hashing.js

// assume we have a hash function called "hash"

// this is the array of already-stored data
let data = [{
  url: 'google.com',
  salt: 'asdf1234',
  hashed_pw: '134hsfdo'
}, {
  url: 'cnn.com',
  salt: '123489asdf',
  hashed_pw: '14haef135'
}];

function check_password(password) {
  let matched_urls = [];
  for (let datum of data) {
    if (hash(`${password}${datum.salt}`) === datum.hashed_pw) {
      matched_urls.push(datum.url); // this is a match!
    }
  }
  return matched_urls;
}