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# svg-sanitizer |
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[](https://travis-ci.org/darylldoyle/svg-sanitizer](https://travis-ci.org/darylldoyle/svg-sanitizer](https://travis-ci.org/darylldoyle/svg-sanitizer) [](https://codeclimate.com/github/darylldoyle/svg-sanitizer/coverage](https://codeclimate.com/github/darylldoyle/svg-sanitizer/coverage](https://codeclimate.com/github/darylldoyle/svg-sanitizer/coverage) |
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This is my attempt at building a decent SVG sanitizer in PHP. The work is largely borrowed from [](https://github.com/cure53/DOMPurifyDOMPurify](https://github.com/cure53/DOMPurify](https://github.com/cure53/DOMPurify). |
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## Installation |
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Either require `enshrined/svg-sanitize` through composer or download the repo and include the old way! |
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## Usage |
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Using this is fairly easy. Create a new instance of `enshrined\svgSanitize\Sanitizer` and then call the `sanitize` whilst passing in your dirty SVG/XML |
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**Basic Example** |
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```php |
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use enshrined\svgSanitize\Sanitizer; |
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// Create a new sanitizer instance |
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$sanitizer = new Sanitizer(); |
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// Load the dirty svg |
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$dirtySVG = file_get_contents('filthy.svg'); |
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// Pass it to the sanitizer and get it back clean |
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$cleanSVG = $sanitizer->sanitize($dirtySVG); |
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// Now do what you want with your clean SVG/XML data |
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``` |
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## Output |
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This will either return a sanitized SVG/XML string or boolean `false` if XML parsing failed (usually due to a badly formatted file). |
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## Options |
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You may pass your own whitelist of tags and attributes by using the `Sanitizer::setAllowedTags` and `Sanitizer::setAllowedAttrs` methods respectively. |
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These methods require that you implement the `enshrined\svgSanitize\data\TagInterface` or `enshrined\svgSanitize\data\AttributeInterface`. |
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## Remove remote references |
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You have the option to remove attributes that reference remote files, this will stop HTTP leaks but will add an overhead to the sanitizer. |
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This defaults to false, set to true to remove references. |
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`$sanitizer->removeRemoteReferences(true);` |
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When enabled, remote references are also stripped from CSS inside `<style>` elements and `style` attributes (`url()`, `@import`, and `image-set()`). This CSS handling is best-effort: it is not a full CSS parser, so some obscure forms (such as the bare-string forms of `image()`/`src()`) are not covered. Treat it as defence-in-depth rather than a guarantee, and isolate untrusted CSS at the point where the SVG is embedded. |
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Note: if a `<style>` element or `style` attribute contains a remote reference that gets stripped, any CSS escape sequences in that same block are normalised (decoded) in the output. This is semantically identical CSS but will rewrite escapes an author wrote by hand. |
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## Viewing Sanitization Issues |
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You may use the `getXmlIssues()` method to return an array of issues that occurred during sanitization. |
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This may be useful for logging or providing feedback to the user on why an SVG was refused. |
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`$issues = $sanitizer->getXmlIssues();` |
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## Minification |
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You can minify the XML output by calling `$sanitizer->minify(true);`. |
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## Demo |
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There is a demo available at: [](http://svg.enshrined.co.uk/http://svg.enshrined.co.uk/](http://svg.enshrined.co.uk/](http://svg.enshrined.co.uk/) |
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## WordPress |
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I've just released a WordPress plugin containing this code so you can sanitize your WordPress uploads. It's available from the WordPress plugin directory: [](https://wordpress.org/plugins/safe-svg/https://wordpress.org/plugins/safe-svg/](https://wordpress.org/plugins/safe-svg/](https://wordpress.org/plugins/safe-svg/) |
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## Drupal |
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[](https://github.com/heyMPMichael Potter](https://github.com/heyMP](https://github.com/heyMP) has kindly created a Drupal module for this library which is available at: [](https://www.drupal.org/project/svg_sanitizerhttps://www.drupal.org/project/svg_sanitizer](https://www.drupal.org/project/svg_sanitizer](https://www.drupal.org/project/svg_sanitizer) |
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## TYPO3 |
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This SVG sanitizer library is used per default in the core of TYPO3 v9 and later versions. |
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See [](https://docs.typo3.org/c/typo3/cms-core/main/en-us/Changelog/9.5.x/Important-94492-IntroduceSVGSanitizer.htmlcorresponding changelog entry](https://docs.typo3.org/c/typo3/cms-core/main/en-us/Changelog/9.5.x/Important-94492-IntroduceSVGSanitizer.html](https://docs.typo3.org/c/typo3/cms-core/main/en-us/Changelog/9.5.x/Important-94492-IntroduceSVGSanitizer.html) for more details. |
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## Tests |
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You can run these by running `vendor/bin/phpunit` from the base directory of this package. |
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## Standalone scanning of files via CLI |
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Thanks to the work by [](https://github.com/gudmdharaldsgudmdharalds](https://github.com/gudmdharalds](https://github.com/gudmdharalds) there's now a standalone scanner that can be used via the CLI. |
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Any errors will be output in JSON format. See [](https://github.com/darylldoyle/svg-sanitizer/pull/25the PR](https://github.com/darylldoyle/svg-sanitizer/pull/25](https://github.com/darylldoyle/svg-sanitizer/pull/25) for an example. |
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Use it as follows: `php svg-scanner.php ~/svgs/myfile.svg` |
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## To-Do |
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More extensive testing for the SVGs/XML would be lovely, I'll try and add these soon. If you feel like doing it for me, please do and make a PR! |
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