JezK
Edit File: kses.php
<?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 */ /** * 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. * * When using this constant, make sure to set all of these globals to arrays: * * - `$allowedposttags` * - `$allowedtags` * - `$allowedentitynames` * - `$allowedxmlentitynames` * * @see wp_kses_allowed_html() * @since 1.2.0 * * @var array[]|false 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, $allowedxmlentitynames; 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, ), 'aside' => array( 'align' => true, ), 'audio' => array( 'autoplay' => true, 'controls' => true, 'loop' => true, 'muted' => true, 'preload' => true, 'src' => true, ), 'b' => array(), 'bdo' => array(), 'big' => array(), 'blockquote' => array( 'cite' => true, ), 'br' => array(), 'button' => array( 'command' => true, 'commandfor' => true, 'disabled' => true, 'name' => true, 'type' => true, 'value' => true, 'popovertarget' => true, 'popovertargetaction' => true, 'aria-haspopup' => true, ), 'caption' => array( 'align' => true, ), 'cite' => array(), 'code' => array(), 'col' => array( 'align' => true, 'char' => true, 'charoff' => true, 'span' => true, 'valign' => true, 'width' => true, ), 'colgroup' => array( 'align' => true, 'char' => true, 'charoff' => true, 'span' => true, 'valign' => true, 'width' => true, ), 'data' => array( 'value' => true, ), 'del' => array( 'datetime' => true, ), 'dd' => array(), 'dfn' => array(), 'details' => array( 'align' => true, 'open' => true, 'name' => true, ), 'div' => array( 'align' => true, 'popover' => true, ), 'dialog' => array( 'closedby' => true, 'open' => true, 'popover' => true, 'autofocus' => true, ), 'dl' => array(), 'dt' => array(), 'em' => array(), 'fieldset' => array(), 'figure' => array( 'align' => true, ), 'figcaption' => array( 'align' => true, ), 'font' => array( 'color' => true, 'face' => true, 'size' => true, ), 'footer' => array( 'align' => 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, ), 'hgroup' => array( 'align' => 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, 'loading' => 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, ), 'main' => array( 'align' => true, ), 'map' => array( 'name' => true, ), 'mark' => array(), 'menu' => array( 'type' => true, ), 'meter' => array( 'high' => true, 'low' => true, 'max' => true, 'min' => true, 'optimum' => true, 'value' => true, ), 'nav' => array( 'align' => true, ), 'object' => array( 'data' => array( 'required' => true, 'value_callback' => '_wp_kses_allow_pdf_objects', ), 'type' => array( 'required' => true, 'values' => array( 'application/pdf' ), ), ), 'p' => array( 'align' => true, ), 'pre' => array( 'width' => true, ), 'progress' => array( 'max' => true, 'value' => true, ), 'q' => array( 'cite' => true, ), 'rb' => array(), 'rp' => array(), 'rt' => array(), 'rtc' => array(), 'ruby' => array(), 's' => array(), 'samp' => array(), 'search' => array(), 'span' => array( 'align' => true, ), 'section' => array( 'align' => true, ), 'small' => array(), 'strike' => array(), 'strong' => array(), 'sub' => array(), 'summary' => array( 'align' => true, ), 'sup' => array(), 'table' => array( 'align' => true, 'bgcolor' => true, 'border' => true, 'cellpadding' => true, 'cellspacing' => 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, '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, ), 'time' => array( 'datetime' => 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, 'popover' => true, 'role' => true, ), 'ol' => array( 'start' => true, 'type' => true, 'reversed' => true, ), 'var' => array(), 'video' => array( 'autoplay' => true, 'controls' => true, 'height' => true, 'loop' => true, 'muted' => true, 'playsinline' => true, 'poster' => true, 'preload' => true, 'src' => true, 'width' => true, ), 'wbr' => array(), ); // https://www.w3.org/TR/mathml-core/#global-attributes // Except common attributes added by _wp_add_global_attributes. $math_global_attributes = array( 'displaystyle' => true, 'scriptlevel' => true, 'mathbackground' => true, 'mathcolor' => true, 'mathsize' => true, // Common attributes also defined by _wp_add_global_attributes. // We do not want to add all those global attributes though. 'class' => true, 'data-*' => true, 'dir' => true, 'id' => true, 'style' => true, ); $math_overunder_attributes = array( 'accentunder' => true, 'accent' => true, ); $allowedposttags = array_merge( $allowedposttags, array( // https://www.w3.org/TR/mathml-core/#the-top-level-math-element 'math' => array_merge( $math_global_attributes, array( 'display' => true, ) ), // https://www.w3.org/TR/mathml-core/#token-elements // https://www.w3.org/TR/mathml-core/#text-mtext 'mtext' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#the-mi-element 'mi' => array_merge( $math_global_attributes, array( 'mathvariant' => true, ) ), // https://www.w3.org/TR/mathml-core/#number-mn 'mn' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#operator-fence-separator-or-accent-mo 'mo' => array_merge( $math_global_attributes, array( 'form' => true, 'fence' => true, 'separator' => true, 'lspace' => true, 'rspace' => true, 'stretchy' => true, 'symmetric' => true, 'maxsize' => true, 'minsize' => true, 'largeop' => true, 'movablelimits' => true, ) ), // https://www.w3.org/TR/mathml-core/#space-mspace 'mspace' => array_merge( $math_global_attributes, array( 'width' => true, 'height' => true, 'depth' => true, ) ), // https://www.w3.org/TR/mathml-core/#string-literal-ms 'ms' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#general-layout-schemata // https://www.w3.org/TR/mathml-core/#horizontally-group-sub-expressions-mrow 'mrow' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#fractions-mfrac 'mfrac' => array_merge( $math_global_attributes, array( 'linethickness' => true, ) ), // https://www.w3.org/TR/mathml-core/#radicals-msqrt-mroot 'msqrt' => $math_global_attributes, 'mroot' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#style-change-mstyle 'mstyle' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#error-message-merror 'merror' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#adjust-space-around-content-mpadded 'mpadded' => array_merge( $math_global_attributes, array( 'width' => true, 'height' => true, 'depth' => true, 'lspace' => true, 'voffset' => true, ) ), // https://www.w3.org/TR/mathml-core/#making-sub-expressions-invisible-mphantom 'mphantom' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#script-and-limit-schemata // https://www.w3.org/TR/mathml-core/#subscripts-and-superscripts-msub-msup-msubsup 'msub' => $math_global_attributes, 'msup' => $math_global_attributes, 'msubsup' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#underscripts-and-overscripts-munder-mover-munderover 'munder' => array_merge( $math_global_attributes, $math_overunder_attributes ), 'mover' => array_merge( $math_global_attributes, $math_overunder_attributes ), 'munderover' => array_merge( $math_global_attributes, $math_overunder_attributes ), // https://www.w3.org/TR/mathml-core/#prescripts-and-tensor-indices-mmultiscripts 'mmultiscripts' => $math_global_attributes, 'mprescripts' => $math_global_attributes, // https://www.w3.org/TR/mathml-core/#tabular-math // https://www.w3.org/TR/mathml-core/#table-or-matrix-mtable 'mtable' => array_merge( $math_global_attributes, array( // Non-standard, used by temml/katex. // https://developer.mozilla.org/en-US/docs/Web/MathML/Reference/Element/mtable 'columnalign' => true, 'rowspacing' => true, 'columnspacing' => true, 'align' => true, 'rowalign' => true, 'columnlines' => true, 'rowlines' => true, 'frame' => true, 'framespacing' => true, 'width' => true, ) ), // https://www.w3.org/TR/mathml-core/#row-in-table-or-matrix-mtr 'mtr' => array_merge( $math_global_attributes, array( // Non-standard, used by temml/katex. // https://developer.mozilla.org/en-US/docs/Web/MathML/Reference/Element/mtr 'columnalign' => true, 'rowalign' => true, ) ), // https://www.w3.org/TR/mathml-core/#entry-in-table-or-matrix-mtd 'mtd' => array_merge( $math_global_attributes, array( 'columnspan' => true, 'rowspan' => true, // Non-standard, used by temml/katex. // https://developer.mozilla.org/en-US/docs/Web/MathML/Reference/Element/mtd 'columnalign' => true, 'rowalign' => true, ) ), // https://www.w3.org/TR/mathml-core/#semantics-and-presentation 'semantics' => $math_global_attributes, 'annotation' => array_merge( $math_global_attributes, array( 'encoding' => true, ) ), // Non-standard but widely supported, used by temml/katex. 'menclose' => array_merge( $math_global_attributes, array( 'notation' => 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 entity 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', ); /** * @var string[] $allowedxmlentitynames Array of KSES allowed XML entity names. * @since 5.5.0 */ $allowedxmlentitynames = array( 'amp', 'lt', 'gt', 'apos', 'quot', ); $allowedposttags = array_map( '_wp_add_global_attributes', $allowedposttags ); } else { $required_kses_globals = array( 'allowedposttags', 'allowedtags', 'allowedentitynames', 'allowedxmlentitynames', ); $missing_kses_globals = array(); foreach ( $required_kses_globals as $global_name ) { if ( ! isset( $GLOBALS[ $global_name ] ) || ! is_array( $GLOBALS[ $global_name ] ) ) { $missing_kses_globals[] = '<code>$' . $global_name . '</code>'; } } if ( $missing_kses_globals ) { _doing_it_wrong( 'wp_kses_allowed_html', sprintf( /* translators: 1: CUSTOM_TAGS, 2: Global variable names. */ __( 'When using the %1$s constant, make sure to set these globals to an array: %2$s.' ), '<code>CUSTOM_TAGS</code>', implode( ', ', $missing_kses_globals ) ), '6.2.0' ); } $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 $content 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 Optional. Array of allowed URL protocols. * Defaults to the result of wp_allowed_protocols(). * @return string Filtered content containing only the allowed HTML. */ function wp_kses( $content, $allowed_html, $allowed_protocols = array() ) { if ( empty( $allowed_protocols ) ) { $allowed_protocols = wp_allowed_protocols(); } $content = wp_kses_no_null( $content, array( 'slash_zero' => 'keep' ) ); $content = wp_kses_normalize_entities( $content ); $content = wp_kses_hook( $content, $allowed_html, $allowed_protocols ); return wp_kses_split( $content, $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 $attr 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( $attr, $element ) { $uris = wp_kses_uri_attributes(); $allowed_html = wp_kses_allowed_html( 'post' ); $allowed_protocols = wp_allowed_protocols(); $attr = wp_kses_no_null( $attr, array( 'slash_zero' => 'keep' ) ); // Preserve leading and trailing whitespace. $matches = array(); preg_match( '/^\s*/', $attr, $matches ); $lead = $matches[0]; preg_match( '/\s*$/', $attr, $matches ); $trail = $matches[0]; if ( empty( $trail ) ) { $attr = substr( $attr, strlen( $lead ) ); } else { $attr = substr( $attr, strlen( $lead ), -strlen( $trail ) ); } // Parse attribute name and value from input. $split = preg_split( '/\s*=\s*/', $attr, 2 ); $name = $split[0]; if ( count( $split ) === 2 ) { $value = $split[1]; /* * Remove quotes surrounding $value. * Also guarantee correct quoting in $attr for this one attribute. */ if ( '' === $value ) { $quote = ''; } else { $quote = $value[0]; } if ( '"' === $quote || "'" === $quote ) { if ( ! str_ends_with( $value, $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, true ) ) { $value = wp_kses_bad_protocol( $value, $allowed_protocols ); } $attr = "$name=$quote$value$quote"; $vless = 'n'; } else { $value = ''; $vless = 'y'; } // Sanitize attribute by name. wp_kses_attr_check( $name, $value, $attr, $vless, $element, $allowed_html ); // Restore whitespace. return $lead . $attr . $trail; } /** * Returns an array of allowed HTML tags and attributes for a given context. * * @since 3.5.0 * @since 5.0.1 `form` removed as allowable HTML tag. * * @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', or an array of allowed HTML elements and attributes. * @return array Array of allowed HTML tags and their allowed attributes. */ function wp_kses_allowed_html( $context = '' ) { global $allowedposttags, $allowedtags, $allowedentitynames; if ( is_array( $context ) ) { // When `$context` is an array it's actually an array of allowed HTML elements and attributes. $html = $context; $context = 'explicit'; /** * Filters the HTML tags that are allowed for a given context. * * HTML tags and attribute names are case-insensitive in HTML but must be * added to the KSES allow list in lowercase. An item added to the allow list * in upper or mixed case will not recognized as permitted by KSES. * * @since 3.5.0 * * @param array[] $html Allowed HTML tags. * @param string $context Context name. */ return apply_filters( 'wp_kses_allowed_html', $html, $context ); } switch ( $context ) { case 'post': /** This filter is documented in wp-includes/kses.php */ $tags = apply_filters( 'wp_kses_allowed_html', $allowedposttags, $context ); // 5.0.1 removed the `<form>` tag, allow it if a filter is allowing it's sub-elements `<input>` or `<select>`. if ( ! CUSTOM_TAGS && ! isset( $tags['form'] ) && ( isset( $tags['input'] ) || isset( $tags['select'] ) ) ) { $tags = $allowedposttags; $tags['form'] = array( 'action' => true, 'accept' => true, 'accept-charset' => true, 'enctype' => true, 'method' => true, 'name' => true, 'target' => true, ); /** This filter is documented in wp-includes/kses.php */ $tags = apply_filters( 'wp_kses_allowed_html', $tags, $context ); } return $tags; case 'user_description': case 'pre_term_description': case 'pre_user_description': $tags = $allowedtags; $tags['a']['rel'] = true; $tags['a']['target'] = 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 ); } } /** * Allows the note mention chip markup in comment content. * * The notes `@` mention completer stores a mention as a chip carrying the * mentioned user's ID in a class token: * `<span class="wp-note-mention user-N">@Name</span>`. The default comment * allowlist does not allow `span` at all, so for users without * `unfiltered_html` the mention would be stripped on save. * * The allowance is deliberately narrow and always on: `span` is a * semantics-free element and _wp_kses_sanitize_note_mention_classes() * reduces its `class` to the two mention tokens right after kses runs, so * regular (including anonymous) commenters gain nothing beyond the inert * mention markup itself. * * @since 7.1.0 * @access private * * @param array<string, array<string, bool>> $allowed The allowed tags structure for the context. * @param string $context The kses context. * @return array<string, array<string, bool>> Modified allowed tags structure. */ function _wp_kses_allow_note_mention_span( $allowed, $context ): array { if ( ! is_array( $allowed ) ) { $allowed = array(); } if ( 'pre_comment_content' !== $context ) { return $allowed; } if ( ! isset( $allowed['span'] ) || ! is_array( $allowed['span'] ) ) { $allowed['span'] = array(); } $allowed['span']['class'] = true; return $allowed; } /** * Reduces `span` classes in comment content to the note mention tokens. * * _wp_kses_allow_note_mention_span() lets `class` through kses on `span` so * the mention chip survives, but `class` is an open-ended styling and * scripting hook, so this companion pass - running right after * `wp_filter_kses` at priority 10 - strips every class token except the two * the mention markup uses: `wp-note-mention` and `user-N`. `span` is the only * comment tag allowed to carry `class` at all, so walking `span` tags covers * the entire allowance. * * The pass only applies while the restrictive comment allowlist is active: * users with `unfiltered_html` are filtered through `wp_filter_post_kses` * (or not at all), where arbitrary classes are already permitted, and * narrowing their markup here would restrict what core allows them to post. * * @since 7.1.0 * @access private * * @param string $content Slashed comment content, already filtered by kses. * @return string Slashed comment content with span classes reduced. */ function _wp_kses_sanitize_note_mention_classes( $content ): string { if ( ! is_string( $content ) ) { $content = ''; } if ( false === has_filter( 'pre_comment_content', 'wp_filter_kses' ) ) { return $content; } $processor = new WP_HTML_Tag_Processor( wp_unslash( $content ) ); while ( $processor->next_tag( 'SPAN' ) ) { foreach ( $processor->class_list() as $token ) { if ( 'wp-note-mention' !== $token && ! preg_match( '/^user-[1-9][0-9]*$/', $token ) ) { // Removing the last class also removes the attribute itself. $processor->remove_class( $token ); } } } return wp_slash( $processor->get_updated_html() ); } /** * 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 $content Content to filter through KSES. * @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 through {@see 'pre_kses'} hook. */ function wp_kses_hook( $content, $allowed_html, $allowed_protocols ) { /** * Filters content to be run through KSES. * * @since 2.3.0 * * @param string $content Content to filter through KSES. * @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 apply_filters( 'pre_kses', $content, $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 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. * * @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. * * @param string $content 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 */ function wp_kses_split( $content, $allowed_html, $allowed_protocols ) { global $pass_allowed_html, $pass_allowed_protocols; $pass_allowed_html = $allowed_html; $pass_allowed_protocols = $allowed_protocols; $token_pattern = <<<REGEX ~ ( # Detect comments of various flavors before attempting to find tags. (<!--.*?(-->|$)) # - Normative HTML comments. | </[^a-zA-Z][^>]*> # - Closing tags with invalid tag names. | <![^>]*> # - Invalid markup declaration nodes. Not all invalid nodes # are matched so as to avoid breaking legacy behaviors. ) | (<[^>]*(>|$)|>) # Tag-like spans of text. ~x REGEX; return preg_replace_callback( $token_pattern, '_wp_kses_split_callback', $content ); } /** * 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. */ 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 string[] $uri_attributes HTML attribute names whose value contains 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[]|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. * * @param array $matches preg_replace regexp matches * @return string */ function _wp_kses_split_callback( $matches ) { global $pass_allowed_html, $pass_allowed_protocols; return wp_kses_split2( $matches[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 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. * * @param string $content 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 */ function wp_kses_split2( $content, $allowed_html, $allowed_protocols ) { $content = wp_kses_stripslashes( $content ); /* * The regex pattern used to split HTML into chunks attempts * to split on HTML token boundaries. This function should * thus receive chunks that _either_ start with meaningful * syntax tokens, like a tag `<div>` or a comment `<!-- ... -->`. * * If the first character of the `$content` chunk _isn't_ one * of these syntax elements, which always starts with `<`, then * the match had to be for the final alternation of `>`. In such * case, it's probably standing on its own and could be encoded * with a character reference to remove ambiguity. * * In other words, if this chunk isn't from a match of a syntax * token, it's just a plaintext greater-than (`>`) sign. */ if ( ! str_starts_with( $content, '<' ) ) { return '>'; } /* * When certain invalid syntax constructs appear, the HTML parser * shifts into what's called the "bogus comment state." This is a * plaintext state that consumes everything until the nearest `>` * and then transforms the entire span into an HTML comment. * * Preserve these comments and do not treat them like tags. * * @see https://html.spec.whatwg.org/#bogus-comment-state */ if ( 1 === preg_match( '~^(?:</[^a-zA-Z][^>]*>|<![a-z][^>]*>)$~', $content ) ) { /** * Since the pattern matches `</…>` and also `<!…>`, this will * preserve the type of the cleaned-up token in the output. */ $opener = $content[1]; $content = substr( $content, 2, -1 ); do { $prev = $content; $content = wp_kses( $content, $allowed_html, $allowed_protocols ); } while ( $prev !== $content ); // Recombine the modified inner content with the original token structure. return "<{$opener}{$content}>"; } /* * Normative HTML comments should be handled separately as their * parsing rules differ from those for tags and text nodes. */ if ( str_starts_with( $content, '<!--' ) ) { $content = str_replace( array( '<!--', '-->' ), '', $content ); while ( ( $newstring = wp_kses( $content, $allowed_html, $allowed_protocols ) ) !== $content ) { $content = $newstring; } if ( '' === $content ) { return ''; } // Prevent multiple dashes in comments. $content = preg_replace( '/--+/', '-', $content ); // Prevent three dashes closing a comment. $content = preg_replace( '/-$/', '', $content ); return "<!--{$content}-->"; } // It's seriously malformed. if ( ! preg_match( '%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $content, $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 ( '' !== $slash ) { return "</$elem>"; } 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 `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. * * @since 1.0.0 * @since 5.9.0 Added support for an array of allowed values for attributes. * Added support for required attributes. * * @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. */ 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 ); // Check if there are attributes that are required. $required_attrs = array_filter( $allowed_html[ $element_low ], static 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>"; } /** * Determines whether an attribute is allowed. * * @since 4.2.3 * @since 5.0.0 Added 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 ) { $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. */ if ( str_starts_with( $name_low, 'data-' ) && ! 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 ) { $decoded_value = WP_HTML_Decoder::decode_attribute( $value ); $new_value = safecss_filter_attr( $decoded_value ); if ( empty( $new_value ) ) { $name = ''; $value = ''; $whole = ''; return false; } if ( $new_value !== $decoded_value ) { $encoded_value = esc_attr( $new_value ); $whole = str_replace( $value, $encoded_value, $whole ); $value = $encoded_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; } /** * Given a string of HTML attributes and values, parse into a structured attribute list. * * This function performs a number of transformations while parsing attribute strings: * - It normalizes attribute values and surrounds them with double quotes. * - It normalizes HTML character references inside attribute values. * - It removes “bad” URL protocols from attribute values. * * Otherwise this reads the attributes as if they were part of an HTML tag. It performs * these transformations to lower the risk of mis-parsing down the line and to perform * URL sanitization in line with the rest of the `kses` subsystem. Importantly, it does * not decode the attribute values, meaning that special HTML syntax characters will * be left with character references in the `value` property. * * Example: * * $attrs = wp_kses_hair( 'class="is-wide" inert data-lazy=\'<img>\' =/🐮=/' ); * $attrs === array( * 'class' => array( 'name' => 'class', 'value' => 'is-wide', 'whole' => 'class="is-wide"', 'vless' => 'n' ), * 'inert' => array( 'name' => 'inert', 'value' => '', 'whole' => 'inert', 'vless' => 'y' ), * 'data-lazy' => array( 'name' => 'data-lazy', 'value' => '<img>', 'whole' => 'data-lazy="<img>"', 'vless' => 'n' ), * '=' => array( 'name' => '=', 'value' => '', 'whole' => '=', 'vless' => 'y' ), * '🐮' => array( 'name' => '🐮', 'value' => '/', 'whole' => '🐮="/"', 'vless' => 'n' ), * ); * * @since 1.0.0 * @since 7.0.0 Reliably parses HTML via the HTML API. * * @param string $attr Attribute list from HTML element to closing HTML element tag. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return array<string, array{name: string, value: string, whole: string, vless: 'y'|'n'}> Array of attribute information after parsing. */ function wp_kses_hair( $attr, $allowed_protocols ) { $attributes = array(); $uris = wp_kses_uri_attributes(); $processor = new WP_HTML_Tag_Processor( "<wp {$attr}>" ); $processor->next_token(); $attribute_names = $processor->get_attribute_names_with_prefix( '' ); if ( null === $attribute_names || 0 === count( $attribute_names ) ) { return $attributes; } $syntax_characters = array( '&' => '&', '<' => '<', '>' => '>', "'" => ''', '"' => '"', ); foreach ( $attribute_names as $name ) { $value = $processor->get_attribute( $name ); $is_bool = true === $value; if ( is_string( $value ) && in_array( $name, $uris, true ) ) { $value = wp_kses_bad_protocol( $value, $allowed_protocols ); } // Reconstruct and normalize the attribute value. $recoded = $is_bool ? '' : strtr( $value, $syntax_characters ); $whole = $is_bool ? $name : "{$name}=\"{$recoded}\""; $attributes[ $name ] = array( 'name' => $name, 'value' => $recoded, 'whole' => $whole, 'vless' => $is_bool ? 'y' : 'n', ); } return $attributes; } /** * 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|false 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|false List of attributes found in $attr. Returns false on failure. */ function wp_kses_hair_parse( $attr ) { if ( '' === $attr ) { return array(); } $regex = '(?: [_a-zA-Z][-_a-zA-Z0-9:.]* # 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. '; /* * Although it is possible to reduce this procedure to a single regexp, * we must run that regexp twice to get exactly the expected result. * * Note: do NOT remove the `x` modifiers as they are essential for the above regex! */ $validation = "/^($regex)+$/x"; $extraction = "/$regex/x"; 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 `<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 ( ! in_array( 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; } /** * 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 $content Content to filter bad protocols from. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Filtered content. */ function wp_kses_bad_protocol( $content, $allowed_protocols ) { $content = wp_kses_no_null( $content ); // Short-circuit if the string starts with `https://` or `http://`. Most common cases. if ( ( str_starts_with( $content, 'https://' ) && in_array( 'https', $allowed_protocols, true ) ) || ( str_starts_with( $content, 'http://' ) && in_array( 'http', $allowed_protocols, true ) ) ) { return $content; } $iterations = 0; do { $original_content = $content; $content = wp_kses_bad_protocol_once( $content, $allowed_protocols ); } while ( $original_content !== $content && ++$iterations < 6 ); if ( $original_content !== $content ) { return ''; } return $content; } /** * Removes any invalid control characters in a text string. * * Also removes any instance of the `\0` string. * * @since 1.0.0 * * @param string $content 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( $content, $options = null ) { if ( ! isset( $options['slash_zero'] ) ) { $options = array( 'slash_zero' => 'remove' ); } $content = preg_replace( '/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content ); if ( 'remove' === $options['slash_zero'] ) { $content = preg_replace( '/\\\\+0+/', '', $content ); } return $content; } /** * 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 $content String to strip slashes from. * @return string Fixed string with quoted slashes. */ function wp_kses_stripslashes( $content ) { return preg_replace( '%\\\\"%', '"', $content ); } /** * 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 $attr * @return string */ function wp_kses_html_error( $attr ) { return preg_replace( '/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $attr ); } /** * 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 $content 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. */ function wp_kses_bad_protocol_once( $content, $allowed_protocols, $count = 1 ) { $content = preg_replace( '/(�*58(?![;0-9])|�*3a(?![;a-f0-9]))/i', '$1;', $content ); $content2 = preg_split( '/:|�*58;|�*3a;|:/i', $content, 2 ); if ( isset( $content2[1] ) && ! preg_match( '%/\?%', $content2[0] ) ) { $content = trim( $content2[1] ); $protocol = wp_kses_bad_protocol_once2( $content2[0], $allowed_protocols ); if ( 'feed:' === $protocol ) { if ( $count > 2 ) { return ''; } $content = wp_kses_bad_protocol_once( $content, $allowed_protocols, ++$count ); if ( empty( $content ) ) { return $content; } } $content = $protocol . $content; } return $content; } /** * 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 * @ignore * @since 1.0.0 * * @param string $scheme URI scheme to check against the list of allowed protocols. * @param string[] $allowed_protocols Array of allowed URL protocols. * @return string Sanitized content. */ function wp_kses_bad_protocol_once2( $scheme, $allowed_protocols ) { $scheme = wp_kses_decode_entities( $scheme ); $scheme = preg_replace( '/\s/', '', $scheme ); $scheme = wp_kses_no_null( $scheme ); $scheme = strtolower( $scheme ); $allowed = array_any( (array) $allowed_protocols, fn( $protocol ) => strtolower( $protocol ) === $scheme ); if ( $allowed ) { return "$scheme:"; } 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. * * When `$context` is set to 'xml', HTML entities are converted to their code points. For * example, `AT&T…&#XYZZY;` is converted to `AT&T…&#XYZZY;`. * * @since 1.0.0 * @since 5.5.0 Added `$context` parameter. * * @param string $content Content to normalize entities. * @param string $context Context for normalization. Can be either 'html' or 'xml'. * Default 'html'. * @return string Content with normalized entities. */ function wp_kses_normalize_entities( $content, $context = 'html' ) { // Disarm all entities by converting & to & $content = str_replace( '&', '&', $content ); /* * Decode any character references that are now double-encoded. * * It's important that the following normalizations happen in the correct order. * * At this point, all `&` have been transformed to `&`. Double-encoded named character * references like `&amp;` will be decoded back to their single-encoded form `&`. * * First, numeric (decimal and hexadecimal) character references must be handled so that * `&#09;` becomes `	`. If the named character references were handled first, there * would be no way to know whether the double-encoded character reference had been produced * in this function or was the original input. * * Consider the two examples, first with named entity decoding followed by numeric * entity decoding. We'll use U+002E FULL STOP (.) in our example, this table follows the * string processing from left to right: * * | Input | &-encoded | Named ref double-decoded | Numeric ref double-decoded | * | ------------ | ---------------- | ------------------------- | -------------------------- | * | `.` | `&#x2E;` | `&#x2E;` | `.` | * | `&#x2E;` | `&amp;#x2E;` | `&#x2E;` | `.` | * * Notice in the example above that different inputs result in the same result. The second case * was not normalized and produced HTML that is semantically different from the input. * * | Input | &-encoded | Numeric ref double-decoded | Named ref double-decoded | * | ------------ | ---------------- | --------------------------- | ------------------------ | * | `.` | `&#x2E;` | `.` | `.` | * | `&#x2E;` | `&amp;#x2E;` | `&amp;#x2E;` | `&#x2E;` | * * Here, each input is normalized to an appropriate output. */ $content = preg_replace_callback( '/&#(0*[1-9][0-9]{0,6});/', 'wp_kses_normalize_entities2', $content ); $content = preg_replace_callback( '/&#[Xx](0*[1-9A-Fa-f][0-9A-Fa-f]{0,5});/', 'wp_kses_normalize_entities3', $content ); if ( 'xml' === $context ) { $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_xml_named_entities', $content ); } else { $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_named_entities', $content ); } return $content; } /** * 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, $allowedentitynames, true ) ) ? "&$i;" : "&$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 XML validators. HTML named entity * references are converted to their code points. * * @since 5.5.0 * * @global array $allowedentitynames * @global array $allowedxmlentitynames * * @param array $matches preg_replace_callback() matches array. * @return string Correctly encoded entity. */ 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 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. * * The definition of a valid Unicode codepoint is taken from the XML definition: * * > Characters * > * > … * > Legal characters are tab, carriage return, line feed, and the legal characters of * > Unicode and ISO/IEC 10646. * > … * > Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] * * @since 2.7.0 * * @see https://www.w3.org/TR/xml/#charsets * * @param int $i Unicode codepoint. * @return bool Whether or not the codepoint is a valid Unicode codepoint. */ function valid_unicode( $i ) { $i = (int) $i; return ( 0x9 === $i || // U+0009 HORIZONTAL TABULATION (HT) 0xA === $i || // U+000A LINE FEED (LF) 0xD === $i || // U+000D CARRIAGE RETURN (CR) /* * The valid Unicode characters according to the XML specification: * * > any Unicode character, excluding the surrogate blocks, FFFE, and FFFF. */ ( 0x20 <= $i && $i <= 0xD7FF ) || ( 0xE000 <= $i && $i <= 0xFFFD ) || ( 0x10000 <= $i && $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 allowed URL protocols system anyway. * * @since 1.0.0 * * @param string $content Content to change entities. * @return string Content after decoded entities. */ function wp_kses_decode_entities( $content ) { $content = preg_replace_callback( '/&#([0-9]+);/', '_wp_kses_decode_entities_chr', $content ); $content = preg_replace_callback( '/&#[Xx]([0-9A-Fa-f]+);/', '_wp_kses_decode_entities_chr_hexdec', $content ); return $content; } /** * Regex callback for `wp_kses_decode_entities()`. * * @since 2.9.0 * @access private * @ignore * * @param array $matches preg match * @return string */ function _wp_kses_decode_entities_chr( $matches ) { return chr( $matches[1] ); } /** * Regex callback for `wp_kses_decode_entities()`. * * @since 2.9.0 * @access private * @ignore * * @param array $matches preg match * @return string */ function _wp_kses_decode_entities_chr_hexdec( $matches ) { return chr( hexdec( $matches[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 global styles user content removing unsafe rules. * * @since 5.9.0 * * @param string $data Post content to filter. * @return string Filtered post content with unsafe rules removed. */ function wp_filter_global_styles_post( $data ) { $decoded_data = json_decode( wp_unslash( $data ), true ); $json_decoding_error = json_last_error(); if ( JSON_ERROR_NONE === $json_decoding_error && is_array( $decoded_data ) && isset( $decoded_data['isGlobalStylesUserThemeJSON'] ) && $decoded_data['isGlobalStylesUserThemeJSON'] ) { unset( $decoded_data['isGlobalStylesUserThemeJSON'] ); $data_to_encode = WP_Theme_JSON::remove_insecure_properties( $decoded_data, 'custom' ); $data_to_encode['isGlobalStylesUserThemeJSON'] = true; /** * JSON encode the data stored in post content. * Escape characters that are likely to be mangled by HTML filters: "<>&". * * This matches the escaping in {@see WP_REST_Global_Styles_Controller::prepare_item_for_database()}. */ return wp_slash( wp_json_encode( $data_to_encode, JSON_UNESCAPED_SLASHES | JSON_HEX_TAG | JSON_HEX_AMP ) ); } return $data; } /** * Sanitizes content for allowed HTML tags for post content. * * Post content refers to the page contents of the 'post' type and not `$_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' ); } // Global Styles filtering: Global Styles filters should be executed before normal post_kses HTML filters. add_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); add_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); // 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' ); // Global Styles filtering. remove_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); remove_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); // 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 * @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. * Extended `background-*` support for 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. * @since 6.1.0 Added support for `min()`, `max()`, `minmax()`, `clamp()`, * nested `var()` values, and assigning values to CSS variables. * Added support for `object-fit`, `gap`, `column-gap`, `row-gap`, and `flex-wrap`. * Extended `margin-*` and `padding-*` support for logical properties. * @since 6.2.0 Added support for `aspect-ratio`, `position`, `top`, `right`, `bottom`, `left`, * and `z-index` CSS properties. * @since 6.3.0 Extended support for `filter` to accept a URL and added support for repeat(). * Added support for `box-shadow`. * @since 6.4.0 Added support for `writing-mode`. * @since 6.5.0 Added support for `background-repeat`. * @since 6.6.0 Added support for `grid-column`, `grid-row`, and `container-type`. * @since 6.9.0 Added support for `white-space`. * @since 7.1.0 Extended gradient support to allow any single-level nested function. * Added support for transform functions, `clip-path` basic shapes, * and URLs in the SVG element reference properties. * * @param string $css A string of CSS rules, decoded from an HTML `style` attribute. * @param string $deprecated Not used. * @return string Filtered string of CSS rules, needing HTML escaping before sending back to a `style` attribute. */ 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(); /** @todo Parse enough CSS to split rules without breaking on things like quoted strings. */ $css_array = explode( ';', trim( $css ) ); /** * Filters the list of allowed CSS attributes. * * @since 2.8.1 * @since 7.1.0 Added support for SVG presentation attributes. * * @param string[] $attr Array of allowed CSS attributes. */ $allowed_attr = apply_filters( 'safe_style_css', array( 'background', 'background-color', 'background-image', 'background-position', 'background-repeat', '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', 'display', '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', 'white-space', 'height', 'min-height', 'max-height', 'width', 'min-width', 'max-width', 'margin', 'margin-right', 'margin-bottom', 'margin-left', 'margin-top', 'margin-block-start', 'margin-block-end', 'margin-inline-start', 'margin-inline-end', 'padding', 'padding-right', 'padding-bottom', 'padding-left', 'padding-top', 'padding-block-start', 'padding-block-end', 'padding-inline-start', 'padding-inline-end', 'flex', 'flex-basis', 'flex-direction', 'flex-flow', 'flex-grow', 'flex-shrink', 'flex-wrap', 'gap', 'column-gap', 'row-gap', 'grid-template-columns', 'grid-auto-columns', 'grid-column-start', 'grid-column-end', 'grid-column', 'grid-column-gap', 'grid-template-rows', 'grid-auto-rows', 'grid-row-start', 'grid-row-end', 'grid-row', '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-fit', 'object-position', 'opacity', 'overflow', 'vertical-align', 'writing-mode', 'position', 'top', 'right', 'bottom', 'left', 'z-index', 'box-shadow', 'aspect-ratio', 'container-type', 'fill', 'fill-opacity', 'fill-rule', 'stroke', 'stroke-dasharray', 'stroke-dashoffset', 'stroke-linecap', 'stroke-linejoin', 'stroke-miterlimit', 'stroke-opacity', 'stroke-width', 'color-interpolation', 'color-interpolation-filters', 'paint-order', 'stop-color', 'stop-opacity', 'flood-color', 'flood-opacity', 'lighting-color', 'marker', 'marker-end', 'marker-mid', 'marker-start', 'clip-path', 'clip-rule', 'mask', 'mask-type', 'cx', 'cy', 'r', 'rx', 'ry', 'x', 'y', 'd', 'alignment-baseline', 'baseline-shift', 'dominant-baseline', 'glyph-orientation-horizontal', 'glyph-orientation-vertical', 'text-anchor', 'unicode-bidi', 'word-spacing', 'font-size-adjust', 'font-stretch', 'color-rendering', 'image-rendering', 'shape-rendering', 'text-rendering', 'vector-effect', 'transform', 'transform-origin', 'pointer-events', 'visibility', // Custom CSS properties. '--*', ) ); /* * 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', 'filter', 'list-style', 'list-style-image', // SVG presentation properties that accept url() references. 'clip-path', 'fill', 'marker', 'marker-end', 'marker-mid', 'marker-start', 'mask', 'stroke', ); /* * 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; $is_custom_var = false; if ( ! str_contains( $css_item, ':' ) ) { $found = true; } else { $parts = explode( ':', $css_item, 2 ); $css_selector = trim( $parts[0] ); // Allow assigning values to CSS variables. if ( in_array( '--*', $allowed_attr, true ) && preg_match( '/^--[a-zA-Z0-9-_]+$/', $css_selector ) ) { $allowed_attr[] = $css_selector; $is_custom_var = true; } 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 ( $is_custom_var ) { $css_value = trim( $parts[1] ); $url_attr = str_starts_with( $css_value, 'url(' ); $gradient_attr = str_contains( $css_value, '-gradient(' ); } } 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 ) { /* * Match every `*-gradient()` in the value, allowing one level of nested functions * (e.g. rgb(), hsl(), var()). Matching each occurrence, rather than requiring the * whole value to be a single gradient, lets a gradient combine with a url() image. */ preg_match_all( '/(?:repeating-)?(?:linear|radial|conic)-gradient\((?:[^()]|\([^()]*\))*\)/', $css_test_string, $gradient_matches ); foreach ( $gradient_matches[0] as $gradient_match ) { // Remove each `gradient()` bit that was matched above from the CSS. $css_test_string = str_replace( $gradient_match, '', $css_test_string ); } } if ( $found ) { /* * Allow CSS functions like var(), calc(), etc. by removing them from the test string. * Nested functions and parentheses are also removed, so long as the parentheses are balanced. */ $css_test_string = preg_replace( '/\b(?:' // General purpose value functions. . 'var|calc|min|max|minmax|clamp|repeat' // Transform functions. . '|matrix|matrix3d|perspective' . '|rotate|rotate3d|rotateX|rotateY|rotateZ' . '|scale|scale3d|scaleX|scaleY|scaleZ' . '|skew|skewX|skewY' . '|translate|translate3d|translateX|translateY|translateZ' // Basic shape functions, as used by `clip-path`. . '|circle|ellipse|inset|path|polygon|rect|shape|xywh' . ')(\((?:[^()]|(?1))*\))/', '', $css_test_string ); // Bail if the recursive function stripping hit a PCRE error (e.g. stack/backtrack limit). if ( null === $css_test_string ) { continue; } /* * Disallow CSS containing \ ( & } = or comments, except for within url(), var(), calc(), etc. * which were removed from the test string above. */ $allow_css = 0 === 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. * * @since 5.5.0 * * @param bool $allow_css Whether the CSS in the test string is considered safe. * @param string $css_test_string The CSS string to test. */ $allow_css = apply_filters( 'safecss_filter_attr_allow_css', $allow_css, $css_test_string ); // Only add the CSS part if it passes the regex check. if ( $allow_css ) { 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 Added support for `data-*` wildcard attributes. * @since 6.0.0 Added `dir`, `lang`, and `xml:lang` to global attributes. * @since 6.3.0 Added `aria-controls`, `aria-current`, and `aria-expanded` attributes. * @since 6.4.0 Added `aria-live` and `hidden` attributes. * @since 7.1.0 Added `tabindex` attribute. * * @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-controls' => true, 'aria-current' => true, 'aria-describedby' => true, 'aria-details' => true, 'aria-expanded' => true, 'aria-hidden' => true, 'aria-label' => true, 'aria-labelledby' => true, 'aria-live' => true, 'class' => true, 'data-*' => true, 'dir' => true, 'hidden' => true, 'id' => true, 'lang' => true, 'style' => true, 'tabindex' => true, 'title' => true, 'role' => true, 'xml:lang' => true, ); if ( true === $value ) { $value = array(); } if ( is_array( $value ) ) { return array_merge( $value, $global_attributes ); } return $value; } /** * Helper function to check if this is a safe PDF URL. * * @since 5.9.0 * @access private * @ignore * * @param string $url The URL to check. * @return bool True if the URL is safe, false otherwise. */ function _wp_kses_allow_pdf_objects( $url ) { // We're not interested in URLs that contain query strings or fragments. if ( str_contains( $url, '?' ) || str_contains( $url, '#' ) ) { return false; } // If it doesn't have a PDF extension, it's not safe. if ( ! str_ends_with( $url, '.pdf' ) ) { return false; } // If the URL host matches the current site's media URL, it's safe. $upload_info = wp_upload_dir( null, false ); $parsed_url = wp_parse_url( $upload_info['url'] ); $upload_host = $parsed_url['host'] ?? ''; $upload_port = isset( $parsed_url['port'] ) ? ':' . $parsed_url['port'] : ''; if ( str_starts_with( $url, "http://$upload_host$upload_port/" ) || str_starts_with( $url, "https://$upload_host$upload_port/" ) ) { return true; } return false; }