| commit | author | age | ||
| 7ac944 | 1 | <?php |
| AM | 2 | |
| 7b9245 | 3 | /* |
| 7ac944 | 4 | +-----------------------------------------------------------------------+ |
| AM | 5 | | This file is part of the Roundcube Webmail client | |
| 6 | | Copyright (C) 2008-2012, The Roundcube Dev Team | | |
| 7 | | | | |
| 8 | | Licensed under the GNU General Public License version 3 or | | |
| 9 | | any later version with exceptions for skins & plugins. | | |
| 10 | | See the README file for a full license statement. | | |
| 11 | | | | |
| 12 | | PURPOSE: | | |
| 13 | | Utility class providing HTML sanityzer (based on Washtml class) | | |
| 14 | +-----------------------------------------------------------------------+ | |
| 15 | | Author: Thomas Bruederli <roundcube@gmail.com> | | |
| 16 | | Author: Aleksander Machniak <alec@alec.pl> | | |
| 17 | | Author: Frederic Motte <fmotte@ubixis.com> | | |
| 18 | +-----------------------------------------------------------------------+ | |
| 19 | */ | |
| 20 | ||
| 7b9245 | 21 | /* |
| 7ac944 | 22 | * Washtml, a HTML sanityzer. |
| AM | 23 | * |
| 24 | * Copyright (c) 2007 Frederic Motte <fmotte@ubixis.com> | |
| 25 | * All rights reserved. | |
| 26 | * | |
| 27 | * Redistribution and use in source and binary forms, with or without | |
| 28 | * modification, are permitted provided that the following conditions | |
| 29 | * are met: | |
| 30 | * 1. Redistributions of source code must retain the above copyright | |
| 31 | * notice, this list of conditions and the following disclaimer. | |
| 32 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 33 | * notice, this list of conditions and the following disclaimer in the | |
| 34 | * documentation and/or other materials provided with the distribution. | |
| 35 | * | |
| 36 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| 37 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
| 38 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| 39 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 40 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 41 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| 42 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| 43 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 44 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 45 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 46 | * | |
| 47 | * OVERVIEW: | |
| 48 | * | |
| 49 | * Wahstml take an untrusted HTML and return a safe html string. | |
| 50 | * | |
| 51 | * SYNOPSIS: | |
| 52 | * | |
| 53 | * $washer = new washtml($config); | |
| 54 | * $washer->wash($html); | |
| 55 | * It return a sanityzed string of the $html parameter without html and head tags. | |
| 56 | * $html is a string containing the html code to wash. | |
| 57 | * $config is an array containing options: | |
| 58 | * $config['allow_remote'] is a boolean to allow link to remote images. | |
| 59 | * $config['blocked_src'] string with image-src to be used for blocked remote images | |
| 60 | * $config['show_washed'] is a boolean to include washed out attributes as x-washed | |
| 61 | * $config['cid_map'] is an array where cid urls index urls to replace them. | |
| 62 | * $config['charset'] is a string containing the charset of the HTML document if it is not defined in it. | |
| 63 | * $washer->extlinks is a reference to a boolean that is set to true if remote images were removed. (FE: show remote images link) | |
| 64 | * | |
| 65 | * INTERNALS: | |
| 66 | * | |
| 67 | * Only tags and attributes in the static lists $html_elements and $html_attributes | |
| 68 | * are kept, inline styles are also filtered: all style identifiers matching | |
| 69 | * /[a-z\-]/i are allowed. Values matching colors, sizes, /[a-z\-]/i and safe | |
| 70 | * urls if allowed and cid urls if mapped are kept. | |
| 71 | * | |
| 72 | * Roundcube Changes: | |
| 73 | * - added $block_elements | |
| 74 | * - changed $ignore_elements behaviour | |
| 75 | * - added RFC2397 support | |
| 76 | * - base URL support | |
| 77 | * - invalid HTML comments removal before parsing | |
| 78 | * - "fixing" unitless CSS values for XHTML output | |
| 79 | * - base url resolving | |
| 80 | */ | |
| 81 | ||
| 82 | /** | |
| 83 | * Utility class providing HTML sanityzer | |
| 84 | * | |
| 85 | * @package Framework | |
| 86 | * @subpackage Utils | |
| 87 | */ | |
| 88 | class rcube_washtml | |
| 89 | { | |
| 90 | /* Allowed HTML elements (default) */ | |
| 91 | static $html_elements = array('a', 'abbr', 'acronym', 'address', 'area', 'b', | |
| 92 | 'basefont', 'bdo', 'big', 'blockquote', 'br', 'caption', 'center', | |
| 93 | 'cite', 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl', | |
| 94 | 'dt', 'em', 'fieldset', 'font', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hr', 'i', | |
| 95 | 'ins', 'label', 'legend', 'li', 'map', 'menu', 'nobr', 'ol', 'p', 'pre', 'q', | |
| 96 | 's', 'samp', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'table', | |
| 97 | 'tbody', 'td', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u', 'ul', 'var', 'wbr', 'img', | |
| c5bfe6 | 98 | 'video', 'source', |
| 7ac944 | 99 | // form elements |
| AM | 100 | 'button', 'input', 'textarea', 'select', 'option', 'optgroup' |
| 101 | ); | |
| 102 | ||
| 103 | /* Ignore these HTML tags and their content */ | |
| 104 | static $ignore_elements = array('script', 'applet', 'embed', 'object', 'style'); | |
| 105 | ||
| 106 | /* Allowed HTML attributes */ | |
| 107 | static $html_attribs = array('name', 'class', 'title', 'alt', 'width', 'height', | |
| 108 | 'align', 'nowrap', 'col', 'row', 'id', 'rowspan', 'colspan', 'cellspacing', | |
| 109 | 'cellpadding', 'valign', 'bgcolor', 'color', 'border', 'bordercolorlight', | |
| 110 | 'bordercolordark', 'face', 'marginwidth', 'marginheight', 'axis', 'border', | |
| 111 | 'abbr', 'char', 'charoff', 'clear', 'compact', 'coords', 'vspace', 'hspace', | |
| 112 | 'cellborder', 'size', 'lang', 'dir', 'usemap', 'shape', 'media', | |
| 113 | // attributes of form elements | |
| 114 | 'type', 'rows', 'cols', 'disabled', 'readonly', 'checked', 'multiple', 'value' | |
| 115 | ); | |
| 116 | ||
| cb3e2f | 117 | /* Elements which could be empty and be returned in short form (<tag />) */ |
| AM | 118 | static $void_elements = array('area', 'base', 'br', 'col', 'command', 'embed', 'hr', |
| 119 | 'img', 'input', 'keygen', 'link', 'meta', 'param', 'source', 'track', 'wbr' | |
| 7ac944 | 120 | ); |
| AM | 121 | |
| 122 | /* State for linked objects in HTML */ | |
| 123 | public $extlinks = false; | |
| 124 | ||
| 125 | /* Current settings */ | |
| 126 | private $config = array(); | |
| 127 | ||
| 128 | /* Registered callback functions for tags */ | |
| 129 | private $handlers = array(); | |
| 130 | ||
| 131 | /* Allowed HTML elements */ | |
| 132 | private $_html_elements = array(); | |
| 133 | ||
| 134 | /* Ignore these HTML tags but process their content */ | |
| 135 | private $_ignore_elements = array(); | |
| 136 | ||
| cb3e2f | 137 | /* Elements which could be empty and be returned in short form (<tag />) */ |
| AM | 138 | private $_void_elements = array(); |
| 7ac944 | 139 | |
| AM | 140 | /* Allowed HTML attributes */ |
| 141 | private $_html_attribs = array(); | |
| 142 | ||
| a89940 | 143 | /* Max nesting level */ |
| AM | 144 | private $max_nesting_level; |
| 145 | ||
| 7ac944 | 146 | |
| AM | 147 | /** |
| 148 | * Class constructor | |
| 149 | */ | |
| 150 | public function __construct($p = array()) | |
| 151 | { | |
| 152 | $this->_html_elements = array_flip((array)$p['html_elements']) + array_flip(self::$html_elements) ; | |
| 153 | $this->_html_attribs = array_flip((array)$p['html_attribs']) + array_flip(self::$html_attribs); | |
| 154 | $this->_ignore_elements = array_flip((array)$p['ignore_elements']) + array_flip(self::$ignore_elements); | |
| cb3e2f | 155 | $this->_void_elements = array_flip((array)$p['void_elements']) + array_flip(self::$void_elements); |
| 7ac944 | 156 | |
| cb3e2f | 157 | unset($p['html_elements'], $p['html_attribs'], $p['ignore_elements'], $p['void_elements']); |
| 7ac944 | 158 | |
| AM | 159 | $this->config = $p + array('show_washed' => true, 'allow_remote' => false, 'cid_map' => array()); |
| 160 | } | |
| 161 | ||
| 162 | /** | |
| 163 | * Register a callback function for a certain tag | |
| 164 | */ | |
| 165 | public function add_callback($tagName, $callback) | |
| 166 | { | |
| 167 | $this->handlers[$tagName] = $callback; | |
| 168 | } | |
| 169 | ||
| 170 | /** | |
| 171 | * Check CSS style | |
| 172 | */ | |
| 173 | private function wash_style($style) | |
| 174 | { | |
| f96fec | 175 | $result = array(); |
| 7ac944 | 176 | |
| ca7fc7 | 177 | // Remove unwanted white-space characters so regular expressions below work better |
| AM | 178 | $style = preg_replace('/[\n\r\s\t]+/', ' ', $style); |
| 179 | ||
| 7ac944 | 180 | foreach (explode(';', $style) as $declaration) { |
| AM | 181 | if (preg_match('/^\s*([a-z\-]+)\s*:\s*(.*)\s*$/i', $declaration, $match)) { |
| 182 | $cssid = $match[1]; | |
| 183 | $str = $match[2]; | |
| 184 | $value = ''; | |
| 185 | ||
| f96fec | 186 | foreach ($this->explode_style($str) as $val) { |
| AM | 187 | if (preg_match('/^url\(/i', $val)) { |
| 188 | if (preg_match('/^url\(\s*[\'"]?([^\'"\)]*)[\'"]?\s*\)/iu', $val, $match)) { | |
| 189 | $url = $match[1]; | |
| 190 | if (($src = $this->config['cid_map'][$url]) | |
| 191 | || ($src = $this->config['cid_map'][$this->config['base_url'].$url]) | |
| 192 | ) { | |
| 193 | $value .= ' url('.htmlspecialchars($src, ENT_QUOTES) . ')'; | |
| 7ac944 | 194 | } |
| f96fec | 195 | else if (preg_match('!^(https?:)?//[a-z0-9/._+-]+$!i', $url, $m)) { |
| AM | 196 | if ($this->config['allow_remote']) { |
| 197 | $value .= ' url('.htmlspecialchars($m[0], ENT_QUOTES).')'; | |
| 198 | } | |
| 199 | else { | |
| 200 | $this->extlinks = true; | |
| 201 | } | |
| 7ac944 | 202 | } |
| f96fec | 203 | else if (preg_match('/^data:.+/i', $url)) { // RFC2397 |
| AM | 204 | $value .= ' url('.htmlspecialchars($url, ENT_QUOTES).')'; |
| 205 | } | |
| 7ac944 | 206 | } |
| AM | 207 | } |
| f96fec | 208 | else if (!preg_match('/^(behavior|expression)/i', $val)) { |
| 7ac944 | 209 | // whitelist ? |
| f96fec | 210 | $value .= ' ' . $val; |
| 7ac944 | 211 | |
| AM | 212 | // #1488535: Fix size units, so width:800 would be changed to width:800px |
| 5bf83d | 213 | if (preg_match('/^(left|right|top|bottom|width|height)/i', $cssid) |
| f96fec | 214 | && preg_match('/^[0-9]+$/', $val) |
| 7ac944 | 215 | ) { |
| AM | 216 | $value .= 'px'; |
| 217 | } | |
| 218 | } | |
| 219 | } | |
| 220 | ||
| 221 | if (isset($value[0])) { | |
| f96fec | 222 | $result[] = $cssid . ':' . $value; |
| 7ac944 | 223 | } |
| AM | 224 | } |
| 225 | } | |
| 226 | ||
| f96fec | 227 | return implode('; ', $result); |
| 7ac944 | 228 | } |
| AM | 229 | |
| 230 | /** | |
| 231 | * Take a node and return allowed attributes and check values | |
| 232 | */ | |
| 233 | private function wash_attribs($node) | |
| 234 | { | |
| 235 | $t = ''; | |
| 236 | $washed = ''; | |
| 237 | ||
| 238 | foreach ($node->attributes as $key => $plop) { | |
| 239 | $key = strtolower($key); | |
| 240 | $value = $node->getAttribute($key); | |
| 241 | ||
| 242 | if (isset($this->_html_attribs[$key]) || | |
| 1f910c | 243 | ($key == 'href' && ($value = trim($value)) |
| AM | 244 | && !preg_match('!^(javascript|vbscript|data:text)!i', $value) |
| 7ac944 | 245 | && preg_match('!^([a-z][a-z0-9.+-]+:|//|#).+!i', $value)) |
| AM | 246 | ) { |
| 247 | $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"'; | |
| 248 | } | |
| 249 | else if ($key == 'style' && ($style = $this->wash_style($value))) { | |
| 786aa0 | 250 | // replace double quotes to prevent syntax error and XSS issues (#1490227) |
| AM | 251 | $t .= ' style="' . str_replace('"', '"', $style) . '"'; |
| 7ac944 | 252 | } |
| c5bfe6 | 253 | else if ($key == 'background' |
| AM | 254 | || ($key == 'src' && preg_match('/^(img|source)$/i', $node->tagName)) |
| 255 | || ($key == 'poster' && strtolower($node->tagName) == 'video') | |
| 256 | ) { | |
| 7ac944 | 257 | if (($src = $this->config['cid_map'][$value]) |
| AM | 258 | || ($src = $this->config['cid_map'][$this->config['base_url'].$value]) |
| 259 | ) { | |
| 260 | $t .= ' ' . $key . '="' . htmlspecialchars($src, ENT_QUOTES) . '"'; | |
| 261 | } | |
| 262 | else if (preg_match('/^(http|https|ftp):.+/i', $value)) { | |
| 263 | if ($this->config['allow_remote']) { | |
| 264 | $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"'; | |
| 265 | } | |
| 266 | else { | |
| 267 | $this->extlinks = true; | |
| 268 | if ($this->config['blocked_src']) { | |
| 269 | $t .= ' ' . $key . '="' . htmlspecialchars($this->config['blocked_src'], ENT_QUOTES) . '"'; | |
| 270 | } | |
| 271 | } | |
| 272 | } | |
| 273 | else if (preg_match('/^data:.+/i', $value)) { // RFC2397 | |
| 274 | $t .= ' ' . $key . '="' . htmlspecialchars($value, ENT_QUOTES) . '"'; | |
| 275 | } | |
| 276 | } | |
| 277 | else { | |
| 278 | $washed .= ($washed ? ' ' : '') . $key; | |
| 279 | } | |
| 280 | } | |
| 281 | ||
| 282 | return $t . ($washed && $this->config['show_washed'] ? ' x-washed="'.$washed.'"' : ''); | |
| 283 | } | |
| 284 | ||
| 285 | /** | |
| 286 | * The main loop that recurse on a node tree. | |
| c77a84 | 287 | * It output only allowed tags with allowed attributes and allowed inline styles |
| AM | 288 | * |
| 289 | * @param DOMNode $node HTML element | |
| 290 | * @param int $level Recurrence level (safe initial value found empirically) | |
| 7ac944 | 291 | */ |
| c77a84 | 292 | private function dumpHtml($node, $level = 20) |
| 7ac944 | 293 | { |
| AM | 294 | if (!$node->hasChildNodes()) { |
| 295 | return ''; | |
| a89940 | 296 | } |
| AM | 297 | |
| 298 | $level++; | |
| 299 | ||
| 300 | if ($this->max_nesting_level > 0 && $level == $this->max_nesting_level - 1) { | |
| 301 | // log error message once | |
| 302 | if (!$this->max_nesting_level_error) { | |
| 303 | $this->max_nesting_level_error = true; | |
| 304 | rcube::raise_error(array('code' => 500, 'type' => 'php', | |
| 305 | 'line' => __LINE__, 'file' => __FILE__, | |
| 306 | 'message' => "Maximum nesting level exceeded (xdebug.max_nesting_level={$this->max_nesting_level})"), | |
| 307 | true, false); | |
| 308 | } | |
| 309 | return '<!-- ignored -->'; | |
| 7ac944 | 310 | } |
| AM | 311 | |
| 312 | $node = $node->firstChild; | |
| 313 | $dump = ''; | |
| 314 | ||
| 315 | do { | |
| c7c09f | 316 | switch ($node->nodeType) { |
| 7ac944 | 317 | case XML_ELEMENT_NODE: //Check element |
| AM | 318 | $tagName = strtolower($node->tagName); |
| 319 | if ($callback = $this->handlers[$tagName]) { | |
| 320 | $dump .= call_user_func($callback, $tagName, | |
| a89940 | 321 | $this->wash_attribs($node), $this->dumpHtml($node, $level), $this); |
| 7ac944 | 322 | } |
| AM | 323 | else if (isset($this->_html_elements[$tagName])) { |
| a89940 | 324 | $content = $this->dumpHtml($node, $level); |
| 7ac944 | 325 | $dump .= '<' . $tagName . $this->wash_attribs($node) . |
| cb3e2f | 326 | ($content === '' && isset($this->_void_elements[$tagName]) ? ' />' : ">$content</$tagName>"); |
| 7ac944 | 327 | } |
| AM | 328 | else if (isset($this->_ignore_elements[$tagName])) { |
| 329 | $dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' not allowed -->'; | |
| 330 | } | |
| 331 | else { | |
| 332 | $dump .= '<!-- ' . htmlspecialchars($tagName, ENT_QUOTES) . ' ignored -->'; | |
| a89940 | 333 | $dump .= $this->dumpHtml($node, $level); // ignore tags not its content |
| 7ac944 | 334 | } |
| AM | 335 | break; |
| 336 | ||
| 337 | case XML_CDATA_SECTION_NODE: | |
| 338 | $dump .= $node->nodeValue; | |
| 339 | break; | |
| 340 | ||
| 341 | case XML_TEXT_NODE: | |
| 342 | $dump .= htmlspecialchars($node->nodeValue); | |
| 343 | break; | |
| 344 | ||
| 345 | case XML_HTML_DOCUMENT_NODE: | |
| a89940 | 346 | $dump .= $this->dumpHtml($node, $level); |
| 7ac944 | 347 | break; |
| AM | 348 | } |
| c7c09f | 349 | } |
| AM | 350 | while($node = $node->nextSibling); |
| 7ac944 | 351 | |
| AM | 352 | return $dump; |
| 353 | } | |
| 354 | ||
| 355 | /** | |
| 356 | * Main function, give it untrusted HTML, tell it if you allow loading | |
| 357 | * remote images and give it a map to convert "cid:" urls. | |
| 358 | */ | |
| 359 | public function wash($html) | |
| 360 | { | |
| 361 | // Charset seems to be ignored (probably if defined in the HTML document) | |
| 362 | $node = new DOMDocument('1.0', $this->config['charset']); | |
| 363 | $this->extlinks = false; | |
| 364 | ||
| 365 | $html = $this->cleanup($html); | |
| 366 | ||
| 367 | // Find base URL for images | |
| 368 | if (preg_match('/<base\s+href=[\'"]*([^\'"]+)/is', $html, $matches)) { | |
| 369 | $this->config['base_url'] = $matches[1]; | |
| 370 | } | |
| 371 | else { | |
| 372 | $this->config['base_url'] = ''; | |
| 373 | } | |
| a89940 | 374 | |
| AM | 375 | // Detect max nesting level (for dumpHTML) (#1489110) |
| 376 | $this->max_nesting_level = (int) @ini_get('xdebug.max_nesting_level'); | |
| 7ac944 | 377 | |
| bfd24f | 378 | // Use optimizations if supported |
| 75bbad | 379 | if (PHP_VERSION_ID >= 50400) { |
| bfd24f | 380 | @$node->loadHTML($html, LIBXML_PARSEHUGE | LIBXML_COMPACT); |
| AM | 381 | } |
| 382 | else { | |
| 383 | @$node->loadHTML($html); | |
| 384 | } | |
| 385 | ||
| 7ac944 | 386 | return $this->dumpHtml($node); |
| AM | 387 | } |
| 388 | ||
| 389 | /** | |
| 390 | * Getter for config parameters | |
| 391 | */ | |
| 392 | public function get_config($prop) | |
| 393 | { | |
| 394 | return $this->config[$prop]; | |
| 395 | } | |
| 396 | ||
| 397 | /** | |
| 398 | * Clean HTML input | |
| 399 | */ | |
| 400 | private function cleanup($html) | |
| 401 | { | |
| 402 | // special replacements (not properly handled by washtml class) | |
| 403 | $html_search = array( | |
| b7048d | 404 | // space(s) between <NOBR> |
| AM | 405 | '/(<\/nobr>)(\s+)(<nobr>)/i', |
| 406 | // PHP bug #32547 workaround: remove title tag | |
| 407 | '/<title[^>]*>[^<]*<\/title>/i', | |
| 408 | // remove <!doctype> before BOM (#1490291) | |
| 409 | '/<\!doctype[^>]+>[^<]*/im', | |
| 410 | // byte-order mark (only outlook?) | |
| 411 | '/^(\0\0\xFE\xFF|\xFF\xFE\0\0|\xFE\xFF|\xFF\xFE|\xEF\xBB\xBF)/', | |
| 412 | // washtml/DOMDocument cannot handle xml namespaces | |
| 413 | '/<html\s[^>]+>/i', | |
| 7ac944 | 414 | ); |
| AM | 415 | |
| 416 | $html_replace = array( | |
| 417 | '\\1'.' '.'\\3', | |
| 418 | '', | |
| 419 | '', | |
| b7048d | 420 | '', |
| 7ac944 | 421 | '<html>', |
| AM | 422 | ); |
| 423 | $html = preg_replace($html_search, $html_replace, trim($html)); | |
| 424 | ||
| b6a640 | 425 | //-> Replace all of those weird MS Word quotes and other high characters |
| c72507 | 426 | $badwordchars = array( |
| b6a640 | 427 | "\xe2\x80\x98", // left single quote |
| R | 428 | "\xe2\x80\x99", // right single quote |
| 429 | "\xe2\x80\x9c", // left double quote | |
| 430 | "\xe2\x80\x9d", // right double quote | |
| 431 | "\xe2\x80\x94", // em dash | |
| 432 | "\xe2\x80\xa6" // elipses | |
| 433 | ); | |
| c72507 | 434 | $fixedwordchars = array( |
| b6a640 | 435 | "'", |
| R | 436 | "'", |
| 437 | '"', | |
| 438 | '"', | |
| 439 | '—', | |
| 440 | '...' | |
| 441 | ); | |
| c72507 | 442 | $html = str_replace($badwordchars, $fixedwordchars, $html); |
| b6a640 | 443 | |
| 7ac944 | 444 | // PCRE errors handling (#1486856), should we use something like for every preg_* use? |
| AM | 445 | if ($html === null && ($preg_error = preg_last_error()) != PREG_NO_ERROR) { |
| 446 | $errstr = "Could not clean up HTML message! PCRE Error: $preg_error."; | |
| 447 | ||
| 448 | if ($preg_error == PREG_BACKTRACK_LIMIT_ERROR) { | |
| 449 | $errstr .= " Consider raising pcre.backtrack_limit!"; | |
| 450 | } | |
| 451 | if ($preg_error == PREG_RECURSION_LIMIT_ERROR) { | |
| 452 | $errstr .= " Consider raising pcre.recursion_limit!"; | |
| 453 | } | |
| 454 | ||
| 455 | rcube::raise_error(array('code' => 620, 'type' => 'php', | |
| 456 | 'line' => __LINE__, 'file' => __FILE__, | |
| 457 | 'message' => $errstr), true, false); | |
| a89940 | 458 | |
| 7ac944 | 459 | return ''; |
| AM | 460 | } |
| 461 | ||
| 462 | // fix (unknown/malformed) HTML tags before "wash" | |
| ffec85 | 463 | $html = preg_replace_callback('/(<(?!\!)[\/]*)([^\s>]+)([^>]*)/', array($this, 'html_tag_callback'), $html); |
| 7ac944 | 464 | |
| AM | 465 | // Remove invalid HTML comments (#1487759) |
| 466 | // Don't remove valid conditional comments | |
| 1bce14 | 467 | // Don't remove MSOutlook (<!-->) conditional comments (#1489004) |
| 82ed25 | 468 | $html = preg_replace('/<!--[^-<>\[\n]+>/', '', $html); |
| c72507 | 469 | |
| AM | 470 | // fix broken nested lists |
| 471 | self::fix_broken_lists($html); | |
| 7ac944 | 472 | |
| AM | 473 | // turn relative into absolute urls |
| 474 | $html = self::resolve_base($html); | |
| 475 | ||
| 476 | return $html; | |
| 477 | } | |
| 478 | ||
| 479 | /** | |
| 480 | * Callback function for HTML tags fixing | |
| 481 | */ | |
| 482 | public static function html_tag_callback($matches) | |
| 483 | { | |
| 484 | $tagname = $matches[2]; | |
| 485 | $tagname = preg_replace(array( | |
| 486 | '/:.*$/', // Microsoft's Smart Tags <st1:xxxx> | |
| 487 | '/[^a-z0-9_\[\]\!-]/i', // forbidden characters | |
| 488 | ), '', $tagname); | |
| 489 | ||
| ffec85 | 490 | // fix invalid closing tags - remove any attributes (#1489446) |
| AM | 491 | if ($matches[1] == '</') { |
| 492 | $matches[3] = ''; | |
| 493 | } | |
| 494 | ||
| 495 | return $matches[1] . $tagname . $matches[3]; | |
| 7ac944 | 496 | } |
| AM | 497 | |
| 498 | /** | |
| 499 | * Convert all relative URLs according to a <base> in HTML | |
| 500 | */ | |
| 501 | public static function resolve_base($body) | |
| 502 | { | |
| 503 | // check for <base href=...> | |
| 504 | if (preg_match('!(<base.*href=["\']?)([hftps]{3,5}://[a-z0-9/.%-]+)!i', $body, $regs)) { | |
| 505 | $replacer = new rcube_base_replacer($regs[2]); | |
| 506 | $body = $replacer->replace($body); | |
| 507 | } | |
| 508 | ||
| 509 | return $body; | |
| 510 | } | |
| 511 | ||
| c72507 | 512 | /** |
| AM | 513 | * Fix broken nested lists, they are not handled properly by DOMDocument (#1488768) |
| 514 | */ | |
| 515 | public static function fix_broken_lists(&$html) | |
| 516 | { | |
| 517 | // do two rounds, one for <ol>, one for <ul> | |
| 518 | foreach (array('ol', 'ul') as $tag) { | |
| 519 | $pos = 0; | |
| 520 | while (($pos = stripos($html, '<' . $tag, $pos)) !== false) { | |
| 521 | $pos++; | |
| 522 | ||
| 523 | // make sure this is an ol/ul tag | |
| 524 | if (!in_array($html[$pos+2], array(' ', '>'))) { | |
| 525 | continue; | |
| 526 | } | |
| 527 | ||
| 528 | $p = $pos; | |
| 529 | $in_li = false; | |
| 530 | $li_pos = 0; | |
| 531 | ||
| 532 | while (($p = strpos($html, '<', $p)) !== false) { | |
| 533 | $tt = strtolower(substr($html, $p, 4)); | |
| 534 | ||
| 535 | // li open tag | |
| 536 | if ($tt == '<li>' || $tt == '<li ') { | |
| 537 | $in_li = true; | |
| 538 | $p += 4; | |
| 539 | } | |
| 540 | // li close tag | |
| 541 | else if ($tt == '</li' && in_array($html[$p+4], array(' ', '>'))) { | |
| 542 | $li_pos = $p; | |
| 543 | $p += 4; | |
| 544 | $in_li = false; | |
| 545 | } | |
| 546 | // ul/ol closing tag | |
| 547 | else if ($tt == '</' . $tag && in_array($html[$p+4], array(' ', '>'))) { | |
| 548 | break; | |
| 549 | } | |
| 550 | // nested ol/ul element out of li | |
| 551 | else if (!$in_li && $li_pos && ($tt == '<ol>' || $tt == '<ol ' || $tt == '<ul>' || $tt == '<ul ')) { | |
| 552 | // find closing tag of this ul/ol element | |
| 553 | $element = substr($tt, 1, 2); | |
| 554 | $cpos = $p; | |
| 555 | do { | |
| 556 | $tpos = stripos($html, '<' . $element, $cpos+1); | |
| 557 | $cpos = stripos($html, '</' . $element, $cpos+1); | |
| 558 | } | |
| 559 | while ($tpos !== false && $cpos !== false && $cpos > $tpos); | |
| 560 | ||
| 561 | // not found, this is invalid HTML, skip it | |
| 562 | if ($cpos === false) { | |
| 563 | break; | |
| 564 | } | |
| 565 | ||
| 566 | // get element content | |
| 567 | $end = strpos($html, '>', $cpos); | |
| 568 | $len = $end - $p + 1; | |
| 569 | $element = substr($html, $p, $len); | |
| 570 | ||
| 571 | // move element to the end of the last li | |
| 572 | $html = substr_replace($html, '', $p, $len); | |
| 573 | $html = substr_replace($html, $element, $li_pos, 0); | |
| 574 | ||
| 575 | $p = $end; | |
| 576 | } | |
| 577 | else { | |
| 578 | $p++; | |
| 579 | } | |
| 580 | } | |
| 581 | } | |
| 582 | } | |
| 583 | } | |
| f96fec | 584 | |
| AM | 585 | /** |
| 586 | * Explode css style value | |
| 587 | */ | |
| 588 | protected function explode_style($style) | |
| 589 | { | |
| 590 | $style = trim($style); | |
| 591 | ||
| 592 | // first remove comments | |
| 593 | $pos = 0; | |
| 594 | while (($pos = strpos($style, '/*', $pos)) !== false) { | |
| 595 | $end = strpos($style, '*/', $pos+2); | |
| 596 | ||
| 597 | if ($end === false) { | |
| 598 | $style = substr($style, 0, $pos); | |
| 599 | } | |
| 600 | else { | |
| 601 | $style = substr_replace($style, '', $pos, $end - $pos + 2); | |
| 602 | } | |
| 603 | } | |
| 604 | ||
| 605 | $strlen = strlen($style); | |
| 606 | $result = array(); | |
| 607 | ||
| 608 | // explode value | |
| 609 | for ($p=$i=0; $i < $strlen; $i++) { | |
| 610 | if (($style[$i] == "\"" || $style[$i] == "'") && $style[$i-1] != "\\") { | |
| 611 | if ($q == $style[$i]) { | |
| 612 | $q = false; | |
| 613 | } | |
| 614 | else if (!$q) { | |
| 615 | $q = $style[$i]; | |
| 616 | } | |
| 617 | } | |
| 618 | ||
| 619 | if (!$q && $style[$i] == ' ' && !preg_match('/[,\(]/', $style[$i-1])) { | |
| 620 | $result[] = substr($style, $p, $i - $p); | |
| 621 | $p = $i + 1; | |
| 622 | } | |
| 623 | } | |
| 624 | ||
| 625 | $result[] = (string) substr($style, $p); | |
| 626 | ||
| 627 | return $result; | |
| 628 | } | |
| c72507 | 629 | } |
