<?php
global $allowedentitynames, $allowedxmlentitynames;
$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',
);
$allowedxmlentitynames = array(
'amp',
'lt',
'gt',
'apos',
'quot',
);
/**
* Filters text content and strips out disallowed HTML.
*
* This function makes sure that only the allowed HTML element names, attribute
* names, attribute values, and HTML entities will occur in the given text string.
*
* This function expects unslashed data.
*
* @param string $string Text content to filter.
* @param array[]|string $allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'. See wp_kses_allowed_html()
* for the list of accepted context names.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Filtered content containing only the allowed HTML.
* @see wp_allowed_protocols() for the default allowed protocols in link URLs.
*
* @since 1.0.0
*
* @see wp_kses_post() for specifically filtering post content and fields.
*/
if (!function_exists('wp_kses')) {
function wp_kses($string, $allowed_html, $allowed_protocols = array()) {
if (empty($allowed_protocols)) {
$allowed_protocols = wp_allowed_protocols();
}
$string = wp_kses_no_null($string, array('slash_zero' => 'keep'));
$string = wp_kses_normalize_entities($string);
return wp_kses_split($string, $allowed_html, $allowed_protocols);
}
}
/**
* Retrieve a list of protocols to allow in HTML attributes.
*
* @return string[] Array of allowed protocols. Defaults to an array containing 'http', 'https',
* 'ftp', 'ftps', 'mailto', 'news', 'irc', 'irc6', 'ircs', 'gopher', 'nntp', 'feed',
* 'telnet', 'mms', 'rtsp', 'sms', 'svn', 'tel', 'fax', 'xmpp', 'webcal', and 'urn'.
* This covers all common link protocols, except for 'javascript' which should not
* be allowed for untrusted users.
* @since 4.3.0 Added 'webcal' to the protocols array.
* @since 4.7.0 Added 'urn' to the protocols array.
* @since 5.3.0 Added 'sms' to the protocols array.
* @since 5.6.0 Added 'irc6' and 'ircs' to the protocols array.
*
* @see wp_kses()
* @see esc_url()
*
* @since 3.3.0
*/
if (!function_exists('wp_allowed_protocols')) {
function wp_allowed_protocols() {
static $protocols = array();
if (empty($protocols)) {
$protocols = array(
'http',
'https',
'ftp',
'ftps',
'mailto',
'news',
'irc',
'irc6',
'ircs',
'gopher',
'nntp',
'feed',
'telnet',
'mms',
'rtsp',
'sms',
'svn',
'tel',
'fax',
'xmpp',
'webcal',
'urn'
);
}
return $protocols;
}
}
/**
* Removes any invalid control characters in a text string.
*
* Also removes any instance of the `\0` string.
*
* @param string $string Content to filter null characters from.
* @param array $options Set 'slash_zero' => 'keep' when '\0' is allowed. Default is 'remove'.
*
* @return string Filtered content.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_no_null')) {
function wp_kses_no_null($string, $options = null) {
if (!isset($options['slash_zero'])) {
$options = array('slash_zero' => 'remove');
}
$string = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $string);
if ('remove' === $options['slash_zero']) {
$string = preg_replace('/\\\\+0+/', '', $string);
}
return $string;
}
}
/**
* Converts lone less than signs.
*
* KSES already converts lone greater than signs.
*
* @param string $text Text to be converted.
*
* @return string Converted text.
* @since 2.3.0
*
*/
if (!function_exists('wp_pre_kses_less_than')) {
function wp_pre_kses_less_than($text) {
return preg_replace_callback('%<[^>]*?((?=<)|>|$)%', 'wp_pre_kses_less_than_callback', $text);
}
}
/**
* Callback function used by preg_replace.
*
* @param string[] $matches Populated by matches to preg_replace.
*
* @return string The text returned after esc_html if needed.
* @since 2.3.0
*
*/
if (!function_exists('wp_pre_kses_less_than_callback')) {
function wp_pre_kses_less_than_callback($matches) {
if (false === strpos($matches[0], '>')) {
return esc_html($matches[0]);
}
return $matches[0];
}
}
/**
* Converts and fixes HTML entities.
*
* This function normalizes HTML entities. It will convert `AT&T` to the correct
* `AT&T`, `:` to `:`, `&#XYZZY;` to `&#XYZZY;` and so on.
*
* When `$context` is set to 'xml', HTML entities are converted to their code points. For
* example, `AT&T…&#XYZZY;` is converted to `AT&T…&#XYZZY;`.
*
* @param string $string Content to normalize entities.
* @param string $context Context for normalization. Can be either 'html' or 'xml'.
* Default 'html'.
*
* @return string Content with normalized entities.
* @since 5.5.0 Added `$context` parameter.
*
* @since 1.0.0
*/
if (!function_exists('wp_kses_normalize_entities')) {
function wp_kses_normalize_entities($string, $context = 'html') {
// Disarm all entities by converting & to &
$string = str_replace('&', '&', $string);
// Change back the allowed entities in our list of allowed entities.
if ('xml' === $context) {
$string = preg_replace_callback('/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_xml_named_entities', $string);
} else {
$string = preg_replace_callback('/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_named_entities', $string);
}
$string = preg_replace_callback('/&#(0*[0-9]{1,7});/', 'wp_kses_normalize_entities2', $string);
$string = preg_replace_callback('/&#[Xx](0*[0-9A-Fa-f]{1,6});/', 'wp_kses_normalize_entities3', $string);
return $string;
}
}
/**
* Callback for `wp_kses_normalize_entities()` regular expression.
*
* This function only accepts valid named entity references, which are finite,
* case-sensitive, and highly scrutinized by XML validators. HTML named entity
* references are converted to their code points.
*
* @param array $matches preg_replace_callback() matches array.
*
* @return string Correctly encoded entity.
* @global array $allowedxmlentitynames
*
* @since 5.5.0
*
* @global array $allowedentitynames
*/
if (!function_exists('wp_kses_xml_named_entities')) {
function wp_kses_xml_named_entities($matches) {
global $allowedentitynames, $allowedxmlentitynames;
if (empty($matches[1])) {
return '';
}
$i = $matches[1];
if (in_array($i, $allowedxmlentitynames, true)) {
return "&$i;";
} elseif (in_array($i, $allowedentitynames, true)) {
return html_entity_decode("&$i;", ENT_HTML5);
}
return "&$i;";
}
}
/**
* Callback for `wp_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.
*
* @param array $matches preg_replace_callback() matches array.
*
* @return string Correctly encoded entity.
* @since 3.0.0
*
* @global array $allowedentitynames
*
*/
if (!function_exists('wp_kses_named_entities')) {
function wp_kses_named_entities($matches) {
global $allowedentitynames;
if (empty($matches[1])) {
return '';
}
$i = $matches[1];
return (!in_array($i, $allowedentitynames, true)) ? "&$i;" : "&$i;";
}
}
/**
* Callback for `wp_kses_normalize_entities()` regular expression.
*
* This function helps `wp_kses_normalize_entities()` to only accept 16-bit
* values and nothing more for `&#number;` entities.
*
* @access private
*
* @param array $matches `preg_replace_callback()` matches array.
*
* @return string Correctly encoded entity.
* @ignore
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_normalize_entities2')) {
function wp_kses_normalize_entities2($matches) {
if (empty($matches[1])) {
return '';
}
$i = $matches[1];
if (valid_unicode($i)) {
$i = str_pad(ltrim($i, '0'), 3, '0', STR_PAD_LEFT);
$i = "&#$i;";
} else {
$i = "&#$i;";
}
return $i;
}
}
/**
* Callback for `wp_kses_normalize_entities()` for regular expression.
*
* This function helps `wp_kses_normalize_entities()` to only accept valid Unicode
* numeric entities in hex form.
*
* @param array $matches `preg_replace_callback()` matches array.
*
* @return string Correctly encoded entity.
* @since 2.7.0
* @access private
* @ignore
*
*/
if (!function_exists('wp_kses_normalize_entities3')) {
function wp_kses_normalize_entities3($matches) {
if (empty($matches[1])) {
return '';
}
$hexchars = $matches[1];
return (!valid_unicode(hexdec($hexchars))) ? "&#x$hexchars;" : '&#x' . ltrim($hexchars, '0') . ';';
}
}
/**
* Searches for HTML tags, no matter how malformed.
*
* It also matches stray `>` characters.
*
* @param string $string Content to filter.
* @param array[]|string $allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'. See wp_kses_allowed_html()
* for the list of accepted context names.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Content with fixed HTML tags
* @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'.
* @global string[] $pass_allowed_protocols Array of allowed URL protocols.
*
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_split')) {
function wp_kses_split($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()`.
*
* @param array $match preg_replace regexp matches
*
* @return string
* @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'.
* @global string[] $pass_allowed_protocols Array of allowed URL protocols.
*
* @since 3.1.0
* @access private
* @ignore
*
*/
if (!function_exists('_wp_kses_split_callback')) {
function _wp_kses_split_callback($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
*
* @param string $string Content to filter.
* @param array[]|string $allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'. See wp_kses_allowed_html()
* for the list of accepted context names.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Fixed HTML element
* @ignore
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_split2')) {
function wp_kses_split2($string, $allowed_html, $allowed_protocols) {
$string = wp_kses_stripslashes($string);
// It matched a ">" character.
if ('<' !== substr($string, 0, 1)) {
return '>';
}
// Allow HTML comments.
if ('<!--' === substr($string, 0, 4)) {
$string = str_replace(array(
'<!--',
'-->'
), '', $string);
while (($newstring = wp_kses($string, $allowed_html, $allowed_protocols)) != $string) {
$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}-->";
}
// It's seriously malformed.
if (!preg_match('%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $string, $matches)) {
return '';
}
$slash = trim($matches[1]);
$elem = $matches[2];
$attrlist = $matches[3];
// They are using a not allowed HTML element.
if (!isset($allowed_html[strtolower($elem)])) {
return '';
}
// No attributes are allowed for closing elements.
if ('' !== $slash) {
return "</$elem>";
}
return wp_kses_attr($elem, $attrlist, $allowed_html, $allowed_protocols);
}
}
/**
* Strips slashes from in front of quotes.
*
* This function changes the character sequence `\"` to just `"`. It leaves all other
* slashes alone. The quoting from `preg_replace(//e)` requires this.
*
* @param string $string String to strip slashes from.
*
* @return string Fixed string with quoted slashes.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_stripslashes')) {
function wp_kses_stripslashes($string) {
return preg_replace('%\\\\"%', '"', $string);
}
}
/**
* 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 `wp_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.
*
* An array of allowed values can be defined for attributes. If the attribute value
* doesn't fall into the list, the attribute will be removed from the tag.
*
* Attributes can be marked as required. If a required attribute is not present,
* KSES will remove all attributes from the tag. As KSES doesn't match opening and
* closing tags, it's not possible to safely remove the tag itself, the safest
* fallback is to strip all attributes from the tag, instead.
*
* @param string $element HTML element/tag.
* @param string $attr HTML attributes from HTML element to closing HTML element tag.
* @param array[]|string $allowed_html An array of allowed HTML elements and attributes,
* or a context name such as 'post'. See wp_kses_allowed_html()
* for the list of accepted context names.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Sanitized HTML element.
* @since 5.9.0 Added support for an array of allowed values for attributes.
* Added support for required attributes.
*
* @since 1.0.0
*/
if (!function_exists('wp_kses_attr')) {
function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
// Is there a closing XHTML slash at the end of the attributes?
$xhtml_slash = '';
if (preg_match('%\s*/\s*$%', $attr)) {
$xhtml_slash = ' /';
}
// Are any attributes allowed at all for this element?
$element_low = strtolower($element);
if (empty($allowed_html[$element_low]) || true === $allowed_html[$element_low]) {
return "<$element$xhtml_slash>";
}
// Split it.
$attrarr = wp_kses_hair($attr, $allowed_protocols);
// Check if there are attributes that are required.
$required_attrs = array_filter($allowed_html[$element_low], function ($required_attr_limits) {
return isset($required_attr_limits['required']) && true === $required_attr_limits['required'];
});
/*
* If a required attribute check fails, we can return nothing for a self-closing tag,
* but for a non-self-closing tag the best option is to return the element with attributes,
* as KSES doesn't handle matching the relevant closing tag.
*/
$stripped_tag = '';
if (empty($xhtml_slash)) {
$stripped_tag = "<$element>";
}
// Go through $attrarr, and save the allowed attributes for this element in $attr2.
$attr2 = '';
foreach ($attrarr as $arreach) {
// Check if this attribute is required.
$required = isset($required_attrs[strtolower($arreach['name'])]);
if (wp_kses_attr_check($arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html)) {
$attr2 .= ' ' . $arreach['whole'];
// If this was a required attribute, we can mark it as found.
if ($required) {
unset($required_attrs[strtolower($arreach['name'])]);
}
} elseif ($required) {
// This attribute was required, but didn't pass the check. The entire tag is not allowed.
return $stripped_tag;
}
}
// If some required attributes weren't set, the entire tag is not allowed.
if (!empty($required_attrs)) {
return $stripped_tag;
}
// 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'`).
*
* @param string $attr Attribute list from HTML element to closing HTML element tag.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return array[] Array of attribute information after parsing.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_hair')) {
function wp_kses_hair($attr, $allowed_protocols) {
$attrarr = array();
$mode = 0;
$attrname = '';
$uris = wp_kses_uri_attributes();
// Loop through the whole attribute list.
while (strlen($attr) != 0) {
$working = 0; // Was the last operation successful?
switch ($mode) {
case 0:
if (preg_match('/^([_a-zA-Z][-_a-zA-Z0-9:.]*)/', $attr, $match)) {
$attrname = $match[1];
$working = 1;
$mode = 1;
$attr = preg_replace('/^[_a-zA-Z][-_a-zA-Z0-9:.]*/', '', $attr);
}
break;
case 1:
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+/', '', $attr);
}
break;
case 2:
if (preg_match('%^"([^"]*)"(\s+|/?$)%', $attr, $match)) {
// "value"
$thisval = $match[1];
if (in_array(strtolower($attrname), $uris, true)) {
$thisval = wp_kses_bad_protocol($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, true)) {
$thisval = wp_kses_bad_protocol($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, true)) {
$thisval = wp_kses_bad_protocol($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;
} // End switch.
if (0 == $working) { // Not well-formed, remove and try again.
$attr = wp_kses_html_error($attr);
$mode = 0;
}
} // End while.
if (1 == $mode && false === array_key_exists($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;
}
}
/**
* Determines whether an attribute is allowed.
*
* @param string $name The attribute name. Passed by reference. Returns empty string when not allowed.
* @param string $value The attribute value. Passed by reference. Returns a filtered value.
* @param string $whole The `name=value` input. Passed by reference. Returns filtered input.
* @param string $vless Whether the attribute is valueless. Use 'y' or 'n'.
* @param string $element The name of the element to which this attribute belongs.
* @param array $allowed_html The full list of allowed elements and attributes.
*
* @return bool Whether or not the attribute is allowed.
* @since 5.0.0 Added support for `data-*` wildcard attributes.
*
* @since 4.2.3
*/
if (!function_exists('wp_kses_attr_check')) {
function wp_kses_attr_check(&$name, &$value, &$whole, $vless, $element, $allowed_html) {
$name_low = strtolower($name);
$element_low = strtolower($element);
if (!isset($allowed_html[$element_low])) {
$name = '';
$value = '';
$whole = '';
return false;
}
$allowed_attr = $allowed_html[$element_low];
if (!isset($allowed_attr[$name_low]) || '' === $allowed_attr[$name_low]) {
/*
* Allow `data-*` attributes.
*
* When specifying `$allowed_html`, the attribute name should be set as
* `data-*` (not to be mixed with the HTML 4.0 `data` attribute, see
* https://www.w3.org/TR/html40/struct/objects.html#adef-data).
*
* Note: the attribute name should only contain `A-Za-z0-9_-` chars,
* double hyphens `--` are not accepted by WordPress.
*/
if (strpos($name_low, 'data-') === 0 && !empty($allowed_attr['data-*']) && preg_match('/^data(?:-[a-z0-9_]+)+$/', $name_low, $match)) {
/*
* Add the whole attribute name to the allowed attributes and set any restrictions
* for the `data-*` attribute values for the current element.
*/
$allowed_attr[$match[0]] = $allowed_attr['data-*'];
} else {
$name = '';
$value = '';
$whole = '';
return false;
}
}
if ('style' === $name_low) {
$new_value = safecss_filter_attr($value);
if (empty($new_value)) {
$name = '';
$value = '';
$whole = '';
return false;
}
$whole = str_replace($value, $new_value, $whole);
$value = $new_value;
}
if (is_array($allowed_attr[$name_low])) {
// There are some checks.
foreach ($allowed_attr[$name_low] as $currkey => $currval) {
if (!wp_kses_check_attr_val($value, $vless, $currkey, $currval)) {
$name = '';
$value = '';
$whole = '';
return false;
}
}
}
return true;
}
}
/**
* Returns an array of HTML attribute names whose value contains a URL.
*
* This function returns a list of all HTML attributes that must contain
* a URL according to the HTML specification.
*
* This list includes URI attributes both allowed and disallowed by KSES.
*
* @link https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes
*
* @since 5.0.1
*
* @return string[] HTML attribute names whose value contains a URL.
*/
if (!function_exists('wp_kses_uri_attributes')) {
function wp_kses_uri_attributes() {
$uri_attributes = array(
'action',
'archive',
'background',
'cite',
'classid',
'codebase',
'data',
'formaction',
'href',
'icon',
'longdesc',
'manifest',
'poster',
'profile',
'src',
'usemap',
'xmlns',
);
return $uri_attributes;
}
}
/**
* Sanitizes a string and removed disallowed URL protocols.
*
* This function removes all non-allowed protocols from the beginning of the
* string. It ignores whitespace and the case of the letters, and it does
* understand HTML entities. It does its work recursively, so it won't be
* fooled by a string like `javascript:javascript:alert(57)`.
*
* @param string $string Content to filter bad protocols from.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Filtered content.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_bad_protocol')) {
function wp_kses_bad_protocol($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;
}
}
/**
* Sanitizes content from bad protocols and other characters.
*
* This function searches for URL protocols at the beginning of the string, while
* handling whitespace and HTML entities.
*
* @param string $string Content to check for bad protocols.
* @param string[] $allowed_protocols Array of allowed URL protocols.
* @param int $count Depth of call recursion to this function.
*
* @return string Sanitized content.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_bad_protocol_once')) {
function wp_kses_bad_protocol_once($string, $allowed_protocols, $count = 1) {
$string = preg_replace('/(�*58(?![;0-9])|�*3a(?![;a-f0-9]))/i', '$1;', $string);
$string2 = preg_split('/:|�*58;|�*3a;|:/i', $string, 2);
if (isset($string2[1]) && !preg_match('%/\?%', $string2[0])) {
$string = trim($string2[1]);
$protocol = wp_kses_bad_protocol_once2($string2[0], $allowed_protocols);
if ('feed:' === $protocol) {
if ($count > 2) {
return '';
}
$string = wp_kses_bad_protocol_once($string, $allowed_protocols, ++$count);
if (empty($string)) {
return $string;
}
}
$string = $protocol . $string;
}
return $string;
}
}
/**
* Callback for `wp_kses_bad_protocol_once()` regular expression.
*
* This function processes URL protocols, checks to see if they're in the
* list of allowed protocols or not, and returns different data depending
* on the answer.
*
* @access private
*
* @param string $string URI scheme to check against the list of allowed protocols.
* @param string[] $allowed_protocols Array of allowed URL protocols.
*
* @return string Sanitized content.
* @since 1.0.0
*
* @ignore
*/
if (!function_exists('wp_kses_bad_protocol_once2')) {
function wp_kses_bad_protocol_once2($string, $allowed_protocols) {
$string2 = wp_kses_decode_entities($string);
$string2 = preg_replace('/\s/', '', $string2);
$string2 = wp_kses_no_null($string2);
$string2 = strtolower($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 all numeric HTML entities to their named counterparts.
*
* This function decodes numeric HTML entities (`A` and `A`).
* It doesn't do anything with named entities like `ä`, but we don't
* need them in the allowed URL protocols system anyway.
*
* @param string $string Content to change entities.
*
* @return string Content after decoded entities.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_decode_entities')) {
function wp_kses_decode_entities($string) {
$string = preg_replace_callback('/&#([0-9]+);/', '_wp_kses_decode_entities_chr', $string);
$string = preg_replace_callback('/&#[Xx]([0-9A-Fa-f]+);/', '_wp_kses_decode_entities_chr_hexdec', $string);
return $string;
}
}
/**
* Regex callback for `wp_kses_decode_entities()`.
*
* @param array $match preg match
*
* @return string
* @since 2.9.0
* @access private
* @ignore
*
*/
if (!function_exists('_wp_kses_decode_entities_chr')) {
function _wp_kses_decode_entities_chr($match) {
return chr($match[1]);
}
}
/**
* Regex callback for `wp_kses_decode_entities()`.
*
* @param array $match preg match
*
* @return string
* @since 2.9.0
* @access private
* @ignore
*
*/
if (!function_exists('_wp_kses_decode_entities_chr_hexdec')) {
function _wp_kses_decode_entities_chr_hexdec($match) {
return chr(hexdec($match[1]));
}
}
/**
* Handles parsing errors in `wp_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 $string
*
* @return string
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_html_error')) {
function wp_kses_html_error($string) {
return preg_replace('/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $string);
}
}
/**
* Filters an inline style attribute and removes disallowed rules.
*
* @param string $css A string of CSS rules.
*
* @return string Filtered string of CSS rules.
* @since 2.8.1
* @since 4.4.0 Added support for `min-height`, `max-height`, `min-width`, and `max-width`.
* @since 4.6.0 Added support for `list-style-type`.
* @since 5.0.0 Added support for `background-image`.
* @since 5.1.0 Added support for `text-transform`.
* @since 5.2.0 Added support for `background-position` and `grid-template-columns`.
* @since 5.3.0 Added support for `grid`, `flex` and `column` layout properties.
* Extend `background-*` support of individual properties.
* @since 5.3.1 Added support for gradient backgrounds.
* @since 5.7.1 Added support for `object-position`.
* @since 5.8.0 Added support for `calc()` and `var()` values.
*
*/
if (!function_exists('safecss_filter_attr')) {
function safecss_filter_attr($css) {
$css = wp_kses_no_null($css);
$css = str_replace(array(
"\n",
"\r",
"\t"
), '', $css);
$allowed_protocols = wp_allowed_protocols();
$css_array = explode(';', trim($css));
/**
* Filters the list of allowed CSS attributes.
*
* @param string[] $attr Array of allowed CSS attributes.
*
* @since 2.8.1
*
*/
$allowed_attr = array(
'background',
'background-color',
'background-image',
'background-position',
'background-size',
'background-attachment',
'background-blend-mode',
'border',
'border-radius',
'border-width',
'border-color',
'border-style',
'border-right',
'border-right-color',
'border-right-style',
'border-right-width',
'border-bottom',
'border-bottom-color',
'border-bottom-left-radius',
'border-bottom-right-radius',
'border-bottom-style',
'border-bottom-width',
'border-bottom-right-radius',
'border-bottom-left-radius',
'border-left',
'border-left-color',
'border-left-style',
'border-left-width',
'border-top',
'border-top-color',
'border-top-left-radius',
'border-top-right-radius',
'border-top-style',
'border-top-width',
'border-top-left-radius',
'border-top-right-radius',
'border-spacing',
'border-collapse',
'caption-side',
'columns',
'column-count',
'column-fill',
'column-gap',
'column-rule',
'column-span',
'column-width',
'color',
'filter',
'font',
'font-family',
'font-size',
'font-style',
'font-variant',
'font-weight',
'letter-spacing',
'line-height',
'text-align',
'text-decoration',
'text-indent',
'text-transform',
'height',
'min-height',
'max-height',
'width',
'min-width',
'max-width',
'margin',
'margin-right',
'margin-bottom',
'margin-left',
'margin-top',
'padding',
'padding-right',
'padding-bottom',
'padding-left',
'padding-top',
'flex',
'flex-basis',
'flex-direction',
'flex-flow',
'flex-grow',
'flex-shrink',
'grid-template-columns',
'grid-auto-columns',
'grid-column-start',
'grid-column-end',
'grid-column-gap',
'grid-template-rows',
'grid-auto-rows',
'grid-row-start',
'grid-row-end',
'grid-row-gap',
'grid-gap',
'justify-content',
'justify-items',
'justify-self',
'align-content',
'align-items',
'align-self',
'clear',
'cursor',
'direction',
'float',
'list-style-type',
'object-position',
'overflow',
'vertical-align',
);
/*
* CSS attributes that accept URL data types.
*
* This is in accordance to the CSS spec and unrelated to
* the sub-set of supported attributes above.
*
* See: https://developer.mozilla.org/en-US/docs/Web/CSS/url
*/
$css_url_data_types = array(
'background',
'background-image',
'cursor',
'list-style',
'list-style-image',
);
/*
* CSS attributes that accept gradient data types.
*
*/
$css_gradient_data_types = array(
'background',
'background-image',
);
if (empty($allowed_attr)) {
return $css;
}
$css = '';
foreach ($css_array as $css_item) {
if ('' === $css_item) {
continue;
}
$css_item = trim($css_item);
$css_test_string = $css_item;
$found = false;
$url_attr = false;
$gradient_attr = false;
if (strpos($css_item, ':') === false) {
$found = true;
} else {
$parts = explode(':', $css_item, 2);
$css_selector = trim($parts[0]);
if (in_array($css_selector, $allowed_attr, true)) {
$found = true;
$url_attr = in_array($css_selector, $css_url_data_types, true);
$gradient_attr = in_array($css_selector, $css_gradient_data_types, true);
}
}
if ($found && $url_attr) {
// Simplified: matches the sequence `url(*)`.
preg_match_all('/url\([^)]+\)/', $parts[1], $url_matches);
foreach ($url_matches[0] as $url_match) {
// Clean up the URL from each of the matches above.
preg_match('/^url\(\s*([\'\"]?)(.*)(\g1)\s*\)$/', $url_match, $url_pieces);
if (empty($url_pieces[2])) {
$found = false;
break;
}
$url = trim($url_pieces[2]);
if (empty($url) || wp_kses_bad_protocol($url, $allowed_protocols) !== $url) {
$found = false;
break;
} else {
// Remove the whole `url(*)` bit that was matched above from the CSS.
$css_test_string = str_replace($url_match, '', $css_test_string);
}
}
}
if ($found && $gradient_attr) {
$css_value = trim($parts[1]);
if (preg_match('/^(repeating-)?(linear|radial|conic)-gradient\(([^()]|rgb[a]?\([^()]*\))*\)$/', $css_value)) {
// Remove the whole `gradient` bit that was matched above from the CSS.
$css_test_string = str_replace($css_value, '', $css_test_string);
}
}
if ($found) {
// Allow CSS calc().
$css_test_string = preg_replace('/calc\(((?:\([^()]*\)?|[^()])*)\)/', '', $css_test_string);
// Allow CSS var().
$css_test_string = preg_replace('/\(?var\(--[a-zA-Z0-9_-]*\)/', '', $css_test_string);
// Check for any CSS containing \ ( & } = or comments,
// except for url(), calc(), or var() usage checked above.
$allow_css = !preg_match('%[\\\(&=}]|/\*%', $css_test_string);
/**
* Filters the check for unsafe CSS in `safecss_filter_attr`.
*
* Enables developers to determine whether a section of CSS should be allowed or discarded.
* By default, the value will be false if the part contains \ ( & } = or comments.
* Return true to allow the CSS part to be included in the output.
*
* @param bool $allow_css Whether the CSS in the test string is considered safe.
* @param string $css_test_string The CSS string to test.
*
* @since 5.5.0
*
*/
// Only add the CSS part if it passes the regex check.
if ($allow_css) {
if ('' !== $css) {
$css .= ';';
}
$css .= $css_item;
}
}
}
return $css;
}
}
/**
* Performs different checks for attribute values.
*
* The currently implemented checks are "maxlen", "minlen", "maxval", "minval",
* and "valueless".
*
* @param string $value Attribute value.
* @param string $vless Whether the attribute is valueless. Use 'y' or 'n'.
* @param string $checkname What $checkvalue is checking for.
* @param mixed $checkvalue What constraint the value should pass.
*
* @return bool Whether check passes.
* @since 1.0.0
*
*/
if (!function_exists('wp_kses_check_attr_val')) {
function wp_kses_check_attr_val($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) {
$ok = false;
}
break;
case 'valueless':
/*
* The valueless check makes sure if the attribute has a value
* (like `<a href="blah">`) or not (`<option selected>`). If the given value
* is a "y" or a "Y", the attribute must not have a value.
* If the given value is an "n" or an "N", the attribute must have a value.
*/
if (strtolower($checkvalue) != $vless) {
$ok = false;
}
break;
case 'values':
/*
* The values check is used when you want to make sure that the attribute
* has one of the given values.
*/
if (false === array_search(strtolower($value), $checkvalue, true)) {
$ok = false;
}
break;
case 'value_callback':
/*
* The value_callback check is used when you want to make sure that the attribute
* value is accepted by the callback function.
*/
if (!call_user_func($checkvalue, $value)) {
$ok = false;
}
break;
} // End switch.
return $ok;
}
}