Authorization plays a core role in ASP.NET Core by determining what an authenticated user can do. While authentication confirms the user’s identity, authorization controls access to resources, APIs, and features.
ASP.NET Core mainly supports two authorization approaches:
- Role-Based Authorization
- Policy-Based Authorization
This guide explains both approaches in a simple, practical, and interview-friendly way, helping you choose the right one for real-world applications.
What Is Authorization in ASP.NET Core?
Authorization ensures that only permitted users can access specific parts of an application.
It works using:
- Roles
- Claims
- Policies
- Authorization handlers
Authorization always runs after authentication.
Role-Based Authorization in ASP.NET Core
Role-based authorization grants access based on user roles such as Admin, Manager, or User.
How It Works
Each user is assigned one or more roles. ASP.NET Core checks these roles before allowing access.
[Authorize(Roles = "Admin")]
public IActionResult AdminDashboard()
{
return View();
}
Only users with the Admin role can access this action.
Role-Based Authorization Flow
- User logs in
- Role is added to user identity
- Role is checked
- Access is allowed or denied
Advantages of Role-Based Authorization
- Easy to understand
- Quick to implement
- Suitable for small applications
Limitations of Role-Based Authorization
- Poor scalability
- Hard to manage many roles
- Not suitable for complex permissions
- Leads to role explosion
Policy-Based Authorization in ASP.NET Core
Policy-based authorization is more flexible and powerful. Instead of checking roles directly, it evaluates rules (policies) defined using claims, roles, or custom logic.
How It Works
A policy is defined during application startup and applied where needed.
services.AddAuthorization(options =>
{
options.AddPolicy("AdminOnly", policy =>
policy.RequireRole("Admin"));
});
Usage:
[Authorize(Policy = "AdminOnly")]
public IActionResult AdminDashboard()
{
return View();
}
Policy-Based Authorization Flow
- User logs in
- Claims are added
- Policy is evaluated
- Requirements are checked
- Access is granted or denied
Why Policy-Based Authorization Is Better
- Supports claims-based security
- Handles complex business rules
- Centralized authorization logic
- Easy to maintain and extend
- Best for enterprise applications
Role-Based vs Policy-Based Authorization – Quick Comparison
| Feature | Role-Based | Policy-Based |
|---|---|---|
| Ease of use | Easy | Moderate |
| Flexibility | Low | High |
| Claims support | Limited | Full |
| Custom rules | ❌ | ✅ |
| Scalability | Low | High |
| Recommended for large apps | ❌ | ✅ |
When Should You Use Role-Based Authorization?
Use role-based authorization when:
- Application is small
- Few user types
- Simple access rules
- No complex permissions
When Should You Use Policy-Based Authorization?
Use policy-based authorization when:
- Application is large or growing
- Permissions are dynamic
- Business rules are complex
- Claims-based access is required
Most Important Interview Questions (Simple & Practical)
1. What is the main difference between Role-Based and Policy-Based Authorization?
Role-based authorization checks roles only, while policy-based authorization checks rules made of claims, roles, or custom logic.
2. Why do most ASP.NET Core applications prefer policy-based authorization?
Because it is flexible, scalable, and avoids role explosion. It also supports complex business rules.
3. Can roles be used inside policies?
Yes. Policies can include role checks along with claims and other requirements.
4. What are claims in ASP.NET Core?
Claims are key-value pairs that store user information such as role, permission, or department.
5. Where should authorization logic be written?
ASP.NET Core applications should implement authorization logic using policies and handlers instead of controllers.
Best Practices
- Prefer policy-based authorization for long-term projects
- Avoid hardcoding roles everywhere
- Use claims instead of many roles
- Keep authorization logic centralized
- Separate authentication and authorization
Final Thoughts
Role-based authorization is good for simple applications, but it does not scale well.
Policy-based authorization is the recommended and future-ready approach in ASP.NET Core, especially for professional and enterprise-level applications.
If you are preparing for .NET interviews or building real-world systems, understanding policy-based authorization is essential.
Read our detailed guides on Request Pipeline – Complete Execution & Exception Handling in detail.