File vendor/simplepie/simplepie/library/SimplePie/Sanitize.php

  1 <?php
  2 /**
  3  * SimplePie
  4  *
  5  * A PHP-Based RSS and Atom Feed Framework.
  6  * Takes the hard work out of managing a complete RSS/Atom solution.
  7  *
  8  * Copyright (c) 2004-2012, Ryan Parman, Geoffrey Sneddon, Ryan McCue, and contributors
  9  * All rights reserved.
 10  *
 11  * Redistribution and use in source and binary forms, with or without modification, are
 12  * permitted provided that the following conditions are met:
 13  *
 14  *  * Redistributions of source code must retain the above copyright notice, this list of
 15  *    conditions and the following disclaimer.
 16  *
 17  *  * Redistributions in binary form must reproduce the above copyright notice, this list
 18  *    of conditions and the following disclaimer in the documentation and/or other materials
 19  *    provided with the distribution.
 20  *
 21  *  * Neither the name of the SimplePie Team nor the names of its contributors may be used
 22  *    to endorse or promote products derived from this software without specific prior
 23  *    written permission.
 24  *
 25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 26  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 27  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
 28  * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 30  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33  * POSSIBILITY OF SUCH DAMAGE.
 34  *
 35  * @package SimplePie
 36  * @version 1.3.1
 37  * @copyright 2004-2012 Ryan Parman, Geoffrey Sneddon, Ryan McCue
 38  * @author Ryan Parman
 39  * @author Geoffrey Sneddon
 40  * @author Ryan McCue
 41  * @link http://simplepie.org/ SimplePie
 42  * @license http://www.opensource.org/licenses/bsd-license.php BSD License
 43  */
 44 
 45 /**
 46  * Used for data cleanup and post-processing
 47  *
 48  *
 49  * This class can be overloaded with {@see SimplePie::set_sanitize_class()}
 50  *
 51  * @package SimplePie
 52  * @todo Move to using an actual HTML parser (this will allow tags to be properly stripped, and to switch between HTML and XHTML), this will also make it easier to shorten a string while preserving HTML tags
 53  */
 54 class SimplePie_Sanitize
 55 {
 56     // Private vars
 57     var $base;
 58 
 59     // Options
 60     var $remove_div = true;
 61     var $image_handler = '';
 62     var $strip_htmltags = array('base', 'blink', 'body', 'doctype', 'embed', 'font', 'form', 'frame', 'frameset', 'html', 'iframe', 'input', 'marquee', 'meta', 'noscript', 'object', 'param', 'script', 'style');
 63     var $encode_instead_of_strip = false;
 64     var $strip_attributes = array('bgsound', 'class', 'expr', 'id', 'style', 'onclick', 'onerror', 'onfinish', 'onmouseover', 'onmouseout', 'onfocus', 'onblur', 'lowsrc', 'dynsrc');
 65     var $strip_comments = false;
 66     var $output_encoding = 'UTF-8';
 67     var $enable_cache = true;
 68     var $cache_location = './cache';
 69     var $cache_name_function = 'md5';
 70     var $timeout = 10;
 71     var $useragent = '';
 72     var $force_fsockopen = false;
 73     var $replace_url_attributes = null;
 74 
 75     public function __construct()
 76     {
 77         // Set defaults
 78         $this->set_url_replacements(null);
 79     }
 80 
 81     public function remove_div($enable = true)
 82     {
 83         $this->remove_div = (bool) $enable;
 84     }
 85 
 86     public function set_image_handler($page = false)
 87     {
 88         if ($page)
 89         {
 90             $this->image_handler = (string) $page;
 91         }
 92         else
 93         {
 94             $this->image_handler = false;
 95         }
 96     }
 97 
 98     public function set_registry(SimplePie_Registry $registry)
 99     {
100         $this->registry = $registry;
101     }
102 
103     public function pass_cache_data($enable_cache = true, $cache_location = './cache', $cache_name_function = 'md5', $cache_class = 'SimplePie_Cache')
104     {
105         if (isset($enable_cache))
106         {
107             $this->enable_cache = (bool) $enable_cache;
108         }
109 
110         if ($cache_location)
111         {
112             $this->cache_location = (string) $cache_location;
113         }
114 
115         if ($cache_name_function)
116         {
117             $this->cache_name_function = (string) $cache_name_function;
118         }
119     }
120 
121     public function pass_file_data($file_class = 'SimplePie_File', $timeout = 10, $useragent = '', $force_fsockopen = false)
122     {
123         if ($timeout)
124         {
125             $this->timeout = (string) $timeout;
126         }
127 
128         if ($useragent)
129         {
130             $this->useragent = (string) $useragent;
131         }
132 
133         if ($force_fsockopen)
134         {
135             $this->force_fsockopen = (string) $force_fsockopen;
136         }
137     }
138 
139     public function strip_htmltags($tags = array('base', 'blink', 'body', 'doctype', 'embed', 'font', 'form', 'frame', 'frameset', 'html', 'iframe', 'input', 'marquee', 'meta', 'noscript', 'object', 'param', 'script', 'style'))
140     {
141         if ($tags)
142         {
143             if (is_array($tags))
144             {
145                 $this->strip_htmltags = $tags;
146             }
147             else
148             {
149                 $this->strip_htmltags = explode(',', $tags);
150             }
151         }
152         else
153         {
154             $this->strip_htmltags = false;
155         }
156     }
157 
158     public function encode_instead_of_strip($encode = false)
159     {
160         $this->encode_instead_of_strip = (bool) $encode;
161     }
162 
163     public function strip_attributes($attribs = array('bgsound', 'class', 'expr', 'id', 'style', 'onclick', 'onerror', 'onfinish', 'onmouseover', 'onmouseout', 'onfocus', 'onblur', 'lowsrc', 'dynsrc'))
164     {
165         if ($attribs)
166         {
167             if (is_array($attribs))
168             {
169                 $this->strip_attributes = $attribs;
170             }
171             else
172             {
173                 $this->strip_attributes = explode(',', $attribs);
174             }
175         }
176         else
177         {
178             $this->strip_attributes = false;
179         }
180     }
181 
182     public function strip_comments($strip = false)
183     {
184         $this->strip_comments = (bool) $strip;
185     }
186 
187     public function set_output_encoding($encoding = 'UTF-8')
188     {
189         $this->output_encoding = (string) $encoding;
190     }
191 
192     /**
193      * Set element/attribute key/value pairs of HTML attributes
194      * containing URLs that need to be resolved relative to the feed
195      *
196      * Defaults to |a|@href, |area|@href, |blockquote|@cite, |del|@cite,
197      * |form|@action, |img|@longdesc, |img|@src, |input|@src, |ins|@cite,
198      * |q|@cite
199      *
200      * @since 1.0
201      * @param array|null $element_attribute Element/attribute key/value pairs, null for default
202      */
203     public function set_url_replacements($element_attribute = null)
204     {
205         if ($element_attribute === null)
206         {
207             $element_attribute = array(
208                 'a' => 'href',
209                 'area' => 'href',
210                 'blockquote' => 'cite',
211                 'del' => 'cite',
212                 'form' => 'action',
213                 'img' => array(
214                     'longdesc',
215                     'src'
216                 ),
217                 'input' => 'src',
218                 'ins' => 'cite',
219                 'q' => 'cite'
220             );
221         }
222         $this->replace_url_attributes = (array) $element_attribute;
223     }
224 
225     public function sanitize($data, $type, $base = '')
226     {
227         $data = trim($data);
228         if ($data !== '' || $type & SIMPLEPIE_CONSTRUCT_IRI)
229         {
230             if ($type & SIMPLEPIE_CONSTRUCT_MAYBE_HTML)
231             {
232                 if (preg_match('/(&(#(x[0-9a-fA-F]+|[0-9]+)|[a-zA-Z0-9]+)|<\/[A-Za-z][^\x09\x0A\x0B\x0C\x0D\x20\x2F\x3E]*' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>)/', $data))
233                 {
234                     $type |= SIMPLEPIE_CONSTRUCT_HTML;
235                 }
236                 else
237                 {
238                     $type |= SIMPLEPIE_CONSTRUCT_TEXT;
239                 }
240             }
241 
242             if ($type & SIMPLEPIE_CONSTRUCT_BASE64)
243             {
244                 $data = base64_decode($data);
245             }
246 
247             if ($type & (SIMPLEPIE_CONSTRUCT_HTML | SIMPLEPIE_CONSTRUCT_XHTML))
248             {
249 
250                 $document = new DOMDocument();
251                 $document->encoding = 'UTF-8';
252                 $data = $this->preprocess($data, $type);
253 
254                 set_error_handler(array('SimplePie_Misc', 'silence_errors'));
255                 $document->loadHTML($data);
256                 restore_error_handler();
257 
258                 // Strip comments
259                 if ($this->strip_comments)
260                 {
261                     $xpath = new DOMXPath($document);
262                     $comments = $xpath->query('//comment()');
263 
264                     foreach ($comments as $comment)
265                     {
266                         $comment->parentNode->removeChild($comment);
267                     }
268                 }
269 
270                 // Strip out HTML tags and attributes that might cause various security problems.
271                 // Based on recommendations by Mark Pilgrim at:
272                 // http://diveintomark.org/archives/2003/06/12/how_to_consume_rss_safely
273                 if ($this->strip_htmltags)
274                 {
275                     foreach ($this->strip_htmltags as $tag)
276                     {
277                         $this->strip_tag($tag, $document, $type);
278                     }
279                 }
280 
281                 if ($this->strip_attributes)
282                 {
283                     foreach ($this->strip_attributes as $attrib)
284                     {
285                         $this->strip_attr($attrib, $document);
286                     }
287                 }
288 
289                 // Replace relative URLs
290                 $this->base = $base;
291                 foreach ($this->replace_url_attributes as $element => $attributes)
292                 {
293                     $this->replace_urls($document, $element, $attributes);
294                 }
295 
296                 // If image handling (caching, etc.) is enabled, cache and rewrite all the image tags.
297                 if (isset($this->image_handler) && ((string) $this->image_handler) !== '' && $this->enable_cache)
298                 {
299                     $images = $document->getElementsByTagName('img');
300                     foreach ($images as $img)
301                     {
302                         if ($img->hasAttribute('src'))
303                         {
304                             $image_url = call_user_func($this->cache_name_function, $img->getAttribute('src'));
305                             $cache = $this->registry->call('Cache', 'get_handler', array($this->cache_location, $image_url, 'spi'));
306 
307                             if ($cache->load())
308                             {
309                                 $img->setAttribute('src', $this->image_handler . $image_url);
310                             }
311                             else
312                             {
313                                 $file = $this->registry->create('File', array($img['attribs']['src']['data'], $this->timeout, 5, array('X-FORWARDED-FOR' => $_SERVER['REMOTE_ADDR']), $this->useragent, $this->force_fsockopen));
314                                 $headers = $file->headers;
315 
316                                 if ($file->success && ($file->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($file->status_code === 200 || $file->status_code > 206 && $file->status_code < 300)))
317                                 {
318                                     if ($cache->save(array('headers' => $file->headers, 'body' => $file->body)))
319                                     {
320                                         $img->setAttribute('src', $this->image_handler . $image_url);
321                                     }
322                                     else
323                                     {
324                                         trigger_error("$this->cache_location is not writeable. Make sure you've set the correct relative or absolute path, and that the location is server-writable.", E_USER_WARNING);
325                                     }
326                                 }
327                             }
328                         }
329                     }
330                 }
331 
332                 // Remove the DOCTYPE
333                 // Seems to cause segfaulting if we don't do this
334                 if ($document->firstChild instanceof DOMDocumentType)
335                 {
336                     $document->removeChild($document->firstChild);
337                 }
338 
339                 // Move everything from the body to the root
340                 $real_body = $document->getElementsByTagName('body')->item(0)->childNodes->item(0);
341                 $document->replaceChild($real_body, $document->firstChild);
342 
343                 // Finally, convert to a HTML string
344                 $data = trim($document->saveHTML());
345 
346                 if ($this->remove_div)
347                 {
348                     $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '', $data);
349                     $data = preg_replace('/<\/div>$/', '', $data);
350                 }
351                 else
352                 {
353                     $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '<div>', $data);
354                 }
355             }
356 
357             if ($type & SIMPLEPIE_CONSTRUCT_IRI)
358             {
359                 $absolute = $this->registry->call('Misc', 'absolutize_url', array($data, $base));
360                 if ($absolute !== false)
361                 {
362                     $data = $absolute;
363                 }
364             }
365 
366             if ($type & (SIMPLEPIE_CONSTRUCT_TEXT | SIMPLEPIE_CONSTRUCT_IRI))
367             {
368                 $data = htmlspecialchars($data, ENT_COMPAT, 'UTF-8');
369             }
370 
371             if ($this->output_encoding !== 'UTF-8')
372             {
373                 $data = $this->registry->call('Misc', 'change_encoding', array($data, 'UTF-8', $this->output_encoding));
374             }
375         }
376         return $data;
377     }
378 
379     protected function preprocess($html, $type)
380     {
381         $ret = '';
382         if ($type & ~SIMPLEPIE_CONSTRUCT_XHTML)
383         {
384             // Atom XHTML constructs are wrapped with a div by default
385             // Note: No protection if $html contains a stray </div>!
386             $html = '<div>' . $html . '</div>';
387             $ret .= '<!DOCTYPE html>';
388             $content_type = 'text/html';
389         }
390         else
391         {
392             $ret .= '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">';
393             $content_type = 'application/xhtml+xml';
394         }
395 
396         $ret .= '<html><head>';
397         $ret .= '<meta http-equiv="Content-Type" content="' . $content_type . '; charset=utf-8" />';
398         $ret .= '</head><body>' . $html . '</body></html>';
399         return $ret;
400     }
401 
402     public function replace_urls($document, $tag, $attributes)
403     {
404         if (!is_array($attributes))
405         {
406             $attributes = array($attributes);
407         }
408 
409         if (!is_array($this->strip_htmltags) || !in_array($tag, $this->strip_htmltags))
410         {
411             $elements = $document->getElementsByTagName($tag);
412             foreach ($elements as $element)
413             {
414                 foreach ($attributes as $attribute)
415                 {
416                     if ($element->hasAttribute($attribute))
417                     {
418                         $value = $this->registry->call('Misc', 'absolutize_url', array($element->getAttribute($attribute), $this->base));
419                         if ($value !== false)
420                         {
421                             $element->setAttribute($attribute, $value);
422                         }
423                     }
424                 }
425             }
426         }
427     }
428 
429     public function do_strip_htmltags($match)
430     {
431         if ($this->encode_instead_of_strip)
432         {
433             if (isset($match[4]) && !in_array(strtolower($match[1]), array('script', 'style')))
434             {
435                 $match[1] = htmlspecialchars($match[1], ENT_COMPAT, 'UTF-8');
436                 $match[2] = htmlspecialchars($match[2], ENT_COMPAT, 'UTF-8');
437                 return "&lt;$match[1]$match[2]&gt;$match[3]&lt;/$match[1]&gt;";
438             }
439             else
440             {
441                 return htmlspecialchars($match[0], ENT_COMPAT, 'UTF-8');
442             }
443         }
444         elseif (isset($match[4]) && !in_array(strtolower($match[1]), array('script', 'style')))
445         {
446             return $match[4];
447         }
448         else
449         {
450             return '';
451         }
452     }
453 
454     protected function strip_tag($tag, $document, $type)
455     {
456         $xpath = new DOMXPath($document);
457         $elements = $xpath->query('body//' . $tag);
458         if ($this->encode_instead_of_strip)
459         {
460             foreach ($elements as $element)
461             {
462                 $fragment = $document->createDocumentFragment();
463 
464                 // For elements which aren't script or style, include the tag itself
465                 if (!in_array($tag, array('script', 'style')))
466                 {
467                     $text = '<' . $tag;
468                     if ($element->hasAttributes())
469                     {
470                         $attrs = array();
471                         foreach ($element->attributes as $name => $attr)
472                         {
473                             $value = $attr->value;
474 
475                             // In XHTML, empty values should never exist, so we repeat the value
476                             if (empty($value) && ($type & SIMPLEPIE_CONSTRUCT_XHTML))
477                             {
478                                 $value = $name;
479                             }
480                             // For HTML, empty is fine
481                             elseif (empty($value) && ($type & SIMPLEPIE_CONSTRUCT_HTML))
482                             {
483                                 $attrs[] = $name;
484                                 continue;
485                             }
486 
487                             // Standard attribute text
488                             $attrs[] = $name . '="' . $attr->value . '"';
489                         }
490                         $text .= ' ' . implode(' ', $attrs);
491                     }
492                     $text .= '>';
493                     $fragment->appendChild(new DOMText($text));
494                 }
495 
496                 $number = $element->childNodes->length;
497                 for ($i = $number; $i > 0; $i--)
498                 {
499                     $child = $element->childNodes->item(0);
500                     $fragment->appendChild($child);
501                 }
502 
503                 if (!in_array($tag, array('script', 'style')))
504                 {
505                     $fragment->appendChild(new DOMText('</' . $tag . '>'));
506                 }
507 
508                 $element->parentNode->replaceChild($fragment, $element);
509             }
510 
511             return;
512         }
513         elseif (in_array($tag, array('script', 'style')))
514         {
515             foreach ($elements as $element)
516             {
517                 $element->parentNode->removeChild($element);
518             }
519 
520             return;
521         }
522         else
523         {
524             foreach ($elements as $element)
525             {
526                 $fragment = $document->createDocumentFragment();
527                 $number = $element->childNodes->length;
528                 for ($i = $number; $i > 0; $i--)
529                 {
530                     $child = $element->childNodes->item(0);
531                     $fragment->appendChild($child);
532                 }
533 
534                 $element->parentNode->replaceChild($fragment, $element);
535             }
536         }
537     }
538 
539     protected function strip_attr($attrib, $document)
540     {
541         $xpath = new DOMXPath($document);
542         $elements = $xpath->query('//*[@' . $attrib . ']');
543 
544         foreach ($elements as $element)
545         {
546             $element->removeAttribute($attrib);
547         }
548     }
549 }
550
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