`blake2b`

Blake2b (64-bit version) in pure Javascript

This module is based on @dcposch implementation of BLAKE2b, with some changes:

This module requires you to pass in a out buffer, saving an allocation
This module allows you to set the salt and personal parameters
This module exports constants for the parameters in libsodium style
Uses a WASM version (where it is supported) for massive performance boosts

All credit goes to @dcposch for doing the hard work of porting the implementation from C to Javascript.

Usage

var blake2b = require('blake2b')

var output = new Uint8Array(64)
var input = Buffer.from('hello world')

console.log('hash:', blake2b(output.length).update(input).digest('hex'))

API

`var hash = blake2b(outLength, [key], [salt], [personal], [noAssert = false])`

Create a new hash instance, optionally with key, salt and personal. Bypass input assertions by setting noAssert to true.

All parameters must be Uint8Array, Buffer or another object with a compatible API. All parameters must also fulfill the following constraints, or an AssertionError will be thrown (unless noAssert = true):

outLength must within the byte ranges defined by the constants below.
key is optional, but must within the byte ranges defined by the constants below, if given. This value must be kept secret, and can be used to create prefix-MACs.
salt is optional, but must be exactly SALTBYTES, if given. You can use this parameter as a kind of per user id, or local versioning scheme. This value is not required to be secret.
personal is optional, but must be exactly PERSONALBYTES, if given. You can use this parameter as a kind of app id, or global versioning scheme. This value is not required to be secret.

`var hash = hash.update(input)`

Update the hash with new input. Calling this method after .digest will throw an error.

`var out = hash.digest(out)`

Finalise the the hash and write the digest to out. out must be exactly equal to outLength given in the blake2b method.

Optionally you can pass hex to get the hash as a hex string or no arguments to have the hash return a new Uint8Array with the hash.

Constants

blake2b.BYTES_MIN Minimum length of out
blake2b.BYTES_MAX Maximum length of out
blake2b.BYTES Recommended default length of out
blake2b.KEYBYTES_MIN Minimum length of key
blake2b.KEYBYTES_MAX Maximum length of key
blake2b.KEYBYTES Recommended default length of key
blake2b.SALTBYTES Required length of salt
blake2b.PERSONALBYTES Required length of personal

Install

npm install blake2b

Test vectors

This repository includes test vectors with {outlen, out, input, key, salt, personal} objects for testing conformance against the spec and other implementations:

Lines 2 - 257 are tests for hashing with no key, taken from BLAKE2 test vectors
Lines 258 - 513 are tests for hashing with keys, taken from BLAKE2 test vectors
Lines 514- 577 are tests for hashing with key, salt and personalisation, derived from the libsodium tests