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 "comms.h"
  20 #include "usb_cmd.h"
  21 #include "cmdmain.h"
  22 #include "ui.h"
  23 #include "parity.h"
  24 #include "util.h"
  25 #include "iso14443crc.h"
  26
  27 #include "mifare.h"
  28
  29 // mifare tracer flags used in mfTraceDecode()
  30 #define TRACE_IDLE                                              0x00
  31 #define TRACE_AUTH1                                             0x01
  32 #define TRACE_AUTH2                                             0x02
  33 #define TRACE_AUTH_OK                                   0x03
  34 #define TRACE_READ_DATA                                 0x04
  35 #define TRACE_WRITE_OK                                  0x05
  36 #define TRACE_WRITE_DATA                                0x06
  37 #define TRACE_ERROR                                             0xFF
  38
  39
  40 static int compare_uint64(const void *a, const void *b) {
  41         // didn't work: (the result is truncated to 32 bits)
  42         //return (*(int64_t*)b - *(int64_t*)a);
  43
  44         // better:
  45         if (*(uint64_t*)b == *(uint64_t*)a) return 0;
  46         else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
  47         else return -1;
  48 }
  49
  50
  51 // create the intersection (common members) of two sorted lists. Lists are terminated by -1. Result will be in list1. Number of elements is returned.
  52 static uint32_t intersection(uint64_t *list1, uint64_t *list2)
  53 {
  54         if (list1 == NULL || list2 == NULL) {
  55                 return 0;
  56         }
  57         uint64_t *p1, *p2, *p3;
  58         p1 = p3 = list1;
  59         p2 = list2;
  60
  61         while ( *p1 != -1 && *p2 != -1 ) {
  62                 if (compare_uint64(p1, p2) == 0) {
  63                         *p3++ = *p1++;
  64                         p2++;
  65                 }
  66                 else {
  67                         while (compare_uint64(p1, p2) < 0) ++p1;
  68                         while (compare_uint64(p1, p2) > 0) ++p2;
  69                 }
  70         }
  71         *p3 = -1;
  72         return p3 - list1;
  73 }
  74
  75
  76 // Darkside attack (hf mf mifare)
  77 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) {
  78         struct Crypto1State *states;
  79         uint32_t i, pos;
  80         uint8_t bt, ks3x[8], par[8][8];
  81         uint64_t key_recovered;
  82         uint64_t *keylist;
  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, ar, 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, ar = 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 = (uint32_t)bytes_to_num(resp.d.asBytes + 24, 4);
 163                                 ar = (uint32_t)bytes_to_num(resp.d.asBytes + 28, 4);
 164                                 break;
 165                         }
 166                 }
 167
 168                 if (par_list == 0 && c.arg[0] == true) {
 169                         PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");
 170                 }
 171                 c.arg[0] = false;
 172
 173                 keycount = nonce2key(uid, nt, nr, ar, 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                 if (par_list == 0) {
 182                         qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
 183                         keycount = intersection(last_keylist, keylist);
 184                         if (keycount == 0) {
 185                                 free(last_keylist);
 186                                 last_keylist = keylist;
 187                                 continue;
 188                         }
 189                 }
 190
 191                 if (keycount > 1) {
 192                         PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
 193                 } else {
 194                         PrintAndLog("Found a possible key. Trying to authenticate...\n");
 195                 }
 196
 197                 *key = -1;
 198                 uint8_t keyBlock[USB_CMD_DATA_SIZE];
 199                 int max_keys = USB_CMD_DATA_SIZE/6;
 200                 for (int i = 0; i < keycount; i += max_keys) {
 201                         int size = keycount - i > max_keys ? max_keys : keycount - i;
 202                         for (int j = 0; j < size; j++) {
 203                                 if (par_list == 0) {
 204                                         num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock+(j*6));
 205                                 } else {
 206                                         num_to_bytes(keylist[i*max_keys + j], 6, keyBlock+(j*6));
 207                                 }
 208                         }
 209                         if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
 210                                 break;
 211                         }
 212                 }
 213
 214                 if (*key != -1) {
 215                         free(last_keylist);
 216                         free(keylist);
 217                         break;
 218                 } else {
 219                         PrintAndLog("Authentication failed. Trying again...");
 220                         free(last_keylist);
 221                         last_keylist = keylist;
 222                 }
 223         }
 224
 225         return 0;
 226 }
 227
 228
 229 int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 230
 231         *key = -1;
 232
 233         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType & 0xff) << 8)), clear_trace, keycnt}};
 234         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 235         SendCommand(&c);
 236
 237         UsbCommand resp;
 238         if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
 239         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 240         *key = bytes_to_num(resp.d.asBytes, 6);
 241         return 0;
 242 }
 243
 244 int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){
 245
 246         uint8_t keyPtr = 0;
 247
 248         if (e_sector == NULL)
 249                 return -1;
 250
 251         UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}};
 252         memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
 253         SendCommand(&c);
 254
 255         UsbCommand resp;
 256         if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth
 257         if ((resp.arg[0] & 0xff) != 0x01) return 2;
 258
 259         bool foundAKey = false;
 260         for(int sec = 0; sec < sectorCnt; sec++){
 261                 for(int keyAB = 0; keyAB < 2; keyAB++){
 262                         keyPtr = *(resp.d.asBytes + keyAB * 40 + sec);
 263                         if (keyPtr){
 264                                 e_sector[sec].foundKey[keyAB] = true;
 265                                 e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6);
 266                                 foundAKey = true;
 267                         }
 268                 }
 269         }
 270         return foundAKey ? 0 : 3;
 271 }
 272
 273 // Compare 16 Bits out of cryptostate
 274 int Compare16Bits(const void * a, const void * b) {
 275         if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
 276         else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
 277         else return -1;
 278 }
 279
 280 typedef
 281         struct {
 282                 union {
 283                         struct Crypto1State *slhead;
 284                         uint64_t *keyhead;
 285                 } head;
 286                 union {
 287                         struct Crypto1State *sltail;
 288                         uint64_t *keytail;
 289                 } tail;
 290                 uint32_t len;
 291                 uint32_t uid;
 292                 uint32_t blockNo;
 293                 uint32_t keyType;
 294                 uint32_t nt;
 295                 uint32_t ks1;
 296         } StateList_t;
 297
 298
 299 // wrapper function for multi-threaded lfsr_recovery32
 300 void
 301 #ifdef __has_attribute
 302 #if __has_attribute(force_align_arg_pointer)
 303 __attribute__((force_align_arg_pointer))
 304 #endif
 305 #endif
 306 *nested_worker_thread(void *arg)
 307 {
 308         struct Crypto1State *p1;
 309         StateList_t *statelist = arg;
 310
 311         statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
 312         for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
 313         statelist->len = p1 - statelist->head.slhead;
 314         statelist->tail.sltail = --p1;
 315         qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
 316
 317         return statelist->head.slhead;
 318 }
 319
 320
 321 int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
 322 {
 323         uint16_t i;
 324         uint32_t uid;
 325         UsbCommand resp;
 326
 327         StateList_t statelists[2];
 328         struct Crypto1State *p1, *p2, *p3, *p4;
 329
 330         // flush queue
 331         (void)WaitForResponseTimeout(CMD_ACK,NULL,100);
 332
 333         UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
 334         memcpy(c.d.asBytes, key, 6);
 335         SendCommand(&c);
 336
 337         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 338                 return -1;
 339         }
 340
 341         if (resp.arg[0]) {
 342                 return resp.arg[0];  // error during nested
 343         }
 344
 345         memcpy(&uid, resp.d.asBytes, 4);
 346         PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
 347
 348         for (i = 0; i < 2; i++) {
 349                 statelists[i].blockNo = resp.arg[2] & 0xff;
 350                 statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
 351                 statelists[i].uid = uid;
 352                 memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
 353                 memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
 354         }
 355
 356         // calc keys
 357
 358         pthread_t thread_id[2];
 359
 360         // create and run worker threads
 361         for (i = 0; i < 2; i++) {
 362                 pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
 363         }
 364
 365         // wait for threads to terminate:
 366         for (i = 0; i < 2; i++) {
 367                 pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
 368         }
 369
 370
 371         // the first 16 Bits of the cryptostate already contain part of our key.
 372         // Create the intersection of the two lists based on these 16 Bits and
 373         // roll back the cryptostate
 374         p1 = p3 = statelists[0].head.slhead;
 375         p2 = p4 = statelists[1].head.slhead;
 376         while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
 377                 if (Compare16Bits(p1, p2) == 0) {
 378                         struct Crypto1State savestate, *savep = &savestate;
 379                         savestate = *p1;
 380                         while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
 381                                 *p3 = *p1;
 382                                 lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
 383                                 p3++;
 384                                 p1++;
 385                         }
 386                         savestate = *p2;
 387                         while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
 388                                 *p4 = *p2;
 389                                 lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
 390                                 p4++;
 391                                 p2++;
 392                         }
 393                 }
 394                 else {
 395                         while (Compare16Bits(p1, p2) == -1) p1++;
 396                         while (Compare16Bits(p1, p2) == 1) p2++;
 397                 }
 398         }
 399         *(uint64_t*)p3 = -1;
 400         *(uint64_t*)p4 = -1;
 401         statelists[0].len = p3 - statelists[0].head.slhead;
 402         statelists[1].len = p4 - statelists[1].head.slhead;
 403         statelists[0].tail.sltail=--p3;
 404         statelists[1].tail.sltail=--p4;
 405
 406         // the statelists now contain possible keys. The key we are searching for must be in the
 407         // intersection of both lists. Create the intersection:
 408         qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
 409         qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
 410         statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
 411
 412         memset(resultKey, 0, 6);
 413         // The list may still contain several key candidates. Test each of them with mfCheckKeys
 414         for (i = 0; i < statelists[0].len; i++) {
 415                 uint8_t keyBlock[6];
 416                 uint64_t key64;
 417                 crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
 418                 num_to_bytes(key64, 6, keyBlock);
 419                 key64 = 0;
 420                 if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
 421                         num_to_bytes(key64, 6, resultKey);
 422                         break;
 423                 }
 424         }
 425
 426         free(statelists[0].head.slhead);
 427         free(statelists[1].head.slhead);
 428
 429         return 0;
 430 }
 431
 432 // EMULATOR
 433
 434 int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 435         UsbCommand c = {CMD_MIFARE_EML_MEMGET, {blockNum, blocksCount, 0}};
 436         SendCommand(&c);
 437
 438   UsbCommand resp;
 439         if (!WaitForResponseTimeout(CMD_ACK,&resp,1500)) return 1;
 440         memcpy(data, resp.d.asBytes, blocksCount * 16);
 441         return 0;
 442 }
 443
 444 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 445         UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
 446         memcpy(c.d.asBytes, data, blocksCount * 16);
 447         SendCommand(&c);
 448         return 0;
 449 }
 450
 451 // "MAGIC" CARD
 452
 453 int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 454         uint8_t isOK = 0;
 455
 456         UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 457         SendCommand(&c);
 458
 459         UsbCommand resp;
 460         if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 461                 isOK  = resp.arg[0] & 0xff;
 462                 memcpy(data, resp.d.asBytes, 16);
 463                 if (!isOK) return 2;
 464         } else {
 465                 PrintAndLog("Command execute timeout");
 466                 return 1;
 467         }
 468         return 0;
 469 }
 470
 471 int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 472
 473         uint8_t isOK = 0;
 474         UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
 475         memcpy(c.d.asBytes, data, 16);
 476         SendCommand(&c);
 477
 478         UsbCommand resp;
 479         if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 480                 isOK  = resp.arg[0] & 0xff;
 481                 if (uid != NULL)
 482                         memcpy(uid, resp.d.asBytes, 4);
 483                 if (!isOK)
 484                         return 2;
 485         } else {
 486                 PrintAndLog("Command execute timeout");
 487                 return 1;
 488         }
 489
 490         return 0;
 491 }
 492
 493 int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) {
 494         uint8_t isOK = 0;
 495         uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04;
 496         UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}};
 497         SendCommand(&c);
 498
 499         UsbCommand resp;
 500         WaitForResponse(CMD_ACK,&resp);
 501         isOK  = resp.arg[0] & 0xff;
 502
 503         return isOK;
 504 }
 505
 506 int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) {
 507         uint8_t oldblock0[16] = {0x00};
 508         uint8_t block0[16] = {0x00};
 509         int gen = 0, res;
 510
 511         gen = mfCIdentify();
 512
 513         /* generation 1a magic card by default */
 514         uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;
 515         if (gen == 2) {
 516                 /* generation 1b magic card */
 517                 cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;
 518         }
 519
 520         res = mfCGetBlock(0, oldblock0, cmdParams);
 521
 522         if (res == 0) {
 523                 memcpy(block0, oldblock0, 16);
 524                 PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
 525         } else {
 526                 PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
 527         }
 528
 529         // fill in the new values
 530         // UID
 531         memcpy(block0, uid, 4);
 532         // Mifare UID BCC
 533         block0[4] = block0[0] ^ block0[1] ^ block0[2] ^ block0[3];
 534         // mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
 535         if (sak != NULL)
 536                 block0[5] = sak[0];
 537         if (atqa != NULL) {
 538                 block0[6] = atqa[1];
 539                 block0[7] = atqa[0];
 540         }
 541         PrintAndLog("new block 0:  %s", sprint_hex(block0, 16));
 542
 543         res = mfCSetBlock(0, block0, oldUID, false, cmdParams);
 544         if (res) {
 545                 PrintAndLog("Can't set block 0. Error: %d", res);
 546                 return res;
 547         }
 548
 549         return 0;
 550 }
 551
 552 int mfCIdentify() {
 553         UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};
 554         SendCommand(&c);
 555         UsbCommand resp;
 556         WaitForResponse(CMD_ACK,&resp);
 557
 558         uint8_t isGeneration = resp.arg[0] & 0xff;
 559         switch( isGeneration ){
 560                 case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break;
 561                 case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break;
 562                 default: PrintAndLog("No chinese magic backdoor command detected"); break;
 563         }
 564
 565         return (int) isGeneration;
 566 }
 567
 568
 569 // SNIFFER
 570
 571 // constants
 572 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 573
 574 // variables
 575 char logHexFileName[FILE_PATH_SIZE] = {0x00};
 576 static uint8_t traceCard[4096] = {0x00};
 577 static char traceFileName[FILE_PATH_SIZE] = {0x00};
 578 static int traceState = TRACE_IDLE;
 579 static uint8_t traceCurBlock = 0;
 580 static uint8_t traceCurKey = 0;
 581
 582 struct Crypto1State *traceCrypto1 = NULL;
 583
 584 struct Crypto1State *revstate;
 585 uint64_t lfsr;
 586 uint64_t ui64Key;
 587 uint32_t ks2;
 588 uint32_t ks3;
 589
 590 uint32_t uid;       // serial number
 591 uint32_t nt;        // tag challenge
 592 uint32_t nt_enc;    // encrypted tag challenge
 593 uint8_t nt_enc_par; // encrypted tag challenge parity
 594 uint32_t nr_enc;    // encrypted reader challenge
 595 uint32_t ar_enc;    // encrypted reader response
 596 uint8_t ar_enc_par; // encrypted reader response parity
 597 uint32_t at_enc;    // encrypted tag response
 598 uint8_t at_enc_par; // encrypted tag response parity
 599
 600 int isTraceCardEmpty(void) {
 601         return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 602 }
 603
 604 int isBlockEmpty(int blockN) {
 605         for (int i = 0; i < 16; i++)
 606                 if (traceCard[blockN * 16 + i] != 0) return 0;
 607
 608         return 1;
 609 }
 610
 611 int isBlockTrailer(int blockN) {
 612  return ((blockN & 0x03) == 0x03);
 613 }
 614
 615 int saveTraceCard(void) {
 616         FILE * f;
 617
 618         if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
 619
 620         f = fopen(traceFileName, "w+");
 621         if ( !f ) return 1;
 622
 623         for (int i = 0; i < 64; i++) {  // blocks
 624                 for (int j = 0; j < 16; j++)  // bytes
 625                         fprintf(f, "%02x", *(traceCard + i * 16 + j));
 626                 if (i < 63)
 627                         fprintf(f,"\n");
 628         }
 629         fclose(f);
 630         return 0;
 631 }
 632
 633 int loadTraceCard(uint8_t *tuid) {
 634         FILE * f;
 635         char buf[64] = {0x00};
 636         uint8_t buf8[64] = {0x00};
 637         int i, blockNum;
 638
 639         if (!isTraceCardEmpty())
 640                 saveTraceCard();
 641
 642         memset(traceCard, 0x00, 4096);
 643         memcpy(traceCard, tuid + 3, 4);
 644
 645         FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 646
 647         f = fopen(traceFileName, "r");
 648         if (!f) return 1;
 649
 650         blockNum = 0;
 651
 652         while(!feof(f)){
 653
 654                 memset(buf, 0, sizeof(buf));
 655                 if (fgets(buf, sizeof(buf), f) == NULL) {
 656                         PrintAndLog("File reading error.");
 657                         fclose(f);
 658                         return 2;
 659         }
 660
 661                 if (strlen(buf) < 32){
 662                         if (feof(f)) break;
 663                         PrintAndLog("File content error. Block data must include 32 HEX symbols");
 664                         fclose(f);
 665                         return 2;
 666                 }
 667                 for (i = 0; i < 32; i += 2)
 668                         sscanf(&buf[i], "%02x", (unsigned int *)&buf8[i / 2]);
 669
 670                 memcpy(traceCard + blockNum * 16, buf8, 16);
 671
 672                 blockNum++;
 673         }
 674         fclose(f);
 675
 676         return 0;
 677 }
 678
 679 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 680
 681         if (traceCrypto1)
 682                 crypto1_destroy(traceCrypto1);
 683
 684         traceCrypto1 = NULL;
 685
 686         if (wantSaveToEmlFile)
 687                 loadTraceCard(tuid);
 688
 689         traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 690         traceCard[5] = sak;
 691         memcpy(&traceCard[6], atqa, 2);
 692         traceCurBlock = 0;
 693         uid = bytes_to_num(tuid + 3, 4);
 694
 695         traceState = TRACE_IDLE;
 696
 697         return 0;
 698 }
 699
 700 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 701         uint8_t bt = 0;
 702         int i;
 703
 704         if (len != 1) {
 705                 for (i = 0; i < len; i++)
 706                         data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
 707         } else {
 708                 bt = 0;
 709                 for (i = 0; i < 4; i++)
 710                         bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
 711
 712                 data[0] = bt;
 713         }
 714         return;
 715 }
 716
 717 bool NTParityCheck(uint32_t ntx) {
 718         if (
 719                 (oddparity8(ntx >> 8 & 0xff) ^ (ntx & 0x01) ^ ((nt_enc_par >> 5) & 0x01) ^ (nt_enc & 0x01)) ||
 720                 (oddparity8(ntx >> 16 & 0xff) ^ (ntx >> 8 & 0x01) ^ ((nt_enc_par >> 6) & 0x01) ^ (nt_enc >> 8 & 0x01)) ||
 721                 (oddparity8(ntx >> 24 & 0xff) ^ (ntx >> 16 & 0x01) ^ ((nt_enc_par >> 7) & 0x01) ^ (nt_enc >> 16 & 0x01))
 722                 )
 723                 return false;
 724
 725         uint32_t ar = prng_successor(ntx, 64);
 726         if (
 727                 (oddparity8(ar >> 8 & 0xff) ^ (ar & 0x01) ^ ((ar_enc_par >> 5) & 0x01) ^ (ar_enc & 0x01)) ||
 728                 (oddparity8(ar >> 16 & 0xff) ^ (ar >> 8 & 0x01) ^ ((ar_enc_par >> 6) & 0x01) ^ (ar_enc >> 8 & 0x01)) ||
 729                 (oddparity8(ar >> 24 & 0xff) ^ (ar >> 16 & 0x01) ^ ((ar_enc_par >> 7) & 0x01) ^ (ar_enc >> 16 & 0x01))
 730                 )
 731                 return false;
 732
 733         uint32_t at = prng_successor(ntx, 96);
 734         if (
 735                 (oddparity8(ar & 0xff) ^ (at >> 24 & 0x01) ^ ((ar_enc_par >> 4) & 0x01) ^ (at_enc >> 24 & 0x01)) ||
 736                 (oddparity8(at >> 8 & 0xff) ^ (at & 0x01) ^ ((at_enc_par >> 5) & 0x01) ^ (at_enc & 0x01)) ||
 737                 (oddparity8(at >> 16 & 0xff) ^ (at >> 8 & 0x01) ^ ((at_enc_par >> 6) & 0x01) ^ (at_enc >> 8 & 0x01)) ||
 738                 (oddparity8(at >> 24 & 0xff) ^ (at >> 16 & 0x01) ^ ((at_enc_par >> 7) & 0x01) ^ (at_enc >> 16 & 0x01))
 739                 )
 740                 return false;
 741
 742         return true;
 743 }
 744
 745
 746 int mfTraceDecode(uint8_t *data_src, int len, uint8_t parity, bool wantSaveToEmlFile) {
 747         uint8_t data[64];
 748
 749         if (traceState == TRACE_ERROR) return 1;
 750         if (len > 64) {
 751                 traceState = TRACE_ERROR;
 752                 return 1;
 753         }
 754
 755         memcpy(data, data_src, len);
 756         if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 757                 mf_crypto1_decrypt(traceCrypto1, data, len, 0);
 758                 uint8_t parity[16];
 759                 oddparitybuf(data, len, parity);
 760                 PrintAndLog("dec> %s [%s]", sprint_hex(data, len), printBitsPar(parity, len));
 761                 AddLogHex(logHexFileName, "dec> ", data, len);
 762         }
 763
 764         switch (traceState) {
 765         case TRACE_IDLE:
 766                 // check packet crc16!
 767                 if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 768                         PrintAndLog("dec> CRC ERROR!!!");
 769                         AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 770                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 771                         return 1;
 772                 }
 773
 774                 // AUTHENTICATION
 775                 if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 776                         traceState = TRACE_AUTH1;
 777                         traceCurBlock = data[1];
 778                         traceCurKey = data[0] == 60 ? 1:0;
 779                         return 0;
 780                 }
 781
 782                 // READ
 783                 if ((len ==4) && ((data[0] == 0x30))) {
 784                         traceState = TRACE_READ_DATA;
 785                         traceCurBlock = data[1];
 786                         return 0;
 787                 }
 788
 789                 // WRITE
 790                 if ((len ==4) && ((data[0] == 0xA0))) {
 791                         traceState = TRACE_WRITE_OK;
 792                         traceCurBlock = data[1];
 793                         return 0;
 794                 }
 795
 796                 // HALT
 797                 if ((len ==4) && ((data[0] == 0x50) && (data[1] == 0x00))) {
 798                         traceState = TRACE_ERROR;  // do not decrypt the next commands
 799                         return 0;
 800                 }
 801
 802                 return 0;
 803         break;
 804
 805         case TRACE_READ_DATA:
 806                 if (len == 18) {
 807                         traceState = TRACE_IDLE;
 808
 809                         if (isBlockTrailer(traceCurBlock)) {
 810                                 memcpy(traceCard + traceCurBlock * 16 + 6, data + 6, 4);
 811                         } else {
 812                                 memcpy(traceCard + traceCurBlock * 16, data, 16);
 813                         }
 814                         if (wantSaveToEmlFile) saveTraceCard();
 815                         return 0;
 816                 } else {
 817                         traceState = TRACE_ERROR;
 818                         return 1;
 819                 }
 820         break;
 821
 822         case TRACE_WRITE_OK:
 823                 if ((len == 1) && (data[0] == 0x0a)) {
 824                         traceState = TRACE_WRITE_DATA;
 825
 826                         return 0;
 827                 } else {
 828                         traceState = TRACE_ERROR;
 829                         return 1;
 830                 }
 831         break;
 832
 833         case TRACE_WRITE_DATA:
 834                 if (len == 18) {
 835                         traceState = TRACE_IDLE;
 836
 837                         memcpy(traceCard + traceCurBlock * 16, data, 16);
 838                         if (wantSaveToEmlFile) saveTraceCard();
 839                         return 0;
 840                 } else {
 841                         traceState = TRACE_ERROR;
 842                         return 1;
 843                 }
 844         break;
 845
 846         case TRACE_AUTH1:
 847                 if (len == 4) {
 848                         traceState = TRACE_AUTH2;
 849                         if (!traceCrypto1) {
 850                                 nt = bytes_to_num(data, 4);
 851                         } else {
 852                                 nt_enc = bytes_to_num(data, 4);
 853                                 nt_enc_par = parity;
 854                         }
 855                         return 0;
 856                 } else {
 857                         traceState = TRACE_ERROR;
 858                         return 1;
 859                 }
 860         break;
 861
 862         case TRACE_AUTH2:
 863                 if (len == 8) {
 864                         traceState = TRACE_AUTH_OK;
 865
 866                         nr_enc = bytes_to_num(data, 4);
 867                         ar_enc = bytes_to_num(data + 4, 4);
 868                         ar_enc_par = parity << 4;
 869                         return 0;
 870                 } else {
 871                         traceState = TRACE_ERROR;
 872                         return 1;
 873                 }
 874         break;
 875
 876         case TRACE_AUTH_OK:
 877                 if (len ==4) {
 878                         traceState = TRACE_IDLE;
 879
 880                         at_enc = bytes_to_num(data, 4);
 881                         at_enc_par = parity;
 882                         if (!traceCrypto1) {
 883
 884                                 //  decode key here)
 885                                 ks2 = ar_enc ^ prng_successor(nt, 64);
 886                                 ks3 = at_enc ^ prng_successor(nt, 96);
 887                                 revstate = lfsr_recovery64(ks2, ks3);
 888                                 lfsr_rollback_word(revstate, 0, 0);
 889                                 lfsr_rollback_word(revstate, 0, 0);
 890                                 lfsr_rollback_word(revstate, nr_enc, 1);
 891                                 lfsr_rollback_word(revstate, uid ^ nt, 0);
 892
 893                                 crypto1_get_lfsr(revstate, &lfsr);
 894                                 crypto1_destroy(revstate);
 895                                 ui64Key = lfsr;
 896                                 printf("key> probable key:%x%x Prng:%s ks2:%08x ks3:%08x\n",
 897                                         (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF),
 898                                         validate_prng_nonce(nt) ? "WEAK": "HARDEND",
 899                                         ks2,
 900                                         ks3);
 901                                 AddLogUint64(logHexFileName, "key> ", lfsr);
 902                         } else {
 903                                 if (validate_prng_nonce(nt)) {
 904                                         struct Crypto1State *pcs;
 905                                         pcs = crypto1_create(ui64Key);
 906                                         uint32_t nt1 = crypto1_word(pcs, nt_enc ^ uid, 1) ^ nt_enc;
 907                                         uint32_t ar = prng_successor(nt1, 64);
 908                                         uint32_t at = prng_successor(nt1, 96);
 909                                         printf("key> nested auth uid: %08x nt: %08x nt_parity: %s ar: %08x at: %08x\n", uid, nt1, printBitsPar(&nt_enc_par, 4), ar, at);
 910                                         uint32_t nr1 = crypto1_word(pcs, nr_enc, 1) ^ nr_enc;
 911                                         uint32_t ar1 = crypto1_word(pcs, 0, 0) ^ ar_enc;
 912                                         uint32_t at1 = crypto1_word(pcs, 0, 0) ^ at_enc;
 913                                         crypto1_destroy(pcs);
 914                                         printf("key> the same key test. nr1: %08x ar1: %08x at1: %08x \n", nr1, ar1, at1);
 915
 916                                         if (NTParityCheck(nt1))
 917                                                 printf("key> the same key test OK. key=%x%x\n", (unsigned int)((ui64Key & 0xFFFFFFFF00000000) >> 32), (unsigned int)(ui64Key & 0xFFFFFFFF));
 918                                         else
 919                                                 printf("key> the same key test. check nt parity error.\n");
 920
 921                                         uint32_t ntc = prng_successor(nt, 90);
 922                                         uint32_t ntx = 0;
 923                                         int ntcnt = 0;
 924                                         for (int i = 0; i < 16383; i++) {
 925                                                 ntc = prng_successor(ntc, 1);
 926                                                 if (NTParityCheck(ntc)){
 927                                                         if (!ntcnt)
 928                                                                 ntx = ntc;
 929                                                         ntcnt++;
 930                                                 }
 931                                         }
 932                                         if (ntcnt)
 933                                                 printf("key> nt candidate=%08x nonce distance=%d candidates count=%d\n", ntx, nonce_distance(nt, ntx), ntcnt);
 934                                         else
 935                                                 printf("key> don't have any nt candidate( \n");
 936
 937                                         nt = ntx;
 938                                         ks2 = ar_enc ^ prng_successor(ntx, 64);
 939                                         ks3 = at_enc ^ prng_successor(ntx, 96);
 940
 941                                         // decode key
 942                                         revstate = lfsr_recovery64(ks2, ks3);
 943                                         lfsr_rollback_word(revstate, 0, 0);
 944                                         lfsr_rollback_word(revstate, 0, 0);
 945                                         lfsr_rollback_word(revstate, nr_enc, 1);
 946                                         lfsr_rollback_word(revstate, uid ^ nt, 0);
 947
 948                                         crypto1_get_lfsr(revstate, &lfsr);
 949                                         crypto1_destroy(revstate);
 950                                         ui64Key = lfsr;
 951                                         printf("key> probable key:%x%x  ks2:%08x ks3:%08x\n",
 952                                                 (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF),
 953                                                 ks2,
 954                                                 ks3);
 955                                         AddLogUint64(logHexFileName, "key> ", lfsr);
 956                                 } else {
 957                                         printf("key> hardnested not implemented!\n");
 958
 959                                         crypto1_destroy(traceCrypto1);
 960
 961                                         // not implemented
 962                                         traceState = TRACE_ERROR;
 963                                 }
 964                         }
 965
 966                         int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 967                         if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
 968
 969                         if (traceCurKey) {
 970                                 num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 971                         } else {
 972                                 num_to_bytes(lfsr, 6, traceCard + blockShift);
 973                         }
 974                         if (wantSaveToEmlFile) saveTraceCard();
 975
 976                         if (traceCrypto1) {
 977                                 crypto1_destroy(traceCrypto1);
 978                         }
 979
 980                         // set cryptosystem state
 981                         traceCrypto1 = lfsr_recovery64(ks2, ks3);
 982                         return 0;
 983                 } else {
 984                         traceState = TRACE_ERROR;
 985                         return 1;
 986                 }
 987         break;
 988
 989         default:
 990                 traceState = TRACE_ERROR;
 991                 return 1;
 992         }
 993
 994         return 0;
 995 }
 996
 997 // DECODING
 998
 999 int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
1000         /*
1001         uint32_t nt;      // tag challenge
1002         uint32_t ar_enc;  // encrypted reader response
1003         uint32_t at_enc;  // encrypted tag response
1004         */
1005         if (traceCrypto1) {
1006                 crypto1_destroy(traceCrypto1);
1007         }
1008         ks2 = ar_enc ^ prng_successor(nt, 64);
1009         ks3 = at_enc ^ prng_successor(nt, 96);
1010         traceCrypto1 = lfsr_recovery64(ks2, ks3);
1011
1012         mf_crypto1_decrypt(traceCrypto1, data, len, 0);
1013
1014         PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
1015         crypto1_destroy(traceCrypto1);
1016         return 0;
1017 }
1018
1019 /** validate_prng_nonce
1020  * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.
1021  * returns
1022  *   true = weak prng
1023  *   false = hardend prng
1024  */
1025 bool validate_prng_nonce(uint32_t nonce) {
1026         uint16_t *dist = 0;
1027         uint16_t x, i;
1028
1029         dist = malloc(2 << 16);
1030         if(!dist)
1031                 return -1;
1032
1033         // init prng table:
1034         for (x = i = 1; i; ++i) {
1035                 dist[(x & 0xff) << 8 | x >> 8] = i;
1036                 x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
1037         }
1038
1039         uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;
1040
1041         free(dist);
1042         return (res == 16);
1043 }
1044
1045 /* Detect Tag Prng,
1046 * function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
1047 * the tag nonce is check to see if it has a predictable PRNG.
1048 * @returns
1049 *       TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)
1050 *   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
1051 */
1052 int DetectClassicPrng(void){
1053
1054         UsbCommand resp, respA;
1055         uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA
1056         uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;
1057
1058         UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
1059         memcpy(c.d.asBytes, cmd, sizeof(cmd));
1060
1061         clearCommandBuffer();
1062         SendCommand(&c);
1063         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {
1064         PrintAndLog("PRNG UID: Reply timeout.");
1065                 return -1;
1066         }
1067
1068         // if select tag failed.
1069         if (resp.arg[0] == 0) {
1070                 PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");
1071                 return -1;
1072         }
1073
1074         if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {
1075         PrintAndLog("PRNG data: Reply timeout.");
1076                 return -1;
1077         }
1078
1079         // check respA
1080         if (respA.arg[0] != 4) {
1081                 PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);
1082                 return -1;
1083         }
1084
1085         uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
1086         return validate_prng_nonce(nonce);
1087 }