Implement OTP rate limiting on the signup

Author: devkiran

apps/web/lib/actions/create-user-account.ts

@@ -2,9 +2,9 @@
 
 import { ratelimit } from "@/lib/upstash";
 import { prisma } from "@dub/prisma";
+import { waitUntil } from "@vercel/functions";
 import { flattenValidationErrors } from "next-safe-action";
 import { createId } from "../api/create-id";
-import { getIP } from "../api/utils";
 import { hashPassword } from "../auth/password";
 import z from "../zod";
 import { signUpSchema } from "../zod/schemas/auth";
@@ -15,6 +15,9 @@ const schema = signUpSchema.extend({
   code: z.string().min(6, "OTP must be 6 characters long."),
 });
 
+const MAX_OTP_ATTEMPTS = 5; // Block after 5 failed attempts
+const OTP_LOCKOUT_DURATION = "24 h"; // Block for 24 hours
+
 // Sign up a new user using email and password
 export const createUserAccountAction = actionClient
   .schema(schema, {
@@ -25,26 +28,45 @@ export const createUserAccountAction = actionClient
   .action(async ({ parsedInput }) => {
     const { email, password, code } = parsedInput;
 
-    const { success } = await ratelimit(2, "1 m").limit(`signup:${getIP()}`);
+    const signupAttemptKey = `signup:attempts:${email}`;
+
+    const { remaining: attemptsRemaining } = await ratelimit(
+      MAX_OTP_ATTEMPTS,
+      OTP_LOCKOUT_DURATION,
+    ).getRemaining(signupAttemptKey);
 
-    if (!success) {
-      throw new Error("Too many requests. Please try again later.");
+    if (attemptsRemaining <= 0) {
+      throw new Error("Too many failed attempts. You have to try again later.");
     }
 
     const verificationToken = await prisma.emailVerificationToken.findUnique({
       where: {
         identifier: email,
         token: code,
-        expires: {
-          gte: new Date(),
-        },
       },
     });
 
     if (!verificationToken) {
+      await ratelimit(MAX_OTP_ATTEMPTS, OTP_LOCKOUT_DURATION).limit(
+        signupAttemptKey,
+      );
+
       throw new Error("Invalid verification code entered.");
     }
 
+    if (verificationToken.expires && verificationToken.expires < new Date()) {
+      waitUntil(
+        prisma.emailVerificationToken.delete({
+          where: {
+            identifier: email,
+            token: code,
+          },
+        }),
+      );
+
+      throw new Error("The OTP has expired. Please request a new one.");
+    }
+
     await prisma.emailVerificationToken.delete({
       where: {
         identifier: email,