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 #include "mifare.h"
  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, uint32_t ar, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {
  77         struct Crypto1State *states;
  78         uint32_t i, pos;
  79         uint8_t bt, ks3x[8], par[8][8];
  80         uint64_t key_recovered;
  81         uint64_t *keylist;
  82
  83         // Reset the last three significant bits of the reader nonce
  84         nr &= 0xffffff1f;
  85
  86         for (pos=0; pos<8; pos++) {
  87                 ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
  88                 bt = (par_info >> (pos*8)) & 0xff;
  89                 for (i=0; i<8; i++)     {
  90                                 par[7-pos][i] = (bt >> i) & 0x01;
  91                 }
  92         }
  93
  94         states = lfsr_common_prefix(nr, ar, ks3x, par, (par_info == 0));
  95
  96         if (states == NULL) {
  97                 *keys = NULL;
  98                 return 0;
  99         }
 100
 101         keylist = (uint64_t*)states;
 102
 103         for (i = 0; keylist[i]; i++) {
 104                 lfsr_rollback_word(states+i, uid^nt, 0);
 105                 crypto1_get_lfsr(states+i, &key_recovered);
 106                 keylist[i] = key_recovered;
 107         }
 108         keylist[i] = -1;
 109
 110         *keys = keylist;
 111         return i;
 112 }
 113
 114
 115 int mfDarkside(uint64_t *key)
 116 {
 117         uint32_t uid = 0;
 118         uint32_t nt = 0, nr = 0, ar = 0;
 119         uint64_t par_list = 0, ks_list = 0;
 120         uint64_t *keylist = NULL, *last_keylist = NULL;
 121         uint32_t keycount = 0;
 122         int16_t isOK = 0;
 123
 124         UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
 125
 126         // message
 127         printf("-------------------------------------------------------------------------\n");
 128         printf("Executing command. Expected execution time: 25sec on average\n");
 129         printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
 130         printf("-------------------------------------------------------------------------\n");
 131
 132
 133         while (true) {
 134                 clearCommandBuffer();
 135                 SendCommand(&c);
 136
 137                 //flush queue
 138                 while (ukbhit()) {
 139                         int c = getchar(); (void) c;
 140                 }
 141
 142                 // wait cycle
 143                 while (true) {
 144                         printf(".");
 145                         fflush(stdout);
 146                         if (ukbhit()) {
 147                                 return -5;
 148                                 break;
 149                         }
 150
 151                         UsbCommand resp;
 152                         if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
 153                                 isOK  = resp.arg[0];
 154                                 if (isOK < 0) {
 155                                         return isOK;
 156                                 }
 157                                 uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
 158                                 nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
 159                                 par_list = bytes_to_num(resp.d.asBytes +  8, 8);
 160                                 ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
 161                                 nr = (uint32_t)bytes_to_num(resp.d.asBytes + 24, 4);
 162                                 ar = (uint32_t)bytes_to_num(resp.d.asBytes + 28, 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                 }
 170                 c.arg[0] = false;
 171
 172                 keycount = nonce2key(uid, nt, nr, ar, par_list, ks_list, &keylist);
 173
 174                 if (keycount == 0) {
 175                         PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);
 176                         PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce...");
 177                         continue;
 178                 }
 179
 180                 if (par_list == 0) {
 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
 190                 if (keycount > 1) {
 191                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 192                 } else {
 193                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 194                 }
 195
 196                 *key = -1;
 197                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 198                 int max_keys = USB_CMD_DATA_SIZE/6;
 199                 for (int i = 0; i < keycount; i += max_keys) {
 200                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 201                         for (int j = 0; j < size; j++) {
 202                                 if (par_list == 0) {
 203                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock+(j*6));
 204                                 } else {
 205                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock+(j*6));
 206                                 }
 207                         }
 208                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 209                                 break;
 210                         }
 211                 }
 212
 213                 if (*key != -1) {
 214                         free(last_keylist);
 215                         free(keylist);
 216                         break;
 217                 } else {
 218                         PrintAndLog("Authentication failed. Trying again...");
 219                         free(last_keylist);
 220                         last_keylist = keylist;
 221                 }
 222         }
 223
 224         return 0;
 225 }
 226
 227
 228 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 229
 230         *key = -1;
 231
 232         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType & 0xff) << 8)), clear_trace, keycnt}};
 233         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 234         SendCommand(&c);
 235
 236         UsbCommand resp;
 237         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 238         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 239         *key = bytes_to_num(resp.d.asBytes, 6);
 240         return 0;
 241 }
 242
 243 int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){
 244
 245         uint8_t keyPtr = 0;
 246
 247         if (e_sector == NULL)
 248                 return -1;
 249
 250         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}};
 251         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 252         SendCommand(&c);
 253
 254         UsbCommand resp;
 255         if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth
 256         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 257
 258         bool foundAKey = false;
 259         for(int sec = 0; sec < sectorCnt; sec++){
 260                 for(int keyAB = 0; keyAB < 2; keyAB++){
 261                         keyPtr = *(resp.d.asBytes + keyAB * 40 + sec);
 262                         if (keyPtr){
 263                                 e_sector[sec].foundKey[keyAB] = true;
 264                                 e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6);
 265                                 foundAKey = true;
 266                         }
 267                 }
 268         }
 269         return foundAKey ? 0 : 3;
 270 }
 271
 272 // Compare 16 Bits out of cryptostate
 273 int Compare16Bits(const void * a, const void * b) {
 274         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 275         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
 276         else return -1;
 277 }
 278
 279 typedef
 280         struct {
 281                 union {
 282                         struct Crypto1State *slhead;
 283                         uint64_t *keyhead;
 284                 } head;
 285                 union {
 286                         struct Crypto1State *sltail;
 287                         uint64_t *keytail;
 288                 } tail;
 289                 uint32_t len;
 290                 uint32_t uid;
 291                 uint32_t blockNo;
 292                 uint32_t keyType;
 293                 uint32_t nt;
 294                 uint32_t ks1;
 295         } StateList_t;
 296
 297
 298 // wrapper function for multi-threaded lfsr_recovery32
 299 void
 300 #ifdef __has_attribute
 301 #if __has_attribute(force_align_arg_pointer)
 302 __attribute__((force_align_arg_pointer))
 303 #endif
 304 #endif
 305 *nested_worker_thread(void *arg)
 306 {
 307         struct Crypto1State *p1;
 308         StateList_t *statelist = arg;
 309
 310         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 311         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 312         statelist->len = p1 - statelist->head.slhead;
 313         statelist->tail.sltail = --p1;
 314         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 315
 316         return statelist->head.slhead;
 317 }
 318
 319
 320 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
 321 {
 322         uint16_t i;
 323         uint32_t uid;
 324         UsbCommand resp;
 325
 326         StateList_t statelists[2];
 327         struct Crypto1State *p1, *p2, *p3, *p4;
 328
 329         // flush queue
 330         WaitForResponseTimeout(CMD_ACK, NULL, 100);
 331
 332         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 333         memcpy(c.d.asBytes, key, 6);
 334         SendCommand(&c);
 335
 336         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 337                 return -1;
 338         }
 339
 340         if (resp.arg[0]) {
 341                 return resp.arg[0];  // error during nested
 342         }
 343
 344         memcpy(&uid, resp.d.asBytes, 4);
 345         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 346
 347         for (i = 0; i < 2; i++) {
 348                 statelists[i].blockNo = resp.arg[2] & 0xff;
 349                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 350                 statelists[i].uid = uid;
 351                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 352                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 353         }
 354
 355         // calc keys
 356
 357         pthread_t thread_id[2];
 358
 359         // create and run worker threads
 360         for (i = 0; i < 2; i++) {
 361                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 362         }
 363
 364         // wait for threads to terminate:
 365         for (i = 0; i < 2; i++) {
 366                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 367         }
 368
 369
 370         // the first 16 Bits of the cryptostate already contain part of our key.
 371         // Create the intersection of the two lists based on these 16 Bits and
 372         // roll back the cryptostate
 373         p1 = p3 = statelists[0].head.slhead;
 374         p2 = p4 = statelists[1].head.slhead;
 375         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 376                 if (Compare16Bits(p1, p2) == 0) {
 377                         struct Crypto1State savestate, *savep = &savestate;
 378                         savestate = *p1;
 379                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 380                                 *p3 = *p1;
 381                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 382                                 p3++;
 383                                 p1++;
 384                         }
 385                         savestate = *p2;
 386                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 387                                 *p4 = *p2;
 388                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 389                                 p4++;
 390                                 p2++;
 391                         }
 392                 }
 393                 else {
 394                         while (Compare16Bits(p1, p2) == -1) p1++;
 395                         while (Compare16Bits(p1, p2) == 1) p2++;
 396                 }
 397         }
 398         *(uint64_t*)p3 = -1;
 399         *(uint64_t*)p4 = -1;
 400         statelists[0].len = p3 - statelists[0].head.slhead;
 401         statelists[1].len = p4 - statelists[1].head.slhead;
 402         statelists[0].tail.sltail=--p3;
 403         statelists[1].tail.sltail=--p4;
 404
 405         // the statelists now contain possible keys. The key we are searching for must be in the
 406         // intersection of both lists. Create the intersection:
 407         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 408         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 409         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 410
 411         memset(resultKey, 0, 6);
 412         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 413         for (i = 0; i < statelists[0].len; i++) {
 414                 uint8_t keyBlock[6];
 415                 uint64_t key64;
 416                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 417                 num_to_bytes(key64, 6, keyBlock);
 418                 key64 = 0;
 419                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 420                         num_to_bytes(key64, 6, resultKey);
 421                         break;
 422                 }
 423         }
 424
 425         free(statelists[0].head.slhead);
 426         free(statelists[1].head.slhead);
 427
 428         return 0;
 429 }
 430
 431 // EMULATOR
 432
 433 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 434         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 435         SendCommand(&c);
 436
 437   UsbCommand resp;
 438         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 439         memcpy(data, resp.d.asBytes, blocksCount * 16);
 440         return 0;
 441 }
 442
 443 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 444         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 445         memcpy(c.d.asBytes, data, blocksCount * 16);
 446         SendCommand(&c);
 447         return 0;
 448 }
 449
 450 // "MAGIC" CARD
 451
 452 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 453         uint8_t isOK = 0;
 454
 455         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 456         SendCommand(&c);
 457
 458         UsbCommand resp;
 459         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 460                 isOK  = resp.arg[0] & 0xff;
 461                 memcpy(data, resp.d.asBytes, 16);
 462                 if (!isOK) return 2;
 463         } else {
 464                 PrintAndLog("Command execute timeout");
 465                 return 1;
 466         }
 467         return 0;
 468 }
 469
 470 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 471
 472         uint8_t isOK = 0;
 473         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 474         memcpy(c.d.asBytes, data, 16);
 475         SendCommand(&c);
 476
 477         UsbCommand resp;
 478         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 479                 isOK  = resp.arg[0] & 0xff;
 480                 if (uid != NULL)
 481                         memcpy(uid, resp.d.asBytes, 4);
 482                 if (!isOK)
 483                         return 2;
 484         } else {
 485                 PrintAndLog("Command execute timeout");
 486                 return 1;
 487         }
 488
 489         return 0;
 490 }
 491
 492 int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) {
 493         uint8_t isOK = 0;
 494         uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04;
 495         UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}};
 496         SendCommand(&c);
 497
 498         UsbCommand resp;
 499         WaitForResponse(CMD_ACK,&resp);
 500         isOK  = resp.arg[0] & 0xff;
 501
 502         return isOK;
 503 }
 504
 505 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) {
 506         uint8_t oldblock0[16] = {0x00};
 507         uint8_t block0[16] = {0x00};
 508         int gen = 0, res;
 509
 510         gen = mfCIdentify();
 511
 512         /* generation 1a magic card by default */
 513         uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;
 514         if (gen == 2) {
 515                 /* generation 1b magic card */
 516                 cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;
 517         }
 518
 519         res = mfCGetBlock(0, oldblock0, cmdParams);
 520
 521         if (res == 0) {
 522                 memcpy(block0, oldblock0, 16);
 523                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 524         } else {
 525                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 526         }
 527
 528         // fill in the new values
 529         // UID
 530         memcpy(block0, uid, 4);
 531         // Mifare UID BCC
 532         block0[4] = block0[0] ^ block0[1] ^ block0[2] ^ block0[3];
 533         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 534         if (sak != NULL)
 535                 block0[5] = sak[0];
 536         if (atqa != NULL) {
 537                 block0[6] = atqa[1];
 538                 block0[7] = atqa[0];
 539         }
 540         PrintAndLog("new block 0:  %s", sprint_hex(block0, 16));
 541
 542         res = mfCSetBlock(0, block0, oldUID, false, cmdParams);
 543         if (res) {
 544                 PrintAndLog("Can't set block 0. Error: %d", res);
 545                 return res;
 546         }
 547
 548         return 0;
 549 }
 550
 551 int mfCIdentify() {
 552         UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};
 553         SendCommand(&c);
 554         UsbCommand resp;
 555         WaitForResponse(CMD_ACK,&resp);
 556
 557         uint8_t isGeneration = resp.arg[0] & 0xff;
 558         switch( isGeneration ){
 559                 case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break;
 560                 case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break;
 561                 default: PrintAndLog("No chinese magic backdoor command detected"); break;
 562         }
 563
 564         return (int) isGeneration;
 565 }
 566
 567
 568 // SNIFFER
 569
 570 // constants
 571 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 572
 573 // variables
 574 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 575 static uint8_t traceCard[4096] = {0x00};
 576 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 577 static int traceState = TRACE_IDLE;
 578 static uint8_t traceCurBlock = 0;
 579 static uint8_t traceCurKey = 0;
 580
 581 struct Crypto1State *traceCrypto1 = NULL;
 582
 583 struct Crypto1State *revstate;
 584 uint64_t lfsr;
 585 uint32_t ks2;
 586 uint32_t ks3;
 587
 588 uint32_t uid;     // serial number
 589 uint32_t nt;      // tag challenge
 590 uint32_t nr_enc;  // encrypted reader challenge
 591 uint32_t ar_enc;  // encrypted reader response
 592 uint32_t at_enc;  // encrypted tag response
 593
 594 int isTraceCardEmpty(void) {
 595         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 596 }
 597
 598 int isBlockEmpty(int blockN) {
 599         for (int i = 0; i < 16; i++)
 600                 if (traceCard[blockN * 16 + i] != 0) return 0;
 601
 602         return 1;
 603 }
 604
 605 int isBlockTrailer(int blockN) {
 606  return ((blockN & 0x03) == 0x03);
 607 }
 608
 609 int saveTraceCard(void) {
 610         FILE * f;
 611
 612         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 613
 614         f = fopen(traceFileName, "w+");
 615         if ( !f ) return 1;
 616
 617         for (int i = 0; i < 64; i++) {  // blocks
 618                 for (int j = 0; j < 16; j++)  // bytes
 619                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 620                 if (i < 63)
 621                         fprintf(f,"\n");
 622         }
 623         fclose(f);
 624         return 0;
 625 }
 626
 627 int loadTraceCard(uint8_t *tuid) {
 628         FILE * f;
 629         char buf[64] = {0x00};
 630         uint8_t buf8[64] = {0x00};
 631         int i, blockNum;
 632
 633         if (!isTraceCardEmpty())
 634                 saveTraceCard();
 635
 636         memset(traceCard, 0x00, 4096);
 637         memcpy(traceCard, tuid + 3, 4);
 638
 639         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 640
 641         f = fopen(traceFileName, "r");
 642         if (!f) return 1;
 643
 644         blockNum = 0;
 645
 646         while(!feof(f)){
 647
 648                 memset(buf, 0, sizeof(buf));
 649                 if (fgets(buf, sizeof(buf), f) == NULL) {
 650                         PrintAndLog("File reading error.");
 651                         fclose(f);
 652                         return 2;
 653         }
 654
 655                 if (strlen(buf) < 32){
 656                         if (feof(f)) break;
 657                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 658                         fclose(f);
 659                         return 2;
 660                 }
 661                 for (i = 0; i < 32; i += 2)
 662                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 663
 664                 memcpy(traceCard + blockNum * 16, buf8, 16);
 665
 666                 blockNum++;
 667         }
 668         fclose(f);
 669
 670         return 0;
 671 }
 672
 673 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 674
 675         if (traceCrypto1)
 676                 crypto1_destroy(traceCrypto1);
 677
 678         traceCrypto1 = NULL;
 679
 680         if (wantSaveToEmlFile)
 681                 loadTraceCard(tuid);
 682
 683         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 684         traceCard[5] = sak;
 685         memcpy(&traceCard[6], atqa, 2);
 686         traceCurBlock = 0;
 687         uid = bytes_to_num(tuid + 3, 4);
 688
 689         traceState = TRACE_IDLE;
 690
 691         return 0;
 692 }
 693
 694 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 695         uint8_t bt = 0;
 696         int i;
 697
 698         if (len != 1) {
 699                 for (i = 0; i < len; i++)
 700                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 701         } else {
 702                 bt = 0;
 703                 for (i = 0; i < 4; i++)
 704                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 705
 706                 data[0] = bt;
 707         }
 708         return;
 709 }
 710
 711
 712 int mfTraceDecode(uint8_t *data_src, int len, bool wantSaveToEmlFile) {
 713         uint8_t data[64];
 714
 715         if (traceState == TRACE_ERROR) return 1;
 716         if (len > 64) {
 717                 traceState = TRACE_ERROR;
 718                 return 1;
 719         }
 720
 721         memcpy(data, data_src, len);
 722         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 723                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 724                 PrintAndLog("dec> %s", sprint_hex(data, len));
 725                 AddLogHex(logHexFileName, "dec> ", data, len);
 726         }
 727
 728         switch (traceState) {
 729         case TRACE_IDLE:
 730                 // check packet crc16!
 731                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 732                         PrintAndLog("dec> CRC ERROR!!!");
 733                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 734                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 735                         return 1;
 736                 }
 737
 738                 // AUTHENTICATION
 739                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 740                         traceState = TRACE_AUTH1;
 741                         traceCurBlock = data[1];
 742                         traceCurKey = data[0] == 60 ? 1:0;
 743                         return 0;
 744                 }
 745
 746                 // READ
 747                 if ((len ==4) && ((data[0] == 0x30))) {
 748                         traceState = TRACE_READ_DATA;
 749                         traceCurBlock = data[1];
 750                         return 0;
 751                 }
 752
 753                 // WRITE
 754                 if ((len ==4) && ((data[0] == 0xA0))) {
 755                         traceState = TRACE_WRITE_OK;
 756                         traceCurBlock = data[1];
 757                         return 0;
 758                 }
 759
 760                 // HALT
 761                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 762                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 763                         return 0;
 764                 }
 765
 766                 return 0;
 767         break;
 768
 769         case TRACE_READ_DATA:
 770                 if (len == 18) {
 771                         traceState = TRACE_IDLE;
 772
 773                         if (isBlockTrailer(traceCurBlock)) {
 774                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 775                         } else {
 776                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 777                         }
 778                         if (wantSaveToEmlFile) saveTraceCard();
 779                         return 0;
 780                 } else {
 781                         traceState = TRACE_ERROR;
 782                         return 1;
 783                 }
 784         break;
 785
 786         case TRACE_WRITE_OK:
 787                 if ((len == 1) && (data[0] == 0x0a)) {
 788                         traceState = TRACE_WRITE_DATA;
 789
 790                         return 0;
 791                 } else {
 792                         traceState = TRACE_ERROR;
 793                         return 1;
 794                 }
 795         break;
 796
 797         case TRACE_WRITE_DATA:
 798                 if (len == 18) {
 799                         traceState = TRACE_IDLE;
 800
 801                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 802                         if (wantSaveToEmlFile) saveTraceCard();
 803                         return 0;
 804                 } else {
 805                         traceState = TRACE_ERROR;
 806                         return 1;
 807                 }
 808         break;
 809
 810         case TRACE_AUTH1:
 811                 if (len == 4) {
 812                         traceState = TRACE_AUTH2;
 813                         nt = bytes_to_num(data, 4);
 814                         return 0;
 815                 } else {
 816                         traceState = TRACE_ERROR;
 817                         return 1;
 818                 }
 819         break;
 820
 821         case TRACE_AUTH2:
 822                 if (len == 8) {
 823                         traceState = TRACE_AUTH_OK;
 824
 825                         nr_enc = bytes_to_num(data, 4);
 826                         ar_enc = bytes_to_num(data + 4, 4);
 827                         return 0;
 828                 } else {
 829                         traceState = TRACE_ERROR;
 830                         return 1;
 831                 }
 832         break;
 833
 834         case TRACE_AUTH_OK:
 835                 if (len ==4) {
 836                         traceState = TRACE_IDLE;
 837
 838                         if (!traceCrypto1) {
 839                                 at_enc = bytes_to_num(data, 4);
 840
 841                                 //  decode key here)
 842                                 ks2 = ar_enc ^ prng_successor(nt, 64);
 843                                 ks3 = at_enc ^ prng_successor(nt, 96);
 844                                 revstate = lfsr_recovery64(ks2, ks3);
 845                                 lfsr_rollback_word(revstate, 0, 0);
 846                                 lfsr_rollback_word(revstate, 0, 0);
 847                                 lfsr_rollback_word(revstate, nr_enc, 1);
 848                                 lfsr_rollback_word(revstate, uid ^ nt, 0);
 849
 850                                 crypto1_get_lfsr(revstate, &lfsr);
 851                                 printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
 852                                 AddLogUint64(logHexFileName, "key> ", lfsr);
 853                         } else {
 854                                 printf("key> nested not implemented!\n");
 855                                 at_enc = bytes_to_num(data, 4);
 856
 857                                 crypto1_destroy(traceCrypto1);
 858
 859                                 // not implemented
 860                                 traceState = TRACE_ERROR;
 861                         }
 862
 863                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 864                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 865
 866                         if (traceCurKey) {
 867                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 868                         } else {
 869                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 870                         }
 871                         if (wantSaveToEmlFile) saveTraceCard();
 872
 873                         if (traceCrypto1) {
 874                                 crypto1_destroy(traceCrypto1);
 875                         }
 876
 877                         // set cryptosystem state
 878                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 879                         return 0;
 880                 } else {
 881                         traceState = TRACE_ERROR;
 882                         return 1;
 883                 }
 884         break;
 885
 886         default:
 887                 traceState = TRACE_ERROR;
 888                 return 1;
 889         }
 890
 891         return 0;
 892 }
 893
 894 // DECODING
 895
 896 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
 897         /*
 898         uint32_t nt;      // tag challenge
 899         uint32_t ar_enc;  // encrypted reader response
 900         uint32_t at_enc;  // encrypted tag response
 901         */
 902         if (traceCrypto1) {
 903                 crypto1_destroy(traceCrypto1);
 904         }
 905         ks2 = ar_enc ^ prng_successor(nt, 64);
 906         ks3 = at_enc ^ prng_successor(nt, 96);
 907         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 908
 909         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 910
 911         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
 912         crypto1_destroy(traceCrypto1);
 913         return 0;
 914 }
 915
 916 /** validate_prng_nonce
 917  * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.
 918  * returns
 919  *   true = weak prng
 920  *   false = hardend prng
 921  */
 922 bool validate_prng_nonce(uint32_t nonce) {
 923         uint16_t *dist = 0;
 924         uint16_t x, i;
 925
 926         dist = malloc(2 << 16);
 927         if(!dist)
 928                 return -1;
 929
 930         // init prng table:
 931         for (x = i = 1; i; ++i) {
 932                 dist[(x & 0xff) << 8 | x >> 8] = i;
 933                 x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
 934         }
 935
 936         uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;
 937
 938         free(dist);
 939         return (res == 16);
 940 }
 941
 942 /* Detect Tag Prng,
 943 * function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
 944 * the tag nonce is check to see if it has a predictable PRNG.
 945 * @returns
 946 *       TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)
 947 *   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
 948 */
 949 int DetectClassicPrng(void){
 950
 951         UsbCommand resp, respA;
 952         uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA
 953         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;
 954
 955         UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
 956         memcpy(c.d.asBytes, cmd, sizeof(cmd));
 957
 958         clearCommandBuffer();
 959         SendCommand(&c);
 960         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {
 961         PrintAndLog("PRNG UID: Reply timeout.");
 962                 return -1;
 963         }
 964
 965         // if select tag failed.
 966         if (resp.arg[0] == 0) {
 967                 PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");
 968                 return -1;
 969         }
 970
 971         if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {
 972         PrintAndLog("PRNG data: Reply timeout.");
 973                 return -1;
 974         }
 975
 976         // check respA
 977         if (respA.arg[0] != 4) {
 978                 PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);
 979                 return -1;
 980         }
 981
 982         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
 983         return validate_prng_nonce(nonce);
 984 }