clerk-authentication

Clerk 身份验证

你是 Next.js 应用中 Clerk 身份验证实现方面的专家。集成 Clerk 时请遵循以下指南。

核心原则

• 通过多个身份验证层实现纵深防御
• 在每个数据访问点验证身份，而不仅仅依赖中间件
• 单独保护每个服务端操作
• 使用 Clerk 内置的安全功能（HttpOnly Cookie、CSRF 保护）

安装与设置

npm install @clerk/nextjs

环境变量

# Required
NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=pk_...
CLERK_SECRET_KEY=sk_...

# Optional: Custom URLs
NEXT_PUBLIC_CLERK_SIGN_IN_URL=/sign-in
NEXT_PUBLIC_CLERK_SIGN_UP_URL=/sign-up
NEXT_PUBLIC_CLERK_AFTER_SIGN_IN_URL=/dashboard
NEXT_PUBLIC_CLERK_AFTER_SIGN_UP_URL=/dashboard

提供程序设置

App Router（app/layout.tsx）

import { ClerkProvider } from '@clerk/nextjs';

export default function RootLayout({
  children,
}: {
  children: React.ReactNode;
}) {
  return (
    <ClerkProvider>
      <html lang="en">
        <body>{children}</body>
      </html>
    </ClerkProvider>
  );
}

使用自定义外观

import { ClerkProvider } from '@clerk/nextjs';
import { dark } from '@clerk/themes';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <ClerkProvider
      appearance={{
        baseTheme: dark,
        variables: {
          colorPrimary: '#3b82f6',
        },
        elements: {
          formButtonPrimary: 'bg-blue-500 hover:bg-blue-600',
        },
      }}
    >
      <html lang="en">
        <body>{children}</body>
      </html>
    </ClerkProvider>
  );
}

中间件配置

基本中间件（middleware.ts）

import { clerkMiddleware, createRouteMatcher } from '@clerk/nextjs/server';

// Define protected routes
const isProtectedRoute = createRouteMatcher([
  '/dashboard(.*)',
  '/api/protected(.*)',
  '/settings(.*)',
]);

// Define public routes (optional, for clarity)
const isPublicRoute = createRouteMatcher([
  '/',
  '/sign-in(.*)',
  '/sign-up(.*)',
  '/api/public(.*)',
]);

export default clerkMiddleware(async (auth, req) => {
  if (isProtectedRoute(req)) {
    await auth.protect();
  }
});

export const config = {
  matcher: [
    // Skip Next.js internals and static files
    '/((?!_next|[^?]*\\.(?:html?|css|js(?!on)|jpe?g|webp|png|gif|svg|ttf|woff2?|ico|csv|docx?|xlsx?|zip|webmanifest)).*)',
    // Always run for API routes
    '/(api|trpc)(.*)',
  ],
};

带有基于角色的访问控制的高级中间件

import { clerkMiddleware, createRouteMatcher } from '@clerk/nextjs/server';

const isAdminRoute = createRouteMatcher(['/admin(.*)']);
const isProtectedRoute = createRouteMatcher(['/dashboard(.*)', '/api/protected(.*)']);

export default clerkMiddleware(async (auth, req) => {
  const { userId, sessionClaims } = await auth();

  // Admin routes require admin role
  if (isAdminRoute(req)) {
    if (!userId || sessionClaims?.metadata?.role !== 'admin') {
      return new Response('Forbidden', { status: 403 });
    }
  }

  // Protected routes require authentication
  if (isProtectedRoute(req)) {
    await auth.protect();
  }
});

在服务端组件中进行身份验证

使用 auth()

import { auth } from '@clerk/nextjs/server';

export default async function DashboardPage() {
  const { userId } = await auth();

  if (!userId) {
    redirect('/sign-in');
  }

  // Fetch user-specific data
  const data = await fetchUserData(userId);

  return <Dashboard data={data} />;
}

使用 currentUser()

import { currentUser } from '@clerk/nextjs/server';

export default async function ProfilePage() {
  const user = await currentUser();

  if (!user) {
    redirect('/sign-in');
  }

  return (
    <div>
      <h1>Welcome, {user.firstName}!</h1>
      <p>Email: {user.emailAddresses[0]?.emailAddress}</p>
    </div>
  );
}

在客户端组件中进行身份验证

useUser Hook

'use client';

import { useUser } from '@clerk/nextjs';

export function UserProfile() {
  const { isLoaded, isSignedIn, user } = useUser();

  if (!isLoaded) {
    return <Skeleton />;
  }

  if (!isSignedIn) {
    return <SignInPrompt />;
  }

  return (
    <div>
      <img src={user.imageUrl} alt={user.fullName ?? 'User'} />
      <p>{user.fullName}</p>
    </div>
  );
}

useAuth Hook

'use client';

import { useAuth } from '@clerk/nextjs';

export function ProtectedAction() {
  const { isLoaded, userId, getToken } = useAuth();

  async function handleAction() {
    if (!userId) return;

    // Get a fresh token for API calls
    const token = await getToken();

    const response = await fetch('/api/protected', {
      headers: {
        Authorization: `Bearer ${token}`,
      },
    });
  }

  if (!isLoaded || !userId) {
    return null;
  }

  return <button onClick={handleAction}>Perform Action</button>;
}

保护服务端操作

始终单独保护每个服务端操作：

'use server';

import { auth } from '@clerk/nextjs/server';

export async function createPost(formData: FormData) {
  const { userId } = await auth();

  if (!userId) {
    throw new Error('Unauthorized');
  }

  const title = formData.get('title') as string;
  const content = formData.get('content') as string;

  // Create post with user ID
  const post = await db.post.create({
    data: {
      title,
      content,
      authorId: userId,
    },
  });

  revalidatePath('/posts');
  return post;
}

使用角色验证

'use server';

import { auth } from '@clerk/nextjs/server';

export async function deleteUser(userId: string) {
  const { userId: currentUserId, sessionClaims } = await auth();

  if (!currentUserId) {
    throw new Error('Unauthorized');
  }

  if (sessionClaims?.metadata?.role !== 'admin') {
    throw new Error('Forbidden: Admin access required');
  }

  await db.user.delete({ where: { id: userId } });
  revalidatePath('/admin/users');
}

保护 API 路由

路由处理程序（App Router）

import { auth } from '@clerk/nextjs/server';
import { NextResponse } from 'next/server';

export async function GET() {
  const { userId } = await auth();

  if (!userId) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const data = await fetchUserData(userId);
  return NextResponse.json(data);
}

export async function POST(request: Request) {
  const { userId } = await auth();

  if (!userId) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const body = await request.json();
  // Process request...

  return NextResponse.json({ success: true });
}

外部 API 的 JWT 验证

import { auth } from '@clerk/nextjs/server';

export async function GET() {
  const { getToken } = await auth();

  // Get JWT for external API
  const token = await getToken({ template: 'external-api' });

  const response = await fetch('https://external-api.com/data', {
    headers: {
      Authorization: `Bearer ${token}`,
    },
  });

  return Response.json(await response.json());
}

组织支持

import { auth } from '@clerk/nextjs/server';

export async function getOrganizationData() {
  const { userId, orgId, orgRole } = await auth();

  if (!userId || !orgId) {
    throw new Error('Must be in an organization');
  }

  // Check organization role
  if (orgRole !== 'org:admin') {
    throw new Error('Admin access required');
  }

  return await db.organization.findUnique({
    where: { clerkOrgId: orgId },
  });
}

自定义会话声明

在 Clerk Dashboard 中配置

通过 JWT Templates 添加自定义声明，然后访问这些声明：

import { auth } from '@clerk/nextjs/server';

export async function checkSubscription() {
  const { sessionClaims } = await auth();

  const plan = sessionClaims?.metadata?.subscriptionPlan;

  if (plan !== 'pro') {
    throw new Error('Pro subscription required');
  }
}

UI 组件

预构建组件

import {
  SignIn,
  SignUp,
  SignOutButton,
  UserButton,
  SignedIn,
  SignedOut,
} from '@clerk/nextjs';

export function Header() {
  return (
    <header>
      <SignedIn>
        <UserButton afterSignOutUrl="/" />
      </SignedIn>
      <SignedOut>
        <SignInButton mode="modal" />
      </SignedOut>
    </header>
  );
}

// Dedicated sign-in page
export default function SignInPage() {
  return (
    <div className="flex justify-center items-center min-h-screen">
      <SignIn />
    </div>
  );
}

安全最佳实践

1. 纵深防御

// Layer 1: Middleware
export default clerkMiddleware(async (auth, req) => {
  if (isProtectedRoute(req)) {
    await auth.protect();
  }
});

// Layer 2: Server Component
export default async function Page() {
  const { userId } = await auth();
  if (!userId) redirect('/sign-in');
  // ...
}

// Layer 3: Data Access
async function fetchUserData(userId: string) {
  const { userId: currentUserId } = await auth();
  if (currentUserId !== userId) throw new Error('Forbidden');
  // ...
}

2. 保护所有服务端操作

// Every server action should verify auth independently
'use server';

export async function sensitiveAction() {
  const { userId } = await auth();
  if (!userId) throw new Error('Unauthorized');
  // ...
}

3. 避免仅在客户端进行保护

// BAD: Client-side only check
'use client';
export function SecretComponent() {
  const { isSignedIn } = useAuth();
  if (!isSignedIn) return null;
  return <div>Secret Data</div>; // Data still sent to client!
}

// GOOD: Server-side protection
export default async function SecretPage() {
  const { userId } = await auth();
  if (!userId) redirect('/sign-in');
  const data = await fetchSecretData(userId);
  return <SecretComponent data={data} />;
}

错误处理

import { auth } from '@clerk/nextjs/server';
import { redirect } from 'next/navigation';

export default async function ProtectedPage() {
  try {
    const { userId } = await auth();

    if (!userId) {
      redirect('/sign-in');
    }

    const data = await fetchUserData(userId);
    return <Dashboard data={data} />;
  } catch (error) {
    if (error instanceof AuthenticationError) {
      redirect('/sign-in');
    }
    throw error;
  }
}

测试

// Mock Clerk for testing
import { auth } from '@clerk/nextjs/server';

jest.mock('@clerk/nextjs/server', () => ({
  auth: jest.fn(),
}));

describe('Protected API', () => {
  it('returns 401 for unauthenticated requests', async () => {
    (auth as jest.Mock).mockResolvedValue({ userId: null });

    const response = await GET();
    expect(response.status).toBe(401);
  });

  it('returns data for authenticated requests', async () => {
    (auth as jest.Mock).mockResolvedValue({ userId: 'user_123' });

    const response = await GET();
    expect(response.status).toBe(200);
  });
});

应避免的常见反模式

1. 仅依赖中间件进行保护
2. 不单独保护服务端操作
3. 使用客户端身份验证检查来保护敏感数据
4. 未验证所有权便公开用户数据
5. 未验证组织范围资源的组织成员资格
6. 将角色检查硬编码，而不使用 Clerk 的 RBAC
7. 未处理客户端组件中的加载状态