csrf token and browser detection

2 files changed, 196 insertions, 24 deletions

diff --git a/apps/web/src/app/api/waitlist/route.ts b/apps/web/src/app/api/waitlist/route.ts
index f6f81103..4d64be77 100644
--- a/apps/web/src/app/api/waitlist/route.ts
+++ b/apps/web/src/app/api/waitlist/route.ts
@@ -4,51 +4,179 @@ import { waitlist } from "@opencut/db/schema";
 import { nanoid } from "nanoid";

 import { waitlistRateLimit } from "@/lib/rate-limit";

 import { z } from "zod";

+import { env } from "@/env";

+import { cookies } from "next/headers";

+import crypto from "crypto";

 

 const waitlistSchema = z.object({

   email: z.string().email("Invalid email format").min(1, "Email is required"),

 });

 

+const CSRF_TOKEN_NAME = "waitlist-csrf";

+const TOKEN_EXPIRY = 60 * 60 * 1000;

+

+function validateBrowserRequest(request: NextRequest): boolean {

+  const origin = request.headers.get("origin");

+  const referer = request.headers.get("referer");

+  const userAgent = request.headers.get("user-agent") || "";

+  const secFetchSite = request.headers.get("sec-fetch-site");

+  const secFetchMode = request.headers.get("sec-fetch-mode");

+  const secFetchDest = request.headers.get("sec-fetch-dest");

+  const contentType = request.headers.get("content-type");

+  const accept = request.headers.get("accept");

+

+  if (env.NODE_ENV === "development") {

+    console.log("=== Validating Browser Request ===");

+    console.log("Origin:", origin);

+    console.log("Referer:", referer);

+    console.log("User-Agent:", userAgent);

+    console.log("Sec-Fetch-Site:", secFetchSite);

+    console.log("Sec-Fetch-Mode:", secFetchMode);

+    console.log("Sec-Fetch-Dest:", secFetchDest);

+    console.log("Content-Type:", contentType);

+    console.log("Accept:", accept);

+  }

+

+  const allowedOrigins =

+    env.NODE_ENV === "development" ? ["http://localhost:3000", "http://127.0.0.1:3000"] : ["https://opencut.app", "https://www.opencut.app"];

+

+  if (!origin || !allowedOrigins.includes(origin)) {

+    console.log("Failed: Invalid origin");

+    return false;

+  }

+

+  if (!referer || !referer.startsWith(origin)) {

+    console.log("Failed: Invalid referer");

+    return false;

+  }

+

+  const suspiciousUserAgents = [

+    "curl",

+    "wget",

+    "postman",

+    "insomnia",

+    "thunder client",

+    "httpie",

+    "python-requests",

+    "node-fetch",

+    "axios",

+    "scrapy",

+    "httpclient",

+    "okhttp",

+    "libwww-perl",

+    "python-urllib",

+    "go-http-client",

+    "java/",

+    "apache-httpclient",

+  ];

+

+  const lowerUserAgent = userAgent.toLowerCase();

+  if (!userAgent || suspiciousUserAgents.some((agent) => lowerUserAgent.includes(agent))) {

+    console.log("Failed: Suspicious user agent");

+    return false;

+  }

+

+  const hasBrowserIndicators =

+    lowerUserAgent.includes("mozilla/") ||

+    lowerUserAgent.includes("chrome/") ||

+    lowerUserAgent.includes("safari/") ||

+    lowerUserAgent.includes("firefox/") ||

+    lowerUserAgent.includes("edge/");

+

+  if (!hasBrowserIndicators) {

+    console.log("Failed: No browser indicators in user agent");

+    return false;

+  }

+

+  if (secFetchSite && secFetchSite !== "same-origin") {

+    console.log("Failed: Invalid Sec-Fetch-Site:", secFetchSite);

+    return false;

+  }

+

+  if (secFetchMode && secFetchMode !== "cors") {

+    console.log("Failed: Invalid Sec-Fetch-Mode:", secFetchMode);

+    return false;

+  }

+

+  if (secFetchDest && secFetchDest !== "empty") {

+    console.log("Failed: Invalid Sec-Fetch-Dest:", secFetchDest);

+    return false;

+  }

+

+  if (!contentType || !contentType.includes("application/json")) {

+    console.log("Failed: Invalid Content-Type");

+    return false;

+  }

+

+  if (!accept || (!accept.includes("application/json") && !accept.includes("*/*"))) {

+    console.log("Failed: Invalid Accept header");

+    return false;

+  }

+

+  console.log("Browser validation passed!");

+  return true;

+}

+

+async function validateCSRFToken(request: NextRequest): Promise<boolean> {

+  const clientToken = request.headers.get("x-csrf-token");

+  if (!clientToken) return false;

+

+  const cookieStore = await cookies();

+  const cookieValue = cookieStore.get(CSRF_TOKEN_NAME)?.value;

+  if (!cookieValue) return false;

+

+  const [token, timestamp, signature] = cookieValue.split(":");

+  if (!token || !timestamp || !signature) return false;

+

+  if (clientToken !== token) return false;

+

+  const now = Date.now();

+  const tokenTime = parseInt(timestamp);

+  if (now - tokenTime > TOKEN_EXPIRY) return false;

+

+  const expectedSignature = crypto

+    .createHmac("sha256", env.BETTER_AUTH_SECRET || "fallback-secret")

+    .update(`${token}:${timestamp}`)

+    .digest("hex");

+

+  return signature === expectedSignature;

+}

+

 export async function POST(request: NextRequest) {

-  // Rate limit check

   const identifier = request.headers.get("x-forwarded-for") ?? "127.0.0.1";

   const { success } = await waitlistRateLimit.limit(identifier);

 

   if (!success) {

-    return NextResponse.json(

-      { error: "Too many requests. Please try again later." },

-      { status: 429 }

-    );

+    return NextResponse.json({ error: "Too many requests. Please try again later." }, { status: 429 });

+  }

+

+  if (!validateBrowserRequest(request)) {

+    await new Promise((resolve) => setTimeout(resolve, Math.random() * 2000 + 1000));

+

+    return NextResponse.json({ error: "Invalid request" }, { status: 403 });

+  }

+

+  const isValidToken = await validateCSRFToken(request);

+  if (!isValidToken) {

+    return NextResponse.json({ error: "Invalid security token" }, { status: 403 });

   }

 

   try {

     const body = await request.json();

     const { email } = waitlistSchema.parse(body);

 

-    // Check if email already exists

-    const existingEmail = await db

-      .select()

-      .from(waitlist)

-      .where(eq(waitlist.email, email.toLowerCase()))

-      .limit(1);

+    const existingEmail = await db.select().from(waitlist).where(eq(waitlist.email, email.toLowerCase())).limit(1);

 

     if (existingEmail.length > 0) {

-      return NextResponse.json(

-        { error: "Email already registered" },

-        { status: 409 }

-      );

+      return NextResponse.json({ error: "Email already registered" }, { status: 409 });

     }

 

-    // Add to waitlist

     await db.insert(waitlist).values({

       id: nanoid(),

       email: email.toLowerCase(),

     });

 

-    return NextResponse.json(

-      { message: "Successfully joined waitlist!" },

-      { status: 201 }

-    );

+    return NextResponse.json({ message: "Successfully joined waitlist!" }, { status: 201 });

   } catch (error) {

     if (error instanceof z.ZodError) {

       const firstError = error.errors[0];

@@ -56,9 +184,6 @@ export async function POST(request: NextRequest) {
     }

 

     console.error("Waitlist signup error:", error);

-    return NextResponse.json(

-      { error: "Internal server error" },

-      { status: 500 }

-    );

+    return NextResponse.json({ error: "Internal server error" }, { status: 500 });

   }

 }

diff --git a/apps/web/src/app/api/waitlist/token/route.ts b/apps/web/src/app/api/waitlist/token/route.ts
new file mode 100644
index 00000000..76622fc5
--- /dev/null
+++ b/apps/web/src/app/api/waitlist/token/route.ts
@@ -0,0 +1,47 @@
+import { NextRequest, NextResponse } from "next/server";
+import { cookies } from "next/headers";
+import crypto from "crypto";
+import { env } from "@/env";
+
+const CSRF_TOKEN_NAME = "waitlist-csrf";
+const TOKEN_EXPIRY = 60 * 60 * 1000;
+
+export async function GET(request: NextRequest) {
+  const referer = request.headers.get("referer");
+  const host = request.headers.get("host");
+
+  if (referer) {
+    const refererUrl = new URL(referer);
+    const allowedHosts = env.NODE_ENV === "development" ? ["localhost:3000", "127.0.0.1:3000"] : ["opencut.app", "www.opencut.app"];
+
+    if (!allowedHosts.some((allowed) => refererUrl.host === allowed || refererUrl.host.endsWith(allowed))) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+  } else if (host) {
+    const allowedHosts = env.NODE_ENV === "development" ? ["localhost:3000", "127.0.0.1:3000"] : ["opencut.app", "www.opencut.app"];
+
+    if (!allowedHosts.some((allowed) => host === allowed || host.endsWith(allowed))) {
+      return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+    }
+  } else {
+    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
+  }
+
+  const token = crypto.randomBytes(32).toString("hex");
+  const timestamp = Date.now();
+  const signature = crypto
+    .createHmac("sha256", env.BETTER_AUTH_SECRET || "fallback-secret")
+    .update(`${token}:${timestamp}`)
+    .digest("hex");
+
+  const cookieStore = await cookies();
+  cookieStore.set(CSRF_TOKEN_NAME, `${token}:${timestamp}:${signature}`, {
+    httpOnly: true,
+    secure: env.NODE_ENV === "production",
+    sameSite: "strict",
+    maxAge: TOKEN_EXPIRY / 1000,
+    path: "/",
+  });
+
+  return NextResponse.json({ token });
+}