From e91406d587f978c0dfad7816bb9d208c4743bbff Mon Sep 17 00:00:00 2001
From: Timo Glastra <timo@animo.id>
Date: Sat, 7 Dec 2024 11:47:34 +0100
Subject: [PATCH] feat: allow setting purpose

Signed-off-by: Timo Glastra <timo@animo.id>
---
 agent/src/endpoints.ts           | 18 ++++++++++++++----
 agent/src/verifiers/turboKeys.ts |  4 ++++
 app/components/VerifyBlock.tsx   |  7 +++++++
 app/lib/api.ts                   |  1 +
 4 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/agent/src/endpoints.ts b/agent/src/endpoints.ts
index 8b97e7c..bf52cb0 100644
--- a/agent/src/endpoints.ts
+++ b/agent/src/endpoints.ts
@@ -12,7 +12,7 @@ import {
   getJwkFromKey,
 } from '@credo-ts/core'
 import { OpenId4VcVerificationSessionState } from '@credo-ts/openid4vc'
-import express, { type NextFunction, type Request, type Response } from 'express'
+import express, { query, type NextFunction, type Request, type Response } from 'express'
 import z from 'zod'
 import { agent } from './agent'
 import { validateVerificationRequest, zValidateVerificationRequestSchema } from './ai'
@@ -248,10 +248,11 @@ const zCreatePresentationRequestBody = z.object({
   presentationDefinitionId: z.string(),
   requestScheme: z.string(),
   responseMode: z.enum(['direct_post.jwt', 'direct_post']),
+  purpose: z.string().optional(),
 })
 
 apiRouter.post('/requests/create', async (request: Request, response: Response) => {
-  const { requestSignerType, presentationDefinitionId, requestScheme, responseMode } =
+  const { requestSignerType, presentationDefinitionId, requestScheme, responseMode, purpose } =
     await zCreatePresentationRequestBody.parseAsync(request.body)
 
   const x509Certificate = getX509Certificate()
@@ -293,13 +294,22 @@ apiRouter.post('/requests/create', async (request: Request, response: Response)
       presentationExchange:
         'input_descriptors' in definition
           ? {
-              definition,
+              definition: {
+                ...definition,
+                purpose: purpose ?? definition.purpose,
+              },
             }
           : undefined,
       dcql:
         'credentials' in definition
           ? {
-              query: definition,
+              query: {
+                ...definition,
+                credential_sets:
+                  purpose && definition.credential_sets
+                    ? definition.credential_sets.map((set) => ({ ...set, purpose }))
+                    : definition.credential_sets,
+              },
             }
           : undefined,
       responseMode,
diff --git a/agent/src/verifiers/turboKeys.ts b/agent/src/verifiers/turboKeys.ts
index c0c012f..41f1d21 100644
--- a/agent/src/verifiers/turboKeys.ts
+++ b/agent/src/verifiers/turboKeys.ts
@@ -125,9 +125,11 @@ export const turboKeysVerifier = {
       name: 'PID and MDL - Rent a Car (both either sd-jwt vc or mso_mdoc, prefer sd-jwt vc)',
       credential_sets: [
         {
+          purpose: 'To secure your car reservations and finalize the transaction, we require the following attributes',
           options: [['pid_sd_jwt'], ['pid_mdoc']],
         },
         {
+          purpose: 'To secure your car reservations and finalize the transaction, we require the following attributes',
           options: [['mdl_sd_jwt'], ['mdl_mdoc']],
         },
       ],
@@ -176,9 +178,11 @@ export const turboKeysVerifier = {
       name: 'PID and MDL - Rent a Car (both either sd-jwt vc or mso_mdoc, prefer mdoc)',
       credential_sets: [
         {
+          purpose: 'To secure your car reservations and finalize the transaction, we require the following attributes',
           options: [['pid_mdoc'], ['pid_sd_jwt']],
         },
         {
+          purpose: 'To secure your car reservations and finalize the transaction, we require the following attributes',
           options: [['mdl_mdoc'], ['mdl_sd_jwt']],
         },
       ],
diff --git a/app/components/VerifyBlock.tsx b/app/components/VerifyBlock.tsx
index d7c9835..e0cd553 100644
--- a/app/components/VerifyBlock.tsx
+++ b/app/components/VerifyBlock.tsx
@@ -61,6 +61,7 @@ export const VerifyBlock: React.FC<VerifyBlockProps> = ({ createRequest, flowNam
   const isSuccess = requestStatus?.responseStatus === 'ResponseVerified'
   const [presentationDefinitionId, setPresentationDefinitionId] = useState<string>()
   const [requestScheme, setRequestScheme] = useState<string>('openid4vp://')
+  const [purpose, setPurpose] = useState<string>()
   const [requestSignerType, setRequestSignerType] = useState<RequestSignerType>('x5c')
   const [useCase, setUseCase] = useState<string>('')
   useEffect(() => {
@@ -94,6 +95,7 @@ export const VerifyBlock: React.FC<VerifyBlockProps> = ({ createRequest, flowNam
       presentationDefinitionId: id,
       requestScheme,
       responseMode,
+      purpose: purpose && purpose !== '' ? purpose : undefined,
       requestSignerType,
     })
     setRequestStatus(request)
@@ -194,6 +196,11 @@ export const VerifyBlock: React.FC<VerifyBlockProps> = ({ createRequest, flowNam
             onChange={({ target }) => setRequestScheme(target.value)}
           />
         </div>
+        <div className="space-y-2">
+          <Label htmlFor="request-purpose">Purpose</Label>
+          <span className="text-xs"> - Optional. Each request has an associated default purpose</span>
+          <Input name="request-purpose" required value={purpose} onChange={({ target }) => setPurpose(target.value)} />
+        </div>
         <div className="space-y-2">
           <Label htmlFor="response-mode">Response Mode</Label>
           <Select
diff --git a/app/lib/api.ts b/app/lib/api.ts
index b37b78b..f028493 100644
--- a/app/lib/api.ts
+++ b/app/lib/api.ts
@@ -92,6 +92,7 @@ export async function createRequest(data: {
   presentationDefinitionId: string
   requestScheme: string
   responseMode: 'direct_post' | 'direct_post.jwt'
+  purpose?: string
 }) {
   const response = await fetch(`${NEXT_PUBLIC_API_URL}/api/requests/create`, {
     method: 'POST',