用PHP语言实现ReCaptcha v2

<?php
// 验证用户提交的reCAPTCHA响应
function verifyRecaptcha($response) {
    $url = 'https://www.google.com/recaptcha/api/siteverify';
    $secretKey = 'YOUR_SECRET_KEY'; // 替换为您的Secret Key

    $data = array(
        'secret' => $secretKey,
        'response' => $response
    );

    $options = array(
        'http' => array(
            'header' => "Content-type: application/x-www-form-urlencoded\r\n",
            'method' => 'POST',
            'content' => http_build_query($data)
        )
    );

    $context = stream_context_create($options);
    $result = file_get_contents($url, false, $context);
    $json = json_decode($result);

    return $json->success;
}

// 处理表单提交
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $recaptchaResponse = $_POST['g-recaptcha-response'];

    if (verifyRecaptcha($recaptchaResponse)) {
        // 验证通过，执行其他逻辑
        echo "reCAPTCHA验证通过！";
    } else {
        // 验证失败，显示错误信息
        echo "reCAPTCHA验证失败！";
    }
}
?>

<!-- 在您的HTML表单中添加reCAPTCHA小部件 -->
<form method="POST" action="">
    <!-- 其他表单字段 -->
    <div class="g-recaptcha" data-sitekey="YOUR_SITE_KEY"></div>
    <button type="submit">提交</button>
</form>