- PrintAndLog("\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]);
- }
+ 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) {
+ key_count = 0;
+ 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) {
+ key_count = 0;
+ 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;
+}
+
+// 32 bit recover key from 2 nonces
+bool tryMfk32(nonces_t data, uint64_t *outputkey, bool verbose) {
+ struct Crypto1State *s,*t;
+ uint64_t outkey = 0;
+ uint64_t key=0; // recovered key
+ uint32_t uid = data.cuid;
+ uint32_t nt = data.nonce; // first tag challenge (nonce)
+ uint32_t nr0_enc = data.nr; // first encrypted reader challenge
+ uint32_t ar0_enc = data.ar; // first encrypted reader response
+ uint32_t nr1_enc = data.nr2; // second encrypted reader challenge
+ uint32_t ar1_enc = data.ar2; // second encrypted reader response
+ bool isSuccess = FALSE;
+ uint8_t counter = 0;
+
+ clock_t t1 = clock();
+ uint32_t p64 = prng_successor(nt, 64);
+
+ if ( verbose ) {
+ printf("Recovering key for:\n");
+ 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);
+ printf("\nLFSR succesors of the tag challenge:\n");
+ printf(" nt': %08x\n", p64);
+ printf(" nt'': %08x\n", prng_successor(p64, 32));
+ }
+
+ s = lfsr_recovery32(ar0_enc ^ p64, 0);
projects / proxmark3-svn / blobdiff