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
  81         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
  82         memcpy(c.d.asBytes, key, 6);
  83         clearCommandBuffer();
  84         SendCommand(&c);
  85
  86         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) return -1;
  87
  88         // error during nested
  89         if (resp.arg[0]) return resp.arg[0];
  90
  91         memcpy(&uid, resp.d.asBytes, 4);
  92         PrintAndLog("UID: %08x Block:%d Key: %c", uid, (uint16_t)resp.arg[2] & 0xff, (resp.arg[2] >> 8) ?'A':'B' );
  93
  94         for (i = 0; i < 2; i++) {
  95                 statelists[i].blockNo = resp.arg[2] & 0xff;
  96                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
  97                 statelists[i].uid = uid;
  98                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
  99                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 100         }
 101
 102         // calc keys
 103
 104         pthread_t thread_id[2];
 105
 106         // create and run worker threads
 107         for (i = 0; i < 2; i++) {
 108                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 109         }
 110
 111         // wait for threads to terminate:
 112         for (i = 0; i < 2; i++) {
 113                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 114         }
 115
 116
 117         // the first 16 Bits of the cryptostate already contain part of our key.
 118         // Create the intersection of the two lists based on these 16 Bits and
 119         // roll back the cryptostate
 120         p1 = p3 = statelists[0].head.slhead;
 121         p2 = p4 = statelists[1].head.slhead;
 122         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 123                 if (Compare16Bits(p1, p2) == 0) {
 124                         struct Crypto1State savestate, *savep = &savestate;
 125                         savestate = *p1;
 126                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 127                                 *p3 = *p1;
 128                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 129                                 p3++;
 130                                 p1++;
 131                         }
 132                         savestate = *p2;
 133                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 134                                 *p4 = *p2;
 135                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 136                                 p4++;
 137                                 p2++;
 138                         }
 139                 }
 140                 else {
 141                         while (Compare16Bits(p1, p2) == -1) p1++;
 142                         while (Compare16Bits(p1, p2) == 1) p2++;
 143                 }
 144         }
 145         p3->even = 0; p3->odd = 0;
 146         p4->even = 0; p4->odd = 0;
 147         statelists[0].len = p3 - statelists[0].head.slhead;
 148         statelists[1].len = p4 - statelists[1].head.slhead;
 149         statelists[0].tail.sltail=--p3;
 150         statelists[1].tail.sltail=--p4;
 151
 152         // the statelists now contain possible keys. The key we are searching for must be in the
 153         // intersection of both lists. Create the intersection:
 154         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compar_int);
 155         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compar_int);
 156
 157         uint64_t *p5, *p6, *p7;
 158         p5 = p7 = statelists[0].head.keyhead;
 159         p6 = statelists[1].head.keyhead;
 160         while (p5 <= statelists[0].tail.keytail && p6 <= statelists[1].tail.keytail) {
 161                 if (compar_int(p5, p6) == 0) {
 162                         *p7++ = *p5++;
 163                         p6++;
 164                 }
 165                 else {
 166                         while (compar_int(p5, p6) == -1) p5++;
 167                         while (compar_int(p5, p6) == 1) p6++;
 168                 }
 169         }
 170         statelists[0].len = p7 - statelists[0].head.keyhead;
 171         statelists[0].tail.keytail=--p7;
 172
 173         memset(resultKey, 0, 6);
 174         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 175         for (i = 0; i < statelists[0].len; i++) {
 176                 uint8_t keyBlock[6];
 177                 uint64_t key64;
 178                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 179                 num_to_bytes(key64, 6, keyBlock);
 180                 key64 = 0;
 181                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 182                         num_to_bytes(key64, 6, resultKey);
 183                         break;
 184                 }
 185         }
 186
 187         free(statelists[0].head.slhead);
 188         free(statelists[1].head.slhead);
 189         return 0;
 190 }
 191
 192 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 193
 194         *key = 0;
 195
 196         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
 197         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 198
 199         clearCommandBuffer();
 200         SendCommand(&c);
 201         UsbCommand resp;
 202         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 203         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 204         *key = bytes_to_num(resp.d.asBytes, 6);
 205         return 0;
 206 }
 207
 208 // EMULATOR
 209
 210 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 211         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 212         clearCommandBuffer();
 213         SendCommand(&c);
 214         UsbCommand resp;
 215         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 216         memcpy(data, resp.d.asBytes, blocksCount * 16);
 217         return 0;
 218 }
 219
 220 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 221         return mfEmlSetMem_xt(data, blockNum, blocksCount, 16);
 222 }
 223
 224 int mfEmlSetMem_xt(uint8_t *data, int blockNum, int blocksCount, int blockBtWidth) {
 225         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, blockBtWidth}};
 226         memcpy(c.d.asBytes, data, blocksCount * blockBtWidth);
 227
 228         clearCommandBuffer();
 229         SendCommand(&c);
 230         return 0;
 231 }
 232
 233 // "MAGIC" CARD
 234
 235 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, uint8_t wipecard) {
 236
 237         uint8_t params = MAGIC_SINGLE;
 238         uint8_t block0[16];
 239         memset(block0, 0x00, sizeof(block0));
 240
 241
 242         int old = mfCGetBlock(0, block0, params);
 243         if (old == 0) {
 244                 PrintAndLog("old block 0:  %s", sprint_hex(block0, sizeof(block0)));
 245         } else {
 246                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 247         }
 248
 249         // fill in the new values
 250         // UID
 251         memcpy(block0, uid, 4);
 252         // Mifare UID BCC
 253         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 254         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 255         if ( sak != NULL )
 256                 block0[5]=sak[0];
 257
 258         if ( atqa != NULL ) {
 259                 block0[6]=atqa[1];
 260                 block0[7]=atqa[0];
 261         }
 262         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 263
 264         if ( wipecard )          params |= MAGIC_WIPE;
 265         if ( oldUID == NULL) params |= MAGIC_UID;
 266
 267         return mfCSetBlock(0, block0, oldUID, params);
 268 }
 269
 270 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, uint8_t params) {
 271
 272         uint8_t isOK = 0;
 273         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {params, blockNo, 0}};
 274         memcpy(c.d.asBytes, data, 16);
 275         clearCommandBuffer();
 276         SendCommand(&c);
 277         UsbCommand resp;
 278         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 279                 isOK  = resp.arg[0] & 0xff;
 280                 if (uid != NULL)
 281                         memcpy(uid, resp.d.asBytes, 4);
 282                 if (!isOK)
 283                         return 2;
 284         } else {
 285                 PrintAndLog("Command execute timeout");
 286                 return 1;
 287         }
 288         return 0;
 289 }
 290
 291 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 292         uint8_t isOK = 0;
 293         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, blockNo, 0}};
 294         clearCommandBuffer();
 295         SendCommand(&c);
 296         UsbCommand resp;
 297         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 298                 isOK  = resp.arg[0] & 0xff;
 299                 memcpy(data, resp.d.asBytes, 16);
 300                 if (!isOK) return 2;
 301         } else {
 302                 PrintAndLog("Command execute timeout");
 303                 return 1;
 304         }
 305         return 0;
 306 }
 307
 308 // SNIFFER
 309
 310 // constants
 311 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 312
 313 // variables
 314 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 315 static uint8_t traceCard[4096] = {0x00};
 316 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 317 static int traceState = TRACE_IDLE;
 318 static uint8_t traceCurBlock = 0;
 319 static uint8_t traceCurKey = 0;
 320
 321 struct Crypto1State *traceCrypto1 = NULL;
 322
 323 struct Crypto1State *revstate = NULL;
 324
 325 uint64_t key = 0;
 326 uint32_t ks2 = 0;
 327 uint32_t ks3 = 0;
 328
 329 uint32_t uid = 0;     // serial number
 330 uint32_t nt =0;      // tag challenge
 331 uint32_t nr_enc =0;  // encrypted reader challenge
 332 uint32_t ar_enc =0;  // encrypted reader response
 333 uint32_t at_enc =0;  // encrypted tag response
 334
 335 int isTraceCardEmpty(void) {
 336         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 337 }
 338
 339 int isBlockEmpty(int blockN) {
 340         for (int i = 0; i < 16; i++)
 341                 if (traceCard[blockN * 16 + i] != 0) return 0;
 342
 343         return 1;
 344 }
 345
 346 int isBlockTrailer(int blockN) {
 347  return ((blockN & 0x03) == 0x03);
 348 }
 349
 350 int loadTraceCard(uint8_t *tuid) {
 351         FILE * f;
 352         char buf[64] = {0x00};
 353         uint8_t buf8[64] = {0x00};
 354         int i, blockNum;
 355
 356         if (!isTraceCardEmpty())
 357                 saveTraceCard();
 358
 359         memset(traceCard, 0x00, 4096);
 360         memcpy(traceCard, tuid + 3, 4);
 361
 362         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 363
 364         f = fopen(traceFileName, "r");
 365         if (!f) return 1;
 366
 367         blockNum = 0;
 368
 369         while(!feof(f)){
 370
 371                 memset(buf, 0, sizeof(buf));
 372                 if (fgets(buf, sizeof(buf), f) == NULL) {
 373                         PrintAndLog("File reading error.");
 374                         fclose(f);
 375                         return 2;
 376                 }
 377
 378                 if (strlen(buf) < 32){
 379                         if (feof(f)) break;
 380                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 381                         fclose(f);
 382                         return 2;
 383                 }
 384                 for (i = 0; i < 32; i += 2)
 385                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 386
 387                 memcpy(traceCard + blockNum * 16, buf8, 16);
 388
 389                 blockNum++;
 390         }
 391         fclose(f);
 392
 393         return 0;
 394 }
 395
 396 int saveTraceCard(void) {
 397         FILE * f;
 398
 399         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 400
 401         f = fopen(traceFileName, "w+");
 402         if ( !f ) return 1;
 403
 404         for (int i = 0; i < 64; i++) {  // blocks
 405                 for (int j = 0; j < 16; j++)  // bytes
 406                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 407                 fprintf(f,"\n");
 408         }
 409         fclose(f);
 410         return 0;
 411 }
 412
 413 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 414
 415         if (traceCrypto1)
 416                 crypto1_destroy(traceCrypto1);
 417
 418         traceCrypto1 = NULL;
 419
 420         if (wantSaveToEmlFile)
 421                 loadTraceCard(tuid);
 422
 423         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 424         traceCard[5] = sak;
 425         memcpy(&traceCard[6], atqa, 2);
 426         traceCurBlock = 0;
 427         uid = bytes_to_num(tuid + 3, 4);
 428
 429         traceState = TRACE_IDLE;
 430
 431         return 0;
 432 }
 433
 434 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 435         uint8_t bt = 0;
 436         int i;
 437
 438         if (len != 1) {
 439                 for (i = 0; i < len; i++)
 440                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 441         } else {
 442                 bt = 0;
 443                 for (i = 0; i < 4; i++)
 444                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 445
 446                 data[0] = bt;
 447         }
 448         return;
 449 }
 450
 451
 452 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 453         uint8_t data[64];
 454
 455         if (traceState == TRACE_ERROR) return 1;
 456         if (len > 64) {
 457                 traceState = TRACE_ERROR;
 458                 return 1;
 459         }
 460
 461         memcpy(data, data_src, len);
 462         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 463                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 464                 PrintAndLog("dec> %s", sprint_hex(data, len));
 465                 AddLogHex(logHexFileName, "dec> ", data, len);
 466         }
 467
 468         switch (traceState) {
 469         case TRACE_IDLE:
 470                 // check packet crc16!
 471                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 472                         PrintAndLog("dec> CRC ERROR!!!");
 473                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 474                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 475                         return 1;
 476                 }
 477
 478                 // AUTHENTICATION
 479                 if ((len == 4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 480                         traceState = TRACE_AUTH1;
 481                         traceCurBlock = data[1];
 482                         traceCurKey = data[0] == 60 ? 1:0;
 483                         return 0;
 484                 }
 485
 486                 // READ
 487                 if ((len ==4) && ((data[0] == 0x30))) {
 488                         traceState = TRACE_READ_DATA;
 489                         traceCurBlock = data[1];
 490                         return 0;
 491                 }
 492
 493                 // WRITE
 494                 if ((len ==4) && ((data[0] == 0xA0))) {
 495                         traceState = TRACE_WRITE_OK;
 496                         traceCurBlock = data[1];
 497                         return 0;
 498                 }
 499
 500                 // HALT
 501                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 502                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 503                         return 0;
 504                 }
 505
 506                 return 0;
 507         break;
 508
 509         case TRACE_READ_DATA:
 510                 if (len == 18) {
 511                         traceState = TRACE_IDLE;
 512
 513                         if (isBlockTrailer(traceCurBlock)) {
 514                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 515                         } else {
 516                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 517                         }
 518                         if (wantSaveToEmlFile) saveTraceCard();
 519                         return 0;
 520                 } else {
 521                         traceState = TRACE_ERROR;
 522                         return 1;
 523                 }
 524         break;
 525
 526         case TRACE_WRITE_OK:
 527                 if ((len == 1) && (data[0] == 0x0a)) {
 528                         traceState = TRACE_WRITE_DATA;
 529
 530                         return 0;
 531                 } else {
 532                         traceState = TRACE_ERROR;
 533                         return 1;
 534                 }
 535         break;
 536
 537         case TRACE_WRITE_DATA:
 538                 if (len == 18) {
 539                         traceState = TRACE_IDLE;
 540
 541                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 542                         if (wantSaveToEmlFile) saveTraceCard();
 543                         return 0;
 544                 } else {
 545                         traceState = TRACE_ERROR;
 546                         return 1;
 547                 }
 548         break;
 549
 550         case TRACE_AUTH1:
 551                 if (len == 4) {
 552                         traceState = TRACE_AUTH2;
 553                         nt = bytes_to_num(data, 4);
 554                         return 0;
 555                 } else {
 556                         traceState = TRACE_ERROR;
 557                         return 1;
 558                 }
 559         break;
 560
 561         case TRACE_AUTH2:
 562                 if (len == 8) {
 563                         traceState = TRACE_AUTH_OK;
 564
 565                         nr_enc = bytes_to_num(data, 4);
 566                         ar_enc = bytes_to_num(data + 4, 4);
 567                         return 0;
 568                 } else {
 569                         traceState = TRACE_ERROR;
 570                         return 1;
 571                 }
 572         break;
 573
 574         case TRACE_AUTH_OK:
 575                 if (len ==4) {
 576                         traceState = TRACE_IDLE;
 577
 578                         at_enc = bytes_to_num(data, 4);
 579
 580                         //  decode key here)
 581                         ks2 = ar_enc ^ prng_successor(nt, 64);
 582                         ks3 = at_enc ^ prng_successor(nt, 96);
 583                         revstate = lfsr_recovery64(ks2, ks3);
 584                         lfsr_rollback_word(revstate, 0, 0);
 585                         lfsr_rollback_word(revstate, 0, 0);
 586                         lfsr_rollback_word(revstate, nr_enc, 1);
 587                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 588
 589                         crypto1_get_lfsr(revstate, &key);
 590                         printf("Key: %012"llx"\n",key);
 591                         AddLogUint64(logHexFileName, "key: ", key);
 592
 593                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 594                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 595
 596                         if (traceCurKey) {
 597                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 598                         } else {
 599                                 num_to_bytes(key, 6, traceCard + blockShift);
 600                         }
 601                         if (wantSaveToEmlFile) saveTraceCard();
 602
 603                         if (traceCrypto1) {
 604                                 crypto1_destroy(traceCrypto1);
 605                         }
 606
 607                         // set cryptosystem state
 608                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 609
 610 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 611
 612         /*      traceCrypto1 = crypto1_create(key); // key in lfsr
 613                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 614                 crypto1_word(traceCrypto1, ar, 1);
 615                 crypto1_word(traceCrypto1, 0, 0);
 616                 crypto1_word(traceCrypto1, 0, 0);*/
 617
 618                         return 0;
 619                 } else {
 620                         traceState = TRACE_ERROR;
 621                         return 1;
 622                 }
 623         break;
 624
 625         default:
 626                 traceState = TRACE_ERROR;
 627                 return 1;
 628         }
 629
 630         return 0;
 631 }
 632
 633 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 634         /*
 635         uint32_t nt;      // tag challenge
 636         uint32_t nr_enc;  // encrypted reader challenge
 637         uint32_t ar_enc;  // encrypted reader response
 638         uint32_t at_enc;  // encrypted tag response
 639         */
 640
 641         struct Crypto1State *pcs = NULL;
 642
 643         ks2 = ar_enc ^ prng_successor(nt, 64);
 644         ks3 = at_enc ^ prng_successor(nt, 96);
 645
 646         PrintAndLog("Decrypting data with:");
 647         PrintAndLog("      nt: %08x",nt);
 648         PrintAndLog("  ar_enc: %08x",ar_enc);
 649         PrintAndLog("  at_enc: %08x",at_enc);
 650         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data,len) );
 651
 652         pcs = lfsr_recovery64(ks2, ks3);
 653         mf_crypto1_decrypt(pcs, data, len, FALSE);
 654         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 655         crypto1_destroy(pcs);
 656         return 0;
 657 }