DOMSanitizer

A simple but effective DOM/SVG/MathML Sanitizer for PHP 7.3+. This was created due to my requirements for a performant DOM and specifically SVG sanitizer that was MIT compatible.

This borrows the extensive list of valid tags and attributes in the excellent DOMPurify library for JavaScript, but uses PHP DOMDocument to parse the DOM and filter out dangerous tags and attributes.

Installation

composer require rhukster/dom-sanitizer

Options

Options can be passed to the sanitize() method as an optional array. Default values are:

$options = [
    'remove-namespaces' => false,
    'remove-php-tags' => true,
    'remove-html-tags' => true,
    'remove-xml-tags' => true,
    'compress-output' => true,
];

Usage

Sanitizing HTML

The default option but provides with the full list of HTML tags and attributes.

require 'vendor/autoload.php';

use Rhukster\DomSanitizer\DOMSanitizer;

$input = file_get_contents('bad.html');

$sanitizer = new DOMSanitizer(DOMSanitizer::HTML);
$output = $sanitizer->sanitize($input, [
    'remove-html-tags' => false,
]);

Sanitizing SVG

You can limit the valid tags and attributes by passing DOMSanitizer::SVG to the constructor. This is advisable if you know you are dealing with SVGs.

require 'vendor/autoload.php';

use Rhukster\DomSanitizer\DOMSanitizer;

$input = file_get_contents('bad.svg');
$sanitizer = new DOMSanitizer(DOMSanitizer::SVG);
$output = $sanitizer->sanitize($input);

Sanitizing MathML

You can limit the valid tags and attributes by passing DOMSanitizer::MATHML to the constructor. This is advisable if you know you are dealing with MathML code.

require 'vendor/autoload.php';

use Rhukster\DomSanitizer\DOMSanitizer;

$input = file_get_contents('mathml-sample.xml');
$sanitizer = new DOMSanitizer(DOMSanitizer::MATHML);
$output = $sanitizer->sanitize($input, [
    'compress-output' => false,
]);

Modifying the allowed tags and attributes

You have full access to the tags and attributes via the following methods:

public function addAllowedTags(array $allowed_tags): void

public function addAllowedAttributes(array $allowed_attributes): void

public function addDisallowedTags(array $disallowed_tags): void

public function addDisallowedAttributes(array $disallowed_attributes): void

public function getAllowedTags(): array

public function setAllowedTags(array $allowed_tags): void

public function getAllowedAttributes(): array

public function setAllowedAttributes(array $allowed_attributes): void

public function getDisallowedTags(): array

public function setDisallowedTags(array $disallowed_tags): void

public function getDisallowedAttributes(): array

public function setDisallowedAttributes($disallowed_attributes): void