Telegram authorization data checker

telegram-login.js

const { createHash, createHmac } = require('crypto')
  
function checkSignature (token, { hash, ...data }) {
  const secret = createHash('sha256')
    .update(token)
    .digest()
  const checkString = Object.keys(data)
    .sort()
    .map(k => `${k}=${data[k]}`)
    .join('\n')
  const hmac = createHmac('sha256', secret)
    .update(checkString)
    .digest('hex')
  return hmac === hash
}

const payload = {
  id: '424242424242',
  first_name: 'John',
  last_name: 'Doe',
  username: 'username',
  photo_url: 'https://t.me/i/userpic/320/username.jpg',
  auth_date: '1519400000',
  hash: '87e5a7e644d0ee362334d92bc8ecc981ca11ffc11eca809505'
}

checkSignature('ABC:12345...', payload)

Great, thanks!

danny