| 1 |
<?php |
| 2 |
namespace Elementor\Core\Utils\Svg; |
| 3 |
|
| 4 |
use Elementor\Utils; |
| 5 |
|
| 6 |
if ( ! defined( 'ABSPATH' ) ) { |
| 7 |
exit; // Exit if accessed directly. |
| 8 |
} |
| 9 |
|
| 10 |
/** |
| 11 |
* Elementor SVG Sanitizer. |
| 12 |
* |
| 13 |
* A class that is responsible for sanitizing SVG files. |
| 14 |
* |
| 15 |
* @since 3.16.0 |
| 16 |
*/ |
| 17 |
class Svg_Sanitizer { |
| 18 |
|
| 19 |
/** |
| 20 |
* @var \DOMDocument |
| 21 |
*/ |
| 22 |
private $svg_dom = null; |
| 23 |
|
| 24 |
/** |
| 25 |
* Sanitize File |
| 26 |
* |
| 27 |
* @since 3.16.0 |
| 28 |
* @access public |
| 29 |
* |
| 30 |
* @param $filename |
| 31 |
* @return bool |
| 32 |
*/ |
| 33 |
public function sanitize_file( $filename ) { |
| 34 |
$original_content = Utils::file_get_contents( $filename ); |
| 35 |
$is_encoded = $this->is_encoded( $original_content ); |
| 36 |
|
| 37 |
if ( $is_encoded ) { |
| 38 |
$decoded = $this->decode_svg( $original_content ); |
| 39 |
if ( false === $decoded ) { |
| 40 |
return false; |
| 41 |
} |
| 42 |
$original_content = $decoded; |
| 43 |
} |
| 44 |
|
| 45 |
$valid_svg = $this->sanitize( $original_content ); |
| 46 |
|
| 47 |
if ( false === $valid_svg ) { |
| 48 |
return false; |
| 49 |
} |
| 50 |
|
| 51 |
// If we were gzipped, we need to re-zip |
| 52 |
if ( $is_encoded ) { |
| 53 |
$valid_svg = $this->encode_svg( $valid_svg ); |
| 54 |
} |
| 55 |
file_put_contents( $filename, $valid_svg ); |
| 56 |
|
| 57 |
return true; |
| 58 |
} |
| 59 |
|
| 60 |
/** |
| 61 |
* Sanitize |
| 62 |
* |
| 63 |
* @since 3.16.0 |
| 64 |
* @access public |
| 65 |
* |
| 66 |
* @param $content |
| 67 |
* @return bool|string |
| 68 |
*/ |
| 69 |
public function sanitize( $content ) { |
| 70 |
// Strip php tags |
| 71 |
$content = $this->strip_comments( $content ); |
| 72 |
$content = $this->strip_php_tags( $content ); |
| 73 |
$content = $this->strip_line_breaks( $content ); |
| 74 |
|
| 75 |
// Find the start and end tags so we can cut out miscellaneous garbage. |
| 76 |
$start = strpos( $content, '<svg' ); |
| 77 |
$end = strrpos( $content, '</svg>' ); |
| 78 |
if ( false === $start || false === $end ) { |
| 79 |
return false; |
| 80 |
} |
| 81 |
|
| 82 |
$content = substr( $content, $start, ( $end - $start + 6 ) ); |
| 83 |
|
| 84 |
// If the server's PHP version is 8 or up, make sure to Disable the ability to load external entities |
| 85 |
$php_version_under_eight = version_compare( PHP_VERSION, '8.0.0', '<' ); |
| 86 |
if ( $php_version_under_eight ) { |
| 87 |
$libxml_disable_entity_loader = libxml_disable_entity_loader( true ); // phpcs:ignore Generic.PHP.DeprecatedFunctions.Deprecated |
| 88 |
} |
| 89 |
// Suppress the errors |
| 90 |
$libxml_use_internal_errors = libxml_use_internal_errors( true ); |
| 91 |
|
| 92 |
// Create DomDocument instance |
| 93 |
$this->svg_dom = new \DOMDocument(); |
| 94 |
$this->svg_dom->formatOutput = false; |
| 95 |
$this->svg_dom->preserveWhiteSpace = false; |
| 96 |
$this->svg_dom->strictErrorChecking = false; |
| 97 |
|
| 98 |
$open_svg = $this->svg_dom->loadXML( $content ); |
| 99 |
if ( ! $open_svg ) { |
| 100 |
return false; |
| 101 |
} |
| 102 |
|
| 103 |
$this->strip_doctype(); |
| 104 |
$this->sanitize_elements(); |
| 105 |
|
| 106 |
// Export sanitized svg to string |
| 107 |
// Using documentElement to strip out <?xml version="1.0" encoding="UTF-8"... |
| 108 |
$sanitized = $this->svg_dom->saveXML( $this->svg_dom->documentElement, LIBXML_NOEMPTYTAG ); |
| 109 |
|
| 110 |
// Restore defaults |
| 111 |
if ( $php_version_under_eight ) { |
| 112 |
libxml_disable_entity_loader( $libxml_disable_entity_loader ); // phpcs:ignore Generic.PHP.DeprecatedFunctions.Deprecated |
| 113 |
} |
| 114 |
libxml_use_internal_errors( $libxml_use_internal_errors ); |
| 115 |
|
| 116 |
return $sanitized; |
| 117 |
} |
| 118 |
|
| 119 |
/** |
| 120 |
* Is Encoded |
| 121 |
* |
| 122 |
* Check if the contents of the SVG file are gzipped |
| 123 |
* |
| 124 |
* @see http://www.gzip.org/zlib/rfc-gzip.html#member-format |
| 125 |
* |
| 126 |
* @since 3.16.0 |
| 127 |
* @access private |
| 128 |
* |
| 129 |
* @param $contents |
| 130 |
* |
| 131 |
* @return bool |
| 132 |
*/ |
| 133 |
private function is_encoded( $contents ) { |
| 134 |
$needle = "\x1f\x8b\x08"; |
| 135 |
if ( function_exists( 'mb_strpos' ) ) { |
| 136 |
return 0 === mb_strpos( $contents, $needle ); |
| 137 |
} else { |
| 138 |
return 0 === strpos( $contents, $needle ); |
| 139 |
} |
| 140 |
} |
| 141 |
|
| 142 |
/** |
| 143 |
* Encode SVG |
| 144 |
* |
| 145 |
* @since 3.16.0 |
| 146 |
* @access private |
| 147 |
* |
| 148 |
* @param $content |
| 149 |
* @return string |
| 150 |
*/ |
| 151 |
private function encode_svg( $content ) { |
| 152 |
return gzencode( $content ); |
| 153 |
} |
| 154 |
|
| 155 |
/** |
| 156 |
* Decode SVG |
| 157 |
* |
| 158 |
* @since 3.16.0 |
| 159 |
* @access private |
| 160 |
* |
| 161 |
* @param $content |
| 162 |
* |
| 163 |
* @return string |
| 164 |
*/ |
| 165 |
private function decode_svg( $content ) { |
| 166 |
return gzdecode( $content ); |
| 167 |
} |
| 168 |
|
| 169 |
/** |
| 170 |
* Is Allowed Tag |
| 171 |
* |
| 172 |
* @since 3.16.0 |
| 173 |
* @access private |
| 174 |
* |
| 175 |
* @param $element |
| 176 |
* @return bool |
| 177 |
*/ |
| 178 |
private function is_allowed_tag( $element ) { |
| 179 |
static $allowed_tags = false; |
| 180 |
if ( false === $allowed_tags ) { |
| 181 |
$allowed_tags = $this->get_allowed_elements(); |
| 182 |
} |
| 183 |
|
| 184 |
$tag_name = $element->tagName; // phpcs:ignore -- php DomDocument |
| 185 |
|
| 186 |
if ( ! in_array( strtolower( $tag_name ), $allowed_tags ) ) { |
| 187 |
$this->remove_element( $element ); |
| 188 |
return false; |
| 189 |
} |
| 190 |
|
| 191 |
return true; |
| 192 |
} |
| 193 |
|
| 194 |
/** |
| 195 |
* Remove Element |
| 196 |
* |
| 197 |
* Removes the passed element from its DomDocument tree |
| 198 |
* |
| 199 |
* @since 3.16.0 |
| 200 |
* @access private |
| 201 |
* |
| 202 |
* @param $element |
| 203 |
*/ |
| 204 |
private function remove_element( $element ) { |
| 205 |
$element->parentNode->removeChild( $element ); // phpcs:ignore -- php DomDocument |
| 206 |
} |
| 207 |
|
| 208 |
/** |
| 209 |
* Is It An Attribute |
| 210 |
* |
| 211 |
* @since 3.16.0 |
| 212 |
* @access private |
| 213 |
* |
| 214 |
* @param $name |
| 215 |
* @param $check |
| 216 |
* @return bool |
| 217 |
*/ |
| 218 |
private function is_a_attribute( $name, $check ) { |
| 219 |
return 0 === strpos( $name, $check . '-' ); |
| 220 |
} |
| 221 |
|
| 222 |
/** |
| 223 |
* Is Remote Value |
| 224 |
* |
| 225 |
* @since 3.16.0 |
| 226 |
* @access private |
| 227 |
* |
| 228 |
* @param $value |
| 229 |
* @return string |
| 230 |
*/ |
| 231 |
private function is_remote_value( $value ) { |
| 232 |
$value = trim( preg_replace( '/[^ -~]/xu', '', $value ) ); |
| 233 |
$wrapped_in_url = preg_match( '~^url\(\s*[\'"]\s*(.*)\s*[\'"]\s*\)$~xi', $value, $match ); |
| 234 |
if ( ! $wrapped_in_url ) { |
| 235 |
return false; |
| 236 |
} |
| 237 |
|
| 238 |
$value = trim( $match[1], '\'"' ); |
| 239 |
return preg_match( '~^((https?|ftp|file):)?//~xi', $value ); |
| 240 |
} |
| 241 |
|
| 242 |
/** |
| 243 |
* Has JS Value |
| 244 |
* |
| 245 |
* @since 3.16.0 |
| 246 |
* @access private |
| 247 |
* |
| 248 |
* @param $value |
| 249 |
* @return false|int |
| 250 |
*/ |
| 251 |
private function has_js_value( $value ) { |
| 252 |
return preg_match( '/base64|data|(?:java)?script|alert\(|window\.|document/i', $value ); |
| 253 |
} |
| 254 |
|
| 255 |
/** |
| 256 |
* Get Allowed Attributes |
| 257 |
* |
| 258 |
* Returns an array of allowed tag attributes in SVG files. |
| 259 |
* |
| 260 |
* @since 3.16.0 |
| 261 |
* @access private |
| 262 |
* |
| 263 |
* @return array |
| 264 |
*/ |
| 265 |
private function get_allowed_attributes() { |
| 266 |
$allowed_attributes = [ |
| 267 |
'accent-height', |
| 268 |
'accumulate', |
| 269 |
'additivive', |
| 270 |
'alignment-baseline', |
| 271 |
'aria-hidden', |
| 272 |
'aria-controls', |
| 273 |
'aria-describedby', |
| 274 |
'aria-description', |
| 275 |
'aria-expanded', |
| 276 |
'aria-haspopup', |
| 277 |
'aria-label', |
| 278 |
'aria-labelledby', |
| 279 |
'aria-roledescription', |
| 280 |
'ascent', |
| 281 |
'attributename', |
| 282 |
'attributetype', |
| 283 |
'azimuth', |
| 284 |
'basefrequency', |
| 285 |
'baseline-shift', |
| 286 |
'begin', |
| 287 |
'bias', |
| 288 |
'by', |
| 289 |
'class', |
| 290 |
'clip', |
| 291 |
'clip-path', |
| 292 |
'clip-rule', |
| 293 |
'clippathunits', |
| 294 |
'color', |
| 295 |
'color-interpolation', |
| 296 |
'color-interpolation-filters', |
| 297 |
'color-profile', |
| 298 |
'color-rendering', |
| 299 |
'cx', |
| 300 |
'cy', |
| 301 |
'd', |
| 302 |
'dx', |
| 303 |
'dy', |
| 304 |
'diffuseconstant', |
| 305 |
'direction', |
| 306 |
'display', |
| 307 |
'divisor', |
| 308 |
'dominant-baseline', |
| 309 |
'dur', |
| 310 |
'edgemode', |
| 311 |
'elevation', |
| 312 |
'end', |
| 313 |
'fill', |
| 314 |
'fill-opacity', |
| 315 |
'fill-rule', |
| 316 |
'filter', |
| 317 |
'filterres', |
| 318 |
'filterunits', |
| 319 |
'flood-color', |
| 320 |
'flood-opacity', |
| 321 |
'font-family', |
| 322 |
'font-size', |
| 323 |
'font-size-adjust', |
| 324 |
'font-stretch', |
| 325 |
'font-style', |
| 326 |
'font-variant', |
| 327 |
'font-weight', |
| 328 |
'fx', |
| 329 |
'fy', |
| 330 |
'g1', |
| 331 |
'g2', |
| 332 |
'glyph-name', |
| 333 |
'glyphref', |
| 334 |
'gradienttransform', |
| 335 |
'gradientunits', |
| 336 |
'height', |
| 337 |
'href', |
| 338 |
'id', |
| 339 |
'image-rendering', |
| 340 |
'in', |
| 341 |
'in2', |
| 342 |
'k', |
| 343 |
'k1', |
| 344 |
'k2', |
| 345 |
'k3', |
| 346 |
'k4', |
| 347 |
'kerning', |
| 348 |
'keypoints', |
| 349 |
'keysplines', |
| 350 |
'keytimes', |
| 351 |
'lang', |
| 352 |
'lengthadjust', |
| 353 |
'letter-spacing', |
| 354 |
'kernelmatrix', |
| 355 |
'kernelunitlength', |
| 356 |
'lighting-color', |
| 357 |
'local', |
| 358 |
'marker-end', |
| 359 |
'marker-mid', |
| 360 |
'marker-start', |
| 361 |
'markerheight', |
| 362 |
'markerunits', |
| 363 |
'markerwidth', |
| 364 |
'mask', |
| 365 |
'maskcontentunits', |
| 366 |
'maskunits', |
| 367 |
'max', |
| 368 |
'media', |
| 369 |
'method', |
| 370 |
'mode', |
| 371 |
'min', |
| 372 |
'name', |
| 373 |
'numoctaves', |
| 374 |
'offset', |
| 375 |
'opacity', |
| 376 |
'operator', |
| 377 |
'order', |
| 378 |
'orient', |
| 379 |
'orientation', |
| 380 |
'origin', |
| 381 |
'overflow', |
| 382 |
'paint-order', |
| 383 |
'path', |
| 384 |
'pathlength', |
| 385 |
'patterncontentunits', |
| 386 |
'patterntransform', |
| 387 |
'patternunits', |
| 388 |
'points', |
| 389 |
'preservealpha', |
| 390 |
'preserveaspectratio', |
| 391 |
'primitiveunits', |
| 392 |
'r', |
| 393 |
'rx', |
| 394 |
'ry', |
| 395 |
'radius', |
| 396 |
'refx', |
| 397 |
'refy', |
| 398 |
'repeatcount', |
| 399 |
'repeatdur', |
| 400 |
'requiredfeatures', |
| 401 |
'restart', |
| 402 |
'result', |
| 403 |
'role', |
| 404 |
'rotate', |
| 405 |
'scale', |
| 406 |
'seed', |
| 407 |
'shape-rendering', |
| 408 |
'spacing', |
| 409 |
'specularconstant', |
| 410 |
'specularexponent', |
| 411 |
'spreadmethod', |
| 412 |
'startoffset', |
| 413 |
'stddeviation', |
| 414 |
'stitchtiles', |
| 415 |
'stop-color', |
| 416 |
'stop-opacity', |
| 417 |
'stroke', |
| 418 |
'stroke-dasharray', |
| 419 |
'stroke-dashoffset', |
| 420 |
'stroke-linecap', |
| 421 |
'stroke-linejoin', |
| 422 |
'stroke-miterlimit', |
| 423 |
'stroke-opacity', |
| 424 |
'stroke-width', |
| 425 |
'style', |
| 426 |
'surfacescale', |
| 427 |
'systemlanguage', |
| 428 |
'tabindex', |
| 429 |
'targetx', |
| 430 |
'targety', |
| 431 |
'transform', |
| 432 |
'transform-origin', |
| 433 |
'text-anchor', |
| 434 |
'text-decoration', |
| 435 |
'text-rendering', |
| 436 |
'textlength', |
| 437 |
'type', |
| 438 |
'u1', |
| 439 |
'u2', |
| 440 |
'underline-position', |
| 441 |
'underline-thickness', |
| 442 |
'unicode', |
| 443 |
'unicode-bidi', |
| 444 |
'values', |
| 445 |
'vector-effect', |
| 446 |
'vert-adv-y', |
| 447 |
'vert-origin-x', |
| 448 |
'vert-origin-y', |
| 449 |
'viewbox', |
| 450 |
'visibility', |
| 451 |
'width', |
| 452 |
'word-spacing', |
| 453 |
'wrap', |
| 454 |
'writing-mode', |
| 455 |
'x', |
| 456 |
'x1', |
| 457 |
'x2', |
| 458 |
'xchannelselector', |
| 459 |
'xlink:href', |
| 460 |
'xlink:title', |
| 461 |
'xmlns', |
| 462 |
'xmlns:se', |
| 463 |
'xmlns:xlink', |
| 464 |
'xml:lang', |
| 465 |
'xml:space', |
| 466 |
'y', |
| 467 |
'y1', |
| 468 |
'y2', |
| 469 |
'ychannelselector', |
| 470 |
'z', |
| 471 |
'zoomandpan', |
| 472 |
]; |
| 473 |
|
| 474 |
/** |
| 475 |
* Allowed attributes in SVG file. |
| 476 |
* |
| 477 |
* Filters the list of allowed attributes in SVG files. |
| 478 |
* |
| 479 |
* Since SVG files can run JS code that may inject malicious code, all attributes |
| 480 |
* are removed except the allowed attributes. |
| 481 |
* |
| 482 |
* This hook can be used to manage allowed SVG attributes. To either add new |
| 483 |
* attributes or delete existing attributes. To strengthen or weaken site security. |
| 484 |
* |
| 485 |
* @param array $allowed_attributes A list of allowed attributes. |
| 486 |
*/ |
| 487 |
$allowed_attributes = apply_filters( 'elementor/files/svg/allowed_attributes', $allowed_attributes ); |
| 488 |
|
| 489 |
return $allowed_attributes; |
| 490 |
} |
| 491 |
|
| 492 |
/** |
| 493 |
* Get Allowed Elements |
| 494 |
* |
| 495 |
* Returns an array of allowed element tags to be in SVG files. |
| 496 |
* |
| 497 |
* @since 3.16.0 |
| 498 |
* @access private |
| 499 |
* |
| 500 |
* @return array |
| 501 |
*/ |
| 502 |
private function get_allowed_elements() { |
| 503 |
$allowed_elements = [ |
| 504 |
'a', |
| 505 |
'animate', |
| 506 |
'animateMotion', |
| 507 |
'animateTransform', |
| 508 |
'circle', |
| 509 |
'clippath', |
| 510 |
'defs', |
| 511 |
'desc', |
| 512 |
'ellipse', |
| 513 |
'feBlend', |
| 514 |
'feColorMatrix', |
| 515 |
'feComponentTransfer', |
| 516 |
'feComposite', |
| 517 |
'feConvolveMatrix', |
| 518 |
'feDiffuseLighting', |
| 519 |
'feDisplacementMap', |
| 520 |
'feDistantLight', |
| 521 |
'feDropShadow', |
| 522 |
'feFlood', |
| 523 |
'feFuncA', |
| 524 |
'feFuncB', |
| 525 |
'feFuncG', |
| 526 |
'feFuncR', |
| 527 |
'feGaussianBlur', |
| 528 |
'feImage', |
| 529 |
'feMerge', |
| 530 |
'feMergeNode', |
| 531 |
'feMorphology', |
| 532 |
'feOffset', |
| 533 |
'fePointLight', |
| 534 |
'feSpecularLighting', |
| 535 |
'feSpotLight', |
| 536 |
'feTile', |
| 537 |
'feTurbulence', |
| 538 |
'filter', |
| 539 |
'foreignobject', |
| 540 |
'g', |
| 541 |
'image', |
| 542 |
'line', |
| 543 |
'lineargradient', |
| 544 |
'marker', |
| 545 |
'mask', |
| 546 |
'metadata', |
| 547 |
'mpath', |
| 548 |
'path', |
| 549 |
'pattern', |
| 550 |
'polygon', |
| 551 |
'polyline', |
| 552 |
'radialgradient', |
| 553 |
'rect', |
| 554 |
'set', |
| 555 |
'stop', |
| 556 |
'style', |
| 557 |
'svg', |
| 558 |
'switch', |
| 559 |
'symbol', |
| 560 |
'text', |
| 561 |
'textpath', |
| 562 |
'title', |
| 563 |
'tspan', |
| 564 |
'use', |
| 565 |
'view', |
| 566 |
]; |
| 567 |
|
| 568 |
/** |
| 569 |
* Allowed elements in SVG file. |
| 570 |
* |
| 571 |
* Filters the list of allowed elements in SVG files. |
| 572 |
* |
| 573 |
* Since SVG files can run JS code that may inject malicious code, all elements |
| 574 |
* are removed except the allowed elements. |
| 575 |
* |
| 576 |
* This hook can be used to manage SVG elements. To either add new elements or |
| 577 |
* delete existing elements. To strengthen or weaken site security. |
| 578 |
* |
| 579 |
* @param array $allowed_elements A list of allowed elements. |
| 580 |
*/ |
| 581 |
$allowed_elements = apply_filters( 'elementor/files/svg/allowed_elements', $allowed_elements ); |
| 582 |
|
| 583 |
return $allowed_elements; |
| 584 |
} |
| 585 |
|
| 586 |
/** |
| 587 |
* Validate Allowed Attributes |
| 588 |
* |
| 589 |
* @since 3.16.0 |
| 590 |
* @access private |
| 591 |
* |
| 592 |
* @param \DOMElement $element |
| 593 |
*/ |
| 594 |
private function validate_allowed_attributes( $element ) { |
| 595 |
static $allowed_attributes = false; |
| 596 |
if ( false === $allowed_attributes ) { |
| 597 |
$allowed_attributes = $this->get_allowed_attributes(); |
| 598 |
} |
| 599 |
|
| 600 |
for ( $index = $element->attributes->length - 1; $index >= 0; $index-- ) { |
| 601 |
// get attribute name |
| 602 |
$attr_name = $element->attributes->item( $index )->name; |
| 603 |
$attr_name_lowercase = strtolower( $attr_name ); |
| 604 |
// Remove attribute if not in whitelist |
| 605 |
if ( ! in_array( $attr_name_lowercase, $allowed_attributes ) && ! $this->is_a_attribute( $attr_name_lowercase, 'aria' ) && ! $this->is_a_attribute( $attr_name_lowercase, 'data' ) ) { |
| 606 |
$element->removeAttribute( $attr_name ); |
| 607 |
continue; |
| 608 |
} |
| 609 |
|
| 610 |
$attr_value = $element->attributes->item( $index )->value; |
| 611 |
|
| 612 |
// Remove attribute if it has a remote reference or js or data-URI/base64 |
| 613 |
if ( ! empty( $attr_value ) && ( $this->is_remote_value( $attr_value ) || $this->has_js_value( $attr_value ) ) ) { |
| 614 |
$element->removeAttribute( $attr_name ); |
| 615 |
continue; |
| 616 |
} |
| 617 |
} |
| 618 |
} |
| 619 |
|
| 620 |
/** |
| 621 |
* Strip xlinks |
| 622 |
* |
| 623 |
* @since 3.16.0 |
| 624 |
* @access private |
| 625 |
* |
| 626 |
* @param \DOMElement $element |
| 627 |
*/ |
| 628 |
private function strip_xlinks( $element ) { |
| 629 |
$xlinks = $element->getAttributeNS( 'http://www.w3.org/1999/xlink', 'href' ); |
| 630 |
|
| 631 |
if ( ! $xlinks ) { |
| 632 |
return; |
| 633 |
} |
| 634 |
|
| 635 |
if ( ! $this->is_safe_href( $xlinks ) ) { |
| 636 |
$element->removeAttributeNS( 'http://www.w3.org/1999/xlink', 'href' ); |
| 637 |
} |
| 638 |
} |
| 639 |
|
| 640 |
/** |
| 641 |
* @see https://github.com/darylldoyle/svg-sanitizer/blob/2321a914e/src/Sanitizer.php#L454 |
| 642 |
*/ |
| 643 |
private function is_safe_href( $value ) { |
| 644 |
// Allow empty values. |
| 645 |
if ( empty( $value ) ) { |
| 646 |
return true; |
| 647 |
} |
| 648 |
|
| 649 |
// Allow fragment identifiers. |
| 650 |
if ( '#' === substr( $value, 0, 1 ) ) { |
| 651 |
return true; |
| 652 |
} |
| 653 |
|
| 654 |
// Allow relative URIs. |
| 655 |
if ( '/' === substr( $value, 0, 1 ) ) { |
| 656 |
return true; |
| 657 |
} |
| 658 |
|
| 659 |
// Allow HTTPS domains. |
| 660 |
if ( 'https://' === substr( $value, 0, 8 ) ) { |
| 661 |
return true; |
| 662 |
} |
| 663 |
|
| 664 |
// Allow HTTP domains. |
| 665 |
if ( 'http://' === substr( $value, 0, 7 ) ) { |
| 666 |
return true; |
| 667 |
} |
| 668 |
|
| 669 |
// Allow known data URIs. |
| 670 |
if ( in_array( substr( $value, 0, 14 ), [ |
| 671 |
'data:image/png', // PNG |
| 672 |
'data:image/gif', // GIF |
| 673 |
'data:image/jpg', // JPG |
| 674 |
'data:image/jpe', // JPEG |
| 675 |
'data:image/pjp', // PJPEG |
| 676 |
], true ) ) { |
| 677 |
return true; |
| 678 |
} |
| 679 |
|
| 680 |
// Allow known short data URIs. |
| 681 |
if ( in_array( substr( $value, 0, 12 ), [ |
| 682 |
'data:img/png', // PNG |
| 683 |
'data:img/gif', // GIF |
| 684 |
'data:img/jpg', // JPG |
| 685 |
'data:img/jpe', // JPEG |
| 686 |
'data:img/pjp', // PJPEG |
| 687 |
], true ) ) { |
| 688 |
return true; |
| 689 |
} |
| 690 |
|
| 691 |
return false; |
| 692 |
} |
| 693 |
|
| 694 |
/** |
| 695 |
* Validate Use Tag |
| 696 |
* |
| 697 |
* @since 3.16.0 |
| 698 |
* @access private |
| 699 |
* |
| 700 |
* @param $element |
| 701 |
*/ |
| 702 |
private function validate_use_tag( $element ) { |
| 703 |
$xlinks = $element->getAttributeNS( 'http://www.w3.org/1999/xlink', 'href' ); |
| 704 |
if ( $xlinks && '#' !== substr( $xlinks, 0, 1 ) ) { |
| 705 |
$element->parentNode->removeChild( $element ); // phpcs:ignore -- php DomNode |
| 706 |
} |
| 707 |
} |
| 708 |
|
| 709 |
/** |
| 710 |
* Strip Doctype |
| 711 |
* |
| 712 |
* @since 3.16.0 |
| 713 |
* @access private |
| 714 |
*/ |
| 715 |
private function strip_doctype() { |
| 716 |
foreach ( $this->svg_dom->childNodes as $child ) { |
| 717 |
if ( XML_DOCUMENT_TYPE_NODE === $child->nodeType ) { // phpcs:ignore -- php DomDocument |
| 718 |
$child->parentNode->removeChild( $child ); // phpcs:ignore -- php DomDocument |
| 719 |
} |
| 720 |
} |
| 721 |
} |
| 722 |
|
| 723 |
/** |
| 724 |
* Sanitize Elements |
| 725 |
* |
| 726 |
* @since 3.16.0 |
| 727 |
* @access private |
| 728 |
*/ |
| 729 |
private function sanitize_elements() { |
| 730 |
$elements = $this->svg_dom->getElementsByTagName( '*' ); |
| 731 |
// loop through all elements |
| 732 |
// we do this backwards so we don't skip anything if we delete a node |
| 733 |
// see comments at: http://php.net/manual/en/class.domnamednodemap.php |
| 734 |
for ( $index = $elements->length - 1; $index >= 0; $index-- ) { |
| 735 |
/** |
| 736 |
* @var \DOMElement $current_element |
| 737 |
*/ |
| 738 |
$current_element = $elements->item( $index ); |
| 739 |
// If the tag isn't in the whitelist, remove it and continue with next iteration |
| 740 |
if ( ! $this->is_allowed_tag( $current_element ) ) { |
| 741 |
continue; |
| 742 |
} |
| 743 |
|
| 744 |
// validate element attributes |
| 745 |
$this->validate_allowed_attributes( $current_element ); |
| 746 |
|
| 747 |
$this->strip_xlinks( $current_element ); |
| 748 |
|
| 749 |
if ( 'use' === strtolower( $current_element->tagName ) ) { // phpcs:ignore -- php DomDocument |
| 750 |
$this->validate_use_tag( $current_element ); |
| 751 |
} |
| 752 |
} |
| 753 |
} |
| 754 |
|
| 755 |
/** |
| 756 |
* Strip PHP Tags |
| 757 |
* |
| 758 |
* @since 3.16.0 |
| 759 |
* @access private |
| 760 |
* |
| 761 |
* @param string $content |
| 762 |
* @return string |
| 763 |
*/ |
| 764 |
private function strip_php_tags( $content ) { |
| 765 |
$content = preg_replace( '/<\?(=|php)(.+?)\?>/i', '', $content ); |
| 766 |
// Remove XML, ASP, etc. |
| 767 |
$content = preg_replace( '/<\?(.*)\?>/Us', '', $content ); |
| 768 |
$content = preg_replace( '/<\%(.*)\%>/Us', '', $content ); |
| 769 |
|
| 770 |
if ( ( false !== strpos( $content, '<?' ) ) || ( false !== strpos( $content, '<%' ) ) ) { |
| 771 |
return ''; |
| 772 |
} |
| 773 |
return $content; |
| 774 |
} |
| 775 |
|
| 776 |
/** |
| 777 |
* Strip Comments |
| 778 |
* |
| 779 |
* @since 3.16.0 |
| 780 |
* @access private |
| 781 |
* |
| 782 |
* @param string $content |
| 783 |
* @return string |
| 784 |
*/ |
| 785 |
private function strip_comments( $content ) { |
| 786 |
// Remove comments. |
| 787 |
$content = preg_replace( '/<!--(.*)-->/Us', '', $content ); |
| 788 |
$content = preg_replace( '/\/\*(.*)\*\//Us', '', $content ); |
| 789 |
if ( ( false !== strpos( $content, '<!--' ) ) || ( false !== strpos( $content, '/*' ) ) ) { |
| 790 |
return ''; |
| 791 |
} |
| 792 |
return $content; |
| 793 |
} |
| 794 |
|
| 795 |
/** |
| 796 |
* Strip Line Breaks |
| 797 |
* |
| 798 |
* @since 3.16.0 |
| 799 |
* @access private |
| 800 |
* |
| 801 |
* @param string $content |
| 802 |
* @return string |
| 803 |
*/ |
| 804 |
private function strip_line_breaks( $content ) { |
| 805 |
// Remove line breaks. |
| 806 |
return preg_replace( '/\r|\n/', '', $content ); |
| 807 |
} |
| 808 |
} |
| 809 |
|
