FIX: 'hf mf mifare' - special zero parity attack vector now works. Thanks to the...

[proxmark3-svn] / client / cmdhfmfhard.c

diff --git a/client/cmdhfmfhard.c b/client/cmdhfmfhard.c
index 5b9a64946ea905593eeb210c6775b7387866adcf..fb576441bc5271b8ffa093915a684fcab7ac7e37 100644 (file)
--- a/client/cmdhfmfhard.c
+++ b/client/cmdhfmfhard.c
@@ -13,31 +13,15 @@
 //   Mifare Classic Cards" in Proceedings of the 22nd ACM SIGSAC Conference on 
 //   Computer and Communications Security, 2015
 //-----------------------------------------------------------------------------
 //   Mifare Classic Cards" in Proceedings of the 22nd ACM SIGSAC Conference on 
 //   Computer and Communications Security, 2015
 //-----------------------------------------------------------------------------

-
-#include <stdlib.h> 
-#include <stdio.h>
-#include <string.h>
-#include <pthread.h>
-#include <locale.h>
-#include <math.h>
-#include "proxmark3.h"
-#include "cmdmain.h"
-#include "ui.h"
-#include "util.h"
-#include "nonce2key/crapto1.h"
-#include "nonce2key/crypto1_bs.h"
-#include "parity.h"
-#ifdef __WIN32
-       #include <windows.h>
-#endif
-#include <malloc.h>
-#include <assert.h>
-
-// uint32_t test_state_odd = 0;
-// uint32_t test_state_even = 0;
+#include "cmdhfmfhard.h"

 
 #define CONFIDENCE_THRESHOLD   0.95            // Collect nonces until we are certain enough that the following brute force is successfull
 
 #define CONFIDENCE_THRESHOLD   0.95            // Collect nonces until we are certain enough that the following brute force is successfull

-#define GOOD_BYTES_REQUIRED            28
+#define GOOD_BYTES_REQUIRED    13              // default 28, could be smaller == faster
+#define MIN_NONCES_REQUIRED    4000            // 4000-5000 could be good
+#define NONCES_TRIGGER         2500            // every 2500 nonces check if we can crack the key
+#define CRACKING_THRESHOLD     39.00f          // as 2^39
+
+#define END_OF_LIST_MARKER             0xFFFFFFFF

 
 static const float p_K[257] = {                // the probability that a random nonce has a Sum Property == K 
        0.0290, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 
 
 static const float p_K[257] = {                // the probability that a random nonce has a Sum Property == K 
        0.0290, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 


@@ -73,7 +57,6 @@ static const float p_K[257] = {               // the probability that a random nonce has a Su
        0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000,
        0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000,
        0.0290 };
        0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000,
        0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000,
        0.0290 };

-

                
 typedef struct noncelistentry {
        uint32_t nonce_enc;
                
 typedef struct noncelistentry {
        uint32_t nonce_enc;


@@ -92,7 +75,6 @@ typedef struct noncelist {
        float score1, score2;
 } noncelist_t;
 
        float score1, score2;
 } noncelist_t;
 

-

 static size_t nonces_to_bruteforce = 0;
 static noncelistentry_t *brute_force_nonces[256];
 static uint32_t cuid = 0;
 static size_t nonces_to_bruteforce = 0;
 static noncelistentry_t *brute_force_nonces[256];
 static uint32_t cuid = 0;


@@ -130,9 +112,17 @@ typedef struct {
 
 static partial_indexed_statelist_t partial_statelist[17];
 static partial_indexed_statelist_t statelist_bitflip;
 
 static partial_indexed_statelist_t partial_statelist[17];
 static partial_indexed_statelist_t statelist_bitflip;

-

 static statelist_t *candidates = NULL;
 
 static statelist_t *candidates = NULL;
 

+bool thread_check_started = false;
+bool thread_check_done = false;
+bool field_off = false;
+
+pthread_t thread_check;
+
+static void* check_thread();
+static bool generate_candidates(uint16_t, uint16_t);
+static bool brute_force(void);

 
 static int add_nonce(uint32_t nonce_enc, uint8_t par_enc) 
 {
 
 static int add_nonce(uint32_t nonce_enc, uint8_t par_enc) 
 {


@@ -203,7 +193,6 @@ static void init_nonce_memory(void)
        num_good_first_bytes = 0;
 }
 
        num_good_first_bytes = 0;
 }
 

-

 static void free_nonce_list(noncelistentry_t *p)
 {
        if (p == NULL) {
 static void free_nonce_list(noncelistentry_t *p)
 {
        if (p == NULL) {


@@ -272,7 +261,10 @@ static double p_hypergeometric(uint16_t N, uint16_t K, uint16_t n, uint16_t k)
                for (int16_t i = N; i >= N-n+1; i--) {
                        log_result -= log(i);
                }
                for (int16_t i = N; i >= N-n+1; i--) {
                        log_result -= log(i);
                }

-               return exp(log_result);
+               if ( log_result > 0 )
+                       return exp(log_result);
+               else 
+                       return 0.0;

        } else {
                if (n-k == N-K) {       // special case. The published recursion below would fail with a divide by zero exception
                        double log_result = 0.0;
        } else {
                if (n-k == N-K) {       // special case. The published recursion below would fail with a divide by zero exception
                        double log_result = 0.0;


@@ -448,32 +440,31 @@ static void Tests()
        // crypto1_destroy(pcs);
 
        
        // crypto1_destroy(pcs);
 
        

-       

        // printf("\nTests: number of states with BitFlipProperty: %d, (= %1.3f%% of total states)\n", statelist_bitflip.len[0], 100.0 * statelist_bitflip.len[0] / (1<<20));
 
        // printf("\nTests: number of states with BitFlipProperty: %d, (= %1.3f%% of total states)\n", statelist_bitflip.len[0], 100.0 * statelist_bitflip.len[0] / (1<<20));
 

-       printf("\nTests: Actual BitFlipProperties odd/even:\n");
-       for (uint16_t i = 0; i < 256; i++) {
-               printf("[%02x]:%c  ", i, nonces[i].BitFlip[ODD_STATE]?'o':nonces[i].BitFlip[EVEN_STATE]?'e':' ');
-               if (i % 8 == 7) {
-                       printf("\n");
-               }
-       }
+       // printf("\nTests: Actual BitFlipProperties odd/even:\n");
+       // for (uint16_t i = 0; i < 256; i++) {
+               // printf("[%02x]:%c  ", i, nonces[i].BitFlip[ODD_STATE]?'o':nonces[i].BitFlip[EVEN_STATE]?'e':' ');
+               // if (i % 8 == 7) {
+                       // printf("\n");
+               // }
+       // }

        
        

-       printf("\nTests: Sorted First Bytes:\n");
-       for (uint16_t i = 0; i < 256; i++) {
-               uint8_t best_byte = best_first_bytes[i];
-               printf("#%03d Byte: %02x, n = %3d, k = %3d, Sum(a8): %3d, Confidence: %5.1f%%, Bitflip: %c\n", 
-               //printf("#%03d Byte: %02x, n = %3d, k = %3d, Sum(a8): %3d, Confidence: %5.1f%%, Bitflip: %c, score1: %1.5f, score2: %1.0f\n", 
-                       i, best_byte, 
-                       nonces[best_byte].num,
-                       nonces[best_byte].Sum,
-                       nonces[best_byte].Sum8_guess,
-                       nonces[best_byte].Sum8_prob * 100,
-                       nonces[best_byte].BitFlip[ODD_STATE]?'o':nonces[best_byte].BitFlip[EVEN_STATE]?'e':' '
-                       //nonces[best_byte].score1,
-                       //nonces[best_byte].score2
-                       );
-       }
+       // printf("\nTests: Sorted First Bytes:\n");
+       // for (uint16_t i = 0; i < 256; i++) {
+               // uint8_t best_byte = best_first_bytes[i];
+               // printf("#%03d Byte: %02x, n = %3d, k = %3d, Sum(a8): %3d, Confidence: %5.1f%%, Bitflip: %c\n", 
+               // //printf("#%03d Byte: %02x, n = %3d, k = %3d, Sum(a8): %3d, Confidence: %5.1f%%, Bitflip: %c, score1: %1.5f, score2: %1.0f\n", 
+                       // i, best_byte, 
+                       // nonces[best_byte].num,
+                       // nonces[best_byte].Sum,
+                       // nonces[best_byte].Sum8_guess,
+                       // nonces[best_byte].Sum8_prob * 100,
+                       // nonces[best_byte].BitFlip[ODD_STATE]?'o':nonces[best_byte].BitFlip[EVEN_STATE]?'e':' '
+                       // //nonces[best_byte].score1,
+                       // //nonces[best_byte].score2
+                       // );
+       // }

        
        // printf("\nTests: parity performance\n");
        // time_t time1p = clock();
        
        // printf("\nTests: parity performance\n");
        // time_t time1p = clock();


@@ -613,11 +604,11 @@ static uint16_t estimate_second_byte_sum(void)
 static int read_nonce_file(void)
 {
        FILE *fnonces = NULL;
 static int read_nonce_file(void)
 {
        FILE *fnonces = NULL;

-       uint8_t trgBlockNo;
-       uint8_t trgKeyType;
+       uint8_t trgBlockNo = 0;
+       uint8_t trgKeyType = 0;

        uint8_t read_buf[9];
        uint8_t read_buf[9];

-       uint32_t nt_enc1, nt_enc2;
-       uint8_t par_enc;
+       uint32_t nt_enc1 = 0, nt_enc2 = 0;
+       uint8_t par_enc = 0;

        int total_num_nonces = 0;
        
        if ((fnonces = fopen("nonces.bin","rb")) == NULL) { 
        int total_num_nonces = 0;
        
        if ((fnonces = fopen("nonces.bin","rb")) == NULL) { 


@@ -630,6 +621,7 @@ static int read_nonce_file(void)
        if ( bytes_read == 0) {
                PrintAndLog("File reading error.");
                fclose(fnonces);
        if ( bytes_read == 0) {
                PrintAndLog("File reading error.");
                fclose(fnonces);

+               fnonces = NULL;

                return 1;
        }
        cuid = bytes_to_num(read_buf, 4);
                return 1;
        }
        cuid = bytes_to_num(read_buf, 4);


@@ -647,8 +639,8 @@ static int read_nonce_file(void)
                total_num_nonces += 2;
        }
        fclose(fnonces);
                total_num_nonces += 2;
        }
        fclose(fnonces);

+       fnonces = NULL;

        PrintAndLog("Read %d nonces from file. cuid=%08x, Block=%d, Keytype=%c", total_num_nonces, cuid, trgBlockNo, trgKeyType==0?'A':'B');
        PrintAndLog("Read %d nonces from file. cuid=%08x, Block=%d, Keytype=%c", total_num_nonces, cuid, trgBlockNo, trgKeyType==0?'A':'B');

-

        return 0;
 }
 
        return 0;
 }
 


@@ -761,7 +753,6 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
 {
        clock_t time1 = clock();
        bool initialize = true;
 {
        clock_t time1 = clock();
        bool initialize = true;

-       bool field_off = false;

        bool finished = false;
        bool filter_flip_checked = false;
        uint32_t flags = 0;
        bool finished = false;
        bool filter_flip_checked = false;
        uint32_t flags = 0;


@@ -769,14 +760,24 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
        uint32_t total_num_nonces = 0;
        uint32_t next_fivehundred = 500;
        uint32_t total_added_nonces = 0;
        uint32_t total_num_nonces = 0;
        uint32_t next_fivehundred = 500;
        uint32_t total_added_nonces = 0;

+       uint32_t idx = 1;

        FILE *fnonces = NULL;
        UsbCommand resp;
 
        FILE *fnonces = NULL;
        UsbCommand resp;
 

+       field_off = false;
+       thread_check_started = false;
+       thread_check_done = false;
+

        printf("Acquiring nonces...\n");
        printf("Acquiring nonces...\n");

-       
+

        clearCommandBuffer();
 
        do {
        clearCommandBuffer();
 
        do {

+               if (thread_check_started && !thread_check_done) {
+                       sleep(3);
+                       continue;
+               }
+

                flags = 0;
                flags |= initialize ? 0x0001 : 0;
                flags |= slow ? 0x0002 : 0;
                flags = 0;
                flags |= initialize ? 0x0001 : 0;
                flags |= slow ? 0x0002 : 0;


@@ -822,8 +823,7 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
                                //printf("Encrypted nonce: %08x, encrypted_parity: %02x\n", nt_enc2, par_enc & 0x0f);
                                total_added_nonces += add_nonce(nt_enc2, par_enc & 0x0f);
                                
                                //printf("Encrypted nonce: %08x, encrypted_parity: %02x\n", nt_enc2, par_enc & 0x0f);
                                total_added_nonces += add_nonce(nt_enc2, par_enc & 0x0f);
                                

-
-                               if (nonce_file_write) {
+                               if (nonce_file_write && fnonces) {

                                        fwrite(bufp, 1, 9, fnonces);
                                }
                                
                                        fwrite(bufp, 1, 9, fnonces);
                                }
                                


@@ -833,12 +833,13 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
                        total_num_nonces += num_acquired_nonces;
                }
                
                        total_num_nonces += num_acquired_nonces;
                }
                

-               if (first_byte_num == 256 ) {
+               if (first_byte_num == 256 && !field_off) {

                        // printf("first_byte_num = %d, first_byte_Sum = %d\n", first_byte_num, first_byte_Sum);
                        if (!filter_flip_checked) {
                                Check_for_FilterFlipProperties();
                                filter_flip_checked = true;
                        }
                        // printf("first_byte_num = %d, first_byte_Sum = %d\n", first_byte_num, first_byte_Sum);
                        if (!filter_flip_checked) {
                                Check_for_FilterFlipProperties();
                                filter_flip_checked = true;
                        }

+

                        num_good_first_bytes = estimate_second_byte_sum();
                        if (total_num_nonces > next_fivehundred) {
                                next_fivehundred = (total_num_nonces/500+1) * 500;
                        num_good_first_bytes = estimate_second_byte_sum();
                        if (total_num_nonces > next_fivehundred) {
                                next_fivehundred = (total_num_nonces/500+1) * 500;


@@ -848,18 +849,39 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
                                        CONFIDENCE_THRESHOLD * 100.0,
                                        num_good_first_bytes);
                        }
                                        CONFIDENCE_THRESHOLD * 100.0,
                                        num_good_first_bytes);
                        }

-                       if (num_good_first_bytes >= GOOD_BYTES_REQUIRED) {
-                               field_off = true;       // switch off field with next SendCommand and then finish
+
+                       if (thread_check_started) {
+                               if (thread_check_done) {
+                                       pthread_join (thread_check, 0);
+                                       thread_check_started = thread_check_done = false;
+                               }
+                       } else {
+                               if (total_added_nonces >= MIN_NONCES_REQUIRED)
+                               {
+                                       num_good_first_bytes = estimate_second_byte_sum();
+                                       if (total_added_nonces > (NONCES_TRIGGER*idx) || num_good_first_bytes >= GOOD_BYTES_REQUIRED) {
+                                               pthread_create (&thread_check, NULL, check_thread, NULL);
+                                               thread_check_started = true;
+                                               idx++;
+                                       }
+                               }

                        }
                }
 
                if (!initialize) {
                        if (!WaitForResponseTimeout(CMD_ACK, &resp, 3000)) {
                        }
                }
 
                if (!initialize) {
                        if (!WaitForResponseTimeout(CMD_ACK, &resp, 3000)) {

-                               fclose(fnonces);
+                               if (fnonces) { // fix segfault on proxmark3 v1 when reset button is pressed
+                                       fclose(fnonces);
+                                       fnonces = NULL;
+                               }

                                return 1;
                        }
                                return 1;
                        }

+

                        if (resp.arg[0]) {
                        if (resp.arg[0]) {

-                               fclose(fnonces);
+                               if (fnonces) { // fix segfault on proxmark3 v1 when reset button is pressed
+                                       fclose(fnonces);
+                                       fnonces = NULL;
+                               }

                                return resp.arg[0];  // error during nested_hard
                        }
                }
                                return resp.arg[0];  // error during nested_hard
                        }
                }


@@ -868,17 +890,17 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
 
        } while (!finished);
 
 
        } while (!finished);
 

-       
-       if (nonce_file_write) {
+       if (nonce_file_write && fnonces) {

                fclose(fnonces);
                fclose(fnonces);

+               fnonces = NULL;

        }
        
        time1 = clock() - time1;
        if ( time1 > 0 ) {
        }
        
        time1 = clock() - time1;
        if ( time1 > 0 ) {

-       PrintAndLog("Acquired a total of %d nonces in %1.1f seconds (%0.0f nonces/minute)", 
-               total_num_nonces, 
-               ((float)time1)/CLOCKS_PER_SEC, 
-               total_num_nonces * 60.0 * CLOCKS_PER_SEC/(float)time1
+               PrintAndLog("Acquired a total of %d nonces in %1.1f seconds (%0.0f nonces/minute)", 
+                       total_num_nonces, 
+                       ((float)time1)/CLOCKS_PER_SEC, 
+                       total_num_nonces * 60.0 * CLOCKS_PER_SEC/(float)time1

                );
        }
        return 0;
                );
        }
        return 0;


@@ -887,7 +909,8 @@ static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_
 static int init_partial_statelists(void)
 {
        const uint32_t sizes_odd[17] = { 126757, 0, 18387, 0, 74241, 0, 181737, 0, 248801, 0, 182033, 0, 73421, 0, 17607, 0, 125601 };
 static int init_partial_statelists(void)
 {
        const uint32_t sizes_odd[17] = { 126757, 0, 18387, 0, 74241, 0, 181737, 0, 248801, 0, 182033, 0, 73421, 0, 17607, 0, 125601 };

-       const uint32_t sizes_even[17] = { 125723, 0, 17867, 0, 74305, 0, 178707, 0, 248801, 0, 185063, 0, 73356, 0, 18127, 0, 126634 };
+//     const uint32_t sizes_even[17] = { 125723, 0, 17867, 0, 74305, 0, 178707, 0, 248801, 0, 185063, 0, 73356, 0, 18127, 0, 126634 };
+       const uint32_t sizes_even[17] = { 125723, 0, 17867, 0, 74305, 0, 178707, 0, 248801, 0, 185063, 0, 73357, 0, 18127, 0, 126635 };

        
        printf("Allocating memory for partial statelists...\n");
        for (odd_even_t odd_even = EVEN_STATE; odd_even <= ODD_STATE; odd_even++) {
        
        printf("Allocating memory for partial statelists...\n");
        for (odd_even_t odd_even = EVEN_STATE; odd_even <= ODD_STATE; odd_even++) {


@@ -927,7 +950,7 @@ static int init_partial_statelists(void)
                for (uint16_t i = 0; i <= 16; i += 2) {
                        uint32_t *p = partial_statelist[i].states[odd_even];
                        p += partial_statelist[i].len[odd_even];
                for (uint16_t i = 0; i <= 16; i += 2) {
                        uint32_t *p = partial_statelist[i].states[odd_even];
                        p += partial_statelist[i].len[odd_even];

-                       *p = 0xffffffff;
+                       *p = END_OF_LIST_MARKER;

                }
        }
        
                }
        }
        


@@ -953,7 +976,7 @@ static void init_BitFlip_statelist(void)
        }
        // set len and add End Of List marker
        statelist_bitflip.len[0] = p - statelist_bitflip.states[0];
        }
        // set len and add End Of List marker
        statelist_bitflip.len[0] = p - statelist_bitflip.states[0];

-       *p = 0xffffffff;
+       *p = END_OF_LIST_MARKER;

        statelist_bitflip.states[0] = realloc(statelist_bitflip.states[0], sizeof(uint32_t) * (statelist_bitflip.len[0] + 1));
 }
                
        statelist_bitflip.states[0] = realloc(statelist_bitflip.states[0], sizeof(uint32_t) * (statelist_bitflip.len[0] + 1));
 }
                


@@ -963,7 +986,7 @@ static inline uint32_t *find_first_state(uint32_t state, uint32_t mask, partial_
 
        if (p == NULL) return NULL;
        while (*p < (state & mask)) p++;
 
        if (p == NULL) return NULL;
        while (*p < (state & mask)) p++;

-       if (*p == 0xffffffff) return NULL;                                      // reached end of list, no match
+       if (*p == END_OF_LIST_MARKER) return NULL;                                      // reached end of list, no match

        if ((*p & mask) == (state & mask)) return p;            // found a match.
        return NULL;                                                                            // no match
 } 
        if ((*p & mask) == (state & mask)) return p;            // found a match.
        return NULL;                                                                            // no match
 } 


@@ -1041,7 +1064,7 @@ static bool all_other_first_bytes_match(uint32_t state, odd_even_t odd_even)
                                        uint16_t part_sum_a8 = (odd_even == ODD_STATE) ? r : s;
                                        uint32_t *p = find_first_state(state, mask, &partial_statelist[part_sum_a8], odd_even);
                                        if (p != NULL) {
                                        uint16_t part_sum_a8 = (odd_even == ODD_STATE) ? r : s;
                                        uint32_t *p = find_first_state(state, mask, &partial_statelist[part_sum_a8], odd_even);
                                        if (p != NULL) {

-                                               while ((state & mask) == (*p & mask) && (*p != 0xffffffff)) {
+                                               while ((state & mask) == (*p & mask) && (*p != END_OF_LIST_MARKER)) {

                                                        if (remaining_bits_match(j, bytes_diff, state, (state&0x00fffff0) | *p, odd_even)) {
                                                                found_match = true;
                                                                // if ((odd_even == ODD_STATE && state == test_state_odd)
                                                        if (remaining_bits_match(j, bytes_diff, state, (state&0x00fffff0) | *p, odd_even)) {
                                                                found_match = true;
                                                                // if ((odd_even == ODD_STATE && state == test_state_odd)


@@ -1099,7 +1122,7 @@ static bool all_bit_flips_match(uint32_t state, odd_even_t odd_even)
                        bool found_match = false;
                        uint32_t *p = find_first_state(state, mask, &statelist_bitflip, 0);
                        if (p != NULL) {
                        bool found_match = false;
                        uint32_t *p = find_first_state(state, mask, &statelist_bitflip, 0);
                        if (p != NULL) {

-                               while ((state & mask) == (*p & mask) && (*p != 0xffffffff)) {
+                               while ((state & mask) == (*p & mask) && (*p != END_OF_LIST_MARKER)) {

                                        if (remaining_bits_match(j, bytes_diff, state, (state&0x00fffff0) | *p, odd_even)) {
                                                found_match = true;
                                                // if ((odd_even == ODD_STATE && state == test_state_odd)
                                        if (remaining_bits_match(j, bytes_diff, state, (state&0x00fffff0) | *p, odd_even)) {
                                                found_match = true;
                                                // if ((odd_even == ODD_STATE && state == test_state_odd)


@@ -1172,11 +1195,11 @@ static int add_matching_states(statelist_t *candidates, uint16_t part_sum_a0, ui
                return 4;
        }
        uint32_t *add_p = candidates->states[odd_even]; 
                return 4;
        }
        uint32_t *add_p = candidates->states[odd_even]; 

-       for (uint32_t *p1 = partial_statelist[part_sum_a0].states[odd_even]; *p1 != 0xffffffff; p1++) {
+       for (uint32_t *p1 = partial_statelist[part_sum_a0].states[odd_even]; *p1 != END_OF_LIST_MARKER; p1++) {

                uint32_t search_mask = 0x000ffff0;
                uint32_t *p2 = find_first_state((*p1 << 4), search_mask, &partial_statelist[part_sum_a8], odd_even);
                if (p2 != NULL) {
                uint32_t search_mask = 0x000ffff0;
                uint32_t *p2 = find_first_state((*p1 << 4), search_mask, &partial_statelist[part_sum_a8], odd_even);
                if (p2 != NULL) {

-                       while (((*p1 << 4) & search_mask) == (*p2 & search_mask) && *p2 != 0xffffffff) {
+                       while (((*p1 << 4) & search_mask) == (*p2 & search_mask) && *p2 != END_OF_LIST_MARKER) {

                                if ((nonces[best_first_bytes[0]].BitFlip[odd_even] && find_first_state((*p1 << 4) | *p2, 0x000fffff, &statelist_bitflip, 0))
                                        || !nonces[best_first_bytes[0]].BitFlip[odd_even]) {
                                if (all_other_first_bytes_match((*p1 << 4) | *p2, odd_even)) {
                                if ((nonces[best_first_bytes[0]].BitFlip[odd_even] && find_first_state((*p1 << 4) | *p2, 0x000fffff, &statelist_bitflip, 0))
                                        || !nonces[best_first_bytes[0]].BitFlip[odd_even]) {
                                if (all_other_first_bytes_match((*p1 << 4) | *p2, odd_even)) {


@@ -1191,7 +1214,7 @@ static int add_matching_states(statelist_t *candidates, uint16_t part_sum_a0, ui
        }
 
        // set end of list marker and len
        }
 
        // set end of list marker and len

-       *add_p = 0xffffffff; 
+       *add_p = END_OF_LIST_MARKER; 

        candidates->len[odd_even] = add_p - candidates->states[odd_even];
 
        candidates->states[odd_even] = realloc(candidates->states[odd_even], sizeof(uint32_t) * (candidates->len[odd_even] + 1));
        candidates->len[odd_even] = add_p - candidates->states[odd_even];
 
        candidates->states[odd_even] = realloc(candidates->states[odd_even], sizeof(uint32_t) * (candidates->len[odd_even] + 1));


@@ -1221,7 +1244,7 @@ static statelist_t *add_more_candidates(statelist_t *current_candidates)
        return new_candidates;
 }
 
        return new_candidates;
 }
 

-static void TestIfKeyExists(uint64_t key)
+static bool TestIfKeyExists(uint64_t key)

 {
        struct Crypto1State *pcs;
        pcs = crypto1_create(key);
 {
        struct Crypto1State *pcs;
        pcs = crypto1_create(key);


@@ -1237,14 +1260,14 @@ static void TestIfKeyExists(uint64_t key)
                bool found_even = false;
                uint32_t *p_odd = p->states[ODD_STATE];
                uint32_t *p_even = p->states[EVEN_STATE];
                bool found_even = false;
                uint32_t *p_odd = p->states[ODD_STATE];
                uint32_t *p_even = p->states[EVEN_STATE];

-               while (*p_odd != 0xffffffff) {
+               while (*p_odd != END_OF_LIST_MARKER) {

                        if ((*p_odd & 0x00ffffff) == state_odd) {
                                found_odd = true;
                                break;
                        }
                        p_odd++;
                }
                        if ((*p_odd & 0x00ffffff) == state_odd) {
                                found_odd = true;
                                break;
                        }
                        p_odd++;
                }

-               while (*p_even != 0xffffffff) {
+               while (*p_even != END_OF_LIST_MARKER) {

                        if ((*p_even & 0x00ffffff) == state_even) {
                                found_even = true;
                        }
                        if ((*p_even & 0x00ffffff) == state_even) {
                                found_even = true;
                        }


@@ -1252,15 +1275,17 @@ static void TestIfKeyExists(uint64_t key)
                }
                count += (p_odd - p->states[ODD_STATE]) * (p_even - p->states[EVEN_STATE]);
                if (found_odd && found_even) {
                }
                count += (p_odd - p->states[ODD_STATE]) * (p_even - p->states[EVEN_STATE]);
                if (found_odd && found_even) {

-                       PrintAndLog("Key Found after testing %lld (2^%1.1f) out of %lld (2^%1.1f) keys. A brute force would have taken approx %lld minutes.", 
-                               count, log(count)/log(2), 
-                               maximum_states, log(maximum_states)/log(2),
-                               (count>>23)/60);
+                       PrintAndLog("Key Found after testing %lld (2^%1.1f) out of %lld (2^%1.1f) keys. ", 
+                               count,
+                               log(count)/log(2), 
+                               maximum_states,
+                               log(maximum_states)/log(2)
+                               );

                        if (write_stats) {
                                fprintf(fstats, "1\n");
                        }
                        crypto1_destroy(pcs);
                        if (write_stats) {
                                fprintf(fstats, "1\n");
                        }
                        crypto1_destroy(pcs);

-                       return;
+                       return true;

                }
        }
 
                }
        }
 


@@ -1269,9 +1294,11 @@ static void TestIfKeyExists(uint64_t key)
                fprintf(fstats, "0\n");
        }
        crypto1_destroy(pcs);
                fprintf(fstats, "0\n");
        }
        crypto1_destroy(pcs);

+
+       return false;

 }
 
 }
 

-static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8)
+static bool generate_candidates(uint16_t sum_a0, uint16_t sum_a8)

 {
        printf("Generating crypto1 state candidates... \n");
        
 {
        printf("Generating crypto1 state candidates... \n");
        


@@ -1285,15 +1312,18 @@ static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8)
                        }
                }
        }
                        }
                }
        }

-       printf("Number of possible keys with Sum(a0) = %d: %"PRIu64" (2^%1.1f)\n", sum_a0, maximum_states, log(maximum_states)/log(2.0));
+
+       if (maximum_states == 0) return false; // prevent keyspace reduction error (2^-inf)
+
+       printf("Number of possible keys with Sum(a0) = %d: %"PRIu64" (2^%1.1f)\n", sum_a0, maximum_states, log(maximum_states)/log(2));

        
        init_statelist_cache();
        
        for (uint16_t p = 0; p <= 16; p += 2) {
                for (uint16_t q = 0; q <= 16; q += 2) {
                        if (p*(16-q) + (16-p)*q == sum_a0) {
        
        init_statelist_cache();
        
        for (uint16_t p = 0; p <= 16; p += 2) {
                for (uint16_t q = 0; q <= 16; q += 2) {
                        if (p*(16-q) + (16-p)*q == sum_a0) {

-                               printf("Reducing Partial Statelists (p,q) = (%d,%d) with lengths %d, %d\n", 
-                                               p, q, partial_statelist[p].len[ODD_STATE], partial_statelist[q].len[EVEN_STATE]);
+                               // printf("Reducing Partial Statelists (p,q) = (%d,%d) with lengths %d, %d\n", 
+                                               // p, q, partial_statelist[p].len[ODD_STATE], partial_statelist[q].len[EVEN_STATE]);

                                for (uint16_t r = 0; r <= 16; r += 2) {
                                        for (uint16_t s = 0; s <= 16; s += 2) {
                                                if (r*(16-s) + (16-r)*s == sum_a8) {
                                for (uint16_t r = 0; r <= 16; r += 2) {
                                        for (uint16_t s = 0; s <= 16; s += 2) {
                                                if (r*(16-s) + (16-r)*s == sum_a8) {


@@ -1302,13 +1332,13 @@ static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8)
                                                        // and eliminate the need to calculate the other part
                                                        if (MIN(partial_statelist[p].len[ODD_STATE], partial_statelist[r].len[ODD_STATE]) 
                                                                        < MIN(partial_statelist[q].len[EVEN_STATE], partial_statelist[s].len[EVEN_STATE])) { 
                                                        // and eliminate the need to calculate the other part
                                                        if (MIN(partial_statelist[p].len[ODD_STATE], partial_statelist[r].len[ODD_STATE]) 
                                                                        < MIN(partial_statelist[q].len[EVEN_STATE], partial_statelist[s].len[EVEN_STATE])) { 

-                                                       add_matching_states(current_candidates, p, r, ODD_STATE);
+                                                               add_matching_states(current_candidates, p, r, ODD_STATE);

                                                                if(current_candidates->len[ODD_STATE]) {
                                                                if(current_candidates->len[ODD_STATE]) {

-                                                       add_matching_states(current_candidates, q, s, EVEN_STATE);
+                                                                       add_matching_states(current_candidates, q, s, EVEN_STATE);

                                                                } else {
                                                                        current_candidates->len[EVEN_STATE] = 0;
                                                                        uint32_t *p = current_candidates->states[EVEN_STATE] = malloc(sizeof(uint32_t));
                                                                } else {
                                                                        current_candidates->len[EVEN_STATE] = 0;
                                                                        uint32_t *p = current_candidates->states[EVEN_STATE] = malloc(sizeof(uint32_t));

-                                                                       *p = 0xffffffff;
+                                                                       *p = END_OF_LIST_MARKER;

                                                                }
                                                        } else {
                                                                add_matching_states(current_candidates, q, s, EVEN_STATE);
                                                                }
                                                        } else {
                                                                add_matching_states(current_candidates, q, s, EVEN_STATE);


@@ -1317,11 +1347,11 @@ static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8)
                                                                } else {
                                                                        current_candidates->len[ODD_STATE] = 0;
                                                                        uint32_t *p = current_candidates->states[ODD_STATE] = malloc(sizeof(uint32_t));
                                                                } else {
                                                                        current_candidates->len[ODD_STATE] = 0;
                                                                        uint32_t *p = current_candidates->states[ODD_STATE] = malloc(sizeof(uint32_t));

-                                                                       *p = 0xffffffff;
+                                                                       *p = END_OF_LIST_MARKER;

                                                                }
                                                        }
                                                                }
                                                        }

-                                                       printf("Odd  state candidates: %6d (2^%0.1f)\n", current_candidates->len[ODD_STATE], log(current_candidates->len[ODD_STATE])/log(2)); 
-                                                       printf("Even state candidates: %6d (2^%0.1f)\n", current_candidates->len[EVEN_STATE], log(current_candidates->len[EVEN_STATE])/log(2)); 
+                                                       //printf("Odd  state candidates: %6d (2^%0.1f)\n", current_candidates->len[ODD_STATE], log(current_candidates->len[ODD_STATE])/log(2)); 
+                                                       //printf("Even state candidates: %6d (2^%0.1f)\n", current_candidates->len[EVEN_STATE], log(current_candidates->len[EVEN_STATE])/log(2)); 

                                                }
                                        }
                                }
                                                }
                                        }
                                }


@@ -1329,19 +1359,25 @@ static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8)
                }
        }                                       
 
                }
        }                                       
 

-       

        maximum_states = 0;
        for (statelist_t *sl = candidates; sl != NULL; sl = sl->next) {
                maximum_states += (uint64_t)sl->len[ODD_STATE] * sl->len[EVEN_STATE];
        }
        maximum_states = 0;
        for (statelist_t *sl = candidates; sl != NULL; sl = sl->next) {
                maximum_states += (uint64_t)sl->len[ODD_STATE] * sl->len[EVEN_STATE];
        }

-       printf("Number of remaining possible keys: %"PRIu64" (2^%1.1f)\n", maximum_states, log(maximum_states)/log(2.0));
+
+       if (maximum_states == 0) return false; // prevent keyspace reduction error (2^-inf)
+
+       float kcalc = log(maximum_states)/log(2);
+       printf("Number of remaining possible keys: %"PRIu64" (2^%1.1f)\n", maximum_states, kcalc);

        if (write_stats) {
                if (maximum_states != 0) {
        if (write_stats) {
                if (maximum_states != 0) {

-                       fprintf(fstats, "%1.1f;", log(maximum_states)/log(2.0));
+                       fprintf(fstats, "%1.1f;", kcalc);

                } else {
                        fprintf(fstats, "%1.1f;", 0.0);
                }
        }
                } else {
                        fprintf(fstats, "%1.1f;", 0.0);
                }
        }

+       if (kcalc < CRACKING_THRESHOLD) return true;
+
+       return false;

 }
 
 static void    free_candidates_memory(statelist_t *sl)
 }
 
 static void    free_candidates_memory(statelist_t *sl)


@@ -1365,6 +1401,7 @@ static void free_statelist_cache(void)
        }               
 }
 
        }               
 }
 

+uint64_t foundkey = 0;

 size_t keys_found = 0;
 size_t bucket_count = 0;
 statelist_t* buckets[128];
 size_t keys_found = 0;
 size_t bucket_count = 0;
 statelist_t* buckets[128];


@@ -1407,7 +1444,11 @@ static const uint64_t crack_states_bitsliced(statelist_t *p){
                bitslice_t * restrict lstate_p = _aligned_malloc((STATE_SIZE+ROLLBACK_SIZE) * bSize, bSize);
        #endif
 #else
                bitslice_t * restrict lstate_p = _aligned_malloc((STATE_SIZE+ROLLBACK_SIZE) * bSize, bSize);
        #endif
 #else

+       #ifdef __APPLE__
+               bitslice_t * restrict lstate_p = malloc((STATE_SIZE+ROLLBACK_SIZE) * bSize);
+       #else

                bitslice_t * restrict lstate_p = memalign(bSize, (STATE_SIZE+ROLLBACK_SIZE) * bSize);
                bitslice_t * restrict lstate_p = memalign(bSize, (STATE_SIZE+ROLLBACK_SIZE) * bSize);

+       #endif

 #endif
 
                if ( !lstate_p )        {
 #endif
 
                if ( !lstate_p )        {


@@ -1473,7 +1514,7 @@ static const uint64_t crack_states_bitsliced(statelist_t *p){
         const bitslice_value_t odd_feedback = odd_feedback_bit ? bs_ones.value : bs_zeroes.value;
 
         for(size_t block_idx = 0; block_idx < bitsliced_blocks; ++block_idx){
         const bitslice_value_t odd_feedback = odd_feedback_bit ? bs_ones.value : bs_zeroes.value;
 
         for(size_t block_idx = 0; block_idx < bitsliced_blocks; ++block_idx){

-            const bitslice_t const * restrict bitsliced_even_state = bitsliced_even_states[block_idx];
+            const bitslice_t * const restrict bitsliced_even_state = bitsliced_even_states[block_idx];

             size_t state_idx;
             // set even bits
             for(state_idx = 0; state_idx < STATE_SIZE-ROLLBACK_SIZE; state_idx+=2){
             size_t state_idx;
             // set even bits
             for(state_idx = 0; state_idx < STATE_SIZE-ROLLBACK_SIZE; state_idx+=2){


@@ -1598,7 +1639,7 @@ out:
                _aligned_free(bitsliced_even_states[block_idx]-ROLLBACK_SIZE);          
        #endif
 #else
                _aligned_free(bitsliced_even_states[block_idx]-ROLLBACK_SIZE);          
        #endif
 #else

-               memfree(bitsliced_even_states[block_idx]-ROLLBACK_SIZE);
+               free(bitsliced_even_states[block_idx]-ROLLBACK_SIZE);

 #endif         
                
     }
 #endif         
                
     }


@@ -1606,6 +1647,24 @@ out:
     return key;
 }
 
     return key;
 }
 

+static void* check_thread()
+{
+       num_good_first_bytes = estimate_second_byte_sum();
+
+       clock_t time1 = clock();
+       bool cracking = generate_candidates(first_byte_Sum, nonces[best_first_bytes[0]].Sum8_guess);
+       time1 = clock() - time1;
+       if (time1 > 0) PrintAndLog("Time for generating key candidates list: %1.0f seconds", ((float)time1)/CLOCKS_PER_SEC);
+
+       if (cracking || known_target_key != -1) {
+               field_off = brute_force(); // switch off field with next SendCommand and then finish
+       }
+
+       thread_check_done = true;
+
+       return (void *) NULL;
+}
+

 static void* crack_states_thread(void* x){
     const size_t thread_id = (size_t)x;
     size_t current_bucket = thread_id;
 static void* crack_states_thread(void* x){
     const size_t thread_id = (size_t)x;
     size_t current_bucket = thread_id;


@@ -1614,8 +1673,8 @@ static void* crack_states_thread(void* x){
                if(bucket){
             const uint64_t key = crack_states_bitsliced(bucket);
             if(key != -1){
                if(bucket){
             const uint64_t key = crack_states_bitsliced(bucket);
             if(key != -1){

-                printf("\nFound key: %012"PRIx64"\n", key);

                 __sync_fetch_and_add(&keys_found, 1);
                 __sync_fetch_and_add(&keys_found, 1);

+                               __sync_fetch_and_add(&foundkey, key);

                 break;
             } else if(keys_found){
                 break;
                 break;
             } else if(keys_found){
                 break;


@@ -1628,67 +1687,81 @@ static void* crack_states_thread(void* x){
     }
     return NULL;
 }
     }
     return NULL;
 }

-#define _USE_32BIT_TIME_T
-static void brute_force(void)
+
+static bool brute_force(void)

 {
 {

+       bool ret = false;

        if (known_target_key != -1) {
                PrintAndLog("Looking for known target key in remaining key space...");
        if (known_target_key != -1) {
                PrintAndLog("Looking for known target key in remaining key space...");

-               TestIfKeyExists(known_target_key);
+               ret = TestIfKeyExists(known_target_key);

        } else {
        } else {

-        PrintAndLog("Brute force phase starting.");
-        time_t start, end;
-        time(&start);
-        keys_found = 0;
-
-        crypto1_bs_init();
-
-        PrintAndLog("Using %u-bit bitslices", MAX_BITSLICES);
-        PrintAndLog("Bitslicing best_first_byte^uid[3] (rollback byte): %02x...", best_first_bytes[0]^(cuid>>24));
-        // convert to 32 bit little-endian
-        crypto1_bs_bitslice_value32(rev32((best_first_bytes[0]^(cuid>>24))), bitsliced_rollback_byte, 8);
-
-        PrintAndLog("Bitslicing nonces...");
-        for(size_t tests = 0; tests < NONCE_TESTS; tests++){
-            uint32_t test_nonce = brute_force_nonces[tests]->nonce_enc;
-            uint8_t test_parity = brute_force_nonces[tests]->par_enc;
-            // pre-xor the uid into the decrypted nonces, and also pre-xor the cuid parity into the encrypted parity bits - otherwise an exta xor is required in the decryption routine
-            crypto1_bs_bitslice_value32(cuid^test_nonce, bitsliced_encrypted_nonces[tests], 32);
-            // convert to 32 bit little-endian
-            crypto1_bs_bitslice_value32(rev32( ~(test_parity ^ ~(parity(cuid>>24 & 0xff)<<3 | parity(cuid>>16 & 0xff)<<2 | parity(cuid>>8 & 0xff)<<1 | parity(cuid&0xff)))), bitsliced_encrypted_parity_bits[tests], 4);
-        }
-        total_states_tested = 0;
+               if (maximum_states == 0) return false; // prevent keyspace reduction error (2^-inf)
+
+               PrintAndLog("Brute force phase starting.");
+               time_t start, end;
+               time(&start);
+               keys_found = 0;
+               foundkey = 0;
+
+               crypto1_bs_init();
+
+               PrintAndLog("Using %u-bit bitslices", MAX_BITSLICES);
+               PrintAndLog("Bitslicing best_first_byte^uid[3] (rollback byte): %02X ...", best_first_bytes[0]^(cuid>>24));
+               // convert to 32 bit little-endian
+               crypto1_bs_bitslice_value32((best_first_bytes[0]<<24)^cuid, bitsliced_rollback_byte, 8);
+
+               PrintAndLog("Bitslicing nonces...");
+               for(size_t tests = 0; tests < NONCE_TESTS; tests++){
+                       uint32_t test_nonce = brute_force_nonces[tests]->nonce_enc;
+                       uint8_t test_parity = brute_force_nonces[tests]->par_enc;
+                       // pre-xor the uid into the decrypted nonces, and also pre-xor the cuid parity into the encrypted parity bits - otherwise an exta xor is required in the decryption routine
+                       crypto1_bs_bitslice_value32(cuid^test_nonce, bitsliced_encrypted_nonces[tests], 32);
+                       // convert to 32 bit little-endian
+                       crypto1_bs_bitslice_value32(rev32( ~(test_parity ^ ~(parity(cuid>>24 & 0xff)<<3 | parity(cuid>>16 & 0xff)<<2 | parity(cuid>>8 & 0xff)<<1 | parity(cuid&0xff)))), bitsliced_encrypted_parity_bits[tests], 4);
+               }
+               total_states_tested = 0;

 
 

-        // count number of states to go
-        bucket_count = 0;
-        for (statelist_t *p = candidates; p != NULL; p = p->next) {
-            buckets[bucket_count] = p;
-            bucket_count++;
-        }
+               // count number of states to go
+               bucket_count = 0;
+               for (statelist_t *p = candidates; p != NULL; p = p->next) {
+                       buckets[bucket_count] = p;
+                       bucket_count++;
+               }

 
 #ifndef __WIN32
 
 #ifndef __WIN32

-        thread_count = sysconf(_SC_NPROCESSORS_CONF);
+               thread_count = sysconf(_SC_NPROCESSORS_CONF);
+               if ( thread_count < 1)
+                       thread_count = 1;

 #endif  /* _WIN32 */
 #endif  /* _WIN32 */

-        pthread_t threads[thread_count];
-               
-        // enumerate states using all hardware threads, each thread handles one bucket
-        PrintAndLog("Starting %u cracking threads to search %u buckets containing a total of %"PRIu32" states...", thread_count, bucket_count, maximum_states);
-               
-        for(size_t i = 0; i < thread_count; i++){
-            pthread_create(&threads[i], NULL, crack_states_thread, (void*) i);
-        }
-        for(size_t i = 0; i < thread_count; i++){
-            pthread_join(threads[i], 0);
-        }

 
 

-        time(&end);
-        unsigned long elapsed_time = difftime(end, start);
-        PrintAndLog("Tested %"PRIu32" states, found %u keys after %u seconds", total_states_tested, keys_found, elapsed_time);
-        if(!keys_found){
-            assert(total_states_tested == maximum_states);
-        }
-        // reset this counter for the next call
-        nonces_to_bruteforce = 0;
+               pthread_t threads[thread_count];
+
+               // enumerate states using all hardware threads, each thread handles one bucket
+               PrintAndLog("Starting %u cracking threads to search %u buckets containing a total of %"PRIu64" states...", thread_count, bucket_count, maximum_states);
+
+               for(size_t i = 0; i < thread_count; i++){
+                       pthread_create(&threads[i], NULL, crack_states_thread, (void*) i);
+               }
+               for(size_t i = 0; i < thread_count; i++){
+                       pthread_join(threads[i], 0);
+               }
+
+               time(&end);
+               unsigned long  elapsed_time = difftime(end, start);
+
+               if (keys_found && TestIfKeyExists(foundkey)) {
+                       PrintAndLog("Success! Tested %"PRIu32" states, found %u keys after %u seconds", total_states_tested, keys_found, elapsed_time);
+                       PrintAndLog("\nFound key: %012"PRIx64"\n", foundkey);
+                       ret = true;
+               } else {
+                       PrintAndLog("Fail! Tested %"PRIu32" states, in %u seconds", total_states_tested, elapsed_time);
+               }
+
+               // reset this counter for the next call
+               nonces_to_bruteforce = 0;

        }
        }

+
+       return ret;

 }
 
 int mfnestedhard(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *trgkey, bool nonce_file_read, bool nonce_file_write, bool slow, int tests) 
 }
 
 int mfnestedhard(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *trgkey, bool nonce_file_read, bool nonce_file_write, bool slow, int tests) 


@@ -1729,25 +1802,36 @@ int mfnestedhard(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBloc
                        candidates = NULL;
                }
                fclose(fstats);
                        candidates = NULL;
                }
                fclose(fstats);

+               fstats = NULL;

        } else {
                init_nonce_memory();
        } else {
                init_nonce_memory();

-               if (nonce_file_read) {          // use pre-acquired data from file nonces.bin
+               if (nonce_file_read) { // use pre-acquired data from file nonces.bin

                        if (read_nonce_file() != 0) {
                                return 3;
                        }
                        Check_for_FilterFlipProperties();
                        num_good_first_bytes = MIN(estimate_second_byte_sum(), GOOD_BYTES_REQUIRED);
                        if (read_nonce_file() != 0) {
                                return 3;
                        }
                        Check_for_FilterFlipProperties();
                        num_good_first_bytes = MIN(estimate_second_byte_sum(), GOOD_BYTES_REQUIRED);

-               } else {                                        // acquire nonces.
+                       PrintAndLog("Number of first bytes with confidence > %2.1f%%: %d", CONFIDENCE_THRESHOLD*100.0, num_good_first_bytes);
+
+                       clock_t time1 = clock();
+                       bool cracking = generate_candidates(first_byte_Sum, nonces[best_first_bytes[0]].Sum8_guess);
+                       time1 = clock() - time1;
+                       if (time1 > 0)
+                               PrintAndLog("Time for generating key candidates list: %1.0f seconds", ((float)time1)/CLOCKS_PER_SEC);
+
+                       if (cracking)
+                               brute_force();
+               } else { // acquire nonces.

                        uint16_t is_OK = acquire_nonces(blockNo, keyType, key, trgBlockNo, trgKeyType, nonce_file_write, slow);
                        if (is_OK != 0) {
                                return is_OK;
                        }
                }
 
                        uint16_t is_OK = acquire_nonces(blockNo, keyType, key, trgBlockNo, trgKeyType, nonce_file_write, slow);
                        if (is_OK != 0) {
                                return is_OK;
                        }
                }
 

-               Tests();
+               //Tests();

 
 

-               PrintAndLog("");
-               PrintAndLog("Sum(a0) = %d", first_byte_Sum);
+               //PrintAndLog("");
+               //PrintAndLog("Sum(a0) = %d", first_byte_Sum);

                // PrintAndLog("Best 10 first bytes: %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x",
                        // best_first_bytes[0],
                        // best_first_bytes[1],
                // PrintAndLog("Best 10 first bytes: %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x, %02x",
                        // best_first_bytes[0],
                        // best_first_bytes[1],


@@ -1759,20 +1843,12 @@ int mfnestedhard(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBloc
                        // best_first_bytes[7],
                        // best_first_bytes[8],
                        // best_first_bytes[9]  );
                        // best_first_bytes[7],
                        // best_first_bytes[8],
                        // best_first_bytes[9]  );

-               PrintAndLog("Number of first bytes with confidence > %2.1f%%: %d", CONFIDENCE_THRESHOLD*100.0, num_good_first_bytes);

 
 

-               clock_t time1 = clock();
-               generate_candidates(first_byte_Sum, nonces[best_first_bytes[0]].Sum8_guess);
-               time1 = clock() - time1;
-               if ( time1 > 0 )
-                       PrintAndLog("Time for generating key candidates list: %1.0f seconds", ((float)time1)/CLOCKS_PER_SEC);
-       
-               brute_force();

                free_nonces_memory();
                free_statelist_cache();
                free_candidates_memory(candidates);
                candidates = NULL;
                free_nonces_memory();
                free_statelist_cache();
                free_candidates_memory(candidates);
                candidates = NULL;

-       }       
+       }

        return 0;
 }
 
        return 0;
 }