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

   1 #include "crapto1/crapto1.h"
   2 #include <inttypes.h>
   3 #include <stdio.h>
   4 typedef unsigned char byte_t;
   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   byte_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   {
  31     ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  32     bt = (par_info >> (pos*8)) & 0xff;
  33     for (i=0; i<8; i++)
  34     {
  35       par[7-pos][i] = (bt >> i) & 0x01;
  36     }
  37   }
  38
  39   printf("|diff|{nr}    |ks3|ks3^5|parity         |\n");
  40   printf("+----+--------+---+-----+---------------+\n");
  41   for (i=0; i<8; i++)
  42   {
  43     nr_diff = nr | i << 5;
  44     printf("| %02x |%08x|",i << 5, nr_diff);
  45     printf(" %01x |  %01x  |",ks3x[i], ks3x[i]^5);
  46     for (pos=0; pos<7; pos++) printf("%01x,",par[i][pos]);
  47     printf("%01x|\n",par[i][7]);
  48   }
  49
  50   state = lfsr_common_prefix(nr,rr,ks3x,par);
  51   lfsr_rollback_word(state,uid^nt,0);
  52   crypto1_get_lfsr(state,&key_recovered);
  53   printf("\nkey recovered: %012" PRIx64 "\n\n",key_recovered);
  54   crypto1_destroy(state);
  55
  56   return 0;
  57 }