From 7ac94421bf85eb04c00c5ed05390e1ea0c6bcb0b Mon Sep 17 00:00:00 2001 From: Aleksander Machniak Date: Tue, 25 Dec 2012 18:06:17 +0100 Subject: Move washtml class into Roundcube Framework (rcube_washtml), add some improvements --- program/lib/washtml.php | 330 ------------------------------------------------ 1 file changed, 330 deletions(-) delete mode 100644 program/lib/washtml.php (limited to 'program/lib/washtml.php') diff --git a/program/lib/washtml.php b/program/lib/washtml.php deleted file mode 100644 index d13d66404..000000000 --- a/program/lib/washtml.php +++ /dev/null @@ -1,330 +0,0 @@ - - * 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: '' - * - ... - * - * 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 () */ - 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 () */ - 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" : ' />'); - } - else if (isset($this->_ignore_elements[$tagName])) { - $dump .= ''; - } - else { - $dump .= ''; - $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: - $dump . ''; - } - } while($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('/config['base_url'] = $matches[1]; - else - $this->config['base_url'] = ''; - - // Remove invalid HTML comments (#1487759) - // Don't remove valid conditional comments - $html = preg_replace('/