Aug 4, 2020

What is JWT?

JWT stands for JSON web Token

  • It is very popular technology to verify the json data of user (User authentication).

  • It is very secure as once it is send to frontend then no one can modify it if someone modify it user lose the access of the information.

  • It is mostly used for rest API authentication.

Now let’s understand it by writing some code.

We will be understanding it by using Node.js

We also need a NPM package called jsonwebtoken

Step1:- Generation a json web token using the user information payload with an expire time.

Importing jwt from package installed

Var jwt = require(‘jsonwebtoken’);
 
 Const payload = {
 Name: ‘user’
 Username: ‘username’,
 }
 
 Jwt.sign(
 //injecting payload
 {…payoad},
 //key
 ‘authentication’,
 {
 // the jwt token will be expire in 10hrs.
 expiresIn: ‘10hrs’
 },
 // we will get an error or an token
 (err, token) => {
 //check if error is there
 If(err){
 return Console.log(err);
 }
 Console.log(token);
 }
 )

Step2:- Method to verify token

Jwt.verify(
 Usertoken,
 ‘authentication’,
 (err, decodedToken) => {
 If(err){
 return console.log(‘unauthorized’)
 }
 // you will get the same payload object that you have set
 return console.log(decodedToken)
 }
 )

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