Authorization in Web API
Learn how authorization works in ASP.NET Core Web API and how to control access to resources based on roles, permissions, and policies after a user has been authenticated.
Part 1: What Is Authorization?
Authorization is the process of determining what an authenticated user is allowed to do.
It answers the question: "What are you allowed to access?"
Authorization always happens after authentication.
Part 2: Authorization vs Authentication
| Authentication | Authorization |
|---|---|
| Verifies identity | Controls access |
| "Who are you?" | "What can you do?" |
Both are essential for securing applications.
Part 3: Using the Authorize Attribute
You can restrict access to API endpoints using the [Authorize] attribute.
[HttpGet]
public IActionResult GetData()
{
return Ok("Authorized access");
}
Only authenticated users can access this endpoint.
Part 4: Role-Based Authorization
You can restrict access based on user roles.
public IActionResult DeleteStudent(int id)
Only users with the Admin role can perform this action.
Part 5: Policy-Based Authorization
Policies provide a more flexible way to control access.
Policies are defined in Program.cs and can include multiple rules.
Part 6: Combining Authorization Rules
You can combine roles and policies to create fine-grained control over access.
- Allow only admins to delete records
- Allow both teachers and admins to edit data
- Restrict sensitive endpoints to specific roles
This ensures proper access control across your application.
Part 7: Authorization in the Student Project
In your Student API, authorization can be used to:
- Restrict viewing of sensitive data
- Allow only authorized users to create or update records
- Limit deletion operations to administrators
- Protect the overall integrity of the system
This creates a secure and structured access system.
Part 8: Best Practices
- Always use authorization after authentication
- Apply the principle of least privilege
- Use roles and policies appropriately
- Protect sensitive endpoints
- Test authorization rules thoroughly
Strong authorization ensures your application remains secure and reliable.
Summary
Authorization is a key component of Web API security. By controlling access based on roles and policies, you ensure that users can only perform actions they are permitted to do, making your application safe and professional.
