Two-Factor Authentication (2FA) adds an extra layer of security to your Web3 applications by requiring not only a password and username but also something that only the user

Two-Factor Authentication (2FA) adds an extra layer of security to your Web3 applications by requiring not only a password and username but also something that only the user has, such as a one-time code generated by an authenticator app. This guide will walk you through the steps to implement 2FA in a Web3.js application.

1. Prerequisites

• Node.js installed on your machine.
• A basic understanding of JavaScript and Web3.js.
• Libraries: express, otplib, qrcode, and body-parser.

2. Setting Up Your Project

First, create a new directory for your project and initialize it:

mkdir web3-2fa
cd web3-2fa
npm init -y
npm install express otplib qrcode body-parser

3. Create the Server

Create a file named index.js and set up a basic Express server:

const express = require('express');
const bodyParser = require('body-parser');
const otplib = require('otplib');
const qrcode = require('qrcode');
const app = express();

app.use(bodyParser.json());
app.use(express.static('public'));

const users = {}; // In-memory user storage

app.listen(3000, () => {
    console.log('Server running on http://localhost:3000');
});

4. User Registration with 2FA

Implement a registration endpoint that generates a secret key for 2FA:

app.post('/register', async (req, res) => {
    const { username, password } = req.body;
    const secret = otplib.authenticator.generateSecret();
    users[username] = { password, secret, backupCodes: generateBackupCodes() };

    const qrCodeUrl = otplib.authenticator.keyuri(username, 'MyApp', secret);
    const qrCodeImage = await qrcode.toDataURL(qrCodeUrl);

    res.send({ secret, qrCodeImage, backupCodes: users[username].backupCodes });
});

function generateBackupCodes() {
    return Array.from({ length: 10 }, () => Math.random().toString(36).substring(2, 8));
}

5. Verifying 2FA Codes

Create an endpoint to verify the 2FA code provided by the user:

app.post('/verify-2fa', (req, res) => {
    const { username, token } = req.body;
    const user = users[username];

    if (!user) {
        return res.status(400).send('User  not found');
    }

    const isValid = otplib.authenticator.check(token, user.secret);
    if (!isValid) {
        return res.status(401).send('Invalid 2FA token');
    }

    res.send('2FA verification successful');
});

6. Frontend Implementation

Create a simple HTML form for user registration and verification. Create a public directory and add otplib0:

otplib1

7.

Handle the registration form submission in otplib2 to send the data to the server:

otplib3

8. Testing the Implementation

To test the implementation, start your server:

otplib4

Open your browser and navigate to otplib5. Register a new user and scan the QR code with an authenticator app (like Google Authenticator). After registration, you can create a verification form to input the 2FA token.

9. Conclusion

Implementing Two-Factor Authentication in your Web3.js application enhances security significantly. By following the steps outlined above, you can ensure that only authorized users can access sensitive functionalities in your application. Always keep security best practices in mind and stay updated with the latest security trends.