Add ability to generate() a did from a secret key seed.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # did-web-driver ChangeLog
 
+## 2.2.0 -
+
+### Added
+- Add ability to `.generate()` from a secret key seed.
+
 ## 2.1.1 - 2022-01-19
 
 ### Changed

README.md

@@ -58,9 +58,40 @@ resolver.use(didWebDriver)
 
 ### Generating a new DID
 
+#### Generating from seed
+
+If you have a deterministic secret seed (created with [`did-cli`](https://github.com/digitalcredentials/did-cli),
+for example) and would like to generate a `did:web` document from it:
+
 ```js
-const { didDocument, keyPairs, methodFor } = await didWebDriver.generate()
+const url = 'https://example.com'
+const seed = 'z1AhV1bADy7RepJ64mvH7Kk7htFNGc7EA1WA5nGzLSTWc6o'
 
+const { didDocument, keyPairs, methodFor } = await didWebDriver.generate({ url, seed })
+// didDocument
+{
+  '@context': [
+    'https://www.w3.org/ns/did/v1',
+    'https://w3id.org/security/suites/ed25519-2020/v1',
+    'https://w3id.org/security/suites/x25519-2020/v1'
+  ],
+  id: 'did:web:example.com',
+  assertionMethod: [{
+    id: 'did:web:example.com#z6MkmDMjfkjs9XPCN1LfoQQRHz1mJ8PEdiVYC66XKhj3wGyB',
+    type: 'Ed25519VerificationKey2020',
+    controller: 'did:web:example.com',
+    publicKeyMultibase: 'z6MkmDMjfkjs9XPCN1LfoQQRHz1mJ8PEdiVYC66XKhj3wGyB'
+  }]
+}
+```
+
+#### Generating new random keys
+
+Invoking `generate()` by itself will create new keypairs for each proof purpose.
+
+```js
+const { didDocument, keyPairs, methodFor } = await didWebDriver.generate()
+// didDocument
 {
   '@context': [
     'https://www.w3.org/ns/did/v1',

package.json

@@ -43,6 +43,7 @@
     "./package.json": "./package.json"
   },
   "dependencies": {
+    "@digitalcredentials/bnid": "^2.1.1",
     "@digitalcredentials/did-io": "^1.0.2",
     "@digitalcredentials/http-client": "^1.2.2",
     "did-context": "^3.1.1",
@@ -61,8 +62,8 @@
     "chai": "^4.3.4",
     "cross-env": "^7.0.3",
     "crypto-ld": "^6.0.0",
-    "esm": "^3.2.25",
     "dirty-chai": "^2.0.1",
+    "esm": "^3.2.25",
     "karma": "^6.3.9",
     "karma-babel-preprocessor": "^8.0.1",
     "karma-chai": "^0.1.0",
@@ -73,10 +74,10 @@
     "karma-webpack": "^5.0.0",
     "mocha": "^8.4.0",
     "nyc": "^15.1.0",
-    "sinon": "^12.0.1",
-    "standard": "^16.0.4",
     "rimraf": "^3.0.2",
     "rollup": "^2.62.0",
+    "sinon": "^12.0.1",
+    "standard": "^16.0.4",
     "webpack": "^5.65.0"
   },
   "nyc": {

src/DidWebResolver.js

@@ -3,6 +3,7 @@ import * as didIo from '@digitalcredentials/did-io'
 import ed25519Context from 'ed25519-signature-2020-context'
 import x25519Context from 'x25519-key-agreement-2020-context'
 import didContext from 'did-context'
+import { decodeSecretKeySeed } from '@digitalcredentials/bnid'
 
 const { VERIFICATION_RELATIONSHIPS } = didIo
 
@@ -103,7 +104,7 @@ export function urlFromDid ({ did } = {}) {
  *   DID Document initialized with keys, as well as the map of the corresponding
  *   key pairs (by key id).
  */
-export async function initKeys ({ didDocument, cryptoLd, keyMap = {} } = {}) {
+export async function initKeys ({ didDocument, cryptoLd, keyMap } = {}) {
   const doc = { ...didDocument }
   if (!doc.id) {
     throw new TypeError(
@@ -167,7 +168,7 @@ export class DidWebResolver {
    * @param [id] {string} - A did:web DID. If absent, will be converted from url
    * @param [url] {string}
    *
-   * @param [keyMap=DEFAULT_KEY_MAP] {object} A hashmap of key types by purpose.
+   * @param [keyMap] {object} A hashmap of key types by purpose.
    *
    * @parma [cryptoLd] {object} CryptoLD instance with support for supported
    *   crypto suites installed.
@@ -177,9 +178,27 @@ export class DidWebResolver {
    *   with the corresponding key pairs used to generate it (for storage in a
    *   KMS).
    */
-  async generate ({ id, url, keyMap = this.keyMap, cryptoLd = this.cryptoLd } = {}) {
+  async generate ({ id, url, seed, keyMap, cryptoLd = this.cryptoLd } = {}) {
+    if (!id && !url) {
+      throw new TypeError('A "url" or an "id" parameter is required.')
+    }
+    if (seed && keyMap) {
+      throw new TypeError(
+        'Either a "seed" or a "keyMap" param must be provided, but not both.'
+      )
+    }
+
     const did = id || didFromUrl({ url })
 
+    if (seed) {
+      const keyPair = await _keyPairFromSecretSeed({
+        seed, controller: did, cryptoLd
+      })
+      keyMap = { assertionMethod: keyPair }
+    } else {
+      keyMap = keyMap || this.keyMap
+    }
+
     // Compose the DID Document
     let didDocument = {
       '@context': [
@@ -300,3 +319,27 @@ export class DidWebResolver {
     return method
   }
 }
+
+/**
+ * @param options {object}
+ * @param options.seed {string|Uint8Array}
+ * @param controller {string}
+ * @param cryptoLd {object}
+ *
+ * @return {Promise<LDKeyPair>}
+ */
+async function _keyPairFromSecretSeed ({ seed, controller, cryptoLd } = {}) {
+  let seedBytes
+  if (typeof seed === 'string') {
+    // Currently only supports base58 multibase / identity multihash encoding.
+    if (!seed.startsWith('z1A')) {
+      throw new TypeError('"seed" parameter must be a multibase/multihash encoded string, or a Uint8Array.')
+    }
+    seedBytes = decodeSecretKeySeed({ secretKeySeed: seed })
+  } else {
+    seedBytes = new Uint8Array(seed)
+  }
+  return cryptoLd.generate({
+    controller, seed: seedBytes, type: 'Ed25519VerificationKey2020'
+  })
+}

test/unit/DidWebResolver.spec.js

@@ -73,6 +73,21 @@ describe('DidWebDriver', () => {
       expect(keyAgreementKey).to.have.property('publicKeyMultibase')
       expect(keyAgreementKey).to.have.property('privateKeyMultibase')
     })
+
+    it('should generate from seed', async () => {
+      const seed = 'z1AhV1bADy7RepJ64mvH7Kk7htFNGc7EA1WA5nGzLSTWc6o'
+      const url = 'https://example.com'
+      const { didDocument, methodFor } = await didWeb.generate({ url, seed })
+
+      expect(didDocument).to.have.property('id', 'did:web:example.com')
+
+      const assertionKey = methodFor({ purpose: 'assertionMethod' })
+      expect(assertionKey).to.have.property('id', 'did:web:example.com#z6MkmDMjfkjs9XPCN1LfoQQRHz1mJ8PEdiVYC66XKhj3wGyB')
+      expect(assertionKey).to.have.property('type', 'Ed25519VerificationKey2020')
+      expect(assertionKey).to.have.property('controller', 'did:web:example.com')
+      expect(assertionKey).to.have.property('publicKeyMultibase', 'z6MkmDMjfkjs9XPCN1LfoQQRHz1mJ8PEdiVYC66XKhj3wGyB')
+      expect(assertionKey).to.have.property('privateKeyMultibase')
+    })
   })
 
   describe('urlFromDid()', () => {