Node.js Public-key cryptography microlib :: Encypt against public key & Decrypt against private key

public-key-crypto.js

const crypto = require('crypto');
const path = require('path');
const fs = require('fs');

// Expose module
module.exports = { encrypt, decrypt };

/**
 * Encypt against public key
 * @param {String} str - The string to encrypt
 * @param {String} pathToPublicKey - The path to the public key, in .pem format
 * @example $ openssl rsautl -sign -inkey key.pem -in plain.txt -out encrypted.txt
 * @returns {String}
 */
function encrypt(str, pathToPublicKey) {
  const absolutePath = path.resolve(pathToPublicKey);
  const publicKey = fs.readFileSync(absolutePath, 'utf8');
  const encrypted = crypto.publicEncrypt(publicKey, new Buffer(str));
  return encrypted.toString('base64');
}

/**
 * Decrypt against private key
 * @param {String} str - The string to decrypt
 * @param {String} pathToPrivateKey - The path to the private key
 * @example $ openssl rsautl -verify -inkey key.pem -in encrypted.txt -out decrypted.txt
 * @returns {String}
 */
function decrypt(str, pathToPrivateKey) {
  const absolutePath = path.resolve(pathToPrivateKey);
  const privateKey = fs.readFileSync(absolutePath, 'utf8');
  const decrypted = crypto.privateDecrypt(privateKey, new Buffer(str, 'base64'));
  return decrypted.toString('utf8');
}