import java.io.*;
import java.security.*;

public class KeyHandler {

   private static String fileName = "key";

   public static void main(String[] args) {
      // Gör publika och privata nycklar och spara dessa till fil
      KeyPair keyPair = makeKeyPair();
      
      PrivateKey priKey = keyPair.getPrivate();
      saveKey(priKey, args[0]);

      PublicKey pubKey = keyPair.getPublic();
      saveKey(pubKey, args[1]);

      System.exit(1);
   }

   private static KeyPair makeKeyPair() {
      KeyPairGenerator keyGen = null;
      try {
         keyGen = KeyPairGenerator.getInstance("DSA", "SUN");
         System.out.println("DONE MAKING KEY GENERATOR");
      } catch(NoSuchProviderException nspe) {
         System.out.println("NoSuchProviderException generated");
      } catch(NoSuchAlgorithmException nsae) {
         System.out.println("NoSuchAlgorithmException generated");
      }

      SecureRandom random = null;
      try {
         random = SecureRandom.getInstance("SHA1PRNG", "SUN");
      } catch(NoSuchProviderException nspe) {
         System.out.println("NoSuchProviderException generated");
      } catch(NoSuchAlgorithmException nsae) {
         System.out.println("NoSuchAlgorithmException generated");
      }

      keyGen.initialize(1024, random);
      System.out.println("DONE MAKING KEY GENERATOR INITIALISATION");

      KeyPair keyPair = keyGen.generateKeyPair();
      System.out.println("DONE MAKING KEY PAIR");

      return keyPair;
   }

   public static void saveKey(Key key, String fileName) {
      try {
         ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(fileName));
         oos.writeObject(key);
         oos.close();
         System.out.println("DONE SAVING KEY");
      } catch (IOException ioe) {
         System.out.println("IOException generated");
      }
   }

   public static Key loadKey(String fileName) {
      Key key = null;
      try {
         ObjectInputStream ois = new ObjectInputStream(new FileInputStream(fileName));
         key = (Key) ois.readObject();
         ois.close();
         System.out.println("DONE LOADING KEY");
      } catch (Exception ioe) {
         System.out.println("IOException generated");
      }
      return key;
   } 
}