Angular Login & Logout with Asp.Net Core Identity & JWT

Introduction

Welcome to this in-depth guide on implementing user authentication and management in your Angular application using ASP.NET Core Identity and JWT (Json Web Token). In this article, we will walk through the implementation of user registration, login, and logout features, as well as the essential concepts you need to understand as you create secure web applications.

Introduction

In our previous video, we discussed user registration. If you haven't had a chance to watch that yet, make sure to check it out via the links provided in the description. In this article, we will focus on implementing login functionality with JWT for user authentication in an Angular client, alongside ASP.NET Core Web API and the Identity Framework.

What is JWT?

JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. JWT can be used to verify the authenticity of the claims made by the sender. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) structure or as the plain text in a JSON Web Encryption (JWE) structure.

Setting Up the Angular Login Form

We begin by designing a beautiful login form in Angular. Using Angular routing, we can replace the user registration form with a login form. By creating an Angular component for the login, we allow users to authenticate themselves easily.

1. Generate Login and Dashboard Components:

   • Run the Angular CLI commands to create these components:

   ng g c user/login
   ng g c dashboard
   

2. Set Up Routing:

   • Configure routing to handle the user login and registration. Make sure to define paths to render the respective components.

3. Designing the Login Form:

   • Include form controls for email and password along with necessary validation.

Implementing User Authentication with ASP.NET Core Identity

We move on to implementing user authentication in the ASP.NET Core Web API using Identity Framework.

1. Configure Services for Authentication:

   • Add services for authentication and configure JWT settings. Install the required NuGet package for JWT handling.

2. Creating Login API:

   • Implement a POST endpoint for user sign-in. Validate user credentials and return a JWT if authentication is successful.

3. Generating the JWT:

   • Generate a token with user claims upon successful login. The generated token includes the header, payload, and signature.

4. Validating Token Signature:

   • During API requests that require authentication, validate the JWT signature to ensure it hasn’t been tampered with.

Handling Login Logic in Angular

Back in the Angular component, we will handle user interactions when the form is submitted.

1. Make a POST Request:

   • On form submission, send a POST request to the sign-in endpoint.
   • On success, store the received token in local storage.
   • Redirect the user to the dashboard.

2. Logout Functionality:

   • Create a logout button in the dashboard component that removes the token from local storage and redirects the user to the login page.

Conclusion

With this complete setup, your Angular application is now equipped with secure login and logout functionalities using ASP.NET Core Identity and JWT. This implementation provides a firm foundation for adding user authorization in future steps.

Keyword

Angular, ASP.NET Core, Identity, JWT, authentication, login, logout, registration, JSON Web Token, routing.

FAQ

1. What is JWT in web applications?

   • JWT (JSON Web Token) is used in web applications for securely transmitting information between parties and is commonly used for authentication and authorization.

2. How do I create a login form using Angular?

   • You can create a login form by setting up a new Angular component, using Angular forms, and managing the routing to navigate between login and registration pages.

3. What is ASP.NET Core Identity Framework?

   • ASP.NET Core Identity is a membership system that allows you to add login functionality to your applications, including user registration, password management, and role-based authorization.

4. How can I secure my web API endpoints?

   • You can secure web API endpoints by implementing JWT authentication, where tokens are validated before allowing access to sensitive resources.