recaptcha.module in reCAPTCHA 6

Uses the reCAPTCHA web service to improve the CAPTCHA system.

File

recaptcha.module

<?php

/**
 * @file
 * Uses the reCAPTCHA web service to improve the CAPTCHA system.
 */

/**
 * Implements hook_help().
 */
function recaptcha_help($path, $arg) {
  $output = '';
  switch ($path) {
    case 'admin/modules#name':
      $output .= t('reCAPTCHA');
      break;
    case 'admin/modules#description':
    case 'admin/user/captcha/recaptcha':
      $output .= t('Uses the <a href="@url">reCAPTCHA</a> web service to improve the CAPTCHA system and protect email addresses.', array(
        '@url' => url('https://www.google.com/recaptcha'),
      ));
      break;
    case 'admin/help#recaptcha':
      $output .= '<p>' . t('Uses the reCAPTCHA web service to improve the CAPTCHA module and protect email addresses. For more information on what reCAPTCHA is, visit <a href="@url">the official website</a>.', array(
        '@url' => url('https://www.google.com/recaptcha'),
      )) . '</p><h3>' . t('Configuration') . '</h3><p>' . t('The settings associated with reCAPTCHA can be found in the <a href="@recaptchatab">reCAPTCHA tab</a>, in the <a href="@captchasettings">CAPTCHA settings</a>. You must set your public and private reCAPTCHA keys in order to use the module. Once the public and private keys are set, visit the <a href="@captchasettings">CAPTCHA settings</a>, where you can choose where reCAPTCHA should be displayed.', array(
        '@recaptchatab' => url('admin/user/captcha/recaptcha'),
        '@captchasettings' => url('admin/user/captcha'),
      )) . '</p>';
      break;
  }
  return $output;
}

/**
 * Implements hook_menu().
 */
function recaptcha_menu() {
  $items = array();
  $items['admin/user/captcha/recaptcha'] = array(
    'title' => 'reCAPTCHA',
    'description' => 'Administer the reCAPTCHA web service.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'recaptcha_admin_settings',
    ),
    'access arguments' => array(
      'administer recaptcha',
    ),
    'type' => MENU_LOCAL_TASK,
    'file' => 'recaptcha.admin.inc',
  );
  return $items;
}

/**
 * Implements hook_perm().
 */
function recaptcha_perm() {
  return array(
    'administer recaptcha',
  );
}

/**
 * Implements hook_captcha().
 */
function recaptcha_captcha() {
  $args = func_get_args();
  $op = array_shift($args);
  switch ($op) {
    case 'list':
      return array(
        'reCAPTCHA',
      );
    case 'generate':
      $captcha_type = array_shift($args);
      $captcha = array();
      if ($captcha_type == 'reCAPTCHA') {

        // Retrieve configuration variables.
        $recaptcha_theme = variable_get('recaptcha_theme', 'red');
        $recaptcha_tabindex = variable_get('recaptcha_tabindex', '');
        $recaptcha_public_key = variable_get('recaptcha_public_key', '');
        $recaptcha_ajax_api = variable_get('recaptcha_ajax_api', FALSE);

        // Test if reCAPTCHA can be used, falling back to Math if it is not
        // configured, the library won't load, or the server is down.
        if (empty($recaptcha_public_key) || !_recaptcha_load_library() || !_recaptcha_server_is_up()) {
          return captcha_captcha('generate', 'Math', $args);
        }
        if ($recaptcha_ajax_api) {

          // By default CAPTCHA turns off page caching on any page where a
          // CAPTCHA challenge appears. If recaptcha is using AJAX API, set
          // caching back to its old state as stored in DB.
          global $conf;
          $conf['cache'] = unserialize(db_result(db_query("SELECT value FROM {variable} WHERE name = 'cache'")));
        }
        $recaptcha_options = array(
          'theme' => $recaptcha_theme,
        );

        // Localization support.
        global $language;
        if (isset($language->language)) {

          // reCAPTCHA uses two-character language codes, so 'pt-br' must be
          // passed as 'pt'; cf. https://developers.google.com/recaptcha/docs/customization#i18n
          $recaptcha_options['lang'] = drupal_substr($language->language, 0, 2);
        }

        // Construct the Javascript, but only display it once.
        static $_recaptcha_jsadded = FALSE;
        if ($_recaptcha_jsadded == FALSE && $recaptcha_ajax_api == FALSE) {
          $_recaptcha_jsadded = TRUE;

          // Add support to display the custom theme.
          if ($recaptcha_theme == 'custom') {
            $recaptcha_options['custom_theme_widget'] = 'recaptcha_custom_theme_widget';
          }

          // Set the default tab index.
          if (!empty($recaptcha_tabindex)) {
            $recaptcha_options['tabindex'] = $recaptcha_tabindex;
          }
          drupal_add_js('var RecaptchaOptions = ' . drupal_to_js($recaptcha_options) . ';', 'inline');
        }

        // Create the form. Captcha requires TRUE to be returned in solution.
        $captcha['solution'] = TRUE;
        $captcha['captcha_validate'] = 'recaptcha_captcha_validation';

        // If 'Disable Client-Side Cookies' is set, then add query string to
        // end of the public key string before passing to recaptchalib.
        if (variable_get('recaptcha_nocookies', FALSE)) {
          $recaptcha_public_key .= '&nocookie=1';
        }
        $captcha['form']['captcha_response'] = array(
          '#type' => 'hidden',
          '#value' => 'reCAPTCHA',
        );

        // Expose the form, either straight HTML, or using the AJAX API.
        // Build the custom theme HTML if necessary.
        $recaptcha_custom_html = $recaptcha_theme == 'custom' ? theme('recaptcha_custom_widget') : '';
        if ($recaptcha_ajax_api == FALSE) {

          // Only generate recaptcha_get_html() if we're not using the AJAX API.
          $html = recaptcha_get_html($recaptcha_public_key, NULL, TRUE);
          $captcha['form']['captcha_form'] = array(
            '#type' => 'item',
            '#value' => (!empty($recaptcha_custom_html) ? '<div id="recaptcha_custom_theme_widget">' . $recaptcha_custom_html . '</div>' : '') . $html,
          );
        }
        else {
          $captcha['form']['captcha_form'] = array(
            '#type' => 'item',
            // Create the destination container, inserting any custom theme HTML
            // necessary ($recaptcha_custom_html will be empty if we are not
            // using custom theme).
            '#value' => '<div id="recaptcha_ajax_api_container">' . $recaptcha_custom_html . '</div>',
          );
          $js = '$(function() { Recaptcha.create(' . drupal_to_js($recaptcha_public_key) . ', "recaptcha_ajax_api_container", {theme: ' . drupal_to_js($recaptcha_theme) . '});});';
          drupal_add_js($js, 'inline', 'header');
          drupal_set_html_head('<script type="text/javascript" src="https://www.google.com/recaptcha/api/js/recaptcha_ajax.js"></script>');
        }
      }
      return $captcha;
  }
}

/**
 * @return bool
 *   TRUE if the reCAPTCHA server is up, FALSE otherwise.
 */
function _recaptcha_test_recaptcha_server() {
  $response = drupal_http_request('https://' . RECAPTCHA_VERIFY_SERVER);
  if (empty($response->error)) {
    return TRUE;
  }
  else {
    watchdog('reCAPTCHA', 'Unable to connect with the reCAPTCHA server (@server): @errno: @errstr', array(
      '@server' => RECAPTCHA_VERIFY_SERVER,
      '@errno' => $response->code,
      '@errstr' => $response->error,
    ), WATCHDOG_ERROR);
    return FALSE;
  }
}

/**
 * Return the cached output of _recaptcha_test_recaptcha_server().
 *
 * @return bool
 *   TRUE if the reCAPTCHA server was up last time it was checked, FALSE
 *   otherwise.
 */
function _recaptcha_server_is_up() {
  static $server_status;

  // Use static cache value, if available.
  if (isset($server_status)) {
    return $server_status;
  }

  // Check if the status is cached already.
  // D6 cache_get() may return 0 what makes the condition failing
  $status_cache = (bool) cache_get('recaptcha_server_status');
  if ($status_cache !== FALSE) {
    $server_status = $status_cache;
    return $server_status;
  }

  // Status is not cached. Check if server is up.
  $server_status = _recaptcha_test_recaptcha_server();

  // Set to 5 minutes, if interval is not set.
  $cache_period = variable_get('recaptcha_server_status_check_interval', 5);

  // Save it as integer as cache_get returns FALSE, if not found.
  cache_set('recaptcha_server_status', (int) $server_status, 'cache', time() + $cache_period * 60);
  return $server_status;
}

/**
 * CAPTCHA Callback; Validates the reCAPTCHA code.
 */
function recaptcha_captcha_validation($solution = NULL, $response = NULL) {
  global $user;
  $recaptcha_private_key = variable_get('recaptcha_private_key', '');
  $ip_address = ip_address();
  if (!empty($recaptcha_private_key) && $ip_address && $response === 'reCAPTCHA' && !empty($_POST['recaptcha_challenge_field']) && !empty($_POST['recaptcha_response_field']) && _recaptcha_server_is_up()) {
    $resp = recaptcha_check_answer($recaptcha_private_key, $ip_address, check_plain($_POST['recaptcha_challenge_field']), check_plain($_POST['recaptcha_response_field']));
    return $resp->is_valid;
  }
  return FALSE;
}

/**
 * Implements hook_theme().
 */
function recaptcha_theme() {
  return array(
    'recaptcha_custom_widget' => array(
      'arguments' => array(),
    ),
  );
}

/**
 * Theme function: creates the custom themed recaptcha widget.
 *
 * @ingroup themeable
 */
function theme_recaptcha_custom_widget() {
  $recaptcha_only_if_incorrect_sol = t('Incorrect please try again');
  $recaptcha_only_if_image_enter = t('Enter the words above:');
  $recaptcha_only_if_audio_enter = t('Enter the words you hear:');
  $recaptcha_get_another_captcha = t('Get another CAPTCHA');
  $recaptcha_only_if_image = t('Get an audio CAPTCHA');
  $recaptcha_only_if_audio = t('Get an image CAPTCHA');
  $help = t('Help');
  return <<<EOT
    <div id="recaptcha_image"></div>
    <div class="recaptcha_only_if_incorrect_sol" style="color:red">{<span class="php-variable">$recaptcha_only_if_incorrect_sol</span>}</div>
    <span class="recaptcha_only_if_image">{<span class="php-variable">$recaptcha_only_if_image_enter</span>}</span>
    <span class="recaptcha_only_if_audio">{<span class="php-variable">$recaptcha_only_if_audio_enter</span>}</span>
    <input type="text" id="recaptcha_response_field" name="recaptcha_response_field" />
    <div class="recaptcha_get_another_captcha"><a href="javascript:Recaptcha.reload()">{<span class="php-variable">$recaptcha_get_another_captcha</span>}</a></div>
    <div class="recaptcha_only_if_image"><a href="javascript:Recaptcha.switch_type('audio')">{<span class="php-variable">$recaptcha_only_if_image</span>}</a></div>
    <div class="recaptcha_only_if_audio"><a href="javascript:Recaptcha.switch_type('image')">{<span class="php-variable">$recaptcha_only_if_audio</span>}</a></div>
    <div class="recaptcha_help"><a href="javascript:Recaptcha.showhelp()">{<span class="php-variable">$help</span>}</a></div>
EOT;
}

/**
 * Load the recaptcha library.
 */
function _recaptcha_load_library() {

  // D6 core does not return TRUE if include has been loaded successfully.
  return module_load_include('php', 'recaptcha', 'recaptcha-php-1.11/recaptchalib') === FALSE ? FALSE : TRUE;
}

Functions

Name	Description
recaptcha_captcha	Implements hook_captcha().
recaptcha_captcha_validation	CAPTCHA Callback; Validates the reCAPTCHA code.
recaptcha_help	Implements hook_help().
recaptcha_menu	Implements hook_menu().
recaptcha_perm	Implements hook_perm().
recaptcha_theme	Implements hook_theme().
theme_recaptcha_custom_widget	Theme function: creates the custom themed recaptcha widget.
_recaptcha_load_library	Load the recaptcha library.
_recaptcha_server_is_up	Return the cached output of _recaptcha_test_recaptcha_server().
_recaptcha_test_recaptcha_server