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

   1 #define __STDC_FORMAT_MACROS
   2 #include <inttypes.h>
   3 #define llx PRIx64
   4 #define lli PRIi64
   5
   6 // Test-file: test2.c
   7 #include "crapto1.h"
   8 #include <stdio.h>
   9 #include <string.h>
  10
  11 int main (int argc, char *argv[]) {
  12   struct Crypto1State *revstate;
  13   uint64_t key;     // recovered key
  14   uint32_t uid;     // serial number
  15   uint32_t nt;      // tag challenge
  16   uint32_t nr_enc;  // encrypted reader challenge
  17   uint32_t ar_enc;  // encrypted reader response
  18   uint32_t at_enc;  // encrypted tag response
  19   uint32_t ks2;     // keystream used to encrypt reader response
  20   uint32_t ks3;     // keystream used to encrypt tag response
  21
  22   printf("MIFARE Classic key recovery - based 64 bits of keystream\n");
  23   printf("Recover key from only one complete authentication!\n\n");
  24
  25   if (argc < 6 ) {
  26     printf(" syntax: %s <uid> <nt> <{nr}> <{ar}> <{at}> [enc] [enc...]\n\n", argv[0]);
  27     return 1;
  28   }
  29
  30   int encc = argc - 6;
  31   int enclen[encc];
  32   uint8_t enc[encc][120];
  33
  34   sscanf(argv[1], "%x", &uid);
  35   sscanf(argv[2], "%x", &nt);
  36   sscanf(argv[3], "%x", &nr_enc);
  37   sscanf(argv[4], "%x", &ar_enc);
  38   sscanf(argv[5], "%x", &at_enc);
  39   for (int i = 0; i < encc; i++) {
  40     enclen[i] = strlen(argv[i + 6]) / 2;
  41     for (int i2 = 0; i2 < enclen[i]; i2++) {
  42       sscanf(argv[i+6] + i2*2,"%2x", (uint8_t*)&enc[i][i2]);
  43     }
  44   }
  45   printf("Recovering key for:\n");
  46
  47   printf("  uid: %08x\n", uid);
  48   printf("   nt: %08x\n", nt);
  49   printf(" {nr}: %08x\n", nr_enc);
  50   printf(" {ar}: %08x\n", ar_enc);
  51   printf(" {at}: %08x\n", at_enc);
  52   for (int i = 0; i < encc; i++) {
  53       printf("{enc%d}: ", i);
  54       for (int i2 = 0; i2 < enclen[i]; i2++) {
  55           printf("%02x", enc[i][i2]);
  56       }
  57       printf("\n");
  58   }
  59
  60
  61   /*
  62   uint32_t uid                = 0x9c599b32;
  63   uint32_t tag_challenge      = 0x82a4166c;
  64   uint32_t nr_enc             = 0xa1e458ce;
  65   uint32_t reader_response    = 0x6eea41e0;
  66   uint32_t tag_response       = 0x5cadf439;
  67 */
  68   // Generate lfsr succesors of the tag challenge
  69   printf("\nLFSR succesors of the tag challenge:\n");
  70   printf("  nt': %08x\n",prng_successor(nt, 64));
  71   printf(" nt'': %08x\n",prng_successor(nt, 96));
  72
  73   // Extract the keystream from the messages
  74   printf("\nKeystream used to generate {ar} and {at}:\n");
  75   ks2 = ar_enc ^ prng_successor(nt, 64);
  76   ks3 = at_enc ^ prng_successor(nt, 96);
  77   printf("  ks2: %08x\n",ks2);
  78   printf("  ks3: %08x\n",ks3);
  79
  80   revstate = lfsr_recovery64(ks2, ks3);
  81
  82   // Decrypting communication using keystream if presented
  83   if (argc > 6 ) {
  84   printf("\nDecrypted communication:\n");
  85   uint8_t ks4;
  86   int rollb = 0;
  87   for (int i = 0; i < encc; i++) {
  88     printf("{dec%d}: ", i);
  89     for (int i2 = 0; i2 < enclen[i]; i2++) {
  90       ks4 = crypto1_byte(revstate, 0, 0);
  91       printf("%02x", ks4 ^ enc[i][i2]);
  92       rollb += 1;
  93     }
  94     printf("\n");
  95   }
  96   for (int i = 0; i < rollb; i++) {
  97     lfsr_rollback_byte(revstate, 0, 0);
  98     }
  99   }
 100
 101   lfsr_rollback_word(revstate, 0, 0);
 102   lfsr_rollback_word(revstate, 0, 0);
 103   lfsr_rollback_word(revstate, nr_enc, 1);
 104   lfsr_rollback_word(revstate, uid ^ nt, 0);
 105   crypto1_get_lfsr(revstate, &key);
 106   printf("\nFound Key: [%012"llx"]\n\n",key);
 107   crypto1_destroy(revstate);
 108
 109   return 0;
 110 }