fix(auth): hash stored api keys

src/handlers/identity.ts

@@ -22,6 +22,7 @@ import {
 } from './account-passkeys';
 import { isAuthRequestExpired } from '../services/storage-auth-request-repo';
 import { createPasskeyUserVerificationToken } from '../utils/user-verification-token';
+import { constantTimeEquals, verifyApiKey } from '../utils/api-key';
 
 const TWO_FACTOR_REMEMBER_TTL_MS = 30 * 24 * 60 * 60 * 1000;
 const TWO_FACTOR_PROVIDER_AUTHENTICATOR = 0;
@@ -106,18 +107,6 @@ function parseCookieValue(request: Request, name: string): string | null {
   return null;
 }
 
-function constantTimeEquals(a: string, b: string): boolean {
-  const encA = new TextEncoder().encode(a);
-  const encB = new TextEncoder().encode(b);
-  if (encA.length !== encB.length) return false;
-
-  let diff = 0;
-  for (let i = 0; i < encA.length; i++) {
-    diff |= encA[i] ^ encB[i];
-  }
-  return diff === 0;
-}
-
 function readBodyValue(body: Record<string, string>, names: string[]): string | undefined {
   for (const name of names) {
     const value = body[name];
@@ -688,7 +677,7 @@ export async function handleToken(request: Request, env: Env): Promise<Response>
       return identityErrorResponse('Account is disabled', 'invalid_grant', 400);
     }
 
-    if (!user.apiKey || !constantTimeEquals(clientSecret, user.apiKey)) {
+    if (!user.apiKey || !(await verifyApiKey(clientSecret, user.apiKey))) {
       await rateLimit.recordFailedLogin(loginIdentifier);
       await safeWriteAuditEvent(env, {
         actorUserId: user.id,