servlets.module.challenge.CsrfChallengeTargetJSON.java Source code

Introduction

Here is the source code for servlets.module.challenge.CsrfChallengeTargetJSON.java

Source

package servlets.module.challenge;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.Scanner;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;

import utils.ShepherdLogManager;
import utils.Validate;
import dbProcs.Getter;
import dbProcs.Setter;

/**
 * Cross Site Request Forgery Challenge Target SON - Does not return Result key
 * <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 CsrfChallengeTargetJSON extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private static org.apache.log4j.Logger log = Logger.getLogger(CsrfChallengeTargetJSON.class);
    private static String levelName = "CSRF JSON Target";

    /**
     * CSRF vulnerable function that can be used by users to force other users to mark their CSRF challenge as complete. Function expecting JSON formed data
     * @param userId User identifier to be incremented
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        //Setting IpAddress To Log and taking header for original IP if forwarded from proxy
        ShepherdLogManager.setRequestIp(request.getRemoteAddr(), request.getHeader("X-Forwarded-For"));
        log.debug(levelName + " Servlet");

        //Translation Stuff
        Locale locale = new Locale(Validate.validateLanguage(request.getSession()));
        ResourceBundle errors = ResourceBundle.getBundle("i18n.servlets.errors", locale);
        ResourceBundle csrfGenerics = ResourceBundle.getBundle("i18n.servlets.challenges.csrf.csrfGenerics",
                locale);

        PrintWriter out = response.getWriter();
        out.print(getServletInfo());
        try {
            boolean result = false;
            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());

                log.debug("Getting JSON String");
                String jsonData = extractPostRequestBody(request);
                log.debug("POST body: " + jsonData);
                JSONObject json = (JSONObject) JSONValue.parse(jsonData);
                log.debug("Getting userId");
                String plusId = (String) json.get("userId");
                log.debug("User Submitted - " + plusId);
                String userId = (String) ses.getAttribute("userStamp");
                if (!userId.equals(plusId)) {
                    String ApplicationRoot = getServletContext().getRealPath("");
                    String userName = (String) ses.getAttribute("userName");
                    String attackerName = Getter.getUserName(ApplicationRoot, plusId);
                    if (attackerName != null) {
                        log.debug(userName + " is been CSRF'd by " + attackerName);

                        log.debug("Attempting to Increment ");
                        String moduleHash = CsrfChallengeJSON.getLevelHash();
                        String moduleId = Getter.getModuleIdFromHash(ApplicationRoot, moduleHash);
                        result = Setter.updateCsrfCounter(ApplicationRoot, moduleId, plusId);
                    } else {
                        log.error("UserId '" + plusId + "' could not be found.");
                    }
                }

                if (result) {
                    out.write(csrfGenerics.getString("target.incrementSuccess"));
                } else {
                    out.write(csrfGenerics.getString("target.incrementFailed"));
                }
            } else {
                out.write(csrfGenerics.getString("target.noSession"));
            }
        } catch (Exception e) {
            out.write(errors.getString("error.funky"));
            log.fatal(levelName + " - " + e.toString());
        }
    }

    @SuppressWarnings("resource")
    static String extractPostRequestBody(HttpServletRequest request) throws IOException {
        if ("POST".equalsIgnoreCase(request.getMethod())) {
            Scanner s = new Scanner(request.getInputStream(), "UTF-8").useDelimiter("\\A");
            return s.hasNext() ? s.next() : "";
        }
        return "";
    }
}