Java tutorial
package servlets.module.challenge; import java.io.IOException; import java.io.PrintWriter; import java.util.Locale; import java.util.ResourceBundle; import javax.servlet.ServletException; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.codec.binary.Base64; import org.apache.log4j.Logger; import utils.Hash; import utils.ShepherdLogManager; import utils.Validate; /** * Session Management Challenge Four * <br/><br/> * This file is part of the Security Shepherd Project. * * The Security Shepherd project is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version.<br/> * * The Security Shepherd project is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details.<br/> * * You should have received a copy of the GNU General Public License * along with the Security Shepherd project. If not, see <http://www.gnu.org/licenses/>. * @author Mark Denihan * */ public class SessionManagement4 extends HttpServlet { private static final long serialVersionUID = 1L; private static org.apache.log4j.Logger log = Logger.getLogger(SessionManagement4.class); private static String levelName = "Session Management Challenge Four"; public static String levelHash = "ec43ae137b8bf7abb9c85a87cf95c23f7fadcf08a092e05620c9968bd60fcba6"; private static String levelResult = "238a43b12dde07f39d14599a780ae90f87a23e"; /** * Users must discover the session id for this sub application is very weak. The default session ID for a guest will be 00000001 base64'd. The admin's session will be 00000021 * @param upgraeUserToAdmin Red herring * @param returnPassword Red herring * @param adminDetected Red herring * @param checksum Cookie encoded base 64 that manages who is signed in to the sub schema */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); out.print(getServletInfo()); //Translation Stuff Locale locale = new Locale(Validate.validateLanguage(request.getSession())); ResourceBundle errors = ResourceBundle.getBundle("i18n.servlets.errors", locale); ResourceBundle bundle = ResourceBundle .getBundle("i18n.servlets.challenges.sessionManagement.sessionManagement4", locale); try { //Setting IpAddress To Log and taking header for original IP if forwarded from proxy ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For")); HttpSession ses = request.getSession(true); if (Validate.validateSession(ses)) { ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"), ses.getAttribute("userName").toString()); log.debug(levelName + " servlet accessed by: " + ses.getAttribute("userName").toString()); Cookie userCookies[] = request.getCookies(); int i = 0; Cookie theCookie = null; for (i = 0; i < userCookies.length; i++) { if (userCookies[i].getName().compareTo("SubSessionID") == 0) { theCookie = userCookies[i]; break; //End Loop, because we found the token } } String htmlOutput = null; if (theCookie != null) { log.debug("Cookie value: " + theCookie.getValue()); //Decode Twice byte[] decodedCookieBytes = Base64.decodeBase64(theCookie.getValue()); String decodedCookie = new String(decodedCookieBytes, "UTF-8"); decodedCookieBytes = Base64.decodeBase64(decodedCookie.getBytes()); decodedCookie = new String(decodedCookieBytes, "UTF-8"); log.debug("Decoded Cookie: " + decodedCookie); if (decodedCookie.equals("0000000000000001")) //Guest Session { log.debug("Guest Session Detected"); } else if (decodedCookie.equals("0000000000000021")) //Admin Session { log.debug("Admin Session Detected: Challenge Complete"); // Get key and add it to the output String userKey = Hash.generateUserSolution(levelResult, (String) ses.getAttribute("userName")); htmlOutput = "<h2 class='title'>" + bundle.getString("response.adminClub") + "</h2>" + "<p>" + bundle.getString("response.welcomeAdmin") + " " + "<a>" + userKey + "</a>" + "</p>"; } else //Unknown or Dead session { log.debug("Dead Session Detected"); } } if (htmlOutput == null) { log.debug("Challenge Not Complete"); boolean hackDetected = false; hackDetected = !(request.getParameter("useSecurity") != null && request.getParameter("userId") != null); if (!hackDetected) { log.debug("useSecurity: " + request.getParameter("useSecurity")); log.debug("userId: " + request.getParameter("userId")); hackDetected = !(request.getParameter("useSecurity").toString().equalsIgnoreCase("true")); } else { log.debug("Parameters Missing"); } if (!hackDetected) { htmlOutput = "<h2 class='title'>" + bundle.getString("response.notAdmin") + "</h2>" + "<p>" + bundle.getString("response.notAdminMessage") + "</p>"; } else { htmlOutput = "<h2 class='title'>" + bundle.getString("response.hackDetected") + "</h2>" + "<p>" + bundle.getString("response.hackDetectedMessage") + "</p>"; } } log.debug("Outputting HTML"); out.write(htmlOutput); } else { log.error(levelName + " servlet accessed with no session"); } } catch (Exception e) { out.write(errors.getString("error.funky")); log.fatal(levelName + " - " + e.toString()); } } }