OK weirdly, I couldn't pass the value byref but works fine
byvalfingerprint now working fine with sha512 in php changed return
hash_hmac("md5", $loginid . "^" . $sequence . "^" . $tstamp . "^" .
$amount . "^" . $currency, $x_tran_key); to $x_tran_key...
I think the terminology is just confusing here. We aren't talking about
the "md5 hash" which as you noted was always optional. This is about the
new fingerprint which is also referred to as "x_fp_hash" and used to use
the login id and transaction key...
