cvs.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, bool wantWipe) {
 241         uint8_t oldblock0[16] = {0x00};
 242         uint8_t block0[16] = {0x00};
 243
 244         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);
 245         if (old == 0) {
 246                 memcpy(block0, oldblock0, 16);
 247                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 248         } else {
 249                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 250         }
 251
 252         // fill in the new values
 253         // UID
 254         memcpy(block0, uid, 4);
 255         // Mifare UID BCC
 256         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 257         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 258         if (sak!=NULL)
 259                 block0[5]=sak[0];
 260         if (atqa!=NULL) {
 261                 block0[6]=atqa[1];
 262                 block0[7]=atqa[0];
 263         }
 264         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 265         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
 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
 274         clearCommandBuffer();
 275         SendCommand(&c);
 276         UsbCommand resp;
 277         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 278                 isOK  = resp.arg[0] & 0xff;
 279                 if (uid != NULL)
 280                         memcpy(uid, resp.d.asBytes, 4);
 281                 if (!isOK)
 282                         return 2;
 283         } else {
 284                 PrintAndLog("Command execute timeout");
 285                 return 1;
 286         }
 287         return 0;
 288 }
 289
 290 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 291         uint8_t isOK = 0;
 292
 293         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 294
 295         clearCommandBuffer();
 296         SendCommand(&c);
 297         UsbCommand resp;
 298         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 299                 isOK  = resp.arg[0] & 0xff;
 300                 memcpy(data, resp.d.asBytes, 16);
 301                 if (!isOK) return 2;
 302         } else {
 303                 PrintAndLog("Command execute timeout");
 304                 return 1;
 305         }
 306         return 0;
 307 }
 308
 309 // SNIFFER
 310
 311 // constants
 312 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 313
 314 // variables
 315 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 316 static uint8_t traceCard[4096] = {0x00};
 317 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 318 static int traceState = TRACE_IDLE;
 319 static uint8_t traceCurBlock = 0;
 320 static uint8_t traceCurKey = 0;
 321
 322 struct Crypto1State *traceCrypto1 = NULL;
 323
 324 struct Crypto1State *revstate = NULL;
 325
 326 uint64_t key = 0;
 327 uint32_t ks2 = 0;
 328 uint32_t ks3 = 0;
 329
 330 uint32_t uid = 0;     // serial number
 331 uint32_t nt =0;      // tag challenge
 332 uint32_t nr_enc =0;  // encrypted reader challenge
 333 uint32_t ar_enc =0;  // encrypted reader response
 334 uint32_t at_enc =0;  // encrypted tag response
 335
 336 int isTraceCardEmpty(void) {
 337         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 338 }
 339
 340 int isBlockEmpty(int blockN) {
 341         for (int i = 0; i < 16; i++)
 342                 if (traceCard[blockN * 16 + i] != 0) return 0;
 343
 344         return 1;
 345 }
 346
 347 int isBlockTrailer(int blockN) {
 348  return ((blockN & 0x03) == 0x03);
 349 }
 350
 351 int loadTraceCard(uint8_t *tuid) {
 352         FILE * f;
 353         char buf[64] = {0x00};
 354         uint8_t buf8[64] = {0x00};
 355         int i, blockNum;
 356
 357         if (!isTraceCardEmpty())
 358                 saveTraceCard();
 359
 360         memset(traceCard, 0x00, 4096);
 361         memcpy(traceCard, tuid + 3, 4);
 362
 363         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 364
 365         f = fopen(traceFileName, "r");
 366         if (!f) return 1;
 367
 368         blockNum = 0;
 369
 370         while(!feof(f)){
 371
 372                 memset(buf, 0, sizeof(buf));
 373                 if (fgets(buf, sizeof(buf), f) == NULL) {
 374                         PrintAndLog("File reading error.");
 375                         fclose(f);
 376                         return 2;
 377                 }
 378
 379                 if (strlen(buf) < 32){
 380                         if (feof(f)) break;
 381                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 382                         fclose(f);
 383                         return 2;
 384                 }
 385                 for (i = 0; i < 32; i += 2)
 386                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 387
 388                 memcpy(traceCard + blockNum * 16, buf8, 16);
 389
 390                 blockNum++;
 391         }
 392         fclose(f);
 393
 394         return 0;
 395 }
 396
 397 int saveTraceCard(void) {
 398         FILE * f;
 399
 400         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 401
 402         f = fopen(traceFileName, "w+");
 403         if ( !f ) return 1;
 404
 405         for (int i = 0; i < 64; i++) {  // blocks
 406                 for (int j = 0; j < 16; j++)  // bytes
 407                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 408                 fprintf(f,"\n");
 409         }
 410         fclose(f);
 411         return 0;
 412 }
 413
 414 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 415
 416         if (traceCrypto1)
 417                 crypto1_destroy(traceCrypto1);
 418
 419         traceCrypto1 = NULL;
 420
 421         if (wantSaveToEmlFile)
 422                 loadTraceCard(tuid);
 423
 424         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 425         traceCard[5] = sak;
 426         memcpy(&traceCard[6], atqa, 2);
 427         traceCurBlock = 0;
 428         uid = bytes_to_num(tuid + 3, 4);
 429
 430         traceState = TRACE_IDLE;
 431
 432         return 0;
 433 }
 434
 435 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 436         uint8_t bt = 0;
 437         int i;
 438
 439         if (len != 1) {
 440                 for (i = 0; i < len; i++)
 441                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 442         } else {
 443                 bt = 0;
 444                 for (i = 0; i < 4; i++)
 445                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 446
 447                 data[0] = bt;
 448         }
 449         return;
 450 }
 451
 452
 453 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 454         uint8_t data[64];
 455
 456         if (traceState == TRACE_ERROR) return 1;
 457         if (len > 64) {
 458                 traceState = TRACE_ERROR;
 459                 return 1;
 460         }
 461
 462         memcpy(data, data_src, len);
 463         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 464                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 465                 PrintAndLog("dec> %s", sprint_hex(data, len));
 466                 AddLogHex(logHexFileName, "dec> ", data, len);
 467         }
 468
 469         switch (traceState) {
 470         case TRACE_IDLE:
 471                 // check packet crc16!
 472                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 473                         PrintAndLog("dec> CRC ERROR!!!");
 474                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 475                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 476                         return 1;
 477                 }
 478
 479                 // AUTHENTICATION
 480                 if ((len == 4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 481                         traceState = TRACE_AUTH1;
 482                         traceCurBlock = data[1];
 483                         traceCurKey = data[0] == 60 ? 1:0;
 484                         return 0;
 485                 }
 486
 487                 // READ
 488                 if ((len ==4) && ((data[0] == 0x30))) {
 489                         traceState = TRACE_READ_DATA;
 490                         traceCurBlock = data[1];
 491                         return 0;
 492                 }
 493
 494                 // WRITE
 495                 if ((len ==4) && ((data[0] == 0xA0))) {
 496                         traceState = TRACE_WRITE_OK;
 497                         traceCurBlock = data[1];
 498                         return 0;
 499                 }
 500
 501                 // HALT
 502                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 503                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 504                         return 0;
 505                 }
 506
 507                 return 0;
 508         break;
 509
 510         case TRACE_READ_DATA:
 511                 if (len == 18) {
 512                         traceState = TRACE_IDLE;
 513
 514                         if (isBlockTrailer(traceCurBlock)) {
 515                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 516                         } else {
 517                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 518                         }
 519                         if (wantSaveToEmlFile) saveTraceCard();
 520                         return 0;
 521                 } else {
 522                         traceState = TRACE_ERROR;
 523                         return 1;
 524                 }
 525         break;
 526
 527         case TRACE_WRITE_OK:
 528                 if ((len == 1) && (data[0] == 0x0a)) {
 529                         traceState = TRACE_WRITE_DATA;
 530
 531                         return 0;
 532                 } else {
 533                         traceState = TRACE_ERROR;
 534                         return 1;
 535                 }
 536         break;
 537
 538         case TRACE_WRITE_DATA:
 539                 if (len == 18) {
 540                         traceState = TRACE_IDLE;
 541
 542                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 543                         if (wantSaveToEmlFile) saveTraceCard();
 544                         return 0;
 545                 } else {
 546                         traceState = TRACE_ERROR;
 547                         return 1;
 548                 }
 549         break;
 550
 551         case TRACE_AUTH1:
 552                 if (len == 4) {
 553                         traceState = TRACE_AUTH2;
 554                         nt = bytes_to_num(data, 4);
 555                         return 0;
 556                 } else {
 557                         traceState = TRACE_ERROR;
 558                         return 1;
 559                 }
 560         break;
 561
 562         case TRACE_AUTH2:
 563                 if (len == 8) {
 564                         traceState = TRACE_AUTH_OK;
 565
 566                         nr_enc = bytes_to_num(data, 4);
 567                         ar_enc = bytes_to_num(data + 4, 4);
 568                         return 0;
 569                 } else {
 570                         traceState = TRACE_ERROR;
 571                         return 1;
 572                 }
 573         break;
 574
 575         case TRACE_AUTH_OK:
 576                 if (len ==4) {
 577                         traceState = TRACE_IDLE;
 578
 579                         at_enc = bytes_to_num(data, 4);
 580
 581                         //  decode key here)
 582                         ks2 = ar_enc ^ prng_successor(nt, 64);
 583                         ks3 = at_enc ^ prng_successor(nt, 96);
 584                         revstate = lfsr_recovery64(ks2, ks3);
 585                         lfsr_rollback_word(revstate, 0, 0);
 586                         lfsr_rollback_word(revstate, 0, 0);
 587                         lfsr_rollback_word(revstate, nr_enc, 1);
 588                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 589
 590                         crypto1_get_lfsr(revstate, &key);
 591                         printf("Key: %012"llx"\n",key);
 592                         AddLogUint64(logHexFileName, "key: ", key);
 593
 594                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 595                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 596
 597                         if (traceCurKey) {
 598                                 num_to_bytes(key, 6, traceCard + blockShift + 10);
 599                         } else {
 600                                 num_to_bytes(key, 6, traceCard + blockShift);
 601                         }
 602                         if (wantSaveToEmlFile) saveTraceCard();
 603
 604                         if (traceCrypto1) {
 605                                 crypto1_destroy(traceCrypto1);
 606                         }
 607
 608                         // set cryptosystem state
 609                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 610
 611 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 612
 613         /*      traceCrypto1 = crypto1_create(key); // key in lfsr
 614                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 615                 crypto1_word(traceCrypto1, ar, 1);
 616                 crypto1_word(traceCrypto1, 0, 0);
 617                 crypto1_word(traceCrypto1, 0, 0);*/
 618
 619                         return 0;
 620                 } else {
 621                         traceState = TRACE_ERROR;
 622                         return 1;
 623                 }
 624         break;
 625
 626         default:
 627                 traceState = TRACE_ERROR;
 628                 return 1;
 629         }
 630
 631         return 0;
 632 }
 633
 634 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 635         /*
 636         uint32_t nt;      // tag challenge
 637         uint32_t nr_enc;  // encrypted reader challenge
 638         uint32_t ar_enc;  // encrypted reader response
 639         uint32_t at_enc;  // encrypted tag response
 640         */
 641
 642         struct Crypto1State *pcs = NULL;
 643
 644         ks2 = ar_enc ^ prng_successor(nt, 64);
 645         ks3 = at_enc ^ prng_successor(nt, 96);
 646
 647         PrintAndLog("Decrypting data with:");
 648         PrintAndLog("      nt: %08x",nt);
 649         PrintAndLog("  ar_enc: %08x",ar_enc);
 650         PrintAndLog("  at_enc: %08x",at_enc);
 651         PrintAndLog("\nEncrypted data: [%s]", sprint_hex(data,len) );
 652
 653         pcs = lfsr_recovery64(ks2, ks3);
 654         mf_crypto1_decrypt(pcs, data, len, FALSE);
 655         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 656         crypto1_destroy(pcs);
 657         return 0;
 658 }