proxmark3/tools/nonce2key/nonce2key.c
2009-12-30 00:12:17 +00:00

57 lines
1.5 KiB
C

#include "crapto1.h"
#include <inttypes.h>
#include <stdio.h>
typedef unsigned char byte_t;
int main(const int argc, const char* argv[]) {
struct Crypto1State *state;
uint32_t pos, uid, nt, nr, rr, nr_diff, ks1, ks2;
byte_t bt, i, ks3x[8], par[8][8];
uint64_t key, 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],"%016llx",&par_info);
sscanf(argv[4],"%016llx",&ks_info);
// Reset the last three significant bits of the reader nonce
nr &= 0xffffff1f;
printf("\nuid(%08x) nt(%08x) par(%016llx) ks(%016llx)\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|",i << 5, nr_diff);
printf(" %01x | %01x |",ks3x[i], ks3x[i]^5);
for (pos=0; pos<7; pos++) printf("%01x,",par[i][pos]);
printf("%01x|\n",par[i][7]);
}
state = lfsr_common_prefix(nr,rr,ks3x,par);
lfsr_rollback_word(state,uid^nt,0);
crypto1_get_lfsr(state,&key_recovered);
printf("\nkey recovered: %012llx\n\n",key_recovered);
crypto1_destroy(state);
return 0;
}