Turnstile is Cloudflare’s smart CAPTCHA alternative.
https://www.cloudflare.com/products/turnstile/
<?php
if (isset($_POST["cf-turnstile-response"])) {
$captcha = $_POST['cf-turnstile-response'];
$secretKey = "__Secret_Key__";
$ip = $_SERVER['REMOTE_ADDR'];
$url = 'https://challenges.cloudflare.com/turnstile/v0/siteverify';
$data = array('secret' => $secretKey, 'response' => $captcha, 'remoteip' => $ip);
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_TIMEOUT, 10);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
$curlData = curl_exec($curl);
curl_close($curl);
$result = json_decode($curlData, true);
if (intval($result["success"]) == 1) {
echo "success";
exit();
} else {
echo "error";
exit();
}
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Test Turnstile</title>
<script src="https://challenges.cloudflare.com/turnstile/v0/api.js" async defer></script>
</head>
<body>
<form method="POST" action="">
<div>
<!-- The following line controls and configures the Turnstile widget. -->
<div class="cf-turnstile" data-sitekey="__Site_Key__" data-theme="light"></div>
<!-- end. -->
</div>
<button type="submit">Sign in</button>
</form>
</body>
</html>
