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1 <?php 2 /** 3 * kses 0.2.2 - HTML/XHTML filter that only allows some elements and attributes 4 * Copyright (C) 2002, 2003, 2005 Ulf Harnhammar 5 * 6 * This program is free software and open source software; you can redistribute 7 * it and/or modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of the License, 9 * or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along 17 * with this program; if not, write to the Free Software Foundation, Inc., 18 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA 19 * http://www.gnu.org/licenses/gpl.html 20 * 21 * [kses strips evil scripts!] 22 * 23 * Added wp_ prefix to avoid conflicts with existing kses users 24 * 25 * @version 0.2.2 26 * @copyright (C) 2002, 2003, 2005 27 * @author Ulf Harnhammar <http://advogato.org/person/metaur/> 28 * 29 * @package External 30 * @subpackage KSES 31 */ 32 33 /** 34 * Specifies the default allowable HTML tags. 35 * 36 * Using `CUSTOM_TAGS` is not recommended and should be considered deprecated. The 37 * {@see 'wp_kses_allowed_html'} filter is more powerful and supplies context. 38 * 39 * When using this constant, make sure to set all of these globals to arrays: 40 * 41 * - `$allowedposttags` 42 * - `$allowedtags` 43 * - `$allowedentitynames` 44 * - `$allowedxmlentitynames` 45 * 46 * @see wp_kses_allowed_html() 47 * @since 1.2.0 48 * 49 * @var array[]|false Array of default allowable HTML tags, or false to use the defaults. 50 */ 51 if ( ! defined( 'CUSTOM_TAGS' ) ) { 52 define( 'CUSTOM_TAGS', false ); 53 } 54 55 // Ensure that these variables are added to the global namespace 56 // (e.g. if using namespaces / autoload in the current PHP environment). 57 global $allowedposttags, $allowedtags, $allowedentitynames, $allowedxmlentitynames; 58 59 if ( ! CUSTOM_TAGS ) { 60 /** 61 * KSES global for default allowable HTML tags. 62 * 63 * Can be overridden with the `CUSTOM_TAGS` constant. 64 * 65 * @var array[] $allowedposttags Array of default allowable HTML tags. 66 * @since 2.0.0 67 */ 68 $allowedposttags = array( 69 'address' => array(), 70 'a' => array( 71 'href' => true, 72 'rel' => true, 73 'rev' => true, 74 'name' => true, 75 'target' => true, 76 'download' => array( 77 'valueless' => 'y', 78 ), 79 ), 80 'abbr' => array(), 81 'acronym' => array(), 82 'area' => array( 83 'alt' => true, 84 'coords' => true, 85 'href' => true, 86 'nohref' => true, 87 'shape' => true, 88 'target' => true, 89 ), 90 'article' => array( 91 'align' => true, 92 ), 93 'aside' => array( 94 'align' => true, 95 ), 96 'audio' => array( 97 'autoplay' => true, 98 'controls' => true, 99 'loop' => true, 100 'muted' => true, 101 'preload' => true, 102 'src' => true, 103 ), 104 'b' => array(), 105 'bdo' => array(), 106 'big' => array(), 107 'blockquote' => array( 108 'cite' => true, 109 ), 110 'br' => array(), 111 'button' => array( 112 'disabled' => true, 113 'name' => true, 114 'type' => true, 115 'value' => true, 116 ), 117 'caption' => array( 118 'align' => true, 119 ), 120 'cite' => array(), 121 'code' => array(), 122 'col' => array( 123 'align' => true, 124 'char' => true, 125 'charoff' => true, 126 'span' => true, 127 'valign' => true, 128 'width' => true, 129 ), 130 'colgroup' => array( 131 'align' => true, 132 'char' => true, 133 'charoff' => true, 134 'span' => true, 135 'valign' => true, 136 'width' => true, 137 ), 138 'del' => array( 139 'datetime' => true, 140 ), 141 'dd' => array(), 142 'dfn' => array(), 143 'details' => array( 144 'align' => true, 145 'open' => true, 146 ), 147 'div' => array( 148 'align' => true, 149 ), 150 'dl' => array(), 151 'dt' => array(), 152 'em' => array(), 153 'fieldset' => array(), 154 'figure' => array( 155 'align' => true, 156 ), 157 'figcaption' => array( 158 'align' => true, 159 ), 160 'font' => array( 161 'color' => true, 162 'face' => true, 163 'size' => true, 164 ), 165 'footer' => array( 166 'align' => true, 167 ), 168 'h1' => array( 169 'align' => true, 170 ), 171 'h2' => array( 172 'align' => true, 173 ), 174 'h3' => array( 175 'align' => true, 176 ), 177 'h4' => array( 178 'align' => true, 179 ), 180 'h5' => array( 181 'align' => true, 182 ), 183 'h6' => array( 184 'align' => true, 185 ), 186 'header' => array( 187 'align' => true, 188 ), 189 'hgroup' => array( 190 'align' => true, 191 ), 192 'hr' => array( 193 'align' => true, 194 'noshade' => true, 195 'size' => true, 196 'width' => true, 197 ), 198 'i' => array(), 199 'img' => array( 200 'alt' => true, 201 'align' => true, 202 'border' => true, 203 'height' => true, 204 'hspace' => true, 205 'loading' => true, 206 'longdesc' => true, 207 'vspace' => true, 208 'src' => true, 209 'usemap' => true, 210 'width' => true, 211 ), 212 'ins' => array( 213 'datetime' => true, 214 'cite' => true, 215 ), 216 'kbd' => array(), 217 'label' => array( 218 'for' => true, 219 ), 220 'legend' => array( 221 'align' => true, 222 ), 223 'li' => array( 224 'align' => true, 225 'value' => true, 226 ), 227 'main' => array( 228 'align' => true, 229 ), 230 'map' => array( 231 'name' => true, 232 ), 233 'mark' => array(), 234 'menu' => array( 235 'type' => true, 236 ), 237 'nav' => array( 238 'align' => true, 239 ), 240 'object' => array( 241 'data' => array( 242 'required' => true, 243 'value_callback' => '_wp_kses_allow_pdf_objects', 244 ), 245 'type' => array( 246 'required' => true, 247 'values' => array( 'application/pdf' ), 248 ), 249 ), 250 'p' => array( 251 'align' => true, 252 ), 253 'pre' => array( 254 'width' => true, 255 ), 256 'q' => array( 257 'cite' => true, 258 ), 259 'rb' => array(), 260 'rp' => array(), 261 'rt' => array(), 262 'rtc' => array(), 263 'ruby' => array(), 264 's' => array(), 265 'samp' => array(), 266 'span' => array( 267 'align' => true, 268 ), 269 'section' => array( 270 'align' => true, 271 ), 272 'small' => array(), 273 'strike' => array(), 274 'strong' => array(), 275 'sub' => array(), 276 'summary' => array( 277 'align' => true, 278 ), 279 'sup' => array(), 280 'table' => array( 281 'align' => true, 282 'bgcolor' => true, 283 'border' => true, 284 'cellpadding' => true, 285 'cellspacing' => true, 286 'rules' => true, 287 'summary' => true, 288 'width' => true, 289 ), 290 'tbody' => array( 291 'align' => true, 292 'char' => true, 293 'charoff' => true, 294 'valign' => true, 295 ), 296 'td' => array( 297 'abbr' => true, 298 'align' => true, 299 'axis' => true, 300 'bgcolor' => true, 301 'char' => true, 302 'charoff' => true, 303 'colspan' => true, 304 'headers' => true, 305 'height' => true, 306 'nowrap' => true, 307 'rowspan' => true, 308 'scope' => true, 309 'valign' => true, 310 'width' => true, 311 ), 312 'textarea' => array( 313 'cols' => true, 314 'rows' => true, 315 'disabled' => true, 316 'name' => true, 317 'readonly' => true, 318 ), 319 'tfoot' => array( 320 'align' => true, 321 'char' => true, 322 'charoff' => true, 323 'valign' => true, 324 ), 325 'th' => array( 326 'abbr' => true, 327 'align' => true, 328 'axis' => true, 329 'bgcolor' => true, 330 'char' => true, 331 'charoff' => true, 332 'colspan' => true, 333 'headers' => true, 334 'height' => true, 335 'nowrap' => true, 336 'rowspan' => true, 337 'scope' => true, 338 'valign' => true, 339 'width' => true, 340 ), 341 'thead' => array( 342 'align' => true, 343 'char' => true, 344 'charoff' => true, 345 'valign' => true, 346 ), 347 'title' => array(), 348 'tr' => array( 349 'align' => true, 350 'bgcolor' => true, 351 'char' => true, 352 'charoff' => true, 353 'valign' => true, 354 ), 355 'track' => array( 356 'default' => true, 357 'kind' => true, 358 'label' => true, 359 'src' => true, 360 'srclang' => true, 361 ), 362 'tt' => array(), 363 'u' => array(), 364 'ul' => array( 365 'type' => true, 366 ), 367 'ol' => array( 368 'start' => true, 369 'type' => true, 370 'reversed' => true, 371 ), 372 'var' => array(), 373 'video' => array( 374 'autoplay' => true, 375 'controls' => true, 376 'height' => true, 377 'loop' => true, 378 'muted' => true, 379 'playsinline' => true, 380 'poster' => true, 381 'preload' => true, 382 'src' => true, 383 'width' => true, 384 ), 385 ); 386 387 /** 388 * @var array[] $allowedtags Array of KSES allowed HTML elements. 389 * @since 1.0.0 390 */ 391 $allowedtags = array( 392 'a' => array( 393 'href' => true, 394 'title' => true, 395 ), 396 'abbr' => array( 397 'title' => true, 398 ), 399 'acronym' => array( 400 'title' => true, 401 ), 402 'b' => array(), 403 'blockquote' => array( 404 'cite' => true, 405 ), 406 'cite' => array(), 407 'code' => array(), 408 'del' => array( 409 'datetime' => true, 410 ), 411 'em' => array(), 412 'i' => array(), 413 'q' => array( 414 'cite' => true, 415 ), 416 's' => array(), 417 'strike' => array(), 418 'strong' => array(), 419 ); 420 421 /** 422 * @var string[] $allowedentitynames Array of KSES allowed HTML entity names. 423 * @since 1.0.0 424 */ 425 $allowedentitynames = array( 426 'nbsp', 427 'iexcl', 428 'cent', 429 'pound', 430 'curren', 431 'yen', 432 'brvbar', 433 'sect', 434 'uml', 435 'copy', 436 'ordf', 437 'laquo', 438 'not', 439 'shy', 440 'reg', 441 'macr', 442 'deg', 443 'plusmn', 444 'acute', 445 'micro', 446 'para', 447 'middot', 448 'cedil', 449 'ordm', 450 'raquo', 451 'iquest', 452 'Agrave', 453 'Aacute', 454 'Acirc', 455 'Atilde', 456 'Auml', 457 'Aring', 458 'AElig', 459 'Ccedil', 460 'Egrave', 461 'Eacute', 462 'Ecirc', 463 'Euml', 464 'Igrave', 465 'Iacute', 466 'Icirc', 467 'Iuml', 468 'ETH', 469 'Ntilde', 470 'Ograve', 471 'Oacute', 472 'Ocirc', 473 'Otilde', 474 'Ouml', 475 'times', 476 'Oslash', 477 'Ugrave', 478 'Uacute', 479 'Ucirc', 480 'Uuml', 481 'Yacute', 482 'THORN', 483 'szlig', 484 'agrave', 485 'aacute', 486 'acirc', 487 'atilde', 488 'auml', 489 'aring', 490 'aelig', 491 'ccedil', 492 'egrave', 493 'eacute', 494 'ecirc', 495 'euml', 496 'igrave', 497 'iacute', 498 'icirc', 499 'iuml', 500 'eth', 501 'ntilde', 502 'ograve', 503 'oacute', 504 'ocirc', 505 'otilde', 506 'ouml', 507 'divide', 508 'oslash', 509 'ugrave', 510 'uacute', 511 'ucirc', 512 'uuml', 513 'yacute', 514 'thorn', 515 'yuml', 516 'quot', 517 'amp', 518 'lt', 519 'gt', 520 'apos', 521 'OElig', 522 'oelig', 523 'Scaron', 524 'scaron', 525 'Yuml', 526 'circ', 527 'tilde', 528 'ensp', 529 'emsp', 530 'thinsp', 531 'zwnj', 532 'zwj', 533 'lrm', 534 'rlm', 535 'ndash', 536 'mdash', 537 'lsquo', 538 'rsquo', 539 'sbquo', 540 'ldquo', 541 'rdquo', 542 'bdquo', 543 'dagger', 544 'Dagger', 545 'permil', 546 'lsaquo', 547 'rsaquo', 548 'euro', 549 'fnof', 550 'Alpha', 551 'Beta', 552 'Gamma', 553 'Delta', 554 'Epsilon', 555 'Zeta', 556 'Eta', 557 'Theta', 558 'Iota', 559 'Kappa', 560 'Lambda', 561 'Mu', 562 'Nu', 563 'Xi', 564 'Omicron', 565 'Pi', 566 'Rho', 567 'Sigma', 568 'Tau', 569 'Upsilon', 570 'Phi', 571 'Chi', 572 'Psi', 573 'Omega', 574 'alpha', 575 'beta', 576 'gamma', 577 'delta', 578 'epsilon', 579 'zeta', 580 'eta', 581 'theta', 582 'iota', 583 'kappa', 584 'lambda', 585 'mu', 586 'nu', 587 'xi', 588 'omicron', 589 'pi', 590 'rho', 591 'sigmaf', 592 'sigma', 593 'tau', 594 'upsilon', 595 'phi', 596 'chi', 597 'psi', 598 'omega', 599 'thetasym', 600 'upsih', 601 'piv', 602 'bull', 603 'hellip', 604 'prime', 605 'Prime', 606 'oline', 607 'frasl', 608 'weierp', 609 'image', 610 'real', 611 'trade', 612 'alefsym', 613 'larr', 614 'uarr', 615 'rarr', 616 'darr', 617 'harr', 618 'crarr', 619 'lArr', 620 'uArr', 621 'rArr', 622 'dArr', 623 'hArr', 624 'forall', 625 'part', 626 'exist', 627 'empty', 628 'nabla', 629 'isin', 630 'notin', 631 'ni', 632 'prod', 633 'sum', 634 'minus', 635 'lowast', 636 'radic', 637 'prop', 638 'infin', 639 'ang', 640 'and', 641 'or', 642 'cap', 643 'cup', 644 'int', 645 'sim', 646 'cong', 647 'asymp', 648 'ne', 649 'equiv', 650 'le', 651 'ge', 652 'sub', 653 'sup', 654 'nsub', 655 'sube', 656 'supe', 657 'oplus', 658 'otimes', 659 'perp', 660 'sdot', 661 'lceil', 662 'rceil', 663 'lfloor', 664 'rfloor', 665 'lang', 666 'rang', 667 'loz', 668 'spades', 669 'clubs', 670 'hearts', 671 'diams', 672 'sup1', 673 'sup2', 674 'sup3', 675 'frac14', 676 'frac12', 677 'frac34', 678 'there4', 679 ); 680 681 /** 682 * @var string[] $allowedxmlentitynames Array of KSES allowed XML entity names. 683 * @since 5.5.0 684 */ 685 $allowedxmlentitynames = array( 686 'amp', 687 'lt', 688 'gt', 689 'apos', 690 'quot', 691 ); 692 693 $allowedposttags = array_map( '_wp_add_global_attributes', $allowedposttags ); 694 } else { 695 $required_kses_globals = array( 696 'allowedposttags', 697 'allowedtags', 698 'allowedentitynames', 699 'allowedxmlentitynames', 700 ); 701 $missing_kses_globals = array(); 702 703 foreach ( $required_kses_globals as $global_name ) { 704 if ( ! isset( $GLOBALS[ $global_name ] ) || ! is_array( $GLOBALS[ $global_name ] ) ) { 705 $missing_kses_globals[] = '<code>$' . $global_name . '</code>'; 706 } 707 } 708 709 if ( $missing_kses_globals ) { 710 _doing_it_wrong( 711 'wp_kses_allowed_html', 712 sprintf( 713 /* translators: 1: CUSTOM_TAGS, 2: Global variable names. */ 714 __( 'When using the %1$s constant, make sure to set these globals to an array: %2$s.' ), 715 '<code>CUSTOM_TAGS</code>', 716 implode( ', ', $missing_kses_globals ) 717 ), 718 '6.2.0' 719 ); 720 } 721 722 $allowedtags = wp_kses_array_lc( $allowedtags ); 723 $allowedposttags = wp_kses_array_lc( $allowedposttags ); 724 } 725 726 /** 727 * Filters text content and strips out disallowed HTML. 728 * 729 * This function makes sure that only the allowed HTML element names, attribute 730 * names, attribute values, and HTML entities will occur in the given text string. 731 * 732 * This function expects unslashed data. 733 * 734 * @see wp_kses_post() for specifically filtering post content and fields. 735 * @see wp_allowed_protocols() for the default allowed protocols in link URLs. 736 * 737 * @since 1.0.0 738 * 739 * @param string $content Text content to filter. 740 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 741 * or a context name such as 'post'. See wp_kses_allowed_html() 742 * for the list of accepted context names. 743 * @param string[] $allowed_protocols Optional. Array of allowed URL protocols. 744 * Defaults to the result of wp_allowed_protocols(). 745 * @return string Filtered content containing only the allowed HTML. 746 */ 747 function wp_kses( $content, $allowed_html, $allowed_protocols = array() ) { 748 if ( empty( $allowed_protocols ) ) { 749 $allowed_protocols = wp_allowed_protocols(); 750 } 751 752 $content = wp_kses_no_null( $content, array( 'slash_zero' => 'keep' ) ); 753 $content = wp_kses_normalize_entities( $content ); 754 $content = wp_kses_hook( $content, $allowed_html, $allowed_protocols ); 755 756 return wp_kses_split( $content, $allowed_html, $allowed_protocols ); 757 } 758 759 /** 760 * Filters one HTML attribute and ensures its value is allowed. 761 * 762 * This function can escape data in some situations where `wp_kses()` must strip the whole attribute. 763 * 764 * @since 4.2.3 765 * 766 * @param string $attr The 'whole' attribute, including name and value. 767 * @param string $element The HTML element name to which the attribute belongs. 768 * @return string Filtered attribute. 769 */ 770 function wp_kses_one_attr( $attr, $element ) { 771 $uris = wp_kses_uri_attributes(); 772 $allowed_html = wp_kses_allowed_html( 'post' ); 773 $allowed_protocols = wp_allowed_protocols(); 774 $attr = wp_kses_no_null( $attr, array( 'slash_zero' => 'keep' ) ); 775 776 // Preserve leading and trailing whitespace. 777 $matches = array(); 778 preg_match( '/^\s*/', $attr, $matches ); 779 $lead = $matches[0]; 780 preg_match( '/\s*$/', $attr, $matches ); 781 $trail = $matches[0]; 782 if ( empty( $trail ) ) { 783 $attr = substr( $attr, strlen( $lead ) ); 784 } else { 785 $attr = substr( $attr, strlen( $lead ), -strlen( $trail ) ); 786 } 787 788 // Parse attribute name and value from input. 789 $split = preg_split( '/\s*=\s*/', $attr, 2 ); 790 $name = $split[0]; 791 if ( count( $split ) === 2 ) { 792 $value = $split[1]; 793 794 /* 795 * Remove quotes surrounding $value. 796 * Also guarantee correct quoting in $attr for this one attribute. 797 */ 798 if ( '' === $value ) { 799 $quote = ''; 800 } else { 801 $quote = $value[0]; 802 } 803 if ( '"' === $quote || "'" === $quote ) { 804 if ( ! str_ends_with( $value, $quote ) ) { 805 return ''; 806 } 807 $value = substr( $value, 1, -1 ); 808 } else { 809 $quote = '"'; 810 } 811 812 // Sanitize quotes, angle braces, and entities. 813 $value = esc_attr( $value ); 814 815 // Sanitize URI values. 816 if ( in_array( strtolower( $name ), $uris, true ) ) { 817 $value = wp_kses_bad_protocol( $value, $allowed_protocols ); 818 } 819 820 $attr = "$name=$quote$value$quote"; 821 $vless = 'n'; 822 } else { 823 $value = ''; 824 $vless = 'y'; 825 } 826 827 // Sanitize attribute by name. 828 wp_kses_attr_check( $name, $value, $attr, $vless, $element, $allowed_html ); 829 830 // Restore whitespace. 831 return $lead . $attr . $trail; 832 } 833 834 /** 835 * Returns an array of allowed HTML tags and attributes for a given context. 836 * 837 * @since 3.5.0 838 * @since 5.0.1 `form` removed as allowable HTML tag. 839 * 840 * @global array $allowedposttags 841 * @global array $allowedtags 842 * @global array $allowedentitynames 843 * 844 * @param string|array $context The context for which to retrieve tags. Allowed values are 'post', 845 * 'strip', 'data', 'entities', or the name of a field filter such as 846 * 'pre_user_description', or an array of allowed HTML elements and attributes. 847 * @return array Array of allowed HTML tags and their allowed attributes. 848 */ 849 function wp_kses_allowed_html( $context = '' ) { 850 global $allowedposttags, $allowedtags, $allowedentitynames; 851 852 if ( is_array( $context ) ) { 853 // When `$context` is an array it's actually an array of allowed HTML elements and attributes. 854 $html = $context; 855 $context = 'explicit'; 856 857 /** 858 * Filters the HTML tags that are allowed for a given context. 859 * 860 * HTML tags and attribute names are case-insensitive in HTML but must be 861 * added to the KSES allow list in lowercase. An item added to the allow list 862 * in upper or mixed case will not recognized as permitted by KSES. 863 * 864 * @since 3.5.0 865 * 866 * @param array[] $html Allowed HTML tags. 867 * @param string $context Context name. 868 */ 869 return apply_filters( 'wp_kses_allowed_html', $html, $context ); 870 } 871 872 switch ( $context ) { 873 case 'post': 874 /** This filter is documented in wp-includes/kses.php */ 875 $tags = apply_filters( 'wp_kses_allowed_html', $allowedposttags, $context ); 876 877 // 5.0.1 removed the `<form>` tag, allow it if a filter is allowing it's sub-elements `<input>` or `<select>`. 878 if ( ! CUSTOM_TAGS && ! isset( $tags['form'] ) && ( isset( $tags['input'] ) || isset( $tags['select'] ) ) ) { 879 $tags = $allowedposttags; 880 881 $tags['form'] = array( 882 'action' => true, 883 'accept' => true, 884 'accept-charset' => true, 885 'enctype' => true, 886 'method' => true, 887 'name' => true, 888 'target' => true, 889 ); 890 891 /** This filter is documented in wp-includes/kses.php */ 892 $tags = apply_filters( 'wp_kses_allowed_html', $tags, $context ); 893 } 894 895 return $tags; 896 897 case 'user_description': 898 case 'pre_user_description': 899 $tags = $allowedtags; 900 $tags['a']['rel'] = true; 901 /** This filter is documented in wp-includes/kses.php */ 902 return apply_filters( 'wp_kses_allowed_html', $tags, $context ); 903 904 case 'strip': 905 /** This filter is documented in wp-includes/kses.php */ 906 return apply_filters( 'wp_kses_allowed_html', array(), $context ); 907 908 case 'entities': 909 /** This filter is documented in wp-includes/kses.php */ 910 return apply_filters( 'wp_kses_allowed_html', $allowedentitynames, $context ); 911 912 case 'data': 913 default: 914 /** This filter is documented in wp-includes/kses.php */ 915 return apply_filters( 'wp_kses_allowed_html', $allowedtags, $context ); 916 } 917 } 918 919 /** 920 * You add any KSES hooks here. 921 * 922 * There is currently only one KSES WordPress hook, {@see 'pre_kses'}, and it is called here. 923 * All parameters are passed to the hooks and expected to receive a string. 924 * 925 * @since 1.0.0 926 * 927 * @param string $content Content to filter through KSES. 928 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 929 * or a context name such as 'post'. See wp_kses_allowed_html() 930 * for the list of accepted context names. 931 * @param string[] $allowed_protocols Array of allowed URL protocols. 932 * @return string Filtered content through {@see 'pre_kses'} hook. 933 */ 934 function wp_kses_hook( $content, $allowed_html, $allowed_protocols ) { 935 /** 936 * Filters content to be run through KSES. 937 * 938 * @since 2.3.0 939 * 940 * @param string $content Content to filter through KSES. 941 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 942 * or a context name such as 'post'. See wp_kses_allowed_html() 943 * for the list of accepted context names. 944 * @param string[] $allowed_protocols Array of allowed URL protocols. 945 */ 946 return apply_filters( 'pre_kses', $content, $allowed_html, $allowed_protocols ); 947 } 948 949 /** 950 * Returns the version number of KSES. 951 * 952 * @since 1.0.0 953 * 954 * @return string KSES version number. 955 */ 956 function wp_kses_version() { 957 return '0.2.2'; 958 } 959 960 /** 961 * Searches for HTML tags, no matter how malformed. 962 * 963 * It also matches stray `>` characters. 964 * 965 * @since 1.0.0 966 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. 967 * 968 * @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes, 969 * or a context name such as 'post'. 970 * @global string[] $pass_allowed_protocols Array of allowed URL protocols. 971 * 972 * @param string $content Content to filter. 973 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 974 * or a context name such as 'post'. See wp_kses_allowed_html() 975 * for the list of accepted context names. 976 * @param string[] $allowed_protocols Array of allowed URL protocols. 977 * @return string Content with fixed HTML tags 978 */ 979 function wp_kses_split( $content, $allowed_html, $allowed_protocols ) { 980 global $pass_allowed_html, $pass_allowed_protocols; 981 982 $pass_allowed_html = $allowed_html; 983 $pass_allowed_protocols = $allowed_protocols; 984 985 $token_pattern = <<<REGEX 986 ~ 987 ( # Detect comments of various flavors before attempting to find tags. 988 (<!--.*?(-->|$)) # - Normative HTML comments. 989 | 990 </[^a-zA-Z][^>]*> # - Closing tags with invalid tag names. 991 | 992 <![^>]*> # - Invalid markup declaration nodes. Not all invalid nodes 993 # are matched so as to avoid breaking legacy behaviors. 994 ) 995 | 996 (<[^>]*(>|$)|>) # Tag-like spans of text. 997 ~x 998 REGEX; 999 return preg_replace_callback( $token_pattern, '_wp_kses_split_callback', $content ); 1000 } 1001 1002 /** 1003 * Returns an array of HTML attribute names whose value contains a URL. 1004 * 1005 * This function returns a list of all HTML attributes that must contain 1006 * a URL according to the HTML specification. 1007 * 1008 * This list includes URI attributes both allowed and disallowed by KSES. 1009 * 1010 * @link https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes 1011 * 1012 * @since 5.0.1 1013 * 1014 * @return string[] HTML attribute names whose value contains a URL. 1015 */ 1016 function wp_kses_uri_attributes() { 1017 $uri_attributes = array( 1018 'action', 1019 'archive', 1020 'background', 1021 'cite', 1022 'classid', 1023 'codebase', 1024 'data', 1025 'formaction', 1026 'href', 1027 'icon', 1028 'longdesc', 1029 'manifest', 1030 'poster', 1031 'profile', 1032 'src', 1033 'usemap', 1034 'xmlns', 1035 ); 1036 1037 /** 1038 * Filters the list of attributes that are required to contain a URL. 1039 * 1040 * Use this filter to add any `data-` attributes that are required to be 1041 * validated as a URL. 1042 * 1043 * @since 5.0.1 1044 * 1045 * @param string[] $uri_attributes HTML attribute names whose value contains a URL. 1046 */ 1047 $uri_attributes = apply_filters( 'wp_kses_uri_attributes', $uri_attributes ); 1048 1049 return $uri_attributes; 1050 } 1051 1052 /** 1053 * Callback for `wp_kses_split()`. 1054 * 1055 * @since 3.1.0 1056 * @access private 1057 * @ignore 1058 * 1059 * @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes, 1060 * or a context name such as 'post'. 1061 * @global string[] $pass_allowed_protocols Array of allowed URL protocols. 1062 * 1063 * @param array $matches preg_replace regexp matches 1064 * @return string 1065 */ 1066 function _wp_kses_split_callback( $matches ) { 1067 global $pass_allowed_html, $pass_allowed_protocols; 1068 1069 return wp_kses_split2( $matches[0], $pass_allowed_html, $pass_allowed_protocols ); 1070 } 1071 1072 /** 1073 * Callback for `wp_kses_split()` for fixing malformed HTML tags. 1074 * 1075 * This function does a lot of work. It rejects some very malformed things like 1076 * `<:::>`. It returns an empty string, if the element isn't allowed (look ma, no 1077 * `strip_tags()`!). Otherwise it splits the tag into an element and an attribute 1078 * list. 1079 * 1080 * After the tag is split into an element and an attribute list, it is run 1081 * through another filter which will remove illegal attributes and once that is 1082 * completed, will be returned. 1083 * 1084 * @access private 1085 * @ignore 1086 * @since 1.0.0 1087 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. 1088 * 1089 * @param string $content Content to filter. 1090 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 1091 * or a context name such as 'post'. See wp_kses_allowed_html() 1092 * for the list of accepted context names. 1093 * @param string[] $allowed_protocols Array of allowed URL protocols. 1094 * 1095 * @return string Fixed HTML element 1096 */ 1097 function wp_kses_split2( $content, $allowed_html, $allowed_protocols ) { 1098 $content = wp_kses_stripslashes( $content ); 1099 1100 /* 1101 * The regex pattern used to split HTML into chunks attempts 1102 * to split on HTML token boundaries. This function should 1103 * thus receive chunks that _either_ start with meaningful 1104 * syntax tokens, like a tag `<div>` or a comment `<!-- ... -->`. 1105 * 1106 * If the first character of the `$content` chunk _isn't_ one 1107 * of these syntax elements, which always starts with `<`, then 1108 * the match had to be for the final alternation of `>`. In such 1109 * case, it's probably standing on its own and could be encoded 1110 * with a character reference to remove ambiguity. 1111 * 1112 * In other words, if this chunk isn't from a match of a syntax 1113 * token, it's just a plaintext greater-than (`>`) sign. 1114 */ 1115 if ( ! str_starts_with( $content, '<' ) ) { 1116 return '>'; 1117 } 1118 1119 /* 1120 * When certain invalid syntax constructs appear, the HTML parser 1121 * shifts into what's called the "bogus comment state." This is a 1122 * plaintext state that consumes everything until the nearest `>` 1123 * and then transforms the entire span into an HTML comment. 1124 * 1125 * Preserve these comments and do not treat them like tags. 1126 * 1127 * @see https://html.spec.whatwg.org/#bogus-comment-state 1128 */ 1129 if ( 1 === preg_match( '~^(?:</[^a-zA-Z][^>]*>|<![a-z][^>]*>)$~', $content ) ) { 1130 /** 1131 * Since the pattern matches `</…>` and also `<!…>`, this will 1132 * preserve the type of the cleaned-up token in the output. 1133 */ 1134 $opener = $content[1]; 1135 $content = substr( $content, 2, -1 ); 1136 1137 do { 1138 $prev = $content; 1139 $content = wp_kses( $content, $allowed_html, $allowed_protocols ); 1140 } while ( $prev !== $content ); 1141 1142 // Recombine the modified inner content with the original token structure. 1143 return "<{$opener}{$content}>"; 1144 } 1145 1146 /* 1147 * Normative HTML comments should be handled separately as their 1148 * parsing rules differ from those for tags and text nodes. 1149 */ 1150 if ( str_starts_with( $content, '<!--' ) ) { 1151 $content = str_replace( array( '<!--', '-->' ), '', $content ); 1152 1153 while ( ( $newstring = wp_kses( $content, $allowed_html, $allowed_protocols ) ) !== $content ) { 1154 $content = $newstring; 1155 } 1156 1157 if ( '' === $content ) { 1158 return ''; 1159 } 1160 1161 // Prevent multiple dashes in comments. 1162 $content = preg_replace( '/--+/', '-', $content ); 1163 // Prevent three dashes closing a comment. 1164 $content = preg_replace( '/-$/', '', $content ); 1165 1166 return "<!--{$content}-->"; 1167 } 1168 1169 // It's seriously malformed. 1170 if ( ! preg_match( '%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $content, $matches ) ) { 1171 return ''; 1172 } 1173 1174 $slash = trim( $matches[1] ); 1175 $elem = $matches[2]; 1176 $attrlist = $matches[3]; 1177 1178 if ( ! is_array( $allowed_html ) ) { 1179 $allowed_html = wp_kses_allowed_html( $allowed_html ); 1180 } 1181 1182 // They are using a not allowed HTML element. 1183 if ( ! isset( $allowed_html[ strtolower( $elem ) ] ) ) { 1184 return ''; 1185 } 1186 1187 // No attributes are allowed for closing elements. 1188 if ( '' !== $slash ) { 1189 return "</$elem>"; 1190 } 1191 1192 return wp_kses_attr( $elem, $attrlist, $allowed_html, $allowed_protocols ); 1193 } 1194 1195 /** 1196 * Removes all attributes, if none are allowed for this element. 1197 * 1198 * If some are allowed it calls `wp_kses_hair()` to split them further, and then 1199 * it builds up new HTML code from the data that `wp_kses_hair()` returns. It also 1200 * removes `<` and `>` characters, if there are any left. One more thing it does 1201 * is to check if the tag has a closing XHTML slash, and if it does, it puts one 1202 * in the returned code as well. 1203 * 1204 * An array of allowed values can be defined for attributes. If the attribute value 1205 * doesn't fall into the list, the attribute will be removed from the tag. 1206 * 1207 * Attributes can be marked as required. If a required attribute is not present, 1208 * KSES will remove all attributes from the tag. As KSES doesn't match opening and 1209 * closing tags, it's not possible to safely remove the tag itself, the safest 1210 * fallback is to strip all attributes from the tag, instead. 1211 * 1212 * @since 1.0.0 1213 * @since 5.9.0 Added support for an array of allowed values for attributes. 1214 * Added support for required attributes. 1215 * 1216 * @param string $element HTML element/tag. 1217 * @param string $attr HTML attributes from HTML element to closing HTML element tag. 1218 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 1219 * or a context name such as 'post'. See wp_kses_allowed_html() 1220 * for the list of accepted context names. 1221 * @param string[] $allowed_protocols Array of allowed URL protocols. 1222 * @return string Sanitized HTML element. 1223 */ 1224 function wp_kses_attr( $element, $attr, $allowed_html, $allowed_protocols ) { 1225 if ( ! is_array( $allowed_html ) ) { 1226 $allowed_html = wp_kses_allowed_html( $allowed_html ); 1227 } 1228 1229 // Is there a closing XHTML slash at the end of the attributes? 1230 $xhtml_slash = ''; 1231 if ( preg_match( '%\s*/\s*$%', $attr ) ) { 1232 $xhtml_slash = ' /'; 1233 } 1234 1235 // Are any attributes allowed at all for this element? 1236 $element_low = strtolower( $element ); 1237 if ( empty( $allowed_html[ $element_low ] ) || true === $allowed_html[ $element_low ] ) { 1238 return "<$element$xhtml_slash>"; 1239 } 1240 1241 // Split it. 1242 $attrarr = wp_kses_hair( $attr, $allowed_protocols ); 1243 1244 // Check if there are attributes that are required. 1245 $required_attrs = array_filter( 1246 $allowed_html[ $element_low ], 1247 static function ( $required_attr_limits ) { 1248 return isset( $required_attr_limits['required'] ) && true === $required_attr_limits['required']; 1249 } 1250 ); 1251 1252 /* 1253 * If a required attribute check fails, we can return nothing for a self-closing tag, 1254 * but for a non-self-closing tag the best option is to return the element with attributes, 1255 * as KSES doesn't handle matching the relevant closing tag. 1256 */ 1257 $stripped_tag = ''; 1258 if ( empty( $xhtml_slash ) ) { 1259 $stripped_tag = "<$element>"; 1260 } 1261 1262 // Go through $attrarr, and save the allowed attributes for this element in $attr2. 1263 $attr2 = ''; 1264 foreach ( $attrarr as $arreach ) { 1265 // Check if this attribute is required. 1266 $required = isset( $required_attrs[ strtolower( $arreach['name'] ) ] ); 1267 1268 if ( wp_kses_attr_check( $arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html ) ) { 1269 $attr2 .= ' ' . $arreach['whole']; 1270 1271 // If this was a required attribute, we can mark it as found. 1272 if ( $required ) { 1273 unset( $required_attrs[ strtolower( $arreach['name'] ) ] ); 1274 } 1275 } elseif ( $required ) { 1276 // This attribute was required, but didn't pass the check. The entire tag is not allowed. 1277 return $stripped_tag; 1278 } 1279 } 1280 1281 // If some required attributes weren't set, the entire tag is not allowed. 1282 if ( ! empty( $required_attrs ) ) { 1283 return $stripped_tag; 1284 } 1285 1286 // Remove any "<" or ">" characters. 1287 $attr2 = preg_replace( '/[<>]/', '', $attr2 ); 1288 1289 return "<$element$attr2$xhtml_slash>"; 1290 } 1291 1292 /** 1293 * Determines whether an attribute is allowed. 1294 * 1295 * @since 4.2.3 1296 * @since 5.0.0 Added support for `data-*` wildcard attributes. 1297 * 1298 * @param string $name The attribute name. Passed by reference. Returns empty string when not allowed. 1299 * @param string $value The attribute value. Passed by reference. Returns a filtered value. 1300 * @param string $whole The `name=value` input. Passed by reference. Returns filtered input. 1301 * @param string $vless Whether the attribute is valueless. Use 'y' or 'n'. 1302 * @param string $element The name of the element to which this attribute belongs. 1303 * @param array $allowed_html The full list of allowed elements and attributes. 1304 * @return bool Whether or not the attribute is allowed. 1305 */ 1306 function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowed_html ) { 1307 $name_low = strtolower( $name ); 1308 $element_low = strtolower( $element ); 1309 1310 if ( ! isset( $allowed_html[ $element_low ] ) ) { 1311 $name = ''; 1312 $value = ''; 1313 $whole = ''; 1314 return false; 1315 } 1316 1317 $allowed_attr = $allowed_html[ $element_low ]; 1318 1319 if ( ! isset( $allowed_attr[ $name_low ] ) || '' === $allowed_attr[ $name_low ] ) { 1320 /* 1321 * Allow `data-*` attributes. 1322 * 1323 * When specifying `$allowed_html`, the attribute name should be set as 1324 * `data-*` (not to be mixed with the HTML 4.0 `data` attribute, see 1325 * https://www.w3.org/TR/html40/struct/objects.html#adef-data). 1326 * 1327 * Note: the attribute name should only contain `A-Za-z0-9_-` chars. 1328 */ 1329 if ( str_starts_with( $name_low, 'data-' ) && ! empty( $allowed_attr['data-*'] ) 1330 && preg_match( '/^data-[a-z0-9_-]+$/', $name_low, $match ) 1331 ) { 1332 /* 1333 * Add the whole attribute name to the allowed attributes and set any restrictions 1334 * for the `data-*` attribute values for the current element. 1335 */ 1336 $allowed_attr[ $match[0] ] = $allowed_attr['data-*']; 1337 } else { 1338 $name = ''; 1339 $value = ''; 1340 $whole = ''; 1341 return false; 1342 } 1343 } 1344 1345 if ( 'style' === $name_low ) { 1346 $new_value = safecss_filter_attr( $value ); 1347 1348 if ( empty( $new_value ) ) { 1349 $name = ''; 1350 $value = ''; 1351 $whole = ''; 1352 return false; 1353 } 1354 1355 $whole = str_replace( $value, $new_value, $whole ); 1356 $value = $new_value; 1357 } 1358 1359 if ( is_array( $allowed_attr[ $name_low ] ) ) { 1360 // There are some checks. 1361 foreach ( $allowed_attr[ $name_low ] as $currkey => $currval ) { 1362 if ( ! wp_kses_check_attr_val( $value, $vless, $currkey, $currval ) ) { 1363 $name = ''; 1364 $value = ''; 1365 $whole = ''; 1366 return false; 1367 } 1368 } 1369 } 1370 1371 return true; 1372 } 1373 1374 /** 1375 * Builds an attribute list from string containing attributes. 1376 * 1377 * This function does a lot of work. It parses an attribute list into an array 1378 * with attribute data, and tries to do the right thing even if it gets weird 1379 * input. It will add quotes around attribute values that don't have any quotes 1380 * or apostrophes around them, to make it easier to produce HTML code that will 1381 * conform to W3C's HTML specification. It will also remove bad URL protocols 1382 * from attribute values. It also reduces duplicate attributes by using the 1383 * attribute defined first (`foo='bar' foo='baz'` will result in `foo='bar'`). 1384 * 1385 * @since 1.0.0 1386 * 1387 * @param string $attr Attribute list from HTML element to closing HTML element tag. 1388 * @param string[] $allowed_protocols Array of allowed URL protocols. 1389 * @return array[] Array of attribute information after parsing. 1390 */ 1391 function wp_kses_hair( $attr, $allowed_protocols ) { 1392 $attrarr = array(); 1393 $mode = 0; 1394 $attrname = ''; 1395 $uris = wp_kses_uri_attributes(); 1396 1397 // Loop through the whole attribute list. 1398 1399 while ( strlen( $attr ) !== 0 ) { 1400 $working = 0; // Was the last operation successful? 1401 1402 switch ( $mode ) { 1403 case 0: 1404 if ( preg_match( '/^([_a-zA-Z][-_a-zA-Z0-9:.]*)/', $attr, $match ) ) { 1405 $attrname = $match[1]; 1406 $working = 1; 1407 $mode = 1; 1408 $attr = preg_replace( '/^[_a-zA-Z][-_a-zA-Z0-9:.]*/', '', $attr ); 1409 } 1410 1411 break; 1412 1413 case 1: 1414 if ( preg_match( '/^\s*=\s*/', $attr ) ) { // Equals sign. 1415 $working = 1; 1416 $mode = 2; 1417 $attr = preg_replace( '/^\s*=\s*/', '', $attr ); 1418 break; 1419 } 1420 1421 if ( preg_match( '/^\s+/', $attr ) ) { // Valueless. 1422 $working = 1; 1423 $mode = 0; 1424 1425 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1426 $attrarr[ $attrname ] = array( 1427 'name' => $attrname, 1428 'value' => '', 1429 'whole' => $attrname, 1430 'vless' => 'y', 1431 ); 1432 } 1433 1434 $attr = preg_replace( '/^\s+/', '', $attr ); 1435 } 1436 1437 break; 1438 1439 case 2: 1440 if ( preg_match( '%^"([^"]*)"(\s+|/?$)%', $attr, $match ) ) { 1441 // "value" 1442 $thisval = $match[1]; 1443 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1444 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1445 } 1446 1447 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1448 $attrarr[ $attrname ] = array( 1449 'name' => $attrname, 1450 'value' => $thisval, 1451 'whole' => "$attrname=\"$thisval\"", 1452 'vless' => 'n', 1453 ); 1454 } 1455 1456 $working = 1; 1457 $mode = 0; 1458 $attr = preg_replace( '/^"[^"]*"(\s+|$)/', '', $attr ); 1459 break; 1460 } 1461 1462 if ( preg_match( "%^'([^']*)'(\s+|/?$)%", $attr, $match ) ) { 1463 // 'value' 1464 $thisval = $match[1]; 1465 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1466 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1467 } 1468 1469 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1470 $attrarr[ $attrname ] = array( 1471 'name' => $attrname, 1472 'value' => $thisval, 1473 'whole' => "$attrname='$thisval'", 1474 'vless' => 'n', 1475 ); 1476 } 1477 1478 $working = 1; 1479 $mode = 0; 1480 $attr = preg_replace( "/^'[^']*'(\s+|$)/", '', $attr ); 1481 break; 1482 } 1483 1484 if ( preg_match( "%^([^\s\"']+)(\s+|/?$)%", $attr, $match ) ) { 1485 // value 1486 $thisval = $match[1]; 1487 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1488 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1489 } 1490 1491 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1492 $attrarr[ $attrname ] = array( 1493 'name' => $attrname, 1494 'value' => $thisval, 1495 'whole' => "$attrname=\"$thisval\"", 1496 'vless' => 'n', 1497 ); 1498 } 1499 1500 // We add quotes to conform to W3C's HTML spec. 1501 $working = 1; 1502 $mode = 0; 1503 $attr = preg_replace( "%^[^\s\"']+(\s+|$)%", '', $attr ); 1504 } 1505 1506 break; 1507 } // End switch. 1508 1509 if ( 0 === $working ) { // Not well-formed, remove and try again. 1510 $attr = wp_kses_html_error( $attr ); 1511 $mode = 0; 1512 } 1513 } // End while. 1514 1515 if ( 1 === $mode && false === array_key_exists( $attrname, $attrarr ) ) { 1516 /* 1517 * Special case, for when the attribute list ends with a valueless 1518 * attribute like "selected". 1519 */ 1520 $attrarr[ $attrname ] = array( 1521 'name' => $attrname, 1522 'value' => '', 1523 'whole' => $attrname, 1524 'vless' => 'y', 1525 ); 1526 } 1527 1528 return $attrarr; 1529 } 1530 1531 /** 1532 * Finds all attributes of an HTML element. 1533 * 1534 * Does not modify input. May return "evil" output. 1535 * 1536 * Based on `wp_kses_split2()` and `wp_kses_attr()`. 1537 * 1538 * @since 4.2.3 1539 * 1540 * @param string $element HTML element. 1541 * @return array|false List of attributes found in the element. Returns false on failure. 1542 */ 1543 function wp_kses_attr_parse( $element ) { 1544 $valid = preg_match( '%^(<\s*)(/\s*)?([a-zA-Z0-9]+\s*)([^>]*)(>?)$%', $element, $matches ); 1545 if ( 1 !== $valid ) { 1546 return false; 1547 } 1548 1549 $begin = $matches[1]; 1550 $slash = $matches[2]; 1551 $elname = $matches[3]; 1552 $attr = $matches[4]; 1553 $end = $matches[5]; 1554 1555 if ( '' !== $slash ) { 1556 // Closing elements do not get parsed. 1557 return false; 1558 } 1559 1560 // Is there a closing XHTML slash at the end of the attributes? 1561 if ( 1 === preg_match( '%\s*/\s*$%', $attr, $matches ) ) { 1562 $xhtml_slash = $matches[0]; 1563 $attr = substr( $attr, 0, -strlen( $xhtml_slash ) ); 1564 } else { 1565 $xhtml_slash = ''; 1566 } 1567 1568 // Split it. 1569 $attrarr = wp_kses_hair_parse( $attr ); 1570 if ( false === $attrarr ) { 1571 return false; 1572 } 1573 1574 // Make sure all input is returned by adding front and back matter. 1575 array_unshift( $attrarr, $begin . $slash . $elname ); 1576 array_push( $attrarr, $xhtml_slash . $end ); 1577 1578 return $attrarr; 1579 } 1580 1581 /** 1582 * Builds an attribute list from string containing attributes. 1583 * 1584 * Does not modify input. May return "evil" output. 1585 * In case of unexpected input, returns false instead of stripping things. 1586 * 1587 * Based on `wp_kses_hair()` but does not return a multi-dimensional array. 1588 * 1589 * @since 4.2.3 1590 * 1591 * @param string $attr Attribute list from HTML element to closing HTML element tag. 1592 * @return array|false List of attributes found in $attr. Returns false on failure. 1593 */ 1594 function wp_kses_hair_parse( $attr ) { 1595 if ( '' === $attr ) { 1596 return array(); 1597 } 1598 1599 $regex = 1600 '(?: 1601 [_a-zA-Z][-_a-zA-Z0-9:.]* # Attribute name. 1602 | 1603 \[\[?[^\[\]]+\]\]? # Shortcode in the name position implies unfiltered_html. 1604 ) 1605 (?: # Attribute value. 1606 \s*=\s* # All values begin with "=". 1607 (?: 1608 "[^"]*" # Double-quoted. 1609 | 1610 \'[^\']*\' # Single-quoted. 1611 | 1612 [^\s"\']+ # Non-quoted. 1613 (?:\s|$) # Must have a space. 1614 ) 1615 | 1616 (?:\s|$) # If attribute has no value, space is required. 1617 ) 1618 \s* # Trailing space is optional except as mentioned above. 1619 '; 1620 1621 /* 1622 * Although it is possible to reduce this procedure to a single regexp, 1623 * we must run that regexp twice to get exactly the expected result. 1624 * 1625 * Note: do NOT remove the `x` modifiers as they are essential for the above regex! 1626 */ 1627 1628 $validation = "/^($regex)+$/x"; 1629 $extraction = "/$regex/x"; 1630 1631 if ( 1 === preg_match( $validation, $attr ) ) { 1632 preg_match_all( $extraction, $attr, $attrarr ); 1633 return $attrarr[0]; 1634 } else { 1635 return false; 1636 } 1637 } 1638 1639 /** 1640 * Performs different checks for attribute values. 1641 * 1642 * The currently implemented checks are "maxlen", "minlen", "maxval", "minval", 1643 * and "valueless". 1644 * 1645 * @since 1.0.0 1646 * 1647 * @param string $value Attribute value. 1648 * @param string $vless Whether the attribute is valueless. Use 'y' or 'n'. 1649 * @param string $checkname What $checkvalue is checking for. 1650 * @param mixed $checkvalue What constraint the value should pass. 1651 * @return bool Whether check passes. 1652 */ 1653 function wp_kses_check_attr_val( $value, $vless, $checkname, $checkvalue ) { 1654 $ok = true; 1655 1656 switch ( strtolower( $checkname ) ) { 1657 case 'maxlen': 1658 /* 1659 * The maxlen check makes sure that the attribute value has a length not 1660 * greater than the given value. This can be used to avoid Buffer Overflows 1661 * in WWW clients and various Internet servers. 1662 */ 1663 1664 if ( strlen( $value ) > $checkvalue ) { 1665 $ok = false; 1666 } 1667 break; 1668 1669 case 'minlen': 1670 /* 1671 * The minlen check makes sure that the attribute value has a length not 1672 * smaller than the given value. 1673 */ 1674 1675 if ( strlen( $value ) < $checkvalue ) { 1676 $ok = false; 1677 } 1678 break; 1679 1680 case 'maxval': 1681 /* 1682 * The maxval check does two things: it checks that the attribute value is 1683 * an integer from 0 and up, without an excessive amount of zeroes or 1684 * whitespace (to avoid Buffer Overflows). It also checks that the attribute 1685 * value is not greater than the given value. 1686 * This check can be used to avoid Denial of Service attacks. 1687 */ 1688 1689 if ( ! preg_match( '/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value ) ) { 1690 $ok = false; 1691 } 1692 if ( $value > $checkvalue ) { 1693 $ok = false; 1694 } 1695 break; 1696 1697 case 'minval': 1698 /* 1699 * The minval check makes sure that the attribute value is a positive integer, 1700 * and that it is not smaller than the given value. 1701 */ 1702 1703 if ( ! preg_match( '/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value ) ) { 1704 $ok = false; 1705 } 1706 if ( $value < $checkvalue ) { 1707 $ok = false; 1708 } 1709 break; 1710 1711 case 'valueless': 1712 /* 1713 * The valueless check makes sure if the attribute has a value 1714 * (like `<a href="blah">`) or not (`<option selected>`). If the given value 1715 * is a "y" or a "Y", the attribute must not have a value. 1716 * If the given value is an "n" or an "N", the attribute must have a value. 1717 */ 1718 1719 if ( strtolower( $checkvalue ) !== $vless ) { 1720 $ok = false; 1721 } 1722 break; 1723 1724 case 'values': 1725 /* 1726 * The values check is used when you want to make sure that the attribute 1727 * has one of the given values. 1728 */ 1729 1730 if ( false === array_search( strtolower( $value ), $checkvalue, true ) ) { 1731 $ok = false; 1732 } 1733 break; 1734 1735 case 'value_callback': 1736 /* 1737 * The value_callback check is used when you want to make sure that the attribute 1738 * value is accepted by the callback function. 1739 */ 1740 1741 if ( ! call_user_func( $checkvalue, $value ) ) { 1742 $ok = false; 1743 } 1744 break; 1745 } // End switch. 1746 1747 return $ok; 1748 } 1749 1750 /** 1751 * Sanitizes a string and removed disallowed URL protocols. 1752 * 1753 * This function removes all non-allowed protocols from the beginning of the 1754 * string. It ignores whitespace and the case of the letters, and it does 1755 * understand HTML entities. It does its work recursively, so it won't be 1756 * fooled by a string like `javascript:javascript:alert(57)`. 1757 * 1758 * @since 1.0.0 1759 * 1760 * @param string $content Content to filter bad protocols from. 1761 * @param string[] $allowed_protocols Array of allowed URL protocols. 1762 * @return string Filtered content. 1763 */ 1764 function wp_kses_bad_protocol( $content, $allowed_protocols ) { 1765 $content = wp_kses_no_null( $content ); 1766 1767 // Short-circuit if the string starts with `https://` or `http://`. Most common cases. 1768 if ( 1769 ( str_starts_with( $content, 'https://' ) && in_array( 'https', $allowed_protocols, true ) ) || 1770 ( str_starts_with( $content, 'http://' ) && in_array( 'http', $allowed_protocols, true ) ) 1771 ) { 1772 return $content; 1773 } 1774 1775 $iterations = 0; 1776 1777 do { 1778 $original_content = $content; 1779 $content = wp_kses_bad_protocol_once( $content, $allowed_protocols ); 1780 } while ( $original_content !== $content && ++$iterations < 6 ); 1781 1782 if ( $original_content !== $content ) { 1783 return ''; 1784 } 1785 1786 return $content; 1787 } 1788 1789 /** 1790 * Removes any invalid control characters in a text string. 1791 * 1792 * Also removes any instance of the `\0` string. 1793 * 1794 * @since 1.0.0 1795 * 1796 * @param string $content Content to filter null characters from. 1797 * @param array $options Set 'slash_zero' => 'keep' when '\0' is allowed. Default is 'remove'. 1798 * @return string Filtered content. 1799 */ 1800 function wp_kses_no_null( $content, $options = null ) { 1801 if ( ! isset( $options['slash_zero'] ) ) { 1802 $options = array( 'slash_zero' => 'remove' ); 1803 } 1804 1805 $content = preg_replace( '/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content ); 1806 if ( 'remove' === $options['slash_zero'] ) { 1807 $content = preg_replace( '/\\\\+0+/', '', $content ); 1808 } 1809 1810 return $content; 1811 } 1812 1813 /** 1814 * Strips slashes from in front of quotes. 1815 * 1816 * This function changes the character sequence `\"` to just `"`. It leaves all other 1817 * slashes alone. The quoting from `preg_replace(//e)` requires this. 1818 * 1819 * @since 1.0.0 1820 * 1821 * @param string $content String to strip slashes from. 1822 * @return string Fixed string with quoted slashes. 1823 */ 1824 function wp_kses_stripslashes( $content ) { 1825 return preg_replace( '%\\\\"%', '"', $content ); 1826 } 1827 1828 /** 1829 * Converts the keys of an array to lowercase. 1830 * 1831 * @since 1.0.0 1832 * 1833 * @param array $inarray Unfiltered array. 1834 * @return array Fixed array with all lowercase keys. 1835 */ 1836 function wp_kses_array_lc( $inarray ) { 1837 $outarray = array(); 1838 1839 foreach ( (array) $inarray as $inkey => $inval ) { 1840 $outkey = strtolower( $inkey ); 1841 $outarray[ $outkey ] = array(); 1842 1843 foreach ( (array) $inval as $inkey2 => $inval2 ) { 1844 $outkey2 = strtolower( $inkey2 ); 1845 $outarray[ $outkey ][ $outkey2 ] = $inval2; 1846 } 1847 } 1848 1849 return $outarray; 1850 } 1851 1852 /** 1853 * Handles parsing errors in `wp_kses_hair()`. 1854 * 1855 * The general plan is to remove everything to and including some whitespace, 1856 * but it deals with quotes and apostrophes as well. 1857 * 1858 * @since 1.0.0 1859 * 1860 * @param string $attr 1861 * @return string 1862 */ 1863 function wp_kses_html_error( $attr ) { 1864 return preg_replace( '/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $attr ); 1865 } 1866 1867 /** 1868 * Sanitizes content from bad protocols and other characters. 1869 * 1870 * This function searches for URL protocols at the beginning of the string, while 1871 * handling whitespace and HTML entities. 1872 * 1873 * @since 1.0.0 1874 * 1875 * @param string $content Content to check for bad protocols. 1876 * @param string[] $allowed_protocols Array of allowed URL protocols. 1877 * @param int $count Depth of call recursion to this function. 1878 * @return string Sanitized content. 1879 */ 1880 function wp_kses_bad_protocol_once( $content, $allowed_protocols, $count = 1 ) { 1881 $content = preg_replace( '/(�*58(?![;0-9])|�*3a(?![;a-f0-9]))/i', '$1;', $content ); 1882 $content2 = preg_split( '/:|�*58;|�*3a;|:/i', $content, 2 ); 1883 1884 if ( isset( $content2[1] ) && ! preg_match( '%/\?%', $content2[0] ) ) { 1885 $content = trim( $content2[1] ); 1886 $protocol = wp_kses_bad_protocol_once2( $content2[0], $allowed_protocols ); 1887 if ( 'feed:' === $protocol ) { 1888 if ( $count > 2 ) { 1889 return ''; 1890 } 1891 $content = wp_kses_bad_protocol_once( $content, $allowed_protocols, ++$count ); 1892 if ( empty( $content ) ) { 1893 return $content; 1894 } 1895 } 1896 $content = $protocol . $content; 1897 } 1898 1899 return $content; 1900 } 1901 1902 /** 1903 * Callback for `wp_kses_bad_protocol_once()` regular expression. 1904 * 1905 * This function processes URL protocols, checks to see if they're in the 1906 * list of allowed protocols or not, and returns different data depending 1907 * on the answer. 1908 * 1909 * @access private 1910 * @ignore 1911 * @since 1.0.0 1912 * 1913 * @param string $scheme URI scheme to check against the list of allowed protocols. 1914 * @param string[] $allowed_protocols Array of allowed URL protocols. 1915 * @return string Sanitized content. 1916 */ 1917 function wp_kses_bad_protocol_once2( $scheme, $allowed_protocols ) { 1918 $scheme = wp_kses_decode_entities( $scheme ); 1919 $scheme = preg_replace( '/\s/', '', $scheme ); 1920 $scheme = wp_kses_no_null( $scheme ); 1921 $scheme = strtolower( $scheme ); 1922 1923 $allowed = false; 1924 foreach ( (array) $allowed_protocols as $one_protocol ) { 1925 if ( strtolower( $one_protocol ) === $scheme ) { 1926 $allowed = true; 1927 break; 1928 } 1929 } 1930 1931 if ( $allowed ) { 1932 return "$scheme:"; 1933 } else { 1934 return ''; 1935 } 1936 } 1937 1938 /** 1939 * Converts and fixes HTML entities. 1940 * 1941 * This function normalizes HTML entities. It will convert `AT&T` to the correct 1942 * `AT&T`, `:` to `:`, `&#XYZZY;` to `&#XYZZY;` and so on. 1943 * 1944 * When `$context` is set to 'xml', HTML entities are converted to their code points. For 1945 * example, `AT&T…&#XYZZY;` is converted to `AT&T…&#XYZZY;`. 1946 * 1947 * @since 1.0.0 1948 * @since 5.5.0 Added `$context` parameter. 1949 * 1950 * @param string $content Content to normalize entities. 1951 * @param string $context Context for normalization. Can be either 'html' or 'xml'. 1952 * Default 'html'. 1953 * @return string Content with normalized entities. 1954 */ 1955 function wp_kses_normalize_entities( $content, $context = 'html' ) { 1956 // Disarm all entities by converting & to & 1957 $content = str_replace( '&', '&', $content ); 1958 1959 // Change back the allowed entities in our list of allowed entities. 1960 if ( 'xml' === $context ) { 1961 $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_xml_named_entities', $content ); 1962 } else { 1963 $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_named_entities', $content ); 1964 } 1965 $content = preg_replace_callback( '/&#(0*[0-9]{1,7});/', 'wp_kses_normalize_entities2', $content ); 1966 $content = preg_replace_callback( '/&#[Xx](0*[0-9A-Fa-f]{1,6});/', 'wp_kses_normalize_entities3', $content ); 1967 1968 return $content; 1969 } 1970 1971 /** 1972 * Callback for `wp_kses_normalize_entities()` regular expression. 1973 * 1974 * This function only accepts valid named entity references, which are finite, 1975 * case-sensitive, and highly scrutinized by HTML and XML validators. 1976 * 1977 * @since 3.0.0 1978 * 1979 * @global array $allowedentitynames 1980 * 1981 * @param array $matches preg_replace_callback() matches array. 1982 * @return string Correctly encoded entity. 1983 */ 1984 function wp_kses_named_entities( $matches ) { 1985 global $allowedentitynames; 1986 1987 if ( empty( $matches[1] ) ) { 1988 return ''; 1989 } 1990 1991 $i = $matches[1]; 1992 return ( ! in_array( $i, $allowedentitynames, true ) ) ? "&$i;" : "&$i;"; 1993 } 1994 1995 /** 1996 * Callback for `wp_kses_normalize_entities()` regular expression. 1997 * 1998 * This function only accepts valid named entity references, which are finite, 1999 * case-sensitive, and highly scrutinized by XML validators. HTML named entity 2000 * references are converted to their code points. 2001 * 2002 * @since 5.5.0 2003 * 2004 * @global array $allowedentitynames 2005 * @global array $allowedxmlentitynames 2006 * 2007 * @param array $matches preg_replace_callback() matches array. 2008 * @return string Correctly encoded entity. 2009 */ 2010 function wp_kses_xml_named_entities( $matches ) { 2011 global $allowedentitynames, $allowedxmlentitynames; 2012 2013 if ( empty( $matches[1] ) ) { 2014 return ''; 2015 } 2016 2017 $i = $matches[1]; 2018 2019 if ( in_array( $i, $allowedxmlentitynames, true ) ) { 2020 return "&$i;"; 2021 } elseif ( in_array( $i, $allowedentitynames, true ) ) { 2022 return html_entity_decode( "&$i;", ENT_HTML5 ); 2023 } 2024 2025 return "&$i;"; 2026 } 2027 2028 /** 2029 * Callback for `wp_kses_normalize_entities()` regular expression. 2030 * 2031 * This function helps `wp_kses_normalize_entities()` to only accept 16-bit 2032 * values and nothing more for `&#number;` entities. 2033 * 2034 * @access private 2035 * @ignore 2036 * @since 1.0.0 2037 * 2038 * @param array $matches `preg_replace_callback()` matches array. 2039 * @return string Correctly encoded entity. 2040 */ 2041 function wp_kses_normalize_entities2( $matches ) { 2042 if ( empty( $matches[1] ) ) { 2043 return ''; 2044 } 2045 2046 $i = $matches[1]; 2047 2048 if ( valid_unicode( $i ) ) { 2049 $i = str_pad( ltrim( $i, '0' ), 3, '0', STR_PAD_LEFT ); 2050 $i = "&#$i;"; 2051 } else { 2052 $i = "&#$i;"; 2053 } 2054 2055 return $i; 2056 } 2057 2058 /** 2059 * Callback for `wp_kses_normalize_entities()` for regular expression. 2060 * 2061 * This function helps `wp_kses_normalize_entities()` to only accept valid Unicode 2062 * numeric entities in hex form. 2063 * 2064 * @since 2.7.0 2065 * @access private 2066 * @ignore 2067 * 2068 * @param array $matches `preg_replace_callback()` matches array. 2069 * @return string Correctly encoded entity. 2070 */ 2071 function wp_kses_normalize_entities3( $matches ) { 2072 if ( empty( $matches[1] ) ) { 2073 return ''; 2074 } 2075 2076 $hexchars = $matches[1]; 2077 2078 return ( ! valid_unicode( hexdec( $hexchars ) ) ) ? "&#x$hexchars;" : '&#x' . ltrim( $hexchars, '0' ) . ';'; 2079 } 2080 2081 /** 2082 * Determines if a Unicode codepoint is valid. 2083 * 2084 * @since 2.7.0 2085 * 2086 * @param int $i Unicode codepoint. 2087 * @return bool Whether or not the codepoint is a valid Unicode codepoint. 2088 */ 2089 function valid_unicode( $i ) { 2090 $i = (int) $i; 2091 2092 return ( 0x9 === $i || 0xa === $i || 0xd === $i || 2093 ( 0x20 <= $i && $i <= 0xd7ff ) || 2094 ( 0xe000 <= $i && $i <= 0xfffd ) || 2095 ( 0x10000 <= $i && $i <= 0x10ffff ) 2096 ); 2097 } 2098 2099 /** 2100 * Converts all numeric HTML entities to their named counterparts. 2101 * 2102 * This function decodes numeric HTML entities (`A` and `A`). 2103 * It doesn't do anything with named entities like `ä`, but we don't 2104 * need them in the allowed URL protocols system anyway. 2105 * 2106 * @since 1.0.0 2107 * 2108 * @param string $content Content to change entities. 2109 * @return string Content after decoded entities. 2110 */ 2111 function wp_kses_decode_entities( $content ) { 2112 $content = preg_replace_callback( '/&#([0-9]+);/', '_wp_kses_decode_entities_chr', $content ); 2113 $content = preg_replace_callback( '/&#[Xx]([0-9A-Fa-f]+);/', '_wp_kses_decode_entities_chr_hexdec', $content ); 2114 2115 return $content; 2116 } 2117 2118 /** 2119 * Regex callback for `wp_kses_decode_entities()`. 2120 * 2121 * @since 2.9.0 2122 * @access private 2123 * @ignore 2124 * 2125 * @param array $matches preg match 2126 * @return string 2127 */ 2128 function _wp_kses_decode_entities_chr( $matches ) { 2129 return chr( $matches[1] ); 2130 } 2131 2132 /** 2133 * Regex callback for `wp_kses_decode_entities()`. 2134 * 2135 * @since 2.9.0 2136 * @access private 2137 * @ignore 2138 * 2139 * @param array $matches preg match 2140 * @return string 2141 */ 2142 function _wp_kses_decode_entities_chr_hexdec( $matches ) { 2143 return chr( hexdec( $matches[1] ) ); 2144 } 2145 2146 /** 2147 * Sanitize content with allowed HTML KSES rules. 2148 * 2149 * This function expects slashed data. 2150 * 2151 * @since 1.0.0 2152 * 2153 * @param string $data Content to filter, expected to be escaped with slashes. 2154 * @return string Filtered content. 2155 */ 2156 function wp_filter_kses( $data ) { 2157 return addslashes( wp_kses( stripslashes( $data ), current_filter() ) ); 2158 } 2159 2160 /** 2161 * Sanitize content with allowed HTML KSES rules. 2162 * 2163 * This function expects unslashed data. 2164 * 2165 * @since 2.9.0 2166 * 2167 * @param string $data Content to filter, expected to not be escaped. 2168 * @return string Filtered content. 2169 */ 2170 function wp_kses_data( $data ) { 2171 return wp_kses( $data, current_filter() ); 2172 } 2173 2174 /** 2175 * Sanitizes content for allowed HTML tags for post content. 2176 * 2177 * Post content refers to the page contents of the 'post' type and not `$_POST` 2178 * data from forms. 2179 * 2180 * This function expects slashed data. 2181 * 2182 * @since 2.0.0 2183 * 2184 * @param string $data Post content to filter, expected to be escaped with slashes. 2185 * @return string Filtered post content with allowed HTML tags and attributes intact. 2186 */ 2187 function wp_filter_post_kses( $data ) { 2188 return addslashes( wp_kses( stripslashes( $data ), 'post' ) ); 2189 } 2190 2191 /** 2192 * Sanitizes global styles user content removing unsafe rules. 2193 * 2194 * @since 5.9.0 2195 * 2196 * @param string $data Post content to filter. 2197 * @return string Filtered post content with unsafe rules removed. 2198 */ 2199 function wp_filter_global_styles_post( $data ) { 2200 $decoded_data = json_decode( wp_unslash( $data ), true ); 2201 $json_decoding_error = json_last_error(); 2202 if ( 2203 JSON_ERROR_NONE === $json_decoding_error && 2204 is_array( $decoded_data ) && 2205 isset( $decoded_data['isGlobalStylesUserThemeJSON'] ) && 2206 $decoded_data['isGlobalStylesUserThemeJSON'] 2207 ) { 2208 unset( $decoded_data['isGlobalStylesUserThemeJSON'] ); 2209 2210 $data_to_encode = WP_Theme_JSON::remove_insecure_properties( $decoded_data, 'custom' ); 2211 2212 $data_to_encode['isGlobalStylesUserThemeJSON'] = true; 2213 return wp_slash( wp_json_encode( $data_to_encode ) ); 2214 } 2215 return $data; 2216 } 2217 2218 /** 2219 * Sanitizes content for allowed HTML tags for post content. 2220 * 2221 * Post content refers to the page contents of the 'post' type and not `$_POST` 2222 * data from forms. 2223 * 2224 * This function expects unslashed data. 2225 * 2226 * @since 2.9.0 2227 * 2228 * @param string $data Post content to filter. 2229 * @return string Filtered post content with allowed HTML tags and attributes intact. 2230 */ 2231 function wp_kses_post( $data ) { 2232 return wp_kses( $data, 'post' ); 2233 } 2234 2235 /** 2236 * Navigates through an array, object, or scalar, and sanitizes content for 2237 * allowed HTML tags for post content. 2238 * 2239 * @since 4.4.2 2240 * 2241 * @see map_deep() 2242 * 2243 * @param mixed $data The array, object, or scalar value to inspect. 2244 * @return mixed The filtered content. 2245 */ 2246 function wp_kses_post_deep( $data ) { 2247 return map_deep( $data, 'wp_kses_post' ); 2248 } 2249 2250 /** 2251 * Strips all HTML from a text string. 2252 * 2253 * This function expects slashed data. 2254 * 2255 * @since 2.1.0 2256 * 2257 * @param string $data Content to strip all HTML from. 2258 * @return string Filtered content without any HTML. 2259 */ 2260 function wp_filter_nohtml_kses( $data ) { 2261 return addslashes( wp_kses( stripslashes( $data ), 'strip' ) ); 2262 } 2263 2264 /** 2265 * Adds all KSES input form content filters. 2266 * 2267 * All hooks have default priority. The `wp_filter_kses()` function is added to 2268 * the 'pre_comment_content' and 'title_save_pre' hooks. 2269 * 2270 * The `wp_filter_post_kses()` function is added to the 'content_save_pre', 2271 * 'excerpt_save_pre', and 'content_filtered_save_pre' hooks. 2272 * 2273 * @since 2.0.0 2274 */ 2275 function kses_init_filters() { 2276 // Normal filtering. 2277 add_filter( 'title_save_pre', 'wp_filter_kses' ); 2278 2279 // Comment filtering. 2280 if ( current_user_can( 'unfiltered_html' ) ) { 2281 add_filter( 'pre_comment_content', 'wp_filter_post_kses' ); 2282 } else { 2283 add_filter( 'pre_comment_content', 'wp_filter_kses' ); 2284 } 2285 2286 // Global Styles filtering: Global Styles filters should be executed before normal post_kses HTML filters. 2287 add_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); 2288 add_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); 2289 2290 // Post filtering. 2291 add_filter( 'content_save_pre', 'wp_filter_post_kses' ); 2292 add_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); 2293 add_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); 2294 } 2295 2296 /** 2297 * Removes all KSES input form content filters. 2298 * 2299 * A quick procedural method to removing all of the filters that KSES uses for 2300 * content in WordPress Loop. 2301 * 2302 * Does not remove the `kses_init()` function from {@see 'init'} hook (priority is 2303 * default). Also does not remove `kses_init()` function from {@see 'set_current_user'} 2304 * hook (priority is also default). 2305 * 2306 * @since 2.0.6 2307 */ 2308 function kses_remove_filters() { 2309 // Normal filtering. 2310 remove_filter( 'title_save_pre', 'wp_filter_kses' ); 2311 2312 // Comment filtering. 2313 remove_filter( 'pre_comment_content', 'wp_filter_post_kses' ); 2314 remove_filter( 'pre_comment_content', 'wp_filter_kses' ); 2315 2316 // Global Styles filtering. 2317 remove_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); 2318 remove_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); 2319 2320 // Post filtering. 2321 remove_filter( 'content_save_pre', 'wp_filter_post_kses' ); 2322 remove_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); 2323 remove_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); 2324 } 2325 2326 /** 2327 * Sets up most of the KSES filters for input form content. 2328 * 2329 * First removes all of the KSES filters in case the current user does not need 2330 * to have KSES filter the content. If the user does not have `unfiltered_html` 2331 * capability, then KSES filters are added. 2332 * 2333 * @since 2.0.0 2334 */ 2335 function kses_init() { 2336 kses_remove_filters(); 2337 2338 if ( ! current_user_can( 'unfiltered_html' ) ) { 2339 kses_init_filters(); 2340 } 2341 } 2342 2343 /** 2344 * Filters an inline style attribute and removes disallowed rules. 2345 * 2346 * @since 2.8.1 2347 * @since 4.4.0 Added support for `min-height`, `max-height`, `min-width`, and `max-width`. 2348 * @since 4.6.0 Added support for `list-style-type`. 2349 * @since 5.0.0 Added support for `background-image`. 2350 * @since 5.1.0 Added support for `text-transform`. 2351 * @since 5.2.0 Added support for `background-position` and `grid-template-columns`. 2352 * @since 5.3.0 Added support for `grid`, `flex` and `column` layout properties. 2353 * Extended `background-*` support for individual properties. 2354 * @since 5.3.1 Added support for gradient backgrounds. 2355 * @since 5.7.1 Added support for `object-position`. 2356 * @since 5.8.0 Added support for `calc()` and `var()` values. 2357 * @since 6.1.0 Added support for `min()`, `max()`, `minmax()`, `clamp()`, 2358 * nested `var()` values, and assigning values to CSS variables. 2359 * Added support for `object-fit`, `gap`, `column-gap`, `row-gap`, and `flex-wrap`. 2360 * Extended `margin-*` and `padding-*` support for logical properties. 2361 * @since 6.2.0 Added support for `aspect-ratio`, `position`, `top`, `right`, `bottom`, `left`, 2362 * and `z-index` CSS properties. 2363 * @since 6.3.0 Extended support for `filter` to accept a URL and added support for repeat(). 2364 * Added support for `box-shadow`. 2365 * @since 6.4.0 Added support for `writing-mode`. 2366 * @since 6.5.0 Added support for `background-repeat`. 2367 * @since 6.6.0 Added support for `grid-column`, `grid-row`, and `container-type`. 2368 * 2369 * @param string $css A string of CSS rules. 2370 * @param string $deprecated Not used. 2371 * @return string Filtered string of CSS rules. 2372 */ 2373 function safecss_filter_attr( $css, $deprecated = '' ) { 2374 if ( ! empty( $deprecated ) ) { 2375 _deprecated_argument( __FUNCTION__, '2.8.1' ); // Never implemented. 2376 } 2377 2378 $css = wp_kses_no_null( $css ); 2379 $css = str_replace( array( "\n", "\r", "\t" ), '', $css ); 2380 2381 $allowed_protocols = wp_allowed_protocols(); 2382 2383 $css_array = explode( ';', trim( $css ) ); 2384 2385 /** 2386 * Filters the list of allowed CSS attributes. 2387 * 2388 * @since 2.8.1 2389 * 2390 * @param string[] $attr Array of allowed CSS attributes. 2391 */ 2392 $allowed_attr = apply_filters( 2393 'safe_style_css', 2394 array( 2395 'background', 2396 'background-color', 2397 'background-image', 2398 'background-position', 2399 'background-repeat', 2400 'background-size', 2401 'background-attachment', 2402 'background-blend-mode', 2403 2404 'border', 2405 'border-radius', 2406 'border-width', 2407 'border-color', 2408 'border-style', 2409 'border-right', 2410 'border-right-color', 2411 'border-right-style', 2412 'border-right-width', 2413 'border-bottom', 2414 'border-bottom-color', 2415 'border-bottom-left-radius', 2416 'border-bottom-right-radius', 2417 'border-bottom-style', 2418 'border-bottom-width', 2419 'border-bottom-right-radius', 2420 'border-bottom-left-radius', 2421 'border-left', 2422 'border-left-color', 2423 'border-left-style', 2424 'border-left-width', 2425 'border-top', 2426 'border-top-color', 2427 'border-top-left-radius', 2428 'border-top-right-radius', 2429 'border-top-style', 2430 'border-top-width', 2431 'border-top-left-radius', 2432 'border-top-right-radius', 2433 2434 'border-spacing', 2435 'border-collapse', 2436 'caption-side', 2437 2438 'columns', 2439 'column-count', 2440 'column-fill', 2441 'column-gap', 2442 'column-rule', 2443 'column-span', 2444 'column-width', 2445 2446 'color', 2447 'filter', 2448 'font', 2449 'font-family', 2450 'font-size', 2451 'font-style', 2452 'font-variant', 2453 'font-weight', 2454 'letter-spacing', 2455 'line-height', 2456 'text-align', 2457 'text-decoration', 2458 'text-indent', 2459 'text-transform', 2460 2461 'height', 2462 'min-height', 2463 'max-height', 2464 2465 'width', 2466 'min-width', 2467 'max-width', 2468 2469 'margin', 2470 'margin-right', 2471 'margin-bottom', 2472 'margin-left', 2473 'margin-top', 2474 'margin-block-start', 2475 'margin-block-end', 2476 'margin-inline-start', 2477 'margin-inline-end', 2478 2479 'padding', 2480 'padding-right', 2481 'padding-bottom', 2482 'padding-left', 2483 'padding-top', 2484 'padding-block-start', 2485 'padding-block-end', 2486 'padding-inline-start', 2487 'padding-inline-end', 2488 2489 'flex', 2490 'flex-basis', 2491 'flex-direction', 2492 'flex-flow', 2493 'flex-grow', 2494 'flex-shrink', 2495 'flex-wrap', 2496 2497 'gap', 2498 'column-gap', 2499 'row-gap', 2500 2501 'grid-template-columns', 2502 'grid-auto-columns', 2503 'grid-column-start', 2504 'grid-column-end', 2505 'grid-column', 2506 'grid-column-gap', 2507 'grid-template-rows', 2508 'grid-auto-rows', 2509 'grid-row-start', 2510 'grid-row-end', 2511 'grid-row', 2512 'grid-row-gap', 2513 'grid-gap', 2514 2515 'justify-content', 2516 'justify-items', 2517 'justify-self', 2518 'align-content', 2519 'align-items', 2520 'align-self', 2521 2522 'clear', 2523 'cursor', 2524 'direction', 2525 'float', 2526 'list-style-type', 2527 'object-fit', 2528 'object-position', 2529 'opacity', 2530 'overflow', 2531 'vertical-align', 2532 'writing-mode', 2533 2534 'position', 2535 'top', 2536 'right', 2537 'bottom', 2538 'left', 2539 'z-index', 2540 'box-shadow', 2541 'aspect-ratio', 2542 'container-type', 2543 2544 // Custom CSS properties. 2545 '--*', 2546 ) 2547 ); 2548 2549 /* 2550 * CSS attributes that accept URL data types. 2551 * 2552 * This is in accordance to the CSS spec and unrelated to 2553 * the sub-set of supported attributes above. 2554 * 2555 * See: https://developer.mozilla.org/en-US/docs/Web/CSS/url 2556 */ 2557 $css_url_data_types = array( 2558 'background', 2559 'background-image', 2560 2561 'cursor', 2562 'filter', 2563 2564 'list-style', 2565 'list-style-image', 2566 ); 2567 2568 /* 2569 * CSS attributes that accept gradient data types. 2570 * 2571 */ 2572 $css_gradient_data_types = array( 2573 'background', 2574 'background-image', 2575 ); 2576 2577 if ( empty( $allowed_attr ) ) { 2578 return $css; 2579 } 2580 2581 $css = ''; 2582 foreach ( $css_array as $css_item ) { 2583 if ( '' === $css_item ) { 2584 continue; 2585 } 2586 2587 $css_item = trim( $css_item ); 2588 $css_test_string = $css_item; 2589 $found = false; 2590 $url_attr = false; 2591 $gradient_attr = false; 2592 $is_custom_var = false; 2593 2594 if ( ! str_contains( $css_item, ':' ) ) { 2595 $found = true; 2596 } else { 2597 $parts = explode( ':', $css_item, 2 ); 2598 $css_selector = trim( $parts[0] ); 2599 2600 // Allow assigning values to CSS variables. 2601 if ( in_array( '--*', $allowed_attr, true ) && preg_match( '/^--[a-zA-Z0-9-_]+$/', $css_selector ) ) { 2602 $allowed_attr[] = $css_selector; 2603 $is_custom_var = true; 2604 } 2605 2606 if ( in_array( $css_selector, $allowed_attr, true ) ) { 2607 $found = true; 2608 $url_attr = in_array( $css_selector, $css_url_data_types, true ); 2609 $gradient_attr = in_array( $css_selector, $css_gradient_data_types, true ); 2610 } 2611 2612 if ( $is_custom_var ) { 2613 $css_value = trim( $parts[1] ); 2614 $url_attr = str_starts_with( $css_value, 'url(' ); 2615 $gradient_attr = str_contains( $css_value, '-gradient(' ); 2616 } 2617 } 2618 2619 if ( $found && $url_attr ) { 2620 // Simplified: matches the sequence `url(*)`. 2621 preg_match_all( '/url\([^)]+\)/', $parts[1], $url_matches ); 2622 2623 foreach ( $url_matches[0] as $url_match ) { 2624 // Clean up the URL from each of the matches above. 2625 preg_match( '/^url\(\s*([\'\"]?)(.*)(\g1)\s*\)$/', $url_match, $url_pieces ); 2626 2627 if ( empty( $url_pieces[2] ) ) { 2628 $found = false; 2629 break; 2630 } 2631 2632 $url = trim( $url_pieces[2] ); 2633 2634 if ( empty( $url ) || wp_kses_bad_protocol( $url, $allowed_protocols ) !== $url ) { 2635 $found = false; 2636 break; 2637 } else { 2638 // Remove the whole `url(*)` bit that was matched above from the CSS. 2639 $css_test_string = str_replace( $url_match, '', $css_test_string ); 2640 } 2641 } 2642 } 2643 2644 if ( $found && $gradient_attr ) { 2645 $css_value = trim( $parts[1] ); 2646 if ( preg_match( '/^(repeating-)?(linear|radial|conic)-gradient\(([^()]|rgb[a]?\([^()]*\))*\)$/', $css_value ) ) { 2647 // Remove the whole `gradient` bit that was matched above from the CSS. 2648 $css_test_string = str_replace( $css_value, '', $css_test_string ); 2649 } 2650 } 2651 2652 if ( $found ) { 2653 /* 2654 * Allow CSS functions like var(), calc(), etc. by removing them from the test string. 2655 * Nested functions and parentheses are also removed, so long as the parentheses are balanced. 2656 */ 2657 $css_test_string = preg_replace( 2658 '/\b(?:var|calc|min|max|minmax|clamp|repeat)(\((?:[^()]|(?1))*\))/', 2659 '', 2660 $css_test_string 2661 ); 2662 2663 /* 2664 * Disallow CSS containing \ ( & } = or comments, except for within url(), var(), calc(), etc. 2665 * which were removed from the test string above. 2666 */ 2667 $allow_css = ! preg_match( '%[\\\(&=}]|/\*%', $css_test_string ); 2668 2669 /** 2670 * Filters the check for unsafe CSS in `safecss_filter_attr`. 2671 * 2672 * Enables developers to determine whether a section of CSS should be allowed or discarded. 2673 * By default, the value will be false if the part contains \ ( & } = or comments. 2674 * Return true to allow the CSS part to be included in the output. 2675 * 2676 * @since 5.5.0 2677 * 2678 * @param bool $allow_css Whether the CSS in the test string is considered safe. 2679 * @param string $css_test_string The CSS string to test. 2680 */ 2681 $allow_css = apply_filters( 'safecss_filter_attr_allow_css', $allow_css, $css_test_string ); 2682 2683 // Only add the CSS part if it passes the regex check. 2684 if ( $allow_css ) { 2685 if ( '' !== $css ) { 2686 $css .= ';'; 2687 } 2688 2689 $css .= $css_item; 2690 } 2691 } 2692 } 2693 2694 return $css; 2695 } 2696 2697 /** 2698 * Helper function to add global attributes to a tag in the allowed HTML list. 2699 * 2700 * @since 3.5.0 2701 * @since 5.0.0 Added support for `data-*` wildcard attributes. 2702 * @since 6.0.0 Added `dir`, `lang`, and `xml:lang` to global attributes. 2703 * @since 6.3.0 Added `aria-controls`, `aria-current`, and `aria-expanded` attributes. 2704 * @since 6.4.0 Added `aria-live` and `hidden` attributes. 2705 * 2706 * @access private 2707 * @ignore 2708 * 2709 * @param array $value An array of attributes. 2710 * @return array The array of attributes with global attributes added. 2711 */ 2712 function _wp_add_global_attributes( $value ) { 2713 $global_attributes = array( 2714 'aria-controls' => true, 2715 'aria-current' => true, 2716 'aria-describedby' => true, 2717 'aria-details' => true, 2718 'aria-expanded' => true, 2719 'aria-hidden' => true, 2720 'aria-label' => true, 2721 'aria-labelledby' => true, 2722 'aria-live' => true, 2723 'class' => true, 2724 'data-*' => true, 2725 'dir' => true, 2726 'hidden' => true, 2727 'id' => true, 2728 'lang' => true, 2729 'style' => true, 2730 'title' => true, 2731 'role' => true, 2732 'xml:lang' => true, 2733 ); 2734 2735 if ( true === $value ) { 2736 $value = array(); 2737 } 2738 2739 if ( is_array( $value ) ) { 2740 return array_merge( $value, $global_attributes ); 2741 } 2742 2743 return $value; 2744 } 2745 2746 /** 2747 * Helper function to check if this is a safe PDF URL. 2748 * 2749 * @since 5.9.0 2750 * @access private 2751 * @ignore 2752 * 2753 * @param string $url The URL to check. 2754 * @return bool True if the URL is safe, false otherwise. 2755 */ 2756 function _wp_kses_allow_pdf_objects( $url ) { 2757 // We're not interested in URLs that contain query strings or fragments. 2758 if ( str_contains( $url, '?' ) || str_contains( $url, '#' ) ) { 2759 return false; 2760 } 2761 2762 // If it doesn't have a PDF extension, it's not safe. 2763 if ( ! str_ends_with( $url, '.pdf' ) ) { 2764 return false; 2765 } 2766 2767 // If the URL host matches the current site's media URL, it's safe. 2768 $upload_info = wp_upload_dir( null, false ); 2769 $parsed_url = wp_parse_url( $upload_info['url'] ); 2770 $upload_host = isset( $parsed_url['host'] ) ? $parsed_url['host'] : ''; 2771 $upload_port = isset( $parsed_url['port'] ) ? ':' . $parsed_url['port'] : ''; 2772 2773 if ( str_starts_with( $url, "http://$upload_host$upload_port/" ) 2774 || str_starts_with( $url, "https://$upload_host$upload_port/" ) 2775 ) { 2776 return true; 2777 } 2778 2779 return false; 2780 }
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