rehype-sanitize

rehype plugin to sanitize HTML.

Install

npm:

npm install rehype-sanitize

Use

Say we have the following file, index.html:

<div onmouseover="alert('alpha')">
  <a href="jAva script:alert('bravo')">delta</a>
  <img src="x" onerror="alert('charlie')">
  <iframe src="javascript:alert('delta')"></iframe>
  <math>
    <mi xlink:href="data:x,<script>alert('echo')</script>"></mi>
  </math>
</div>
<script>
require('child_process').spawn('rm', ['-r', '-f', process.env.HOME]);
</script>

And our script, example.js, looks as follows:

var fs = require('fs')
var rehype = require('rehype')
var merge = require('deepmerge')
var gh = require('hast-util-sanitize/lib/github')
var sanitize = require('rehype-sanitize')

var schema = merge(gh, {tagNames: ['math', 'mi']})

rehype()
  .data('settings', {fragment: true})
  .use(sanitize, schema)
  .process(fs.readFileSync('index.html'), function(err, file) {
    if (err) throw err
    console.log(String(file))
  })

Now, running node example yields:

<div>
  <a>delta</a>
  <img src="x">

  <math>
    <mi></mi>
  </math>
</div>

API

rehype().use(sanitize[, schema])

Remove potentially dangerous things from HTML, or more correct: keep only the safe things in a document.

schema

The sanitation schema defines how and if nodes and properties should be cleaned. The schema is documented in hast-util-sanitize.

Security

Improper use of rehype-sanitize can open you up to a cross-site scripting (XSS) attack. The defaults are safe, but deviating from them is likely unsafe.

Use rehype-sanitize after all other plugins, as other plugins are likely also unsafe.

Related

• hast-util-sanitize — Core utility that does the sanitation

Contribute

See contributing.md in rehypejs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer