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Merge "Hard deprecate Password::equals()"
[lhc/web/wiklou.git] / includes / parser / Sanitizer.php
1 <?php
2 /**
3 * HTML sanitizer for %MediaWiki.
4 *
5 * Copyright © 2002-2005 Brion Vibber <brion@pobox.com> et al
6 * https://www.mediawiki.org/
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
22 *
23 * @file
24 * @ingroup Parser
25 */
26
27 use MediaWiki\MediaWikiServices;
28
29 /**
30 * HTML sanitizer for MediaWiki
31 * @ingroup Parser
32 */
33 class Sanitizer {
34 /**
35 * Regular expression to match various types of character references in
36 * Sanitizer::normalizeCharReferences and Sanitizer::decodeCharReferences
37 */
38 const CHAR_REFS_REGEX =
39 '/&([A-Za-z0-9\x80-\xff]+);
40 |&\#([0-9]+);
41 |&\#[xX]([0-9A-Fa-f]+);
42 |(&)/x';
43
44 /**
45 * Acceptable tag name charset from HTML5 parsing spec
46 * https://www.w3.org/TR/html5/syntax.html#tag-open-state
47 */
48 const ELEMENT_BITS_REGEX = '!^(/?)([A-Za-z][^\t\n\v />\0]*+)([^>]*?)(/?>)([^<]*)$!';
49
50 /**
51 * Blacklist for evil uris like javascript:
52 * WARNING: DO NOT use this in any place that actually requires blacklisting
53 * for security reasons. There are NUMEROUS[1] ways to bypass blacklisting, the
54 * only way to be secure from javascript: uri based xss vectors is to whitelist
55 * things that you know are safe and deny everything else.
56 * [1]: http://ha.ckers.org/xss.html
57 */
58 const EVIL_URI_PATTERN = '!(^|\s|\*/\s*)(javascript|vbscript)([^\w]|$)!i';
59 const XMLNS_ATTRIBUTE_PATTERN = "/^xmlns:[:A-Z_a-z-.0-9]+$/";
60
61 /**
62 * Tells escapeUrlForHtml() to encode the ID using the wiki's primary encoding.
63 *
64 * @since 1.30
65 */
66 const ID_PRIMARY = 0;
67
68 /**
69 * Tells escapeUrlForHtml() to encode the ID using the fallback encoding, or return false
70 * if no fallback is configured.
71 *
72 * @since 1.30
73 */
74 const ID_FALLBACK = 1;
75
76 /**
77 * List of all named character entities defined in HTML 4.01
78 * https://www.w3.org/TR/html4/sgml/entities.html
79 * As well as &apos; which is only defined starting in XHTML1.
80 */
81 private static $htmlEntities = [
82 'Aacute' => 193,
83 'aacute' => 225,
84 'Acirc' => 194,
85 'acirc' => 226,
86 'acute' => 180,
87 'AElig' => 198,
88 'aelig' => 230,
89 'Agrave' => 192,
90 'agrave' => 224,
91 'alefsym' => 8501,
92 'Alpha' => 913,
93 'alpha' => 945,
94 'amp' => 38,
95 'and' => 8743,
96 'ang' => 8736,
97 'apos' => 39, // New in XHTML & HTML 5; avoid in output for compatibility with IE.
98 'Aring' => 197,
99 'aring' => 229,
100 'asymp' => 8776,
101 'Atilde' => 195,
102 'atilde' => 227,
103 'Auml' => 196,
104 'auml' => 228,
105 'bdquo' => 8222,
106 'Beta' => 914,
107 'beta' => 946,
108 'brvbar' => 166,
109 'bull' => 8226,
110 'cap' => 8745,
111 'Ccedil' => 199,
112 'ccedil' => 231,
113 'cedil' => 184,
114 'cent' => 162,
115 'Chi' => 935,
116 'chi' => 967,
117 'circ' => 710,
118 'clubs' => 9827,
119 'cong' => 8773,
120 'copy' => 169,
121 'crarr' => 8629,
122 'cup' => 8746,
123 'curren' => 164,
124 'dagger' => 8224,
125 'Dagger' => 8225,
126 'darr' => 8595,
127 'dArr' => 8659,
128 'deg' => 176,
129 'Delta' => 916,
130 'delta' => 948,
131 'diams' => 9830,
132 'divide' => 247,
133 'Eacute' => 201,
134 'eacute' => 233,
135 'Ecirc' => 202,
136 'ecirc' => 234,
137 'Egrave' => 200,
138 'egrave' => 232,
139 'empty' => 8709,
140 'emsp' => 8195,
141 'ensp' => 8194,
142 'Epsilon' => 917,
143 'epsilon' => 949,
144 'equiv' => 8801,
145 'Eta' => 919,
146 'eta' => 951,
147 'ETH' => 208,
148 'eth' => 240,
149 'Euml' => 203,
150 'euml' => 235,
151 'euro' => 8364,
152 'exist' => 8707,
153 'fnof' => 402,
154 'forall' => 8704,
155 'frac12' => 189,
156 'frac14' => 188,
157 'frac34' => 190,
158 'frasl' => 8260,
159 'Gamma' => 915,
160 'gamma' => 947,
161 'ge' => 8805,
162 'gt' => 62,
163 'harr' => 8596,
164 'hArr' => 8660,
165 'hearts' => 9829,
166 'hellip' => 8230,
167 'Iacute' => 205,
168 'iacute' => 237,
169 'Icirc' => 206,
170 'icirc' => 238,
171 'iexcl' => 161,
172 'Igrave' => 204,
173 'igrave' => 236,
174 'image' => 8465,
175 'infin' => 8734,
176 'int' => 8747,
177 'Iota' => 921,
178 'iota' => 953,
179 'iquest' => 191,
180 'isin' => 8712,
181 'Iuml' => 207,
182 'iuml' => 239,
183 'Kappa' => 922,
184 'kappa' => 954,
185 'Lambda' => 923,
186 'lambda' => 955,
187 'lang' => 9001,
188 'laquo' => 171,
189 'larr' => 8592,
190 'lArr' => 8656,
191 'lceil' => 8968,
192 'ldquo' => 8220,
193 'le' => 8804,
194 'lfloor' => 8970,
195 'lowast' => 8727,
196 'loz' => 9674,
197 'lrm' => 8206,
198 'lsaquo' => 8249,
199 'lsquo' => 8216,
200 'lt' => 60,
201 'macr' => 175,
202 'mdash' => 8212,
203 'micro' => 181,
204 'middot' => 183,
205 'minus' => 8722,
206 'Mu' => 924,
207 'mu' => 956,
208 'nabla' => 8711,
209 'nbsp' => 160,
210 'ndash' => 8211,
211 'ne' => 8800,
212 'ni' => 8715,
213 'not' => 172,
214 'notin' => 8713,
215 'nsub' => 8836,
216 'Ntilde' => 209,
217 'ntilde' => 241,
218 'Nu' => 925,
219 'nu' => 957,
220 'Oacute' => 211,
221 'oacute' => 243,
222 'Ocirc' => 212,
223 'ocirc' => 244,
224 'OElig' => 338,
225 'oelig' => 339,
226 'Ograve' => 210,
227 'ograve' => 242,
228 'oline' => 8254,
229 'Omega' => 937,
230 'omega' => 969,
231 'Omicron' => 927,
232 'omicron' => 959,
233 'oplus' => 8853,
234 'or' => 8744,
235 'ordf' => 170,
236 'ordm' => 186,
237 'Oslash' => 216,
238 'oslash' => 248,
239 'Otilde' => 213,
240 'otilde' => 245,
241 'otimes' => 8855,
242 'Ouml' => 214,
243 'ouml' => 246,
244 'para' => 182,
245 'part' => 8706,
246 'permil' => 8240,
247 'perp' => 8869,
248 'Phi' => 934,
249 'phi' => 966,
250 'Pi' => 928,
251 'pi' => 960,
252 'piv' => 982,
253 'plusmn' => 177,
254 'pound' => 163,
255 'prime' => 8242,
256 'Prime' => 8243,
257 'prod' => 8719,
258 'prop' => 8733,
259 'Psi' => 936,
260 'psi' => 968,
261 'quot' => 34,
262 'radic' => 8730,
263 'rang' => 9002,
264 'raquo' => 187,
265 'rarr' => 8594,
266 'rArr' => 8658,
267 'rceil' => 8969,
268 'rdquo' => 8221,
269 'real' => 8476,
270 'reg' => 174,
271 'rfloor' => 8971,
272 'Rho' => 929,
273 'rho' => 961,
274 'rlm' => 8207,
275 'rsaquo' => 8250,
276 'rsquo' => 8217,
277 'sbquo' => 8218,
278 'Scaron' => 352,
279 'scaron' => 353,
280 'sdot' => 8901,
281 'sect' => 167,
282 'shy' => 173,
283 'Sigma' => 931,
284 'sigma' => 963,
285 'sigmaf' => 962,
286 'sim' => 8764,
287 'spades' => 9824,
288 'sub' => 8834,
289 'sube' => 8838,
290 'sum' => 8721,
291 'sup' => 8835,
292 'sup1' => 185,
293 'sup2' => 178,
294 'sup3' => 179,
295 'supe' => 8839,
296 'szlig' => 223,
297 'Tau' => 932,
298 'tau' => 964,
299 'there4' => 8756,
300 'Theta' => 920,
301 'theta' => 952,
302 'thetasym' => 977,
303 'thinsp' => 8201,
304 'THORN' => 222,
305 'thorn' => 254,
306 'tilde' => 732,
307 'times' => 215,
308 'trade' => 8482,
309 'Uacute' => 218,
310 'uacute' => 250,
311 'uarr' => 8593,
312 'uArr' => 8657,
313 'Ucirc' => 219,
314 'ucirc' => 251,
315 'Ugrave' => 217,
316 'ugrave' => 249,
317 'uml' => 168,
318 'upsih' => 978,
319 'Upsilon' => 933,
320 'upsilon' => 965,
321 'Uuml' => 220,
322 'uuml' => 252,
323 'weierp' => 8472,
324 'Xi' => 926,
325 'xi' => 958,
326 'Yacute' => 221,
327 'yacute' => 253,
328 'yen' => 165,
329 'Yuml' => 376,
330 'yuml' => 255,
331 'Zeta' => 918,
332 'zeta' => 950,
333 'zwj' => 8205,
334 'zwnj' => 8204
335 ];
336
337 /**
338 * Character entity aliases accepted by MediaWiki
339 */
340 private static $htmlEntityAliases = [
341 'רלמ' => 'rlm',
342 'رلم' => 'rlm',
343 ];
344
345 /**
346 * Lazy-initialised attributes regex, see getAttribsRegex()
347 */
348 private static $attribsRegex;
349
350 /**
351 * Regular expression to match HTML/XML attribute pairs within a tag.
352 * Based on https://www.w3.org/TR/html5/syntax.html#before-attribute-name-state
353 * Used in Sanitizer::decodeTagAttributes
354 * @return string
355 */
356 static function getAttribsRegex() {
357 if ( self::$attribsRegex === null ) {
358 $spaceChars = '\x09\x0a\x0c\x0d\x20';
359 $space = "[{$spaceChars}]";
360 $attrib = "[^{$spaceChars}\/>=]";
361 $attribFirst = "(?:{$attrib}|=)";
362 self::$attribsRegex =
363 "/({$attribFirst}{$attrib}*)
364 ($space*=$space*
365 (?:
366 # The attribute value: quoted or alone
367 \"([^\"]*)(?:\"|\$)
368 | '([^']*)(?:'|\$)
369 | (((?!$space|>).)*)
370 )
371 )?/sxu";
372 }
373 return self::$attribsRegex;
374 }
375
376 /**
377 * Lazy-initialised attribute name regex, see getAttribNameRegex()
378 */
379 private static $attribNameRegex;
380
381 /**
382 * Used in Sanitizer::decodeTagAttributes to filter attributes.
383 * @return string
384 */
385 static function getAttribNameRegex() {
386 if ( self::$attribNameRegex === null ) {
387 $attribFirst = "[:_\p{L}\p{N}]";
388 $attrib = "[:_\.\-\p{L}\p{N}]";
389 self::$attribNameRegex = "/^({$attribFirst}{$attrib}*)$/sxu";
390 }
391 return self::$attribNameRegex;
392 }
393
394 /**
395 * Return the various lists of recognized tags
396 * @param array $extratags For any extra tags to include
397 * @param array $removetags For any tags (default or extra) to exclude
398 * @return array
399 */
400 public static function getRecognizedTagData( $extratags = [], $removetags = [] ) {
401 global $wgAllowImageTag;
402
403 static $htmlpairsStatic, $htmlsingle, $htmlsingleonly, $htmlnest, $tabletags,
404 $htmllist, $listtags, $htmlsingleallowed, $htmlelementsStatic, $staticInitialised;
405
406 // Base our staticInitialised variable off of the global config state so that if the globals
407 // are changed (like in the screwed up test system) we will re-initialise the settings.
408 $globalContext = $wgAllowImageTag;
409 if ( !$staticInitialised || $staticInitialised != $globalContext ) {
410 $htmlpairsStatic = [ # Tags that must be closed
411 'b', 'bdi', 'del', 'i', 'ins', 'u', 'font', 'big', 'small', 'sub', 'sup', 'h1',
412 'h2', 'h3', 'h4', 'h5', 'h6', 'cite', 'code', 'em', 's',
413 'strike', 'strong', 'tt', 'var', 'div', 'center',
414 'blockquote', 'ol', 'ul', 'dl', 'table', 'caption', 'pre',
415 'ruby', 'rb', 'rp', 'rt', 'rtc', 'p', 'span', 'abbr', 'dfn',
416 'kbd', 'samp', 'data', 'time', 'mark'
417 ];
418 $htmlsingle = [
419 'br', 'wbr', 'hr', 'li', 'dt', 'dd', 'meta', 'link'
420 ];
421
422 # Elements that cannot have close tags. This is (not coincidentally)
423 # also the list of tags for which the HTML 5 parsing algorithm
424 # requires you to "acknowledge the token's self-closing flag", i.e.
425 # a self-closing tag like <br/> is not an HTML 5 parse error only
426 # for this list.
427 $htmlsingleonly = [
428 'br', 'wbr', 'hr', 'meta', 'link'
429 ];
430
431 $htmlnest = [ # Tags that can be nested--??
432 'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
433 'li', 'dl', 'dt', 'dd', 'font', 'big', 'small', 'sub', 'sup', 'span',
434 'var', 'kbd', 'samp', 'em', 'strong', 'q', 'ruby', 'bdo'
435 ];
436 $tabletags = [ # Can only appear inside table, we will close them
437 'td', 'th', 'tr',
438 ];
439 $htmllist = [ # Tags used by list
440 'ul', 'ol',
441 ];
442 $listtags = [ # Tags that can appear in a list
443 'li',
444 ];
445
446 if ( $wgAllowImageTag ) {
447 $htmlsingle[] = 'img';
448 $htmlsingleonly[] = 'img';
449 }
450
451 $htmlsingleallowed = array_unique( array_merge( $htmlsingle, $tabletags ) );
452 $htmlelementsStatic = array_unique( array_merge( $htmlsingle, $htmlpairsStatic, $htmlnest ) );
453
454 # Convert them all to hashtables for faster lookup
455 $vars = [ 'htmlpairsStatic', 'htmlsingle', 'htmlsingleonly', 'htmlnest', 'tabletags',
456 'htmllist', 'listtags', 'htmlsingleallowed', 'htmlelementsStatic' ];
457 foreach ( $vars as $var ) {
458 $$var = array_flip( $$var );
459 }
460 $staticInitialised = $globalContext;
461 }
462
463 # Populate $htmlpairs and $htmlelements with the $extratags and $removetags arrays
464 $extratags = array_flip( $extratags );
465 $removetags = array_flip( $removetags );
466 $htmlpairs = array_merge( $extratags, $htmlpairsStatic );
467 $htmlelements = array_diff_key( array_merge( $extratags, $htmlelementsStatic ), $removetags );
468
469 return [
470 'htmlpairs' => $htmlpairs,
471 'htmlsingle' => $htmlsingle,
472 'htmlsingleonly' => $htmlsingleonly,
473 'htmlnest' => $htmlnest,
474 'tabletags' => $tabletags,
475 'htmllist' => $htmllist,
476 'listtags' => $listtags,
477 'htmlsingleallowed' => $htmlsingleallowed,
478 'htmlelements' => $htmlelements,
479 ];
480 }
481
482 /**
483 * Cleans up HTML, removes dangerous tags and attributes, and
484 * removes HTML comments
485 * @param string $text
486 * @param callable|null $processCallback Callback to do any variable or parameter
487 * replacements in HTML attribute values
488 * @param array|bool $args Arguments for the processing callback
489 * @param array $extratags For any extra tags to include
490 * @param array $removetags For any tags (default or extra) to exclude
491 * @param callable|null $warnCallback (Deprecated) Callback allowing the
492 * addition of a tracking category when bad input is encountered.
493 * DO NOT ADD NEW PARAMETERS AFTER $warnCallback, since it will be
494 * removed shortly.
495 * @return string
496 */
497 public static function removeHTMLtags( $text, $processCallback = null,
498 $args = [], $extratags = [], $removetags = [], $warnCallback = null
499 ) {
500 $tagData = self::getRecognizedTagData( $extratags, $removetags );
501 $htmlpairs = $tagData['htmlpairs'];
502 $htmlsingle = $tagData['htmlsingle'];
503 $htmlsingleonly = $tagData['htmlsingleonly'];
504 $htmlnest = $tagData['htmlnest'];
505 $tabletags = $tagData['tabletags'];
506 $htmllist = $tagData['htmllist'];
507 $listtags = $tagData['listtags'];
508 $htmlsingleallowed = $tagData['htmlsingleallowed'];
509 $htmlelements = $tagData['htmlelements'];
510
511 # Remove HTML comments
512 $text = self::removeHTMLcomments( $text );
513 $bits = explode( '<', $text );
514 $text = str_replace( '>', '&gt;', array_shift( $bits ) );
515 if ( !MWTidy::isEnabled() ) {
516 wfDeprecated( 'disabling tidy', '1.33' );
517 $tagstack = $tablestack = [];
518 foreach ( $bits as $x ) {
519 $regs = [];
520 # $slash: Does the current element start with a '/'?
521 # $t: Current element name
522 # $params: String between element name and >
523 # $brace: Ending '>' or '/>'
524 # $rest: Everything until the next element of $bits
525 if ( preg_match( self::ELEMENT_BITS_REGEX, $x, $regs ) ) {
526 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
527 } else {
528 $slash = $t = $params = $brace = $rest = null;
529 }
530
531 $badtag = false;
532 $t = strtolower( $t );
533 if ( isset( $htmlelements[$t] ) ) {
534 # Check our stack
535 if ( $slash && isset( $htmlsingleonly[$t] ) ) {
536 $badtag = true;
537 } elseif ( $slash ) {
538 # Closing a tag... is it the one we just opened?
539 Wikimedia\suppressWarnings();
540 $ot = array_pop( $tagstack );
541 Wikimedia\restoreWarnings();
542
543 if ( $ot != $t ) {
544 if ( isset( $htmlsingleallowed[$ot] ) ) {
545 # Pop all elements with an optional close tag
546 # and see if we find a match below them
547 $optstack = [];
548 array_push( $optstack, $ot );
549 Wikimedia\suppressWarnings();
550 $ot = array_pop( $tagstack );
551 Wikimedia\restoreWarnings();
552 while ( $ot != $t && isset( $htmlsingleallowed[$ot] ) ) {
553 array_push( $optstack, $ot );
554 Wikimedia\suppressWarnings();
555 $ot = array_pop( $tagstack );
556 Wikimedia\restoreWarnings();
557 }
558 if ( $t != $ot ) {
559 # No match. Push the optional elements back again
560 $badtag = true;
561 Wikimedia\suppressWarnings();
562 $ot = array_pop( $optstack );
563 Wikimedia\restoreWarnings();
564 while ( $ot ) {
565 array_push( $tagstack, $ot );
566 Wikimedia\suppressWarnings();
567 $ot = array_pop( $optstack );
568 Wikimedia\restoreWarnings();
569 }
570 }
571 } else {
572 Wikimedia\suppressWarnings();
573 array_push( $tagstack, $ot );
574 Wikimedia\restoreWarnings();
575
576 # <li> can be nested in <ul> or <ol>, skip those cases:
577 if ( !isset( $htmllist[$ot] ) || !isset( $listtags[$t] ) ) {
578 $badtag = true;
579 }
580 }
581 } elseif ( $t == 'table' ) {
582 $tagstack = array_pop( $tablestack );
583 }
584 $newparams = '';
585 } else {
586 # Keep track for later
587 if ( isset( $tabletags[$t] ) && !in_array( 'table', $tagstack ) ) {
588 $badtag = true;
589 } elseif ( in_array( $t, $tagstack ) && !isset( $htmlnest[$t] ) ) {
590 $badtag = true;
591 #  Is it a self closed htmlpair ? (T7487)
592 } elseif ( $brace == '/>' && isset( $htmlpairs[$t] ) ) {
593 // Eventually we'll just remove the self-closing
594 // slash, in order to be consistent with HTML5
595 // semantics.
596 // $brace = '>';
597 // For now, let's just warn authors to clean up.
598 if ( is_callable( $warnCallback ) ) {
599 call_user_func_array( $warnCallback, [ 'deprecated-self-close-category' ] );
600 }
601 $badtag = true;
602 } elseif ( isset( $htmlsingleonly[$t] ) ) {
603 # Hack to force empty tag for unclosable elements
604 $brace = '/>';
605 } elseif ( isset( $htmlsingle[$t] ) ) {
606 # Hack to not close $htmlsingle tags
607 $brace = null;
608 # Still need to push this optionally-closed tag to
609 # the tag stack so that we can match end tags
610 # instead of marking them as bad.
611 array_push( $tagstack, $t );
612 } elseif ( isset( $tabletags[$t] ) && in_array( $t, $tagstack ) ) {
613 // New table tag but forgot to close the previous one
614 $text .= "</$t>";
615 } else {
616 if ( $t == 'table' ) {
617 array_push( $tablestack, $tagstack );
618 $tagstack = [];
619 }
620 array_push( $tagstack, $t );
621 }
622
623 # Replace any variables or template parameters with
624 # plaintext results.
625 if ( is_callable( $processCallback ) ) {
626 call_user_func_array( $processCallback, [ &$params, $args ] );
627 }
628
629 if ( !self::validateTag( $params, $t ) ) {
630 $badtag = true;
631 }
632
633 # Strip non-approved attributes from the tag
634 $newparams = self::fixTagAttributes( $params, $t );
635 }
636 if ( !$badtag ) {
637 $rest = str_replace( '>', '&gt;', $rest );
638 $close = ( $brace == '/>' && !$slash ) ? ' /' : '';
639 $text .= "<$slash$t$newparams$close>$rest";
640 continue;
641 }
642 }
643 $text .= '&lt;' . str_replace( '>', '&gt;', $x );
644 }
645 # Close off any remaining tags
646 while ( is_array( $tagstack ) && ( $t = array_pop( $tagstack ) ) ) {
647 $text .= "</$t>\n";
648 if ( $t == 'table' ) {
649 $tagstack = array_pop( $tablestack );
650 }
651 }
652 } else {
653 # this might be possible using tidy itself
654 foreach ( $bits as $x ) {
655 if ( preg_match( self::ELEMENT_BITS_REGEX, $x, $regs ) ) {
656 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
657
658 $badtag = false;
659 $t = strtolower( $t );
660 if ( isset( $htmlelements[$t] ) ) {
661 if ( is_callable( $processCallback ) ) {
662 call_user_func_array( $processCallback, [ &$params, $args ] );
663 }
664
665 if ( $brace == '/>' && !( isset( $htmlsingle[$t] ) || isset( $htmlsingleonly[$t] ) ) ) {
666 // Eventually we'll just remove the self-closing
667 // slash, in order to be consistent with HTML5
668 // semantics.
669 // $brace = '>';
670 // For now, let's just warn authors to clean up.
671 if ( is_callable( $warnCallback ) ) {
672 call_user_func_array( $warnCallback, [ 'deprecated-self-close-category' ] );
673 }
674 }
675 if ( !self::validateTag( $params, $t ) ) {
676 $badtag = true;
677 }
678
679 $newparams = self::fixTagAttributes( $params, $t );
680 if ( !$badtag ) {
681 if ( $brace === '/>' && !isset( $htmlsingleonly[$t] ) ) {
682 # Interpret self-closing tags as empty tags even when
683 # HTML 5 would interpret them as start tags. Such input
684 # is commonly seen on Wikimedia wikis with this intention.
685 $brace = "></$t>";
686 }
687
688 $rest = str_replace( '>', '&gt;', $rest );
689 $text .= "<$slash$t$newparams$brace$rest";
690 continue;
691 }
692 }
693 }
694 $text .= '&lt;' . str_replace( '>', '&gt;', $x );
695 }
696 }
697 return $text;
698 }
699
700 /**
701 * Remove '<!--', '-->', and everything between.
702 * To avoid leaving blank lines, when a comment is both preceded
703 * and followed by a newline (ignoring spaces), trim leading and
704 * trailing spaces and one of the newlines.
705 *
706 * @param string $text
707 * @return string
708 */
709 public static function removeHTMLcomments( $text ) {
710 while ( ( $start = strpos( $text, '<!--' ) ) !== false ) {
711 $end = strpos( $text, '-->', $start + 4 );
712 if ( $end === false ) {
713 # Unterminated comment; bail out
714 break;
715 }
716
717 $end += 3;
718
719 # Trim space and newline if the comment is both
720 # preceded and followed by a newline
721 $spaceStart = max( $start - 1, 0 );
722 $spaceLen = $end - $spaceStart;
723 while ( substr( $text, $spaceStart, 1 ) === ' ' && $spaceStart > 0 ) {
724 $spaceStart--;
725 $spaceLen++;
726 }
727 while ( substr( $text, $spaceStart + $spaceLen, 1 ) === ' ' ) {
728 $spaceLen++;
729 }
730 if ( substr( $text, $spaceStart, 1 ) === "\n"
731 && substr( $text, $spaceStart + $spaceLen, 1 ) === "\n" ) {
732 # Remove the comment, leading and trailing
733 # spaces, and leave only one newline.
734 $text = substr_replace( $text, "\n", $spaceStart, $spaceLen + 1 );
735 } else {
736 # Remove just the comment.
737 $text = substr_replace( $text, '', $start, $end - $start );
738 }
739 }
740 return $text;
741 }
742
743 /**
744 * Takes attribute names and values for a tag and the tag name and
745 * validates that the tag is allowed to be present.
746 * This DOES NOT validate the attributes, nor does it validate the
747 * tags themselves. This method only handles the special circumstances
748 * where we may want to allow a tag within content but ONLY when it has
749 * specific attributes set.
750 *
751 * @param string $params
752 * @param string $element
753 * @return bool
754 */
755 static function validateTag( $params, $element ) {
756 $params = self::decodeTagAttributes( $params );
757
758 if ( $element == 'meta' || $element == 'link' ) {
759 if ( !isset( $params['itemprop'] ) ) {
760 // <meta> and <link> must have an itemprop="" otherwise they are not valid or safe in content
761 return false;
762 }
763 if ( $element == 'meta' && !isset( $params['content'] ) ) {
764 // <meta> must have a content="" for the itemprop
765 return false;
766 }
767 if ( $element == 'link' && !isset( $params['href'] ) ) {
768 // <link> must have an associated href=""
769 return false;
770 }
771 }
772
773 return true;
774 }
775
776 /**
777 * Take an array of attribute names and values and normalize or discard
778 * illegal values for the given element type.
779 *
780 * - Discards attributes not on a whitelist for the given element
781 * - Unsafe style attributes are discarded
782 * - Invalid id attributes are re-encoded
783 *
784 * @param array $attribs
785 * @param string $element
786 * @return array
787 *
788 * @todo Check for legal values where the DTD limits things.
789 * @todo Check for unique id attribute :P
790 */
791 static function validateTagAttributes( $attribs, $element ) {
792 return self::validateAttributes( $attribs,
793 self::attributeWhitelist( $element ) );
794 }
795
796 /**
797 * Take an array of attribute names and values and normalize or discard
798 * illegal values for the given whitelist.
799 *
800 * - Discards attributes not on the given whitelist
801 * - Unsafe style attributes are discarded
802 * - Invalid id attributes are re-encoded
803 *
804 * @param array $attribs
805 * @param array $whitelist List of allowed attribute names
806 * @return array
807 *
808 * @todo Check for legal values where the DTD limits things.
809 * @todo Check for unique id attribute :P
810 */
811 static function validateAttributes( $attribs, $whitelist ) {
812 $whitelist = array_flip( $whitelist );
813 $hrefExp = '/^(' . wfUrlProtocols() . ')[^\s]+$/';
814
815 $out = [];
816 foreach ( $attribs as $attribute => $value ) {
817 # Allow XML namespace declaration to allow RDFa
818 if ( preg_match( self::XMLNS_ATTRIBUTE_PATTERN, $attribute ) ) {
819 if ( !preg_match( self::EVIL_URI_PATTERN, $value ) ) {
820 $out[$attribute] = $value;
821 }
822
823 continue;
824 }
825
826 # Allow any attribute beginning with "data-"
827 # However:
828 # * Disallow data attributes used by MediaWiki code
829 # * Ensure that the attribute is not namespaced by banning
830 # colons.
831 if ( !preg_match( '/^data-[^:]*$/i', $attribute )
832 && !isset( $whitelist[$attribute] )
833 || self::isReservedDataAttribute( $attribute )
834 ) {
835 continue;
836 }
837
838 # Strip javascript "expression" from stylesheets.
839 # https://msdn.microsoft.com/en-us/library/ms537634.aspx
840 if ( $attribute == 'style' ) {
841 $value = self::checkCss( $value );
842 }
843
844 # Escape HTML id attributes
845 if ( $attribute === 'id' ) {
846 $value = self::escapeIdForAttribute( $value, self::ID_PRIMARY );
847 }
848
849 # Escape HTML id reference lists
850 if ( $attribute === 'aria-describedby'
851 || $attribute === 'aria-flowto'
852 || $attribute === 'aria-labelledby'
853 || $attribute === 'aria-owns'
854 ) {
855 $value = self::escapeIdReferenceList( $value );
856 }
857
858 // RDFa and microdata properties allow URLs, URIs and/or CURIs.
859 // Check them for sanity.
860 if ( $attribute === 'rel' || $attribute === 'rev'
861 # RDFa
862 || $attribute === 'about' || $attribute === 'property'
863 || $attribute === 'resource' || $attribute === 'datatype'
864 || $attribute === 'typeof'
865 # HTML5 microdata
866 || $attribute === 'itemid' || $attribute === 'itemprop'
867 || $attribute === 'itemref' || $attribute === 'itemscope'
868 || $attribute === 'itemtype'
869 ) {
870 // Paranoia. Allow "simple" values but suppress javascript
871 if ( preg_match( self::EVIL_URI_PATTERN, $value ) ) {
872 continue;
873 }
874 }
875
876 # NOTE: even though elements using href/src are not allowed directly, supply
877 # validation code that can be used by tag hook handlers, etc
878 if ( $attribute === 'href' || $attribute === 'src' || $attribute === 'poster' ) {
879 if ( !preg_match( $hrefExp, $value ) ) {
880 continue; // drop any href or src attributes not using an allowed protocol.
881 // NOTE: this also drops all relative URLs
882 }
883 }
884
885 // If this attribute was previously set, override it.
886 // Output should only have one attribute of each name.
887 $out[$attribute] = $value;
888 }
889
890 # itemtype, itemid, itemref don't make sense without itemscope
891 if ( !array_key_exists( 'itemscope', $out ) ) {
892 unset( $out['itemtype'] );
893 unset( $out['itemid'] );
894 unset( $out['itemref'] );
895 }
896 # TODO: Strip itemprop if we aren't descendants of an itemscope or pointed to by an itemref.
897
898 return $out;
899 }
900
901 /**
902 * Given an attribute name, checks whether it is a reserved data attribute
903 * (such as data-mw-foo) which is unavailable to user-generated HTML so MediaWiki
904 * core and extension code can safely use it to communicate with frontend code.
905 * @param string $attr Attribute name.
906 * @return bool
907 */
908 public static function isReservedDataAttribute( $attr ) {
909 // data-ooui is reserved for ooui.
910 // data-mw and data-parsoid are reserved for parsoid.
911 // data-mw-<name here> is reserved for extensions (or core) if
912 // they need to communicate some data to the client and want to be
913 // sure that it isn't coming from an untrusted user.
914 // We ignore the possibility of namespaces since user-generated HTML
915 // can't use them anymore.
916 return (bool)preg_match( '/^data-(ooui|mw|parsoid)/i', $attr );
917 }
918
919 /**
920 * Merge two sets of HTML attributes. Conflicting items in the second set
921 * will override those in the first, except for 'class' attributes which
922 * will be combined (if they're both strings).
923 *
924 * @todo implement merging for other attributes such as style
925 * @param array $a
926 * @param array $b
927 * @return array
928 */
929 static function mergeAttributes( $a, $b ) {
930 $out = array_merge( $a, $b );
931 if ( isset( $a['class'] ) && isset( $b['class'] )
932 && is_string( $a['class'] ) && is_string( $b['class'] )
933 && $a['class'] !== $b['class']
934 ) {
935 $classes = preg_split( '/\s+/', "{$a['class']} {$b['class']}",
936 -1, PREG_SPLIT_NO_EMPTY );
937 $out['class'] = implode( ' ', array_unique( $classes ) );
938 }
939 return $out;
940 }
941
942 /**
943 * Normalize CSS into a format we can easily search for hostile input
944 * - decode character references
945 * - decode escape sequences
946 * - convert characters that IE6 interprets into ascii
947 * - remove comments, unless the entire value is one single comment
948 * @param string $value the css string
949 * @return string normalized css
950 */
951 public static function normalizeCss( $value ) {
952 // Decode character references like &#123;
953 $value = self::decodeCharReferences( $value );
954
955 // Decode escape sequences and line continuation
956 // See the grammar in the CSS 2 spec, appendix D.
957 // This has to be done AFTER decoding character references.
958 // This means it isn't possible for this function to return
959 // unsanitized escape sequences. It is possible to manufacture
960 // input that contains character references that decode to
961 // escape sequences that decode to character references, but
962 // it's OK for the return value to contain character references
963 // because the caller is supposed to escape those anyway.
964 static $decodeRegex;
965 if ( !$decodeRegex ) {
966 $space = '[\\x20\\t\\r\\n\\f]';
967 $nl = '(?:\\n|\\r\\n|\\r|\\f)';
968 $backslash = '\\\\';
969 $decodeRegex = "/ $backslash
970 (?:
971 ($nl) | # 1. Line continuation
972 ([0-9A-Fa-f]{1,6})$space? | # 2. character number
973 (.) | # 3. backslash cancelling special meaning
974 () | # 4. backslash at end of string
975 )/xu";
976 }
977 $value = preg_replace_callback( $decodeRegex,
978 [ __CLASS__, 'cssDecodeCallback' ], $value );
979
980 // Normalize Halfwidth and Fullwidth Unicode block that IE6 might treat as ascii
981 $value = preg_replace_callback(
982 '/[！-［］-ｚ]/u', // U+FF01 to U+FF5A, excluding U+FF3C (T60088)
983 function ( $matches ) {
984 $cp = UtfNormal\Utils::utf8ToCodepoint( $matches[0] );
985 if ( $cp === false ) {
986 return '';
987 }
988 return chr( $cp - 65248 ); // ASCII range \x21-\x7A
989 },
990 $value
991 );
992
993 // Convert more characters IE6 might treat as ascii
994 // U+0280, U+0274, U+207F, U+029F, U+026A, U+207D, U+208D
995 $value = str_replace(
996 [ 'ʀ', 'ɴ', 'ⁿ', 'ʟ', 'ɪ', '⁽', '₍' ],
997 [ 'r', 'n', 'n', 'l', 'i', '(', '(' ],
998 $value
999 );
1000
1001 // Let the value through if it's nothing but a single comment, to
1002 // allow other functions which may reject it to pass some error
1003 // message through.
1004 if ( !preg_match( '! ^ \s* /\* [^*\\/]* \*/ \s* $ !x', $value ) ) {
1005 // Remove any comments; IE gets token splitting wrong
1006 // This must be done AFTER decoding character references and
1007 // escape sequences, because those steps can introduce comments
1008 // This step cannot introduce character references or escape
1009 // sequences, because it replaces comments with spaces rather
1010 // than removing them completely.
1011 $value = StringUtils::delimiterReplace( '/*', '*/', ' ', $value );
1012
1013 // Remove anything after a comment-start token, to guard against
1014 // incorrect client implementations.
1015 $commentPos = strpos( $value, '/*' );
1016 if ( $commentPos !== false ) {
1017 $value = substr( $value, 0, $commentPos );
1018 }
1019 }
1020
1021 // S followed by repeat, iteration, or prolonged sound marks,
1022 // which IE will treat as "ss"
1023 $value = preg_replace(
1024 '/s(?:
1025 \xE3\x80\xB1 | # U+3031
1026 \xE3\x82\x9D | # U+309D
1027 \xE3\x83\xBC | # U+30FC
1028 \xE3\x83\xBD | # U+30FD
1029 \xEF\xB9\xBC | # U+FE7C
1030 \xEF\xB9\xBD | # U+FE7D
1031 \xEF\xBD\xB0 # U+FF70
1032 )/ix',
1033 'ss',
1034 $value
1035 );
1036
1037 return $value;
1038 }
1039
1040 /**
1041 * Pick apart some CSS and check it for forbidden or unsafe structures.
1042 * Returns a sanitized string. This sanitized string will have
1043 * character references and escape sequences decoded and comments
1044 * stripped (unless it is itself one valid comment, in which case the value
1045 * will be passed through). If the input is just too evil, only a comment
1046 * complaining about evilness will be returned.
1047 *
1048 * Currently URL references, 'expression', 'tps' are forbidden.
1049 *
1050 * NOTE: Despite the fact that character references are decoded, the
1051 * returned string may contain character references given certain
1052 * clever input strings. These character references must
1053 * be escaped before the return value is embedded in HTML.
1054 *
1055 * @param string $value
1056 * @return string
1057 */
1058 static function checkCss( $value ) {
1059 $value = self::normalizeCss( $value );
1060
1061 // Reject problematic keywords and control characters
1062 if ( preg_match( '/[\000-\010\013\016-\037\177]/', $value ) ||
1063 strpos( $value, UtfNormal\Constants::UTF8_REPLACEMENT ) !== false ) {
1064 return '/* invalid control char */';
1065 } elseif ( preg_match(
1066 '! expression
1067 | filter\s*:
1068 | accelerator\s*:
1069 | -o-link\s*:
1070 | -o-link-source\s*:
1071 | -o-replace\s*:
1072 | url\s*\(
1073 | image\s*\(
1074 | image-set\s*\(
1075 | attr\s*\([^)]+[\s,]+url
1076 !ix', $value ) ) {
1077 return '/* insecure input */';
1078 }
1079 return $value;
1080 }
1081
1082 /**
1083 * @param array $matches
1084 * @return string
1085 */
1086 static function cssDecodeCallback( $matches ) {
1087 if ( $matches[1] !== '' ) {
1088 // Line continuation
1089 return '';
1090 } elseif ( $matches[2] !== '' ) {
1091 $char = UtfNormal\Utils::codepointToUtf8( hexdec( $matches[2] ) );
1092 } elseif ( $matches[3] !== '' ) {
1093 $char = $matches[3];
1094 } else {
1095 $char = '\\';
1096 }
1097 if ( $char == "\n" || $char == '"' || $char == "'" || $char == '\\' ) {
1098 // These characters need to be escaped in strings
1099 // Clean up the escape sequence to avoid parsing errors by clients
1100 return '\\' . dechex( ord( $char ) ) . ' ';
1101 } else {
1102 // Decode unnecessary escape
1103 return $char;
1104 }
1105 }
1106
1107 /**
1108 * Take a tag soup fragment listing an HTML element's attributes
1109 * and normalize it to well-formed XML, discarding unwanted attributes.
1110 * Output is safe for further wikitext processing, with escaping of
1111 * values that could trigger problems.
1112 *
1113 * - Normalizes attribute names to lowercase
1114 * - Discards attributes not on a whitelist for the given element
1115 * - Turns broken or invalid entities into plaintext
1116 * - Double-quotes all attribute values
1117 * - Attributes without values are given the name as attribute
1118 * - Double attributes are discarded
1119 * - Unsafe style attributes are discarded
1120 * - Prepends space if there are attributes.
1121 * - (Optionally) Sorts attributes by name.
1122 *
1123 * @param string $text
1124 * @param string $element
1125 * @param bool $sorted Whether to sort the attributes (default: false)
1126 * @return string
1127 */
1128 static function fixTagAttributes( $text, $element, $sorted = false ) {
1129 if ( trim( $text ) == '' ) {
1130 return '';
1131 }
1132
1133 $decoded = self::decodeTagAttributes( $text );
1134 $stripped = self::validateTagAttributes( $decoded, $element );
1135
1136 if ( $sorted ) {
1137 ksort( $stripped );
1138 }
1139
1140 return self::safeEncodeTagAttributes( $stripped );
1141 }
1142
1143 /**
1144 * Encode an attribute value for HTML output.
1145 * @param string $text
1146 * @return string HTML-encoded text fragment
1147 */
1148 static function encodeAttribute( $text ) {
1149 $encValue = htmlspecialchars( $text, ENT_QUOTES );
1150
1151 // Whitespace is normalized during attribute decoding,
1152 // so if we've been passed non-spaces we must encode them
1153 // ahead of time or they won't be preserved.
1154 $encValue = strtr( $encValue, [
1155 "\n" => '&#10;',
1156 "\r" => '&#13;',
1157 "\t" => '&#9;',
1158 ] );
1159
1160 return $encValue;
1161 }
1162
1163 /**
1164 * Armor French spaces with a replacement character
1165 *
1166 * @since 1.32
1167 * @param string $text Text to armor
1168 * @param string $space Space character for the French spaces, defaults to '&#160;'
1169 * @return string Armored text
1170 */
1171 public static function armorFrenchSpaces( $text, $space = '&#160;' ) {
1172 // Replace $ with \$ and \ with \\
1173 $space = preg_replace( '#(?<!\\\\)(\\$|\\\\)#', '\\\\$1', $space );
1174 $fixtags = [
1175 # French spaces, last one Guillemet-left
1176 # only if there is something before the space
1177 # and a non-word character after the punctuation.
1178 '/(\S) (?=[?:;!%»›](?!\w))/u' => "\\1$space",
1179 # French spaces, Guillemet-right
1180 '/([«‹]) /u' => "\\1$space",
1181 ];
1182 return preg_replace( array_keys( $fixtags ), array_values( $fixtags ), $text );
1183 }
1184
1185 /**
1186 * Encode an attribute value for HTML tags, with extra armoring
1187 * against further wiki processing.
1188 * @param string $text
1189 * @return string HTML-encoded text fragment
1190 */
1191 static function safeEncodeAttribute( $text ) {
1192 $encValue = self::encodeAttribute( $text );
1193
1194 # Templates and links may be expanded in later parsing,
1195 # creating invalid or dangerous output. Suppress this.
1196 $encValue = strtr( $encValue, [
1197 '<' => '&lt;', // This should never happen,
1198 '>' => '&gt;', // we've received invalid input
1199 '"' => '&quot;', // which should have been escaped.
1200 '{' => '&#123;',
1201 '}' => '&#125;', // prevent unpaired language conversion syntax
1202 '[' => '&#91;',
1203 ']' => '&#93;',
1204 "''" => '&#39;&#39;',
1205 'ISBN' => '&#73;SBN',
1206 'RFC' => '&#82;FC',
1207 'PMID' => '&#80;MID',
1208 '|' => '&#124;',
1209 '__' => '&#95;_',
1210 ] );
1211
1212 # Armor against French spaces detection (T5158)
1213 $encValue = self::armorFrenchSpaces( $encValue, '&#32;' );
1214
1215 # Stupid hack
1216 $encValue = preg_replace_callback(
1217 '/((?i)' . wfUrlProtocols() . ')/',
1218 function ( $matches ) {
1219 return str_replace( ':', '&#58;', $matches[1] );
1220 },
1221 $encValue );
1222 return $encValue;
1223 }
1224
1225 /**
1226 * Given a value, escape it so that it can be used in an id attribute and
1227 * return it. This will use HTML5 validation, allowing anything but ASCII
1228 * whitespace.
1229 *
1230 * To ensure we don't have to bother escaping anything, we also strip ', ".
1231 * TODO: Is this the best tactic?
1232 *
1233 * We also strip # because it upsets IE, and % because it could be
1234 * ambiguous if it's part of something that looks like a percent escape
1235 * (which don't work reliably in fragments cross-browser).
1236 *
1237 * @deprecated since 1.30, use one of this class' escapeIdFor*() functions
1238 *
1239 * @see https://www.w3.org/TR/html401/types.html#type-name Valid characters
1240 * in the id and name attributes
1241 * @see https://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with
1242 * the id attribute
1243 * @see https://www.w3.org/TR/html5/dom.html#the-id-attribute
1244 * HTML5 definition of id attribute
1245 *
1246 * @param string $id Id to escape
1247 * @param string|array $options String or array of strings (default is array()):
1248 * 'noninitial': This is a non-initial fragment of an id, not a full id,
1249 * so don't pay attention if the first character isn't valid at the
1250 * beginning of an id.
1251 * @return string
1252 */
1253 static function escapeId( $id, $options = [] ) {
1254 $options = (array)$options;
1255
1256 // HTML4-style escaping
1257 static $replace = [
1258 '%3A' => ':',
1259 '%' => '.'
1260 ];
1261
1262 $id = urlencode( strtr( $id, ' ', '_' ) );
1263 $id = strtr( $id, $replace );
1264
1265 if ( !preg_match( '/^[a-zA-Z]/', $id ) && !in_array( 'noninitial', $options ) ) {
1266 // Initial character must be a letter!
1267 $id = "x$id";
1268 }
1269 return $id;
1270 }
1271
1272 /**
1273 * Given a section name or other user-generated or otherwise unsafe string, escapes it to be
1274 * a valid HTML id attribute.
1275 *
1276 * WARNING: unlike escapeId(), the output of this function is not guaranteed to be HTML safe,
1277 * be sure to use proper escaping.
1278 *
1279 * @param string $id String to escape
1280 * @param int $mode One of ID_* constants, specifying whether the primary or fallback encoding
1281 * should be used.
1282 * @return string|bool Escaped ID or false if fallback encoding is requested but it's not
1283 * configured.
1284 *
1285 * @since 1.30
1286 */
1287 public static function escapeIdForAttribute( $id, $mode = self::ID_PRIMARY ) {
1288 global $wgFragmentMode;
1289
1290 if ( !isset( $wgFragmentMode[$mode] ) ) {
1291 if ( $mode === self::ID_PRIMARY ) {
1292 throw new UnexpectedValueException( '$wgFragmentMode is configured with no primary mode' );
1293 }
1294 return false;
1295 }
1296
1297 $internalMode = $wgFragmentMode[$mode];
1298
1299 return self::escapeIdInternal( $id, $internalMode );
1300 }
1301
1302 /**
1303 * Given a section name or other user-generated or otherwise unsafe string, escapes it to be
1304 * a valid URL fragment.
1305 *
1306 * WARNING: unlike escapeId(), the output of this function is not guaranteed to be HTML safe,
1307 * be sure to use proper escaping.
1308 *
1309 * @param string $id String to escape
1310 * @return string Escaped ID
1311 *
1312 * @since 1.30
1313 */
1314 public static function escapeIdForLink( $id ) {
1315 global $wgFragmentMode;
1316
1317 if ( !isset( $wgFragmentMode[self::ID_PRIMARY] ) ) {
1318 throw new UnexpectedValueException( '$wgFragmentMode is configured with no primary mode' );
1319 }
1320
1321 $mode = $wgFragmentMode[self::ID_PRIMARY];
1322
1323 $id = self::escapeIdInternal( $id, $mode );
1324
1325 return $id;
1326 }
1327
1328 /**
1329 * Given a section name or other user-generated or otherwise unsafe string, escapes it to be
1330 * a valid URL fragment for external interwikis.
1331 *
1332 * @param string $id String to escape
1333 * @return string Escaped ID
1334 *
1335 * @since 1.30
1336 */
1337 public static function escapeIdForExternalInterwiki( $id ) {
1338 global $wgExternalInterwikiFragmentMode;
1339
1340 $id = self::escapeIdInternal( $id, $wgExternalInterwikiFragmentMode );
1341
1342 return $id;
1343 }
1344
1345 /**
1346 * Helper for escapeIdFor*() functions. Performs most of the actual escaping.
1347 *
1348 * @param string $id String to escape
1349 * @param string $mode One of modes from $wgFragmentMode
1350 * @return string
1351 */
1352 private static function escapeIdInternal( $id, $mode ) {
1353 switch ( $mode ) {
1354 case 'html5':
1355 $id = str_replace( ' ', '_', $id );
1356 break;
1357 case 'legacy':
1358 // This corresponds to 'noninitial' mode of the old escapeId()
1359 static $replace = [
1360 '%3A' => ':',
1361 '%' => '.'
1362 ];
1363
1364 $id = urlencode( str_replace( ' ', '_', $id ) );
1365 $id = strtr( $id, $replace );
1366 break;
1367 default:
1368 throw new InvalidArgumentException( "Invalid mode '$mode' passed to '" . __METHOD__ );
1369 }
1370
1371 return $id;
1372 }
1373
1374 /**
1375 * Given a string containing a space delimited list of ids, escape each id
1376 * to match ids escaped by the escapeIdForAttribute() function.
1377 *
1378 * @since 1.27
1379 *
1380 * @param string $referenceString Space delimited list of ids
1381 * @return string
1382 */
1383 public static function escapeIdReferenceList( $referenceString ) {
1384 # Explode the space delimited list string into an array of tokens
1385 $references = preg_split( '/\s+/', "{$referenceString}", -1, PREG_SPLIT_NO_EMPTY );
1386
1387 # Escape each token as an id
1388 foreach ( $references as &$ref ) {
1389 $ref = self::escapeIdForAttribute( $ref );
1390 }
1391
1392 # Merge the array back to a space delimited list string
1393 # If the array is empty, the result will be an empty string ('')
1394 $referenceString = implode( ' ', $references );
1395
1396 return $referenceString;
1397 }
1398
1399 /**
1400 * Given a value, escape it so that it can be used as a CSS class and
1401 * return it.
1402 *
1403 * @todo For extra validity, input should be validated UTF-8.
1404 *
1405 * @see https://www.w3.org/TR/CSS21/syndata.html Valid characters/format
1406 *
1407 * @param string $class
1408 * @return string
1409 */
1410 static function escapeClass( $class ) {
1411 // Convert ugly stuff to underscores and kill underscores in ugly places
1412 return rtrim( preg_replace(
1413 [ '/(^[0-9\\-])|[\\x00-\\x20!"#$%&\'()*+,.\\/:;<=>?@[\\]^`{|}~]|\\xC2\\xA0/', '/_+/' ],
1414 '_',
1415 $class ), '_' );
1416 }
1417
1418 /**
1419 * Given HTML input, escape with htmlspecialchars but un-escape entities.
1420 * This allows (generally harmless) entities like &#160; to survive.
1421 *
1422 * @param string $html HTML to escape
1423 * @return string Escaped input
1424 */
1425 static function escapeHtmlAllowEntities( $html ) {
1426 $html = self::decodeCharReferences( $html );
1427 # It seems wise to escape ' as well as ", as a matter of course. Can't
1428 # hurt. Use ENT_SUBSTITUTE so that incorrectly truncated multibyte characters
1429 # don't cause the entire string to disappear.
1430 $html = htmlspecialchars( $html, ENT_QUOTES | ENT_SUBSTITUTE );
1431 return $html;
1432 }
1433
1434 /**
1435 * Return an associative array of attribute names and values from
1436 * a partial tag string. Attribute names are forced to lowercase,
1437 * character references are decoded to UTF-8 text.
1438 *
1439 * @param string $text
1440 * @return array
1441 */
1442 public static function decodeTagAttributes( $text ) {
1443 if ( trim( $text ) == '' ) {
1444 return [];
1445 }
1446
1447 $pairs = [];
1448 if ( !preg_match_all(
1449 self::getAttribsRegex(),
1450 $text,
1451 $pairs,
1452 PREG_SET_ORDER ) ) {
1453 return [];
1454 }
1455
1456 $attribs = [];
1457 foreach ( $pairs as $set ) {
1458 $attribute = strtolower( $set[1] );
1459
1460 // Filter attribute names with unacceptable characters
1461 if ( !preg_match( self::getAttribNameRegex(), $attribute ) ) {
1462 continue;
1463 }
1464
1465 $value = self::getTagAttributeCallback( $set );
1466
1467 // Normalize whitespace
1468 $value = preg_replace( '/[\t\r\n ]+/', ' ', $value );
1469 $value = trim( $value );
1470
1471 // Decode character references
1472 $attribs[$attribute] = self::decodeCharReferences( $value );
1473 }
1474 return $attribs;
1475 }
1476
1477 /**
1478 * Build a partial tag string from an associative array of attribute
1479 * names and values as returned by decodeTagAttributes.
1480 *
1481 * @param array $assoc_array
1482 * @return string
1483 */
1484 public static function safeEncodeTagAttributes( $assoc_array ) {
1485 $attribs = [];
1486 foreach ( $assoc_array as $attribute => $value ) {
1487 $encAttribute = htmlspecialchars( $attribute );
1488 $encValue = self::safeEncodeAttribute( $value );
1489
1490 $attribs[] = "$encAttribute=\"$encValue\"";
1491 }
1492 return count( $attribs ) ? ' ' . implode( ' ', $attribs ) : '';
1493 }
1494
1495 /**
1496 * Pick the appropriate attribute value from a match set from the
1497 * attribs regex matches.
1498 *
1499 * @param array $set
1500 * @throws MWException When tag conditions are not met.
1501 * @return string
1502 */
1503 private static function getTagAttributeCallback( $set ) {
1504 if ( isset( $set[5] ) ) {
1505 # No quotes.
1506 return $set[5];
1507 } elseif ( isset( $set[4] ) ) {
1508 # Single-quoted
1509 return $set[4];
1510 } elseif ( isset( $set[3] ) ) {
1511 # Double-quoted
1512 return $set[3];
1513 } elseif ( !isset( $set[2] ) ) {
1514 # In XHTML, attributes must have a value so return an empty string.
1515 # See "Empty attribute syntax",
1516 # https://www.w3.org/TR/html5/syntax.html#syntax-attribute-name
1517 return "";
1518 } else {
1519 throw new MWException( "Tag conditions not met. This should never happen and is a bug." );
1520 }
1521 }
1522
1523 /**
1524 * @param string $text
1525 * @return string
1526 */
1527 private static function normalizeWhitespace( $text ) {
1528 return trim( preg_replace(
1529 '/(?:\r\n|[\x20\x0d\x0a\x09])+/',
1530 ' ',
1531 $text ) );
1532 }
1533
1534 /**
1535 * Normalizes whitespace in a section name, such as might be returned
1536 * by Parser::stripSectionName(), for use in the id's that are used for
1537 * section links.
1538 *
1539 * @param string $section
1540 * @return string
1541 */
1542 static function normalizeSectionNameWhitespace( $section ) {
1543 return trim( preg_replace( '/[ _]+/', ' ', $section ) );
1544 }
1545
1546 /**
1547 * Ensure that any entities and character references are legal
1548 * for XML and XHTML specifically. Any stray bits will be
1549 * &amp;-escaped to result in a valid text fragment.
1550 *
1551 * a. named char refs can only be &lt; &gt; &amp; &quot;, others are
1552 * numericized (this way we're well-formed even without a DTD)
1553 * b. any numeric char refs must be legal chars, not invalid or forbidden
1554 * c. use lower cased "&#x", not "&#X"
1555 * d. fix or reject non-valid attributes
1556 *
1557 * @param string $text
1558 * @return string
1559 * @private
1560 */
1561 static function normalizeCharReferences( $text ) {
1562 return preg_replace_callback(
1563 self::CHAR_REFS_REGEX,
1564 [ self::class, 'normalizeCharReferencesCallback' ],
1565 $text );
1566 }
1567
1568 /**
1569 * @param string $matches
1570 * @return string
1571 */
1572 static function normalizeCharReferencesCallback( $matches ) {
1573 $ret = null;
1574 if ( $matches[1] != '' ) {
1575 $ret = self::normalizeEntity( $matches[1] );
1576 } elseif ( $matches[2] != '' ) {
1577 $ret = self::decCharReference( $matches[2] );
1578 } elseif ( $matches[3] != '' ) {
1579 $ret = self::hexCharReference( $matches[3] );
1580 }
1581 if ( is_null( $ret ) ) {
1582 return htmlspecialchars( $matches[0] );
1583 } else {
1584 return $ret;
1585 }
1586 }
1587
1588 /**
1589 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1590 * return the equivalent numeric entity reference (except for the core &lt;
1591 * &gt; &amp; &quot;). If the entity is a MediaWiki-specific alias, returns
1592 * the HTML equivalent. Otherwise, returns HTML-escaped text of
1593 * pseudo-entity source (eg &amp;foo;)
1594 *
1595 * @param string $name
1596 * @return string
1597 */
1598 static function normalizeEntity( $name ) {
1599 if ( isset( self::$htmlEntityAliases[$name] ) ) {
1600 return '&' . self::$htmlEntityAliases[$name] . ';';
1601 } elseif ( in_array( $name, [ 'lt', 'gt', 'amp', 'quot' ] ) ) {
1602 return "&$name;";
1603 } elseif ( isset( self::$htmlEntities[$name] ) ) {
1604 return '&#' . self::$htmlEntities[$name] . ';';
1605 } else {
1606 return "&amp;$name;";
1607 }
1608 }
1609
1610 /**
1611 * @param int $codepoint
1612 * @return null|string
1613 */
1614 static function decCharReference( $codepoint ) {
1615 $point = intval( $codepoint );
1616 if ( self::validateCodepoint( $point ) ) {
1617 return sprintf( '&#%d;', $point );
1618 } else {
1619 return null;
1620 }
1621 }
1622
1623 /**
1624 * @param int $codepoint
1625 * @return null|string
1626 */
1627 static function hexCharReference( $codepoint ) {
1628 $point = hexdec( $codepoint );
1629 if ( self::validateCodepoint( $point ) ) {
1630 return sprintf( '&#x%x;', $point );
1631 } else {
1632 return null;
1633 }
1634 }
1635
1636 /**
1637 * Returns true if a given Unicode codepoint is a valid character in
1638 * both HTML5 and XML.
1639 * @param int $codepoint
1640 * @return bool
1641 */
1642 private static function validateCodepoint( $codepoint ) {
1643 # U+000C is valid in HTML5 but not allowed in XML.
1644 # U+000D is valid in XML but not allowed in HTML5.
1645 # U+007F - U+009F are disallowed in HTML5 (control characters).
1646 return $codepoint == 0x09
1647 || $codepoint == 0x0a
1648 || ( $codepoint >= 0x20 && $codepoint <= 0x7e )
1649 || ( $codepoint >= 0xa0 && $codepoint <= 0xd7ff )
1650 || ( $codepoint >= 0xe000 && $codepoint <= 0xfffd )
1651 || ( $codepoint >= 0x10000 && $codepoint <= 0x10ffff );
1652 }
1653
1654 /**
1655 * Decode any character references, numeric or named entities,
1656 * in the text and return a UTF-8 string.
1657 *
1658 * @param string $text
1659 * @return string
1660 */
1661 public static function decodeCharReferences( $text ) {
1662 return preg_replace_callback(
1663 self::CHAR_REFS_REGEX,
1664 [ self::class, 'decodeCharReferencesCallback' ],
1665 $text );
1666 }
1667
1668 /**
1669 * Decode any character references, numeric or named entities,
1670 * in the next and normalize the resulting string. (T16952)
1671 *
1672 * This is useful for page titles, not for text to be displayed,
1673 * MediaWiki allows HTML entities to escape normalization as a feature.
1674 *
1675 * @param string $text Already normalized, containing entities
1676 * @return string Still normalized, without entities
1677 */
1678 public static function decodeCharReferencesAndNormalize( $text ) {
1679 $text = preg_replace_callback(
1680 self::CHAR_REFS_REGEX,
1681 [ self::class, 'decodeCharReferencesCallback' ],
1682 $text,
1683 -1, //limit
1684 $count
1685 );
1686
1687 if ( $count ) {
1688 return MediaWikiServices::getInstance()->getContentLanguage()->normalize( $text );
1689 } else {
1690 return $text;
1691 }
1692 }
1693
1694 /**
1695 * @param string $matches
1696 * @return string
1697 */
1698 static function decodeCharReferencesCallback( $matches ) {
1699 if ( $matches[1] != '' ) {
1700 return self::decodeEntity( $matches[1] );
1701 } elseif ( $matches[2] != '' ) {
1702 return self::decodeChar( intval( $matches[2] ) );
1703 } elseif ( $matches[3] != '' ) {
1704 return self::decodeChar( hexdec( $matches[3] ) );
1705 }
1706 # Last case should be an ampersand by itself
1707 return $matches[0];
1708 }
1709
1710 /**
1711 * Return UTF-8 string for a codepoint if that is a valid
1712 * character reference, otherwise U+FFFD REPLACEMENT CHARACTER.
1713 * @param int $codepoint
1714 * @return string
1715 * @private
1716 */
1717 static function decodeChar( $codepoint ) {
1718 if ( self::validateCodepoint( $codepoint ) ) {
1719 return UtfNormal\Utils::codepointToUtf8( $codepoint );
1720 } else {
1721 return UtfNormal\Constants::UTF8_REPLACEMENT;
1722 }
1723 }
1724
1725 /**
1726 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1727 * return the UTF-8 encoding of that character. Otherwise, returns
1728 * pseudo-entity source (eg "&foo;")
1729 *
1730 * @param string $name
1731 * @return string
1732 */
1733 static function decodeEntity( $name ) {
1734 if ( isset( self::$htmlEntityAliases[$name] ) ) {
1735 $name = self::$htmlEntityAliases[$name];
1736 }
1737 if ( isset( self::$htmlEntities[$name] ) ) {
1738 return UtfNormal\Utils::codepointToUtf8( self::$htmlEntities[$name] );
1739 } else {
1740 return "&$name;";
1741 }
1742 }
1743
1744 /**
1745 * Fetch the whitelist of acceptable attributes for a given element name.
1746 *
1747 * @param string $element
1748 * @return array
1749 */
1750 static function attributeWhitelist( $element ) {
1751 $list = self::setupAttributeWhitelist();
1752 return $list[$element] ?? [];
1753 }
1754
1755 /**
1756 * Foreach array key (an allowed HTML element), return an array
1757 * of allowed attributes
1758 * @return array
1759 */
1760 static function setupAttributeWhitelist() {
1761 static $whitelist;
1762
1763 if ( $whitelist !== null ) {
1764 return $whitelist;
1765 }
1766
1767 $common = [
1768 # HTML
1769 'id',
1770 'class',
1771 'style',
1772 'lang',
1773 'dir',
1774 'title',
1775
1776 # WAI-ARIA
1777 'aria-describedby',
1778 'aria-flowto',
1779 'aria-label',
1780 'aria-labelledby',
1781 'aria-owns',
1782 'role',
1783
1784 # RDFa
1785 # These attributes are specified in section 9 of
1786 # https://www.w3.org/TR/2008/REC-rdfa-syntax-20081014
1787 'about',
1788 'property',
1789 'resource',
1790 'datatype',
1791 'typeof',
1792
1793 # Microdata. These are specified by
1794 # https://html.spec.whatwg.org/multipage/microdata.html#the-microdata-model
1795 'itemid',
1796 'itemprop',
1797 'itemref',
1798 'itemscope',
1799 'itemtype',
1800 ];
1801
1802 $block = array_merge( $common, [ 'align' ] );
1803 $tablealign = [ 'align', 'valign' ];
1804 $tablecell = [
1805 'abbr',
1806 'axis',
1807 'headers',
1808 'scope',
1809 'rowspan',
1810 'colspan',
1811 'nowrap', # deprecated
1812 'width', # deprecated
1813 'height', # deprecated
1814 'bgcolor', # deprecated
1815 ];
1816
1817 # Numbers refer to sections in HTML 4.01 standard describing the element.
1818 # See: https://www.w3.org/TR/html4/
1819 $whitelist = [
1820 # 7.5.4
1821 'div' => $block,
1822 'center' => $common, # deprecated
1823 'span' => $common,
1824
1825 # 7.5.5
1826 'h1' => $block,
1827 'h2' => $block,
1828 'h3' => $block,
1829 'h4' => $block,
1830 'h5' => $block,
1831 'h6' => $block,
1832
1833 # 7.5.6
1834 # address
1835
1836 # 8.2.4
1837 'bdo' => $common,
1838
1839 # 9.2.1
1840 'em' => $common,
1841 'strong' => $common,
1842 'cite' => $common,
1843 'dfn' => $common,
1844 'code' => $common,
1845 'samp' => $common,
1846 'kbd' => $common,
1847 'var' => $common,
1848 'abbr' => $common,
1849 # acronym
1850
1851 # 9.2.2
1852 'blockquote' => array_merge( $common, [ 'cite' ] ),
1853 'q' => array_merge( $common, [ 'cite' ] ),
1854
1855 # 9.2.3
1856 'sub' => $common,
1857 'sup' => $common,
1858
1859 # 9.3.1
1860 'p' => $block,
1861
1862 # 9.3.2
1863 'br' => array_merge( $common, [ 'clear' ] ),
1864
1865 # https://www.w3.org/TR/html5/text-level-semantics.html#the-wbr-element
1866 'wbr' => $common,
1867
1868 # 9.3.4
1869 'pre' => array_merge( $common, [ 'width' ] ),
1870
1871 # 9.4
1872 'ins' => array_merge( $common, [ 'cite', 'datetime' ] ),
1873 'del' => array_merge( $common, [ 'cite', 'datetime' ] ),
1874
1875 # 10.2
1876 'ul' => array_merge( $common, [ 'type' ] ),
1877 'ol' => array_merge( $common, [ 'type', 'start', 'reversed' ] ),
1878 'li' => array_merge( $common, [ 'type', 'value' ] ),
1879
1880 # 10.3
1881 'dl' => $common,
1882 'dd' => $common,
1883 'dt' => $common,
1884
1885 # 11.2.1
1886 'table' => array_merge( $common,
1887 [ 'summary', 'width', 'border', 'frame',
1888 'rules', 'cellspacing', 'cellpadding',
1889 'align', 'bgcolor',
1890 ] ),
1891
1892 # 11.2.2
1893 'caption' => $block,
1894
1895 # 11.2.3
1896 'thead' => $common,
1897 'tfoot' => $common,
1898 'tbody' => $common,
1899
1900 # 11.2.4
1901 'colgroup' => array_merge( $common, [ 'span' ] ),
1902 'col' => array_merge( $common, [ 'span' ] ),
1903
1904 # 11.2.5
1905 'tr' => array_merge( $common, [ 'bgcolor' ], $tablealign ),
1906
1907 # 11.2.6
1908 'td' => array_merge( $common, $tablecell, $tablealign ),
1909 'th' => array_merge( $common, $tablecell, $tablealign ),
1910
1911 # 12.2
1912 # NOTE: <a> is not allowed directly, but the attrib
1913 # whitelist is used from the Parser object
1914 'a' => array_merge( $common, [ 'href', 'rel', 'rev' ] ), # rel/rev esp. for RDFa
1915
1916 # 13.2
1917 # Not usually allowed, but may be used for extension-style hooks
1918 # such as <math> when it is rasterized, or if $wgAllowImageTag is
1919 # true
1920 'img' => array_merge( $common, [ 'alt', 'src', 'width', 'height', 'srcset' ] ),
1921 # Attributes for A/V tags added in T163583 / T133673
1922 'audio' => array_merge( $common, [ 'controls', 'preload', 'width', 'height' ] ),
1923 'video' => array_merge( $common, [ 'poster', 'controls', 'preload', 'width', 'height' ] ),
1924 'source' => array_merge( $common, [ 'type', 'src' ] ),
1925 'track' => array_merge( $common, [ 'type', 'src', 'srclang', 'kind', 'label' ] ),
1926
1927 # 15.2.1
1928 'tt' => $common,
1929 'b' => $common,
1930 'i' => $common,
1931 'big' => $common,
1932 'small' => $common,
1933 'strike' => $common,
1934 's' => $common,
1935 'u' => $common,
1936
1937 # 15.2.2
1938 'font' => array_merge( $common, [ 'size', 'color', 'face' ] ),
1939 # basefont
1940
1941 # 15.3
1942 'hr' => array_merge( $common, [ 'width' ] ),
1943
1944 # HTML Ruby annotation text module, simple ruby only.
1945 # https://www.w3.org/TR/html5/text-level-semantics.html#the-ruby-element
1946 'ruby' => $common,
1947 # rbc
1948 'rb' => $common,
1949 'rp' => $common,
1950 'rt' => $common, # array_merge( $common, array( 'rbspan' ) ),
1951 'rtc' => $common,
1952
1953 # MathML root element, where used for extensions
1954 # 'title' may not be 100% valid here; it's XHTML
1955 # https://www.w3.org/TR/REC-MathML/
1956 'math' => [ 'class', 'style', 'id', 'title' ],
1957
1958 // HTML 5 section 4.5
1959 'figure' => $common,
1960 'figure-inline' => $common, # T118520
1961 'figcaption' => $common,
1962
1963 # HTML 5 section 4.6
1964 'bdi' => $common,
1965
1966 # HTML5 elements, defined by:
1967 # https://html.spec.whatwg.org/multipage/semantics.html#the-data-element
1968 'data' => array_merge( $common, [ 'value' ] ),
1969 'time' => array_merge( $common, [ 'datetime' ] ),
1970 'mark' => $common,
1971
1972 // meta and link are only permitted by removeHTMLtags when Microdata
1973 // is enabled so we don't bother adding a conditional to hide these
1974 // Also meta and link are only valid in WikiText as Microdata elements
1975 // (ie: validateTag rejects tags missing the attributes needed for Microdata)
1976 // So we don't bother including $common attributes that have no purpose.
1977 'meta' => [ 'itemprop', 'content' ],
1978 'link' => [ 'itemprop', 'href', 'title' ],
1979 ];
1980
1981 return $whitelist;
1982 }
1983
1984 /**
1985 * Take a fragment of (potentially invalid) HTML and return
1986 * a version with any tags removed, encoded as plain text.
1987 *
1988 * Warning: this return value must be further escaped for literal
1989 * inclusion in HTML output as of 1.10!
1990 *
1991 * @param string $html HTML fragment
1992 * @return string
1993 */
1994 static function stripAllTags( $html ) {
1995 // Use RemexHtml to tokenize $html and extract the text
1996 $handler = new RemexStripTagHandler;
1997 $tokenizer = new RemexHtml\Tokenizer\Tokenizer( $handler, $html, [
1998 'ignoreErrors' => true,
1999 // don't ignore char refs, we want them to be decoded
2000 'ignoreNulls' => true,
2001 'skipPreprocess' => true,
2002 ] );
2003 $tokenizer->execute();
2004 $text = $handler->getResult();
2005
2006 $text = self::normalizeWhitespace( $text );
2007 return $text;
2008 }
2009
2010 /**
2011 * Hack up a private DOCTYPE with HTML's standard entity declarations.
2012 * PHP 4 seemed to know these if you gave it an HTML doctype, but
2013 * PHP 5.1 doesn't.
2014 *
2015 * Use for passing XHTML fragments to PHP's XML parsing functions
2016 *
2017 * @return string
2018 */
2019 static function hackDocType() {
2020 $out = "<!DOCTYPE html [\n";
2021 foreach ( self::$htmlEntities as $entity => $codepoint ) {
2022 $out .= "<!ENTITY $entity \"&#$codepoint;\">";
2023 }
2024 $out .= "]>\n";
2025 return $out;
2026 }
2027
2028 /**
2029 * @param string $url
2030 * @return mixed|string
2031 */
2032 static function cleanUrl( $url ) {
2033 # Normalize any HTML entities in input. They will be
2034 # re-escaped by makeExternalLink().
2035 $url = self::decodeCharReferences( $url );
2036
2037 # Escape any control characters introduced by the above step
2038 $url = preg_replace_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
2039 [ __CLASS__, 'cleanUrlCallback' ], $url );
2040
2041 # Validate hostname portion
2042 $matches = [];
2043 if ( preg_match( '!^([^:]+:)(//[^/]+)?(.*)$!iD', $url, $matches ) ) {
2044 list( /* $whole */, $protocol, $host, $rest ) = $matches;
2045
2046 // Characters that will be ignored in IDNs.
2047 // https://tools.ietf.org/html/rfc3454#section-3.1
2048 // Strip them before further processing so blacklists and such work.
2049 $strip = "/
2050 \\s| # general whitespace
2051 \xc2\xad| # 00ad SOFT HYPHEN
2052 \xe1\xa0\x86| # 1806 MONGOLIAN TODO SOFT HYPHEN
2053 \xe2\x80\x8b| # 200b ZERO WIDTH SPACE
2054 \xe2\x81\xa0| # 2060 WORD JOINER
2055 \xef\xbb\xbf| # feff ZERO WIDTH NO-BREAK SPACE
2056 \xcd\x8f| # 034f COMBINING GRAPHEME JOINER
2057 \xe1\xa0\x8b| # 180b MONGOLIAN FREE VARIATION SELECTOR ONE
2058 \xe1\xa0\x8c| # 180c MONGOLIAN FREE VARIATION SELECTOR TWO
2059 \xe1\xa0\x8d| # 180d MONGOLIAN FREE VARIATION SELECTOR THREE
2060 \xe2\x80\x8c| # 200c ZERO WIDTH NON-JOINER
2061 \xe2\x80\x8d| # 200d ZERO WIDTH JOINER
2062 [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe0f VARIATION SELECTOR-1-16
2063 /xuD";
2064
2065 $host = preg_replace( $strip, '', $host );
2066
2067 // IPv6 host names are bracketed with []. Url-decode these.
2068 if ( substr_compare( "//%5B", $host, 0, 5 ) === 0 &&
2069 preg_match( '!^//%5B([0-9A-Fa-f:.]+)%5D((:\d+)?)$!', $host, $matches )
2070 ) {
2071 $host = '//[' . $matches[1] . ']' . $matches[2];
2072 }
2073
2074 // @todo FIXME: Validate hostnames here
2075
2076 return $protocol . $host . $rest;
2077 } else {
2078 return $url;
2079 }
2080 }
2081
2082 /**
2083 * @param array $matches
2084 * @return string
2085 */
2086 static function cleanUrlCallback( $matches ) {
2087 return urlencode( $matches[0] );
2088 }
2089
2090 /**
2091 * Does a string look like an e-mail address?
2092 *
2093 * This validates an email address using an HTML5 specification found at:
2094 * http://www.whatwg.org/html/states-of-the-type-attribute.html#valid-e-mail-address
2095 * Which as of 2011-01-24 says:
2096 *
2097 * A valid e-mail address is a string that matches the ABNF production
2098 * 1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
2099 * in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
2100 * 3.5.
2101 *
2102 * This function is an implementation of the specification as requested in
2103 * T24449.
2104 *
2105 * Client-side forms will use the same standard validation rules via JS or
2106 * HTML 5 validation; additional restrictions can be enforced server-side
2107 * by extensions via the 'isValidEmailAddr' hook.
2108 *
2109 * Note that this validation doesn't 100% match RFC 2822, but is believed
2110 * to be liberal enough for wide use. Some invalid addresses will still
2111 * pass validation here.
2112 *
2113 * @since 1.18
2114 *
2115 * @param string $addr E-mail address
2116 * @return bool
2117 */
2118 public static function validateEmail( $addr ) {
2119 $result = null;
2120 if ( !Hooks::run( 'isValidEmailAddr', [ $addr, &$result ] ) ) {
2121 return $result;
2122 }
2123
2124 // Please note strings below are enclosed in brackets [], this make the
2125 // hyphen "-" a range indicator. Hence it is double backslashed below.
2126 // See T28948
2127 $rfc5322_atext = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~";
2128 $rfc1034_ldh_str = "a-z0-9\\-";
2129
2130 $html5_email_regexp = "/
2131 ^ # start of string
2132 [$rfc5322_atext\\.]+ # user part which is liberal :p
2133 @ # 'apostrophe'
2134 [$rfc1034_ldh_str]+ # First domain part
2135 (\\.[$rfc1034_ldh_str]+)* # Following part prefixed with a dot
2136 $ # End of string
2137 /ix"; // case Insensitive, eXtended
2138
2139 return (bool)preg_match( $html5_email_regexp, $addr );
2140 }
2141 }
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