public void Listen()
{
Console.WriteLine($"SS started on 127.0.0.1:{Config.SS_port}");
UdpClient reciever = new UdpClient(Config.SS_port);
IPEndPoint remoteIP = null;
try
{
while (true)
{
byte[] data = reciever.Receive(ref remoteIP);
remoteIP.Port = Config.C_port;
var message = Serialiser <Message> .Deserialise(data);
Console.WriteLine(message.ToString() + $"from {remoteIP.Address}:{remoteIP.Port};");
if (message.Type == MessageType.CToSs)
{
var tgs_bytes = Helper.RecoverData(
new List <byte>(DES.Decrypt(message.Data[0].ToArray(), Config.K_TGS_SS)));
var tgs = Serialiser <TicketGranting> .Deserialise(tgs_bytes);
var aut2_bytes = Helper.RecoverData(
new List <byte>(DES.Decrypt(message.Data[1].ToArray(), Config.K_C_SS)));
var aut2 = Serialiser <TimeMark> .Deserialise(aut2_bytes);
Message ReMessage = new Message();
if (Helper.CheckTime(tgs.IssuingTime, aut2.T, tgs.Duration))
{
ReMessage.Type = MessageType.SsToC;
DateTime reTime = aut2.T;
var time_bytes = Serialiser <long> .Serialise(aut2.T.Ticks + 1);
var bytes = DES.Encrypt(Helper.ExtendData(time_bytes),
Config.K_C_SS);
ReMessage.Data.Add(new List <byte>(bytes));
}
else
{
ReMessage.Type = MessageType.TicketNotValid;
}
ReMessage.Send(remoteIP);
Console.WriteLine($"Message sended from SS to {remoteIP.Address}:{remoteIP.Port}");
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
}
}
public void Send(IPEndPoint remoteIP)
{
UdpClient sender = new UdpClient();
try
{
byte[] dgram = Serialiser <Message> .Serialise(this);
sender.Send(dgram, dgram.Length, remoteIP);
}
finally
{
sender.Close();
}
}
public void Listen()
{
UdpClient reciever = new UdpClient(Config.TGS_port);
Console.WriteLine($"TGS started on 127.0.0.1:{Config.TGS_port}");
IPEndPoint remoteIP = null;
try
{
while (true)
{
byte[] data = reciever.Receive(ref remoteIP);
remoteIP.Port = Config.C_port;
var message = Serialiser <Message> .Deserialise(data);
if (message.Type == MessageType.СToTgs)
{
var tgt_json = Helper.RecoverData(
new List <byte>(DES.Decrypt(message.Data[0].ToArray(), Config.K_AS_TGS)));
var tgt = Serialiser <TicketGranting> .Deserialise(tgt_json);
var aut1_json = Helper.RecoverData(
new List <byte>(DES.Decrypt(message.Data[1].ToArray(), Config.K_C_TGS)));
var a = Encoding.UTF8.GetString(aut1_json);
var aut1 = Serialiser <TimeMark> .Deserialise(aut1_json);
var ID = Encoding.UTF8.GetString(message.Data[2].ToArray());
Message ReMessage = new Message();
if (tgt.ClientIdentity == aut1.C)
{
if (Helper.CheckTime(tgt.IssuingTime, aut1.T, tgt.Duration))
{
ReMessage.Type = MessageType.TgsToC;
var TGS = new TicketGranting()
{
ClientIdentity = aut1.C,
ServiceIdentity = ID,
Duration = Config.TGSTicketDuration.Ticks,
IssuingTime = DateTime.Now,
Key = Encoding.UTF8.GetString(Config.K_C_SS)
};
var ticket_bytes = Helper.ExtendData(Serialiser <TicketGranting> .Serialise(TGS));
var k_c_ss_bytes = Helper.ExtendData(Config.K_C_SS);
var tb_enc = DES.Encrypt(ticket_bytes, Config.K_TGS_SS);
tb_enc = DES.Encrypt(tb_enc, Config.K_C_TGS);
var k_c_ss_enc = DES.Encrypt(k_c_ss_bytes, Config.K_C_TGS);
ReMessage.Data.Add(new List <byte>(tb_enc));
ReMessage.Data.Add(new List <byte>(k_c_ss_enc));
}
else
{
ReMessage.Type = MessageType.TicketNotValid;
Console.WriteLine("TicketNotValid in TGS;");
}
}
else
{
ReMessage.Type = MessageType.AccessDenied;
Console.WriteLine("AccessDenied in TGS;");
}
ReMessage.Send(remoteIP);
Console.WriteLine($"Message sended from TGS to {remoteIP.Address}:{remoteIP.Port}!");
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.WriteLine(ex.StackTrace);
}
}
