с# get GOST 3410 certificate from container

public static X509Certificate2 GetCertFromCont(string pin, string CertCont)
        {
            CspParameters cspParameters = new CspParameters(75);
            cspParameters.KeyContainerName = CertCont;
            cspParameters.Flags = CspProviderFlags.NoPrompt;
 
 
 
            if (pin != "")
            {
                System.Security.SecureString s = new System.Security.SecureString();
                foreach (char z in pin)
                    s.AppendChar(z);
                cspParameters.KeyPassword = s;
            }
 
            try
            {
                Gost3410CryptoServiceProvider prov = new Gost3410CryptoServiceProvider(
                    cspParameters);
                return prov.ContainerCertificate;
            }
            catch (Exception e)
            {
                //System.Windows.MessageBox.Show(e.Message);
                return null;
            }
 
        }