php - Facebook PHP SDK 5::API 2.4::跨站请求伪造验证失败。缺少必需的参数 "state"

Question

我做了一个非常简单的 PHP 脚本，只是为了尝试通过 Facebook 登录并获取 accessToken。但是当我尝试以下代码时，我从 SDK 中得到一个异常:« 跨站点请求伪造验证失败。缺少必需的参数“state”。 ».

这是我的代码:

require_once __DIR__ . '/facebook-sdk-v5/autoload.php';
session_start();

$fb = new Facebook\Facebook([
    'app_id' => '{my-own-app-id}',
    'app_secret' => '{my-own-app-secret}'
]);

// Check to see if we already have an accessToken ?
if (isset($_SESSION['facebook_access_token'] )) {
    $accessToken = $_SESSION['facebook_access_token'];
    echo "Horray we have our accessToken:$accessToken<br />\n";

} else {
    // We don't have the accessToken
    // But are we in the process of getting it ? 
    if (isset($_REQUEST['code'])) {
        $helper = $fb->getRedirectLoginHelper();
        try {
            $accessToken = $helper->getAccessToken();
            } catch(Facebook\Exceptions\FacebookResponseException $e) {
              // When Graph returns an error
              echo 'Graph returned an error: ' . $e->getMessage();
              exit;
        } catch(Facebook\Exceptions\FacebookSDKException $e) {
              // When validation fails or other local issues
              echo 'Facebook SDK returned an error: ' . $e->getMessage();
            exit;
        }

        if (isset($accessToken)) {
              // Logged in!
              $_SESSION['facebook_access_token'] = (string) $accessToken;

              // Now you can redirect to another page and use the
              // access token from $_SESSION['facebook_access_token']

              echo "Finally logged in! Token:$accessToken";
        }           
    } else {
        // Well looks like we are a fresh dude, login to Facebook!
        $helper = $fb->getRedirectLoginHelper();
        $permissions = ['email', 'user_likes']; // optional
        $loginUrl = $helper->getLoginUrl('http://mywebsite.com/myapp/index.php', $permissions);

        echo '<a href="' . $loginUrl . '">Log in with Facebook!</a>';
    }

}

exit;

Answer 1

我不得不在一些服务器中添加这一行:

$helper = $fb->getRedirectLoginHelper();
if (isset($_GET['state'])) {
    $helper->getPersistentDataHandler()->set('state', $_GET['state']);
}

我随机收到此错误，具体取决于服务器配置。