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

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
   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 // High frequency Legic commands
   9 //-----------------------------------------------------------------------------
  10 #include "cmdhflegic.h"
  11
  12 static int CmdHelp(const char *Cmd);
  13
  14 int usage_legic_calccrc8(void){
  15         PrintAndLog("Calculates the legic crc8/crc16 on the input hexbytes.");
  16         PrintAndLog("There must be an even number of hexsymbols as input.");
  17         PrintAndLog("Usage:  hf legic crc8 [h] b <hexbytes> u <uidcrc> c <crc type>");
  18         PrintAndLog("Options:");
  19         PrintAndLog("      b <hexbytes>  : hex bytes");
  20         PrintAndLog("      u <uidcrc>    : MCC hexbyte");
  21         PrintAndLog("      c <crc type>  : 8|16 bit crc size");
  22         PrintAndLog("");
  23         PrintAndLog("Samples:");
  24         PrintAndLog("      hf legic crc8 b deadbeef1122");
  25         PrintAndLog("      hf legic crc8 b deadbeef1122 u 9A c 16");
  26         return 0;
  27 }
  28
  29 int usage_legic_load(void){
  30         PrintAndLog("It loads datasamples from the file `filename` to device memory");
  31         PrintAndLog("Usage:  hf legic load <file name>");
  32         PrintAndLog("");
  33         PrintAndLog("Samples:");
  34         PrintAndLog("      hf legic load filename");
  35         return 0;
  36 }
  37
  38 int usage_legic_read(void){
  39         PrintAndLog("Read data from a legic tag.");
  40         PrintAndLog("Usage:  hf legic read <offset> <num of bytes>");
  41         PrintAndLog("Options:");
  42         PrintAndLog("  <offset>        : offset in data array to start download from");
  43         PrintAndLog("  <num of bytes>  : number of bytes to download");
  44         PrintAndLog("");
  45         PrintAndLog("Samples:");
  46         PrintAndLog("      hf legic read");
  47         return 0;
  48 }
  49
  50 /*
  51  *  Output BigBuf and deobfuscate LEGIC RF tag data.
  52  *  This is based on information given in the talk held
  53  *  by Henryk Ploetz and Karsten Nohl at 26c3
  54  */
  55 int CmdLegicDecode(const char *Cmd) {
  56         // Index for the bytearray.
  57         int i = 0;
  58         int k = 0, segmentNum;
  59         int segment_len = 0;
  60         int segment_flag = 0;
  61         uint8_t stamp_len = 0;
  62         int crc = 0;
  63         int wrp = 0;
  64         int wrc = 0;
  65         uint8_t data_buf[1052]; // receiver buffer,  should be 1024..
  66         char token_type[5];
  67         int dcf;
  68         int bIsSegmented = 0;
  69
  70         // download EML memory, where the "legic read" command puts the data.
  71         GetEMLFromBigBuf(data_buf, sizeof(data_buf), 0);
  72         if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2000)){
  73                 PrintAndLog("Command execute timeout");
  74                 return 1;
  75         }
  76
  77         // Output CDF System area (9 bytes) plus remaining header area (12 bytes)
  78         crc = data_buf[4];
  79         uint32_t calc_crc =  CRC8Legic(data_buf, 4);
  80
  81         PrintAndLog("\nCDF: System Area");
  82         PrintAndLog("------------------------------------------------------");
  83         PrintAndLog("MCD: %02x, MSN: %02x %02x %02x, MCC: %02x %s",
  84                 data_buf[0],
  85                 data_buf[1],
  86                 data_buf[2],
  87                 data_buf[3],
  88                 data_buf[4],
  89                 (calc_crc == crc) ? "OK":"Fail"
  90         );
  91
  92
  93         token_type[0] = 0;
  94         dcf = ((int)data_buf[6] << 8) | (int)data_buf[5];
  95
  96         // New unwritten media?
  97         if(dcf == 0xFFFF) {
  98
  99                 PrintAndLog("DCF: %d (%02x %02x), Token Type=NM (New Media)",
 100                         dcf,
 101                         data_buf[5],
 102                         data_buf[6]
 103                 );
 104
 105         } else if(dcf > 60000) {                // Master token?
 106
 107                 int fl = 0;
 108
 109                 if(data_buf[6] == 0xec) {
 110                         strncpy(token_type, "XAM", sizeof(token_type));
 111                         fl = 1;
 112                         stamp_len = 0x0c - (data_buf[5] >> 4);
 113                 } else {
 114         switch (data_buf[5] & 0x7f) {
 115                 case 0x00 ... 0x2f:
 116                         strncpy(token_type, "IAM",sizeof(token_type));
 117                                         fl = (0x2f - (data_buf[5] & 0x7f)) + 1;
 118                         break;
 119                 case 0x30 ... 0x6f:
 120                         strncpy(token_type, "SAM",sizeof(token_type));
 121                                         fl = (0x6f - (data_buf[5] & 0x7f)) + 1;
 122                         break;
 123                 case 0x70 ... 0x7f:
 124                         strncpy(token_type, "GAM",sizeof(token_type));
 125                                         fl = (0x7f - (data_buf[5] & 0x7f)) + 1;
 126                         break;
 127         }
 128
 129         stamp_len = 0xfc - data_buf[6];
 130                 }
 131
 132                 PrintAndLog("DCF: %d (%02x %02x), Token Type=%s (OLE=%01u), OL=%02u, FL=%02u",
 133                         dcf,
 134                 data_buf[5],
 135                 data_buf[6],
 136                 token_type,
 137                 (data_buf[5]&0x80)>>7,
 138                         stamp_len,
 139                         fl
 140         );
 141
 142         } else {                                                // Is IM(-S) type of card...
 143
 144                 if(data_buf[7] == 0x9F && data_buf[8] == 0xFF) {
 145                         bIsSegmented = 1;
 146                         strncpy(token_type, "IM-S", sizeof(token_type));
 147                 } else {
 148                         strncpy(token_type, "IM", sizeof(token_type));
 149                 }
 150
 151                 PrintAndLog("DCF: %d (%02x %02x), Token Type=%s (OLE=%01u)",
 152                         dcf,
 153                         data_buf[5],
 154                         data_buf[6],
 155                         token_type,
 156                         (data_buf[5]&0x80)>>7
 157                 );
 158         }
 159
 160         // Makes no sence to show this on blank media...
 161         if(dcf != 0xFFFF) {
 162
 163                 if(bIsSegmented) {
 164                         PrintAndLog("WRP=%02u, WRC=%01u, RD=%01u, SSC=%02x",
 165                 data_buf[7]&0x0f,
 166                 (data_buf[7]&0x70)>>4,
 167                 (data_buf[7]&0x80)>>7,
 168                 data_buf[8]
 169         );
 170                 }
 171
 172                 // Header area is only available on IM-S cards, on master tokens this data is the master token data itself
 173                 if(bIsSegmented || dcf > 60000) {
 174                         if(dcf > 60000) {
 175                                 PrintAndLog("Master token data");
 176                                 PrintAndLog("%s", sprint_hex(data_buf+8, 14));
 177                         } else {
 178         PrintAndLog("Remaining Header Area");
 179         PrintAndLog("%s", sprint_hex(data_buf+9, 13));
 180                         }
 181                 }
 182         }
 183
 184
 185         uint8_t segCrcBytes[8] = {0x00};
 186         uint32_t segCalcCRC = 0;
 187         uint32_t segCRC = 0;
 188
 189
 190         // Data card?
 191         if(dcf <= 60000) {
 192
 193         PrintAndLog("\nADF: User Area");
 194         PrintAndLog("------------------------------------------------------");
 195
 196                 if(bIsSegmented) {
 197
 198                         // Data start point on segmented cards
 199         i = 22;
 200
 201                         // decode segments
 202                         for (segmentNum=1; segmentNum < 128; segmentNum++ )
 203                         {
 204                 segment_len = ((data_buf[i+1]^crc)&0x0f) * 256 + (data_buf[i]^crc);
 205                 segment_flag = ((data_buf[i+1]^crc)&0xf0)>>4;
 206                 wrp = (data_buf[i+2]^crc);
 207                 wrc = ((data_buf[i+3]^crc)&0x70)>>4;
 208
 209                 bool hasWRC = (wrc > 0);
 210                 bool hasWRP = (wrp > wrc);
 211                 int wrp_len = (wrp - wrc);
 212                 int remain_seg_payload_len = (segment_len - wrp - 5);
 213
 214                 // validate segment-crc
 215                 segCrcBytes[0]=data_buf[0];                     //uid0
 216                 segCrcBytes[1]=data_buf[1];                     //uid1
 217                 segCrcBytes[2]=data_buf[2];                     //uid2
 218                 segCrcBytes[3]=data_buf[3];                     //uid3
 219                 segCrcBytes[4]=(data_buf[i]^crc);       //hdr0
 220                 segCrcBytes[5]=(data_buf[i+1]^crc); //hdr1
 221                 segCrcBytes[6]=(data_buf[i+2]^crc); //hdr2
 222                 segCrcBytes[7]=(data_buf[i+3]^crc); //hdr3
 223
 224                 segCalcCRC = CRC8Legic(segCrcBytes, 8);
 225                 segCRC = data_buf[i+4]^crc;
 226
 227                 PrintAndLog("Segment %02u \nraw header | 0x%02X 0x%02X 0x%02X 0x%02X \nSegment len: %u,  Flag: 0x%X (valid:%01u, last:%01u), WRP: %02u, WRC: %02u, RD: %01u, CRC: 0x%02X (%s)",
 228                         segmentNum,
 229                         data_buf[i]^crc,
 230                         data_buf[i+1]^crc,
 231                         data_buf[i+2]^crc,
 232                         data_buf[i+3]^crc,
 233                         segment_len,
 234                         segment_flag,
 235                         (segment_flag & 0x4) >> 2,
 236                         (segment_flag & 0x8) >> 3,
 237                         wrp,
 238                         wrc,
 239                         ((data_buf[i+3]^crc) & 0x80) >> 7,
 240                         segCRC,
 241                         ( segCRC == segCalcCRC ) ? "OK" : "fail"
 242                 );
 243
 244                 i += 5;
 245
 246                 if ( hasWRC ) {
 247                         PrintAndLog("WRC protected area:   (I %d | K %d| WRC %d)", i, k, wrc);
 248                         PrintAndLog("\nrow  | data");
 249                         PrintAndLog("-----+------------------------------------------------");
 250
 251                                         for ( k=i; k < (i+wrc); ++k)
 252                                         data_buf[k] ^= crc;
 253
 254                         print_hex_break( data_buf+i, wrc, 16);
 255
 256                         i += wrc;
 257                 }
 258
 259                 if ( hasWRP ) {
 260                         PrintAndLog("Remaining write protected area:  (I %d | K %d | WRC %d | WRP %d  WRP_LEN %d)",i, k, wrc, wrp, wrp_len);
 261                         PrintAndLog("\nrow  | data");
 262                         PrintAndLog("-----+------------------------------------------------");
 263
 264                                         for (k=i; k < (i+wrp_len); ++k)
 265                                         data_buf[k] ^= crc;
 266
 267                         print_hex_break( data_buf+i, wrp_len, 16);
 268
 269                         i += wrp_len;
 270
 271                                         // does this one work? (Answer: Only if KGH/BGH is used with BCD encoded card number! So maybe this will show just garbage...)
 272                         if( wrp_len == 8 )
 273                                 PrintAndLog("Card ID: %2X%02X%02X", data_buf[i-4]^crc, data_buf[i-3]^crc, data_buf[i-2]^crc);
 274                 }
 275
 276                 PrintAndLog("Remaining segment payload:  (I %d | K %d | Remain LEN %d)", i, k, remain_seg_payload_len);
 277                 PrintAndLog("\nrow  | data");
 278                 PrintAndLog("-----+------------------------------------------------");
 279
 280                                 for ( k=i; k < (i+remain_seg_payload_len); ++k)
 281                                 data_buf[k] ^= crc;
 282
 283                 print_hex_break( data_buf+i, remain_seg_payload_len, 16);
 284
 285                 i += remain_seg_payload_len;
 286
 287                 PrintAndLog("-----+------------------------------------------------\n");
 288
 289                 // end with last segment
 290                 if (segment_flag & 0x8) return 0;
 291
 292         } // end for loop
 293
 294                 } else {
 295
 296                         // Data start point on unsegmented cards
 297                         i = 8;
 298
 299                         wrp          = data_buf[7] & 0x0F;
 300                         wrc          = (data_buf[7] & 0x07) >> 4;
 301
 302                         bool hasWRC = (wrc > 0);
 303                         bool hasWRP = (wrp > wrc);
 304                         int wrp_len = (wrp - wrc);
 305                         int remain_seg_payload_len = (1024 - 22 - wrp); // Any chance to get physical card size here!?
 306
 307                         PrintAndLog("Unsegmented card - WRP: %02u, WRC: %02u, RD: %01u",
 308                                 wrp,
 309                                 wrc,
 310                                 (data_buf[7] & 0x80) >> 7
 311                         );
 312
 313                         if ( hasWRC ) {
 314                                 PrintAndLog("WRC protected area:   (I %d | WRC %d)", i, wrc);
 315                                 PrintAndLog("\nrow  | data");
 316                                 PrintAndLog("-----+------------------------------------------------");
 317                                 print_hex_break( data_buf+i, wrc, 16);
 318                                 i += wrc;
 319                         }
 320
 321                         if ( hasWRP ) {
 322                                 PrintAndLog("Remaining write protected area:  (I %d | WRC %d | WRP %d | WRP_LEN %d)", i, wrc, wrp, wrp_len);
 323                                 PrintAndLog("\nrow  | data");
 324                                 PrintAndLog("-----+------------------------------------------------");
 325                                 print_hex_break( data_buf+i, wrp_len, 16);
 326                                 i += wrp_len;
 327
 328                                 // does this one work? (Answer: Only if KGH/BGH is used with BCD encoded card number! So maybe this will show just garbage...)
 329                                 if( wrp_len == 8 )
 330                                         PrintAndLog("Card ID: %2X%02X%02X", data_buf[i-4], data_buf[i-3], data_buf[i-2]);
 331                         }
 332
 333                         PrintAndLog("Remaining segment payload:  (I %d | Remain LEN %d)", i, remain_seg_payload_len);
 334                         PrintAndLog("\nrow  | data");
 335                         PrintAndLog("-----+------------------------------------------------");
 336                         print_hex_break( data_buf+i, remain_seg_payload_len, 16);
 337                         i += remain_seg_payload_len;
 338
 339                         PrintAndLog("-----+------------------------------------------------\n");
 340                 }
 341         }
 342
 343         return 0;
 344 }
 345
 346 int CmdLegicRFRead(const char *Cmd) {
 347
 348         // params:
 349         // offset in data
 350         // number of bytes.
 351         char cmdp = param_getchar(Cmd, 0);
 352         if ( cmdp == 'H' || cmdp == 'h' ) return usage_legic_read();
 353
 354         int byte_count=0, offset=0;
 355         sscanf(Cmd, "%i %i", &offset, &byte_count);
 356         if(byte_count == 0) byte_count = -1;
 357         if(byte_count + offset > 1024) byte_count = 1024 - offset;
 358
 359         UsbCommand c= {CMD_READER_LEGIC_RF, {offset, byte_count, 0}};
 360         clearCommandBuffer();
 361         SendCommand(&c);
 362         return 0;
 363 }
 364
 365 int CmdLegicLoad(const char *Cmd) {
 366
 367         char cmdp = param_getchar(Cmd, 0);
 368         if ( cmdp == 'H' || cmdp == 'h' || cmdp == 0x00) return usage_legic_load();
 369
 370         char filename[FILE_PATH_SIZE] = {0x00};
 371         int len = strlen(Cmd);
 372
 373         if (len > FILE_PATH_SIZE) {
 374                 PrintAndLog("Filepath too long (was %s bytes), max allowed is %s ", len, FILE_PATH_SIZE);
 375                 return 0;
 376         }
 377         memcpy(filename, Cmd, len);
 378
 379     FILE *f = fopen(filename, "r");
 380     if(!f) {
 381         PrintAndLog("couldn't open '%s'", Cmd);
 382         return -1;
 383     }
 384
 385     char line[80];
 386         int offset = 0;
 387         uint8_t data[USB_CMD_DATA_SIZE] = {0x00};
 388         int index = 0;
 389         int totalbytes = 0;
 390     while ( fgets(line, sizeof(line), f) ) {
 391         int res = sscanf(line, "%x %x %x %x %x %x %x %x",
 392             (unsigned int *)&data[index],
 393                         (unsigned int *)&data[index + 1],
 394                         (unsigned int *)&data[index + 2],
 395                         (unsigned int *)&data[index + 3],
 396             (unsigned int *)&data[index + 4],
 397                         (unsigned int *)&data[index + 5],
 398                         (unsigned int *)&data[index + 6],
 399                         (unsigned int *)&data[index + 7]);
 400
 401         if(res != 8) {
 402           PrintAndLog("Error: could not read samples");
 403           fclose(f);
 404           return -1;
 405         }
 406                 index += res;
 407
 408                 if ( index == USB_CMD_DATA_SIZE ){
 409 //                      PrintAndLog("sent %d | %d | %d", index, offset, totalbytes);
 410                         UsbCommand c = { CMD_DOWNLOADED_SIM_SAMPLES_125K, {offset, 0, 0}};
 411                         memcpy(c.d.asBytes, data, sizeof(data));
 412                         clearCommandBuffer();
 413                         SendCommand(&c);
 414                         if ( !WaitForResponseTimeout(CMD_ACK, NULL, 1500)){
 415                                 PrintAndLog("Command execute timeout");
 416                                 fclose(f);
 417                                 return 1;
 418                         }
 419                         offset += index;
 420                         totalbytes += index;
 421                         index = 0;
 422                 }
 423     }
 424     fclose(f);
 425
 426         // left over bytes?
 427         if ( index != 0 ) {
 428                 UsbCommand c = { CMD_DOWNLOADED_SIM_SAMPLES_125K, {offset, 0, 0}};
 429                 memcpy(c.d.asBytes, data, 8);
 430                 clearCommandBuffer();
 431                 SendCommand(&c);
 432                 if ( !WaitForResponseTimeout(CMD_ACK, NULL, 1500)){
 433                                 PrintAndLog("Command execute timeout");
 434                                 return 1;
 435                 }
 436                 totalbytes += index;
 437         }
 438
 439     PrintAndLog("loaded %u samples", totalbytes);
 440     return 0;
 441 }
 442
 443 int CmdLegicSave(const char *Cmd) {
 444         int requested = 1024;
 445         int offset = 0;
 446         int delivered = 0;
 447         char filename[FILE_PATH_SIZE];
 448         uint8_t got[1024] = {0x00};
 449
 450         sscanf(Cmd, " %s %i %i", filename, &requested, &offset);
 451
 452         /* If no length given save entire legic read buffer */
 453         /* round up to nearest 8 bytes so the saved data can be used with legicload */
 454         if (requested == 0)
 455                 requested = 1024;
 456
 457         if (requested % 8 != 0) {
 458                 int remainder = requested % 8;
 459                 requested = requested + 8 - remainder;
 460         }
 461
 462         if (offset + requested > sizeof(got)) {
 463                 PrintAndLog("Tried to read past end of buffer, <bytes> + <offset> > 1024");
 464                 return 0;
 465         }
 466
 467         GetFromBigBuf(got, requested, offset);
 468         if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2000)){
 469                 PrintAndLog("Command execute timeout");
 470                 return 1;
 471         }
 472
 473         FILE *f = fopen(filename, "w");
 474         if(!f) {
 475                 PrintAndLog("couldn't open '%s'", Cmd+1);
 476                 return -1;
 477         }
 478
 479         for (int j = 0; j < requested; j += 8) {
 480                 fprintf(f, "%02x %02x %02x %02x %02x %02x %02x %02x\n",
 481                         got[j+0], got[j+1], got[j+2], got[j+3],
 482                         got[j+4], got[j+5],     got[j+6], got[j+7]
 483                 );
 484                 delivered += 8;
 485                 if (delivered >= requested) break;
 486         }
 487
 488         fclose(f);
 489         PrintAndLog("saved %u samples", delivered);
 490         return 0;
 491 }
 492
 493 //TODO: write a help text (iceman)
 494 int CmdLegicRfSim(const char *Cmd) {
 495         UsbCommand c = {CMD_SIMULATE_TAG_LEGIC_RF, {6,3,0}};
 496         sscanf(Cmd, " %"lli" %"lli" %"lli, &c.arg[0], &c.arg[1], &c.arg[2]);
 497         clearCommandBuffer();
 498         SendCommand(&c);
 499         return 0;
 500 }
 501
 502 //TODO: write a help text (iceman)
 503 int CmdLegicRfWrite(const char *Cmd) {
 504     UsbCommand c = {CMD_WRITER_LEGIC_RF};
 505     int res = sscanf(Cmd, " 0x%"llx" 0x%"llx, &c.arg[0], &c.arg[1]);
 506         if(res != 2) {
 507                 PrintAndLog("Please specify the offset and length as two hex strings");
 508         return -1;
 509     }
 510         clearCommandBuffer();
 511     SendCommand(&c);
 512     return 0;
 513 }
 514
 515 //TODO: write a help text (iceman)
 516 int CmdLegicRfRawWrite(const char *Cmd) {
 517         char answer;
 518     UsbCommand c = { CMD_RAW_WRITER_LEGIC_RF, {0,0,0} };
 519     int res = sscanf(Cmd, " 0x%"llx" 0x%"llx, &c.arg[0], &c.arg[1]);
 520         if(res != 2) {
 521                 PrintAndLog("Please specify the offset and value as two hex strings");
 522         return -1;
 523     }
 524
 525         if (c.arg[0] == 0x05 || c.arg[0] == 0x06) {
 526                 PrintAndLog("############# DANGER !! #############");
 527                 PrintAndLog("# changing the DCF is irreversible  #");
 528                 PrintAndLog("#####################################");
 529                 PrintAndLog("do youe really want to continue? y(es) n(o)");
 530                 if (scanf(" %c", &answer) > 0 && (answer == 'y' || answer == 'Y')) {
 531                         SendCommand(&c);
 532                         return 0;
 533                 }
 534                 return -1;
 535         }
 536
 537         clearCommandBuffer();
 538     SendCommand(&c);
 539         return 0;
 540 }
 541
 542 //TODO: write a help text (iceman)
 543 int CmdLegicRfFill(const char *Cmd) {
 544     UsbCommand cmd = {CMD_WRITER_LEGIC_RF, {0,0,0} };
 545     int res = sscanf(Cmd, " 0x%"llx" 0x%"llx" 0x%"llx, &cmd.arg[0], &cmd.arg[1], &cmd.arg[2]);
 546     if(res != 3) {
 547         PrintAndLog("Please specify the offset, length and value as two hex strings");
 548         return -1;
 549     }
 550
 551     int i;
 552     UsbCommand c = {CMD_DOWNLOADED_SIM_SAMPLES_125K, {0, 0, 0}};
 553         memset(c.d.asBytes, cmd.arg[2], 48);
 554
 555         for(i = 0; i < 22; i++) {
 556                 c.arg[0] = i*48;
 557
 558                 clearCommandBuffer();
 559                 SendCommand(&c);
 560                 WaitForResponse(CMD_ACK, NULL);
 561         }
 562         clearCommandBuffer();
 563     SendCommand(&cmd);
 564     return 0;
 565  }
 566
 567 int CmdLegicCalcCrc8(const char *Cmd){
 568
 569         uint8_t *data = NULL;
 570         uint8_t cmdp = 0, uidcrc = 0, type=0;
 571         bool errors = false;
 572         int len = 0;
 573         int bg, en;
 574
 575         while(param_getchar(Cmd, cmdp) != 0x00) {
 576                 switch(param_getchar(Cmd, cmdp)) {
 577                 case 'b':
 578                 case 'B':
 579                         // peek at length of the input string so we can
 580                         // figure out how many elements to malloc in "data"
 581                         bg=en=0;
 582                         if (param_getptr(Cmd, &bg, &en, cmdp+1)) {
 583                                 errors = true;
 584                                 break;
 585                         }
 586                         len = (en - bg + 1);
 587
 588                         // check that user entered even number of characters
 589                         // for hex data string
 590                         if (len & 1) {
 591                                 errors = true;
 592                                 break;
 593                         }
 594
 595                         // it's possible for user to accidentally enter "b" parameter
 596                         // more than once - we have to clean previous malloc
 597                         if (data) free(data);
 598                         data = malloc(len >> 1);
 599                         if ( data == NULL ) {
 600                                 PrintAndLog("Can't allocate memory. exiting");
 601                                 errors = true;
 602                                 break;
 603                         }
 604
 605                         if (param_gethex(Cmd, cmdp+1, data, len)) {
 606                                 errors = true;
 607                                 break;
 608                         }
 609
 610                         len >>= 1;
 611                         cmdp += 2;
 612                         break;
 613                 case 'u':
 614                 case 'U':
 615                         uidcrc = param_get8ex(Cmd, cmdp+1, 0, 16);
 616                         cmdp += 2;
 617                         break;
 618                 case 'c':
 619                 case 'C':
 620                         type = param_get8ex(Cmd, cmdp+1, 0, 10);
 621                         cmdp += 2;
 622                         break;
 623                 case 'h':
 624                 case 'H':
 625                         errors = true;
 626                         break;
 627                 default:
 628                         PrintAndLog("Unknown parameter '%c'", param_getchar(Cmd, cmdp));
 629                         errors = true;
 630                         break;
 631                 }
 632                 if (errors) break;
 633         }
 634         //Validations
 635         if (errors){
 636                 if (data) free(data);
 637                 return usage_legic_calccrc8();
 638         }
 639
 640         switch (type){
 641                 case 16:
 642                         PrintAndLog("LEGIC CRC16: %X", CRC16Legic(data, len, uidcrc));
 643                         break;
 644                 default:
 645                         PrintAndLog("LEGIC CRC8: %X",  CRC8Legic(data, len) );
 646                         break;
 647         }
 648
 649         if (data) free(data);
 650         return 0;
 651 }
 652
 653 static command_t CommandTable[] =  {
 654         {"help",        CmdHelp,        1, "This help"},
 655         {"decode",      CmdLegicDecode, 0, "Display deobfuscated and decoded LEGIC RF tag data (use after hf legic reader)"},
 656         {"read",        CmdLegicRFRead, 0, "[offset][length] -- read bytes from a LEGIC card"},
 657         {"save",        CmdLegicSave,   0, "<filename> [<length>] -- Store samples"},
 658         {"load",        CmdLegicLoad,   0, "<filename> -- Restore samples"},
 659         {"sim",         CmdLegicRfSim,  0, "[phase drift [frame drift [req/resp drift]]] Start tag simulator (use after load or read)"},
 660         {"write",       CmdLegicRfWrite,0, "<offset> <length> -- Write sample buffer (user after load or read)"},
 661         {"writeRaw",CmdLegicRfRawWrite, 0, "<address> <value> -- Write direct to address"},
 662         {"fill",        CmdLegicRfFill, 0, "<offset> <length> <value> -- Fill/Write tag with constant value"},
 663         {"crc8",        CmdLegicCalcCrc8, 1, "Calculate Legic CRC8 over given hexbytes"},
 664         {NULL, NULL, 0, NULL}
 665 };
 666
 667 int CmdHFLegic(const char *Cmd) {
 668         clearCommandBuffer();
 669         CmdsParse(CommandTable, Cmd);
 670         return 0;
 671 }
 672
 673 int CmdHelp(const char *Cmd) {
 674         CmdsHelp(CommandTable);
 675         return 0;
 676 }