ChangeUsername.java

package servlets;

import dbProcs.Setter;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.owasp.encoder.Encode;
import utils.ShepherdLogManager;
import utils.Validate;

/**
 * Control class for the Change Username function <br>
 * <br>
 * This file is part of the Security Shepherd Project.
 *
 * <p>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>
 *
 * <p>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>
 *
 * <p>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 ChangeUsername extends HttpServlet {

  private static final long serialVersionUID = 1L;
  private static final Logger log = LogManager.getLogger(ChangeUsername.class);

  /**
   * Initiated by index.jsp, getStarted.jsp. This changes a users username.
   *
   * @param csrfToken
   * @param newUsername Submitted new username
   */
  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("*** servlets.ChangeUsername ***");

    request.setCharacterEncoding("UTF-8");

    HttpSession ses = request.getSession(true);
    if (Validate.validateSession(ses)) {
      ShepherdLogManager.setRequestIp(
          request.getRemoteAddr(),
          request.getHeader("X-Forwarded-For"),
          ses.getAttribute("userName").toString());
      log.debug("Current username: " + ses.getAttribute("userName").toString());
      Cookie tokenCookie = Validate.getToken(request.getCookies());

      Object tokenParmeter = request.getParameter("csrfToken");
      if (Validate.validateTokens(tokenCookie, tokenParmeter)) {
        log.debug("Getting Parameters");
        String userName = (String) ses.getAttribute("userName");
        String newUsername = Encode.forHtml((String) request.getParameter("newUsername"));
        String ApplicationRoot = getServletContext().getRealPath("");
        log.debug("New username: " + newUsername);

        boolean validUsername = false;
        validUsername = newUsername.length() > 3 && newUsername.length() <= 32;
        if (validUsername) {

          log.debug("New username passed validation! Username Change gets the go ahead");
          Setter.updateUsername(ApplicationRoot, userName, newUsername);
          ses.setAttribute("ChangeUsername", "false");
          ses.setAttribute("userName", newUsername);
          log.debug("Username changed");

          response.sendRedirect("index.jsp");

        } else {

          log.error("Invalid Username Submitted (Too Short/Long)");
          ses.setAttribute("errorMessage", "Invalid Username! Please try again.");
          response.sendRedirect("index.jsp");
        }
      } else {
        log.error("CSRF Attack Detected");
      }
    } else {
      log.error("Change Username Function Called with no valid session");
      response.sendRedirect("index.jsp");
    }

    log.debug("*** END ChangeUsername ***");
  }
}