the are to bugs int the code.

1º

if you want to compile on 32-bit you have to change in crapto1.h


 asm(    "movl %1, %%eax\n"

to this

__asm__("movl %1, %%eax\n"




2º

when any version if is compiled on 32-bit system, dosen't work 


the last 2 bytes of the keys are always good, but the first 4 bytes are always 
wrong (sometimes random, sometimes the same).

the problem is here i think

#if !defined __i386__ || !defined __GNUC__
        x ^= x >> 16;
        x ^= x >> 8;
        x ^= x >> 4;
        return BIT(0x6996, x & 0xf);

i think this is not correct, i have to look more deep


lot of people have problems with this issue

http://www.libnfc.org/community/topic/98/mifare-classic-key-recovery-tool-dark-s
ide-attack/page/3/