proxmark3/tools/nonce2key/nonce2key.c
2019-03-10 11:20:22 +01:00

57 lines
1.7 KiB
C

#include "crapto1.h"
#define __STDC_FORMAT_MACROS
#include <inttypes.h>
#include <stdio.h>
int main(const int argc, const char *argv[]) {
struct Crypto1State *state;
uint32_t pos, uid, nt, nr, rr, nr_diff;
uint8_t bt, i, ks3x[8], par[8][8];
uint64_t key_recovered;
uint64_t par_info;
uint64_t ks_info;
nr = rr = 0;
if (argc < 5) {
printf("\nsyntax: %s <uid> <nt> <par> <ks>\n\n", argv[0]);
return 1;
}
sscanf(argv[1], "%08x", &uid);
sscanf(argv[2], "%08x", &nt);
sscanf(argv[3], "%016" SCNx64, &par_info);
sscanf(argv[4], "%016" SCNx64, &ks_info);
// Reset the last three significant bits of the reader nonce
nr &= 0xffffff1f;
printf("\nuid(%08x) nt(%08x) par(%016" PRIx64 ") ks(%016" PRIx64 ")\n\n", uid, nt, par_info, ks_info);
for (pos = 0; pos < 8; pos++) {
ks3x[7 - pos] = (ks_info >> (pos * 8)) & 0x0f;
bt = (par_info >> (pos * 8)) & 0xff;
for (i = 0; i < 8; i++) {
par[7 - pos][i] = (bt >> i) & 0x01;
}
}
printf("|diff|{nr} |ks3|ks3^5|parity |\n");
printf("+----+--------+---+-----+---------------+\n");
for (i = 0; i < 8; i++) {
nr_diff = nr | i << 5;
printf("| %02x |%08x| %01x | %01x |", i << 5, nr_diff, ks3x[i], ks3x[i] ^ 5);
for (pos = 0; pos < 7; pos++)
printf("%01x,", par[i][pos]);
printf("%01x|\n", par[i][7]);
}
printf("+----+--------+---+-----+---------------+\n");
state = lfsr_common_prefix(nr, rr, ks3x, par);
lfsr_rollback_word(state, uid ^ nt, 0);
crypto1_get_lfsr(state, &key_recovered);
printf("\nkey recovered: %012" PRIx64 "\n\n", key_recovered);
crypto1_destroy(state);
return 0;
}