private object[] BlockingReceive(sClient sC)
{
byte[] bSize = new byte[4];
sC.cSocket.Receive(bSize);
byte[] sBuf = new byte[BitConverter.ToInt32(bSize, 0)];
int iReceived = 0;
while (iReceived < sBuf.Length)
{
iReceived += sC.cSocket.Receive(sBuf, iReceived, sBuf.Length - iReceived, SocketFlags.None);
}
Log($"Receiving {sBuf.Length} bytes...", ConsoleColor.Cyan);
if (sC.eCls != null)
{
sBuf = sC.eCls.AES_Decrypt(sBuf);
}
else
{
sBuf = Encryption.Decompress(sBuf);
}
return(Encryption.BinaryFormatterSerializer.Deserialize(sBuf));
}
private void AcceptCallback(IAsyncResult iAR)
//Our method for accepting clients
{
var client = default(Socket);
try
{
client = sSocket.EndAccept(iAR);
}
catch { return; } // This will happen when we shutdown the server
Log($"Client connected from IP: {client.RemoteEndPoint}", ConsoleColor.Green, true);
var sC = new sClient
{
cSocket = client,
eCls = null,
bSize = new byte[4],
sClass = new SharedClass()
};
Clients.Add(sC.cSocket.RemoteEndPoint, sC);
BeginEncrypting(ref sC);
sC.cSocket.BeginReceive(sC.bSize, 0, sC.bSize.Length, SocketFlags.None, RetrieveCallback, sC.cSocket.RemoteEndPoint);
sSocket.BeginAccept(AcceptCallback, null);
}
private void BlockingSend(sClient sC, params object[] param)
{
byte[] bSend = Encryption.BinaryFormatterSerializer.Serialize(param);
if (sC.eCls != null)
{
bSend = sC.eCls.AES_Encrypt(bSend);
}
else
{
bSend = Encryption.Compress(bSend);
}
Log($"Sending {bSend.Length} bytes...", ConsoleColor.Cyan);
sC.cSocket.Send(BitConverter.GetBytes(bSend.Length));
sC.cSocket.Send(bSend);
}
private void BeginEncrypting(ref sClient sC)
{
byte[] sSymKey;
CngKey sCngKey = CngKey.Create(CngAlgorithm.ECDiffieHellmanP521);
byte[] sPublic = sCngKey.Export(CngKeyBlobFormat.EccPublicBlob);
BlockingSend(sC, Headers.HEADER_HANDSHAKE, sPublic);
object[] oRecv = BlockingReceive(sC);
if (!oRecv[0].Equals(Headers.HEADER_HANDSHAKE))
{
sC.cSocket.Disconnect(true);
}
byte[] cBuf = oRecv[1] as byte[];
using (var sAlgo = new ECDiffieHellmanCng(sCngKey))
using (CngKey cPubKey = CngKey.Import(cBuf, CngKeyBlobFormat.EccPublicBlob))
sSymKey = sAlgo.DeriveKeyMaterial(cPubKey);
sC.eCls = new Encryption(sSymKey, HASH_STRENGTH.MINIMAL);
}
