BookStack Code Mirror - bookstack/blobdiff - app/Util/HtmlNonceApplicator.php

namespace BookStack\Util;

-use DOMDocument;

use DOMElement;

use DOMNodeList;

use DOMElement;

use DOMNodeList;

-use DOMXPath;

class HtmlNonceApplicator

{

class HtmlNonceApplicator

{

+ protected static string $placeholder = '[CSP_NONCE_VALUE]';

+

/**

- * Apply the given nonce to all scripts and styles in the given html.

+ * Prepare the given HTML content with nonce attributes including a placeholder

+ * value which we can target later.

*/

- public static function apply(string $html, string $nonce): string

+ public static function prepare(string $html): string

{

if (empty($html)) {

return $html;

}

{

if (empty($html)) {

return $html;

}

- $html = '<body>' . $html . '</body>';

- libxml_use_internal_errors(true);

- $doc = new DOMDocument();

- $doc->loadHTML(mb_convert_encoding($html, 'HTML-ENTITIES', 'UTF-8'));

- $xPath = new DOMXPath($doc);

+ // LIBXML_SCHEMA_CREATE was found to be required here otherwise

+ // the PHP DOMDocument handling will attempt to format/close

+ // HTML tags within scripts and therefore change JS content.

+ $doc = new HtmlDocument($html, LIBXML_SCHEMA_CREATE);

// Apply to scripts

- $scriptElems = $xPath->query('//script');

- static::addNonceAttributes($scriptElems, $nonce);

+ $scriptElems = $doc->queryXPath('//script');

+ static::addNonceAttributes($scriptElems, static::$placeholder);

// Apply to styles

- $styleElems = $xPath->query('//style');

- static::addNonceAttributes($styleElems, $nonce);

+ $styleElems = $doc->queryXPath('//style');

+ static::addNonceAttributes($styleElems, static::$placeholder);

- $returnHtml = '';

- $topElems = $doc->documentElement->childNodes->item(0)->childNodes;

- foreach ($topElems as $child) {

- $returnHtml .= $doc->saveHTML($child);

- }

+ return $doc->getBodyInnerHtml();

+ }

- return $returnHtml;

+ /**

+ * Apply the give nonce value to the given prepared HTML.

+ */

+ public static function apply(string $html, string $nonce): string

+ {

+ return str_replace(static::$placeholder, $nonce, $html);

}

- protected static function addNonceAttributes(DOMNodeList $nodes, string $nonce): void

+ protected static function addNonceAttributes(DOMNodeList $nodes, string $attrValue): void

{

/** @var DOMElement $node */

foreach ($nodes as $node) {

{

/** @var DOMElement $node */

foreach ($nodes as $node) {

- $node->setAttribute('nonce', $nonce);

+ $node->setAttribute('nonce', $attrValue);

}

-

}