buf.WriteString(c.Endpoint.AuthURL)
	v := url.Values{
		"response_type": {"id_token"},
		"response_mode": {"form_post"},
		"client_id":     {c.ClientID},
	}
	if c.RedirectURL != "" {
		v.Set("redirect_uri", c.RedirectURL)
	}
	if len(c.Scopes) > 0 {
		v.Set("scope", strings.Join(c.Scopes, " "))
	}
	v.Set("state", state)
	v.Set("nonce", state)
	if strings.Contains(c.Endpoint.AuthURL, "?") {