Access Control

Learn how to implement robust access control mechanisms in your applications. This guide covers role-based access control, permissions, and security best practices.

Prerequisites

Basic understanding of authentication concepts
Familiarity with middleware patterns
Knowledge of JWT or session-based auth
Completed the Authentication tutorial

Access Control Overview

Visual representation of role-based access control flow in a typical application.

Configure User Roles

Define user roles and permissions in your application:

// Example role configuration
const roles = {
  admin: {
    name: 'Administrator',
    permissions: ['read', 'write', 'delete', 'manage_users']
  },
  editor: {
    name: 'Editor',
    permissions: ['read', 'write']
  },
  viewer: {
    name: 'Viewer',
    permissions: ['read']
  }
}

Implement Role-Based Access Control

Set up RBAC middleware to protect your routes:

// Middleware to check user permissions
const checkPermission = (requiredPermission) => {
  return (req, res, next) => {
    const userRole = req.user.role;
    const userPermissions = roles[userRole].permissions;
    
    if (userPermissions.includes(requiredPermission)) {
      next();
    } else {
      res.status(403).json({ error: 'Access denied' });
    }
  };
};

// Apply middleware to routes
app.get('/admin', checkPermission('manage_users'), (req, res) => {
  // Admin route handler
});

Set Up Authentication Integration

Integrate with authentication providers:

// Configure auth provider
const authConfig = {
  providers: ['email', 'google'],
  callbacks: {
    async jwt({ token, user }) {
      if (user) {
        token.role = user.role;
        token.permissions = roles[user.role].permissions;
      }
      return token;
    }
  }
};

// Protect API routes
export const config = {
  matcher: '/api/:path*',
  middleware: ['auth']
};

Implement Permission Checks

Add permission checks in your components:

// React component example
const SecuredComponent = ({ children, requiredPermission }) => {
  const { user } = useAuth();
  const hasPermission = user?.permissions.includes(requiredPermission);

  if (!hasPermission) {
    return <AccessDenied />;
  }

  return children;
};

// Usage
<SecuredComponent requiredPermission="manage_users">
  <AdminPanel />
</SecuredComponent>

Best Practices

Principle of Least Privilege

Grant users only the permissions they need:

Start with minimal permissions
Regular permission audits
Time-bound access grants
Role-based access control

Security Measures

Implement additional security features:

Session management
Token rotation
Activity logging
Access monitoring

Error Handling

Properly handle access control errors:

Clear error messages
Secure error logging
Graceful degradation
User notifications

Troubleshooting

Permission Issues

Common permission problems:

Verify role assignments
Check permission inheritance
Validate token claims
Review middleware order

Authentication Problems

Authentication-related issues:

Token validation errors
Session expiration
Invalid credentials
Missing headers

Next Steps

Now that you've implemented access control, explore these related topics: