//----------------------------------------------------------------------------- // Copyright (C) 2015 piwi // // This code is licensed to you under the terms of the GNU GPL, version 2 or, // at your option, any later version. See the LICENSE.txt file for the text of // the license. //----------------------------------------------------------------------------- // Implements a card only attack based on crypto text (encrypted nonces // received during a nested authentication) only. Unlike other card only // attacks this doesn't rely on implementation errors but only on the // inherent weaknesses of the crypto1 cypher. Described in // Carlo Meijer, Roel Verdult, "Ciphertext-only Cryptanalysis on Hardened // Mifare Classic Cards" in Proceedings of the 22nd ACM SIGSAC Conference on // Computer and Communications Security, 2015 //----------------------------------------------------------------------------- #include #include #include #include #include #include "proxmark3.h" #include "cmdmain.h" #include "ui.h" #include "util.h" #include "nonce2key/crapto1.h" #include "parity.h" // uint32_t test_state_odd = 0; // uint32_t test_state_even = 0; #define CONFIDENCE_THRESHOLD 0.95 // Collect nonces until we are certain enough that the following brute force is successfull #define GOOD_BYTES_REQUIRED 60 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, 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, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0083, 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, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0006, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0339, 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, 0.0048, 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, 0.0934, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0119, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0489, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0602, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.4180, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0602, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0489, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0119, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0934, 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, 0.0048, 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, 0.0339, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0006, 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, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0083, 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, 0.0000, 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; uint8_t par_enc; void *next; } noncelistentry_t; typedef struct noncelist { uint16_t num; uint16_t Sum; uint16_t Sum8_guess; uint8_t BitFlip[2]; float Sum8_prob; bool updated; noncelistentry_t *first; } noncelist_t; static uint32_t cuid; static noncelist_t nonces[256]; static uint16_t first_byte_Sum = 0; static uint16_t first_byte_num = 0; static uint16_t num_good_first_bytes = 0; static uint64_t maximum_states = 0; static uint64_t known_target_key; #define MAX_BEST_BYTES 256 static uint8_t best_first_bytes[MAX_BEST_BYTES]; typedef enum { EVEN_STATE = 0, ODD_STATE = 1 } odd_even_t; #define STATELIST_INDEX_WIDTH 16 #define STATELIST_INDEX_SIZE (1<> 24; noncelistentry_t *p1 = nonces[first_byte].first; noncelistentry_t *p2 = NULL; if (p1 == NULL) { // first nonce with this 1st byte first_byte_num++; first_byte_Sum += evenparity32((nonce_enc & 0xff000000) | (par_enc & 0x08)); // printf("Adding nonce 0x%08x, par_enc 0x%02x, parity(0x%08x) = %d\n", // nonce_enc, // par_enc, // (nonce_enc & 0xff000000) | (par_enc & 0x08) |0x01, // parity((nonce_enc & 0xff000000) | (par_enc & 0x08)); } while (p1 != NULL && (p1->nonce_enc & 0x00ff0000) < (nonce_enc & 0x00ff0000)) { p2 = p1; p1 = p1->next; } if (p1 == NULL) { // need to add at the end of the list if (p2 == NULL) { // list is empty yet. Add first entry. p2 = nonces[first_byte].first = malloc(sizeof(noncelistentry_t)); } else { // add new entry at end of existing list. p2 = p2->next = malloc(sizeof(noncelistentry_t)); } } else if ((p1->nonce_enc & 0x00ff0000) != (nonce_enc & 0x00ff0000)) { // found distinct 2nd byte. Need to insert. if (p2 == NULL) { // need to insert at start of list p2 = nonces[first_byte].first = malloc(sizeof(noncelistentry_t)); } else { p2 = p2->next = malloc(sizeof(noncelistentry_t)); } } else { // we have seen this 2nd byte before. Nothing to add or insert. return (0); } // add or insert new data p2->next = p1; p2->nonce_enc = nonce_enc; p2->par_enc = par_enc; nonces[first_byte].num++; nonces[first_byte].Sum += evenparity32((nonce_enc & 0x00ff0000) | (par_enc & 0x04)); nonces[first_byte].updated = true; // indicates that we need to recalculate the Sum(a8) probability for this first byte return (1); // new nonce added } static uint16_t PartialSumProperty(uint32_t state, odd_even_t odd_even) { uint16_t sum = 0; for (uint16_t j = 0; j < 16; j++) { uint32_t st = state; uint16_t part_sum = 0; if (odd_even == ODD_STATE) { for (uint16_t i = 0; i < 5; i++) { part_sum ^= filter(st); st = (st << 1) | ((j >> (3-i)) & 0x01) ; } part_sum ^= 1; // XOR 1 cancelled out for the other 8 bits } else { for (uint16_t i = 0; i < 4; i++) { st = (st << 1) | ((j >> (3-i)) & 0x01) ; part_sum ^= filter(st); } } sum += part_sum; } return sum; } static uint16_t SumProperty(struct Crypto1State *s) { uint16_t sum_odd = PartialSumProperty(s->odd, ODD_STATE); uint16_t sum_even = PartialSumProperty(s->even, EVEN_STATE); return (sum_odd*(16-sum_even) + (16-sum_odd)*sum_even); } static double p_hypergeometric(uint16_t N, uint16_t K, uint16_t n, uint16_t k) { // for efficient computation we are using the recursive definition // (K-k+1) * (n-k+1) // P(X=k) = P(X=k-1) * -------------------- // k * (N-K-n+k) // and // (N-K)*(N-K-1)*...*(N-K-n+1) // P(X=0) = ----------------------------- // N*(N-1)*...*(N-n+1) if (n-k > N-K || k > K) return 0.0; // avoids log(x<=0) in calculation below if (k == 0) { // use logarithms to avoid overflow with huge factorials (double type can only hold 170!) double log_result = 0.0; for (int16_t i = N-K; i >= N-K-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); } 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; for (int16_t i = k+1; i <= n; i++) { log_result += log(i); } for (int16_t i = K+1; i <= N; i++) { log_result -= log(i); } return exp(log_result); } else { // recursion return (p_hypergeometric(N, K, n, k-1) * (K-k+1) * (n-k+1) / (k * (N-K-n+k))); } } } static float sum_probability(uint16_t K, uint16_t n, uint16_t k) { const uint16_t N = 256; if (k > K || p_K[K] == 0.0) return 0.0; double p_T_is_k_when_S_is_K = p_hypergeometric(N, K, n, k); double p_S_is_K = p_K[K]; double p_T_is_k = 0; for (uint16_t i = 0; i <= 256; i++) { if (p_K[i] != 0.0) { p_T_is_k += p_K[i] * p_hypergeometric(N, i, n, k); } } return(p_T_is_k_when_S_is_K * p_S_is_K / p_T_is_k); } static void Tests() { printf("Tests: Partial Statelist sizes\n"); for (uint16_t i = 0; i <= 16; i+=2) { printf("Partial State List Odd [%2d] has %8d entries\n", i, partial_statelist[i].len[ODD_STATE]); } for (uint16_t i = 0; i <= 16; i+=2) { printf("Partial State List Even [%2d] has %8d entries\n", i, partial_statelist[i].len[EVEN_STATE]); } // #define NUM_STATISTICS 100000 // uint32_t statistics_odd[17]; // uint64_t statistics[257]; // uint32_t statistics_even[17]; // struct Crypto1State cs; // time_t time1 = clock(); // for (uint16_t i = 0; i < 257; i++) { // statistics[i] = 0; // } // for (uint16_t i = 0; i < 17; i++) { // statistics_odd[i] = 0; // statistics_even[i] = 0; // } // for (uint64_t i = 0; i < NUM_STATISTICS; i++) { // cs.odd = (rand() & 0xfff) << 12 | (rand() & 0xfff); // cs.even = (rand() & 0xfff) << 12 | (rand() & 0xfff); // uint16_t sum_property = SumProperty(&cs); // statistics[sum_property] += 1; // sum_property = PartialSumProperty(cs.even, EVEN_STATE); // statistics_even[sum_property]++; // sum_property = PartialSumProperty(cs.odd, ODD_STATE); // statistics_odd[sum_property]++; // if (i%(NUM_STATISTICS/100) == 0) printf("."); // } // printf("\nTests: Calculated %d Sum properties in %0.3f seconds (%0.0f calcs/second)\n", NUM_STATISTICS, ((float)clock() - time1)/CLOCKS_PER_SEC, NUM_STATISTICS/((float)clock() - time1)*CLOCKS_PER_SEC); // for (uint16_t i = 0; i < 257; i++) { // if (statistics[i] != 0) { // printf("probability[%3d] = %0.5f\n", i, (float)statistics[i]/NUM_STATISTICS); // } // } // for (uint16_t i = 0; i <= 16; i++) { // if (statistics_odd[i] != 0) { // printf("probability odd [%2d] = %0.5f\n", i, (float)statistics_odd[i]/NUM_STATISTICS); // } // } // for (uint16_t i = 0; i <= 16; i++) { // if (statistics_odd[i] != 0) { // printf("probability even [%2d] = %0.5f\n", i, (float)statistics_even[i]/NUM_STATISTICS); // } // } // printf("Tests: Sum Probabilities based on Partial Sums\n"); // for (uint16_t i = 0; i < 257; i++) { // statistics[i] = 0; // } // uint64_t num_states = 0; // for (uint16_t oddsum = 0; oddsum <= 16; oddsum += 2) { // for (uint16_t evensum = 0; evensum <= 16; evensum += 2) { // uint16_t sum = oddsum*(16-evensum) + (16-oddsum)*evensum; // statistics[sum] += (uint64_t)partial_statelist[oddsum].len[ODD_STATE] * partial_statelist[evensum].len[EVEN_STATE] * (1<<8); // num_states += (uint64_t)partial_statelist[oddsum].len[ODD_STATE] * partial_statelist[evensum].len[EVEN_STATE] * (1<<8); // } // } // printf("num_states = %lld, expected %lld\n", num_states, (1LL<<48)); // for (uint16_t i = 0; i < 257; i++) { // if (statistics[i] != 0) { // printf("probability[%3d] = %0.5f\n", i, (float)statistics[i]/num_states); // } // } // printf("\nTests: Hypergeometric Probability for selected parameters\n"); // printf("p_hypergeometric(256, 206, 255, 206) = %0.8f\n", p_hypergeometric(256, 206, 255, 206)); // printf("p_hypergeometric(256, 206, 255, 205) = %0.8f\n", p_hypergeometric(256, 206, 255, 205)); // printf("p_hypergeometric(256, 156, 1, 1) = %0.8f\n", p_hypergeometric(256, 156, 1, 1)); // printf("p_hypergeometric(256, 156, 1, 0) = %0.8f\n", p_hypergeometric(256, 156, 1, 0)); // printf("p_hypergeometric(256, 1, 1, 1) = %0.8f\n", p_hypergeometric(256, 1, 1, 1)); // printf("p_hypergeometric(256, 1, 1, 0) = %0.8f\n", p_hypergeometric(256, 1, 1, 0)); struct Crypto1State *pcs; pcs = crypto1_create(0xffffffffffff); printf("\nTests: for key = 0xffffffffffff:\nSum(a0) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); crypto1_byte(pcs, (cuid >> 24) ^ best_first_bytes[0], true); printf("After adding best first byte 0x%02x:\nSum(a8) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", best_first_bytes[0], SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); //test_state_odd = pcs->odd & 0x00ffffff; //test_state_even = pcs->even & 0x00ffffff; crypto1_destroy(pcs); pcs = crypto1_create(0xa0a1a2a3a4a5); printf("Tests: for key = 0xa0a1a2a3a4a5:\nSum(a0) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); crypto1_byte(pcs, (cuid >> 24) ^ best_first_bytes[0], true); printf("After adding best first byte 0x%02x:\nSum(a8) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", best_first_bytes[0], SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); // test_state_odd = pcs->odd & 0x00ffffff; // test_state_even = pcs->even & 0x00ffffff; crypto1_destroy(pcs); pcs = crypto1_create(0xa6b9aa97b955); printf("Tests: for key = 0xa6b9aa97b955:\nSum(a0) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); crypto1_byte(pcs, (cuid >> 24) ^ best_first_bytes[0], true); printf("After adding best first byte 0x%02x:\nSum(a8) = %d\nodd_state = 0x%06x\neven_state = 0x%06x\n", best_first_bytes[0], SumProperty(pcs), pcs->odd & 0x00ffffff, pcs->even & 0x00ffffff); //test_state_odd = pcs->odd & 0x00ffffff; //test_state_even = pcs->even & 0x00ffffff; 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: Actual BitFlipProperties odd/even:\n"); for (uint16_t i = 0; i < 256; i++) { printf("[%02x]:%c%c ", i, nonces[i].BitFlip[ODD_STATE]?'o':' ', nonces[i].BitFlip[EVEN_STATE]?'e':' '); if (i % 8 == 7) { printf("\n"); } } printf("\nTests: Best %d first bytes:\n", MAX_BEST_BYTES); for (uint16_t i = 0; i < MAX_BEST_BYTES; i++) { uint8_t best_byte = best_first_bytes[i]; uint16_t best_num = nonces[best_byte].num; uint16_t best_sum = nonces[best_byte].Sum; uint16_t best_sum8 = nonces[best_byte].Sum8_guess; float confidence = nonces[best_byte].Sum8_prob; printf("#%03d Byte: %02x, n = %2d, k = %2d, Sum(a8): %3d, Confidence: %2.1f%%\n", i, best_byte, best_num, best_sum, best_sum8, confidence*100); } // printf("\nTests: parity performance\n"); // time_t time1p = clock(); // uint32_t par_sum = 0; // for (uint32_t i = 0; i < 100000000; i++) { // par_sum += parity(i); // } // printf("parsum oldparity = %d, time = %1.5fsec\n", par_sum, (float)(clock() - time1p)/CLOCKS_PER_SEC); // time1p = clock(); // par_sum = 0; // for (uint32_t i = 0; i < 100000000; i++) { // par_sum += evenparity32(i); // } // printf("parsum newparity = %d, time = %1.5fsec\n", par_sum, (float)(clock() - time1p)/CLOCKS_PER_SEC); } static int common_bits(uint8_t byte1, uint8_t byte2) { uint8_t common_bits = byte1 ^ byte2; uint8_t j = 0; while ((common_bits & 0x01) == 0 && j < 8) { j++; common_bits >>= 1; } return j; } static void sort_best_first_bytes(void) { // first, sort based on probability for correct guess for (uint16_t i = 0; i < 256; i++ ) { uint16_t j = 0; float prob1 = nonces[i].Sum8_prob; float prob2 = nonces[best_first_bytes[0]].Sum8_prob; while (prob1 < prob2 && j < MAX_BEST_BYTES-1) { prob2 = nonces[best_first_bytes[++j]].Sum8_prob; } if (prob1 >= prob2) { for (uint16_t k = MAX_BEST_BYTES-1; k > j; k--) { best_first_bytes[k] = best_first_bytes[k-1]; } best_first_bytes[j] = i; } } // determine, how many are above the CONFIDENCE_THRESHOLD uint16_t num_good_nonces = 0; for (uint16_t i = 0; i < MAX_BEST_BYTES; i++) { if (nonces[best_first_bytes[i]].Sum8_prob > CONFIDENCE_THRESHOLD) { ++num_good_nonces; } } uint16_t best_first_byte = 0; // select the best possible first byte based on number of common bits with all {b'} // uint16_t max_common_bits = 0; // for (uint16_t i = 0; i < num_good_nonces; i++) { // uint16_t sum_common_bits = 0; // for (uint16_t j = 0; j < num_good_nonces; j++) { // if (i != j) { // sum_common_bits += common_bits(best_first_bytes[i],best_first_bytes[j]); // } // } // if (sum_common_bits > max_common_bits) { // max_common_bits = sum_common_bits; // best_first_byte = i; // } // } // select best possible first byte {b} based on least likely sum/bitflip property float min_p_K = 1.0; for (uint16_t i = 0; i < num_good_nonces; i++ ) { uint16_t sum8 = nonces[best_first_bytes[i]].Sum8_guess; float bitflip_prob = 1.0; if (nonces[best_first_bytes[i]].BitFlip[ODD_STATE] || nonces[best_first_bytes[i]].BitFlip[EVEN_STATE]) { bitflip_prob = 0.09375; } if (p_K[sum8] * bitflip_prob <= min_p_K) { min_p_K = p_K[sum8] * bitflip_prob; best_first_byte = i; } } // use number of commmon bits as a tie breaker uint16_t max_common_bits = 0; for (uint16_t i = 0; i < num_good_nonces; i++) { float bitflip_prob = 1.0; if (nonces[best_first_bytes[i]].BitFlip[ODD_STATE] || nonces[best_first_bytes[i]].BitFlip[EVEN_STATE]) { bitflip_prob = 0.09375; } if (p_K[nonces[best_first_bytes[i]].Sum8_guess] * bitflip_prob == min_p_K) { uint16_t sum_common_bits = 0; for (uint16_t j = 0; j < num_good_nonces; j++) { sum_common_bits += common_bits(best_first_bytes[i],best_first_bytes[j]); } if (sum_common_bits > max_common_bits) { max_common_bits = sum_common_bits; best_first_byte = i; } } } // swap best possible first bytes to the pole position uint16_t temp = best_first_bytes[0]; best_first_bytes[0] = best_first_bytes[best_first_byte]; best_first_bytes[best_first_byte] = temp; } static uint16_t estimate_second_byte_sum(void) { for (uint16_t i = 0; i < MAX_BEST_BYTES; i++) { best_first_bytes[i] = 0; } for (uint16_t first_byte = 0; first_byte < 256; first_byte++) { float Sum8_prob = 0.0; uint16_t Sum8 = 0; if (nonces[first_byte].updated) { for (uint16_t sum = 0; sum <= 256; sum++) { float prob = sum_probability(sum, nonces[first_byte].num, nonces[first_byte].Sum); if (prob > Sum8_prob) { Sum8_prob = prob; Sum8 = sum; } } nonces[first_byte].Sum8_guess = Sum8; nonces[first_byte].Sum8_prob = Sum8_prob; nonces[first_byte].updated = false; } } sort_best_first_bytes(); uint16_t num_good_nonces = 0; for (uint16_t i = 0; i < MAX_BEST_BYTES; i++) { if (nonces[best_first_bytes[i]].Sum8_prob > CONFIDENCE_THRESHOLD) { ++num_good_nonces; } } return num_good_nonces; } static int read_nonce_file(void) { FILE *fnonces = NULL; uint8_t trgBlockNo; uint8_t trgKeyType; uint8_t read_buf[9]; uint32_t nt_enc1, nt_enc2; uint8_t par_enc; int total_num_nonces = 0; if ((fnonces = fopen("nonces.bin","rb")) == NULL) { PrintAndLog("Could not open file nonces.bin"); return 1; } PrintAndLog("Reading nonces from file nonces.bin..."); if (fread(read_buf, 1, 6, fnonces) == 0) { PrintAndLog("File reading error."); fclose(fnonces); return 1; } cuid = bytes_to_num(read_buf, 4); trgBlockNo = bytes_to_num(read_buf+4, 1); trgKeyType = bytes_to_num(read_buf+5, 1); while (fread(read_buf, 1, 9, fnonces) == 9) { nt_enc1 = bytes_to_num(read_buf, 4); nt_enc2 = bytes_to_num(read_buf+4, 4); par_enc = bytes_to_num(read_buf+8, 1); //printf("Encrypted nonce: %08x, encrypted_parity: %02x\n", nt_enc1, par_enc >> 4); //printf("Encrypted nonce: %08x, encrypted_parity: %02x\n", nt_enc2, par_enc & 0x0f); add_nonce(nt_enc1, par_enc >> 4); add_nonce(nt_enc2, par_enc & 0x0f); total_num_nonces += 2; } fclose(fnonces); PrintAndLog("Read %d nonces from file. cuid=%08x, Block=%d, Keytype=%c", total_num_nonces, cuid, trgBlockNo, trgKeyType==0?'A':'B'); return 0; } static int acquire_nonces(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, bool nonce_file_write, bool slow) { clock_t time1 = clock(); bool initialize = true; bool field_off = false; bool finished = false; uint32_t flags = 0; uint8_t write_buf[9]; uint32_t total_num_nonces = 0; uint32_t next_fivehundred = 500; uint32_t total_added_nonces = 0; FILE *fnonces = NULL; UsbCommand resp; printf("Acquiring nonces...\n"); clearCommandBuffer(); do { flags = 0; flags |= initialize ? 0x0001 : 0; flags |= slow ? 0x0002 : 0; flags |= field_off ? 0x0004 : 0; UsbCommand c = {CMD_MIFARE_ACQUIRE_ENCRYPTED_NONCES, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, flags}}; memcpy(c.d.asBytes, key, 6); SendCommand(&c); if (field_off) finished = true; if (initialize) { if (!WaitForResponseTimeout(CMD_ACK, &resp, 3000)) return 1; if (resp.arg[0]) return resp.arg[0]; // error during nested_hard cuid = resp.arg[1]; // PrintAndLog("Acquiring nonces for CUID 0x%08x", cuid); if (nonce_file_write && fnonces == NULL) { if ((fnonces = fopen("nonces.bin","wb")) == NULL) { PrintAndLog("Could not create file nonces.bin"); return 3; } PrintAndLog("Writing acquired nonces to binary file nonces.bin"); num_to_bytes(cuid, 4, write_buf); fwrite(write_buf, 1, 4, fnonces); fwrite(&trgBlockNo, 1, 1, fnonces); fwrite(&trgKeyType, 1, 1, fnonces); } } if (!initialize) { uint32_t nt_enc1, nt_enc2; uint8_t par_enc; uint16_t num_acquired_nonces = resp.arg[2]; uint8_t *bufp = resp.d.asBytes; for (uint16_t i = 0; i < num_acquired_nonces; i+=2) { nt_enc1 = bytes_to_num(bufp, 4); nt_enc2 = bytes_to_num(bufp+4, 4); par_enc = bytes_to_num(bufp+8, 1); //printf("Encrypted nonce: %08x, encrypted_parity: %02x\n", nt_enc1, par_enc >> 4); total_added_nonces += add_nonce(nt_enc1, par_enc >> 4); //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) { fwrite(bufp, 1, 9, fnonces); } bufp += 9; } total_num_nonces += num_acquired_nonces; } if (first_byte_num == 256 ) { // printf("first_byte_num = %d, first_byte_Sum = %d\n", first_byte_num, first_byte_Sum); num_good_first_bytes = estimate_second_byte_sum(); if (total_num_nonces > next_fivehundred) { next_fivehundred = (total_num_nonces/500+1) * 500; printf("Acquired %5d nonces (%5d with distinct bytes 0 and 1). Number of bytes with probability for correctly guessed Sum(a8) > %1.1f%%: %d\n", total_num_nonces, total_added_nonces, 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 (!initialize) { if (!WaitForResponseTimeout(CMD_ACK, &resp, 3000)) return 1; if (resp.arg[0]) return resp.arg[0]; // error during nested_hard } initialize = false; } while (!finished); if (nonce_file_write) { fclose(fnonces); } PrintAndLog("Acquired a total of %d nonces in %1.1f seconds (%0.0f nonces/minute)", total_num_nonces, ((float)clock()-time1)/CLOCKS_PER_SEC, total_num_nonces*60.0*CLOCKS_PER_SEC/((float)clock()-time1)); return 0; } 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 }; printf("Allocating memory for partial statelists...\n"); for (odd_even_t odd_even = EVEN_STATE; odd_even <= ODD_STATE; odd_even++) { for (uint16_t i = 0; i <= 16; i+=2) { partial_statelist[i].len[odd_even] = 0; uint32_t num_of_states = odd_even == ODD_STATE ? sizes_odd[i] : sizes_even[i]; partial_statelist[i].states[odd_even] = malloc(sizeof(uint32_t) * num_of_states); if (partial_statelist[i].states[odd_even] == NULL) { PrintAndLog("Cannot allocate enough memory. Aborting"); return 4; } for (uint32_t j = 0; j < STATELIST_INDEX_SIZE; j++) { partial_statelist[i].index[odd_even][j] = NULL; } } } printf("Generating partial statelists...\n"); for (odd_even_t odd_even = EVEN_STATE; odd_even <= ODD_STATE; odd_even++) { uint32_t index = -1; uint32_t num_of_states = 1<<20; for (uint32_t state = 0; state < num_of_states; state++) { uint16_t sum_property = PartialSumProperty(state, odd_even); uint32_t *p = partial_statelist[sum_property].states[odd_even]; p += partial_statelist[sum_property].len[odd_even]; *p = state; partial_statelist[sum_property].len[odd_even]++; uint32_t index_mask = (STATELIST_INDEX_SIZE-1) << (20-STATELIST_INDEX_WIDTH); if ((state & index_mask) != index) { index = state & index_mask; } if (partial_statelist[sum_property].index[odd_even][index >> (20-STATELIST_INDEX_WIDTH)] == NULL) { partial_statelist[sum_property].index[odd_even][index >> (20-STATELIST_INDEX_WIDTH)] = p; } } // add End Of List markers 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; } } return 0; } static void init_BitFlip_statelist(void) { printf("Generating bitflip statelist...\n"); uint32_t *p = statelist_bitflip.states[0] = malloc(sizeof(uint32_t) * 1<<20); uint32_t index = -1; uint32_t index_mask = (STATELIST_INDEX_SIZE-1) << (20-STATELIST_INDEX_WIDTH); for (uint32_t state = 0; state < (1 << 20); state++) { if (filter(state) != filter(state^1)) { if ((state & index_mask) != index) { index = state & index_mask; } if (statelist_bitflip.index[0][index >> (20-STATELIST_INDEX_WIDTH)] == NULL) { statelist_bitflip.index[0][index >> (20-STATELIST_INDEX_WIDTH)] = p; } *p++ = state; } } // set len and add End Of List marker statelist_bitflip.len[0] = p - statelist_bitflip.states[0]; *p = 0xffffffff; statelist_bitflip.states[0] = realloc(statelist_bitflip.states[0], sizeof(uint32_t) * (statelist_bitflip.len[0] + 1)); } static void add_state(statelist_t *sl, uint32_t state, odd_even_t odd_even) { uint32_t *p; p = sl->states[odd_even]; p += sl->len[odd_even]; *p = state; sl->len[odd_even]++; } static uint32_t *find_first_state(uint32_t state, uint32_t mask, partial_indexed_statelist_t *sl, odd_even_t odd_even) { uint32_t *p = sl->index[odd_even][(state & mask) >> (20-STATELIST_INDEX_WIDTH)]; // first Bits as index if (p == NULL) return NULL; while ((*p & mask) < (state & mask)) p++; if (*p == 0xffffffff) return NULL; // reached end of list, no match if ((*p & mask) == (state & mask)) return p; // found a match. return NULL; // no match } static bool remaining_bits_match(uint8_t num_common_bits, uint8_t byte1, uint8_t byte2, uint32_t state1, uint32_t state2, odd_even_t odd_even) { uint8_t j = num_common_bits; if (odd_even == ODD_STATE) { j |= 0x01; // consider the next odd bit } else { j = (j+1) & 0xfe; // consider the next even bit } while (j <= 7) { if (j != num_common_bits) { // this is not the first differing bit, we need first to check if the invariant still holds uint32_t bit_diff = ((byte1 ^ byte2) << (17-j)) & 0x00010000; // difference of (j-1)th bit -> bit 16 uint32_t filter_diff = filter(state1 >> (4-j/2)) ^ filter(state2 >> (4-j/2)); // difference in filter function -> bit 0 uint32_t mask_y12_y13 = 0x000000c0 >> (j/2); uint32_t state_diff = (state1 ^ state2) & mask_y12_y13; // difference in state bits 12 and 13 -> bits 6/7 ... 3/4 uint32_t all_diff = parity(bit_diff | state_diff | filter_diff); // use parity function to XOR all 4 bits if (all_diff) { // invariant doesn't hold any more. Accept this state. // if ((odd_even == ODD_STATE && state1 == test_state_odd) // || (odd_even == EVEN_STATE && state1 == test_state_even)) { // printf("remaining_bits_match(): %s test state: Invariant doesn't hold. Bytes = %02x, %02x, Common Bits=%d, Testing Bit %d, State1=0x%08x, State2=0x%08x\n", // odd_even==ODD_STATE?"odd":"even", byte1, byte2, num_common_bits, j, state1, state2); // } return true; } } // check for validity of state candidate uint32_t bit_diff = ((byte1 ^ byte2) << (16-j)) & 0x00010000; // difference of jth bit -> bit 16 uint32_t mask_y13_y16 = 0x00000048 >> (j/2); uint32_t state_diff = (state1 ^ state2) & mask_y13_y16; // difference in state bits 13 and 16 -> bits 3/6 ... 0/3 uint32_t all_diff = parity(bit_diff | state_diff); // use parity function to XOR all 3 bits if (all_diff) { // not a valid state // if ((odd_even == ODD_STATE && state1 == test_state_odd) // || (odd_even == EVEN_STATE && state1 == test_state_even)) { // printf("remaining_bits_match(): %s test state: Invalid state. Bytes = %02x, %02x, Common Bits=%d, Testing Bit %d, State1=0x%08x, State2=0x%08x\n", // odd_even==ODD_STATE?"odd":"even", byte1, byte2, num_common_bits, j, state1, state2); // printf(" byte1^byte2: 0x%02x, bit_diff: 0x%08x, state_diff: 0x%08x, all_diff: 0x%08x\n", // byte1^byte2, bit_diff, state_diff, all_diff); // } return false; } // continue checking for the next bit j += 2; } return true; // valid state } static bool all_other_first_bytes_match(uint32_t state, odd_even_t odd_even) { for (uint16_t i = 1; i < num_good_first_bytes; i++) { uint16_t sum_a8 = nonces[best_first_bytes[i]].Sum8_guess; uint8_t j = 0; // number of common bits uint8_t common_bits = best_first_bytes[0] ^ best_first_bytes[i]; uint32_t mask = 0xfffffff0; if (odd_even == ODD_STATE) { while ((common_bits & 0x01) == 0 && j < 8) { j++; common_bits >>= 1; if (j % 2 == 0) { // the odd bits mask >>= 1; } } } else { while ((common_bits & 0x01) == 0 && j < 8) { j++; common_bits >>= 1; if (j % 2 == 1) { // the even bits mask >>= 1; } } } mask &= 0x000fffff; //printf("bytes 0x%02x and 0x%02x: %d common bits, mask = 0x%08x, state = 0x%08x, sum_a8 = %d", best_first_bytes[0], best_first_bytes[i], j, mask, state, sum_a8); bool found_match = false; for (uint16_t r = 0; r <= 16 && !found_match; r += 2) { for (uint16_t s = 0; s <= 16 && !found_match; s += 2) { if (r*(16-s) + (16-r)*s == sum_a8) { //printf("Checking byte 0x%02x for partial sum (%s) %d\n", best_first_bytes[i], odd_even==ODD_STATE?"odd":"even", odd_even==ODD_STATE?r:s); 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)) { if (remaining_bits_match(j, best_first_bytes[0], best_first_bytes[i], state, (state&0x00fffff0) | *p, odd_even)) { found_match = true; // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: remaining bits matched. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } break; } else { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: remaining bits didn't match. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } } p++; } } else { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: couldn't find a matching state. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } } } } } if (!found_match) { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: Eliminated. Bytes = %02x, %02x, Common Bits = %d\n", odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j); // } return false; } } return true; } static bool all_bit_flips_match(uint32_t state, odd_even_t odd_even) { for (uint16_t i = 0; i < 256; i++) { if (nonces[i].BitFlip[odd_even] && i != best_first_bytes[0]) { uint8_t j = 0; // number of common bits uint8_t common_bits = best_first_bytes[0] ^ i; uint32_t mask = 0xfffffff0; if (odd_even == ODD_STATE) { while ((common_bits & 0x01) == 0 && j < 8) { j++; common_bits >>= 1; if (j % 2 == 0) { // the odd bits mask >>= 1; } } } else { while ((common_bits & 0x01) == 0 && j < 8) { j++; common_bits >>= 1; if (j % 2 == 1) { // the even bits mask >>= 1; } } } mask &= 0x000fffff; //printf("bytes 0x%02x and 0x%02x: %d common bits, mask = 0x%08x, state = 0x%08x, sum_a8 = %d", best_first_bytes[0], best_first_bytes[i], j, mask, state, sum_a8); 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)) { if (remaining_bits_match(j, best_first_bytes[0], i, state, (state&0x00fffff0) | *p, odd_even)) { found_match = true; // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: remaining bits matched. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } break; } else { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: remaining bits didn't match. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } } p++; } } else { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: couldn't find a matching state. Bytes = %02x, %02x, Common Bits=%d, mask=0x%08x, PartSum(a8)=%d\n", // odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j, mask, part_sum_a8); // } } if (!found_match) { // if ((odd_even == ODD_STATE && state == test_state_odd) // || (odd_even == EVEN_STATE && state == test_state_even)) { // printf("all_other_first_bytes_match(): %s test state: Eliminated. Bytes = %02x, %02x, Common Bits = %d\n", odd_even==ODD_STATE?"odd":"even", best_first_bytes[0], best_first_bytes[i], j); // } return false; } } } return true; } #define INVALID_BIT (1<<30) #define SET_INVALID(pstate) (*(pstate) |= INVALID_BIT) #define IS_INVALID(state) (state & INVALID_BIT) static int add_matching_states(statelist_t *candidates, uint16_t part_sum_a0, uint16_t part_sum_a8, odd_even_t odd_even) { uint32_t worstcase_size = 1<<20; candidates->states[odd_even] = (uint32_t *)malloc(sizeof(uint32_t) * worstcase_size); if (candidates->states[odd_even] == NULL) { PrintAndLog("Out of memory error.\n"); return 4; } for (uint32_t *p1 = partial_statelist[part_sum_a0].states[odd_even]; *p1 != 0xffffffff; 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) { while (((*p1 << 4) & search_mask) == (*p2 & search_mask) && *p2 != 0xffffffff) { if (all_other_first_bytes_match((*p1 << 4) | *p2, odd_even)) { if (all_bit_flips_match((*p1 << 4) | *p2, odd_even)) { add_state(candidates, (*p1 << 4) | *p2, odd_even); } } p2++; } } } // set end of list marker uint32_t *p = candidates->states[odd_even]; p += candidates->len[odd_even]; *p = 0xffffffff; candidates->states[odd_even] = realloc(candidates->states[odd_even], sizeof(uint32_t) * (candidates->len[odd_even] + 1)); return 0; } static statelist_t *add_more_candidates(statelist_t *current_candidates) { statelist_t *new_candidates = NULL; if (current_candidates == NULL) { if (candidates == NULL) { candidates = (statelist_t *)malloc(sizeof(statelist_t)); } new_candidates = candidates; } else { new_candidates = current_candidates->next = (statelist_t *)malloc(sizeof(statelist_t)); } new_candidates->next = NULL; new_candidates->len[ODD_STATE] = 0; new_candidates->len[EVEN_STATE] = 0; new_candidates->states[ODD_STATE] = NULL; new_candidates->states[EVEN_STATE] = NULL; return new_candidates; } static void TestIfKeyExists(uint64_t key) { struct Crypto1State *pcs; pcs = crypto1_create(key); crypto1_byte(pcs, (cuid >> 24) ^ best_first_bytes[0], true); uint32_t state_odd = pcs->odd & 0x00ffffff; uint32_t state_even = pcs->even & 0x00ffffff; //printf("Tests: searching for key %llx after first byte 0x%02x (state_odd = 0x%06x, state_even = 0x%06x) ...\n", key, best_first_bytes[0], state_odd, state_even); uint64_t count = 0; for (statelist_t *p = candidates; p != NULL; p = p->next) { bool found_odd = false; bool found_even = false; uint32_t *p_odd = p->states[ODD_STATE]; uint32_t *p_even = p->states[EVEN_STATE]; while (*p_odd != 0xffffffff) { if ((*p_odd & 0x00ffffff) == state_odd) { found_odd = true; break; } p_odd++; } while (*p_even != 0xffffffff) { if ((*p_even & 0x00ffffff) == state_even) { found_even = true; } p_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>>22)/60); crypto1_destroy(pcs); return; } } printf("Key NOT found!\n"); crypto1_destroy(pcs); } static void generate_candidates(uint16_t sum_a0, uint16_t sum_a8) { printf("Generating crypto1 state candidates... \n"); statelist_t *current_candidates = NULL; // estimate maximum candidate states maximum_states = 0; for (uint16_t sum_odd = 0; sum_odd <= 16; sum_odd += 2) { for (uint16_t sum_even = 0; sum_even <= 16; sum_even += 2) { if (sum_odd*(16-sum_even) + (16-sum_odd)*sum_even == sum_a0) { maximum_states += (uint64_t)partial_statelist[sum_odd].len[ODD_STATE] * partial_statelist[sum_even].len[EVEN_STATE] * (1<<8); } } } printf("Number of possible keys with Sum(a0) = %d: %lld (2^%1.1f)\n", sum_a0, maximum_states, log(maximum_states)/log(2.0)); 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]); 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) { current_candidates = add_more_candidates(current_candidates); add_matching_states(current_candidates, p, r, ODD_STATE); printf("Odd state candidates: %d (2^%0.1f)\n", current_candidates->len[ODD_STATE], log(current_candidates->len[ODD_STATE])/log(2)); add_matching_states(current_candidates, q, s, EVEN_STATE); printf("Even state candidates: %d (2^%0.1f)\n", current_candidates->len[EVEN_STATE], log(current_candidates->len[EVEN_STATE])/log(2)); } } } } } } 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: %lld (2^%1.1f)\n", maximum_states, log(maximum_states)/log(2.0)); } static void Check_for_FilterFlipProperties(void) { printf("Checking for Filter Flip Properties...\n"); for (uint16_t i = 0; i < 256; i++) { nonces[i].BitFlip[ODD_STATE] = false; nonces[i].BitFlip[EVEN_STATE] = false; } for (uint16_t i = 0; i < 256; i++) { uint8_t parity1 = (nonces[i].first->par_enc) >> 3; // parity of first byte uint8_t parity2_odd = (nonces[i^0x80].first->par_enc) >> 3; // XOR 0x80 = last bit flipped uint8_t parity2_even = (nonces[i^0x40].first->par_enc) >> 3; // XOR 0x40 = second last bit flipped if (parity1 == parity2_odd) { // has Bit Flip Property for odd bits nonces[i].BitFlip[ODD_STATE] = true; } else if (parity1 == parity2_even) { // has Bit Flip Property for even bits nonces[i].BitFlip[EVEN_STATE] = true; } } } static void brute_force(void) { if (known_target_key != -1) { PrintAndLog("Looking for known target key in remaining key space..."); TestIfKeyExists(known_target_key); return; } else { PrintAndLog("Brute Force phase is not implemented."); return; } } 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) { if (trgkey != NULL) { known_target_key = bytes_to_num(trgkey, 6); } else { known_target_key = -1; } // initialize the list of nonces for (uint16_t i = 0; i < 256; i++) { nonces[i].num = 0; nonces[i].Sum = 0; nonces[i].Sum8_guess = 0; nonces[i].Sum8_prob = 0.0; nonces[i].updated = true; nonces[i].first = NULL; } first_byte_num = 0; first_byte_Sum = 0; num_good_first_bytes = 0; init_partial_statelists(); init_BitFlip_statelist(); if (nonce_file_read) { // use pre-acquired data from file nonces.bin if (read_nonce_file() != 0) { return 3; } num_good_first_bytes = MIN(estimate_second_byte_sum(), GOOD_BYTES_REQUIRED); } 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; } } Check_for_FilterFlipProperties(); Tests(); 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], // best_first_bytes[2], // best_first_bytes[3], // best_first_bytes[4], // best_first_bytes[5], // best_first_bytes[6], // 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); generate_candidates(first_byte_Sum, nonces[best_first_bytes[0]].Sum8_guess); brute_force(); return 0; }