GitHub service hook example in PHP

hook.php

<?php

// basic GitHub service hook example

$payload = file_get_contents("php://input");

$secret_key = 'secret';

$computed_signature = 'sha1=' . hash_hmac('sha1', $payload, $secret_key, false);

$posted_signature = $_SERVER['HTTP_X_HUB_SIGNATURE'];

if ($computed_signature !== $posted_signature) {
    file_put_contents(__DIR__ . '/test.txt', 'INVALID');
    throw new RuntimeException("invalid payload signature");
}

file_put_contents(__DIR__ . '/test.txt', $payload);