For this method:
ISteamUserAuth
AuthenticateUser
Version: 1
HTTP Method: POST
Parameters:
Name: steamid
Type: uint64
Optional:
Description: Should be the users steamid, unencrypted.
Parameters:
Name: sessionkey
Type: rawbinary
Optional:
Description: Should be a 32 byte random blob of data, which is then encrypted with RSA using the Steam system's public key. Randomness is important here for security.
Parameters:
Name: encrypted_loginkey
Type: rawbinary
Optional:
Description: Should be the users hashed loginkey, AES encrypted with the sessionkey.
I need 3 parameters. For the second parameter sessionkey, I need to encrypt it using the Steam system's public key. How exactly do I get that?
After some research I figured out that I have to get a public key by using a certificate, and it should look like this.
I am using php, and thus I am using this code to retrieve a public key from a certificate:
<?php
$pub_key = openssl_pkey_get_public(file_get_contents('./cert.crt'));
$keyData = openssl_pkey_get_details($pub_key);
file_put_contents('./key.pub', $keyData['key']);
?>
I am confused as to which certificate do I use. Do I use the certificate of the Steam website? (cert.crt would be the certificate)
