Merge branch 'master' of github.com:roundcube/roundcubemail
Thomas Bruederli
12 years ago
commit
c942e4a2e9
@ -0,0 +1,451 @@
|
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<?php
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|
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/**
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+-----------------------------------------------------------------------+
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| This file is part of the Roundcube Webmail client |
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| Copyright (C) 2008-2012, The Roundcube Dev Team |
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| |
|
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| Licensed under the GNU General Public License version 3 or |
|
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| any later version with exceptions for skins & plugins. |
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| See the README file for a full license statement. |
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| |
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| PURPOSE: |
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| Utility class providing HTML sanityzer (based on Washtml class) |
|
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+-----------------------------------------------------------------------+
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| Author: Thomas Bruederli <roundcube@gmail.com> |
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| Author: Aleksander Machniak <alec@alec.pl> |
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| Author: Frederic Motte <fmotte@ubixis.com> |
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+-----------------------------------------------------------------------+
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*/
|
||||
|
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/**
|
||||
* Washtml, a HTML sanityzer.
|
||||
*
|
||||
* Copyright (c) 2007 Frederic Motte <fmotte@ubixis.com>
|
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* All rights reserved.
|
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*
|
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* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
||||
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
||||
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
||||
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
||||
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||||
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||||
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*
|
||||
* OVERVIEW:
|
||||
*
|
||||
* Wahstml take an untrusted HTML and return a safe html string.
|
||||
*
|
||||
* SYNOPSIS:
|
||||
*
|
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* $washer = new washtml($config);
|
||||
* $washer->wash($html);
|
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* It return a sanityzed string of the $html parameter without html and head tags.
|
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* $html is a string containing the html code to wash.
|
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* $config is an array containing options:
|
||||
* $config['allow_remote'] is a boolean to allow link to remote images.
|
||||
* $config['blocked_src'] string with image-src to be used for blocked remote images
|
||||
* $config['show_washed'] is a boolean to include washed out attributes as x-washed
|
||||
* $config['cid_map'] is an array where cid urls index urls to replace them.
|
||||
* $config['charset'] is a string containing the charset of the HTML document if it is not defined in it.
|
||||
* $washer->extlinks is a reference to a boolean that is set to true if remote images were removed. (FE: show remote images link)
|
||||
*
|
||||
* INTERNALS:
|
||||
*
|
||||
* Only tags and attributes in the static lists $html_elements and $html_attributes
|
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* are kept, inline styles are also filtered: all style identifiers matching
|
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* /[a-z\-]/i are allowed. Values matching colors, sizes, /[a-z\-]/i and safe
|
||||
* urls if allowed and cid urls if mapped are kept.
|
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*
|
||||
* Roundcube Changes:
|
||||
* - added $block_elements
|
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* - changed $ignore_elements behaviour
|
||||
* - added RFC2397 support
|
||||
* - base URL support
|
||||
* - invalid HTML comments removal before parsing
|
||||
* - "fixing" unitless CSS values for XHTML output
|
||||
* - base url resolving
|
||||
*/
|
||||
|
||||
/**
|
||||
* Utility class providing HTML sanityzer
|
||||
*
|
||||
* @package Framework
|
||||
* @subpackage Utils
|
||||
*/
|
||||
class rcube_washtml
|
||||
{
|
||||
/* Allowed HTML elements (default) */
|
||||
static $html_elements = array('a', 'abbr', 'acronym', 'address', 'area', 'b',
|
||||
'basefont', 'bdo', 'big', 'blockquote', 'br', 'caption', 'center',
|
||||
'cite', 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl',
|
||||
'dt', 'em', 'fieldset', 'font', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i',
|
||||
'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',
|
||||
// form elements
|
||||
'button', 'input', 'textarea', 'select', 'option', 'optgroup'
|
||||
);
|
||||
|
||||
/* Ignore these HTML tags and their content */
|
||||
static $ignore_elements = array('script', 'applet', 'embed', 'object', 'style');
|
||||
|
||||
/* Allowed HTML attributes */
|
||||
static $html_attribs = array('name', 'class', 'title', 'alt', 'width', 'height',
|
||||
'align', 'nowrap', 'col', 'row', 'id', 'rowspan', 'colspan', 'cellspacing',
|
||||
'cellpadding', 'valign', 'bgcolor', 'color', 'border', 'bordercolorlight',
|
||||
'bordercolordark', 'face', 'marginwidth', 'marginheight', 'axis', 'border',
|
||||
'abbr', 'char', 'charoff', 'clear', 'compact', 'coords', 'vspace', 'hspace',
|
||||
'cellborder', 'size', 'lang', 'dir', 'usemap', 'shape', 'media',
|
||||
// attributes of form elements
|
||||
'type', 'rows', 'cols', 'disabled', 'readonly', 'checked', 'multiple', 'value'
|
||||
);
|
||||
|
||||
/* Block elements which could be empty but cannot be returned in short form (<tag />) */
|
||||
static $block_elements = array('div', 'p', 'pre', 'blockquote', 'a', 'font', 'center',
|
||||
'table', 'ul', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'ol', 'dl', 'strong',
|
||||
'i', 'b', 'u', 'span',
|
||||
);
|
||||
|
||||
/* State for linked objects in HTML */
|
||||
public $extlinks = false;
|
||||
|
||||
/* Current settings */
|
||||
private $config = array();
|
||||
|
||||
/* Registered callback functions for tags */
|
||||
private $handlers = array();
|
||||
|
||||
/* Allowed HTML elements */
|
||||
private $_html_elements = array();
|
||||
|
||||
/* Ignore these HTML tags but process their content */
|
||||
private $_ignore_elements = array();
|
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|
||||
/* Block elements which could be empty but cannot be returned in short form (<tag />) */
|
||||
private $_block_elements = array();
|
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|
||||
/* Allowed HTML attributes */
|
||||
private $_html_attribs = array();
|
||||
|
||||
|
||||
/**
|
||||
* Class constructor
|
||||
*/
|
||||
public function __construct($p = array())
|
||||
{
|
||||
$this->_html_elements = array_flip((array)$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);
|
||||
$this->_block_elements = array_flip((array)$p['block_elements']) + array_flip(self::$block_elements);
|
||||
|
||||
unset($p['html_elements'], $p['html_attribs'], $p['ignore_elements'], $p['block_elements']);
|
||||
|
||||
$this->config = $p + array('show_washed' => true, 'allow_remote' => false, 'cid_map' => array());
|
||||
}
|
||||
|
||||
/**
|
||||
* Register a callback function for a certain tag
|
||||
*/
|
||||
public function add_callback($tagName, $callback)
|
||||
{
|
||||
$this->handlers[$tagName] = $callback;
|
||||
}
|
||||
|
||||
/**
|
||||
* Check CSS style
|
||||
*/
|
||||
private function wash_style($style)
|
||||
{
|
||||
$s = '';
|
||||
|
||||
foreach (explode(';', $style) as $declaration) {
|
||||
if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) {
|
||||
$cssid = $match[1];
|
||||
$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]) {
|
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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']) {
|
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$value .= ' url('.htmlspecialchars($url[0], ENT_QUOTES).')';
|
||||
}
|
||||
else {
|
||||
$this->extlinks = true;
|
||||
}
|
||||
}
|
||||
else if (preg_match('/^data:.+/i', $match[2])) { // RFC2397
|
||||
$value .= ' url('.htmlspecialchars($match[2], ENT_QUOTES).')';
|
||||
}
|
||||
}
|
||||
else {
|
||||
// whitelist ?
|
||||
$value .= ' ' . $match[0];
|
||||
|
||||
// #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])
|
||||
) {
|
||||
$value .= 'px';
|
||||
}
|
||||
}
|
||||
|
||||
$str = substr($str, strlen($match[0]));
|
||||
}
|
||||
|
||||
if (isset($value[0])) {
|
||||
$s .= ($s?' ':'') . $cssid . ':' . $value . ';';
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return $s;
|
||||
}
|
||||
|
||||
/**
|
||||
* Take a node and return allowed attributes and check values
|
||||
*/
|
||||
private function wash_attribs($node)
|
||||
{
|
||||
$t = '';
|
||||
$washed = '';
|
||||
|
||||
foreach ($node->attributes as $key => $plop) {
|
||||
$key = strtolower($key);
|
||||
$value = $node->getAttribute($key);
|
||||
|
||||
if (isset($this->_html_attribs[$key]) ||
|
||||
($key == 'href' && !preg_match('!^(javascript|vbscript|data:text)!i', $value)
|
||||
&& preg_match('!^([a-z][a-z0-9.+-]+:|//|#).+!i', $value))
|
||||
) {
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
|
||||
}
|
||||
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 {
|
||||
$this->extlinks = true;
|
||||
if ($this->config['blocked_src']) {
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($this->config['blocked_src'], ENT_QUOTES) . '"';
|
||||
}
|
||||
}
|
||||
}
|
||||
else if (preg_match('/^data:.+/i', $value)) { // RFC2397
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
|
||||
}
|
||||
}
|
||||
else {
|
||||
$washed .= ($washed ? ' ' : '') . $key;
|
||||
}
|
||||
}
|
||||
|
||||
return $t . ($washed && $this->config['show_washed'] ? ' x-washed="'.$washed.'"' : '');
|
||||
}
|
||||
|
||||
/**
|
||||
* The main loop that recurse on a node tree.
|
||||
* It output only allowed tags with allowed attributes
|
||||
* and allowed inline styles
|
||||
*/
|
||||
private function dumpHtml($node)
|
||||
{
|
||||
if (!$node->hasChildNodes()) {
|
||||
return '';
|
||||
}
|
||||
|
||||
$node = $node->firstChild;
|
||||
$dump = '';
|
||||
|
||||
do {
|
||||
switch($node->nodeType) {
|
||||
case XML_ELEMENT_NODE: //Check element
|
||||
$tagName = strtolower($node->tagName);
|
||||
if ($callback = $this->handlers[$tagName]) {
|
||||
$dump .= call_user_func($callback, $tagName,
|
||||
$this->wash_attribs($node), $this->dumpHtml($node), $this);
|
||||
}
|
||||
else if (isset($this->_html_elements[$tagName])) {
|
||||
$content = $this->dumpHtml($node);
|
||||
$dump .= '<' . $tagName . $this->wash_attribs($node) .
|
||||
($content != '' || isset($this->_block_elements[$tagName]) ? ">$content</$tagName>" : ' />');
|
||||
}
|
||||
else if (isset($this->_ignore_elements[$tagName])) {
|
||||
$dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' not allowed -->';
|
||||
}
|
||||
else {
|
||||
$dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' ignored -->';
|
||||
$dump .= $this->dumpHtml($node); // ignore tags not its content
|
||||
}
|
||||
break;
|
||||
|
||||
case XML_CDATA_SECTION_NODE:
|
||||
$dump .= $node->nodeValue;
|
||||
break;
|
||||
|
||||
case XML_TEXT_NODE:
|
||||
$dump .= htmlspecialchars($node->nodeValue);
|
||||
break;
|
||||
|
||||
case XML_HTML_DOCUMENT_NODE:
|
||||
$dump .= $this->dumpHtml($node);
|
||||
break;
|
||||
|
||||
case XML_DOCUMENT_TYPE_NODE:
|
||||
break;
|
||||
|
||||
default:
|
||||
$dump . '<!-- node type ' . $node->nodeType . ' -->';
|
||||
}
|
||||
} while($node = $node->nextSibling);
|
||||
|
||||
return $dump;
|
||||
}
|
||||
|
||||
/**
|
||||
* Main function, give it untrusted HTML, tell it if you allow loading
|
||||
* remote images and give it a map to convert "cid:" urls.
|
||||
*/
|
||||
public function wash($html)
|
||||
{
|
||||
// Charset seems to be ignored (probably if defined in the HTML document)
|
||||
$node = new DOMDocument('1.0', $this->config['charset']);
|
||||
$this->extlinks = false;
|
||||
|
||||
$html = $this->cleanup($html);
|
||||
|
||||
// Find base URL for images
|
||||
if (preg_match('/<base\s+href=[\'"]*([^\'"]+)/is', $html, $matches)) {
|
||||
$this->config['base_url'] = $matches[1];
|
||||
}
|
||||
else {
|
||||
$this->config['base_url'] = '';
|
||||
}
|
||||
|
||||
@$node->loadHTML($html);
|
||||
return $this->dumpHtml($node);
|
||||
}
|
||||
|
||||
/**
|
||||
* Getter for config parameters
|
||||
*/
|
||||
public function get_config($prop)
|
||||
{
|
||||
return $this->config[$prop];
|
||||
}
|
||||
|
||||
/**
|
||||
* Clean HTML input
|
||||
*/
|
||||
private function cleanup($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
|
||||
);
|
||||
|
||||
$html_replace = array(
|
||||
'\\1'.' '.'\\3',
|
||||
'',
|
||||
'',
|
||||
'<html>',
|
||||
);
|
||||
$html = preg_replace($html_search, $html_replace, trim($html));
|
||||
|
||||
// PCRE errors handling (#1486856), should we use something like for every preg_* use?
|
||||
if ($html === null && ($preg_error = preg_last_error()) != PREG_NO_ERROR) {
|
||||
$errstr = "Could not clean up HTML message! PCRE Error: $preg_error.";
|
||||
|
||||
if ($preg_error == PREG_BACKTRACK_LIMIT_ERROR) {
|
||||
$errstr .= " Consider raising pcre.backtrack_limit!";
|
||||
}
|
||||
if ($preg_error == PREG_RECURSION_LIMIT_ERROR) {
|
||||
$errstr .= " Consider raising pcre.recursion_limit!";
|
||||
}
|
||||
|
||||
rcube::raise_error(array('code' => 620, 'type' => 'php',
|
||||
'line' => __LINE__, 'file' => __FILE__,
|
||||
'message' => $errstr), true, false);
|
||||
return '';
|
||||
}
|
||||
|
||||
// fix (unknown/malformed) HTML tags before "wash"
|
||||
$html = preg_replace_callback('/(<[\/]*)([^\s>]+)/', array($this, 'html_tag_callback'), $html);
|
||||
|
||||
// Remove invalid HTML comments (#1487759)
|
||||
// Don't remove valid conditional comments
|
||||
$html = preg_replace('/<!--[^->[\n]*>/', '', $html);
|
||||
|
||||
// turn relative into absolute urls
|
||||
$html = self::resolve_base($html);
|
||||
|
||||
return $html;
|
||||
}
|
||||
|
||||
/**
|
||||
* Callback function for HTML tags fixing
|
||||
*/
|
||||
public static function html_tag_callback($matches)
|
||||
{
|
||||
$tagname = $matches[2];
|
||||
$tagname = preg_replace(array(
|
||||
'/:.*$/', // Microsoft's Smart Tags <st1:xxxx>
|
||||
'/[^a-z0-9_\[\]\!-]/i', // forbidden characters
|
||||
), '', $tagname);
|
||||
|
||||
return $matches[1] . $tagname;
|
||||
}
|
||||
|
||||
/**
|
||||
* Convert all relative URLs according to a <base> in HTML
|
||||
*/
|
||||
public static function resolve_base($body)
|
||||
{
|
||||
// check for <base href=...>
|
||||
if (preg_match('!(<base.*href=["\']?)([hftps]{3,5}://[a-z0-9/.%-]+)!i', $body, $regs)) {
|
||||
$replacer = new rcube_base_replacer($regs[2]);
|
||||
$body = $replacer->replace($body);
|
||||
}
|
||||
|
||||
return $body;
|
||||
}
|
||||
}
|
||||
|
||||
@ -1,330 +0,0 @@
|
||||
<?php
|
||||
/* Washtml, a HTML sanityzer.
|
||||
*
|
||||
* Copyright (c) 2007 Frederic Motte <fmotte@ubixis.com>
|
||||
* All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
||||
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
||||
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
||||
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
||||
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
||||
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||||
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||||
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
||||
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
/* Please send me your comments about this code if you have some, thanks, Fred. */
|
||||
|
||||
/* OVERVIEW:
|
||||
*
|
||||
* Wahstml take an untrusted HTML and return a safe html string.
|
||||
*
|
||||
* SYNOPSIS:
|
||||
*
|
||||
* $washer = new washtml($config);
|
||||
* $washer->wash($html);
|
||||
* It return a sanityzed string of the $html parameter without html and head tags.
|
||||
* $html is a string containing the html code to wash.
|
||||
* $config is an array containing options:
|
||||
* $config['allow_remote'] is a boolean to allow link to remote images.
|
||||
* $config['blocked_src'] string with image-src to be used for blocked remote images
|
||||
* $config['show_washed'] is a boolean to include washed out attributes as x-washed
|
||||
* $config['cid_map'] is an array where cid urls index urls to replace them.
|
||||
* $config['charset'] is a string containing the charset of the HTML document if it is not defined in it.
|
||||
* $washer->extlinks is a reference to a boolean that is set to true if remote images were removed. (FE: show remote images link)
|
||||
*
|
||||
* INTERNALS:
|
||||
*
|
||||
* Only tags and attributes in the static lists $html_elements and $html_attributes
|
||||
* are kept, inline styles are also filtered: all style identifiers matching
|
||||
* /[a-z\-]/i are allowed. Values matching colors, sizes, /[a-z\-]/i and safe
|
||||
* urls if allowed and cid urls if mapped are kept.
|
||||
*
|
||||
* BUGS: It MUST be safe !
|
||||
* - Check regexp
|
||||
* - urlencode URLs instead of htmlspecials
|
||||
* - Check is a 3 bytes utf8 first char can eat '">'
|
||||
* - Update PCRE: CVE-2007-1659 - CVE-2007-1660 - CVE-2007-1661 - CVE-2007-1662
|
||||
* CVE-2007-4766 - CVE-2007-4767 - CVE-2007-4768
|
||||
* http://lists.debian.org/debian-security-announce/debian-security-announce-2007/msg00177.html
|
||||
* - ...
|
||||
*
|
||||
* MISSING:
|
||||
* - relative links, can be implemented by prefixing an absolute path, ask me
|
||||
* if you need it...
|
||||
* - ...
|
||||
*
|
||||
* Dont be a fool:
|
||||
* - Dont alter data on a GET: '<img src="http://yourhost/mail?action=delete&uid=3267" />'
|
||||
* - ...
|
||||
*
|
||||
* Roundcube Changes:
|
||||
* - added $block_elements
|
||||
* - changed $ignore_elements behaviour
|
||||
* - added RFC2397 support
|
||||
* - base URL support
|
||||
* - invalid HTML comments removal before parsing
|
||||
* - "fixing" unitless CSS values for XHTML output
|
||||
*/
|
||||
|
||||
class washtml
|
||||
{
|
||||
/* Allowed HTML elements (default) */
|
||||
static $html_elements = array('a', 'abbr', 'acronym', 'address', 'area', 'b',
|
||||
'basefont', 'bdo', 'big', 'blockquote', 'br', 'caption', 'center',
|
||||
'cite', 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl',
|
||||
'dt', 'em', 'fieldset', 'font', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i',
|
||||
'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',
|
||||
// form elements
|
||||
'button', 'input', 'textarea', 'select', 'option', 'optgroup'
|
||||
);
|
||||
|
||||
/* Ignore these HTML tags and their content */
|
||||
static $ignore_elements = array('script', 'applet', 'embed', 'object', 'style');
|
||||
|
||||
/* Allowed HTML attributes */
|
||||
static $html_attribs = array('name', 'class', 'title', 'alt', 'width', 'height',
|
||||
'align', 'nowrap', 'col', 'row', 'id', 'rowspan', 'colspan', 'cellspacing',
|
||||
'cellpadding', 'valign', 'bgcolor', 'color', 'border', 'bordercolorlight',
|
||||
'bordercolordark', 'face', 'marginwidth', 'marginheight', 'axis', 'border',
|
||||
'abbr', 'char', 'charoff', 'clear', 'compact', 'coords', 'vspace', 'hspace',
|
||||
'cellborder', 'size', 'lang', 'dir', 'usemap', 'shape', 'media',
|
||||
// attributes of form elements
|
||||
'type', 'rows', 'cols', 'disabled', 'readonly', 'checked', 'multiple', 'value'
|
||||
);
|
||||
|
||||
/* Block elements which could be empty but cannot be returned in short form (<tag />) */
|
||||
static $block_elements = array('div', 'p', 'pre', 'blockquote', 'a', 'font', 'center',
|
||||
'table', 'ul', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'ol', 'dl', 'strong', 'i', 'b', 'u', 'span');
|
||||
|
||||
/* State for linked objects in HTML */
|
||||
public $extlinks = false;
|
||||
|
||||
/* Current settings */
|
||||
private $config = array();
|
||||
|
||||
/* Registered callback functions for tags */
|
||||
private $handlers = array();
|
||||
|
||||
/* Allowed HTML elements */
|
||||
private $_html_elements = array();
|
||||
|
||||
/* Ignore these HTML tags but process their content */
|
||||
private $_ignore_elements = array();
|
||||
|
||||
/* Block elements which could be empty but cannot be returned in short form (<tag />) */
|
||||
private $_block_elements = array();
|
||||
|
||||
/* Allowed HTML attributes */
|
||||
private $_html_attribs = array();
|
||||
|
||||
|
||||
/* Constructor */
|
||||
public function __construct($p = array())
|
||||
{
|
||||
$this->_html_elements = array_flip((array)$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);
|
||||
$this->_block_elements = array_flip((array)$p['block_elements']) + array_flip(self::$block_elements);
|
||||
unset($p['html_elements'], $p['html_attribs'], $p['ignore_elements'], $p['block_elements']);
|
||||
$this->config = $p + array('show_washed'=>true, 'allow_remote'=>false, 'cid_map'=>array());
|
||||
}
|
||||
|
||||
/* Register a callback function for a certain tag */
|
||||
public function add_callback($tagName, $callback)
|
||||
{
|
||||
$this->handlers[$tagName] = $callback;
|
||||
}
|
||||
|
||||
/* Check CSS style */
|
||||
private function wash_style($style)
|
||||
{
|
||||
$s = '';
|
||||
|
||||
foreach (explode(';', $style) as $declaration) {
|
||||
if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) {
|
||||
$cssid = $match[1];
|
||||
$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).')';
|
||||
else
|
||||
$this->extlinks = true;
|
||||
}
|
||||
else if (preg_match('/^data:.+/i', $match[2])) { // RFC2397
|
||||
$value .= ' url('.htmlspecialchars($match[2], ENT_QUOTES).')';
|
||||
}
|
||||
}
|
||||
else { //whitelist ?
|
||||
$value .= ' ' . $match[0];
|
||||
|
||||
// #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])) {
|
||||
$value .= 'px';
|
||||
}
|
||||
}
|
||||
|
||||
$str = substr($str, strlen($match[0]));
|
||||
}
|
||||
|
||||
if (isset($value[0])) {
|
||||
$s .= ($s?' ':'') . $cssid . ':' . $value . ';';
|
||||
}
|
||||
}
|
||||
}
|
||||
return $s;
|
||||
}
|
||||
|
||||
/* Take a node and return allowed attributes and check values */
|
||||
private function wash_attribs($node)
|
||||
{
|
||||
$t = '';
|
||||
$washed;
|
||||
|
||||
foreach ($node->attributes as $key => $plop) {
|
||||
$key = strtolower($key);
|
||||
$value = $node->getAttribute($key);
|
||||
if (isset($this->_html_attribs[$key]) ||
|
||||
($key == 'href' && !preg_match('!^(javascript|vbscript|data:text)!i', $value)
|
||||
&& preg_match('!^([a-z][a-z0-9.+-]+:|//|#).+!i', $value))
|
||||
) {
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
|
||||
}
|
||||
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 {
|
||||
$this->extlinks = true;
|
||||
if ($this->config['blocked_src'])
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($this->config['blocked_src'], ENT_QUOTES) . '"';
|
||||
}
|
||||
}
|
||||
else if (preg_match('/^data:.+/i', $value)) { // RFC2397
|
||||
$t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"';
|
||||
}
|
||||
}
|
||||
else
|
||||
$washed .= ($washed?' ':'') . $key;
|
||||
}
|
||||
return $t . ($washed && $this->config['show_washed']?' x-washed="'.$washed.'"':'');
|
||||
}
|
||||
|
||||
/* The main loop that recurse on a node tree.
|
||||
* It output only allowed tags with allowed attributes
|
||||
* and allowed inline styles */
|
||||
private function dumpHtml($node)
|
||||
{
|
||||
if(!$node->hasChildNodes())
|
||||
return '';
|
||||
|
||||
$node = $node->firstChild;
|
||||
$dump = '';
|
||||
|
||||
do {
|
||||
switch($node->nodeType) {
|
||||
case XML_ELEMENT_NODE: //Check element
|
||||
$tagName = strtolower($node->tagName);
|
||||
if ($callback = $this->handlers[$tagName]) {
|
||||
$dump .= call_user_func($callback, $tagName, $this->wash_attribs($node), $this->dumpHtml($node), $this);
|
||||
}
|
||||
else if (isset($this->_html_elements[$tagName])) {
|
||||
$content = $this->dumpHtml($node);
|
||||
$dump .= '<' . $tagName . $this->wash_attribs($node) .
|
||||
($content != '' || isset($this->_block_elements[$tagName]) ? ">$content</$tagName>" : ' />');
|
||||
}
|
||||
else if (isset($this->_ignore_elements[$tagName])) {
|
||||
$dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' not allowed -->';
|
||||
}
|
||||
else {
|
||||
$dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' ignored -->';
|
||||
$dump .= $this->dumpHtml($node); // ignore tags not its content
|
||||
}
|
||||
break;
|
||||
case XML_CDATA_SECTION_NODE:
|
||||
$dump .= $node->nodeValue;
|
||||
break;
|
||||
case XML_TEXT_NODE:
|
||||
$dump .= htmlspecialchars($node->nodeValue);
|
||||
break;
|
||||
case XML_HTML_DOCUMENT_NODE:
|
||||
$dump .= $this->dumpHtml($node);
|
||||
break;
|
||||
case XML_DOCUMENT_TYPE_NODE:
|
||||
break;
|
||||
default:
|
||||
$dump . '<!-- node type ' . $node->nodeType . ' -->';
|
||||
}
|
||||
} while($node = $node->nextSibling);
|
||||
|
||||
return $dump;
|
||||
}
|
||||
|
||||
/* Main function, give it untrusted HTML, tell it if you allow loading
|
||||
* remote images and give it a map to convert "cid:" urls. */
|
||||
public function wash($html)
|
||||
{
|
||||
// Charset seems to be ignored (probably if defined in the HTML document)
|
||||
$node = new DOMDocument('1.0', $this->config['charset']);
|
||||
$this->extlinks = false;
|
||||
|
||||
// Find base URL for images
|
||||
if (preg_match('/<base\s+href=[\'"]*([^\'"]+)/is', $html, $matches))
|
||||
$this->config['base_url'] = $matches[1];
|
||||
else
|
||||
$this->config['base_url'] = '';
|
||||
|
||||
// Remove invalid HTML comments (#1487759)
|
||||
// Don't remove valid conditional comments
|
||||
$html = preg_replace('/<!--[^->[\n]*>/', '', $html);
|
||||
|
||||
@$node->loadHTML($html);
|
||||
return $this->dumpHtml($node);
|
||||
}
|
||||
|
||||
/**
|
||||
* Getter for config parameters
|
||||
*/
|
||||
public function get_config($prop)
|
||||
{
|
||||
return $this->config[$prop];
|
||||
}
|
||||
|
||||
}
|
||||
@ -0,0 +1,28 @@
|
||||
<?php
|
||||
|
||||
/**
|
||||
* Test class to test rcube_washtml class
|
||||
*
|
||||
* @package Tests
|
||||
*/
|
||||
class Framework_Washtml extends PHPUnit_Framework_TestCase
|
||||
{
|
||||
|
||||
/**
|
||||
* Test the elimination of some XSS vulnerabilities
|
||||
*/
|
||||
function test_html_xss3()
|
||||
{
|
||||
// #1488850
|
||||
$html = '<p><a href="data:text/html,<script>alert(document.cookie)</script>">Firefox</a>'
|
||||
.'<a href="vbscript:alert(document.cookie)">Internet Explorer</a></p>';
|
||||
|
||||
$washer = new rcube_washtml;
|
||||
|
||||
$washed = $washer->wash($html);
|
||||
|
||||
$this->assertNotRegExp('/data:text/', $washed, "Remove data:text/html links");
|
||||
$this->assertNotRegExp('/vbscript:/', $washed, "Remove vbscript: links");
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue