/**

  * Copyright 2010 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.osedu.org/licenses/ECL-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.kuali.student.security.saml.service;

 import java.io.BufferedReader;

 import java.io.InputStreamReader;

 import java.io.StringWriter;

 import java.io.UnsupportedEncodingException;

 import java.net.HttpURLConnection;

 import java.net.URL;

 import java.net.URLEncoder;

 import java.util.HashMap;

 import java.util.Map;

 import javax.jws.WebService;

 import javax.xml.transform.Transformer;

 import javax.xml.transform.TransformerFactory;

 import javax.xml.transform.dom.DOMSource;

 import javax.xml.transform.stream.StreamResult;

 import org.jasig.cas.client.util.CommonUtils;

 import org.jasig.cas.client.util.XmlUtils;

 import org.kuali.student.security.exceptions.KSSecurityException;

 import org.kuali.student.security.util.SamlUtils;

 import org.opensaml.SAMLAssertion;

 import org.w3c.dom.Document;

 @WebService(endpointInterface = "org.kuali.student.security.saml.service.SamlIssuerService", serviceName = "SamlIssuerService", portName = "SamlIssuerService", targetNamespace = "http://student.kuali.org/wsdl/security/saml")

 public class SamlIssuerServiceImpl implements SamlIssuerService {

     private String casServerUrl;

     private String samlIssuerForUser;

     private String proxyCallBackUrl;

     public String validateCasProxyTicket(String proxyTicketId, String proxyTargetService) throws KSSecurityException{

         String url = constructUrl(proxyTicketId, proxyTargetService);

         HttpURLConnection conn = null;

         try {

             URL constructedUrl = new URL(url);

             conn = (HttpURLConnection) constructedUrl.openConnection();

             BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));

             String line;

             StringBuffer stringBuffer = new StringBuffer(255);

             String response;

             while ((line = in.readLine()) != null) {

                 stringBuffer.append(line);

             }

             response = stringBuffer.toString();

             String error = XmlUtils.getTextForElement(response, "authenticationFailure");

             if (CommonUtils.isNotEmpty(error)) {

                 return error;

             }

             String user = XmlUtils.getTextForElement(response, "user");

             String pgt  = XmlUtils.getTextForElement(response, "proxyGrantingTicket");

             String proxies = XmlUtils.getTextForElement(response, "proxies");

             Map<String,String> samlProperties = new HashMap<String,String>();

             samlProperties.put("user", user.trim());

             samlProperties.put("proxyGrantingTicket", pgt.trim());

             samlProperties.put("proxies", proxies.trim());

             samlProperties.put("samlIssuerForUser", samlIssuerForUser.trim());

             SamlUtils.setSamlProperties(samlProperties);

             SAMLAssertion samlAssertion = SamlUtils.createAssertion();

             Document signedSAML = SamlUtils.signAssertion(samlAssertion);

             // transform the saml DOM into a writer, and return as a string response

             DOMSource domSource = new DOMSource(signedSAML);

             StringWriter writer = new StringWriter();

             StreamResult result = new StreamResult(writer);

             TransformerFactory tf = TransformerFactory.newInstance();

             Transformer transformer;

             transformer = tf.newTransformer();

             transformer.transform(domSource, result);

             writer.flush();

             return writer.toString();

         } catch (final Exception e) {

             throw new KSSecurityException(e);

         } finally {

             if (conn != null) {

                 conn.disconnect();

             }

         }

     }

     private String constructUrl(String proxyTicketId, String proxyTargetService) throws KSSecurityException{

         try {

             return this.casServerUrl + (this.casServerUrl.endsWith("/") ? "" : "/") + "proxyValidate" + "?ticket=" 

             + proxyTicketId + "&service=" + URLEncoder.encode(proxyTargetService, "UTF-8") 

             + "&pgtUrl=" + URLEncoder.encode(proxyCallBackUrl, "UTF-8");

         } catch (UnsupportedEncodingException e) {

             throw new KSSecurityException(e);

         }

     }

     /* Use this method when not using a CAS proxy. 

      * Example if the ProxyTicketRetrieverFilter useCasProxyMechanism = false

      */

     public String getSamlPrincipal(String principal) throws KSSecurityException{

         try {      

             Map<String,String> samlProperties = new HashMap<String,String>();

             samlProperties.put("user", principal);

             samlProperties.put("proxyGrantingTicket", "");

             samlProperties.put("proxies", "");

             samlProperties.put("samlIssuerForUser", samlIssuerForUser.trim());

             SamlUtils.setSamlProperties(samlProperties);

             SAMLAssertion samlAssertion = SamlUtils.createAssertion();

             Document signedSAML = SamlUtils.signAssertion(samlAssertion);

             // transform the saml DOM into a writer, and return as a string response

             DOMSource domSource = new DOMSource(signedSAML);

             StringWriter writer = new StringWriter();

             StreamResult result = new StreamResult(writer);

             TransformerFactory tf = TransformerFactory.newInstance();

             Transformer transformer;

             transformer = tf.newTransformer();

             transformer.transform(domSource, result);

             writer.flush();

             return writer.toString();

         } catch (final Exception e) {

             throw new KSSecurityException(e);

         } 

     }

     public String getCasServerUrl() {

         return casServerUrl;

     }

     public void setCasServerUrl(String casServerUrl) {

         this.casServerUrl = casServerUrl;

     }

     public String getSamlIssuerForUser() {

         return samlIssuerForUser;

     }

     public void setSamlIssuerForUser(String samlIssuerForUser) {

         this.samlIssuerForUser = samlIssuerForUser;

     }

     public String getProxyCallBackUrl() {

         return proxyCallBackUrl;

     }

     public void setProxyCallBackUrl(String proxyCallBackUrl) {

         this.proxyCallBackUrl = proxyCallBackUrl;

     }

 }