open-sri

Ultralight, non-dependent and minimalist open-source package to recursively generate sha-256, sha-384 or sha-512 subresource integrity hashes to authenticate .js and .css files.

const sri = require("open-sri");

sri.get("./public/css", "sha384");

Subresource Integrity or SRI is a W3C recommendation to provide a method to protect website delivery from CDN-served malicious code.

To use SRI, a website author wishing to include a static resource can specify a cryptographic hash of the resource in addition to the location of the resource. Browsers fetching the resource can then compare the hash provided by the website author with the hash computed from the resource. If the hashes don't match, the resource is discarded.

<script src="https://cdn.example.com/app.js"
        integrity="sha384-+/M6kredJcxdsqkczBUjMLvqyHb1K/JThDXWsBVxMEeZHEaMKEOEct339VItX1zB"
></script>

This package aims at automating the process of generating cryptographic hashes in order to facilitate their access, by parsing directories and subdirectories to extract static files.

Features

• Low memory usage
• Executable for generating applications quickly
• High availability for synchronization with CDN systems
• Simple deployment with one-line integration

Tech Stack

Server: Node, Express

Installation

This is a Node.js module available through the npm registry.

Before installing, download and install Node.js. Node.js 0.10 or higher is required.

If this is a brand new project, make sure to create a package.json first with the npm init command. Then:

  npm i open-sri

Importing

// Using Node.js 'require()'
const sri = require('open-sri');

Documentation

The get function take two arguments, the directory (string) containing static files we want to obtain hashes from, and the required algorithm for the calculation sha256, sha384 or sha512 (string).

Return JSON object.

Usage/Examples

const sri = require("open-sri");

sri.get("./public/css", "sha384");

[
  {
    filepath: 'public/css/index.css',
    hash: 'sha384-yTRuc6ItZNScTYLXkpwURSAsaZLKgfoWi69Nku5bK2/1HW2O8OOgcli2jdgvIJnE'
  }
]

Then, we can observe the creation of a JSON element, containing each filepath contained in the directory and its subdirectories, as well as the assignment of a unique hash preceded by the mention "sha256-", "sha384-" or "sha512-" directly exploitable in your routes configuration file.

🚀 About Me

My name is Louis, student researcher in corporate taxation at Dauphine-PSL University and full-stack developer (NodeJS, MongoDB, Express, Front-End), specializing in French cryptocurrency law issues, SEO optimization and user experience improvement.

License

Copyright (c) 2022 Louis Brulé Naudet [email protected].

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.

Feedback

If you have any feedback, please reach out to us at [email protected].