protected_pages.module

<?php

/**
 * @file
 * This module allows you to protect any page of the website by secure password.
 *
 * You can enter urls of pages to protect and set password per page.
 *
 * Admin (uid = 1) or user with bypass protection permission can view page.
 */

use Drupal\Component\Utility\Html;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Drupal\Core\Url;

/**
 * Implements hook_mail().
 */
function protected_pages_mail($key, &$message, $params) {

  switch ($key) {
    // Send a simple message from the contact form.
    case 'protected_pages_details_mail':

      $tokens = ['[protected-page-url]', '[site-name]'];
      $replcements = [
        $params['protected_page_url'],
        \Drupal::config('system.site')->get('name'),
      ];

      $body = str_replace($tokens, $replcements, $params['body']);

      $subject = $params['subject'];
      $message['subject'] = Html::escape($subject);
      $message['body'][] = Html::escape($body);

      break;
  }
}

/**
 * Implements hook_file_download().
 */
function protected_pages_file_download($uri) {
  $account = \Drupal::currentUser();
  if ($account->hasPermission('bypass pages password protection')) {
    return;
  }

  $target = file_uri_target($uri);
  $file_path = '/system/files/' . $target;

  $fields = ['pid'];
  $conditions = [];
  $conditions['general'][] = [
    'field' => 'path',
    'value' => $file_path,
    'operator' => '=',
  ];

  $protected_pages_storage = \Drupal::service('protected_pages.storage');

  $pid = $protected_pages_storage->loadProtectedPage($fields, $conditions, TRUE);

  if (isset($_SESSION['_protected_page']['passwords'][$pid]['expire_time'])) {
    if (time() >= $_SESSION['_protected_page']['passwords'][$pid]['expire_time']) {
      unset($_SESSION['_protected_page']['passwords'][$pid]['request_time']);
      unset($_SESSION['_protected_page']['passwords'][$pid]['expire_time']);
    }
  }
  if (isset($_SESSION['_protected_page']['passwords'][$pid]['request_time'])) {
    return NULL;
  }
  if ($pid) {
    $destination_path_array = \Drupal::destination()->getAsArray();
    $destination_path_array['destination'] = $destination_path_array['destination'] . '/' . $target;
    $destination_path_array['protected_page'] = $pid;
    $response = new RedirectResponse(Url::fromUri('internal:/protected-page', ['query' => $destination_path_array])
            ->toString());
    $response->send();
    return;
  }
  else {
    return NULL;
  }
}