Node style SHA on pure JavaScript.

var shajs = require('sha.js')

console.log(shajs('sha256').update('42').digest('hex'))
// => 73475cb40a568e8da8a045ced110137e159f890ac4da883b6b17dc651b3a8049
console.log(new shajs.SHA256().update('42').digest('hex'))
// => 73475cb40a568e8da8a045ced110137e159f890ac4da883b6b17dc651b3a8049

var sha256stream = shajs('sha256')
sha256stream.end('42')
console.log(sha256stream.read().toString('hex'))
// => 73475cb40a568e8da8a045ced110137e159f890ac4da883b6b17dc651b3a8049

sha.js currently implements:

• SHA (SHA-0) -- legacy, do not use in new systems
• SHA-1 -- legacy, do not use in new systems
• SHA-224
• SHA-256
• SHA-384
• SHA-512

Note, this doesn't actually implement a stream, but wrapping this in a stream is trivial. It does update incrementally, so you can hash things larger than RAM, as it uses a constant amount of memory (except when using base64 or utf8 encoding, see code comments).

This work is derived from Paul Johnston's A JavaScript implementation of the Secure Hash Algorithm.