const { promisify } = require('util');
const { randomBytes, pbkdf2 } = require('crypto');

const generateRandomBytes = promisify(randomBytes);
const hashPassword = promisify(pbkdf2);

const _ = {
 async hashPassword(args){
 const { pw } = args;
 const salt = (args.salt || await generateRandomBytes(64)).toString('hex');
 const iter = (args.iter || await this.generateRandomInt(1024)) + 10000;

 const hash = await hashPassword(pw, salt, iter, 64, 'sha512').toString('hex');
 return `${hash}:${salt}:${iter}`;
    }
};