/**
    * 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.security.Signature;
  import java.security.cert.Certificate;
  
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.ksb.util.KSBConstants;
  
  /**
   * A DigitalSinger which places the alias and digital signature into the response headers of an HttpServletResponse.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ResponseHeaderDigitalSigner extends AbstractDigitalSigner {
  
  	private String alias;
  	private Certificate certificate;
  	private HttpServletResponse response;
  	
      public ResponseHeaderDigitalSigner(Signature signature, String alias, HttpServletResponse response) {
          super(signature);
          this.alias = alias;
          this.response = response;
      }
      
      public ResponseHeaderDigitalSigner(Signature signature, String alias, Certificate certificate, HttpServletResponse response) {
          this(signature, alias, response);
          this.certificate = certificate;
      }
      
      public ResponseHeaderDigitalSigner(Signature signature, Certificate certificate, HttpServletResponse response) {
          super(signature);
          this.certificate = certificate;
          this.response = response;
      }
      
  	public void sign() throws Exception {
  	    if (StringUtils.isNotBlank(this.alias) ) {
  	        this.response.setHeader(KSBConstants.KEYSTORE_ALIAS_HEADER, this.alias);
  	    }
  	    if (this.certificate != null) {
  	        this.response.setHeader(KSBConstants.KEYSTORE_CERTIFICATE_HEADER, getEncodedCertificate(this.certificate));
  	    }
  	    this.response.setHeader(KSBConstants.DIGITAL_SIGNATURE_HEADER, getEncodedSignature());
  	}
  
  }