Package Exports

x448-js
x448-js/dist/index.js
x448-js/dist/x448-js.esm.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (x448-js) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

X448-js

Pure JavaScript/TypeScript implementation of the X448 elliptic curve (RFC 7748) for ECDH key exchange. Uses the jsbn library for big integer operations.

Installation

Using npm:

npm install x448-js

or yarn:

yarn add x448-js

Then include it in your code:

import { getPublicKey, getSharedSecret } from "x448-js";

Usage

`getPublicKey(privateKey)`

Calculate public key from a provided private key

const privateKey = crypto.randomFillSync(new Uint8Array(56));
const publicKey = getPublicKey(privateKey);

The private key can be any random generated Buffer/byte-array of length 56

`getSharedSecret(privateKey, publicKey)`

Calculate shared secret from a locally stored private key and a remote public key

The results are represented as plain number arrays. They can be converted using Buffer.from, or Uint8Array.from.

Example

ECDH shared secret exchange

const alice_private = random(56); // 9a8f4925d1519f5775cf46b04b5800d4ee9ee8bae8bc5565d498c28dd9c9baf574a9419744897391006382a6f127ab1d9ac2d8c0a598726b
const bob_private = random(56); // 1c306a7ac2a0e2e0990b294470cba339e6453772b075811d8fad0d1d6927c120bb5ee8972b0d3e21374c9c921b09d1b0366f10b65173992d

const alice_public = getPublicKey(alice_private); // 9b08f7cc31b7e3e67d22d5aea121074a273bd2b83de09c63faa73d2c22c5d9bbc836647241d953d40c5b12da88120d53177f80e532c41fa0
const bob_public = getPublicKey(bob_private); // 3eb7a829b0cd20f5bcfc0b599b6feccf6da4627107bdb0d4f345b43027d8b972fc3e34fb4232a13ca706dcb57aec3dae07bdc1c67bf33609

const alice_shared_secret = getSharedSecret(alice_private, bob_public); // 07fff4181ac6cc95ec1c16a94a0f74d12da232ce40a77552281d282bb60c0b56fd2464c335543936521c24403085d59a449a5037514a879d
const bob_shared_secret = getSharedSecret(bob_private, alice_public); // 07fff4181ac6cc95ec1c16a94a0f74d12da232ce40a77552281d282bb60c0b56fd2464c335543936521c24403085d59a449a5037514a879d