KeyExchangeSNtruP761X25519Sha512
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Agreement;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Pqc.Crypto.NtruPrime;
using Renci.SshNet.Abstractions;
using Renci.SshNet.Common;
using Renci.SshNet.Messages.Transport;
using System;
using System.Globalization;
namespace Renci.SshNet.Security
{
internal sealed class KeyExchangeSNtruP761X25519Sha512 : KeyExchangeEC
{
private SNtruPrimeKemExtractor _sntrup761Extractor;
private X25519Agreement _x25519Agreement;
public override string Name => "sntrup761x25519-sha512";
protected override int HashSize => 512;
public override void Start(Session session, KeyExchangeInitMessage message, bool sendClientInitMessage)
{
base.Start(session, message, sendClientInitMessage);
base.Session.RegisterMessage("SSH_MSG_KEX_ECDH_REPLY");
base.Session.KeyExchangeEcdhReplyMessageReceived += Session_KeyExchangeEcdhReplyMessageReceived;
SNtruPrimeKeyPairGenerator sNtruPrimeKeyPairGenerator = new SNtruPrimeKeyPairGenerator();
sNtruPrimeKeyPairGenerator.Init(new SNtruPrimeKeyGenerationParameters(CryptoAbstraction.SecureRandom, SNtruPrimeParameters.sntrup761));
AsymmetricCipherKeyPair asymmetricCipherKeyPair = sNtruPrimeKeyPairGenerator.GenerateKeyPair();
_sntrup761Extractor = new SNtruPrimeKemExtractor((SNtruPrimePrivateKeyParameters)asymmetricCipherKeyPair.Private);
X25519KeyPairGenerator x25519KeyPairGenerator = new X25519KeyPairGenerator();
x25519KeyPairGenerator.Init(new X25519KeyGenerationParameters(CryptoAbstraction.SecureRandom));
AsymmetricCipherKeyPair asymmetricCipherKeyPair2 = x25519KeyPairGenerator.GenerateKeyPair();
_x25519Agreement = new X25519Agreement();
_x25519Agreement.Init(asymmetricCipherKeyPair2.Private);
byte[] encoded = ((SNtruPrimePublicKeyParameters)asymmetricCipherKeyPair.Public).GetEncoded();
byte[] encoded2 = ((X25519PublicKeyParameters)asymmetricCipherKeyPair2.Public).GetEncoded();
_clientExchangeValue = encoded.Concat(encoded2);
SendMessage(new KeyExchangeEcdhInitMessage(_clientExchangeValue));
}
public override void Finish()
{
base.Finish();
base.Session.KeyExchangeEcdhReplyMessageReceived -= Session_KeyExchangeEcdhReplyMessageReceived;
}
protected override byte[] Hash(byte[] hashData)
{
return CryptoAbstraction.HashSHA512(hashData);
}
private void Session_KeyExchangeEcdhReplyMessageReceived(object sender, MessageEventArgs<KeyExchangeEcdhReplyMessage> e)
{
KeyExchangeEcdhReplyMessage message = e.Message;
base.Session.UnRegisterMessage("SSH_MSG_KEX_ECDH_REPLY");
HandleServerEcdhReply(message.KS, message.QS, message.Signature);
Finish();
}
private void HandleServerEcdhReply(byte[] hostKey, byte[] serverExchangeValue, byte[] signature)
{
_serverExchangeValue = serverExchangeValue;
_hostKey = hostKey;
_signature = signature;
if (serverExchangeValue.Length != _sntrup761Extractor.EncapsulationLength + X25519PublicKeyParameters.KeySize)
throw new SshConnectionException(string.Format(CultureInfo.CurrentCulture, "Bad Q_S length: {0}.", serverExchangeValue.Length), DisconnectReason.KeyExchangeFailed);
byte[] encapsulation = serverExchangeValue.Take(_sntrup761Extractor.EncapsulationLength);
byte[] array = _sntrup761Extractor.ExtractSecret(encapsulation);
int num = array.Length;
X25519PublicKeyParameters publicKey = new X25519PublicKeyParameters(serverExchangeValue, _sntrup761Extractor.EncapsulationLength);
Array.Resize(ref array, num + _x25519Agreement.AgreementSize);
_x25519Agreement.CalculateAgreement(publicKey, array, num);
base.SharedKey = CryptoAbstraction.HashSHA512(array);
}
}
}