* * @package External * @subpackage KSES */ /** * Specifies the default allowable HTML tags. * * Using `CUSTOM_TAGS` is not recommended and should be considered deprecated. The * {@see 'wp_kses_allowed_html'} filter is more powerful and supplies context. * * @see wp_kses_allowed_html() * @since 1.2.0 * * @var array[]|bool Array of default allowable HTML tags, or false to use the defaults. */ 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 overridden with the `CUSTOM_TAGS` constant. * * @var array[] $allowedposttags Array of default allowable HTML tags. * @since 2.0.0 */ $allowedposttags = array( 'address' => array(), 'a' => array( 'href' => true, 'rel' => true, 'rev' => true, 'name' => true, 'target' => true, 'download' => array( 'valueless' => 'y', ), ), '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, ), 'audio' => array( 'autoplay' => true, 'controls' => true, 'loop' => true, 'muted' => true, 'preload' => true, 'src' => true, ), 'b' => array(), 'bdo' => array( 'dir' => true, ), '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, ), 'colgroup' => array( 'align' => true, 'char' => true, 'charoff' => true, 'span' => 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, ), 'track' => array( 'default' => true, 'kind' => true, 'label' => true, 'src' => true, 'srclang' => true, ), 'tt' => array(), 'u' => array(), 'ul' => array( 'type' => true, ), 'ol' => array( 'start' => true, 'type' => true, 'reversed' => true, ), 'var' => array(), 'video' => array( 'autoplay' => true, 'controls' => true, 'height' => true, 'loop' => true, 'muted' => true, 'poster' => true, 'preload' => true, 'src' => true, 'width' => true, ), ); /** * @var array[] $allowedtags Array of KSES allowed HTML elements. * @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, ), 's' => array(), 'strike' => array(), 'strong' => array(), ); /** * @var string[] $allowedentitynames Array of KSES allowed HTML entitity names. * @since 1.0.0 */ $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 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. * * @see wp_kses_post() for specifically filtering post content and fields. * @see wp_allowed_protocols() for the default allowed protocols in link URLs. * * @since 1.0.0 * * @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'. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Filtered content containing only the allowed HTML. */ 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 ); $string = wp_kses_hook( $string, $allowed_html, $allowed_protocols ); return wp_kses_split( $string, $allowed_html, $allowed_protocols ); } /** * Filters one HTML attribute and ensures its value is allowed. * * This function can escape data in some situations where `wp_kses()` must strip the whole attribute. * * @since 4.2.3 * * @param string $string The 'whole' attribute, including name and value. * @param string $element The HTML element name to which the attribute belongs. * @return string Filtered attribute. */ function wp_kses_one_attr( $string, $element ) { $uris = wp_kses_uri_attributes(); $allowed_html = wp_kses_allowed_html( 'post' ); $allowed_protocols = wp_allowed_protocols(); $string = wp_kses_no_null( $string, array( 'slash_zero' => 'keep' ) ); // Preserve leading and trailing whitespace. $matches = array(); preg_match( '/^\s*/', $string, $matches ); $lead = $matches[0]; preg_match( '/\s*$/', $string, $matches ); $trail = $matches[0]; if ( empty( $trail ) ) { $string = substr( $string, strlen( $lead ) ); } else { $string = substr( $string, strlen( $lead ), -strlen( $trail ) ); } // Parse attribute name and value from input. $split = preg_split( '/\s*=\s*/', $string, 2 ); $name = $split[0]; if ( count( $split ) == 2 ) { $value = $split[1]; // Remove quotes surrounding $value. // Also guarantee correct quoting in $string for this one attribute. if ( '' == $value ) { $quote = ''; } else { $quote = $value[0]; } if ( '"' == $quote || "'" == $quote ) { if ( substr( $value, -1 ) != $quote ) { return ''; } $value = substr( $value, 1, -1 ); } else { $quote = '"'; } // Sanitize quotes, angle braces, and entities. $value = esc_attr( $value ); // Sanitize URI values. if ( in_array( strtolower( $name ), $uris ) ) { $value = wp_kses_bad_protocol( $value, $allowed_protocols ); } $string = "$name=$quote$value$quote"; $vless = 'n'; } else { $value = ''; $vless = 'y'; } // Sanitize attribute by name. wp_kses_attr_check( $name, $value, $string, $vless, $element, $allowed_html ); // Restore whitespace. return $lead . $string . $trail; } /** * Returns an array of allowed HTML tags and attributes for a given context. * * @since 3.5.0 * * @global array $allowedposttags * @global array $allowedtags * @global array $allowedentitynames * * @param string|array $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 Array of allowed HTML tags and their allowed attributes. */ function wp_kses_allowed_html( $context = '' ) { global $allowedposttags, $allowedtags, $allowedentitynames; if ( is_array( $context ) ) { /** * Filters the HTML that is allowed for a given context. * * @since 3.5.0 * * @param array[]|string $context Context to judge allowed tags by. * @param string $context_type Context name. */ 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 ); 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 ); case 'strip': /** This filter is documented in wp-includes/kses.php */ return apply_filters( 'wp_kses_allowed_html', array(), $context ); case 'entities': /** This filter is documented in wp-includes/kses.php */ return apply_filters( 'wp_kses_allowed_html', $allowedentitynames, $context ); 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, {@see 'pre_kses'}, 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[]|string $allowed_html List of allowed HTML elements. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Filtered content through {@see 'pre_kses'} hook. */ function wp_kses_hook( $string, $allowed_html, $allowed_protocols ) { /** * Filters content to be run through kses. * * @since 2.3.0 * * @param string $string Content to run through KSES. * @param array[]|string $allowed_html Allowed HTML elements. * @param string[] $allowed_protocols Array of allowed URL protocols. */ return apply_filters( 'pre_kses', $string, $allowed_html, $allowed_protocols ); } /** * Returns the version number of KSES. * * @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 * * @global array $pass_allowed_html * @global array $pass_allowed_protocols * * @param string $string Content to filter. * @param array $allowed_html Allowed HTML elements. * @param string[] $allowed_protocols Array of allowed URL protocols. * @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 ); } /** * Helper function listing HTML attributes containing 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 array HTML attributes that must include a URL. */ 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', ); /** * Filters the list of attributes that are required to contain a URL. * * Use this filter to add any `data-` attributes that are required to be * validated as a URL. * * @since 5.0.1 * * @param array $uri_attributes HTML attributes requiring validation as a URL. */ $uri_attributes = apply_filters( 'wp_kses_uri_attributes', $uri_attributes ); return $uri_attributes; } /** * Callback for `wp_kses_split()`. * * @since 3.1.0 * @access private * @ignore * * @global array $pass_allowed_html * @global array $pass_allowed_protocols * * @return string */ 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 * @ignore * @since 1.0.0 * * @param string $string Content to filter. * @param array $allowed_html Allowed HTML elements. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Fixed HTML element */ 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 ( '' ), '', $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 $string = preg_replace( '/-$/', '', $string ); return ""; } // It's seriously malformed. if ( ! preg_match( '%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $string, $matches ) ) { return ''; } $slash = trim( $matches[1] ); $elem = $matches[2]; $attrlist = $matches[3]; if ( ! is_array( $allowed_html ) ) { $allowed_html = wp_kses_allowed_html( $allowed_html ); } // 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 ""; } 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 string[] $allowed_protocols Array of allowed URL protocols. * @return string Sanitized HTML element. */ function wp_kses_attr( $element, $attr, $allowed_html, $allowed_protocols ) { if ( ! is_array( $allowed_html ) ) { $allowed_html = wp_kses_allowed_html( $allowed_html ); } // 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 ); // Go through $attrarr, and save the allowed attributes for this element // in $attr2 $attr2 = ''; foreach ( $attrarr as $arreach ) { if ( wp_kses_attr_check( $arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html ) ) { $attr2 .= ' ' . $arreach['whole']; } } // Remove any "<" or ">" characters $attr2 = preg_replace( '/[<>]/', '', $attr2 ); return "<$element$attr2$xhtml_slash>"; } /** * Determines whether an attribute is allowed. * * @since 4.2.3 * @since 5.0.0 Add support for `data-*` wildcard attributes. * * @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 $allowed_html The full list of allowed elements and attributes. * @return bool Whether or not the attribute is allowed. */ function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowed_html ) { $allowed_attr = $allowed_html[ strtolower( $element ) ]; $name_low = strtolower( $name ); 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; } /** * 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 string[] $allowed_protocols Array of allowed URL protocols. * @return array[] Array of attribute information after parsing. */ 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:]+)/', $attr, $match ) ) { $attrname = $match[1]; $working = $mode = 1; $attr = preg_replace( '/^[-a-zA-Z:]+/', '', $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 ) ) { $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; } /** * Finds all attributes of an HTML element. * * Does not modify input. May return "evil" output. * * Based on `wp_kses_split2()` and `wp_kses_attr()`. * * @since 4.2.3 * * @param string $element HTML element. * @return array|bool List of attributes found in the element. Returns false on failure. */ function wp_kses_attr_parse( $element ) { $valid = preg_match( '%^(<\s*)(/\s*)?([a-zA-Z0-9]+\s*)([^>]*)(>?)$%', $element, $matches ); if ( 1 !== $valid ) { return false; } $begin = $matches[1]; $slash = $matches[2]; $elname = $matches[3]; $attr = $matches[4]; $end = $matches[5]; if ( '' !== $slash ) { // Closing elements do not get parsed. return false; } // Is there a closing XHTML slash at the end of the attributes? if ( 1 === preg_match( '%\s*/\s*$%', $attr, $matches ) ) { $xhtml_slash = $matches[0]; $attr = substr( $attr, 0, -strlen( $xhtml_slash ) ); } else { $xhtml_slash = ''; } // Split it $attrarr = wp_kses_hair_parse( $attr ); if ( false === $attrarr ) { return false; } // Make sure all input is returned by adding front and back matter. array_unshift( $attrarr, $begin . $slash . $elname ); array_push( $attrarr, $xhtml_slash . $end ); return $attrarr; } /** * Builds an attribute list from string containing attributes. * * Does not modify input. May return "evil" output. * In case of unexpected input, returns false instead of stripping things. * * Based on `wp_kses_hair()` but does not return a multi-dimensional array. * * @since 4.2.3 * * @param string $attr Attribute list from HTML element to closing HTML element tag. * @return array|bool List of attributes found in $attr. Returns false on failure. */ function wp_kses_hair_parse( $attr ) { if ( '' === $attr ) { return array(); } // phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation $regex = '(?:' . '[-a-zA-Z:]+' // Attribute name. . '|' . '\[\[?[^\[\]]+\]\]?' // Shortcode in the name position implies unfiltered_html. . ')' . '(?:' // Attribute value. . '\s*=\s*' // All values begin with '=' . '(?:' . '"[^"]*"' // Double-quoted . '|' . "'[^']*'" // Single-quoted . '|' . '[^\s"\']+' // Non-quoted . '(?:\s|$)' // Must have a space . ')' . '|' . '(?:\s|$)' // If attribute has no value, space is required. . ')' . '\s*'; // Trailing space is optional except as mentioned above. // phpcs:enable // Although it is possible to reduce this procedure to a single regexp, // we must run that regexp twice to get exactly the expected result. $validation = "%^($regex)+$%"; $extraction = "%$regex%"; if ( 1 === preg_match( $validation, $attr ) ) { preg_match_all( $extraction, $attr, $attrarr ); return $attrarr[0]; } else { return false; } } /** * 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 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. */ 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 ``) or not (``). 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; } // switch return $ok; } /** * 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)`. * * @since 1.0.0 * * @param string $string Content to filter bad protocols from. * @param string[] $allowed_protocols Array of allowed URL protocols. * @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 a text string. * * Also removes any instance of the `\0` string. * * @since 1.0.0 * * @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. */ 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; } /** * 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. * * @since 1.0.0 * * @param string $string String to strip slashes from. * @return string Fixed string with quoted slashes. */ function wp_kses_stripslashes( $string ) { return preg_replace( '%\\\\"%', '"', $string ); } /** * Converts the keys of an array to lowercase. * * @since 1.0.0 * * @param array $inarray Unfiltered array. * @return array Fixed array with all lowercase keys. */ function wp_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; } } return $outarray; } /** * 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. * * @since 1.0.0 * * @param string $string * @return string */ function wp_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 the string, while * handling whitespace and HTML entities. * * @since 1.0.0 * * @param string $string Content to check for bad protocols. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Sanitized content. */ function wp_kses_bad_protocol_once( $string, $allowed_protocols, $count = 1 ) { $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 * whitelist or not, and returns different data depending on the answer. * * @access private * @ignore * @since 1.0.0 * * @param string $string URI scheme to check against the whitelist. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Sanitized content. */ 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 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. * * @since 1.0.0 * * @param string $string Content to normalize entities. * @return string Content with normalized entities. */ function wp_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}[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 HTML and XML validators. * * @since 3.0.0 * * @global array $allowedentitynames * * @param array $matches preg_replace_callback() matches array. * @return string Correctly encoded entity. */ function wp_kses_named_entities( $matches ) { global $allowedentitynames; if ( empty( $matches[1] ) ) { return ''; } $i = $matches[1]; return ( ! in_array( $i, $allowedentitynames ) ) ? "&$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 * @ignore * @since 1.0.0 * * @param array $matches `preg_replace_callback()` matches array. * @return string Correctly encoded entity. */ 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. * * @since 2.7.0 * @access private * @ignore * * @param array $matches `preg_replace_callback()` matches array. * @return string Correctly encoded entity. */ 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' ) . ';'; } /** * Determines if a Unicode codepoint is valid. * * @since 2.7.0 * * @param int $i Unicode codepoint. * @return bool Whether or not the codepoint is a valid Unicode codepoint. */ function valid_unicode( $i ) { return ( $i == 0x9 || $i == 0xa || $i == 0xd || ( $i >= 0x20 && $i <= 0xd7ff ) || ( $i >= 0xe000 && $i <= 0xfffd ) || ( $i >= 0x10000 && $i <= 0x10ffff ) ); } /** * 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 URL protocol whitelisting system anyway. * * @since 1.0.0 * * @param string $string Content to change entities. * @return string Content after decoded 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()`. * * @since 2.9.0 * @access private * @ignore * * @param array $match preg match * @return string */ function _wp_kses_decode_entities_chr( $match ) { return chr( $match[1] ); } /** * Regex callback for `wp_kses_decode_entities()`. * * @since 2.9.0 * @access private * @ignore * * @param array $match preg match * @return string */ function _wp_kses_decode_entities_chr_hexdec( $match ) { return chr( hexdec( $match[1] ) ); } /** * Sanitize content with allowed HTML KSES rules. * * This function expects slashed data. * * @since 1.0.0 * * @param string $data Content to filter, expected to be escaped with slashes. * @return string Filtered content. */ function wp_filter_kses( $data ) { return addslashes( wp_kses( stripslashes( $data ), current_filter() ) ); } /** * Sanitize content with allowed HTML KSES rules. * * This function expects unslashed data. * * @since 2.9.0 * * @param string $data Content to filter, expected to not be escaped. * @return string Filtered content. */ function wp_kses_data( $data ) { return wp_kses( $data, current_filter() ); } /** * Sanitizes content for allowed HTML tags for post content. * * Post content refers to the page contents of the 'post' type and not `$_POST` * data from forms. * * This function expects slashed data. * * @since 2.0.0 * * @param string $data Post content to filter, expected to be escaped with slashes. * @return string Filtered post content with allowed HTML tags and attributes intact. */ function wp_filter_post_kses( $data ) { return addslashes( wp_kses( stripslashes( $data ), 'post' ) ); } /** * Sanitizes content for allowed HTML tags for post content. * * Post content refers to the page contents of the 'post' type and not `$_POST` * data from forms. * * This function expects unslashed data. * * @since 2.9.0 * * @param string $data Post content to filter. * @return string Filtered post content with allowed HTML tags and attributes intact. */ function wp_kses_post( $data ) { return wp_kses( $data, 'post' ); } /** * Navigates through an array, object, or scalar, and sanitizes content for * allowed HTML tags for post content. * * @since 4.4.2 * * @see map_deep() * * @param mixed $data The array, object, or scalar value to inspect. * @return mixed The filtered content. */ function wp_kses_post_deep( $data ) { return map_deep( $data, 'wp_kses_post' ); } /** * Strips all HTML from a text string. * * This function expects slashed data. * * @since 2.1.0 * * @param string $data Content to strip all HTML from. * @return string Filtered content without any HTML. */ function wp_filter_nohtml_kses( $data ) { return addslashes( wp_kses( stripslashes( $data ), 'strip' ) ); } /** * Adds all KSES input form content filters. * * All hooks have default priority. The `wp_filter_kses()` function is added to * the 'pre_comment_content' and 'title_save_pre' hooks. * * The `wp_filter_post_kses()` function is added to the 'content_save_pre', * 'excerpt_save_pre', and 'content_filtered_save_pre' hooks. * * @since 2.0.0 */ function kses_init_filters() { // Normal filtering add_filter( 'title_save_pre', 'wp_filter_kses' ); // Comment filtering if ( current_user_can( 'unfiltered_html' ) ) { add_filter( 'pre_comment_content', 'wp_filter_post_kses' ); } else { add_filter( 'pre_comment_content', 'wp_filter_kses' ); } // Post filtering add_filter( 'content_save_pre', 'wp_filter_post_kses' ); add_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); add_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); } /** * Removes all KSES input form content filters. * * A quick procedural method to removing all of the filters that KSES uses for * content in WordPress Loop. * * Does not remove the `kses_init()` function from {@see 'init'} hook (priority is * default). Also does not remove `kses_init()` function from {@see 'set_current_user'} * hook (priority is also default). * * @since 2.0.6 */ function kses_remove_filters() { // Normal filtering remove_filter( 'title_save_pre', 'wp_filter_kses' ); // Comment filtering remove_filter( 'pre_comment_content', 'wp_filter_post_kses' ); remove_filter( 'pre_comment_content', 'wp_filter_kses' ); // Post filtering remove_filter( 'content_save_pre', 'wp_filter_post_kses' ); remove_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); remove_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); } /** * Sets up most of the KSES filters for input form content. * * First removes all of the KSES filters in case the current user does not need * to have KSES filter the content. If the user does not have `unfiltered_html` * capability, then KSES filters are added. * * @since 2.0.0 */ function kses_init() { kses_remove_filters(); if ( ! current_user_can( 'unfiltered_html' ) ) { kses_init_filters(); } } /** * Filters an inline style attribute and removes disallowed rules. * * @since 2.8.1 * * @param string $css A string of CSS rules. * @param string $deprecated Not used. * @return string Filtered string of CSS rules. */ function safecss_filter_attr( $css, $deprecated = '' ) { if ( ! empty( $deprecated ) ) { _deprecated_argument( __FUNCTION__, '2.8.1' ); // Never implemented } $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 list of allowed CSS attributes. * * @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 `text-transform`. * @since 5.0.0 Added support for `background-image`. * * @param string[] $attr Array of allowed CSS attributes. */ $allowed_attr = apply_filters( 'safe_style_css', array( 'background', 'background-color', 'background-image', 'border', 'border-width', 'border-color', 'border-style', 'border-right', 'border-right-color', 'border-right-style', 'border-right-width', 'border-bottom', 'border-bottom-color', 'border-bottom-style', 'border-bottom-width', 'border-left', 'border-left-color', 'border-left-style', 'border-left-width', 'border-top', 'border-top-color', 'border-top-style', 'border-top-width', 'border-spacing', 'border-collapse', 'caption-side', 'color', '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', 'clear', 'cursor', 'direction', 'float', 'overflow', 'vertical-align', 'list-style-type', ) ); /* * 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', ); 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; 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 ); } } 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 ) || $url !== wp_kses_bad_protocol( $url, $allowed_protocols ) ) { $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 ); } } } // Remove any CSS containing containing \ ( & } = or comments, except for url() useage checked above. if ( $found && ! preg_match( '%[\\\(&=}]|/\*%', $css_test_string ) ) { if ( $css != '' ) { $css .= ';'; } $css .= $css_item; } } return $css; } /** * Helper function to add global attributes to a tag in the allowed html list. * * @since 3.5.0 * @since 5.0.0 Add support for `data-*` wildcard attributes. * @access private * @ignore * * @param array $value An array of attributes. * @return array The array of attributes with global attributes added. */ function _wp_add_global_attributes( $value ) { $global_attributes = array( 'aria-describedby' => true, 'aria-details' => true, 'aria-label' => true, 'aria-labelledby' => true, 'aria-hidden' => true, 'class' => true, 'id' => true, 'style' => true, 'title' => true, 'role' => true, 'data-*' => true, ); if ( true === $value ) { $value = array(); } if ( is_array( $value ) ) { return array_merge( $value, $global_attributes ); } return $value; }