client/src/cmdlfpyramid.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
   3 //
   4 // This program is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // This program is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // See LICENSE.txt for the text of the license.
  15 //-----------------------------------------------------------------------------
  16 // Low frequency Farpoint / Pyramid tag commands
  17 // FSK2a, rf/50, 128 bits (complete)
  18 //-----------------------------------------------------------------------------
  19 #include "cmdlfpyramid.h"
  20 #include "common.h"
  21 #include <string.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <ctype.h>
  25 #include "commonutil.h"   // ARRAYLEN
  26 #include "cmdparser.h"    // command_t
  27 #include "comms.h"
  28 #include "ui.h"
  29 #include "graph.h"
  30 #include "cmddata.h"
  31 #include "cmdlf.h"
  32 #include "protocols.h"  // for T55xx config register definitions
  33 #include "lfdemod.h"    // parityTest
  34 #include "crc.h"
  35 #include "cmdlft55xx.h" // verifywrite
  36 #include "cliparser.h"
  37 #include "cmdlfem4x05.h"  // EM Defines
  38
  39 static int CmdHelp(const char *Cmd);
  40
  41 //Pyramid Prox demod - FSK RF/50 with preamble of 0000000000000001  (always a 128 bit data stream)
  42 //print full Farpointe Data/Pyramid Prox ID and some bit format details if found
  43 int demodPyramid(bool verbose) {
  44     (void) verbose; // unused so far
  45     //raw fsk demod no manchester decoding no start bit finding just get binary from wave
  46     uint8_t *bits = calloc(MAX_GRAPH_TRACE_LEN, sizeof(uint8_t));
  47     if (bits == NULL) {
  48         PrintAndLogEx(FAILED, "failed to allocate memory");
  49         return PM3_EMALLOC;
  50     }
  51     size_t size = getFromGraphBuffer(bits);
  52     if (size == 0) {
  53         PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid not enough samples");
  54         free(bits);
  55         return PM3_ESOFT;
  56     }
  57     //get binary from fsk wave
  58     int waveIdx = 0;
  59     int idx = detectPyramid(bits, &size, &waveIdx);
  60     if (idx < 0) {
  61         if (idx == -1)
  62             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: not enough samples");
  63         else if (idx == -2)
  64             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: only noise found");
  65         else if (idx == -3)
  66             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: problem during FSK demod");
  67         else if (idx == -4)
  68             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: preamble not found");
  69         else if (idx == -5)
  70             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: size not correct: %zu", size);
  71         else
  72             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: error demoding fsk idx: %d", idx);
  73         free(bits);
  74         return PM3_ESOFT;
  75     }
  76     setDemodBuff(bits, size, idx);
  77     setClockGrid(50, waveIdx + (idx * 50));
  78
  79     // Index map
  80     // 0           10          20          30            40          50          60
  81     // |           |           |           |             |           |           |
  82     // 0123456 7 8901234 5 6789012 3 4567890 1 2345678 9 0123456 7 8901234 5 6789012 3
  83     // -----------------------------------------------------------------------------
  84     // 0000000 0 0000000 1 0000000 1 0000000 1 0000000 1 0000000 1 0000000 1 0000000 1
  85     // premable  xxxxxxx o xxxxxxx o xxxxxxx o xxxxxxx o xxxxxxx o xxxxxxx o xxxxxxx o
  86
  87     // 64    70            80          90          100         110           120
  88     // |     |             |           |           |           |             |
  89     // 4567890 1 2345678 9 0123456 7 8901234 5 6789012 3 4567890 1 2345678 9 0123456 7
  90     // -----------------------------------------------------------------------------
  91     // 0000000 1 0000000 1 0000000 1 0110111 0 0011000 1 0000001 0 0001100 1 1001010 0
  92     // xxxxxxx o xxxxxxx o xxxxxxx o xswffff o ffffccc o ccccccc o ccccccw o ppppppp o
  93     //                                  |---115---||---------71---------|
  94     // s = format start bit, o = odd parity of last 7 bits
  95     // f = facility code, c = card number
  96     // w = wiegand parity, x = extra space for other formats
  97     // p = CRC8maxim checksum
  98     // (26 bit format shown)
  99
 100     //get bytes for checksum calc
 101     uint8_t checksum = bytebits_to_byte(bits + idx + 120, 8);
 102     uint8_t csBuff[14] = {0x00};
 103     for (uint8_t i = 0; i < 13; i++) {
 104         csBuff[i] = bytebits_to_byte(bits + idx + 16 + (i * 8), 8);
 105     }
 106     //check checksum calc
 107     //checksum calc thanks to ICEMAN!!
 108     uint32_t checkCS =  CRC8Maxim(csBuff, 13);
 109
 110     //get raw ID before removing parities
 111     uint32_t rawLo = bytebits_to_byte(bits + idx + 96, 32);
 112     uint32_t rawHi = bytebits_to_byte(bits + idx + 64, 32);
 113     uint32_t rawHi2 = bytebits_to_byte(bits + idx + 32, 32);
 114     uint32_t rawHi3 = bytebits_to_byte(bits + idx, 32);
 115
 116     size = removeParity(bits, idx + 8, 8, 1, 120);
 117     if (size != 105) {
 118         if (size == 0)
 119             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: parity check failed - IDX: %d, hi3: %08X", idx, rawHi3);
 120         else
 121             PrintAndLogEx(DEBUG, "DEBUG: Error - Pyramid: at parity check - tag size does not match Pyramid format, SIZE: %zu, IDX: %d, hi3: %08X", size, idx, rawHi3);
 122         free(bits);
 123         return PM3_ESOFT;
 124     }
 125
 126     // ok valid card found!
 127
 128     // Index map
 129     // 0         10        20        30        40        50        60        70
 130     // |         |         |         |         |         |         |         |
 131     // 01234567890123456789012345678901234567890123456789012345678901234567890
 132     // -----------------------------------------------------------------------
 133     // 00000000000000000000000000000000000000000000000000000000000000000000000
 134     // xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 135
 136     // 71         80         90          100
 137     // |          |          |           |
 138     // 1 2 34567890 1234567890123456 7 8901234
 139     // ---------------------------------------
 140     // 1 1 01110011 0000000001000110 0 1001010
 141     // s w ffffffff cccccccccccccccc w ppppppp
 142     //     |--115-| |------71------|
 143     // s = format start bit, o = odd parity of last 7 bits
 144     // f = facility code, c = card number
 145     // w = wiegand parity, x = extra space for other formats
 146     // p = CRC8-Maxim checksum
 147     // (26 bit format shown)
 148
 149     //find start bit to get fmtLen
 150     int j;
 151     for (j = 0; j < size; ++j) {
 152         if (bits[j]) break;
 153     }
 154
 155     uint8_t fmtLen = size - j - 8;
 156
 157     if (fmtLen == 26) {
 158         uint32_t fc = bytebits_to_byte(bits + 73, 8);
 159         uint32_t cardnum = bytebits_to_byte(bits + 81, 16);
 160         uint32_t code1 = bytebits_to_byte(bits + 72, fmtLen);
 161         PrintAndLogEx(SUCCESS, "Pyramid - len: " _GREEN_("%d") ", FC: " _GREEN_("%d") " Card: " _GREEN_("%d") " - Wiegand: " _GREEN_("%x")", Raw: %08x%08x%08x%08x", fmtLen, fc, cardnum, code1, rawHi3, rawHi2, rawHi, rawLo);
 162     } else if (fmtLen == 45) {
 163         fmtLen = 42; //end = 10 bits not 7 like 26 bit fmt
 164         uint32_t fc = bytebits_to_byte(bits + 53, 10);
 165         uint32_t cardnum = bytebits_to_byte(bits + 63, 32);
 166         PrintAndLogEx(SUCCESS, "Pyramid - len: " _GREEN_("%d") ", FC: " _GREEN_("%d") " Card: " _GREEN_("%d") ", Raw: %08x%08x%08x%08x", fmtLen, fc, cardnum, rawHi3, rawHi2, rawHi, rawLo);
 167         /*
 168             } else if (fmtLen > 32) {
 169                 uint32_t cardnum = bytebits_to_byte(bits + 81, 16);
 170                 //uint32_t code1 = bytebits_to_byte(bits+(size-fmtLen),fmtLen-32);
 171                 //code2 = bytebits_to_byte(bits+(size-32),32);
 172                 PrintAndLogEx(SUCCESS, "Pyramid ID Found - BitLength: %d -unknown BitLength- (%d), Raw: %08x%08x%08x%08x", fmtLen, cardnum, rawHi3, rawHi2, rawHi, rawLo);
 173                 */
 174     } else {
 175         uint32_t cardnum = bytebits_to_byte(bits + 81, 16);
 176         //uint32_t code1 = bytebits_to_byte(bits+(size-fmtLen),fmtLen);
 177         PrintAndLogEx(SUCCESS, "Pyramid - len: " _GREEN_("%d") " -unknown- Card: " _GREEN_("%d") ", Raw: %08x%08x%08x%08x", fmtLen, cardnum, rawHi3, rawHi2, rawHi, rawLo);
 178     }
 179
 180     PrintAndLogEx(DEBUG, "DEBUG: Pyramid: checksum : 0x%02X - 0x%02X ( %s )"
 181                   , checksum
 182                   , checkCS
 183                   , (checksum == checkCS) ? _GREEN_("ok") : _RED_("fail")
 184                  );
 185
 186     PrintAndLogEx(DEBUG, "DEBUG: Pyramid: idx: %d, Len: %d, Printing DemodBuffer:", idx, 128);
 187     if (g_debugMode) {
 188         printDemodBuff(0, false, false, false);
 189     }
 190
 191     free(bits);
 192     return PM3_SUCCESS;
 193 }
 194
 195 static int CmdPyramidDemod(const char *Cmd) {
 196     CLIParserContext *ctx;
 197     CLIParserInit(&ctx, "lf pyramid demod",
 198                   "Try to find Farpoint/Pyramid preamble, if found decode / descramble data",
 199                   "lf pyramid demod"
 200                  );
 201
 202     void *argtable[] = {
 203         arg_param_begin,
 204         arg_param_end
 205     };
 206     CLIExecWithReturn(ctx, Cmd, argtable, true);
 207     CLIParserFree(ctx);
 208     return demodPyramid(true);
 209 }
 210
 211 static int CmdPyramidReader(const char *Cmd) {
 212     CLIParserContext *ctx;
 213     CLIParserInit(&ctx, "lf pyramid reader",
 214                   "read a Farpointe/Pyramid tag",
 215                   "lf pyramid reader -@   -> continuous reader mode"
 216                  );
 217
 218     void *argtable[] = {
 219         arg_param_begin,
 220         arg_lit0("@", NULL, "optional - continuous reader mode"),
 221         arg_param_end
 222     };
 223     CLIExecWithReturn(ctx, Cmd, argtable, true);
 224     bool cm = arg_get_lit(ctx, 1);
 225     CLIParserFree(ctx);
 226
 227     if (cm) {
 228         PrintAndLogEx(INFO, "Press " _GREEN_("<Enter>") " to exit");
 229     }
 230
 231     do {
 232         lf_read(false, 15000);
 233         demodPyramid(true);
 234     } while (cm && !kbd_enter_pressed());
 235
 236     return PM3_SUCCESS;
 237 }
 238
 239 static int CmdPyramidClone(const char *Cmd) {
 240
 241     CLIParserContext *ctx;
 242     CLIParserInit(&ctx, "lf pyramid clone",
 243                   "clone a Farpointe/Pyramid tag to a T55x7, Q5/T5555 or EM4305/4469 tag.\n"
 244                   "The facility-code is 8-bit and the card number is 16-bit. Larger values are truncated.\n"
 245                   "Currently only works on 26bit",
 246                   "lf pyramid clone --fc 123 --cn 11223       -> encode for T55x7 tag\n"
 247                   "lf pyramid clone --raw 0001010101010101010440013223921c -> idem, raw mode\n"
 248                   "lf pyramid clone --fc 123 --cn 11223 --q5  -> encode for Q5/T5555 tag\n"
 249                   "lf pyramid clone --fc 123 --cn 11223 --em  -> encode for EM4305/4469\n"
 250                  );
 251
 252     void *argtable[] = {
 253         arg_param_begin,
 254         arg_u64_0(NULL, "fc", "<dec>", "8-bit value facility code"),
 255         arg_u64_0(NULL, "cn", "<dec>", "16-bit value card number"),
 256         arg_lit0(NULL, "q5", "optional - specify writing to Q5/T5555 tag"),
 257         arg_lit0(NULL, "em", "optional - specify writing to EM4305/4469 tag"),
 258         arg_str0("r", "raw", "<hex>", "raw hex data. 16 bytes"),
 259         arg_param_end
 260     };
 261     CLIExecWithReturn(ctx, Cmd, argtable, false);
 262
 263     uint32_t fc = arg_get_u32_def(ctx, 1, -1);
 264     uint32_t cn = arg_get_u32_def(ctx, 2, -1);
 265     bool q5 = arg_get_lit(ctx, 3);
 266     bool em = arg_get_lit(ctx, 4);
 267
 268     int raw_len = 0;
 269     // skip first block,  4*4 = 16 bytes left
 270     uint8_t raw[16] = {0};
 271     int res = CLIParamHexToBuf(arg_get_str(ctx, 5), raw, sizeof raw, &raw_len);
 272     if (res) {
 273         CLIParserFree(ctx);
 274         return PM3_EINVARG;
 275     }
 276
 277     CLIParserFree(ctx);
 278
 279     if (q5 && em) {
 280         PrintAndLogEx(FAILED, "Can't specify both Q5 and EM4305 at the same time");
 281         return PM3_EINVARG;
 282     }
 283
 284     bool use_raw = (raw_len > 0);
 285
 286     if (fc == -1 && cn == -1) {
 287         if (use_raw == false) {
 288             PrintAndLogEx(FAILED, "Must specify either raw data to clone, or fc/cn");
 289             return PM3_EINVARG;
 290         }
 291     } else {
 292         // --raw and --fc/cn are mutually exclusive
 293         if (use_raw) {
 294             PrintAndLogEx(FAILED, "Can't specify both raw and fc/cn at the same time");
 295             return PM3_EINVARG;
 296         }
 297     }
 298
 299     uint32_t blocks[5];
 300     if (use_raw) {
 301         for (uint8_t i = 1; i < ARRAYLEN(blocks); i++) {
 302             blocks[i] = bytes_to_num(raw + ((i - 1) * 4), sizeof(uint32_t));
 303         }
 304     } else {
 305
 306         uint8_t *bs = calloc(128, sizeof(uint8_t));
 307         if (bs == NULL) {
 308             return PM3_EMALLOC;
 309         }
 310
 311         uint32_t facilitycode = (fc & 0x000000FF);
 312         uint32_t cardnumber = (cn & 0x0000FFFF);
 313
 314         if (getPyramidBits(facilitycode, cardnumber, bs) != PM3_SUCCESS) {
 315             PrintAndLogEx(ERR, "Error with tag bitstream generation.");
 316             return PM3_ESOFT;
 317         }
 318
 319         blocks[1] = bytebits_to_byte(bs, 32);
 320         blocks[2] = bytebits_to_byte(bs + 32, 32);
 321         blocks[3] = bytebits_to_byte(bs + 64, 32);
 322         blocks[4] = bytebits_to_byte(bs + 96, 32);
 323
 324         free(bs);
 325     }
 326
 327     //Pyramid - compat mode, FSK2a, data rate 50, 4 data blocks
 328     blocks[0] = T55x7_MODULATION_FSK2a | T55x7_BITRATE_RF_50 | 4 << T55x7_MAXBLOCK_SHIFT;
 329     char cardtype[16] = {"T55x7"};
 330
 331     // Q5
 332     if (q5) {
 333         blocks[0] = T5555_FIXED | T5555_MODULATION_FSK2 | T5555_INVERT_OUTPUT | T5555_SET_BITRATE(50) | 4 << T5555_MAXBLOCK_SHIFT;
 334         snprintf(cardtype, sizeof(cardtype), "Q5/T5555");
 335     }
 336     // EM4305
 337     if (em) {
 338         PrintAndLogEx(WARNING, "Beware some EM4305 tags don't support FSK and datarate = RF/50, check your tag copy!");
 339         blocks[0] = EM4305_PYRAMID_CONFIG_BLOCK;
 340         // invert FSK data
 341         for (uint8_t i = 1; i < ARRAYLEN(blocks) ; i++) {
 342             blocks[i] = blocks[i] ^ 0xFFFFFFFF;
 343         }
 344         snprintf(cardtype, sizeof(cardtype), "EM4305/4469");
 345     }
 346
 347     PrintAndLogEx(INFO, "Preparing to clone Farpointe/Pyramid to " _YELLOW_("%s") " from %s.",
 348                   cardtype,
 349                   use_raw ? "raw hex" : "specified data"
 350                  );
 351     print_blocks(blocks,  ARRAYLEN(blocks));
 352
 353     if (em) {
 354         res = em4x05_clone_tag(blocks, ARRAYLEN(blocks), 0, false);
 355     } else {
 356         res = clone_t55xx_tag(blocks, ARRAYLEN(blocks));
 357     }
 358     PrintAndLogEx(SUCCESS, "Done");
 359     PrintAndLogEx(HINT, "Hint: try " _YELLOW_("`lf pyramid reader`") " to verify");
 360     return res;
 361 }
 362
 363 static int CmdPyramidSim(const char *Cmd) {
 364     CLIParserContext *ctx;
 365     CLIParserInit(&ctx, "lf pyramid sim",
 366                   "Enables simulation of Farpointe/Pyramid card with specified card number.\n"
 367                   "Simulation runs until the button is pressed or another USB command is issued.\n"
 368                   "The facility-code is 8-bit and the card number is 16-bit. Larger values are truncated.\n"
 369                   "Currently work only on 26bit",
 370                   "lf pyramid sim --fc 123 --cn 1337\n"
 371                   "lf pyramid sim --raw 0001010101010101010440013223921c"
 372                  );
 373
 374     void *argtable[] = {
 375         arg_param_begin,
 376         arg_u64_0(NULL, "fc", "<dec>", "8-bit value facility code"),
 377         arg_u64_0(NULL, "cn", "<dec>", "16-bit value card number"),
 378         arg_str0("r", "raw", "<hex>", "raw hex data. 16 bytes"),
 379         arg_param_end
 380     };
 381     CLIExecWithReturn(ctx, Cmd, argtable, false);
 382     uint32_t fc = arg_get_u32_def(ctx, 1, -1);
 383     uint32_t cn = arg_get_u32_def(ctx, 2, -1);
 384
 385     int raw_len = 0;
 386     // skip first block,  4*4 = 16 bytes left
 387     uint8_t raw[16] = {0};
 388     int res = CLIParamHexToBuf(arg_get_str(ctx, 3), raw, sizeof raw, &raw_len);
 389     if (res) {
 390         CLIParserFree(ctx);
 391         return PM3_EINVARG;
 392     }
 393
 394     CLIParserFree(ctx);
 395
 396     bool use_raw = (raw_len > 0);
 397
 398     if (fc == -1 && cn == -1) {
 399         if (use_raw == false) {
 400             PrintAndLogEx(FAILED, "Must specify either raw data to clone, or fc/cn");
 401             return PM3_EINVARG;
 402         }
 403     } else {
 404         // --raw and --fc/cn are mutually exclusive
 405         if (use_raw) {
 406             PrintAndLogEx(FAILED, "Can't specify both raw and fc/cn at the same time");
 407             return PM3_EINVARG;
 408         }
 409     }
 410
 411     uint8_t bs[sizeof(raw) * 8];
 412     memset(bs, 0x00, sizeof(bs));
 413
 414     if (use_raw == false) {
 415         uint32_t facilitycode = (fc & 0x000000FF);
 416         uint32_t cardnumber = (cn & 0x0000FFFF);
 417
 418         if (getPyramidBits(facilitycode, cardnumber, bs) != PM3_SUCCESS) {
 419             PrintAndLogEx(ERR, "Error with tag bitstream generation.");
 420             return PM3_ESOFT;
 421         }
 422         PrintAndLogEx(SUCCESS, "Simulating Farpointe/Pyramid - Facility Code: " _YELLOW_("%u") ", CardNumber: " _YELLOW_("%u"), facilitycode, cardnumber);
 423     } else {
 424         PrintAndLogEx(SUCCESS, "Simulating Farpointe/Pyramid - raw " _YELLOW_("%s"), sprint_hex_inrow(raw, sizeof(raw)));
 425         bytes_to_bytebits(raw, sizeof(raw), bs);
 426     }
 427
 428     // Pyramid uses:  fcHigh: 10, fcLow: 8, clk: 50, invert: 0
 429     lf_fsksim_t *payload = calloc(1, sizeof(lf_fsksim_t) + sizeof(bs));
 430     payload->fchigh = 10;
 431     payload->fclow =  8;
 432     payload->separator = 0;
 433     payload->clock = 50;
 434     memcpy(payload->data, bs, sizeof(bs));
 435
 436     clearCommandBuffer();
 437     SendCommandNG(CMD_LF_FSK_SIMULATE, (uint8_t *)payload,  sizeof(lf_fsksim_t) + sizeof(bs));
 438     free(payload);
 439
 440     return lfsim_wait_check(CMD_LF_FSK_SIMULATE);
 441 }
 442
 443 static command_t CommandTable[] = {
 444     {"help",    CmdHelp,          AlwaysAvailable, "this help"},
 445     {"demod",   CmdPyramidDemod,  AlwaysAvailable, "demodulate a Pyramid FSK tag from the GraphBuffer"},
 446     {"reader",  CmdPyramidReader, IfPm3Lf,         "attempt to read and extract tag data"},
 447     {"clone",   CmdPyramidClone,  IfPm3Lf,         "clone pyramid tag to T55x7, Q5/T5555 or EM4305/4469"},
 448     {"sim",     CmdPyramidSim,    IfPm3Lf,         "simulate pyramid tag"},
 449     {NULL, NULL, NULL, NULL}
 450 };
 451
 452 int CmdLFPyramid(const char *Cmd) {
 453     clearCommandBuffer();
 454     return CmdsParse(CommandTable, Cmd);
 455 }
 456
 457 int CmdHelp(const char *Cmd) {
 458     (void)Cmd; // Cmd is not used so far
 459     CmdsHelp(CommandTable);
 460     return PM3_SUCCESS;
 461 }
 462
 463 // Works for 26bits.
 464 int getPyramidBits(uint32_t fc, uint32_t cn, uint8_t *pyramidBits) {
 465
 466     uint8_t pre[128];
 467     memset(pre, 0x00, sizeof(pre));
 468
 469     // format start bit
 470     pre[79] = 1;
 471
 472     // Get 26 wiegand from FacilityCode, CardNumber
 473     uint8_t wiegand[24];
 474     memset(wiegand, 0x00, sizeof(wiegand));
 475     num_to_bytebits(fc, 8, wiegand);
 476     num_to_bytebits(cn, 16, wiegand + 8);
 477
 478     // add wiegand parity bits (dest, source, len)
 479     wiegand_add_parity(pre + 80, wiegand, 24);
 480
 481     // add paritybits (bitsource, dest, sourcelen, paritylen, parityType (odd, even,)
 482     addParity(pre + 8, pyramidBits + 8, 102, 8, 1);
 483
 484     // add checksum
 485     uint8_t csBuff[13];
 486     for (uint8_t i = 0; i < 13; i++)
 487         csBuff[i] = bytebits_to_byte(pyramidBits + 16 + (i * 8), 8);
 488
 489     uint32_t crc = CRC8Maxim(csBuff, 13);
 490     num_to_bytebits(crc, 8, pyramidBits + 120);
 491     return PM3_SUCCESS;
 492 }
 493
 494 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
 495 int detectPyramid(uint8_t *dest, size_t *size, int *waveStartIdx) {
 496     //make sure buffer has data
 497     if (*size < 128 * 50) return -1;
 498
 499     //test samples are not just noise
 500     if (getSignalProperties()->isnoise) return -2;
 501
 502     // FSK demodulator RF/50 FSK 10,8
 503     *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx);  // pyramid fsk2
 504
 505     //did we get a good demod?
 506     if (*size < 128) return -3;
 507
 508     size_t startIdx = 0;
 509     uint8_t preamble[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1};
 510     if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
 511         return -4; //preamble not found
 512
 513     // wrong size?  (between to preambles)
 514     if (*size < 128) return -5;
 515
 516     return (int)startIdx;
 517 }