git.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" PRIx64 "]",
 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 // EMULATOR
 254 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 255         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 256         clearCommandBuffer();
 257         SendCommand(&c);
 258         UsbCommand resp;
 259         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) return 1;
 260         memcpy(data, resp.d.asBytes, blocksCount * 16);
 261         return 0;
 262 }
 263
 264 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 265         return mfEmlSetMem_xt(data, blockNum, blocksCount, 16);
 266 }
 267
 268 int mfEmlSetMem_xt(uint8_t *data, int blockNum, int blocksCount, int blockBtWidth) {
 269         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, blockBtWidth}};
 270         memcpy(c.d.asBytes, data, blocksCount * blockBtWidth);
 271         clearCommandBuffer();
 272         SendCommand(&c);
 273         return 0;
 274 }
 275
 276 // "MAGIC" CARD
 277 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, uint8_t wipecard) {
 278
 279         uint8_t params = MAGIC_SINGLE;
 280         uint8_t block0[16];
 281         memset(block0, 0x00, sizeof(block0));
 282
 283         int old = mfCGetBlock(0, block0, params);
 284         if (old == 0)
 285                 PrintAndLog("old block 0:  %s", sprint_hex(block0, sizeof(block0)));
 286         else
 287                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 288
 289         // fill in the new values
 290         // UID
 291         memcpy(block0, uid, 4);
 292         // Mifare UID BCC
 293         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 294         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 295         if ( sak != NULL )
 296                 block0[5]=sak[0];
 297
 298         if ( atqa != NULL ) {
 299                 block0[6]=atqa[1];
 300                 block0[7]=atqa[0];
 301         }
 302         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 303
 304         if ( wipecard )          params |= MAGIC_WIPE;
 305         if ( oldUID == NULL) params |= MAGIC_UID;
 306
 307         return mfCSetBlock(0, block0, oldUID, params);
 308 }
 309
 310 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, uint8_t params) {
 311
 312         uint8_t isOK = 0;
 313         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {params, blockNo, 0}};
 314         memcpy(c.d.asBytes, data, 16);
 315         clearCommandBuffer();
 316         SendCommand(&c);
 317         UsbCommand resp;
 318         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 319                 isOK  = resp.arg[0] & 0xff;
 320                 if (uid != NULL)
 321                         memcpy(uid, resp.d.asBytes, 4);
 322                 if (!isOK)
 323                         return 2;
 324         } else {
 325                 PrintAndLog("Command execute timeout");
 326                 return 1;
 327         }
 328         return 0;
 329 }
 330
 331 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 332         uint8_t isOK = 0;
 333         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, blockNo, 0}};
 334         clearCommandBuffer();
 335         SendCommand(&c);
 336         UsbCommand resp;
 337         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 338                 isOK  = resp.arg[0] & 0xff;
 339                 memcpy(data, resp.d.asBytes, 16);
 340                 if (!isOK) return 2;
 341         } else {
 342                 PrintAndLog("Command execute timeout");
 343                 return 1;
 344         }
 345         return 0;
 346 }
 347
 348 // SNIFFER
 349 // [iceman] so many global variables....
 350
 351 // constants
 352 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 353
 354 // variables
 355 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 356 static uint8_t traceCard[4096] = {0x00};
 357 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 358 static int traceState = TRACE_IDLE;
 359 static uint8_t traceCurBlock = 0;
 360 static uint8_t traceCurKey = 0;
 361
 362 struct Crypto1State *traceCrypto1 = NULL;
 363 struct Crypto1State *revstate = NULL;
 364 uint64_t key = 0;
 365 uint32_t ks2 = 0;
 366 uint32_t ks3 = 0;
 367
 368 uint32_t cuid = 0;    // serial number
 369 uint32_t nt =0;      // tag challenge
 370 uint32_t nr_enc =0;  // encrypted reader challenge
 371 uint32_t ar_enc =0;  // encrypted reader response
 372 uint32_t at_enc =0;  // encrypted tag response
 373
 374 int isTraceCardEmpty(void) {
 375         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 376 }
 377
 378 int isBlockEmpty(int blockN) {
 379         for (int i = 0; i < 16; i++)
 380                 if (traceCard[blockN * 16 + i] != 0) return 0;
 381
 382         return 1;
 383 }
 384
 385 int isBlockTrailer(int blockN) {
 386         return ((blockN & 0x03) == 0x03);
 387 }
 388
 389 int loadTraceCard(uint8_t *tuid, uint8_t uidlen) {
 390         FILE * f;
 391         char buf[64] = {0x00};
 392         uint8_t buf8[64] = {0x00};
 393         int i, blockNum;
 394
 395         if (!isTraceCardEmpty())
 396                 saveTraceCard();
 397
 398         memset(traceCard, 0x00, 4096);
 399         memcpy(traceCard, tuid, uidlen);
 400
 401         FillFileNameByUID(traceFileName, tuid, ".eml", uidlen);
 402
 403         f = fopen(traceFileName, "r");
 404         if (!f) return 1;
 405
 406         blockNum = 0;
 407
 408         while(!feof(f)){
 409
 410                 memset(buf, 0, sizeof(buf));
 411                 if (fgets(buf, sizeof(buf), f) == NULL) {
 412                         PrintAndLog("No trace file found or reading error.");
 413                         if (f) {
 414                                 fclose(f);
 415                                 f = NULL;
 416                         }
 417                         return 2;
 418                 }
 419
 420                 if (strlen(buf) < 32){
 421                         if (feof(f)) break;
 422                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 423                         if (f) {
 424                                 fclose(f);
 425                                 f = NULL;
 426                         }
 427                         return 2;
 428                 }
 429                 for (i = 0; i < 32; i += 2)
 430                         sscanf(&buf[i], "%02X", (unsigned int *)&buf8[i / 2]);
 431
 432                 memcpy(traceCard + blockNum * 16, buf8, 16);
 433
 434                 blockNum++;
 435         }
 436         if (f) {
 437                 fclose(f);
 438                 f = NULL;
 439         }
 440         return 0;
 441 }
 442
 443 int saveTraceCard(void) {
 444
 445         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 446
 447         FILE * f;
 448         f = fopen(traceFileName, "w+");
 449         if ( !f ) return 1;
 450
 451         for (int i = 0; i < 64; i++) {  // blocks
 452                 for (int j = 0; j < 16; j++)  // bytes
 453                         fprintf(f, "%02X", *(traceCard + i * 16 + j));
 454                 fprintf(f,"\n");
 455         }
 456         fflush(f);
 457         if (f) {
 458                 fclose(f);
 459                 f = NULL;
 460         }
 461         return 0;
 462 }
 463
 464 int mfTraceInit(uint8_t *tuid, uint8_t uidlen, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 465
 466         if (traceCrypto1)
 467                 crypto1_destroy(traceCrypto1);
 468
 469         traceCrypto1 = NULL;
 470
 471         if (wantSaveToEmlFile)
 472                 loadTraceCard(tuid, uidlen);
 473
 474         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 475         traceCard[5] = sak;
 476         memcpy(&traceCard[6], atqa, 2);
 477         traceCurBlock = 0;
 478         cuid = bytes_to_num(tuid+(uidlen-4), 4);
 479         traceState = TRACE_IDLE;
 480         return 0;
 481 }
 482
 483 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 484         uint8_t bt = 0;
 485         int i;
 486
 487         if (len != 1) {
 488                 for (i = 0; i < len; i++)
 489                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 490         } else {
 491                 bt = 0;
 492                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 0)) << 0;
 493                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 1)) << 1;
 494                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 2)) << 2;
 495                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 3)) << 3;
 496                 data[0] = bt;
 497         }
 498         return;
 499 }
 500
 501 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 502
 503         if (traceState == TRACE_ERROR) return 1;
 504
 505         if (len > 64) {
 506                 traceState = TRACE_ERROR;
 507                 return 1;
 508         }
 509
 510         uint8_t data[64];
 511         memset(data, 0x00, sizeof(data));
 512
 513         memcpy(data, data_src, len);
 514
 515         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 516                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 517                 PrintAndLog("DEC| %s", sprint_hex(data, len));
 518                 AddLogHex(logHexFileName, "DEC| ", data, len);
 519         }
 520
 521         switch (traceState) {
 522         case TRACE_IDLE:
 523                 // check packet crc16!
 524                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 525                         PrintAndLog("DEC| CRC ERROR!!!");
 526                         AddLogLine(logHexFileName, "DEC| ", "CRC ERROR!!!");
 527                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 528                         return 1;
 529                 }
 530
 531                 // AUTHENTICATION
 532                 if ((len == 4) && ((data[0] == MIFARE_AUTH_KEYA) || (data[0] == MIFARE_AUTH_KEYB))) {
 533                         traceState = TRACE_AUTH1;
 534                         traceCurBlock = data[1];
 535                         traceCurKey = data[0] == 60 ? 1:0;
 536                         return 0;
 537                 }
 538
 539                 // READ
 540                 if ((len ==4) && ((data[0] == ISO14443A_CMD_READBLOCK))) {
 541                         traceState = TRACE_READ_DATA;
 542                         traceCurBlock = data[1];
 543                         return 0;
 544                 }
 545
 546                 // WRITE
 547                 if ((len ==4) && ((data[0] == ISO14443A_CMD_WRITEBLOCK))) {
 548                         traceState = TRACE_WRITE_OK;
 549                         traceCurBlock = data[1];
 550                         return 0;
 551                 }
 552
 553                 // HALT
 554                 if ((len ==4) && ((data[0] == ISO14443A_CMD_HALT) && (data[1] == 0x00))) {
 555                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 556                         return 0;
 557                 }
 558                 return 0;
 559         case TRACE_READ_DATA:
 560                 if (len == 18) {
 561                         traceState = TRACE_IDLE;
 562
 563                         if (isBlockTrailer(traceCurBlock)) {
 564                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 565                         } else {
 566                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 567                         }
 568                         if (wantSaveToEmlFile) saveTraceCard();
 569                         return 0;
 570                 } else {
 571                         traceState = TRACE_ERROR;
 572                         return 1;
 573                 }
 574                 break;
 575         case TRACE_WRITE_OK:
 576                 if ((len == 1) && (data[0] == 0x0a)) {
 577                         traceState = TRACE_WRITE_DATA;
 578                         return 0;
 579                 } else {
 580                         traceState = TRACE_ERROR;
 581                         return 1;
 582                 }
 583                 break;
 584         case TRACE_WRITE_DATA:
 585                 if (len == 18) {
 586                         traceState = TRACE_IDLE;
 587                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 588                         if (wantSaveToEmlFile) saveTraceCard();
 589                         return 0;
 590                 } else {
 591                         traceState = TRACE_ERROR;
 592                         return 1;
 593                 }
 594                 break;
 595         case TRACE_AUTH1:
 596                 if (len == 4) {
 597                         traceState = TRACE_AUTH2;
 598                         nt = bytes_to_num(data, 4);
 599                         return 0;
 600                 } else {
 601                         traceState = TRACE_ERROR;
 602                         return 1;
 603                 }
 604                 break;
 605         case TRACE_AUTH2:
 606                 if (len == 8) {
 607                         traceState = TRACE_AUTH_OK;
 608                         nr_enc = bytes_to_num(data, 4);
 609                         ar_enc = bytes_to_num(data + 4, 4);
 610                         return 0;
 611                 } else {
 612                         traceState = TRACE_ERROR;
 613                         return 1;
 614                 }
 615                 break;
 616         case TRACE_AUTH_OK:
 617                 if (len == 4) {
 618                         traceState = TRACE_IDLE;
 619                         at_enc = bytes_to_num(data, 4);
 620
 621                         //  decode key here)
 622                         ks2 = ar_enc ^ prng_successor(nt, 64);
 623                         ks3 = at_enc ^ prng_successor(nt, 96);
 624                         revstate = lfsr_recovery64(ks2, ks3);
 625                         lfsr_rollback_word(revstate, 0, 0);
 626                         lfsr_rollback_word(revstate, 0, 0);
 627                         lfsr_rollback_word(revstate, nr_enc, 1);
 628                         lfsr_rollback_word(revstate, cuid ^ nt, 0);
 629                         crypto1_get_lfsr(revstate, &key);
 630                         PrintAndLog("Found Key: [%012" PRIx64 "]", key);
 631
 632                         //if ( tryMfk64(cuid, nt, nr_enc, ar_enc, at_enc, &key) )
 633                         AddLogUint64(logHexFileName, "Found Key: ", key);
 634
 635                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 636                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 637
 638                         if (traceCurKey)
 639                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 640                         else
 641                                 num_to_bytes(key, 6, traceCard + blockShift);
 642
 643                         if (wantSaveToEmlFile)
 644                                 saveTraceCard();
 645
 646                         if (traceCrypto1)
 647                                 crypto1_destroy(traceCrypto1);
 648
 649                         // set cryptosystem state
 650                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 651
 652                         return 0;
 653                 } else {
 654                         traceState = TRACE_ERROR;
 655                         return 1;
 656                 }
 657                 break;
 658         default:
 659                 traceState = TRACE_ERROR;
 660                 return 1;
 661         }
 662         return 0;
 663 }
 664
 665 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 666         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data, len) );
 667         struct Crypto1State *s;
 668         ks2 = ar_enc ^ prng_successor(nt, 64);
 669         ks3 = at_enc ^ prng_successor(nt, 96);
 670         s = lfsr_recovery64(ks2, ks3);
 671         mf_crypto1_decrypt(s, data, len, FALSE);
 672         PrintAndLog("Decrypted data: [%s]", sprint_hex(data, len) );
 673         crypto1_destroy(s);
 674         return 0;
 675 }