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 // MIFARE
  14 extern int compar_int(const void * a, const void * b) {
  15         // didn't work: (the result is truncated to 32 bits)
  16         //return (*(uint64_t*)b - *(uint64_t*)a);
  17
  18         // better:
  19         if (*(uint64_t*)b > *(uint64_t*)a) return 1;
  20         if (*(uint64_t*)b < *(uint64_t*)a) return -1;
  21         return 0;
  22
  23         //return (*(uint64_t*)b > *(uint64_t*)a) - (*(uint64_t*)b < *(uint64_t*)a);
  24 }
  25
  26 // Compare 16 Bits out of cryptostate
  27 int Compare16Bits(const void * a, const void * b) {
  28          if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
  29          if ((*(uint64_t*)b & 0x00ff000000ff0000) < (*(uint64_t*)a & 0x00ff000000ff0000)) return -1;
  30          return 0;
  31
  32 /*      return
  33                 ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000))
  34                 -
  35                 ((*(uint64_t*)b & 0x00ff000000ff0000) < (*(uint64_t*)a & 0x00ff000000ff0000))
  36                 ;
  37 */
  38 }
  39
  40 // wrapper function for multi-threaded lfsr_recovery32
  41 void* nested_worker_thread(void *arg)
  42 {
  43         struct Crypto1State *p1;
  44         StateList_t *statelist = arg;
  45         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
  46
  47         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
  48
  49         statelist->len = p1 - statelist->head.slhead;
  50         statelist->tail.sltail = --p1;
  51         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
  52         return statelist->head.slhead;
  53 }
  54
  55 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t * key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t * resultKey, bool calibrate)
  56 {
  57         uint16_t i;
  58         uint32_t uid;
  59         UsbCommand resp;
  60         StateList_t statelists[2];
  61         struct Crypto1State *p1, *p2, *p3, *p4;
  62
  63         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
  64         memcpy(c.d.asBytes, key, 6);
  65         clearCommandBuffer();
  66         SendCommand(&c);
  67         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) return -1;
  68
  69         // error during nested
  70         if (resp.arg[0]) return resp.arg[0];
  71
  72         memcpy(&uid, resp.d.asBytes, 4);
  73
  74         for (i = 0; i < 2; i++) {
  75                 statelists[i].blockNo = resp.arg[2] & 0xff;
  76                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
  77                 statelists[i].uid = uid;
  78                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
  79                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
  80         }
  81
  82         // calc keys
  83         pthread_t thread_id[2];
  84
  85         // create and run worker threads
  86         for (i = 0; i < 2; i++)
  87                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
  88
  89         // wait for threads to terminate:
  90         for (i = 0; i < 2; i++)
  91                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
  92
  93         // the first 16 Bits of the cryptostate already contain part of our key.
  94         // Create the intersection of the two lists based on these 16 Bits and
  95         // roll back the cryptostate
  96         p1 = p3 = statelists[0].head.slhead;
  97         p2 = p4 = statelists[1].head.slhead;
  98
  99         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 100                 if (Compare16Bits(p1, p2) == 0) {
 101
 102                         struct Crypto1State savestate, *savep = &savestate;
 103                         savestate = *p1;
 104                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 105                                 *p3 = *p1;
 106                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 107                                 p3++;
 108                                 p1++;
 109                         }
 110                         savestate = *p2;
 111                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 112                                 *p4 = *p2;
 113                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 114                                 p4++;
 115                                 p2++;
 116                         }
 117                 }
 118                 else {
 119                         while (Compare16Bits(p1, p2) == -1) p1++;
 120                         while (Compare16Bits(p1, p2) == 1) p2++;
 121                 }
 122         }
 123
 124         p3->even = 0; p3->odd = 0;
 125         p4->even = 0; p4->odd = 0;
 126         statelists[0].len = p3 - statelists[0].head.slhead;
 127         statelists[1].len = p4 - statelists[1].head.slhead;
 128         statelists[0].tail.sltail = --p3;
 129         statelists[1].tail.sltail = --p4;
 130
 131         // the statelists now contain possible keys. The key we are searching for must be in the
 132         // intersection of both lists. Create the intersection:
 133         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compar_int);
 134         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compar_int);
 135
 136         uint64_t *p5, *p6, *p7;
 137         p5 = p7 = statelists[0].head.keyhead;
 138         p6 = statelists[1].head.keyhead;
 139
 140         while (p5 <= statelists[0].tail.keytail && p6 <= statelists[1].tail.keytail) {
 141                 if (compar_int(p5, p6) == 0) {
 142                         *p7++ = *p5++;
 143                         p6++;
 144                 }
 145                 else {
 146                         while (compar_int(p5, p6) == -1) p5++;
 147                         while (compar_int(p5, p6) == 1) p6++;
 148                 }
 149         }
 150         statelists[0].len = p7 - statelists[0].head.keyhead;
 151         statelists[0].tail.keytail = --p7;
 152
 153         uint32_t numOfCandidates = statelists[0].len;
 154         if ( numOfCandidates == 0 ) goto out;
 155
 156         memset(resultKey, 0, 6);
 157         uint64_t key64 = 0;
 158
 159         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 160         // uint32_t max_keys = keycnt > (USB_CMD_DATA_SIZE/6) ? (USB_CMD_DATA_SIZE/6) : keycnt;
 161         uint8_t keyBlock[USB_CMD_DATA_SIZE] = {0x00};
 162
 163         for (i = 0; i < numOfCandidates; ++i){
 164                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 165                 num_to_bytes(key64, 6, keyBlock + i * 6);
 166         }
 167
 168         if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, numOfCandidates, keyBlock, &key64)) {
 169                 free(statelists[0].head.slhead);
 170                 free(statelists[1].head.slhead);
 171                 num_to_bytes(key64, 6, resultKey);
 172
 173                 PrintAndLog("UID: %08x target block:%3u key type: %c  -- Found key [%012"llx"]",
 174                         uid,
 175                         (uint16_t)resp.arg[2] & 0xff,
 176                         (resp.arg[2] >> 8) ? 'B' : 'A',
 177                         key64
 178                 );
 179                 return -5;
 180         }
 181
 182 out:
 183         PrintAndLog("UID: %08x target block:%3u key type: %c",
 184                         uid,
 185                         (uint16_t)resp.arg[2] & 0xff,
 186                         (resp.arg[2] >> 8) ? 'B' : 'A'
 187         );
 188
 189         free(statelists[0].head.slhead);
 190         free(statelists[1].head.slhead);
 191         return -4;
 192 }
 193
 194 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 195         *key = 0;
 196         UsbCommand c = {CMD_MIFARE_CHKKEYS, { (blockNo | (keyType<<8)), clear_trace, keycnt}};
 197         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 198         clearCommandBuffer();
 199         SendCommand(&c);
 200         UsbCommand resp;
 201         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2500)) return 1;
 202         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 203         *key = bytes_to_num(resp.d.asBytes, 6);
 204         return 0;
 205 }
 206 // PM3 imp of J-Run mf_key_brute (part 2)
 207 // ref: https://github.com/J-Run/mf_key_brute
 208 int mfKeyBrute(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint64_t *resultkey){
 209
 210         #define KEYS_IN_BLOCK 85
 211         #define KEYBLOCK_SIZE 510
 212         #define CANDIDATE_SIZE 0xFFFF * 6
 213         uint8_t found = FALSE;
 214         uint64_t key64 = 0;
 215         uint8_t candidates[CANDIDATE_SIZE] = {0x00};
 216         uint8_t keyBlock[KEYBLOCK_SIZE] = {0x00};
 217
 218         memset(candidates, 0, sizeof(candidates));
 219         memset(keyBlock, 0, sizeof(keyBlock));
 220
 221         // Generate all possible keys for the first two unknown bytes.
 222         for (uint16_t i = 0; i < 0xFFFF; ++i) {
 223                 uint32_t j = i * 6;
 224                 candidates[0 + j] = i >> 8;
 225                 candidates[1 + j] = i;
 226                 candidates[2 + j] = key[2];
 227                 candidates[3 + j] = key[3];
 228                 candidates[4 + j] = key[4];
 229                 candidates[5 + j] = key[5];
 230         }
 231         uint32_t counter, i;
 232         for ( i = 0, counter = 1; i < CANDIDATE_SIZE; i += KEYBLOCK_SIZE, ++counter){
 233
 234                 key64 = 0;
 235
 236                 // copy candidatekeys to test key block
 237                 memcpy(keyBlock, candidates + i, KEYBLOCK_SIZE);
 238
 239                 // check a block of generated candidate keys.
 240                 if (!mfCheckKeys(blockNo, keyType, TRUE, KEYS_IN_BLOCK, keyBlock, &key64)) {
 241                         *resultkey = key64;
 242                         found = TRUE;
 243                         break;
 244                 }
 245
 246                 // progress
 247                 if ( counter % 20 == 0 )
 248                         PrintAndLog("tried : %s.. \t %u keys", sprint_hex(candidates + i, 6),  counter * KEYS_IN_BLOCK  );
 249         }
 250         return found;
 251 }
 252
 253
 254 // EMULATOR
 255
 256 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 257         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 258         clearCommandBuffer();
 259         SendCommand(&c);
 260         UsbCommand resp;
 261         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 262         memcpy(data, resp.d.asBytes, blocksCount * 16);
 263         return 0;
 264 }
 265
 266 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 267         return mfEmlSetMem_xt(data, blockNum, blocksCount, 16);
 268 }
 269
 270 int mfEmlSetMem_xt(uint8_t *data, int blockNum, int blocksCount, int blockBtWidth) {
 271         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, blockBtWidth}};
 272         memcpy(c.d.asBytes, data, blocksCount * blockBtWidth);
 273         clearCommandBuffer();
 274         SendCommand(&c);
 275         return 0;
 276 }
 277
 278 // "MAGIC" CARD
 279 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, uint8_t wipecard) {
 280
 281         uint8_t params = MAGIC_SINGLE;
 282         uint8_t block0[16];
 283         memset(block0, 0x00, sizeof(block0));
 284
 285         int old = mfCGetBlock(0, block0, params);
 286         if (old == 0)
 287                 PrintAndLog("old block 0:  %s", sprint_hex(block0, sizeof(block0)));
 288         else
 289                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 290
 291         // fill in the new values
 292         // UID
 293         memcpy(block0, uid, 4);
 294         // Mifare UID BCC
 295         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 296         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 297         if ( sak != NULL )
 298                 block0[5]=sak[0];
 299
 300         if ( atqa != NULL ) {
 301                 block0[6]=atqa[1];
 302                 block0[7]=atqa[0];
 303         }
 304         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 305
 306         if ( wipecard )          params |= MAGIC_WIPE;
 307         if ( oldUID == NULL) params |= MAGIC_UID;
 308
 309         return mfCSetBlock(0, block0, oldUID, params);
 310 }
 311
 312 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, uint8_t params) {
 313
 314         uint8_t isOK = 0;
 315         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {params, blockNo, 0}};
 316         memcpy(c.d.asBytes, data, 16);
 317         clearCommandBuffer();
 318         SendCommand(&c);
 319         UsbCommand resp;
 320         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 321                 isOK  = resp.arg[0] & 0xff;
 322                 if (uid != NULL)
 323                         memcpy(uid, resp.d.asBytes, 4);
 324                 if (!isOK)
 325                         return 2;
 326         } else {
 327                 PrintAndLog("Command execute timeout");
 328                 return 1;
 329         }
 330         return 0;
 331 }
 332
 333 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 334         uint8_t isOK = 0;
 335         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, blockNo, 0}};
 336         clearCommandBuffer();
 337         SendCommand(&c);
 338         UsbCommand resp;
 339         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 340                 isOK  = resp.arg[0] & 0xff;
 341                 memcpy(data, resp.d.asBytes, 16);
 342                 if (!isOK) return 2;
 343         } else {
 344                 PrintAndLog("Command execute timeout");
 345                 return 1;
 346         }
 347         return 0;
 348 }
 349
 350 // SNIFFER
 351 // [iceman] so many global variables....
 352
 353 // constants
 354 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 355
 356 // variables
 357 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 358 static uint8_t traceCard[4096] = {0x00};
 359 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 360 static int traceState = TRACE_IDLE;
 361 static uint8_t traceCurBlock = 0;
 362 static uint8_t traceCurKey = 0;
 363
 364 struct Crypto1State *traceCrypto1 = NULL;
 365 struct Crypto1State *revstate = NULL;
 366 uint64_t key = 0;
 367 uint32_t ks2 = 0;
 368 uint32_t ks3 = 0;
 369
 370 uint32_t cuid = 0;    // serial number
 371 uint32_t nt =0;      // tag challenge
 372 uint32_t nr_enc =0;  // encrypted reader challenge
 373 uint32_t ar_enc =0;  // encrypted reader response
 374 uint32_t at_enc =0;  // encrypted tag response
 375
 376 int isTraceCardEmpty(void) {
 377         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 378 }
 379
 380 int isBlockEmpty(int blockN) {
 381         for (int i = 0; i < 16; i++)
 382                 if (traceCard[blockN * 16 + i] != 0) return 0;
 383
 384         return 1;
 385 }
 386
 387 int isBlockTrailer(int blockN) {
 388         return ((blockN & 0x03) == 0x03);
 389 }
 390
 391 int loadTraceCard(uint8_t *tuid, uint8_t uidlen) {
 392         FILE * f;
 393         char buf[64] = {0x00};
 394         uint8_t buf8[64] = {0x00};
 395         int i, blockNum;
 396
 397         if (!isTraceCardEmpty())
 398                 saveTraceCard();
 399
 400         memset(traceCard, 0x00, 4096);
 401         memcpy(traceCard, tuid, uidlen);
 402
 403         FillFileNameByUID(traceFileName, tuid, ".eml", uidlen);
 404
 405         f = fopen(traceFileName, "r");
 406         if (!f) return 1;
 407
 408         blockNum = 0;
 409
 410         while(!feof(f)){
 411
 412                 memset(buf, 0, sizeof(buf));
 413                 if (fgets(buf, sizeof(buf), f) == NULL) {
 414                         PrintAndLog("No trace file found or reading error.");
 415                         if (f) {
 416                                 fclose(f);
 417                                 f = NULL;
 418                         }
 419                         return 2;
 420                 }
 421
 422                 if (strlen(buf) < 32){
 423                         if (feof(f)) break;
 424                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 425                         if (f) {
 426                                 fclose(f);
 427                                 f = NULL;
 428                         }
 429                         return 2;
 430                 }
 431                 for (i = 0; i < 32; i += 2)
 432                         sscanf(&buf[i], "%02X", (unsigned int *)&buf8[i / 2]);
 433
 434                 memcpy(traceCard + blockNum * 16, buf8, 16);
 435
 436                 blockNum++;
 437         }
 438         if (f) {
 439                 fclose(f);
 440                 f = NULL;
 441         }
 442         return 0;
 443 }
 444
 445 int saveTraceCard(void) {
 446
 447         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 448
 449         FILE * f;
 450         f = fopen(traceFileName, "w+");
 451         if ( !f ) return 1;
 452
 453         for (int i = 0; i < 64; i++) {  // blocks
 454                 for (int j = 0; j < 16; j++)  // bytes
 455                         fprintf(f, "%02X", *(traceCard + i * 16 + j));
 456                 fprintf(f,"\n");
 457         }
 458         fflush(f);
 459         if (f) {
 460                 fclose(f);
 461                 f = NULL;
 462         }
 463         return 0;
 464 }
 465
 466 int mfTraceInit(uint8_t *tuid, uint8_t uidlen, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 467
 468         if (traceCrypto1)
 469                 crypto1_destroy(traceCrypto1);
 470
 471         traceCrypto1 = NULL;
 472
 473         if (wantSaveToEmlFile)
 474                 loadTraceCard(tuid, uidlen);
 475
 476         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 477         traceCard[5] = sak;
 478         memcpy(&traceCard[6], atqa, 2);
 479         traceCurBlock = 0;
 480         cuid = bytes_to_num(tuid+(uidlen-4), 4);
 481         traceState = TRACE_IDLE;
 482         return 0;
 483 }
 484
 485 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 486         uint8_t bt = 0;
 487         int i;
 488
 489         if (len != 1) {
 490                 for (i = 0; i < len; i++)
 491                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 492         } else {
 493                 bt = 0;
 494                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 0)) << 0;
 495                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 1)) << 1;
 496                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 2)) << 2;
 497                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 3)) << 3;
 498                 data[0] = bt;
 499         }
 500         return;
 501 }
 502
 503 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 504
 505         if (traceState == TRACE_ERROR) return 1;
 506
 507         if (len > 64) {
 508                 traceState = TRACE_ERROR;
 509                 return 1;
 510         }
 511
 512         uint8_t data[64];
 513         memset(data, 0x00, sizeof(data));
 514
 515         memcpy(data, data_src, len);
 516
 517         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 518                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 519                 PrintAndLog("DEC| %s", sprint_hex(data, len));
 520                 AddLogHex(logHexFileName, "DEC| ", data, len);
 521         }
 522
 523         switch (traceState) {
 524         case TRACE_IDLE:
 525                 // check packet crc16!
 526                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 527                         PrintAndLog("DEC| CRC ERROR!!!");
 528                         AddLogLine(logHexFileName, "DEC| ", "CRC ERROR!!!");
 529                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 530                         return 1;
 531                 }
 532
 533                 // AUTHENTICATION
 534                 if ((len == 4) && ((data[0] == MIFARE_AUTH_KEYA) || (data[0] == MIFARE_AUTH_KEYB))) {
 535                         traceState = TRACE_AUTH1;
 536                         traceCurBlock = data[1];
 537                         traceCurKey = data[0] == 60 ? 1:0;
 538                         return 0;
 539                 }
 540
 541                 // READ
 542                 if ((len ==4) && ((data[0] == ISO14443A_CMD_READBLOCK))) {
 543                         traceState = TRACE_READ_DATA;
 544                         traceCurBlock = data[1];
 545                         return 0;
 546                 }
 547
 548                 // WRITE
 549                 if ((len ==4) && ((data[0] == ISO14443A_CMD_WRITEBLOCK))) {
 550                         traceState = TRACE_WRITE_OK;
 551                         traceCurBlock = data[1];
 552                         return 0;
 553                 }
 554
 555                 // HALT
 556                 if ((len ==4) && ((data[0] == ISO14443A_CMD_HALT) && (data[1] == 0x00))) {
 557                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 558                         return 0;
 559                 }
 560                 return 0;
 561         case TRACE_READ_DATA:
 562                 if (len == 18) {
 563                         traceState = TRACE_IDLE;
 564
 565                         if (isBlockTrailer(traceCurBlock)) {
 566                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 567                         } else {
 568                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 569                         }
 570                         if (wantSaveToEmlFile) saveTraceCard();
 571                         return 0;
 572                 } else {
 573                         traceState = TRACE_ERROR;
 574                         return 1;
 575                 }
 576                 break;
 577         case TRACE_WRITE_OK:
 578                 if ((len == 1) && (data[0] == 0x0a)) {
 579                         traceState = TRACE_WRITE_DATA;
 580                         return 0;
 581                 } else {
 582                         traceState = TRACE_ERROR;
 583                         return 1;
 584                 }
 585                 break;
 586         case TRACE_WRITE_DATA:
 587                 if (len == 18) {
 588                         traceState = TRACE_IDLE;
 589                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 590                         if (wantSaveToEmlFile) saveTraceCard();
 591                         return 0;
 592                 } else {
 593                         traceState = TRACE_ERROR;
 594                         return 1;
 595                 }
 596                 break;
 597         case TRACE_AUTH1:
 598                 if (len == 4) {
 599                         traceState = TRACE_AUTH2;
 600                         nt = bytes_to_num(data, 4);
 601                         return 0;
 602                 } else {
 603                         traceState = TRACE_ERROR;
 604                         return 1;
 605                 }
 606                 break;
 607         case TRACE_AUTH2:
 608                 if (len == 8) {
 609                         traceState = TRACE_AUTH_OK;
 610                         nr_enc = bytes_to_num(data, 4);
 611                         ar_enc = bytes_to_num(data + 4, 4);
 612                         return 0;
 613                 } else {
 614                         traceState = TRACE_ERROR;
 615                         return 1;
 616                 }
 617                 break;
 618         case TRACE_AUTH_OK:
 619                 if (len == 4) {
 620                         traceState = TRACE_IDLE;
 621                         at_enc = bytes_to_num(data, 4);
 622
 623                         //  decode key here)
 624                         ks2 = ar_enc ^ prng_successor(nt, 64);
 625                         ks3 = at_enc ^ prng_successor(nt, 96);
 626                         revstate = lfsr_recovery64(ks2, ks3);
 627                         lfsr_rollback_word(revstate, 0, 0);
 628                         lfsr_rollback_word(revstate, 0, 0);
 629                         lfsr_rollback_word(revstate, nr_enc, 1);
 630                         lfsr_rollback_word(revstate, cuid ^ nt, 0);
 631                         crypto1_get_lfsr(revstate, &key);
 632                         PrintAndLog("Found Key: [%012"llx"]", key);
 633
 634                         //if ( tryMfk64(cuid, nt, nr_enc, ar_enc, at_enc, &key) )
 635                         AddLogUint64(logHexFileName, "Found Key: ", key);
 636
 637                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 638                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 639
 640                         if (traceCurKey)
 641                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 642                         else
 643                                 num_to_bytes(key, 6, traceCard + blockShift);
 644
 645                         if (wantSaveToEmlFile)
 646                                 saveTraceCard();
 647
 648                         if (traceCrypto1)
 649                                 crypto1_destroy(traceCrypto1);
 650
 651                         // set cryptosystem state
 652                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 653
 654                         return 0;
 655                 } else {
 656                         traceState = TRACE_ERROR;
 657                         return 1;
 658                 }
 659                 break;
 660         default:
 661                 traceState = TRACE_ERROR;
 662                 return 1;
 663         }
 664         return 0;
 665 }
 666
 667 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 668         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data, len) );
 669         struct Crypto1State *s;
 670         ks2 = ar_enc ^ prng_successor(nt, 64);
 671         ks3 = at_enc ^ prng_successor(nt, 96);
 672         s = lfsr_recovery64(ks2, ks3);
 673         mf_crypto1_decrypt(s, data, len, FALSE);
 674         PrintAndLog("Decrypted data: [%s]", sprint_hex(data, len) );
 675         crypto1_destroy(s);
 676         return 0;
 677 }