cvs.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 #include "mifare.h"     // for ISO14A_CONNECT etc
  26 #include "protocols.h"  // for MIFARE_AUTH_KEYA
  27
  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
  37
  38
  39 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);
  42
  43         // better:
  44         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  45         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
  46         else return -1;
  47 }
  48
  49
  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.
  51 static uint32_t intersection(uint64_t *list1, uint64_t *list2)
  52 {
  53         if (list1 == NULL || list2 == NULL) {
  54                 return 0;
  55         }
  56         uint64_t *p1, *p2, *p3;
  57         p1 = p3 = list1;
  58         p2 = list2;
  59
  60         while ( *p1 != -1 && *p2 != -1 ) {
  61                 if (compare_uint64(p1, p2) == 0) {
  62                         *p3++ = *p1++;
  63                         p2++;
  64                 }
  65                 else {
  66                         while (compare_uint64(p1, p2) < 0) ++p1;
  67                         while (compare_uint64(p1, p2) > 0) ++p2;
  68                 }
  69         }
  70         *p3 = -1;
  71         return p3 - list1;
  72 }
  73
  74
  75 // Darkside attack (hf mf mifare)
  76 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;
  78         uint32_t i, pos, rr; //nr_diff;
  79         uint8_t bt, ks3x[8], par[8][8];
  80         uint64_t key_recovered;
  81         static uint64_t *keylist;
  82         rr = 0;
  83
  84         // Reset the last three significant bits of the reader nonce
  85         nr &= 0xffffff1f;
  86
  87         for (pos=0; pos<8; pos++) {
  88                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  89                 bt = (par_info >> (pos*8)) & 0xff;
  90                 for (i=0; i<8; i++)     {
  91                                 par[7-pos][i] = (bt >> i) & 0x01;
  92                 }
  93         }
  94
  95         states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));
  96
  97         if (states == NULL) {
  98                 *keys = NULL;
  99                 return 0;
 100         }
 101
 102         keylist = (uint64_t*)states;
 103
 104         for (i = 0; keylist[i]; i++) {
 105                 lfsr_rollback_word(states+i, uid^nt, 0);
 106                 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
 116 int mfDarkside(uint64_t *key)
 117 {
 118         uint32_t uid = 0;
 119         uint32_t nt = 0, nr = 0;
 120         uint64_t par_list = 0, ks_list = 0;
 121         uint64_t *keylist = NULL, *last_keylist = NULL;
 122         uint32_t keycount = 0;
 123         int16_t isOK = 0;
 124
 125         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
 126
 127         // message
 128         printf("-------------------------------------------------------------------------\n");
 129         printf("Executing command. Expected execution time: 25sec on average\n");
 130         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
 131         printf("-------------------------------------------------------------------------\n");
 132
 133
 134         while (true) {
 135                 clearCommandBuffer();
 136                 SendCommand(&c);
 137
 138                 //flush queue
 139                 while (ukbhit()) {
 140                         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;
 153                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
 154                                 isOK  = resp.arg[0];
 155                                 if (isOK < 0) {
 156                                         return isOK;
 157                                 }
 158                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
 159                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
 160                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);
 161                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
 162                                 nr = bytes_to_num(resp.d.asBytes + 24, 4);
 163                                 break;
 164                         }
 165                 }
 166
 167                 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                 }
 171                 c.arg[0] = false;
 172
 173                 keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);
 174
 175                 if (keycount == 0) {
 176                         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
 181                 qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
 182                 keycount = intersection(last_keylist, keylist);
 183                 if (keycount == 0) {
 184                         free(last_keylist);
 185                         last_keylist = keylist;
 186                         continue;
 187                 }
 188
 189                 if (keycount > 1) {
 190                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 191                 } else {
 192                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 193                 }
 194
 195                 *key = -1;
 196                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 197                 int max_keys = USB_CMD_DATA_SIZE/6;
 198                 for (int i = 0; i < keycount; i += max_keys) {
 199                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 200                         for (int j = 0; j < size; j++) {
 201                                 if (last_keylist == NULL) {
 202                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock);
 203                                 } else {
 204                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock);
 205                                 }
 206                         }
 207                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 208                                 break;
 209                         }
 210                 }
 211
 212                 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
 227 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
 231         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType&0xff)<<8)), clear_trace, keycnt}};
 232         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 233         SendCommand(&c);
 234
 235         UsbCommand resp;
 236         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 237         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 238         *key = bytes_to_num(resp.d.asBytes, 6);
 239         return 0;
 240 }
 241
 242 // Compare 16 Bits out of cryptostate
 243 int Compare16Bits(const void * a, const void * b) {
 244         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 245         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
 246         else return -1;
 247 }
 248
 249 typedef
 250         struct {
 251                 union {
 252                         struct Crypto1State *slhead;
 253                         uint64_t *keyhead;
 254                 } head;
 255                 union {
 256                         struct Crypto1State *sltail;
 257                         uint64_t *keytail;
 258                 } tail;
 259                 uint32_t len;
 260                 uint32_t uid;
 261                 uint32_t blockNo;
 262                 uint32_t keyType;
 263                 uint32_t nt;
 264                 uint32_t ks1;
 265         } StateList_t;
 266
 267
 268 // wrapper function for multi-threaded lfsr_recovery32
 269 void* nested_worker_thread(void *arg)
 270 {
 271         struct Crypto1State *p1;
 272         StateList_t *statelist = arg;
 273
 274         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 275         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 276         statelist->len = p1 - statelist->head.slhead;
 277         statelist->tail.sltail = --p1;
 278         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 279
 280         return statelist->head.slhead;
 281 }
 282
 283 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
 284 {
 285         uint16_t i;
 286         uint32_t uid;
 287         UsbCommand resp;
 288
 289         StateList_t statelists[2];
 290         struct Crypto1State *p1, *p2, *p3, *p4;
 291
 292         // flush queue
 293         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 294
 295         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 296         memcpy(c.d.asBytes, key, 6);
 297         SendCommand(&c);
 298
 299         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 300                 return -1;
 301         }
 302
 303         if (resp.arg[0]) {
 304                 return resp.arg[0];  // error during nested
 305         }
 306
 307         memcpy(&uid, resp.d.asBytes, 4);
 308         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 309
 310         for (i = 0; i < 2; i++) {
 311                 statelists[i].blockNo = resp.arg[2] & 0xff;
 312                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 313                 statelists[i].uid = uid;
 314                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 315                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 316         }
 317
 318         // calc keys
 319
 320         pthread_t thread_id[2];
 321
 322         // create and run worker threads
 323         for (i = 0; i < 2; i++) {
 324                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 325         }
 326
 327         // wait for threads to terminate:
 328         for (i = 0; i < 2; i++) {
 329                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 330         }
 331
 332
 333         // the first 16 Bits of the cryptostate already contain part of our key.
 334         // Create the intersection of the two lists based on these 16 Bits and
 335         // roll back the cryptostate
 336         p1 = p3 = statelists[0].head.slhead;
 337         p2 = p4 = statelists[1].head.slhead;
 338         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 339                 if (Compare16Bits(p1, p2) == 0) {
 340                         struct Crypto1State savestate, *savep = &savestate;
 341                         savestate = *p1;
 342                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 343                                 *p3 = *p1;
 344                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 345                                 p3++;
 346                                 p1++;
 347                         }
 348                         savestate = *p2;
 349                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 350                                 *p4 = *p2;
 351                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 352                                 p4++;
 353                                 p2++;
 354                         }
 355                 }
 356                 else {
 357                         while (Compare16Bits(p1, p2) == -1) p1++;
 358                         while (Compare16Bits(p1, p2) == 1) p2++;
 359                 }
 360         }
 361         *(uint64_t*)p3 = -1;
 362         *(uint64_t*)p4 = -1;
 363         statelists[0].len = p3 - statelists[0].head.slhead;
 364         statelists[1].len = p4 - statelists[1].head.slhead;
 365         statelists[0].tail.sltail=--p3;
 366         statelists[1].tail.sltail=--p4;
 367
 368         // the statelists now contain possible keys. The key we are searching for must be in the
 369         // intersection of both lists. Create the intersection:
 370         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 371         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 372         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 373
 374         memset(resultKey, 0, 6);
 375         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 376         for (i = 0; i < statelists[0].len; i++) {
 377                 uint8_t keyBlock[6];
 378                 uint64_t key64;
 379                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 380                 num_to_bytes(key64, 6, keyBlock);
 381                 key64 = 0;
 382                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 383                         num_to_bytes(key64, 6, resultKey);
 384                         break;
 385                 }
 386         }
 387
 388         free(statelists[0].head.slhead);
 389         free(statelists[1].head.slhead);
 390
 391         return 0;
 392 }
 393
 394 // EMULATOR
 395
 396 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 397         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 398         SendCommand(&c);
 399
 400   UsbCommand resp;
 401         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 402         memcpy(data, resp.d.asBytes, blocksCount * 16);
 403         return 0;
 404 }
 405
 406 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 407         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 408         memcpy(c.d.asBytes, data, blocksCount * 16);
 409         SendCommand(&c);
 410         return 0;
 411 }
 412
 413 // "MAGIC" CARD
 414
 415 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 416         uint8_t isOK = 0;
 417
 418         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 419         SendCommand(&c);
 420
 421   UsbCommand resp;
 422         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 423                 isOK  = resp.arg[0] & 0xff;
 424                 memcpy(data, resp.d.asBytes, 16);
 425                 if (!isOK) return 2;
 426         } else {
 427                 PrintAndLog("Command execute timeout");
 428                 return 1;
 429         }
 430         return 0;
 431 }
 432
 433 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 434
 435         uint8_t isOK = 0;
 436         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 437         memcpy(c.d.asBytes, data, 16);
 438         SendCommand(&c);
 439
 440   UsbCommand resp;
 441         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 442                 isOK  = resp.arg[0] & 0xff;
 443                 if (uid != NULL)
 444                         memcpy(uid, resp.d.asBytes, 4);
 445                 if (!isOK)
 446                         return 2;
 447         } else {
 448                 PrintAndLog("Command execute timeout");
 449                 return 1;
 450         }
 451         return 0;
 452 }
 453
 454 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID, bool wantWipe) {
 455         uint8_t oldblock0[16] = {0x00};
 456         uint8_t block0[16] = {0x00};
 457
 458         int old = mfCGetBlock(0, oldblock0, CSETBLOCK_SINGLE_OPER);
 459         if (old == 0) {
 460                 memcpy(block0, oldblock0, 16);
 461                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 462         } else {
 463                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 464         }
 465
 466         // fill in the new values
 467         // UID
 468         memcpy(block0, uid, 4);
 469         // Mifare UID BCC
 470         block0[4] = block0[0]^block0[1]^block0[2]^block0[3];
 471         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 472         if (sak!=NULL)
 473                 block0[5]=sak[0];
 474         if (atqa!=NULL) {
 475                 block0[6]=atqa[1];
 476                 block0[7]=atqa[0];
 477         }
 478         PrintAndLog("new block 0:  %s", sprint_hex(block0,16));
 479         return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
 480 }
 481
 482 // SNIFFER
 483
 484 // constants
 485 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 486
 487 // variables
 488 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 489 static uint8_t traceCard[4096] = {0x00};
 490 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 491 static int traceState = TRACE_IDLE;
 492 static uint8_t traceCurBlock = 0;
 493 static uint8_t traceCurKey = 0;
 494
 495 struct Crypto1State *traceCrypto1 = NULL;
 496
 497 struct Crypto1State *revstate;
 498 uint64_t lfsr;
 499 uint32_t ks2;
 500 uint32_t ks3;
 501
 502 uint32_t uid;     // serial number
 503 uint32_t nt;      // tag challenge
 504 uint32_t nr_enc;  // encrypted reader challenge
 505 uint32_t ar_enc;  // encrypted reader response
 506 uint32_t at_enc;  // encrypted tag response
 507
 508 int isTraceCardEmpty(void) {
 509         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 510 }
 511
 512 int isBlockEmpty(int blockN) {
 513         for (int i = 0; i < 16; i++)
 514                 if (traceCard[blockN * 16 + i] != 0) return 0;
 515
 516         return 1;
 517 }
 518
 519 int isBlockTrailer(int blockN) {
 520  return ((blockN & 0x03) == 0x03);
 521 }
 522
 523 int saveTraceCard(void) {
 524         FILE * f;
 525
 526         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 527
 528         f = fopen(traceFileName, "w+");
 529         if ( !f ) return 1;
 530
 531         for (int i = 0; i < 64; i++) {  // blocks
 532                 for (int j = 0; j < 16; j++)  // bytes
 533                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 534                 fprintf(f,"\n");
 535         }
 536         fclose(f);
 537         return 0;
 538 }
 539
 540 int loadTraceCard(uint8_t *tuid) {
 541         FILE * f;
 542         char buf[64] = {0x00};
 543         uint8_t buf8[64] = {0x00};
 544         int i, blockNum;
 545
 546         if (!isTraceCardEmpty())
 547                 saveTraceCard();
 548
 549         memset(traceCard, 0x00, 4096);
 550         memcpy(traceCard, tuid + 3, 4);
 551
 552         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 553
 554         f = fopen(traceFileName, "r");
 555         if (!f) return 1;
 556
 557         blockNum = 0;
 558
 559         while(!feof(f)){
 560
 561                 memset(buf, 0, sizeof(buf));
 562                 if (fgets(buf, sizeof(buf), f) == NULL) {
 563                         PrintAndLog("File reading error.");
 564                         fclose(f);
 565                         return 2;
 566         }
 567
 568                 if (strlen(buf) < 32){
 569                         if (feof(f)) break;
 570                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 571                         fclose(f);
 572                         return 2;
 573                 }
 574                 for (i = 0; i < 32; i += 2)
 575                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 576
 577                 memcpy(traceCard + blockNum * 16, buf8, 16);
 578
 579                 blockNum++;
 580         }
 581         fclose(f);
 582
 583         return 0;
 584 }
 585
 586 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 587
 588         if (traceCrypto1)
 589                 crypto1_destroy(traceCrypto1);
 590
 591         traceCrypto1 = NULL;
 592
 593         if (wantSaveToEmlFile)
 594                 loadTraceCard(tuid);
 595
 596         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 597         traceCard[5] = sak;
 598         memcpy(&traceCard[6], atqa, 2);
 599         traceCurBlock = 0;
 600         uid = bytes_to_num(tuid + 3, 4);
 601
 602         traceState = TRACE_IDLE;
 603
 604         return 0;
 605 }
 606
 607 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 608         uint8_t bt = 0;
 609         int i;
 610
 611         if (len != 1) {
 612                 for (i = 0; i < len; i++)
 613                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 614         } else {
 615                 bt = 0;
 616                 for (i = 0; i < 4; i++)
 617                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 618
 619                 data[0] = bt;
 620         }
 621         return;
 622 }
 623
 624
 625 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 626         uint8_t data[64];
 627
 628         if (traceState == TRACE_ERROR) return 1;
 629         if (len > 64) {
 630                 traceState = TRACE_ERROR;
 631                 return 1;
 632         }
 633
 634         memcpy(data, data_src, len);
 635         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 636                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 637                 PrintAndLog("dec> %s", sprint_hex(data, len));
 638                 AddLogHex(logHexFileName, "dec> ", data, len);
 639         }
 640
 641         switch (traceState) {
 642         case TRACE_IDLE:
 643                 // check packet crc16!
 644                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 645                         PrintAndLog("dec> CRC ERROR!!!");
 646                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 647                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 648                         return 1;
 649                 }
 650
 651                 // AUTHENTICATION
 652                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 653                         traceState = TRACE_AUTH1;
 654                         traceCurBlock = data[1];
 655                         traceCurKey = data[0] == 60 ? 1:0;
 656                         return 0;
 657                 }
 658
 659                 // READ
 660                 if ((len ==4) && ((data[0] == 0x30))) {
 661                         traceState = TRACE_READ_DATA;
 662                         traceCurBlock = data[1];
 663                         return 0;
 664                 }
 665
 666                 // WRITE
 667                 if ((len ==4) && ((data[0] == 0xA0))) {
 668                         traceState = TRACE_WRITE_OK;
 669                         traceCurBlock = data[1];
 670                         return 0;
 671                 }
 672
 673                 // HALT
 674                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 675                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 676                         return 0;
 677                 }
 678
 679                 return 0;
 680         break;
 681
 682         case TRACE_READ_DATA:
 683                 if (len == 18) {
 684                         traceState = TRACE_IDLE;
 685
 686                         if (isBlockTrailer(traceCurBlock)) {
 687                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 688                         } else {
 689                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 690                         }
 691                         if (wantSaveToEmlFile) saveTraceCard();
 692                         return 0;
 693                 } else {
 694                         traceState = TRACE_ERROR;
 695                         return 1;
 696                 }
 697         break;
 698
 699         case TRACE_WRITE_OK:
 700                 if ((len == 1) && (data[0] == 0x0a)) {
 701                         traceState = TRACE_WRITE_DATA;
 702
 703                         return 0;
 704                 } else {
 705                         traceState = TRACE_ERROR;
 706                         return 1;
 707                 }
 708         break;
 709
 710         case TRACE_WRITE_DATA:
 711                 if (len == 18) {
 712                         traceState = TRACE_IDLE;
 713
 714                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 715                         if (wantSaveToEmlFile) saveTraceCard();
 716                         return 0;
 717                 } else {
 718                         traceState = TRACE_ERROR;
 719                         return 1;
 720                 }
 721         break;
 722
 723         case TRACE_AUTH1:
 724                 if (len == 4) {
 725                         traceState = TRACE_AUTH2;
 726                         nt = bytes_to_num(data, 4);
 727                         return 0;
 728                 } else {
 729                         traceState = TRACE_ERROR;
 730                         return 1;
 731                 }
 732         break;
 733
 734         case TRACE_AUTH2:
 735                 if (len == 8) {
 736                         traceState = TRACE_AUTH_OK;
 737
 738                         nr_enc = bytes_to_num(data, 4);
 739                         ar_enc = bytes_to_num(data + 4, 4);
 740                         return 0;
 741                 } else {
 742                         traceState = TRACE_ERROR;
 743                         return 1;
 744                 }
 745         break;
 746
 747         case TRACE_AUTH_OK:
 748                 if (len ==4) {
 749                         traceState = TRACE_IDLE;
 750
 751                         at_enc = bytes_to_num(data, 4);
 752
 753                         //  decode key here)
 754                         ks2 = ar_enc ^ prng_successor(nt, 64);
 755                         ks3 = at_enc ^ prng_successor(nt, 96);
 756                         revstate = lfsr_recovery64(ks2, ks3);
 757                         lfsr_rollback_word(revstate, 0, 0);
 758                         lfsr_rollback_word(revstate, 0, 0);
 759                         lfsr_rollback_word(revstate, nr_enc, 1);
 760                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 761
 762                         crypto1_get_lfsr(revstate, &lfsr);
 763                         printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 764                         AddLogUint64(logHexFileName, "key> ", lfsr);
 765
 766                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 767                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 768
 769                         if (traceCurKey) {
 770                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 771                         } else {
 772                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 773                         }
 774                         if (wantSaveToEmlFile) saveTraceCard();
 775
 776                         if (traceCrypto1) {
 777                                 crypto1_destroy(traceCrypto1);
 778                         }
 779
 780                         // set cryptosystem state
 781                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 782
 783 //      nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
 784
 785         /*      traceCrypto1 = crypto1_create(lfsr); // key in lfsr
 786                 crypto1_word(traceCrypto1, nt ^ uid, 0);
 787                 crypto1_word(traceCrypto1, ar, 1);
 788                 crypto1_word(traceCrypto1, 0, 0);
 789                 crypto1_word(traceCrypto1, 0, 0);*/
 790
 791                         return 0;
 792                 } else {
 793                         traceState = TRACE_ERROR;
 794                         return 1;
 795                 }
 796         break;
 797
 798         default:
 799                 traceState = TRACE_ERROR;
 800                 return 1;
 801         }
 802
 803         return 0;
 804 }
 805
 806 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 807         /*
 808         uint32_t nt;      // tag challenge
 809         uint32_t ar_enc;  // encrypted reader response
 810         uint32_t at_enc;  // encrypted tag response
 811         */
 812         if (traceCrypto1) {
 813                 crypto1_destroy(traceCrypto1);
 814         }
 815         ks2 = ar_enc ^ prng_successor(nt, 64);
 816         ks3 = at_enc ^ prng_successor(nt, 96);
 817         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 818
 819         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 820
 821         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 822         crypto1_destroy(traceCrypto1);
 823         return 0;
 824 }
 825 /* Detect Tag Prng,
 826 * function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
 827 * the tag nonce is check to see if it has a predictable PRNG.
 828 * @returns
 829 *       TRUE if tag uses WEAK prng (ie Darkside attack possible)
 830 *   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
 831 */
 832 bool detect_classic_prng(){
 833
 834         UsbCommand resp, respA;
 835         uint8_t cmd[] = {MIFARE_AUTH_KEYA, 0x00};
 836         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC;
 837
 838         UsbCommand cAuth = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
 839         memcpy(cAuth.d.asBytes, cmd, sizeof(cmd));
 840
 841         clearCommandBuffer();
 842         SendCommand(&cAuth);
 843         WaitForResponse(CMD_ACK, &resp);
 844         WaitForResponse(CMD_ACK, &respA);
 845
 846         // if select tag failed.
 847         if ( resp.arg[0] == 0 ) {
 848                 printf("Error:  selecting tag failed,  can't detect prng\n");
 849                 return false;
 850         }
 851
 852         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
 853         return validate_prng_nonce(nonce);
 854 }