16 bit checksums

**Doodman** · #21 08-06-2004, 04:29 PM

Plus, beyond the leading op_code (OP_SessionRequest is 0x01 and Op_SessionResponse is 0x02) here is the structure of the SessionRequest and SessionResponse packets:

Code:

struct SessionRequest {
        unsigned long UnknownA;
        unsigned long Session;
        unsigned short UnknownB;
        unsigned short MaxLength;
};              
                
struct SessionResponse {
        unsigned long Session;
        unsigned long Key;
        unsigned short UnknownA;
        unsigned char UnknownB;
        unsigned char UnknownC;
        unsigned short MaxLength;
        unsigned long UnknownD;
};

In the login server Key is ignored and unused. In the chatchannels it is used to "scramble" the packets being sent.