git.zerfleddert.de Git - proxmark3-svn/blob - tools/nonce2key/nonce2key.c

   1 #include "crapto1.h"
   2 #define __STDC_FORMAT_MACROS
   3 #include <inttypes.h>
   4 #include <stdio.h>
   5
   6 int main(const int argc, const char* argv[]) {
   7         struct Crypto1State *state;
   8         uint32_t pos, uid, nt, nr, rr, nr_diff;
   9         uint8_t bt, i, ks3x[8], par[8][8];
  10         uint64_t key_recovered;
  11         uint64_t par_info;
  12         uint64_t ks_info;
  13         nr = rr = 0;
  14
  15         if (argc < 5) {
  16                 printf("\nsyntax: %s <uid> <nt> <par> <ks>\n\n",argv[0]);
  17                 return 1;
  18         }
  19         sscanf(argv[1],"%08x", &uid);
  20         sscanf(argv[2],"%08x", &nt);
  21         sscanf(argv[3],"%016" SCNx64 ,&par_info);
  22         sscanf(argv[4],"%016" SCNx64 ,&ks_info);
  23
  24         // Reset the last three significant bits of the reader nonce
  25         nr &= 0xffffff1f;
  26
  27         printf("\nuid(%08x) nt(%08x) par(%016" PRIx64 ") ks(%016" PRIx64 ")\n\n", uid, nt, par_info, ks_info);
  28
  29         for ( pos = 0; pos < 8; pos++ ) {
  30                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  31                 bt = (par_info >> (pos*8)) & 0xff;
  32
  33                 for ( i = 0; i < 8; i++) {
  34                         par[7-pos][i] = (bt >> i) & 0x01;
  35                 }
  36         }
  37
  38         printf("|diff|{nr}    |ks3|ks3^5|parity         |\n");
  39         printf("+----+--------+---+-----+---------------+\n");
  40
  41         for ( i = 0; i < 8; i++) {
  42                 nr_diff = nr | i << 5;
  43                 printf("| %02x |%08x| %01x |  %01x  |", i << 5, nr_diff, ks3x[i], ks3x[i]^5);
  44
  45                 for ( pos = 0; pos < 7; pos++)
  46                         printf("%01x,", par[i][pos]);
  47                 printf("%01x|\n", par[i][7]);
  48         }
  49         printf("+----+--------+---+-----+---------------+\n");
  50
  51         state = lfsr_common_prefix(nr,rr,ks3x,par);
  52         lfsr_rollback_word(state,uid^nt,0);
  53         crypto1_get_lfsr(state,&key_recovered);
  54         printf("\nkey recovered: %012" PRIx64 "\n\n", key_recovered);
  55         crypto1_destroy(state);
  56         return 0;
  57 }