/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.ksb.security;

 import java.io.IOException;

 import java.io.PrintWriter;

 import java.security.Signature;

 import javax.servlet.ServletOutputStream;

 import javax.servlet.http.HttpServletResponse;

 import javax.servlet.http.HttpServletResponseWrapper;

 import org.kuali.rice.ksb.service.KSBServiceLocator;

 /**

  * An HttpServletResponseWrapper which wraps the underlying response's OutputStream in a 

  * SignatureSingingOutputStream which will generate a digital signature for the outgoing message.

  *  

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class SignatureSigningResponseWrapper extends HttpServletResponseWrapper {

         private DigitalSigner signer;

         private ServletOutputStream outputStream;

         private PrintWriter writer;

         public SignatureSigningResponseWrapper(HttpServletResponse response) {

                 super(response);

                 try {                

                         Signature signature = KSBServiceLocator.getDigitalSignatureService().getSignatureForSigning();

                         String alias = KSBServiceLocator.getJavaSecurityManagementService().getModuleKeyStoreAlias();        

                         this.signer = new ResponseHeaderDigitalSigner(signature, alias, response);

                 } catch (Exception e) {

                         throw new RuntimeException("Failed to initialize digital signature verification.", e);

                 }

         }

         @Override

         public ServletOutputStream getOutputStream() throws IOException {

                 if (this.outputStream == null) {

                     this.outputStream = new SignatureSigningOutputStream(this.signer, super.getOutputStream(), true);

                 }

                 return this.outputStream;

         }

         @Override

         public PrintWriter getWriter() throws IOException {

                 if (this.writer == null) {

                     this.writer =  new PrintWriter(getOutputStream());

                 }

                 return this.writer;

         }

 }