'length must be a multiple of 8',
        'OperationError');
    }
    byteLength = length / 8;
  }

  return new Promise((resolve, reject) => {
    pbkdf2(raw, salt, iterations, byteLength, hash, (err, result) => {
      if (err) return reject(err);
      resolve(result.buffer);
    });
  });
}

module.exports = {
  pbkdf2,
  pbkdf2Sync,
  pbkdf2DeriveBits,
};