+int compar_intA(const void * a, const void * b) {
+ if (*(int64_t*)b == *(int64_t*)a) return 0;
+ if (*(int64_t*)b > *(int64_t*)a) return 1;
+ return -1;
+}
+
+// call when PAR == 0, special attack? It seems to need two calls. with same uid, block, keytype
+int nonce2key_ex(uint8_t blockno, uint8_t keytype, 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;
+ uint8_t ks3x[8];
+ uint64_t key_recovered;
+ int64_t *state_s;
+ static uint8_t last_blockno;
+ static uint8_t last_keytype;
+ static uint32_t last_uid;
+ static int64_t *last_keylist;
+
+ if (last_uid != uid &&
+ last_blockno != blockno &&
+ last_keytype != keytype &&
+ last_keylist != NULL)
+ {
+ free(last_keylist);
+ last_keylist = NULL;
+ }
+ last_uid = uid;
+ last_blockno = blockno;
+ last_keytype = keytype;
+
+ // Reset the last three significant bits of the reader nonce
+ nr &= 0xffffff1f;
+
+ // split keystream into array
+ for (pos=0; pos<8; pos++) {
+ ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
+ }
+
+ // find possible states for this keystream
+ state = lfsr_common_prefix_ex(nr, ks3x);
+
+ if (!state) {
+ PrintAndLog("Failed getting states");
+ return 1;
+ }
+
+ state_s = (int64_t*)state;
+
+ uint32_t xored = uid ^ nt;
+
+ for (i = 0; (state) && ((state + i)->odd != -1); i++) {
+ lfsr_rollback_word(state + i, xored, 0);
+ crypto1_get_lfsr(state + i, &key_recovered);
+ *(state_s + i) = key_recovered;
+ }
+
+ qsort(state_s, i, sizeof(int64_t), compar_intA);
+ *(state_s + i) = -1;
+
+ // first call to this function. clear all other stuff and set new found states.
+ if (last_keylist == NULL) {
+ free(last_keylist);
+ last_keylist = state_s;
+ PrintAndLog("parity is all zero, testing special attack. First call, this attack needs at least two calls. Hold on...");
+ PrintAndLog("uid(%08x) nt(%08x) ks(%016"llx") nr(%08x)\n", uid, nt, ks_info, nr);
+ return 1;
+ }
+
+ PrintAndLog("uid(%08x) nt(%08x) ks(%016"llx") nr(%08x)\n", uid, nt, ks_info, nr);
+
+ //Create the intersection:
+ int64_t *p1, *p2, *p3;
+ p1 = p3 = last_keylist;
+ p2 = state_s;
+
+ while ( *p1 != -1 && *p2 != -1 ) {
+ if (compar_intA(p1, p2) == 0) {
+ printf("p1:%"llx" p2:%"llx" p3:%"llx" key:%012"llx"\n",(uint64_t)(p1-last_keylist),(uint64_t)(p2-state_s),(uint64_t)(p3-last_keylist),*p1);
+ *p3++ = *p1++;
+ p2++;
+ }
+ else {
+ while (compar_intA(p1, p2) == -1) ++p1;
+ while (compar_intA(p1, p2) == 1) ++p2;
+ }
+ }
+ key_count = p3 - last_keylist;
+ printf("key_count: %d\n", key_count);
+ if ( key_count == 0 ){
+ free(state);
+ state = NULL;
+ return 0;
+ }
+
+ uint8_t retval = 1;
+ // Validate all key candidates with testing each of them with mfCheckKeys
+ uint8_t keyBlock[6] = {0,0,0,0,0,0};
+ uint64_t key64;
+ for (i = 0; i < key_count; i++) {
+ key64 = *(last_keylist + i);
+ num_to_bytes(key64, 6, keyBlock);
+ key64 = 0;
+ if (!mfCheckKeys(blockno, keytype, false, 1, keyBlock, &key64)) {
+ *key = key64;
+ retval = 0;
+ goto out;
+ }
+ }
+
+out:
+ free(last_keylist);
+ last_keylist = NULL;
+ free(state);
+ state = NULL;
+ return retval;
+}
projects / proxmark3-svn / blobdiff