Javascript Encryption v2

Encryption Class

Create a new Encryption.js class and paste in the following Javascript code.

const crypto = require('crypto');

class Encryption{
    constructor(ivKey, secretKey, algorithm) {
        this.IVKey = ivKey;
        this.secretKey = secretKey;
        this.algorithm = algorithm;
    }

    encrypt(payload){
        let key = crypto
            .createHash('sha256')
            .update(this.secretKey)
            .digest('hex')
            .substring(0, 32);

        key = Buffer.from(key);

        // prepare the IV key
        let iv = crypto
            .createHash('sha256')
            .update(this.IVKey)
            .digest('hex')
            .substring(0, 16);

        iv = Buffer.from(iv);

        const cipher = crypto
            .createCipheriv(this.algorithm, Buffer.from(key), iv);

        let encrypted = cipher.update(payload);

        encrypted = Buffer
            .concat([encrypted, cipher.final()]);

        let base64 =  Buffer
            .from(encrypted, 'binary')
            .toString('base64');
        return Buffer
            .from(base64, 'binary')
            .toString('base64')
    }
}

module.exports = Encryption

Encryption Class Usage (Node.js)

Most people still have a misconception that Node.js would run on the browser. Node.js is a run-time environment that only runs on a server. For this example, we will use the Express Framework to create a realistic use case.

Create an Express app if you do not have one using the following commands. A more in-depth guide can be found here.

Step 1: Create a project directory $ mkdir checkout-demo

Step 2: Go into the project directory $ cd checkout-demo

Step 3: Initialize an NPM project accepting all prompts $ npm init -y

Step 4: Install the express framework $ npm install express --save

Then create a file CheckoutEncryption.js and paste in the code below. Open a terminal session in your project directory and run the application using the command node CheckoutEncryption.js

const cors = require("cors")

const express = require('express');
const Encryption = require('./Encryption')

const app = express();
const port = 3000;

app.use(cors())
// enable parsing application/json
app.use(express.json());

app.post('/checkout-encryption', (req, res) => {
    const accessKey = "<YOUR_ACCESS_KEY>"
    const IVKey = "<YOUR_IV_KEY>";
    const secretKey = "<YOUR_SECRET_KEY>";
    const algorithm = "aes-256-cbc";

    // get the request body
    const requestBody = req.body;
    
    let encryption = new Encryption(IVKey, secretKey, algorithm)

    const payload = JSON
        .stringify(requestBody)
        .replace(/\//g, '\\/');

    console.log(`https://developer.tingg.africa/checkout/v2/express/?params=${encryption.encrypt(payload)}&accessKey=${accessKey}&countryCode=${requestBody.countryCode}`)
    // return a JSON response
    res.json({
        params: encryption.encrypt(payload),
        accessKey,
        countryCode: requestBody.countryCode
    });
});

app.listen(
    port,
    () => console.log(`Listening on port ${port}!`)
);