key++ problem generating keys ..!

[newcslover]

hi,

i wish to generate all possible key combinations ranging:

HEX: "0F FF FF FF FF FF FF FF" TO HEX: FF FF FF FF FF FF FF FF

i also test each key after incrementing by 1, for test i want the key to be a an unsigned char[8]

key start rang and end range can be initialize/declare in any format.

Problem is if :

unsigned char key[] = {0x0F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};

then i can not increment this key by +1 , though if i initialize this key in decimal as:

unsigned long long key = 1152921504606846975;

then i can increment the key in for loop by key++ but then i cant convert it back into unsigned char array :(

i want to achieve something like this soory i am c noob :(

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
 
unsigned char key[] = {0x0F,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
 
 
int main()
{
    int idx;
 
    for(idx=0;;idx++)
    {
 
    //key[]++; here i want to add +1 in key for increamenting
 
 
printf ("Current key: %02X %02X %02X %02X %02X %02X %02X %02X \n",key[0],key[1],key[2],key[3],key[4],key[5],key[6],key[7]); // this way i want to print the final incremented key
    }
 
}
 
 

In my programer i also have function that test each key but key has to be unsigned char so i am kinda stuck :(


Thanks all

[donbock]

Start with the lowest order byte (key[7]), if current value is not 0xFF then increment it, otherwise set the value to 0 and increment the next higher byte using this same algorithm. Make sure you handle the highest order byte (key[0]) properly.

[weaknessforcats]

Usually, when working with keys you use a tree structure rather than an array. The tree holds the keys actually used rather then reserving a place for all possible keys.

That said, use a small key, like 256 in an int. Get the code working with values 1-255. Reserve 0 as a null key in case you need it.

Later you can expand the code for larger ranges of keys and when you do, you will be starting with code that works.

[newcslover]

hi thanks for reply i think i sorted it out by incrementing byte in for loop ... i wanted to make a brute force app but now i calc , PC can generate and test 256keys/seconds :( if i increase number of threads to 16 then its 4096keys/second but still not enough to process all keys 18374686479671623679 :( i guess it will take months ... have to find some efficient way.