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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_term_description': 899 case 'pre_user_description': 900 $tags = $allowedtags; 901 $tags['a']['rel'] = true; 902 $tags['a']['target'] = true; 903 /** This filter is documented in wp-includes/kses.php */ 904 return apply_filters( 'wp_kses_allowed_html', $tags, $context ); 905 906 case 'strip': 907 /** This filter is documented in wp-includes/kses.php */ 908 return apply_filters( 'wp_kses_allowed_html', array(), $context ); 909 910 case 'entities': 911 /** This filter is documented in wp-includes/kses.php */ 912 return apply_filters( 'wp_kses_allowed_html', $allowedentitynames, $context ); 913 914 case 'data': 915 default: 916 /** This filter is documented in wp-includes/kses.php */ 917 return apply_filters( 'wp_kses_allowed_html', $allowedtags, $context ); 918 } 919 } 920 921 /** 922 * You add any KSES hooks here. 923 * 924 * There is currently only one KSES WordPress hook, {@see 'pre_kses'}, and it is called here. 925 * All parameters are passed to the hooks and expected to receive a string. 926 * 927 * @since 1.0.0 928 * 929 * @param string $content Content to filter through KSES. 930 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 931 * or a context name such as 'post'. See wp_kses_allowed_html() 932 * for the list of accepted context names. 933 * @param string[] $allowed_protocols Array of allowed URL protocols. 934 * @return string Filtered content through {@see 'pre_kses'} hook. 935 */ 936 function wp_kses_hook( $content, $allowed_html, $allowed_protocols ) { 937 /** 938 * Filters content to be run through KSES. 939 * 940 * @since 2.3.0 941 * 942 * @param string $content Content to filter through KSES. 943 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 944 * or a context name such as 'post'. See wp_kses_allowed_html() 945 * for the list of accepted context names. 946 * @param string[] $allowed_protocols Array of allowed URL protocols. 947 */ 948 return apply_filters( 'pre_kses', $content, $allowed_html, $allowed_protocols ); 949 } 950 951 /** 952 * Returns the version number of KSES. 953 * 954 * @since 1.0.0 955 * 956 * @return string KSES version number. 957 */ 958 function wp_kses_version() { 959 return '0.2.2'; 960 } 961 962 /** 963 * Searches for HTML tags, no matter how malformed. 964 * 965 * It also matches stray `>` characters. 966 * 967 * @since 1.0.0 968 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. 969 * 970 * @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes, 971 * or a context name such as 'post'. 972 * @global string[] $pass_allowed_protocols Array of allowed URL protocols. 973 * 974 * @param string $content Content to filter. 975 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 976 * or a context name such as 'post'. See wp_kses_allowed_html() 977 * for the list of accepted context names. 978 * @param string[] $allowed_protocols Array of allowed URL protocols. 979 * @return string Content with fixed HTML tags 980 */ 981 function wp_kses_split( $content, $allowed_html, $allowed_protocols ) { 982 global $pass_allowed_html, $pass_allowed_protocols; 983 984 $pass_allowed_html = $allowed_html; 985 $pass_allowed_protocols = $allowed_protocols; 986 987 $token_pattern = <<<REGEX 988 ~ 989 ( # Detect comments of various flavors before attempting to find tags. 990 (<!--.*?(-->|$)) # - Normative HTML comments. 991 | 992 </[^a-zA-Z][^>]*> # - Closing tags with invalid tag names. 993 | 994 <![^>]*> # - Invalid markup declaration nodes. Not all invalid nodes 995 # are matched so as to avoid breaking legacy behaviors. 996 ) 997 | 998 (<[^>]*(>|$)|>) # Tag-like spans of text. 999 ~x 1000 REGEX; 1001 return preg_replace_callback( $token_pattern, '_wp_kses_split_callback', $content ); 1002 } 1003 1004 /** 1005 * Returns an array of HTML attribute names whose value contains a URL. 1006 * 1007 * This function returns a list of all HTML attributes that must contain 1008 * a URL according to the HTML specification. 1009 * 1010 * This list includes URI attributes both allowed and disallowed by KSES. 1011 * 1012 * @link https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes 1013 * 1014 * @since 5.0.1 1015 * 1016 * @return string[] HTML attribute names whose value contains a URL. 1017 */ 1018 function wp_kses_uri_attributes() { 1019 $uri_attributes = array( 1020 'action', 1021 'archive', 1022 'background', 1023 'cite', 1024 'classid', 1025 'codebase', 1026 'data', 1027 'formaction', 1028 'href', 1029 'icon', 1030 'longdesc', 1031 'manifest', 1032 'poster', 1033 'profile', 1034 'src', 1035 'usemap', 1036 'xmlns', 1037 ); 1038 1039 /** 1040 * Filters the list of attributes that are required to contain a URL. 1041 * 1042 * Use this filter to add any `data-` attributes that are required to be 1043 * validated as a URL. 1044 * 1045 * @since 5.0.1 1046 * 1047 * @param string[] $uri_attributes HTML attribute names whose value contains a URL. 1048 */ 1049 $uri_attributes = apply_filters( 'wp_kses_uri_attributes', $uri_attributes ); 1050 1051 return $uri_attributes; 1052 } 1053 1054 /** 1055 * Callback for `wp_kses_split()`. 1056 * 1057 * @since 3.1.0 1058 * @access private 1059 * @ignore 1060 * 1061 * @global array[]|string $pass_allowed_html An array of allowed HTML elements and attributes, 1062 * or a context name such as 'post'. 1063 * @global string[] $pass_allowed_protocols Array of allowed URL protocols. 1064 * 1065 * @param array $matches preg_replace regexp matches 1066 * @return string 1067 */ 1068 function _wp_kses_split_callback( $matches ) { 1069 global $pass_allowed_html, $pass_allowed_protocols; 1070 1071 return wp_kses_split2( $matches[0], $pass_allowed_html, $pass_allowed_protocols ); 1072 } 1073 1074 /** 1075 * Callback for `wp_kses_split()` for fixing malformed HTML tags. 1076 * 1077 * This function does a lot of work. It rejects some very malformed things like 1078 * `<:::>`. It returns an empty string, if the element isn't allowed (look ma, no 1079 * `strip_tags()`!). Otherwise it splits the tag into an element and an attribute 1080 * list. 1081 * 1082 * After the tag is split into an element and an attribute list, it is run 1083 * through another filter which will remove illegal attributes and once that is 1084 * completed, will be returned. 1085 * 1086 * @access private 1087 * @ignore 1088 * @since 1.0.0 1089 * @since 6.6.0 Recognize additional forms of invalid HTML which convert into comments. 1090 * 1091 * @param string $content Content to filter. 1092 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 1093 * or a context name such as 'post'. See wp_kses_allowed_html() 1094 * for the list of accepted context names. 1095 * @param string[] $allowed_protocols Array of allowed URL protocols. 1096 * 1097 * @return string Fixed HTML element 1098 */ 1099 function wp_kses_split2( $content, $allowed_html, $allowed_protocols ) { 1100 $content = wp_kses_stripslashes( $content ); 1101 1102 /* 1103 * The regex pattern used to split HTML into chunks attempts 1104 * to split on HTML token boundaries. This function should 1105 * thus receive chunks that _either_ start with meaningful 1106 * syntax tokens, like a tag `<div>` or a comment `<!-- ... -->`. 1107 * 1108 * If the first character of the `$content` chunk _isn't_ one 1109 * of these syntax elements, which always starts with `<`, then 1110 * the match had to be for the final alternation of `>`. In such 1111 * case, it's probably standing on its own and could be encoded 1112 * with a character reference to remove ambiguity. 1113 * 1114 * In other words, if this chunk isn't from a match of a syntax 1115 * token, it's just a plaintext greater-than (`>`) sign. 1116 */ 1117 if ( ! str_starts_with( $content, '<' ) ) { 1118 return '>'; 1119 } 1120 1121 /* 1122 * When certain invalid syntax constructs appear, the HTML parser 1123 * shifts into what's called the "bogus comment state." This is a 1124 * plaintext state that consumes everything until the nearest `>` 1125 * and then transforms the entire span into an HTML comment. 1126 * 1127 * Preserve these comments and do not treat them like tags. 1128 * 1129 * @see https://html.spec.whatwg.org/#bogus-comment-state 1130 */ 1131 if ( 1 === preg_match( '~^(?:</[^a-zA-Z][^>]*>|<![a-z][^>]*>)$~', $content ) ) { 1132 /** 1133 * Since the pattern matches `</…>` and also `<!…>`, this will 1134 * preserve the type of the cleaned-up token in the output. 1135 */ 1136 $opener = $content[1]; 1137 $content = substr( $content, 2, -1 ); 1138 1139 do { 1140 $prev = $content; 1141 $content = wp_kses( $content, $allowed_html, $allowed_protocols ); 1142 } while ( $prev !== $content ); 1143 1144 // Recombine the modified inner content with the original token structure. 1145 return "<{$opener}{$content}>"; 1146 } 1147 1148 /* 1149 * Normative HTML comments should be handled separately as their 1150 * parsing rules differ from those for tags and text nodes. 1151 */ 1152 if ( str_starts_with( $content, '<!--' ) ) { 1153 $content = str_replace( array( '<!--', '-->' ), '', $content ); 1154 1155 while ( ( $newstring = wp_kses( $content, $allowed_html, $allowed_protocols ) ) !== $content ) { 1156 $content = $newstring; 1157 } 1158 1159 if ( '' === $content ) { 1160 return ''; 1161 } 1162 1163 // Prevent multiple dashes in comments. 1164 $content = preg_replace( '/--+/', '-', $content ); 1165 // Prevent three dashes closing a comment. 1166 $content = preg_replace( '/-$/', '', $content ); 1167 1168 return "<!--{$content}-->"; 1169 } 1170 1171 // It's seriously malformed. 1172 if ( ! preg_match( '%^<\s*(/\s*)?([a-zA-Z0-9-]+)([^>]*)>?$%', $content, $matches ) ) { 1173 return ''; 1174 } 1175 1176 $slash = trim( $matches[1] ); 1177 $elem = $matches[2]; 1178 $attrlist = $matches[3]; 1179 1180 if ( ! is_array( $allowed_html ) ) { 1181 $allowed_html = wp_kses_allowed_html( $allowed_html ); 1182 } 1183 1184 // They are using a not allowed HTML element. 1185 if ( ! isset( $allowed_html[ strtolower( $elem ) ] ) ) { 1186 return ''; 1187 } 1188 1189 // No attributes are allowed for closing elements. 1190 if ( '' !== $slash ) { 1191 return "</$elem>"; 1192 } 1193 1194 return wp_kses_attr( $elem, $attrlist, $allowed_html, $allowed_protocols ); 1195 } 1196 1197 /** 1198 * Removes all attributes, if none are allowed for this element. 1199 * 1200 * If some are allowed it calls `wp_kses_hair()` to split them further, and then 1201 * it builds up new HTML code from the data that `wp_kses_hair()` returns. It also 1202 * removes `<` and `>` characters, if there are any left. One more thing it does 1203 * is to check if the tag has a closing XHTML slash, and if it does, it puts one 1204 * in the returned code as well. 1205 * 1206 * An array of allowed values can be defined for attributes. If the attribute value 1207 * doesn't fall into the list, the attribute will be removed from the tag. 1208 * 1209 * Attributes can be marked as required. If a required attribute is not present, 1210 * KSES will remove all attributes from the tag. As KSES doesn't match opening and 1211 * closing tags, it's not possible to safely remove the tag itself, the safest 1212 * fallback is to strip all attributes from the tag, instead. 1213 * 1214 * @since 1.0.0 1215 * @since 5.9.0 Added support for an array of allowed values for attributes. 1216 * Added support for required attributes. 1217 * 1218 * @param string $element HTML element/tag. 1219 * @param string $attr HTML attributes from HTML element to closing HTML element tag. 1220 * @param array[]|string $allowed_html An array of allowed HTML elements and attributes, 1221 * or a context name such as 'post'. See wp_kses_allowed_html() 1222 * for the list of accepted context names. 1223 * @param string[] $allowed_protocols Array of allowed URL protocols. 1224 * @return string Sanitized HTML element. 1225 */ 1226 function wp_kses_attr( $element, $attr, $allowed_html, $allowed_protocols ) { 1227 if ( ! is_array( $allowed_html ) ) { 1228 $allowed_html = wp_kses_allowed_html( $allowed_html ); 1229 } 1230 1231 // Is there a closing XHTML slash at the end of the attributes? 1232 $xhtml_slash = ''; 1233 if ( preg_match( '%\s*/\s*$%', $attr ) ) { 1234 $xhtml_slash = ' /'; 1235 } 1236 1237 // Are any attributes allowed at all for this element? 1238 $element_low = strtolower( $element ); 1239 if ( empty( $allowed_html[ $element_low ] ) || true === $allowed_html[ $element_low ] ) { 1240 return "<$element$xhtml_slash>"; 1241 } 1242 1243 // Split it. 1244 $attrarr = wp_kses_hair( $attr, $allowed_protocols ); 1245 1246 // Check if there are attributes that are required. 1247 $required_attrs = array_filter( 1248 $allowed_html[ $element_low ], 1249 static function ( $required_attr_limits ) { 1250 return isset( $required_attr_limits['required'] ) && true === $required_attr_limits['required']; 1251 } 1252 ); 1253 1254 /* 1255 * If a required attribute check fails, we can return nothing for a self-closing tag, 1256 * but for a non-self-closing tag the best option is to return the element with attributes, 1257 * as KSES doesn't handle matching the relevant closing tag. 1258 */ 1259 $stripped_tag = ''; 1260 if ( empty( $xhtml_slash ) ) { 1261 $stripped_tag = "<$element>"; 1262 } 1263 1264 // Go through $attrarr, and save the allowed attributes for this element in $attr2. 1265 $attr2 = ''; 1266 foreach ( $attrarr as $arreach ) { 1267 // Check if this attribute is required. 1268 $required = isset( $required_attrs[ strtolower( $arreach['name'] ) ] ); 1269 1270 if ( wp_kses_attr_check( $arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html ) ) { 1271 $attr2 .= ' ' . $arreach['whole']; 1272 1273 // If this was a required attribute, we can mark it as found. 1274 if ( $required ) { 1275 unset( $required_attrs[ strtolower( $arreach['name'] ) ] ); 1276 } 1277 } elseif ( $required ) { 1278 // This attribute was required, but didn't pass the check. The entire tag is not allowed. 1279 return $stripped_tag; 1280 } 1281 } 1282 1283 // If some required attributes weren't set, the entire tag is not allowed. 1284 if ( ! empty( $required_attrs ) ) { 1285 return $stripped_tag; 1286 } 1287 1288 // Remove any "<" or ">" characters. 1289 $attr2 = preg_replace( '/[<>]/', '', $attr2 ); 1290 1291 return "<$element$attr2$xhtml_slash>"; 1292 } 1293 1294 /** 1295 * Determines whether an attribute is allowed. 1296 * 1297 * @since 4.2.3 1298 * @since 5.0.0 Added support for `data-*` wildcard attributes. 1299 * 1300 * @param string $name The attribute name. Passed by reference. Returns empty string when not allowed. 1301 * @param string $value The attribute value. Passed by reference. Returns a filtered value. 1302 * @param string $whole The `name=value` input. Passed by reference. Returns filtered input. 1303 * @param string $vless Whether the attribute is valueless. Use 'y' or 'n'. 1304 * @param string $element The name of the element to which this attribute belongs. 1305 * @param array $allowed_html The full list of allowed elements and attributes. 1306 * @return bool Whether or not the attribute is allowed. 1307 */ 1308 function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowed_html ) { 1309 $name_low = strtolower( $name ); 1310 $element_low = strtolower( $element ); 1311 1312 if ( ! isset( $allowed_html[ $element_low ] ) ) { 1313 $name = ''; 1314 $value = ''; 1315 $whole = ''; 1316 return false; 1317 } 1318 1319 $allowed_attr = $allowed_html[ $element_low ]; 1320 1321 if ( ! isset( $allowed_attr[ $name_low ] ) || '' === $allowed_attr[ $name_low ] ) { 1322 /* 1323 * Allow `data-*` attributes. 1324 * 1325 * When specifying `$allowed_html`, the attribute name should be set as 1326 * `data-*` (not to be mixed with the HTML 4.0 `data` attribute, see 1327 * https://www.w3.org/TR/html40/struct/objects.html#adef-data). 1328 * 1329 * Note: the attribute name should only contain `A-Za-z0-9_-` chars. 1330 */ 1331 if ( str_starts_with( $name_low, 'data-' ) && ! empty( $allowed_attr['data-*'] ) 1332 && preg_match( '/^data-[a-z0-9_-]+$/', $name_low, $match ) 1333 ) { 1334 /* 1335 * Add the whole attribute name to the allowed attributes and set any restrictions 1336 * for the `data-*` attribute values for the current element. 1337 */ 1338 $allowed_attr[ $match[0] ] = $allowed_attr['data-*']; 1339 } else { 1340 $name = ''; 1341 $value = ''; 1342 $whole = ''; 1343 return false; 1344 } 1345 } 1346 1347 if ( 'style' === $name_low ) { 1348 $new_value = safecss_filter_attr( $value ); 1349 1350 if ( empty( $new_value ) ) { 1351 $name = ''; 1352 $value = ''; 1353 $whole = ''; 1354 return false; 1355 } 1356 1357 $whole = str_replace( $value, $new_value, $whole ); 1358 $value = $new_value; 1359 } 1360 1361 if ( is_array( $allowed_attr[ $name_low ] ) ) { 1362 // There are some checks. 1363 foreach ( $allowed_attr[ $name_low ] as $currkey => $currval ) { 1364 if ( ! wp_kses_check_attr_val( $value, $vless, $currkey, $currval ) ) { 1365 $name = ''; 1366 $value = ''; 1367 $whole = ''; 1368 return false; 1369 } 1370 } 1371 } 1372 1373 return true; 1374 } 1375 1376 /** 1377 * Builds an attribute list from string containing attributes. 1378 * 1379 * This function does a lot of work. It parses an attribute list into an array 1380 * with attribute data, and tries to do the right thing even if it gets weird 1381 * input. It will add quotes around attribute values that don't have any quotes 1382 * or apostrophes around them, to make it easier to produce HTML code that will 1383 * conform to W3C's HTML specification. It will also remove bad URL protocols 1384 * from attribute values. It also reduces duplicate attributes by using the 1385 * attribute defined first (`foo='bar' foo='baz'` will result in `foo='bar'`). 1386 * 1387 * @since 1.0.0 1388 * 1389 * @param string $attr Attribute list from HTML element to closing HTML element tag. 1390 * @param string[] $allowed_protocols Array of allowed URL protocols. 1391 * @return array[] Array of attribute information after parsing. 1392 */ 1393 function wp_kses_hair( $attr, $allowed_protocols ) { 1394 $attrarr = array(); 1395 $mode = 0; 1396 $attrname = ''; 1397 $uris = wp_kses_uri_attributes(); 1398 1399 // Loop through the whole attribute list. 1400 1401 while ( strlen( $attr ) !== 0 ) { 1402 $working = 0; // Was the last operation successful? 1403 1404 switch ( $mode ) { 1405 case 0: 1406 if ( preg_match( '/^([_a-zA-Z][-_a-zA-Z0-9:.]*)/', $attr, $match ) ) { 1407 $attrname = $match[1]; 1408 $working = 1; 1409 $mode = 1; 1410 $attr = preg_replace( '/^[_a-zA-Z][-_a-zA-Z0-9:.]*/', '', $attr ); 1411 } 1412 1413 break; 1414 1415 case 1: 1416 if ( preg_match( '/^\s*=\s*/', $attr ) ) { // Equals sign. 1417 $working = 1; 1418 $mode = 2; 1419 $attr = preg_replace( '/^\s*=\s*/', '', $attr ); 1420 break; 1421 } 1422 1423 if ( preg_match( '/^\s+/', $attr ) ) { // Valueless. 1424 $working = 1; 1425 $mode = 0; 1426 1427 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1428 $attrarr[ $attrname ] = array( 1429 'name' => $attrname, 1430 'value' => '', 1431 'whole' => $attrname, 1432 'vless' => 'y', 1433 ); 1434 } 1435 1436 $attr = preg_replace( '/^\s+/', '', $attr ); 1437 } 1438 1439 break; 1440 1441 case 2: 1442 if ( preg_match( '%^"([^"]*)"(\s+|/?$)%', $attr, $match ) ) { 1443 // "value" 1444 $thisval = $match[1]; 1445 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1446 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1447 } 1448 1449 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1450 $attrarr[ $attrname ] = array( 1451 'name' => $attrname, 1452 'value' => $thisval, 1453 'whole' => "$attrname=\"$thisval\"", 1454 'vless' => 'n', 1455 ); 1456 } 1457 1458 $working = 1; 1459 $mode = 0; 1460 $attr = preg_replace( '/^"[^"]*"(\s+|$)/', '', $attr ); 1461 break; 1462 } 1463 1464 if ( preg_match( "%^'([^']*)'(\s+|/?$)%", $attr, $match ) ) { 1465 // 'value' 1466 $thisval = $match[1]; 1467 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1468 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1469 } 1470 1471 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1472 $attrarr[ $attrname ] = array( 1473 'name' => $attrname, 1474 'value' => $thisval, 1475 'whole' => "$attrname='$thisval'", 1476 'vless' => 'n', 1477 ); 1478 } 1479 1480 $working = 1; 1481 $mode = 0; 1482 $attr = preg_replace( "/^'[^']*'(\s+|$)/", '', $attr ); 1483 break; 1484 } 1485 1486 if ( preg_match( "%^([^\s\"']+)(\s+|/?$)%", $attr, $match ) ) { 1487 // value 1488 $thisval = $match[1]; 1489 if ( in_array( strtolower( $attrname ), $uris, true ) ) { 1490 $thisval = wp_kses_bad_protocol( $thisval, $allowed_protocols ); 1491 } 1492 1493 if ( false === array_key_exists( $attrname, $attrarr ) ) { 1494 $attrarr[ $attrname ] = array( 1495 'name' => $attrname, 1496 'value' => $thisval, 1497 'whole' => "$attrname=\"$thisval\"", 1498 'vless' => 'n', 1499 ); 1500 } 1501 1502 // We add quotes to conform to W3C's HTML spec. 1503 $working = 1; 1504 $mode = 0; 1505 $attr = preg_replace( "%^[^\s\"']+(\s+|$)%", '', $attr ); 1506 } 1507 1508 break; 1509 } // End switch. 1510 1511 if ( 0 === $working ) { // Not well-formed, remove and try again. 1512 $attr = wp_kses_html_error( $attr ); 1513 $mode = 0; 1514 } 1515 } // End while. 1516 1517 if ( 1 === $mode && false === array_key_exists( $attrname, $attrarr ) ) { 1518 /* 1519 * Special case, for when the attribute list ends with a valueless 1520 * attribute like "selected". 1521 */ 1522 $attrarr[ $attrname ] = array( 1523 'name' => $attrname, 1524 'value' => '', 1525 'whole' => $attrname, 1526 'vless' => 'y', 1527 ); 1528 } 1529 1530 return $attrarr; 1531 } 1532 1533 /** 1534 * Finds all attributes of an HTML element. 1535 * 1536 * Does not modify input. May return "evil" output. 1537 * 1538 * Based on `wp_kses_split2()` and `wp_kses_attr()`. 1539 * 1540 * @since 4.2.3 1541 * 1542 * @param string $element HTML element. 1543 * @return array|false List of attributes found in the element. Returns false on failure. 1544 */ 1545 function wp_kses_attr_parse( $element ) { 1546 $valid = preg_match( '%^(<\s*)(/\s*)?([a-zA-Z0-9]+\s*)([^>]*)(>?)$%', $element, $matches ); 1547 if ( 1 !== $valid ) { 1548 return false; 1549 } 1550 1551 $begin = $matches[1]; 1552 $slash = $matches[2]; 1553 $elname = $matches[3]; 1554 $attr = $matches[4]; 1555 $end = $matches[5]; 1556 1557 if ( '' !== $slash ) { 1558 // Closing elements do not get parsed. 1559 return false; 1560 } 1561 1562 // Is there a closing XHTML slash at the end of the attributes? 1563 if ( 1 === preg_match( '%\s*/\s*$%', $attr, $matches ) ) { 1564 $xhtml_slash = $matches[0]; 1565 $attr = substr( $attr, 0, -strlen( $xhtml_slash ) ); 1566 } else { 1567 $xhtml_slash = ''; 1568 } 1569 1570 // Split it. 1571 $attrarr = wp_kses_hair_parse( $attr ); 1572 if ( false === $attrarr ) { 1573 return false; 1574 } 1575 1576 // Make sure all input is returned by adding front and back matter. 1577 array_unshift( $attrarr, $begin . $slash . $elname ); 1578 array_push( $attrarr, $xhtml_slash . $end ); 1579 1580 return $attrarr; 1581 } 1582 1583 /** 1584 * Builds an attribute list from string containing attributes. 1585 * 1586 * Does not modify input. May return "evil" output. 1587 * In case of unexpected input, returns false instead of stripping things. 1588 * 1589 * Based on `wp_kses_hair()` but does not return a multi-dimensional array. 1590 * 1591 * @since 4.2.3 1592 * 1593 * @param string $attr Attribute list from HTML element to closing HTML element tag. 1594 * @return array|false List of attributes found in $attr. Returns false on failure. 1595 */ 1596 function wp_kses_hair_parse( $attr ) { 1597 if ( '' === $attr ) { 1598 return array(); 1599 } 1600 1601 $regex = 1602 '(?: 1603 [_a-zA-Z][-_a-zA-Z0-9:.]* # Attribute name. 1604 | 1605 \[\[?[^\[\]]+\]\]? # Shortcode in the name position implies unfiltered_html. 1606 ) 1607 (?: # Attribute value. 1608 \s*=\s* # All values begin with "=". 1609 (?: 1610 "[^"]*" # Double-quoted. 1611 | 1612 \'[^\']*\' # Single-quoted. 1613 | 1614 [^\s"\']+ # Non-quoted. 1615 (?:\s|$) # Must have a space. 1616 ) 1617 | 1618 (?:\s|$) # If attribute has no value, space is required. 1619 ) 1620 \s* # Trailing space is optional except as mentioned above. 1621 '; 1622 1623 /* 1624 * Although it is possible to reduce this procedure to a single regexp, 1625 * we must run that regexp twice to get exactly the expected result. 1626 * 1627 * Note: do NOT remove the `x` modifiers as they are essential for the above regex! 1628 */ 1629 1630 $validation = "/^($regex)+$/x"; 1631 $extraction = "/$regex/x"; 1632 1633 if ( 1 === preg_match( $validation, $attr ) ) { 1634 preg_match_all( $extraction, $attr, $attrarr ); 1635 return $attrarr[0]; 1636 } else { 1637 return false; 1638 } 1639 } 1640 1641 /** 1642 * Performs different checks for attribute values. 1643 * 1644 * The currently implemented checks are "maxlen", "minlen", "maxval", "minval", 1645 * and "valueless". 1646 * 1647 * @since 1.0.0 1648 * 1649 * @param string $value Attribute value. 1650 * @param string $vless Whether the attribute is valueless. Use 'y' or 'n'. 1651 * @param string $checkname What $checkvalue is checking for. 1652 * @param mixed $checkvalue What constraint the value should pass. 1653 * @return bool Whether check passes. 1654 */ 1655 function wp_kses_check_attr_val( $value, $vless, $checkname, $checkvalue ) { 1656 $ok = true; 1657 1658 switch ( strtolower( $checkname ) ) { 1659 case 'maxlen': 1660 /* 1661 * The maxlen check makes sure that the attribute value has a length not 1662 * greater than the given value. This can be used to avoid Buffer Overflows 1663 * in WWW clients and various Internet servers. 1664 */ 1665 1666 if ( strlen( $value ) > $checkvalue ) { 1667 $ok = false; 1668 } 1669 break; 1670 1671 case 'minlen': 1672 /* 1673 * The minlen check makes sure that the attribute value has a length not 1674 * smaller than the given value. 1675 */ 1676 1677 if ( strlen( $value ) < $checkvalue ) { 1678 $ok = false; 1679 } 1680 break; 1681 1682 case 'maxval': 1683 /* 1684 * The maxval check does two things: it checks that the attribute value is 1685 * an integer from 0 and up, without an excessive amount of zeroes or 1686 * whitespace (to avoid Buffer Overflows). It also checks that the attribute 1687 * value is not greater than the given value. 1688 * This check can be used to avoid Denial of Service attacks. 1689 */ 1690 1691 if ( ! preg_match( '/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value ) ) { 1692 $ok = false; 1693 } 1694 if ( $value > $checkvalue ) { 1695 $ok = false; 1696 } 1697 break; 1698 1699 case 'minval': 1700 /* 1701 * The minval check makes sure that the attribute value is a positive integer, 1702 * and that it is not smaller than the given value. 1703 */ 1704 1705 if ( ! preg_match( '/^\s{0,6}[0-9]{1,6}\s{0,6}$/', $value ) ) { 1706 $ok = false; 1707 } 1708 if ( $value < $checkvalue ) { 1709 $ok = false; 1710 } 1711 break; 1712 1713 case 'valueless': 1714 /* 1715 * The valueless check makes sure if the attribute has a value 1716 * (like `<a href="blah">`) or not (`<option selected>`). If the given value 1717 * is a "y" or a "Y", the attribute must not have a value. 1718 * If the given value is an "n" or an "N", the attribute must have a value. 1719 */ 1720 1721 if ( strtolower( $checkvalue ) !== $vless ) { 1722 $ok = false; 1723 } 1724 break; 1725 1726 case 'values': 1727 /* 1728 * The values check is used when you want to make sure that the attribute 1729 * has one of the given values. 1730 */ 1731 1732 if ( false === array_search( strtolower( $value ), $checkvalue, true ) ) { 1733 $ok = false; 1734 } 1735 break; 1736 1737 case 'value_callback': 1738 /* 1739 * The value_callback check is used when you want to make sure that the attribute 1740 * value is accepted by the callback function. 1741 */ 1742 1743 if ( ! call_user_func( $checkvalue, $value ) ) { 1744 $ok = false; 1745 } 1746 break; 1747 } // End switch. 1748 1749 return $ok; 1750 } 1751 1752 /** 1753 * Sanitizes a string and removed disallowed URL protocols. 1754 * 1755 * This function removes all non-allowed protocols from the beginning of the 1756 * string. It ignores whitespace and the case of the letters, and it does 1757 * understand HTML entities. It does its work recursively, so it won't be 1758 * fooled by a string like `javascript:javascript:alert(57)`. 1759 * 1760 * @since 1.0.0 1761 * 1762 * @param string $content Content to filter bad protocols from. 1763 * @param string[] $allowed_protocols Array of allowed URL protocols. 1764 * @return string Filtered content. 1765 */ 1766 function wp_kses_bad_protocol( $content, $allowed_protocols ) { 1767 $content = wp_kses_no_null( $content ); 1768 1769 // Short-circuit if the string starts with `https://` or `http://`. Most common cases. 1770 if ( 1771 ( str_starts_with( $content, 'https://' ) && in_array( 'https', $allowed_protocols, true ) ) || 1772 ( str_starts_with( $content, 'http://' ) && in_array( 'http', $allowed_protocols, true ) ) 1773 ) { 1774 return $content; 1775 } 1776 1777 $iterations = 0; 1778 1779 do { 1780 $original_content = $content; 1781 $content = wp_kses_bad_protocol_once( $content, $allowed_protocols ); 1782 } while ( $original_content !== $content && ++$iterations < 6 ); 1783 1784 if ( $original_content !== $content ) { 1785 return ''; 1786 } 1787 1788 return $content; 1789 } 1790 1791 /** 1792 * Removes any invalid control characters in a text string. 1793 * 1794 * Also removes any instance of the `\0` string. 1795 * 1796 * @since 1.0.0 1797 * 1798 * @param string $content Content to filter null characters from. 1799 * @param array $options Set 'slash_zero' => 'keep' when '\0' is allowed. Default is 'remove'. 1800 * @return string Filtered content. 1801 */ 1802 function wp_kses_no_null( $content, $options = null ) { 1803 if ( ! isset( $options['slash_zero'] ) ) { 1804 $options = array( 'slash_zero' => 'remove' ); 1805 } 1806 1807 $content = preg_replace( '/[\x00-\x08\x0B\x0C\x0E-\x1F]/', '', $content ); 1808 if ( 'remove' === $options['slash_zero'] ) { 1809 $content = preg_replace( '/\\\\+0+/', '', $content ); 1810 } 1811 1812 return $content; 1813 } 1814 1815 /** 1816 * Strips slashes from in front of quotes. 1817 * 1818 * This function changes the character sequence `\"` to just `"`. It leaves all other 1819 * slashes alone. The quoting from `preg_replace(//e)` requires this. 1820 * 1821 * @since 1.0.0 1822 * 1823 * @param string $content String to strip slashes from. 1824 * @return string Fixed string with quoted slashes. 1825 */ 1826 function wp_kses_stripslashes( $content ) { 1827 return preg_replace( '%\\\\"%', '"', $content ); 1828 } 1829 1830 /** 1831 * Converts the keys of an array to lowercase. 1832 * 1833 * @since 1.0.0 1834 * 1835 * @param array $inarray Unfiltered array. 1836 * @return array Fixed array with all lowercase keys. 1837 */ 1838 function wp_kses_array_lc( $inarray ) { 1839 $outarray = array(); 1840 1841 foreach ( (array) $inarray as $inkey => $inval ) { 1842 $outkey = strtolower( $inkey ); 1843 $outarray[ $outkey ] = array(); 1844 1845 foreach ( (array) $inval as $inkey2 => $inval2 ) { 1846 $outkey2 = strtolower( $inkey2 ); 1847 $outarray[ $outkey ][ $outkey2 ] = $inval2; 1848 } 1849 } 1850 1851 return $outarray; 1852 } 1853 1854 /** 1855 * Handles parsing errors in `wp_kses_hair()`. 1856 * 1857 * The general plan is to remove everything to and including some whitespace, 1858 * but it deals with quotes and apostrophes as well. 1859 * 1860 * @since 1.0.0 1861 * 1862 * @param string $attr 1863 * @return string 1864 */ 1865 function wp_kses_html_error( $attr ) { 1866 return preg_replace( '/^("[^"]*("|$)|\'[^\']*(\'|$)|\S)*\s*/', '', $attr ); 1867 } 1868 1869 /** 1870 * Sanitizes content from bad protocols and other characters. 1871 * 1872 * This function searches for URL protocols at the beginning of the string, while 1873 * handling whitespace and HTML entities. 1874 * 1875 * @since 1.0.0 1876 * 1877 * @param string $content Content to check for bad protocols. 1878 * @param string[] $allowed_protocols Array of allowed URL protocols. 1879 * @param int $count Depth of call recursion to this function. 1880 * @return string Sanitized content. 1881 */ 1882 function wp_kses_bad_protocol_once( $content, $allowed_protocols, $count = 1 ) { 1883 $content = preg_replace( '/(�*58(?![;0-9])|�*3a(?![;a-f0-9]))/i', '$1;', $content ); 1884 $content2 = preg_split( '/:|�*58;|�*3a;|:/i', $content, 2 ); 1885 1886 if ( isset( $content2[1] ) && ! preg_match( '%/\?%', $content2[0] ) ) { 1887 $content = trim( $content2[1] ); 1888 $protocol = wp_kses_bad_protocol_once2( $content2[0], $allowed_protocols ); 1889 if ( 'feed:' === $protocol ) { 1890 if ( $count > 2 ) { 1891 return ''; 1892 } 1893 $content = wp_kses_bad_protocol_once( $content, $allowed_protocols, ++$count ); 1894 if ( empty( $content ) ) { 1895 return $content; 1896 } 1897 } 1898 $content = $protocol . $content; 1899 } 1900 1901 return $content; 1902 } 1903 1904 /** 1905 * Callback for `wp_kses_bad_protocol_once()` regular expression. 1906 * 1907 * This function processes URL protocols, checks to see if they're in the 1908 * list of allowed protocols or not, and returns different data depending 1909 * on the answer. 1910 * 1911 * @access private 1912 * @ignore 1913 * @since 1.0.0 1914 * 1915 * @param string $scheme URI scheme to check against the list of allowed protocols. 1916 * @param string[] $allowed_protocols Array of allowed URL protocols. 1917 * @return string Sanitized content. 1918 */ 1919 function wp_kses_bad_protocol_once2( $scheme, $allowed_protocols ) { 1920 $scheme = wp_kses_decode_entities( $scheme ); 1921 $scheme = preg_replace( '/\s/', '', $scheme ); 1922 $scheme = wp_kses_no_null( $scheme ); 1923 $scheme = strtolower( $scheme ); 1924 1925 $allowed = false; 1926 foreach ( (array) $allowed_protocols as $one_protocol ) { 1927 if ( strtolower( $one_protocol ) === $scheme ) { 1928 $allowed = true; 1929 break; 1930 } 1931 } 1932 1933 if ( $allowed ) { 1934 return "$scheme:"; 1935 } else { 1936 return ''; 1937 } 1938 } 1939 1940 /** 1941 * Converts and fixes HTML entities. 1942 * 1943 * This function normalizes HTML entities. It will convert `AT&T` to the correct 1944 * `AT&T`, `:` to `:`, `&#XYZZY;` to `&#XYZZY;` and so on. 1945 * 1946 * When `$context` is set to 'xml', HTML entities are converted to their code points. For 1947 * example, `AT&T…&#XYZZY;` is converted to `AT&T…&#XYZZY;`. 1948 * 1949 * @since 1.0.0 1950 * @since 5.5.0 Added `$context` parameter. 1951 * 1952 * @param string $content Content to normalize entities. 1953 * @param string $context Context for normalization. Can be either 'html' or 'xml'. 1954 * Default 'html'. 1955 * @return string Content with normalized entities. 1956 */ 1957 function wp_kses_normalize_entities( $content, $context = 'html' ) { 1958 // Disarm all entities by converting & to & 1959 $content = str_replace( '&', '&', $content ); 1960 1961 // Change back the allowed entities in our list of allowed entities. 1962 if ( 'xml' === $context ) { 1963 $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_xml_named_entities', $content ); 1964 } else { 1965 $content = preg_replace_callback( '/&([A-Za-z]{2,8}[0-9]{0,2});/', 'wp_kses_named_entities', $content ); 1966 } 1967 $content = preg_replace_callback( '/&#(0*[0-9]{1,7});/', 'wp_kses_normalize_entities2', $content ); 1968 $content = preg_replace_callback( '/&#[Xx](0*[0-9A-Fa-f]{1,6});/', 'wp_kses_normalize_entities3', $content ); 1969 1970 return $content; 1971 } 1972 1973 /** 1974 * Callback for `wp_kses_normalize_entities()` regular expression. 1975 * 1976 * This function only accepts valid named entity references, which are finite, 1977 * case-sensitive, and highly scrutinized by HTML and XML validators. 1978 * 1979 * @since 3.0.0 1980 * 1981 * @global array $allowedentitynames 1982 * 1983 * @param array $matches preg_replace_callback() matches array. 1984 * @return string Correctly encoded entity. 1985 */ 1986 function wp_kses_named_entities( $matches ) { 1987 global $allowedentitynames; 1988 1989 if ( empty( $matches[1] ) ) { 1990 return ''; 1991 } 1992 1993 $i = $matches[1]; 1994 return ( ! in_array( $i, $allowedentitynames, true ) ) ? "&$i;" : "&$i;"; 1995 } 1996 1997 /** 1998 * Callback for `wp_kses_normalize_entities()` regular expression. 1999 * 2000 * This function only accepts valid named entity references, which are finite, 2001 * case-sensitive, and highly scrutinized by XML validators. HTML named entity 2002 * references are converted to their code points. 2003 * 2004 * @since 5.5.0 2005 * 2006 * @global array $allowedentitynames 2007 * @global array $allowedxmlentitynames 2008 * 2009 * @param array $matches preg_replace_callback() matches array. 2010 * @return string Correctly encoded entity. 2011 */ 2012 function wp_kses_xml_named_entities( $matches ) { 2013 global $allowedentitynames, $allowedxmlentitynames; 2014 2015 if ( empty( $matches[1] ) ) { 2016 return ''; 2017 } 2018 2019 $i = $matches[1]; 2020 2021 if ( in_array( $i, $allowedxmlentitynames, true ) ) { 2022 return "&$i;"; 2023 } elseif ( in_array( $i, $allowedentitynames, true ) ) { 2024 return html_entity_decode( "&$i;", ENT_HTML5 ); 2025 } 2026 2027 return "&$i;"; 2028 } 2029 2030 /** 2031 * Callback for `wp_kses_normalize_entities()` regular expression. 2032 * 2033 * This function helps `wp_kses_normalize_entities()` to only accept 16-bit 2034 * values and nothing more for `&#number;` entities. 2035 * 2036 * @access private 2037 * @ignore 2038 * @since 1.0.0 2039 * 2040 * @param array $matches `preg_replace_callback()` matches array. 2041 * @return string Correctly encoded entity. 2042 */ 2043 function wp_kses_normalize_entities2( $matches ) { 2044 if ( empty( $matches[1] ) ) { 2045 return ''; 2046 } 2047 2048 $i = $matches[1]; 2049 2050 if ( valid_unicode( $i ) ) { 2051 $i = str_pad( ltrim( $i, '0' ), 3, '0', STR_PAD_LEFT ); 2052 $i = "&#$i;"; 2053 } else { 2054 $i = "&#$i;"; 2055 } 2056 2057 return $i; 2058 } 2059 2060 /** 2061 * Callback for `wp_kses_normalize_entities()` for regular expression. 2062 * 2063 * This function helps `wp_kses_normalize_entities()` to only accept valid Unicode 2064 * numeric entities in hex form. 2065 * 2066 * @since 2.7.0 2067 * @access private 2068 * @ignore 2069 * 2070 * @param array $matches `preg_replace_callback()` matches array. 2071 * @return string Correctly encoded entity. 2072 */ 2073 function wp_kses_normalize_entities3( $matches ) { 2074 if ( empty( $matches[1] ) ) { 2075 return ''; 2076 } 2077 2078 $hexchars = $matches[1]; 2079 2080 return ( ! valid_unicode( hexdec( $hexchars ) ) ) ? "&#x$hexchars;" : '&#x' . ltrim( $hexchars, '0' ) . ';'; 2081 } 2082 2083 /** 2084 * Determines if a Unicode codepoint is valid. 2085 * 2086 * The definition of a valid Unicode codepoint is taken from the XML definition: 2087 * 2088 * > Characters 2089 * > 2090 * > … 2091 * > Legal characters are tab, carriage return, line feed, and the legal characters of 2092 * > Unicode and ISO/IEC 10646. 2093 * > … 2094 * > Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] 2095 * 2096 * @since 2.7.0 2097 * 2098 * @see https://www.w3.org/TR/xml/#charsets 2099 * 2100 * @param int $i Unicode codepoint. 2101 * @return bool Whether or not the codepoint is a valid Unicode codepoint. 2102 */ 2103 function valid_unicode( $i ) { 2104 $i = (int) $i; 2105 2106 return ( 2107 0x9 === $i || // U+0009 HORIZONTAL TABULATION (HT) 2108 0xA === $i || // U+000A LINE FEED (LF) 2109 0xD === $i || // U+000D CARRIAGE RETURN (CR) 2110 /* 2111 * The valid Unicode characters according to the XML specification: 2112 * 2113 * > any Unicode character, excluding the surrogate blocks, FFFE, and FFFF. 2114 */ 2115 ( 0x20 <= $i && $i <= 0xD7FF ) || 2116 ( 0xE000 <= $i && $i <= 0xFFFD ) || 2117 ( 0x10000 <= $i && $i <= 0x10FFFF ) 2118 ); 2119 } 2120 2121 /** 2122 * Converts all numeric HTML entities to their named counterparts. 2123 * 2124 * This function decodes numeric HTML entities (`A` and `A`). 2125 * It doesn't do anything with named entities like `ä`, but we don't 2126 * need them in the allowed URL protocols system anyway. 2127 * 2128 * @since 1.0.0 2129 * 2130 * @param string $content Content to change entities. 2131 * @return string Content after decoded entities. 2132 */ 2133 function wp_kses_decode_entities( $content ) { 2134 $content = preg_replace_callback( '/&#([0-9]+);/', '_wp_kses_decode_entities_chr', $content ); 2135 $content = preg_replace_callback( '/&#[Xx]([0-9A-Fa-f]+);/', '_wp_kses_decode_entities_chr_hexdec', $content ); 2136 2137 return $content; 2138 } 2139 2140 /** 2141 * Regex callback for `wp_kses_decode_entities()`. 2142 * 2143 * @since 2.9.0 2144 * @access private 2145 * @ignore 2146 * 2147 * @param array $matches preg match 2148 * @return string 2149 */ 2150 function _wp_kses_decode_entities_chr( $matches ) { 2151 return chr( $matches[1] ); 2152 } 2153 2154 /** 2155 * Regex callback for `wp_kses_decode_entities()`. 2156 * 2157 * @since 2.9.0 2158 * @access private 2159 * @ignore 2160 * 2161 * @param array $matches preg match 2162 * @return string 2163 */ 2164 function _wp_kses_decode_entities_chr_hexdec( $matches ) { 2165 return chr( hexdec( $matches[1] ) ); 2166 } 2167 2168 /** 2169 * Sanitize content with allowed HTML KSES rules. 2170 * 2171 * This function expects slashed data. 2172 * 2173 * @since 1.0.0 2174 * 2175 * @param string $data Content to filter, expected to be escaped with slashes. 2176 * @return string Filtered content. 2177 */ 2178 function wp_filter_kses( $data ) { 2179 return addslashes( wp_kses( stripslashes( $data ), current_filter() ) ); 2180 } 2181 2182 /** 2183 * Sanitize content with allowed HTML KSES rules. 2184 * 2185 * This function expects unslashed data. 2186 * 2187 * @since 2.9.0 2188 * 2189 * @param string $data Content to filter, expected to not be escaped. 2190 * @return string Filtered content. 2191 */ 2192 function wp_kses_data( $data ) { 2193 return wp_kses( $data, current_filter() ); 2194 } 2195 2196 /** 2197 * Sanitizes content for allowed HTML tags for post content. 2198 * 2199 * Post content refers to the page contents of the 'post' type and not `$_POST` 2200 * data from forms. 2201 * 2202 * This function expects slashed data. 2203 * 2204 * @since 2.0.0 2205 * 2206 * @param string $data Post content to filter, expected to be escaped with slashes. 2207 * @return string Filtered post content with allowed HTML tags and attributes intact. 2208 */ 2209 function wp_filter_post_kses( $data ) { 2210 return addslashes( wp_kses( stripslashes( $data ), 'post' ) ); 2211 } 2212 2213 /** 2214 * Sanitizes global styles user content removing unsafe rules. 2215 * 2216 * @since 5.9.0 2217 * 2218 * @param string $data Post content to filter. 2219 * @return string Filtered post content with unsafe rules removed. 2220 */ 2221 function wp_filter_global_styles_post( $data ) { 2222 $decoded_data = json_decode( wp_unslash( $data ), true ); 2223 $json_decoding_error = json_last_error(); 2224 if ( 2225 JSON_ERROR_NONE === $json_decoding_error && 2226 is_array( $decoded_data ) && 2227 isset( $decoded_data['isGlobalStylesUserThemeJSON'] ) && 2228 $decoded_data['isGlobalStylesUserThemeJSON'] 2229 ) { 2230 unset( $decoded_data['isGlobalStylesUserThemeJSON'] ); 2231 2232 $data_to_encode = WP_Theme_JSON::remove_insecure_properties( $decoded_data, 'custom' ); 2233 2234 $data_to_encode['isGlobalStylesUserThemeJSON'] = true; 2235 return wp_slash( wp_json_encode( $data_to_encode ) ); 2236 } 2237 return $data; 2238 } 2239 2240 /** 2241 * Sanitizes content for allowed HTML tags for post content. 2242 * 2243 * Post content refers to the page contents of the 'post' type and not `$_POST` 2244 * data from forms. 2245 * 2246 * This function expects unslashed data. 2247 * 2248 * @since 2.9.0 2249 * 2250 * @param string $data Post content to filter. 2251 * @return string Filtered post content with allowed HTML tags and attributes intact. 2252 */ 2253 function wp_kses_post( $data ) { 2254 return wp_kses( $data, 'post' ); 2255 } 2256 2257 /** 2258 * Navigates through an array, object, or scalar, and sanitizes content for 2259 * allowed HTML tags for post content. 2260 * 2261 * @since 4.4.2 2262 * 2263 * @see map_deep() 2264 * 2265 * @param mixed $data The array, object, or scalar value to inspect. 2266 * @return mixed The filtered content. 2267 */ 2268 function wp_kses_post_deep( $data ) { 2269 return map_deep( $data, 'wp_kses_post' ); 2270 } 2271 2272 /** 2273 * Strips all HTML from a text string. 2274 * 2275 * This function expects slashed data. 2276 * 2277 * @since 2.1.0 2278 * 2279 * @param string $data Content to strip all HTML from. 2280 * @return string Filtered content without any HTML. 2281 */ 2282 function wp_filter_nohtml_kses( $data ) { 2283 return addslashes( wp_kses( stripslashes( $data ), 'strip' ) ); 2284 } 2285 2286 /** 2287 * Adds all KSES input form content filters. 2288 * 2289 * All hooks have default priority. The `wp_filter_kses()` function is added to 2290 * the 'pre_comment_content' and 'title_save_pre' hooks. 2291 * 2292 * The `wp_filter_post_kses()` function is added to the 'content_save_pre', 2293 * 'excerpt_save_pre', and 'content_filtered_save_pre' hooks. 2294 * 2295 * @since 2.0.0 2296 */ 2297 function kses_init_filters() { 2298 // Normal filtering. 2299 add_filter( 'title_save_pre', 'wp_filter_kses' ); 2300 2301 // Comment filtering. 2302 if ( current_user_can( 'unfiltered_html' ) ) { 2303 add_filter( 'pre_comment_content', 'wp_filter_post_kses' ); 2304 } else { 2305 add_filter( 'pre_comment_content', 'wp_filter_kses' ); 2306 } 2307 2308 // Global Styles filtering: Global Styles filters should be executed before normal post_kses HTML filters. 2309 add_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); 2310 add_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); 2311 2312 // Post filtering. 2313 add_filter( 'content_save_pre', 'wp_filter_post_kses' ); 2314 add_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); 2315 add_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); 2316 } 2317 2318 /** 2319 * Removes all KSES input form content filters. 2320 * 2321 * A quick procedural method to removing all of the filters that KSES uses for 2322 * content in WordPress Loop. 2323 * 2324 * Does not remove the `kses_init()` function from {@see 'init'} hook (priority is 2325 * default). Also does not remove `kses_init()` function from {@see 'set_current_user'} 2326 * hook (priority is also default). 2327 * 2328 * @since 2.0.6 2329 */ 2330 function kses_remove_filters() { 2331 // Normal filtering. 2332 remove_filter( 'title_save_pre', 'wp_filter_kses' ); 2333 2334 // Comment filtering. 2335 remove_filter( 'pre_comment_content', 'wp_filter_post_kses' ); 2336 remove_filter( 'pre_comment_content', 'wp_filter_kses' ); 2337 2338 // Global Styles filtering. 2339 remove_filter( 'content_save_pre', 'wp_filter_global_styles_post', 9 ); 2340 remove_filter( 'content_filtered_save_pre', 'wp_filter_global_styles_post', 9 ); 2341 2342 // Post filtering. 2343 remove_filter( 'content_save_pre', 'wp_filter_post_kses' ); 2344 remove_filter( 'excerpt_save_pre', 'wp_filter_post_kses' ); 2345 remove_filter( 'content_filtered_save_pre', 'wp_filter_post_kses' ); 2346 } 2347 2348 /** 2349 * Sets up most of the KSES filters for input form content. 2350 * 2351 * First removes all of the KSES filters in case the current user does not need 2352 * to have KSES filter the content. If the user does not have `unfiltered_html` 2353 * capability, then KSES filters are added. 2354 * 2355 * @since 2.0.0 2356 */ 2357 function kses_init() { 2358 kses_remove_filters(); 2359 2360 if ( ! current_user_can( 'unfiltered_html' ) ) { 2361 kses_init_filters(); 2362 } 2363 } 2364 2365 /** 2366 * Filters an inline style attribute and removes disallowed rules. 2367 * 2368 * @since 2.8.1 2369 * @since 4.4.0 Added support for `min-height`, `max-height`, `min-width`, and `max-width`. 2370 * @since 4.6.0 Added support for `list-style-type`. 2371 * @since 5.0.0 Added support for `background-image`. 2372 * @since 5.1.0 Added support for `text-transform`. 2373 * @since 5.2.0 Added support for `background-position` and `grid-template-columns`. 2374 * @since 5.3.0 Added support for `grid`, `flex` and `column` layout properties. 2375 * Extended `background-*` support for individual properties. 2376 * @since 5.3.1 Added support for gradient backgrounds. 2377 * @since 5.7.1 Added support for `object-position`. 2378 * @since 5.8.0 Added support for `calc()` and `var()` values. 2379 * @since 6.1.0 Added support for `min()`, `max()`, `minmax()`, `clamp()`, 2380 * nested `var()` values, and assigning values to CSS variables. 2381 * Added support for `object-fit`, `gap`, `column-gap`, `row-gap`, and `flex-wrap`. 2382 * Extended `margin-*` and `padding-*` support for logical properties. 2383 * @since 6.2.0 Added support for `aspect-ratio`, `position`, `top`, `right`, `bottom`, `left`, 2384 * and `z-index` CSS properties. 2385 * @since 6.3.0 Extended support for `filter` to accept a URL and added support for repeat(). 2386 * Added support for `box-shadow`. 2387 * @since 6.4.0 Added support for `writing-mode`. 2388 * @since 6.5.0 Added support for `background-repeat`. 2389 * @since 6.6.0 Added support for `grid-column`, `grid-row`, and `container-type`. 2390 * 2391 * @param string $css A string of CSS rules. 2392 * @param string $deprecated Not used. 2393 * @return string Filtered string of CSS rules. 2394 */ 2395 function safecss_filter_attr( $css, $deprecated = '' ) { 2396 if ( ! empty( $deprecated ) ) { 2397 _deprecated_argument( __FUNCTION__, '2.8.1' ); // Never implemented. 2398 } 2399 2400 $css = wp_kses_no_null( $css ); 2401 $css = str_replace( array( "\n", "\r", "\t" ), '', $css ); 2402 2403 $allowed_protocols = wp_allowed_protocols(); 2404 2405 $css_array = explode( ';', trim( $css ) ); 2406 2407 /** 2408 * Filters the list of allowed CSS attributes. 2409 * 2410 * @since 2.8.1 2411 * 2412 * @param string[] $attr Array of allowed CSS attributes. 2413 */ 2414 $allowed_attr = apply_filters( 2415 'safe_style_css', 2416 array( 2417 'background', 2418 'background-color', 2419 'background-image', 2420 'background-position', 2421 'background-repeat', 2422 'background-size', 2423 'background-attachment', 2424 'background-blend-mode', 2425 2426 'border', 2427 'border-radius', 2428 'border-width', 2429 'border-color', 2430 'border-style', 2431 'border-right', 2432 'border-right-color', 2433 'border-right-style', 2434 'border-right-width', 2435 'border-bottom', 2436 'border-bottom-color', 2437 'border-bottom-left-radius', 2438 'border-bottom-right-radius', 2439 'border-bottom-style', 2440 'border-bottom-width', 2441 'border-bottom-right-radius', 2442 'border-bottom-left-radius', 2443 'border-left', 2444 'border-left-color', 2445 'border-left-style', 2446 'border-left-width', 2447 'border-top', 2448 'border-top-color', 2449 'border-top-left-radius', 2450 'border-top-right-radius', 2451 'border-top-style', 2452 'border-top-width', 2453 'border-top-left-radius', 2454 'border-top-right-radius', 2455 2456 'border-spacing', 2457 'border-collapse', 2458 'caption-side', 2459 2460 'columns', 2461 'column-count', 2462 'column-fill', 2463 'column-gap', 2464 'column-rule', 2465 'column-span', 2466 'column-width', 2467 2468 'color', 2469 'filter', 2470 'font', 2471 'font-family', 2472 'font-size', 2473 'font-style', 2474 'font-variant', 2475 'font-weight', 2476 'letter-spacing', 2477 'line-height', 2478 'text-align', 2479 'text-decoration', 2480 'text-indent', 2481 'text-transform', 2482 2483 'height', 2484 'min-height', 2485 'max-height', 2486 2487 'width', 2488 'min-width', 2489 'max-width', 2490 2491 'margin', 2492 'margin-right', 2493 'margin-bottom', 2494 'margin-left', 2495 'margin-top', 2496 'margin-block-start', 2497 'margin-block-end', 2498 'margin-inline-start', 2499 'margin-inline-end', 2500 2501 'padding', 2502 'padding-right', 2503 'padding-bottom', 2504 'padding-left', 2505 'padding-top', 2506 'padding-block-start', 2507 'padding-block-end', 2508 'padding-inline-start', 2509 'padding-inline-end', 2510 2511 'flex', 2512 'flex-basis', 2513 'flex-direction', 2514 'flex-flow', 2515 'flex-grow', 2516 'flex-shrink', 2517 'flex-wrap', 2518 2519 'gap', 2520 'column-gap', 2521 'row-gap', 2522 2523 'grid-template-columns', 2524 'grid-auto-columns', 2525 'grid-column-start', 2526 'grid-column-end', 2527 'grid-column', 2528 'grid-column-gap', 2529 'grid-template-rows', 2530 'grid-auto-rows', 2531 'grid-row-start', 2532 'grid-row-end', 2533 'grid-row', 2534 'grid-row-gap', 2535 'grid-gap', 2536 2537 'justify-content', 2538 'justify-items', 2539 'justify-self', 2540 'align-content', 2541 'align-items', 2542 'align-self', 2543 2544 'clear', 2545 'cursor', 2546 'direction', 2547 'float', 2548 'list-style-type', 2549 'object-fit', 2550 'object-position', 2551 'opacity', 2552 'overflow', 2553 'vertical-align', 2554 'writing-mode', 2555 2556 'position', 2557 'top', 2558 'right', 2559 'bottom', 2560 'left', 2561 'z-index', 2562 'box-shadow', 2563 'aspect-ratio', 2564 'container-type', 2565 2566 // Custom CSS properties. 2567 '--*', 2568 ) 2569 ); 2570 2571 /* 2572 * CSS attributes that accept URL data types. 2573 * 2574 * This is in accordance to the CSS spec and unrelated to 2575 * the sub-set of supported attributes above. 2576 * 2577 * See: https://developer.mozilla.org/en-US/docs/Web/CSS/url 2578 */ 2579 $css_url_data_types = array( 2580 'background', 2581 'background-image', 2582 2583 'cursor', 2584 'filter', 2585 2586 'list-style', 2587 'list-style-image', 2588 ); 2589 2590 /* 2591 * CSS attributes that accept gradient data types. 2592 * 2593 */ 2594 $css_gradient_data_types = array( 2595 'background', 2596 'background-image', 2597 ); 2598 2599 if ( empty( $allowed_attr ) ) { 2600 return $css; 2601 } 2602 2603 $css = ''; 2604 foreach ( $css_array as $css_item ) { 2605 if ( '' === $css_item ) { 2606 continue; 2607 } 2608 2609 $css_item = trim( $css_item ); 2610 $css_test_string = $css_item; 2611 $found = false; 2612 $url_attr = false; 2613 $gradient_attr = false; 2614 $is_custom_var = false; 2615 2616 if ( ! str_contains( $css_item, ':' ) ) { 2617 $found = true; 2618 } else { 2619 $parts = explode( ':', $css_item, 2 ); 2620 $css_selector = trim( $parts[0] ); 2621 2622 // Allow assigning values to CSS variables. 2623 if ( in_array( '--*', $allowed_attr, true ) && preg_match( '/^--[a-zA-Z0-9-_]+$/', $css_selector ) ) { 2624 $allowed_attr[] = $css_selector; 2625 $is_custom_var = true; 2626 } 2627 2628 if ( in_array( $css_selector, $allowed_attr, true ) ) { 2629 $found = true; 2630 $url_attr = in_array( $css_selector, $css_url_data_types, true ); 2631 $gradient_attr = in_array( $css_selector, $css_gradient_data_types, true ); 2632 } 2633 2634 if ( $is_custom_var ) { 2635 $css_value = trim( $parts[1] ); 2636 $url_attr = str_starts_with( $css_value, 'url(' ); 2637 $gradient_attr = str_contains( $css_value, '-gradient(' ); 2638 } 2639 } 2640 2641 if ( $found && $url_attr ) { 2642 // Simplified: matches the sequence `url(*)`. 2643 preg_match_all( '/url\([^)]+\)/', $parts[1], $url_matches ); 2644 2645 foreach ( $url_matches[0] as $url_match ) { 2646 // Clean up the URL from each of the matches above. 2647 preg_match( '/^url\(\s*([\'\"]?)(.*)(\g1)\s*\)$/', $url_match, $url_pieces ); 2648 2649 if ( empty( $url_pieces[2] ) ) { 2650 $found = false; 2651 break; 2652 } 2653 2654 $url = trim( $url_pieces[2] ); 2655 2656 if ( empty( $url ) || wp_kses_bad_protocol( $url, $allowed_protocols ) !== $url ) { 2657 $found = false; 2658 break; 2659 } else { 2660 // Remove the whole `url(*)` bit that was matched above from the CSS. 2661 $css_test_string = str_replace( $url_match, '', $css_test_string ); 2662 } 2663 } 2664 } 2665 2666 if ( $found && $gradient_attr ) { 2667 $css_value = trim( $parts[1] ); 2668 if ( preg_match( '/^(repeating-)?(linear|radial|conic)-gradient\(([^()]|rgb[a]?\([^()]*\))*\)$/', $css_value ) ) { 2669 // Remove the whole `gradient` bit that was matched above from the CSS. 2670 $css_test_string = str_replace( $css_value, '', $css_test_string ); 2671 } 2672 } 2673 2674 if ( $found ) { 2675 /* 2676 * Allow CSS functions like var(), calc(), etc. by removing them from the test string. 2677 * Nested functions and parentheses are also removed, so long as the parentheses are balanced. 2678 */ 2679 $css_test_string = preg_replace( 2680 '/\b(?:var|calc|min|max|minmax|clamp|repeat)(\((?:[^()]|(?1))*\))/', 2681 '', 2682 $css_test_string 2683 ); 2684 2685 /* 2686 * Disallow CSS containing \ ( & } = or comments, except for within url(), var(), calc(), etc. 2687 * which were removed from the test string above. 2688 */ 2689 $allow_css = ! preg_match( '%[\\\(&=}]|/\*%', $css_test_string ); 2690 2691 /** 2692 * Filters the check for unsafe CSS in `safecss_filter_attr`. 2693 * 2694 * Enables developers to determine whether a section of CSS should be allowed or discarded. 2695 * By default, the value will be false if the part contains \ ( & } = or comments. 2696 * Return true to allow the CSS part to be included in the output. 2697 * 2698 * @since 5.5.0 2699 * 2700 * @param bool $allow_css Whether the CSS in the test string is considered safe. 2701 * @param string $css_test_string The CSS string to test. 2702 */ 2703 $allow_css = apply_filters( 'safecss_filter_attr_allow_css', $allow_css, $css_test_string ); 2704 2705 // Only add the CSS part if it passes the regex check. 2706 if ( $allow_css ) { 2707 if ( '' !== $css ) { 2708 $css .= ';'; 2709 } 2710 2711 $css .= $css_item; 2712 } 2713 } 2714 } 2715 2716 return $css; 2717 } 2718 2719 /** 2720 * Helper function to add global attributes to a tag in the allowed HTML list. 2721 * 2722 * @since 3.5.0 2723 * @since 5.0.0 Added support for `data-*` wildcard attributes. 2724 * @since 6.0.0 Added `dir`, `lang`, and `xml:lang` to global attributes. 2725 * @since 6.3.0 Added `aria-controls`, `aria-current`, and `aria-expanded` attributes. 2726 * @since 6.4.0 Added `aria-live` and `hidden` attributes. 2727 * 2728 * @access private 2729 * @ignore 2730 * 2731 * @param array $value An array of attributes. 2732 * @return array The array of attributes with global attributes added. 2733 */ 2734 function _wp_add_global_attributes( $value ) { 2735 $global_attributes = array( 2736 'aria-controls' => true, 2737 'aria-current' => true, 2738 'aria-describedby' => true, 2739 'aria-details' => true, 2740 'aria-expanded' => true, 2741 'aria-hidden' => true, 2742 'aria-label' => true, 2743 'aria-labelledby' => true, 2744 'aria-live' => true, 2745 'class' => true, 2746 'data-*' => true, 2747 'dir' => true, 2748 'hidden' => true, 2749 'id' => true, 2750 'lang' => true, 2751 'style' => true, 2752 'title' => true, 2753 'role' => true, 2754 'xml:lang' => true, 2755 ); 2756 2757 if ( true === $value ) { 2758 $value = array(); 2759 } 2760 2761 if ( is_array( $value ) ) { 2762 return array_merge( $value, $global_attributes ); 2763 } 2764 2765 return $value; 2766 } 2767 2768 /** 2769 * Helper function to check if this is a safe PDF URL. 2770 * 2771 * @since 5.9.0 2772 * @access private 2773 * @ignore 2774 * 2775 * @param string $url The URL to check. 2776 * @return bool True if the URL is safe, false otherwise. 2777 */ 2778 function _wp_kses_allow_pdf_objects( $url ) { 2779 // We're not interested in URLs that contain query strings or fragments. 2780 if ( str_contains( $url, '?' ) || str_contains( $url, '#' ) ) { 2781 return false; 2782 } 2783 2784 // If it doesn't have a PDF extension, it's not safe. 2785 if ( ! str_ends_with( $url, '.pdf' ) ) { 2786 return false; 2787 } 2788 2789 // If the URL host matches the current site's media URL, it's safe. 2790 $upload_info = wp_upload_dir( null, false ); 2791 $parsed_url = wp_parse_url( $upload_info['url'] ); 2792 $upload_host = isset( $parsed_url['host'] ) ? $parsed_url['host'] : ''; 2793 $upload_port = isset( $parsed_url['port'] ) ? ':' . $parsed_url['port'] : ''; 2794 2795 if ( str_starts_with( $url, "http://$upload_host$upload_port/" ) 2796 || str_starts_with( $url, "https://$upload_host$upload_port/" ) 2797 ) { 2798 return true; 2799 } 2800 2801 return false; 2802 }
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