x25519-key-pair

X25519KeyPair (x25519-key-pair)

An X25519 (Curve25519) DH key implementation to work with the crypto-ld LDKeyPair API

Table of Contents

• Security
• Background
• Install
• Usage
• Contribute
• Commercial Support
• License

Security

TBD

Background

This is a low-level level library to generate and serialize X25519 (Curve25519) key pairs (uses nacl.box under the hood).

To actually perform encryption with those keys, we recommend you use the https://github.com/digitalbazaar/minimal-cipher library.

See also (related specs):

• Linked Data Proofs
• Linked Data Cryptographic Suite Registry

Install

Requires Node.js 8.3+

To install locally (for development):

git clone https://github.com/digitalbazaar/x25519-key-pair.git
cd x25519-key-pair
npm install

Usage

Importing:

const {X25519KeyPair} = require('x25519-key-pair');

// Or, if you're testing code in the interactive Node CLI, right in this repo:
const {X25519KeyPair} = require('./');

Generating:

const keyPair = await X25519KeyPair.generate({
  controller: 'did:example:1234'
});
// Don't forget to set your key's id. For example, DID + fingerprint
keyPair.id = 'did:example:1234#' + keyPair.fingerprint();

Serializing just the public key:

keyPair.publicNode();
// ->
{
  id: 'did:example:1234#z6LSbh9HiAU2zzBdFMdKZGHfg1UjvAYF8C8kYnkfGKuCxYEB',
  type: 'X25519KeyAgreementKey2019',
  controller: 'did:example:1234',
  publicKeyBase58: '1y8BrfAuXTt9yFZ2cmiMRGG5218Raxbfp2ymsFgFATR'
}

Serializing both the private and public key:

// a different key pair than the previous example
await keyPair.export()
// ->
 {
  id: 'did:example:1234#z6LSjeJZaUHMvEKW7tEJXV4PrSm61NzxxHhDXF6zHnVtDu9g',
  type: 'X25519KeyAgreementKey2019',
  controller: 'did:example:1234',
  publicKeyBase58: '8y8Q4AUVpmbm2VrXzqYSXrYcAETrFgX4eGPJoKrMWXNv',
  privateKeyBase58: '95tmYuhqSuJqY77FEg78Zy3LFQ1cENxGv2wMvayk7Lqf'
}

Deserializing:

// Loading public key only
const keyPair = await X25519KeyPair.from({
  id: 'did:example:1234#z6LSjeJZaUHMvEKW7tEJXV4PrSm61NzxxHhDXF6zHnVtDu9g',
  type: 'X25519KeyAgreementKey2019',
  controller: 'did:example:1234',
  publicKeyBase58: '8y8Q4AUVpmbm2VrXzqYSXrYcAETrFgX4eGPJoKrMWXNv'
});

Contribute

See the contribute file!

PRs accepted.

Small note: If editing the Readme, please conform to the standard-readme specification.

Commercial Support

Commercial support for this library is available upon request from Digital Bazaar: [e-mail]

License

New BSD License (3-clause) © Digital Bazaar

Changelog

2.0.0 - 2020-03-09

Changed

• BREAKING: Changed the key fingerprint prefix to the recently registered multicodec value of 0xec.