streams/Zotlabs/Lib/SvgSanitizer.php
2019-11-14 14:47:15 -08:00

156 lines
10 KiB
PHP

<?php
namespace Zotlabs\Lib;
use DomDocument;
use Zotlabs\Lib\Config;
/**
* SVGSantiizer
*
* Whitelist-based PHP SVG sanitizer.
*
* @link https://github.com/alister-/SVG-Sanitizer}
* @author Alister Norris
* @copyright Copyright (c) 2013 Alister Norris
* @license http://opensource.org/licenses/mit-license.php The MIT License
* @package svgsanitizer
*/
class SvgSanitizer {
private $xmlDoc; // PHP XML DOMDocument
private $removedattrs = [];
private static $allowed_functions = [ 'matrix', 'url', 'translate', 'rgb' ];
// defines the whitelist of elements and attributes allowed.
private static $whitelist = [
'a' => [ 'class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'href', 'xlink:href', 'xlink:title' ],
'circle' => [ 'class', 'clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'r', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform' ],
'clipPath' => [ 'class', 'clipPathUnits', 'id' ],
'defs' => [ ],
'style' => [ 'type' ],
'desc' => [ ],
'ellipse' => [ 'class', 'clip-path', 'clip-rule', 'cx', 'cy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform' ],
'feGaussianBlur' => [ 'class', 'color-interpolation-filters', 'id', 'requiredFeatures', 'stdDeviation' ],
'filter' => [ 'class', 'color-interpolation-filters', 'filterRes', 'filterUnits', 'height', 'id', 'primitiveUnits', 'requiredFeatures', 'width', 'x', 'xlink:href', 'y' ],
'foreignObject' => [ 'class', 'font-size', 'height', 'id', 'opacity', 'requiredFeatures', 'style', 'transform', 'width', 'x', 'y' ],
'g' => [ 'class', 'clip-path', 'clip-rule', 'id', 'display', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'font-family', 'font-size', 'font-style', 'font-weight', 'text-anchor' ],
'image' => [ 'class', 'clip-path', 'clip-rule', 'filter', 'height', 'id', 'mask', 'opacity', 'requiredFeatures', 'style', 'systemLanguage', 'transform', 'width', 'x', 'xlink:href', 'xlink:title', 'y' ],
'line' => [ 'class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'x1', 'x2', 'y1', 'y2' ],
'linearGradient' => [ 'class', 'id', 'gradientTransform', 'gradientUnits', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'x1', 'x2', 'xlink:href', 'y1', 'y2' ],
'marker' => [ 'id', 'class', 'markerHeight', 'markerUnits', 'markerWidth', 'orient', 'preserveAspectRatio', 'refX', 'refY', 'systemLanguage', 'viewBox' ],
'mask' => [ 'class', 'height', 'id', 'maskContentUnits', 'maskUnits', 'width', 'x', 'y' ],
'metadata' => [ 'class', 'id' ],
'path' => [ 'class', 'clip-path', 'clip-rule', 'd', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform' ],
'pattern' => [ 'class', 'height', 'id', 'patternContentUnits', 'patternTransform', 'patternUnits', 'requiredFeatures', 'style', 'systemLanguage', 'viewBox', 'width', 'x', 'xlink:href', 'y' ],
'polygon' => [ 'class', 'clip-path', 'clip-rule', 'id', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'id', 'class', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform' ],
'polyline' => [ 'class', 'clip-path', 'clip-rule', 'id', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'opacity', 'points', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform' ],
'radialGradient' => [ 'class', 'cx', 'cy', 'fx', 'fy', 'gradientTransform', 'gradientUnits', 'id', 'r', 'requiredFeatures', 'spreadMethod', 'systemLanguage', 'xlink:href' ],
'rect' => [ 'class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'id', 'mask', 'opacity', 'requiredFeatures', 'rx', 'ry', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'width', 'x', 'y' ],
'stop' => [ 'class', 'id', 'offset', 'requiredFeatures', 'stop-color', 'stop-opacity', 'style', 'systemLanguage' ],
'svg' => [ 'class', 'clip-path', 'clip-rule', 'filter', 'id', 'height', 'mask', 'preserveAspectRatio', 'requiredFeatures', 'style', 'systemLanguage', 'viewBox', 'width', 'x', 'xmlns', 'xmlns:se', 'xmlns:xlink', 'y' ],
'switch' => [ 'class', 'id', 'requiredFeatures', 'systemLanguage' ],
'symbol' => [ 'class', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'opacity', 'preserveAspectRatio', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'transform', 'viewBox' ],
'text' => [ 'class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'mask', 'opacity', 'requiredFeatures', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'transform', 'x', 'xml:space', 'y' ],
'textPath' => [ 'class', 'id', 'method', 'requiredFeatures', 'spacing', 'startOffset', 'style', 'systemLanguage', 'transform', 'xlink:href' ],
'title' => [ ],
'tspan' => [ 'class', 'clip-path', 'clip-rule', 'dx', 'dy', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'font-family', 'font-size', 'font-style', 'font-weight', 'id', 'mask', 'opacity', 'requiredFeatures', 'rotate', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'systemLanguage', 'text-anchor', 'textLength', 'transform', 'x', 'xml:space', 'y' ],
'use' => [ 'class', 'clip-path', 'clip-rule', 'fill', 'fill-opacity', 'fill-rule', 'filter', 'height', 'id', 'mask', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'style', 'transform', 'width', 'x', 'xlink:href', 'y' ],
];
function __construct() {
$this->xmlDoc = new DOMDocument('1.0','UTF-8');
$this->xmlDoc->preserveWhiteSpace = false;
libxml_use_internal_errors(true);
}
// load XML SVG
function load($file) {
$this->xmlDoc->load($file);
}
function loadXML($str) {
if (! $str) {
logger('loadxml: empty input', LOGGER_DEBUG);
return false;
}
if (! $this->xmlDoc->loadXML($str)) {
logger('loadxml: ' . print_r(array_slice(libxml_get_errors(),0,Config::Get('system','svg_backtrace_limit',3)),true), LOGGER_DEBUG);
return false;
}
return true;
}
function sanitize()
{
// all elements in xml doc
$allElements = $this->xmlDoc->getElementsByTagName('*');
// loop through all elements
for($i = 0; $i < $allElements->length; $i++)
{
$this->removedattrs = [];
$currentNode = $allElements->item($i);
// logger('current_node: ' . print_r($currentNode,true));
// array of allowed attributes in specific element
$whitelist_attr_arr = self::$whitelist[$currentNode->tagName];
// does element exist in whitelist?
if(isset($whitelist_attr_arr)) {
$total = $currentNode->attributes->length;
for($x = 0; $x < $total; $x++) {
// get attributes name
$attrName = $currentNode->attributes->item($x)->nodeName;
// logger('checking: ' . print_r($currentNode->attributes->item($x),true));
$matches = false;
// check if attribute isn't in whitelist
if(! in_array($attrName, $whitelist_attr_arr)) {
$this->removedattrs[] = $attrName;
}
// check for disallowed functions
elseif (preg_match_all('/([a-zA-Z0-9]+)[\s]*\(/',
$currentNode->attributes->item($x)->textContent,$matches,PREG_SET_ORDER)) {
if ($attrName === 'text') {
continue;
}
foreach ($matches as $match) {
if(! in_array($match[1],self::$allowed_functions)) {
logger('queue_remove_function: ' . $match[1],LOGGER_DEBUG);
$this->removedattrs[] = $attrName;
}
}
}
}
if ($this->removedattrs) {
foreach ($this->removedattrs as $attr) {
$currentNode->removeAttribute($attr);
logger('removed: ' . $attr, LOGGER_DEBUG);
}
}
}
// else remove element
else {
logger('remove_node: ' . print_r($currentNode,true));
$currentNode->parentNode->removeChild($currentNode);
}
}
return true;
}
function saveSVG() {
$this->xmlDoc->formatOutput = true;
return($this->xmlDoc->saveXML());
}
}