function getMetadata()
    {
        $auth = $this->auth;
        $settings = $auth->getSettings();
        $metadata = $settings->getSPMetadata();
        $errors = $settings->validateMetadata($metadata);

        if (empty($errors)) {

            return $metadata;
        } else {

            throw new InvalidArgumentException(
                'Invalid SP metadata: ' . implode(', ', $errors),
                OneLogin_Saml2_Error::METADATA_SP_INVALID
            );
        }
    }