cvs.zerfleddert.de Git - proxmark3-svn/blob - client/mifarehost.c

   1 // Merlok, 2011, 2012
   2 // people from mifare@nethemba.com, 2010
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // mifare commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include "mifarehost.h"
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <pthread.h>
  17
  18 #include "crapto1/crapto1.h"
  19 #include "proxmark3.h"
  20 #include "usb_cmd.h"
  21 #include "cmdmain.h"
  22 #include "ui.h"
  23 #include "util.h"
  24 #include "iso14443crc.h"
  25
  26 #include "mifare.h"
  27
  28 // mifare tracer flags used in mfTraceDecode()
  29 #define TRACE_IDLE                                              0x00
  30 #define TRACE_AUTH1                                             0x01
  31 #define TRACE_AUTH2                                             0x02
  32 #define TRACE_AUTH_OK                                   0x03
  33 #define TRACE_READ_DATA                                 0x04
  34 #define TRACE_WRITE_OK                                  0x05
  35 #define TRACE_WRITE_DATA                                0x06
  36 #define TRACE_ERROR                                             0xFF
  37
  38
  39 static int compare_uint64(const void *a, const void *b) {
  40         // didn't work: (the result is truncated to 32 bits)
  41         //return (*(int64_t*)b - *(int64_t*)a);
  42
  43         // better:
  44         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  45         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
  46         else return -1;
  47 }
  48
  49
  50 // create the intersection (common members) of two sorted lists. Lists are terminated by -1. Result will be in list1. Number of elements is returned.
  51 static uint32_t intersection(uint64_t *list1, uint64_t *list2)
  52 {
  53         if (list1 == NULL || list2 == NULL) {
  54                 return 0;
  55         }
  56         uint64_t *p1, *p2, *p3;
  57         p1 = p3 = list1;
  58         p2 = list2;
  59
  60         while ( *p1 != -1 && *p2 != -1 ) {
  61                 if (compare_uint64(p1, p2) == 0) {
  62                         *p3++ = *p1++;
  63                         p2++;
  64                 }
  65                 else {
  66                         while (compare_uint64(p1, p2) < 0) ++p1;
  67                         while (compare_uint64(p1, p2) > 0) ++p2;
  68                 }
  69         }
  70         *p3 = -1;
  71         return p3 - list1;
  72 }
  73
  74
  75 // Darkside attack (hf mf mifare)
  76 static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {
  77         struct Crypto1State *states;
  78         uint32_t i, pos, rr; //nr_diff;
  79         uint8_t bt, ks3x[8], par[8][8];
  80         uint64_t key_recovered;
  81         static uint64_t *keylist;
  82         rr = 0;
  83
  84         // Reset the last three significant bits of the reader nonce
  85         nr &= 0xffffff1f;
  86
  87         for (pos=0; pos<8; pos++) {
  88                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  89                 bt = (par_info >> (pos*8)) & 0xff;
  90                 for (i=0; i<8; i++)     {
  91                                 par[7-pos][i] = (bt >> i) & 0x01;
  92                 }
  93         }
  94
  95         states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));
  96
  97         if (states == NULL) {
  98                 *keys = NULL;
  99                 return 0;
 100         }
 101
 102         keylist = (uint64_t*)states;
 103
 104         for (i = 0; keylist[i]; i++) {
 105                 lfsr_rollback_word(states+i, uid^nt, 0);
 106                 crypto1_get_lfsr(states+i, &key_recovered);
 107                 keylist[i] = key_recovered;
 108         }
 109         keylist[i] = -1;
 110
 111         *keys = keylist;
 112         return i;
 113 }
 114
 115
 116 int mfDarkside(uint64_t *key)
 117 {
 118         uint32_t uid = 0;
 119         uint32_t nt = 0, nr = 0;
 120         uint64_t par_list = 0, ks_list = 0;
 121         uint64_t *keylist = NULL, *last_keylist = NULL;
 122         uint32_t keycount = 0;
 123         int16_t isOK = 0;
 124
 125         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
 126
 127         // message
 128         printf("-------------------------------------------------------------------------\n");
 129         printf("Executing command. Expected execution time: 25sec on average\n");
 130         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
 131         printf("-------------------------------------------------------------------------\n");
 132
 133
 134         while (true) {
 135                 clearCommandBuffer();
 136                 SendCommand(&c);
 137
 138                 //flush queue
 139                 while (ukbhit()) {
 140                         int c = getchar(); (void) c;
 141                 }
 142
 143                 // wait cycle
 144                 while (true) {
 145                         printf(".");
 146                         fflush(stdout);
 147                         if (ukbhit()) {
 148                                 return -5;
 149                                 break;
 150                         }
 151
 152                         UsbCommand resp;
 153                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
 154                                 isOK  = resp.arg[0];
 155                                 if (isOK < 0) {
 156                                         return isOK;
 157                                 }
 158                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
 159                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
 160                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);
 161                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
 162                                 nr = bytes_to_num(resp.d.asBytes + 24, 4);
 163                                 break;
 164                         }
 165                 }
 166
 167                 if (par_list == 0 && c.arg[0] == true) {
 168                         PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");
 169                         PrintAndLog("Attack will take a few seconds longer because we need two consecutive successful runs.");
 170                 }
 171                 c.arg[0] = false;
 172
 173                 keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);
 174
 175                 if (keycount == 0) {
 176                         PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);
 177                         PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce...");
 178                         continue;
 179                 }
 180
 181                 qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
 182                 keycount = intersection(last_keylist, keylist);
 183                 if (keycount == 0) {
 184                         free(last_keylist);
 185                         last_keylist = keylist;
 186                         continue;
 187                 }
 188
 189                 if (keycount > 1) {
 190                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 191                 } else {
 192                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 193                 }
 194
 195                 *key = -1;
 196                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 197                 int max_keys = USB_CMD_DATA_SIZE/6;
 198                 for (int i = 0; i < keycount; i += max_keys) {
 199                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 200                         for (int j = 0; j < size; j++) {
 201                                 if (last_keylist == NULL) {
 202                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock);
 203                                 } else {
 204                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock);
 205                                 }
 206                         }
 207                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 208                                 break;
 209                         }
 210                 }
 211
 212                 if (*key != -1) {
 213                         free(last_keylist);
 214                         free(keylist);
 215                         break;
 216                 } else {
 217                         PrintAndLog("Authentication failed. Trying again...");
 218                         free(last_keylist);
 219                         last_keylist = keylist;
 220                 }
 221         }
 222
 223         return 0;
 224 }
 225
 226
 227 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 228
 229         *key = -1;
 230
 231         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType & 0xff) << 8)), clear_trace, keycnt}};
 232         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 233         SendCommand(&c);
 234
 235         UsbCommand resp;
 236         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 237         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 238         *key = bytes_to_num(resp.d.asBytes, 6);
 239         return 0;
 240 }
 241
 242 int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){
 243
 244         uint8_t keyPtr = 0;
 245
 246         if (e_sector == NULL)
 247                 return -1;
 248
 249         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}};
 250         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 251         SendCommand(&c);
 252
 253         UsbCommand resp;
 254         if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth
 255         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 256
 257         bool foundAKey = false;
 258         for(int sec = 0; sec < sectorCnt; sec++){
 259                 for(int keyAB = 0; keyAB < 2; keyAB++){
 260                         keyPtr = *(resp.d.asBytes + keyAB * 40 + sec);
 261                         if (keyPtr){
 262                                 e_sector[sec].foundKey[keyAB] = true;
 263                                 e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6);
 264                                 foundAKey = true;
 265                         }
 266                 }
 267         }
 268         return foundAKey ? 0 : 3;
 269 }
 270
 271 // Compare 16 Bits out of cryptostate
 272 int Compare16Bits(const void * a, const void * b) {
 273         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 274         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
 275         else return -1;
 276 }
 277
 278 typedef
 279         struct {
 280                 union {
 281                         struct Crypto1State *slhead;
 282                         uint64_t *keyhead;
 283                 } head;
 284                 union {
 285                         struct Crypto1State *sltail;
 286                         uint64_t *keytail;
 287                 } tail;
 288                 uint32_t len;
 289                 uint32_t uid;
 290                 uint32_t blockNo;
 291                 uint32_t keyType;
 292                 uint32_t nt;
 293                 uint32_t ks1;
 294         } StateList_t;
 295
 296
 297 // wrapper function for multi-threaded lfsr_recovery32
 298 void* nested_worker_thread(void *arg)
 299 {
 300         struct Crypto1State *p1;
 301         StateList_t *statelist = arg;
 302
 303         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 304         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 305         statelist->len = p1 - statelist->head.slhead;
 306         statelist->tail.sltail = --p1;
 307         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 308
 309         return statelist->head.slhead;
 310 }
 311
 312 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
 313 {
 314         uint16_t i;
 315         uint32_t uid;
 316         UsbCommand resp;
 317
 318         StateList_t statelists[2];
 319         struct Crypto1State *p1, *p2, *p3, *p4;
 320
 321         // flush queue
 322         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 323
 324         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 325         memcpy(c.d.asBytes, key, 6);
 326         SendCommand(&c);
 327
 328         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 329                 return -1;
 330         }
 331
 332         if (resp.arg[0]) {
 333                 return resp.arg[0];  // error during nested
 334         }
 335
 336         memcpy(&uid, resp.d.asBytes, 4);
 337         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 338
 339         for (i = 0; i < 2; i++) {
 340                 statelists[i].blockNo = resp.arg[2] & 0xff;
 341                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 342                 statelists[i].uid = uid;
 343                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 344                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 345         }
 346
 347         // calc keys
 348
 349         pthread_t thread_id[2];
 350
 351         // create and run worker threads
 352         for (i = 0; i < 2; i++) {
 353                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 354         }
 355
 356         // wait for threads to terminate:
 357         for (i = 0; i < 2; i++) {
 358                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 359         }
 360
 361
 362         // the first 16 Bits of the cryptostate already contain part of our key.
 363         // Create the intersection of the two lists based on these 16 Bits and
 364         // roll back the cryptostate
 365         p1 = p3 = statelists[0].head.slhead;
 366         p2 = p4 = statelists[1].head.slhead;
 367         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 368                 if (Compare16Bits(p1, p2) == 0) {
 369                         struct Crypto1State savestate, *savep = &savestate;
 370                         savestate = *p1;
 371                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 372                                 *p3 = *p1;
 373                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 374                                 p3++;
 375                                 p1++;
 376                         }
 377                         savestate = *p2;
 378                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 379                                 *p4 = *p2;
 380                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 381                                 p4++;
 382                                 p2++;
 383                         }
 384                 }
 385                 else {
 386                         while (Compare16Bits(p1, p2) == -1) p1++;
 387                         while (Compare16Bits(p1, p2) == 1) p2++;
 388                 }
 389         }
 390         *(uint64_t*)p3 = -1;
 391         *(uint64_t*)p4 = -1;
 392         statelists[0].len = p3 - statelists[0].head.slhead;
 393         statelists[1].len = p4 - statelists[1].head.slhead;
 394         statelists[0].tail.sltail=--p3;
 395         statelists[1].tail.sltail=--p4;
 396
 397         // the statelists now contain possible keys. The key we are searching for must be in the
 398         // intersection of both lists. Create the intersection:
 399         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 400         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 401         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 402
 403         memset(resultKey, 0, 6);
 404         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 405         for (i = 0; i < statelists[0].len; i++) {
 406                 uint8_t keyBlock[6];
 407                 uint64_t key64;
 408                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 409                 num_to_bytes(key64, 6, keyBlock);
 410                 key64 = 0;
 411                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 412                         num_to_bytes(key64, 6, resultKey);
 413                         break;
 414                 }
 415         }
 416
 417         free(statelists[0].head.slhead);
 418         free(statelists[1].head.slhead);
 419
 420         return 0;
 421 }
 422
 423 // EMULATOR
 424
 425 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 426         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 427         SendCommand(&c);
 428
 429   UsbCommand resp;
 430         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 431         memcpy(data, resp.d.asBytes, blocksCount * 16);
 432         return 0;
 433 }
 434
 435 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 436         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 437         memcpy(c.d.asBytes, data, blocksCount * 16);
 438         SendCommand(&c);
 439         return 0;
 440 }
 441
 442 // "MAGIC" CARD
 443
 444 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 445         uint8_t isOK = 0;
 446
 447         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 448         SendCommand(&c);
 449
 450         UsbCommand resp;
 451         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 452                 isOK  = resp.arg[0] & 0xff;
 453                 memcpy(data, resp.d.asBytes, 16);
 454                 if (!isOK) return 2;
 455         } else {
 456                 PrintAndLog("Command execute timeout");
 457                 return 1;
 458         }
 459         return 0;
 460 }
 461
 462 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 463
 464         uint8_t isOK = 0;
 465         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 466         memcpy(c.d.asBytes, data, 16);
 467         SendCommand(&c);
 468
 469         UsbCommand resp;
 470         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 471                 isOK  = resp.arg[0] & 0xff;
 472                 if (uid != NULL)
 473                         memcpy(uid, resp.d.asBytes, 4);
 474                 if (!isOK)
 475                         return 2;
 476         } else {
 477                 PrintAndLog("Command execute timeout");
 478                 return 1;
 479         }
 480
 481         return 0;
 482 }
 483
 484 int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) {
 485         uint8_t isOK = 0;
 486         uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04;
 487         UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}};
 488         SendCommand(&c);
 489
 490         UsbCommand resp;
 491         WaitForResponse(CMD_ACK,&resp);
 492         isOK  = resp.arg[0] & 0xff;
 493
 494         return isOK;
 495 }
 496
 497 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) {
 498         uint8_t oldblock0[16] = {0x00};
 499         uint8_t block0[16] = {0x00};
 500         int gen = 0, res;
 501
 502         gen = mfCIdentify();
 503
 504         /* generation 1a magic card by default */
 505         uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;
 506         if (gen == 2) {
 507                 /* generation 1b magic card */
 508                 cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;
 509         }
 510
 511         res = mfCGetBlock(0, oldblock0, cmdParams);
 512
 513         if (res == 0) {
 514                 memcpy(block0, oldblock0, 16);
 515                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 516         } else {
 517                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 518         }
 519
 520         // fill in the new values
 521         // UID
 522         memcpy(block0, uid, 4);
 523         // Mifare UID BCC
 524         block0[4] = block0[0] ^ block0[1] ^ block0[2] ^ block0[3];
 525         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 526         if (sak != NULL)
 527                 block0[5] = sak[0];
 528         if (atqa != NULL) {
 529                 block0[6] = atqa[1];
 530                 block0[7] = atqa[0];
 531         }
 532         PrintAndLog("new block 0:  %s", sprint_hex(block0, 16));
 533
 534         res = mfCSetBlock(0, block0, oldUID, false, cmdParams);
 535         if (res) {
 536                 PrintAndLog("Can't set block 0. Error: %d", res);
 537                 return res;
 538         }
 539
 540         return 0;
 541 }
 542
 543 int mfCIdentify() {
 544         UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};
 545         SendCommand(&c);
 546         UsbCommand resp;
 547         WaitForResponse(CMD_ACK,&resp);
 548
 549         uint8_t isGeneration = resp.arg[0] & 0xff;
 550         switch( isGeneration ){
 551                 case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break;
 552                 case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break;
 553                 default: PrintAndLog("No chinese magic backdoor command detected"); break;
 554         }
 555
 556         return (int) isGeneration;
 557 }
 558
 559
 560 // SNIFFER
 561
 562 // constants
 563 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 564
 565 // variables
 566 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 567 static uint8_t traceCard[4096] = {0x00};
 568 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 569 static int traceState = TRACE_IDLE;
 570 static uint8_t traceCurBlock = 0;
 571 static uint8_t traceCurKey = 0;
 572
 573 struct Crypto1State *traceCrypto1 = NULL;
 574
 575 struct Crypto1State *revstate;
 576 uint64_t lfsr;
 577 uint32_t ks2;
 578 uint32_t ks3;
 579
 580 uint32_t uid;     // serial number
 581 uint32_t nt;      // tag challenge
 582 uint32_t nr_enc;  // encrypted reader challenge
 583 uint32_t ar_enc;  // encrypted reader response
 584 uint32_t at_enc;  // encrypted tag response
 585
 586 int isTraceCardEmpty(void) {
 587         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 588 }
 589
 590 int isBlockEmpty(int blockN) {
 591         for (int i = 0; i < 16; i++)
 592                 if (traceCard[blockN * 16 + i] != 0) return 0;
 593
 594         return 1;
 595 }
 596
 597 int isBlockTrailer(int blockN) {
 598  return ((blockN & 0x03) == 0x03);
 599 }
 600
 601 int saveTraceCard(void) {
 602         FILE * f;
 603
 604         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 605
 606         f = fopen(traceFileName, "w+");
 607         if ( !f ) return 1;
 608
 609         for (int i = 0; i < 64; i++) {  // blocks
 610                 for (int j = 0; j < 16; j++)  // bytes
 611                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 612                 if (i < 63)
 613                         fprintf(f,"\n");
 614         }
 615         fclose(f);
 616         return 0;
 617 }
 618
 619 int loadTraceCard(uint8_t *tuid) {
 620         FILE * f;
 621         char buf[64] = {0x00};
 622         uint8_t buf8[64] = {0x00};
 623         int i, blockNum;
 624
 625         if (!isTraceCardEmpty())
 626                 saveTraceCard();
 627
 628         memset(traceCard, 0x00, 4096);
 629         memcpy(traceCard, tuid + 3, 4);
 630
 631         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 632
 633         f = fopen(traceFileName, "r");
 634         if (!f) return 1;
 635
 636         blockNum = 0;
 637
 638         while(!feof(f)){
 639
 640                 memset(buf, 0, sizeof(buf));
 641                 if (fgets(buf, sizeof(buf), f) == NULL) {
 642                         PrintAndLog("File reading error.");
 643                         fclose(f);
 644                         return 2;
 645         }
 646
 647                 if (strlen(buf) < 32){
 648                         if (feof(f)) break;
 649                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 650                         fclose(f);
 651                         return 2;
 652                 }
 653                 for (i = 0; i < 32; i += 2)
 654                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 655
 656                 memcpy(traceCard + blockNum * 16, buf8, 16);
 657
 658                 blockNum++;
 659         }
 660         fclose(f);
 661
 662         return 0;
 663 }
 664
 665 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 666
 667         if (traceCrypto1)
 668                 crypto1_destroy(traceCrypto1);
 669
 670         traceCrypto1 = NULL;
 671
 672         if (wantSaveToEmlFile)
 673                 loadTraceCard(tuid);
 674
 675         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 676         traceCard[5] = sak;
 677         memcpy(&traceCard[6], atqa, 2);
 678         traceCurBlock = 0;
 679         uid = bytes_to_num(tuid + 3, 4);
 680
 681         traceState = TRACE_IDLE;
 682
 683         return 0;
 684 }
 685
 686 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 687         uint8_t bt = 0;
 688         int i;
 689
 690         if (len != 1) {
 691                 for (i = 0; i < len; i++)
 692                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 693         } else {
 694                 bt = 0;
 695                 for (i = 0; i < 4; i++)
 696                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 697
 698                 data[0] = bt;
 699         }
 700         return;
 701 }
 702
 703
 704 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 705         uint8_t data[64];
 706
 707         if (traceState == TRACE_ERROR) return 1;
 708         if (len > 64) {
 709                 traceState = TRACE_ERROR;
 710                 return 1;
 711         }
 712
 713         memcpy(data, data_src, len);
 714         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 715                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 716                 PrintAndLog("dec> %s", sprint_hex(data, len));
 717                 AddLogHex(logHexFileName, "dec> ", data, len);
 718         }
 719
 720         switch (traceState) {
 721         case TRACE_IDLE:
 722                 // check packet crc16!
 723                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 724                         PrintAndLog("dec> CRC ERROR!!!");
 725                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 726                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 727                         return 1;
 728                 }
 729
 730                 // AUTHENTICATION
 731                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 732                         traceState = TRACE_AUTH1;
 733                         traceCurBlock = data[1];
 734                         traceCurKey = data[0] == 60 ? 1:0;
 735                         return 0;
 736                 }
 737
 738                 // READ
 739                 if ((len ==4) && ((data[0] == 0x30))) {
 740                         traceState = TRACE_READ_DATA;
 741                         traceCurBlock = data[1];
 742                         return 0;
 743                 }
 744
 745                 // WRITE
 746                 if ((len ==4) && ((data[0] == 0xA0))) {
 747                         traceState = TRACE_WRITE_OK;
 748                         traceCurBlock = data[1];
 749                         return 0;
 750                 }
 751
 752                 // HALT
 753                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 754                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 755                         return 0;
 756                 }
 757
 758                 return 0;
 759         break;
 760
 761         case TRACE_READ_DATA:
 762                 if (len == 18) {
 763                         traceState = TRACE_IDLE;
 764
 765                         if (isBlockTrailer(traceCurBlock)) {
 766                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 767                         } else {
 768                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 769                         }
 770                         if (wantSaveToEmlFile) saveTraceCard();
 771                         return 0;
 772                 } else {
 773                         traceState = TRACE_ERROR;
 774                         return 1;
 775                 }
 776         break;
 777
 778         case TRACE_WRITE_OK:
 779                 if ((len == 1) && (data[0] == 0x0a)) {
 780                         traceState = TRACE_WRITE_DATA;
 781
 782                         return 0;
 783                 } else {
 784                         traceState = TRACE_ERROR;
 785                         return 1;
 786                 }
 787         break;
 788
 789         case TRACE_WRITE_DATA:
 790                 if (len == 18) {
 791                         traceState = TRACE_IDLE;
 792
 793                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 794                         if (wantSaveToEmlFile) saveTraceCard();
 795                         return 0;
 796                 } else {
 797                         traceState = TRACE_ERROR;
 798                         return 1;
 799                 }
 800         break;
 801
 802         case TRACE_AUTH1:
 803                 if (len == 4) {
 804                         traceState = TRACE_AUTH2;
 805                         nt = bytes_to_num(data, 4);
 806                         return 0;
 807                 } else {
 808                         traceState = TRACE_ERROR;
 809                         return 1;
 810                 }
 811         break;
 812
 813         case TRACE_AUTH2:
 814                 if (len == 8) {
 815                         traceState = TRACE_AUTH_OK;
 816
 817                         nr_enc = bytes_to_num(data, 4);
 818                         ar_enc = bytes_to_num(data + 4, 4);
 819                         return 0;
 820                 } else {
 821                         traceState = TRACE_ERROR;
 822                         return 1;
 823                 }
 824         break;
 825
 826         case TRACE_AUTH_OK:
 827                 if (len ==4) {
 828                         traceState = TRACE_IDLE;
 829
 830                         if (!traceCrypto1) {
 831                                 at_enc = bytes_to_num(data, 4);
 832
 833                                 //  decode key here)
 834                                 ks2 = ar_enc ^ prng_successor(nt, 64);
 835                                 ks3 = at_enc ^ prng_successor(nt, 96);
 836                                 revstate = lfsr_recovery64(ks2, ks3);
 837                                 lfsr_rollback_word(revstate, 0, 0);
 838                                 lfsr_rollback_word(revstate, 0, 0);
 839                                 lfsr_rollback_word(revstate, nr_enc, 1);
 840                                 lfsr_rollback_word(revstate, uid ^ nt, 0);
 841
 842                                 crypto1_get_lfsr(revstate, &lfsr);
 843                                 printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 844                                 AddLogUint64(logHexFileName, "key> ", lfsr);
 845                         } else {
 846                                 printf("key> nested not implemented!\n");
 847                                 at_enc = bytes_to_num(data, 4);
 848
 849                                 crypto1_destroy(traceCrypto1);
 850
 851                                 // not implemented
 852                                 traceState = TRACE_ERROR;
 853                         }
 854
 855                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 856                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 857
 858                         if (traceCurKey) {
 859                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 860                         } else {
 861                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 862                         }
 863                         if (wantSaveToEmlFile) saveTraceCard();
 864
 865                         if (traceCrypto1) {
 866                                 crypto1_destroy(traceCrypto1);
 867                         }
 868
 869                         // set cryptosystem state
 870                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 871                         return 0;
 872                 } else {
 873                         traceState = TRACE_ERROR;
 874                         return 1;
 875                 }
 876         break;
 877
 878         default:
 879                 traceState = TRACE_ERROR;
 880                 return 1;
 881         }
 882
 883         return 0;
 884 }
 885
 886 // DECODING
 887
 888 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 889         /*
 890         uint32_t nt;      // tag challenge
 891         uint32_t ar_enc;  // encrypted reader response
 892         uint32_t at_enc;  // encrypted tag response
 893         */
 894         if (traceCrypto1) {
 895                 crypto1_destroy(traceCrypto1);
 896         }
 897         ks2 = ar_enc ^ prng_successor(nt, 64);
 898         ks3 = at_enc ^ prng_successor(nt, 96);
 899         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 900
 901         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 902
 903         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 904         crypto1_destroy(traceCrypto1);
 905         return 0;
 906 }
 907
 908 /** validate_prng_nonce
 909  * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.
 910  * returns
 911  *   true = weak prng
 912  *   false = hardend prng
 913  */
 914 bool validate_prng_nonce(uint32_t nonce) {
 915         uint16_t *dist = 0;
 916         uint16_t x, i;
 917
 918         dist = malloc(2 << 16);
 919         if(!dist)
 920                 return -1;
 921
 922         // init prng table:
 923         for (x = i = 1; i; ++i) {
 924                 dist[(x & 0xff) << 8 | x >> 8] = i;
 925                 x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
 926         }
 927
 928         uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;
 929
 930         free(dist);
 931         return (res == 16);
 932 }
 933
 934 /* Detect Tag Prng,
 935 * function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
 936 * the tag nonce is check to see if it has a predictable PRNG.
 937 * @returns
 938 *       TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)
 939 *   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
 940 */
 941 int DetectClassicPrng(void){
 942
 943         UsbCommand resp, respA;
 944         uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA
 945         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;
 946
 947         UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
 948         memcpy(c.d.asBytes, cmd, sizeof(cmd));
 949
 950         clearCommandBuffer();
 951         SendCommand(&c);
 952         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {
 953         PrintAndLog("PRNG UID: Reply timeout.");
 954                 return -1;
 955         }
 956
 957         // if select tag failed.
 958         if (resp.arg[0] == 0) {
 959                 PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");
 960                 return -1;
 961         }
 962
 963         if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {
 964         PrintAndLog("PRNG data: Reply timeout.");
 965                 return -1;
 966         }
 967
 968         // check respA
 969         if (respA.arg[0] != 4) {
 970                 PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);
 971                 return -1;
 972         }
 973
 974         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
 975         return validate_prng_nonce(nonce);
 976 }