94 lines
3.3 KiB
PHP
94 lines
3.3 KiB
PHP
|
<?php
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Implements data: URI for base64 encoded images supported by GD.
|
||
|
|
*/
|
||
|
|
class HTMLPurifier_URIScheme_data extends HTMLPurifier_URIScheme {
|
||
|
|
|
||
|
|
public $browsable = true;
|
||
|
|
public $allowed_types = array(
|
||
|
|
// you better write validation code for other types if you
|
||
|
|
// decide to allow them
|
||
|
|
'image/jpeg' => true,
|
||
|
|
'image/gif' => true,
|
||
|
|
'image/png' => true,
|
||
|
|
);
|
||
|
|
|
||
|
|
public function validate(&$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);
|
||
|
|
} elseif (function_exists('getimagesize')) {
|
||
|
|
set_error_handler(array($this, 'muteErrorHandler'));
|
||
|
|
$info = getimagesize($file);
|
||
|
|
restore_error_handler();
|
||
|
|
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($raw_data);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
public function muteErrorHandler($errno, $errstr) {}
|
||
|
|
|
||
|
|
}
|
||
|
|
|