@
navossoc: SimpleModulus is not used by the ChatServer at all - everything uses C1 or C2-packets.
A little update:
After I found everything out about the communication between game client and chat server, I examined what happens in its log when I send stuff the original chat server due port 55906 and 55907. The chat server opens this ports and waits for connections.
Port 55907 just seems to be some port to check if you can connect to the chat server. It processes no packet and sends nothing back, just prints some messages about "port check" to the log.
Port 55906 is responsible to receive chat room creations from ExDB-Server, and returns ticket and room ids back. I iterated every C1 packet type from 00 to FF and found reactions in the logs with A0 and A1 packet types.
A0 is used to create a chat room and registering the clients.
Example for A0:
I sent C1 16 A0 41 42 43 44 45 46 47 48 49 4A 50 51 52 53 54 55 56 57 58 59
It contains the first and second client name after A0 (each 10 bytes).
The chat server then returns two packets, one for each client with its index and ticket
Code:
s |rid| |-----client name-----------| |---------other client name-| |------???------| |-ticket--| |--------???----------|
C1 2C A0 01 00 00 41 42 43 44 45 46 47 48 49 4A 50 51 52 53 54 55 56 57 58 59 00 00 00 00 CC CC 00 00 11 04 CC CC CC CC 00 CC CC CC
C1 2C A0 01 00 00 50 51 52 53 54 55 56 57 58 59 41 42 43 44 45 46 47 48 49 4A 00 00 00 00 CC CC 01 00 BB 05 CC CC CC CC 01 CC CC CC
In the log you see two tickets; 6822976 for ABC... and 96141313 for PQR...
For example, to get the ticket of the second packet: 01 00 BB 05 -> 0x05BB0001 ---[hex to decimal]--> 96141313
What seems crazy is, that the ticket contains the index as well, and in the 4th last byte the index is there as well. But as you will see later, the 4th last byte is not useful.
So, the chat server creates just 2 random bytes for the tickets - not very secure ;)
Then there is only one packet type left: A1. It's used to register additional clients to an existing chat room. Not many people know that you can invite additional players to a chat room ;)
Example: C1 10 A1 00 00 00 61 62 63 64 65 66 67 68 69 6F
Index 4 and 5 is the room id, the rest behind is the client name.
The chat server answers this with the same packets as above (ticket 96862210):
C1 2C A0 01 00 00 61 62 63 64 65 66 67 68 69 6F CC CC CC CC CC CC CC CC CC CC 53 54 55 56 CC CC
02 00 C6 05 CC CC CC CC 57 CC CC CC
The main part of my chat server which speaks with the game clients is already fully working, and the part about registering clients is working internally within my other game server architecture.
As a spin-off project I could implement the listener which is responsible for the communication with the ExDB-Server, so it would be a full chat server which could replace the original one of Webzen.
I guess I will release a first version soon :)
