git.zerfleddert.de Git - proxmark3-svn/blob - tools/mfkey/mfkey32v2.c

   1 #define __STDC_FORMAT_MACROS
   2 #include <inttypes.h>
   3 #include "crapto1.h"
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6
   7 int main (int argc, char *argv[]) {
   8         struct Crypto1State *s,*t;
   9         uint64_t key;     // recovered key
  10         uint32_t uid;     // serial number
  11         uint32_t nt0;      // tag challenge first
  12         uint32_t nt1;      // tag challenge second
  13         uint32_t nr0_enc; // first encrypted reader challenge
  14         uint32_t ar0_enc; // first encrypted reader response
  15         uint32_t nr1_enc; // second encrypted reader challenge
  16         uint32_t ar1_enc; // second encrypted reader response
  17         uint32_t ks2;     // keystream used to encrypt reader response
  18
  19         printf("MIFARE Classic key recovery - based 32 bits of keystream  VERSION2\n");
  20         printf("Recover key from two 32-bit reader authentication answers only\n");
  21         printf("This version implements Moebius two different nonce solution (like the supercard)\n\n");
  22
  23         if (argc < 8) {
  24                 printf("syntax: %s <uid> <nt> <nr_0> <ar_0> <nt1> <nr_1> <ar_1>\n\n", argv[0]);
  25                 return 1;
  26         }
  27
  28         sscanf(argv[1],"%x",&uid);
  29         sscanf(argv[2],"%x",&nt0);
  30         sscanf(argv[3],"%x",&nr0_enc);
  31         sscanf(argv[4],"%x",&ar0_enc);
  32         sscanf(argv[5],"%x",&nt1);
  33         sscanf(argv[6],"%x",&nr1_enc);
  34         sscanf(argv[7],"%x",&ar1_enc);
  35
  36         printf("Recovering key for:\n");
  37         printf("    uid: %08x\n",uid);
  38         printf("   nt_0: %08x\n",nt0);
  39         printf(" {nr_0}: %08x\n",nr0_enc);
  40         printf(" {ar_0}: %08x\n",ar0_enc);
  41         printf("   nt_1: %08x\n",nt1);
  42         printf(" {nr_1}: %08x\n",nr1_enc);
  43         printf(" {ar_1}: %08x\n",ar1_enc);
  44
  45         // Generate lfsr succesors of the tag challenge
  46         printf("\nLFSR succesors of the tag challenge:\n");
  47         uint32_t p64 = prng_successor(nt0, 64);
  48         uint32_t p64b = prng_successor(nt1, 64);
  49
  50         printf("  nt': %08x\n", p64);
  51         printf(" nt'': %08x\n", prng_successor(p64, 32));
  52
  53         // Extract the keystream from the messages
  54         printf("\nKeystream used to generate {ar} and {at}:\n");
  55         ks2 = ar0_enc ^ p64;
  56         printf("  ks2: %08x\n",ks2);
  57
  58         s = lfsr_recovery32(ar0_enc ^ p64, 0);
  59
  60         for(t = s; t->odd | t->even; ++t) {
  61                 lfsr_rollback_word(t, 0, 0);
  62                 lfsr_rollback_word(t, nr0_enc, 1);
  63                 lfsr_rollback_word(t, uid ^ nt0, 0);
  64                 crypto1_get_lfsr(t, &key);
  65
  66                 crypto1_word(t, uid ^ nt1, 0);
  67                 crypto1_word(t, nr1_enc, 1);
  68                 if (ar1_enc == (crypto1_word(t, 0, 0) ^ p64b)) {
  69                         printf("\nFound Key: [%012" PRIx64 "]\n\n",key);
  70                         break;}
  71         }
  72         free(s);
  73         return 0;
  74 }