/// <summary>
/// Create a message by a clients authentication state and authentication method
/// </summary>
/// <param name="data">Input data received from client</param>
/// <param name="authenticationState">Clients current authentication state</param>
/// <param name="authenticationMethod">If authentication state is Authenticating, a authenticationMethod is required to return a message according to sub negotation</param>
/// <returns>A socks message, or null if Parsing failed</returns>
private Plugin.ISocksMessage GetMessage(byte[] data, Socks.Constants.AuthenticationState authenticationState, Socks.Constants.AuthenticationMethod authenticationMethod)
{
Plugin.ISocksMessage message = null;
using (MemoryStream stream = new MemoryStream(data))
using (BinaryReader reader = new BinaryReader(stream))
{
if (authenticationState == Socks.Constants.AuthenticationState.Awaiting)
{
message = this.SocksMessageFactory.Create <Socks.Message.Awaiting>(reader);
}
else if (authenticationState == Socks.Constants.AuthenticationState.Authenticating &&
authenticationMethod == Socks.Constants.AuthenticationMethod.UsernamePassword)
{
message = this.SocksMessageFactory.Create <Socks.Message.Authentication.UsernamePassword>(reader);
}
else if (authenticationState == Socks.Constants.AuthenticationState.Authenticated)
{
message = this.SocksMessageFactory.Create <Socks.Message.Command>(reader);
}
}
return(message);
}
/// <summary>
/// EventHandler for AsyncTCPLib.Server.OnClientDataReceived
/// </summary>
private async void OnClientDataReceived(object sender, OnClientDataReceivedEventArgs <Socks.Client> e)
{
var localEvent = new OnClientDataReceivedEventArgs <VirtualClient>(e.Client, e.Data, e.RemoteEndPoint);
Socks.Constants.AuthenticationState currentState = e.Client.Data.AuthenticationState;
Plugin.ISocksMessage message = this.GetMessage(e.Data, currentState, e.Client.Data.AuthenticationMethod);
if (currentState != Socks.Constants.AuthenticationState.Transmitting && message == null)
{
this.Log.Debug("Received invalid data from ");
e.Client.Disconnect();
return;
}
// go through each plugin to process data
foreach (Plugin.IPlugin plugin in this.Plugins)
{
if (plugin.HasRawHandler())
{
plugin.RawHandler.OnClientDataReceived(localEvent);
}
if (plugin.HasStateDependentHandler())
{
// AuthenticationState.Awaiting
if (currentState == Socks.Constants.AuthenticationState.Awaiting)
{
if (!await plugin.StateDependentHandler.Awaiting(e.Client, message))
{
e.Client.Disconnect();
return;
}
}
// AuthenticationState.Authenticating, awaiting sub negotiation
else if (currentState == Socks.Constants.AuthenticationState.Authenticating)
{
if (!await plugin.StateDependentHandler.Authenticating(e.Client, message))
{
e.Client.Disconnect();
return;
}
}
// AuthenticationState.Authenticated
else if (currentState == Socks.Constants.AuthenticationState.Authenticated)
{
if (!await plugin.StateDependentHandler.Command(e.Client, message))
{
e.Client.Disconnect();
return;
}
}
else if (currentState == Socks.Constants.AuthenticationState.Transmitting)
{
if (!await plugin.StateDependentHandler.Transmission(e.Client, e.Data))
{
e.Client.Disconnect();
return;
}
}
}
}
}
