/*
    * Copyright (c) 2002-2014, Mairie de Paris
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    *
    *  1. Redistributions of source code must retain the above copyright notice
   *     and the following disclaimer.
   *
   *  2. Redistributions in binary form must reproduce the above copyright notice
   *     and the following disclaimer in the documentation and/or other materials
   *     provided with the distribution.
   *
   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
   *     contributors may be used to endorse or promote products derived from
   *     this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * License 1.0
   */
  package fr.paris.lutece.plugins.mylutece.modules.saml.authentication.engine;
  
  import fr.paris.lutece.plugins.mylutece.modules.saml.authentication.config.Constants;
  import fr.paris.lutece.plugins.mylutece.modules.saml.authentication.exceptions.SAMLTokenExtractorException;
  import fr.paris.lutece.portal.service.util.AppLogService;
  
  import org.opensaml.Configuration;
  
  import org.opensaml.saml2.core.Response;
  
  import org.opensaml.xml.io.Unmarshaller;
  import org.opensaml.xml.io.UnmarshallerFactory;
  import org.opensaml.xml.io.UnmarshallingException;
  import org.opensaml.xml.parse.BasicParserPool;
  import org.opensaml.xml.parse.XMLParserException;
  import org.opensaml.xml.util.Base64;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  
  import java.io.StringReader;
  import java.io.UnsupportedEncodingException;
  
  import javax.servlet.http.HttpServletRequest;
  
  
  public class SAMLTokenExtractor implements Constants
  {
      /**
       * M�thode de construction de la SAMLResponse � partir d'une string XML
       *
       * @param xmlToken
       * @throws SAMLTokenExtractorException
       */
      public static Response extractSAMLResponse( HttpServletRequest request )
          throws SAMLTokenExtractorException
      {
          Response response = null;
  
          // Extraction de la SAMLResponse de la requete HTTP
          String SAMLResponseB64Str = request.getParameter( SAML_RESPONSE_REQUEST_PARAM );
  
          // Decodage URL encoding et Base64
          String SAMLResponseStr = null;
  
          try
          {
              SAMLResponseStr = new String( Base64.decode( SAMLResponseB64Str ), "UTF-8" );
          }
          catch ( UnsupportedEncodingException e1 )
          {
              String message = "Mauvais encodage de la Response : " + e1.getLocalizedMessage(  );
              AppLogService.info( message );
              throw new SAMLTokenExtractorException( message );
          }
  
          // Get parser pool manager
          BasicParserPool ppMgr = new BasicParserPool(  );
          ppMgr.setNamespaceAware( true );
  
          Document inCommonMDDoc;
  
          try
          {
              inCommonMDDoc = ppMgr.parse( new StringReader( SAMLResponseStr ) );
  
             Element ResponseRoot = inCommonMDDoc.getDocumentElement(  );
 
             // Get apropriate unmarshaller
             UnmarshallerFactory unmarshallerFactory = Configuration.getUnmarshallerFactory(  );
             Unmarshaller unmarshaller = unmarshallerFactory.getUnmarshaller( ResponseRoot );
 
             // Unmarshall using the document root element, an EntitiesDescriptor
             // in this case
             response = (Response) unmarshaller.unmarshall( ResponseRoot );
         }
         catch ( XMLParserException e )
         {
             String message = "Erreur de parsing de la SAMLResponse : " + e.getLocalizedMessage(  );
             AppLogService.info( message );
             throw new SAMLTokenExtractorException( message );
         }
         catch ( UnmarshallingException e )
         {
             String message = "Erreur de unmarshalling de la SAMLResponse : " + e.getLocalizedMessage(  );
             AppLogService.info( message );
             throw new SAMLTokenExtractorException( message );
         }
 
         return response;
     }
 }