/*
    * Copyright 2001-2008 The Apache Software Foundation.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  package org.apache.juddi.adminconsole;
  
  import javax.servlet.ServletContextEvent;
  import java.io.FileOutputStream;
  import java.io.InputStream;
  import java.util.Properties;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  /**
   * This startup servlet's job is to generate an encryption key which will be
   * used for encrypting cached user credentials in the http session object
   *
   * @author <a href="mailto:alexoree@apache.org">Alex O'Ree</a>
   */
  public class StartupServlet implements javax.servlet.ServletContextListener {
  
      static final Logger log = Logger.getLogger(StartupServlet.class.getCanonicalName());
  
      /**
       * creates a new AES key and stores it to the properties files
       *
       * @param sce
       */
      @Override
      public void contextInitialized(ServletContextEvent sce) {
          log.info("juddi-admin gui startup");
          FileOutputStream fos = null;
          try {
              Properties p = new Properties();
              String key = generateKey();
              if (key == null) return;
              p.put("key", key);
              fos = new FileOutputStream(sce.getServletContext().getRealPath("/WEB-INF/config.properties"));
              log.log(Level.INFO, "Storing key to " + sce.getServletContext().getRealPath("/WEB-INF/config.properties"));
              p.store(fos, "No comments");
              fos.flush();
              fos.close();
          } catch (Exception ex) {
              log.log(Level.WARNING, null, ex);
              try {
                  if (fos != null) {
                      fos.close();
                  }
              } catch (Exception e) {
              }
          }
      }
  
      private String generateKey() {
          String key = generateKey(256);
          if (key == null) {
              key = generateKey(128);
          }
          if (key == null) {
              log.severe("128 bit key validation failed! giving up, user's won't be able to login! ");
              return null;
          }
          return key;
      }
  
      private String generateKey(int length) {
          log.info("Attempting to generate "+length+" bit AES key");
          String key = AES.GEN(length);
          if (key != null) {
              if (AES.ValidateKey(key)) {
                  log.info("Generation of "+length+" bit AES key successful");
              } else {
                  log.warning(length+" bit key validation failed. To use higher key sizes, try installing the Java Cryptographic Extensions (JCE) Unlimited Strength");
                  return null;
              }
          }
          return key;
      }
  
      /**
       *
       * @param sce
       */
      @Override
      public void contextDestroyed(ServletContextEvent sce) {
          removeKeyFromConfigurationFile(sce);
      }
 
     private void removeKeyFromConfigurationFile(ServletContextEvent sce) {
         FileOutputStream fos = null;
         try {
             log.info("Cleaning up juddi-admin");
             Properties p = new Properties();
             InputStream is = sce.getServletContext().getResourceAsStream("/WEB-INF/config.properties");
             p.load(is);
             p.remove("key");
             is.close();
             fos = new FileOutputStream(sce.getServletContext().getRealPath("/WEB-INF/config.properties"));
             p.store(fos, "No comments");
             fos.flush();
             fos.close();
         } catch (Exception ex) {
             log.log(Level.WARNING, null, ex);
             try {
                 if (fos != null) {
                     fos.close();
                 }
             } catch (Exception e) {
             }
         }
         try {
             sce.getServletContext().removeAttribute("username");
             sce.getServletContext().removeAttribute("password");
             sce.getServletContext().removeAttribute("locale");
             sce.getServletContext().removeAttribute("hub");
         } catch (Exception ex) {
             log.log(Level.WARNING, null, ex);
         }
     }
 }