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 #define llx PRIx64
   5 #include <stdio.h>
   6 typedef unsigned char byte_t;
   7
   8 int main(const int argc, const char* argv[]) {
   9   struct Crypto1State *state;
  10   uint32_t pos, uid, nt, nr, rr, nr_diff, ks1, ks2;
  11   byte_t bt, i, ks3x[8], par[8][8];
  12   uint64_t key, key_recovered;
  13   uint64_t par_info;
  14   uint64_t ks_info;
  15   nr = rr = 0;
  16
  17   if (argc < 5) {
  18     printf("\nsyntax: %s <uid> <nt> <par> <ks>\n\n",argv[0]);
  19     return 1;
  20   }
  21   sscanf(argv[1],"%08x",&uid);
  22   sscanf(argv[2],"%08x",&nt);
  23   sscanf(argv[3],"%016"llx,&par_info);
  24   sscanf(argv[4],"%016"llx,&ks_info);
  25
  26   // Reset the last three significant bits of the reader nonce
  27   nr &= 0xffffff1f;
  28
  29   printf("\nuid(%08x) nt(%08x) par(%016"llx") ks(%016"llx")\n\n",uid,nt,par_info,ks_info);
  30
  31   for (pos=0; pos<8; pos++)
  32   {
  33     ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  34     bt = (par_info >> (pos*8)) & 0xff;
  35     for (i=0; i<8; i++)
  36     {
  37       par[7-pos][i] = (bt >> i) & 0x01;
  38     }
  39   }
  40
  41   printf("|diff|{nr}    |ks3|ks3^5|parity         |\n");
  42   printf("+----+--------+---+-----+---------------+\n");
  43   for (i=0; i<8; i++)
  44   {
  45     nr_diff = nr | i << 5;
  46     printf("| %02x |%08x|",i << 5, nr_diff);
  47     printf(" %01x |  %01x  |",ks3x[i], ks3x[i]^5);
  48     for (pos=0; pos<7; pos++) printf("%01x,",par[i][pos]);
  49     printf("%01x|\n",par[i][7]);
  50   }
  51
  52   state = lfsr_common_prefix(nr,rr,ks3x,par);
  53   lfsr_rollback_word(state,uid^nt,0);
  54   crypto1_get_lfsr(state,&key_recovered);
  55   printf("\nkey recovered: %012"llx"\n\n",key_recovered);
  56   crypto1_destroy(state);
  57
  58   return 0;
  59 }