readme

README.md

@@ -31,6 +31,68 @@ npm i @transmute/verifiable-credentials@latest --save
 import * as transmute from "@transmute/verifiable-credentials";
 ```
 
+```ts
+const privateKey = await transmute.key.generate({
+  alg: "ES384",
+  cty: "application/jwk+json",
+});
+
+const publicKey = await transmute.key.publicFromPrivate({
+  cty: "application/jwk+json",
+  content: privateKey,
+});
+
+const vc = await transmute
+  .issuer({
+    alg: "ES384",
+    iss: "https://university.example/issuers/565049",
+    kid: "key-42",
+    cty: "application/vc+ld+json+jwt",
+    privateKey: {
+      cty: "application/jwk+json",
+      content: privateKey,
+    },
+  })
+  .issue({
+    claimset: new TextEncoder().encode(
+      JSON.stringify({
+        "@context": [
+          "https://www.w3.org/ns/credentials/v2",
+          "https://www.w3.org/ns/credentials/examples/v2",
+        ],
+        id: "https://university.example/credentials/1872",
+        type: ["VerifiableCredential", "ExampleAlumniCredential"],
+        issuer: {
+          id: "https://university.example/issuers/565049",
+        },
+        validFrom: "2010-01-01T19:23:24Z",
+        credentialSubject: {
+          id: "did:example:ebfeb1f712ebc6f1c276e12ec21",
+          alumniOf: {
+            id: "did:example:c276e12ec21ebfeb1f712ebc6f1",
+            name: "Example University",
+          },
+        },
+      })
+    ),
+  });
+const verified = await cr1
+  .verifier({
+    resolver: {
+      resolve: async () => {
+        return {
+          cty: "application/jwk+json",
+          content: publicKey,
+        };
+      },
+    },
+  })
+  .verify<transmute.VerifiableCredentialWithIssuerObject>({
+    cty: "application/vc+ld+json+jwt",
+    content: vc,
+  });
+```
+
 ## Develop
 
 ```bash

src/cr1/key/index.ts

@@ -1,3 +1,5 @@
 export * from './generate'
 export * from './importJWK'
-export * from './importKeyLike'
+export * from './importKeyLike'
+
+export * from './publicFromPrivate'

src/cr1/key/publicFromPrivate.ts

@@ -0,0 +1,29 @@
+
+
+
+import * as cose from '@transmute/cose'
+import * as jose from 'jose'
+
+import { SupportedKeyFormats } from '../types'
+
+import { encoder, decoder } from '../text'
+
+export const publicFromPrivate = async (
+  key: {
+    cty: SupportedKeyFormats,
+    content: Uint8Array
+  }) => {
+  if (key.cty === 'application/jwk+json') {
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const { d, ...publicKeyJwk } = JSON.parse(decoder.decode(key.content))
+    return encoder.encode(JSON.stringify(publicKeyJwk))
+  } else if (key.cty === 'application/cose-key') {
+    const coseKey = cose.cbor.decode(key.content)
+    const jwk = await cose.key.convertCoseKeyToJsonWebKey<jose.JWK>(coseKey)
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    const { d, ...publicKeyJwk } = jwk
+    const publicKey = cose.key.convertJsonWebKeyToCoseKey(publicKeyJwk)
+    return cose.cbor.encode(publicKey)
+  }
+  throw new Error('Unsupported key type.')
+}

test/w3c-cr-1/0-keys.test.ts

@@ -12,6 +12,21 @@ it('has version', () => {
   expect(cr1.version).toBe('https://www.w3.org/TR/2024/CR-vc-data-model-2.0-20240201/')
 })
 
+it('publicFromPrivate', async () => {
+  const privateKey = await cr1.key.generate({
+    alg: 'ES384',
+    cty: 'application/jwk+json'
+  })
+  const publicKey = await cr1.key.publicFromPrivate({
+    cty: 'application/jwk+json',
+    content: privateKey
+  })
+  const parsed0 = JSON.parse(decoder.decode(privateKey))
+  delete parsed0.d
+  const parsed1 = JSON.parse(decoder.decode(publicKey))
+  expect(parsed0).toEqual(parsed1)
+})
+
 describe.skip('key generation', () => {
   it('application/jwk+json', async () => {
     const k1 = await cr1.key.generate({