/*
    * @(#)Login.java
    *
    * Copyright 2001-2002 Sun Microsystems, Inc. All Rights Reserved.
    *
    * Redistribution and use in source and binary forms, with or 
    * without modification, are permitted provided that the following 
    * conditions are met:
    * 
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   * notice, this  list of conditions and the following disclaimer.
   * 
   * -Redistribution in binary form must reproduct the above copyright 
   * notice, this list of conditions and the following disclaimer in 
   * the documentation and/or other materials provided with the 
   * distribution.
   * 
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   * contributors may be used to endorse or promote products derived 
   * from this software without specific prior written permission.
   * 
   * This software is provided "AS IS," without a warranty of any 
   * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
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   * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
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   */
  
  package no.feide.mellon.jaas.loginutility;
  
  
  import javax.security.auth.login.*;
  import javax.security.auth.Subject;
  
  import no.feide.mellon.jaas.callbackhandlers.CommandlineCallbackHandler;
  
  
  
  /***
   * @author Rikke Amilde Løvlid
   *
   * The original class file has been modified.
   */
  
  /***
   * <p> This class authenticates a <code>Subject</code> and then
   * executes a specified application as that <code>Subject</code>.
   * To use this class, the java interpreter would typically be invoked as:
   *
   * <pre>
   *    % java -Djava.security.manager \
   *        Login \
   *        <applicationclass> <applicationClass_args>
   * </pre>
   *
   * <p> <i>applicationClass</i> represents the application to be executed
   * as the authenticated <code>Subject</code>,
   * and <i>applicationClass_args</i> are passed as arguments to
   * <i>applicationClass</i>.
   *
   * <p> To perform the authentication, <code>Login</code> uses a
   * <code>LoginContext</code>.  A <code>LoginContext</code> relies on a
   * <code>Configuration</code> to determine the modules that should be used
   * to perform the actual authentication.  The location of the Configuration
   * is dependent upon each Configuration implementation.
   * The default Configuration implementation
   * (<code>com.sun.security.auth.login.ConfigFile</code>)
   * allows the Configuration location to be specified (among other ways)
   * via the <code>java.security.auth.login.config</code> system property.
   * Therefore, the <code>Login</code> class can also be invoked as:
   *
   * <pre>
   *    % java -Djava.security.manager \
   *        -Djava.security.auth.login.config=<configuration_url> \
   *        Login \
   *        <your_application_class> <your_application_class_args>
   * </pre>
   */ 
  
  public class Login {
  
      /***
       * <p> Instantate a <code>LoginContext</code> using the
       * provided application classname as the index for the login
       * <code>Configuration</code>.  Authenticate the <code>Subject</code>
       * (three retries are allowed) and invoke
       * <code>Subject.doAsPrivileged</code>
      * with the authenticated <code>Subject</code> and a
      * <code>PrivilegedExceptionAction</code>.
      * The <code>PrivilegedExceptionAction</code> 
      * loads the provided application class, and then invokes
      * its public static <code>main</code> method, passing it
      * the application arguments.
      *
      * <p>
      *
      * @param args the arguments for <code>Login</code>.  The first
      *argument must be the class name of the application to be
      *invoked once authentication has completed, and the
      *subsequent arguments are the arguments to be passed
      *to that application's public static <code>main</code> method.
      */
     public static void main(String[] args) {
 
     	// check for the application's main class
     	if (args == null || args.length == 0) {
     		System.err.println("Invalid arguments: " +
     		"Did not provide name of application class.");
     		System.exit(-1);
     	}
 
     	
     	LoginContext lc = null;
 		try{
 			//The name in the loginconfiguration must be the same as the application name.
 			lc = new LoginContext(args[0], new CommandlineCallbackHandler());
 		}
 		catch(LoginException le){
 			System.err.println("Cannot create Logincontext. " + le.getMessage());
 			System.exit(-1);
 		}
 		catch(SecurityException se){
 			System.err.println("Cannot create LoginContext. " + se.getMessage());
 			System.exit(-1);
 		}
 
 		//The user has 3 attempts to authenticate successfully.
 		int attempts;
 		for(attempts=0; attempts<3; attempts++){
 			try{
 				lc.login();
 				break;
 			}
 			catch(LoginException le){
 				System.err.println("Authentication failed.");
 				System.err.println(" " + le.getMessage());
 				try{
 					Thread.currentThread().sleep(3000);
 				}
 				catch(Exception e){
 					//ignore
 				}
 			}
 			catch(Exception e){
 				System.err.println("Unexpected Exception - unable to continue");
 				e.printStackTrace();
 				System.exit(-1);
 			}
 		}
 
     	// did they fail three times?
     	if (attempts == 3) {
     		System.err.println("Sorry");
     		System.exit(-1);
     	}
     	
     	try{
     		Subject.doAsPrivileged(lc.getSubject(), new  MoriaAction(args), null);
     	}
     	catch (java.security.PrivilegedActionException pae) {
     		pae.printStackTrace();
     		System.exit(-1);
     	}
 		
 		try{
 			lc.logout();
 		}
 		catch(LoginException le){
 			System.err.println("Logout failed");
 			System.err.println(" " + le.getMessage());
 		}
 	}
 }