Node.js/Express-Server als Ersatz fuer den Cloudflare gate-worker.js

server/gate.js

@@ -0,0 +1,99 @@
+/* =====================================================================
+   gate.js — Zugangs-Schranke vor der ganzen statischen Website. 1:1 portiert aus
+   gate-worker.js (Cloudflare Worker), auf Express-Middleware umgestellt. Gleiche Logik:
+   HMAC-signierte Session-Cookies, Fail-open falls Secrets fehlen, gate.html + Assets immer
+   erreichbar, "/" wird intern auf "/index.html" abgebildet.
+   ===================================================================== */
+
+export const COOKIE_NAME = "dogi_session";
+export const ROLE_COOKIE_NAME = "dogi_role";
+export const SESSION_TAGE = 90;
+
+function b64urlEncode(bytes) {
+  let bin = "";
+  bytes.forEach((b) => (bin += String.fromCharCode(b)));
+  return btoa(bin).replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
+}
+function b64urlDecodeToBytes(str) {
+  str = str.replace(/-/g, "+").replace(/_/g, "/");
+  while (str.length % 4) str += "=";
+  const bin = atob(str);
+  return Uint8Array.from(bin, (c) => c.charCodeAt(0));
+}
+async function hmacKey(secret) {
+  return crypto.subtle.importKey("raw", new TextEncoder().encode(secret), { name: "HMAC", hash: "SHA-256" }, false, ["sign", "verify"]);
+}
+
+export async function signSession(role, secret) {
+  const payload = JSON.stringify({ role, exp: Date.now() + SESSION_TAGE * 24 * 60 * 60 * 1000 });
+  const payloadB64 = b64urlEncode(new TextEncoder().encode(payload));
+  const key = await hmacKey(secret);
+  const sig = await crypto.subtle.sign("HMAC", key, new TextEncoder().encode(payloadB64));
+  return `${payloadB64}.${b64urlEncode(new Uint8Array(sig))}`;
+}
+
+export async function verifySession(token, secret) {
+  if (!token || !token.includes(".")) return null;
+  const [payloadB64, sigB64] = token.split(".");
+  try {
+    const key = await hmacKey(secret);
+    const valid = await crypto.subtle.verify("HMAC", key, b64urlDecodeToBytes(sigB64), new TextEncoder().encode(payloadB64));
+    if (!valid) return null;
+    const payload = JSON.parse(new TextDecoder().decode(b64urlDecodeToBytes(payloadB64)));
+    if (!payload.exp || payload.exp < Date.now()) return null;
+    return payload;
+  } catch {
+    return null;
+  }
+}
+
+export async function gateAuthHandler(req, res) {
+  const body = req.body || {};
+  const code = (body.code || "").trim();
+  const next = typeof body.next === "string" && body.next.startsWith("/") && body.next !== "/" ? body.next : "/index.html";
+
+  let role = null;
+  if (process.env.SITE_ACCESS_CODE_DOGI && code === process.env.SITE_ACCESS_CODE_DOGI) role = "dogi";
+  else if (process.env.SITE_ACCESS_CODE_VANVAN && code === process.env.SITE_ACCESS_CODE_VANVAN) role = "vanvan";
+
+  if (!role) {
+    return res.status(401).json({ ok: false, error: "Falscher Zugangscode." });
+  }
+
+  const session = await signSession(role, process.env.SITE_ACCESS_SECRET);
+  const maxAge = SESSION_TAGE * 24 * 60 * 60 * 1000;
+  res.cookie(COOKIE_NAME, session, { path: "/", maxAge, httpOnly: true, secure: true, sameSite: "lax" });
+  res.cookie(ROLE_COOKIE_NAME, role, { path: "/", maxAge, secure: true, sameSite: "lax" });
+  return res.json({ ok: true, next });
+}
+
+export function gateMiddleware(req, res, next) {
+  const pfad = req.path;
+
+  const codesKonfiguriert = !!(process.env.SITE_ACCESS_SECRET && (process.env.SITE_ACCESS_CODE_DOGI || process.env.SITE_ACCESS_CODE_VANVAN));
+  if (!codesKonfiguriert) return next();
+
+  if (pfad === "/gate-auth" && req.method === "POST") {
+    return gateAuthHandler(req, res);
+  }
+
+  const sessionToken = req.cookies?.[COOKIE_NAME];
+
+  (async () => {
+    const payload = sessionToken ? await verifySession(sessionToken, process.env.SITE_ACCESS_SECRET) : null;
+    if (payload) return next();
+
+    if (
+      pfad === "/gate.html" ||
+      pfad.startsWith("/assets/") ||
+      pfad === "/manifest.json" ||
+      pfad === "/sw.js" ||
+      pfad === "/favicon.ico"
+    ) {
+      return next();
+    }
+
+    const nextParam = pfad === "/" ? "/index.html" : pfad + (req.originalUrl.includes("?") ? "?" + req.originalUrl.split("?")[1] : "");
+    return res.redirect(302, `/gate.html?next=${encodeURIComponent(nextParam)}`);
+  })();
+}