Zendesk webhook signature validation with Laravel

Controller.php

<?php

// $request comes from your Controller method, but you can adjust with whatever framework you use

$signature = $request->header(ZendeskSupport::WEBHOOK_SIGNATURE_HEADER),
$timestamp = $request->header(ZendeskSupport::WEBHOOK_SIGNATURE_TIMESTAMP_HEADER),
$rawBody = $request->getContent();

$computedSignature = base64_encode(hash_hmac(
    'sha256',
    $timestamp . $rawBody,
    'my_secret_key',
    true // <--- Important: retrieve it in binary format, not lowercase hexits!
));

if ($computedSignature !== $signature) {
    throw new \Exception('signature mismatching');   
}