JS: futoin-hkdf

Node.js implementation of RFC5869: HMAC-based Extract-and-Expand Key Derivation Function (HKDF).

The implementation is fully compliant with test vectors provided in the RFC.

There are alternative modules, but they are:

much less performing and/or
have quite poor code quality at the moment and/or
are not compliant with RFC (e.g. work only with string parameters) and/or
not working with current Node.js versions and/or
do not support arbitrary hash functions and/or
not reliable dependency for FutoIn Security concept in general.

Standalone HKDF extract() and expand() actions are also available for advanced usage.

Performance comparison

The figures in “derived keys per second”.

futoin-hkdf - 74 642
- fully compliant
node-hdkf/hdkf modules - 57 707 (~22% slower)
- seems to be broken by design
- produces wrong results with RFC test vectors
ctrlpanel-hdkf - 52 181 (~30% slower)
- seems to be compliant
@stablelib/hkdf - 39 808 (~46% slower)
- seems to be compliant

Installation for Node.js

Command line:

$ npm install futoin-hkdf --save

or:

$ yarn add futoin-hkdf --save

Examples

const hkdf = require('futoin-hkdf');

// Parameter overview
//-------------------
// initial keying material
const ikm = 'string-or-buffer';
// required output length in bytes
const length = 16;
// can be empty string or false equivalent
const salt = 'strongly-encouraged';
// optional parameter
const info = 'optional-context';
// HMAC hashing algorithm to use
const hash = 'SHA-256';

// Generic derivation
//-------------------
hkdf(ikm, length, {salt, info, hash}); // Buffer(length) - derived key
hkdf(ikm, length, {salt, info, hash}).toString('hex'); // String(2*length)

// NOTE: all optional paramaters are passed in object

// With some parameters omitted
//-------------------
hkdf(ikm, length, {salt});
hkdf(ikm, length, {info});
hkdf(ikm, length, {hash});
hkdf(ikm, length);

// Advanced usage (only if you know what you are doing)
//-------------------
hkdf.hash_length(hash); // get hash_len
hkdf.extract(hash, hash_len, ikm, salt); // run only step #1
hkdf.expand(hash, hash_len. prk, length, info); // run only step #2