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 #define llx PRIx64
  19
  20 // MIFARE
  21 int compar_int(const void * a, const void * b) {
  22         // didn't work: (the result is truncated to 32 bits)
  23         //return (*(uint64_t*)b - *(uint64_t*)a);
  24
  25         // better:
  26         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  27         else if (*(uint64_t*)b > *(uint64_t*)a) return 1;
  28         else return -1;
  29 }
  30
  31 // Compare 16 Bits out of cryptostate
  32 int Compare16Bits(const void * a, const void * b) {
  33         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
  34         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
  35         else return -1;
  36 }
  37
  38 typedef
  39         struct {
  40                 union {
  41                         struct Crypto1State *slhead;
  42                         uint64_t *keyhead;
  43                 } head;
  44                 union {
  45                         struct Crypto1State *sltail;
  46                         uint64_t *keytail;
  47                 } tail;
  48                 uint32_t len;
  49                 uint32_t uid;
  50                 uint32_t blockNo;
  51                 uint32_t keyType;
  52                 uint32_t nt;
  53                 uint32_t ks1;
  54         } StateList_t;
  55
  56
  57 // wrapper function for multi-threaded lfsr_recovery32
  58 void* nested_worker_thread(void *arg)
  59 {
  60         struct Crypto1State *p1;
  61         StateList_t *statelist = arg;
  62
  63         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
  64         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
  65         statelist->len = p1 - statelist->head.slhead;
  66         statelist->tail.sltail = --p1;
  67         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
  68
  69         return statelist->head.slhead;
  70 }
  71
  72 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t * key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t * resultKey, bool calibrate)
  73 {
  74         uint16_t i;
  75         uint32_t uid;
  76         UsbCommand resp;
  77
  78         StateList_t statelists[2];
  79         struct Crypto1State *p1, *p2, *p3, *p4;
  80
  81         // flush queue
  82         WaitForResponseTimeout(CMD_ACK,NULL,100);
  83
  84         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
  85         memcpy(c.d.asBytes, key, 6);
  86         SendCommand(&c);
  87
  88         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
  89                 return -1;
  90         }
  91
  92         if (resp.arg[0]) {
  93                 return resp.arg[0];  // error during nested
  94         }
  95
  96         memcpy(&uid, resp.d.asBytes, 4);
  97         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
  98
  99         for (i = 0; i < 2; i++) {
 100                 statelists[i].blockNo = resp.arg[2] & 0xff;
 101                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 102                 statelists[i].uid = uid;
 103                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 104                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 105         }
 106
 107         // calc keys
 108
 109         pthread_t thread_id[2];
 110
 111         // create and run worker threads
 112         for (i = 0; i < 2; i++) {
 113                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 114         }
 115
 116         // wait for threads to terminate:
 117         for (i = 0; i < 2; i++) {
 118                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 119         }
 120
 121
 122         // the first 16 Bits of the cryptostate already contain part of our key.
 123         // Create the intersection of the two lists based on these 16 Bits and
 124         // roll back the cryptostate
 125         p1 = p3 = statelists[0].head.slhead;
 126         p2 = p4 = statelists[1].head.slhead;
 127         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 128                 if (Compare16Bits(p1, p2) == 0) {
 129                         struct Crypto1State savestate, *savep = &savestate;
 130                         savestate = *p1;
 131                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 132                                 *p3 = *p1;
 133                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 134                                 p3++;
 135                                 p1++;
 136                         }
 137                         savestate = *p2;
 138                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 139                                 *p4 = *p2;
 140                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 141                                 p4++;
 142                                 p2++;
 143                         }
 144                 }
 145                 else {
 146                         while (Compare16Bits(p1, p2) == -1) p1++;
 147                         while (Compare16Bits(p1, p2) == 1) p2++;
 148                 }
 149         }
 150         p3->even = 0; p3->odd = 0;
 151         p4->even = 0; p4->odd = 0;
 152         statelists[0].len = p3 - statelists[0].head.slhead;
 153         statelists[1].len = p4 - statelists[1].head.slhead;
 154         statelists[0].tail.sltail=--p3;
 155         statelists[1].tail.sltail=--p4;
 156
 157         // the statelists now contain possible keys. The key we are searching for must be in the
 158         // intersection of both lists. Create the intersection:
 159         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compar_int);
 160         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compar_int);
 161
 162         uint64_t *p5, *p6, *p7;
 163         p5 = p7 = statelists[0].head.keyhead;
 164         p6 = statelists[1].head.keyhead;
 165         while (p5 <= statelists[0].tail.keytail && p6 <= statelists[1].tail.keytail) {
 166                 if (compar_int(p5, p6) == 0) {
 167                         *p7++ = *p5++;
 168                         p6++;
 169                 }
 170                 else {
 171                         while (compar_int(p5, p6) == -1) p5++;
 172                         while (compar_int(p5, p6) == 1) p6++;
 173                 }
 174         }
 175         statelists[0].len = p7 - statelists[0].head.keyhead;
 176         statelists[0].tail.keytail=--p7;
 177
 178         memset(resultKey, 0, 6);
 179         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 180         for (i = 0; i < statelists[0].len; i++) {
 181                 uint8_t keyBlock[6];
 182                 uint64_t key64;
 183                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 184                 num_to_bytes(key64, 6, keyBlock);
 185                 key64 = 0;
 186                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 187                         num_to_bytes(key64, 6, resultKey);
 188                         break;
 189                 }
 190         }
 191
 192         free(statelists[0].head.slhead);
 193         free(statelists[1].head.slhead);
 194         return 0;
 195 }
 196
 197 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 198
 199         *key = 0;
 200
 201         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
 202         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 203
 204         clearCommandBuffer();
 205         SendCommand(&c);
 206         UsbCommand resp;
 207         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 208         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 209         *key = bytes_to_num(resp.d.asBytes, 6);
 210         return 0;
 211 }
 212
 213 // EMULATOR
 214
 215 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 216         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 217         clearCommandBuffer();
 218         SendCommand(&c);
 219         UsbCommand resp;
 220         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 221         memcpy(data, resp.d.asBytes, blocksCount * 16);
 222         return 0;
 223 }
 224
 225 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 226         return mfEmlSetMem_xt(data, blockNum, blocksCount, 16);
 227 }
 228
 229 int mfEmlSetMem_xt(uint8_t *data, int blockNum, int blocksCount, int blockBtWidth) {
 230         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, blockBtWidth}};
 231         memcpy(c.d.asBytes, data, blocksCount * blockBtWidth);
 232
 233         clearCommandBuffer();
 234         SendCommand(&c);
 235         return 0;
 236 }
 237
 238 // "MAGIC" CARD
 239
 240 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, uint8_t wipecard) {
 241
 242         uint8_t params = MAGIC_SINGLE;
 243         uint8_t block0[16];
 244         memset(block0, 0x00, sizeof(block0));
 245
 246
 247         int old = mfCGetBlock(0, block0, params);
 248         if (old == 0) {
 249                 PrintAndLog("old block 0:  %s", sprint_hex(block0, sizeof(block0)));
 250         } else {
 251                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 252         }
 253
 254         // fill in the new values
 255         // UID
 256         memcpy(block0, uid, 4);
 257         // Mifare UID BCC
 258         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 259         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 260         if ( sak != NULL )
 261                 block0[5]=sak[0];
 262
 263         if ( atqa != NULL ) {
 264                 block0[6]=atqa[1];
 265                 block0[7]=atqa[0];
 266         }
 267         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 268
 269         if ( wipecard )          params |= MAGIC_WIPE;
 270         if ( oldUID == NULL) params |= MAGIC_UID;
 271
 272         return mfCSetBlock(0, block0, oldUID, params);
 273 }
 274
 275 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, uint8_t params) {
 276
 277         uint8_t isOK = 0;
 278         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {params, blockNo, 0}};
 279         memcpy(c.d.asBytes, data, 16);
 280         clearCommandBuffer();
 281         SendCommand(&c);
 282         UsbCommand resp;
 283         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 284                 isOK  = resp.arg[0] & 0xff;
 285                 if (uid != NULL)
 286                         memcpy(uid, resp.d.asBytes, 4);
 287                 if (!isOK)
 288                         return 2;
 289         } else {
 290                 PrintAndLog("Command execute timeout");
 291                 return 1;
 292         }
 293         return 0;
 294 }
 295
 296 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 297         uint8_t isOK = 0;
 298         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, blockNo, 0}};
 299         clearCommandBuffer();
 300         SendCommand(&c);
 301         UsbCommand resp;
 302         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 303                 isOK  = resp.arg[0] & 0xff;
 304                 memcpy(data, resp.d.asBytes, 16);
 305                 if (!isOK) return 2;
 306         } else {
 307                 PrintAndLog("Command execute timeout");
 308                 return 1;
 309         }
 310         return 0;
 311 }
 312
 313 // SNIFFER
 314
 315 // constants
 316 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 317
 318 // variables
 319 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 320 static uint8_t traceCard[4096] = {0x00};
 321 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 322 static int traceState = TRACE_IDLE;
 323 static uint8_t traceCurBlock = 0;
 324 static uint8_t traceCurKey = 0;
 325
 326 struct Crypto1State *traceCrypto1 = NULL;
 327
 328 struct Crypto1State *revstate = NULL;
 329
 330 uint64_t key = 0;
 331 uint32_t ks2 = 0;
 332 uint32_t ks3 = 0;
 333
 334 uint32_t uid = 0;     // serial number
 335 uint32_t nt =0;      // tag challenge
 336 uint32_t nr_enc =0;  // encrypted reader challenge
 337 uint32_t ar_enc =0;  // encrypted reader response
 338 uint32_t at_enc =0;  // encrypted tag response
 339
 340 int isTraceCardEmpty(void) {
 341         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 342 }
 343
 344 int isBlockEmpty(int blockN) {
 345         for (int i = 0; i < 16; i++)
 346                 if (traceCard[blockN * 16 + i] != 0) return 0;
 347
 348         return 1;
 349 }
 350
 351 int isBlockTrailer(int blockN) {
 352  return ((blockN & 0x03) == 0x03);
 353 }
 354
 355 int loadTraceCard(uint8_t *tuid) {
 356         FILE * f;
 357         char buf[64] = {0x00};
 358         uint8_t buf8[64] = {0x00};
 359         int i, blockNum;
 360
 361         if (!isTraceCardEmpty())
 362                 saveTraceCard();
 363
 364         memset(traceCard, 0x00, 4096);
 365         memcpy(traceCard, tuid + 3, 4);
 366
 367         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 368
 369         f = fopen(traceFileName, "r");
 370         if (!f) return 1;
 371
 372         blockNum = 0;
 373
 374         while(!feof(f)){
 375
 376                 memset(buf, 0, sizeof(buf));
 377                 if (fgets(buf, sizeof(buf), f) == NULL) {
 378                         PrintAndLog("File reading error.");
 379                         fclose(f);
 380                         return 2;
 381                 }
 382
 383                 if (strlen(buf) < 32){
 384                         if (feof(f)) break;
 385                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 386                         fclose(f);
 387                         return 2;
 388                 }
 389                 for (i = 0; i < 32; i += 2)
 390                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 391
 392                 memcpy(traceCard + blockNum * 16, buf8, 16);
 393
 394                 blockNum++;
 395         }
 396         fclose(f);
 397
 398         return 0;
 399 }
 400
 401 int saveTraceCard(void) {
 402         FILE * f;
 403
 404         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 405
 406         f = fopen(traceFileName, "w+");
 407         if ( !f ) return 1;
 408
 409         for (int i = 0; i < 64; i++) {  // blocks
 410                 for (int j = 0; j < 16; j++)  // bytes
 411                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 412                 fprintf(f,"\n");
 413         }
 414         fclose(f);
 415         return 0;
 416 }
 417
 418 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 419
 420         if (traceCrypto1)
 421                 crypto1_destroy(traceCrypto1);
 422
 423         traceCrypto1 = NULL;
 424
 425         if (wantSaveToEmlFile)
 426                 loadTraceCard(tuid);
 427
 428         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 429         traceCard[5] = sak;
 430         memcpy(&traceCard[6], atqa, 2);
 431         traceCurBlock = 0;
 432         uid = bytes_to_num(tuid + 3, 4);
 433
 434         traceState = TRACE_IDLE;
 435
 436         return 0;
 437 }
 438
 439 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 440         uint8_t bt = 0;
 441         int i;
 442
 443         if (len != 1) {
 444                 for (i = 0; i < len; i++)
 445                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 446         } else {
 447                 bt = 0;
 448                 for (i = 0; i < 4; i++)
 449                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 450
 451                 data[0] = bt;
 452         }
 453         return;
 454 }
 455
 456
 457 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 458         uint8_t data[64];
 459
 460         if (traceState == TRACE_ERROR) return 1;
 461         if (len > 64) {
 462                 traceState = TRACE_ERROR;
 463                 return 1;
 464         }
 465
 466         memcpy(data, data_src, len);
 467         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 468                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 469                 PrintAndLog("dec> %s", sprint_hex(data, len));
 470                 AddLogHex(logHexFileName, "dec> ", data, len);
 471         }
 472
 473         switch (traceState) {
 474         case TRACE_IDLE:
 475                 // check packet crc16!
 476                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 477                         PrintAndLog("dec> CRC ERROR!!!");
 478                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 479                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 480                         return 1;
 481                 }
 482
 483                 // AUTHENTICATION
 484                 if ((len == 4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 485                         traceState = TRACE_AUTH1;
 486                         traceCurBlock = data[1];
 487                         traceCurKey = data[0] == 60 ? 1:0;
 488                         return 0;
 489                 }
 490
 491                 // READ
 492                 if ((len ==4) && ((data[0] == 0x30))) {
 493                         traceState = TRACE_READ_DATA;
 494                         traceCurBlock = data[1];
 495                         return 0;
 496                 }
 497
 498                 // WRITE
 499                 if ((len ==4) && ((data[0] == 0xA0))) {
 500                         traceState = TRACE_WRITE_OK;
 501                         traceCurBlock = data[1];
 502                         return 0;
 503                 }
 504
 505                 // HALT
 506                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 507                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 508                         return 0;
 509                 }
 510
 511                 return 0;
 512         break;
 513
 514         case TRACE_READ_DATA:
 515                 if (len == 18) {
 516                         traceState = TRACE_IDLE;
 517
 518                         if (isBlockTrailer(traceCurBlock)) {
 519                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 520                         } else {
 521                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 522                         }
 523                         if (wantSaveToEmlFile) saveTraceCard();
 524                         return 0;
 525                 } else {
 526                         traceState = TRACE_ERROR;
 527                         return 1;
 528                 }
 529         break;
 530
 531         case TRACE_WRITE_OK:
 532                 if ((len == 1) && (data[0] == 0x0a)) {
 533                         traceState = TRACE_WRITE_DATA;
 534
 535                         return 0;
 536                 } else {
 537                         traceState = TRACE_ERROR;
 538                         return 1;
 539                 }
 540         break;
 541
 542         case TRACE_WRITE_DATA:
 543                 if (len == 18) {
 544                         traceState = TRACE_IDLE;
 545
 546                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 547                         if (wantSaveToEmlFile) saveTraceCard();
 548                         return 0;
 549                 } else {
 550                         traceState = TRACE_ERROR;
 551                         return 1;
 552                 }
 553         break;
 554
 555         case TRACE_AUTH1:
 556                 if (len == 4) {
 557                         traceState = TRACE_AUTH2;
 558                         nt = bytes_to_num(data, 4);
 559                         return 0;
 560                 } else {
 561                         traceState = TRACE_ERROR;
 562                         return 1;
 563                 }
 564         break;
 565
 566         case TRACE_AUTH2:
 567                 if (len == 8) {
 568                         traceState = TRACE_AUTH_OK;
 569
 570                         nr_enc = bytes_to_num(data, 4);
 571                         ar_enc = bytes_to_num(data + 4, 4);
 572                         return 0;
 573                 } else {
 574                         traceState = TRACE_ERROR;
 575                         return 1;
 576                 }
 577         break;
 578
 579         case TRACE_AUTH_OK:
 580                 if (len ==4) {
 581                         traceState = TRACE_IDLE;
 582
 583                         at_enc = bytes_to_num(data, 4);
 584
 585                         //  decode key here)
 586                         ks2 = ar_enc ^ prng_successor(nt, 64);
 587                         ks3 = at_enc ^ prng_successor(nt, 96);
 588                         revstate = lfsr_recovery64(ks2, ks3);
 589                         lfsr_rollback_word(revstate, 0, 0);
 590                         lfsr_rollback_word(revstate, 0, 0);
 591                         lfsr_rollback_word(revstate, nr_enc, 1);
 592                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 593
 594                         crypto1_get_lfsr(revstate, &key);
 595                         printf("Key: %012"llx"\n",key);
 596                         AddLogUint64(logHexFileName, "key: ", key);
 597
 598                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 599                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 600
 601                         if (traceCurKey) {
 602                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 603                         } else {
 604                                 num_to_bytes(key, 6, traceCard + blockShift);
 605                         }
 606                         if (wantSaveToEmlFile) saveTraceCard();
 607
 608                         if (traceCrypto1) {
 609                                 crypto1_destroy(traceCrypto1);
 610                         }
 611
 612                         // set cryptosystem state
 613                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 614
 615 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 616
 617         /*      traceCrypto1 = crypto1_create(key); // key in lfsr
 618                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 619                 crypto1_word(traceCrypto1, ar, 1);
 620                 crypto1_word(traceCrypto1, 0, 0);
 621                 crypto1_word(traceCrypto1, 0, 0);*/
 622
 623                         return 0;
 624                 } else {
 625                         traceState = TRACE_ERROR;
 626                         return 1;
 627                 }
 628         break;
 629
 630         default:
 631                 traceState = TRACE_ERROR;
 632                 return 1;
 633         }
 634
 635         return 0;
 636 }
 637
 638 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 639         /*
 640         uint32_t nt;      // tag challenge
 641         uint32_t nr_enc;  // encrypted reader challenge
 642         uint32_t ar_enc;  // encrypted reader response
 643         uint32_t at_enc;  // encrypted tag response
 644         */
 645
 646         struct Crypto1State *pcs = NULL;
 647
 648         ks2 = ar_enc ^ prng_successor(nt, 64);
 649         ks3 = at_enc ^ prng_successor(nt, 96);
 650
 651         PrintAndLog("Decrypting data with:");
 652         PrintAndLog("      nt: %08x",nt);
 653         PrintAndLog("  ar_enc: %08x",ar_enc);
 654         PrintAndLog("  at_enc: %08x",at_enc);
 655         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data,len) );
 656
 657         pcs = lfsr_recovery64(ks2, ks3);
 658         mf_crypto1_decrypt(pcs, data, len, FALSE);
 659         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 660         crypto1_destroy(pcs);
 661         return 0;
 662 }