http-signature-zcap-verify (@digitalbazaar/http-signature-zcap-verify)

A library for verifying Authorization Capability (ZCAP) invocations via HTTP signatures

Install

Browsers and Node.js 22+ are supported.
Web Crypto API required. Older browsers and Node.js 14 must use a polyfill.

To install from NPM:

npm install @digitalbazaar/http-signature-zcap-verify

Example "getVerifier" for "verifyCapabilityInvocation"

import * as Ed25519Multikey from '@digitalbazaar/ed25519-multikey';

async function getVerifier({keyId, documentLoader}) {
  const {document} = await documentLoader(keyId);
  const key = await Ed25519Multikey.from(document);
  if(key.revoked) {
    throw new Error('Verification method has been revoked.');
  }
  const verificationMethod = await key.export(
    {publicKey: true, includeContext: true});
  const verifier = key.verifier();
  return {verifier, verificationMethod};
}