Init middleware: CORS & Rate Limiting

Signed-off-by: Hadi <112569860+anotherhadi@users.noreply.github.com>

src/middleware.ts

@@ -0,0 +1,124 @@
+import { defineMiddleware } from "astro:middleware";
+
+const RATE_LIMIT_WINDOW_MS = 60_000; // 1 minute
+const RATE_LIMIT_MAX_REQUESTS = 60; // requests per window
+
+interface RateLimitEntry {
+  count: number;
+  resetAt: number;
+}
+
+const store = new Map<string, RateLimitEntry>();
+
+// Cleanup stale entries every 5 minutes to avoid memory leaks
+setInterval(() => {
+  const now = Date.now();
+  for (const [key, entry] of store) {
+    if (now >= entry.resetAt) store.delete(key);
+  }
+}, 5 * 60_000);
+
+function getClientIp(request: Request): string {
+  // Cloudflare sets CF-Connecting-IP — use it first.
+  return (
+    request.headers.get("CF-Connecting-IP") ??
+    request.headers.get("X-Forwarded-For")?.split(",")[0].trim() ??
+    "unknown"
+  );
+}
+
+function isRateLimited(ip: string): { limited: boolean; retryAfter: number } {
+  const now = Date.now();
+  const entry = store.get(ip);
+
+  if (!entry || now >= entry.resetAt) {
+    store.set(ip, { count: 1, resetAt: now + RATE_LIMIT_WINDOW_MS });
+    return { limited: false, retryAfter: 0 };
+  }
+
+  entry.count++;
+
+  if (entry.count > RATE_LIMIT_MAX_REQUESTS) {
+    const retryAfter = Math.ceil((entry.resetAt - now) / 1000);
+    return { limited: true, retryAfter };
+  }
+
+  return { limited: false, retryAfter: 0 };
+}
+
+const SECURITY_HEADERS: Record<string, string> = {
+  // Prevent MIME-type sniffing
+  "X-Content-Type-Options": "nosniff",
+
+  // Disallow embedding in iframes (clickjacking)
+  "X-Frame-Options": "DENY",
+
+  // Only send referrer on same-origin requests
+  "Referrer-Policy": "strict-origin-when-cross-origin",
+
+  // Disable browser features you don't use
+  "Permissions-Policy": "camera=(), microphone=(), geolocation=()",
+
+  // Content Security Policy
+  // - default-src 'self'          → only load resources from your own origin by default
+  // - img-src 'self' cdn.jsdelivr.net data: → allow Simple Icons CDN + inline SVGs
+  // - style-src 'self' 'unsafe-inline' → DaisyUI injects inline styles at runtime
+  // - script-src 'self'           → no third-party scripts
+  // - connect-src 'self'          → API calls only to your own origin
+  // - frame-ancestors 'none'      → redundant with X-Frame-Options but defense-in-depth
+  "Content-Security-Policy": [
+    "default-src 'self'",
+    "img-src 'self' cdn.jsdelivr.net data:",
+    "style-src 'self' 'unsafe-inline'",
+    "script-src 'self'",
+    "connect-src 'self'",
+    "frame-ancestors 'none'",
+  ].join("; "),
+};
+
+const CORS_HEADERS: Record<string, string> = {
+  "Access-Control-Allow-Origin": "*",
+  "Access-Control-Allow-Methods": "GET, OPTIONS",
+  "Access-Control-Allow-Headers": "Content-Type",
+};
+
+export const onRequest = defineMiddleware(async ({ request, url }, next) => {
+  const isApiRoute = url.pathname.startsWith("/api/");
+
+  if (request.method === "OPTIONS" && isApiRoute) {
+    return new Response(null, {
+      status: 204,
+      headers: CORS_HEADERS,
+    });
+  }
+
+  if (isApiRoute) {
+    const ip = getClientIp(request);
+    const { limited, retryAfter } = isRateLimited(ip);
+
+    if (limited) {
+      return new Response(JSON.stringify({ error: "Too Many Requests" }), {
+        status: 429,
+        headers: {
+          "Content-Type": "application/json",
+          "Retry-After": String(retryAfter),
+          ...CORS_HEADERS,
+        },
+      });
+    }
+  }
+
+  const response = await next();
+
+  for (const [key, value] of Object.entries(SECURITY_HEADERS)) {
+    response.headers.set(key, value);
+  }
+
+  if (isApiRoute) {
+    for (const [key, value] of Object.entries(CORS_HEADERS)) {
+      response.headers.set(key, value);
+    }
+  }
+
+  return response;
+});