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<?php
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/**
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* @file
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* Honeypot module, for deterring spam bots from completing Drupal forms.
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*/
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/**
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* Implements hook_menu().
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*/
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function honeypot_menu() {
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$items['admin/config/content/honeypot'] = array(
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'title' => 'Honeypot configuration',
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'description' => 'Configure Honeypot spam prevention and the forms on which Honeypot will be used.',
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'page callback' => 'drupal_get_form',
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'page arguments' => array('honeypot_admin_form'),
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'access arguments' => array('administer honeypot'),
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'file' => 'honeypot.admin.inc',
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);
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return $items;
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}
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/**
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* Implements hook_permission().
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*/
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function honeypot_permission() {
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return array(
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'administer honeypot' => array(
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'title' => t('Administer Honeypot'),
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'description' => t('Administer Honeypot-protected forms and settings'),
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),
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'bypass honeypot protection' => array(
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'title' => t('Bypass Honeypot protection'),
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'description' => t('Bypass Honeypot form protection.'),
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),
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);
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}
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/**
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* Implements hook_cron().
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*/
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function honeypot_cron() {
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// Delete {honeypot_user} entries older than the value of honeypot_expire.
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db_delete('honeypot_user')
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->condition('timestamp', REQUEST_TIME - variable_get('honeypot_expire', 300), '<')
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->execute();
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// Regenerate the honeypot css file if it does not exist or is outdated.
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$honeypot_css = honeypot_get_css_file_path();
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$honeypot_element_name = variable_get('honeypot_element_name', 'url');
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if (!file_exists($honeypot_css) || !honeypot_check_css($honeypot_element_name)) {
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honeypot_create_css($honeypot_element_name);
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}
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}
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/**
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* Implements hook_form_alter().
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*
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* Add Honeypot features to forms enabled in the Honeypot admin interface.
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*/
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function honeypot_form_alter(&$form, &$form_state, $form_id) {
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// Don't use for maintenance mode forms (install, update, etc.).
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if (defined('MAINTENANCE_MODE')) {
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return;
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}
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$unprotected_forms = array(
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'user_login',
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'user_login_block',
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'search_form',
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'search_block_form',
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'views_exposed_form',
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'honeypot_admin_form',
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);
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// If configured to protect all forms, add protection to every form.
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if (variable_get('honeypot_protect_all_forms', 0) && !in_array($form_id, $unprotected_forms)) {
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// Don't protect system forms - only admins should have access, and system
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// forms may be programmatically submitted by drush and other modules.
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if (strpos($form_id, 'system_') === FALSE && strpos($form_id, 'search_') === FALSE && strpos($form_id, 'views_exposed_form_') === FALSE) {
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honeypot_add_form_protection($form, $form_state, array('honeypot', 'time_restriction'));
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}
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}
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// Otherwise add form protection to admin-configured forms.
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elseif ($forms_to_protect = honeypot_get_protected_forms()) {
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foreach ($forms_to_protect as $protect_form_id) {
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// For most forms, do a straight check on the form ID.
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if ($form_id == $protect_form_id) {
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honeypot_add_form_protection($form, $form_state, array('honeypot', 'time_restriction'));
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}
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// For webforms use a special check for variable form ID.
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elseif ($protect_form_id == 'webforms' && (strpos($form_id, 'webform_client_form') !== FALSE)) {
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honeypot_add_form_protection($form, $form_state, array('honeypot', 'time_restriction'));
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}
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}
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}
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}
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/**
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* Implements hook_trigger_info().
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*/
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function honeypot_trigger_info() {
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return array(
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'honeypot' => array(
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'honeypot_reject' => array(
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'label' => t('Honeypot rejection'),
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),
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),
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);
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}
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/**
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* Implements hook_rules_event_info().
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*/
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function honeypot_rules_event_info() {
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return array(
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'honeypot_reject' => array(
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'label' => t('Honeypot rejection'),
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'group' => t('Honeypot'),
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'variables' => array(
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'form_id' => array(
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'type' => 'text',
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'label' => t('Form ID of the form the user was disallowed from submitting.'),
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),
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// Don't provide 'uid' in context because it is available as
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// site:current-user:uid.
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'type' => array(
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'type' => 'text',
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'label' => t('String indicating the reason the submission was blocked.'),
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),
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),
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),
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);
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}
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/**
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* Build an array of all the protected forms on the site, by form_id.
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*
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* @todo - Add in API call/hook to allow modules to add to this array.
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*/
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function honeypot_get_protected_forms() {
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$forms = &drupal_static(__FUNCTION__);
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// If the data isn't already in memory, get from cache or look it up fresh.
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if (!isset($forms)) {
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if ($cache = cache_get('honeypot_protected_forms')) {
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$forms = $cache->data;
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}
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else {
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$forms = array();
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// Look up all the honeypot forms in the variables table.
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$result = db_query("SELECT name FROM {variable} WHERE name LIKE 'honeypot_form_%'")->fetchCol();
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// Add each form that's enabled to the $forms array.
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foreach ($result as $variable) {
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if (variable_get($variable, 0)) {
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$forms[] = substr($variable, 14);
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}
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}
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// Save the cached data.
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cache_set('honeypot_protected_forms', $forms, 'cache');
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}
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}
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return $forms;
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}
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/**
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* Form builder function to add different types of protection to forms.
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*
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* @param array $options
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* Array of options to be added to form. Currently accepts 'honeypot' and
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* 'time_restriction'.
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*
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* @return array
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* Returns elements to be placed in a form's elements array to prevent spam.
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*/
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function honeypot_add_form_protection(&$form, &$form_state, $options = array()) {
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global $user;
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// Allow other modules to alter the protections applied to this form.
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drupal_alter('honeypot_form_protections', $options, $form);
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// Don't add any protections if the user can bypass the Honeypot.
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if (user_access('bypass honeypot protection')) {
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return;
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}
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// Build the honeypot element.
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if (in_array('honeypot', $options)) {
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// Get the element name (default is generic 'url').
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$honeypot_element = variable_get('honeypot_element_name', 'url');
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// Add 'autocomplete="off"' if configured.
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$attributes = array();
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if (variable_get('honeypot_autocomplete_attribute', 1)) {
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$attributes = array('autocomplete' => 'off');
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}
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// Get the path to the honeypot css file.
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$honeypot_css = honeypot_get_css_file_path();
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// Build the honeypot element.
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$honeypot_class = $honeypot_element . '-textfield';
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$form[$honeypot_element] = array(
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'#type' => 'textfield',
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'#title' => t('Leave this field blank'),
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'#size' => 20,
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'#weight' => 100,
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'#attributes' => $attributes,
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'#element_validate' => array('_honeypot_honeypot_validate'),
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'#prefix' => '<div class="' . $honeypot_class . '">',
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'#suffix' => '</div>',
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// Hide honeypot using CSS.
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'#attached' => array(
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'css' => array(
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'data' => $honeypot_css,
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),
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),
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);
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}
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// Build the time restriction element (if it's not disabled).
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if (in_array('time_restriction', $options) && variable_get('honeypot_time_limit', 5) != 0) {
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// Set the current time in a hidden value to be checked later.
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$form['honeypot_time'] = array(
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'#type' => 'hidden',
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'#title' => t('Timestamp'),
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'#default_value' => honeypot_get_signed_timestamp(REQUEST_TIME),
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'#element_validate' => array('_honeypot_time_restriction_validate'),
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);
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// Disable page caching to make sure timestamp isn't cached.
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if (user_is_anonymous()) {
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drupal_page_is_cacheable(FALSE);
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}
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}
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// Allow other modules to react to addition of form protection.
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if (!empty($options)) {
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module_invoke_all('honeypot_add_form_protection', $options, $form);
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}
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}
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/**
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* Validate honeypot field.
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*/
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function _honeypot_honeypot_validate($element, &$form_state) {
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// Get the honeypot field value.
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$honeypot_value = $element['#value'];
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// Make sure it's empty.
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if (!empty($honeypot_value)) {
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_honeypot_log($form_state['values']['form_id'], 'honeypot');
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form_set_error('', t('There was a problem with your form submission. Please refresh the page and try again.'));
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}
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}
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/**
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* Validate honeypot's time restriction field.
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*/
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function _honeypot_time_restriction_validate($element, &$form_state) {
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if (!empty($form_state['programmed'])) {
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// Don't do anything if the form was submitted programmatically.
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return;
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}
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// Don't do anything if the triggering element is a preview button.
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if ($form_state['triggering_element']['#value'] == t('Preview')) {
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return;
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}
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// Get the time value.
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$honeypot_time = honeypot_get_time_from_signed_timestamp($form_state['values']['honeypot_time']);
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// Get the honeypot_time_limit.
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$time_limit = honeypot_get_time_limit($form_state['values']);
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// Make sure current time - (time_limit + form time value) is greater than 0.
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// If not, throw an error.
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if (!$honeypot_time || REQUEST_TIME < ($honeypot_time + $time_limit)) {
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_honeypot_log($form_state['values']['form_id'], 'honeypot_time');
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// Get the time limit again, since it increases after first failure.
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$time_limit = honeypot_get_time_limit($form_state['values']);
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$form_state['values']['honeypot_time'] = honeypot_get_signed_timestamp(REQUEST_TIME);
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form_set_error('', t('There was a problem with your form submission. Please wait @limit seconds and try again.', array('@limit' => $time_limit)));
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}
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}
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291
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/**
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* Log blocked form submissions.
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*
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* @param string $form_id
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* Form ID for the form on which submission was blocked.
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* @param string $type
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* String indicating the reason the submission was blocked. Allowed values:
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* - honeypot: If honeypot field was filled in.
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* - honeypot_time: If form was completed before the configured time limit.
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*/
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function _honeypot_log($form_id, $type) {
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honeypot_log_failure($form_id, $type);
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if (variable_get('honeypot_log', 0)) {
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$variables = array(
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'%form' => $form_id,
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'@cause' => ($type == 'honeypot') ? t('submission of a value in the honeypot field') : t('submission of the form in less than minimum required time'),
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);
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watchdog('honeypot', 'Blocked submission of %form due to @cause.', $variables);
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}
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}
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/**
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314
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* Look up the time limit for the current user.
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315
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*
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* @param array $form_values
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* Array of form values (optional).
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318
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*/
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319
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function honeypot_get_time_limit($form_values = array()) {
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global $user;
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$honeypot_time_limit = variable_get('honeypot_time_limit', 5);
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322
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// Only calculate time limit if honeypot_time_limit has a value > 0.
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if ($honeypot_time_limit) {
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$expire_time = variable_get('honeypot_expire', 300);
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// Query the {honeypot_user} table to determine the number of failed
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// submissions for the current user.
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$query = db_select('honeypot_user', 'hs')
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329
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->condition('uid', $user->uid)
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->condition('timestamp', REQUEST_TIME - $expire_time, '>');
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331
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332
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// For anonymous users, take the hostname into account.
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333
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if ($user->uid === 0) {
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$query->condition('hostname', ip_address());
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}
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$number = $query->countQuery()->execute()->fetchField();
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// Don't add more than 30 days' worth of extra time.
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$honeypot_time_limit = (int) min($honeypot_time_limit + exp($number) - 1, 2592000);
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$additions = module_invoke_all('honeypot_time_limit', $honeypot_time_limit, $form_values, $number);
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if (count($additions)) {
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$honeypot_time_limit += array_sum($additions);
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}
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}
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345
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return $honeypot_time_limit;
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347
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}
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348
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349
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/**
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350
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* Log the failed submision with timestamp and hostname.
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351
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*
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352
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* @param string $form_id
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353
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* Form ID for the rejected form submission.
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* @param string $type
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* String indicating the reason the submission was blocked. Allowed values:
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* - honeypot: If honeypot field was filled in.
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* - honeypot_time: If form was completed before the configured time limit.
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358
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*/
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359
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function honeypot_log_failure($form_id, $type) {
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360
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global $user;
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361
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362
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db_insert('honeypot_user')
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363
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->fields(array(
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364
|
'uid' => $user->uid,
|
|
365
|
'hostname' => ip_address(),
|
|
366
|
'timestamp' => REQUEST_TIME,
|
|
367
|
))
|
|
368
|
->execute();
|
|
369
|
|
|
370
|
// Allow other modules to react to honeypot rejections.
|
|
371
|
module_invoke_all('honeypot_reject', $form_id, $user->uid, $type);
|
|
372
|
|
|
373
|
// Trigger honeypot_reject action.
|
|
374
|
if (module_exists('trigger')) {
|
|
375
|
$aids = trigger_get_assigned_actions('honeypot_reject');
|
|
376
|
$context = array(
|
|
377
|
'group' => 'honeypot',
|
|
378
|
'hook' => 'honeypot_reject',
|
|
379
|
'form_id' => $form_id,
|
|
380
|
// Do not provide $user in context because it is available as a global.
|
|
381
|
'type' => $type,
|
|
382
|
);
|
|
383
|
// Honeypot does not act on any specific object.
|
|
384
|
$object = NULL;
|
|
385
|
actions_do(array_keys($aids), $object, $context);
|
|
386
|
}
|
|
387
|
|
|
388
|
// Trigger rules honeypot_reject event.
|
|
389
|
if (module_exists('rules')) {
|
|
390
|
rules_invoke_event('honeypot_reject', $form_id, $type);
|
|
391
|
}
|
|
392
|
}
|
|
393
|
|
|
394
|
/**
|
|
395
|
* Retrieve the location of the Honeypot CSS file.
|
|
396
|
*
|
|
397
|
* @return string
|
|
398
|
* The path to the honeypot.css file.
|
|
399
|
*/
|
|
400
|
function honeypot_get_css_file_path() {
|
|
401
|
return variable_get('file_public_path', conf_path() . '/files') . '/honeypot/honeypot.css';
|
|
402
|
}
|
|
403
|
|
|
404
|
/**
|
|
405
|
* Create CSS file to hide the Honeypot field.
|
|
406
|
*
|
|
407
|
* @param string $element_name
|
|
408
|
* The honeypot element class name (e.g. 'url').
|
|
409
|
*/
|
|
410
|
function honeypot_create_css($element_name) {
|
|
411
|
$path = 'public://honeypot';
|
|
412
|
|
|
413
|
if (!file_prepare_directory($path, FILE_CREATE_DIRECTORY)) {
|
|
414
|
drupal_set_message(t('Unable to create Honeypot CSS directory, %path. Check the permissions on your files directory.', array('%path' => file_uri_target($path))), 'error');
|
|
415
|
}
|
|
416
|
else {
|
|
417
|
$filename = $path . '/honeypot.css';
|
|
418
|
$data = '.' . $element_name . '-textfield { display: none !important; }';
|
|
419
|
file_unmanaged_save_data($data, $filename, FILE_EXISTS_REPLACE);
|
|
420
|
}
|
|
421
|
}
|
|
422
|
|
|
423
|
/**
|
|
424
|
* Check Honeypot's CSS file for a given Honeypot element name.
|
|
425
|
*
|
|
426
|
* This function assumes the Honeypot CSS file already exists.
|
|
427
|
*
|
|
428
|
* @param string $element_name
|
|
429
|
* The honeypot element class name (e.g. 'url').
|
|
430
|
*
|
|
431
|
* @return bool
|
|
432
|
* TRUE if CSS is has element class name, FALSE if not.
|
|
433
|
*/
|
|
434
|
function honeypot_check_css($element_name) {
|
|
435
|
$path = honeypot_get_css_file_path();
|
|
436
|
$handle = fopen($path, 'r');
|
|
437
|
$contents = fread($handle, filesize($path));
|
|
438
|
fclose($handle);
|
|
439
|
|
|
440
|
if (strpos($contents, $element_name) === 1) {
|
|
441
|
return TRUE;
|
|
442
|
}
|
|
443
|
|
|
444
|
return FALSE;
|
|
445
|
}
|
|
446
|
|
|
447
|
/**
|
|
448
|
* Sign the timestamp $time.
|
|
449
|
*
|
|
450
|
* @param mixed $time
|
|
451
|
* The timestamp to sign.
|
|
452
|
*
|
|
453
|
* @return string
|
|
454
|
* A signed timestamp in the form timestamp|HMAC.
|
|
455
|
*/
|
|
456
|
function honeypot_get_signed_timestamp($time) {
|
|
457
|
return $time . '|' . drupal_hmac_base64($time, drupal_get_private_key());
|
|
458
|
}
|
|
459
|
|
|
460
|
/**
|
|
461
|
* Validate a signed timestamp.
|
|
462
|
*
|
|
463
|
* @param string $signed_timestamp
|
|
464
|
* A timestamp concateneted with the signature
|
|
465
|
*
|
|
466
|
* @return int
|
|
467
|
* The timestamp if the signature is correct, 0 otherwise.
|
|
468
|
*/
|
|
469
|
function honeypot_get_time_from_signed_timestamp($signed_timestamp) {
|
|
470
|
$honeypot_time = 0;
|
|
471
|
|
|
472
|
// Fail fast if timestamp was forged or saved with an older Honeypot version.
|
|
473
|
if (strpos($signed_timestamp, '|') === FALSE) {
|
|
474
|
return $honeypot_time;
|
|
475
|
}
|
|
476
|
|
|
477
|
list($timestamp, $received_hmac) = explode('|', $signed_timestamp);
|
|
478
|
|
|
479
|
if ($timestamp && $received_hmac) {
|
|
480
|
$calculated_hmac = drupal_hmac_base64($timestamp, drupal_get_private_key());
|
|
481
|
// Prevent leaking timing information, compare second order hmacs.
|
|
482
|
$random_key = drupal_random_bytes(32);
|
|
483
|
if (drupal_hmac_base64($calculated_hmac, $random_key) === drupal_hmac_base64($received_hmac, $random_key)) {
|
|
484
|
$honeypot_time = $timestamp;
|
|
485
|
}
|
|
486
|
}
|
|
487
|
|
|
488
|
return $honeypot_time;
|
|
489
|
}
|
