generateKeyPair.js

// Import the built-in crypto module for generating keys
const crypto = require('crypto');
const publicKeyToBase64 = require("publicKeyToBase64")

// Import the built-in fs module for writing keys to files
const fs = require('fs');

// Define a function to generate the key pair
function generateKeyPair() {
    // Generate a new key pair using RSA algorithm with a modulus length of 2048 bits ( size of the key )
    // RSA is related to the RS256, RS384, RS512 algorithms. We support the following algorithms: RS256, RS384, RS512, ECDSA256, ECDSA384, ECDSA512.
    const { publicKey, privateKey } = crypto.generateKeyPairSync('rsa', {
        modulusLength: 2048,
    });

    // Write the private key to a file named 'private_key.pem'
    // The export function exports the key in the specified format (in this case, PKCS #1)
    // PKCS#1 is a standard format that represents an RSA private key. It is widely used and compatible with many libraries and services.
    fs.writeFileSync('private_key.pem', privateKey.export({
        type: 'pkcs1',
        format: 'pem'
    }));

    // Write the public key to a file named 'public_key.pem'
    // The export function exports the key in the specified format (in this case, SPKI)
    // We require the public key in 'spki' (Subject Public Key Info) format, as it's a standard format that 
    // includes the algorithm identifier along with the key data , which is important for properly reading and using the key.
    fs.writeFileSync('public_key.pem', publicKey.export({
        type: 'spki',
        format: 'pem'
    }));

    // Log that the key pair was generated and saved to files
    console.log('Key pair generated and saved to files "private_key.pem" and "public_key.pem".\n');
    publicKeyToBase64()
    console.log('\nRemember to save the console logged encoded string above to the .env file as per README env instructions!".');
}

// Execute the function to generate the key pair
generateKeyPair();