proxmark3/tools/mfkey/mfkey32.c

71 lines
2.3 KiB
C
Raw Normal View History

2013-03-07 20:23:31 +08:00
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <stdbool.h>
2013-03-07 20:23:31 +08:00
#include <stdio.h>
#include <stdlib.h>
#include "crapto1/crapto1.h"
2019-03-28 21:19:41 +08:00
#include "util_posix.h"
2013-03-07 20:23:31 +08:00
int main(int argc, char *argv[]) {
2019-03-10 07:00:59 +08:00
struct Crypto1State *s, *t;
2019-03-09 17:46:59 +08:00
uint64_t key; // recovered key
uint32_t uid; // serial number
uint32_t nt; // tag challenge
uint32_t nr0_enc; // first encrypted reader challenge
uint32_t ar0_enc; // first encrypted reader response
uint32_t nr1_enc; // second encrypted reader challenge
uint32_t ar1_enc; // second encrypted reader response
uint32_t ks2; // keystream used to encrypt reader response
2013-03-07 20:23:31 +08:00
printf("MIFARE Classic key recovery - based on 32 bits of keystream\n");
2019-03-09 17:46:59 +08:00
printf("Recover key from two 32-bit reader authentication answers only!\n\n");
2013-03-07 20:23:31 +08:00
2019-03-09 17:46:59 +08:00
if (argc < 7) {
2019-03-10 07:00:59 +08:00
printf(" syntax: %s <uid> <nt> <nr_0> <ar_0> <nr_1> <ar_1>\n\n", argv[0]);
2019-03-09 17:46:59 +08:00
return 1;
}
2013-03-07 20:23:31 +08:00
2019-03-10 07:00:59 +08:00
sscanf(argv[1], "%x", &uid);
sscanf(argv[2], "%x", &nt);
sscanf(argv[3], "%x", &nr0_enc);
sscanf(argv[4], "%x", &ar0_enc);
sscanf(argv[5], "%x", &nr1_enc);
sscanf(argv[6], "%x", &ar1_enc);
2013-03-07 20:23:31 +08:00
2019-03-09 17:46:59 +08:00
printf("Recovering key for:\n");
2019-03-10 07:00:59 +08:00
printf(" uid: %08x\n", uid);
printf(" nt: %08x\n", nt);
printf(" {nr_0}: %08x\n", nr0_enc);
printf(" {ar_0}: %08x\n", ar0_enc);
printf(" {nr_1}: %08x\n", nr1_enc);
printf(" {ar_1}: %08x\n", ar1_enc);
2013-03-07 20:23:31 +08:00
2021-10-10 07:35:38 +08:00
// Generate lfsr successors of the tag challenge
printf("\nLFSR successors of the tag challenge:\n");
2019-03-09 17:46:59 +08:00
uint32_t p64 = prng_successor(nt, 64);
printf(" nt': %08x\n", p64);
printf(" nt'': %08x\n", prng_successor(p64, 32));
2019-03-09 17:46:59 +08:00
// Extract the keystream from the messages
printf("\nKeystream used to generate {ar} and {at}:\n");
ks2 = ar0_enc ^ p64;
printf(" ks2: %08x\n", ks2);
2013-03-07 20:23:31 +08:00
2019-03-09 17:46:59 +08:00
s = lfsr_recovery32(ar0_enc ^ p64, 0);
2019-03-10 07:00:59 +08:00
for (t = s; t->odd | t->even; ++t) {
2019-03-09 17:46:59 +08:00
lfsr_rollback_word(t, 0, 0);
lfsr_rollback_word(t, nr0_enc, 1);
lfsr_rollback_word(t, uid ^ nt, 0);
crypto1_get_lfsr(t, &key);
crypto1_word(t, uid ^ nt, 0);
crypto1_word(t, nr1_enc, 1);
if (ar1_enc == (crypto1_word(t, 0, 0) ^ p64)) {
2019-03-10 07:00:59 +08:00
printf("\nFound Key: [%012" PRIx64 "]\n\n", key);
break;
}
2019-03-09 17:46:59 +08:00
}
free(s);
return 0;
2013-03-07 20:23:31 +08:00
}