security: bound Zod inputs, add SSE per-user cap and tRPC body limit (#51, PR #59)

Closes #51 (ESLint rule + conventions doc remain as follow-up).

Co-authored-by: Hartmut Nörenberg <hn@hartmut-noerenberg.com>
Co-committed-by: Hartmut Nörenberg <hn@hartmut-noerenberg.com>

apps/web/src/app/api/reports/allocations/route.ts

@@ -1,6 +1,7 @@
 import { renderToBuffer } from "@react-pdf/renderer";
 import { createElement } from "react";
 import { NextResponse } from "next/server";
+import { z } from "zod";
 import { buildSplitAllocationReadModel } from "@capakraken/application";
 import { anonymizeResource, getAnonymizationDirectory } from "@capakraken/api";
 import { prisma } from "@capakraken/db";
@@ -11,6 +12,17 @@ import { createWorkbookArrayBuffer } from "~/lib/workbook-export.js";
 
 const ALLOWED_ROLES = new Set(["ADMIN", "MANAGER", "CONTROLLER"]);
 
+// Reject fantasy dates from clients — years outside [2000, 2100] are almost
+// certainly malformed input and would generate nonsensical SQL range scans.
+const DATE_MIN = new Date("2000-01-01T00:00:00.000Z");
+const DATE_MAX = new Date("2100-01-01T00:00:00.000Z");
+
+const queryParamsSchema = z.object({
+  startDate: z.coerce.date().min(DATE_MIN).max(DATE_MAX).optional(),
+  endDate: z.coerce.date().min(DATE_MIN).max(DATE_MAX).optional(),
+  format: z.enum(["pdf", "xlsx"]).default("pdf"),
+});
+
 export async function GET(request: Request) {
   const session = await auth();
   if (!session?.user) {
@@ -23,9 +35,20 @@ export async function GET(request: Request) {
   }
 
   const { searchParams } = new URL(request.url);
-  const startDate = searchParams.get("startDate") ? new Date(searchParams.get("startDate")!) : new Date();
-  const endDate = searchParams.get("endDate") ? new Date(searchParams.get("endDate")!) : new Date(Date.now() + 90 * 24 * 60 * 60 * 1000);
-  const format = searchParams.get("format") ?? "pdf";
+  const parsed = queryParamsSchema.safeParse({
+    startDate: searchParams.get("startDate") ?? undefined,
+    endDate: searchParams.get("endDate") ?? undefined,
+    format: searchParams.get("format") ?? undefined,
+  });
+  if (!parsed.success) {
+    return new NextResponse("Invalid query parameters", { status: 400 });
+  }
+  const startDate = parsed.data.startDate ?? new Date();
+  const endDate = parsed.data.endDate ?? new Date(Date.now() + 90 * 24 * 60 * 60 * 1000);
+  if (endDate < startDate) {
+    return new NextResponse("endDate must be >= startDate", { status: 400 });
+  }
+  const format = parsed.data.format;
 
   const [demandRequirements, assignments] = await Promise.all([
     prisma.demandRequirement.findMany({
@@ -62,21 +85,25 @@ export async function GET(request: Request) {
   const assignmentRows = allocationView.assignments.slice(0, 500);
   const directory = await getAnonymizationDirectory(prisma);
 
-  const rows = assignmentRows.map((a: AllocationLike & {
-    resource?: { id: string; displayName?: string | null } | null;
-    project?: { shortCode: string; name: string } | null;
-  }) => {
-    const resource = a.resource ? anonymizeResource(a.resource, directory) : null;
-    return {
-      resourceName: resource?.displayName ?? "Unknown",
-      projectName: a.project ? `${a.project.shortCode} — ${a.project.name}` : "Unknown project",
-      role: a.role ?? "",
-      startDate: new Date(a.startDate).toLocaleDateString("en-GB"),
-      endDate: new Date(a.endDate).toLocaleDateString("en-GB"),
-      hoursPerDay: a.hoursPerDay,
-      dailyCostCents: a.dailyCostCents,
-    };
-  });
+  const rows = assignmentRows.map(
+    (
+      a: AllocationLike & {
+        resource?: { id: string; displayName?: string | null } | null;
+        project?: { shortCode: string; name: string } | null;
+      },
+    ) => {
+      const resource = a.resource ? anonymizeResource(a.resource, directory) : null;
+      return {
+        resourceName: resource?.displayName ?? "Unknown",
+        projectName: a.project ? `${a.project.shortCode} — ${a.project.name}` : "Unknown project",
+        role: a.role ?? "",
+        startDate: new Date(a.startDate).toLocaleDateString("en-GB"),
+        endDate: new Date(a.endDate).toLocaleDateString("en-GB"),
+        hoursPerDay: a.hoursPerDay,
+        dailyCostCents: a.dailyCostCents,
+      };
+    },
+  );
 
   const ts = Date.now();
 

apps/web/src/app/api/sse/timeline/route.ts

@@ -9,6 +9,11 @@ import { auth } from "~/server/auth.js";
 export const dynamic = "force-dynamic";
 export const runtime = "nodejs";
 
+// Bounded connection tracking: a single user opening 100 tabs should not be
+// able to pin 100 persistent subscriptions on this node.
+const MAX_SSE_CONNECTIONS_PER_USER = 8;
+const sseConnectionsByUser = new Map<string, number>();
+
 export async function GET() {
   // Start lazily on the first real SSE request so builds/import-time evaluation
   // never attempt reminder processing against a live database.
@@ -43,6 +48,24 @@ export async function GET() {
     return new Response("Unauthorized", { status: 401 });
   }
 
+  const currentCount = sseConnectionsByUser.get(dbUser.id) ?? 0;
+  if (currentCount >= MAX_SSE_CONNECTIONS_PER_USER) {
+    return new Response("Too many SSE connections", {
+      status: 429,
+      headers: { "Retry-After": "30" },
+    });
+  }
+  sseConnectionsByUser.set(dbUser.id, currentCount + 1);
+
+  const releaseSlot = () => {
+    const next = (sseConnectionsByUser.get(dbUser.id) ?? 1) - 1;
+    if (next <= 0) {
+      sseConnectionsByUser.delete(dbUser.id);
+    } else {
+      sseConnectionsByUser.set(dbUser.id, next);
+    }
+  };
+
   const roleDefaults = await loadRoleDefaults();
   const subscription = deriveUserSseSubscription(
     {
@@ -85,6 +108,7 @@ export async function GET() {
         } catch {
           clearInterval(heartbeat);
           unsubscribe();
+          releaseSlot();
         }
       }, 30000);
 
@@ -92,8 +116,12 @@ export async function GET() {
       return () => {
         clearInterval(heartbeat);
         unsubscribe();
+        releaseSlot();
       };
     },
+    cancel() {
+      releaseSlot();
+    },
   });
 
   return new Response(stream, {

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

@@ -17,6 +17,11 @@ function extractClientIp(req: NextRequest): string | null {
   return null;
 }
 
+// Hard cap on tRPC request body size to prevent memory/CPU amplification from
+// a single oversized payload. Stream uploads (files, reports) don't go through
+// tRPC. 2 MiB is comfortably above any legitimate tRPC batch call.
+const MAX_TRPC_BODY_BYTES = 2 * 1024 * 1024;
+
 // Throttle lastActiveAt updates: max once per 60s per user
 const lastActiveCache = new Map<string, number>();
 const ACTIVITY_THROTTLE_MS = 60_000;
@@ -37,6 +42,23 @@ function trackActivity(userId: string) {
 }
 
 const handler = async (req: NextRequest) => {
+  // Reject oversized bodies before we touch auth, DB, or the router. A tRPC
+  // mutation should never exceed MAX_TRPC_BODY_BYTES. Content-Length is
+  // advisory — also guard against chunked requests below via length check
+  // on the cloned body.
+  if (req.method !== "GET") {
+    const declaredLength = req.headers.get("content-length");
+    if (declaredLength) {
+      const parsed = Number(declaredLength);
+      if (Number.isFinite(parsed) && parsed > MAX_TRPC_BODY_BYTES) {
+        return new Response(JSON.stringify({ error: "Request body too large" }), {
+          status: 413,
+          headers: { "Content-Type": "application/json" },
+        });
+      }
+    }
+  }
+
   const session = await auth();
 
   // Validate active session registry on every authenticated request.