git.zerfleddert.de Git - proxmark3-svn/blob - client/mifarehost.c

   1 // Merlok, 2011, 2012
   2 // people from mifare@nethemba.com, 2010
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // mifare commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <pthread.h>
  15
  16 #include "crapto1/crapto1.h"
  17 #include "proxmark3.h"
  18 #include "usb_cmd.h"
  19 #include "cmdmain.h"
  20 #include "ui.h"
  21 #include "util.h"
  22 #include "iso14443crc.h"
  23 #include "mifarehost.h"
  24
  25 // mifare tracer flags used in mfTraceDecode()
  26 #define TRACE_IDLE                                              0x00
  27 #define TRACE_AUTH1                                             0x01
  28 #define TRACE_AUTH2                                             0x02
  29 #define TRACE_AUTH_OK                                   0x03
  30 #define TRACE_READ_DATA                                 0x04
  31 #define TRACE_WRITE_OK                                  0x05
  32 #define TRACE_WRITE_DATA                                0x06
  33 #define TRACE_ERROR                                             0xFF
  34
  35
  36 static int compare_uint64(const void *a, const void *b) {
  37         // didn't work: (the result is truncated to 32 bits)
  38         //return (*(int64_t*)b - *(int64_t*)a);
  39
  40         // better:
  41         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  42         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
  43         else return -1;
  44 }
  45
  46
  47 // create the intersection (common members) of two sorted lists. Lists are terminated by -1. Result will be in list1. Number of elements is returned.
  48 static uint32_t intersection(uint64_t *list1, uint64_t *list2)
  49 {
  50         if (list1 == NULL || list2 == NULL) {
  51                 return 0;
  52         }
  53         uint64_t *p1, *p2, *p3;
  54         p1 = p3 = list1;
  55         p2 = list2;
  56
  57         while ( *p1 != -1 && *p2 != -1 ) {
  58                 if (compare_uint64(p1, p2) == 0) {
  59                         *p3++ = *p1++;
  60                         p2++;
  61                 }
  62                 else {
  63                         while (compare_uint64(p1, p2) < 0) ++p1;
  64                         while (compare_uint64(p1, p2) > 0) ++p2;
  65                 }
  66         }
  67         *p3 = -1;
  68         return p3 - list1;
  69 }
  70
  71
  72 // Darkside attack (hf mf mifare)
  73 static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {
  74         struct Crypto1State *states;
  75         uint32_t i, pos, rr; //nr_diff;
  76         uint8_t bt, ks3x[8], par[8][8];
  77         uint64_t key_recovered;
  78         static uint64_t *keylist;
  79         rr = 0;
  80
  81         // Reset the last three significant bits of the reader nonce
  82         nr &= 0xffffff1f;
  83
  84         for (pos=0; pos<8; pos++) {
  85                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  86                 bt = (par_info >> (pos*8)) & 0xff;
  87                 for (i=0; i<8; i++)     {
  88                                 par[7-pos][i] = (bt >> i) & 0x01;
  89                 }
  90         }
  91
  92         states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));
  93
  94         if (states == NULL) {
  95                 *keys = NULL;
  96                 return 0;
  97         }
  98
  99         keylist = (uint64_t*)states;
 100
 101         for (i = 0; keylist[i]; i++) {
 102                 lfsr_rollback_word(states+i, uid^nt, 0);
 103                 crypto1_get_lfsr(states+i, &key_recovered);
 104                 keylist[i] = key_recovered;
 105         }
 106         keylist[i] = -1;
 107
 108         *keys = keylist;
 109         return i;
 110 }
 111
 112
 113 int mfDarkside(uint64_t *key)
 114 {
 115         uint32_t uid = 0;
 116         uint32_t nt = 0, nr = 0;
 117         uint64_t par_list = 0, ks_list = 0;
 118         uint64_t *keylist = NULL, *last_keylist = NULL;
 119         uint32_t keycount = 0;
 120         int16_t isOK = 0;
 121
 122         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
 123
 124         // message
 125         printf("-------------------------------------------------------------------------\n");
 126         printf("Executing command. Expected execution time: 25sec on average\n");
 127         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
 128         printf("-------------------------------------------------------------------------\n");
 129
 130
 131         while (true) {
 132                 clearCommandBuffer();
 133                 SendCommand(&c);
 134
 135                 //flush queue
 136                 while (ukbhit()) {
 137                         int c = getchar(); (void) c;
 138                 }
 139
 140                 // wait cycle
 141                 while (true) {
 142                         printf(".");
 143                         fflush(stdout);
 144                         if (ukbhit()) {
 145                                 return -5;
 146                                 break;
 147                         }
 148
 149                         UsbCommand resp;
 150                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
 151                                 isOK  = resp.arg[0];
 152                                 if (isOK < 0) {
 153                                         return isOK;
 154                                 }
 155                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
 156                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
 157                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);
 158                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
 159                                 nr = bytes_to_num(resp.d.asBytes + 24, 4);
 160                                 break;
 161                         }
 162                 }
 163
 164                 if (par_list == 0 && c.arg[0] == true) {
 165                         PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");
 166                         PrintAndLog("Attack will take a few seconds longer because we need two consecutive successful runs.");
 167                 }
 168                 c.arg[0] = false;
 169
 170                 keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);
 171
 172                 if (keycount == 0) {
 173                         PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);
 174                         PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce...");
 175                         continue;
 176                 }
 177
 178                 qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
 179                 keycount = intersection(last_keylist, keylist);
 180                 if (keycount == 0) {
 181                         free(last_keylist);
 182                         last_keylist = keylist;
 183                         continue;
 184                 }
 185
 186                 if (keycount > 1) {
 187                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 188                 } else {
 189                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 190                 }
 191
 192                 *key = -1;
 193                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 194                 int max_keys = USB_CMD_DATA_SIZE/6;
 195                 for (int i = 0; i < keycount; i += max_keys) {
 196                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 197                         for (int j = 0; j < size; j++) {
 198                                 if (last_keylist == NULL) {
 199                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock);
 200                                 } else {
 201                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock);
 202                                 }
 203                         }
 204                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 205                                 break;
 206                         }
 207                 }
 208
 209                 if (*key != -1) {
 210                         free(last_keylist);
 211                         free(keylist);
 212                         break;
 213                 } else {
 214                         PrintAndLog("Authentication failed. Trying again...");
 215                         free(last_keylist);
 216                         last_keylist = keylist;
 217                 }
 218         }
 219
 220         return 0;
 221 }
 222
 223
 224 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 225
 226         *key = 0;
 227
 228         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
 229         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 230         SendCommand(&c);
 231
 232         UsbCommand resp;
 233         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 234         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 235         *key = bytes_to_num(resp.d.asBytes, 6);
 236         return 0;
 237 }
 238
 239 // Compare 16 Bits out of cryptostate
 240 int Compare16Bits(const void * a, const void * b) {
 241         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 242         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
 243         else return -1;
 244 }
 245
 246 typedef
 247         struct {
 248                 union {
 249                         struct Crypto1State *slhead;
 250                         uint64_t *keyhead;
 251                 } head;
 252                 union {
 253                         struct Crypto1State *sltail;
 254                         uint64_t *keytail;
 255                 } tail;
 256                 uint32_t len;
 257                 uint32_t uid;
 258                 uint32_t blockNo;
 259                 uint32_t keyType;
 260                 uint32_t nt;
 261                 uint32_t ks1;
 262         } StateList_t;
 263
 264
 265 // wrapper function for multi-threaded lfsr_recovery32
 266 void* nested_worker_thread(void *arg)
 267 {
 268         struct Crypto1State *p1;
 269         StateList_t *statelist = arg;
 270
 271         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 272         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 273         statelist->len = p1 - statelist->head.slhead;
 274         statelist->tail.sltail = --p1;
 275         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 276
 277         return statelist->head.slhead;
 278 }
 279
 280 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
 281 {
 282         uint16_t i;
 283         uint32_t uid;
 284         UsbCommand resp;
 285
 286         StateList_t statelists[2];
 287         struct Crypto1State *p1, *p2, *p3, *p4;
 288
 289         // flush queue
 290         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 291
 292         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 293         memcpy(c.d.asBytes, key, 6);
 294         SendCommand(&c);
 295
 296         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 297                 return -1;
 298         }
 299
 300         if (resp.arg[0]) {
 301                 return resp.arg[0];  // error during nested
 302         }
 303
 304         memcpy(&uid, resp.d.asBytes, 4);
 305         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 306
 307         for (i = 0; i < 2; i++) {
 308                 statelists[i].blockNo = resp.arg[2] & 0xff;
 309                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 310                 statelists[i].uid = uid;
 311                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 312                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 313         }
 314
 315         // calc keys
 316
 317         pthread_t thread_id[2];
 318
 319         // create and run worker threads
 320         for (i = 0; i < 2; i++) {
 321                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 322         }
 323
 324         // wait for threads to terminate:
 325         for (i = 0; i < 2; i++) {
 326                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 327         }
 328
 329
 330         // the first 16 Bits of the cryptostate already contain part of our key.
 331         // Create the intersection of the two lists based on these 16 Bits and
 332         // roll back the cryptostate
 333         p1 = p3 = statelists[0].head.slhead;
 334         p2 = p4 = statelists[1].head.slhead;
 335         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 336                 if (Compare16Bits(p1, p2) == 0) {
 337                         struct Crypto1State savestate, *savep = &savestate;
 338                         savestate = *p1;
 339                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 340                                 *p3 = *p1;
 341                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 342                                 p3++;
 343                                 p1++;
 344                         }
 345                         savestate = *p2;
 346                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 347                                 *p4 = *p2;
 348                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 349                                 p4++;
 350                                 p2++;
 351                         }
 352                 }
 353                 else {
 354                         while (Compare16Bits(p1, p2) == -1) p1++;
 355                         while (Compare16Bits(p1, p2) == 1) p2++;
 356                 }
 357         }
 358         *(uint64_t*)p3 = -1;
 359         *(uint64_t*)p4 = -1;
 360         statelists[0].len = p3 - statelists[0].head.slhead;
 361         statelists[1].len = p4 - statelists[1].head.slhead;
 362         statelists[0].tail.sltail=--p3;
 363         statelists[1].tail.sltail=--p4;
 364
 365         // the statelists now contain possible keys. The key we are searching for must be in the
 366         // intersection of both lists. Create the intersection:
 367         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 368         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 369         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 370
 371         memset(resultKey, 0, 6);
 372         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 373         for (i = 0; i < statelists[0].len; i++) {
 374                 uint8_t keyBlock[6];
 375                 uint64_t key64;
 376                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 377                 num_to_bytes(key64, 6, keyBlock);
 378                 key64 = 0;
 379                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 380                         num_to_bytes(key64, 6, resultKey);
 381                         break;
 382                 }
 383         }
 384
 385         free(statelists[0].head.slhead);
 386         free(statelists[1].head.slhead);
 387
 388         return 0;
 389 }
 390
 391 // EMULATOR
 392
 393 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 394         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 395         SendCommand(&c);
 396
 397   UsbCommand resp;
 398         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 399         memcpy(data, resp.d.asBytes, blocksCount * 16);
 400         return 0;
 401 }
 402
 403 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 404         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 405         memcpy(c.d.asBytes, data, blocksCount * 16);
 406         SendCommand(&c);
 407         return 0;
 408 }
 409
 410 // "MAGIC" CARD
 411
 412 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 413         uint8_t isOK = 0;
 414
 415         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 416         SendCommand(&c);
 417
 418   UsbCommand resp;
 419         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 420                 isOK  = resp.arg[0] & 0xff;
 421                 memcpy(data, resp.d.asBytes, 16);
 422                 if (!isOK) return 2;
 423         } else {
 424                 PrintAndLog("Command execute timeout");
 425                 return 1;
 426         }
 427         return 0;
 428 }
 429
 430 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 431
 432         uint8_t isOK = 0;
 433         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 434         memcpy(c.d.asBytes, data, 16);
 435         SendCommand(&c);
 436
 437   UsbCommand resp;
 438         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 439                 isOK  = resp.arg[0] & 0xff;
 440                 if (uid != NULL)
 441                         memcpy(uid, resp.d.asBytes, 4);
 442                 if (!isOK)
 443                         return 2;
 444         } else {
 445                 PrintAndLog("Command execute timeout");
 446                 return 1;
 447         }
 448         return 0;
 449 }
 450
 451 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) {
 452         uint8_t oldblock0[16] = {0x00};
 453         uint8_t block0[16] = {0x00};
 454
 455         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);
 456         if (old == 0) {
 457                 memcpy(block0, oldblock0, 16);
 458                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 459         } else {
 460                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 461         }
 462
 463         // fill in the new values
 464         // UID
 465         memcpy(block0, uid, 4);
 466         // Mifare UID BCC
 467         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 468         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 469         if (sak!=NULL)
 470                 block0[5]=sak[0];
 471         if (atqa!=NULL) {
 472                 block0[6]=atqa[1];
 473                 block0[7]=atqa[0];
 474         }
 475         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 476         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
 477 }
 478
 479 // SNIFFER
 480
 481 // constants
 482 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 483
 484 // variables
 485 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 486 static uint8_t traceCard[4096] = {0x00};
 487 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 488 static int traceState = TRACE_IDLE;
 489 static uint8_t traceCurBlock = 0;
 490 static uint8_t traceCurKey = 0;
 491
 492 struct Crypto1State *traceCrypto1 = NULL;
 493
 494 struct Crypto1State *revstate;
 495 uint64_t lfsr;
 496 uint32_t ks2;
 497 uint32_t ks3;
 498
 499 uint32_t uid;     // serial number
 500 uint32_t nt;      // tag challenge
 501 uint32_t nr_enc;  // encrypted reader challenge
 502 uint32_t ar_enc;  // encrypted reader response
 503 uint32_t at_enc;  // encrypted tag response
 504
 505 int isTraceCardEmpty(void) {
 506         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 507 }
 508
 509 int isBlockEmpty(int blockN) {
 510         for (int i = 0; i < 16; i++)
 511                 if (traceCard[blockN * 16 + i] != 0) return 0;
 512
 513         return 1;
 514 }
 515
 516 int isBlockTrailer(int blockN) {
 517  return ((blockN & 0x03) == 0x03);
 518 }
 519
 520 int saveTraceCard(void) {
 521         FILE * f;
 522
 523         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 524
 525         f = fopen(traceFileName, "w+");
 526         if ( !f ) return 1;
 527
 528         for (int i = 0; i < 64; i++) {  // blocks
 529                 for (int j = 0; j < 16; j++)  // bytes
 530                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 531                 fprintf(f,"\n");
 532         }
 533         fclose(f);
 534         return 0;
 535 }
 536
 537 int loadTraceCard(uint8_t *tuid) {
 538         FILE * f;
 539         char buf[64] = {0x00};
 540         uint8_t buf8[64] = {0x00};
 541         int i, blockNum;
 542
 543         if (!isTraceCardEmpty())
 544                 saveTraceCard();
 545
 546         memset(traceCard, 0x00, 4096);
 547         memcpy(traceCard, tuid + 3, 4);
 548
 549         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 550
 551         f = fopen(traceFileName, "r");
 552         if (!f) return 1;
 553
 554         blockNum = 0;
 555
 556         while(!feof(f)){
 557
 558                 memset(buf, 0, sizeof(buf));
 559                 if (fgets(buf, sizeof(buf), f) == NULL) {
 560                         PrintAndLog("File reading error.");
 561                         fclose(f);
 562                         return 2;
 563         }
 564
 565                 if (strlen(buf) < 32){
 566                         if (feof(f)) break;
 567                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 568                         fclose(f);
 569                         return 2;
 570                 }
 571                 for (i = 0; i < 32; i += 2)
 572                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 573
 574                 memcpy(traceCard + blockNum * 16, buf8, 16);
 575
 576                 blockNum++;
 577         }
 578         fclose(f);
 579
 580         return 0;
 581 }
 582
 583 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 584
 585         if (traceCrypto1)
 586                 crypto1_destroy(traceCrypto1);
 587
 588         traceCrypto1 = NULL;
 589
 590         if (wantSaveToEmlFile)
 591                 loadTraceCard(tuid);
 592
 593         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 594         traceCard[5] = sak;
 595         memcpy(&traceCard[6], atqa, 2);
 596         traceCurBlock = 0;
 597         uid = bytes_to_num(tuid + 3, 4);
 598
 599         traceState = TRACE_IDLE;
 600
 601         return 0;
 602 }
 603
 604 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 605         uint8_t bt = 0;
 606         int i;
 607
 608         if (len != 1) {
 609                 for (i = 0; i < len; i++)
 610                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 611         } else {
 612                 bt = 0;
 613                 for (i = 0; i < 4; i++)
 614                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 615
 616                 data[0] = bt;
 617         }
 618         return;
 619 }
 620
 621
 622 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 623         uint8_t data[64];
 624
 625         if (traceState == TRACE_ERROR) return 1;
 626         if (len > 64) {
 627                 traceState = TRACE_ERROR;
 628                 return 1;
 629         }
 630
 631         memcpy(data, data_src, len);
 632         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 633                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 634                 PrintAndLog("dec> %s", sprint_hex(data, len));
 635                 AddLogHex(logHexFileName, "dec> ", data, len);
 636         }
 637
 638         switch (traceState) {
 639         case TRACE_IDLE:
 640                 // check packet crc16!
 641                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 642                         PrintAndLog("dec> CRC ERROR!!!");
 643                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 644                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 645                         return 1;
 646                 }
 647
 648                 // AUTHENTICATION
 649                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 650                         traceState = TRACE_AUTH1;
 651                         traceCurBlock = data[1];
 652                         traceCurKey = data[0] == 60 ? 1:0;
 653                         return 0;
 654                 }
 655
 656                 // READ
 657                 if ((len ==4) && ((data[0] == 0x30))) {
 658                         traceState = TRACE_READ_DATA;
 659                         traceCurBlock = data[1];
 660                         return 0;
 661                 }
 662
 663                 // WRITE
 664                 if ((len ==4) && ((data[0] == 0xA0))) {
 665                         traceState = TRACE_WRITE_OK;
 666                         traceCurBlock = data[1];
 667                         return 0;
 668                 }
 669
 670                 // HALT
 671                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 672                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 673                         return 0;
 674                 }
 675
 676                 return 0;
 677         break;
 678
 679         case TRACE_READ_DATA:
 680                 if (len == 18) {
 681                         traceState = TRACE_IDLE;
 682
 683                         if (isBlockTrailer(traceCurBlock)) {
 684                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 685                         } else {
 686                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 687                         }
 688                         if (wantSaveToEmlFile) saveTraceCard();
 689                         return 0;
 690                 } else {
 691                         traceState = TRACE_ERROR;
 692                         return 1;
 693                 }
 694         break;
 695
 696         case TRACE_WRITE_OK:
 697                 if ((len == 1) && (data[0] == 0x0a)) {
 698                         traceState = TRACE_WRITE_DATA;
 699
 700                         return 0;
 701                 } else {
 702                         traceState = TRACE_ERROR;
 703                         return 1;
 704                 }
 705         break;
 706
 707         case TRACE_WRITE_DATA:
 708                 if (len == 18) {
 709                         traceState = TRACE_IDLE;
 710
 711                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 712                         if (wantSaveToEmlFile) saveTraceCard();
 713                         return 0;
 714                 } else {
 715                         traceState = TRACE_ERROR;
 716                         return 1;
 717                 }
 718         break;
 719
 720         case TRACE_AUTH1:
 721                 if (len == 4) {
 722                         traceState = TRACE_AUTH2;
 723                         nt = bytes_to_num(data, 4);
 724                         return 0;
 725                 } else {
 726                         traceState = TRACE_ERROR;
 727                         return 1;
 728                 }
 729         break;
 730
 731         case TRACE_AUTH2:
 732                 if (len == 8) {
 733                         traceState = TRACE_AUTH_OK;
 734
 735                         nr_enc = bytes_to_num(data, 4);
 736                         ar_enc = bytes_to_num(data + 4, 4);
 737                         return 0;
 738                 } else {
 739                         traceState = TRACE_ERROR;
 740                         return 1;
 741                 }
 742         break;
 743
 744         case TRACE_AUTH_OK:
 745                 if (len ==4) {
 746                         traceState = TRACE_IDLE;
 747
 748                         at_enc = bytes_to_num(data, 4);
 749
 750                         //  decode key here)
 751                         ks2 = ar_enc ^ prng_successor(nt, 64);
 752                         ks3 = at_enc ^ prng_successor(nt, 96);
 753                         revstate = lfsr_recovery64(ks2, ks3);
 754                         lfsr_rollback_word(revstate, 0, 0);
 755                         lfsr_rollback_word(revstate, 0, 0);
 756                         lfsr_rollback_word(revstate, nr_enc, 1);
 757                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 758
 759                         crypto1_get_lfsr(revstate, &lfsr);
 760                         printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 761                         AddLogUint64(logHexFileName, "key> ", lfsr);
 762
 763                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 764                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 765
 766                         if (traceCurKey) {
 767                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 768                         } else {
 769                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 770                         }
 771                         if (wantSaveToEmlFile) saveTraceCard();
 772
 773                         if (traceCrypto1) {
 774                                 crypto1_destroy(traceCrypto1);
 775                         }
 776
 777                         // set cryptosystem state
 778                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 779
 780 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 781
 782         /*      traceCrypto1 = crypto1_create(lfsr); // key in lfsr
 783                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 784                 crypto1_word(traceCrypto1, ar, 1);
 785                 crypto1_word(traceCrypto1, 0, 0);
 786                 crypto1_word(traceCrypto1, 0, 0);*/
 787
 788                         return 0;
 789                 } else {
 790                         traceState = TRACE_ERROR;
 791                         return 1;
 792                 }
 793         break;
 794
 795         default:
 796                 traceState = TRACE_ERROR;
 797                 return 1;
 798         }
 799
 800         return 0;
 801 }
 802
 803 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 804         /*
 805         uint32_t nt;      // tag challenge
 806         uint32_t ar_enc;  // encrypted reader response
 807         uint32_t at_enc;  // encrypted tag response
 808         */
 809         if (traceCrypto1) {
 810                 crypto1_destroy(traceCrypto1);
 811         }
 812         ks2 = ar_enc ^ prng_successor(nt, 64);
 813         ks3 = at_enc ^ prng_successor(nt, 96);
 814         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 815
 816         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 817
 818         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 819         crypto1_destroy(traceCrypto1);
 820         return 0;
 821 }