KeyExchangeECDH
using Org.BouncyCastle.Asn1.X9;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Agreement;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math.EC;
using Renci.SshNet.Abstractions;
using Renci.SshNet.Common;
using Renci.SshNet.Messages.Transport;
using System;
namespace Renci.SshNet.Security
{
internal abstract class KeyExchangeECDH : KeyExchangeEC
{
private sealed class BouncyCastleImpl : Impl
{
private readonly ECDomainParameters _domainParameters;
private readonly ECDHCBasicAgreement _keyAgreement;
public BouncyCastleImpl(X9ECParameters curveParameters)
{
_domainParameters = new ECDomainParameters(curveParameters);
_keyAgreement = new ECDHCBasicAgreement();
}
public override byte[] GenerateClientECPoint()
{
ECKeyPairGenerator val = new ECKeyPairGenerator();
val.Init(new ECKeyGenerationParameters(_domainParameters, CryptoAbstraction.SecureRandom));
AsymmetricCipherKeyPair val2 = val.GenerateKeyPair();
_keyAgreement.Init(val2.get_Private());
return val2.get_Public().get_Q().GetEncoded();
}
public override byte[] CalculateAgreement(byte[] serverECPoint)
{
ECPoint val = _domainParameters.get_Curve().DecodePoint(serverECPoint);
ECPublicKeyParameters val2 = new ECPublicKeyParameters("ECDH", val, _domainParameters);
return _keyAgreement.CalculateAgreement(val2).ToByteArray();
}
}
private abstract class Impl : IDisposable
{
public abstract byte[] GenerateClientECPoint();
public abstract byte[] CalculateAgreement(byte[] serverECPoint);
protected virtual void Dispose(bool disposing)
{
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
private BouncyCastleImpl _impl;
protected abstract X9ECParameters CurveParameter { get; }
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;
_impl = new BouncyCastleImpl(CurveParameter);
_clientExchangeValue = _impl.GenerateClientECPoint();
SendMessage(new KeyExchangeEcdhInitMessage(_clientExchangeValue));
}
public override void Finish()
{
base.Finish();
base.Session.KeyExchangeEcdhReplyMessageReceived -= Session_KeyExchangeEcdhReplyMessageReceived;
}
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;
byte[] data = _impl.CalculateAgreement(serverExchangeValue);
base.SharedKey = data.ToBigInteger2().ToByteArray(false, true);
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (disposing)
_impl?.Dispose();
}
}
}