Example image, generated with the current settings:
!img', array('!img' => $img)); } return $output; } } /** * Implementation of hook_menu(). */ function image_captcha_menu($may_cache) { $items = array(); if ($may_cache) { // add an administration tab for image_captcha $items[] = array( 'path' => 'admin/user/captcha/image_captcha', 'title' => t('Image CAPTCHA'), 'callback' => 'drupal_get_form', 'callback arguments' => array('image_captcha_settings_form'), 'type' => MENU_LOCAL_TASK, ); // callback for generating an image $items[] = array( 'path' => 'image_captcha', 'type' => MENU_CALLBACK, 'access' => TRUE, 'callback' => 'image_captcha_image', ); } return $items; } /* * Implementation of hook_requirements() * @todo these checks should be for the install phase, * but this is not possible now for contributed modules (modules outside the * drupal/modules directory) */ function image_captcha_requirements($phase) { $requirements = array(); $t = get_t(); if ($phase == 'runtime') { if (function_exists('imagegd2')) { $gd_info = gd_info(); if (!$gd_info['FreeType Support']) { $requirements['image_captcha_ft'] = array( 'title' => $t('Image CAPTCHA'), 'value' => $t('No FreeType support'), 'description' => $t('FreeType support is required for working with TrueType fonts (.ttf), but the GD library for PHP does not support it.'), 'severity' => REQUIREMENT_ERROR, ); } } else { $requirements['image_captcha_gd'] = array( 'title' => $t('Image CAPTCHA'), 'value' => $t('No GD library'), 'description' => $t('The GD library for PHP is missing or outdated. Please check the PHP image documentation for information on how to correct this.', array('@url' => 'http://www.php.net/manual/en/ref.image.php')), 'severity' => REQUIREMENT_ERROR, ); } } return $requirements; } /** * Returns: * - the path to the image CAPTCHA font or FALSE when an error occured * - error message */ function _image_captcha_get_font() { $font = variable_get('image_captcha_font', 'BUILTIN'); $errmsg = FALSE; if ($font != 'BUILTIN' && (!is_file($font) || !is_readable($font))) { $errmsg = t('Could not find or read the configured font "%font" for the image CAPTCHA.', array('%font' => $font)); $font = FALSE; } return array($font, $errmsg); } /** * Configuration form for image_captcha * Implemented by _image_captcha_settings_form() in image_captcha.admin.inc */ function image_captcha_settings_form() { require_once(drupal_get_path('module', 'image_captcha') . '/image_captcha.admin.inc'); return _image_captcha_settings_form(); } /** * Helper function for splitting an utf8 string correctly in characters. * Assumes the given utf8 string is well formed. * See http://en.wikipedia.org/wiki/Utf8 for more info */ function _image_captcha_utf8_split($str) { $characters = array(); $len = strlen($str); for ($i=0; $i < $len; ) { $chr = ord($str[$i]); if (($chr & 0x80) == 0x00) { // one byte character (0zzzzzzz) $width = 1; } else { if (($chr & 0xE0) == 0xC0) { // two byte character (first byte: 110yyyyy) $width = 2; } elseif (($chr & 0xF0) == 0xE0) { // three byte character (first byte: 1110xxxx) $width = 3; } elseif (($chr & 0xF8) == 0xF0) { // four byte character (first byte: 11110www) $width = 4; } else { watchdog('CAPTCHA', t('Encountered an illegal byte while splitting an utf8 string in characters.'), WATCHDOG_ERROR); return $characters; } } $characters[] = substr($str, $i, $width); $i += $width; } return $characters; } /** * Implementation of hook_captcha(). */ function image_captcha_captcha($op, $captcha_type='', $response='') { switch ($op) { case 'list': // only offer image CAPTCHA if possible to generate an image CAPTCHA list($font, $errmsg) = _image_captcha_get_font(); if (function_exists('imagejpeg') && $font) { return array('Image'); } else { return array(); } break; case 'generate': if ($captcha_type == 'Image') { // In offline mode, the image CAPTCHA does not work because the request // for the image itself won't succeed (only ?q=user is permitted for // unauthenticated users). We fall back to the Math CAPTCHA in that case. global $user; if (variable_get('site_offline', FALSE) && $user->uid == 0) { return captcha_captcha('generate', 'Math'); } // generate a CAPTCHA code $allowed_chars = _image_captcha_utf8_split(variable_get('image_captcha_image_allowed_chars', IMAGE_CAPTCHA_ALLOWED_CHARACTERS)); $code_length = (int)variable_get('image_captcha_code_length', 5); $code = ''; for ($i = 0; $i < $code_length; $i++) { $code .= $allowed_chars[array_rand($allowed_chars)]; } // store the answer in $_SESSION for the image generator function (which happens in another http request) $seed = mt_rand(); $_SESSION['image_captcha'][$seed] = $code; // build the result to return $result = array(); // Handle the case insesitivity option and change the code to lower case // before saving it as solution. if (variable_get('image_captcha_case_insensitive', FALSE)) { $code = strtolower($code); $result['preprocess'] = TRUE; $description = t('Enter the characters shown in the image without spaces.'); } else { $description = t('Enter the characters shown in the image without spaces, also respect upper and lower case.'); } $result['solution'] = $code; // Create the image CAPTCHA form elements // The img markup isn't done with theme('image', ...) because that // function needs a path to a real file (not applicable) // or a full absolute URL (which requires to add protocol and domain) $result['form']['captcha_image'] = array( '#type' => 'markup', '#value' => '