// Read an authentication message and return a valid ClientCon if successful.
private ClientCon Authenticate(TcpClient tcpClient, BinaryWriter writer, BinaryReader reader)
{
var pubkey = reader.ReadString();
var authToken = reader.ReadLenBytes();
var signature = reader.ReadLenBytes();
try
{
// verify signature
if (!EncryptionService.VerifySigned(authToken, signature, pubkey))
{
return new ClientCon();
}
// extract nick from token
var authReader = new BinaryReader(new MemoryStream(authToken));
var nick = authReader.ReadString();
lock (clients)
{
// check to see if logging in same as someone else
foreach (var other in clients)
{
if (other.Pubkey == pubkey && other.Name != nick)
{
Console.WriteLine(nick + " (" + tcpClient.Client.RemoteEndPoint +
"): Cannot log in with the same publickey as " + other.Name);
return new ClientCon();
}
}
}
switch (CheckDatabase(nick, pubkey))
{
case 0:
return new ClientCon(tcpClient, writer, nick, pubkey);
case 1:
return new ClientCon(tcpClient, writer, nick, pubkey);
case 2:
// user connecting with public key that does not match the username
return new ClientCon();
default:
// something else happened
return new ClientCon();
}
}
catch (Exception e)
{
Console.WriteLine(e);
return new ClientCon();
}
}
// Process (send to dest) a message from a client
private void ProcessMsg(BinaryReader reader, ClientCon me)
{
var sendToKey = reader.ReadString();
var message = reader.ReadLenBytes();
lock (clients)
{
var found = false;
foreach (var other in clients)
{
if (other.Pubkey == sendToKey)
{
found = true;
other.Writer.Write("msgrecv");
other.Writer.Write(me.Name);
other.Writer.WriteLenBytes(message);
}
}
if (!found)
{
me.Writer.Write("usernotfound");
me.Writer.Write(sendToKey);
}
}
}
// Process the `recv` message - name, encrypted message pair
private void ProcessMsgRecv(BinaryReader reader)
{
var name = reader.ReadString();
var message = reader.ReadLenBytes();
var decrypt = encryption.Decrypt(message);
AddIncomingMessage(name, decrypt);
}
