]> git.zerfleddert.de Git - proxmark3-svn/blame - tools/mfkey/mfkey32.c
chg: @piwi's code cleanup and some more.
[proxmark3-svn] / tools / mfkey / mfkey32.c
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cda056bb 1#define __STDC_FORMAT_MACROS
2#include <inttypes.h>
cda056bb 3#include "crapto1.h"
4#include <stdio.h>
5#include <stdlib.h>
838c15a6 6#include <time.h>
cda056bb 7
8int main (int argc, char *argv[]) {
838c15a6 9 struct Crypto1State *s,*t;
10 uint64_t key; // recovered key
11 uint32_t uid; // serial number
12 uint32_t nt; // tag challenge
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
cda056bb 18
838c15a6 19 printf("MIFARE Classic key recovery - based 32 bits of keystream\n");
20 printf("Recover key from two 32-bit reader authentication answers only!\n\n");
cda056bb 21
838c15a6 22 if (argc < 7) {
23 printf(" syntax: %s <uid> <nt> <nr_0> <ar_0> <nr_1> <ar_1>\n\n",argv[0]);
24 return 1;
25 }
cda056bb 26
838c15a6 27 sscanf(argv[1],"%x",&uid);
28 sscanf(argv[2],"%x",&nt);
29 sscanf(argv[3],"%x",&nr0_enc);
30 sscanf(argv[4],"%x",&ar0_enc);
31 sscanf(argv[5],"%x",&nr1_enc);
32 sscanf(argv[6],"%x",&ar1_enc);
cda056bb 33
838c15a6 34 printf("Recovering key for:\n");
35 printf(" uid: %08x\n",uid);
36 printf(" nt: %08x\n",nt);
37 printf(" {nr_0}: %08x\n",nr0_enc);
38 printf(" {ar_0}: %08x\n",ar0_enc);
39 printf(" {nr_1}: %08x\n",nr1_enc);
40 printf(" {ar_1}: %08x\n",ar1_enc);
cda056bb 41
42 // Generate lfsr succesors of the tag challenge
838c15a6 43 printf("\nLFSR succesors of the tag challenge:\n");
a1ab594e 44 uint32_t p64 = prng_successor(nt, 64);
45 printf(" nt': %08x\n", p64);
46 printf(" nt'': %08x\n", prng_successor(p64, 32));
cda056bb 47
838c15a6 48 clock_t t1 = clock();
49
50 // Extract the keystream from the messages
51 printf("\nKeystream used to generate {ar} and {at}:\n");
a1ab594e 52 ks2 = ar0_enc ^ p64;
53 printf(" ks2: %08x\n", ks2);
cda056bb 54
a1ab594e 55 s = lfsr_recovery32(ar0_enc ^ p64, 0);
cda056bb 56
57 for(t = s; t->odd | t->even; ++t) {
58 lfsr_rollback_word(t, 0, 0);
59 lfsr_rollback_word(t, nr0_enc, 1);
60 lfsr_rollback_word(t, uid ^ nt, 0);
61 crypto1_get_lfsr(t, &key);
62 crypto1_word(t, uid ^ nt, 0);
63 crypto1_word(t, nr1_enc, 1);
a1ab594e 64 if (ar1_enc == (crypto1_word(t, 0, 0) ^ p64)) {
9c624f67 65 printf("\nFound Key: [%012" PRIx64 "]\n\n",key);
a198737b 66 break;}
cda056bb 67 }
838c15a6 68 free(s);
69 t1 = clock() - t1;
70 if ( t1 > 0 ) printf("Time : %.0f ticks \n", (float)t1);
71 return 0;
cda056bb 72}
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