Update OID4VP support to Draft 28 (#22)

Author: MasterKale

deno.json

@@ -23,6 +23,7 @@
   "imports": {
     "@deno/dnt": "jsr:@deno/dnt@^0.41.3",
     "@std/assert": "jsr:@std/assert@^1.0.9",
+    "@std/encoding": "jsr:@std/encoding@^1.0.10",
     "@std/testing": "jsr:@std/testing@^1.0.6",
     "hono": "npm:hono@^4.7.2"
   }

deno.lock

@@ -95,7 +95,7 @@ app.get("/options", async (ctx) => {
    */
   const request = await generatePresentationRequest({
     credentialOptions: sdjwtvcRequestComplex,
-    // encryptResponse: true, // Optional, defaults to `true`
+    // encryptResponse: false, // Optional, defaults to `true`
     serverAESKeySecret,
   });
 

example/main.ts

@@ -19,20 +19,21 @@ export type DigitalCredentialRequestOptions = {
 };
 
 export type DigitalCredentialRequest = {
-  protocol: string;
+  /** https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-A.1-3 */
+  protocol: 'openid4vp-v1-unsigned';
   data: DCAPIRequestOID4VP;
 };
 /**
  * Credential-agnostic OID4VP-specific request parameters
  *
- * https://openid.net/specs/openid-4-verifiable-presentations-1_0-24.html#appendix-A.2
+ * https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-A.2
  */
 export type DCAPIRequestOID4VP = {
   /** The value `"vp_token"` */
   response_type: 'vp_token';
   /** The value `"dc_api"` (when unsigned and unencrypted) or `"dc_api.jwt"` (when signed or encrypted) */
   response_mode: 'dc_api' | 'dc_api.jwt';
-  /** Ex: `"web-origin:https://example.com"` */
+  /** Only used for signed requests (not currently supported) */
   client_id?: string;
   /** Base64URL-encoded random bytes to ensure uniqueness of the presentation */
   nonce: string;

packages/server/src/dcapi/types.ts

@@ -1,23 +1,51 @@
 import { assertEquals } from '@std/assert';
+import { decodeHex, encodeHex } from '@std/encoding';
+import { encodeCBOR } from '@levischuck/tiny-cbor';
 
 import { generateSessionTranscript } from './generateSessionTranscript.ts';
-import { base64url } from '../../helpers/index.ts';
+import type { Uint8Array_ } from '../../helpers/types.ts';
 
-Deno.test('should generate OID4VP-specific session transcript', async () => {
+Deno.test('matches OID4VP Draft 28 SessionTranscript test example', async () => {
+  /**
+   * Yes, I know it's weird that this test uses hex encoding when comparing outputs. These hex
+   * strings were pulled from OID4VP Draft 28, so I'm keeping them as-is for sake of finding them
+   * later within the spec with a simple copy-paste.
+   *
+   * Example pulled from here:
+   * https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-B.2.6.1
+   */
   const sessionTranscript = await generateSessionTranscript(
-    'http://localhost:8000',
-    'web-origin:http://localhost:8000',
-    'Y_Sl5cgcgTiw7XnikC24SCDvPEFb81gcOp3lrsdSwZ8',
+    'https://example.com',
+    'exc7gBkxjx1rdc9udRrveKvSsJIq80avlXeLHhGwqtA',
+    {
+      kty: 'EC',
+      crv: 'P-256',
+      x: 'DxiH5Q4Yx3UrukE2lWCErq8N8bqC9CHLLrAwLz5BmE0',
+      y: 'XtLM4-3h5o3HUH0MHVJV0kyq0iBlrBwlh8qEDMZ4-Pc',
+      use: 'enc',
+      alg: 'ECDH-ES',
+      // @ts-ignore: It's in the example
+      kid: '1',
+    },
   );
 
+  /** https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-B.2.6.1-9 */
+  assertEquals(
+    encodeHex(encodeCBOR(sessionTranscript) as Uint8Array_),
+    '83f6f682764f70656e4944345650444341504948616e646f7665725820fbece366f4212f9762c74cfdbf83b8c69e371d5d68cea09cb4c48ca6daab761a',
+  );
+
+  /** https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-B.2.6.1-13 */
   assertEquals(
     sessionTranscript,
     [
       null,
       null,
       [
         'OpenID4VPDCAPIHandover',
-        base64url.base64URLToBuffer('_PyOmRZ-t89FGXttog73cBXC1EGe9dQUICV3odM9ihk'),
+        decodeHex(
+          'fbece366f4212f9762c74cfdbf83b8c69e371d5d68cea09cb4c48ca6daab761a',
+        ),
       ],
     ],
   );

packages/server/src/formats/mdoc/generateSessionTranscript.test.ts

@@ -1,23 +1,32 @@
 import { encodeCBOR } from '@levischuck/tiny-cbor';
+import * as jose from 'jose';
 
 import type { DCAPIOID4VPSessionTranscript } from './types.ts';
+import type { Uint8Array_ } from '../../helpers/types.ts';
+import { base64url } from '../../helpers/index.ts';
 
 /**
  * See OID4VP for SessionTranscript composition:
- * https://openid.net/specs/openid-4-verifiable-presentations-1_0-24.html#appendix-B.3.4
+ * https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-B.2.6
  */
 export async function generateSessionTranscript(
   requestOrigin: string,
-  clientID: string,
   nonce: string,
+  verifierPublicKeyJWK?: JsonWebKey,
 ): Promise<DCAPIOID4VPSessionTranscript> {
   type OpenID4VPDCAPIHandoverInfo = [
     origin: string,
-    client_id: string,
     nonce: string,
+    jwk_thumbprint: Uint8Array_ | null,
   ];
 
-  const handoverInfo: OpenID4VPDCAPIHandoverInfo = [requestOrigin, clientID, nonce];
+  let jwkThumbprint: Uint8Array_ | null = null;
+  if (verifierPublicKeyJWK) {
+    const thumbprintBase64URL = await jose.calculateJwkThumbprint(verifierPublicKeyJWK);
+    jwkThumbprint = base64url.base64URLToBuffer(thumbprintBase64URL);
+  }
+
+  const handoverInfo: OpenID4VPDCAPIHandoverInfo = [requestOrigin, nonce, jwkThumbprint];
 
   const handoverInfoCBOR = encodeCBOR(handoverInfo);
   const handoverInfoHash = await crypto.subtle.digest('SHA-256', handoverInfoCBOR);

packages/server/src/formats/mdoc/generateSessionTranscript.ts

@@ -210,7 +210,7 @@ export type MdocCOSESign1SigStructure = [
 ];
 
 /**
- * https://openid.net/specs/openid-4-verifiable-presentations-1_0-24.html#appendix-B.3.4.1
+ * https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-B.2.6
  */
 export type DCAPIOID4VPSessionTranscript = [
   deviceEngagementBytes: null,

packages/server/src/formats/mdoc/types.ts

@@ -12,10 +12,16 @@ import type {
 import { SimpleDigiCredsError } from '../../helpers/simpleDigiCredsError.ts';
 import type { Uint8Array_ } from '../../helpers/types.ts';
 
-export async function verifyDeviceSigned({ document, nonce, possibleOrigins }: {
+export async function verifyDeviceSigned({
+  document,
+  nonce,
+  possibleOrigins,
+  verifierPublicKeyJWK,
+}: {
   document: DecodedDocument;
   nonce: string;
   possibleOrigins: string[];
+  verifierPublicKeyJWK?: JsonWebKey;
 }): Promise<VerifiedDeviceSigned> {
   const issuerSigned = document.get('issuerSigned');
   const deviceSigned = document.get('deviceSigned');
@@ -35,9 +41,16 @@ export async function verifyDeviceSigned({ document, nonce, possibleOrigins }: {
   const dateValidUntil = new Date(Date.parse(validUntil));
   const now = new Date(Date.now());
 
-  if (dateValidFrom > now || dateValidUntil < now) {
+  if (dateValidFrom > now) {
     throw new SimpleDigiCredsError({
-      message: `Credential is not yet valid or is expired`,
+      message: 'Credential is not yet valid',
+      code: 'MdocVerificationError',
+    });
+  }
+
+  if (dateValidUntil < now) {
+    throw new SimpleDigiCredsError({
+      message: `Credential is expired`,
       code: 'MdocVerificationError',
     });
   }
@@ -54,9 +67,11 @@ export async function verifyDeviceSigned({ document, nonce, possibleOrigins }: {
   let verified: boolean = false;
   let verifiedOrigin: string = '';
   for (const origin of possibleOrigins) {
-    const clientID = `web-origin:${origin}`;
-
-    const sessionTranscript = await generateSessionTranscript(origin, clientID, nonce);
+    const sessionTranscript = await generateSessionTranscript(
+      origin,
+      nonce,
+      verifierPublicKeyJWK,
+    );
 
     const deviceSignedNameSpaces = deviceSigned.get('nameSpaces');
 

packages/server/src/formats/mdoc/verifyDeviceSigned.ts

@@ -15,10 +15,12 @@ export async function verifyMDocPresentation({
   presentation,
   nonce,
   possibleOrigins,
+  verifierPublicKeyJWK,
 }: {
   presentation: string;
   nonce: string;
   possibleOrigins: string[];
+  verifierPublicKeyJWK?: JsonWebKey;
 }): Promise<VerifiedCredential> {
   if (!base64url.isBase64URLString(presentation)) {
     throw new SimpleDigiCredsError({
@@ -42,7 +44,7 @@ export async function verifyMDocPresentation({
     return {
       claims: {},
       issuerMeta: {},
-      credentialMeta: { verifiedOrigin: '' },
+      presentationMeta: { verifiedOrigin: '' },
     };
   }
 
@@ -53,13 +55,13 @@ export async function verifyMDocPresentation({
     expiresOn,
     issuedAt,
     validFrom,
-  } = await verifyDeviceSigned({ document, nonce, possibleOrigins });
+  } = await verifyDeviceSigned({ document, nonce, possibleOrigins, verifierPublicKeyJWK });
   if (!deviceSignedVerified) {
     console.error('could not verify DeviceSigned (mdoc)');
     return {
       claims: {},
       issuerMeta: {},
-      credentialMeta: { verifiedOrigin: '' },
+      presentationMeta: { verifiedOrigin: '' },
     };
   }
 
@@ -91,7 +93,7 @@ export async function verifyMDocPresentation({
       expiresOn,
       validFrom,
     },
-    credentialMeta: {
+    presentationMeta: {
       verifiedOrigin,
     },
   };

packages/server/src/formats/mdoc/verifyMdocPresentation.ts

@@ -19,12 +19,12 @@ export function assertKeyBindingJWTClaims({
   // Verify `iat`
   const issuedAtDate = new Date(payload.iat * 1000);
   const currentDate = new Date();
-  // Add 1 second to the current date to account for clock skew
-  const currentDatePlus1Second = new Date(currentDate.getTime() + 1000);
+  // Add a bit of time to the current date to account for clock skew
+  const currentDatePlusSkew = new Date(currentDate.getTime() + 1500);
 
-  if (issuedAtDate > currentDatePlus1Second) {
+  if (issuedAtDate > currentDatePlusSkew) {
     const iatISO = issuedAtDate.toISOString();
-    const currentISO = currentDatePlus1Second.toISOString();
+    const currentISO = currentDatePlusSkew.toISOString();
     throw new SimpleDigiCredsError({
       message: `Key Binding JWT was issued at (${iatISO}), after the current date (${currentISO})`,
       code: 'SDJWTVerificationError',
@@ -35,7 +35,8 @@ export function assertKeyBindingJWTClaims({
   let verifiedAUD = false;
   let verifiedOrigin = '';
   for (const origin of possibleOrigins) {
-    if (payload.aud === `web-origin:${origin}`) {
+    /** https://openid.net/specs/openid-4-verifiable-presentations-1_0-28.html#appendix-A.4-6 */
+    if (payload.aud === `origin:${origin}`) {
       verifiedAUD = true;
       verifiedOrigin = origin;
       break;