Is the social authentication feature in Azure Mobile Apps available outside of Azure?

Question

For example, if I deploy a mirror of my app on Amazon S3, is there any way to provide the same social login experience? Is it possible to store the login information on my own SQL server instead of in Azure? I currently use the default

        MobileAppSettingsDictionary settings = config.GetMobileAppSettingsProvider().GetMobileAppSettings();

        // http://blogs.perficient.com/microsoft/2016/05/how-to-add-custom-claims-to-azure-mobile-app-authentication/
        if (string.IsNullOrEmpty(settings.HostName))
        {
            app.UseAppServiceAuthentication(new AppServiceAuthenticationOptions
            {
                // This middleware is intended to be used locally for debugging. By default, HostName will
                // only have a value when running in an App Service application.
                SigningKey = ConfigurationManager.AppSettings["SigningKey"],
                ValidAudiences = new[] { ConfigurationManager.AppSettings["ValidAudience"] },
                ValidIssuers = new[] { ConfigurationManager.AppSettings["ValidIssuer"] },
                TokenHandler = config.GetAppServiceTokenHandler()
            });
        }

I do see that there is a way to make a custom auth - https://azure.microsoft.com/en-us/documentation/articles/app-service-mobile-dotnet-backend-how-to-use-server-sdk/#custom-auth - but I wonder if there are pre-backed auths for the social logins that I can use.