EcdsaMultikey Key Pair Library for Linked Data (@digitalbazaar/ecdsa-multikey)

Javascript library for generating and working with EcdsaMultikey key pairs.

Table of Contents

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

Background

For use with:

• @digitalbazaar/ecdsa-2019-cryptosuite ^1.0.0 crypto suite (with jsonld-signatures ^11.0.0)
• @digitalbazaar/data-integrity ^1.0.0

See also (related specs):

• Verifiable Credential Data Integrity

Security

As with most security- and cryptography-related tools, the overall security of your system will largely depend on your design decisions.

Install

• Node.js 16+ is required.

To install locally (for development):

git clone https://github.com/digitalbazaar/ecdsa-multikey.git
cd ecdsa-multikey
npm install

Usage

Generating a new public/secret key pair

To generate a new public/secret key pair:

• {string} [curve] [Required] ECDSA curve used to generate the key: ['P-256', 'P-384', 'P-521'].
• {string} [id] [Optional] ID for the generated key.
• {string} [controller] [Optional] Controller URI or DID to initialize the generated key. (This will be used to generate id if it is not explicitly defined.)

import * as EcdsaMultikey from '@digitalbazaar/ecdsa-multikey';

const keyPair = await EcdsaMultikey.generate({curve: 'P-384'});

Importing a key pair from storage

To create an instance of a public/secret key pair from data imported from storage, use .from():

const serializedKeyPair = { ... };

const keyPair = await EcdsaMultikey.from(serializedKeyPair);

Exporting the public key only

To export just the public key of a pair:

await keyPair.export({publicKey: true});
// ->
{
  type: 'Multikey',
  id: 'did:example:1234#zDnaeSMnptAKpH4AD41vTkwzjznW7yNetdRh9FJn8bJsbsdbw',
  controller: 'did:example:1234',
  publicKeyMultibase: 'zDnaeSMnptAKpH4AD41vTkwzjznW7yNetdRh9FJn8bJsbsdbw'
}

Exporting the full public-secret key pair

To export the full key pair, including secret key (warning: this should be a carefully considered operation, best left to dedicated Key Management Systems):

await keyPair.export({publicKey: true, secretKey: true});
// ->
{
  type: 'Multikey',
  id: 'did:example:1234#zDnaeSMnptAKpH4AD41vTkwzjznW7yNetdRh9FJn8bJsbsdbw',
  controller: 'did:example:1234',
  publicKeyMultibase: 'zDnaeSMnptAKpH4AD41vTkwzjznW7yNetdRh9FJn8bJsbsdbw',
  secretKeyMultibase: 'z42twirSb1PULt5Sg6gjgNMsdiLycu6fbA83aX1vVb8e3ncP'
}

Creating a signer function

In order to perform a cryptographic signature, you need to create a sign function, and then invoke it.

const keyPair = EcdsaMultikey.generate({curve: 'P-256'});

const {sign} = keyPair.signer();

// data is a Uint8Array of bytes
const data = (new TextEncoder()).encode('test data goes here');
// Signing also outputs a Uint8Array, which you can serialize to text etc.
const signature = await sign({data});

Creating a verifier function

In order to verify a cryptographic signature, you need to create a verify function, and then invoke it (passing it the data to verify, and the signature).

const keyPair = EcdsaMultikey.generate({curve: 'P-521'});

const {verify} = keyPair.verifier();

const valid = await verify({data, signature});
// true

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: [email protected]

License

New BSD License (3-clause) © 2023 Digital Bazaar