iCTF 2011. Challenge 32 ($ ?)

signed int __cdecl check(int *a1)
{
  signed int result; // eax@2
  int v2; // eax@3
  int v3; // [sp+Ch] [bp-4h]@7
 
  if ( *a1 == 0x65BCFF45 )
  {
    v2 = __ROL__(a1[1], 13);
    if ( v2 == 0x34A7FB12 )
    {
      if ( *a1 + a1[1] == a1[2] )
      {
        v3 = a1[3];
        if ( v3 - 0x75718FF8u <= 0x7C40 &&
           (unsigned __int16)v3 == 0xAB39 )
        {
          if ( (signed int (__cdecl *)(int *))a1[4] == check )
          {
            if ( a1[5] == 0xDEADBABE )
              result = 0;
            else
              result = -1;
          }
          else
          {
            result = -1;
          }
        }
        else
        {
          result = 1;
        }
      }
      else
      {
        result = 1;
      }
    }
    else
    {
      result = 1;
    }
  }
  else
  {
    result = 1;
  }
  return result;
}

#include <stdio.h>
#include <windows.h>
 
unsigned int key[6];
int main(int argc, char* argv[])
{
	key[0] = 0x65BCFF45;
	unsigned int tmp = 0x34A7FB12;
	__asm {
			push eax
			mov eax, tmp
			ror eax, 13
			mov tmp, eax
			pop eax
	}
	key[1] = tmp;
        key[2] = key[1] + key[0];
	tmp = 0x75718FF8;
	key[3] = 0;
	for (int i = 0; i <= 0x7C40 ; i++)
	{
		if (((tmp + i)&0xFFFF) == 0xAB39)
			key[3] = (tmp + i);
	}
        if (key[3] == 0)
	{
		printf ("Error! can't generate key[3]!\n");
		return -1;
	}
	key[4] = 0x080484E4;
	key[5] = 0xDEADBABE;
	printf("Secret code: ");
	for (int i = 0; i < 0x18; i++)
		printf("%02x", (*((char*)key+i))&0xFF);
 
}