C＃确定X509Certificate2私钥是否可导出（redux）

Question

我有时间决定X509Certificate2证书的私钥是否可导出。根据我所做的研究，我应该使用 CspKeyContainerInfo 。这是我到目前为止（为简洁起见，删除错误检查）。假设RSA证书指纹 存在且 拥有私钥。

X509Certificate2 cert = Cryptography.GetCertificateFromStore(thumbprint);
RSACryptoServiceProvider provider = (RSACryptoServiceProvider)cert.PublicKey.Key;
Debug.WriteLine("RSA Certificate Gettting Exportable status");
// next line generates exception "Key does not exist"
bool isexportable = provider.CspKeyContainerInfo.Exportable;
Debug.WriteLine("RSA Certificate Exportable="+isexportable.ToString());