コピペで簡単！WordPressのログインページを変更してセキュリティ対策

/**
 *  ログインURLを変更
 */
if (!class_exists('Login_Security')) :

  class Login_Security
  {
      const DEFAULT_LOGIN_NAME = 'wp-login.html';

      public function __construct()
      {
          $this->init();
      }

      private function init()
      {
          $this->hooks();
      }

      private function hooks()
      {
          add_action('template_redirect', array($this, 'login_redirect'));
          add_action('login_init', array($this, 'return_error_default_login_url'));
          add_filter('site_url', array($this, 'login_change_site_url'), 10, 2);
          add_filter('wp_redirect', array($this, 'login_wp_redirect'));
      }

      public static function return_error_default_login_url()
      {
          if (!defined('LOGIN_CHANGE') || sha1('page_changed') !== LOGIN_CHANGE) {
              global $wp_query;
              $wp_query->set_404();
              status_header(404);
              get_template_part(404);
              exit;
          }
      }

      public static function login_change_site_url($url, $path)
      {
          $require_login_name = apply_filters('login_endpoint_name', self::DEFAULT_LOGIN_NAME);
          if (strpos($path, 'wp-login.php') !== false
              && (is_user_logged_in()
                  || strpos($_SERVER['REQUEST_URI'], $require_login_name) !== false)) {
              $url = str_replace('wp-login.php', $require_login_name, $url);
          }
          return $url;
      }

      public static function login_wp_redirect($location)
      {
          $require_login_name = apply_filters('login_endpoint_name', self::DEFAULT_LOGIN_NAME);

          if (strpos($_SERVER['REQUEST_URI'], $require_login_name) !== false) {
              $location = str_replace('wp-login.php', $require_login_name, $location);
          }
          return $location;
      }

      public static function login_redirect()
      {
          $full_uri = (is_ssl() ? 'https' : 'http') . '://' . $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"];
          $full_uri = explode('?', $full_uri)[0];

          $require_login_name = apply_filters('login_endpoint_name', self::DEFAULT_LOGIN_NAME);
          if ($full_uri === home_url('/') . $require_login_name) {
              header("HTTP/1.1 200 LOGIN PAGE");
              define('LOGIN_CHANGE', sha1('page_changed'));
              require_once(ABSPATH . '/wp-login.php');
              exit;
          }
      }
  }

  new Login_Security;

endif;

add_filter('login_endpoint_name', function() {
  return 'login';
});

/** / ログインURLの変更 */

function delete_jquery () {
  if( !is_admin() && !is_login_page() ) {
    wp_deregister_script( 'jquery' );
  }
}

function delete_jquery () {
  if( !is_admin() && !is_login_page() && !defined('LOGIN_CHANGE') ) {
    wp_deregister_script( 'jquery' );
  }
}