gistfile1.cpp

typedef unsigned long int uint32;

#define FlipBytes32(A) ((((uint32)(A) & 0xff000000) >> 24) | (((uint32)(A) & 0x00ff0000) >> 8)  | (((uint32)(A) & 0x0000ff00) << 8)  | (((uint32)(A) & 0x000000ff) << 24))

static const unsigned char MungeTable2[] = {0x05, 0x61, 0x7A, 0xED, 0x1B, 0xCA, 0x0D, 0x9B, 0x4A, 0xF1, 0x64, 0xC7, 0xB5, 0x8E, 0xDF, 0xA0 };

void Crypt(char *packet, int length, int z, bool unpack)
{
    unsigned int * lbuff = (unsigned int *)packet;
    unsigned int ebpc;
    int i, count = 0;
    int notz = ~z;
    
if(length < 1) { return; }
    
length = length >> 2;

while(length--)
{
    if(unpack)
        ebpc = *lbuff ^ z;
    else
        ebpc = FlipBytes32(*lbuff ^ notz);
    
    for(i=0;i<4;i++)
        *((unsigned char *)(&ebpc) + i) ^= (((MungeTable2[(count + i) & 0x0F] | (i << i)) | i) | 0xA5);
    
    if(unpack)
        *lbuff = FlipBytes32(ebpc) ^ notz;
    else
        *lbuff = ebpc ^ z;
    
    lbuff++;
    count++;
}
}