Skip to main content

How Are JWTs Used to Authenticate Angular 4 Applications?

In Annular, the following Steps are used to building authentication and authorization for RESTful APIs and applications. It might help you -
1.     The users send their credentials to the server which is verified by the database credentials. If everything is verified successfully, the JWT is sent back to them.
2.     The JWT is saved in the user's browser in local storage or in a cookie and so on.
3.     The presence of a JWT saved in the browser is used as an indicator that a user is currently logged in.
4.     The expiry time of JWT is continually checked to maintain an authenticated state in the Angular applications.
5.     The client side routes are protected and access by authenticated users only.
6.     When user sends the XHR requests for APIs, the JWT gets sent an Authorization header using your cookies or Bearer.
7.     When XHR requests coming on the server, before send back the responses it’s validated first with configured app's secret keys. If everything is looking good then returns successfully responses other send the back to the bad request.


There are several open source libraries are available for angular which are helps with JWTs and has the ability to Decode the JWT, Authorization header to XHR requests and so on.

What is JSON Web Token?
JSON Web Token (JWT) is an open standard which used for securely transmitting information between parties as a JSON object.

The JWTs can be signed with -
1.     HMAC algorithm
2.     RSA algorithm

When should you use JSON Web Tokens?
There are some scenarios where we can used JSON Web Tokens -
1.     Authentication
2.     Information Exchange

What is the JSON Web Token structure?
The JSON Web Tokens consist of three parts separated by dots (.), which are:
1.     Header
2.     Payload
3.     Signature

A JWT typically looks like –
######.######.######


Let's break down the different parts -
Header
{
  "alg": "HS256",
  "typ": "JWT"
}
//OR
{
  "alg": "RS256",
  "typ": "JWT"
}


Payload
{
  "sub": "1234567890",
  "name": "Anil Singh",
  "admin": true
}


Signature
HMACSHA256(base64UrlEncode(header) + "."base64UrlEncode(payload),  secret);





I hope you are enjoying with this post! Please share with you friends!! Thank you!!!
By Anil Singh | Rating of this article (*****)

Popular posts from this blog

List of Countries, Nationalities and their Code In Excel File

Download JSON file for this List - Click on JSON file    Countries List, Nationalities and Code Excel ID Country Country Code Nationality Person 1 UNITED KINGDOM GB British a Briton 2 ARGENTINA AR Argentinian an Argentinian 3 AUSTRALIA AU Australian an Australian 4 BAHAMAS BS Bahamian a Bahamian 5 BELGIUM BE Belgian a Belgian 6 BRAZIL BR Brazilian a Brazilian 7 CANADA CA Canadian a Canadian 8 CHINA CN Chinese a Chinese 9 COLOMBIA CO Colombian a Colombian 10 CUBA CU Cuban a Cuban 11 DOMINICAN REPUBLIC DO Dominican a Dominican 12 ECUADOR EC Ecuadorean an Ecuadorean 13 EL SALVA...

39 Best Object Oriented JavaScript Interview Questions and Answers

Most Popular 37 Key Questions for JavaScript Interviews. What is Object in JavaScript? What is the Prototype object in JavaScript and how it is used? What is "this"? What is its value? Explain why "self" is needed instead of "this". What is a Closure and why are they so useful to us? Explain how to write class methods vs. instance methods. Can you explain the difference between == and ===? Can you explain the difference between call and apply? Explain why Asynchronous code is important in JavaScript? Can you please tell me a story about JavaScript performance problems? Tell me your JavaScript Naming Convention? How do you define a class and its constructor? What is Hoisted in JavaScript? What is function overloadin...

nullinjectorerror no provider for httpclient angular 17

In Angular 17 where the standalone true option is set by default, the app.config.ts file is generated in src/app/ and provideHttpClient(). We can be added to the list of providers in app.config.ts Step 1:   To provide HttpClient in a standalone app we could do this in the app.config.ts file, app.config.ts: import { ApplicationConfig } from '@angular/core'; import { provideRouter } from '@angular/router'; import { routes } from './app.routes'; import { provideClientHydration } from '@angular/platform-browser'; //This (provideHttpClient) will help us to resolve the issue  import {provideHttpClient} from '@angular/common/http'; export const appConfig: ApplicationConfig = {   providers: [ provideRouter(routes),  provideClientHydration(), provideHttpClient ()      ] }; The appConfig const is used in the main.ts file, see the code, main.ts : import { bootstrapApplication } from '@angular/platform-browser'; import { appConfig } from ...

React Lifecycle Components | Mounting, Updating, Unmounting

In React, each component has a life-cycle which manipulate during its three main phases. The following three phases are: 1.       Mounting 2.       Updating 3.       Unmounting React does so by “ Mounting ” (adding nodes to the DOM), “ Unmounting ” (removing them from the DOM), and “ Updating ” (making changes to nodes already in the DOM). Mounting - Lifecycle Phase 1 Mounting is used for adding nodes (elements) to the DOM. The React has four built-in methods that gets called, in this order, when mounting a component - 1.       constructor() 2.       getDerivedStateFromProps() 3.       render() 4.       componentDidMount() Note – 1)       The render() method is required and It always be called and the others methods are optional (you will call...

Top 50 C# OOPS Interview Questions and Answers | Freshers and Experience

List of 50 C# Object-Oriented Programming (OOP) interview questions along with brief answers. What is Object-Oriented Programming (OOP)? Answer : OOP is a programming paradigm that uses objects and classes for organizing code. It revolves around the concepts of encapsulation, inheritance, and polymorphism.   Define encapsulation? Answer : Encapsulation is the bundling of data and the methods that operate on that data into a single unit, known as a class.   What is a class in C#? Answer : A class is a blueprint or a template for creating objects. It defines the data and behavior that the objects of the class will have.   Explain inheritance in C#. Answer : Inheritance is a mechanism by which a class can inherit the properties and behaviors of another class. It promotes code reuse and establishes a relationship between the parent (base) class and the child (derived) class. How is polymorphism achieved in C#? Answer : Polymorphism is achieved through ...