A script to encrypt and decrypt data using RSA public and private keys

keys.js

const crypto = require("crypto");
const fs = require("fs");

// helper
function writeFile(file, data, callback = () => { }) {
	fs.writeFile(file, data, (error) => {
		if (error) throw error;
		callback();
	});
}

function generateKeys() {
	crypto.generateKeyPair("rsa", {
		modulusLength: 2048
	}, (error, publicKey, privateKey) => {
		if (error) throw error;
		exportKeys(publicKey, privateKey, () => {
			const data = "Some secret data";
			const encrypted = crypto.publicEncrypt({
				key: publicKey,
				padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
				oaepHash: "sha256"
			}, Buffer.from(data));

			const decrypted = crypto.privateDecrypt({
				key: privateKey,
				padding: crypto.constants.RSA_PKCS1_OAEP_PADDING,
				oaepHash: "sha256"
			}, encrypted);

			console.log(decrypted.toString("utf-8") === data);
		});
	});
}

function exportKeys(publicKey, privateKey, callback = () => { }) {
	writeFile("./private.key", privateKey.export({
		format: "pem",
		type: "pkcs1"
	}), callback);

	writeFile("./public.key", publicKey.export({
		format: "pem",
		type: "pkcs1"
	}), callback);
}

generateKeys();