private void HandleStunRequest(IPEndPoint from, byte[] data)
{
try
{
if (StunPacket.TryParse(data, out var packet) != StunPacket.ResultCodes.Ok)
{
return;
}
if (packet.MessageType != StunPacket.MessageTypes.BindingRequest || packet.MessageIntegrity != null)
{
return;
}
var answer = new StunPacket
{
MessageType = StunPacket.MessageTypes.BindingSuccessResponse,
TransactionId = packet.TransactionId,
XorMappedAddress = from,
Fingerprint = true,
};
_stunServer.Send(from, answer.Pack());
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
private Client FindClientAndCheckIntegrity(StunPacket packet)
{
if (packet.MessageIntegrity == null || packet.Username == null)
{
return(null);
}
var client = Clients.Find(a => a.Ufrag == packet.Username.Split(':')[1]);
if (client == null)
{
return(null);
}
if (!packet.VerifyIntegrity(IcePasswordBytes))
{
return(null);
}
return(client);
}
private void HandleRtpPacket(IPEndPoint from, byte[] data)
{
try
{
var client = FindClient(from);
if (client != null &&
client.SrtpContext.TryParseSrtpPacket(data, out var rtp) == RtpPacket.ResultCodes.Ok)
{
_debugFile.Write(rtp.Payload, 0, rtp.Payload.Length);
foreach (var another in Clients)
{
IPEndPoint remoteEp;
byte[] packet;
rtp.Ssrc = client.ClientId;
if (client == another)
{
continue;
}
if ((remoteEp = another.RemoteRtp) == null)
{
continue;
}
if ((packet = another.SrtpContext.PackSrtpPacket(rtp)) == null)
{
continue;
}
_rtpServer.Send(remoteEp, packet);
}
}
else if (StunPacket.TryParse(data, out var stun) == StunPacket.ResultCodes.Ok)
{
if (stun.MessageType != StunPacket.MessageTypes.BindingRequest)
{
return;
}
client = FindClientAndCheckIntegrity(stun);
if (client == null)
{
Console.Error.WriteLineAsync($"Cannot found client with username {stun.Username}");
// TODO implement error
//var answer = new StunPacket
//{
// MessageType = StunPacket.MessageTypes.BindingSuccessResponse,
// TransactionId = packet.TransactionId,
// Fingerprint = true,
//};
//_rtpServer.Send(from, answer.Pack());
return;
}
var answer = new StunPacket
{
MessageType = StunPacket.MessageTypes.BindingSuccessResponse,
TransactionId = stun.TransactionId,
XorMappedAddress = from,
MessageIntegrityKey = IcePasswordBytes,
Fingerprint = true,
};
client.SetRtpParam(from);
_rtpServer.Send(from, answer.Pack());
client.Dtls.DoHandshake(() => client.SrtpContext.SetMasterKeys(client.Dtls.Ssl, true));
}
else if (DtlsPacket.CheckPacket(data, 0) == DtlsPacket.ResultCodes.Ok)
{
if (client == null)
{
Console.Error.WriteLineAsync($"Cannot found client with ip {from}");
return;
}
client.Dtls.Add(data);
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
}