AuthBucket\OAuth2\ResponseType\AbstractResponseTypeHandler::checkClientId PHP Method

    protected function checkClientId(Request $request)
    {
        // client_id is required and in valid format.
        $clientId = $request->query->get('client_id');
        $errors = $this->validator->validate($clientId, [new NotBlank(), new ClientId()]);
        if (count($errors) > 0) {
            throw new InvalidRequestException(['error_description' => 'The request includes an invalid parameter value.']);
        }
        // Compare client_id with database record.
        $clientManager = $this->modelManagerFactory->getModelManager('client');
        $result = $clientManager->readModelOneBy(['clientId' => $clientId]);
        if ($result === null) {
            throw new UnauthorizedClientException(['error_description' => 'The client is not authorized.']);
        }
        return $clientId;
    }