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 * http://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 * http://www.w3.org/TR/html4/sgml/entities.html
62 * As well as ' which is only defined starting in XHTML1.
64 private static $htmlEntities = array(
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 = array(
329 * Lazy-initialised attributes regex, see getAttribsRegex()
331 private static $attribsRegex;
334 * Regular expression to match HTML/XML attribute pairs within a tag.
335 * Allows some... latitude.
336 * Used in Sanitizer::fixTagAttributes and Sanitizer::decodeTagAttributes
339 static function getAttribsRegex() {
340 if ( self
::$attribsRegex === null ) {
341 $attribFirst = '[:A-Z_a-z0-9]';
342 $attrib = '[:A-Z_a-z-.0-9]';
343 $space = '[\x09\x0a\x0d\x20]';
344 self
::$attribsRegex =
345 "/(?:^|$space)({$attribFirst}{$attrib}*)
348 # The attribute value: quoted or alone
351 | ([a-zA-Z0-9!#$%&()*,\\-.\\/:;<>?@[\\]^_`{|}~]+)
355 return self
::$attribsRegex;
359 * Return the various lists of recognized tags
360 * @param array $extratags For any extra tags to include
361 * @param array $removetags For any tags (default or extra) to exclude
364 public static function getRecognizedTagData( $extratags = array(), $removetags = array() ) {
365 global $wgAllowMicrodataAttributes, $wgAllowImageTag;
367 static $htmlpairsStatic, $htmlsingle, $htmlsingleonly, $htmlnest, $tabletags,
368 $htmllist, $listtags, $htmlsingleallowed, $htmlelementsStatic, $staticInitialised;
370 // Base our staticInitialised variable off of the global config state so that if the globals
371 // are changed (like in the screwed up test system) we will re-initialise the settings.
372 $globalContext = implode( '-', compact( 'wgAllowMicrodataAttributes', 'wgAllowImageTag' ) );
373 if ( !$staticInitialised ||
$staticInitialised != $globalContext ) {
374 $htmlpairsStatic = array( # Tags that must be closed
375 'b', 'bdi', 'del', 'i', 'ins', 'u', 'font', 'big', 'small', 'sub', 'sup', 'h1',
376 'h2', 'h3', 'h4', 'h5', 'h6', 'cite', 'code', 'em', 's',
377 'strike', 'strong', 'tt', 'var', 'div', 'center',
378 'blockquote', 'ol', 'ul', 'dl', 'table', 'caption', 'pre',
379 'ruby', 'rb', 'rp', 'rt', 'rtc', 'p', 'span', 'abbr', 'dfn',
380 'kbd', 'samp', 'data', 'time', 'mark'
383 'br', 'wbr', 'hr', 'li', 'dt', 'dd'
385 $htmlsingleonly = array( # Elements that cannot have close tags
388 if ( $wgAllowMicrodataAttributes ) {
389 $htmlsingle[] = $htmlsingleonly[] = 'meta';
390 $htmlsingle[] = $htmlsingleonly[] = 'link';
392 $htmlnest = array( # Tags that can be nested--??
393 'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
394 'li', 'dl', 'dt', 'dd', 'font', 'big', 'small', 'sub', 'sup', 'span',
395 'var', 'kbd', 'samp', 'em', 'strong', 'q', 'ruby', 'bdo'
397 $tabletags = array( # Can only appear inside table, we will close them
400 $htmllist = array( # Tags used by list
403 $listtags = array( # Tags that can appear in a list
407 if ( $wgAllowImageTag ) {
408 $htmlsingle[] = 'img';
409 $htmlsingleonly[] = 'img';
412 $htmlsingleallowed = array_unique( array_merge( $htmlsingle, $tabletags ) );
413 $htmlelementsStatic = array_unique( array_merge( $htmlsingle, $htmlpairsStatic, $htmlnest ) );
415 # Convert them all to hashtables for faster lookup
416 $vars = array( 'htmlpairsStatic', 'htmlsingle', 'htmlsingleonly', 'htmlnest', 'tabletags',
417 'htmllist', 'listtags', 'htmlsingleallowed', 'htmlelementsStatic' );
418 foreach ( $vars as $var ) {
419 $
$var = array_flip( $
$var );
421 $staticInitialised = $globalContext;
424 # Populate $htmlpairs and $htmlelements with the $extratags and $removetags arrays
425 $extratags = array_flip( $extratags );
426 $removetags = array_flip( $removetags );
427 $htmlpairs = array_merge( $extratags, $htmlpairsStatic );
428 $htmlelements = array_diff_key( array_merge( $extratags, $htmlelementsStatic ), $removetags );
431 'htmlpairs' => $htmlpairs,
432 'htmlsingle' => $htmlsingle,
433 'htmlsingleonly' => $htmlsingleonly,
434 'htmlnest' => $htmlnest,
435 'tabletags' => $tabletags,
436 'htmllist' => $htmllist,
437 'listtags' => $listtags,
438 'htmlsingleallowed' => $htmlsingleallowed,
439 'htmlelements' => $htmlelements,
444 * Cleans up HTML, removes dangerous tags and attributes, and
445 * removes HTML comments
446 * @param string $text
447 * @param callable $processCallback Callback to do any variable or parameter
448 * replacements in HTML attribute values
449 * @param array|bool $args Arguments for the processing callback
450 * @param array $extratags For any extra tags to include
451 * @param array $removetags For any tags (default or extra) to exclude
454 public static function removeHTMLtags( $text, $processCallback = null,
455 $args = array(), $extratags = array(), $removetags = array()
457 extract( self
::getRecognizedTagData( $extratags, $removetags ) );
459 # Remove HTML comments
460 $text = Sanitizer
::removeHTMLcomments( $text );
461 $bits = explode( '<', $text );
462 $text = str_replace( '>', '>', array_shift( $bits ) );
463 if ( !MWTidy
::isEnabled() ) {
464 $tagstack = $tablestack = array();
465 foreach ( $bits as $x ) {
467 # $slash: Does the current element start with a '/'?
468 # $t: Current element name
469 # $params: String between element name and >
470 # $brace: Ending '>' or '/>'
471 # $rest: Everything until the next element of $bits
472 if ( preg_match( self
::ELEMENT_BITS_REGEX
, $x, $regs ) ) {
473 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
475 $slash = $t = $params = $brace = $rest = null;
479 $t = strtolower( $t );
480 if ( isset( $htmlelements[$t] ) ) {
482 if ( $slash && isset( $htmlsingleonly[$t] ) ) {
484 } elseif ( $slash ) {
485 # Closing a tag... is it the one we just opened?
486 MediaWiki\
suppressWarnings();
487 $ot = array_pop( $tagstack );
488 MediaWiki\restoreWarnings
();
491 if ( isset( $htmlsingleallowed[$ot] ) ) {
492 # Pop all elements with an optional close tag
493 # and see if we find a match below them
495 array_push( $optstack, $ot );
496 MediaWiki\
suppressWarnings();
497 $ot = array_pop( $tagstack );
498 MediaWiki\restoreWarnings
();
499 while ( $ot != $t && isset( $htmlsingleallowed[$ot] ) ) {
500 array_push( $optstack, $ot );
501 MediaWiki\
suppressWarnings();
502 $ot = array_pop( $tagstack );
503 MediaWiki\restoreWarnings
();
506 # No match. Push the optional elements back again
508 MediaWiki\
suppressWarnings();
509 $ot = array_pop( $optstack );
510 MediaWiki\restoreWarnings
();
512 array_push( $tagstack, $ot );
513 MediaWiki\
suppressWarnings();
514 $ot = array_pop( $optstack );
515 MediaWiki\restoreWarnings
();
519 MediaWiki\
suppressWarnings();
520 array_push( $tagstack, $ot );
521 MediaWiki\restoreWarnings
();
523 # <li> can be nested in <ul> or <ol>, skip those cases:
524 if ( !isset( $htmllist[$ot] ) ||
!isset( $listtags[$t] ) ) {
529 if ( $t == 'table' ) {
530 $tagstack = array_pop( $tablestack );
535 # Keep track for later
536 if ( isset( $tabletags[$t] ) && !in_array( 'table', $tagstack ) ) {
538 } elseif ( in_array( $t, $tagstack ) && !isset( $htmlnest[$t] ) ) {
540 # Is it a self closed htmlpair ? (bug 5487)
541 } elseif ( $brace == '/>' && isset( $htmlpairs[$t] ) ) {
543 } elseif ( isset( $htmlsingleonly[$t] ) ) {
544 # Hack to force empty tag for unclosable elements
546 } elseif ( isset( $htmlsingle[$t] ) ) {
547 # Hack to not close $htmlsingle tags
549 # Still need to push this optionally-closed tag to
550 # the tag stack so that we can match end tags
551 # instead of marking them as bad.
552 array_push( $tagstack, $t );
553 } elseif ( isset( $tabletags[$t] ) && in_array( $t, $tagstack ) ) {
554 // New table tag but forgot to close the previous one
557 if ( $t == 'table' ) {
558 array_push( $tablestack, $tagstack );
561 array_push( $tagstack, $t );
564 # Replace any variables or template parameters with
566 if ( is_callable( $processCallback ) ) {
567 call_user_func_array( $processCallback, array( &$params, $args ) );
570 if ( !Sanitizer
::validateTag( $params, $t ) ) {
574 # Strip non-approved attributes from the tag
575 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
578 $rest = str_replace( '>', '>', $rest );
579 $close = ( $brace == '/>' && !$slash ) ?
' /' : '';
580 $text .= "<$slash$t$newparams$close>$rest";
584 $text .= '<' . str_replace( '>', '>', $x );
586 # Close off any remaining tags
587 while ( is_array( $tagstack ) && ( $t = array_pop( $tagstack ) ) ) {
589 if ( $t == 'table' ) {
590 $tagstack = array_pop( $tablestack );
594 # this might be possible using tidy itself
595 foreach ( $bits as $x ) {
596 if ( preg_match( self
::ELEMENT_BITS_REGEX
, $x, $regs ) ) {
597 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
600 $t = strtolower( $t );
601 if ( isset( $htmlelements[$t] ) ) {
602 if ( is_callable( $processCallback ) ) {
603 call_user_func_array( $processCallback, array( &$params, $args ) );
606 if ( !Sanitizer
::validateTag( $params, $t ) ) {
610 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
612 $rest = str_replace( '>', '>', $rest );
613 $text .= "<$slash$t$newparams$brace$rest";
618 $text .= '<' . str_replace( '>', '>', $x );
625 * Remove '<!--', '-->', and everything between.
626 * To avoid leaving blank lines, when a comment is both preceded
627 * and followed by a newline (ignoring spaces), trim leading and
628 * trailing spaces and one of the newlines.
630 * @param string $text
633 public static function removeHTMLcomments( $text ) {
634 while ( ( $start = strpos( $text, '<!--' ) ) !== false ) {
635 $end = strpos( $text, '-->', $start +
4 );
636 if ( $end === false ) {
637 # Unterminated comment; bail out
643 # Trim space and newline if the comment is both
644 # preceded and followed by a newline
645 $spaceStart = max( $start - 1, 0 );
646 $spaceLen = $end - $spaceStart;
647 while ( substr( $text, $spaceStart, 1 ) === ' ' && $spaceStart > 0 ) {
651 while ( substr( $text, $spaceStart +
$spaceLen, 1 ) === ' ' ) {
654 if ( substr( $text, $spaceStart, 1 ) === "\n"
655 && substr( $text, $spaceStart +
$spaceLen, 1 ) === "\n" ) {
656 # Remove the comment, leading and trailing
657 # spaces, and leave only one newline.
658 $text = substr_replace( $text, "\n", $spaceStart, $spaceLen +
1 );
660 # Remove just the comment.
661 $text = substr_replace( $text, '', $start, $end - $start );
668 * Takes attribute names and values for a tag and the tag name and
669 * validates that the tag is allowed to be present.
670 * This DOES NOT validate the attributes, nor does it validate the
671 * tags themselves. This method only handles the special circumstances
672 * where we may want to allow a tag within content but ONLY when it has
673 * specific attributes set.
675 * @param string $params
676 * @param string $element
679 static function validateTag( $params, $element ) {
680 $params = Sanitizer
::decodeTagAttributes( $params );
682 if ( $element == 'meta' ||
$element == 'link' ) {
683 if ( !isset( $params['itemprop'] ) ) {
684 // <meta> and <link> must have an itemprop="" otherwise they are not valid or safe in content
687 if ( $element == 'meta' && !isset( $params['content'] ) ) {
688 // <meta> must have a content="" for the itemprop
691 if ( $element == 'link' && !isset( $params['href'] ) ) {
692 // <link> must have an associated href=""
701 * Take an array of attribute names and values and normalize or discard
702 * illegal values for the given element type.
704 * - Discards attributes not on a whitelist for the given element
705 * - Unsafe style attributes are discarded
706 * - Invalid id attributes are re-encoded
708 * @param array $attribs
709 * @param string $element
712 * @todo Check for legal values where the DTD limits things.
713 * @todo Check for unique id attribute :P
715 static function validateTagAttributes( $attribs, $element ) {
716 return Sanitizer
::validateAttributes( $attribs,
717 Sanitizer
::attributeWhitelist( $element ) );
721 * Take an array of attribute names and values and normalize or discard
722 * illegal values for the given whitelist.
724 * - Discards attributes not the given whitelist
725 * - Unsafe style attributes are discarded
726 * - Invalid id attributes are re-encoded
728 * @param array $attribs
729 * @param array $whitelist List of allowed attribute names
732 * @todo Check for legal values where the DTD limits things.
733 * @todo Check for unique id attribute :P
735 static function validateAttributes( $attribs, $whitelist ) {
736 global $wgAllowRdfaAttributes, $wgAllowMicrodataAttributes;
738 $whitelist = array_flip( $whitelist );
739 $hrefExp = '/^(' . wfUrlProtocols() . ')[^\s]+$/';
742 foreach ( $attribs as $attribute => $value ) {
743 # allow XML namespace declaration if RDFa is enabled
744 if ( $wgAllowRdfaAttributes && preg_match( self
::XMLNS_ATTRIBUTE_PATTERN
, $attribute ) ) {
745 if ( !preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
746 $out[$attribute] = $value;
752 # Allow any attribute beginning with "data-"
754 # * data-ooui is reserved for ooui
755 # * data-mw and data-parsoid are reserved for parsoid
756 # * data-mw-<name here> is reserved for extensions (or core) if
757 # they need to communicate some data to the client and want to be
758 # sure that it isn't coming from an untrusted user.
759 # * Ensure that the attribute is not namespaced by banning
761 if ( !preg_match( '/^data-(?!ooui|mw|parsoid)[^:]*$/i', $attribute )
762 && !isset( $whitelist[$attribute] )
767 # Strip javascript "expression" from stylesheets.
768 # http://msdn.microsoft.com/workshop/author/dhtml/overview/recalc.asp
769 if ( $attribute == 'style' ) {
770 $value = Sanitizer
::checkCss( $value );
773 if ( $attribute === 'id' ) {
774 $value = Sanitizer
::escapeId( $value, 'noninitial' );
778 # http://www.w3.org/TR/wai-aria/
779 # http://www.whatwg.org/html/elements.html#wai-aria
780 # For now we only support role="presentation" until we work out what roles should be
781 # usable by content and we ensure that our code explicitly rejects patterns that
782 # violate HTML5's ARIA restrictions.
783 if ( $attribute === 'role' && $value !== 'presentation' ) {
787 // RDFa and microdata properties allow URLs, URIs and/or CURIs.
788 // Check them for sanity.
789 if ( $attribute === 'rel' ||
$attribute === 'rev'
791 ||
$attribute === 'about' ||
$attribute === 'property'
792 ||
$attribute === 'resource' ||
$attribute === 'datatype'
793 ||
$attribute === 'typeof'
795 ||
$attribute === 'itemid' ||
$attribute === 'itemprop'
796 ||
$attribute === 'itemref' ||
$attribute === 'itemscope'
797 ||
$attribute === 'itemtype'
799 // Paranoia. Allow "simple" values but suppress javascript
800 if ( preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
805 # NOTE: even though elements using href/src are not allowed directly, supply
806 # validation code that can be used by tag hook handlers, etc
807 if ( $attribute === 'href' ||
$attribute === 'src' ) {
808 if ( !preg_match( $hrefExp, $value ) ) {
809 continue; // drop any href or src attributes not using an allowed protocol.
810 // NOTE: this also drops all relative URLs
814 // If this attribute was previously set, override it.
815 // Output should only have one attribute of each name.
816 $out[$attribute] = $value;
819 if ( $wgAllowMicrodataAttributes ) {
820 # itemtype, itemid, itemref don't make sense without itemscope
821 if ( !array_key_exists( 'itemscope', $out ) ) {
822 unset( $out['itemtype'] );
823 unset( $out['itemid'] );
824 unset( $out['itemref'] );
826 # TODO: Strip itemprop if we aren't descendants of an itemscope or pointed to by an itemref.
832 * Merge two sets of HTML attributes. Conflicting items in the second set
833 * will override those in the first, except for 'class' attributes which
834 * will be combined (if they're both strings).
836 * @todo implement merging for other attributes such as style
841 static function mergeAttributes( $a, $b ) {
842 $out = array_merge( $a, $b );
843 if ( isset( $a['class'] ) && isset( $b['class'] )
844 && is_string( $a['class'] ) && is_string( $b['class'] )
845 && $a['class'] !== $b['class']
847 $classes = preg_split( '/\s+/', "{$a['class']} {$b['class']}",
848 -1, PREG_SPLIT_NO_EMPTY
);
849 $out['class'] = implode( ' ', array_unique( $classes ) );
855 * Normalize CSS into a format we can easily search for hostile input
856 * - decode character references
857 * - decode escape sequences
858 * - convert characters that IE6 interprets into ascii
859 * - remove comments, unless the entire value is one single comment
860 * @param string $value the css string
861 * @return string normalized css
863 public static function normalizeCss( $value ) {
865 // Decode character references like {
866 $value = Sanitizer
::decodeCharReferences( $value );
868 // Decode escape sequences and line continuation
869 // See the grammar in the CSS 2 spec, appendix D.
870 // This has to be done AFTER decoding character references.
871 // This means it isn't possible for this function to return
872 // unsanitized escape sequences. It is possible to manufacture
873 // input that contains character references that decode to
874 // escape sequences that decode to character references, but
875 // it's OK for the return value to contain character references
876 // because the caller is supposed to escape those anyway.
878 if ( !$decodeRegex ) {
879 $space = '[\\x20\\t\\r\\n\\f]';
880 $nl = '(?:\\n|\\r\\n|\\r|\\f)';
882 $decodeRegex = "/ $backslash
884 ($nl) | # 1. Line continuation
885 ([0-9A-Fa-f]{1,6})$space? | # 2. character number
886 (.) | # 3. backslash cancelling special meaning
887 () | # 4. backslash at end of string
890 $value = preg_replace_callback( $decodeRegex,
891 array( __CLASS__
, 'cssDecodeCallback' ), $value );
893 // Normalize Halfwidth and Fullwidth Unicode block that IE6 might treat as ascii
894 $value = preg_replace_callback(
895 '/[!-[]-z]/u', // U+FF01 to U+FF5A, excluding U+FF3C (bug 58088)
896 function ( $matches ) {
897 $cp = UtfNormal\Utils
::utf8ToCodepoint( $matches[0] );
898 if ( $cp === false ) {
901 return chr( $cp - 65248 ); // ASCII range \x21-\x7A
906 // Convert more characters IE6 might treat as ascii
907 // U+0280, U+0274, U+207F, U+029F, U+026A, U+207D, U+208D
908 $value = str_replace(
909 array( 'ʀ', 'ɴ', 'ⁿ', 'ʟ', 'ɪ', '⁽', '₍' ),
910 array( 'r', 'n', 'n', 'l', 'i', '(', '(' ),
914 // Let the value through if it's nothing but a single comment, to
915 // allow other functions which may reject it to pass some error
917 if ( !preg_match( '! ^ \s* /\* [^*\\/]* \*/ \s* $ !x', $value ) ) {
918 // Remove any comments; IE gets token splitting wrong
919 // This must be done AFTER decoding character references and
920 // escape sequences, because those steps can introduce comments
921 // This step cannot introduce character references or escape
922 // sequences, because it replaces comments with spaces rather
923 // than removing them completely.
924 $value = StringUtils
::delimiterReplace( '/*', '*/', ' ', $value );
926 // Remove anything after a comment-start token, to guard against
927 // incorrect client implementations.
928 $commentPos = strpos( $value, '/*' );
929 if ( $commentPos !== false ) {
930 $value = substr( $value, 0, $commentPos );
934 // S followed by repeat, iteration, or prolonged sound marks,
935 // which IE will treat as "ss"
936 $value = preg_replace(
938 \xE3\x80\xB1 | # U+3031
939 \xE3\x82\x9D | # U+309D
940 \xE3\x83\xBC | # U+30FC
941 \xE3\x83\xBD | # U+30FD
942 \xEF\xB9\xBC | # U+FE7C
943 \xEF\xB9\xBD | # U+FE7D
944 \xEF\xBD\xB0 # U+FF70
955 * Pick apart some CSS and check it for forbidden or unsafe structures.
956 * Returns a sanitized string. This sanitized string will have
957 * character references and escape sequences decoded and comments
958 * stripped (unless it is itself one valid comment, in which case the value
959 * will be passed through). If the input is just too evil, only a comment
960 * complaining about evilness will be returned.
962 * Currently URL references, 'expression', 'tps' are forbidden.
964 * NOTE: Despite the fact that character references are decoded, the
965 * returned string may contain character references given certain
966 * clever input strings. These character references must
967 * be escaped before the return value is embedded in HTML.
969 * @param string $value
972 static function checkCss( $value ) {
973 $value = self
::normalizeCss( $value );
975 // Reject problematic keywords and control characters
976 if ( preg_match( '/[\000-\010\013\016-\037\177]/', $value ) ||
977 strpos( $value, UtfNormal\Constants
::UTF8_REPLACEMENT
) !== false ) {
978 return '/* invalid control char */';
979 } elseif ( preg_match(
990 return '/* insecure input */';
996 * @param array $matches
999 static function cssDecodeCallback( $matches ) {
1000 if ( $matches[1] !== '' ) {
1001 // Line continuation
1003 } elseif ( $matches[2] !== '' ) {
1004 $char = UtfNormal\Utils
::codepointToUtf8( hexdec( $matches[2] ) );
1005 } elseif ( $matches[3] !== '' ) {
1006 $char = $matches[3];
1010 if ( $char == "\n" ||
$char == '"' ||
$char == "'" ||
$char == '\\' ) {
1011 // These characters need to be escaped in strings
1012 // Clean up the escape sequence to avoid parsing errors by clients
1013 return '\\' . dechex( ord( $char ) ) . ' ';
1015 // Decode unnecessary escape
1021 * Take a tag soup fragment listing an HTML element's attributes
1022 * and normalize it to well-formed XML, discarding unwanted attributes.
1023 * Output is safe for further wikitext processing, with escaping of
1024 * values that could trigger problems.
1026 * - Normalizes attribute names to lowercase
1027 * - Discards attributes not on a whitelist for the given element
1028 * - Turns broken or invalid entities into plaintext
1029 * - Double-quotes all attribute values
1030 * - Attributes without values are given the name as attribute
1031 * - Double attributes are discarded
1032 * - Unsafe style attributes are discarded
1033 * - Prepends space if there are attributes.
1035 * @param string $text
1036 * @param string $element
1039 static function fixTagAttributes( $text, $element ) {
1040 if ( trim( $text ) == '' ) {
1044 $decoded = Sanitizer
::decodeTagAttributes( $text );
1045 $stripped = Sanitizer
::validateTagAttributes( $decoded, $element );
1047 return Sanitizer
::safeEncodeTagAttributes( $stripped );
1051 * Encode an attribute value for HTML output.
1052 * @param string $text
1053 * @return string HTML-encoded text fragment
1055 static function encodeAttribute( $text ) {
1056 $encValue = htmlspecialchars( $text, ENT_QUOTES
);
1058 // Whitespace is normalized during attribute decoding,
1059 // so if we've been passed non-spaces we must encode them
1060 // ahead of time or they won't be preserved.
1061 $encValue = strtr( $encValue, array(
1071 * Encode an attribute value for HTML tags, with extra armoring
1072 * against further wiki processing.
1073 * @param string $text
1074 * @return string HTML-encoded text fragment
1076 static function safeEncodeAttribute( $text ) {
1077 $encValue = Sanitizer
::encodeAttribute( $text );
1079 # Templates and links may be expanded in later parsing,
1080 # creating invalid or dangerous output. Suppress this.
1081 $encValue = strtr( $encValue, array(
1082 '<' => '<', // This should never happen,
1083 '>' => '>', // we've received invalid input
1084 '"' => '"', // which should have been escaped.
1087 "''" => '''',
1088 'ISBN' => 'ISBN',
1090 'PMID' => 'PMID',
1096 $encValue = preg_replace_callback(
1097 '/((?i)' . wfUrlProtocols() . ')/',
1098 array( 'Sanitizer', 'armorLinksCallback' ),
1104 * Given a value, escape it so that it can be used in an id attribute and
1105 * return it. This will use HTML5 validation if $wgExperimentalHtmlIds is
1106 * true, allowing anything but ASCII whitespace. Otherwise it will use
1107 * HTML 4 rules, which means a narrow subset of ASCII, with bad characters
1108 * escaped with lots of dots.
1110 * To ensure we don't have to bother escaping anything, we also strip ', ",
1111 * & even if $wgExperimentalIds is true. TODO: Is this the best tactic?
1112 * We also strip # because it upsets IE, and % because it could be
1113 * ambiguous if it's part of something that looks like a percent escape
1114 * (which don't work reliably in fragments cross-browser).
1116 * @see http://www.w3.org/TR/html401/types.html#type-name Valid characters
1117 * in the id and name attributes
1118 * @see http://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with
1120 * @see http://www.whatwg.org/html/elements.html#the-id-attribute
1121 * HTML5 definition of id attribute
1123 * @param string $id Id to escape
1124 * @param string|array $options String or array of strings (default is array()):
1125 * 'noninitial': This is a non-initial fragment of an id, not a full id,
1126 * so don't pay attention if the first character isn't valid at the
1127 * beginning of an id. Only matters if $wgExperimentalHtmlIds is
1129 * 'legacy': Behave the way the old HTML 4-based ID escaping worked even
1130 * if $wgExperimentalHtmlIds is used, so we can generate extra
1131 * anchors and links won't break.
1134 static function escapeId( $id, $options = array() ) {
1135 global $wgExperimentalHtmlIds;
1136 $options = (array)$options;
1138 $id = Sanitizer
::decodeCharReferences( $id );
1140 if ( $wgExperimentalHtmlIds && !in_array( 'legacy', $options ) ) {
1141 $id = preg_replace( '/[ \t\n\r\f_\'"&#%]+/', '_', $id );
1142 $id = trim( $id, '_' );
1144 // Must have been all whitespace to start with.
1151 // HTML4-style escaping
1152 static $replace = array(
1157 $id = urlencode( strtr( $id, ' ', '_' ) );
1158 $id = str_replace( array_keys( $replace ), array_values( $replace ), $id );
1160 if ( !preg_match( '/^[a-zA-Z]/', $id ) && !in_array( 'noninitial', $options ) ) {
1161 // Initial character must be a letter!
1168 * Given a value, escape it so that it can be used as a CSS class and
1171 * @todo For extra validity, input should be validated UTF-8.
1173 * @see http://www.w3.org/TR/CSS21/syndata.html Valid characters/format
1175 * @param string $class
1178 static function escapeClass( $class ) {
1179 // Convert ugly stuff to underscores and kill underscores in ugly places
1180 return rtrim( preg_replace(
1181 array( '/(^[0-9\\-])|[\\x00-\\x20!"#$%&\'()*+,.\\/:;<=>?@[\\]^`{|}~]|\\xC2\\xA0/', '/_+/' ),
1187 * Given HTML input, escape with htmlspecialchars but un-escape entities.
1188 * This allows (generally harmless) entities like   to survive.
1190 * @param string $html HTML to escape
1191 * @return string Escaped input
1193 static function escapeHtmlAllowEntities( $html ) {
1194 $html = Sanitizer
::decodeCharReferences( $html );
1195 # It seems wise to escape ' as well as ", as a matter of course. Can't
1197 $html = htmlspecialchars( $html, ENT_QUOTES
);
1202 * Regex replace callback for armoring links against further processing.
1203 * @param array $matches
1206 private static function armorLinksCallback( $matches ) {
1207 return str_replace( ':', ':', $matches[1] );
1211 * Return an associative array of attribute names and values from
1212 * a partial tag string. Attribute names are forces to lowercase,
1213 * character references are decoded to UTF-8 text.
1215 * @param string $text
1218 public static function decodeTagAttributes( $text ) {
1219 if ( trim( $text ) == '' ) {
1225 if ( !preg_match_all(
1226 self
::getAttribsRegex(),
1229 PREG_SET_ORDER
) ) {
1233 foreach ( $pairs as $set ) {
1234 $attribute = strtolower( $set[1] );
1235 $value = Sanitizer
::getTagAttributeCallback( $set );
1237 // Normalize whitespace
1238 $value = preg_replace( '/[\t\r\n ]+/', ' ', $value );
1239 $value = trim( $value );
1241 // Decode character references
1242 $attribs[$attribute] = Sanitizer
::decodeCharReferences( $value );
1248 * Build a partial tag string from an associative array of attribute
1249 * names and values as returned by decodeTagAttributes.
1251 * @param array $assoc_array
1254 public static function safeEncodeTagAttributes( $assoc_array ) {
1256 foreach ( $assoc_array as $attribute => $value ) {
1257 $encAttribute = htmlspecialchars( $attribute );
1258 $encValue = Sanitizer
::safeEncodeAttribute( $value );
1260 $attribs[] = "$encAttribute=\"$encValue\"";
1262 return count( $attribs ) ?
' ' . implode( ' ', $attribs ) : '';
1266 * Pick the appropriate attribute value from a match set from the
1267 * attribs regex matches.
1270 * @throws MWException When tag conditions are not met.
1273 private static function getTagAttributeCallback( $set ) {
1274 if ( isset( $set[5] ) ) {
1277 } elseif ( isset( $set[4] ) ) {
1280 } elseif ( isset( $set[3] ) ) {
1283 } elseif ( !isset( $set[2] ) ) {
1284 # In XHTML, attributes must have a value so return an empty string.
1285 # See "Empty attribute syntax",
1286 # http://www.w3.org/TR/html5/syntax.html#syntax-attribute-name
1289 throw new MWException( "Tag conditions not met. This should never happen and is a bug." );
1294 * @param string $text
1297 private static function normalizeWhitespace( $text ) {
1298 return preg_replace(
1299 '/\r\n|[\x20\x0d\x0a\x09]/',
1305 * Normalizes whitespace in a section name, such as might be returned
1306 * by Parser::stripSectionName(), for use in the id's that are used for
1309 * @param string $section
1312 static function normalizeSectionNameWhitespace( $section ) {
1313 return trim( preg_replace( '/[ _]+/', ' ', $section ) );
1317 * Ensure that any entities and character references are legal
1318 * for XML and XHTML specifically. Any stray bits will be
1319 * &-escaped to result in a valid text fragment.
1321 * a. named char refs can only be < > & ", others are
1322 * numericized (this way we're well-formed even without a DTD)
1323 * b. any numeric char refs must be legal chars, not invalid or forbidden
1324 * c. use lower cased "&#x", not "&#X"
1325 * d. fix or reject non-valid attributes
1327 * @param string $text
1331 static function normalizeCharReferences( $text ) {
1332 return preg_replace_callback(
1333 self
::CHAR_REFS_REGEX
,
1334 array( 'Sanitizer', 'normalizeCharReferencesCallback' ),
1339 * @param string $matches
1342 static function normalizeCharReferencesCallback( $matches ) {
1344 if ( $matches[1] != '' ) {
1345 $ret = Sanitizer
::normalizeEntity( $matches[1] );
1346 } elseif ( $matches[2] != '' ) {
1347 $ret = Sanitizer
::decCharReference( $matches[2] );
1348 } elseif ( $matches[3] != '' ) {
1349 $ret = Sanitizer
::hexCharReference( $matches[3] );
1351 if ( is_null( $ret ) ) {
1352 return htmlspecialchars( $matches[0] );
1359 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1360 * return the equivalent numeric entity reference (except for the core <
1361 * > & "). If the entity is a MediaWiki-specific alias, returns
1362 * the HTML equivalent. Otherwise, returns HTML-escaped text of
1363 * pseudo-entity source (eg &foo;)
1365 * @param string $name
1368 static function normalizeEntity( $name ) {
1369 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1370 return '&' . self
::$htmlEntityAliases[$name] . ';';
1371 } elseif ( in_array( $name, array( 'lt', 'gt', 'amp', 'quot' ) ) ) {
1373 } elseif ( isset( self
::$htmlEntities[$name] ) ) {
1374 return '&#' . self
::$htmlEntities[$name] . ';';
1376 return "&$name;";
1381 * @param int $codepoint
1382 * @return null|string
1384 static function decCharReference( $codepoint ) {
1385 $point = intval( $codepoint );
1386 if ( Sanitizer
::validateCodepoint( $point ) ) {
1387 return sprintf( '&#%d;', $point );
1394 * @param int $codepoint
1395 * @return null|string
1397 static function hexCharReference( $codepoint ) {
1398 $point = hexdec( $codepoint );
1399 if ( Sanitizer
::validateCodepoint( $point ) ) {
1400 return sprintf( '&#x%x;', $point );
1407 * Returns true if a given Unicode codepoint is a valid character in
1408 * both HTML5 and XML.
1409 * @param int $codepoint
1412 private static function validateCodepoint( $codepoint ) {
1413 # U+000C is valid in HTML5 but not allowed in XML.
1414 # U+000D is valid in XML but not allowed in HTML5.
1415 # U+007F - U+009F are disallowed in HTML5 (control characters).
1416 return $codepoint == 0x09
1417 ||
$codepoint == 0x0a
1418 ||
( $codepoint >= 0x20 && $codepoint <= 0x7e )
1419 ||
( $codepoint >= 0xa0 && $codepoint <= 0xd7ff )
1420 ||
( $codepoint >= 0xe000 && $codepoint <= 0xfffd )
1421 ||
( $codepoint >= 0x10000 && $codepoint <= 0x10ffff );
1425 * Decode any character references, numeric or named entities,
1426 * in the text and return a UTF-8 string.
1428 * @param string $text
1431 public static function decodeCharReferences( $text ) {
1432 return preg_replace_callback(
1433 self
::CHAR_REFS_REGEX
,
1434 array( 'Sanitizer', 'decodeCharReferencesCallback' ),
1439 * Decode any character references, numeric or named entities,
1440 * in the next and normalize the resulting string. (bug 14952)
1442 * This is useful for page titles, not for text to be displayed,
1443 * MediaWiki allows HTML entities to escape normalization as a feature.
1445 * @param string $text Already normalized, containing entities
1446 * @return string Still normalized, without entities
1448 public static function decodeCharReferencesAndNormalize( $text ) {
1450 $text = preg_replace_callback(
1451 self
::CHAR_REFS_REGEX
,
1452 array( 'Sanitizer', 'decodeCharReferencesCallback' ),
1453 $text, /* limit */ -1, $count );
1456 return $wgContLang->normalize( $text );
1463 * @param string $matches
1466 static function decodeCharReferencesCallback( $matches ) {
1467 if ( $matches[1] != '' ) {
1468 return Sanitizer
::decodeEntity( $matches[1] );
1469 } elseif ( $matches[2] != '' ) {
1470 return Sanitizer
::decodeChar( intval( $matches[2] ) );
1471 } elseif ( $matches[3] != '' ) {
1472 return Sanitizer
::decodeChar( hexdec( $matches[3] ) );
1474 # Last case should be an ampersand by itself
1479 * Return UTF-8 string for a codepoint if that is a valid
1480 * character reference, otherwise U+FFFD REPLACEMENT CHARACTER.
1481 * @param int $codepoint
1485 static function decodeChar( $codepoint ) {
1486 if ( Sanitizer
::validateCodepoint( $codepoint ) ) {
1487 return UtfNormal\Utils
::codepointToUtf8( $codepoint );
1489 return UtfNormal\Constants
::UTF8_REPLACEMENT
;
1494 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1495 * return the UTF-8 encoding of that character. Otherwise, returns
1496 * pseudo-entity source (eg "&foo;")
1498 * @param string $name
1501 static function decodeEntity( $name ) {
1502 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1503 $name = self
::$htmlEntityAliases[$name];
1505 if ( isset( self
::$htmlEntities[$name] ) ) {
1506 return UtfNormal\Utils
::codepointToUtf8( self
::$htmlEntities[$name] );
1513 * Fetch the whitelist of acceptable attributes for a given element name.
1515 * @param string $element
1518 static function attributeWhitelist( $element ) {
1519 $list = Sanitizer
::setupAttributeWhitelist();
1520 return isset( $list[$element] )
1526 * Foreach array key (an allowed HTML element), return an array
1527 * of allowed attributes
1530 static function setupAttributeWhitelist() {
1531 global $wgAllowRdfaAttributes, $wgAllowMicrodataAttributes;
1532 static $whitelist, $staticInitialised;
1534 $globalContext = implode( '-', compact( 'wgAllowRdfaAttributes', 'wgAllowMicrodataAttributes' ) );
1536 if ( $whitelist !== null && $staticInitialised == $globalContext ) {
1553 if ( $wgAllowRdfaAttributes ) {
1554 # RDFa attributes as specified in section 9 of
1555 # http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014
1556 $common = array_merge( $common, array(
1557 'about', 'property', 'resource', 'datatype', 'typeof',
1561 if ( $wgAllowMicrodataAttributes ) {
1562 # add HTML5 microdata tags as specified by
1563 # http://www.whatwg.org/html/microdata.html#the-microdata-model
1564 $common = array_merge( $common, array(
1565 'itemid', 'itemprop', 'itemref', 'itemscope', 'itemtype'
1569 $block = array_merge( $common, array( 'align' ) );
1570 $tablealign = array( 'align', 'valign' );
1578 'nowrap', # deprecated
1579 'width', # deprecated
1580 'height', # deprecated
1581 'bgcolor', # deprecated
1584 # Numbers refer to sections in HTML 4.01 standard describing the element.
1585 # See: http://www.w3.org/TR/html4/
1589 'center' => $common, # deprecated
1608 'strong' => $common,
1619 'blockquote' => array_merge( $common, array( 'cite' ) ),
1620 'q' => array_merge( $common, array( 'cite' ) ),
1630 'br' => array_merge( $common, array( 'clear' ) ),
1632 # http://www.whatwg.org/html/text-level-semantics.html#the-wbr-element
1636 'pre' => array_merge( $common, array( 'width' ) ),
1639 'ins' => array_merge( $common, array( 'cite', 'datetime' ) ),
1640 'del' => array_merge( $common, array( 'cite', 'datetime' ) ),
1643 'ul' => array_merge( $common, array( 'type' ) ),
1644 'ol' => array_merge( $common, array( 'type', 'start', 'reversed' ) ),
1645 'li' => array_merge( $common, array( 'type', 'value' ) ),
1653 'table' => array_merge( $common,
1654 array( 'summary', 'width', 'border', 'frame',
1655 'rules', 'cellspacing', 'cellpadding',
1660 'caption' => $block,
1668 'colgroup' => array_merge( $common, array( 'span' ) ),
1669 'col' => array_merge( $common, array( 'span' ) ),
1672 'tr' => array_merge( $common, array( 'bgcolor' ), $tablealign ),
1675 'td' => array_merge( $common, $tablecell, $tablealign ),
1676 'th' => array_merge( $common, $tablecell, $tablealign ),
1679 # NOTE: <a> is not allowed directly, but the attrib
1680 # whitelist is used from the Parser object
1681 'a' => array_merge( $common, array( 'href', 'rel', 'rev' ) ), # rel/rev esp. for RDFa
1684 # Not usually allowed, but may be used for extension-style hooks
1685 # such as <math> when it is rasterized, or if $wgAllowImageTag is
1687 'img' => array_merge( $common, array( 'alt', 'src', 'width', 'height' ) ),
1695 'strike' => $common,
1700 'font' => array_merge( $common, array( 'size', 'color', 'face' ) ),
1704 'hr' => array_merge( $common, array( 'width' ) ),
1706 # HTML Ruby annotation text module, simple ruby only.
1707 # http://www.whatwg.org/html/text-level-semantics.html#the-ruby-element
1712 'rt' => $common, # array_merge( $common, array( 'rbspan' ) ),
1715 # MathML root element, where used for extensions
1716 # 'title' may not be 100% valid here; it's XHTML
1717 # http://www.w3.org/TR/REC-MathML/
1718 'math' => array( 'class', 'style', 'id', 'title' ),
1720 # HTML 5 section 4.6
1723 # HTML5 elements, defined by:
1724 # http://www.whatwg.org/html/
1725 'data' => array_merge( $common, array( 'value' ) ),
1726 'time' => array_merge( $common, array( 'datetime' ) ),
1729 // meta and link are only permitted by removeHTMLtags when Microdata
1730 // is enabled so we don't bother adding a conditional to hide these
1731 // Also meta and link are only valid in WikiText as Microdata elements
1732 // (ie: validateTag rejects tags missing the attributes needed for Microdata)
1733 // So we don't bother including $common attributes that have no purpose.
1734 'meta' => array( 'itemprop', 'content' ),
1735 'link' => array( 'itemprop', 'href' ),
1738 $staticInitialised = $globalContext;
1744 * Take a fragment of (potentially invalid) HTML and return
1745 * a version with any tags removed, encoded as plain text.
1747 * Warning: this return value must be further escaped for literal
1748 * inclusion in HTML output as of 1.10!
1750 * @param string $text HTML fragment
1753 static function stripAllTags( $text ) {
1755 $text = StringUtils
::delimiterReplace( '<', '>', '', $text );
1757 # Normalize &entities and whitespace
1758 $text = self
::decodeCharReferences( $text );
1759 $text = self
::normalizeWhitespace( $text );
1765 * Hack up a private DOCTYPE with HTML's standard entity declarations.
1766 * PHP 4 seemed to know these if you gave it an HTML doctype, but
1769 * Use for passing XHTML fragments to PHP's XML parsing functions
1773 static function hackDocType() {
1774 $out = "<!DOCTYPE html [\n";
1775 foreach ( self
::$htmlEntities as $entity => $codepoint ) {
1776 $out .= "<!ENTITY $entity \"&#$codepoint;\">";
1783 * @param string $url
1784 * @return mixed|string
1786 static function cleanUrl( $url ) {
1787 # Normalize any HTML entities in input. They will be
1788 # re-escaped by makeExternalLink().
1789 $url = Sanitizer
::decodeCharReferences( $url );
1791 # Escape any control characters introduced by the above step
1792 $url = preg_replace_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
1793 array( __CLASS__
, 'cleanUrlCallback' ), $url );
1795 # Validate hostname portion
1797 if ( preg_match( '!^([^:]+:)(//[^/]+)?(.*)$!iD', $url, $matches ) ) {
1798 list( /* $whole */, $protocol, $host, $rest ) = $matches;
1800 // Characters that will be ignored in IDNs.
1801 // http://tools.ietf.org/html/3454#section-3.1
1802 // Strip them before further processing so blacklists and such work.
1804 \\s| # general whitespace
1805 \xc2\xad| # 00ad SOFT HYPHEN
1806 \xe1\xa0\x86| # 1806 MONGOLIAN TODO SOFT HYPHEN
1807 \xe2\x80\x8b| # 200b ZERO WIDTH SPACE
1808 \xe2\x81\xa0| # 2060 WORD JOINER
1809 \xef\xbb\xbf| # feff ZERO WIDTH NO-BREAK SPACE
1810 \xcd\x8f| # 034f COMBINING GRAPHEME JOINER
1811 \xe1\xa0\x8b| # 180b MONGOLIAN FREE VARIATION SELECTOR ONE
1812 \xe1\xa0\x8c| # 180c MONGOLIAN FREE VARIATION SELECTOR TWO
1813 \xe1\xa0\x8d| # 180d MONGOLIAN FREE VARIATION SELECTOR THREE
1814 \xe2\x80\x8c| # 200c ZERO WIDTH NON-JOINER
1815 \xe2\x80\x8d| # 200d ZERO WIDTH JOINER
1816 [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe0f VARIATION SELECTOR-1-16
1819 $host = preg_replace( $strip, '', $host );
1821 // IPv6 host names are bracketed with []. Url-decode these.
1822 if ( substr_compare( "//%5B", $host, 0, 5 ) === 0 &&
1823 preg_match( '!^//%5B([0-9A-Fa-f:.]+)%5D((:\d+)?)$!', $host, $matches )
1825 $host = '//[' . $matches[1] . ']' . $matches[2];
1828 // @todo FIXME: Validate hostnames here
1830 return $protocol . $host . $rest;
1837 * @param array $matches
1840 static function cleanUrlCallback( $matches ) {
1841 return urlencode( $matches[0] );
1845 * Does a string look like an e-mail address?
1847 * This validates an email address using an HTML5 specification found at:
1848 * http://www.whatwg.org/html/states-of-the-type-attribute.html#valid-e-mail-address
1849 * Which as of 2011-01-24 says:
1851 * A valid e-mail address is a string that matches the ABNF production
1852 * 1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
1853 * in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
1856 * This function is an implementation of the specification as requested in
1859 * Client-side forms will use the same standard validation rules via JS or
1860 * HTML 5 validation; additional restrictions can be enforced server-side
1861 * by extensions via the 'isValidEmailAddr' hook.
1863 * Note that this validation doesn't 100% match RFC 2822, but is believed
1864 * to be liberal enough for wide use. Some invalid addresses will still
1865 * pass validation here.
1869 * @param string $addr E-mail address
1872 public static function validateEmail( $addr ) {
1874 if ( !Hooks
::run( 'isValidEmailAddr', array( $addr, &$result ) ) ) {
1878 // Please note strings below are enclosed in brackets [], this make the
1879 // hyphen "-" a range indicator. Hence it is double backslashed below.
1881 $rfc5322_atext = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~";
1882 $rfc1034_ldh_str = "a-z0-9\\-";
1884 $html5_email_regexp = "/
1886 [$rfc5322_atext\\.]+ # user part which is liberal :p
1888 [$rfc1034_ldh_str]+ # First domain part
1889 (\\.[$rfc1034_ldh_str]+)* # Following part prefixed with a dot
1891 /ix"; // case Insensitive, eXtended
1893 return (bool)preg_match( $html5_email_regexp, $addr );