reCAPTCHA验证报错排查：file_get_contents未指定Content-Type

Hey there, let's tackle this reCAPTCHA issue step by step. The error you're seeing is a direct result of missing the Content-Type header in your HTTP request to Google's reCAPTCHA verification endpoint, and there are a couple other small issues in your code that might be causing unexpected behavior too.

1. 修复Content-Type警告（错误根源） #

$verify = file_get_contents($url, false, $context)抛出警告的原因是你的$options数组没有显式设置Content-Type请求头。虽然http_build_query()会将数据格式化为application/x-www-form-urlencoded格式，但PHP的流上下文不会自动添加这个头，所以我们需要手动指定。

修改你的$options数组，添加请求头：

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

2. 修复二次请求中未定义的$query变量 #

在你后续的$content数组代码中，你使用了未定义的$query变量来计算Content-Length，这会在修复第一个问题后引发新的错误。如果这个变量是用来指代http_build_query($data)生成的编码数据，需要先定义它：

$encodedData = http_build_query($data);
$content = array (
    'http' => array (
        'header' => "Content-Type: application/x-www-form-urlencoded\r\n".
        "Content-Length: ".strlen($encodedData)."\r\n".
        "User-Agent:MyAgent/1.0\r\n",
        'method' => 'POST',
        'content' => $encodedData
    )
);

3. 用Laravel的Request对象替代$_POST #

既然你在Laravel控制器中开发，建议使用注入的$request对象来获取请求参数，而不是直接访问$_POST，这更符合框架规范且更安全：

$response = $request->input('g-recaptcha-response');
// ...
$data = array(
    'secret' => '6LcwXi8UAAAAAE9zNCVfqwDOIWNazNgdK-0wQv9L',
    'response' => $request->input('g-recaptcha-response')
);

4. reCAPTCHA功能的额外检查项 #

• 再次确认你的reCAPTCHA密钥是否正确（看起来你用的是v2密钥，如果前端也是reCAPTCHA v2的话没问题）。
• 验证密钥关联的域名是否和表单所在域名一致（Google会阻止未授权域名的请求）。
• 确保前端正确渲染了reCAPTCHA组件，并且表单提交时确实发送了g-recaptcha-response参数。

整合以上修改，你的message方法最终代码如下：

public function message(Request $request) {
    $response = $request->input('g-recaptcha-response');
    $url = 'https://www.google.com/recaptcha/api/siteverify';
    $data = array(
        'secret' => '6LcwXi8UAAAAAE9zNCVfqwDOIWNazNgdK-0wQv9L',
        'response' => $response
    );

    // For debug purpose (remove comments)
    // dd($request->all());

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

    $context = stream_context_create($options);
    $verify = file_get_contents($url, false, $context);
    $captchaSuccess = json_decode($verify);

    if (!$captchaSuccess->success) {
        return redirect('/')->with('success', 'You are a bot! Go away!');
    } else {
        $content = array (
            'http' => array (
                'header' => "Content-Type: application/x-www-form-urlencoded\r\n".
                "Content-Length: ".strlen($encodedData)."\r\n".
                "User-Agent:MyAgent/1.0\r\n",
                'method' => 'POST',
                'content' => $encodedData
            )
        );
        // 这里添加你后续的业务逻辑...
    }
}

以上修改应该能解决Content-Type警告，同时修复相关的reCAPTCHA验证问题。

内容的提问来源于stack exchange，提问作者Japracool