/*

  * Copyright (c) 2003-2011, Simon Brown

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  *

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in

  *     the documentation and/or other materials provided with the

  *     distribution.

  *

  *   - Neither the name of Pebble 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 OWNER 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.

  */

 package net.sourceforge.pebble.security;

 import org.springframework.security.web.RedirectStrategy;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import java.io.IOException;

 import java.net.URI;

 /**

  * Redirect strategy that prevents redirection to URLs outside of Pebble.  It does this by removing the URI authority

  * section if it exists.

  */

 public class PebbleRedirectStrategy implements RedirectStrategy {

   public void sendRedirect(HttpServletRequest request, HttpServletResponse response, String url) throws IOException {

     response.sendRedirect(response.encodeRedirectURL(sanitiseUrl(request.getContextPath(), url)));

   }

   public static String sanitiseUrl(String contextPath, String url) {

     // Need to make sure there is no authority section

     URI uri = URI.create(url);

     if (uri.getRawAuthority() != null) {

       StringBuilder sb = new StringBuilder();

       if (uri.getRawPath() != null) {

         sb.append(uri.getRawPath());

       }

       if (uri.getRawQuery() != null) {

         sb.append("?").append(uri.getRawQuery());

       }

       return sb.toString();

     } else {

       return contextPath + url;

     }

   }

 }