code: public static boolean authenticate(String userName, String userPassword) {
          LOGGER.entering(userName, StringUtils.isBlank(userPassword) ? userPassword : userPassword.replaceAll(".", "*"));
          boolean validLogin = false;
          byte[] currentAuthData;
          byte[] hashedInputData;
          if (StringUtils.isBlank(userName) || StringUtils.isBlank(userPassword)) {
              return validLogin;
          }
          try {
              File authFile = new File(AUTH_FILE_LOCATION);
              if (!authFile.exists()) {
                  authFile.createNewFile();
                  createAuthFile(authFile, DEFAULT_USERNAME, DEFAULT_PASSWORD);
              }
              currentAuthData = getBytesFromFile(authFile);
              hashedInputData = hashData(userName, userPassword);
              validLogin = Arrays.equals(currentAuthData, hashedInputData);
          } catch (Exception e) {
              validLogin = false;
          }
          LOGGER.exiting(validLogin);
          return validLogin;
      }
docs: Tries authenticating a given credentials and returns <code>true</code> if the credentials were valid.
  
  @param userName
  @param userPassword
  @return - <code>true</code> if the credentials were valid.