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 <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <pthread.h>
  15
  16 #include "nonce2key/crapto1.h"
  17 #include "proxmark3.h"
  18 #include "usb_cmd.h"
  19 #include "cmdmain.h"
  20 #include "ui.h"
  21 #include "util.h"
  22 #include "iso14443crc.h"
  23 #include "mifarehost.h"
  24
  25 // mifare tracer flags used in mfTraceDecode()
  26 #define TRACE_IDLE                                              0x00
  27 #define TRACE_AUTH1                                             0x01
  28 #define TRACE_AUTH2                                             0x02
  29 #define TRACE_AUTH_OK                                   0x03
  30 #define TRACE_READ_DATA                                 0x04
  31 #define TRACE_WRITE_OK                                  0x05
  32 #define TRACE_WRITE_DATA                                0x06
  33 #define TRACE_ERROR                                             0xFF
  34
  35
  36 // MIFARE
  37 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
  38
  39         *key = 0;
  40
  41         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
  42         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
  43         SendCommand(&c);
  44
  45         UsbCommand resp;
  46         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
  47         if ((resp.arg[0] & 0xff) != 0x01) return 2;
  48         *key = bytes_to_num(resp.d.asBytes, 6);
  49         return 0;
  50 }
  51
  52 int compar_int(const void * a, const void * b) {
  53         // didn't work: (the result is truncated to 32 bits)
  54         //return (*(uint64_t*)b - *(uint64_t*)a);
  55
  56         // better:
  57         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  58         else if (*(uint64_t*)b > *(uint64_t*)a) return 1;
  59         else return -1;
  60 }
  61
  62 // Compare 16 Bits out of cryptostate
  63 int Compare16Bits(const void * a, const void * b) {
  64         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
  65         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
  66         else return -1;
  67 }
  68
  69 typedef
  70         struct {
  71                 union {
  72                         struct Crypto1State *slhead;
  73                         uint64_t *keyhead;
  74                 } head;
  75                 union {
  76                         struct Crypto1State *sltail;
  77                         uint64_t *keytail;
  78                 } tail;
  79                 uint32_t len;
  80                 uint32_t uid;
  81                 uint32_t blockNo;
  82                 uint32_t keyType;
  83                 uint32_t nt;
  84                 uint32_t ks1;
  85         } StateList_t;
  86
  87
  88 // wrapper function for multi-threaded lfsr_recovery32
  89 void* nested_worker_thread(void *arg)
  90 {
  91         struct Crypto1State *p1;
  92         StateList_t *statelist = arg;
  93
  94         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
  95         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
  96         statelist->len = p1 - statelist->head.slhead;
  97         statelist->tail.sltail = --p1;
  98         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
  99
 100         return statelist->head.slhead;
 101 }
 102
 103 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t * key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t * resultKey, bool calibrate)
 104 {
 105         uint16_t i;
 106         uint32_t uid;
 107         UsbCommand resp;
 108
 109         StateList_t statelists[2];
 110         struct Crypto1State *p1, *p2, *p3, *p4;
 111
 112         // flush queue
 113         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 114
 115         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 116         memcpy(c.d.asBytes, key, 6);
 117         SendCommand(&c);
 118
 119         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 120                 return -1;
 121         }
 122
 123         if (resp.arg[0]) {
 124                 return resp.arg[0];  // error during nested
 125         }
 126
 127         memcpy(&uid, resp.d.asBytes, 4);
 128         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 129
 130         for (i = 0; i < 2; i++) {
 131                 statelists[i].blockNo = resp.arg[2] & 0xff;
 132                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 133                 statelists[i].uid = uid;
 134                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 135                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 136         }
 137
 138         // calc keys
 139
 140         pthread_t thread_id[2];
 141
 142         // create and run worker threads
 143         for (i = 0; i < 2; i++) {
 144                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 145         }
 146
 147         // wait for threads to terminate:
 148         for (i = 0; i < 2; i++) {
 149                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 150         }
 151
 152
 153         // the first 16 Bits of the cryptostate already contain part of our key.
 154         // Create the intersection of the two lists based on these 16 Bits and
 155         // roll back the cryptostate
 156         p1 = p3 = statelists[0].head.slhead;
 157         p2 = p4 = statelists[1].head.slhead;
 158         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 159                 if (Compare16Bits(p1, p2) == 0) {
 160                         struct Crypto1State savestate, *savep = &savestate;
 161                         savestate = *p1;
 162                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 163                                 *p3 = *p1;
 164                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 165                                 p3++;
 166                                 p1++;
 167                         }
 168                         savestate = *p2;
 169                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 170                                 *p4 = *p2;
 171                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 172                                 p4++;
 173                                 p2++;
 174                         }
 175                 }
 176                 else {
 177                         while (Compare16Bits(p1, p2) == -1) p1++;
 178                         while (Compare16Bits(p1, p2) == 1) p2++;
 179                 }
 180         }
 181         p3->even = 0; p3->odd = 0;
 182         p4->even = 0; p4->odd = 0;
 183         statelists[0].len = p3 - statelists[0].head.slhead;
 184         statelists[1].len = p4 - statelists[1].head.slhead;
 185         statelists[0].tail.sltail=--p3;
 186         statelists[1].tail.sltail=--p4;
 187
 188         // the statelists now contain possible keys. The key we are searching for must be in the
 189         // intersection of both lists. Create the intersection:
 190         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compar_int);
 191         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compar_int);
 192
 193         uint64_t *p5, *p6, *p7;
 194         p5 = p7 = statelists[0].head.keyhead;
 195         p6 = statelists[1].head.keyhead;
 196         while (p5 <= statelists[0].tail.keytail && p6 <= statelists[1].tail.keytail) {
 197                 if (compar_int(p5, p6) == 0) {
 198                         *p7++ = *p5++;
 199                         p6++;
 200                 }
 201                 else {
 202                         while (compar_int(p5, p6) == -1) p5++;
 203                         while (compar_int(p5, p6) == 1) p6++;
 204                 }
 205         }
 206         statelists[0].len = p7 - statelists[0].head.keyhead;
 207         statelists[0].tail.keytail=--p7;
 208
 209         memset(resultKey, 0, 6);
 210         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 211         for (i = 0; i < statelists[0].len; i++) {
 212                 uint8_t keyBlock[6];
 213                 uint64_t key64;
 214                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 215                 num_to_bytes(key64, 6, keyBlock);
 216                 key64 = 0;
 217                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 218                         num_to_bytes(key64, 6, resultKey);
 219                         break;
 220                 }
 221         }
 222
 223         free(statelists[0].head.slhead);
 224         free(statelists[1].head.slhead);
 225
 226         return 0;
 227 }
 228
 229 // EMULATOR
 230
 231 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 232         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 233         SendCommand(&c);
 234
 235   UsbCommand resp;
 236         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 237         memcpy(data, resp.d.asBytes, blocksCount * 16);
 238         return 0;
 239 }
 240
 241 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 242         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 243         memcpy(c.d.asBytes, data, blocksCount * 16);
 244         SendCommand(&c);
 245         return 0;
 246 }
 247
 248 // "MAGIC" CARD
 249
 250 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 251         uint8_t isOK = 0;
 252
 253         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 254         SendCommand(&c);
 255
 256   UsbCommand resp;
 257         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 258                 isOK  = resp.arg[0] & 0xff;
 259                 memcpy(data, resp.d.asBytes, 16);
 260                 if (!isOK) return 2;
 261         } else {
 262                 PrintAndLog("Command execute timeout");
 263                 return 1;
 264         }
 265         return 0;
 266 }
 267
 268 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 269
 270         uint8_t isOK = 0;
 271         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 272         memcpy(c.d.asBytes, data, 16);
 273         SendCommand(&c);
 274
 275   UsbCommand resp;
 276         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 277                 isOK  = resp.arg[0] & 0xff;
 278                 if (uid != NULL)
 279                         memcpy(uid, resp.d.asBytes, 4);
 280                 if (!isOK)
 281                         return 2;
 282         } else {
 283                 PrintAndLog("Command execute timeout");
 284                 return 1;
 285         }
 286         return 0;
 287 }
 288
 289 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) {
 290         uint8_t oldblock0[16] = {0x00};
 291         uint8_t block0[16] = {0x00};
 292
 293         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);
 294         if (old == 0) {
 295                 memcpy(block0, oldblock0, 16);
 296                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 297         } else {
 298                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 299         }
 300
 301         // fill in the new values
 302         // UID
 303         memcpy(block0, uid, 4);
 304         // Mifare UID BCC
 305         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 306         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 307         if (sak!=NULL)
 308                 block0[5]=sak[0];
 309         if (atqa!=NULL) {
 310                 block0[6]=atqa[1];
 311                 block0[7]=atqa[0];
 312         }
 313         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 314         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
 315 }
 316
 317 // SNIFFER
 318
 319 // constants
 320 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 321
 322 // variables
 323 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 324 static uint8_t traceCard[4096] = {0x00};
 325 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 326 static int traceState = TRACE_IDLE;
 327 static uint8_t traceCurBlock = 0;
 328 static uint8_t traceCurKey = 0;
 329
 330 struct Crypto1State *traceCrypto1 = NULL;
 331
 332 struct Crypto1State *revstate;
 333 uint64_t lfsr;
 334 uint32_t ks2;
 335 uint32_t ks3;
 336
 337 uint32_t uid;     // serial number
 338 uint32_t nt;      // tag challenge
 339 uint32_t nr_enc;  // encrypted reader challenge
 340 uint32_t ar_enc;  // encrypted reader response
 341 uint32_t at_enc;  // encrypted tag response
 342
 343 int isTraceCardEmpty(void) {
 344         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 345 }
 346
 347 int isBlockEmpty(int blockN) {
 348         for (int i = 0; i < 16; i++)
 349                 if (traceCard[blockN * 16 + i] != 0) return 0;
 350
 351         return 1;
 352 }
 353
 354 int isBlockTrailer(int blockN) {
 355  return ((blockN & 0x03) == 0x03);
 356 }
 357
 358 int saveTraceCard(void) {
 359         FILE * f;
 360
 361         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 362
 363         f = fopen(traceFileName, "w+");
 364         if ( !f ) return 1;
 365
 366         for (int i = 0; i < 64; i++) {  // blocks
 367                 for (int j = 0; j < 16; j++)  // bytes
 368                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 369                 fprintf(f,"\n");
 370         }
 371         fclose(f);
 372         return 0;
 373 }
 374
 375 int loadTraceCard(uint8_t *tuid) {
 376         FILE * f;
 377         char buf[64] = {0x00};
 378         uint8_t buf8[64] = {0x00};
 379         int i, blockNum;
 380
 381         if (!isTraceCardEmpty())
 382                 saveTraceCard();
 383
 384         memset(traceCard, 0x00, 4096);
 385         memcpy(traceCard, tuid + 3, 4);
 386
 387         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 388
 389         f = fopen(traceFileName, "r");
 390         if (!f) return 1;
 391
 392         blockNum = 0;
 393
 394         while(!feof(f)){
 395
 396                 memset(buf, 0, sizeof(buf));
 397                 if (fgets(buf, sizeof(buf), f) == NULL) {
 398                         PrintAndLog("File reading error.");
 399                         fclose(f);
 400                         return 2;
 401         }
 402
 403                 if (strlen(buf) < 32){
 404                         if (feof(f)) break;
 405                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 406                         fclose(f);
 407                         return 2;
 408                 }
 409                 for (i = 0; i < 32; i += 2)
 410                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 411
 412                 memcpy(traceCard + blockNum * 16, buf8, 16);
 413
 414                 blockNum++;
 415         }
 416         fclose(f);
 417
 418         return 0;
 419 }
 420
 421 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 422
 423         if (traceCrypto1)
 424                 crypto1_destroy(traceCrypto1);
 425
 426         traceCrypto1 = NULL;
 427
 428         if (wantSaveToEmlFile)
 429                 loadTraceCard(tuid);
 430
 431         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 432         traceCard[5] = sak;
 433         memcpy(&traceCard[6], atqa, 2);
 434         traceCurBlock = 0;
 435         uid = bytes_to_num(tuid + 3, 4);
 436
 437         traceState = TRACE_IDLE;
 438
 439         return 0;
 440 }
 441
 442 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 443         uint8_t bt = 0;
 444         int i;
 445
 446         if (len != 1) {
 447                 for (i = 0; i < len; i++)
 448                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 449         } else {
 450                 bt = 0;
 451                 for (i = 0; i < 4; i++)
 452                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 453
 454                 data[0] = bt;
 455         }
 456         return;
 457 }
 458
 459
 460 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 461         uint8_t data[64];
 462
 463         if (traceState == TRACE_ERROR) return 1;
 464         if (len > 64) {
 465                 traceState = TRACE_ERROR;
 466                 return 1;
 467         }
 468
 469         memcpy(data, data_src, len);
 470         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 471                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 472                 PrintAndLog("dec> %s", sprint_hex(data, len));
 473                 AddLogHex(logHexFileName, "dec> ", data, len);
 474         }
 475
 476         switch (traceState) {
 477         case TRACE_IDLE:
 478                 // check packet crc16!
 479                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 480                         PrintAndLog("dec> CRC ERROR!!!");
 481                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 482                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 483                         return 1;
 484                 }
 485
 486                 // AUTHENTICATION
 487                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 488                         traceState = TRACE_AUTH1;
 489                         traceCurBlock = data[1];
 490                         traceCurKey = data[0] == 60 ? 1:0;
 491                         return 0;
 492                 }
 493
 494                 // READ
 495                 if ((len ==4) && ((data[0] == 0x30))) {
 496                         traceState = TRACE_READ_DATA;
 497                         traceCurBlock = data[1];
 498                         return 0;
 499                 }
 500
 501                 // WRITE
 502                 if ((len ==4) && ((data[0] == 0xA0))) {
 503                         traceState = TRACE_WRITE_OK;
 504                         traceCurBlock = data[1];
 505                         return 0;
 506                 }
 507
 508                 // HALT
 509                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 510                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 511                         return 0;
 512                 }
 513
 514                 return 0;
 515         break;
 516
 517         case TRACE_READ_DATA:
 518                 if (len == 18) {
 519                         traceState = TRACE_IDLE;
 520
 521                         if (isBlockTrailer(traceCurBlock)) {
 522                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 523                         } else {
 524                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 525                         }
 526                         if (wantSaveToEmlFile) saveTraceCard();
 527                         return 0;
 528                 } else {
 529                         traceState = TRACE_ERROR;
 530                         return 1;
 531                 }
 532         break;
 533
 534         case TRACE_WRITE_OK:
 535                 if ((len == 1) && (data[0] == 0x0a)) {
 536                         traceState = TRACE_WRITE_DATA;
 537
 538                         return 0;
 539                 } else {
 540                         traceState = TRACE_ERROR;
 541                         return 1;
 542                 }
 543         break;
 544
 545         case TRACE_WRITE_DATA:
 546                 if (len == 18) {
 547                         traceState = TRACE_IDLE;
 548
 549                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 550                         if (wantSaveToEmlFile) saveTraceCard();
 551                         return 0;
 552                 } else {
 553                         traceState = TRACE_ERROR;
 554                         return 1;
 555                 }
 556         break;
 557
 558         case TRACE_AUTH1:
 559                 if (len == 4) {
 560                         traceState = TRACE_AUTH2;
 561                         nt = bytes_to_num(data, 4);
 562                         return 0;
 563                 } else {
 564                         traceState = TRACE_ERROR;
 565                         return 1;
 566                 }
 567         break;
 568
 569         case TRACE_AUTH2:
 570                 if (len == 8) {
 571                         traceState = TRACE_AUTH_OK;
 572
 573                         nr_enc = bytes_to_num(data, 4);
 574                         ar_enc = bytes_to_num(data + 4, 4);
 575                         return 0;
 576                 } else {
 577                         traceState = TRACE_ERROR;
 578                         return 1;
 579                 }
 580         break;
 581
 582         case TRACE_AUTH_OK:
 583                 if (len ==4) {
 584                         traceState = TRACE_IDLE;
 585
 586                         at_enc = bytes_to_num(data, 4);
 587
 588                         //  decode key here)
 589                         ks2 = ar_enc ^ prng_successor(nt, 64);
 590                         ks3 = at_enc ^ prng_successor(nt, 96);
 591                         revstate = lfsr_recovery64(ks2, ks3);
 592                         lfsr_rollback_word(revstate, 0, 0);
 593                         lfsr_rollback_word(revstate, 0, 0);
 594                         lfsr_rollback_word(revstate, nr_enc, 1);
 595                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 596
 597                         crypto1_get_lfsr(revstate, &lfsr);
 598                         printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 599                         AddLogUint64(logHexFileName, "key> ", lfsr);
 600
 601                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 602                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 603
 604                         if (traceCurKey) {
 605                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 606                         } else {
 607                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 608                         }
 609                         if (wantSaveToEmlFile) saveTraceCard();
 610
 611                         if (traceCrypto1) {
 612                                 crypto1_destroy(traceCrypto1);
 613                         }
 614
 615                         // set cryptosystem state
 616                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 617
 618 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 619
 620         /*      traceCrypto1 = crypto1_create(lfsr); // key in lfsr
 621                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 622                 crypto1_word(traceCrypto1, ar, 1);
 623                 crypto1_word(traceCrypto1, 0, 0);
 624                 crypto1_word(traceCrypto1, 0, 0);*/
 625
 626                         return 0;
 627                 } else {
 628                         traceState = TRACE_ERROR;
 629                         return 1;
 630                 }
 631         break;
 632
 633         default:
 634                 traceState = TRACE_ERROR;
 635                 return 1;
 636         }
 637
 638         return 0;
 639 }
 640
 641 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 642         /*
 643         uint32_t nt;      // tag challenge
 644         uint32_t ar_enc;  // encrypted reader response
 645         uint32_t at_enc;  // encrypted tag response
 646         */
 647         if (traceCrypto1) {
 648                 crypto1_destroy(traceCrypto1);
 649         }
 650         ks2 = ar_enc ^ prng_successor(nt, 64);
 651         ks3 = at_enc ^ prng_successor(nt, 96);
 652         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 653
 654         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 655
 656         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 657         crypto1_destroy(traceCrypto1);
 658         return 0;
 659 }