securepages.module

<?php
/**
 * @file
 * Allows certain pages to be viewable only via HTTPS.
 */

use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Url;

function securepages_form_alter(&$form, &$form_state, $form_id) {
  global  $is_https, $user, $language;

  $config = \Drupal::config('securepages.settings');
  $securepages_enable = $config->get('securepages_enable');
  $securepages_switch = $config->get('securepages_switch');
  $securepagesservice = \Drupal::service('securepages.securepagesservice');

  if (!$securepages_enable) {
    return;
  }

  $securePagesCanAlterUrl = $securepagesservice->securePagesCanAlterUrl($form['#action']);

  if (isset($form['#action']) && $securePagesCanAlterUrl) {

    // Remove the base_path, and extract the path component.
    $url = substr(rawurldecode($form['#action']), strlen(base_path()));
    // Filter out any language prefixes as it will be automatically added to
    // the URL again.
    // @todo: language prefix
    $langcode = \Drupal::languageManager()->getCurrentLanguage()->getId();

    if (!empty($language->prefix) && preg_match('/^' . $language->prefix . '/', $url) > 0) {
      $url = preg_replace('/^' . $language->prefix . '\//', '', $url);
    }
    $url = UrlHelper::parse($url);

    $path = \Drupal::service('path.alias_manager')->getPathByAlias($url['path'], $langcode);
    $page_match = $securepagesservice->securePagesMatch($path);
    $role_match = $securepagesservice->securePagesRoles($user);

    if ($role_match) {
      if (!$is_https) {
        $form['#https'] = TRUE;
      }
      return;
    }

    if (isset($form['#https'])) {
          // if the #https is set don't reset it as module that set it knows better.
    }
    elseif ($page_match && !$is_https) {
      $form['#https'] = TRUE;
    }
    elseif ($page_match === 0 && $is_https && $securepages_switch) {
      $url['https'] = FALSE;
      $url['absolute'] = TRUE;
      $form['#action'] = Url::fromUri($url['path'], $url)->toString();
    }
  }

  // Check to see if this form needs to be secured.
  $args = $form_state->getBuildInfo()['args'];
  $secure_form = securepages_match_form($form_id, $args);
  if (!$is_https && $secure_form) {
    $form['#https'] = TRUE;
  }
}

/**
 * Check form Id to see if this form should be secured.
 */
function securepages_match_form($form_id, $args = array()) {
  $forms = & drupal_static(__FUNCTION__);
  $securepagesservice = \Drupal::service('securepages.securepagesservice');
  $config = \Drupal::config('securepages.settings');
  $securepages_forms = $config->get('securepages_forms');

  $form_match = \Drupal::service('path.matcher')->matchPath($form_id, $securepages_forms);
  if ($form_match) {
    $securepagesservice->securePagesLog('Secure Form (Form: "@path", Line: @line, Pattern: "@pattern")', $form_id, $securepages_forms);
    return TRUE;
  }

  if (!isset($forms)) {
    //$forms = module_invoke_all('forms', $form_id, $args);
    //@todo:check functionality
    \Drupal::moduleHandler()->invokeAll('forms', $args);
  }

  if (isset($forms[$form_id])) {
    $form_definition = $forms[$form_id];

    $form_callback_match = \Drupal::service('path.matcher')->matchPath($form_definition['callback'], $securepages_forms);
    if ($form_callback_match) {
      $securepagesservice->securePagesLog('Secure Form (Path: "@path", Line: @line, Pattern: "@pattern")', $form_definition['callback'], $securepages_forms);
      return TRUE;
    }
  }

  return FALSE;
}