Code examples in readme

[DePasqualeOrg]

I'm new to JSON-LD signatures, and I'm finding it difficult to get started in this space. Could you provide some code examples for signing JSON-LD documents in the readme?

[mattcollier]

You'll want to refer to the documentation provided by the crypto suite that is of interest to you: https://github.com/digitalbazaar/jsonld-signatures#usage

https://github.com/digitalbazaar/ed25519-signature-2020#usage

https://github.com/digitalbazaar/ed25519-signature-2020/tree/main/test

[DePasqualeOrg]

Thanks. I tried to piece together the examples you cited:

import jsigs from 'jsonld-signatures';
const { purposes: { AssertionProofPurpose } } = jsigs;
import pkg from '@digitalbazaar/ed25519-verification-key-2020';
const { Ed25519VerificationKey2020 } = pkg;
import pkg2 from '@digitalbazaar/ed25519-signature-2020';
const { Ed25519Signature2020 } = pkg2;
import { JsonLdDocumentLoader } from 'jsonld-document-loader';

const documentLoader = new JsonLdDocumentLoader();

// create the unsigned credential
const unsignedCredential = {
  '@context': [
    'https://www.w3.org/2018/credentials/v1',
    {
      AlumniCredential: 'https://schema.org#AlumniCredential',
      alumniOf: 'https://schema.org#alumniOf',
    },
  ],
  id: 'http://example.edu/credentials/1872',
  type: ['VerifiableCredential', 'AlumniCredential'],
  issuer: 'https://example.edu/issuers/565049',
  issuanceDate: '2010-01-01T19:23:24Z',
  credentialSubject: {
    id: 'https://example.edu/students/alice',
    alumniOf: 'Example University',
  },
};

// create the keypair to use when signing
const controller = 'https://example.edu/issuers/565049';
const keyPair = await Ed25519VerificationKey2020.from({
  type: 'Ed25519VerificationKey2020',
  controller,
  id: `${controller}#z6MknCCLeeHBUaHu4aHSVLDCYQW9gjVJ7a63FpMvtuVMy53T`,
  publicKeyMultibase: 'z6MknCCLeeHBUaHu4aHSVLDCYQW9gjVJ7a63FpMvtuVMy53T',
  privateKeyMultibase: 'zrv2EET2WWZ8T1Jbg4fEH5cQxhbUS22XxdweypUbjWVzv1YD6VqYu' + 'W6LH7heQCNYQCuoKaDwvv2qCWz3uBzG2xesqmf',
});

const suite = new Ed25519Signature2020({ key: keyPair });
suite.date = '2010-01-01T19:23:24Z';

const signedCredential = await jsigs.sign(unsignedCredential, {
  suite,
  purpose: new AssertionProofPurpose(),
  documentLoader,
});

console.log(signedCredential);

But I get the following error:

TypeError: Cannot read properties of undefined (reading 'from')

[mattcollier]

This should get you going: https://gist.github.com/mattcollier/75042d08b5b911df80676ea8b2b0c739

Support for pure ESM in Node.js is problematic and the esm module and webpack are typically used to fill the gap.

[DePasqualeOrg]

Thanks, I'm starting to understand how this works now. I wasn't able to find any examples using AuthenticationProofPurpose in these repositories, which is the main use case I'm interested in. I think I have it working now that I supplied a UUID as a challenge value. If there were more code examples like this readily available, it would really help newcomers get started.

[DePasqualeOrg]

Support for pure ESM in Node.js is problematic and the esm module and webpack are typically used to fill the gap.

It's proving difficult for me to integrate this solution into my project using node-fetch. What is the main hurdle to offering ESM support in Node?

[dmitrizagidulin]

@DePasqualeOrg - try out the DCC fork of this library, over at https://github.com/digitalcredentials/jsonld-signatures (which has been refactored to not use the esm runtime transpiler). Same usage/same api.

[DePasqualeOrg]

Thanks! This fork and others from DCC solved this problem for me, but I noticed that there are some NPM warnings about outdated/insecure dependancies when I install them.