+ clock_t t1 = clock();
+
+ state = lfsr_common_prefix(nr, rr, ks3x, par);
+ lfsr_rollback_word(state, uid^nt, 0);
+ crypto1_get_lfsr(state, key);
+ crypto1_destroy(state);
+
+ t1 = clock() - t1;
+ if ( t1 > 0 ) PrintAndLog("Time in nonce2key: %.0f ticks \n", (float)t1);
+ return 0;
+}
+
+// call when PAR == 0, special attack?
+int nonce2key_ex(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t ks_info, uint64_t * key) {
+ struct Crypto1State *state;
+ uint32_t i, pos, key_count;
+ byte_t ks3x[8];
+
+ uint64_t key_recovered;
+ int64_t *state_s;
+ static uint32_t last_uid;
+ static int64_t *last_keylist;
+
+ if (last_uid != uid && last_keylist != NULL) {
+ free(last_keylist);
+ last_keylist = NULL;
+ }
+ last_uid = uid;
+
+ // Reset the last three significant bits of the reader nonce
+ nr &= 0xffffff1f;
+
+ PrintAndLog("uid(%08x) nt(%08x) ks(%016"llx") nr(%08"llx")\n", uid, nt, ks_info, nr);
+
+ for (pos=0; pos<8; pos++) {
+ ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
+ }