Autentikasi Modern di 2026: JWT, Session, OAuth, dan Passkey

// Pembuatan session yang disederhanakan
import { randomBytes } from "crypto";
import { cookies } from "next/headers";
 
interface Session {
  userId: string;
  createdAt: Date;
  expiresAt: Date;
  ipAddress: string;
  userAgent: string;
}
 
async function createSession(userId: string, request: Request): Promise<string> {
  const sessionId = randomBytes(32).toString("hex");
 
  const session: Session = {
    userId,
    createdAt: new Date(),
    expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000), // 24 jam
    ipAddress: request.headers.get("x-forwarded-for") ?? "unknown",
    userAgent: request.headers.get("user-agent") ?? "unknown",
  };
 
  // Simpan di basis data atau Redis Anda
  await redis.set(`session:${sessionId}`, JSON.stringify(session), "EX", 86400);
 
  const cookieStore = await cookies();
  cookieStore.set("session_id", sessionId, {
    httpOnly: true,
    secure: true,
    sameSite: "lax",
    maxAge: 86400,
    path: "/",
  });
 
  return sessionId;
}

import { SignJWT, jwtVerify } from "jose";
 
const secret = new TextEncoder().encode(process.env.JWT_SECRET);
 
async function createAccessToken(userId: string, role: string): Promise<string> {
  return new SignJWT({ sub: userId, role })
    .setProtectedHeader({ alg: "HS256" })
    .setIssuedAt()
    .setExpirationTime("15m")
    .setIssuer("https://example.com")
    .setAudience("https://example.com")
    .sign(secret);
}
 
async function verifyAccessToken(token: string) {
  try {
    const { payload } = await jwtVerify(token, secret, {
      issuer: "https://example.com",
      audience: "https://example.com",
    });
    return payload;
  } catch {
    return null;
  }
}

{
  "alg": "RS256",
  "typ": "JWT"
}

{
  "sub": "user_123", // Subject (tentang siapa ini)
  "iss": "https://auth.example.com", // Issuer (siapa yang membuat)
  "aud": "https://api.example.com", // Audience (siapa yang harus menerima)
  "iat": 1709312000, // Issued At (timestamp Unix)
  "exp": 1709312900, // Expiration (timestamp Unix)
  "role": "admin" // Klaim kustom
}

import { SignJWT, jwtVerify, importPKCS8, importSPKI } from "jose";
 
// RS256 — gunakan ini ketika beberapa layanan memverifikasi token
const privateKeyPem = process.env.JWT_PRIVATE_KEY!;
const publicKeyPem = process.env.JWT_PUBLIC_KEY!;
 
async function signWithRS256(payload: Record<string, unknown>) {
  const privateKey = await importPKCS8(privateKeyPem, "RS256");
 
  return new SignJWT(payload)
    .setProtectedHeader({ alg: "RS256", typ: "JWT" })
    .setIssuedAt()
    .setExpirationTime("15m")
    .sign(privateKey);
}
 
async function verifyWithRS256(token: string) {
  const publicKey = await importSPKI(publicKeyPem, "RS256");
 
  const { payload } = await jwtVerify(token, publicKey, {
    algorithms: ["RS256"], // KRITIS: selalu batasi algoritma
  });
 
  return payload;
}

// RENTAN — jangan pernah lakukan ini
function verifyJwt(token: string) {
  const [headerB64, payloadB64, signature] = token.split(".");
  const header = JSON.parse(atob(headerB64));
 
  if (header.alg === "none") {
    // "Tidak perlu tanda tangan" — BENCANA
    return JSON.parse(atob(payloadB64));
  }
 
  // ... verifikasi tanda tangan
}

// AMAN — algoritma di-hardcode, bukan dibaca dari token
const { payload } = await jwtVerify(token, key, {
  algorithms: ["RS256"], // Hanya terima RS256 — abaikan header
});

import { randomBytes } from "crypto";
 
interface RefreshTokenRecord {
  tokenHash: string;
  userId: string;
  familyId: string; // Mengelompokkan token terkait
  used: boolean;
  expiresAt: Date;
  createdAt: Date;
}
 
async function issueTokenPair(userId: string) {
  const familyId = randomBytes(16).toString("hex");
 
  const accessToken = await createAccessToken(userId);
  const refreshToken = randomBytes(64).toString("hex");
  const refreshTokenHash = await hashToken(refreshToken);
 
  // Simpan catatan refresh token
  await db.refreshToken.create({
    data: {
      tokenHash: refreshTokenHash,
      userId,
      familyId,
      used: false,
      expiresAt: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000),
      createdAt: new Date(),
    },
  });
 
  return { accessToken, refreshToken };
}

async function rotateTokens(incomingRefreshToken: string) {
  const tokenHash = await hashToken(incomingRefreshToken);
  const record = await db.refreshToken.findUnique({
    where: { tokenHash },
  });
 
  if (!record) {
    // Token tidak ada — kemungkinan pencurian
    return null;
  }
 
  if (record.expiresAt < new Date()) {
    // Token kedaluwarsa
    await db.refreshToken.delete({ where: { tokenHash } });
    return null;
  }
 
  if (record.used) {
    // TOKEN INI SUDAH DIGUNAKAN.
    // Seseorang me-replay-nya — entah pengguna sah
    // atau penyerang. Bagaimanapun, matikan seluruh keluarga.
    await db.refreshToken.deleteMany({
      where: { familyId: record.familyId },
    });
 
    console.error(
      `Penggunaan ulang refresh token terdeteksi untuk user ${record.userId}, family ${record.familyId}. Semua token dalam keluarga dibatalkan.`,
    );
 
    return null;
  }
 
  // Tandai token saat ini sebagai terpakai (jangan hapus — kita butuh untuk deteksi penggunaan ulang)
  await db.refreshToken.update({
    where: { tokenHash },
    data: { used: true },
  });
 
  // Terbitkan pasangan baru dengan family ID yang sama
  const newRefreshToken = randomBytes(64).toString("hex");
  const newRefreshTokenHash = await hashToken(newRefreshToken);
 
  await db.refreshToken.create({
    data: {
      tokenHash: newRefreshTokenHash,
      userId: record.userId,
      familyId: record.familyId, // Keluarga yang sama
      used: false,
      expiresAt: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000),
      createdAt: new Date(),
    },
  });
 
  const newAccessToken = await createAccessToken(record.userId);
 
  return { accessToken: newAccessToken, refreshToken: newRefreshToken };
}

import { randomBytes, createHash } from "crypto";
 
// Langkah 1: Buat nilai PKCE dan redirect pengguna
function initiateOAuthFlow() {
  // Code verifier: string acak 43-128 karakter
  const codeVerifier = randomBytes(32).toString("base64url").slice(0, 43);
 
  // Code challenge: hash SHA256 dari verifier, di-encode base64url
  const codeChallenge = createHash("sha256").update(codeVerifier).digest("base64url");
 
  // State: nilai acak untuk perlindungan CSRF
  const state = randomBytes(16).toString("hex");
 
  // Simpan keduanya di session (sisi server!) sebelum me-redirect
  // JANGAN PERNAH taruh code_verifier di cookie atau parameter URL
  session.codeVerifier = codeVerifier;
  session.oauthState = state;
 
  const authUrl = new URL("https://accounts.google.com/o/oauth2/v2/auth");
  authUrl.searchParams.set("client_id", process.env.GOOGLE_CLIENT_ID!);
  authUrl.searchParams.set("redirect_uri", "https://example.com/api/auth/callback/google");
  authUrl.searchParams.set("response_type", "code");
  authUrl.searchParams.set("scope", "openid email profile");
  authUrl.searchParams.set("state", state);
  authUrl.searchParams.set("code_challenge", codeChallenge);
  authUrl.searchParams.set("code_challenge_method", "S256");
 
  return authUrl.toString();
}

// Langkah 2: Tangani callback
async function handleOAuthCallback(request: Request) {
  const url = new URL(request.url);
  const code = url.searchParams.get("code");
  const state = url.searchParams.get("state");
  const error = url.searchParams.get("error");
 
  // Periksa error dari provider
  if (error) {
    throw new Error(`Error OAuth: ${error}`);
  }
 
  // Verifikasi state cocok (perlindungan CSRF)
  if (state !== session.oauthState) {
    throw new Error("State tidak cocok — kemungkinan serangan CSRF");
  }
 
  // Tukar authorization code dengan token
  const tokenResponse = await fetch("https://oauth2.googleapis.com/token", {
    method: "POST",
    headers: { "Content-Type": "application/x-www-form-urlencoded" },
    body: new URLSearchParams({
      grant_type: "authorization_code",
      code: code!,
      redirect_uri: "https://example.com/api/auth/callback/google",
      client_id: process.env.GOOGLE_CLIENT_ID!,
      client_secret: process.env.GOOGLE_CLIENT_SECRET!,
      code_verifier: session.codeVerifier, // PKCE: membuktikan kita yang memulai alur ini
    }),
  });
 
  const tokens = await tokenResponse.json();
  // tokens.access_token — untuk panggilan API ke Google
  // tokens.id_token — JWT dengan identitas pengguna (OIDC)
  // tokens.refresh_token — untuk mendapatkan access token baru
 
  // Langkah 3: Verifikasi ID token dan ekstrak info pengguna
  const idTokenPayload = await verifyGoogleIdToken(tokens.id_token);
 
  return {
    googleId: idTokenPayload.sub,
    email: idTokenPayload.email,
    name: idTokenPayload.name,
    picture: idTokenPayload.picture,
  };
}

// src/lib/auth.ts
import NextAuth from "next-auth";
import Google from "next-auth/providers/google";
import GitHub from "next-auth/providers/github";
import Credentials from "next-auth/providers/credentials";
import { PrismaAdapter } from "@auth/prisma-adapter";
import { prisma } from "@/lib/prisma";
import { verifyPassword } from "@/lib/password";
 
export const { handlers, auth, signIn, signOut } = NextAuth({
  adapter: PrismaAdapter(prisma),
 
  // Gunakan session basis data (bukan JWT) untuk keamanan yang lebih baik
  session: {
    strategy: "database",
    maxAge: 30 * 24 * 60 * 60, // 30 hari
    updateAge: 24 * 60 * 60, // Perpanjang session setiap 24 jam
  },
 
  providers: [
    Google({
      clientId: process.env.GOOGLE_CLIENT_ID!,
      clientSecret: process.env.GOOGLE_CLIENT_SECRET!,
      // Minta scope spesifik
      authorization: {
        params: {
          scope: "openid email profile",
          prompt: "consent",
          access_type: "offline", // Dapatkan refresh token
        },
      },
    }),
 
    GitHub({
      clientId: process.env.GITHUB_CLIENT_ID!,
      clientSecret: process.env.GITHUB_CLIENT_SECRET!,
    }),
 
    // Login email/password (gunakan dengan hati-hati)
    Credentials({
      credentials: {
        email: { label: "Email", type: "email" },
        password: { label: "Password", type: "password" },
      },
      authorize: async (credentials) => {
        if (!credentials?.email || !credentials?.password) {
          return null;
        }
 
        const user = await prisma.user.findUnique({
          where: { email: credentials.email as string },
        });
 
        if (!user || !user.passwordHash) {
          return null;
        }
 
        const isValid = await verifyPassword(credentials.password as string, user.passwordHash);
 
        if (!isValid) {
          return null;
        }
 
        return {
          id: user.id,
          email: user.email,
          name: user.name,
          image: user.image,
        };
      },
    }),
  ],
 
  callbacks: {
    // Kontrol siapa yang bisa masuk
    async signIn({ user, account }) {
      // Blokir sign-in untuk pengguna yang diblokir
      if (user.id) {
        const dbUser = await prisma.user.findUnique({
          where: { id: user.id },
          select: { banned: true },
        });
        if (dbUser?.banned) return false;
      }
      return true;
    },
 
    // Tambahkan field kustom ke session
    async session({ session, user }) {
      if (session.user) {
        session.user.id = user.id;
        // Ambil role dari basis data
        const dbUser = await prisma.user.findUnique({
          where: { id: user.id },
          select: { role: true },
        });
        session.user.role = dbUser?.role ?? "user";
      }
      return session;
    },
  },
 
  pages: {
    signIn: "/login",
    error: "/auth/error",
    verifyRequest: "/auth/verify",
  },
});

// src/app/api/auth/[...nextauth]/route.ts
import { handlers } from "@/lib/auth";
 
export const { GET, POST } = handlers;

// src/middleware.ts
import { auth } from "@/lib/auth";
import { NextResponse } from "next/server";
 
export default auth((req) => {
  const isLoggedIn = !!req.auth;
  const isAuthPage = req.nextUrl.pathname.startsWith("/login") || req.nextUrl.pathname.startsWith("/register");
  const isProtectedRoute =
    req.nextUrl.pathname.startsWith("/dashboard") ||
    req.nextUrl.pathname.startsWith("/settings") ||
    req.nextUrl.pathname.startsWith("/admin");
  const isAdminRoute = req.nextUrl.pathname.startsWith("/admin");
 
  // Redirect pengguna yang sudah login dari halaman autentikasi
  if (isLoggedIn && isAuthPage) {
    return NextResponse.redirect(new URL("/dashboard", req.nextUrl));
  }
 
  // Redirect pengguna yang belum terautentikasi ke login
  if (!isLoggedIn && isProtectedRoute) {
    const callbackUrl = encodeURIComponent(req.nextUrl.pathname);
    return NextResponse.redirect(new URL(`/login?callbackUrl=${callbackUrl}`, req.nextUrl));
  }
 
  // Periksa role admin
  if (isAdminRoute && req.auth?.user?.role !== "admin") {
    return NextResponse.redirect(new URL("/dashboard", req.nextUrl));
  }
 
  return NextResponse.next();
});
 
export const config = {
  matcher: ["/dashboard/:path*", "/settings/:path*", "/admin/:path*", "/login", "/register"],
};

// src/app/dashboard/page.tsx
import { auth } from "@/lib/auth";
import { redirect } from "next/navigation";
 
export default async function DashboardPage() {
  const session = await auth();
 
  if (!session?.user) {
    redirect("/login");
  }
 
  return (
    <div>
      <h1>Selamat datang, {session.user.name}</h1>
      <p>Role: {session.user.role}</p>
    </div>
  );
}

"use client";
 
import { useSession } from "next-auth/react";
 
export function UserMenu() {
  const { data: session, status } = useSession();
 
  if (status === "loading") {
    return <div>Memuat...</div>;
  }
 
  if (status === "unauthenticated") {
    return <a href="/login">Masuk</a>;
  }
 
  return (
    <div>
      <img
        src={session?.user?.image ?? "/default-avatar.png"}
        alt={session?.user?.name ?? "Pengguna"}
      />
      <span>{session?.user?.name}</span>
    </div>
  );
}

// Sisi server: Registrasi
import { generateRegistrationOptions, verifyRegistrationResponse } from "@simplewebauthn/server";
import type { GenerateRegistrationOptionsOpts, VerifiedRegistrationResponse } from "@simplewebauthn/server";
 
const rpName = "example.com";
const rpID = "example.com";
const origin = "https://example.com";
 
async function startRegistration(userId: string, userEmail: string) {
  // Dapatkan passkey pengguna yang sudah ada untuk mengecualikannya
  const existingCredentials = await db.credential.findMany({
    where: { userId },
    select: { credentialId: true, transports: true },
  });
 
  const options: GenerateRegistrationOptionsOpts = {
    rpName,
    rpID,
    userID: new TextEncoder().encode(userId),
    userName: userEmail,
    attestationType: "none", // Kita tidak perlu attestation untuk kebanyakan aplikasi
    excludeCredentials: existingCredentials.map((cred) => ({
      id: cred.credentialId,
      transports: cred.transports,
    })),
    authenticatorSelection: {
      residentKey: "preferred",
      userVerification: "preferred",
    },
  };
 
  const registrationOptions = await generateRegistrationOptions(options);
 
  // Simpan tantangan sementara — kita butuh untuk verifikasi
  await redis.set(
    `webauthn:challenge:${userId}`,
    registrationOptions.challenge,
    "EX",
    300, // Kedaluwarsa 5 menit
  );
 
  return registrationOptions;
}
 
async function finishRegistration(userId: string, response: unknown) {
  const expectedChallenge = await redis.get(`webauthn:challenge:${userId}`);
 
  if (!expectedChallenge) {
    throw new Error("Tantangan kedaluwarsa atau tidak ditemukan");
  }
 
  let verification: VerifiedRegistrationResponse;
  try {
    verification = await verifyRegistrationResponse({
      response: response as any,
      expectedChallenge,
      expectedOrigin: origin,
      expectedRPID: rpID,
    });
  } catch (error) {
    throw new Error(`Verifikasi registrasi gagal: ${error}`);
  }
 
  if (!verification.verified || !verification.registrationInfo) {
    throw new Error("Verifikasi registrasi gagal");
  }
 
  const { credential } = verification.registrationInfo;
 
  // Simpan credential di basis data
  await db.credential.create({
    data: {
      userId,
      credentialId: credential.id,
      publicKey: Buffer.from(credential.publicKey),
      counter: credential.counter,
      transports: credential.transports ?? [],
    },
  });
 
  // Bersihkan
  await redis.del(`webauthn:challenge:${userId}`);
 
  return { verified: true };
}

// Sisi server: Autentikasi
import { generateAuthenticationOptions, verifyAuthenticationResponse } from "@simplewebauthn/server";
 
async function startAuthentication(userId?: string) {
  let allowCredentials;
 
  // Jika kita tahu penggunanya (misalnya, mereka memasukkan email), batasi ke passkey mereka
  if (userId) {
    const credentials = await db.credential.findMany({
      where: { userId },
      select: { credentialId: true, transports: true },
    });
    allowCredentials = credentials.map((cred) => ({
      id: cred.credentialId,
      transports: cred.transports,
    }));
  }
 
  const options = await generateAuthenticationOptions({
    rpID,
    allowCredentials,
    userVerification: "preferred",
  });
 
  // Simpan tantangan untuk verifikasi
  const challengeKey = userId ? `webauthn:auth:${userId}` : `webauthn:auth:${options.challenge}`;
 
  await redis.set(challengeKey, options.challenge, "EX", 300);
 
  return options;
}
 
async function finishAuthentication(response: any, expectedChallenge: string, userId: string) {
  const credential = await db.credential.findUnique({
    where: { credentialId: response.id },
  });
 
  if (!credential) {
    throw new Error("Credential tidak ditemukan");
  }
 
  const verification = await verifyAuthenticationResponse({
    response,
    expectedChallenge,
    expectedOrigin: origin,
    expectedRPID: rpID,
    credential: {
      id: credential.credentialId,
      publicKey: credential.publicKey,
      counter: credential.counter,
      transports: credential.transports,
    },
  });
 
  if (!verification.verified) {
    throw new Error("Verifikasi autentikasi gagal");
  }
 
  // PENTING: Perbarui counter untuk mencegah serangan replay
  await db.credential.update({
    where: { credentialId: response.id },
    data: {
      counter: verification.authenticationInfo.newCounter,
    },
  });
 
  return { verified: true, userId: credential.userId };
}

// Sisi klien: Registrasi
import { startRegistration as webAuthnRegister } from "@simplewebauthn/browser";
 
async function registerPasskey() {
  // Dapatkan opsi dari server Anda
  const optionsResponse = await fetch("/api/auth/webauthn/register", {
    method: "POST",
  });
  const options = await optionsResponse.json();
 
  try {
    // Ini memicu UI passkey browser (prompt biometrik)
    const credential = await webAuthnRegister(options);
 
    // Kirim credential ke server Anda untuk verifikasi
    const verifyResponse = await fetch("/api/auth/webauthn/register/verify", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(credential),
    });
 
    const result = await verifyResponse.json();
    if (result.verified) {
      console.log("Passkey berhasil didaftarkan!");
    }
  } catch (error) {
    if ((error as Error).name === "NotAllowedError") {
      console.log("Pengguna membatalkan pendaftaran passkey");
    }
  }
}

import { createHmac, randomBytes } from "crypto";
 
// Hasilkan secret TOTP untuk pengguna
function generateTOTPSecret(): string {
  const buffer = randomBytes(20);
  return base32Encode(buffer);
}
 
function base32Encode(buffer: Buffer): string {
  const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
  let result = "";
  let bits = 0;
  let value = 0;
 
  for (const byte of buffer) {
    value = (value << 8) | byte;
    bits += 8;
    while (bits >= 5) {
      result += alphabet[(value >>> (bits - 5)) & 0x1f];
      bits -= 5;
    }
  }
 
  if (bits > 0) {
    result += alphabet[(value << (5 - bits)) & 0x1f];
  }
 
  return result;
}
 
// Hasilkan URI TOTP untuk kode QR
function generateTOTPUri(secret: string, userEmail: string, issuer: string = "example.com"): string {
  const encodedIssuer = encodeURIComponent(issuer);
  const encodedEmail = encodeURIComponent(userEmail);
  return `otpauth://totp/${encodedIssuer}:${encodedEmail}?secret=${secret}&issuer=${encodedIssuer}&algorithm=SHA1&digits=6&period=30`;
}

// Verifikasi kode TOTP
function verifyTOTP(secret: string, code: string, window: number = 1): boolean {
  const secretBuffer = base32Decode(secret);
  const now = Math.floor(Date.now() / 1000);
 
  // Periksa langkah waktu saat ini dan yang berdekatan (toleransi perbedaan jam)
  for (let i = -window; i <= window; i++) {
    const timeStep = Math.floor(now / 30) + i;
    const expectedCode = generateTOTPCode(secretBuffer, timeStep);
 
    // Perbandingan waktu konstan untuk mencegah serangan timing
    if (timingSafeEqual(code, expectedCode)) {
      return true;
    }
  }
 
  return false;
}
 
function generateTOTPCode(secret: Buffer, timeStep: number): string {
  // Konversi langkah waktu ke buffer big-endian 8 byte
  const timeBuffer = Buffer.alloc(8);
  timeBuffer.writeBigInt64BE(BigInt(timeStep));
 
  // HMAC-SHA1
  const hmac = createHmac("sha1", secret).update(timeBuffer).digest();
 
  // Dynamic truncation
  const offset = hmac[hmac.length - 1] & 0x0f;
  const code =
    ((hmac[offset] & 0x7f) << 24) |
    ((hmac[offset + 1] & 0xff) << 16) |
    ((hmac[offset + 2] & 0xff) << 8) |
    (hmac[offset + 3] & 0xff);
 
  return (code % 1_000_000).toString().padStart(6, "0");
}
 
function timingSafeEqual(a: string, b: string): boolean {
  if (a.length !== b.length) return false;
  const bufA = Buffer.from(a);
  const bufB = Buffer.from(b);
  return createHmac("sha256", "key").update(bufA).digest().equals(createHmac("sha256", "key").update(bufB).digest());
}

import { randomBytes, createHash } from "crypto";
 
function generateBackupCodes(count: number = 10): string[] {
  return Array.from(
    { length: count },
    () => randomBytes(4).toString("hex").toUpperCase(), // Kode hex 8 karakter
  );
}
 
async function storeBackupCodes(userId: string, codes: string[]) {
  // Hash kode sebelum menyimpan — perlakukan seperti password
  const hashedCodes = codes.map((code) => createHash("sha256").update(code).digest("hex"));
 
  await db.backupCode.createMany({
    data: hashedCodes.map((hash) => ({
      userId,
      codeHash: hash,
      used: false,
    })),
  });
 
  // Kembalikan kode plain SEKALI untuk disimpan pengguna
  // Setelah ini, kita hanya memiliki hash-nya
  return codes;
}
 
async function verifyBackupCode(userId: string, code: string): Promise<boolean> {
  const codeHash = createHash("sha256").update(code.toUpperCase().replace(/\s/g, "")).digest("hex");
 
  const backupCode = await db.backupCode.findFirst({
    where: {
      userId,
      codeHash,
      used: false,
    },
  });
 
  if (!backupCode) return false;
 
  // Tandai sebagai terpakai — setiap kode cadangan hanya berfungsi sekali
  await db.backupCode.update({
    where: { id: backupCode.id },
    data: { used: true, usedAt: new Date() },
  });
 
  return true;
}

async function initiateAccountRecovery(email: string) {
  const user = await db.user.findUnique({ where: { email } });
  if (!user) {
    // Jangan ungkapkan apakah akun ada
    return { message: "Jika email tersebut ada, kami telah mengirim instruksi pemulihan." };
  }
 
  const recoveryToken = randomBytes(32).toString("hex");
  const tokenHash = createHash("sha256").update(recoveryToken).digest("hex");
 
  await db.recoveryRequest.create({
    data: {
      userId: user.id,
      tokenHash,
      expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000), // 24 jam
      status: "pending",
    },
  });
 
  // Kirim email dengan tautan pemulihan
  await sendEmail(email, {
    subject: "Permintaan Pemulihan Akun",
    body: `
      Permintaan dibuat untuk menonaktifkan MFA di akun Anda.
      Jika ini Anda, klik tautan di bawah setelah 24 jam: ...
      Jika ini BUKAN Anda, segera ubah password Anda.
    `,
  });
 
  return { message: "Jika email tersebut ada, kami telah mengirim instruksi pemulihan." };
}

// RBAC — pemeriksaan role yang langsung
type Role = "user" | "editor" | "admin" | "super_admin";
 
const ROLE_PERMISSIONS: Record<Role, string[]> = {
  user: ["read:own_profile", "update:own_profile", "read:posts"],
  editor: ["read:own_profile", "update:own_profile", "read:posts", "create:posts", "update:posts"],
  admin: [
    "read:own_profile",
    "update:own_profile",
    "read:posts",
    "create:posts",
    "update:posts",
    "delete:posts",
    "read:users",
    "update:users",
  ],
  super_admin: ["*"], // Hati-hati dengan wildcard
};
 
function hasPermission(role: Role, permission: string): boolean {
  const permissions = ROLE_PERMISSIONS[role];
  return permissions.includes("*") || permissions.includes(permission);
}
 
// Penggunaan di route API
export async function DELETE(request: Request, { params }: { params: Promise<{ id: string }> }) {
  const session = await auth();
  if (!session?.user) {
    return Response.json({ error: "Tidak terotorisasi" }, { status: 401 });
  }
 
  if (!hasPermission(session.user.role as Role, "delete:posts")) {
    return Response.json({ error: "Dilarang" }, { status: 403 });
  }
 
  const { id } = await params;
  await db.post.delete({ where: { id } });
  return Response.json({ success: true });
}

// ABAC — ketika RBAC tidak cukup
interface PolicyContext {
  user: {
    id: string;
    role: string;
    department: string;
    clearanceLevel: number;
  };
  resource: {
    type: string;
    ownerId: string;
    classification: string;
    department: string;
  };
  action: string;
  environment: {
    ipAddress: string;
    time: Date;
    mfaVerified: boolean;
  };
}
 
function evaluatePolicy(context: PolicyContext): boolean {
  const { user, resource, action, environment } = context;
 
  // Pengguna selalu bisa membaca resource milik mereka sendiri
  if (action === "read" && resource.ownerId === user.id) {
    return true;
  }
 
  // Admin bisa membaca resource apa pun di departemen mereka
  if (action === "read" && user.role === "admin" && user.department === resource.department) {
    return true;
  }
 
  // Resource rahasia memerlukan MFA dan clearance minimum
  if (resource.classification === "confidential") {
    if (!environment.mfaVerified) return false;
    if (user.clearanceLevel < 3) return false;
  }
 
  // Aksi destruktif diblokir di luar jam kerja
  if (action === "delete") {
    const hour = environment.time.getHours();
    if (hour < 9 || hour > 17) return false;
  }
 
  return false; // Default tolak
}

// BURUK — hanya memeriksa di komponen
function DeleteButton({ post }: { post: Post }) {
  const { data: session } = useSession();
 
  // Ini menyembunyikan tombol, tetapi tidak mencegah penghapusan
  if (session?.user?.role !== "admin") return null;
 
  return <button onClick={() => deletePost(post.id)}>Hapus</button>;
}
 
// JUGA BURUK — memeriksa di server action tetapi bukan route API
async function deletePostAction(postId: string) {
  const session = await auth();
  if (session?.user?.role !== "admin") throw new Error("Dilarang");
  await db.post.delete({ where: { id: postId } });
}
// Penyerang masih bisa memanggil POST /api/posts/123 secara langsung
 
// BAIK — periksa di setiap batas
// 1. Sembunyikan tombol di UI (UX, bukan keamanan)
// 2. Periksa di server action (pertahanan berlapis)
// 3. Periksa di route API (batas keamanan yang sebenarnya)
// 4. Opsional, periksa di middleware (untuk perlindungan level route)

// "Apakah pengguna ini diizinkan mengakses bagian ini sama sekali?"
// Pemeriksaan detail ("Bisakah pengguna ini mengedit POST ini?") ada di route handler
// karena middleware tidak memiliki akses mudah ke body request atau parameter route.
 
export default auth((req) => {
  const path = req.nextUrl.pathname;
  const role = req.auth?.user?.role;
 
  // Kontrol akses level route
  const routeAccess: Record<string, Role[]> = {
    "/admin": ["admin", "super_admin"],
    "/editor": ["editor", "admin", "super_admin"],
    "/dashboard": ["user", "editor", "admin", "super_admin"],
  };
 
  for (const [route, allowedRoles] of Object.entries(routeAccess)) {
    if (path.startsWith(route)) {
      if (!role || !allowedRoles.includes(role as Role)) {
        return NextResponse.redirect(new URL("/unauthorized", req.nextUrl));
      }
    }
  }
 
  return NextResponse.next();
});

async function login(credentials: { email: string; password: string }, request: Request) {
  const user = await verifyCredentials(credentials);
  if (!user) throw new Error("Kredensial tidak valid");
 
  // KRITIS: Hapus session lama dan buat yang baru
  const oldSessionId = getSessionIdFromCookie(request);
  if (oldSessionId) {
    await redis.del(`session:${oldSessionId}`);
  }
 
  // Buat session baru sepenuhnya dengan ID baru
  const newSessionId = await createSession(user.id, request);
  return newSessionId;
}

// SameSite=Lax mencakup kebanyakan skenario CSRF:
// - Memblokir cookie pada POST, PUT, DELETE lintas-origin
// - Mengizinkan cookie pada GET lintas-origin (navigasi top-level)
//   Ini tidak masalah karena request GET seharusnya tidak memiliki efek samping
 
cookieStore.set("session_id", sessionId, {
  httpOnly: true,
  secure: true,
  sameSite: "lax", // Ini adalah perlindungan CSRF Anda
  maxAge: 86400,
  path: "/",
});

// RENTAN
async function handleCallback(request: Request) {
  const url = new URL(request.url);
  const redirectTo = url.searchParams.get("redirect_to") ?? "/";
  // ... autentikasi pengguna ...
  return Response.redirect(redirectTo); // Bisa jadi https://evil.com!
}
 
// AMAN
async function handleCallback(request: Request) {
  const url = new URL(request.url);
  const redirectTo = url.searchParams.get("redirect_to") ?? "/";
 
  // Validasi URL redirect
  const safeRedirect = sanitizeRedirectUrl(redirectTo, request.url);
  // ... autentikasi pengguna ...
  return Response.redirect(safeRedirect);
}
 
function sanitizeRedirectUrl(redirect: string, baseUrl: string): string {
  try {
    const url = new URL(redirect, baseUrl);
    const base = new URL(baseUrl);
 
    // Hanya izinkan redirect ke origin yang sama
    if (url.origin !== base.origin) {
      return "/";
    }
 
    // Hanya izinkan redirect path (bukan URI javascript: atau data:)
    if (!url.pathname.startsWith("/")) {
      return "/";
    }
 
    return url.pathname + url.search;
  } catch {
    return "/";
  }
}

// Di middleware atau layout Next.js Anda
const headers = new Headers();
headers.set("Referrer-Policy", "strict-origin-when-cross-origin");

// Ini adalah auth.ts tipikal saya untuk proyek baru
import NextAuth from "next-auth";
import Google from "next-auth/providers/google";
import GitHub from "next-auth/providers/github";
import Passkey from "next-auth/providers/passkey";
import { PrismaAdapter } from "@auth/prisma-adapter";
import { prisma } from "@/lib/prisma";
 
export const { handlers, auth, signIn, signOut } = NextAuth({
  adapter: PrismaAdapter(prisma),
  session: { strategy: "database" },
  providers: [
    Google,
    GitHub,
    Passkey({
      // Auth.js v5 memiliki dukungan passkey bawaan
      // Ini menggunakan SimpleWebAuthn di balik layar
    }),
  ],
  experimental: {
    enableWebAuthn: true,
  },
});

import { hash, verify } from "@node-rs/argon2";
 
// Argon2id adalah algoritma yang direkomendasikan
// Ini adalah default yang masuk akal untuk aplikasi web
async function hashPassword(password: string): Promise<string> {
  return hash(password, {
    memoryCost: 65536, // 64 MB
    timeCost: 3, // 3 iterasi
    parallelism: 4, // 4 thread
  });
}
 
async function verifyPassword(password: string, hashedPassword: string): Promise<boolean> {
  try {
    return await verify(hashedPassword, password);
  } catch {
    return false;
  }
}