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cda056bb 1#define __STDC_FORMAT_MACROS
2#include <inttypes.h>
cda056bb 3#include "crapto1.h"
4#include <stdio.h>
5#include <stdlib.h>
838c15a6 6#include <time.h>
cda056bb 7
838c15a6 8#define llx PRIx64
9#define lli PRIi64
cda056bb 10int main (int argc, char *argv[]) {
838c15a6 11 struct Crypto1State *s,*t;
12 uint64_t key; // recovered key
13 uint32_t uid; // serial number
14 uint32_t nt; // tag challenge
15 uint32_t nr0_enc; // first encrypted reader challenge
16 uint32_t ar0_enc; // first encrypted reader response
17 uint32_t nr1_enc; // second encrypted reader challenge
18 uint32_t ar1_enc; // second encrypted reader response
19 uint32_t ks2; // keystream used to encrypt reader response
cda056bb 20
838c15a6 21 printf("MIFARE Classic key recovery - based 32 bits of keystream\n");
22 printf("Recover key from two 32-bit reader authentication answers only!\n\n");
cda056bb 23
838c15a6 24 if (argc < 7) {
25 printf(" syntax: %s <uid> <nt> <nr_0> <ar_0> <nr_1> <ar_1>\n\n",argv[0]);
26 return 1;
27 }
cda056bb 28
838c15a6 29 sscanf(argv[1],"%x",&uid);
30 sscanf(argv[2],"%x",&nt);
31 sscanf(argv[3],"%x",&nr0_enc);
32 sscanf(argv[4],"%x",&ar0_enc);
33 sscanf(argv[5],"%x",&nr1_enc);
34 sscanf(argv[6],"%x",&ar1_enc);
cda056bb 35
838c15a6 36 printf("Recovering key for:\n");
37 printf(" uid: %08x\n",uid);
38 printf(" nt: %08x\n",nt);
39 printf(" {nr_0}: %08x\n",nr0_enc);
40 printf(" {ar_0}: %08x\n",ar0_enc);
41 printf(" {nr_1}: %08x\n",nr1_enc);
42 printf(" {ar_1}: %08x\n",ar1_enc);
cda056bb 43
44 // Generate lfsr succesors of the tag challenge
838c15a6 45 printf("\nLFSR succesors of the tag challenge:\n");
a1ab594e 46 uint32_t p64 = prng_successor(nt, 64);
47 printf(" nt': %08x\n", p64);
48 printf(" nt'': %08x\n", prng_successor(p64, 32));
cda056bb 49
838c15a6 50 clock_t t1 = clock();
51
52 // Extract the keystream from the messages
53 printf("\nKeystream used to generate {ar} and {at}:\n");
a1ab594e 54 ks2 = ar0_enc ^ p64;
55 printf(" ks2: %08x\n", ks2);
cda056bb 56
a1ab594e 57 s = lfsr_recovery32(ar0_enc ^ p64, 0);
cda056bb 58
59 for(t = s; t->odd | t->even; ++t) {
60 lfsr_rollback_word(t, 0, 0);
61 lfsr_rollback_word(t, nr0_enc, 1);
62 lfsr_rollback_word(t, uid ^ nt, 0);
63 crypto1_get_lfsr(t, &key);
64 crypto1_word(t, uid ^ nt, 0);
65 crypto1_word(t, nr1_enc, 1);
a1ab594e 66 if (ar1_enc == (crypto1_word(t, 0, 0) ^ p64)) {
a198737b 67 printf("\nFound Key: [%012"llx"]\n\n",key);
68 break;}
cda056bb 69 }
838c15a6 70 free(s);
71 t1 = clock() - t1;
72 if ( t1 > 0 ) printf("Time : %.0f ticks \n", (float)t1);
73 return 0;
cda056bb 74}
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