如何使用C#.NET在PEM文件中使用P-256密钥计算ECDSA签名？

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

string pemFilePath = "path/to/pem/file.pem";
string pemContents = File.ReadAllText(pemFilePath);

RSAParameters rsaParams = RSAUtils.GetRSAParametersFromPem(pemContents);

ECDsa ecdsa = ECDsa.Create();
ecdsa.ImportParameters(new ECParameters
{
    Curve = ECCurve.NamedCurves.nistP256,
    D = rsaParams.D,
    Q = new ECPoint
    {
        X = rsaParams.Modulus,
        Y = rsaParams.Exponent
    }
});

string dataToSign = "data to sign";
byte[] dataBytes = Encoding.UTF8.GetBytes(dataToSign);

byte[] signature = ecdsa.SignData(dataBytes, HashAlgorithmName.SHA256);