code.grnet.gr Git - pithos/blob - gss/src/gr/ebs/gss/server/NonceIssuer.java

   1 /*
   2  * Copyright 2008, 2009 Electronic Business Systems Ltd.
   3  *
   4  * This file is part of GSS.
   5  *
   6  * GSS is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GSS is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with GSS.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19 package gr.ebs.gss.server;
  20
  21 import static gr.ebs.gss.server.configuration.GSSConfigurationFactory.getConfiguration;
  22 import gr.ebs.gss.client.exceptions.ObjectNotFoundException;
  23 import gr.ebs.gss.client.exceptions.RpcException;
  24 import gr.ebs.gss.server.domain.Nonce;
  25 import gr.ebs.gss.server.domain.User;
  26 import gr.ebs.gss.server.ejb.ExternalAPI;
  27
  28 import java.io.IOException;
  29 import java.io.PrintWriter;
  30
  31 import javax.naming.Context;
  32 import javax.naming.InitialContext;
  33 import javax.naming.NamingException;
  34 import javax.rmi.PortableRemoteObject;
  35 import javax.servlet.http.HttpServlet;
  36 import javax.servlet.http.HttpServletRequest;
  37 import javax.servlet.http.HttpServletResponse;
  38
  39 import org.apache.commons.logging.Log;
  40 import org.apache.commons.logging.LogFactory;
  41
  42 /**
  43  * The servlet that handles nonce creation.
  44  *
  45  * @author past
  46  */
  47 public class NonceIssuer extends HttpServlet {
  48         /**
  49          * The serial version UID of the class.
  50          */
  51         private static final long serialVersionUID = 1L;
  52
  53         /**
  54          * The request parameter name for the user.
  55          */
  56         private static final String USER_PARAM = "user";
  57
  58         /**
  59          * The logger.
  60          */
  61         private static Log logger = LogFactory.getLog(NonceIssuer.class);
  62
  63         /**
  64          * A helper method that retrieves a reference to the ExternalAPI bean and
  65          * stores it for future use.
  66          *
  67          * @return an ExternalAPI instance
  68          * @throws RpcException in case an error occurs
  69          */
  70         private ExternalAPI getService() throws RpcException {
  71                 try {
  72                         final Context ctx = new InitialContext();
  73                         final Object ref = ctx.lookup(getConfiguration().getString("externalApiPath"));
  74                         return (ExternalAPI) PortableRemoteObject.narrow(ref, ExternalAPI.class);
  75                 } catch (final NamingException e) {
  76                         logger.error("Unable to retrieve the ExternalAPI EJB", e);
  77                         throw new RpcException("An error occurred while contacting the naming service");
  78                 }
  79         }
  80
  81         @Override
  82         public void service(HttpServletRequest request, HttpServletResponse response) throws IOException {
  83                 String username = request.getParameter(USER_PARAM);
  84                 User user = null;
  85                 Nonce nonce = null;
  86                 if (username == null) {
  87                         String error = "No username supplied";
  88                         logger.info(error);
  89                         response.setContentType("text/html");
  90                         response.sendError(HttpServletResponse.SC_FORBIDDEN, error);
  91                         return;
  92                 }
  93                 try {
  94                         user = getService().findUser(username);
  95                         if (user == null) {
  96                                 String error = "User was not found";
  97                                 logger.error(error);
  98                                 response.setContentType("text/html");
  99                                 response.sendError(HttpServletResponse.SC_FORBIDDEN, error);
 100                                 return;
 101                         }
 102                         nonce = getService().createNonce(user.getId());
 103                 } catch (RpcException e) {
 104                         String error = "An error occurred while communicating with the service";
 105                         logger.error(error, e);
 106                         response.setContentType("text/html");
 107                         response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, error);
 108                         return;
 109                 } catch (ObjectNotFoundException e) {
 110                         // The user might not be found in createNonce() since there
 111                         // is no transaction spanning the consecutive service calls.
 112                         String error = "The user was not found";
 113                         logger.error(error, e);
 114                         response.setContentType("text/html");
 115                         response.sendError(HttpServletResponse.SC_FORBIDDEN, error);
 116                         return;
 117                 }
 118                 if (logger.isDebugEnabled())
 119                         logger.debug("user: "+user.getUsername()+" nonce: "+nonce.getEncodedNonce());
 120                 response.setContentType("text/plain");
 121             PrintWriter out = response.getWriter();
 122             out.println(nonce.getEncodedNonce());
 123         }
 124 }