public void RecvHandshakeRequest(Stream handshakeRequest, Stream handshakeResponse)
{
if (status != DhStatus.None)
{
throw new InvalidOperationException($"Wrong status {status}, expected: {DhStatus.None}");
}
BigInteger clientMod;
using (WardenStreamReader reader = new WardenStreamReader(handshakeRequest, true))
{
ushort gotMark = reader.ReadUInt16();
if (mark != gotMark)
{
throw new InvalidOperationException("Handshake failed, wrong mark. Perhaps the other peer is trying to connect with unsecure connection");
}
int publicKeySize = reader.ReadInt32();
publicKey = new BigInteger(reader.ReadBytes(publicKeySize));
int clientModSize = reader.ReadInt32();
clientMod = new BigInteger(reader.ReadBytes(clientModSize));
}
byte[] keyBytes = new byte[64];
rngCsp.GetBytes(keyBytes);
privateKey = new BigInteger(keyBytes);
BigInteger serverMod = (privateKey * publicKey) % mod;
commonKey = ((privateKey * clientMod) % mod).ToByteArray();
using (WardenStreamWriter writer = new WardenStreamWriter(handshakeResponse, true))
{
byte[] serverModBytes = serverMod.ToByteArray();
writer.Write(serverModBytes.Length);
writer.Write(serverModBytes);
}
SetCipherKey();
}
public void RecvHandshakeResponse(Stream handshakeResponse)
{
if (status != DhStatus.WaitingForServerMod)
{
throw new InvalidOperationException($"Wrong status {status}, expected: {DhStatus.WaitingForServerMod}");
}
using (WardenStreamReader reader = new WardenStreamReader(handshakeResponse, true))
{
int serverModSize = reader.ReadInt32();
BigInteger serverMod = new BigInteger(reader.ReadBytes(serverModSize));
commonKey = ((privateKey * serverMod) % mod).ToByteArray();
}
SetCipherKey();
}