nuggets-did-resolver v0.2.0

Nuggets DID resolver

DID (Decentralised Identifier Document) Resolver, specific to the Nuggets private network.

This library is intended to use ethereum addresses as static Decentralized Identifiers and wrap them in a DID Document.

It supports the proposed Decentralized Identifiers spec from the W3C Credentials Community Group.

It requires the did-resolver library, which is the primary interface for resolving DIDs.

DID Method

To encode a DID for an Ethereum address on the nuggets network, convert the address to Base58 and prepend did:nuggets:.

Base 58 conversion example:

// add the "bs58" package to your project & require
const bs58 = require('bs58')

// convert ethereum address to Base 58
const addressBase58 = bs58.encode(Buffer.from('0xB21528447F362da4affFD62B499a7630C6A59f3b'.slice(2), 'hex'))

console.log(addressBase58) // output = "3Uu42t4rzjC1oUUWfxPFnX2FL1bG"

Resulting DID: did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG

DID Document

The did resolver decodes the ethereum address, and looks up the registered DID Document corresponding to the address.

Note: Nuggets ID addresses are derived from the public key in the registration smart contract, meaning that the two are cryptographically linked.

An example DID Document looks like this:

{
  '@context': [
    'https://www.w3.org/ns/did/v1/',
    'https://w3id.org/security/v2',
    'https://w3id.org/security/suites/secp256k1-2019/v1'
  ],
  id: 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG',
  verificationMethod: [
    {
      id: 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG#controller',
      type: 'EcdsaSecp256k1VerificationKey2019',
      controller: 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG',
      publicKeyBase58: '2dsbczEiYyxYGy7mZqtnVxfUobpnFqXz1DT4hPiBXAwCutRgMTReW6vP8hskHyahK6MMPyXoFHfZhTdYrhMV5oQq'
    },
    {
      type: 'Bls12381G2Key2020',
      id: 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG#bls12381g2',
      controller: 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG',
      publicKeyBase58: 'z7iFxbzoB9FsvxYQ26gvXdS7nWkp1RyVdRFazgMcj9T5Wx5PZFyNJyxQqDe8nyZ7BiafJpJTjXj4ULdaCVfcc3rXpWy8Pph23rqi7AkZvKhQr7D9sc8a5Fi7HxibUnrnPPc'
    }
  ],
  authentication: [ 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG#controller' ],
  assertionMethod: [ 'did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG#controller' ]
}

DID Document Build

The DID Document is not stored as a file, however it is cached for the life of the running script.

Resolving a DID document

The library presents a resolve() function that returns a Promise returning the DID document. It is not meant to be used directly but through the did-resolver aggregator.

You can use the getResolver() method to produce an entry that can be used with the Resolver constructor:

const { Resolver } = require('did-resolver')
const nuggets = require('@nuggetslife/nuggets-did-resolver')

const nuggetsResolver = nuggets.getResolver()
const resolver = new Resolver(nuggetsResolver)

const doc = await resolver
  .resolve('did:nuggets:3Uu42t4rzjC1oUUWfxPFnX2FL1bG')