3 * XHTML sanitizer for %MediaWiki.
5 * Copyright © 2002-2005 Brion Vibber <brion@pobox.com> et al
6 * http://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 * XHTML 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 * Blacklist for evil uris like javascript:
44 * WARNING: DO NOT use this in any place that actually requires blacklisting
45 * for security reasons. There are NUMEROUS[1] ways to bypass blacklisting, the
46 * only way to be secure from javascript: uri based xss vectors is to whitelist
47 * things that you know are safe and deny everything else.
48 * [1]: http://ha.ckers.org/xss.html
50 const EVIL_URI_PATTERN
= '!(^|\s|\*/\s*)(javascript|vbscript)([^\w]|$)!i';
51 const XMLNS_ATTRIBUTE_PATTERN
= "/^xmlns:[:A-Z_a-z-.0-9]+$/";
54 * List of all named character entities defined in HTML 4.01
55 * http://www.w3.org/TR/html4/sgml/entities.html
56 * As well as ' which is only defined starting in XHTML1.
59 static $htmlEntities = array(
75 'apos' => 39, // New in XHTML & HTML 5; avoid in output for compatibility with IE.
316 * Character entity aliases accepted by MediaWiki
318 static $htmlEntityAliases = array(
324 * Lazy-initialised attributes regex, see getAttribsRegex()
326 static $attribsRegex;
329 * Regular expression to match HTML/XML attribute pairs within a tag.
330 * Allows some... latitude.
331 * Used in Sanitizer::fixTagAttributes and Sanitizer::decodeTagAttributes
333 static function getAttribsRegex() {
334 if ( self
::$attribsRegex === null ) {
335 $attribFirst = '[:A-Z_a-z0-9]';
336 $attrib = '[:A-Z_a-z-.0-9]';
337 $space = '[\x09\x0a\x0d\x20]';
338 self
::$attribsRegex =
339 "/(?:^|$space)({$attribFirst}{$attrib}*)
342 # The attribute value: quoted or alone
345 | ([a-zA-Z0-9!#$%&()*,\\-.\\/:;<>?@[\\]^_`{|}~]+)
346 | (\#[0-9a-fA-F]+) # Technically wrong, but lots of
347 # colors are specified like this.
348 # We'll be normalizing it.
352 return self
::$attribsRegex;
356 * Cleans up HTML, removes dangerous tags and attributes, and
357 * removes HTML comments
359 * @param $text String
360 * @param $processCallback Callback to do any variable or parameter replacements in HTML attribute values
361 * @param $args Array for the processing callback
362 * @param $extratags Array for any extra tags to include
363 * @param $removetags Array for any tags (default or extra) to exclude
366 static function removeHTMLtags( $text, $processCallback = null, $args = array(), $extratags = array(), $removetags = array() ) {
367 global $wgUseTidy, $wgHtml5, $wgAllowMicrodataAttributes, $wgAllowImageTag;
369 static $htmlpairsStatic, $htmlsingle, $htmlsingleonly, $htmlnest, $tabletags,
370 $htmllist, $listtags, $htmlsingleallowed, $htmlelementsStatic, $staticInitialised;
372 wfProfileIn( __METHOD__
);
374 // Base our staticInitialised variable off of the global config state so that if the globals
375 // are changed (like in the secrewed up test system) we will re-initialise the settings.
376 $globalContext = implode( '-', compact( 'wgHtml5', 'wgAllowMicrodataAttributes', 'wgAllowImageTag' ) );
377 if ( !$staticInitialised ||
$staticInitialised != $globalContext ) {
379 $htmlpairsStatic = array( # Tags that must be closed
380 'b', 'bdi', 'del', 'i', 'ins', 'u', 'font', 'big', 'small', 'sub', 'sup', 'h1',
381 'h2', 'h3', 'h4', 'h5', 'h6', 'cite', 'code', 'em', 's',
382 'strike', 'strong', 'tt', 'var', 'div', 'center',
383 'blockquote', 'ol', 'ul', 'dl', 'table', 'caption', 'pre',
384 'ruby', 'rt' , 'rb' , 'rp', 'p', 'span', 'abbr', 'dfn',
388 $htmlpairsStatic = array_merge( $htmlpairsStatic, array( 'data', 'time', 'mark' ) );
391 'br', 'hr', 'li', 'dt', 'dd'
393 $htmlsingleonly = array( # Elements that cannot have close tags
396 if ( $wgHtml5 && $wgAllowMicrodataAttributes ) {
397 $htmlsingle[] = $htmlsingleonly[] = 'meta';
398 $htmlsingle[] = $htmlsingleonly[] = 'link';
400 $htmlnest = array( # Tags that can be nested--??
401 'table', 'tr', 'td', 'th', 'div', 'blockquote', 'ol', 'ul',
402 'li', 'dl', 'dt', 'dd', 'font', 'big', 'small', 'sub', 'sup', 'span'
404 $tabletags = array( # Can only appear inside table, we will close them
407 $htmllist = array( # Tags used by list
410 $listtags = array( # Tags that can appear in a list
414 if ( $wgAllowImageTag ) {
415 $htmlsingle[] = 'img';
416 $htmlsingleonly[] = 'img';
419 $htmlsingleallowed = array_unique( array_merge( $htmlsingle, $tabletags ) );
420 $htmlelementsStatic = array_unique( array_merge( $htmlsingle, $htmlpairsStatic, $htmlnest ) );
422 # Convert them all to hashtables for faster lookup
423 $vars = array( 'htmlpairsStatic', 'htmlsingle', 'htmlsingleonly', 'htmlnest', 'tabletags',
424 'htmllist', 'listtags', 'htmlsingleallowed', 'htmlelementsStatic' );
425 foreach ( $vars as $var ) {
426 $
$var = array_flip( $
$var );
428 $staticInitialised = $globalContext;
430 # Populate $htmlpairs and $htmlelements with the $extratags and $removetags arrays
431 $extratags = array_flip( $extratags );
432 $removetags = array_flip( $removetags );
433 $htmlpairs = array_merge( $extratags, $htmlpairsStatic );
434 $htmlelements = array_diff_key( array_merge( $extratags, $htmlelementsStatic ) , $removetags );
436 # Remove HTML comments
437 $text = Sanitizer
::removeHTMLcomments( $text );
438 $bits = explode( '<', $text );
439 $text = str_replace( '>', '>', array_shift( $bits ) );
441 $tagstack = $tablestack = array();
442 foreach ( $bits as $x ) {
444 # $slash: Does the current element start with a '/'?
445 # $t: Current element name
446 # $params: String between element name and >
447 # $brace: Ending '>' or '/>'
448 # $rest: Everything until the next element of $bits
449 if( preg_match( '!^(/?)(\\w+)([^>]*?)(/{0,1}>)([^<]*)$!', $x, $regs ) ) {
450 list( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
452 $slash = $t = $params = $brace = $rest = null;
456 if ( isset( $htmlelements[$t = strtolower( $t )] ) ) {
458 if ( $slash && isset( $htmlsingleonly[$t] ) ) {
460 } elseif ( $slash ) {
461 # Closing a tag... is it the one we just opened?
462 $ot = @array_pop
( $tagstack );
464 if ( isset( $htmlsingleallowed[$ot] ) ) {
465 # Pop all elements with an optional close tag
466 # and see if we find a match below them
468 array_push( $optstack, $ot );
469 wfSuppressWarnings();
470 $ot = array_pop( $tagstack );
472 while ( $ot != $t && isset( $htmlsingleallowed[$ot] ) ) {
473 array_push( $optstack, $ot );
474 wfSuppressWarnings();
475 $ot = array_pop( $tagstack );
479 # No match. Push the optional elements back again
481 wfSuppressWarnings();
482 $ot = array_pop( $optstack );
485 array_push( $tagstack, $ot );
486 wfSuppressWarnings();
487 $ot = array_pop( $optstack );
492 @array_push
( $tagstack, $ot );
493 # <li> can be nested in <ul> or <ol>, skip those cases:
494 if ( !isset( $htmllist[$ot] ) ||
!isset( $listtags[$t] ) ) {
499 if ( $t == 'table' ) {
500 $tagstack = array_pop( $tablestack );
505 # Keep track for later
506 if ( isset( $tabletags[$t] ) &&
507 !in_array( 'table', $tagstack ) ) {
509 } elseif ( in_array( $t, $tagstack ) &&
510 !isset( $htmlnest [$t ] ) ) {
512 # Is it a self closed htmlpair ? (bug 5487)
513 } elseif ( $brace == '/>' &&
514 isset( $htmlpairs[$t] ) ) {
516 } elseif ( isset( $htmlsingleonly[$t] ) ) {
517 # Hack to force empty tag for uncloseable elements
519 } elseif ( isset( $htmlsingle[$t] ) ) {
520 # Hack to not close $htmlsingle tags
522 # Still need to push this optionally-closed tag to
523 # the tag stack so that we can match end tags
524 # instead of marking them as bad.
525 array_push( $tagstack, $t );
526 } elseif ( isset( $tabletags[$t] )
527 && in_array( $t, $tagstack ) ) {
528 // New table tag but forgot to close the previous one
531 if ( $t == 'table' ) {
532 array_push( $tablestack, $tagstack );
535 array_push( $tagstack, $t );
538 # Replace any variables or template parameters with
540 if( is_callable( $processCallback ) ) {
541 call_user_func_array( $processCallback, array( &$params, $args ) );
544 if ( !Sanitizer
::validateTag( $params, $t ) ) {
548 # Strip non-approved attributes from the tag
549 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
552 $rest = str_replace( '>', '>', $rest );
553 $close = ( $brace == '/>' && !$slash ) ?
' /' : '';
554 $text .= "<$slash$t$newparams$close>$rest";
558 $text .= '<' . str_replace( '>', '>', $x);
560 # Close off any remaining tags
561 while ( is_array( $tagstack ) && ($t = array_pop( $tagstack )) ) {
563 if ( $t == 'table' ) { $tagstack = array_pop( $tablestack ); }
566 # this might be possible using tidy itself
567 foreach ( $bits as $x ) {
568 preg_match( '/^(\\/?)(\\w+)([^>]*?)(\\/{0,1}>)([^<]*)$/',
570 @list
( /* $qbar */, $slash, $t, $params, $brace, $rest ) = $regs;
572 if ( isset( $htmlelements[$t = strtolower( $t )] ) ) {
573 if( is_callable( $processCallback ) ) {
574 call_user_func_array( $processCallback, array( &$params, $args ) );
577 if ( !Sanitizer
::validateTag( $params, $t ) ) {
581 $newparams = Sanitizer
::fixTagAttributes( $params, $t );
583 $rest = str_replace( '>', '>', $rest );
584 $text .= "<$slash$t$newparams$brace$rest";
588 $text .= '<' . str_replace( '>', '>', $x);
591 wfProfileOut( __METHOD__
);
596 * Remove '<!--', '-->', and everything between.
597 * To avoid leaving blank lines, when a comment is both preceded
598 * and followed by a newline (ignoring spaces), trim leading and
599 * trailing spaces and one of the newlines.
602 * @param $text String
605 static function removeHTMLcomments( $text ) {
606 wfProfileIn( __METHOD__
);
607 while (($start = strpos($text, '<!--')) !== false) {
608 $end = strpos($text, '-->', $start +
4);
609 if ($end === false) {
610 # Unterminated comment; bail out
616 # Trim space and newline if the comment is both
617 # preceded and followed by a newline
618 $spaceStart = max($start - 1, 0);
619 $spaceLen = $end - $spaceStart;
620 while (substr($text, $spaceStart, 1) === ' ' && $spaceStart > 0) {
624 while (substr($text, $spaceStart +
$spaceLen, 1) === ' ')
626 if (substr($text, $spaceStart, 1) === "\n" and substr($text, $spaceStart +
$spaceLen, 1) === "\n") {
627 # Remove the comment, leading and trailing
628 # spaces, and leave only one newline.
629 $text = substr_replace($text, "\n", $spaceStart, $spaceLen +
1);
632 # Remove just the comment.
633 $text = substr_replace($text, '', $start, $end - $start);
636 wfProfileOut( __METHOD__
);
641 * Take an array of attribute names and values and fix some deprecated values
642 * for the given element type.
643 * This does not validate properties, so you should ensure that you call
644 * validateTagAttributes AFTER this to ensure that the resulting style rule
645 * this may add is safe.
647 * - Converts most presentational attributes like align into inline css
649 * @param $attribs Array
650 * @param $element String
653 static function fixDeprecatedAttributes( $attribs, $element ) {
654 global $wgHtml5, $wgCleanupPresentationalAttributes;
656 // presentational attributes were removed from html5, we can leave them
657 // in when html5 is turned off
658 if ( !$wgHtml5 ||
!$wgCleanupPresentationalAttributes ) {
662 $table = array( 'table' );
663 $cells = array( 'td', 'th' );
664 $colls = array( 'col', 'colgroup' );
665 $tblocks = array( 'tbody', 'tfoot', 'thead' );
666 $h = array( 'h1', 'h2', 'h3', 'h4', 'h5', 'h6' );
668 $presentationalAttribs = array(
669 'align' => array( 'text-align', array_merge( array( 'caption', 'hr', 'div', 'p', 'tr' ), $table, $cells, $colls, $tblocks, $h ) ),
670 'clear' => array( 'clear', array( 'br' ) ),
671 'height' => array( 'height', $cells ),
672 'nowrap' => array( 'white-space', $cells ),
673 'size' => array( 'height', array( 'hr' ) ),
674 'type' => array( 'list-style-type', array( 'li', 'ol', 'ul' ) ),
675 'valign' => array( 'vertical-align', array_merge( $cells, $colls, $tblocks ) ),
676 'width' => array( 'width', array_merge( array( 'hr', 'pre' ), $table, $cells, $colls ) ),
679 // Ensure that any upper case or mixed case attributes are converted to lowercase
680 foreach ( $attribs as $attribute => $value ) {
681 if ( $attribute !== strtolower( $attribute ) && array_key_exists( strtolower( $attribute ), $presentationalAttribs ) ) {
682 $attribs[strtolower( $attribute )] = $value;
683 unset( $attribs[$attribute] );
688 foreach ( $presentationalAttribs as $attribute => $info ) {
689 list( $property, $elements ) = $info;
691 // Skip if this attribute is not relevant to this element
692 if ( !in_array( $element, $elements ) ) {
696 // Skip if the attribute is not used
697 if ( !array_key_exists( $attribute, $attribs ) ) {
701 $value = $attribs[$attribute];
703 // For nowrap the value should be nowrap instead of whatever text is in the value
704 if ( $attribute === 'nowrap' ) {
708 // clear="all" is clear: both; in css
709 if ( $attribute === 'clear' && strtolower( $value ) === 'all' ) {
713 // Size based properties should have px applied to them if they have no unit
714 if ( in_array( $attribute, array( 'height', 'width', 'size' ) ) ) {
715 if ( preg_match( '/^[\d.]+$/', $value ) ) {
716 $value = "{$value}px";
720 // Table align is special, it's about block alignment instead of
721 // content align (see also bug 40306)
722 if ( $attribute === 'align' && in_array( $element, $table ) ) {
723 if ( $value === 'center' ) {
724 $style .= ' margin-left: auto;';
725 $property = 'margin-right';
732 $style .= " $property: $value;";
734 unset( $attribs[$attribute] );
738 // Prepend our style rules so that they can be overridden by user css
739 if ( isset($attribs['style']) ) {
740 $style .= " " . $attribs['style'];
742 $attribs['style'] = trim($style);
749 * Takes attribute names and values for a tag and the tah name and
750 * validates that the tag is allowed to be present.
751 * This DOES NOT validate the attributes, nor does it validate the
752 * tags themselves. This method only handles the special circumstances
753 * where we may want to allow a tag within content but ONLY when it has
754 * specific attributes set.
758 static function validateTag( $params, $element ) {
759 $params = Sanitizer
::decodeTagAttributes( $params );
761 if ( $element == 'meta' ||
$element == 'link' ) {
762 if ( !isset( $params['itemprop'] ) ) {
763 // <meta> and <link> must have an itemprop="" otherwise they are not valid or safe in content
766 if ( $element == 'meta' && !isset( $params['content'] ) ) {
767 // <meta> must have a content="" for the itemprop
770 if ( $element == 'link' && !isset( $params['href'] ) ) {
771 // <link> must have an associated href=""
780 * Take an array of attribute names and values and normalize or discard
781 * illegal values for the given element type.
783 * - Discards attributes not on a whitelist for the given element
784 * - Unsafe style attributes are discarded
785 * - Invalid id attributes are reencoded
787 * @param $attribs Array
788 * @param $element String
791 * @todo Check for legal values where the DTD limits things.
792 * @todo Check for unique id attribute :P
794 static function validateTagAttributes( $attribs, $element ) {
795 return Sanitizer
::validateAttributes( $attribs,
796 Sanitizer
::attributeWhitelist( $element ) );
800 * Take an array of attribute names and values and normalize or discard
801 * illegal values for the given whitelist.
803 * - Discards attributes not the given whitelist
804 * - Unsafe style attributes are discarded
805 * - Invalid id attributes are reencoded
807 * @param $attribs Array
808 * @param $whitelist Array: list of allowed attribute names
811 * @todo Check for legal values where the DTD limits things.
812 * @todo Check for unique id attribute :P
814 static function validateAttributes( $attribs, $whitelist ) {
815 global $wgAllowRdfaAttributes, $wgAllowMicrodataAttributes, $wgHtml5;
817 $whitelist = array_flip( $whitelist );
818 $hrefExp = '/^(' . wfUrlProtocols() . ')[^\s]+$/';
821 foreach( $attribs as $attribute => $value ) {
822 #allow XML namespace declaration if RDFa is enabled
823 if ( $wgAllowRdfaAttributes && preg_match( self
::XMLNS_ATTRIBUTE_PATTERN
, $attribute ) ) {
824 if ( !preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
825 $out[$attribute] = $value;
831 # Allow any attribute beginning with "data-", if in HTML5 mode
832 if ( !($wgHtml5 && preg_match( '/^data-/i', $attribute )) && !isset( $whitelist[$attribute] ) ) {
836 # Strip javascript "expression" from stylesheets.
837 # http://msdn.microsoft.com/workshop/author/dhtml/overview/recalc.asp
838 if( $attribute == 'style' ) {
839 $value = Sanitizer
::checkCss( $value );
842 if ( $attribute === 'id' ) {
843 $value = Sanitizer
::escapeId( $value, 'noninitial' );
846 //RDFa and microdata properties allow URLs, URIs and/or CURIs. check them for sanity
847 if ( $attribute === 'rel' ||
$attribute === 'rev' ||
848 $attribute === 'about' ||
$attribute === 'property' ||
$attribute === 'resource' ||
#RDFa
849 $attribute === 'datatype' ||
$attribute === 'typeof' ||
#RDFa
850 $attribute === 'itemid' ||
$attribute === 'itemprop' ||
$attribute === 'itemref' ||
#HTML5 microdata
851 $attribute === 'itemscope' ||
$attribute === 'itemtype' ) { #HTML5 microdata
853 //Paranoia. Allow "simple" values but suppress javascript
854 if ( preg_match( self
::EVIL_URI_PATTERN
, $value ) ) {
859 # NOTE: even though elements using href/src are not allowed directly, supply
860 # validation code that can be used by tag hook handlers, etc
861 if ( $attribute === 'href' ||
$attribute === 'src' ) {
862 if ( !preg_match( $hrefExp, $value ) ) {
863 continue; //drop any href or src attributes not using an allowed protocol.
864 //NOTE: this also drops all relative URLs
868 // If this attribute was previously set, override it.
869 // Output should only have one attribute of each name.
870 $out[$attribute] = $value;
873 if ( $wgAllowMicrodataAttributes ) {
874 # itemtype, itemid, itemref don't make sense without itemscope
875 if ( !array_key_exists( 'itemscope', $out ) ) {
876 unset( $out['itemtype'] );
877 unset( $out['itemid'] );
878 unset( $out['itemref'] );
880 # TODO: Strip itemprop if we aren't descendants of an itemscope or pointed to by an itemref.
886 * Merge two sets of HTML attributes. Conflicting items in the second set
887 * will override those in the first, except for 'class' attributes which
888 * will be combined (if they're both strings).
890 * @todo implement merging for other attributes such as style
895 static function mergeAttributes( $a, $b ) {
896 $out = array_merge( $a, $b );
897 if( isset( $a['class'] ) && isset( $b['class'] )
898 && is_string( $a['class'] ) && is_string( $b['class'] )
899 && $a['class'] !== $b['class'] ) {
900 $classes = preg_split( '/\s+/', "{$a['class']} {$b['class']}",
901 -1, PREG_SPLIT_NO_EMPTY
);
902 $out['class'] = implode( ' ', array_unique( $classes ) );
908 * Pick apart some CSS and check it for forbidden or unsafe structures.
909 * Returns a sanitized string. This sanitized string will have
910 * character references and escape sequences decoded, and comments
911 * stripped. If the input is just too evil, only a comment complaining
912 * about evilness will be returned.
914 * Currently URL references, 'expression', 'tps' are forbidden.
916 * NOTE: Despite the fact that character references are decoded, the
917 * returned string may contain character references given certain
918 * clever input strings. These character references must
919 * be escaped before the return value is embedded in HTML.
921 * @param $value String
924 static function checkCss( $value ) {
925 // Decode character references like {
926 $value = Sanitizer
::decodeCharReferences( $value );
928 // Decode escape sequences and line continuation
929 // See the grammar in the CSS 2 spec, appendix D.
930 // This has to be done AFTER decoding character references.
931 // This means it isn't possible for this function to return
932 // unsanitized escape sequences. It is possible to manufacture
933 // input that contains character references that decode to
934 // escape sequences that decode to character references, but
935 // it's OK for the return value to contain character references
936 // because the caller is supposed to escape those anyway.
938 if ( !$decodeRegex ) {
939 $space = '[\\x20\\t\\r\\n\\f]';
940 $nl = '(?:\\n|\\r\\n|\\r|\\f)';
942 $decodeRegex = "/ $backslash
944 ($nl) | # 1. Line continuation
945 ([0-9A-Fa-f]{1,6})$space? | # 2. character number
946 (.) | # 3. backslash cancelling special meaning
947 () | # 4. backslash at end of string
950 $value = preg_replace_callback( $decodeRegex,
951 array( __CLASS__
, 'cssDecodeCallback' ), $value );
953 // Remove any comments; IE gets token splitting wrong
954 // This must be done AFTER decoding character references and
955 // escape sequences, because those steps can introduce comments
956 // This step cannot introduce character references or escape
957 // sequences, because it replaces comments with spaces rather
958 // than removing them completely.
959 $value = StringUtils
::delimiterReplace( '/*', '*/', ' ', $value );
961 // Remove anything after a comment-start token, to guard against
962 // incorrect client implementations.
963 $commentPos = strpos( $value, '/*' );
964 if ( $commentPos !== false ) {
965 $value = substr( $value, 0, $commentPos );
968 // Reject problematic keywords and control characters
969 if ( preg_match( '/[\000-\010\016-\037\177]/', $value ) ) {
970 return '/* invalid control char */';
971 } elseif ( preg_match( '! expression | filter\s*: | accelerator\s*: | url\s*\( | image\s*\( | image-set\s*\( !ix', $value ) ) {
972 return '/* insecure input */';
978 * @param $matches array
981 static function cssDecodeCallback( $matches ) {
982 if ( $matches[1] !== '' ) {
985 } elseif ( $matches[2] !== '' ) {
986 $char = codepointToUtf8( hexdec( $matches[2] ) );
987 } elseif ( $matches[3] !== '' ) {
992 if ( $char == "\n" ||
$char == '"' ||
$char == "'" ||
$char == '\\' ) {
993 // These characters need to be escaped in strings
994 // Clean up the escape sequence to avoid parsing errors by clients
995 return '\\' . dechex( ord( $char ) ) . ' ';
997 // Decode unnecessary escape
1003 * Take a tag soup fragment listing an HTML element's attributes
1004 * and normalize it to well-formed XML, discarding unwanted attributes.
1005 * Output is safe for further wikitext processing, with escaping of
1006 * values that could trigger problems.
1008 * - Normalizes attribute names to lowercase
1009 * - Discards attributes not on a whitelist for the given element
1010 * - Turns broken or invalid entities into plaintext
1011 * - Double-quotes all attribute values
1012 * - Attributes without values are given the name as attribute
1013 * - Double attributes are discarded
1014 * - Unsafe style attributes are discarded
1015 * - Prepends space if there are attributes.
1017 * @param $text String
1018 * @param $element String
1021 static function fixTagAttributes( $text, $element ) {
1022 if( trim( $text ) == '' ) {
1026 $decoded = Sanitizer
::decodeTagAttributes( $text );
1027 $decoded = Sanitizer
::fixDeprecatedAttributes( $decoded, $element );
1028 $stripped = Sanitizer
::validateTagAttributes( $decoded, $element );
1031 foreach( $stripped as $attribute => $value ) {
1032 $encAttribute = htmlspecialchars( $attribute );
1033 $encValue = Sanitizer
::safeEncodeAttribute( $value );
1035 $attribs[] = "$encAttribute=\"$encValue\"";
1037 return count( $attribs ) ?
' ' . implode( ' ', $attribs ) : '';
1041 * Encode an attribute value for HTML output.
1042 * @param $text String
1043 * @return HTML-encoded text fragment
1045 static function encodeAttribute( $text ) {
1046 $encValue = htmlspecialchars( $text, ENT_QUOTES
);
1048 // Whitespace is normalized during attribute decoding,
1049 // so if we've been passed non-spaces we must encode them
1050 // ahead of time or they won't be preserved.
1051 $encValue = strtr( $encValue, array(
1061 * Encode an attribute value for HTML tags, with extra armoring
1062 * against further wiki processing.
1063 * @param $text String
1064 * @return HTML-encoded text fragment
1066 static function safeEncodeAttribute( $text ) {
1067 $encValue = Sanitizer
::encodeAttribute( $text );
1069 # Templates and links may be expanded in later parsing,
1070 # creating invalid or dangerous output. Suppress this.
1071 $encValue = strtr( $encValue, array(
1072 '<' => '<', // This should never happen,
1073 '>' => '>', // we've received invalid input
1074 '"' => '"', // which should have been escaped.
1077 "''" => '''',
1078 'ISBN' => 'ISBN',
1080 'PMID' => 'PMID',
1086 $encValue = preg_replace_callback(
1087 '/((?i)' . wfUrlProtocols() . ')/',
1088 array( 'Sanitizer', 'armorLinksCallback' ),
1094 * Given a value, escape it so that it can be used in an id attribute and
1095 * return it. This will use HTML5 validation if $wgExperimentalHtmlIds is
1096 * true, allowing anything but ASCII whitespace. Otherwise it will use
1097 * HTML 4 rules, which means a narrow subset of ASCII, with bad characters
1098 * escaped with lots of dots.
1100 * To ensure we don't have to bother escaping anything, we also strip ', ",
1101 * & even if $wgExperimentalIds is true. TODO: Is this the best tactic?
1102 * We also strip # because it upsets IE, and % because it could be
1103 * ambiguous if it's part of something that looks like a percent escape
1104 * (which don't work reliably in fragments cross-browser).
1106 * @see http://www.w3.org/TR/html401/types.html#type-name Valid characters
1109 * @see http://www.w3.org/TR/html401/struct/links.html#h-12.2.3 Anchors with the id attribute
1110 * @see http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#the-id-attribute
1111 * HTML5 definition of id attribute
1113 * @param $id String: id to escape
1114 * @param $options Mixed: string or array of strings (default is array()):
1115 * 'noninitial': This is a non-initial fragment of an id, not a full id,
1116 * so don't pay attention if the first character isn't valid at the
1117 * beginning of an id. Only matters if $wgExperimentalHtmlIds is
1119 * 'legacy': Behave the way the old HTML 4-based ID escaping worked even
1120 * if $wgExperimentalHtmlIds is used, so we can generate extra
1121 * anchors and links won't break.
1124 static function escapeId( $id, $options = array() ) {
1125 global $wgHtml5, $wgExperimentalHtmlIds;
1126 $options = (array)$options;
1128 if ( $wgHtml5 && $wgExperimentalHtmlIds && !in_array( 'legacy', $options ) ) {
1129 $id = Sanitizer
::decodeCharReferences( $id );
1130 $id = preg_replace( '/[ \t\n\r\f_\'"&#%]+/', '_', $id );
1131 $id = trim( $id, '_' );
1133 # Must have been all whitespace to start with.
1140 # HTML4-style escaping
1141 static $replace = array(
1146 $id = urlencode( Sanitizer
::decodeCharReferences( strtr( $id, ' ', '_' ) ) );
1147 $id = str_replace( array_keys( $replace ), array_values( $replace ), $id );
1149 if ( !preg_match( '/^[a-zA-Z]/', $id )
1150 && !in_array( 'noninitial', $options ) ) {
1151 // Initial character must be a letter!
1158 * Given a value, escape it so that it can be used as a CSS class and
1161 * @todo For extra validity, input should be validated UTF-8.
1163 * @see http://www.w3.org/TR/CSS21/syndata.html Valid characters/format
1165 * @param $class String
1168 static function escapeClass( $class ) {
1169 // Convert ugly stuff to underscores and kill underscores in ugly places
1170 return rtrim(preg_replace(
1171 array('/(^[0-9\\-])|[\\x00-\\x20!"#$%&\'()*+,.\\/:;<=>?@[\\]^`{|}~]|\\xC2\\xA0/','/_+/'),
1177 * Given HTML input, escape with htmlspecialchars but un-escape entites.
1178 * This allows (generally harmless) entities like   to survive.
1180 * @param $html String to escape
1181 * @return String: escaped input
1183 static function escapeHtmlAllowEntities( $html ) {
1184 $html = Sanitizer
::decodeCharReferences( $html );
1185 # It seems wise to escape ' as well as ", as a matter of course. Can't
1187 $html = htmlspecialchars( $html, ENT_QUOTES
);
1192 * Regex replace callback for armoring links against further processing.
1193 * @param $matches Array
1196 private static function armorLinksCallback( $matches ) {
1197 return str_replace( ':', ':', $matches[1] );
1201 * Return an associative array of attribute names and values from
1202 * a partial tag string. Attribute names are forces to lowercase,
1203 * character references are decoded to UTF-8 text.
1205 * @param $text String
1208 public static function decodeTagAttributes( $text ) {
1209 if( trim( $text ) == '' ) {
1215 if( !preg_match_all(
1216 self
::getAttribsRegex(),
1219 PREG_SET_ORDER
) ) {
1223 foreach( $pairs as $set ) {
1224 $attribute = strtolower( $set[1] );
1225 $value = Sanitizer
::getTagAttributeCallback( $set );
1227 // Normalize whitespace
1228 $value = preg_replace( '/[\t\r\n ]+/', ' ', $value );
1229 $value = trim( $value );
1231 // Decode character references
1232 $attribs[$attribute] = Sanitizer
::decodeCharReferences( $value );
1238 * Pick the appropriate attribute value from a match set from the
1239 * attribs regex matches.
1242 * @throws MWException
1245 private static function getTagAttributeCallback( $set ) {
1246 if( isset( $set[6] ) ) {
1247 # Illegal #XXXXXX color with no quotes.
1249 } elseif( isset( $set[5] ) ) {
1252 } elseif( isset( $set[4] ) ) {
1255 } elseif( isset( $set[3] ) ) {
1258 } elseif( !isset( $set[2] ) ) {
1259 # In XHTML, attributes must have a value.
1260 # For 'reduced' form, return explicitly the attribute name here.
1263 throw new MWException( "Tag conditions not met. This should never happen and is a bug." );
1268 * Normalize whitespace and character references in an XML source-
1269 * encoded text for an attribute value.
1271 * See http://www.w3.org/TR/REC-xml/#AVNormalize for background,
1272 * but note that we're not returning the value, but are returning
1273 * XML source fragments that will be slapped into output.
1275 * @param $text String
1278 private static function normalizeAttributeValue( $text ) {
1279 return str_replace( '"', '"',
1280 self
::normalizeWhitespace(
1281 Sanitizer
::normalizeCharReferences( $text ) ) );
1285 * @param $text string
1288 private static function normalizeWhitespace( $text ) {
1289 return preg_replace(
1290 '/\r\n|[\x20\x0d\x0a\x09]/',
1296 * Normalizes whitespace in a section name, such as might be returned
1297 * by Parser::stripSectionName(), for use in the id's that are used for
1300 * @param $section String
1303 static function normalizeSectionNameWhitespace( $section ) {
1304 return trim( preg_replace( '/[ _]+/', ' ', $section ) );
1308 * Ensure that any entities and character references are legal
1309 * for XML and XHTML specifically. Any stray bits will be
1310 * &-escaped to result in a valid text fragment.
1312 * a. named char refs can only be < > & ", others are
1313 * numericized (this way we're well-formed even without a DTD)
1314 * b. any numeric char refs must be legal chars, not invalid or forbidden
1315 * c. use lower cased "&#x", not "&#X"
1316 * d. fix or reject non-valid attributes
1318 * @param $text String
1322 static function normalizeCharReferences( $text ) {
1323 return preg_replace_callback(
1324 self
::CHAR_REFS_REGEX
,
1325 array( 'Sanitizer', 'normalizeCharReferencesCallback' ),
1329 * @param $matches String
1332 static function normalizeCharReferencesCallback( $matches ) {
1334 if( $matches[1] != '' ) {
1335 $ret = Sanitizer
::normalizeEntity( $matches[1] );
1336 } elseif( $matches[2] != '' ) {
1337 $ret = Sanitizer
::decCharReference( $matches[2] );
1338 } elseif( $matches[3] != '' ) {
1339 $ret = Sanitizer
::hexCharReference( $matches[3] );
1341 if( is_null( $ret ) ) {
1342 return htmlspecialchars( $matches[0] );
1349 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1350 * return the equivalent numeric entity reference (except for the core <
1351 * > & "). If the entity is a MediaWiki-specific alias, returns
1352 * the HTML equivalent. Otherwise, returns HTML-escaped text of
1353 * pseudo-entity source (eg &foo;)
1355 * @param $name String
1358 static function normalizeEntity( $name ) {
1359 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1360 return '&' . self
::$htmlEntityAliases[$name] . ';';
1361 } elseif ( in_array( $name,
1362 array( 'lt', 'gt', 'amp', 'quot' ) ) ) {
1364 } elseif ( isset( self
::$htmlEntities[$name] ) ) {
1365 return '&#' . self
::$htmlEntities[$name] . ';';
1367 return "&$name;";
1373 * @return null|string
1375 static function decCharReference( $codepoint ) {
1376 $point = intval( $codepoint );
1377 if( Sanitizer
::validateCodepoint( $point ) ) {
1378 return sprintf( '&#%d;', $point );
1386 * @return null|string
1388 static function hexCharReference( $codepoint ) {
1389 $point = hexdec( $codepoint );
1390 if( Sanitizer
::validateCodepoint( $point ) ) {
1391 return sprintf( '&#x%x;', $point );
1398 * Returns true if a given Unicode codepoint is a valid character in XML.
1399 * @param $codepoint Integer
1402 private static function validateCodepoint( $codepoint ) {
1403 return ($codepoint == 0x09)
1404 ||
($codepoint == 0x0a)
1405 ||
($codepoint == 0x0d)
1406 ||
($codepoint >= 0x20 && $codepoint <= 0xd7ff)
1407 ||
($codepoint >= 0xe000 && $codepoint <= 0xfffd)
1408 ||
($codepoint >= 0x10000 && $codepoint <= 0x10ffff);
1412 * Decode any character references, numeric or named entities,
1413 * in the text and return a UTF-8 string.
1415 * @param $text String
1418 public static function decodeCharReferences( $text ) {
1419 return preg_replace_callback(
1420 self
::CHAR_REFS_REGEX
,
1421 array( 'Sanitizer', 'decodeCharReferencesCallback' ),
1426 * Decode any character references, numeric or named entities,
1427 * in the next and normalize the resulting string. (bug 14952)
1429 * This is useful for page titles, not for text to be displayed,
1430 * MediaWiki allows HTML entities to escape normalization as a feature.
1432 * @param $text String (already normalized, containing entities)
1433 * @return String (still normalized, without entities)
1435 public static function decodeCharReferencesAndNormalize( $text ) {
1437 $text = preg_replace_callback(
1438 self
::CHAR_REFS_REGEX
,
1439 array( 'Sanitizer', 'decodeCharReferencesCallback' ),
1440 $text, /* limit */ -1, $count );
1443 return $wgContLang->normalize( $text );
1450 * @param $matches String
1453 static function decodeCharReferencesCallback( $matches ) {
1454 if( $matches[1] != '' ) {
1455 return Sanitizer
::decodeEntity( $matches[1] );
1456 } elseif( $matches[2] != '' ) {
1457 return Sanitizer
::decodeChar( intval( $matches[2] ) );
1458 } elseif( $matches[3] != '' ) {
1459 return Sanitizer
::decodeChar( hexdec( $matches[3] ) );
1461 # Last case should be an ampersand by itself
1466 * Return UTF-8 string for a codepoint if that is a valid
1467 * character reference, otherwise U+FFFD REPLACEMENT CHARACTER.
1468 * @param $codepoint Integer
1472 static function decodeChar( $codepoint ) {
1473 if( Sanitizer
::validateCodepoint( $codepoint ) ) {
1474 return codepointToUtf8( $codepoint );
1476 return UTF8_REPLACEMENT
;
1481 * If the named entity is defined in the HTML 4.0/XHTML 1.0 DTD,
1482 * return the UTF-8 encoding of that character. Otherwise, returns
1483 * pseudo-entity source (eg "&foo;")
1485 * @param $name String
1488 static function decodeEntity( $name ) {
1489 if ( isset( self
::$htmlEntityAliases[$name] ) ) {
1490 $name = self
::$htmlEntityAliases[$name];
1492 if( isset( self
::$htmlEntities[$name] ) ) {
1493 return codepointToUtf8( self
::$htmlEntities[$name] );
1500 * Fetch the whitelist of acceptable attributes for a given element name.
1502 * @param $element String
1505 static function attributeWhitelist( $element ) {
1506 $list = Sanitizer
::setupAttributeWhitelist();
1507 return isset( $list[$element] )
1513 * Foreach array key (an allowed HTML element), return an array
1514 * of allowed attributes
1517 static function setupAttributeWhitelist() {
1518 global $wgAllowRdfaAttributes, $wgHtml5, $wgAllowMicrodataAttributes;
1520 static $whitelist, $staticInitialised;
1521 $globalContext = implode( '-', compact( 'wgAllowRdfaAttributes', 'wgHtml5', 'wgAllowMicrodataAttributes' ) );
1523 if ( isset( $whitelist ) && $staticInitialised == $globalContext ) {
1527 $common = array( 'id', 'class', 'lang', 'dir', 'title', 'style' );
1529 if ( $wgAllowRdfaAttributes ) {
1530 #RDFa attributes as specified in section 9 of http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014
1531 $common = array_merge( $common, array(
1532 'about', 'property', 'resource', 'datatype', 'typeof',
1536 if ( $wgHtml5 && $wgAllowMicrodataAttributes ) {
1537 # add HTML5 microdata tages as pecified by http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#the-microdata-model
1538 $common = array_merge( $common, array(
1539 'itemid', 'itemprop', 'itemref', 'itemscope', 'itemtype'
1543 $block = array_merge( $common, array( 'align' ) );
1544 $tablealign = array( 'align', 'char', 'charoff', 'valign' );
1545 $tablecell = array( 'abbr',
1551 'nowrap', # deprecated
1552 'width', # deprecated
1553 'height', # deprecated
1554 'bgcolor' # deprecated
1557 # Numbers refer to sections in HTML 4.01 standard describing the element.
1558 # See: http://www.w3.org/TR/html4/
1562 'center' => $common, # deprecated
1563 'span' => $block, # ??
1581 'strong' => $common,
1592 'blockquote' => array_merge( $common, array( 'cite' ) ),
1603 'br' => array( 'id', 'class', 'title', 'style', 'clear' ),
1606 'pre' => array_merge( $common, array( 'width' ) ),
1609 'ins' => array_merge( $common, array( 'cite', 'datetime' ) ),
1610 'del' => array_merge( $common, array( 'cite', 'datetime' ) ),
1613 'ul' => array_merge( $common, array( 'type' ) ),
1614 'ol' => array_merge( $common, array( 'type', 'start' ) ),
1615 'li' => array_merge( $common, array( 'type', 'value' ) ),
1623 'table' => array_merge( $common,
1624 array( 'summary', 'width', 'border', 'frame',
1625 'rules', 'cellspacing', 'cellpadding',
1630 'caption' => array_merge( $common, array( 'align' ) ),
1633 'thead' => array_merge( $common, $tablealign ),
1634 'tfoot' => array_merge( $common, $tablealign ),
1635 'tbody' => array_merge( $common, $tablealign ),
1638 'colgroup' => array_merge( $common, array( 'span', 'width' ), $tablealign ),
1639 'col' => array_merge( $common, array( 'span', 'width' ), $tablealign ),
1642 'tr' => array_merge( $common, array( 'bgcolor' ), $tablealign ),
1645 'td' => array_merge( $common, $tablecell, $tablealign ),
1646 'th' => array_merge( $common, $tablecell, $tablealign ),
1648 # 12.2 # NOTE: <a> is not allowed directly, but the attrib whitelist is used from the Parser object
1649 'a' => array_merge( $common, array( 'href', 'rel', 'rev' ) ), # rel/rev esp. for RDFa
1652 # Not usually allowed, but may be used for extension-style hooks
1653 # such as <math> when it is rasterized, or if $wgAllowImageTag is
1655 'img' => array_merge( $common, array( 'alt', 'src', 'width', 'height' ) ),
1663 'strike' => $common,
1668 'font' => array_merge( $common, array( 'size', 'color', 'face' ) ),
1672 'hr' => array_merge( $common, array( 'noshade', 'size', 'width' ) ),
1674 # XHTML Ruby annotation text module, simple ruby only.
1675 # http://www.w3c.org/TR/ruby/
1680 'rt' => $common, #array_merge( $common, array( 'rbspan' ) ),
1683 # MathML root element, where used for extensions
1684 # 'title' may not be 100% valid here; it's XHTML
1685 # http://www.w3.org/TR/REC-MathML/
1686 'math' => array( 'class', 'style', 'id', 'title' ),
1688 # HTML 5 section 4.6
1694 # HTML5 elements, defined by:
1695 # http://www.whatwg.org/specs/web-apps/current-work/multipage/
1696 $whitelist +
= array(
1697 'data' => array_merge( $common, array( 'value' ) ),
1698 'time' => array_merge( $common, array( 'datetime' ) ),
1701 // meta and link are only permitted by removeHTMLtags when Microdata
1702 // is enabled so we don't bother adding a conditional to hide these
1703 // Also meta and link are only valid in WikiText as Microdata elements
1704 // (ie: validateTag rejects tags missing the attributes needed for Microdata)
1705 // So we don't bother including $common attributes that have no purpose.
1706 'meta' => array( 'itemprop', 'content' ),
1707 'link' => array( 'itemprop', 'href' ),
1711 $staticInitialised = $globalContext;
1717 * Take a fragment of (potentially invalid) HTML and return
1718 * a version with any tags removed, encoded as plain text.
1720 * Warning: this return value must be further escaped for literal
1721 * inclusion in HTML output as of 1.10!
1723 * @param $text String: HTML fragment
1726 static function stripAllTags( $text ) {
1728 $text = StringUtils
::delimiterReplace( '<', '>', '', $text );
1730 # Normalize &entities and whitespace
1731 $text = self
::decodeCharReferences( $text );
1732 $text = self
::normalizeWhitespace( $text );
1738 * Hack up a private DOCTYPE with HTML's standard entity declarations.
1739 * PHP 4 seemed to know these if you gave it an HTML doctype, but
1742 * Use for passing XHTML fragments to PHP's XML parsing functions
1746 static function hackDocType() {
1747 $out = "<!DOCTYPE html [\n";
1748 foreach( self
::$htmlEntities as $entity => $codepoint ) {
1749 $out .= "<!ENTITY $entity \"&#$codepoint;\">";
1756 * @param $url string
1757 * @return mixed|string
1759 static function cleanUrl( $url ) {
1760 # Normalize any HTML entities in input. They will be
1761 # re-escaped by makeExternalLink().
1762 $url = Sanitizer
::decodeCharReferences( $url );
1764 # Escape any control characters introduced by the above step
1765 $url = preg_replace_callback( '/[\][<>"\\x00-\\x20\\x7F\|]/',
1766 array( __CLASS__
, 'cleanUrlCallback' ), $url );
1768 # Validate hostname portion
1770 if( preg_match( '!^([^:]+:)(//[^/]+)?(.*)$!iD', $url, $matches ) ) {
1771 list( /* $whole */, $protocol, $host, $rest ) = $matches;
1773 // Characters that will be ignored in IDNs.
1774 // http://tools.ietf.org/html/3454#section-3.1
1775 // Strip them before further processing so blacklists and such work.
1777 \\s| # general whitespace
1778 \xc2\xad| # 00ad SOFT HYPHEN
1779 \xe1\xa0\x86| # 1806 MONGOLIAN TODO SOFT HYPHEN
1780 \xe2\x80\x8b| # 200b ZERO WIDTH SPACE
1781 \xe2\x81\xa0| # 2060 WORD JOINER
1782 \xef\xbb\xbf| # feff ZERO WIDTH NO-BREAK SPACE
1783 \xcd\x8f| # 034f COMBINING GRAPHEME JOINER
1784 \xe1\xa0\x8b| # 180b MONGOLIAN FREE VARIATION SELECTOR ONE
1785 \xe1\xa0\x8c| # 180c MONGOLIAN FREE VARIATION SELECTOR TWO
1786 \xe1\xa0\x8d| # 180d MONGOLIAN FREE VARIATION SELECTOR THREE
1787 \xe2\x80\x8c| # 200c ZERO WIDTH NON-JOINER
1788 \xe2\x80\x8d| # 200d ZERO WIDTH JOINER
1789 [\xef\xb8\x80-\xef\xb8\x8f] # fe00-fe0f VARIATION SELECTOR-1-16
1792 $host = preg_replace( $strip, '', $host );
1794 // @todo FIXME: Validate hostnames here
1796 return $protocol . $host . $rest;
1803 * @param $matches array
1806 static function cleanUrlCallback( $matches ) {
1807 return urlencode( $matches[0] );
1811 * Does a string look like an e-mail address?
1813 * This validates an email address using an HTML5 specification found at:
1814 * http://www.whatwg.org/specs/web-apps/current-work/multipage/states-of-the-type-attribute.html#valid-e-mail-address
1815 * Which as of 2011-01-24 says:
1817 * A valid e-mail address is a string that matches the ABNF production
1818 * 1*( atext / "." ) "@" ldh-str *( "." ldh-str ) where atext is defined
1819 * in RFC 5322 section 3.2.3, and ldh-str is defined in RFC 1034 section
1822 * This function is an implementation of the specification as requested in
1825 * Client-side forms will use the same standard validation rules via JS or
1826 * HTML 5 validation; additional restrictions can be enforced server-side
1827 * by extensions via the 'isValidEmailAddr' hook.
1829 * Note that this validation doesn't 100% match RFC 2822, but is believed
1830 * to be liberal enough for wide use. Some invalid addresses will still
1831 * pass validation here.
1835 * @param $addr String E-mail address
1838 public static function validateEmail( $addr ) {
1840 if( !wfRunHooks( 'isValidEmailAddr', array( $addr, &$result ) ) ) {
1844 // Please note strings below are enclosed in brackets [], this make the
1845 // hyphen "-" a range indicator. Hence it is double backslashed below.
1847 $rfc5322_atext = "a-z0-9!#$%&'*+\\-\/=?^_`{|}~" ;
1848 $rfc1034_ldh_str = "a-z0-9\\-" ;
1850 $HTML5_email_regexp = "/
1852 [$rfc5322_atext\\.]+ # user part which is liberal :p
1854 [$rfc1034_ldh_str]+ # First domain part
1855 (\\.[$rfc1034_ldh_str]+)* # Following part prefixed with a dot
1857 /ix" ; // case Insensitive, eXtended
1859 return (bool) preg_match( $HTML5_email_regexp, $addr );