jwt node code example

Example 1: jwt in node js

// index.js 

const express = require('express');
const jwt = require('jsonwebtoken');

const app = express();

// generate token for another API to use in req.header
app.post('/login', (req, res) => {
    const user = {
        id: 1,
        username: 'abhishek',
        email: "[email protected]"
    }
    let token = jwt.sign({ user: user }, 'shhhhh');
    res.send(token);
})

// verifyToken is a function that is used for check in API that token exist or not
// it can be put in between n number of API to check that authoriZed user loggedin or not.
app.get('/api', verifyToken, (req, res) => {
    try {
        jwt.verify(req.token, 'shhhhh', (error, authData) => {
            if (error) {
                res.send("not logged in")
            }
            res.json({
                message: "post Created",
                authData
            })
        })
    } catch (error) {
        res.send(error)
    }
})

// This funtion is middleware. 
function verifyToken(req, res, next) {
    try {
        const bearerHeader = req.headers['authorization'];
        if (typeof bearerHeader !== 'undefined') {
            const bearerToken = bearerHeader.split(' ')[1];
            req.token = bearerToken;
            next();
        }
        else {
            res.send("Not logged-in")
        }
    }
    catch {
        res.send("something went wrong")
    }
}

app.listen(3000, () => {
    console.log("server is runing")
})

Example 2: throw new Error('algorithms should be set');

expressJwt({ secret:  process.env.JWT_SECRET, algorithms: ['RS256'] });

Example 3: json web token npm

$ npm install jsonwebtoken

Example 4: jsonwebtoken

var jwt = require('jsonwebtoken');var token = jwt.sign({ foo: 'bar' }, 'shhhhh');

Example 5: npm package for jwt

$ npm install jwt-simple

Example 6: decode csrf token online

{
  "alg": "CfDJ8OW5OI0CPGJBgSNlGwO0x4YF7qbYKVv7KOO-N0eFtDUzXOrL7F9Xd9W1otVi4ueJOkAmAhuoHFWNkqRaFD7zvAMHMSKncl6Vo5QXKmpvy6vqxOKxSURdIey8aZPRi3Nnhp2p9la-Al5xrVKz0lignRdcCHf3O7pF9zv_sNx_c_T7pUe3WsxaJEPX3t_9FO2Wjw"
}