/
kses.php
1518 lines (1384 loc) · 41.8 KB
/
kses.php
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<?php
/**
* kses 0.2.2 - HTML/XHTML filter that only allows some elements and attributes
* Copyright (C) 2002, 2003, 2005 Ulf Harnhammar
*
* This program is free software and open source software; you can redistribute
* it and/or modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the License,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
* http://www.gnu.org/licenses/gpl.html
*
* [kses strips evil scripts!]
*
* Added wp_ prefix to avoid conflicts with existing kses users
*
* @version 0.2.2
* @copyright (C) 2002, 2003, 2005
* @author Ulf Harnhammar <http://advogato.org/person/metaur/>
*
* @package External
* @subpackage KSES
*
*/
/**
* You can override this in a plugin.
*
* The wp_kses_allowed_html filter is more powerful and supplies context.
* CUSTOM_TAGS is not recommended and should be considered deprecated.
*
* @see wp_kses_allowed_html()
*
* @since 1.2.0
*/
if ( ! defined( 'CUSTOM_TAGS' ) )
define( 'CUSTOM_TAGS', false );
// Ensure that these variables are added to the global namespace
// (e.g. if using namespaces / autoload in the current PHP environment).
global $allowedposttags, $allowedtags, $allowedentitynames;
if ( ! CUSTOM_TAGS ) {
/**
* Kses global for default allowable HTML tags.
*
* Can be override by using CUSTOM_TAGS constant.
*
* @global array $allowedposttags
* @since 2.0.0
*/
$allowedposttags = array(
'address' => array(),
'a' => array(
'href' => true,
'rel' => true,
'rev' => true,
'name' => true,
'target' => true,
),
'abbr' => array(),
'acronym' => array(),
'area' => array(
'alt' => true,
'coords' => true,
'href' => true,
'nohref' => true,
'shape' => true,
'target' => true,
),
'article' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'aside' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'b' => array(),
'big' => array(),
'blockquote' => array(
'cite' => true,
'lang' => true,
'xml:lang' => true,
),
'br' => array(),
'button' => array(
'disabled' => true,
'name' => true,
'type' => true,
'value' => true,
),
'caption' => array(
'align' => true,
),
'cite' => array(
'dir' => true,
'lang' => true,
),
'code' => array(),
'col' => array(
'align' => true,
'char' => true,
'charoff' => true,
'span' => true,
'dir' => true,
'valign' => true,
'width' => true,
),
'del' => array(
'datetime' => true,
),
'dd' => array(),
'dfn' => array(),
'details' => array(
'align' => true,
'dir' => true,
'lang' => true,
'open' => true,
'xml:lang' => true,
),
'div' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'dl' => array(),
'dt' => array(),
'em' => array(),
'fieldset' => array(),
'figure' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'figcaption' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'font' => array(
'color' => true,
'face' => true,
'size' => true,
),
'footer' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'form' => array(
'action' => true,
'accept' => true,
'accept-charset' => true,
'enctype' => true,
'method' => true,
'name' => true,
'target' => true,
),
'h1' => array(
'align' => true,
),
'h2' => array(
'align' => true,
),
'h3' => array(
'align' => true,
),
'h4' => array(
'align' => true,
),
'h5' => array(
'align' => true,
),
'h6' => array(
'align' => true,
),
'header' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'hgroup' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'hr' => array(
'align' => true,
'noshade' => true,
'size' => true,
'width' => true,
),
'i' => array(),
'img' => array(
'alt' => true,
'align' => true,
'border' => true,
'height' => true,
'hspace' => true,
'longdesc' => true,
'vspace' => true,
'src' => true,
'usemap' => true,
'width' => true,
),
'ins' => array(
'datetime' => true,
'cite' => true,
),
'kbd' => array(),
'label' => array(
'for' => true,
),
'legend' => array(
'align' => true,
),
'li' => array(
'align' => true,
'value' => true,
),
'map' => array(
'name' => true,
),
'mark' => array(),
'menu' => array(
'type' => true,
),
'nav' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'p' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'pre' => array(
'width' => true,
),
'q' => array(
'cite' => true,
),
's' => array(),
'samp' => array(),
'span' => array(
'dir' => true,
'align' => true,
'lang' => true,
'xml:lang' => true,
),
'section' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'small' => array(),
'strike' => array(),
'strong' => array(),
'sub' => array(),
'summary' => array(
'align' => true,
'dir' => true,
'lang' => true,
'xml:lang' => true,
),
'sup' => array(),
'table' => array(
'align' => true,
'bgcolor' => true,
'border' => true,
'cellpadding' => true,
'cellspacing' => true,
'dir' => true,
'rules' => true,
'summary' => true,
'width' => true,
),
'tbody' => array(
'align' => true,
'char' => true,
'charoff' => true,
'valign' => true,
),
'td' => array(
'abbr' => true,
'align' => true,
'axis' => true,
'bgcolor' => true,
'char' => true,
'charoff' => true,
'colspan' => true,
'dir' => true,
'headers' => true,
'height' => true,
'nowrap' => true,
'rowspan' => true,
'scope' => true,
'valign' => true,
'width' => true,
),
'textarea' => array(
'cols' => true,
'rows' => true,
'disabled' => true,
'name' => true,
'readonly' => true,
),
'tfoot' => array(
'align' => true,
'char' => true,
'charoff' => true,
'valign' => true,
),
'th' => array(
'abbr' => true,
'align' => true,
'axis' => true,
'bgcolor' => true,
'char' => true,
'charoff' => true,
'colspan' => true,
'headers' => true,
'height' => true,
'nowrap' => true,
'rowspan' => true,
'scope' => true,
'valign' => true,
'width' => true,
),
'thead' => array(
'align' => true,
'char' => true,
'charoff' => true,
'valign' => true,
),
'title' => array(),
'tr' => array(
'align' => true,
'bgcolor' => true,
'char' => true,
'charoff' => true,
'valign' => true,
),
'tt' => array(),
'u' => array(),
'ul' => array(
'type' => true,
),
'ol' => array(
'start' => true,
'type' => true,
),
'var' => array(),
);
/**
* Kses allowed HTML elements.
*
* @global array $allowedtags
* @since 1.0.0
*/
$allowedtags = array(
'a' => array(
'href' => true,
'title' => true,
),
'abbr' => array(
'title' => true,
),
'acronym' => array(
'title' => true,
),
'b' => array(),
'blockquote' => array(
'cite' => true,
),
'cite' => array(),
'code' => array(),
'del' => array(
'datetime' => true,
),
'em' => array(),
'i' => array(),
'q' => array(
'cite' => true,
),
'strike' => array(),
'strong' => array(),
);
$allowedentitynames = array(
'nbsp', 'iexcl', 'cent', 'pound', 'curren', 'yen',
'brvbar', 'sect', 'uml', 'copy', 'ordf', 'laquo',
'not', 'shy', 'reg', 'macr', 'deg', 'plusmn',
'acute', 'micro', 'para', 'middot', 'cedil', 'ordm',
'raquo', 'iquest', 'Agrave', 'Aacute', 'Acirc', 'Atilde',
'Auml', 'Aring', 'AElig', 'Ccedil', 'Egrave', 'Eacute',
'Ecirc', 'Euml', 'Igrave', 'Iacute', 'Icirc', 'Iuml',
'ETH', 'Ntilde', 'Ograve', 'Oacute', 'Ocirc', 'Otilde',
'Ouml', 'times', 'Oslash', 'Ugrave', 'Uacute', 'Ucirc',
'Uuml', 'Yacute', 'THORN', 'szlig', 'agrave', 'aacute',
'acirc', 'atilde', 'auml', 'aring', 'aelig', 'ccedil',
'egrave', 'eacute', 'ecirc', 'euml', 'igrave', 'iacute',
'icirc', 'iuml', 'eth', 'ntilde', 'ograve', 'oacute',
'ocirc', 'otilde', 'ouml', 'divide', 'oslash', 'ugrave',
'uacute', 'ucirc', 'uuml', 'yacute', 'thorn', 'yuml',
'quot', 'amp', 'lt', 'gt', 'apos', 'OElig',
'oelig', 'Scaron', 'scaron', 'Yuml', 'circ', 'tilde',
'ensp', 'emsp', 'thinsp', 'zwnj', 'zwj', 'lrm',
'rlm', 'ndash', 'mdash', 'lsquo', 'rsquo', 'sbquo',
'ldquo', 'rdquo', 'bdquo', 'dagger', 'Dagger', 'permil',
'lsaquo', 'rsaquo', 'euro', 'fnof', 'Alpha', 'Beta',
'Gamma', 'Delta', 'Epsilon', 'Zeta', 'Eta', 'Theta',
'Iota', 'Kappa', 'Lambda', 'Mu', 'Nu', 'Xi',
'Omicron', 'Pi', 'Rho', 'Sigma', 'Tau', 'Upsilon',
'Phi', 'Chi', 'Psi', 'Omega', 'alpha', 'beta',
'gamma', 'delta', 'epsilon', 'zeta', 'eta', 'theta',
'iota', 'kappa', 'lambda', 'mu', 'nu', 'xi',
'omicron', 'pi', 'rho', 'sigmaf', 'sigma', 'tau',
'upsilon', 'phi', 'chi', 'psi', 'omega', 'thetasym',
'upsih', 'piv', 'bull', 'hellip', 'prime', 'Prime',
'oline', 'frasl', 'weierp', 'image', 'real', 'trade',
'alefsym', 'larr', 'uarr', 'rarr', 'darr', 'harr',
'crarr', 'lArr', 'uArr', 'rArr', 'dArr', 'hArr',
'forall', 'part', 'exist', 'empty', 'nabla', 'isin',
'notin', 'ni', 'prod', 'sum', 'minus', 'lowast',
'radic', 'prop', 'infin', 'ang', 'and', 'or',
'cap', 'cup', 'int', 'sim', 'cong', 'asymp',
'ne', 'equiv', 'le', 'ge', 'sub', 'sup',
'nsub', 'sube', 'supe', 'oplus', 'otimes', 'perp',
'sdot', 'lceil', 'rceil', 'lfloor', 'rfloor', 'lang',
'rang', 'loz', 'spades', 'clubs', 'hearts', 'diams',
'sup1', 'sup2', 'sup3', 'frac14', 'frac12', 'frac34',
'there4',
);
$allowedposttags = array_map( '_wp_add_global_attributes', $allowedposttags );
} else {
$allowedtags = wp_kses_array_lc( $allowedtags );
$allowedposttags = wp_kses_array_lc( $allowedposttags );
}
/**
* Filters content and keeps only allowable HTML elements.
*
* This function makes sure that only the allowed HTML element names, attribute
* names and attribute values plus only sane HTML entities will occur in
* $string. You have to remove any slashes from PHP's magic quotes before you
* call this function.
*
* The default allowed protocols are 'http', 'https', 'ftp', 'mailto', 'news',
* 'irc', 'gopher', 'nntp', 'feed', 'telnet, 'mms', 'rtsp' and 'svn'. This
* covers all common link protocols, except for 'javascript' which should not
* be allowed for untrusted users.
*
* @since 1.0.0
*
* @param string $string Content to filter through kses
* @param array $allowed_html List of allowed HTML elements
* @param array $allowed_protocols Optional. Allowed protocol in links.
* @return string Filtered content with only allowed HTML elements
*/
function wp_kses( $string, $allowed_html, $allowed_protocols = array() ) {
if ( empty( $allowed_protocols ) )
$allowed_protocols = wp_allowed_protocols();
$string = wp_kses_no_null($string);
$string = wp_kses_js_entities($string);
$string = wp_kses_normalize_entities($string);
$string = wp_kses_hook($string, $allowed_html, $allowed_protocols); // WP changed the order of these funcs and added args to wp_kses_hook
return wp_kses_split($string, $allowed_html, $allowed_protocols);
}
/**
* Return a list of allowed tags and attributes for a given context.
*
* @since 3.5.0
*
* @param string $context The context for which to retrieve tags. Allowed values are
* post | strip | data | entities or the name of a field filter such as pre_user_description.
* @return array List of allowed tags and their allowed attributes.
*/
function wp_kses_allowed_html( $context = '' ) {
global $allowedposttags, $allowedtags, $allowedentitynames;
if ( is_array( $context ) ) {
/**
* Filter HTML elements allowed for a given context.
*
* @since 3.5.0
*
* @param string $tags Allowed tags, attributes, and/or entities.
* @param string $context Context to judge allowed tags by. Allowed values are 'post',
* 'data', 'strip', 'entities', 'explicit', or the name of a filter.
*/
return apply_filters( 'wp_kses_allowed_html', $context, 'explicit' );
}
switch ( $context ) {
case 'post':
/** This filter is documented in wp-includes/kses.php */
return apply_filters( 'wp_kses_allowed_html', $allowedposttags, $context );
break;
case 'user_description':
case 'pre_user_description':
$tags = $allowedtags;
$tags['a']['rel'] = true;
/** This filter is documented in wp-includes/kses.php */
return apply_filters( 'wp_kses_allowed_html', $tags, $context );
break;
case 'strip':
/** This filter is documented in wp-includes/kses.php */
return apply_filters( 'wp_kses_allowed_html', array(), $context );
break;
case 'entities':
/** This filter is documented in wp-includes/kses.php */
return apply_filters( 'wp_kses_allowed_html', $allowedentitynames, $context);
break;
case 'data':
default:
/** This filter is documented in wp-includes/kses.php */
return apply_filters( 'wp_kses_allowed_html', $allowedtags, $context );
}
}
/**
* You add any kses hooks here.
*
* There is currently only one kses WordPress hook and it is called here. All
* parameters are passed to the hooks and expected to receive a string.
*
* @since 1.0.0
*
* @param string $string Content to filter through kses
* @param array $allowed_html List of allowed HTML elements
* @param array $allowed_protocols Allowed protocol in links
* @return string Filtered content through 'pre_kses' hook
*/
function wp_kses_hook( $string, $allowed_html, $allowed_protocols ) {
/**
* Filter content to be run through kses.
*
* @since 2.3.0
*
* @param string $string Content to run through kses.
* @param array $allowed_html Allowed HTML elements.
* @param array $allowed_protocols Allowed protocol in links.
*/
$string = apply_filters( 'pre_kses', $string, $allowed_html, $allowed_protocols );
return $string;
}
/**
* This function returns kses' version number.
*
* @since 1.0.0
*
* @return string KSES Version Number
*/
function wp_kses_version() {
return '0.2.2';
}
/**
* Searches for HTML tags, no matter how malformed.
*
* It also matches stray ">" characters.
*
* @since 1.0.0
*
* @param string $string Content to filter
* @param array $allowed_html Allowed HTML elements
* @param array $allowed_protocols Allowed protocols to keep
* @return string Content with fixed HTML tags
*/
function wp_kses_split( $string, $allowed_html, $allowed_protocols ) {
global $pass_allowed_html, $pass_allowed_protocols;
$pass_allowed_html = $allowed_html;
$pass_allowed_protocols = $allowed_protocols;
return preg_replace_callback( '%(<!--.*?(-->|$))|(<[^>]*(>|$)|>)%', '_wp_kses_split_callback', $string );
}
/**
* Callback for wp_kses_split.
*
* @since 3.1.0
* @access private
*/
function _wp_kses_split_callback( $match ) {
global $pass_allowed_html, $pass_allowed_protocols;
return wp_kses_split2( $match[0], $pass_allowed_html, $pass_allowed_protocols );
}
/**
* Callback for wp_kses_split for fixing malformed HTML tags.
*
* This function does a lot of work. It rejects some very malformed things like
* <:::>. It returns an empty string, if the element isn't allowed (look ma, no
* strip_tags()!). Otherwise it splits the tag into an element and an attribute
* list.
*
* After the tag is split into an element and an attribute list, it is run
* through another filter which will remove illegal attributes and once that is
* completed, will be returned.
*
* @access private
* @since 1.0.0
* @uses wp_kses_attr()
*
* @param string $string Content to filter
* @param array $allowed_html Allowed HTML elements
* @param array $allowed_protocols Allowed protocols to keep
* @return string Fixed HTML element
*/
function wp_kses_split2($string, $allowed_html, $allowed_protocols) {
$string = wp_kses_stripslashes($string);
if (substr($string, 0, 1) != '<')
return '>';
# It matched a ">" character
if ( '<!--' == substr( $string, 0, 4 ) ) {
$string = str_replace( array('<!--', '-->'), '', $string );
while ( $string != ($newstring = wp_kses($string, $allowed_html, $allowed_protocols)) )
$string = $newstring;
if ( $string == '' )
return '';
// prevent multiple dashes in comments
$string = preg_replace('/--+/', '-', $string);
// prevent three dashes closing a comment
$string = preg_replace('/-$/', '', $string);
return "<!--{$string}-->";
}
# Allow HTML comments
if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches))
return '';
# It's seriously malformed
$slash = trim($matches[1]);
$elem = $matches[2];
$attrlist = $matches[3];
if ( ! is_array( $allowed_html ) )
$allowed_html = wp_kses_allowed_html( $allowed_html );
if ( ! isset($allowed_html[strtolower($elem)]) )
return '';
# They are using a not allowed HTML element
if ($slash != '')
return "</$elem>";
# No attributes are allowed for closing elements
return wp_kses_attr( $elem, $attrlist, $allowed_html, $allowed_protocols );
}
/**
* Removes all attributes, if none are allowed for this element.
*
* If some are allowed it calls wp_kses_hair() to split them further, and then
* it builds up new HTML code from the data that kses_hair() returns. It also
* removes "<" and ">" characters, if there are any left. One more thing it does
* is to check if the tag has a closing XHTML slash, and if it does, it puts one
* in the returned code as well.
*
* @since 1.0.0
*
* @param string $element HTML element/tag
* @param string $attr HTML attributes from HTML element to closing HTML element tag
* @param array $allowed_html Allowed HTML elements
* @param array $allowed_protocols Allowed protocols to keep
* @return string Sanitized HTML element
*/
function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
# Is there a closing XHTML slash at the end of the attributes?
if ( ! is_array( $allowed_html ) )
$allowed_html = wp_kses_allowed_html( $allowed_html );
$xhtml_slash = '';
if (preg_match('%\s*/\s*$%', $attr))
$xhtml_slash = ' /';
# Are any attributes allowed at all for this element?
if ( ! isset($allowed_html[strtolower($element)]) || count($allowed_html[strtolower($element)]) == 0 )
return "<$element$xhtml_slash>";
# Split it
$attrarr = wp_kses_hair($attr, $allowed_protocols);
# Go through $attrarr, and save the allowed attributes for this element
# in $attr2
$attr2 = '';
$allowed_attr = $allowed_html[strtolower($element)];
foreach ($attrarr as $arreach) {
if ( ! isset( $allowed_attr[strtolower($arreach['name'])] ) )
continue; # the attribute is not allowed
$current = $allowed_attr[strtolower($arreach['name'])];
if ( $current == '' )
continue; # the attribute is not allowed
if ( strtolower( $arreach['name'] ) == 'style' ) {
$orig_value = $arreach['value'];
$value = safecss_filter_attr( $orig_value );
if ( empty( $value ) )
continue;
$arreach['value'] = $value;
$arreach['whole'] = str_replace( $orig_value, $value, $arreach['whole'] );
}
if ( ! is_array($current) ) {
$attr2 .= ' '.$arreach['whole'];
# there are no checks
} else {
# there are some checks
$ok = true;
foreach ($current as $currkey => $currval) {
if ( ! wp_kses_check_attr_val($arreach['value'], $arreach['vless'], $currkey, $currval) ) {
$ok = false;
break;
}
}
if ( $ok )
$attr2 .= ' '.$arreach['whole']; # it passed them
} # if !is_array($current)
} # foreach
# Remove any "<" or ">" characters
$attr2 = preg_replace('/[<>]/', '', $attr2);
return "<$element$attr2$xhtml_slash>";
}
/**
* Builds an attribute list from string containing attributes.
*
* This function does a lot of work. It parses an attribute list into an array
* with attribute data, and tries to do the right thing even if it gets weird
* input. It will add quotes around attribute values that don't have any quotes
* or apostrophes around them, to make it easier to produce HTML code that will
* conform to W3C's HTML specification. It will also remove bad URL protocols
* from attribute values. It also reduces duplicate attributes by using the
* attribute defined first (foo='bar' foo='baz' will result in foo='bar').
*
* @since 1.0.0
*
* @param string $attr Attribute list from HTML element to closing HTML element tag
* @param array $allowed_protocols Allowed protocols to keep
* @return array List of attributes after parsing
*/
function wp_kses_hair($attr, $allowed_protocols) {
$attrarr = array();
$mode = 0;
$attrname = '';
$uris = array('xmlns', 'profile', 'href', 'src', 'cite', 'classid', 'codebase', 'data', 'usemap', 'longdesc', 'action');
# Loop through the whole attribute list
while (strlen($attr) != 0) {
$working = 0; # Was the last operation successful?
switch ($mode) {
case 0 : # attribute name, href for instance
if ( preg_match('/^([-a-zA-Z:]+)/', $attr, $match ) ) {
$attrname = $match[1];
$working = $mode = 1;
$attr = preg_replace( '/^[-a-zA-Z:]+/', '', $attr );
}
break;
case 1 : # equals sign or valueless ("selected")
if (preg_match('/^\s*=\s*/', $attr)) # equals sign
{
$working = 1;
$mode = 2;
$attr = preg_replace('/^\s*=\s*/', '', $attr);
break;
}
if (preg_match('/^\s+/', $attr)) # valueless
{
$working = 1;
$mode = 0;
if(false === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y');
}
$attr = preg_replace('/^\s+/', '', $attr);
}
break;
case 2 : # attribute value, a URL after href= for instance
if (preg_match('%^"([^"]*)"(\s+|/?$)%', $attr, $match))
# "value"
{
$thisval = $match[1];
if ( in_array(strtolower($attrname), $uris) )
$thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(false === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
}
$working = 1;
$mode = 0;
$attr = preg_replace('/^"[^"]*"(\s+|$)/', '', $attr);
break;
}
if (preg_match("%^'([^']*)'(\s+|/?$)%", $attr, $match))
# 'value'
{
$thisval = $match[1];
if ( in_array(strtolower($attrname), $uris) )
$thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(false === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname='$thisval'", 'vless' => 'n');
}
$working = 1;
$mode = 0;
$attr = preg_replace("/^'[^']*'(\s+|$)/", '', $attr);
break;
}
if (preg_match("%^([^\s\"']+)(\s+|/?$)%", $attr, $match))
# value
{
$thisval = $match[1];
if ( in_array(strtolower($attrname), $uris) )
$thisval = wp_kses_bad_protocol($thisval, $allowed_protocols);
if(false === array_key_exists($attrname, $attrarr)) {
$attrarr[$attrname] = array ('name' => $attrname, 'value' => $thisval, 'whole' => "$attrname=\"$thisval\"", 'vless' => 'n');
}
# We add quotes to conform to W3C's HTML spec.
$working = 1;
$mode = 0;
$attr = preg_replace("%^[^\s\"']+(\s+|$)%", '', $attr);
}
break;
} # switch
if ($working == 0) # not well formed, remove and try again
{
$attr = wp_kses_html_error($attr);
$mode = 0;
}
} # while
if ($mode == 1 && false === array_key_exists($attrname, $attrarr))
# special case, for when the attribute list ends with a valueless
# attribute like "selected"
$attrarr[$attrname] = array ('name' => $attrname, 'value' => '', 'whole' => $attrname, 'vless' => 'y');
return $attrarr;
}
/**
* Performs different checks for attribute values.
*
* The currently implemented checks are "maxlen", "minlen", "maxval", "minval"
* and "valueless".
*
* @since 1.0.0
*
* @param string $value Attribute value
* @param string $vless Whether the value is valueless. Use 'y' or 'n'
* @param string $checkname What $checkvalue is checking for.
* @param mixed $checkvalue What constraint the value should pass
* @return bool Whether check passes
*/
function wp_kses_check_attr_val($value, $vless, $checkname, $checkvalue) {
$ok = true;
switch (strtolower($checkname)) {
case 'maxlen' :
# The maxlen check makes sure that the attribute value has a length not
# greater than the given value. This can be used to avoid Buffer Overflows
# in WWW clients and various Internet servers.
if (strlen($value) > $checkvalue)
$ok = false;
break;
case 'minlen' :
# The minlen check makes sure that the attribute value has a length not
# smaller than the given value.
if (strlen($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)
$ok = false;
break;
case 'minval' :
# The minval check makes sure that the attribute value is a positive integer,
# and that it is not smaller than the given value.
if (!preg_match('/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value))
$ok = false;
if ($value < $checkvalue)
$ok = false;
break;
case 'valueless' :
# The valueless check makes sure if the attribute has a value
# (like <a href="blah">) or not (<option selected>). If the given value
# is a "y" or a "Y", the attribute must not have a value.
# If the given value is an "n" or an "N", the attribute must have one.
if (strtolower($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)".
*
* @since 1.0.0
*
* @param string $string Content to filter bad protocols from
* @param array $allowed_protocols Allowed protocols to keep
* @return string Filtered content
*/
function wp_kses_bad_protocol($string, $allowed_protocols) {
$string = wp_kses_no_null($string);
$iterations = 0;
do {
$original_string = $string;
$string = wp_kses_bad_protocol_once($string, $allowed_protocols);
} while ( $original_string != $string && ++$iterations < 6 );
if ( $original_string != $string )
return '';
return $string;
}
/**
* Removes any invalid control characters in $string.
*
* Also removes any instance of the '\0' string.
*
* @since 1.0.0
*
* @param string $string