/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package servlets;
import dao.JdbcConnection;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* This servlet is used to demonstrate SQL injection attacks.
*
*
* @author mark
*/
@WebServlet(name = "LoginServlet", urlPatterns = {"/login"})
public class LoginServlet extends HttpServlet {
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code>
* methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String username = request.getParameter("username");
String password = request.getParameter("password");
String sql = "select name from users where username = '" + username + "' and password = '" + password + "';";
try (
Connection con = JdbcConnection.getConnection();
Statement s = con.createStatement();
ResultSet rs = s.executeQuery(sql);) {
if (rs.next()) {
String uname = rs.getString("name");
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<link rel=\"stylesheet\" href=\"highlight.js/github.css\">");
out.println("<script src=\"highlight.js/highlight.pack.js\"></script>");
out.println("<script>hljs.initHighlightingOnLoad();</script>");
out.println("</head>");
out.println("<body>");
out.println("<h1 style=\"color: green;\">Hi " + uname + ". You have successfully logged in!</h1>");
out.println("<p>Code for generating query:</p>");
out.println("<pre><code class=\"java\">\"select * from users where username = '\" + username + \"' and password = '\" + password + \"';\"</code></pre>");
out.println("<p>Generated query was:</p>");
out.println("<pre><code class=\"sql\">" + sql + "</code></pre>");
out.println("<p>Query found a matching result.</p>");
out.println("<p><a href=\"index.jsp\">Back</a></p>");
out.println("</body></html>");
} else {
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<link rel=\"stylesheet\" href=\"highlight.js/github.css\">");
out.println("<script src=\"highlight.js/highlight.pack.js\"></script>");
out.println("<script>hljs.initHighlightingOnLoad();</script>");
out.println("</head>");
out.println("<body>");
out.println("<h1 style=\"color: red;\">Log in failed!</h1>");
out.println("<p>Code for generating query:</p>");
out.println("<pre><code class=\"java\">\"select * from users where username = '\" + username + \"' and password = '\" + password + \"';\"</code></pre>");
out.println("<p>Generated query was:</p>");
out.println("<pre><code class=\"sql\">" + sql + "</code></pre>");
out.println("<p>Query found no results matching those details.</p>");
out.println("<p><a href=\"index.jsp\">Back</a></p>");
out.println("</body></html>");
}
} catch (SQLException ex) {
Logger.getLogger(LoginServlet.class.getName()).log(Level.SEVERE, null, ex);
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
