using System;

using System.Security.Cryptography;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(System.Runtime.InteropServices.RuntimeInformation.OSDescription + "\n");

        byte[] keyMaterial = Convert.FromHexString("d25a4ea14eb6ad223393fd84ab59a62e"); // keyMaterial with sufficient entropy

        ECDsa key = CreateKeyViaHKDF(keyMaterial, ECCurve.NamedCurves.nistP384, 48);

​

        // Export raw private/public key

        ECParameters privateKey = key.ExportParameters(true);

        ECParameters publicKey = key.ExportParameters(false);

        Console.WriteLine("Private key (raw, Base64):   " + Convert.ToBase64String(privateKey.D));

        Console.WriteLine("Public key, X (raw, Base64): " + Convert.ToBase64String(publicKey.Q.X));

        Console.WriteLine("Public key, Y (raw, Base64): " + Convert.ToBase64String(publicKey.Q.Y));

​

        // Export keys in PKCS#8 (private key) and SPKI (public key) format 

        Console.WriteLine("\nPrivate key (PKCS#8): " + key.ExportPkcs8PrivateKeyPem());

        Console.WriteLine("\nPublic key (SPKI): " + key.ExportSubjectPublicKeyInfoPem());

    }

    private static ECDsa CreateKeyViaHKDF(byte[] keyMaterial, ECCurve ecCurve, int size)

    {

        ECParameters ecp = new ECParameters();

        ecp.Curve = ecCurve;

        ecp.D = HKDF.DeriveKey(HashAlgorithmName.SHA512, keyMaterial, size, null, null);

        return ECDsa.Create(ecp); 

    }

}