@digitalbazaar/x25519-key-agreement-key-2019

X25519KeyAgreementKey2019 (@digitalbazaar/x25519-key-agreement-key-2019)

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

Table of Contents

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

Security

TBD

Background

For use with crypto-ld >= 4.0.

To actually perform encryption with those keys, we recommend you use the minimal-cipher library.

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

See also (related specs):

• Linked Data Proofs
• Linked Data Cryptographic Suite Registry

Install

Requires Node.js 12+

To install locally (for development):

git clone https://github.com/digitalbazaar/x25519-key-agreement-key-2019.git
cd x25519-key-agreement-key-2019
npm install

Usage

Importing:

const {X25519KeyAgreementKey2019} = require('@digitalbazaar/x25519-key-agreement-key-2019');

// Or, if you're testing code in the interactive Node CLI, right in this repo:
const {X25519KeyAgreementKey2019} = require('./');

Generating:

const keyPair = await X25519KeyAgreementKey2019.generate({
  controller: 'did:example:1234'
});

Serializing just the public key:

keyPair.export({publicKey: true});
// ->
{
  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({publicKey: true, privateKey: true})
// ->
 {
  id: 'did:example:1234#z6LSjeJZaUHMvEKW7tEJXV4PrSm61NzxxHhDXF6zHnVtDu9g',
  type: 'X25519KeyAgreementKey2019',
  controller: 'did:example:1234',
  publicKeyBase58: '8y8Q4AUVpmbm2VrXzqYSXrYcAETrFgX4eGPJoKrMWXNv',
  privateKeyBase58: '95tmYuhqSuJqY77FEg78Zy3LFQ1cENxGv2wMvayk7Lqf'
}

Deserializing:

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

Contribute

See the contribute file!

PRs accepted.

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

4.1.0 - 2021-03-14

Added

• fromEdKeyPair() is now an alias for fromEd25519VerificationKey2018() to maintain backwards compatibility. New code should use fromEd25519VerificationKey2020() (or whatever the latest Ed25519 suite is).