🔒️ Harden rate limiting (#1598)

apps/web/src/app/api/trpc/[trpc]/route.ts

@@ -28,11 +28,16 @@ const handler = (req: NextRequest) => {
           }
         : undefined;
 
+      const ip =
+        process.env.NODE_ENV === "development" ? "127.0.0.1" : ipAddress(req);
+
+      const identifier =
+        session?.user?.id ?? req.headers.get("x-vercel-ja4-digest") ?? ip;
+
       return {
         user,
         locale,
-        ip:
+        identifier,
-          process.env.NODE_ENV === "development" ? "127.0.0.1" : ipAddress(req),
       } satisfies TRPCContext;
     },
     onError({ error }) {

apps/web/src/trpc/context.ts

@@ -11,5 +11,5 @@ type User = {
 export type TRPCContext = {
   user?: User;
   locale?: string;
-  ip?: string;
+  identifier?: string;
 };

apps/web/src/trpc/routers/auth.ts

@@ -29,7 +29,7 @@ export const auth = router({
       return { isRegistered: count > 0 };
     }),
   requestRegistration: publicProcedure
-    .use(createRateLimitMiddleware(5, "1 m"))
+    .use(createRateLimitMiddleware("request_registration", 5, "1 m"))
     .input(
       z.object({
         name: z.string().min(1).max(100),

apps/web/src/trpc/routers/polls.ts

@@ -130,7 +130,7 @@ export const polls = router({
 
   // START LEGACY ROUTES
   create: possiblyPublicProcedure
-    .use(createRateLimitMiddleware(20, "1 h"))
+    .use(createRateLimitMiddleware("create_poll", 10, "1 h"))
     .use(requireUserMiddleware)
     .input(
       z.object({
@@ -233,7 +233,6 @@ export const polls = router({
       return { id: poll.id };
     }),
   update: possiblyPublicProcedure
-    .use(createRateLimitMiddleware(60, "1 h"))
     .input(
       z.object({
         urlId: z.string(),
@@ -306,7 +305,6 @@ export const polls = router({
       });
     }),
   delete: possiblyPublicProcedure
-    .use(createRateLimitMiddleware(30, "1 h"))
     .input(
       z.object({
         urlId: z.string(),

apps/web/src/trpc/routers/polls/comments.ts

@@ -72,7 +72,7 @@ export const comments = router({
       });
     }),
   add: publicProcedure
-    .use(createRateLimitMiddleware(5, "1 m"))
+    .use(createRateLimitMiddleware("add_comment", 5, "1 m"))
     .use(requireUserMiddleware)
     .input(
       z.object({

apps/web/src/trpc/routers/polls/participants.ts

@@ -105,7 +105,6 @@ export const participants = router({
       return participants;
     }),
   delete: publicProcedure
-    .use(createRateLimitMiddleware(20, "1 m"))
     .input(
       z.object({
         participantId: z.string(),
@@ -123,7 +122,7 @@ export const participants = router({
       });
     }),
   add: publicProcedure
-    .use(createRateLimitMiddleware(20, "1 m"))
+    .use(createRateLimitMiddleware("add_participant", 5, "1 m"))
     .use(requireUserMiddleware)
     .input(
       z.object({
@@ -218,7 +217,6 @@ export const participants = router({
       return participant;
     }),
   rename: publicProcedure
-    .use(createRateLimitMiddleware(20, "1 m"))
     .input(z.object({ participantId: z.string(), newName: z.string() }))
     .mutation(async ({ input: { participantId, newName } }) => {
       await prisma.participant.update({
@@ -232,7 +230,6 @@ export const participants = router({
       });
     }),
   update: publicProcedure
-    .use(createRateLimitMiddleware(20, "1 m"))
     .input(
       z.object({
         pollId: z.string(),

apps/web/src/trpc/routers/user.ts

@@ -38,22 +38,20 @@ export const user = router({
         },
       });
     }),
-  delete: privateProcedure
+  delete: privateProcedure.mutation(async ({ ctx }) => {
-    .use(createRateLimitMiddleware(5, "1 h"))
+    if (ctx.user.isGuest) {
-    .mutation(async ({ ctx }) => {
+      throw new TRPCError({
-      if (ctx.user.isGuest) {
+        code: "BAD_REQUEST",
-        throw new TRPCError({
+        message: "Guest users cannot be deleted",
-          code: "BAD_REQUEST",
-          message: "Guest users cannot be deleted",
-        });
-      }
-
-      await prisma.user.delete({
-        where: {
-          id: ctx.user.id,
-        },
       });
-    }),
+    }
+
+    await prisma.user.delete({
+      where: {
+        id: ctx.user.id,
+      },
+    });
+  }),
   subscription: publicProcedure.query(
     async ({ ctx }): Promise<{ legacy?: boolean; active: boolean }> => {
       if (!ctx.user || ctx.user.isGuest) {
@@ -67,7 +65,6 @@ export const user = router({
     },
   ),
   changeName: privateProcedure
-    .use(createRateLimitMiddleware(20, "1 h"))
     .input(
       z.object({
         name: z.string().min(1).max(100),
@@ -84,7 +81,6 @@ export const user = router({
       });
     }),
   updatePreferences: privateProcedure
-    .use(createRateLimitMiddleware(30, "1 h"))
     .input(
       z.object({
         locale: z.string().optional(),
@@ -111,7 +107,7 @@ export const user = router({
       return { success: true };
     }),
   requestEmailChange: privateProcedure
-    .use(createRateLimitMiddleware(10, "1 h"))
+    .use(createRateLimitMiddleware("request_email_change", 10, "1 h"))
     .input(z.object({ email: z.string().email() }))
     .mutation(async ({ input, ctx }) => {
       const currentUser = await prisma.user.findUnique({
@@ -163,7 +159,7 @@ export const user = router({
       return { success: true as const };
     }),
   getAvatarUploadUrl: privateProcedure
-    .use(createRateLimitMiddleware(20, "1 h"))
+    .use(createRateLimitMiddleware("get_avatar_upload_url", 10, "1 h"))
     .input(
       z.object({
         fileType: z.enum(["image/jpeg", "image/png"]),
@@ -209,7 +205,6 @@ export const user = router({
     }),
   updateAvatar: privateProcedure
     .input(z.object({ imageKey: z.string().max(255) }))
-    .use(createRateLimitMiddleware(10, "1 h"))
     .mutation(async ({ ctx, input }) => {
       const userId = ctx.user.id;
       const oldImageKey = ctx.user.image;

apps/web/src/trpc/trpc.ts

@@ -90,6 +90,7 @@ export const proProcedure = privateProcedure.use(async ({ ctx, next }) => {
 });
 
 export const createRateLimitMiddleware = (
+  name: string,
   requests: number,
   duration: "1 m" | "1 h",
 ) => {
@@ -98,20 +99,27 @@ export const createRateLimitMiddleware = (
       return next();
     }
 
-    if (!ctx.ip) {
+    if (!ctx.identifier) {
       throw new TRPCError({
         code: "INTERNAL_SERVER_ERROR",
-        message: "Failed to get client IP",
+        message: "Failed to get identifier",
       });
     }
+
     const ratelimit = new Ratelimit({
       redis: kv,
       limiter: Ratelimit.slidingWindow(requests, duration),
     });
 
-    const res = await ratelimit.limit(ctx.ip);
+    const res = await ratelimit.limit(`${name}:${ctx.identifier}`);
 
     if (!res.success) {
+      console.warn("Rate limit exceeded", {
+        identifier: ctx.identifier,
+        endpoint: name,
+        limit: requests,
+        duration,
+      });
       throw new TRPCError({
         code: "TOO_MANY_REQUESTS",
         message: "Too many requests",