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"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
 207 // EMULATOR
 208
 209 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 210         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 211         clearCommandBuffer();
 212         SendCommand(&c);
 213         UsbCommand resp;
 214         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 215         memcpy(data, resp.d.asBytes, blocksCount * 16);
 216         return 0;
 217 }
 218
 219 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 220         return mfEmlSetMem_xt(data, blockNum, blocksCount, 16);
 221 }
 222
 223 int mfEmlSetMem_xt(uint8_t *data, int blockNum, int blocksCount, int blockBtWidth) {
 224         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, blockBtWidth}};
 225         memcpy(c.d.asBytes, data, blocksCount * blockBtWidth);
 226         clearCommandBuffer();
 227         SendCommand(&c);
 228         return 0;
 229 }
 230
 231 // "MAGIC" CARD
 232 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, uint8_t wipecard) {
 233
 234         uint8_t params = MAGIC_SINGLE;
 235         uint8_t block0[16];
 236         memset(block0, 0x00, sizeof(block0));
 237
 238         int old = mfCGetBlock(0, block0, params);
 239         if (old == 0)
 240                 PrintAndLog("old block 0:  %s", sprint_hex(block0, sizeof(block0)));
 241         else
 242                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 243
 244         // fill in the new values
 245         // UID
 246         memcpy(block0, uid, 4);
 247         // Mifare UID BCC
 248         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 249         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 250         if ( sak != NULL )
 251                 block0[5]=sak[0];
 252
 253         if ( atqa != NULL ) {
 254                 block0[6]=atqa[1];
 255                 block0[7]=atqa[0];
 256         }
 257         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 258
 259         if ( wipecard )          params |= MAGIC_WIPE;
 260         if ( oldUID == NULL) params |= MAGIC_UID;
 261
 262         return mfCSetBlock(0, block0, oldUID, params);
 263 }
 264
 265 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, uint8_t params) {
 266
 267         uint8_t isOK = 0;
 268         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {params, blockNo, 0}};
 269         memcpy(c.d.asBytes, data, 16);
 270         clearCommandBuffer();
 271         SendCommand(&c);
 272         UsbCommand resp;
 273         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 274                 isOK  = resp.arg[0] & 0xff;
 275                 if (uid != NULL)
 276                         memcpy(uid, resp.d.asBytes, 4);
 277                 if (!isOK)
 278                         return 2;
 279         } else {
 280                 PrintAndLog("Command execute timeout");
 281                 return 1;
 282         }
 283         return 0;
 284 }
 285
 286 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 287         uint8_t isOK = 0;
 288         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, blockNo, 0}};
 289         clearCommandBuffer();
 290         SendCommand(&c);
 291         UsbCommand resp;
 292         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 293                 isOK  = resp.arg[0] & 0xff;
 294                 memcpy(data, resp.d.asBytes, 16);
 295                 if (!isOK) return 2;
 296         } else {
 297                 PrintAndLog("Command execute timeout");
 298                 return 1;
 299         }
 300         return 0;
 301 }
 302
 303 // SNIFFER
 304 // [iceman] so many global variables....
 305
 306 // constants
 307 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 308
 309 // variables
 310 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 311 static uint8_t traceCard[4096] = {0x00};
 312 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 313 static int traceState = TRACE_IDLE;
 314 static uint8_t traceCurBlock = 0;
 315 static uint8_t traceCurKey = 0;
 316
 317 struct Crypto1State *traceCrypto1 = NULL;
 318 struct Crypto1State *revstate = NULL;
 319 uint64_t key = 0;
 320 uint32_t ks2 = 0;
 321 uint32_t ks3 = 0;
 322
 323 uint32_t cuid = 0;    // serial number
 324 uint32_t nt =0;      // tag challenge
 325 uint32_t nr_enc =0;  // encrypted reader challenge
 326 uint32_t ar_enc =0;  // encrypted reader response
 327 uint32_t at_enc =0;  // encrypted tag response
 328
 329 int isTraceCardEmpty(void) {
 330         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 331 }
 332
 333 int isBlockEmpty(int blockN) {
 334         for (int i = 0; i < 16; i++)
 335                 if (traceCard[blockN * 16 + i] != 0) return 0;
 336
 337         return 1;
 338 }
 339
 340 int isBlockTrailer(int blockN) {
 341         return ((blockN & 0x03) == 0x03);
 342 }
 343
 344 int loadTraceCard(uint8_t *tuid, uint8_t uidlen) {
 345         FILE * f;
 346         char buf[64] = {0x00};
 347         uint8_t buf8[64] = {0x00};
 348         int i, blockNum;
 349
 350         if (!isTraceCardEmpty())
 351                 saveTraceCard();
 352
 353         memset(traceCard, 0x00, 4096);
 354         memcpy(traceCard, tuid, uidlen);
 355
 356         FillFileNameByUID(traceFileName, tuid, ".eml", uidlen);
 357
 358         f = fopen(traceFileName, "r");
 359         if (!f) return 1;
 360
 361         blockNum = 0;
 362
 363         while(!feof(f)){
 364
 365                 memset(buf, 0, sizeof(buf));
 366                 if (fgets(buf, sizeof(buf), f) == NULL) {
 367                         PrintAndLog("No trace file found or reading error.");
 368                         fclose(f);
 369                         return 2;
 370                 }
 371
 372                 if (strlen(buf) < 32){
 373                         if (feof(f)) break;
 374                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 375                         fclose(f);
 376                         return 2;
 377                 }
 378                 for (i = 0; i < 32; i += 2)
 379                         sscanf(&buf[i], "%02X", (unsigned int *)&buf8[i / 2]);
 380
 381                 memcpy(traceCard + blockNum * 16, buf8, 16);
 382
 383                 blockNum++;
 384         }
 385         fclose(f);
 386         return 0;
 387 }
 388
 389 int saveTraceCard(void) {
 390
 391         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 392
 393         FILE * f;
 394         f = fopen(traceFileName, "w+");
 395         if ( !f ) return 1;
 396
 397         for (int i = 0; i < 64; i++) {  // blocks
 398                 for (int j = 0; j < 16; j++)  // bytes
 399                         fprintf(f, "%02X", *(traceCard + i * 16 + j));
 400                 fprintf(f,"\n");
 401         }
 402         fflush(f);
 403         fclose(f);
 404         return 0;
 405 }
 406
 407 int mfTraceInit(uint8_t *tuid, uint8_t uidlen, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 408
 409         if (traceCrypto1)
 410                 crypto1_destroy(traceCrypto1);
 411
 412         traceCrypto1 = NULL;
 413
 414         if (wantSaveToEmlFile)
 415                 loadTraceCard(tuid, uidlen);
 416
 417         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 418         traceCard[5] = sak;
 419         memcpy(&traceCard[6], atqa, 2);
 420         traceCurBlock = 0;
 421         cuid = bytes_to_num(tuid+(uidlen-4), 4);
 422         traceState = TRACE_IDLE;
 423         return 0;
 424 }
 425
 426 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 427         uint8_t bt = 0;
 428         int i;
 429
 430         if (len != 1) {
 431                 for (i = 0; i < len; i++)
 432                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 433         } else {
 434                 bt = 0;
 435                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 0)) << 0;
 436                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 1)) << 1;
 437                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 2)) << 2;
 438                 bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], 3)) << 3;
 439                 data[0] = bt;
 440         }
 441         return;
 442 }
 443
 444 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 445
 446         if (traceState == TRACE_ERROR) return 1;
 447
 448         if (len > 64) {
 449                 traceState = TRACE_ERROR;
 450                 return 1;
 451         }
 452
 453         uint8_t data[64];
 454         memset(data, 0x00, sizeof(data));
 455
 456         memcpy(data, data_src, len);
 457
 458         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 459                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 460                 PrintAndLog("DEC| %s", sprint_hex(data, len));
 461                 AddLogHex(logHexFileName, "DEC| ", data, len);
 462         }
 463
 464         switch (traceState) {
 465         case TRACE_IDLE:
 466                 // check packet crc16!
 467                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 468                         PrintAndLog("DEC| CRC ERROR!!!");
 469                         AddLogLine(logHexFileName, "DEC| ", "CRC ERROR!!!");
 470                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 471                         return 1;
 472                 }
 473
 474                 // AUTHENTICATION
 475                 if ((len == 4) && ((data[0] == MIFARE_AUTH_KEYA) || (data[0] == MIFARE_AUTH_KEYB))) {
 476                         traceState = TRACE_AUTH1;
 477                         traceCurBlock = data[1];
 478                         traceCurKey = data[0] == 60 ? 1:0;
 479                         return 0;
 480                 }
 481
 482                 // READ
 483                 if ((len ==4) && ((data[0] == ISO14443A_CMD_READBLOCK))) {
 484                         traceState = TRACE_READ_DATA;
 485                         traceCurBlock = data[1];
 486                         return 0;
 487                 }
 488
 489                 // WRITE
 490                 if ((len ==4) && ((data[0] == ISO14443A_CMD_WRITEBLOCK))) {
 491                         traceState = TRACE_WRITE_OK;
 492                         traceCurBlock = data[1];
 493                         return 0;
 494                 }
 495
 496                 // HALT
 497                 if ((len ==4) && ((data[0] == ISO14443A_CMD_HALT) && (data[1] == 0x00))) {
 498                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 499                         return 0;
 500                 }
 501                 return 0;
 502         case TRACE_READ_DATA:
 503                 if (len == 18) {
 504                         traceState = TRACE_IDLE;
 505
 506                         if (isBlockTrailer(traceCurBlock)) {
 507                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 508                         } else {
 509                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 510                         }
 511                         if (wantSaveToEmlFile) saveTraceCard();
 512                         return 0;
 513                 } else {
 514                         traceState = TRACE_ERROR;
 515                         return 1;
 516                 }
 517                 break;
 518         case TRACE_WRITE_OK:
 519                 if ((len == 1) && (data[0] == 0x0a)) {
 520                         traceState = TRACE_WRITE_DATA;
 521                         return 0;
 522                 } else {
 523                         traceState = TRACE_ERROR;
 524                         return 1;
 525                 }
 526                 break;
 527         case TRACE_WRITE_DATA:
 528                 if (len == 18) {
 529                         traceState = TRACE_IDLE;
 530                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 531                         if (wantSaveToEmlFile) saveTraceCard();
 532                         return 0;
 533                 } else {
 534                         traceState = TRACE_ERROR;
 535                         return 1;
 536                 }
 537                 break;
 538         case TRACE_AUTH1:
 539                 if (len == 4) {
 540                         traceState = TRACE_AUTH2;
 541                         nt = bytes_to_num(data, 4);
 542                         return 0;
 543                 } else {
 544                         traceState = TRACE_ERROR;
 545                         return 1;
 546                 }
 547                 break;
 548         case TRACE_AUTH2:
 549                 if (len == 8) {
 550                         traceState = TRACE_AUTH_OK;
 551                         nr_enc = bytes_to_num(data, 4);
 552                         ar_enc = bytes_to_num(data + 4, 4);
 553                         return 0;
 554                 } else {
 555                         traceState = TRACE_ERROR;
 556                         return 1;
 557                 }
 558                 break;
 559         case TRACE_AUTH_OK:
 560                 if (len == 4) {
 561                         traceState = TRACE_IDLE;
 562                         at_enc = bytes_to_num(data, 4);
 563
 564                         //  decode key here)
 565                         ks2 = ar_enc ^ prng_successor(nt, 64);
 566                         ks3 = at_enc ^ prng_successor(nt, 96);
 567                         revstate = lfsr_recovery64(ks2, ks3);
 568                         lfsr_rollback_word(revstate, 0, 0);
 569                         lfsr_rollback_word(revstate, 0, 0);
 570                         lfsr_rollback_word(revstate, nr_enc, 1);
 571                         lfsr_rollback_word(revstate, cuid ^ nt, 0);
 572                         crypto1_get_lfsr(revstate, &key);
 573                         PrintAndLog("Found Key: [%012"llx"]", key);
 574
 575                         //if ( tryMfk64(cuid, nt, nr_enc, ar_enc, at_enc, &key) )
 576                         AddLogUint64(logHexFileName, "Found Key: ", key);
 577
 578                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 579                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 580
 581                         if (traceCurKey)
 582                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 583                         else
 584                                 num_to_bytes(key, 6, traceCard + blockShift);
 585
 586                         if (wantSaveToEmlFile)
 587                                 saveTraceCard();
 588
 589                         if (traceCrypto1)
 590                                 crypto1_destroy(traceCrypto1);
 591
 592                         // set cryptosystem state
 593                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 594
 595                         return 0;
 596                 } else {
 597                         traceState = TRACE_ERROR;
 598                         return 1;
 599                 }
 600                 break;
 601         default:
 602                 traceState = TRACE_ERROR;
 603                 return 1;
 604         }
 605         return 0;
 606 }
 607
 608 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 609         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data, len) );
 610         struct Crypto1State *pcs = NULL;
 611         ks2 = ar_enc ^ prng_successor(nt, 64);
 612         ks3 = at_enc ^ prng_successor(nt, 96);
 613         pcs = lfsr_recovery64(ks2, ks3);
 614         mf_crypto1_decrypt(pcs, data, len, FALSE);
 615         PrintAndLog("Decrypted data: [%s]", sprint_hex(data, len) );
 616         crypto1_destroy(pcs);
 617         return 0;
 618 }