From ed1d212ae2daea5e4bd043417610177093e99f19 Mon Sep 17 00:00:00 2001
From: Aleksander Machniak <alec@alec.pl>
Date: Sat, 16 Jan 2016 03:03:51 -0500
Subject: [PATCH] Improved SVG cleanup code
---
program/lib/Roundcube/rcube_washtml.php | 380 ++++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 285 insertions(+), 95 deletions(-)
diff --git a/program/lib/Roundcube/rcube_washtml.php b/program/lib/Roundcube/rcube_washtml.php
index 5a5b3dc..0130a4f 100644
--- a/program/lib/Roundcube/rcube_washtml.php
+++ b/program/lib/Roundcube/rcube_washtml.php
@@ -18,7 +18,7 @@
+-----------------------------------------------------------------------+
*/
-/**
+/*
* Washtml, a HTML sanityzer.
*
* Copyright (c) 2007 Frederic Motte <fmotte@ubixis.com>
@@ -95,8 +95,22 @@
'ins', 'label', 'legend', 'li', 'map', 'menu', 'nobr', 'ol', 'p', 'pre', 'q',
's', 'samp', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'table',
'tbody', 'td', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u', 'ul', 'var', 'wbr', 'img',
+ 'video', 'source',
// form elements
- 'button', 'input', 'textarea', 'select', 'option', 'optgroup'
+ 'button', 'input', 'textarea', 'select', 'option', 'optgroup',
+ // SVG
+ 'svg', 'altglyph', 'altglyphdef', 'altglyphitem', 'animate',
+ 'animatecolor', 'animatetransform', 'circle', 'clippath', 'defs', 'desc',
+ 'ellipse', 'font', 'g', 'glyph', 'glyphref', 'hkern', 'image', 'line',
+ 'lineargradient', 'marker', 'mask', 'mpath', 'path', 'pattern',
+ 'polygon', 'polyline', 'radialgradient', 'rect', 'set', 'stop', 'switch', 'symbol',
+ 'text', 'textpath', 'tref', 'tspan', 'use', 'view', 'vkern', 'filter',
+ // SVG Filters
+ 'feblend', 'fecolormatrix', 'fecomponenttransfer', 'fecomposite',
+ 'feconvolvematrix', 'fediffuselighting', 'fedisplacementmap',
+ 'feflood', 'fefunca', 'fefuncb', 'fefuncg', 'fefuncr', 'fegaussianblur',
+ 'feimage', 'femerge', 'femergenode', 'femorphology', 'feoffset',
+ 'fespecularlighting', 'fetile', 'feturbulence',
);
/* Ignore these HTML tags and their content */
@@ -109,13 +123,41 @@
'bordercolordark', 'face', 'marginwidth', 'marginheight', 'axis', 'border',
'abbr', 'char', 'charoff', 'clear', 'compact', 'coords', 'vspace', 'hspace',
'cellborder', 'size', 'lang', 'dir', 'usemap', 'shape', 'media',
+ 'background', 'src', 'poster', 'href',
// attributes of form elements
- 'type', 'rows', 'cols', 'disabled', 'readonly', 'checked', 'multiple', 'value'
+ 'type', 'rows', 'cols', 'disabled', 'readonly', 'checked', 'multiple', 'value',
+ // SVG
+ 'accent-height', 'accumulate', 'additive', 'alignment-baseline', 'alphabetic',
+ 'ascent', 'attributename', 'attributetype', 'azimuth', 'basefrequency', 'baseprofile',
+ 'baseline-shift', 'begin', 'bias', 'by', 'clip', 'clip-path', 'clip-rule',
+ 'color', 'color-interpolation', 'color-interpolation-filters', 'color-profile',
+ 'color-rendering', 'cx', 'cy', 'd', 'dx', 'dy', 'diffuseconstant', 'direction',
+ 'display', 'divisor', 'dur', 'edgemode', 'elevation', 'end', 'fill', 'fill-opacity',
+ 'fill-rule', 'filter', 'flood-color', 'flood-opacity', 'font-family', 'font-size',
+ 'font-size-adjust', 'font-stretch', 'font-style', 'font-variant', 'font-weight', 'from',
+ 'fx', 'fy', 'g1', 'g2', 'glyph-name', 'glyphref', 'gradientunits', 'gradienttransform',
+ 'image-rendering', 'in', 'in2', 'k', 'k1', 'k2', 'k3', 'k4', 'kerning', 'keypoints',
+ 'keysplines', 'keytimes', 'lengthadjust', 'letter-spacing', 'kernelmatrix',
+ 'kernelunitlength', 'lighting-color', 'local', 'marker-end', 'marker-mid',
+ 'marker-start', 'markerheight', 'markerunits', 'markerwidth', 'maskcontentunits',
+ 'maskunits', 'max', 'mask', 'mode', 'min', 'numoctaves', 'offset', 'operator',
+ 'opacity', 'order', 'orient', 'orientation', 'origin', 'overflow', 'paint-order',
+ 'path', 'pathlength', 'patterncontentunits', 'patterntransform', 'patternunits',
+ 'points', 'preservealpha', 'r', 'rx', 'ry', 'radius', 'refx', 'refy', 'repeatcount',
+ 'repeatdur', 'restart', 'rotate', 'scale', 'seed', 'shape-rendering', 'show', 'specularconstant',
+ 'specularexponent', 'spreadmethod', 'stddeviation', 'stitchtiles', 'stop-color',
+ 'stop-opacity', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap',
+ 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke', 'stroke-width',
+ 'surfacescale', 'targetx', 'targety', 'transform', 'text-anchor', 'text-decoration',
+ 'text-rendering', 'textlength', 'to', 'u1', 'u2', 'unicode', 'values', 'viewbox',
+ 'visibility', 'vert-adv-y', 'version', 'vert-origin-x', 'vert-origin-y', 'word-spacing',
+ 'wrap', 'writing-mode', 'xchannelselector', 'ychannelselector', 'x', 'x1', 'x2',
+ 'xmlns', 'y', 'y1', 'y2', 'z', 'zoomandpan',
);
/* Elements which could be empty and be returned in short form (<tag />) */
static $void_elements = array('area', 'base', 'br', 'col', 'command', 'embed', 'hr',
- 'img', 'input', 'keygen', 'link', 'meta', 'param', 'source', 'track', 'wbr'
+ 'img', 'input', 'keygen', 'link', 'meta', 'param', 'source', 'track', 'wbr',
);
/* State for linked objects in HTML */
@@ -142,13 +184,15 @@
/* Max nesting level */
private $max_nesting_level;
+ private $is_xml = false;
+
/**
* Class constructor
*/
public function __construct($p = array())
{
- $this->_html_elements = array_flip((array)$p['html_elements']) + array_flip(self::$html_elements) ;
+ $this->_html_elements = array_flip((array)$p['html_elements']) + array_flip(self::$html_elements);
$this->_html_attribs = array_flip((array)$p['html_attribs']) + array_flip(self::$html_attribs);
$this->_ignore_elements = array_flip((array)$p['ignore_elements']) + array_flip(self::$ignore_elements);
$this->_void_elements = array_flip((array)$p['void_elements']) + array_flip(self::$void_elements);
@@ -171,7 +215,10 @@
*/
private function wash_style($style)
{
- $s = '';
+ $result = array();
+
+ // Remove unwanted white-space characters so regular expressions below work better
+ $style = preg_replace('/[\n\r\s\t]+/', ' ', $style);
foreach (explode(';', $style) as $declaration) {
if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) {
@@ -179,54 +226,34 @@
$str = $match[2];
$value = '';
- while (sizeof($str) > 0 &&
- preg_match('/^(url\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)'./*1,2*/
- '|rgb\(\s*[0-9]+\s*,\s*[0-9]+\s*,\s*[0-9]+\s*\)'.
- '|-?[0-9.]+\s*(em|ex|px|cm|mm|in|pt|pc|deg|rad|grad|ms|s|hz|khz|%)?'.
- '|#[0-9a-f]{3,6}'.
- '|[a-z0-9", -]+'.
- ')\s*/i', $str, $match)
- ) {
- if ($match[2]) {
- if (($src = $this->config['cid_map'][$match[2]])
- || ($src = $this->config['cid_map'][$this->config['base_url'].$match[2]])
- ) {
- $value .= ' url('.htmlspecialchars($src, ENT_QUOTES) . ')';
- }
- else if (preg_match('!^(https?:)?//[a-z0-9/._+-]+$!i', $match[2], $url)) {
- if ($this->config['allow_remote']) {
- $value .= ' url('.htmlspecialchars($url[0], ENT_QUOTES).')';
+ foreach ($this->explode_style($str) as $val) {
+ if (preg_match('/^url\(/i', $val)) {
+ if (preg_match('/^url\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)/iu', $val, $match)) {
+ if ($url = $this->wash_uri($match[1])) {
+ $value .= ' url(' . htmlspecialchars($url, ENT_QUOTES) . ')';
}
- else {
- $this->extlinks = true;
- }
- }
- else if (preg_match('/^data:.+/i', $match[2])) { // RFC2397
- $value .= ' url('.htmlspecialchars($match[2], ENT_QUOTES).')';
}
}
- else {
+ else if (!preg_match('/^(behavior|expression)/i', $val)) {
// whitelist ?
- $value .= ' ' . $match[0];
+ $value .= ' ' . $val;
// #1488535: Fix size units, so width:800 would be changed to width:800px
- if (preg_match('/(left|right|top|bottom|width|height)/i', $cssid)
- && preg_match('/^[0-9]+$/', $match[0])
+ if (preg_match('/^(left|right|top|bottom|width|height)/i', $cssid)
+ && preg_match('/^[0-9]+$/', $val)
) {
$value .= 'px';
}
}
-
- $str = substr($str, strlen($match[0]));
}
if (isset($value[0])) {
- $s .= ($s?' ':'') . $cssid . ':' . $value . ';';
+ $result[] = $cssid . ':' . $value;
}
}
}
- return $s;
+ return implode('; ', $result);
}
/**
@@ -234,59 +261,147 @@
*/
private function wash_attribs($node)
{
- $t = '';
- $washed = '';
+ $result = '';
+ $washed = array();
- foreach ($node->attributes as $key => $plop) {
- $key = strtolower($key);
- $value = $node->getAttribute($key);
+ foreach ($node->attributes as $name => $attr) {
+ $key = strtolower($name);
+ $value = $attr->nodeValue;
- if (isset($this->_html_attribs[$key]) ||
- ($key == 'href' && ($value = trim($value))
- && !preg_match('!^(javascript|vbscript|data:text)!i', $value)
- && preg_match('!^([a-z][a-z0-9.+-]+:|//|#).+!i', $value))
- ) {
- $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
+ if ($key == 'style' && ($style = $this->wash_style($value))) {
+ // replace double quotes to prevent syntax error and XSS issues (#1490227)
+ $result .= ' style="' . str_replace('"', '"', $style) . '"';
}
- else if ($key == 'style' && ($style = $this->wash_style($value))) {
- $quot = strpos($style, '"') !== false ? "'" : '"';
- $t .= ' style=' . $quot . $style . $quot;
- }
- else if ($key == 'background' || ($key == 'src' && strtolower($node->tagName) == 'img')) { //check tagName anyway
- if (($src = $this->config['cid_map'][$value])
- || ($src = $this->config['cid_map'][$this->config['base_url'].$value])
- ) {
- $t .= ' ' . $key . '="' . htmlspecialchars($src, ENT_QUOTES) . '"';
- }
- else if (preg_match('/^(http|https|ftp):.+/i', $value)) {
- if ($this->config['allow_remote']) {
- $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
+ else if (isset($this->_html_attribs[$key])) {
+ $value = trim($value);
+ $out = null;
+
+ // in SVG to/from attribs may contain anything, including URIs
+ if ($key == 'to' || $key == 'from') {
+ $key = strtolower($node->getAttribute('attributeName'));
+ if ($key && !isset($this->_html_attribs[$key])) {
+ $key = null;
}
- else {
- $this->extlinks = true;
- if ($this->config['blocked_src']) {
- $t .= ' ' . $key . '="' . htmlspecialchars($this->config['blocked_src'], ENT_QUOTES) . '"';
+ }
+
+ if ($this->is_image_attribute($node->tagName, $key)) {
+ $out = $this->wash_uri($value, true);
+ }
+ else if ($this->is_link_attribute($node->tagName, $key)) {
+ if (!preg_match('!^(javascript|vbscript|data:text)!i', $value)
+ && preg_match('!^([a-z][a-z0-9.+-]+:|//|#).+!i', $value)
+ ) {
+ $out = $value;
+ }
+ }
+ else if ($this->is_funciri_attribute($node->tagName, $key)) {
+ if (preg_match('/^[a-z:]*url\(/i', $val)) {
+ if (preg_match('/^([a-z:]*url)\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)/iu', $value, $match)) {
+ if ($url = $this->wash_uri($match[2])) {
+ $result .= ' ' . $attr->nodeName . '="' . $match[1] . '(' . htmlspecialchars($url, ENT_QUOTES) . ')'
+ . substr($val, strlen($match[0])) . '"';
+ continue;
+ }
+ }
+ else {
+ $out = $value;
}
}
+ else {
+ $out = $value;
+ }
}
- else if (preg_match('/^data:.+/i', $value)) { // RFC2397
- $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
+ else if ($key) {
+ $out = $value;
+ }
+
+ if ($out !== null && $out !== '') {
+ $result .= ' ' . $attr->nodeName . '="' . htmlspecialchars($out, ENT_QUOTES) . '"';
+ }
+ else if ($value) {
+ $washed[] = htmlspecialchars($attr->nodeName, ENT_QUOTES);
}
}
else {
- $washed .= ($washed ? ' ' : '') . $key;
+ $washed[] = htmlspecialchars($attr->nodeName, ENT_QUOTES);
}
}
- return $t . ($washed && $this->config['show_washed'] ? ' x-washed="'.$washed.'"' : '');
+ if (!empty($washed) && $this->config['show_washed']) {
+ $result .= ' x-washed="' . implode(' ', $washed) . '"';
+ }
+
+ return $result;
+ }
+
+ /**
+ * Wash URI value
+ */
+ private function wash_uri($uri, $blocked_source = false)
+ {
+ if (($src = $this->config['cid_map'][$uri])
+ || ($src = $this->config['cid_map'][$this->config['base_url'].$uri])
+ ) {
+ return $src;
+ }
+
+ // allow url(#id) used in SVG
+ if ($uri[0] == '#') {
+ return $uri;
+ }
+
+ if (preg_match('/^(http|https|ftp):.+/i', $uri)) {
+ if ($this->config['allow_remote']) {
+ return $uri;
+ }
+
+ $this->extlinks = true;
+ if ($blocked_source && $this->config['blocked_src']) {
+ return $this->config['blocked_src'];
+ }
+ }
+ else if (preg_match('/^data:image.+/i', $uri)) { // RFC2397
+ return $uri;
+ }
+ }
+
+ /**
+ * Check it the tag/attribute may contain an URI
+ */
+ private function is_link_attribute($tag, $attr)
+ {
+ return $tag == 'a' && $attr == 'href';
+ }
+
+ /**
+ * Check it the tag/attribute may contain an image URI
+ */
+ private function is_image_attribute($tag, $attr)
+ {
+ return $attr == 'background'
+ || $attr == 'color-profile' // SVG
+ || ($attr == 'poster' && $tag == 'video')
+ || ($attr == 'src' && preg_match('/^(img|source)$/i', $tag))
+ || ($tag == 'image' && $attr == 'href'); // SVG
+ }
+
+ /**
+ * Check it the tag/attribute may contain a FUNCIRI value
+ */
+ private function is_funciri_attribute($tag, $attr)
+ {
+ return in_array($attr, array('fill', 'filter', 'stroke', 'marker-start',
+ 'marker-end', 'marker-mid', 'clip-path', 'mask', 'cursor'));
}
/**
* The main loop that recurse on a node tree.
- * It output only allowed tags with allowed attributes
- * and allowed inline styles
+ * It output only allowed tags with allowed attributes and allowed inline styles
+ *
+ * @param DOMNode $node HTML element
+ * @param int $level Recurrence level (safe initial value found empirically)
*/
- private function dumpHtml($node, $level = 0)
+ private function dumpHtml($node, $level = 20)
{
if (!$node->hasChildNodes()) {
return '';
@@ -310,7 +425,7 @@
$dump = '';
do {
- switch($node->nodeType) {
+ switch ($node->nodeType) {
case XML_ELEMENT_NODE: //Check element
$tagName = strtolower($node->tagName);
if ($callback = $this->handlers[$tagName]) {
@@ -319,14 +434,31 @@
}
else if (isset($this->_html_elements[$tagName])) {
$content = $this->dumpHtml($node, $level);
- $dump .= '<' . $tagName . $this->wash_attribs($node) .
- ($content === '' && isset($this->_void_elements[$tagName]) ? ' />' : ">$content</$tagName>");
+ $dump .= '<' . $node->tagName;
+
+ if ($tagName == 'svg') {
+ $xpath = new DOMXPath($node->ownerDocument);
+ foreach ($xpath->query('namespace::*') as $ns) {
+ if ($ns->nodeName != 'xmlns:xml') {
+ $dump .= ' ' . $ns->nodeName . '="' . $ns->nodeValue . '"';
+ }
+ }
+ }
+
+ $dump .= $this->wash_attribs($node);
+
+ if ($content === '' && ($this->is_xml || isset($this->_void_elements[$tagName]))) {
+ $dump .= ' />';
+ }
+ else {
+ $dump .= '>' . $content . '</' . $node->tagName . '>';
+ }
}
else if (isset($this->_ignore_elements[$tagName])) {
- $dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' not allowed -->';
+ $dump .= '<!-- ' . htmlspecialchars($node->tagName, ENT_QUOTES) . ' not allowed -->';
}
else {
- $dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' ignored -->';
+ $dump .= '<!-- ' . htmlspecialchars($node->tagName, ENT_QUOTES) . ' ignored -->';
$dump .= $this->dumpHtml($node, $level); // ignore tags not its content
}
break;
@@ -342,14 +474,9 @@
case XML_HTML_DOCUMENT_NODE:
$dump .= $this->dumpHtml($node, $level);
break;
-
- case XML_DOCUMENT_TYPE_NODE:
- break;
-
- default:
- $dump .= '<!-- node type ' . $node->nodeType . ' -->';
}
- } while($node = $node->nextSibling);
+ }
+ while($node = $node->nextSibling);
return $dump;
}
@@ -377,12 +504,18 @@
// Detect max nesting level (for dumpHTML) (#1489110)
$this->max_nesting_level = (int) @ini_get('xdebug.max_nesting_level');
+ // SVG need to be parsed as XML
+ $this->is_xml = stripos($html, '<svg') !== false || stripos($html, '<?xml') !== false;
+ $method = $this->is_xml ? 'loadXML' : 'loadHTML';
+ $options = 0;
+
// Use optimizations if supported
- if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
- @$node->loadHTML($html, LIBXML_PARSEHUGE | LIBXML_COMPACT);
+ if (PHP_VERSION_ID >= 50400) {
+ $options = LIBXML_PARSEHUGE | LIBXML_COMPACT | LIBXML_NONET;
+ @$node->{$method}($html, $options);
}
else {
- @$node->loadHTML($html);
+ @$node->{$method}($html);
}
return $this->dumpHtml($node);
@@ -401,31 +534,42 @@
*/
private function cleanup($html)
{
+ $html = trim($html);
+
// special replacements (not properly handled by washtml class)
$html_search = array(
- '/(<\/nobr>)(\s+)(<nobr>)/i', // space(s) between <NOBR>
- '/<title[^>]*>[^<]*<\/title>/i', // PHP bug #32547 workaround: remove title tag
- '/^(\0\0\xFE\xFF|\xFF\xFE\0\0|\xFE\xFF|\xFF\xFE|\xEF\xBB\xBF)/', // byte-order mark (only outlook?)
- '/<html\s[^>]+>/i', // washtml/DOMDocument cannot handle xml namespaces
+ // space(s) between <NOBR>
+ '/(<\/nobr>)(\s+)(<nobr>)/i',
+ // PHP bug #32547 workaround: remove title tag
+ '/<title[^>]*>[^<]*<\/title>/i',
+ // remove <!doctype> before BOM (#1490291)
+ '/<\!doctype[^>]+>[^<]*/im',
+ // byte-order mark (only outlook?)
+ '/^(\0\0\xFE\xFF|\xFF\xFE\0\0|\xFE\xFF|\xFF\xFE|\xEF\xBB\xBF)/',
+ // washtml/DOMDocument cannot handle xml namespaces
+ '/<html\s[^>]+>/i',
);
$html_replace = array(
'\\1'.' '.'\\3',
'',
'',
+ '',
'<html>',
);
+
$html = preg_replace($html_search, $html_replace, trim($html));
- //-> Replace all of those weird MS Word quotes and other high characters
+ // Replace all of those weird MS Word quotes and other high characters
$badwordchars = array(
"\xe2\x80\x98", // left single quote
"\xe2\x80\x99", // right single quote
"\xe2\x80\x9c", // left double quote
"\xe2\x80\x9d", // right double quote
"\xe2\x80\x94", // em dash
- "\xe2\x80\xa6" // elipses
+ "\xe2\x80\xa6" // elipses
);
+
$fixedwordchars = array(
"'",
"'",
@@ -434,6 +578,7 @@
'—',
'...'
);
+
$html = str_replace($badwordchars, $fixedwordchars, $html);
// PCRE errors handling (#1486856), should we use something like for every preg_* use?
@@ -460,7 +605,7 @@
// Remove invalid HTML comments (#1487759)
// Don't remove valid conditional comments
// Don't remove MSOutlook (<!-->) conditional comments (#1489004)
- $html = preg_replace('/<!--[^->\[\n]+>/', '', $html);
+ $html = preg_replace('/<!--[^-<>\[\n]+>/', '', $html);
// fix broken nested lists
self::fix_broken_lists($html);
@@ -479,7 +624,7 @@
$tagname = $matches[2];
$tagname = preg_replace(array(
'/:.*$/', // Microsoft's Smart Tags <st1:xxxx>
- '/[^a-z0-9_\[\]\!-]/i', // forbidden characters
+ '/[^a-z0-9_\[\]\!?-]/i', // forbidden characters
), '', $tagname);
// fix invalid closing tags - remove any attributes (#1489446)
@@ -576,4 +721,49 @@
}
}
}
+
+ /**
+ * Explode css style value
+ */
+ protected function explode_style($style)
+ {
+ $style = trim($style);
+
+ // first remove comments
+ $pos = 0;
+ while (($pos = strpos($style, '/*', $pos)) !== false) {
+ $end = strpos($style, '*/', $pos+2);
+
+ if ($end === false) {
+ $style = substr($style, 0, $pos);
+ }
+ else {
+ $style = substr_replace($style, '', $pos, $end - $pos + 2);
+ }
+ }
+
+ $strlen = strlen($style);
+ $result = array();
+
+ // explode value
+ for ($p=$i=0; $i < $strlen; $i++) {
+ if (($style[$i] == "\"" || $style[$i] == "'") && $style[$i-1] != "\\") {
+ if ($q == $style[$i]) {
+ $q = false;
+ }
+ else if (!$q) {
+ $q = $style[$i];
+ }
+ }
+
+ if (!$q && $style[$i] == ' ' && !preg_match('/[,\(]/', $style[$i-1])) {
+ $result[] = substr($style, $p, $i - $p);
+ $p = $i + 1;
+ }
+ }
+
+ $result[] = (string) substr($style, $p);
+
+ return $result;
+ }
}
--
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