package org.wcb.gui.util;
   
   
   import javax.crypto.SecretKey;
   import javax.crypto.SecretKeyFactory;
   import javax.crypto.Cipher;
   import javax.crypto.spec.PBEKeySpec;
   import javax.crypto.spec.PBEParameterSpec;
   import java.util.logging.Logger;
  import java.util.logging.Level;
  import java.security.GeneralSecurityException;
  
  /**
   * <small>
   * <p>
   * Copyright (c)  2006  wbogaardt.
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
   * <p/>
   * $File:  $ <br>
   * $Change:  $ submitted by $Author: wbogaardt $ at $DateTime: Sep 26, 2006 11:44:35 AM $ <br>
   * </small>
   *
   * @author wbogaardt
   *         Authentication
   */
  
  public class AuthenticationUtility {
  
  
      private String username;
      private String password;
      private boolean rememberName;
      private Logger LOG = Logger.getLogger(AuthenticationUtility.class.getName());
      
      /**
       * Name of the algorithm used for encryption\decryption.
       */
      private static final String ALGORITHM = "PBEWithMD5AndDES";
  
      /**
       * Password for Key
       */
      private static final char[] KEY_PASSWORD = "pilotlogbook".toCharArray();
      private static final String USERNAME = "username";
      private static final String PASSWORD = "password";
      private static final String REMEMBER_NAME = "username.rembmer";
  
      public AuthenticationUtility() {
          load();
      }
  
      private void load() {
          username = ApplicationPreferences.getInstance().getString(USERNAME);
          password = ApplicationPreferences.getInstance().getString(PASSWORD);
          rememberName = ApplicationPreferences.getInstance().getBoolean(REMEMBER_NAME);
      }
  
      /**
       * Should only be used to clear user name and password
       * in cases of unit testing.
       */
      public void clearAuthentication() {
          ApplicationPreferences.getInstance().removeKey(USERNAME);
          ApplicationPreferences.getInstance().removeKey(PASSWORD);
      }
  
      public void createNewUser(String user, String passwrd) {
          this.setUsername(user);
          this.setPassword(encrypt(passwrd));
          ApplicationPreferences.getInstance().putString(USERNAME, username);
          ApplicationPreferences.getInstance().putString(PASSWORD, encrypt(passwrd));
          /*Preferences prefs = Preferences.userNodeForPackage(AuthenticationUtility.class);
          prefs.put(USERNAME, username);
          prefs.put(PASSWORD, encrypt(passwrd));*/
      }
  
      public boolean authenticateUser(String user, String passwrd) {
          String unencryptPassword = decrypt(password);
          return user.equalsIgnoreCase(username) && passwrd.equalsIgnoreCase(unencryptPassword);
      }
  
      public boolean updatePassword(String oldpasswrd, String passwrd) {
          String unencryptPassword = decrypt(password);
          if(unencryptPassword.equalsIgnoreCase(oldpasswrd) || username.equals("")) {
              this.setPassword(encrypt(passwrd));
              ApplicationPreferences.getInstance().putString(USERNAME, username);
              ApplicationPreferences.getInstance().putString(PASSWORD, encrypt(passwrd));
             /*Preferences prefs = Preferences.userNodeForPackage(AuthenticationUtility.class);
             prefs.put(USERNAME, username);
             prefs.put(PASSWORD, encrypt(passwrd));*/
             return true;
         }
         return false;
     }
 
     public String encrypt(String pass) {
         Cipher cipher;
         SecretKey secretKey;
         PBEParameterSpec pbeParmSpec;
         byte[] encData = null;
         try {
             // create the key
             secretKey = createSecretKey();
 
             // create the PBEParameterSpec
             pbeParmSpec = createParameterSpec();
 
             // create and initialize the Cipher
             // using the secret key, and param spec
             cipher = Cipher.getInstance(ALGORITHM);
             cipher.init(Cipher.ENCRYPT_MODE, secretKey, pbeParmSpec);
 
             // encrypt the data
             encData = cipher.doFinal(pass.getBytes());
 
             // catch an exceptions that may occur
         } catch (GeneralSecurityException gse) {
             LOG.log(Level.WARNING, gse.getMessage());
         }
         return new String(encData);
     }
 
     public String decrypt(String newPassword) {
         Cipher cipher;
         SecretKey secretKey;
         PBEParameterSpec pbeParmSpec;
         byte[] decData = null;
         try {
             // create the key
             secretKey = createSecretKey();
 
             // create the PBEParameterSpec
             pbeParmSpec = createParameterSpec();
 
             // create and initialize the Cipher
             // using the secret key, and param spec
             cipher = Cipher.getInstance(ALGORITHM);
             cipher.init(Cipher.DECRYPT_MODE, secretKey, pbeParmSpec);
 
             // decrypt the data
             decData = cipher.doFinal(newPassword.getBytes());
 
 
 
             // catch an exceptions that may occur
         } catch (GeneralSecurityException gse) {
             LOG.log(Level.WARNING, gse.getMessage(), gse);
         }
         return new String(decData);
     }
 
     public String getUsername() {
         return username;
     }
 
     public void setUsername(String username) {
         this.username = username;
     }
 
     public String getPassword() {
         return password;
     }
 
     public void setPassword(String password) {
         this.password = password;
     }
 
     /**
      * Set to true to remeber the user name on the login form
      * @param val Set to true to remember name on user form
      */
     public void setRememberUsername(boolean val) {
         this.rememberName = val;
         ApplicationPreferences.getInstance().setBoolean(REMEMBER_NAME, val);
     }
 
     /**
      * True indicates user wants to have the login dialog remember their username.
      * @return  true remember username.
      */
     public boolean isRememberName() {
         return this.rememberName;
     }
 
     /**
      * Returns the SecretKey used for encryption and decryption.
      *
      * @return SecretKey - the SecretKey
      * @throws java.security.GeneralSecurityException - on error;
      */
     private SecretKey createSecretKey() throws GeneralSecurityException {
         // tmp variables
         PBEKeySpec pbeKeySpec;
         SecretKeyFactory skFactory;
 
         // create SecretKey
         pbeKeySpec = new PBEKeySpec(KEY_PASSWORD);
         skFactory = SecretKeyFactory.getInstance(ALGORITHM);
 
         // return it
         return skFactory.generateSecret(pbeKeySpec);
     }
 
     /**
      * Returns the PBEParameterSpec used for initializing
      * a Cipher object.
      *
      * @return PBEParameterSpec - the PBEParameterSpec.
      */
     private PBEParameterSpec createParameterSpec() {
         return new PBEParameterSpec(("LMBSALT!".getBytes()), 50);
     }
 }