Add anti-bot registration protection

- Custom /api/register route: honeypot, disposable email blocking, Cloudflare Turnstile verification
- Register form: honeypot hidden field, Turnstile widget (loads when NEXT_PUBLIC_TURNSTILE_SITE_KEY set)
- Install disposable-email-domains package
- Add NEXT_PUBLIC_TURNSTILE_SITE_KEY and TURNSTILE_SECRET_KEY env vars to .env.example

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/(auth)/register/register-form.tsx

@@ -1,8 +1,24 @@
 "use client";
 
-import { useState } from "react";
+import { useState, useEffect, useRef } from "react";
 import Link from "next/link";
-import { signUp } from "@/lib/auth-client";
+
+declare global {
+  interface Window {
+    turnstile?: {
+      render: (
+        container: HTMLElement,
+        options: {
+          sitekey: string;
+          callback: (token: string) => void;
+          "expired-callback"?: () => void;
+          "error-callback"?: () => void;
+        }
+      ) => string;
+      reset: (widgetId: string) => void;
+    };
+  }
+}
 
 interface Props {
   showTermsCheckbox: boolean;
@@ -15,11 +31,43 @@ export function RegisterForm({ showTermsCheckbox, privacyPolicyUrl, termsUrl, of
   const [name, setName] = useState("");
   const [email, setEmail] = useState("");
   const [password, setPassword] = useState("");
+  const [honeypot, setHoneypot] = useState("");
   const [termsAccepted, setTermsAccepted] = useState(false);
+  const [turnstileToken, setTurnstileToken] = useState<string | null>(null);
   const [error, setError] = useState("");
   const [loading, setLoading] = useState(false);
   const [success, setSuccess] = useState(false);
 
+  const turnstileContainerRef = useRef<HTMLDivElement>(null);
+  const turnstileWidgetId = useRef<string | null>(null);
+
+  const siteKey = process.env.NEXT_PUBLIC_TURNSTILE_SITE_KEY;
+
+  useEffect(() => {
+    if (!siteKey || !turnstileContainerRef.current) return;
+
+    const script = document.createElement("script");
+    script.src = "https://challenges.cloudflare.com/turnstile/v0/api.js";
+    script.async = true;
+    script.defer = true;
+    document.head.appendChild(script);
+
+    script.onload = () => {
+      if (!turnstileContainerRef.current || !window.turnstile) return;
+      turnstileWidgetId.current = window.turnstile.render(turnstileContainerRef.current, {
+        sitekey: siteKey,
+        callback: (token) => setTurnstileToken(token),
+        "expired-callback": () => setTurnstileToken(null),
+        "error-callback": () => setTurnstileToken(null),
+      });
+    };
+
+    return () => {
+      if (document.head.contains(script)) document.head.removeChild(script);
+    };
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
   const inputStyle = {
     border: "2px solid var(--border)",
     background: "var(--background)",
@@ -42,18 +90,43 @@ export function RegisterForm({ showTermsCheckbox, privacyPolicyUrl, termsUrl, of
       setError("Необходимо принять условия для продолжения");
       return;
     }
+    if (siteKey && !turnstileToken) {
+      setError("Пожалуйста, подтвердите, что вы не робот");
+      return;
+    }
     setError("");
     setLoading(true);
 
-    const result = await signUp.email({ name, email, password });
+    try {
+      const res = await fetch("/api/register", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          name,
+          email,
+          password,
+          website: honeypot,
+          cfTurnstileResponse: turnstileToken,
+        }),
+      });
 
-    if (result.error) {
-      setError(result.error.message ?? "Ошибка регистрации");
-      setLoading(false);
-      return;
+      const data = await res.json() as { message?: string };
+
+      if (!res.ok) {
+        setError(data.message ?? "Ошибка регистрации");
+        if (turnstileWidgetId.current) {
+          window.turnstile?.reset(turnstileWidgetId.current);
+          setTurnstileToken(null);
+        }
+        setLoading(false);
+        return;
+      }
+
+      setSuccess(true);
+    } catch {
+      setError("Ошибка соединения. Попробуйте ещё раз.");
     }
 
-    setSuccess(true);
     setLoading(false);
   }
 
@@ -74,6 +147,18 @@ export function RegisterForm({ showTermsCheckbox, privacyPolicyUrl, termsUrl, of
 
   return (
     <form onSubmit={handleSubmit} className="space-y-4">
+      {/* Honeypot — hidden from humans, visible to bots */}
+      <div style={{ position: "absolute", left: "-9999px", top: "-9999px" }} aria-hidden="true">
+        <input
+          type="text"
+          name="website"
+          value={honeypot}
+          onChange={(e) => setHoneypot(e.target.value)}
+          tabIndex={-1}
+          autoComplete="off"
+        />
+      </div>
+
       <div className="space-y-1">
         <label className="text-xs font-bold uppercase tracking-widest" style={{ color: "var(--muted-foreground)" }}>
           Имя
@@ -121,6 +206,8 @@ export function RegisterForm({ showTermsCheckbox, privacyPolicyUrl, termsUrl, of
         />
       </div>
 
+      {siteKey && <div ref={turnstileContainerRef} />}
+
       {showTermsCheckbox && (
         <label className="flex items-start gap-2 cursor-pointer">
           <input

src/app/api/register/route.ts

@@ -0,0 +1,76 @@
+import { NextRequest } from "next/server";
+import { auth } from "@/lib/auth";
+
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const disposableDomains = require("disposable-email-domains") as string[];
+
+async function verifyTurnstile(token: string): Promise<boolean> {
+  try {
+    const res = await fetch("https://challenges.cloudflare.com/turnstile/v0/siteverify", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify({
+        secret: process.env.TURNSTILE_SECRET_KEY,
+        response: token,
+      }),
+    });
+    const data = await res.json() as { success: boolean };
+    return data.success;
+  } catch {
+    return false;
+  }
+}
+
+function jsonError(message: string, status: number) {
+  return new Response(JSON.stringify({ message }), {
+    status,
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+export async function POST(request: NextRequest) {
+  let body: Record<string, string>;
+  try {
+    body = await request.json() as Record<string, string>;
+  } catch {
+    return jsonError("Неверный формат запроса", 400);
+  }
+
+  const { name, email, password, website, cfTurnstileResponse } = body;
+
+  // Honeypot — bots fill this field, humans don't see it
+  if (website) {
+    return jsonError("Registration failed", 400);
+  }
+
+  // Disposable email check
+  const domain = email?.split("@")[1]?.toLowerCase();
+  if (domain && disposableDomains.includes(domain)) {
+    return jsonError("Пожалуйста, используйте постоянный email-адрес", 400);
+  }
+
+  // Turnstile check
+  if (process.env.TURNSTILE_SECRET_KEY) {
+    if (!cfTurnstileResponse) {
+      return jsonError("Пожалуйста, подтвердите, что вы не робот", 400);
+    }
+    if (!(await verifyTurnstile(cfTurnstileResponse))) {
+      return jsonError("Проверка капчи не пройдена. Попробуйте ещё раз", 400);
+    }
+  }
+
+  const baseUrl =
+    process.env.BETTER_AUTH_URL ??
+    `https://${request.headers.get("host")}`;
+
+  return auth.handler(
+    new Request(`${baseUrl}/api/auth/sign-up/email`, {
+      method: "POST",
+      headers: new Headers({
+        "Content-Type": "application/json",
+        Origin: baseUrl,
+      }),
+      body: JSON.stringify({ name, email, password }),
+    })
+  );
+}