|
- <?php
-
- /**
- * Implements data: URI for base64 encoded images supported by GD.
- */
- class HTMLPurifier_URIScheme_data extends HTMLPurifier_URIScheme
- {
- /**
- * @type bool
- */
- public $browsable = true;
-
- /**
- * @type array
- */
- public $allowed_types = array(
- // you better write validation code for other types if you
- // decide to allow them
- 'image/jpeg' => true,
- 'image/gif' => true,
- 'image/png' => true,
- );
- // this is actually irrelevant since we only write out the path
- // component
- /**
- * @type bool
- */
- public $may_omit_host = true;
-
- /**
- * @param HTMLPurifier_URI $uri
- * @param HTMLPurifier_Config $config
- * @param HTMLPurifier_Context $context
- * @return bool
- */
- public function doValidate(&$uri, $config, $context)
- {
- $result = explode(',', $uri->path, 2);
- $is_base64 = false;
- $charset = null;
- $content_type = null;
- if (count($result) == 2) {
- list($metadata, $data) = $result;
- // do some legwork on the metadata
- $metas = explode(';', $metadata);
- while (!empty($metas)) {
- $cur = array_shift($metas);
- if ($cur == 'base64') {
- $is_base64 = true;
- break;
- }
- if (substr($cur, 0, 8) == 'charset=') {
- // doesn't match if there are arbitrary spaces, but
- // whatever dude
- if ($charset !== null) {
- continue;
- } // garbage
- $charset = substr($cur, 8); // not used
- } else {
- if ($content_type !== null) {
- continue;
- } // garbage
- $content_type = $cur;
- }
- }
- } else {
- $data = $result[0];
- }
- if ($content_type !== null && empty($this->allowed_types[$content_type])) {
- return false;
- }
- if ($charset !== null) {
- // error; we don't allow plaintext stuff
- $charset = null;
- }
- $data = rawurldecode($data);
- if ($is_base64) {
- $raw_data = base64_decode($data);
- } else {
- $raw_data = $data;
- }
- // XXX probably want to refactor this into a general mechanism
- // for filtering arbitrary content types
- $file = tempnam("/tmp", "");
- file_put_contents($file, $raw_data);
- if (function_exists('exif_imagetype')) {
- $image_code = exif_imagetype($file);
- unlink($file);
- } elseif (function_exists('getimagesize')) {
- set_error_handler(array($this, 'muteErrorHandler'));
- $info = getimagesize($file);
- restore_error_handler();
- unlink($file);
- if ($info == false) {
- return false;
- }
- $image_code = $info[2];
- } else {
- trigger_error("could not find exif_imagetype or getimagesize functions", E_USER_ERROR);
- }
- $real_content_type = image_type_to_mime_type($image_code);
- if ($real_content_type != $content_type) {
- // we're nice guys; if the content type is something else we
- // support, change it over
- if (empty($this->allowed_types[$real_content_type])) {
- return false;
- }
- $content_type = $real_content_type;
- }
- // ok, it's kosher, rewrite what we need
- $uri->userinfo = null;
- $uri->host = null;
- $uri->port = null;
- $uri->fragment = null;
- $uri->query = null;
- $uri->path = "$content_type;base64," . base64_encode($raw_data);
- return true;
- }
-
- /**
- * @param int $errno
- * @param string $errstr
- */
- public function muteErrorHandler($errno, $errstr)
- {
- }
- }
|