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chrrox, posted Wed Apr 28, 2021 2:51 pm (63619)

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for some reason when I try to put the dividing number in the dll code it crashes on me.
This is working code but I was wondering how I could do the / 4 inside the dll.
also is there a way to combine these lines?

Quote:

buffer[i] ^= secretKey;
buffer[i] -= seed;

Code:

set MEMORY_FILE10 string "
typedef unsigned char   u8;
typedef unsigned int    u32;
 
static u32 secretKey = 0x45AF6E5D;
 
void Decrypt(u8* data, int data_size, int seed, int xored_size)
{
   u32* buffer = (u32*)(data);
   int remained = data_size % 4;
   u8* remained_data = (u8*)(buffer);
 
 
   if (xored_size > 0)
   {
      for (int i = 0; i < xored_size; i  )
      {
         buffer[i] ^= secretKey;
         buffer[i] -= seed;
      }
   }
}
"
 
idstring "\x43\x4F\x44\x45\x00\x01\x55\x77"
get CRC32 long
get SEED long
get SIZE asize
math SIZE - 16
set LOOP SIZE
math LOOP / 4
 
get NAME basename
string NAME   .png
log MEMORY_FILE 16 SIZE
calldll MEMORY_FILE10 "Decrypt" "tcc" RET MEMORY_FILE TABLE_SIZE SEED LOOP
log NAME 0 SIZE MEMORY_FILE

aluigi, posted Wed Apr 28, 2021 5:00 pm (63620)

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Do you mean quickbms.dll crashes when running that script?
Honestly I only compiled it so I can't offer much support about it but it's really weird if a crash happens on a simple instruction.

Luckily you can replace divisions with other solutions, for example "/ 4" -> ">> 2".

For the other question:
buffer[i] = (buffer[i] ^ secretKey) - seed;

chrrox, posted Wed Apr 28, 2021 5:23 pm (63622)

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that worked great thanks.