How to write this code in php? Telegram webapp bot documentation

Question

I've got this instrunctions from Telegram documenation

but how to write it in PHP?

I tried this one:

if (pack("H*",hash_hmac('sha256',$string, $secret_key)) == $info['hash']) {

but unsuccesfully.. any ideas how to apply this code in php?

Answer 1

Does this accurately reflect your intent?

if(hach_hmac("sha256", $data_check_string, $secret_key) === $info['hash']){
  // data is from Telegram
}

If the third parameter of the hash_hmac function is not provided or is set to false, it will return a lowercase hexadecimal value. More information can be found at https://www.php.net/manual/ja/function.hash-hmac.php

Answer 2

I figured it out..

secret_key = HMAC_SHA256(<bot_token>, "WebAppData")

php equal is:

$secret_key = hash_hmac('sha256',$bot_token, 'WebAppData', true);

and

hex(HMAC_SHA256(data_check_string, secret_key))

it is just:

hash_hmac('sha256',$dataCheckString, $secret_key);