use jose to verify the jwt

functions/getSassyHashes/index.ts

@@ -1,5 +1,6 @@
 import { PrivyClient } from '@privy-io/server-auth';
 import { Client, fetchExchange, gql } from '@urql/core';
+import { importSPKI, jwtVerify } from 'jose';
 
 import { Env } from '../common';
 
@@ -21,9 +22,24 @@ const getFid = async (privyAuthToken: string, env: Env): Promise<number> => {
   const privy = new PrivyClient(env.REACT_APP_PRIVY_APP_ID, env.PRIVY_APP_SECRET);
 
   try {
+    // one-time bootstrap to see if we can extract the FID from the token
+    const privyVerificationKey = await privy.getVerificationKey();
+    const verificationKey = await importSPKI(privyVerificationKey, 'ES256');
+    console.log('privyVerificationKey:', privyVerificationKey);
+    console.log('verificationKey:', verificationKey);
+
+    try {
+      const payload = await jwtVerify(privyAuthToken, verificationKey, {
+        issuer: 'privy.io',
+        audience: env.REACT_APP_PRIVY_APP_ID || 'insert-your-privy-app-id',
+      });
+      console.log(payload);
+    } catch (error) {
+      console.error(error);
+    }
+
     const verifiedClaims = await privy.verifyAuthToken(privyAuthToken);
     const user = await privy.getUser(verifiedClaims.userId);
-    console.log('Privy User:', user);
 
     // const user2 = await privy.getUser({ idToken: IDTokenFromCookies(request) });
     return user?.farcaster?.fid;

package.json

@@ -32,6 +32,7 @@
     "exponential-backoff": "^3.1.1",
     "i18next": "^20.4.0",
     "idb-keyval": "^6.2.1",
+    "jose": "^5.9.6",
     "lucide-react": "^0.394.0",
     "posthog-js": "^1.142.1",
     "react": "^18.3.1",

yarn.lock

@@ -7760,6 +7760,7 @@ __metadata:
     husky: ^9.0.11
     i18next: ^20.4.0
     idb-keyval: ^6.2.1
+    jose: ^5.9.6
     less: ^4.2.0
     less-plugin-clean-css: ^1.5.1
     lint-staged: ^11.0.0
@@ -12058,6 +12059,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"jose@npm:^5.9.6":
+  version: 5.9.6
+  resolution: "jose@npm:5.9.6"
+  checksum: 4b536da0201858ed4c4582e8bb479081f11e0c63dd0f5e473adde16fc539785e1f2f0409bc1fc7cbbb5b68026776c960b4952da3a06f6fdfff0b9764c9127ae0
+  languageName: node
+  linkType: hard
+
 "joycon@npm:^3.1.1":
   version: 3.1.1
   resolution: "joycon@npm:3.1.1"