使用X509Certificate2密钥进行RSA加密

Question

我正在尝试在存储数据库之前对字符串进行加密，我使用加密解密方法如下

private static readonly X509Certificate2 Cert = GetCert();

private static X509Certificate2 GetCert()
{
    if (Store == null)
    {
        throw new NullReferenceException("Store is null");
    }


    Store.Open(OpenFlags.ReadOnly);
    var collection = Store.Certificates.Find(X509FindType.FindBySubjectName, "TestCert", false);
    if (collection == null || collection.Count == 0)
    {
        throw new NullReferenceException("No certs in store");
    }

    X509Certificate2 certificate = collection.Cast<X509Certificate2>().FirstOrDefault(cert => cert != null && cert.HasPrivateKey);

    if (certificate == null)
    {
        throw new NullReferenceException("Cert is null");
    }

    Store.Close();

    return certificate;
}

用于加密

public static string Encrypt(this string plainText)
{
    using (var rsa = (RSACng)Cert.GetRSAPublicKey())
    {
        var data = Encoding.Unicode.GetBytes(plainText);
        var encrypted = rsa.Encrypt(data,RSAEncryptionPadding.OaepSHA1);
        return Convert.ToBase64String(encrypted);
    }
}

用于解密

public static string Decrypt(this string cipherText)
{
    using (var rsa = Cert.GetRSAPrivateKey())
    {
        var data = Convert.FromBase64String(cipherText);
        var encrypted = rsa.Decrypt(data, RSAEncryptionPadding.OaepSHA1);
        return Encoding.Unicode.GetString(encrypted);
    }
}

问题是当我解密..引发异常说

时

  

WindowsCryptographicException：密钥集不存在

出了什么问题？

谢谢