Add support for external DID resolver.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # bedrock-vc-verifier ChangeLog
 
+## 19.2.0 - 2024-mm-dd
+
+### Added
+- Add support for using a configured external DID resolver.
+
 ## 19.1.0 - 2024-01-25
 
 ### Changed

lib/documentLoader.js

@@ -1,5 +1,5 @@
 /*!
- * Copyright (c) 2019-2022 Digital Bazaar, Inc. All rights reserved.
+ * Copyright (c) 2019-2024 Digital Bazaar, Inc. All rights reserved.
  */
 import * as bedrock from '@bedrock/core';
 import {
@@ -9,6 +9,7 @@ import {
 } from '@bedrock/jsonld-document-loader';
 import {createContextDocumentLoader} from '@bedrock/service-context-store';
 import {didIo} from '@bedrock/did-io';
+import {klona} from 'klona';
 import '@bedrock/credentials-context';
 import '@bedrock/data-integrity-context';
 import '@bedrock/did-context';
@@ -53,9 +54,17 @@ export async function createDocumentLoader({config} = {}) {
     {config, serviceType});
 
   return async function documentLoader(url) {
-    // resolve all DID URLs through did-io
+    // handle DID URLs...
     if(url.startsWith('did:')) {
-      const document = await didIo.get({url});
+      let document;
+      if(config.verifyOptions?.didResolver) {
+        // resolve via configured DID resolver
+        const {verifyOptions: {didResolver}} = config;
+        document = await _resolve({didResolver, didUrl: url});
+      } else {
+        // resolve via did-io
+        document = await didIo.get({url});
+      }
       return {
         contextUrl: null,
         documentUrl: url,
@@ -83,3 +92,61 @@ export async function createDocumentLoader({config} = {}) {
     }
   };
 }
+
+async function _resolve({didResolver, didUrl}) {
+  // split on `?` query or `#` fragment
+  const [did] = didUrl.split(/(?=[\?#])/);
+
+  // fetch DID document using DID resolver;
+  // assume a universal DID resolver 1.0 API in this version
+  const url = `${didResolver.url}/1.0/identifiers/${encodeURIComponent(did)}`;
+  const data = await httpClientHandler.get({url});
+
+  if(data?.id !== did) {
+    throw new Error(`DID document for DID "${did}" not found.`);
+  }
+
+  // FIXME: perform DID document validation
+  // FIXME: handle URL query param / services
+  const didDocument = data;
+
+  // if a fragment was found use the fragment to dereference a subnode
+  // in the did doc
+  const [, fragment] = url.split('#');
+  if(fragment) {
+    const id = `${didDocument.id}${fragment}`;
+    return _getNode({didDocument, id});
+  }
+  // resolve the full DID Document
+  return didDocument;
+}
+
+function _getNode({didDocument, id}) {
+  // do verification method search first
+  let match = didDocument?.verificationMethod?.find(vm => vm?.id === id);
+  if(!match) {
+    // check other top-level nodes
+    for(const [key, value] of Object.entries(didDocument)) {
+      if(key === '@context' || key === 'verificationMethod') {
+        continue;
+      }
+      if(Array.isArray(value)) {
+        match = value.find(e => e?.id === id);
+      } else if(value?.id === id) {
+        match = value;
+      }
+      if(match) {
+        break;
+      }
+    }
+  }
+
+  if(!match) {
+    throw new Error(`DID document entity with id "${id}" not found.`);
+  }
+
+  return {
+    '@context': klona(didDocument['@context']),
+    ...klona(match)
+  };
+}

lib/index.js

@@ -1,20 +1,31 @@
 /*!
- * Copyright (c) 2021-2022 Digital Bazaar, Inc. All rights reserved.
+ * Copyright (c) 2021-2024 Digital Bazaar, Inc. All rights reserved.
  */
 import * as bedrock from '@bedrock/core';
+import {createService, schemas} from '@bedrock/service-core';
 import {
   addRoutes as addContextStoreRoutes
 } from '@bedrock/service-context-store';
 import {addRoutes} from './http.js';
-import {createService} from '@bedrock/service-core';
 import {initializeServiceAgent} from '@bedrock/service-agent';
+import {klona} from 'klona';
+import {verifyOptions} from '../schemas/bedrock-vc-verifier.js';
 
 // load config defaults
 import './config.js';
 
 const serviceType = 'vc-verifier';
 
 bedrock.events.on('bedrock.init', async () => {
+  // add customizations to config validators...
+  const createConfigBody = klona(schemas.createConfigBody);
+  const updateConfigBody = klona(schemas.updateConfigBody);
+  const schemasToUpdate = [createConfigBody, updateConfigBody];
+  for(const schema of schemasToUpdate) {
+    // verify options
+    schema.properties.verifyOptions = verifyOptions;
+  }
+
   // create `vc-verifier` service
   const service = await createService({
     serviceType,
@@ -24,6 +35,8 @@ bedrock.events.on('bedrock.init', async () => {
       revocation: 1
     },
     validation: {
+      createConfigBody,
+      updateConfigBody,
       // require these zcaps (by reference ID)
       zcapReferenceIds: [{
         referenceId: 'edv',

package.json

@@ -41,6 +41,7 @@
     "bnid": "^3.0.0",
     "body-parser": "^1.20.0",
     "cors": "^2.8.5",
+    "klona": "^2.0.6",
     "serialize-error": "^11.0.0"
   },
   "peerDependencies": {

schemas/bedrock-vc-verifier.js

@@ -1,5 +1,5 @@
 /*!
- * Copyright (c) 2022 Digital Bazaar, Inc. All rights reserved.
+ * Copyright (c) 2022-2024 Digital Bazaar, Inc. All rights reserved.
  */
 const context = {
   title: '@context',
@@ -10,6 +10,25 @@ const context = {
   }
 };
 
+export const verifyOptions = {
+  title: 'Verify Options',
+  type: 'object',
+  required: ['didResolver'],
+  additionalProperties: false,
+  properties: {
+    didResolver: {
+      title: 'DID Resolver',
+      type: 'object',
+      required: ['url'],
+      additionalProperties: false,
+      url: {
+        type: 'string',
+        pattern: '^https://[^.]+.[^.]+'
+      }
+    }
+  }
+};
+
 export const createChallengeBody = {
   title: 'Create Challenge Body',
   type: 'object',