@trygve/json-sanitizer v1.0.0

@trygve/json-sanitizer

Replacer function to sanitize JSON for possible malicious HTML.

Installation

$ npm install json-esc

Example

import sanitizer from '@trygve/json-sanitizer';

const escaped = JSON.stringify({}, sanitizer());

Description

Replacer function to sanitize JSON for possible malicious HTML. Prevents possible XSS vectors such as:

<script type="application/json" id="props">
{ 
    "key": "</\/script><script>alert(\"pawned\");</\/script>",
}
</script>

and:

<div id="el"></div>
<script type="application/json" id="props">
{ 
    "key": "<img src=0 onerror=\"alert(\"pawned\")\">",
}
</script>

<script type="text/javascript">
    const data = document.getElementById('props').textContent;
    const decoded = JSON.parse(data);
    document.getElementById('el').innerHTML = decoded['key'];
</script>

This module escapes sertain characters to prevent any possible XSS vectors according to recommendation by the WHATWG spec.

The following escaping is done:

• < to \\u003C
• > to \\u003E
• / to \\u002F
• \u2028 to \\u2028
• \u2029 to \\u2029

API

This module consist of one method which returns a new method intended to be used as a replacer method for JSON.stringify().

import sanitizer from '@trygve/json-sanitizer';

const sanitizer = sanitizer();
const escaped = JSON.stringify({}, sanitizer);

options

The method can take a configuration options object. The following values can be provided:

• disable - Boolean - Disable escaping of given characters - optional

License

The MIT License (MIT)

Copyright (c) 2023 - Trygve Lie - post@trygve-lie.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.