/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
    *
    * 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.acegisecurity.providers.x509.populator;
  
  import org.acegisecurity.AcegiMessageSource;
  import org.acegisecurity.AuthenticationException;
  import org.acegisecurity.BadCredentialsException;
  import org.acegisecurity.AuthenticationServiceException;
  
  import org.acegisecurity.providers.x509.X509AuthoritiesPopulator;
  
  import org.acegisecurity.userdetails.UserDetails;
  import org.acegisecurity.userdetails.UserDetailsService;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.apache.oro.text.regex.MalformedPatternException;
  import org.apache.oro.text.regex.MatchResult;
  import org.apache.oro.text.regex.Pattern;
  import org.apache.oro.text.regex.PatternMatcher;
  import org.apache.oro.text.regex.Perl5Compiler;
  import org.apache.oro.text.regex.Perl5Matcher;
  
  import org.springframework.beans.factory.InitializingBean;
  
  import org.springframework.context.MessageSource;
  import org.springframework.context.MessageSourceAware;
  import org.springframework.context.support.MessageSourceAccessor;
  
  import org.springframework.util.Assert;
  
  import java.security.cert.X509Certificate;
  
  
  /**
   * Populates the X509 authorities via an {@link org.acegisecurity.userdetails.UserDetailsService}.
   *
   * @author Luke Taylor
   * @version $Id: DaoX509AuthoritiesPopulator.java 1994 2007-08-30 20:55:49Z luke_t $
   */
  public class DaoX509AuthoritiesPopulator implements X509AuthoritiesPopulator, InitializingBean, MessageSourceAware {
      //~ Static fields/initializers =====================================================================================
  
      private static final Log logger = LogFactory.getLog(DaoX509AuthoritiesPopulator.class);
  
      //~ Instance fields ================================================================================================
  
      protected MessageSourceAccessor messages = AcegiMessageSource.getAccessor();
      private Pattern subjectDNPattern;
      private String subjectDNRegex = "CN=(.*?),";
      private UserDetailsService userDetailsService;
  
      //~ Methods ========================================================================================================
  
      public void afterPropertiesSet() throws Exception {
          Assert.notNull(userDetailsService, "An authenticationDao must be set");
          Assert.notNull(this.messages, "A message source must be set");
  
          Perl5Compiler compiler = new Perl5Compiler();
  
          try {
              subjectDNPattern = compiler.compile(subjectDNRegex,
                      Perl5Compiler.READ_ONLY_MASK | Perl5Compiler.CASE_INSENSITIVE_MASK);
          } catch (MalformedPatternException mpe) {
              throw new IllegalArgumentException("Malformed regular expression: " + subjectDNRegex);
          }
      }
  
      public UserDetails getUserDetails(X509Certificate clientCert) throws AuthenticationException {
          String subjectDN = clientCert.getSubjectDN().getName();
          PatternMatcher matcher = new Perl5Matcher();
  
          if (!matcher.contains(subjectDN, subjectDNPattern)) {
              throw new BadCredentialsException(messages.getMessage("DaoX509AuthoritiesPopulator.noMatching",
                      new Object[] {subjectDN}, "No matching pattern was found in subjectDN: {0}"));
          }
  
          MatchResult match = matcher.getMatch();
  
          if (match.groups() != 2) { // 2 = 1 + the entire match
              throw new IllegalArgumentException("Regular expression must contain a single group ");
          }
  
          String userName = match.group(1);
  
         UserDetails user = this.userDetailsService.loadUserByUsername(userName);
 
         if (user == null) {
             throw new AuthenticationServiceException(
                 "UserDetailsService returned null, which is an interface contract violation");
         }
 
         return user;
     }
 
     public void setMessageSource(MessageSource messageSource) {
         this.messages = new MessageSourceAccessor(messageSource);
     }
 
     /**
      * Sets the regular expression which will by used to extract the user name from the certificate's Subject
      * DN.
      * <p>It should contain a single group; for example the default expression "CN=(.?)," matches the common
      * name field. So "CN=Jimi Hendrix, OU=..." will give a user name of "Jimi Hendrix".</p>
      * <p>The matches are case insensitive. So "emailAddress=(.?)," will match "EMAILADDRESS=jimi@hendrix.org,
      * CN=..." giving a user name "jimi@hendrix.org"</p>
      *
      * @param subjectDNRegex the regular expression to find in the subject
      */
     public void setSubjectDNRegex(String subjectDNRegex) {
         this.subjectDNRegex = subjectDNRegex;
     }
 
     public void setUserDetailsService(UserDetailsService userDetailsService) {
         this.userDetailsService = userDetailsService;
     }
 }