git.zerfleddert.de Git - proxmark3-svn/blob

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 //-----------------------------------------------------------------------------

11 #include <stdio.h>

12 #include <stdlib.h>

13 #include <string.h>

14 #include <pthread.h>

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"

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

 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);

40 // better:

         if (*(uint64_t*)b == *(uint64_t*)a) return 0;

         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;

43 else return -1;

44 }

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.

 static uint32_t intersection(uint64_t *list1, uint64_t *list2)

49 {

         if (list1 == NULL || list2 == NULL) {

51 return 0;

52 }

         uint64_t *p1, *p2, *p3;

54 p1 = p3 = list1;

55 p2 = list2;

         while ( *p1 != -1 && *p2 != -1 ) {

                 if (compare_uint64(p1, p2) == 0) {

59 *p3++ = *p1++;

60 p2++;

61 }

62 else {

                         while (compare_uint64(p1, p2) < 0) ++p1;

                         while (compare_uint64(p1, p2) > 0) ++p2;

65 }

66 }

67 *p3 = -1;

68 return p3 - list1;

69 }

72 // Darkside attack (hf mf mifare)

 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;

         uint32_t i, pos, rr; //nr_diff;

         uint8_t bt, ks3x[8], par[8][8];

77 uint64_t key_recovered;

78 static uint64_t *keylist;

79 rr = 0;

81 // Reset the last three significant bits of the reader nonce

82 nr &= 0xffffff1f;

         for (pos=0; pos<8; pos++) {

                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;

                 bt = (par_info >> (pos*8)) & 0xff;

                 for (i=0; i<8; i++)     {

                                 par[7-pos][i] = (bt >> i) & 0x01;

89 }

90 }

         states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));

94 if (states == NULL) {

95 *keys = NULL;

96 return 0;

97 }

99 keylist = (uint64_t*)states;

100

         for (i = 0; keylist[i]; i++) {

                 lfsr_rollback_word(states+i, uid^nt, 0);

                 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

 int mfDarkside(uint64_t *key)

114 {

115 uint32_t uid = 0;

         uint32_t nt = 0, nr = 0;

         uint64_t par_list = 0, ks_list = 0;

         uint64_t *keylist = NULL, *last_keylist = NULL;

119 uint32_t keycount = 0;

120 int16_t isOK = 0;

121

         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};

123

124 // message

         printf("-------------------------------------------------------------------------\n");

         printf("Executing command. Expected execution time: 25sec on average\n");

         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");

         printf("-------------------------------------------------------------------------\n");

129

130

131 while (true) {

132 clearCommandBuffer();

133 SendCommand(&c);

134

135 //flush queue

136 while (ukbhit()) {

                         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;

                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {

                                 isOK  = resp.arg[0];

                                 if (isOK < 0) {

153 return isOK;

154 }

                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);

                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);

                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);

                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);

                                 nr = bytes_to_num(resp.d.asBytes + 24, 4);

160 break;

161 }

162 }

163

                 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 }

                 c.arg[0] = false;

169

                 keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);

171

                 if (keycount == 0) {

                         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

                 qsort(keylist, keycount, sizeof(*keylist), compare_uint64);

                 keycount = intersection(last_keylist, keylist);

                 if (keycount == 0) {

181 free(last_keylist);

182 last_keylist = keylist;

183 continue;

184 }

185

                 if (keycount > 1) {

                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);

188 } else {

                         PrintAndLog("Found a possible key. Trying to authenticate...\n");

190 }

191

192 *key = -1;

193 uint8_t keyBlock[USB_CMD_DATA_SIZE];

                 int max_keys = USB_CMD_DATA_SIZE/6;

                 for (int i = 0; i < keycount; i += max_keys) {

                         int size = keycount - i > max_keys ? max_keys : keycount - i;

                         for (int j = 0; j < size; j++) {

198 if (last_keylist == NULL) {

                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock);

200 } else {

                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock);

202 }

203 }

                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {

205 break;

206 }

207 }

208

                 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

 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

         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};

         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);

230 SendCommand(&c);

231

232 UsbCommand resp;

         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;

         if ((resp.arg[0] & 0xff) != 0x01) return 2;

         *key = bytes_to_num(resp.d.asBytes, 6);

236 return 0;

237 }

238

239 // Compare 16 Bits out of cryptostate

 int Compare16Bits(const void * a, const void * b) {

         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;

         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

 void* nested_worker_thread(void *arg)

267 {

268 struct Crypto1State *p1;

269 StateList_t *statelist = arg;

270

         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);

         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);

         statelist->len = p1 - statelist->head.slhead;

274 statelist->tail.sltail = --p1;

         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);

276

277 return statelist->head.slhead;

278 }

279

 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];

         struct Crypto1State *p1, *p2, *p3, *p4;

288

289 // flush queue

         WaitForResponseTimeout(CMD_ACK, NULL, 100);

291

         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};

         memcpy(c.d.asBytes, key, 6);

294 SendCommand(&c);

295

         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {

297 return -1;

298 }

299

         if (resp.arg[0]) {

                 return resp.arg[0];  // error during nested

302 }

303

         memcpy(&uid, resp.d.asBytes, 4);

         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);

306

         for (i = 0; i < 2; i++) {

                 statelists[i].blockNo = resp.arg[2] & 0xff;

                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;

310 statelists[i].uid = uid;

                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);

                 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

         for (i = 0; i < 2; i++) {

                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);

322 }

323

324 // wait for threads to terminate:

         for (i = 0; i < 2; i++) {

                 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

         p1 = p3 = statelists[0].head.slhead; 

         p2 = p4 = statelists[1].head.slhead;

         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {

                 if (Compare16Bits(p1, p2) == 0) {

337 struct Crypto1State savestate, *savep = &savestate;

338 savestate = *p1;

                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {

340 *p3 = *p1;

                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);

342 p3++;

343 p1++;

344 }

345 savestate = *p2;

                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {

347 *p4 = *p2;

                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);

349 p4++;

350 p2++;

351 }

352 }

353 else {

                         while (Compare16Bits(p1, p2) == -1) p1++;

                         while (Compare16Bits(p1, p2) == 1) p2++;

356 }

357 }

         *(uint64_t*)p3 = -1;

         *(uint64_t*)p4 = -1;

         statelists[0].len = p3 - statelists[0].head.slhead;

         statelists[1].len = p4 - statelists[1].head.slhead;

         statelists[0].tail.sltail=--p3;

         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:

         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);

         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);

         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);

370

         memset(resultKey, 0, 6);

372 // The list may still contain several key candidates. Test each of them with mfCheckKeys

         for (i = 0; i < statelists[0].len; i++) {

374 uint8_t keyBlock[6];

375 uint64_t key64;

                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);

                 num_to_bytes(key64, 6, keyBlock);

378 key64 = 0;

                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {

                         num_to_bytes(key64, 6, resultKey);

381 break;

382 }

383 }

384

         free(statelists[0].head.slhead);

         free(statelists[1].head.slhead);

387

388 return 0;

389 }

390

391 // EMULATOR

392

 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {

         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};

395 SendCommand(&c);

396

397 UsbCommand resp;

         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;

         memcpy(data, resp.d.asBytes, blocksCount * 16);

400 return 0;

401 }

402

 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {

         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};

         memcpy(c.d.asBytes, data, blocksCount * 16); 

406 SendCommand(&c);

407 return 0;

408 }

409

410 // "MAGIC" CARD

411

 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {

413 uint8_t isOK = 0;

414

         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};

416 SendCommand(&c);

417

418 UsbCommand resp;

         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {

                 isOK  = resp.arg[0] & 0xff;

                 memcpy(data, resp.d.asBytes, 16);

                 if (!isOK) return 2;

423 } else {

424 PrintAndLog("Command execute timeout");

425 return 1;

426 }

427 return 0;

428 }

429

 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {

431

432 uint8_t isOK = 0;

         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};

         memcpy(c.d.asBytes, data, 16); 

435 SendCommand(&c);

436

437 UsbCommand resp;

         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {

                 isOK  = resp.arg[0] & 0xff;

440 if (uid != NULL)

                         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

 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) {

         uint8_t oldblock0[16] = {0x00};

         uint8_t block0[16] = {0x00};

454

         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);

         if (old == 0) {

                 memcpy(block0, oldblock0, 16);

                 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

         memcpy(block0, uid, 4); 

466 // Mifare UID BCC

         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)

                 block0[5]=sak[0];

471 if (atqa!=NULL) {

                 block0[6]=atqa[1];

                 block0[7]=atqa[0];

474 }

         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));

         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);

477 }

478

479 // SNIFFER

480

481 // constants

 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};

483

484 // variables

 char logHexFileName[FILE_PATH_SIZE] = {0x00};

 static uint8_t traceCard[4096] = {0x00};

 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

 int isTraceCardEmpty(void) {

         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));

507 }

508

 int isBlockEmpty(int blockN) {

         for (int i = 0; i < 16; i++) 

                 if (traceCard[blockN * 16 + i] != 0) return 0;

512

513 return 1;

514 }

515

 int isBlockTrailer(int blockN) {

  return ((blockN & 0x03) == 0x03);

518 }

519

 int saveTraceCard(void) {

521 FILE * f;

522

         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;

524

         f = fopen(traceFileName, "w+");

         if ( !f ) return 1;

527

         for (int i = 0; i < 64; i++) {  // blocks

                 for (int j = 0; j < 16; j++)  // bytes

                         fprintf(f, "%02x", *(traceCard + i * 16 + j)); 

                 fprintf(f,"\n");

532 }

533 fclose(f);

534 return 0;

535 }

536

 int loadTraceCard(uint8_t *tuid) {

538 FILE * f;

         char buf[64] = {0x00};

         uint8_t buf8[64] = {0x00};

541 int i, blockNum;

542

543 if (!isTraceCardEmpty())

544 saveTraceCard();

545

         memset(traceCard, 0x00, 4096);

         memcpy(traceCard, tuid + 3, 4);

548

         FillFileNameByUID(traceFileName, tuid, ".eml", 7);

550

         f = fopen(traceFileName, "r");

         if (!f) return 1;

553

554 blockNum = 0;

555

         while(!feof(f)){

557

                 memset(buf, 0, sizeof(buf));

                 if (fgets(buf, sizeof(buf), f) == NULL) {

560 PrintAndLog("File reading error.");

561 fclose(f);

562 return 2;

563 }

564

                 if (strlen(buf) < 32){

                         if (feof(f)) break;

567 PrintAndLog("File content error. Block data must include 32 HEX symbols");

568 fclose(f);

569 return 2;

570 }

                 for (i = 0; i < 32; i += 2)

                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);

573

                 memcpy(traceCard + blockNum * 16, buf8, 16);

575

576 blockNum++;

577 }

578 fclose(f);

579

580 return 0;

581 }

582

 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

         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];

594 traceCard[5] = sak;

         memcpy(&traceCard[6], atqa, 2);

596 traceCurBlock = 0;

         uid = bytes_to_num(tuid + 3, 4);

598

599 traceState = TRACE_IDLE;

600

601 return 0;

602 }

603

 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){

605 uint8_t bt = 0;

606 int i;

607

         if (len != 1) {

                 for (i = 0; i < len; i++)

                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];

611 } else {

612 bt = 0;

                 for (i = 0; i < 4; i++)

                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;

615

616 data[0] = bt;

617 }

618 return;

619 }

620

621

 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {

623 uint8_t data[64];

624

         if (traceState == TRACE_ERROR) return 1;

         if (len > 64) {

627 traceState = TRACE_ERROR;

628 return 1;

629 }

630

         memcpy(data, data_src, len);

         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {

                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);

                 PrintAndLog("dec> %s", sprint_hex(data, len));

                 AddLogHex(logHexFileName, "dec> ", data, len); 

636 }

637

638 switch (traceState) {

639 case TRACE_IDLE:

640 // check packet crc16!

                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {

642 PrintAndLog("dec> CRC ERROR!!!");

                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!"); 

644 traceState = TRACE_ERROR; // do not decrypt the next commands

645 return 1;

646 }

647

648 // AUTHENTICATION

                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {

650 traceState = TRACE_AUTH1;

651 traceCurBlock = data[1];

                         traceCurKey = data[0] == 60 ? 1:0;

653 return 0;

654 }

655

656 // READ

                 if ((len ==4) && ((data[0] == 0x30))) {

658 traceState = TRACE_READ_DATA;

659 traceCurBlock = data[1];

660 return 0;

661 }

662

663 // WRITE

                 if ((len ==4) && ((data[0] == 0xA0))) {

665 traceState = TRACE_WRITE_OK;

666 traceCurBlock = data[1];

667 return 0;

668 }

669

670 // HALT

                 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:

                 if (len == 18) {

681 traceState = TRACE_IDLE;

682

                         if (isBlockTrailer(traceCurBlock)) {

                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);

685 } else {

                                 memcpy(traceCard + traceCurBlock * 16, data, 16);

687 }

                         if (wantSaveToEmlFile) saveTraceCard();

689 return 0;

690 } else {

691 traceState = TRACE_ERROR;

692 return 1;

693 }

694 break;

695

696 case TRACE_WRITE_OK:

                 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:

                 if (len == 18) {

709 traceState = TRACE_IDLE;

710

                         memcpy(traceCard + traceCurBlock * 16, data, 16);

                         if (wantSaveToEmlFile) saveTraceCard();

713 return 0;

714 } else {

715 traceState = TRACE_ERROR;

716 return 1;

717 }

718 break;

719

720 case TRACE_AUTH1:

                 if (len == 4) {

722 traceState = TRACE_AUTH2;

                         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:

                 if (len == 8) {

733 traceState = TRACE_AUTH_OK;

734

                         nr_enc = bytes_to_num(data, 4);

                         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:

                 if (len ==4) {

746 traceState = TRACE_IDLE;

747

                         at_enc = bytes_to_num(data, 4);

749

750 // decode key here)

                         ks2 = ar_enc ^ prng_successor(nt, 64);

                         ks3 = at_enc ^ prng_successor(nt, 96);

                         revstate = lfsr_recovery64(ks2, ks3);

                         lfsr_rollback_word(revstate, 0, 0);

                         lfsr_rollback_word(revstate, 0, 0);

                         lfsr_rollback_word(revstate, nr_enc, 1);

                         lfsr_rollback_word(revstate, uid ^ nt, 0);

758

759 crypto1_get_lfsr(revstate, &lfsr);

                         printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));

                         AddLogUint64(logHexFileName, "key> ", lfsr); 

762

                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;

                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);

765

766 if (traceCurKey) {

                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);

768 } else {

                                 num_to_bytes(lfsr, 6, traceCard + blockShift);

770 }

                         if (wantSaveToEmlFile) saveTraceCard();

772

773 if (traceCrypto1) {

774 crypto1_destroy(traceCrypto1);

775 }

776

777 // set cryptosystem state

                         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

 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 }

         ks2 = ar_enc ^ prng_successor(nt, 64);

         ks3 = at_enc ^ prng_successor(nt, 96);

         traceCrypto1 = lfsr_recovery64(ks2, ks3);

815

         mf_crypto1_decrypt(traceCrypto1, data, len, 0);

817

         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );

819 crypto1_destroy(traceCrypto1);

820 return 0;

821 }