Club Drupal

 */

/**

 *

 *

 *   "$type (from module $module)" with $module the module name implementing the CAPTCHA

 *   and $type the name of the CAPTCHA type.

 */

  $captcha_types = array();

  if ($add_special_options) {

    $captcha_types['none'] = t('- No challenge -');

}

/**

 */

function captcha_admin_settings() {

  module_load_include('inc', 'captcha');

    $form['captcha_form_protection']['captcha_form_id_overview']['captcha_captcha_points'][$captcha_point->form_id]['operations'] = array(

      '#markup' => implode(", ", array(

        l(t('delete'), "admin/config/people/captcha/captcha/captcha_point/{$captcha_point->form_id}/delete"),

    );

  }

    '#title' => t('Persistence'),

    '#default_value' => variable_get('captcha_persistence', CAPTCHA_PERSISTENCE_SKIP_ONCE_SUCCESSFUL_PER_FORM_INSTANCE),

    '#options' => array(

    ),

    '#description' => t('Define if challenges should be omitted during the rest of a session once the user successfully responds to a challenge.'),

  );

}

/**

 */

function theme_captcha_admin_settings_captcha_points($variables) {

  $form = $variables['form'];

  variable_set('captcha_default_challenge', $form_state['values']['captcha_default_challenge']);

  variable_set('captcha_default_challenge_on_nonlisted_forms', $form_state['values']['captcha_default_challenge_on_nonlisted_forms']);

  if (isset($form_state['values']['captcha_form_id_overview']['captcha_captcha_points'])) {

    foreach ($form_state['values']['captcha_form_id_overview']['captcha_captcha_points'] as $captcha_point_form_id => $data) {

      captcha_set_form_id_setting($captcha_point_form_id, $data['captcha_type']);

  drupal_set_message(t('The CAPTCHA settings have been saved.'), 'status');

}

/**

 * Submit callback; clear CAPTCHA placement cache.

 */

  drupal_set_message(t('Cleared the CAPTCHA placement cache.'));

}

/**

 */

  module_load_include('inc', 'captcha');

  if ($captcha_point_form_id) {

    switch ($op) {

      case 'disable':

        return drupal_get_form('captcha_point_disable_confirm', $captcha_point_form_id, FALSE);

      case 'delete':

        return drupal_get_form('captcha_point_disable_confirm', $captcha_point_form_id, TRUE);

    }

    return drupal_get_form('captcha_point_admin_form', $captcha_point_form_id);

  }

  return drupal_get_form('captcha_point_admin_form');

}

  $form = array();

  $default_captcha_type = 'none';

  if (isset($captcha_point_form_id)) {

    $form['captcha_point_form_id'] = array(

      '#type' => 'textfield',

      '#title' => t('Form ID'),

    }

  }

  else {

    $form['captcha_point_form_id'] = array(

      '#type' => 'textfield',

      '#title' => t('Form ID'),

      '#description' => t('The Drupal form_id of the form to add the CAPTCHA to.'),

    );

  }

  $form['captcha_type'] = array(

    '#type' => 'select',

    '#title' => t('Challenge type'),

    '#default_value' => $default_captcha_type,

    '#options' => _captcha_available_challenge_types(),

  );

  $form['#redirect'] = 'admin/config/people/captcha';

  $form['actions'] = array('#type' => 'actions');

  $form['actions']['submit'] = array(

    '#type' => 'submit',

  return $form;

}

/**

 */

function captcha_point_admin_form_validate($form, $form_state) {

  if (!preg_match('/^[a-z0-9_]+$/', $form_state['values']['captcha_point_form_id'])) {

  }

}

/**

 * Submit function for captcha_point_admin_form.

 */

}

/**

 */

function captcha_point_disable_confirm($form, &$form_state, $captcha_point_form_id, $delete) {

  $form = array();

  $form = array();

  if ($module && $challenge) {

    // Generate 10 example challenges.

      $form["challenge_{$i}"] = _captcha_generate_example_challenge($module, $challenge);

    }

  }

  else {

    $form['info'] = array(

      '#markup' => t('This page gives an overview of all available challenge types, generated with their current settings.'),

    );

/**

 * Helper function for adding/updating a CAPTCHA point.

 *

 *   - 'none' to disable CAPTCHA,

 *   - 'default' to use the default challenge type

 *   - NULL to remove the entry for the CAPTCHA type

 *   - something of the form 'image_captcha/Image'

 *   - an object with attributes $captcha_type->module and $captcha_type->captcha_type

 */

function captcha_set_form_id_setting($form_id, $captcha_type) {

  // Handle 'none'.

      ->execute();

  }

  else {

  }

}

/**

 * Get the CAPTCHA setting for a given form_id.

 *

 *

 *   or a captcha_point object with fields 'module' and 'captcha_type'.

 *   If argument $symbolic is true, returns (symbolic) as 'none', 'default'

 *   or in the form 'captcha/Math'.

 */

  // Fetch setting from database.

  $captcha_point = $result->fetchObject();

  // If no setting is available in database for the given form,

    $captcha_point = (object) array('captcha_type' => 'default');

  }

  return $captcha_point;

}

/**

 * Helper function for generating a new CAPTCHA session.

 *

 */

  global $user;

  // Initialize solution with random data.

  $solution = md5(mt_rand());

/**

 * Helper function for updating the solution in the CAPTCHA session table.

 *

 */

function _captcha_update_captcha_session($captcha_sid, $solution) {

  db_update('captcha_sessions')

}

/**

 * user session info.

 */

function _captcha_required_for_user($captcha_sid, $form_id) {

    return TRUE;

  }

  else {

    switch ($captcha_persistence) {

      case CAPTCHA_PERSISTENCE_SKIP_ONCE_SUCCESSFUL:

        return (count($captcha_success_form_ids) == 0);

      case CAPTCHA_PERSISTENCE_SKIP_ONCE_SUCCESSFUL_PER_FORM_TYPE:

        return !isset($captcha_success_form_ids[$form_id]);

    }

/**

 *

 * If the locale module is enabled, the description will be returned

 * for the current language the page is rendered for. This language

 *

 */

  // If no language code is given: use the language of the current page.

  global $language;

  $lang_code = isset($lang_code) ? $lang_code : $language->language;

/**

 * Parse or interpret the given captcha_type.

 *      e.g. 'default', 'none', 'captcha/Math', 'image_captcha/Image'

 */

function _captcha_parse_captcha_type($captcha_type) {

  if ($captcha_type == 'none') {

/**

 * Helper function to get placement information for a given form_id.

 *   is no placement info for the given form_id, this form is examined to

 *   guess the placement.

 *   info about the fields 'path', 'key' and 'weight'.

 */

function _captcha_get_captcha_placement($form_id, $form) {

/**

 * Helper function for searching the buttons in a form.

 *

 *   A path is an array of keys leading to the button, the last

 *   item in the path is the weight of the button element

 *   (or NULL if undefined).

/**

 * Helper function to insert a CAPTCHA element in a form before a given form element.

 *   $placement should be an associative array with fields:

 *     - 'path': path (array of path items) of the container in the form where the

 *       CAPTCHA element should be inserted.

 *     - 'weight': if 'key' is not NULL: should be the weight of the element defined by 'key'.

 *       If 'key' is NULL and weight is not NULL: set the weight property of the CAPTCHA element

 *       to this value.

 */

function _captcha_insert_captcha_element(&$form, $placement, $captcha_element) {

  // Get path, target and target weight or use defaults if not available.

    if ($target_weight != NULL) {

      $captcha_element['#weight'] = $target_weight;

    }

  }

  // If there is a target available: make sure the CAPTCHA element comes right before it.

  else {

    // and just append the CAPTCHA: sorting will fix the ordering anyway.

    if ($target_weight != NULL) {

      $captcha_element['#weight'] = $target_weight - .1;

    }

    else {

      // If we can't play with weights: insert the CAPTCHA element at the right position.

      // chop of the end, append the CAPTCHA element and put the end back.

      $offset = array_search($target_key, array_keys($form_stepper));

      $end = array_splice($form_stepper, $offset);

      foreach ($end as $k => $v) {

        $form_stepper[$k] = $v;

      }

    }

  }

}

files[] = captcha.install

files[] = captcha.test

core = "7.x"

project = "captcha"

        'type' => 'int',

        'not null' => TRUE,

        'default' => 0,

    ),

    'primary key' => array('csid'),

    'indexes' => array(

}

/**

 */

function captcha_requirements($phase) {

  $requirements = array();

}

/**

 */

function captcha_install() {

  $t = get_t();

  $form_ids = array(

    'contact_site_form', 'contact_personal_form',

    'user_register_form', 'user_pass', 'user_login', 'user_login_block',

  );

  // Add form_ids of all currently known node types too.

  foreach (node_type_get_names() as $type => $name) {

}

/**

 */

function captcha_uninstall() {

  drupal_uninstall_schema('captcha');

}

/**

 */

function captcha_update_6200() {

  $items = array();

        'type' => 'int',

        'not null' => TRUE,

        'default' => 0,

    ),

    'primary key' => array('csid'),

    'indexes' => array(

}

/**

 * Change the captcha points with the old text CAPTCHA, which was

 * removed from the 6.x-2.x branch, to the simple math CAPTCHA.

 */

}

/**

 * Add a CAPTCHA token column to captcha_sessions table.

 */

function captcha_update_6202() {

}

/**

 * Rename the type field to captcha_type in captcha_points.

 */

function captcha_update_6203() {

  Drupal.behaviors.captchaAdmin = {

    attach: function (context) {

      // @todo: div.form-item-captcha-description depends on theming, maybe

      // it's better to add our own wrapper with id (instead of a class).

    }

  };

      ) . '</p>';

      $output .= '<p>' . t('CAPTCHA is a trademark of Carnegie Mellon University.') . '</p>';

      return $output;

    case 'admin/config/people/captcha':

    case 'admin/config/people/captcha/captcha':

    case 'admin/config/people/captcha/captcha/settings':

}

/**

 */

function captcha_menu() {

  $items = array();

  $items['admin/config/people/captcha'] = array(

    'title' => 'CAPTCHA',

    'description' => 'Administer how and where CAPTCHAs are used.',

    'access arguments' => array('administer CAPTCHA settings'),

    'type' => MENU_NORMAL_ITEM,

  );

  $items['admin/config/people/captcha/captcha'] = array(

    'title' => 'CAPTCHA',

    'access arguments' => array('administer CAPTCHA settings'),

}

/**

 */

function captcha_permission() {

  return array(

}

/**

 */

function captcha_theme() {

  return array(

}

/**

 *

 * Remove old entries from captcha_sessions table.

 */

function captcha_cron() {

  // Remove challenges older than 1 day.

  db_delete('captcha_sessions')

    ->execute();

}

/**

 */

function captcha_element_info() {

  // Define the CAPTCHA form element with default properties.

  $captcha_element = array(

    '#input' => TRUE,

    '#process' => array('captcha_element_process'),

    '#captcha_type' => 'default',

    '#default_value' => '',

    // CAPTCHA in admin mode: presolve the CAPTCHA and always show it (despite previous successful responses).

    'captcha_sid' => $captcha_sid,

  );

  if (_captcha_required_for_user($captcha_sid, $this_form_id) || $element['#captcha_admin_mode']) {

    // Generate a CAPTCHA and its solution

    // (note that the CAPTCHA session ID is given as third argument).

      // The selected module did not return what we expected: log about it and quit.

      watchdog('CAPTCHA',

        'CAPTCHA problem: unexpected result from hook_captcha() of module %module when trying to retrieve challenge type %type for form %form_id.',

        WATCHDOG_ERROR);

      return $element;

    }

  return $element;

}

/**

 * Theme function for a CAPTCHA element.

 *

  }

}

/**

 *

 * This function adds a CAPTCHA to forms for untrusted users if needed and adds

 * CAPTCHA administration links for site administrators if this option is enabled.

    // Get CAPTCHA type and module for given form_id.

    $captcha_point = captcha_get_form_id_setting($form_id);

      module_load_include('inc', 'captcha');

      // Build CAPTCHA form element.

      $captcha_element = array(

    module_load_include('inc', 'captcha');

    $captcha_point = captcha_get_form_id_setting($form_id);

    $captcha_element = array(

      '#type' => 'fieldset',

      '#title' => t('CAPTCHA'),

  // Add a warning about caching on the Perfomance settings page.

  if ($form_id == 'system_performance_settings') {

    $form['caching']['captcha'] = array(

      '#type' => 'item',

      '#title' => t('CAPTCHA'),

/**

 * CAPTCHA validation function to tests strict equality.

 */

function captcha_validate_strict_equality($solution, $response) {

  return $solution === $response;

/**

 * CAPTCHA validation function to tests case insensitive equality.

 */

function captcha_validate_case_insensitive_equality($solution, $response) {

  return drupal_strtolower($solution) === drupal_strtolower($response);

/**

 * CAPTCHA validation function to tests equality while ignoring spaces.

 */

function captcha_validate_ignore_spaces($solution, $response) {

  return preg_replace('/\s/', '', $solution) === preg_replace('/\s/', '', $response);

/**

 * CAPTCHA validation function to tests case insensitive equality while ignoring spaces.

 */

function captcha_validate_case_insensitive_ignore_spaces($solution, $response) {

  return preg_replace('/\s/', '', drupal_strtolower($solution)) === preg_replace('/\s/', '', drupal_strtolower($response));

}

/**

 *

 * This function hides the form processing mess for several use cases an

 * browser bug workarounds.

 *

 * @todo for Drupal 7 version: is this IE7 workaround still needed?

 *

 *     (which is not necessarily the form that was posted).

 *

 *     if the values could not be found, e.g. for a fresh form).

 */

function _captcha_get_posted_captcha_info($element, $form_state, $this_form_id) {

    // from the post data.

    // Because we possibly use raw post data here,

    // we should be extra cautious and filter this data.

    if ($posted_form_id == $this_form_id) {

      // Check if the posted CAPTCHA token is valid for the posted CAPTCHA

    // Get CAPTCHA validate function or fall back on strict equality.

    $captcha_validate = $element['#captcha_validate'];

    if (!function_exists($captcha_validate)) {

    }

    // Check the response with the CAPTCHA validation function.

    // Apart from the traditional expected $solution and received $response,

        ->condition('csid', $csid)

        ->expression('attempts', 'attempts + 1')

        ->execute();

      form_set_error('captcha_response', t('The answer you entered for the CAPTCHA was not correct.'));

      if (variable_get('captcha_enable_stats', FALSE)) {

        variable_set('captcha_wrong_response_counter', variable_get('captcha_wrong_response_counter', 0) + 1);

      }

      if (variable_get('captcha_log_wrong_responses', FALSE)) {

        watchdog('CAPTCHA',

          '%form_id post blocked by CAPTCHA module: challenge %challenge (by module %module), user answered "@response", but the solution was "@solution".',

            '@response' => $captcha_response, '@solution' => $solution,

            '%challenge' => $captcha_info['captcha_type'], '%module' => $captcha_info['module'],

          ),

 * This encompasses tasks that should happen after the general FAPI processing

 * (building, submission and validation) but before rendering (e.g. storing the solution).

 *

 */

function captcha_pre_render_process($element) {

  module_load_include('inc', 'captcha');

  // Get form and CAPTCHA information.

  $captcha_info = $element['#captcha_info'];

  $form_id = $captcha_info['form_id'];

  // Check if CAPTCHA is still required.

  // This check is done in a first phase during the element processing

  // (@see captcha_process), but it is also done here for better support

  switch ($op) {

    case 'list':

      return array('Math');

    case 'generate':

      if ($captcha_type == 'Math') {

}

/**

 */

function captcha_modules_enabled() {

  // When new modules are enabled: clear the CAPTCHA placement cache, so that

/**

 * @file

 * Functions for administration/settings interface.

 */

/**

 * Configuration form for image_captcha.

 */

  // Use javascript for some added usability on admin form.

  $form['#attached']['js'] = array(drupal_get_path('module', 'image_captcha') . '/image_captcha.js');

  // First some error checking.

  $setup_status = _image_captcha_check_setup(FALSE);

  if ($setup_status & IMAGE_CAPTCHA_ERROR_NO_GDLIB) {

    );

  }

  // Font related stuff.

  $form['image_captcha_font_settings'] = _image_captcha_settings_form_font_section();

  $form['image_captcha_color_settings'] = array(

    '#type' => 'fieldset',

    '#title' => t('Color and image settings'),

    ),

  );

  $form['image_captcha_distortion_and_noise'] = array(

    '#type' => 'fieldset',

    '#title' => t('Distortion and noise'),

    '#description' => t('With these settings you can control the degree of obfuscation by distortion and added noise. Do not exaggerate the obfuscation and assure that the code in the image is reasonably readable. For example, do not combine high levels of distortion and noise.'),

  );

  $form['image_captcha_distortion_and_noise']['image_captcha_distortion_amplitude'] = array(

    '#type' => 'select',

    '#title' => t('Distortion level'),

    '#default_value' => variable_get('image_captcha_bilinear_interpolation', FALSE),

    '#description' => t('This option enables bilinear interpolation of the distortion which makes the image look smoother, but it is more CPU intensive.'),

  );

  $form['image_captcha_distortion_and_noise']['image_captcha_dot_noise'] = array(

    '#type' => 'checkbox',

    '#title' => t('Add salt and pepper noise'),

  return $form;

}

/**

 * Form elements for the font specific setting.

 *

 * general form function image_captcha_settings_form with some

 * specific logic.

 *

 */

function _image_captcha_settings_form_font_section() {

  // Put it all in a fieldset.

  // First check if there is TrueType support.

  $setup_status = _image_captcha_check_setup(FALSE);

  if ($setup_status & IMAGE_CAPTCHA_ERROR_NO_TTF_SUPPORT) {

    $form['no_ttf_support'] = array(

      '#type' => 'item',

      '#title' => t('No TrueType support'),

  }

  else {

    // Build a list of  all available fonts.

    $available_fonts = array();

    // in separate requests, and we don't want to rescan the filesystem

    // every time, so we cache the result.

    variable_set('image_captcha_fonts_preview_map_cache', $fonts);

    foreach ($fonts as $token => $font) {

      $img_src = check_url(url('admin/config/people/captcha/image_captcha/font_preview/' . $token));

      $title = t('Font preview of @font (@file)', array('@font' => $font->name, '@file' => $font->uri));

      '#process' => array('form_process_checkboxes'),

    );

    // Font size.

    $form['image_captcha_font_size'] = array(

      '#type' => 'select',

/**

 * Helper function to get fonts from the given directories.

 *

 *   to recursively search through, if not given, the default

 *   directories will be used.

 *

 *   'basename' and 'filename'), keyed on the md5 hash of the font

 *   path (to have an easy token that can be used in an url

 *   without en/decoding issues).

 */

  // If no fonts directories are given: use the default.

  if ($directories === NULL) {

    $directories = array(

  return $fonts;

}

/**

 */

function image_captcha_settings_form_validate($form, &$form_state) {

  // Check image_captcha_image_allowed_chars for spaces.

    }

  }

  if (!preg_match('/^#([0-9a-fA-F]{3}){1,2}$/', $form_state['values']['image_captcha_background_color'])) {

    form_set_error('image_captcha_background_color', t('Background color is not a valid hexadecimal color value.'));

  }

/**

 * Menu handler for font preview request.

 */

function image_captcha_font_preview($font_token) {

    // Get the mapping of font tokens to font file objects.

    $fonts = variable_get('image_captcha_fonts_preview_map_cache', array());

    if (!isset($fonts[$font_token])) {

      exit();

    }

    // Get the font path.

    $font = $fonts[$font_token]->uri;

    // Some sanity checks if the given font is valid.

    if (!is_file($font) || !is_readable($font)) {

      exit();

    }

  }

  $color = imagecolorallocate($image, 0, 0, 0);

  imagefilledrectangle($image, 0, 0, $width, $height, $background_color);

  if ($font == 'BUILTIN') {

  }

  else {

  }

  // Set content type.

files[] = image_captcha.admin.inc

files[] = image_captcha.user.inc

core = "7.x"

project = "captcha"

    if (_image_captcha_check_setup(FALSE) & IMAGE_CAPTCHA_ERROR_NO_GDLIB) {

      $requirements['image_captcha_requires_gd'] = array(

        'title' => $t('Image CAPTCHA requires GD library'),

        'severity' => REQUIREMENT_ERROR,

      );

    }

}

/**

 */

function image_captcha_uninstall() {

  db_delete('variable')

      // Helper function to show/hide noise level widget.

      var noise_level_shower = function(speed) {

        speed = (typeof speed == 'undefined') ? 'slow' : speed;

          $(".form-item-image-captcha-noise-level").show(speed);

        } else {

          $(".form-item-image-captcha-noise-level").hide(speed);

        }

      // Add onclick handler to the dot and line noise check boxes.

      $("#edit-image-captcha-dot-noise").click(noise_level_shower);

      $("#edit-image-captcha-line-noise").click(noise_level_shower);

        } else {

          $(".form-item-image-captcha-bilinear-interpolation").hide(speed);

        }

      // Add onchange handler to the distortion level select widget.

      $("#edit-image-captcha-distortion-amplitude").change(

          smooth_distortion_shower);

      // Show or hide appropriately on page load.

    }

  };

define('IMAGE_CAPTCHA_FILE_FORMAT_PNG', 2);

define('IMAGE_CAPTCHA_FILE_FORMAT_TRANSPARENT_PNG', 3);

/**

 * Implements hook_help().

 */

 */

function image_captcha_menu() {

  $items = array();

  $items['admin/config/people/captcha/image_captcha'] = array(

    'title' => 'Image CAPTCHA',

    'file' => 'image_captcha.admin.inc',

    'access arguments' => array('administer CAPTCHA settings'),

    'type' => MENU_CALLBACK,

  );

  $items['image_captcha'] = array(

    'file' => 'image_captcha.user.inc',

    'page callback' => 'image_captcha_image',

/**

 * Helper function for getting the fonts to use in the image CAPTCHA.

 *

 */

function _image_captcha_get_enabled_fonts() {

  if (IMAGE_CAPTCHA_ERROR_NO_TTF_SUPPORT & _image_captcha_check_setup(FALSE)) {

/**

 * Helper function for checking if the specified fonts are available.

 *

 */

function _image_captcha_check_fonts($fonts) {

  $readable_fonts = array();

/**

 * Helper function for splitting an utf8 string correctly in characters.

 * Assumes the given utf8 string is well formed.

 * See http://en.wikipedia.org/wiki/Utf8 for more info

 */

function _image_captcha_utf8_split($str) {

  $characters = array();

  $len = strlen($str);

    $chr = ord($str[$i]);

      $width = 1;

    }

    else {

        $width = 2;

      }

        $width = 3;

      }

        $width = 4;

      }

      else {

 * font files should be readable.

 * This functions checks these things.

 *

 *

 *   IMAGE_CAPTCHA_ERROR_NO_GDLIB, IMAGE_CAPTCHA_ERROR_NO_TTF_SUPPORT,

 *   IMAGE_CAPTCHA_ERROR_TTF_FILE_READ_PROBLEM.

 */

  // Start clean.

  $status = 0;

  // Check if we can use the GD library.

}

/**

 *

 */

function _image_captcha_image_size($code) {

  $font_size = (int) variable_get('image_captcha_font_size', 30);

  $character_spacing = (float) variable_get('image_captcha_character_spacing', '1.2');

  $characters = _image_captcha_utf8_split($code);

  $character_quantity = count($characters);

  $width = $character_spacing * $font_size * $character_quantity;

  $height = 2 * $font_size;

  return array($width, $height);

}

/**

 * Implements hook_captcha().

 */

  switch ($op) {

    case 'list':

      // Only offer the image CAPTCHA if it is possible to generate an image on this setup.

        if (variable_get('maintenance_mode', 0) && $user->uid == 0) {

          return captcha_captcha('generate', 'Math');

        }

        $allowed_chars = _image_captcha_utf8_split(variable_get('image_captcha_image_allowed_chars', IMAGE_CAPTCHA_ALLOWED_CHARACTERS));

        $code = '';

        for ($i = 0; $i < $code_length; $i++) {

          $code .= $allowed_chars[array_rand($allowed_chars)];

        }

        $result = array();

        $result['solution'] = $code;

        $result['form']['captcha_image'] = array(

          '#type' => 'markup',

          '#markup' => '<img src="' . $img_src

          '#weight' => -2,

        );

        $result['form']['captcha_response'] = array(

          case CAPTCHA_DEFAULT_VALIDATION_CASE_SENSITIVE:

            $result['captcha_validate'] = 'captcha_validate_ignore_spaces';

            break;

          case CAPTCHA_DEFAULT_VALIDATION_CASE_INSENSITIVE:

            $result['captcha_validate'] = 'captcha_validate_case_insensitive_ignore_spaces';

            break;

 * Menu callback function that generates the CAPTCHA image.

 */

function image_captcha_image() {

  if (ob_get_level()) {

    ob_end_clean();

  }

    exit();

  }

  $captcha_sid = $_GET['sid'];

    $seed = hexdec(substr(md5($captcha_sid . $code), 0, 8));

    srand($seed);

    mt_srand($seed);

    $image = @_image_captcha_generate_image($code);