@bitgo/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

``js
var blake2b = require('@bitgo/blake2b');

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

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

API

$3

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.

$3

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

$3

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.

$3

- 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

`sh
npm install @bitgo/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

License

ISC