scryptsy

scryptsy is a pure Javascript implementation of the scrypt key derivation function that is fully compatible with Node.js and the browser (via Browserify).

Package Info

• github: https://github.com/cryptocoinjs/scryptsy
• tests: https://github.com/cryptocoinjs/scryptsy/tree/master/test
• issues: https://github.com/cryptocoinjs/scryptsy/issues
• license: MIT
• versioning: http://semver-ftw.org

Why?

Scrypt is an integral part of many crypto currencies. It's a part of the BIP38 standard for encrypting private Bitcoin keys. It also serves as the proof-of-work system for many crypto currencies, most notably: Litecoin and Dogecoin.

Why didn't I just the predominant pure JavaScript imlementation found here? Because it's riddled with bugs, contains no tests, and is a transliteration of the Java version. i.e. it's neither Node.js optimized nor browser optimized. Required optimizations: Buffer in Node.js and type arrays in the browser.

Installation

npm install --save scryptsy

Example

var scrypt = require('scryptsy')

var key = "pleaseletmein"
var salt = "SodiumChloride"
var data = scrypt(key, salt, 16384, 8, 1, 64)
console.log(data.toString('hex')) 
// => 7023bdcb3afd7348461c06cd81fd38ebfda8fbba904f8e3ea9b543f6545da1f2d5432955613f0fcf62d49705242a9af9e61e85dc0d651e40dfcf017b45575887

API

scrypt(key, salt, N, r, p, keyLenBytes, [progressCallback])

• key: The key. Either Buffer or string.
• salt: The salt. Either Buffer or string.
• N: The number of iterations. number (integer)
• r: Memory factor. number (integer)
• p: Parallelization factor. number (integer)
• keyLenBytes: The number of bytes to return. number (integer)
• progressCallback: Call callback on every 1000 ops. Passes in {current, total, percent} as first parameter to progressCallback().

Returns Buffer.

Resources

• Tarsnap Blurb on Scrypt
• node-scrypt A Node.js wrapper for the C++ scrypt utility
• Scrypt Whitepaper
• IETF Scrypt (Test vector params are incorrect.)

Credits

This code was modified from the code found here https://github.com/cheongwy/node-scrypt-js which was based on https://github.com/wg/scrypt.