ed25519.cs

// Nuget: BouncyCastle.NetCoreSdk 1.9.3.1

using System;
using System.IO;
using System.Net;
using System.Net.Security;
using System.Net.Sockets;
using System.Runtime.Intrinsics.Arm;
using System.Runtime.Serialization.Json;
using System.Security.Authentication;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Threading.Channels;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Operators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.X509;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var keyPairGenerator = new Ed25519KeyPairGenerator();
            keyPairGenerator.Init(new Ed25519KeyGenerationParameters(new SecureRandom()));
            var keyPair = keyPairGenerator.GenerateKeyPair();

            var certGen = new X509V3CertificateGenerator();
            certGen.SetNotAfter(DateTime.Today.AddYears(3));
            certGen.SetNotBefore(DateTime.Today.AddDays(-1));
            certGen.SetIssuerDN(new X509Name("CN=sample"));
            certGen.SetSerialNumber(new BigInteger(20*8, new SecureRandom()).Abs());
            certGen.SetSubjectDN(new X509Name("CN=sample"));
            certGen.SetPublicKey(keyPair.Public);
            var x509Certificate = certGen.Generate(new Ed25519Asn1SignatureFactory( keyPair));
            
            var store = new Pkcs12Store();
            string friendlyName = x509Certificate.SubjectDN.ToString();
            var certificateEntry = new X509CertificateEntry(x509Certificate);
            store.SetCertificateEntry(friendlyName, certificateEntry);
            store.SetKeyEntry(friendlyName, new AsymmetricKeyEntry(keyPair.Private), new[] { certificateEntry });
            var ms = new MemoryStream();
            store.Save(ms, null, new SecureRandom());
            File.WriteAllBytes("cert.pfx", ms.ToArray());
            var x509Certificate2 = new X509Certificate2(ms.ToArray());
        }
        
        private class Ed25519Asn1SignatureFactory : ISignatureFactory
        {
            private AsymmetricCipherKeyPair _keyPair;
            private Asn1SignatureFactory _asn1SignatureFactory;
            private string _algorithm;

            public Ed25519Asn1SignatureFactory(AsymmetricCipherKeyPair keyPair)
            {
                _keyPair = keyPair;
                _algorithm = "1.3.101.112";
                _asn1SignatureFactory = new Asn1SignatureFactory(_algorithm, keyPair.Private, new SecureRandom());
            }

            public IStreamCalculator CreateCalculator()
            {
                ISigner signer = SignerUtilities.GetSigner(_algorithm);
                signer.Init(true, _keyPair.Private);
                return new DefaultSignatureCalculator(signer);
            }

            public object AlgorithmDetails => _asn1SignatureFactory.AlgorithmDetails;
        }
    }
}