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