RSA Encrypt & Decrypt NodeJS Module (v12+, no deps)

rsa.js

const {
    generateKeyPairSync, 
    privateDecrypt, 
    publicEncrypt,
    constants: { RSA_PKCS1_OAEP_PADDING },
} = require("crypto"); // core node
const { 
    CRYPTIC_PASSPHRASE, // set to enable for your private key (changes require new keys)
    CRYPTIC_GENERATE_KEYS, // set CRYPTIC_GENERATE_KEYS=1 to write key files
 } = process.env;
const { error, debug } = require('console');  // core node (i actually winston at `info` on prod, `debug` level locally)
const { writeFile, readFile } = require('fs').promises; // core node
let privateKey = '';
let publicKey = '';
let options = { 
    padding: RSA_PKCS1_OAEP_PADDING,
    oaepHash: "sha256",
};

const generateKeys = async () => {
    const privateKeyEncoding = {
        type: 'pkcs8',	
        format: 'pem',	
    };
    if (CRYPTIC_PASSPHRASE) {
        privateKeyEncoding.cipher = 'aes-256-cbc';
        privateKeyEncoding.passphrase =  CRYPTIC_PASSPHRASE;
    }
    const { publicKey, privateKey } = generateKeyPairSync("rsa", {
        modulusLength: 8192,
        publicKeyEncoding: {
            type: 'pkcs1',
            format: 'pem',
        },
        privateKeyEncoding,
    });

    try {
        await writeFile('./public.pem', publicKey.toString());
        await writeFile('./private.pem', privateKey.toString());
        return  { publicKey, privateKey };
    } catch(err) {
        error(err);
    }
};

if (CRYPTIC_GENERATE_KEYS) {
    generateKeys();
}

const setPublicKey = async () => {
    try {
        privateKey = await readFile('./private.pem', 'utf8')
    } catch (err) {
        error(err);
    }
}
const setPrivateKey = async () => {
    try {
        publicKey = await readFile('./public.pem', 'utf8');
    } catch (err) {
        error(err);
    }
}

setPublicKey();
setPrivateKey();

const encrypt = (text) => {
    debug(text); // hide these in prod
    const opts = {...options, key: publicKey};
    let data = publicEncrypt(
        opts,
        Buffer.from(text, 'utf8') // convert the data string 
    );
    data = data.toString('base64');
    data = encodeURIComponent(data); // url encoded
    debug(data); // hide these in prod
    return data;
}

const decrypt = (cypher) => {
    cypher = decodeURIComponent(cypher); // url decoded
    debug(cypher); // hide these in prod
    const opts = {...options, key: privateKey};
    if (CRYPTIC_PASSPHRASE) {
        opts.passphrase = CRYPTIC_PASSPHRASE;
    }
    const data = privateDecrypt(
        opts,
        Buffer.from(cypher, 'base64')
    )
    debug(data.toString()); // hide these in prod
    return data.toString();
}

module.exports = {
    decrypt,
    encrypt,
}