {
         ex.printStackTrace();
      }
   }
}