// RSA public key server
//
// Server which provides a randomly generated RSA public key
// and instantiates a Login Server and "service" server with RMI names based
// on the hex representation of the public key.
//
// R. Perry, July 1998

import java.security.*;

import java.io.*;
import java.net.InetAddress;

import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.LocateRegistry;

import java.lang.reflect.*;

import cryptix.provider.rsa.*;

import cryptix.util.core.Hex;

public class KeyServer
  extends UnicastRemoteObject
  implements Key
{
  private static int port = 21099;

  public KeyServer() throws java.rmi.RemoteException
  {
    super();
//    setLog( System.out);
  }

  public PublicKey getKey( String service)
    throws java.rmi.RemoteException, java.rmi.server.ServerNotActiveException,
      java.security.NoSuchAlgorithmException, java.security.NoSuchProviderException
  {
    KeyPairGenerator kg;	// generator for random RSA keys
    SecureRandom rand;		// to pass to kg.initialize()
    int key_size = 1024;	// number of bits for RSA key
    KeyPair pair;		// RSA key pair
    PublicKey pk;		// RSA public key
    PrivateKey sk;		// RSA private key

  // ToDo: hosts.allow restrictions for ClientHost
  //
    System.out.println( "KeyServer: getKey(): called from " + this.getClientHost());

    rand = SecureRandom.getInstance( "SHA1PRNG");
    rand.setSeed(0);

    kg = KeyPairGenerator.getInstance("RSA");

    System.out.println("KeyServer: getkey(): Generating keypair...");

    kg.initialize(key_size, rand);
    pair = kg.generateKeyPair();
    pk = pair.getPublic();
    sk = pair.getPrivate();

//    System.out.println( "KeyServer: getkey(): returning public key:\n " + pk);

    String pk_hex = Hex.toString(pk.getEncoded());

    System.out.println( "KeyServer: getKey(): RawRSAPublicKey = " + pk_hex);

  // start up a Login Server
  //
    LoginServer L = new LoginServer( sk);

    try {
      Naming.rebind("rmi://:" + port + "/LoginServer-" + pk_hex, (Login) L);
      System.out.println("KeyServer: new LoginServer created and bound in the registry on port " + port);
    } catch( Exception e) {
      System.out.println("KeyServer: " + e);
    }

  // start up the Server class named by the service string
  //
    Class[] args;
    Class serviceClass;
    Constructor C;
    Object o = null;

    try {
      args = new Class[] {LoginServer.class};
      serviceClass = Class.forName( service);
      C = serviceClass.getConstructor( args);
      o = C.newInstance( new Object[] {L});
    } catch( Exception e) {
      System.out.println("KeyServer: " + e);
    }

    try {
      Naming.rebind("rmi://:" + port + "/" + service + "-" + pk_hex, (java.rmi.Remote) o);
      System.out.println("KeyServer: new " + service + " created and bound in the registry on port " + port);
    } catch( Exception e) {
      System.out.println("KeyServer: " + e);
    }
 
    return pk;
  }


 /*
  * createPortFile: save hostname and port number in ./port file
  */
  private static void createPortFile( int port) throws java.io.IOException
  {
    PrintWriter fout = new PrintWriter( new BufferedWriter( new FileWriter( "port")));
    fout.println( InetAddress.getLocalHost().getHostName());
    fout.println( port);
    if( fout.checkError()) {
      System.err.println( "KeyServer: error writing port file.");
      System.exit(1);
    }
    fout.close();
  }


  public static void main (String[] args) throws Exception {

    if (args.length == 1)
      port = Integer.parseInt(args[0]);

//    System.setSecurityManager(new RMISecurityManager()); -- need policy file with JDK1.2

    try {
      LocateRegistry.createRegistry(port);

      Key f = new KeyServer();
      Naming.rebind("rmi://:" + port + "/KeyServer", f);
 
      System.out.println("KeyServer: created and bound in the registry on port " + port);

    } catch (Exception e) {

      System.out.println("KeyServer: " + e);
      System.exit(1);
    }

    createPortFile( port);

    System.out.println("KeyServer: created port file.");
  }
}