src/de/fhswf/in/inf/fit/aufgabe6/LoginServletWithJpaAndJsp.java


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package de.fhswf.in.inf.fit.aufgabe6;

import java.io.IOException;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import de.fhswf.in.inf.fit.aufgabe5.model.Account;

/**
 * Servlet implementation class LoginServletWithJpaAndJsp
 */
@WebServlet("/LoginServletWithJpaAndJsp")
public class LoginServletWithJpaAndJsp extends HttpServlet
{
   private static final long serialVersionUID = 1L;

   /**
    * @see HttpServlet#HttpServlet()
    */
   public LoginServletWithJpaAndJsp()
   {
      super();
   }

   /**
    * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
    *      response)
    */
   protected void doGet(HttpServletRequest request,
         HttpServletResponse response) throws ServletException, IOException
   {
      response.sendRedirect("LoginFormWithJpaAndJsp.jsp");
   }

   /**
    * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
    *      response)
    */
   protected void doPost(HttpServletRequest request,
         HttpServletResponse response) throws ServletException, IOException
   {
      String requestUsername = request.getParameter("username");
      String requestPassword = request.getParameter("password");

      if (requestUsername == null || requestPassword == null)
      {
         doGet(request, response);
      }

      EntityManagerFactory emf = Persistence.createEntityManagerFactory(
            getServletContext().getInitParameter("persistenceUnit"));
      EntityManager em = emf.createEntityManager();

      Account account = em.find(Account.class, requestUsername);
      emf.close();

      // This is very insecure and can be exploited via timing attacks
      if (account != null && account.isPasswordCorrect(requestPassword))
      {
         request.getSession().setAttribute("username", account.getUsername());

         response.sendRedirect("LoginSuccess.jsp");
      }
      else
      {
         doGet(request, response);
      }
   }
}