@cef-ebsi/key-did-resolver

EBSI NP DID Resolver

This library supports the did:key method:

did-key-format := did:key:MULTIBASE(base58-btc, MULTICODEC(public-key-type, raw-public-key-bytes))

Note: the library only supports the jwk_jcs-pub public key type (code: 0xeb51). It corresponds to a JWK with required members only through JCS.

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

Table of Contents

• Installation
• Resolving a DID document
• Creating a DID from a JWK
• Validating a DID
• License

Installation

npm install @cef-ebsi/key-did-resolver

or if you use yarn:

yarn add @cef-ebsi/key-did-resolver

Resolving a DID document

The library provides a resolver that is meant to be used through the did-resolver aggregator.

import { Resolver } from "did-resolver";
import { getResolver } from "@cef-ebsi/key-did-resolver";

// getResolver will return an object with a key/value pair of { "key": resolver } where resolver is a function used by the generic DID resolver.
const keyResolver = getResolver();
const didResolver = new Resolver(keyResolver);

didResolver
  .resolve(
    "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r",
  )
  .then((doc) => console.log(doc));

// You can also use ES7 async/await syntax
const doc = await didResolver.resolve(
  "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r",
);
console.log(doc);

/* 
Prints:

{
  "didDocument": {
    "@context": [
      "https://www.w3.org/ns/did/v1",
      "https://w3id.org/security/suites/jws-2020/v1"
    ],
    "id": "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r",
    "verificationMethod": [
      {
        "id": "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r#z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r",
        "type": "JsonWebKey2020",
        "controller": "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r",
        "publicKeyJwk": {
          "crv": "P-256",
          "kty": "EC",
          "x": "ngy44T1vxAT6Di4nr-UaM9K3Tlnz9pkoksDokKFkmNc",
          "y": "QCRfOKlSM31GTkb4JHx3nXB4G_jSPMsbdjzlkT_UpPc"
        }
      }
    ],
    "authentication": [
      "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r#z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r"
    ],
    "assertionMethod": [
      "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r#z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r"
    ],
    "capabilityInvocation": [
      "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r#z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r"
    ],
    "capabilityDelegation": [
      "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r#z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r"
    ]
  },
  "didDocumentMetadata": {},
  "didResolutionMetadata": {
    "contentType": "application/did+ld+json"
  }
}
*/

Creating a DID from a JWK

The library exposes a method allowing you to create a DID from a JWK:

import { util } from "@cef-ebsi/key-did-resolver";

const jwk = {
  kty: "EC",
  crv: "P-256",
  x: "ngy44T1vxAT6Di4nr-UaM9K3Tlnz9pkoksDokKFkmNc",
  y: "QCRfOKlSM31GTkb4JHx3nXB4G_jSPMsbdjzlkT_UpPc",
};

const did = util.createDid(jwk);

// did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r

Validating a DID

The library also exposes a method to assert if a DID is valid:

import { util } from "@cef-ebsi/key-did-resolver";

const did =
  "did:key:z2dmzD81cgPx8Vki7JbuuMmFYrWPgYoytykUZ3eyqht1j9KbsEYvdrjxMjQ4tpnje9BDBTzuNDP3knn6qLZErzd4bJ5go2CChoPjd5GAH3zpFJP5fuwSk66U5Pq6EhF4nKnHzDnznEP8fX99nZGgwbAh1o7Gj1X52Tdhf7U4KTk66xsA5r";

util.validateDid(did); // Will throw an error if the DID is not valid

License

Copyright (C) 2025 European Union

This program is free software: you can redistribute it and/or modify it under the terms of the EUROPEAN UNION PUBLIC LICENCE v. 1.2 as published by the European Union.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the EUROPEAN UNION PUBLIC LICENCE v. 1.2 for further details.

You should have received a copy of the EUROPEAN UNION PUBLIC LICENCE v. 1.2. along with this program. If not, see https://joinup.ec.europa.eu/collection/eupl/eupl-text-eupl-12.