Как расшифровать libGRF архив?

#include <vcl.h>
#include <windows.h>
 
#define DLL extern "C" __declspec(dllexport)
 
typedef long (__cdecl * compressFunction)(unsigned char *, int *, unsigned char *, int);
typedef long (__cdecl * uncompressFunction)(unsigned char *, int *, unsigned char *, int);
 
compressFunction Compress;
uncompressFunction Uncompress;
 
BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, PVOID lpvReserved)
{
  if (fwdreason == DLL_PROCESS_ATTACH) {
    HINSTANCE hDLL = LoadLibrary(L"cps.dll");
 
    if (hDLL == NULL) {
        ::MessageBox(0, L"Unable to load DLL.L", L"DLL not foundL", MB_OK);
        return FALSE;
    }
 
    Compress = (compressFunction) GetProcAddress(hDLL, "compress");
    Uncompress = (uncompressFunction) GetProcAddress(hDLL, "uncompress");
 
    if (Compress == NULL || Uncompress == NULL) {
        ::MessageBox(0, L"Compression or uncompression method couldn't be found in the DLL.L", L"Function not foundL", MB_OK);
        return FALSE;
    }
 
    return TRUE;
  }
  return FALSE;
}
 
DLL long compress(unsigned char * comp, int * compLength, unsigned char * uncomp, int uncompLength) {
  // This method is never used, leave it like that
  return Compress(comp, compLength, uncomp, uncompLength);
}
 
DLL long uncompress(unsigned char * uncomp, int * uncompLength, unsigned char * comp, int compLength) {
  return Uncompress(uncomp, uncompLength, comp, compLength);
}