Hmac-blake2b NPM

`hmac-blake2b`

HMAC based on BLAKE2b

Even though BLAKE2b is designed to also work as a MAC, specifications like Noise call for a HMAC.

Usage

const { randombytes_buf } = require('sodium-universal/randombytes')
const hmac = require('.')

const mac = Buffer.alloc(hmac.BYTES)
const key = Buffer.alloc(hmac.KEYBYTES)
randombytes_buf(key)

const data = Buffer.from('some data')

hmac(mac, data, key)

API

`hmac.BYTES`

Size of the output MAC in bytes

`hmac.KEYBYTES`

RFC2104 recommended size of the key in bytes.

`hmac(out, data, key)`

Computes a HMAC from data with key and writes it into out.

out must be a Buffer or Uint8Array of length hmac.BYTES
data must be a Buffer, Uint8Array or Array of Buffers or Uint8Arrays.
key must be a Buffer or Uint8Array. Per the HMAC spec key can be as small as 1 byte, in which case it is right-padded with NUL bytes, or any size larger than hmac.KEYBYTES in which case it is hashed down to fit. The recommended size by the spec is hmac.KEYBYTES