Lesson 35 of 40 Security Advanced 45 min

Authentication in Web API

Learn how authentication works in ASP.NET Core Web API and how to secure your APIs so that only authorized users or systems can access your endpoints.

Part 1: What Is Authentication?

Authentication is the process of verifying the identity of a user or system.

It answers the question: "Who are you?"

Once authenticated, the system knows the identity of the user making the request.

Part 2: Authentication vs Authorization

Authentication	Authorization
Verifies identity	Determines access rights
"Who are you?"	"What can you do?"

Authentication comes first, followed by authorization.

Part 3: Common Authentication Methods

Cookie-based authentication
Token-based authentication (JWT)
API keys
OAuth and external providers

For Web APIs, token-based authentication is the most commonly used approach.

Part 4: JWT Authentication Overview

JWT (JSON Web Token) is a popular method for securing APIs.

The process works as follows:

User logs in with credentials
Server generates a token
Client stores the token
Client sends the token with each request
Server validates the token

This approach is stateless and scalable.

Part 5: Securing API Endpoints

You can protect API endpoints using the [Authorize] attribute.

[Authorize]

[HttpGet]

public IActionResult GetSecureData()

{

  return Ok("Secure Data");

}

Only authenticated users can access this endpoint.

Part 6: Sending Tokens in Requests

Clients must include the token in the HTTP request header:

Authorization: Bearer your_token_here

The server reads and validates this token before processing the request.

Part 7: Authentication in the Student Project

In your Student API, authentication can be used to secure sensitive operations:

Restrict access to student records
Protect create, update, and delete actions
Allow only authorized users to manage data
Ensure secure communication between client and server

This makes your application more secure and professional.

Part 8: Best Practices

Use token-based authentication for APIs
Always use HTTPS
Protect sensitive endpoints with [Authorize]
Keep tokens secure and do not expose them
Implement token expiration and renewal

Strong authentication practices are essential for modern applications.

Summary

Authentication is a critical part of Web API security. By verifying user identity and protecting endpoints, you ensure that your application is safe, scalable, and ready for real-world use.