Packet Decryption. [old chinese client]

[albator]

Hi, i have work a little bit on this old client and i saw that packet were encrypt.

After some time i've find the way to decrypt them maybe you will find it interesting. ( but useless >< )

It's an easy encryption with each packet client and server send a key coded on a byte then after some modification you get a final key and client/server convert it using a encryption/desemcyption table.

Login packet struct :

<2F00> <F6> <2AED2C000001> <C1D66E6EF16A6A6A6A6A6A6A6A6A6A6A6A6A6A> <F1F1F1F1F1F16A6A6A6A6A6A6A6A6A6A6A6A6A>

<Packet ID> < First Key> <maybe crc > < login > < pass >

In this exemple i send to server login : gm001 pass : 11111

Next step, get the final key
you have to do two little operation on the key first do a logical and between First key and the hexadecimal value 0F next you shift bits two time to the left. (xD poor englis sorry)

example (first key <F6> )

asm :
mov var,F6h
and var,0Fh
; not sure of my asm code

C :
var = 0xF6;
var &= 0x0F;
var <<= 8;

Finaly add key value with each byte value of the packet to find the rank corresponding to your decrypted character.

DECRYPTED_CHAR = DECRYPT_TABLE [ FINAL_KEY + CRYPTED_CHAR_VALUE ]

In the attachment you will find an example programming in C language including the decrypt table from FirstLoginServer.

Certainly useless ... but i'm now working on the last Chinese client.

 

[Darkco]

Nice job I think c++ people can do something with this like to make the english client work with our server or edit that the server can read the english translation files

But you say Old Chinese client I know only 1 chinese client of trickster that work with our server so why you working on a other one

 

[Aweb]

The one that works with the server is old.
The English client is protected by an ActiveX.

Thanks, albator

 

[albator]

The latest english client use a new loggin method and a ActiveX system to launch the client only from the website ( i have test some things on it and i think we can emulate this but i dont like this loggin method)

I'm dreaming about latest chinese client can read english data client that's why i m working on this chinese client an maybe try to do an emu.

 

[Tsukekun]

The latest english client use a new loggin method and a ActiveX system to launch the client only from the website ( i have test some things on it and i think we can emulate this but i dont like this loggin method)

I'm dreaming about latest chinese client can read english data client that's why i m working on this chinese client an maybe try to do an emu.

Nice!

This is actually good, have you tried to decompile the new client and modify it to connect to your server?

If not i'm in the proccess of seeing how it turns out..

 

[albator]

Latest client use new encryption method, i have a software running to desassemble it and analyse a part, i have all function prototype because chinese dev keep there debug file in the package

 

[Tsukekun]

Latest client use new encryption method, i have a software running to desassemble it and analyse a part, i have all function prototype because chinese dev keep there debug file in the package

LOL, I can't think of why they would do that....

 

[mingcesh]

something might help you..

albator, someone has made a English TO logging script tat doesnt require user to logging from the web by just simply replace the id(email) and pass in the .bat file and execute it..
but we need to do something on the web logging script.
hope this can help you..