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<?php |
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/** |
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* Implements data: URI for base64 encoded images supported by GD. |
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*/ |
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class HTMLPurifier_URIScheme_data extends HTMLPurifier_URIScheme |
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{ |
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/** |
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* @type bool |
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*/ |
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public $browsable = true; |
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/** |
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* @type array |
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*/ |
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public $allowed_types = array( |
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// you better write validation code for other types if you |
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// decide to allow them |
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'image/jpeg' => true, |
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'image/gif' => true, |
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'image/png' => true, |
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); |
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// this is actually irrelevant since we only write out the path |
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// component |
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/** |
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* @type bool |
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*/ |
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public $may_omit_host = true; |
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/** |
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* @param HTMLPurifier_URI $uri |
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* @param HTMLPurifier_Config $config |
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* @param HTMLPurifier_Context $context |
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* @return bool |
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*/ |
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public function doValidate(&$uri, $config, $context) |
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{ |
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$result = explode(',', $uri->path, 2); |
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$is_base64 = false; |
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$charset = null; |
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$content_type = null; |
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if (count($result) == 2) { |
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list($metadata, $data) = $result; |
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// do some legwork on the metadata |
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$metas = explode(';', $metadata); |
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while (!empty($metas)) { |
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$cur = array_shift($metas); |
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if ($cur === 'base64') { |
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$is_base64 = true; |
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break; |
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} |
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if (substr($cur, 0, 8) === 'charset=') { |
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// doesn't match if there are arbitrary spaces, but |
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// whatever dude |
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if ($charset !== null) { |
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continue; |
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} // garbage |
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$charset = substr($cur, 8); // not used |
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} else { |
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if ($content_type !== null) { |
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continue; |
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} // garbage |
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$content_type = $cur; |
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} |
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} |
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} else { |
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$data = $result[0]; |
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} |
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if ($content_type !== null && empty($this->allowed_types[$content_type])) { |
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return false; |
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} |
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if ($charset !== null) { |
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// error; we don't allow plaintext stuff |
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$charset = null; |
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} |
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$data = rawurldecode($data); |
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if ($is_base64) { |
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$raw_data = base64_decode($data); |
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} else { |
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$raw_data = $data; |
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} |
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if ( strlen($raw_data) < 12 ) { |
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// error; exif_imagetype throws exception with small files, |
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// and this likely indicates a corrupt URI/failed parse anyway |
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return false; |
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} |
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// XXX probably want to refactor this into a general mechanism |
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// for filtering arbitrary content types |
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if (function_exists('sys_get_temp_dir')) { |
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$file = tempnam(sys_get_temp_dir(), ""); |
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} else { |
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$file = tempnam("/tmp", ""); |
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} |
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file_put_contents($file, $raw_data); |
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if (function_exists('exif_imagetype')) { |
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$image_code = exif_imagetype($file); |
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unlink($file); |
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} elseif (function_exists('getimagesize')) { |
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set_error_handler(array($this, 'muteErrorHandler')); |
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$info = getimagesize($file); |
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restore_error_handler(); |
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unlink($file); |
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if ($info == false) { |
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return false; |
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} |
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$image_code = $info[2]; |
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} else { |
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trigger_error("could not find exif_imagetype or getimagesize functions", E_USER_ERROR); |
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} |
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$real_content_type = image_type_to_mime_type($image_code); |
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if ($real_content_type != $content_type) { |
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// we're nice guys; if the content type is something else we |
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// support, change it over |
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if (empty($this->allowed_types[$real_content_type])) { |
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return false; |
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} |
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$content_type = $real_content_type; |
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} |
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// ok, it's kosher, rewrite what we need |
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$uri->userinfo = null; |
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$uri->host = null; |
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$uri->port = null; |
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$uri->fragment = null; |
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$uri->query = null; |
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$uri->path = "$content_type;base64," . base64_encode($raw_data); |
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return true; |
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} |
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/** |
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* @param int $errno |
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* @param string $errstr |
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*/ |
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public function muteErrorHandler($errno, $errstr) |
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{ |
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} |
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} |
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This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently.
Both the
$myVarassignment in line 1 and the$higherassignment in line 2 are dead. The first because$myVaris never used and the second because$higheris always overwritten for every possible time line.