NodeJS crypto module: clean cipher reuse

Question

I'm a bit new to the crypto module in Node. I wrote an encryption function that works perfectly fine but looks awful. This there a better way to write this?

const encrypt = data => {
  const iv = crypto.randomBytes(16);
  const key = crypto.randomBytes(32).toString('hex').slice(0, 32);

  const cipher1 = crypto.createCipheriv(algorithm, new Buffer(key), iv);
  const cipher2 = crypto.createCipheriv(algorithm, new Buffer(key), iv);
  const cipher3 = crypto.createCipheriv(algorithm, new Buffer(key), iv);

  const encryptedFile = Buffer.concat([cipher1.update(data.file), cipher1.final()]);
  const encryptedFileName = Buffer.concat([cipher2.update(data.fileName), cipher2.final()]).toString('hex');
  const encryptedId = Buffer.concat([cipher3.update(data.Id), cipher3.final()]).toString('hex');

  return {
    file: encryptedFile,
    fileName: encryptedFileName,
    id: iv.toString('hex') + ':' + encryptedId.toString('hex'),
    key
  };
};

Input is an object of this structure:

{
  file: <Buffer>,
  fileName: <String>,
  Id: <String>
}

I need to encrypt all of the values with the same key + iv, but not the whole object at once. Is there a way to refactor this to avoid duplication?

Answer 1

Try this:

const encrypt = (data, key, iv) => {
    const cipher = crypto.createCipheriv(algorithm, new Buffer(key), iv);

    return Buffer.concat([cipher.update(data), cipher.final()]);
};

const encrypt = data => {
    const iv = crypto.randomBytes(16);
    const key = crypto
      .randomBytes(32)
      .toString('hex')
      .slice(0, 32);

    return {
      file: encrypt(data.file, key, iv),
      fileName: encrypt(data.fileName, key, iv).toString('hex'),
      id: `${iv.toString('hex')}:${encrypt(data.Id, key, iv).toString('hex')}`,
      key,
    };
  };