JavaScript Asymmetric String Encryption using Nodes native "Crypto" Library

/**
 * An example for asynchronous encryption and decryption of a String featuring:
 * - An out of the box working Example
 * - Generation of a RSA 3072 bit keypair
 * - Utf8 Encoding of Strings
 * - Base64 String encoding of byte-Arrays
 * - Logging of exceptions
 */

var crypto = require("crypto"),
  winston = require("winston"),
  keypair = require("keypair");

const logger = winston.createLogger({
  format: winston.format.combine(
    winston.format.splat(),
    winston.format.simple()
  ),
  transports: [
    new winston.transports.Console({
      format: winston.format.simple(),
      handleExceptions: true
    })
  ]
});

const demonstrateKeyBasedAsymmetricEncryption = () => {
  try {
    // replace with your actual String
    let exampleString =
      "Text that is going to be sent over an insecure channel and must be encrypted at all costs!";
    // generate a keypair, in asynchronous encryption both keys need to be related
    // and cannot be independently generated keys
    // keylength adheres to the "ECRYPT-CSA Recommendations" on "www.keylength.com"
    // not needed if you already posses public and private key
    let pair = keypair(3072);

    // encrypt String
    let toEncrypt = Buffer.from(exampleString, "utf8");
    let encrypted = crypto
      .publicEncrypt(pair["public"], toEncrypt)
      .toString("base64");

    // decrypt String
    let toDecrypt = Buffer.from(encrypted, "base64");
    let decrypted = crypto
      .privateDecrypt(pair["private"], toDecrypt)
      .toString("utf8");
    logger.info(
      "Decrypted String and original String are the same: %s",
      exampleString.localeCompare(decrypted) === 0 ? "yes" : "no"
    );
  } catch (error) {
    logger.error(error.message);
  }
};

// run the exampleFunction
demonstrateKeyBasedAsymmetricEncryption();

// for unit testing purposes
module.exports = { demonstrateKeyBasedAsymmetricEncryption, logger };