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

   1 // Merlok, 2011, 2012
   2 // people from mifare@nethemba.com, 2010
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // mifare commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include "mifarehost.h"
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <pthread.h>
  17
  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"
  25
  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
  35
  36
  37 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);
  40
  41         // better:
  42         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  43         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
  44         else return -1;
  45 }
  46
  47
  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.
  49 static uint32_t intersection(uint64_t *list1, uint64_t *list2)
  50 {
  51         if (list1 == NULL || list2 == NULL) {
  52                 return 0;
  53         }
  54         uint64_t *p1, *p2, *p3;
  55         p1 = p3 = list1;
  56         p2 = list2;
  57
  58         while ( *p1 != -1 && *p2 != -1 ) {
  59                 if (compare_uint64(p1, p2) == 0) {
  60                         *p3++ = *p1++;
  61                         p2++;
  62                 }
  63                 else {
  64                         while (compare_uint64(p1, p2) < 0) ++p1;
  65                         while (compare_uint64(p1, p2) > 0) ++p2;
  66                 }
  67         }
  68         *p3 = -1;
  69         return p3 - list1;
  70 }
  71
  72
  73 // Darkside attack (hf mf mifare)
  74 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;
  76         uint32_t i, pos, rr; //nr_diff;
  77         uint8_t bt, ks3x[8], par[8][8];
  78         uint64_t key_recovered;
  79         static uint64_t *keylist;
  80         rr = 0;
  81
  82         // Reset the last three significant bits of the reader nonce
  83         nr &= 0xffffff1f;
  84
  85         for (pos=0; pos<8; pos++) {
  86                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  87                 bt = (par_info >> (pos*8)) & 0xff;
  88                 for (i=0; i<8; i++)     {
  89                                 par[7-pos][i] = (bt >> i) & 0x01;
  90                 }
  91         }
  92
  93         states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));
  94
  95         if (states == NULL) {
  96                 *keys = NULL;
  97                 return 0;
  98         }
  99
 100         keylist = (uint64_t*)states;
 101
 102         for (i = 0; keylist[i]; i++) {
 103                 lfsr_rollback_word(states+i, uid^nt, 0);
 104                 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
 114 int mfDarkside(uint64_t *key)
 115 {
 116         uint32_t uid = 0;
 117         uint32_t nt = 0, nr = 0;
 118         uint64_t par_list = 0, ks_list = 0;
 119         uint64_t *keylist = NULL, *last_keylist = NULL;
 120         uint32_t keycount = 0;
 121         int16_t isOK = 0;
 122
 123         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
 124
 125         // message
 126         printf("-------------------------------------------------------------------------\n");
 127         printf("Executing command. Expected execution time: 25sec on average\n");
 128         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
 129         printf("-------------------------------------------------------------------------\n");
 130
 131
 132         while (true) {
 133                 clearCommandBuffer();
 134                 SendCommand(&c);
 135
 136                 //flush queue
 137                 while (ukbhit()) {
 138                         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;
 151                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
 152                                 isOK  = resp.arg[0];
 153                                 if (isOK < 0) {
 154                                         return isOK;
 155                                 }
 156                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
 157                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
 158                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);
 159                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
 160                                 nr = bytes_to_num(resp.d.asBytes + 24, 4);
 161                                 break;
 162                         }
 163                 }
 164
 165                 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                 }
 169                 c.arg[0] = false;
 170
 171                 keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);
 172
 173                 if (keycount == 0) {
 174                         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
 179                 qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
 180                 keycount = intersection(last_keylist, keylist);
 181                 if (keycount == 0) {
 182                         free(last_keylist);
 183                         last_keylist = keylist;
 184                         continue;
 185                 }
 186
 187                 if (keycount > 1) {
 188                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 189                 } else {
 190                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 191                 }
 192
 193                 *key = -1;
 194                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 195                 int max_keys = USB_CMD_DATA_SIZE/6;
 196                 for (int i = 0; i < keycount; i += max_keys) {
 197                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 198                         for (int j = 0; j < size; j++) {
 199                                 if (last_keylist == NULL) {
 200                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock);
 201                                 } else {
 202                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock);
 203                                 }
 204                         }
 205                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 206                                 break;
 207                         }
 208                 }
 209
 210                 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
 225 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 226
 227         *key = -1;
 228
 229         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
 230         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 231         SendCommand(&c);
 232
 233         UsbCommand resp;
 234         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 235         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 236         *key = bytes_to_num(resp.d.asBytes, 6);
 237         return 0;
 238 }
 239
 240 // Compare 16 Bits out of cryptostate
 241 int Compare16Bits(const void * a, const void * b) {
 242         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 243         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
 267 void* nested_worker_thread(void *arg)
 268 {
 269         struct Crypto1State *p1;
 270         StateList_t *statelist = arg;
 271
 272         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 273         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 274         statelist->len = p1 - statelist->head.slhead;
 275         statelist->tail.sltail = --p1;
 276         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 277
 278         return statelist->head.slhead;
 279 }
 280
 281 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];
 288         struct Crypto1State *p1, *p2, *p3, *p4;
 289
 290         // flush queue
 291         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 292
 293         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 294         memcpy(c.d.asBytes, key, 6);
 295         SendCommand(&c);
 296
 297         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 298                 return -1;
 299         }
 300
 301         if (resp.arg[0]) {
 302                 return resp.arg[0];  // error during nested
 303         }
 304
 305         memcpy(&uid, resp.d.asBytes, 4);
 306         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 307
 308         for (i = 0; i < 2; i++) {
 309                 statelists[i].blockNo = resp.arg[2] & 0xff;
 310                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 311                 statelists[i].uid = uid;
 312                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 313                 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
 321         for (i = 0; i < 2; i++) {
 322                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 323         }
 324
 325         // wait for threads to terminate:
 326         for (i = 0; i < 2; i++) {
 327                 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
 334         p1 = p3 = statelists[0].head.slhead;
 335         p2 = p4 = statelists[1].head.slhead;
 336         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 337                 if (Compare16Bits(p1, p2) == 0) {
 338                         struct Crypto1State savestate, *savep = &savestate;
 339                         savestate = *p1;
 340                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 341                                 *p3 = *p1;
 342                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 343                                 p3++;
 344                                 p1++;
 345                         }
 346                         savestate = *p2;
 347                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 348                                 *p4 = *p2;
 349                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 350                                 p4++;
 351                                 p2++;
 352                         }
 353                 }
 354                 else {
 355                         while (Compare16Bits(p1, p2) == -1) p1++;
 356                         while (Compare16Bits(p1, p2) == 1) p2++;
 357                 }
 358         }
 359         *(uint64_t*)p3 = -1;
 360         *(uint64_t*)p4 = -1;
 361         statelists[0].len = p3 - statelists[0].head.slhead;
 362         statelists[1].len = p4 - statelists[1].head.slhead;
 363         statelists[0].tail.sltail=--p3;
 364         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:
 368         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 369         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 370         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 371
 372         memset(resultKey, 0, 6);
 373         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 374         for (i = 0; i < statelists[0].len; i++) {
 375                 uint8_t keyBlock[6];
 376                 uint64_t key64;
 377                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 378                 num_to_bytes(key64, 6, keyBlock);
 379                 key64 = 0;
 380                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 381                         num_to_bytes(key64, 6, resultKey);
 382                         break;
 383                 }
 384         }
 385
 386         free(statelists[0].head.slhead);
 387         free(statelists[1].head.slhead);
 388
 389         return 0;
 390 }
 391
 392 // EMULATOR
 393
 394 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 395         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 396         SendCommand(&c);
 397
 398   UsbCommand resp;
 399         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 400         memcpy(data, resp.d.asBytes, blocksCount * 16);
 401         return 0;
 402 }
 403
 404 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 405         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 406         memcpy(c.d.asBytes, data, blocksCount * 16);
 407         SendCommand(&c);
 408         return 0;
 409 }
 410
 411 // "MAGIC" CARD
 412
 413 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 414         uint8_t isOK = 0;
 415
 416         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 417         SendCommand(&c);
 418
 419   UsbCommand resp;
 420         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 421                 isOK  = resp.arg[0] & 0xff;
 422                 memcpy(data, resp.d.asBytes, 16);
 423                 if (!isOK) return 2;
 424         } else {
 425                 PrintAndLog("Command execute timeout");
 426                 return 1;
 427         }
 428         return 0;
 429 }
 430
 431 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 432
 433         uint8_t isOK = 0;
 434         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 435         memcpy(c.d.asBytes, data, 16);
 436         SendCommand(&c);
 437
 438   UsbCommand resp;
 439         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 440                 isOK  = resp.arg[0] & 0xff;
 441                 if (uid != NULL)
 442                         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
 452 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) {
 453         uint8_t oldblock0[16] = {0x00};
 454         uint8_t block0[16] = {0x00};
 455
 456         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);
 457         if (old == 0) {
 458                 memcpy(block0, oldblock0, 16);
 459                 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
 466         memcpy(block0, uid, 4);
 467         // Mifare UID BCC
 468         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)
 471                 block0[5]=sak[0];
 472         if (atqa!=NULL) {
 473                 block0[6]=atqa[1];
 474                 block0[7]=atqa[0];
 475         }
 476         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 477         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
 478 }
 479
 480 // SNIFFER
 481
 482 // constants
 483 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 484
 485 // variables
 486 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 487 static uint8_t traceCard[4096] = {0x00};
 488 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
 506 int isTraceCardEmpty(void) {
 507         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 508 }
 509
 510 int isBlockEmpty(int blockN) {
 511         for (int i = 0; i < 16; i++)
 512                 if (traceCard[blockN * 16 + i] != 0) return 0;
 513
 514         return 1;
 515 }
 516
 517 int isBlockTrailer(int blockN) {
 518  return ((blockN & 0x03) == 0x03);
 519 }
 520
 521 int saveTraceCard(void) {
 522         FILE * f;
 523
 524         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 525
 526         f = fopen(traceFileName, "w+");
 527         if ( !f ) return 1;
 528
 529         for (int i = 0; i < 64; i++) {  // blocks
 530                 for (int j = 0; j < 16; j++)  // bytes
 531                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 532                 fprintf(f,"\n");
 533         }
 534         fclose(f);
 535         return 0;
 536 }
 537
 538 int loadTraceCard(uint8_t *tuid) {
 539         FILE * f;
 540         char buf[64] = {0x00};
 541         uint8_t buf8[64] = {0x00};
 542         int i, blockNum;
 543
 544         if (!isTraceCardEmpty())
 545                 saveTraceCard();
 546
 547         memset(traceCard, 0x00, 4096);
 548         memcpy(traceCard, tuid + 3, 4);
 549
 550         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 551
 552         f = fopen(traceFileName, "r");
 553         if (!f) return 1;
 554
 555         blockNum = 0;
 556
 557         while(!feof(f)){
 558
 559                 memset(buf, 0, sizeof(buf));
 560                 if (fgets(buf, sizeof(buf), f) == NULL) {
 561                         PrintAndLog("File reading error.");
 562                         fclose(f);
 563                         return 2;
 564         }
 565
 566                 if (strlen(buf) < 32){
 567                         if (feof(f)) break;
 568                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 569                         fclose(f);
 570                         return 2;
 571                 }
 572                 for (i = 0; i < 32; i += 2)
 573                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 574
 575                 memcpy(traceCard + blockNum * 16, buf8, 16);
 576
 577                 blockNum++;
 578         }
 579         fclose(f);
 580
 581         return 0;
 582 }
 583
 584 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
 594         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 595         traceCard[5] = sak;
 596         memcpy(&traceCard[6], atqa, 2);
 597         traceCurBlock = 0;
 598         uid = bytes_to_num(tuid + 3, 4);
 599
 600         traceState = TRACE_IDLE;
 601
 602         return 0;
 603 }
 604
 605 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 606         uint8_t bt = 0;
 607         int i;
 608
 609         if (len != 1) {
 610                 for (i = 0; i < len; i++)
 611                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 612         } else {
 613                 bt = 0;
 614                 for (i = 0; i < 4; i++)
 615                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 616
 617                 data[0] = bt;
 618         }
 619         return;
 620 }
 621
 622
 623 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 624         uint8_t data[64];
 625
 626         if (traceState == TRACE_ERROR) return 1;
 627         if (len > 64) {
 628                 traceState = TRACE_ERROR;
 629                 return 1;
 630         }
 631
 632         memcpy(data, data_src, len);
 633         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 634                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 635                 PrintAndLog("dec> %s", sprint_hex(data, len));
 636                 AddLogHex(logHexFileName, "dec> ", data, len);
 637         }
 638
 639         switch (traceState) {
 640         case TRACE_IDLE:
 641                 // check packet crc16!
 642                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 643                         PrintAndLog("dec> CRC ERROR!!!");
 644                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 645                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 646                         return 1;
 647                 }
 648
 649                 // AUTHENTICATION
 650                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 651                         traceState = TRACE_AUTH1;
 652                         traceCurBlock = data[1];
 653                         traceCurKey = data[0] == 60 ? 1:0;
 654                         return 0;
 655                 }
 656
 657                 // READ
 658                 if ((len ==4) && ((data[0] == 0x30))) {
 659                         traceState = TRACE_READ_DATA;
 660                         traceCurBlock = data[1];
 661                         return 0;
 662                 }
 663
 664                 // WRITE
 665                 if ((len ==4) && ((data[0] == 0xA0))) {
 666                         traceState = TRACE_WRITE_OK;
 667                         traceCurBlock = data[1];
 668                         return 0;
 669                 }
 670
 671                 // HALT
 672                 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:
 681                 if (len == 18) {
 682                         traceState = TRACE_IDLE;
 683
 684                         if (isBlockTrailer(traceCurBlock)) {
 685                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 686                         } else {
 687                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 688                         }
 689                         if (wantSaveToEmlFile) saveTraceCard();
 690                         return 0;
 691                 } else {
 692                         traceState = TRACE_ERROR;
 693                         return 1;
 694                 }
 695         break;
 696
 697         case TRACE_WRITE_OK:
 698                 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:
 709                 if (len == 18) {
 710                         traceState = TRACE_IDLE;
 711
 712                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 713                         if (wantSaveToEmlFile) saveTraceCard();
 714                         return 0;
 715                 } else {
 716                         traceState = TRACE_ERROR;
 717                         return 1;
 718                 }
 719         break;
 720
 721         case TRACE_AUTH1:
 722                 if (len == 4) {
 723                         traceState = TRACE_AUTH2;
 724                         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:
 733                 if (len == 8) {
 734                         traceState = TRACE_AUTH_OK;
 735
 736                         nr_enc = bytes_to_num(data, 4);
 737                         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:
 746                 if (len ==4) {
 747                         traceState = TRACE_IDLE;
 748
 749                         at_enc = bytes_to_num(data, 4);
 750
 751                         //  decode key here)
 752                         ks2 = ar_enc ^ prng_successor(nt, 64);
 753                         ks3 = at_enc ^ prng_successor(nt, 96);
 754                         revstate = lfsr_recovery64(ks2, ks3);
 755                         lfsr_rollback_word(revstate, 0, 0);
 756                         lfsr_rollback_word(revstate, 0, 0);
 757                         lfsr_rollback_word(revstate, nr_enc, 1);
 758                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 759
 760                         crypto1_get_lfsr(revstate, &lfsr);
 761                         printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 762                         AddLogUint64(logHexFileName, "key> ", lfsr);
 763
 764                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 765                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 766
 767                         if (traceCurKey) {
 768                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 769                         } else {
 770                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 771                         }
 772                         if (wantSaveToEmlFile) saveTraceCard();
 773
 774                         if (traceCrypto1) {
 775                                 crypto1_destroy(traceCrypto1);
 776                         }
 777
 778                         // set cryptosystem state
 779                         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
 804 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         }
 813         ks2 = ar_enc ^ prng_successor(nt, 64);
 814         ks3 = at_enc ^ prng_successor(nt, 96);
 815         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 816
 817         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 818
 819         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 820         crypto1_destroy(traceCrypto1);
 821         return 0;
 822 }
 823 /* Detect Tag Prng,
 824 * function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
 825 * the tag nonce is check to see if it has a predictable PRNG.
 826 * @returns
 827 *       TRUE if tag uses WEAK prng (ie Darkside attack possible)
 828 *   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
 829 */
 830 bool detect_classic_prng(){
 831
 832         UsbCommand resp, respA;
 833         uint8_t cmd[] = {MIFARE_AUTH_KEYA, 0x00};
 834         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC;
 835
 836         UsbCommand cAuth = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
 837         memcpy(cAuth.d.asBytes, cmd, sizeof(cmd));
 838
 839         clearCommandBuffer();
 840         SendCommand(&cAuth);
 841         WaitForResponse(CMD_ACK, &resp);
 842         WaitForResponse(CMD_ACK, &respA);
 843
 844         // if select tag failed.
 845         if ( resp.arg[0] == 0 ) {
 846                 printf("Error:  selecting tag failed,  can't detect prng\n");
 847                 return false;
 848         }
 849
 850         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
 851         return validate_prng_nonce(nonce);
 852 }