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 "mifarehost.h"

13 #include <stdio.h>

14 #include <stdlib.h>

15 #include <string.h>

16 #include <pthread.h>

18 #include "crapto1/crapto1.h"

19 #include "proxmark3.h"

20 #include "usb_cmd.h"

21 #include "cmdmain.h"

22 #include "ui.h"

23 #include "util.h"

24 #include "iso14443crc.h"

26 // mifare tracer flags used in mfTraceDecode()

27 #define TRACE_IDLE 0x00

28 #define TRACE_AUTH1 0x01

29 #define TRACE_AUTH2 0x02

30 #define TRACE_AUTH_OK 0x03

31 #define TRACE_READ_DATA 0x04

32 #define TRACE_WRITE_OK 0x05

33 #define TRACE_WRITE_DATA 0x06

34 #define TRACE_ERROR 0xFF

 static int compare_uint64(const void *a, const void *b) {

38 // didn't work: (the result is truncated to 32 bits)

39 //return (*(int64_t*)b - *(int64_t*)a);

41 // better:

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

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

44 else return -1;

45 }

48 // 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)

50 {

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

52 return 0;

53 }

         uint64_t *p1, *p2, *p3;

55 p1 = p3 = list1;

56 p2 = list2;

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

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

60 *p3++ = *p1++;

61 p2++;

62 }

63 else {

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

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

66 }

67 }

68 *p3 = -1;

69 return p3 - list1;

70 }

73 // 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) {

75 struct Crypto1State *states;

         uint32_t i, pos, rr; //nr_diff;

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

78 uint64_t key_recovered;

79 static uint64_t *keylist;

80 rr = 0;

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

83 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;

90 }

91 }

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

95 if (states == NULL) {

96 *keys = NULL;

97 return 0;

98 }

100 keylist = (uint64_t*)states;

101

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

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

                 crypto1_get_lfsr(states+i, &key_recovered);

105 keylist[i] = key_recovered;

106 }

107 keylist[i] = -1;

108

109 *keys = keylist;

110 return i;

111 }

112

113

 int mfDarkside(uint64_t *key)

115 {

116 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;

120 uint32_t keycount = 0;

121 int16_t isOK = 0;

122

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

124

125 // 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");

130

131

132 while (true) {

133 clearCommandBuffer();

134 SendCommand(&c);

135

136 //flush queue

137 while (ukbhit()) {

                         int c = getchar(); (void) c;

139 }

140

141 // wait cycle

142 while (true) {

143 printf(".");

144 fflush(stdout);

145 if (ukbhit()) {

146 return -5;

147 break;

148 }

149

150 UsbCommand resp;

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

                                 isOK  = resp.arg[0];

                                 if (isOK < 0) {

154 return isOK;

155 }

                                 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);

161 break;

162 }

163 }

164

                 if (par_list == 0 && c.arg[0] == true) {

166 PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");

167 PrintAndLog("Attack will take a few seconds longer because we need two consecutive successful runs.");

168 }

                 c.arg[0] = false;

170

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

172

                 if (keycount == 0) {

                         PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);    

175 PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce...");

176 continue;

177 }

178

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

                 keycount = intersection(last_keylist, keylist);

                 if (keycount == 0) {

182 free(last_keylist);

183 last_keylist = keylist;

184 continue;

185 }

186

                 if (keycount > 1) {

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

189 } else {

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

191 }

192

193 *key = -1;

194 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++) {

199 if (last_keylist == NULL) {

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

201 } else {

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

203 }

204 }

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

206 break;

207 }

208 }

209

                 if (*key != -1) {

211 free(last_keylist);

212 free(keylist);

213 break;

214 } else {

215 PrintAndLog("Authentication failed. Trying again...");

216 free(last_keylist);

217 last_keylist = keylist;

218 }

219 }

220

221 return 0;

222 }

223

224

 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){

226

227 *key = 0;

228

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

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

231 SendCommand(&c);

232

233 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);

237 return 0;

238 }

239

240 // 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;

244 else return -1;

245 }

246

247 typedef

248 struct {

249 union {

250 struct Crypto1State *slhead;

251 uint64_t *keyhead;

252 } head;

253 union {

254 struct Crypto1State *sltail;

255 uint64_t *keytail;

256 } tail;

257 uint32_t len;

258 uint32_t uid;

259 uint32_t blockNo;

260 uint32_t keyType;

261 uint32_t nt;

262 uint32_t ks1;

263 } StateList_t;

264

265

266 // wrapper function for multi-threaded lfsr_recovery32

 void* nested_worker_thread(void *arg)

268 {

269 struct Crypto1State *p1;

270 StateList_t *statelist = arg;

271

         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;

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

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

277

278 return statelist->head.slhead;

279 }

280

 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate) 

282 {

283 uint16_t i;

284 uint32_t uid;

285 UsbCommand resp;

286

287 StateList_t statelists[2];

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

289

290 // flush queue

         WaitForResponseTimeout(CMD_ACK, NULL, 100);

292

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

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

295 SendCommand(&c);

296

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

298 return -1;

299 }

300

         if (resp.arg[0]) {

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

303 }

304

         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);

307

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

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

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

311 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);

314 }

315

316 // calc keys

317

318 pthread_t thread_id[2];

319

320 // create and run worker threads

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

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

323 }

324

325 // wait for threads to terminate:

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

                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);

328 }

329

330

331 // the first 16 Bits of the cryptostate already contain part of our key.

332 // Create the intersection of the two lists based on these 16 Bits and

333 // 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) {

338 struct Crypto1State savestate, *savep = &savestate;

339 savestate = *p1;

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

341 *p3 = *p1;

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

343 p3++;

344 p1++;

345 }

346 savestate = *p2;

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

348 *p4 = *p2;

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

350 p4++;

351 p2++;

352 }

353 }

354 else {

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

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

357 }

358 }

         *(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;

365

366 // the statelists now contain possible keys. The key we are searching for must be in the

367 // 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);

371

         memset(resultKey, 0, 6);

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

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

375 uint8_t keyBlock[6];

376 uint64_t key64;

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

                 num_to_bytes(key64, 6, keyBlock);

379 key64 = 0;

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

                         num_to_bytes(key64, 6, resultKey);

382 break;

383 }

384 }

385

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

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

388

389 return 0;

390 }

391

392 // EMULATOR

393

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

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

396 SendCommand(&c);

397

398 UsbCommand resp;

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

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

401 return 0;

402 }

403

 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); 

407 SendCommand(&c);

408 return 0;

409 }

410

411 // "MAGIC" CARD

412

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

414 uint8_t isOK = 0;

415

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

417 SendCommand(&c);

418

419 UsbCommand resp;

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

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

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

                 if (!isOK) return 2;

424 } else {

425 PrintAndLog("Command execute timeout");

426 return 1;

427 }

428 return 0;

429 }

430

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

432

433 uint8_t isOK = 0;

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

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

436 SendCommand(&c);

437

438 UsbCommand resp;

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

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

441 if (uid != NULL)

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

443 if (!isOK)

444 return 2;

445 } else {

446 PrintAndLog("Command execute timeout");

447 return 1;

448 }

449 return 0;

450 }

451

 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};

455

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

         if (old == 0) {

                 memcpy(block0, oldblock0, 16);

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

460 } else {

461 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");

462 }

463

464 // fill in the new values

465 // UID

         memcpy(block0, uid, 4); 

467 // Mifare UID BCC

         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];

469 // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)

470 if (sak!=NULL)

                 block0[5]=sak[0];

472 if (atqa!=NULL) {

                 block0[6]=atqa[1];

                 block0[7]=atqa[0];

475 }

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

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

478 }

479

480 // SNIFFER

481

482 // constants

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

484

485 // variables

 char logHexFileName[FILE_PATH_SIZE] = {0x00};

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

 static char traceFileName[FILE_PATH_SIZE] = {0x00};

489 static int traceState = TRACE_IDLE;

490 static uint8_t traceCurBlock = 0;

491 static uint8_t traceCurKey = 0;

492

493 struct Crypto1State *traceCrypto1 = NULL;

494

495 struct Crypto1State *revstate;

496 uint64_t lfsr;

497 uint32_t ks2;

498 uint32_t ks3;

499

500 uint32_t uid; // serial number

501 uint32_t nt; // tag challenge

502 uint32_t nr_enc; // encrypted reader challenge

503 uint32_t ar_enc; // encrypted reader response

504 uint32_t at_enc; // encrypted tag response

505

 int isTraceCardEmpty(void) {

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

508 }

509

 int isBlockEmpty(int blockN) {

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

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

513

514 return 1;

515 }

516

 int isBlockTrailer(int blockN) {

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

519 }

520

 int saveTraceCard(void) {

522 FILE * f;

523

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

525

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

         if ( !f ) return 1;

528

         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");

533 }

534 fclose(f);

535 return 0;

536 }

537

 int loadTraceCard(uint8_t *tuid) {

539 FILE * f;

         char buf[64] = {0x00};

         uint8_t buf8[64] = {0x00};

542 int i, blockNum;

543

544 if (!isTraceCardEmpty())

545 saveTraceCard();

546

         memset(traceCard, 0x00, 4096);

         memcpy(traceCard, tuid + 3, 4);

549

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

551

         f = fopen(traceFileName, "r");

         if (!f) return 1;

554

555 blockNum = 0;

556

         while(!feof(f)){

558

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

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

561 PrintAndLog("File reading error.");

562 fclose(f);

563 return 2;

564 }

565

                 if (strlen(buf) < 32){

                         if (feof(f)) break;

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

569 fclose(f);

570 return 2;

571 }

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

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

574

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

576

577 blockNum++;

578 }

579 fclose(f);

580

581 return 0;

582 }

583

 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {

585

586 if (traceCrypto1)

587 crypto1_destroy(traceCrypto1);

588

589 traceCrypto1 = NULL;

590

591 if (wantSaveToEmlFile)

592 loadTraceCard(tuid);

593

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

595 traceCard[5] = sak;

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

597 traceCurBlock = 0;

         uid = bytes_to_num(tuid + 3, 4);

599

600 traceState = TRACE_IDLE;

601

602 return 0;

603 }

604

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

606 uint8_t bt = 0;

607 int i;

608

         if (len != 1) {

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

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

612 } else {

613 bt = 0;

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

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

616

617 data[0] = bt;

618 }

619 return;

620 }

621

622

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

624 uint8_t data[64];

625

         if (traceState == TRACE_ERROR) return 1;

         if (len > 64) {

628 traceState = TRACE_ERROR;

629 return 1;

630 }

631

         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); 

637 }

638

639 switch (traceState) {

640 case TRACE_IDLE:

641 // check packet crc16!

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

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

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

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

646 return 1;

647 }

648

649 // AUTHENTICATION

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

651 traceState = TRACE_AUTH1;

652 traceCurBlock = data[1];

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

654 return 0;

655 }

656

657 // READ

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

659 traceState = TRACE_READ_DATA;

660 traceCurBlock = data[1];

661 return 0;

662 }

663

664 // WRITE

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

666 traceState = TRACE_WRITE_OK;

667 traceCurBlock = data[1];

668 return 0;

669 }

670

671 // HALT

                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {

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

674 return 0;

675 }

676

677 return 0;

678 break;

679

680 case TRACE_READ_DATA:

                 if (len == 18) {

682 traceState = TRACE_IDLE;

683

                         if (isBlockTrailer(traceCurBlock)) {

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

686 } else {

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

688 }

                         if (wantSaveToEmlFile) saveTraceCard();

690 return 0;

691 } else {

692 traceState = TRACE_ERROR;

693 return 1;

694 }

695 break;

696

697 case TRACE_WRITE_OK:

                 if ((len == 1) && (data[0] == 0x0a)) {

699 traceState = TRACE_WRITE_DATA;

700

701 return 0;

702 } else {

703 traceState = TRACE_ERROR;

704 return 1;

705 }

706 break;

707

708 case TRACE_WRITE_DATA:

                 if (len == 18) {

710 traceState = TRACE_IDLE;

711

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

                         if (wantSaveToEmlFile) saveTraceCard();

714 return 0;

715 } else {

716 traceState = TRACE_ERROR;

717 return 1;

718 }

719 break;

720

721 case TRACE_AUTH1:

                 if (len == 4) {

723 traceState = TRACE_AUTH2;

                         nt = bytes_to_num(data, 4);

725 return 0;

726 } else {

727 traceState = TRACE_ERROR;

728 return 1;

729 }

730 break;

731

732 case TRACE_AUTH2:

                 if (len == 8) {

734 traceState = TRACE_AUTH_OK;

735

                         nr_enc = bytes_to_num(data, 4);

                         ar_enc = bytes_to_num(data + 4, 4);

738 return 0;

739 } else {

740 traceState = TRACE_ERROR;

741 return 1;

742 }

743 break;

744

745 case TRACE_AUTH_OK:

                 if (len ==4) {

747 traceState = TRACE_IDLE;

748

                         at_enc = bytes_to_num(data, 4);

750

751 // 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);

759

760 crypto1_get_lfsr(revstate, &lfsr);

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

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

763

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

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

766

767 if (traceCurKey) {

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

769 } else {

                                 num_to_bytes(lfsr, 6, traceCard + blockShift);

771 }

                         if (wantSaveToEmlFile) saveTraceCard();

773

774 if (traceCrypto1) {

775 crypto1_destroy(traceCrypto1);

776 }

777

778 // set cryptosystem state

                         traceCrypto1 = lfsr_recovery64(ks2, ks3);

780

781 // nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;

782

783 /* traceCrypto1 = crypto1_create(lfsr); // key in lfsr

784 crypto1_word(traceCrypto1, nt ^ uid, 0);

785 crypto1_word(traceCrypto1, ar, 1);

786 crypto1_word(traceCrypto1, 0, 0);

787 crypto1_word(traceCrypto1, 0, 0);*/

788

789 return 0;

790 } else {

791 traceState = TRACE_ERROR;

792 return 1;

793 }

794 break;

795

796 default:

797 traceState = TRACE_ERROR;

798 return 1;

799 }

800

801 return 0;

802 }

803

 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){

805 /*

806 uint32_t nt; // tag challenge

807 uint32_t ar_enc; // encrypted reader response

808 uint32_t at_enc; // encrypted tag response

809 */

810 if (traceCrypto1) {

811 crypto1_destroy(traceCrypto1);

812 }

         ks2 = ar_enc ^ prng_successor(nt, 64);

         ks3 = at_enc ^ prng_successor(nt, 96);

         traceCrypto1 = lfsr_recovery64(ks2, ks3);

816

         mf_crypto1_decrypt(traceCrypto1, data, len, 0);

818

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

820 crypto1_destroy(traceCrypto1);

821 return 0;

822 }