Google OAuth 2.0会返回400＆＃34;错误请求＆＃34;甚至来自游乐场

Question

我正在尝试在我的CodeIgniter应用程序中使用PHP League OAuth2 client library进行身份验证。但是，我总是得到错误400“错误请求”。所以，我尝试通过Google's OAuth 2.0 playground使用我自己的客户端ID和客户端密钥，它也会出现同样的错误。有趣的是，当我尝试使用我的Google帐户登录时，Jasper Reports Community会出现同样的错误。回到游乐场，我尝试了Google Plus登录以及旧端点。谷歌有停电吗？

失败的网址是

https://accounts.google.com/o/oauth2/auth?
client_id=xxxxx-xxxxx.apps.googleusercontent.com
&redirect_uri=mywebsite.com%2Fauth%2Fsession%2Fgoogle
&state=yyyyyzzzzzwwwww
&scope=profile
&response_type=code
&approval_prompt=auto

（为安全起见，隐藏了变量state，redirect_uri等）。 这是我的控制器代码，基于Phil Sturgeon的例子：

class Auth extends CI_Controller {
    public function __construct() {
        parent::__construct();
        log_message('debug', 'Auth: controller loaded.');
    }

    public function session($provider_name) {
        $this->load->helper('url_helper');
        switch (strtolower($provider_name)) {
            case "eventbrite":
                $provider_name = 'Eventbrite';
                break;
            case "facebook":
                $provider_name = 'Facebook';
                break;
            case "github":
                $provider_name = 'Github';
                break;
            case "google":
                $provider_name = 'Google';
                break;
            case "instagram":
                $provider_name = 'Instagram';
                break;
            case "linkedin":
                $provider_name = 'LinkedIn';
                break;
            case "microsoft":
                $provider_name = 'Microsoft';
                break;
            case "vkontakte":
                $provider_name = 'Vkontakte';
                break;
        }

        log_message('debug', 'Auth: session to ' . $provider_name);
        $class = 'League\\OAuth2\\Client\\Provider\\'.$provider_name;
        $provider = new $class(array(
            'clientId'     => $this->config->item('client_id'),
            'clientSecret' => $this->config->item('client_secret'),
            'redirectUri'  => $this->config->item('redirect_uri')
        ));
        log_message('debug', 'Auth: connect ' . $this->config->item('client_id'));

        if (! $this->input->get('code')) {
            // By sending no options it'll come back here
            $url = $provider->getAuthorizationUrl();
            log_message('error', 'Auth: redirect to ' . $url);

            redirect($url);
        } else {
            // Have a go at creating an access token from the code
            // Try to get an access token (using the authorization code grant)
            $token = new stdClass();

            // If you are using Eventbrite you will need to add the grant_type parameter (see below)
            if ($provider_name == 'eventbrite') {
                $token = $provider->getAccessToken('authorization_code', [
                    'code'       => $_GET['code'],
                    'grant_type' => 'authorization_code'
                ]);
            } else {
                $token = $provider->getAccessToken('authorization_code', [
                    'code' => $_GET['code']
                ]);
            }


            // Use this object to try and get some user details (username, full name, etc)
            try {

                // We got an access token, let's now get the user's details
                $userDetails = $provider->getUserDetails($token);

                // Use these details to create a new profile
                //printf('Hello %s!', $userDetails->firstName);

            } catch (Exception $e) {

                // Failed to get user details
                show_error("That didn't work: " . $e);
                log_message('error', "Auth: That didn't work: " . $e);
            }

            // Here you should use this information to A) look for a user B) help a new user sign up with existing data.
            // If you store it all in a cookie and redirect to a registration page this is crazy-simple.
            echo "<pre>Tokens: ";
            var_dump($token);

            echo "\n\nUser Info: ";
            var_dump($userDetails);

        }
    }
}