Read .der file private key C#

Question

string LoadPrivateKey = "test.der";

X509Certificate2 x509 = new X509Certificate2(LoadPrivateKey, "test");

it is always show "unknown object in factory: DerInteger\r\nParameter name: obj"

I would like to use in the Elliptic Curve Cryptography

how can solve it?

Thank You!

Answer 1

Finally I solved this problem.

1. Use .pfx include the private key.

2.

X509Certificate2 cert = new X509Certificate2("test.pfx", "test");
                ECDsa mECDsa = cert.GetECDsaPrivateKey();
                Console.WriteLine("[ECDsa]: "+  mECDsa.KeySize);