Implement rate limiting and enhance input validation for API endpoints

web/server/server.js

@@ -1,6 +1,5 @@
 import express from 'express';
 import { WebSocketServer } from 'ws';
-import cors from 'cors';
 import { createServer } from 'http';
 import fs from 'fs';
 import path from 'path';
@@ -18,7 +17,9 @@ const app = express();
 const PORT = process.env.PORT || 3001;
 const HOST = process.env.HOST || '0.0.0.0';
 
-app.use(cors());
+// CORS intentionally omitted — nginx reverse-proxy makes all requests same-origin.
+// If you need direct server access during dev, add: app.use(require('cors')())
+app.disable('x-powered-by');
 app.use(express.json({ limit: '5mb' }));
 
 // ========== API Key Authentication ==========
@@ -48,6 +49,40 @@ app.use((req, res, next) => {
   return requireAuth(req, res, next);
 });
 
+// ========== Rate Limiting (in-memory, no external dependencies) ==========
+
+function createRateLimiter(windowMs, max) {
+  const hits = new Map();
+  setInterval(() => {
+    const cutoff = Date.now() - windowMs;
+    for (const [key, entry] of hits) {
+      if (entry.start < cutoff) hits.delete(key);
+    }
+  }, windowMs);
+  return (req, res, next) => {
+    const key = req.ip || req.socket.remoteAddress || 'unknown';
+    const now = Date.now();
+    const entry = hits.get(key);
+    if (!entry || now - entry.start > windowMs) {
+      hits.set(key, { start: now, count: 1 });
+      return next();
+    }
+    entry.count++;
+    if (entry.count > max) {
+      res.set('Retry-After', String(Math.ceil((entry.start + windowMs - now) / 1000)));
+      return res.status(429).json({ error: 'Too many requests — try again later' });
+    }
+    return next();
+  };
+}
+
+// 30 mutating requests per minute per IP (excludes bridge state updates)
+const commandLimiter = createRateLimiter(60_000, 30);
+app.use((req, res, next) => {
+  if (req.method !== 'POST' || req.path.startsWith('/api/bridge/')) return next();
+  return commandLimiter(req, res, next);
+});
+
 // ========== State ==========
 const webClients = new Set();
 const bridgeClients = new Set();
@@ -330,13 +365,20 @@ app.post('/api/order', (req, res) => {
     if (!itemName || !amount) {
       return res.status(400).json({ error: 'Missing itemName or amount' });
     }
+    if (typeof itemName !== 'string' || itemName.length > 200) {
+      return res.status(400).json({ error: 'Invalid itemName' });
+    }
+    const parsedAmount = parseInt(amount);
+    if (!Number.isFinite(parsedAmount) || parsedAmount < 1 || parsedAmount > 100000) {
+      return res.status(400).json({ error: 'Invalid amount (1–100000)' });
+    }
     
     const command = {
       type: 'command',
       action: 'order',
       commandId,
       itemName,
-      amount: parseInt(amount),
+      amount: parsedAmount,
       dropperName: dropperName || null,
     };
     
@@ -365,7 +407,12 @@ app.post('/api/dropper-nicknames', (req, res) => {
     const cached = checkIdempotent(commandId);
     if (cached) return res.json(cached);
 
-    if (!dropperName) return res.status(400).json({ error: 'Missing dropperName' });
+    if (!dropperName || typeof dropperName !== 'string' || dropperName.length > 200) {
+      return res.status(400).json({ error: 'Missing or invalid dropperName' });
+    }
+    if (nickname && String(nickname).length > 50) {
+      return res.status(400).json({ error: 'Nickname too long (max 50)' });
+    }
     
     if (nickname && nickname.trim()) {
       dropperNicknames[dropperName] = nickname.trim();
@@ -427,7 +474,9 @@ app.post('/api/recipes/toggle', (req, res) => {
     const cached = checkIdempotent(commandId);
     if (cached) return res.json(cached);
 
-    if (!recipe) return res.status(400).json({ error: 'Missing recipe name' });
+    if (!recipe || typeof recipe !== 'string' || recipe.length > 200) {
+      return res.status(400).json({ error: 'Missing or invalid recipe name' });
+    }
     
     pushCommandToBridge({ type: 'command', action: 'toggle_recipe', commandId, recipe });
     const result = { success: true, commandId };
@@ -499,8 +548,12 @@ app.post('/api/craft', (req, res) => {
     if (cached) return res.json(cached);
 
     if (recipeIdx === undefined) return res.status(400).json({ error: 'Missing recipeIdx' });
+    const parsedIdx = parseInt(recipeIdx);
+    if (!Number.isFinite(parsedIdx) || parsedIdx < 1 || parsedIdx > 1000) {
+      return res.status(400).json({ error: 'Invalid recipeIdx' });
+    }
     
-    pushCommandToBridge({ type: 'command', action: 'craft', commandId, recipeIdx: parseInt(recipeIdx) });
+    pushCommandToBridge({ type: 'command', action: 'craft', commandId, recipeIdx: parsedIdx });
     const result = { success: true, commandId };
     recordCommand(commandId, result);
     console.log(`🔨 Craft request: recipe #${recipeIdx}`);
@@ -524,8 +577,8 @@ app.post('/api/bridge/state', (req, res) => {
   }
 });
 
-// Bridge polls for pending commands
-app.get('/api/bridge/commands', (req, res) => {
+// Bridge polls for pending commands (auth required — contains operational data)
+app.get('/api/bridge/commands', requireAuth, (req, res) => {
   try {
     const now = Date.now();
     // Clear old commands (>30s)
@@ -709,7 +762,7 @@ function updateStateFromBridge(data) {
 
 // ========== WebSocket Server ==========
 
-const wss = new WebSocketServer({ noServer: true });
+const wss = new WebSocketServer({ noServer: true, maxPayload: 1 * 1024 * 1024 /* 1 MB */ });
 
 console.log(`🚀 Inventory Manager Web Server starting...`);
 console.log(`📡 HTTP Server: http://localhost:${PORT}`);