PHP HMAC-SHA512 example

sign.php

<?php

// HMAC-SHA512 signing

function get_signature($event, $orderid, $listing_id) {

    // Hashing algorithm to use
    $algo = 'sha512';

    // Shared key used for signing payloads
    $secret_key = 'abcdef';

    // Number of milliseconds since epoch
    $timestamp = time() * 1000;

    // Payload to be signed
    $payload = "t=$timestamp&event=$event&orderid=$orderid&listing_id=$listing_id";

    // Generate the signed payload
    $signed_payload = hash_hmac(
     $algo,
     $payload,
     $secret_key,
     false,
    );

    return "t=$timestamp,$algo=$signed_payload";

}

$sig = get_signature("delivery", "12345", "L98765");

echo $sig . "\n";

// Include this value as a header in the request
// curl 'http://partner.se/diakrit/notify.php?event=change&orderid=XXXXXXX&listing_id=XXXXXXXX' -H 'X-DIAKRIT-SIGNATURE: sig'

?>