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

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

                 keycount = intersection(last_keylist, keylist);

                 if (keycount == 0) {

184 free(last_keylist);

185 last_keylist = keylist;

186 continue;

187 }

188

                 if (keycount > 1) {

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

191 } else {

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

193 }

194

195 *key = -1;

196 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++) {

201 if (last_keylist == NULL) {

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

203 } else {

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

205 }

206 }

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

208 break;

209 }

210 }

211

                 if (*key != -1) {

213 free(last_keylist);

214 free(keylist);

215 break;

216 } else {

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

218 free(last_keylist);

219 last_keylist = keylist;

220 }

221 }

222

223 return 0;

224 }

225

226

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

228

229 *key = -1;

230

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

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

233 SendCommand(&c);

234

235 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);

239 return 0;

240 }

241

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

243

244 uint8_t keyPtr = 0;

245

246 if (e_sector == NULL)

247 return -1;

248

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

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

251 SendCommand(&c);

252

253 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;

256

257 bool foundAKey = false;

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

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

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

261 if (keyPtr){

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

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

264 foundAKey = true;

265 }

266 }

267 }

         return foundAKey ? 0 : 3;

269 }

270

271 // 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;

275 else return -1;

276 }

277

278 typedef

279 struct {

280 union {

281 struct Crypto1State *slhead;

282 uint64_t *keyhead;

283 } head;

284 union {

285 struct Crypto1State *sltail;

286 uint64_t *keytail;

287 } tail;

288 uint32_t len;

289 uint32_t uid;

290 uint32_t blockNo;

291 uint32_t keyType;

292 uint32_t nt;

293 uint32_t ks1;

294 } StateList_t;

295

296

297 // wrapper function for multi-threaded lfsr_recovery32

 void* nested_worker_thread(void *arg)

299 {

300 struct Crypto1State *p1;

301 StateList_t *statelist = arg;

302

         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;

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

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

308

309 return statelist->head.slhead;

310 }

311

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

313 {

314 uint16_t i;

315 uint32_t uid;

316 UsbCommand resp;

317

318 StateList_t statelists[2];

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

320

321 // flush queue

         WaitForResponseTimeout(CMD_ACK, NULL, 100);

323

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

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

326 SendCommand(&c);

327

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

329 return -1;

330 }

331

         if (resp.arg[0]) {

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

334 }

335

         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);

338

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

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

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

342 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);

345 }

346

347 // calc keys

348

349 pthread_t thread_id[2];

350

351 // create and run worker threads

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

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

354 }

355

356 // wait for threads to terminate:

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

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

359 }

360

361

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

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

364 // 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) {

369 struct Crypto1State savestate, *savep = &savestate;

370 savestate = *p1;

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

372 *p3 = *p1;

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

374 p3++;

375 p1++;

376 }

377 savestate = *p2;

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

379 *p4 = *p2;

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

381 p4++;

382 p2++;

383 }

384 }

385 else {

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

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

388 }

389 }

         *(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;

396

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

398 // 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);

402

         memset(resultKey, 0, 6);

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

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

406 uint8_t keyBlock[6];

407 uint64_t key64;

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

                 num_to_bytes(key64, 6, keyBlock);

410 key64 = 0;

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

                         num_to_bytes(key64, 6, resultKey);

413 break;

414 }

415 }

416

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

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

419

420 return 0;

421 }

422

423 // EMULATOR

424

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

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

427 SendCommand(&c);

428

429 UsbCommand resp;

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

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

432 return 0;

433 }

434

 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);

438 SendCommand(&c);

439 return 0;

440 }

441

442 // "MAGIC" CARD

443

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

445 uint8_t isOK = 0;

446

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

448 SendCommand(&c);

449

450 UsbCommand resp;

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

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

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

                 if (!isOK) return 2;

455 } else {

456 PrintAndLog("Command execute timeout");

457 return 1;

458 }

459 return 0;

460 }

461

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

463

464 uint8_t isOK = 0;

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

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

467 SendCommand(&c);

468

469 UsbCommand resp;

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

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

472 if (uid != NULL)

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

474 if (!isOK)

475 return 2;

476 } else {

477 PrintAndLog("Command execute timeout");

478 return 1;

479 }

480

481 return 0;

482 }

483

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

485 uint8_t isOK = 0;

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

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

488 SendCommand(&c);

489

490 UsbCommand resp;

491 WaitForResponse(CMD_ACK,&resp);

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

493

494 return isOK;

495 }

496

 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;

501

502 gen = mfCIdentify();

503

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

505 uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;

         if (gen == 2) {

507 /* generation 1b magic card */

508 cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;

509 }

510

         res = mfCGetBlock(0, oldblock0, cmdParams);

512

         if (res == 0) {

                 memcpy(block0, oldblock0, 16);

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

516 } else {

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

518 }

519

520 // fill in the new values

521 // UID

         memcpy(block0, uid, 4);

523 // Mifare UID BCC

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

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

526 if (sak != NULL)

                 block0[5] = sak[0];

528 if (atqa != NULL) {

                 block0[6] = atqa[1];

                 block0[7] = atqa[0];

531 }

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

533

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

535 if (res) {

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

537 return res;

538 }

539

540 return 0;

541 }

542

543 int mfCIdentify() {

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

545 SendCommand(&c);

546 UsbCommand resp;

547 WaitForResponse(CMD_ACK,&resp);

548

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

550 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;

554 }

555

         return (int) isGeneration;

557 }

558

559

560 // SNIFFER

561

562 // constants

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

564

565 // variables

 char logHexFileName[FILE_PATH_SIZE] = {0x00};

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

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

569 static int traceState = TRACE_IDLE;

570 static uint8_t traceCurBlock = 0;

571 static uint8_t traceCurKey = 0;

572

573 struct Crypto1State *traceCrypto1 = NULL;

574

575 struct Crypto1State *revstate;

576 uint64_t lfsr;

577 uint32_t ks2;

578 uint32_t ks3;

579

580 uint32_t uid; // serial number

581 uint32_t nt; // tag challenge

582 uint32_t nr_enc; // encrypted reader challenge

583 uint32_t ar_enc; // encrypted reader response

584 uint32_t at_enc; // encrypted tag response

585

 int isTraceCardEmpty(void) {

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

588 }

589

 int isBlockEmpty(int blockN) {

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

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

593

594 return 1;

595 }

596

 int isBlockTrailer(int blockN) {

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

599 }

600

 int saveTraceCard(void) {

602 FILE * f;

603

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

605

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

         if ( !f ) return 1;

608

         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");

613 }

614 fclose(f);

615 return 0;

616 }

617

 int loadTraceCard(uint8_t *tuid) {

619 FILE * f;

         char buf[64] = {0x00};

         uint8_t buf8[64] = {0x00};

622 int i, blockNum;

623

624 if (!isTraceCardEmpty())

625 saveTraceCard();

626

         memset(traceCard, 0x00, 4096);

         memcpy(traceCard, tuid + 3, 4);

629

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

631

         f = fopen(traceFileName, "r");

         if (!f) return 1;

634

635 blockNum = 0;

636

         while(!feof(f)){

638

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

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

641 PrintAndLog("File reading error.");

642 fclose(f);

643 return 2;

644 }

645

                 if (strlen(buf) < 32){

                         if (feof(f)) break;

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

649 fclose(f);

650 return 2;

651 }

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

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

654

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

656

657 blockNum++;

658 }

659 fclose(f);

660

661 return 0;

662 }

663

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

665

666 if (traceCrypto1)

667 crypto1_destroy(traceCrypto1);

668

669 traceCrypto1 = NULL;

670

671 if (wantSaveToEmlFile)

672 loadTraceCard(tuid);

673

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

675 traceCard[5] = sak;

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

677 traceCurBlock = 0;

         uid = bytes_to_num(tuid + 3, 4);

679

680 traceState = TRACE_IDLE;

681

682 return 0;

683 }

684

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

686 uint8_t bt = 0;

687 int i;

688

         if (len != 1) {

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

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

692 } else {

693 bt = 0;

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

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

696

697 data[0] = bt;

698 }

699 return;

700 }

701

702

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

704 uint8_t data[64];

705

         if (traceState == TRACE_ERROR) return 1;

         if (len > 64) {

708 traceState = TRACE_ERROR;

709 return 1;

710 }

711

         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);

717 }

718

719 switch (traceState) {

720 case TRACE_IDLE:

721 // check packet crc16!

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

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

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

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

726 return 1;

727 }

728

729 // AUTHENTICATION

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

731 traceState = TRACE_AUTH1;

732 traceCurBlock = data[1];

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

734 return 0;

735 }

736

737 // READ

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

739 traceState = TRACE_READ_DATA;

740 traceCurBlock = data[1];

741 return 0;

742 }

743

744 // WRITE

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

746 traceState = TRACE_WRITE_OK;

747 traceCurBlock = data[1];

748 return 0;

749 }

750

751 // HALT

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

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

754 return 0;

755 }

756

757 return 0;

758 break;

759

760 case TRACE_READ_DATA:

                 if (len == 18) {

762 traceState = TRACE_IDLE;

763

                         if (isBlockTrailer(traceCurBlock)) {

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

766 } else {

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

768 }

                         if (wantSaveToEmlFile) saveTraceCard();

770 return 0;

771 } else {

772 traceState = TRACE_ERROR;

773 return 1;

774 }

775 break;

776

777 case TRACE_WRITE_OK:

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

779 traceState = TRACE_WRITE_DATA;

780

781 return 0;

782 } else {

783 traceState = TRACE_ERROR;

784 return 1;

785 }

786 break;

787

788 case TRACE_WRITE_DATA:

                 if (len == 18) {

790 traceState = TRACE_IDLE;

791

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

                         if (wantSaveToEmlFile) saveTraceCard();

794 return 0;

795 } else {

796 traceState = TRACE_ERROR;

797 return 1;

798 }

799 break;

800

801 case TRACE_AUTH1:

                 if (len == 4) {

803 traceState = TRACE_AUTH2;

                         nt = bytes_to_num(data, 4);

805 return 0;

806 } else {

807 traceState = TRACE_ERROR;

808 return 1;

809 }

810 break;

811

812 case TRACE_AUTH2:

                 if (len == 8) {

814 traceState = TRACE_AUTH_OK;

815

                         nr_enc = bytes_to_num(data, 4);

                         ar_enc = bytes_to_num(data + 4, 4);

818 return 0;

819 } else {

820 traceState = TRACE_ERROR;

821 return 1;

822 }

823 break;

824

825 case TRACE_AUTH_OK:

                 if (len ==4) {

827 traceState = TRACE_IDLE;

828

                         at_enc = bytes_to_num(data, 4);

830

831 // 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);

839

840 crypto1_get_lfsr(revstate, &lfsr);

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

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

843

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

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

846

847 if (traceCurKey) {

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

849 } else {

                                 num_to_bytes(lfsr, 6, traceCard + blockShift);

851 }

                         if (wantSaveToEmlFile) saveTraceCard();

853

854 if (traceCrypto1) {

855 crypto1_destroy(traceCrypto1);

856 }

857

858 // set cryptosystem state

                         traceCrypto1 = lfsr_recovery64(ks2, ks3);

860

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

862

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

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

865 crypto1_word(traceCrypto1, ar, 1);

866 crypto1_word(traceCrypto1, 0, 0);

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

868

869 return 0;

870 } else {

871 traceState = TRACE_ERROR;

872 return 1;

873 }

874 break;

875

876 default:

877 traceState = TRACE_ERROR;

878 return 1;

879 }

880

881 return 0;

882 }

883

884 // DECODING

885

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

887 /*

888 uint32_t nt; // tag challenge

889 uint32_t ar_enc; // encrypted reader response

890 uint32_t at_enc; // encrypted tag response

891 */

892 if (traceCrypto1) {

893 crypto1_destroy(traceCrypto1);

894 }

         ks2 = ar_enc ^ prng_successor(nt, 64);

         ks3 = at_enc ^ prng_successor(nt, 96);

         traceCrypto1 = lfsr_recovery64(ks2, ks3);

898

         mf_crypto1_decrypt(traceCrypto1, data, len, 0);

900

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

902 crypto1_destroy(traceCrypto1);

903 return 0;

904 }

905

906 /** validate_prng_nonce

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

908 * returns

909 * true = weak prng

910 * false = hardend prng

911 */

 bool validate_prng_nonce(uint32_t nonce) {

         uint16_t *dist = 0;

914 uint16_t x, i;

915

         dist = malloc(2 << 16);

917 if(!dist)

918 return -1;

919

920 // 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;

924 }

925

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

927

928 free(dist);

         return (res == 16);

930 }

931

932 /* Detect Tag Prng,

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

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

935 * @returns

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

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

938 */

 int DetectClassicPrng(void){

940

941 UsbCommand resp, respA;

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

         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;

944

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

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

947

948 clearCommandBuffer();

949 SendCommand(&c);

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

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

952 return -1;

953 }

954

955 // if select tag failed.

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

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

958 return -1;

959 }

960

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

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

963 return -1;

964 }

965

966 // check respA

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

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

969 return -1;

970 }

971

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

973 return validate_prng_nonce(nonce);

974 }