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866 lines
29 KiB
866 lines
29 KiB
<?php
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/**
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* kses 0.2.2 - HTML/XHTML filter that only allows some elements and attributes
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* Copyright (C) 2002, 2003, 2005 Ulf Harnhammar
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*
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* This program is free software and open source software; you can redistribute
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* it and/or modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 3 of the License,
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* or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA or visit
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* http://www.gnu.org/licenses/gpl.html
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*
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* *** CONTACT INFORMATION ***
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*
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* E-mail: metaur at users dot sourceforge dot net
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* Web page: http://sourceforge.net/projects/kses
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* Paper mail: Ulf Harnhammar
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* Ymergatan 17 C
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* 753 25 Uppsala
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* SWEDEN
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*
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* [kses strips evil scripts!]
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*
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* @package chamilo.kses
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* @copyright Ulf Harnhammar {@link http://sourceforge.net/projects/kses}
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* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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*/
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$kses_allowedentitynames = array(
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'nbsp', 'iexcl', 'cent', 'pound', 'curren', 'yen',
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'brvbar', 'sect', 'uml', 'copy', 'ordf', 'laquo',
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'not', 'shy', 'reg', 'macr', 'deg', 'plusmn',
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'acute', 'micro', 'para', 'middot', 'cedil', 'ordm',
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'raquo', 'iquest', 'Agrave', 'Aacute', 'Acirc', 'Atilde',
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'Auml', 'Aring', 'AElig', 'Ccedil', 'Egrave', 'Eacute',
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'Ecirc', 'Euml', 'Igrave', 'Iacute', 'Icirc', 'Iuml',
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'ETH', 'Ntilde', 'Ograve', 'Oacute', 'Ocirc', 'Otilde',
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'Ouml', 'times', 'Oslash', 'Ugrave', 'Uacute', 'Ucirc',
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'Uuml', 'Yacute', 'THORN', 'szlig', 'agrave', 'aacute',
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'acirc', 'atilde', 'auml', 'aring', 'aelig', 'ccedil',
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'egrave', 'eacute', 'ecirc', 'euml', 'igrave', 'iacute',
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'icirc', 'iuml', 'eth', 'ntilde', 'ograve', 'oacute',
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'ocirc', 'otilde', 'ouml', 'divide', 'oslash', 'ugrave',
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'uacute', 'ucirc', 'uuml', 'yacute', 'thorn', 'yuml',
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'quot', 'amp', 'lt', 'gt', 'apos', 'OElig',
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'oelig', 'Scaron', 'scaron', 'Yuml', 'circ', 'tilde',
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'ensp', 'emsp', 'thinsp', 'zwnj', 'zwj', 'lrm',
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'rlm', 'ndash', 'mdash', 'lsquo', 'rsquo', 'sbquo',
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'ldquo', 'rdquo', 'bdquo', 'dagger', 'Dagger', 'permil',
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'lsaquo', 'rsaquo', 'euro', 'fnof', 'Alpha', 'Beta',
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'Gamma', 'Delta', 'Epsilon', 'Zeta', 'Eta', 'Theta',
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'Iota', 'Kappa', 'Lambda', 'Mu', 'Nu', 'Xi',
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'Omicron', 'Pi', 'Rho', 'Sigma', 'Tau', 'Upsilon',
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'Phi', 'Chi', 'Psi', 'Omega', 'alpha', 'beta',
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'gamma', 'delta', 'epsilon', 'zeta', 'eta', 'theta',
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'iota', 'kappa', 'lambda', 'mu', 'nu', 'xi',
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'omicron', 'pi', 'rho', 'sigmaf', 'sigma', 'tau',
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'upsilon', 'phi', 'chi', 'psi', 'omega', 'thetasym',
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'upsih', 'piv', 'bull', 'hellip', 'prime', 'Prime',
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'oline', 'frasl', 'weierp', 'image', 'real', 'trade',
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'alefsym', 'larr', 'uarr', 'rarr', 'darr', 'harr',
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'crarr', 'lArr', 'uArr', 'rArr', 'dArr', 'hArr',
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'forall', 'part', 'exist', 'empty', 'nabla', 'isin',
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'notin', 'ni', 'prod', 'sum', 'minus', 'lowast',
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'radic', 'prop', 'infin', 'ang', 'and', 'or',
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'cap', 'cup', 'int', 'sim', 'cong', 'asymp',
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'ne', 'equiv', 'le', 'ge', 'sub', 'sup',
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'nsub', 'sube', 'supe', 'oplus', 'otimes', 'perp',
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'sdot', 'lceil', 'rceil', 'lfloor', 'rfloor', 'lang',
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'rang', 'loz', 'spades', 'clubs', 'hearts', 'diams',
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);
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/**
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* Filters content and keeps only allowable HTML elements.
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*
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* This function makes sure that only the allowed HTML element names, attribute
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* names and attribute values plus only sane HTML entities will occur in
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* $string. You have to remove any slashes from PHP's magic quotes before you
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* call this function.
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*
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* The default allowed protocols are 'http', 'https', 'ftp', 'news',
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* 'nntp', 'telnet', 'gopher', 'mailto'.
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* This covers all common link protocols, except for 'javascript' which should not
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* be allowed for untrusted users.
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*
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* @param string $string
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* @param string $allowed_html
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* @param array $allowed_protocols
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* @return string
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*/
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function kses($string, $allowed_html, $allowed_protocols =
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array('http', 'https', 'ftp', 'news', 'nntp', 'telnet',
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'gopher', 'mailto'))
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{
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$string = kses_no_null($string);
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$string = kses_js_entities($string);
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$string = kses_normalize_entities($string);
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$string = kses_hook($string);
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$allowed_html_fixed = kses_array_lc($allowed_html);
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return kses_split($string, $allowed_html_fixed, $allowed_protocols);
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}
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/**
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* You add any kses hooks here.
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*
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* @param string $string
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* @return string
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*/
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function kses_hook($string)
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{
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return $string;
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}
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/**
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* This function returns kses' version number.
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*
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* @return string KSES Version Number
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*/
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function kses_version()
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{
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return '0.2.2';
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}
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/**
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* This function searches for HTML tags, no matter how malformed.
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* It also matches stray ">" characters.
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*
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* @param string $string Content to filter
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* @param array $allowed_html Allowed HTML elements
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* @param array $allowed_protocols Allowed protocols to keep
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* @return string Content with fixed HTML tags
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*/
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function kses_split($string, $allowed_html, $allowed_protocols)
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{
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global $pass_allowed_html, $pass_allowed_protocols;
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$pass_allowed_html = $allowed_html;
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$pass_allowed_protocols = $allowed_protocols;
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return preg_replace_callback( '%((<!--.*?(-->|$))|(<[^>]*(>|$)|>))%', '_kses_split_callback', $string );
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}
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/**
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* Callback for kses_split.
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*
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* @access private
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*/
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function _kses_split_callback( $match )
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{
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global $pass_allowed_html, $pass_allowed_protocols;
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return kses_split2( $match[1], $pass_allowed_html, $pass_allowed_protocols );
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}
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/**
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* Callback for kses_split for fixing malformed HTML tags.
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*
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* This function does a lot of work. It rejects some very malformed things like
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* <:::>. It returns an empty string, if the element isn't allowed (look ma, no
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* strip_tags()!). Otherwise it splits the tag into an element and an attribute
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* list.
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*
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* After the tag is split into an element and an attribute list, it is run
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* through another filter which will remove illegal attributes and once that is
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* completed, will be returned.
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*
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* @access private
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* @uses kses_attr()
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*
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* @param string $string Content to filter
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* @param array $allowed_html Allowed HTML elements
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* @param array $allowed_protocols Allowed protocols to keep
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* @return string Fixed HTML element
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*/
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function kses_split2($string, $allowed_html, $allowed_protocols)
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{
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$string = kses_stripslashes($string);
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if (substr($string, 0, 1) != '<')
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return '>';
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// It matched a ">" character
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if (preg_match('%^<!--(.*?)(-->)?$%', $string, $matches)) {
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$string = str_replace(array('<!--', '-->'), '', $matches[1]);
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while ( $string != $newstring = kses($string, $allowed_html, $allowed_protocols) )
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$string = $newstring;
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if ( $string == '' )
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return '';
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// prevent multiple dashes in comments
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$string = preg_replace('/--+/', '-', $string);
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// prevent three dashes closing a comment
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$string = preg_replace('/-$/', '', $string);
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return "<!--{$string}-->";
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}
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// Allow HTML comments
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if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
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return '';
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// It's seriously malformed
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$slash = trim($matches[1]);
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$elem = $matches[2];
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$attrlist = $matches[3];
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if (!@isset($allowed_html[strtolower($elem)]))
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return '';
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// They are using a not allowed HTML element
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if ($slash != '')
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return "<$slash$elem>";
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// No attributes are allowed for closing elements
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return kses_attr("$slash$elem", $attrlist, $allowed_html,
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$allowed_protocols);
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}
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/**
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* This function removes all attributes, if none are allowed for this element.
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*
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* If some are allowed it calls kses_hair() to split them further, and then
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* it builds up new HTML code from the data that kses_hair() returns. It also
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* removes "<" and ">" characters, if there are any left. One more thing it does
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* is to check if the tag has a closing XHTML slash, and if it does, it puts one
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* in the returned code as well.
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*
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* @param string $element HTML element/tag
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* @param string $attr HTML attributes from HTML element to closing HTML element tag
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* @param array $allowed_html Allowed HTML elements
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* @param array $allowed_protocols Allowed protocols to keep
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* @return string Sanitized HTML element
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*/
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function kses_attr($element, $attr, $allowed_html, $allowed_protocols)
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{
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// Is there a closing XHTML slash at the end of the attributes?
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$xhtml_slash = '';
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if (preg_match('%\s*/\s*$%', $attr))
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$xhtml_slash = ' /';
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// Are any attributes allowed at all for this element?
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if (@count($allowed_html[strtolower($element)]) == 0)
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return "<$element$xhtml_slash>";
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// Split it
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$attrarr = kses_hair($attr, $allowed_protocols);
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// Go through $attrarr, and save the allowed attributes for this element
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// in $attr2
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$attr2 = '';
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foreach ($attrarr as $arreach)
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{
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if (!@isset($allowed_html[strtolower($element)]
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[strtolower($arreach['name'])]))
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continue; // the attribute is not allowed
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$current = $allowed_html[strtolower($element)]
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[strtolower($arreach['name'])];
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if ($current == '')
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continue; // the attribute is not allowed
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if (!is_array($current))
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$attr2 .= ' '.$arreach['whole'];
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// there are no checks
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else
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{
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// there are some checks
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$ok = true;
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foreach ($current as $currkey => $currval)
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if (!kses_check_attr_val($arreach['value'], $arreach['vless'],
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$currkey, $currval))
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{ $ok = false; break; }
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if ( strtolower($arreach['name']) == 'style' ) {
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$orig_value = $arreach['value'];
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$value = kses_safecss_filter_attr($orig_value);
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if ( empty($value) )
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continue;
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$arreach['value'] = $value;
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$arreach['whole'] = str_replace($orig_value, $value, $arreach['whole']);
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}
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if ($ok)
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$attr2 .= ' '.$arreach['whole']; // it passed them
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} // if !is_array($current)
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} // foreach
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// Remove any "<" or ">" characters
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$attr2 = preg_replace('/[<>]/', '', $attr2);
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return "<$element$attr2$xhtml_slash>";
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}
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/**
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* Builds an attribute list from string containing attributes.
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*
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* This function does a lot of work. It parses an attribute list into an array
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* with attribute data, and tries to do the right thing even if it gets weird
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* input. It will add quotes around attribute values that don't have any quotes
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* or apostrophes around them, to make it easier to produce HTML code that will
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* conform to W3C's HTML specification. It will also remove bad URL protocols
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* from attribute values.
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* It also reduces duplicate attributes by using the
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* attribute defined first (foo='bar' foo='baz' will result in foo='bar').
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*
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* @param string $attr Attribute list from HTML element to closing HTML element tag
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* @param array $allowed_protocols Allowed protocols to keep
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* @return array List of attributes after parsing
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*/
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function kses_hair($attr, $allowed_protocols)
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{
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$attrarr = array();
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$mode = 0;
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$attrname = '';
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$uris = array('xmlns', 'profile', 'href', 'src', 'cite', 'classid', 'codebase', 'data', 'usemap', 'longdesc', 'action');
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// Loop through the whole attribute list
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while (strlen($attr) != 0)
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{
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$working = 0; // Was the last operation successful?
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switch ($mode)
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{
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case 0: // attribute name, href for instance
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if (preg_match('/^([-a-zA-Z]+)/', $attr, $match))
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{
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$attrname = $match[1];
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$working = $mode = 1;
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$attr = preg_replace('/^[-a-zA-Z]+/', '', $attr);
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}
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break;
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case 1: // equals sign or valueless ("selected")
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if (preg_match('/^\s*=\s*/', $attr)) // equals sign
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{
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$working = 1; $mode = 2;
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$attr = preg_replace('/^\s*=\s*/', '', $attr);
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break;
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}
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if (preg_match('/^\s+/', $attr)) // valueless
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{
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$working = 1; $mode = 0;
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if(FALSE === array_key_exists($attrname, $attrarr)) {
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$attrarr[$attrname] = array ('name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y');
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}
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$attr = preg_replace('/^\s+/', '', $attr);
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}
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break;
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case 2: // attribute value, a URL after href= for instance
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if (preg_match('%^"([^"]*)"(\s+|/?$)%', $attr, $match))
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// "value"
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{
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// MDL-2684 - kses stripping CSS styles that it thinks look like protocols
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if ($attrname == 'style') {
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$thisval = $match[1];
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} else {
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$thisval = $match[1];
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if ( in_array(strtolower($attrname), $uris) )
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$thisval = kses_bad_protocol($thisval, $allowed_protocols);
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}
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if(FALSE === array_key_exists($attrname, $attrarr)) {
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$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
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}
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$working = 1; $mode = 0;
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$attr = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr);
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break;
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}
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if (preg_match("%^'([^']*)'(\s+|/?$)%", $attr, $match))
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// 'value'
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{
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$thisval = $match[1];
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if ( in_array(strtolower($attrname), $uris) )
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$thisval = kses_bad_protocol($thisval, $allowed_protocols);
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if(FALSE === array_key_exists($attrname, $attrarr)) {
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$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname='$thisval'", 'vless' => 'n');
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}
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$working = 1; $mode = 0;
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$attr = preg_replace("/^'[^']*'(\s+|$)/", '', $attr);
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break;
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}
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if (preg_match("%^([^\s\"']+)(\s+|/?$)%", $attr, $match))
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// value
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{
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$thisval = $match[1];
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if ( in_array(strtolower($attrname), $uris) )
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$thisval = kses_bad_protocol($thisval, $allowed_protocols);
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if(FALSE === array_key_exists($attrname, $attrarr)) {
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$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
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}
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// We add quotes to conform to W3C's HTML spec.
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$working = 1; $mode = 0;
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$attr = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr);
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}
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break;
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} // switch
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if ($working == 0) // not well formed, remove and try again
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{
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$attr = kses_html_error($attr);
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$mode = 0;
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}
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} // while
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if ($mode == 1 && FALSE === array_key_exists($attrname, $attrarr))
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// special case, for when the attribute list ends with a valueless
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// attribute like "selected"
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$attrarr[$attrname] = array ('name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y');
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return $attrarr;
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}
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/**
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* This function performs different checks for attribute values.
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*
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* The currently implemented checks are "maxlen", "minlen", "maxval", "minval"
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* and "valueless" with even more checks to come soon.
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*
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* @param string $value Attribute value
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* @param string $vless Whether the value is valueless. Use 'y' or 'n'
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* @param string $checkname What $checkvalue is checking for.
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* @param mixed $checkvalue What constraint the value should pass
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* @return bool Whether check passes
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*/
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function kses_check_attr_val($value, $vless, $checkname, $checkvalue)
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{
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$ok = true;
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switch (strtolower($checkname))
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{
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case 'maxlen':
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// The maxlen check makes sure that the attribute value has a length not
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// greater than the given value. This can be used to avoid Buffer Overflows
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// in WWW clients and various Internet servers.
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if (strlen($value) > $checkvalue)
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$ok = false;
|
|
break;
|
|
|
|
case 'minlen':
|
|
// The minlen check makes sure that the attribute value has a length not
|
|
// smaller than the given value.
|
|
|
|
if (strlen($value) < $checkvalue)
|
|
$ok = false;
|
|
break;
|
|
|
|
case 'maxval':
|
|
// The maxval check does two things: it checks that the attribute value is
|
|
// an integer from 0 and up, without an excessive amount of zeroes or
|
|
// whitespace (to avoid Buffer Overflows). It also checks that the attribute
|
|
// value is not greater than the given value.
|
|
// This check can be used to avoid Denial of Service attacks.
|
|
|
|
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
|
|
$ok = false;
|
|
if ($value > $checkvalue)
|
|
$ok = false;
|
|
break;
|
|
|
|
case 'minval':
|
|
// The minval check checks that the attribute value is a positive integer,
|
|
// and that it is not smaller than the given value.
|
|
|
|
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
|
|
$ok = false;
|
|
if ($value < $checkvalue)
|
|
$ok = false;
|
|
break;
|
|
|
|
case 'valueless':
|
|
// The valueless check checks if the attribute has a value
|
|
// (like <a href="blah">) or not (<option selected>). If the given value
|
|
// is a "y" or a "Y", the attribute must not have a value.
|
|
// If the given value is an "n" or an "N", the attribute must have one.
|
|
|
|
if (strtolower($checkvalue) != $vless)
|
|
$ok = false;
|
|
break;
|
|
} // switch
|
|
|
|
return $ok;
|
|
}
|
|
|
|
/**
|
|
* Sanitize string from bad protocols.
|
|
*
|
|
* This function removes all non-allowed protocols from the beginning of
|
|
* $string. It ignores whitespace and the case of the letters, and it does
|
|
* understand HTML entities. It does its work in a while loop, so it won't be
|
|
* fooled by a string like "javascript:javascript:alert(57)".
|
|
*
|
|
* @param string $string Content to filter bad protocols from
|
|
* @param array $allowed_protocols Allowed protocols to keep
|
|
* @return string Filtered content
|
|
*/
|
|
function kses_bad_protocol($string, $allowed_protocols)
|
|
{
|
|
$string = kses_no_null($string);
|
|
$string = preg_replace('/([^\xc3-\xcf])\xad+/', '\\1', $string); // deals with Opera "feature" -- moodle utf8 fix
|
|
$string2 = $string.'a';
|
|
|
|
while ($string != $string2)
|
|
{
|
|
$string2 = $string;
|
|
$string = kses_bad_protocol_once($string, $allowed_protocols);
|
|
} // while
|
|
|
|
return $string;
|
|
}
|
|
|
|
/**
|
|
* This function removes any NULL characters in $string.
|
|
*
|
|
* @param string $string
|
|
* @return string
|
|
*/
|
|
function kses_no_null($string)
|
|
{
|
|
$string = preg_replace('/\0+/', '', $string);
|
|
$string = preg_replace('/(\\\\0)+/', '', $string);
|
|
|
|
return $string;
|
|
}
|
|
|
|
|
|
/**
|
|
* Strips slashes from in front of quotes.
|
|
*
|
|
* This function changes the character sequence \" to just "
|
|
* It leaves all other slashes alone. It's really weird, but the quoting from
|
|
* preg_replace(//e) seems to require this.
|
|
*
|
|
* @param string $string String to strip slashes
|
|
* @return string Fixed strings with quoted slashes
|
|
*/
|
|
function kses_stripslashes($string)
|
|
{
|
|
return preg_replace('%\\\\"%', '"', $string);
|
|
}
|
|
|
|
|
|
/**
|
|
* This function goes through an array, and changes the keys to all lower case.
|
|
*
|
|
* @param array $inarray Unfiltered array
|
|
* @return array Fixed array with all lowercase keys
|
|
*/
|
|
function kses_array_lc($inarray)
|
|
{
|
|
$outarray = array();
|
|
|
|
foreach ( (array) $inarray as $inkey => $inval)
|
|
{
|
|
$outkey = strtolower($inkey);
|
|
$outarray[$outkey] = array();
|
|
|
|
foreach ( (array) $inval as $inkey2 => $inval2)
|
|
{
|
|
$outkey2 = strtolower($inkey2);
|
|
$outarray[$outkey][$outkey2] = $inval2;
|
|
} // foreach $inval
|
|
} // foreach $inarray
|
|
|
|
return $outarray;
|
|
}
|
|
|
|
/**
|
|
* This function removes the HTML JavaScript entities found in early versions of Netscape 4.
|
|
*
|
|
* @param string $string
|
|
* @return string
|
|
*/
|
|
function kses_js_entities($string)
|
|
{
|
|
return preg_replace('%&\s*\{[^}]*(\}\s*;?|$)%', '', $string);
|
|
}
|
|
|
|
/**
|
|
* This function handles parsing errors in kses_hair().
|
|
*
|
|
* The general plan is to remove everything to and including some whitespace,
|
|
* but it deals with quotes and apostrophes as well.
|
|
*
|
|
* @param string $string
|
|
* @return string
|
|
*/
|
|
function kses_html_error($string)
|
|
{
|
|
return preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $string);
|
|
}
|
|
|
|
/**
|
|
* Sanitizes content from bad protocols and other characters.
|
|
*
|
|
* This function searches for URL protocols at the beginning of $string, while
|
|
* handling whitespace and HTML entities.
|
|
*
|
|
* @param string $string Content to check for bad protocols
|
|
* @param string $allowed_protocols Allowed protocols
|
|
* @return string Sanitized content
|
|
*/
|
|
function kses_bad_protocol_once($string, $allowed_protocols)
|
|
{
|
|
$string2 = preg_split('/:|�*58;|�*3a;/i', $string, 2);
|
|
if(isset($string2[1]) && !preg_match('%/\?%',$string2[0]))
|
|
{
|
|
$string = kses_bad_protocol_once2($string2[0],$allowed_protocols).trim($string2[1]);
|
|
}
|
|
return $string;
|
|
}
|
|
|
|
/**
|
|
* Callback for kses_bad_protocol_once() regular expression.
|
|
*
|
|
* This function processes URL protocols, checks to see if they're in the
|
|
* white-list or not, and returns different data depending on the answer.
|
|
*
|
|
* @access private
|
|
*
|
|
* @param string $string URI scheme to check against the whitelist
|
|
* @param string $allowed_protocols Allowed protocols
|
|
* @return string Sanitized content
|
|
*/
|
|
function kses_bad_protocol_once2($string, $allowed_protocols)
|
|
{
|
|
$string2 = kses_decode_entities($string);
|
|
$string2 = preg_replace('/\s/', '', $string2);
|
|
$string2 = kses_no_null($string2);
|
|
$string2 = preg_replace('/\xad+/', '', $string2); // deals with Opera "feature"
|
|
$string2 = strtolower($string2);
|
|
|
|
$allowed = false;
|
|
foreach ( (array) $allowed_protocols as $one_protocol)
|
|
if (strtolower($one_protocol) == $string2)
|
|
{
|
|
$allowed = true;
|
|
break;
|
|
}
|
|
|
|
if ($allowed)
|
|
return "$string2:";
|
|
else
|
|
return '';
|
|
}
|
|
|
|
/**
|
|
* Converts and fixes HTML entities.
|
|
*
|
|
* This function normalizes HTML entities. It will convert "AT&T" to the correct
|
|
* "AT&T", ":" to ":", "&#XYZZY;" to "&#XYZZY;" and so on.
|
|
*
|
|
* @param string $string Content to normalize entities
|
|
* @return string Content with normalized entities
|
|
*/
|
|
function kses_normalize_entities($string)
|
|
{
|
|
// Disarm all entities by converting & to &
|
|
|
|
$string = str_replace('&', '&', $string);
|
|
|
|
// Change back the allowed entities in our entity whitelist
|
|
|
|
$string = preg_replace_callback('/&([A-Za-z]{2,8});/', 'kses_named_entities', $string);
|
|
$string = preg_replace_callback('/&#(0*[0-9]{1,7});/', 'kses_normalize_entities2', $string);
|
|
$string = preg_replace_callback('/&#[Xx](0*[0-9A-Fa-f]{1,6});/', 'kses_normalize_entities3', $string);
|
|
|
|
return $string;
|
|
}
|
|
|
|
/**
|
|
* Callback for kses_normalize_entities() regular expression.
|
|
*
|
|
* This function only accepts valid named entity references, which are finite,
|
|
* case-sensitive, and highly scrutinized by HTML and XML validators.
|
|
*
|
|
* @since 3.0.0
|
|
*
|
|
* @param array $matches preg_replace_callback() matches array
|
|
* @return string Correctly encoded entity
|
|
*/
|
|
function kses_named_entities($matches) {
|
|
global $kses_allowedentitynames;
|
|
|
|
if ( empty($matches[1]) )
|
|
return '';
|
|
|
|
$i = $matches[1];
|
|
return ( ( ! in_array($i, $kses_allowedentitynames) ) ? "&$i;" : "&$i;" );
|
|
}
|
|
|
|
/**
|
|
* Callback for kses_normalize_entities() regular expression.
|
|
*
|
|
* This function helps kses_normalize_entities() to only accept 16 bit values
|
|
* and nothing more for &#number; entities.
|
|
*
|
|
* @access private
|
|
*
|
|
* @param array $matches preg_replace_callback() matches array
|
|
* @return string Correctly encoded entity
|
|
*/
|
|
function kses_normalize_entities2($matches) {
|
|
if ( empty($matches[1]) )
|
|
return '';
|
|
|
|
$i = $matches[1];
|
|
if (kses_valid_unicode($i)) {
|
|
$i = str_pad(ltrim($i,'0'), 3, '0', STR_PAD_LEFT);
|
|
$i = "&#$i;";
|
|
} else {
|
|
$i = "&#$i;";
|
|
}
|
|
|
|
return $i;
|
|
}
|
|
|
|
/**
|
|
* Callback for kses_normalize_entities() for regular expression.
|
|
*
|
|
* This function helps kses_normalize_entities() to only accept valid Unicode
|
|
* numeric entities in hex form.
|
|
*
|
|
* @access private
|
|
*
|
|
* @param array $matches preg_replace_callback() matches array
|
|
* @return string Correctly encoded entity
|
|
*/
|
|
function kses_normalize_entities3($matches) {
|
|
if ( empty($matches[1]) )
|
|
return '';
|
|
|
|
$hexchars = $matches[1];
|
|
return ( ( ! kses_valid_unicode(hexdec($hexchars)) ) ? "&#x$hexchars;" : '&#x'.ltrim($hexchars,'0').';' );
|
|
}
|
|
|
|
/**
|
|
* Helper function to determine if a Unicode value is valid.
|
|
*
|
|
* @param int $i Unicode value
|
|
* @return bool true if the value was a valid Unicode number
|
|
*/
|
|
function kses_valid_unicode($i) {
|
|
return ( $i == 0x9 || $i == 0xa || $i == 0xd ||
|
|
($i >= 0x20 && $i <= 0xd7ff) ||
|
|
($i >= 0xe000 && $i <= 0xfffd) ||
|
|
($i >= 0x10000 && $i <= 0x10ffff) );
|
|
}
|
|
|
|
/**
|
|
* Convert all entities to their character counterparts.
|
|
*
|
|
* This function decodes numeric HTML entities (A and A). It doesn't do
|
|
* anything with other entities like ä, but we don't need them in the URL
|
|
* protocol whitelisting system anyway.
|
|
*
|
|
* @param string $string Content to change entities
|
|
* @return string Content after decoded entities
|
|
*/
|
|
function kses_decode_entities($string)
|
|
{
|
|
$string = preg_replace_callback('/&#([0-9]+);/', '_kses_decode_entities_chr', $string);
|
|
$string = preg_replace_callback('/&#[Xx]([0-9A-Fa-f]+);/', '_kses_decode_entities_chr_hexdec', $string);
|
|
|
|
return $string;
|
|
}
|
|
|
|
/**
|
|
* Regex callback for kses_decode_entities()
|
|
*
|
|
* @param array $match preg match
|
|
* @return string
|
|
*/
|
|
function _kses_decode_entities_chr( $match ) {
|
|
return chr( $match[1] );
|
|
}
|
|
|
|
/**
|
|
* Regex callback for kses_decode_entities()
|
|
*
|
|
* @param array $match preg match
|
|
* @return string
|
|
*/
|
|
function _kses_decode_entities_chr_hexdec( $match ) {
|
|
return chr( hexdec( $match[1] ) );
|
|
}
|
|
|
|
/**
|
|
* Inline CSS filter
|
|
*
|
|
*/
|
|
function kses_safecss_filter_attr( $css ) {
|
|
|
|
$css = kses_no_null($css);
|
|
$css = str_replace(array("\n","\r","\t"), '', $css);
|
|
|
|
if ( preg_match( '%[\\(&=}]|/\*%', $css ) ) // remove any inline css containing \ ( & } = or comments
|
|
return '';
|
|
|
|
$css_array = explode( ';', trim( $css ) );
|
|
$allowed_attr = array( 'text-align', 'margin', 'color', 'float',
|
|
'border', 'background', 'background-color', 'border-bottom', 'border-bottom-color',
|
|
'border-bottom-style', 'border-bottom-width', 'border-collapse', 'border-color', 'border-left',
|
|
'border-left-color', 'border-left-style', 'border-left-width', 'border-right', 'border-right-color',
|
|
'border-right-style', 'border-right-width', 'border-spacing', 'border-style', 'border-top',
|
|
'border-top-color', 'border-top-style', 'border-top-width', 'border-width', 'caption-side',
|
|
'clear', 'cursor', 'direction', 'display', 'font', 'font-family', 'font-size', 'font-style',
|
|
'font-variant', 'font-weight', 'height', 'letter-spacing', 'line-height', 'margin-bottom',
|
|
'margin-left', 'margin-right', 'margin-top', 'overflow', 'padding', 'padding-bottom',
|
|
'padding-left', 'padding-right', 'padding-top', 'text-decoration', 'text-indent', 'vertical-align',
|
|
'width' );
|
|
|
|
if ( empty($allowed_attr) )
|
|
return $css;
|
|
|
|
$css = '';
|
|
foreach ( $css_array as $css_item ) {
|
|
if ( $css_item == '' )
|
|
continue;
|
|
$css_item = trim( $css_item );
|
|
$found = false;
|
|
if ( strpos( $css_item, ':' ) === false ) {
|
|
$found = true;
|
|
} else {
|
|
$parts = split( ':', $css_item );
|
|
if ( in_array( strtolower( trim( $parts[0] ) ), $allowed_attr ) )
|
|
$found = true;
|
|
}
|
|
if ( $found ) {
|
|
if( $css != '' )
|
|
$css .= ';';
|
|
$css .= $css_item;
|
|
}
|
|
}
|
|
|
|
return $css;
|
|
}
|
|
|