3 * HTML sanitizer for %MediaWiki.
5 * Copyright © 2002-2005 Brion Vibber <brion@pobox.com> et al
6 * https://www.mediawiki.org/
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.
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.
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
28 * HTML sanitizer for MediaWiki
33 * Regular expression to match various types of character references in
34 * Sanitizer::normalizeCharReferences and Sanitizer::decodeCharReferences
36 const CHAR_REFS_REGEX
=
37 '/&([A-Za-z0-9\x80-\xff]+);
39 |&\#[xX]([0-9A-Fa-f]+);
43 * Acceptable tag name charset from HTML5 parsing spec
44 * https://www.w3.org/TR/html5/syntax.html#tag-open-state
46 const ELEMENT_BITS_REGEX
= '!^(/?)([A-Za-z][^\t\n\v />\0]*+)([^>]*?)(/?>)([^<]*)$!';
49 * Blacklist for evil uris like javascript:
50 * WARNING: DO NOT use this in any place that actually requires blacklisting
51 * for security reasons. There are NUMEROUS[1] ways to bypass blacklisting, the
52 * only way to be secure from javascript: uri based xss vectors is to whitelist
53 * things that you know are safe and deny everything else.
54 * [1]: http://ha.ckers.org/xss.html
56 const EVIL_URI_PATTERN
= '!(^|\s|\*/\s*)(javascript|vbscript)([^\w]|$)!i';
57 const XMLNS_ATTRIBUTE_PATTERN
= "/^xmlns:[:A-Z_a-z-.0-9]+$/";
60 * List of all named character entities defined in HTML 4.01
61 * https://www.w3.org/TR/html4/sgml/entities.html
62 * As well as ' which is only defined starting in XHTML1.
64 private static $htmlEntities = [
80 'apos' => 39, // New in XHTML & HTML 5; avoid in output for compatibility with IE.
321 * Character entity aliases accepted by MediaWiki
323 private static $htmlEntityAliases = [
329 * Lazy-initialised attributes regex, see getAttribsRegex()
331 private static $attribsRegex;
334 * Regular expression to match HTML/XML attribute pairs within a tag.
335 * Allows some... latitude. Based on,
336 * https://www.w3.org/TR/html5/syntax.html#before-attribute-value-state
337 * Used in Sanitizer::fixTagAttributes and Sanitizer::decodeTagAttributes
340 static function getAttribsRegex() {
341 if ( self
::$attribsRegex === null ) {
342 $attribFirst = '[:A-Z_a-z0-9]';
343 $attrib = '[:A-Z_a-z-.0-9]';
344 $space = '[\x09\x0a\x0c\x0d\x20]';
345 self
::$attribsRegex =
346 "/(?:^|$space)({$attribFirst}{$attrib}*)
349 # The attribute value: quoted or alone
356 return self
::$attribsRegex;
360 * Return the various lists of recognized tags
361 * @param array $extratags For any extra tags to include
362 * @param array $removetags For any tags (default or extra) to exclude
365 public static function getRecognizedTagData( $extratags = [], $removetags = [] ) {
366 global $wgAllowImageTag;
368 static $htmlpairsStatic, $htmlsingle, $htmlsingleonly, $htmlnest, $tabletags,
369 $htmllist, $listtags, $htmlsingleallowed, $htmlelementsStatic, $staticInitialised;
371 // Base our staticInitialised variable off of the global config state so that if the globals
372 // are changed (like in the screwed up test system) we will re-initialise the settings.
373 $globalContext = $wgAllowImageTag;
374 if ( !$staticInitialised ||
$staticInitialised != $globalContext ) {
375 $htmlpairsStatic = [ # Tags that must be closed
376 'b', 'bdi', 'del', 'i', 'ins', 'u', 'font', 'big', 'small', 'sub', 'sup', 'h1',
377 'h2', 'h3', 'h4', 'h5', 'h6', 'cite', 'code', 'em', 's',
378 'strike', 'strong', 'tt', 'var', 'div', 'center',
379 'blockquote', 'ol', 'ul', 'dl', 'table', 'caption', 'pre',
380 'ruby', 'rb', 'rp', 'rt', 'rtc', 'p', 'span', 'abbr', 'dfn',
381 'kbd', 'samp', 'data', 'time', 'mark'
384 'br', 'wbr', 'hr', 'li', 'dt', 'dd', 'meta', 'link'
387 # Elements that cannot have close tags. This is (not coincidentally)
388 # also the list of tags for which the HTML 5 parsing algorithm
389 # requires you to "acknowledge the token's self-closing flag", i.e.
390 # a self-closing tag like <br/> is not an HTML 5 parse error only
393 'br', 'wbr', 'hr', 'meta', 'link'
396 $htmlnest = [ # Tags that can be nested--??
397 'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
398 'li', 'dl', 'dt', 'dd', 'font', 'big', 'small', 'sub', 'sup', 'span',
399 'var', 'kbd', 'samp', 'em', 'strong', 'q', 'ruby', 'bdo'
401 $tabletags = [ # Can only appear inside table, we will close them
404 $htmllist = [ # Tags used by list
407 $listtags = [ # Tags that can appear in a list
411 if ( $wgAllowImageTag ) {
412 $htmlsingle[] = 'img';
413 $htmlsingleonly[] = 'img';
416 $htmlsingleallowed = array_unique( array_merge( $htmlsingle, $tabletags ) );
417 $htmlelementsStatic = array_unique( array_merge( $htmlsingle, $htmlpairsStatic, $htmlnest ) );
419 # Convert them all to hashtables for faster lookup
420 $vars = [ 'htmlpairsStatic', 'htmlsingle', 'htmlsingleonly', 'htmlnest', 'tabletags',
421 'htmllist', 'listtags', 'htmlsingleallowed', 'htmlelementsStatic' ];
422 foreach ( $vars as $var ) {
423 $
$var = array_flip( $
$var );
425 $staticInitialised = $globalContext;
428 # Populate $htmlpairs and $htmlelements with the $extratags and $removetags arrays
429 $extratags = array_flip( $extratags );
430 $removetags = array_flip( $removetags );
431 $htmlpairs = array_merge( $extratags, $htmlpairsStatic );
432 $htmlelements = array_diff_key( array_merge( $extratags, $htmlelementsStatic ), $removetags );
435 'htmlpairs' => $htmlpairs,
436 'htmlsingle' => $htmlsingle,
437 'htmlsingleonly' => $htmlsingleonly,
438 'htmlnest' => $htmlnest,
439 'tabletags' => $tabletags,
440 'htmllist' => $htmllist,
441 'listtags' => $listtags,
442 'htmlsingleallowed' => $htmlsingleallowed,
443 'htmlelements' => $htmlelements,
448 * Cleans up HTML, removes dangerous tags and attributes, and
449 * removes HTML comments
450 * @param string $text
451 * @param callable $processCallback Callback to do any variable or parameter
452 * replacements in HTML attribute values
453 * @param array|bool $args Arguments for the processing callback
454 * @param array $extratags For any extra tags to include
455 * @param array $removetags For any tags (default or extra) to exclude
456 * @param callable $warnCallback (Deprecated) Callback allowing the
457 * addition of a tracking category when bad input is encountered.
458 * DO NOT ADD NEW PARAMETERS AFTER $warnCallback, since it will be
462 public static function removeHTMLtags( $text, $processCallback = null,
463 $args = [], $extratags = [], $removetags = [], $warnCallback = null
465 extract( self
::getRecognizedTagData( $extratags, $removetags ) );
467 # Remove HTML comments
468 $text = Sanitizer
::removeHTMLcomments( $text );
469 $bits = explode( '<', $text );
470 $text = str_replace( '>', '>', array_shift( $bits ) );
471 if ( !MWTidy
::isEnabled() ) {
472 $tagstack = $tablestack = [];
473 foreach ( $bits as $x ) {
475 # $slash: Does the current element start with a '/'?
476 # $t: Current element name
477 # $params: String between element name and >
478 # $brace: Ending '>' or '/>'
479 # $rest: Everything until the next element of $bits
480 if ( preg_match( self
::ELEMENT_BITS_REGEX
, $x, $regs ) ) {
481 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
483 $slash = $t = $params = $brace = $rest = null;
487 $t = strtolower( $t );
488 if ( isset( $htmlelements[$t] ) ) {
490 if ( $slash && isset( $htmlsingleonly[$t] ) ) {
492 } elseif ( $slash ) {
493 # Closing a tag... is it the one we just opened?
494 MediaWiki\
suppressWarnings();
495 $ot = array_pop( $tagstack );
496 MediaWiki\restoreWarnings
();
499 if ( isset( $htmlsingleallowed[$ot] ) ) {
500 # Pop all elements with an optional close tag
501 # and see if we find a match below them
503 array_push( $optstack, $ot );
504 MediaWiki\
suppressWarnings();
505 $ot = array_pop( $tagstack );
506 MediaWiki\restoreWarnings
();
507 while ( $ot != $t && isset( $htmlsingleallowed[$ot] ) ) {
508 array_push( $optstack, $ot );
509 MediaWiki\
suppressWarnings();
510 $ot = array_pop( $tagstack );
511 MediaWiki\restoreWarnings
();
514 # No match. Push the optional elements back again
516 MediaWiki\
suppressWarnings();
517 $ot = array_pop( $optstack );
518 MediaWiki\restoreWarnings
();
520 array_push( $tagstack, $ot );
521 MediaWiki\
suppressWarnings();
522 $ot = array_pop( $optstack );
523 MediaWiki\restoreWarnings
();
527 MediaWiki\
suppressWarnings();
528 array_push( $tagstack, $ot );
529 MediaWiki\restoreWarnings
();
531 # <li> can be nested in <ul> or <ol>, skip those cases:
532 if ( !isset( $htmllist[$ot] ) ||
!isset( $listtags[$t] ) ) {
537 if ( $t == 'table' ) {
538 $tagstack = array_pop( $tablestack );
543 # Keep track for later
544 if ( isset( $tabletags[$t] ) && !in_array( 'table', $tagstack ) ) {
546 } elseif ( in_array( $t, $tagstack ) && !isset( $htmlnest[$t] ) ) {
548 # Is it a self closed htmlpair ? (T7487)
549 } elseif ( $brace == '/>' && isset( $htmlpairs[$t] ) ) {
550 // Eventually we'll just remove the self-closing
551 // slash, in order to be consistent with HTML5
554 // For now, let's just warn authors to clean up.
555 if ( is_callable( $warnCallback ) ) {
556 call_user_func_array( $warnCallback, [ 'deprecated-self-close-category' ] );
559 } elseif ( isset( $htmlsingleonly[$t] ) ) {
560 # Hack to force empty tag for unclosable elements
562 } elseif ( isset( $htmlsingle[$t] ) ) {
563 # Hack to not close $htmlsingle tags
565 # Still need to push this optionally-closed tag to
566 # the tag stack so that we can match end tags
567 # instead of marking them as bad.
568 array_push( $tagstack, $t );
569 } elseif ( isset( $tabletags[$t] ) && in_array( $t, $tagstack ) ) {
570 // New table tag but forgot to close the previous one
573 if ( $t == 'table' ) {
574 array_push( $tablestack, $tagstack );
577 array_push( $tagstack, $t );
580 # Replace any variables or template parameters with
582 if ( is_callable( $processCallback ) ) {
583 call_user_func_array( $processCallback, [ &$params, $args ] );
586 if ( !Sanitizer
::validateTag( $params, $t ) ) {
590 # Strip non-approved attributes from the tag
591 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
594 $rest = str_replace( '>', '>', $rest );
595 $close = ( $brace == '/>' && !$slash ) ?
' /' : '';
596 $text .= "<$slash$t$newparams$close>$rest";
600 $text .= '<' . str_replace( '>', '>', $x );
602 # Close off any remaining tags
603 while ( is_array( $tagstack ) && ( $t = array_pop( $tagstack ) ) ) {
605 if ( $t == 'table' ) {
606 $tagstack = array_pop( $tablestack );
610 # this might be possible using tidy itself
611 foreach ( $bits as $x ) {
612 if ( preg_match( self
::ELEMENT_BITS_REGEX
, $x, $regs ) ) {
613 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
616 $t = strtolower( $t );
617 if ( isset( $htmlelements[$t] ) ) {
618 if ( is_callable( $processCallback ) ) {
619 call_user_func_array( $processCallback, [ &$params, $args ] );
622 if ( $brace == '/>' && !( isset( $htmlsingle[$t] ) ||
isset( $htmlsingleonly[$t] ) ) ) {
623 // Eventually we'll just remove the self-closing
624 // slash, in order to be consistent with HTML5
627 // For now, let's just warn authors to clean up.
628 if ( is_callable( $warnCallback ) ) {
629 call_user_func_array( $warnCallback, [ 'deprecated-self-close-category' ] );
632 if ( !Sanitizer
::validateTag( $params, $t ) ) {
636 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
638 if ( $brace === '/>' && !isset( $htmlsingleonly[$t] ) ) {
639 # Interpret self-closing tags as empty tags even when
640 # HTML 5 would interpret them as start tags. Such input
641 # is commonly seen on Wikimedia wikis with this intention.
645 $rest = str_replace( '>', '>', $rest );
646 $text .= "<$slash$t$newparams$brace$rest";
651 $text .= '<' . str_replace( '>', '>', $x );
658 * Remove '<!--', '-->', and everything between.
659 * To avoid leaving blank lines, when a comment is both preceded
660 * and followed by a newline (ignoring spaces), trim leading and
661 * trailing spaces and one of the newlines.
663 * @param string $text
666 public static function removeHTMLcomments( $text ) {
667 while ( ( $start = strpos( $text, '<!--' ) ) !== false ) {
668 $end = strpos( $text, '-->', $start +
4 );
669 if ( $end === false ) {
670 # Unterminated comment; bail out
676 # Trim space and newline if the comment is both
677 # preceded and followed by a newline
678 $spaceStart = max( $start - 1, 0 );
679 $spaceLen = $end - $spaceStart;
680 while ( substr( $text, $spaceStart, 1 ) === ' ' && $spaceStart > 0 ) {
684 while ( substr( $text, $spaceStart +
$spaceLen, 1 ) === ' ' ) {
687 if ( substr( $text, $spaceStart, 1 ) === "\n"
688 && substr( $text, $spaceStart +
$spaceLen, 1 ) === "\n" ) {
689 # Remove the comment, leading and trailing
690 # spaces, and leave only one newline.
691 $text = substr_replace( $text, "\n", $spaceStart, $spaceLen +
1 );
693 # Remove just the comment.
694 $text = substr_replace( $text, '', $start, $end - $start );
701 * Takes attribute names and values for a tag and the tag name and
702 * validates that the tag is allowed to be present.
703 * This DOES NOT validate the attributes, nor does it validate the
704 * tags themselves. This method only handles the special circumstances
705 * where we may want to allow a tag within content but ONLY when it has
706 * specific attributes set.
708 * @param string $params
709 * @param string $element
712 static function validateTag( $params, $element ) {
713 $params = Sanitizer
::decodeTagAttributes( $params );
715 if ( $element == 'meta' ||
$element == 'link' ) {
716 if ( !isset( $params['itemprop'] ) ) {
717 // <meta> and <link> must have an itemprop="" otherwise they are not valid or safe in content
720 if ( $element == 'meta' && !isset( $params['content'] ) ) {
721 // <meta> must have a content="" for the itemprop
724 if ( $element == 'link' && !isset( $params['href'] ) ) {
725 // <link> must have an associated href=""
734 * Take an array of attribute names and values and normalize or discard
735 * illegal values for the given element type.
737 * - Discards attributes not on a whitelist for the given element
738 * - Unsafe style attributes are discarded
739 * - Invalid id attributes are re-encoded
741 * @param array $attribs
742 * @param string $element
745 * @todo Check for legal values where the DTD limits things.
746 * @todo Check for unique id attribute :P
748 static function validateTagAttributes( $attribs, $element ) {
749 return Sanitizer
::validateAttributes( $attribs,
750 Sanitizer
::attributeWhitelist( $element ) );
754 * Take an array of attribute names and values and normalize or discard
755 * illegal values for the given whitelist.
757 * - Discards attributes not on the given whitelist
758 * - Unsafe style attributes are discarded
759 * - Invalid id attributes are re-encoded
761 * @param array $attribs
762 * @param array $whitelist List of allowed attribute names
765 * @todo Check for legal values where the DTD limits things.
766 * @todo Check for unique id attribute :P
768 static function validateAttributes( $attribs, $whitelist ) {
769 $whitelist = array_flip( $whitelist );
770 $hrefExp = '/^(' . wfUrlProtocols() . ')[^\s]+$/';
773 foreach ( $attribs as $attribute => $value ) {
774 # Allow XML namespace declaration to allow RDFa
775 if ( preg_match( self
::XMLNS_ATTRIBUTE_PATTERN
, $attribute ) ) {
776 if ( !preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
777 $out[$attribute] = $value;
783 # Allow any attribute beginning with "data-"
785 # * Disallow data attributes used by MediaWiki code
786 # * Ensure that the attribute is not namespaced by banning
788 if ( !preg_match( '/^data-[^:]*$/i', $attribute )
789 && !isset( $whitelist[$attribute] )
790 || self
::isReservedDataAttribute( $attribute )
795 # Strip javascript "expression" from stylesheets.
796 # http://msdn.microsoft.com/workshop/author/dhtml/overview/recalc.asp
797 if ( $attribute == 'style' ) {
798 $value = Sanitizer
::checkCss( $value );
801 # Escape HTML id attributes
802 if ( $attribute === 'id' ) {
803 $value = Sanitizer
::escapeId( $value, 'noninitial' );
806 # Escape HTML id reference lists
807 if ( $attribute === 'aria-describedby'
808 ||
$attribute === 'aria-flowto'
809 ||
$attribute === 'aria-labelledby'
810 ||
$attribute === 'aria-owns'
812 $value = Sanitizer
::escapeIdReferenceList( $value, 'noninitial' );
815 // RDFa and microdata properties allow URLs, URIs and/or CURIs.
816 // Check them for sanity.
817 if ( $attribute === 'rel' ||
$attribute === 'rev'
819 ||
$attribute === 'about' ||
$attribute === 'property'
820 ||
$attribute === 'resource' ||
$attribute === 'datatype'
821 ||
$attribute === 'typeof'
823 ||
$attribute === 'itemid' ||
$attribute === 'itemprop'
824 ||
$attribute === 'itemref' ||
$attribute === 'itemscope'
825 ||
$attribute === 'itemtype'
827 // Paranoia. Allow "simple" values but suppress javascript
828 if ( preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
833 # NOTE: even though elements using href/src are not allowed directly, supply
834 # validation code that can be used by tag hook handlers, etc
835 if ( $attribute === 'href' ||
$attribute === 'src' ||
$attribute === 'poster' ) {
836 if ( !preg_match( $hrefExp, $value ) ) {
837 continue; // drop any href or src attributes not using an allowed protocol.
838 // NOTE: this also drops all relative URLs
842 // If this attribute was previously set, override it.
843 // Output should only have one attribute of each name.
844 $out[$attribute] = $value;
847 # itemtype, itemid, itemref don't make sense without itemscope
848 if ( !array_key_exists( 'itemscope', $out ) ) {
849 unset( $out['itemtype'] );
850 unset( $out['itemid'] );
851 unset( $out['itemref'] );
853 # TODO: Strip itemprop if we aren't descendants of an itemscope or pointed to by an itemref.
859 * Given an attribute name, checks whether it is a reserved data attribute
860 * (such as data-mw-foo) which is unavailable to user-generated HTML so MediaWiki
861 * core and extension code can safely use it to communicate with frontend code.
862 * @param string $attr Attribute name.
865 public static function isReservedDataAttribute( $attr ) {
866 // data-ooui is reserved for ooui.
867 // data-mw and data-parsoid are reserved for parsoid.
868 // data-mw-<name here> is reserved for extensions (or core) if
869 // they need to communicate some data to the client and want to be
870 // sure that it isn't coming from an untrusted user.
871 // We ignore the possibility of namespaces since user-generated HTML
872 // can't use them anymore.
873 return (bool)preg_match( '/^data-(ooui|mw|parsoid)/i', $attr );
877 * Merge two sets of HTML attributes. Conflicting items in the second set
878 * will override those in the first, except for 'class' attributes which
879 * will be combined (if they're both strings).
881 * @todo implement merging for other attributes such as style
886 static function mergeAttributes( $a, $b ) {
887 $out = array_merge( $a, $b );
888 if ( isset( $a['class'] ) && isset( $b['class'] )
889 && is_string( $a['class'] ) && is_string( $b['class'] )
890 && $a['class'] !== $b['class']
892 $classes = preg_split( '/\s+/', "{$a['class']} {$b['class']}",
893 -1, PREG_SPLIT_NO_EMPTY
);
894 $out['class'] = implode( ' ', array_unique( $classes ) );
900 * Normalize CSS into a format we can easily search for hostile input
901 * - decode character references
902 * - decode escape sequences
903 * - convert characters that IE6 interprets into ascii
904 * - remove comments, unless the entire value is one single comment
905 * @param string $value the css string
906 * @return string normalized css
908 public static function normalizeCss( $value ) {
910 // Decode character references like {
911 $value = Sanitizer
::decodeCharReferences( $value );
913 // Decode escape sequences and line continuation
914 // See the grammar in the CSS 2 spec, appendix D.
915 // This has to be done AFTER decoding character references.
916 // This means it isn't possible for this function to return
917 // unsanitized escape sequences. It is possible to manufacture
918 // input that contains character references that decode to
919 // escape sequences that decode to character references, but
920 // it's OK for the return value to contain character references
921 // because the caller is supposed to escape those anyway.
923 if ( !$decodeRegex ) {
924 $space = '[\\x20\\t\\r\\n\\f]';
925 $nl = '(?:\\n|\\r\\n|\\r|\\f)';
927 $decodeRegex = "/ $backslash
929 ($nl) | # 1. Line continuation
930 ([0-9A-Fa-f]{1,6})$space? | # 2. character number
931 (.) | # 3. backslash cancelling special meaning
932 () | # 4. backslash at end of string
935 $value = preg_replace_callback( $decodeRegex,
936 [ __CLASS__
, 'cssDecodeCallback' ], $value );
938 // Normalize Halfwidth and Fullwidth Unicode block that IE6 might treat as ascii
939 $value = preg_replace_callback(
940 '/[!-[]-z]/u', // U+FF01 to U+FF5A, excluding U+FF3C (T60088)
941 function ( $matches ) {
942 $cp = UtfNormal\Utils
::utf8ToCodepoint( $matches[0] );
943 if ( $cp === false ) {
946 return chr( $cp - 65248 ); // ASCII range \x21-\x7A
951 // Convert more characters IE6 might treat as ascii
952 // U+0280, U+0274, U+207F, U+029F, U+026A, U+207D, U+208D
953 $value = str_replace(
954 [ 'ʀ', 'ɴ', 'ⁿ', 'ʟ', 'ɪ', '⁽', '₍' ],
955 [ 'r', 'n', 'n', 'l', 'i', '(', '(' ],
959 // Let the value through if it's nothing but a single comment, to
960 // allow other functions which may reject it to pass some error
962 if ( !preg_match( '! ^ \s* /\* [^*\\/]* \*/ \s* $ !x', $value ) ) {
963 // Remove any comments; IE gets token splitting wrong
964 // This must be done AFTER decoding character references and
965 // escape sequences, because those steps can introduce comments
966 // This step cannot introduce character references or escape
967 // sequences, because it replaces comments with spaces rather
968 // than removing them completely.
969 $value = StringUtils
::delimiterReplace( '/*', '*/', ' ', $value );
971 // Remove anything after a comment-start token, to guard against
972 // incorrect client implementations.
973 $commentPos = strpos( $value, '/*' );
974 if ( $commentPos !== false ) {
975 $value = substr( $value, 0, $commentPos );
979 // S followed by repeat, iteration, or prolonged sound marks,
980 // which IE will treat as "ss"
981 $value = preg_replace(
983 \xE3\x80\xB1 | # U+3031
984 \xE3\x82\x9D | # U+309D
985 \xE3\x83\xBC | # U+30FC
986 \xE3\x83\xBD | # U+30FD
987 \xEF\xB9\xBC | # U+FE7C
988 \xEF\xB9\xBD | # U+FE7D
989 \xEF\xBD\xB0 # U+FF70
999 * Pick apart some CSS and check it for forbidden or unsafe structures.
1000 * Returns a sanitized string. This sanitized string will have
1001 * character references and escape sequences decoded and comments
1002 * stripped (unless it is itself one valid comment, in which case the value
1003 * will be passed through). If the input is just too evil, only a comment
1004 * complaining about evilness will be returned.
1006 * Currently URL references, 'expression', 'tps' are forbidden.
1008 * NOTE: Despite the fact that character references are decoded, the
1009 * returned string may contain character references given certain
1010 * clever input strings. These character references must
1011 * be escaped before the return value is embedded in HTML.
1013 * @param string $value
1016 static function checkCss( $value ) {
1017 $value = self
::normalizeCss( $value );
1019 // Reject problematic keywords and control characters
1020 if ( preg_match( '/[\000-\010\013\016-\037\177]/', $value ) ||
1021 strpos( $value, UtfNormal\Constants
::UTF8_REPLACEMENT
) !== false ) {
1022 return '/* invalid control char */';
1023 } elseif ( preg_match(
1028 | -o-link-source\s*:
1033 | attr\s*\([^)]+[\s,]+url
1035 return '/* insecure input */';
1041 * @param array $matches
1044 static function cssDecodeCallback( $matches ) {
1045 if ( $matches[1] !== '' ) {
1046 // Line continuation
1048 } elseif ( $matches[2] !== '' ) {
1049 $char = UtfNormal\Utils
::codepointToUtf8( hexdec( $matches[2] ) );
1050 } elseif ( $matches[3] !== '' ) {
1051 $char = $matches[3];
1055 if ( $char == "\n" ||
$char == '"' ||
$char == "'" ||
$char == '\\' ) {
1056 // These characters need to be escaped in strings
1057 // Clean up the escape sequence to avoid parsing errors by clients
1058 return '\\' . dechex( ord( $char ) ) . ' ';
1060 // Decode unnecessary escape
1066 * Take a tag soup fragment listing an HTML element's attributes
1067 * and normalize it to well-formed XML, discarding unwanted attributes.
1068 * Output is safe for further wikitext processing, with escaping of
1069 * values that could trigger problems.
1071 * - Normalizes attribute names to lowercase
1072 * - Discards attributes not on a whitelist for the given element
1073 * - Turns broken or invalid entities into plaintext
1074 * - Double-quotes all attribute values
1075 * - Attributes without values are given the name as attribute
1076 * - Double attributes are discarded
1077 * - Unsafe style attributes are discarded
1078 * - Prepends space if there are attributes.
1079 * - (Optionally) Sorts attributes by name.
1081 * @param string $text
1082 * @param string $element
1083 * @param bool $sorted Whether to sort the attributes (default: false)
1086 static function fixTagAttributes( $text, $element, $sorted = false ) {
1087 if ( trim( $text ) == '' ) {
1091 $decoded = Sanitizer
::decodeTagAttributes( $text );
1092 $stripped = Sanitizer
::validateTagAttributes( $decoded, $element );
1098 return Sanitizer
::safeEncodeTagAttributes( $stripped );
1102 * Encode an attribute value for HTML output.
1103 * @param string $text
1104 * @return string HTML-encoded text fragment
1106 static function encodeAttribute( $text ) {
1107 $encValue = htmlspecialchars( $text, ENT_QUOTES
);
1109 // Whitespace is normalized during attribute decoding,
1110 // so if we've been passed non-spaces we must encode them
1111 // ahead of time or they won't be preserved.
1112 $encValue = strtr( $encValue, [
1122 * Encode an attribute value for HTML tags, with extra armoring
1123 * against further wiki processing.
1124 * @param string $text
1125 * @return string HTML-encoded text fragment
1127 static function safeEncodeAttribute( $text ) {
1128 $encValue = Sanitizer
::encodeAttribute( $text );
1130 # Templates and links may be expanded in later parsing,
1131 # creating invalid or dangerous output. Suppress this.
1132 $encValue = strtr( $encValue, [
1133 '<' => '<', // This should never happen,
1134 '>' => '>', // we've received invalid input
1135 '"' => '"', // which should have been escaped.
1137 '}' => '}', // prevent unpaired language conversion syntax
1139 "''" => '''',
1140 'ISBN' => 'ISBN',
1142 'PMID' => 'PMID',
1148 $encValue = preg_replace_callback(
1149 '/((?i)' . wfUrlProtocols() . ')/',
1150 [ 'Sanitizer', 'armorLinksCallback' ],
1156 * Given a value, escape it so that it can be used in an id attribute and
1157 * return it. This will use HTML5 validation if $wgExperimentalHtmlIds is
1158 * true, allowing anything but ASCII whitespace. Otherwise it will use
1159 * HTML 4 rules, which means a narrow subset of ASCII, with bad characters
1160 * escaped with lots of dots.
1162 * To ensure we don't have to bother escaping anything, we also strip ', ",
1163 * & even if $wgExperimentalIds is true. TODO: Is this the best tactic?
1164 * We also strip # because it upsets IE, and % because it could be
1165 * ambiguous if it's part of something that looks like a percent escape
1166 * (which don't work reliably in fragments cross-browser).
1168 * @see https://www.w3.org/TR/html401/types.html#type-name Valid characters
1169 * in the id and name attributes
1170 * @see https://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with
1172 * @see https://www.w3.org/TR/html5/dom.html#the-id-attribute
1173 * HTML5 definition of id attribute
1175 * @param string $id Id to escape
1176 * @param string|array $options String or array of strings (default is array()):
1177 * 'noninitial': This is a non-initial fragment of an id, not a full id,
1178 * so don't pay attention if the first character isn't valid at the
1179 * beginning of an id. Only matters if $wgExperimentalHtmlIds is
1181 * 'legacy': Behave the way the old HTML 4-based ID escaping worked even
1182 * if $wgExperimentalHtmlIds is used, so we can generate extra
1183 * anchors and links won't break.
1186 static function escapeId( $id, $options = [] ) {
1187 global $wgExperimentalHtmlIds;
1188 $options = (array)$options;
1190 $id = Sanitizer
::decodeCharReferences( $id );
1192 if ( $wgExperimentalHtmlIds && !in_array( 'legacy', $options ) ) {
1193 $id = preg_replace( '/[ \t\n\r\f_\'"&#%]+/', '_', $id );
1194 $id = trim( $id, '_' );
1196 // Must have been all whitespace to start with.
1203 // HTML4-style escaping
1209 $id = urlencode( strtr( $id, ' ', '_' ) );
1210 $id = str_replace( array_keys( $replace ), array_values( $replace ), $id );
1212 if ( !preg_match( '/^[a-zA-Z]/', $id ) && !in_array( 'noninitial', $options ) ) {
1213 // Initial character must be a letter!
1220 * Given a string containing a space delimited list of ids, escape each id
1221 * to match ids escaped by the escapeId() function.
1225 * @param string $referenceString Space delimited list of ids
1226 * @param string|array $options String or array of strings (default is array()):
1227 * 'noninitial': This is a non-initial fragment of an id, not a full id,
1228 * so don't pay attention if the first character isn't valid at the
1229 * beginning of an id. Only matters if $wgExperimentalHtmlIds is
1231 * 'legacy': Behave the way the old HTML 4-based ID escaping worked even
1232 * if $wgExperimentalHtmlIds is used, so we can generate extra
1233 * anchors and links won't break.
1236 static function escapeIdReferenceList( $referenceString, $options = [] ) {
1237 # Explode the space delimited list string into an array of tokens
1238 $references = preg_split( '/\s+/', "{$referenceString}", -1, PREG_SPLIT_NO_EMPTY
);
1240 # Escape each token as an id
1241 foreach ( $references as &$ref ) {
1242 $ref = Sanitizer
::escapeId( $ref, $options );
1245 # Merge the array back to a space delimited list string
1246 # If the array is empty, the result will be an empty string ('')
1247 $referenceString = implode( ' ', $references );
1249 return $referenceString;
1253 * Given a value, escape it so that it can be used as a CSS class and
1256 * @todo For extra validity, input should be validated UTF-8.
1258 * @see https://www.w3.org/TR/CSS21/syndata.html Valid characters/format
1260 * @param string $class
1263 static function escapeClass( $class ) {
1264 // Convert ugly stuff to underscores and kill underscores in ugly places
1265 return rtrim( preg_replace(
1266 [ '/(^[0-9\\-])|[\\x00-\\x20!"#$%&\'()*+,.\\/:;<=>?@[\\]^`{|}~]|\\xC2\\xA0/', '/_+/' ],
1272 * Given HTML input, escape with htmlspecialchars but un-escape entities.
1273 * This allows (generally harmless) entities like   to survive.
1275 * @param string $html HTML to escape
1276 * @return string Escaped input
1278 static function escapeHtmlAllowEntities( $html ) {
1279 $html = Sanitizer
::decodeCharReferences( $html );
1280 # It seems wise to escape ' as well as ", as a matter of course. Can't
1281 # hurt. Use ENT_SUBSTITUTE so that incorrectly truncated multibyte characters
1282 # don't cause the entire string to disappear.
1283 $html = htmlspecialchars( $html, ENT_QUOTES | ENT_SUBSTITUTE
);
1288 * Regex replace callback for armoring links against further processing.
1289 * @param array $matches
1292 private static function armorLinksCallback( $matches ) {
1293 return str_replace( ':', ':', $matches[1] );
1297 * Return an associative array of attribute names and values from
1298 * a partial tag string. Attribute names are forced to lowercase,
1299 * character references are decoded to UTF-8 text.
1301 * @param string $text
1304 public static function decodeTagAttributes( $text ) {
1305 if ( trim( $text ) == '' ) {
1311 if ( !preg_match_all(
1312 self
::getAttribsRegex(),
1315 PREG_SET_ORDER
) ) {
1319 foreach ( $pairs as $set ) {
1320 $attribute = strtolower( $set[1] );
1321 $value = Sanitizer
::getTagAttributeCallback( $set );
1323 // Normalize whitespace
1324 $value = preg_replace( '/[\t\r\n ]+/', ' ', $value );
1325 $value = trim( $value );
1327 // Decode character references
1328 $attribs[$attribute] = Sanitizer
::decodeCharReferences( $value );
1334 * Build a partial tag string from an associative array of attribute
1335 * names and values as returned by decodeTagAttributes.
1337 * @param array $assoc_array
1340 public static function safeEncodeTagAttributes( $assoc_array ) {
1342 foreach ( $assoc_array as $attribute => $value ) {
1343 $encAttribute = htmlspecialchars( $attribute );
1344 $encValue = Sanitizer
::safeEncodeAttribute( $value );
1346 $attribs[] = "$encAttribute=\"$encValue\"";
1348 return count( $attribs ) ?
' ' . implode( ' ', $attribs ) : '';
1352 * Pick the appropriate attribute value from a match set from the
1353 * attribs regex matches.
1356 * @throws MWException When tag conditions are not met.
1359 private static function getTagAttributeCallback( $set ) {
1360 if ( isset( $set[5] ) ) {
1363 } elseif ( isset( $set[4] ) ) {
1366 } elseif ( isset( $set[3] ) ) {
1369 } elseif ( !isset( $set[2] ) ) {
1370 # In XHTML, attributes must have a value so return an empty string.
1371 # See "Empty attribute syntax",
1372 # https://www.w3.org/TR/html5/syntax.html#syntax-attribute-name
1375 throw new MWException( "Tag conditions not met. This should never happen and is a bug." );
1380 * @param string $text
1383 private static function normalizeWhitespace( $text ) {
1384 return preg_replace(
1385 '/\r\n|[\x20\x0d\x0a\x09]/',
1391 * Normalizes whitespace in a section name, such as might be returned
1392 * by Parser::stripSectionName(), for use in the id's that are used for
1395 * @param string $section
1398 static function normalizeSectionNameWhitespace( $section ) {
1399 return trim( preg_replace( '/[ _]+/', ' ', $section ) );
1403 * Ensure that any entities and character references are legal
1404 * for XML and XHTML specifically. Any stray bits will be
1405 * &-escaped to result in a valid text fragment.
1407 * a. named char refs can only be < > & ", others are
1408 * numericized (this way we're well-formed even without a DTD)
1409 * b. any numeric char refs must be legal chars, not invalid or forbidden
1410 * c. use lower cased "&#x", not "&#X"
1411 * d. fix or reject non-valid attributes
1413 * @param string $text
1417 static function normalizeCharReferences( $text ) {
1418 return preg_replace_callback(
1419 self
::CHAR_REFS_REGEX
,
1420 [ 'Sanitizer', 'normalizeCharReferencesCallback' ],
1425 * @param string $matches
1428 static function normalizeCharReferencesCallback( $matches ) {
1430 if ( $matches[1] != '' ) {
1431 $ret = Sanitizer
::normalizeEntity( $matches[1] );
1432 } elseif ( $matches[2] != '' ) {
1433 $ret = Sanitizer
::decCharReference( $matches[2] );
1434 } elseif ( $matches[3] != '' ) {
1435 $ret = Sanitizer
::hexCharReference( $matches[3] );
1437 if ( is_null( $ret ) ) {
1438 return htmlspecialchars( $matches[0] );
1445 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1446 * return the equivalent numeric entity reference (except for the core <
1447 * > & "). If the entity is a MediaWiki-specific alias, returns
1448 * the HTML equivalent. Otherwise, returns HTML-escaped text of
1449 * pseudo-entity source (eg &foo;)
1451 * @param string $name
1454 static function normalizeEntity( $name ) {
1455 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1456 return '&' . self
::$htmlEntityAliases[$name] . ';';
1457 } elseif ( in_array( $name, [ 'lt', 'gt', 'amp', 'quot' ] ) ) {
1459 } elseif ( isset( self
::$htmlEntities[$name] ) ) {
1460 return '&#' . self
::$htmlEntities[$name] . ';';
1462 return "&$name;";
1467 * @param int $codepoint
1468 * @return null|string
1470 static function decCharReference( $codepoint ) {
1471 $point = intval( $codepoint );
1472 if ( Sanitizer
::validateCodepoint( $point ) ) {
1473 return sprintf( '&#%d;', $point );
1480 * @param int $codepoint
1481 * @return null|string
1483 static function hexCharReference( $codepoint ) {
1484 $point = hexdec( $codepoint );
1485 if ( Sanitizer
::validateCodepoint( $point ) ) {
1486 return sprintf( '&#x%x;', $point );
1493 * Returns true if a given Unicode codepoint is a valid character in
1494 * both HTML5 and XML.
1495 * @param int $codepoint
1498 private static function validateCodepoint( $codepoint ) {
1499 # U+000C is valid in HTML5 but not allowed in XML.
1500 # U+000D is valid in XML but not allowed in HTML5.
1501 # U+007F - U+009F are disallowed in HTML5 (control characters).
1502 return $codepoint == 0x09
1503 ||
$codepoint == 0x0a
1504 ||
( $codepoint >= 0x20 && $codepoint <= 0x7e )
1505 ||
( $codepoint >= 0xa0 && $codepoint <= 0xd7ff )
1506 ||
( $codepoint >= 0xe000 && $codepoint <= 0xfffd )
1507 ||
( $codepoint >= 0x10000 && $codepoint <= 0x10ffff );
1511 * Decode any character references, numeric or named entities,
1512 * in the text and return a UTF-8 string.
1514 * @param string $text
1517 public static function decodeCharReferences( $text ) {
1518 return preg_replace_callback(
1519 self
::CHAR_REFS_REGEX
,
1520 [ 'Sanitizer', 'decodeCharReferencesCallback' ],
1525 * Decode any character references, numeric or named entities,
1526 * in the next and normalize the resulting string. (T16952)
1528 * This is useful for page titles, not for text to be displayed,
1529 * MediaWiki allows HTML entities to escape normalization as a feature.
1531 * @param string $text Already normalized, containing entities
1532 * @return string Still normalized, without entities
1534 public static function decodeCharReferencesAndNormalize( $text ) {
1536 $text = preg_replace_callback(
1537 self
::CHAR_REFS_REGEX
,
1538 [ 'Sanitizer', 'decodeCharReferencesCallback' ],
1539 $text, /* limit */ -1, $count );
1542 return $wgContLang->normalize( $text );
1549 * @param string $matches
1552 static function decodeCharReferencesCallback( $matches ) {
1553 if ( $matches[1] != '' ) {
1554 return Sanitizer
::decodeEntity( $matches[1] );
1555 } elseif ( $matches[2] != '' ) {
1556 return Sanitizer
::decodeChar( intval( $matches[2] ) );
1557 } elseif ( $matches[3] != '' ) {
1558 return Sanitizer
::decodeChar( hexdec( $matches[3] ) );
1560 # Last case should be an ampersand by itself
1565 * Return UTF-8 string for a codepoint if that is a valid
1566 * character reference, otherwise U+FFFD REPLACEMENT CHARACTER.
1567 * @param int $codepoint
1571 static function decodeChar( $codepoint ) {
1572 if ( Sanitizer
::validateCodepoint( $codepoint ) ) {
1573 return UtfNormal\Utils
::codepointToUtf8( $codepoint );
1575 return UtfNormal\Constants
::UTF8_REPLACEMENT
;
1580 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1581 * return the UTF-8 encoding of that character. Otherwise, returns
1582 * pseudo-entity source (eg "&foo;")
1584 * @param string $name
1587 static function decodeEntity( $name ) {
1588 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1589 $name = self
::$htmlEntityAliases[$name];
1591 if ( isset( self
::$htmlEntities[$name] ) ) {
1592 return UtfNormal\Utils
::codepointToUtf8( self
::$htmlEntities[$name] );
1599 * Fetch the whitelist of acceptable attributes for a given element name.
1601 * @param string $element
1604 static function attributeWhitelist( $element ) {
1605 $list = Sanitizer
::setupAttributeWhitelist();
1606 return isset( $list[$element] )
1612 * Foreach array key (an allowed HTML element), return an array
1613 * of allowed attributes
1616 static function setupAttributeWhitelist() {
1619 if ( $whitelist !== null ) {
1641 # These attributes are specified in section 9 of
1642 # https://www.w3.org/TR/2008/REC-rdfa-syntax-20081014
1649 # Microdata. These are specified by
1650 # https://html.spec.whatwg.org/multipage/microdata.html#the-microdata-model
1658 $block = array_merge( $common, [ 'align' ] );
1659 $tablealign = [ 'align', 'valign' ];
1667 'nowrap', # deprecated
1668 'width', # deprecated
1669 'height', # deprecated
1670 'bgcolor', # deprecated
1673 # Numbers refer to sections in HTML 4.01 standard describing the element.
1674 # See: https://www.w3.org/TR/html4/
1678 'center' => $common, # deprecated
1697 'strong' => $common,
1708 'blockquote' => array_merge( $common, [ 'cite' ] ),
1709 'q' => array_merge( $common, [ 'cite' ] ),
1719 'br' => array_merge( $common, [ 'clear' ] ),
1721 # https://www.w3.org/TR/html5/text-level-semantics.html#the-wbr-element
1725 'pre' => array_merge( $common, [ 'width' ] ),
1728 'ins' => array_merge( $common, [ 'cite', 'datetime' ] ),
1729 'del' => array_merge( $common, [ 'cite', 'datetime' ] ),
1732 'ul' => array_merge( $common, [ 'type' ] ),
1733 'ol' => array_merge( $common, [ 'type', 'start', 'reversed' ] ),
1734 'li' => array_merge( $common, [ 'type', 'value' ] ),
1742 'table' => array_merge( $common,
1743 [ 'summary', 'width', 'border', 'frame',
1744 'rules', 'cellspacing', 'cellpadding',
1749 'caption' => $block,
1757 'colgroup' => array_merge( $common, [ 'span' ] ),
1758 'col' => array_merge( $common, [ 'span' ] ),
1761 'tr' => array_merge( $common, [ 'bgcolor' ], $tablealign ),
1764 'td' => array_merge( $common, $tablecell, $tablealign ),
1765 'th' => array_merge( $common, $tablecell, $tablealign ),
1768 # NOTE: <a> is not allowed directly, but the attrib
1769 # whitelist is used from the Parser object
1770 'a' => array_merge( $common, [ 'href', 'rel', 'rev' ] ), # rel/rev esp. for RDFa
1773 # Not usually allowed, but may be used for extension-style hooks
1774 # such as <math> when it is rasterized, or if $wgAllowImageTag is
1776 'img' => array_merge( $common, [ 'alt', 'src', 'width', 'height' ] ),
1778 'video' => array_merge( $common, [ 'poster', 'controls', 'preload', 'width', 'height' ] ),
1779 'source' => array_merge( $common, [ 'type', 'src' ] ),
1780 'track' => array_merge( $common, [ 'type', 'src', 'srclang', 'kind', 'label' ] ),
1788 'strike' => $common,
1793 'font' => array_merge( $common, [ 'size', 'color', 'face' ] ),
1797 'hr' => array_merge( $common, [ 'width' ] ),
1799 # HTML Ruby annotation text module, simple ruby only.
1800 # https://www.w3.org/TR/html5/text-level-semantics.html#the-ruby-element
1805 'rt' => $common, # array_merge( $common, array( 'rbspan' ) ),
1808 # MathML root element, where used for extensions
1809 # 'title' may not be 100% valid here; it's XHTML
1810 # https://www.w3.org/TR/REC-MathML/
1811 'math' => [ 'class', 'style', 'id', 'title' ],
1813 # HTML 5 section 4.6
1816 # HTML5 elements, defined by:
1817 # https://html.spec.whatwg.org/multipage/semantics.html#the-data-element
1818 'data' => array_merge( $common, [ 'value' ] ),
1819 'time' => array_merge( $common, [ 'datetime' ] ),
1822 // meta and link are only permitted by removeHTMLtags when Microdata
1823 // is enabled so we don't bother adding a conditional to hide these
1824 // Also meta and link are only valid in WikiText as Microdata elements
1825 // (ie: validateTag rejects tags missing the attributes needed for Microdata)
1826 // So we don't bother including $common attributes that have no purpose.
1827 'meta' => [ 'itemprop', 'content' ],
1828 'link' => [ 'itemprop', 'href' ],
1835 * Take a fragment of (potentially invalid) HTML and return
1836 * a version with any tags removed, encoded as plain text.
1838 * Warning: this return value must be further escaped for literal
1839 * inclusion in HTML output as of 1.10!
1841 * @param string $text HTML fragment
1844 static function stripAllTags( $text ) {
1846 $text = StringUtils
::delimiterReplace( '<', '>', '', $text );
1848 # Normalize &entities and whitespace
1849 $text = self
::decodeCharReferences( $text );
1850 $text = self
::normalizeWhitespace( $text );
1856 * Hack up a private DOCTYPE with HTML's standard entity declarations.
1857 * PHP 4 seemed to know these if you gave it an HTML doctype, but
1860 * Use for passing XHTML fragments to PHP's XML parsing functions
1864 static function hackDocType() {
1865 $out = "<!DOCTYPE html [\n";
1866 foreach ( self
::$htmlEntities as $entity => $codepoint ) {
1867 $out .= "<!ENTITY $entity \"&#$codepoint;\">";
1874 * @param string $url
1875 * @return mixed|string
1877 static function cleanUrl( $url ) {
1878 # Normalize any HTML entities in input. They will be
1879 # re-escaped by makeExternalLink().
1880 $url = Sanitizer
::decodeCharReferences( $url );
1882 # Escape any control characters introduced by the above step
1883 $url = preg_replace_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
1884 [ __CLASS__
, 'cleanUrlCallback' ], $url );
1886 # Validate hostname portion
1888 if ( preg_match( '!^([^:]+:)(//[^/]+)?(.*)$!iD', $url, $matches ) ) {
1889 list( /* $whole */, $protocol, $host, $rest ) = $matches;
1891 // Characters that will be ignored in IDNs.
1892 // https://tools.ietf.org/html/rfc3454#section-3.1
1893 // Strip them before further processing so blacklists and such work.
1895 \\s| # general whitespace
1896 \xc2\xad| # 00ad SOFT HYPHEN
1897 \xe1\xa0\x86| # 1806 MONGOLIAN TODO SOFT HYPHEN
1898 \xe2\x80\x8b| # 200b ZERO WIDTH SPACE
1899 \xe2\x81\xa0| # 2060 WORD JOINER
1900 \xef\xbb\xbf| # feff ZERO WIDTH NO-BREAK SPACE
1901 \xcd\x8f| # 034f COMBINING GRAPHEME JOINER
1902 \xe1\xa0\x8b| # 180b MONGOLIAN FREE VARIATION SELECTOR ONE
1903 \xe1\xa0\x8c| # 180c MONGOLIAN FREE VARIATION SELECTOR TWO
1904 \xe1\xa0\x8d| # 180d MONGOLIAN FREE VARIATION SELECTOR THREE
1905 \xe2\x80\x8c| # 200c ZERO WIDTH NON-JOINER
1906 \xe2\x80\x8d| # 200d ZERO WIDTH JOINER
1907 [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe0f VARIATION SELECTOR-1-16
1910 $host = preg_replace( $strip, '', $host );
1912 // IPv6 host names are bracketed with []. Url-decode these.
1913 if ( substr_compare( "//%5B", $host, 0, 5 ) === 0 &&
1914 preg_match( '!^//%5B([0-9A-Fa-f:.]+)%5D((:\d+)?)$!', $host, $matches )
1916 $host = '//[' . $matches[1] . ']' . $matches[2];
1919 // @todo FIXME: Validate hostnames here
1921 return $protocol . $host . $rest;
1928 * @param array $matches
1931 static function cleanUrlCallback( $matches ) {
1932 return urlencode( $matches[0] );
1936 * Does a string look like an e-mail address?
1938 * This validates an email address using an HTML5 specification found at:
1939 * http://www.whatwg.org/html/states-of-the-type-attribute.html#valid-e-mail-address
1940 * Which as of 2011-01-24 says:
1942 * A valid e-mail address is a string that matches the ABNF production
1943 * 1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
1944 * in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
1947 * This function is an implementation of the specification as requested in
1950 * Client-side forms will use the same standard validation rules via JS or
1951 * HTML 5 validation; additional restrictions can be enforced server-side
1952 * by extensions via the 'isValidEmailAddr' hook.
1954 * Note that this validation doesn't 100% match RFC 2822, but is believed
1955 * to be liberal enough for wide use. Some invalid addresses will still
1956 * pass validation here.
1960 * @param string $addr E-mail address
1963 public static function validateEmail( $addr ) {
1965 if ( !Hooks
::run( 'isValidEmailAddr', [ $addr, &$result ] ) ) {
1969 // Please note strings below are enclosed in brackets [], this make the
1970 // hyphen "-" a range indicator. Hence it is double backslashed below.
1972 $rfc5322_atext = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~";
1973 $rfc1034_ldh_str = "a-z0-9\\-";
1975 $html5_email_regexp = "/
1977 [$rfc5322_atext\\.]+ # user part which is liberal :p
1979 [$rfc1034_ldh_str]+ # First domain part
1980 (\\.[$rfc1034_ldh_str]+)* # Following part prefixed with a dot
1982 /ix"; // case Insensitive, eXtended
1984 return (bool)preg_match( $html5_email_regexp, $addr );