packet decryption?

K.a. obs noch akutell ist aber:

Packet decryption:

Code:

BYTE *DecryptPacket(BYTE *Packet, DWORD len) {
   BYTE KeyIndex, curKey, lastByte;
   DWORD i;

   KeyIndex = *(CryptInfo + 0x115);

   lastByte = 0;

   for(i = 0; i < len; i++) {      //return the key to the initial state
     KeyIndex--;
       if(KeyIndex == 0xFF)         //-1, bytes are unsigned
        KeyIndex = 39;
   }

   for(i = 0; i < len; i++) {
  curKey   = *(*(BYTE **)(CryptInfo + 0x11C) + KeyIndex);
  tmp = *(Packet + i);
  *(Packet + i) = (*(Packet + i ) - lastByte)) ^ curKey;
  lastByte = tmp;
   }

   return Packet;
}

Crypt Info

Code:

typedef struct WoWKeyIndex {
   BYTE Index;
   BYTE LastByte;
   BYTE CryptLen;     
} WoWKeyIndex;

typedef struct WoWCryptInfo {
   BYTE IsCrypted;               
   WoWKeyIndex SendKey;
   WoWKeyIndex RecvKey;
   BYTE KeyLen;
   char *Key;
} WoWCryptInfo;

typedef struct WoWClientOP {
   WORD Size;
   DWORD Code;
   BYTE Data[MAX_PACKET_LEN];
} WoWClientOP;

typedef struct WoWServerOP {
   WORD Size;
   WORD Code;
   BYTE Data[MAX_PACKET_LEN];
} WoWServerOP;

Ansonsten kannst du dich mit WoW Emulatoren befassen.

Quote:

Originally Posted by AlexM

And yes, you can "sniff" the encryption in the packets. That's basically how emulated servers are able to encrypt/decrypt packets. Someone went through with a disassembler and/or debugger, figured out the encryption in ASM, and finally converted it to C/C++/etc.