cvs.zerfleddert.de Git - proxmark3-svn/blob - client/cmdlfem4x.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 // Low frequency EM4x commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include "cmdlfem4x.h"
  12
  13 uint64_t g_em410xid = 0;
  14
  15 static int CmdHelp(const char *Cmd);
  16
  17 int CmdEMdemodASK(const char *Cmd)
  18 {
  19         char cmdp = param_getchar(Cmd, 0);
  20         uint8_t findone = (cmdp == '1') ? 1 : 0;
  21         UsbCommand c = {CMD_EM410X_DEMOD, {findone, 0, 0}};
  22         SendCommand(&c);
  23         return 0;
  24 }
  25
  26 /* Read the ID of an EM410x tag.
  27  * Format:
  28  *   1111 1111 1           <-- standard non-repeatable header
  29  *   XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
  30  *   ....
  31  *   CCCC                  <-- each bit here is parity for the 10 bits above in corresponding column
  32  *   0                     <-- stop bit, end of tag
  33  */
  34 int CmdEM410xRead(const char *Cmd)
  35 {
  36         uint32_t hi=0;
  37         uint64_t lo=0;
  38
  39         if(!AskEm410xDemod("", &hi, &lo, false)) return 0;
  40         PrintAndLog("EM410x pattern found: ");
  41         printEM410x(hi, lo);
  42         if (hi){
  43                 PrintAndLog ("EM410x XL pattern found");
  44                 return 0;
  45         }
  46         g_em410xid = lo;
  47         return 1;
  48 }
  49
  50
  51 int usage_lf_em410x_sim(void) {
  52         PrintAndLog("Simulating EM410x tag");
  53         PrintAndLog("");
  54         PrintAndLog("Usage:  lf em4x em410xsim [h] <uid> <clock>");
  55         PrintAndLog("Options:");
  56         PrintAndLog("       h         - this help");
  57         PrintAndLog("       uid       - uid (10 HEX symbols)");
  58         PrintAndLog("       clock     - clock (32|64) (optional)");
  59         PrintAndLog("samples:");
  60         PrintAndLog("      lf em4x em410xsim 0F0368568B");
  61         PrintAndLog("      lf em4x em410xsim 0F0368568B 32");
  62         return 0;
  63 }
  64
  65 // emulate an EM410X tag
  66 int CmdEM410xSim(const char *Cmd)
  67 {
  68         int i, n, j, binary[4], parity[4];
  69         uint8_t uid[5] = {0x00};
  70
  71         char cmdp = param_getchar(Cmd, 0);
  72         if (cmdp == 'h' || cmdp == 'H') return usage_lf_em410x_sim();
  73
  74         /* clock is 64 in EM410x tags */
  75         uint8_t clock = 64;
  76
  77         if (param_gethex(Cmd, 0, uid, 10)) {
  78                 PrintAndLog("UID must include 10 HEX symbols");
  79                 return 0;
  80         }
  81
  82         param_getdec(Cmd, 1, &clock);
  83
  84         PrintAndLog("Starting simulating UID %02X%02X%02X%02X%02X  clock: %d", uid[0],uid[1],uid[2],uid[3],uid[4],clock);
  85         PrintAndLog("Press pm3-button to about simulation");
  86
  87         /* clear our graph */
  88         ClearGraph(0);
  89
  90         /* write 9 start bits */
  91         for (i = 0; i < 9; i++)
  92                 AppendGraph(0, clock, 1);
  93
  94         /* for each hex char */
  95         parity[0] = parity[1] = parity[2] = parity[3] = 0;
  96         for (i = 0; i < 10; i++)
  97         {
  98                 /* read each hex char */
  99                 sscanf(&Cmd[i], "%1x", &n);
 100                 for (j = 3; j >= 0; j--, n/= 2)
 101                         binary[j] = n % 2;
 102
 103                 /* append each bit */
 104                 AppendGraph(0, clock, binary[0]);
 105                 AppendGraph(0, clock, binary[1]);
 106                 AppendGraph(0, clock, binary[2]);
 107                 AppendGraph(0, clock, binary[3]);
 108
 109                 /* append parity bit */
 110                 AppendGraph(0, clock, binary[0] ^ binary[1] ^ binary[2] ^ binary[3]);
 111
 112                 /* keep track of column parity */
 113                 parity[0] ^= binary[0];
 114                 parity[1] ^= binary[1];
 115                 parity[2] ^= binary[2];
 116                 parity[3] ^= binary[3];
 117         }
 118
 119         /* parity columns */
 120         AppendGraph(0, clock, parity[0]);
 121         AppendGraph(0, clock, parity[1]);
 122         AppendGraph(0, clock, parity[2]);
 123         AppendGraph(0, clock, parity[3]);
 124
 125         /* stop bit */
 126         AppendGraph(1, clock, 0);
 127
 128         CmdLFSim("0"); //240 start_gap.
 129         return 0;
 130 }
 131
 132 /* Function is equivalent of lf read + data samples + em410xread
 133  * looped until an EM410x tag is detected
 134  *
 135  * Why is CmdSamples("16000")?
 136  *  TBD: Auto-grow sample size based on detected sample rate.  IE: If the
 137  *       rate gets lower, then grow the number of samples
 138  *  Changed by martin, 4000 x 4 = 16000,
 139  *  see http://www.proxmark.org/forum/viewtopic.php?pid=7235#p7235
 140 */
 141 int CmdEM410xWatch(const char *Cmd)
 142 {
 143         do {
 144                 if (ukbhit()) {
 145                         printf("\naborted via keyboard!\n");
 146                         break;
 147                 }
 148
 149                 CmdLFRead("s");
 150                 getSamples("8201",true); //capture enough to get 2 complete preambles (4096*2+9)
 151         } while (!CmdEM410xRead(""));
 152
 153         return 0;
 154 }
 155
 156 //currently only supports manchester modulations
 157 // todo: helptext
 158 int CmdEM410xWatchnSpoof(const char *Cmd)
 159 {
 160         // loops if the captured ID was in XL-format.
 161         CmdEM410xWatch(Cmd);
 162         PrintAndLog("# Replaying captured ID: %llu", g_em410xid);
 163         CmdLFaskSim("");
 164         return 0;
 165 }
 166
 167 int CmdEM410xWrite(const char *Cmd)
 168 {
 169         uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
 170         int card = 0xFF; // invalid card value
 171         uint32_t clock = 0; // invalid clock value
 172
 173         sscanf(Cmd, "%" PRIx64 " %d %d", &id, &card, &clock);
 174
 175         // Check ID
 176         if (id == 0xFFFFFFFFFFFFFFFF) {
 177                 PrintAndLog("Error! ID is required.\n");
 178                 return 0;
 179         }
 180         if (id >= 0x10000000000) {
 181                 PrintAndLog("Error! Given EM410x ID is longer than 40 bits.\n");
 182                 return 0;
 183         }
 184
 185         // Check Card
 186         if (card == 0xFF) {
 187                 PrintAndLog("Error! Card type required.\n");
 188                 return 0;
 189         }
 190         if (card < 0) {
 191                 PrintAndLog("Error! Bad card type selected.\n");
 192                 return 0;
 193         }
 194
 195         // Check Clock
 196                 // Default: 64
 197         if (clock == 0)
 198                 clock = 64;
 199
 200         // Allowed clock rates: 16, 32, 40 and 64
 201         if ((clock != 16) && (clock != 32) && (clock != 64) && (clock != 40)) {
 202                 PrintAndLog("Error! Clock rate %d not valid. Supported clock rates are 16, 32, 40 and 64.\n", clock);
 203                 return 0;
 204         }
 205
 206         if (card == 1) {
 207                 PrintAndLog("Writing %s tag with UID 0x%010" PRIx64 " (clock rate: %d)", "T55x7", id, clock);
 208                 // NOTE: We really should pass the clock in as a separate argument, but to
 209                 //   provide for backwards-compatibility for older firmware, and to avoid
 210                 //   having to add another argument to CMD_EM410X_WRITE_TAG, we just store
 211                 //   the clock rate in bits 8-15 of the card value
 212                 card = (card & 0xFF) | ((clock << 8) & 0xFF00);
 213         }       else if (card == 0) {
 214                 PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
 215                 card = (card & 0xFF) | ((clock << 8) & 0xFF00);
 216         } else {
 217                 PrintAndLog("Error! Bad card type selected.\n");
 218                 return 0;
 219         }
 220
 221         UsbCommand c = {CMD_EM410X_WRITE_TAG, {card, (uint32_t)(id >> 32), (uint32_t)id}};
 222         SendCommand(&c);
 223         return 0;
 224 }
 225
 226 bool EM_EndParityTest(uint8_t *BitStream, size_t size, uint8_t rows, uint8_t cols, uint8_t pType)
 227 {
 228         if (rows*cols>size) return false;
 229         uint8_t colP=0;
 230         //assume last col is a parity and do not test
 231         for (uint8_t colNum = 0; colNum < cols-1; colNum++) {
 232                 for (uint8_t rowNum = 0; rowNum < rows; rowNum++) {
 233                         colP ^= BitStream[(rowNum*cols)+colNum];
 234                 }
 235                 if (colP != pType) return false;
 236         }
 237         return true;
 238 }
 239
 240 bool EM_ByteParityTest(uint8_t *BitStream, size_t size, uint8_t rows, uint8_t cols, uint8_t pType)
 241 {
 242         if (rows*cols>size) return false;
 243         uint8_t rowP=0;
 244         //assume last row is a parity row and do not test
 245         for (uint8_t rowNum = 0; rowNum < rows-1; rowNum++) {
 246                 for (uint8_t colNum = 0; colNum < cols; colNum++) {
 247                         rowP ^= BitStream[(rowNum*cols)+colNum];
 248                 }
 249                 if (rowP != pType) return false;
 250         }
 251         return true;
 252 }
 253
 254 uint32_t OutputEM4x50_Block(uint8_t *BitStream, size_t size, bool verbose, bool pTest)
 255 {
 256         if (size<45) return 0;
 257
 258         uint32_t code = bytebits_to_byte(BitStream,8);
 259         code = code<<8 | bytebits_to_byte(BitStream+9,8);
 260         code = code<<8 | bytebits_to_byte(BitStream+18,8);
 261         code = code<<8 | bytebits_to_byte(BitStream+27,8);
 262
 263         if (verbose || g_debugMode){
 264                 for (uint8_t i = 0; i<5; i++){
 265                         if (i == 4) PrintAndLog(""); //parity byte spacer
 266                         PrintAndLog("%d%d%d%d%d%d%d%d %d -> 0x%02x",
 267                             BitStream[i*9],
 268                             BitStream[i*9+1],
 269                             BitStream[i*9+2],
 270                             BitStream[i*9+3],
 271                             BitStream[i*9+4],
 272                             BitStream[i*9+5],
 273                             BitStream[i*9+6],
 274                             BitStream[i*9+7],
 275                             BitStream[i*9+8],
 276                             bytebits_to_byte(BitStream+i*9,8)
 277                         );
 278                 }
 279                 if (pTest)
 280                         PrintAndLog("Parity Passed");
 281                 else
 282                         PrintAndLog("Parity Failed");
 283         }
 284         return code;
 285 }
 286 /* Read the transmitted data of an EM4x50 tag from the graphbuffer
 287  * Format:
 288  *
 289  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 290  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 291  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 292  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 293  *  CCCCCCCC                         <- column parity bits
 294  *  0                                <- stop bit
 295  *  LW                               <- Listen Window
 296  *
 297  * This pattern repeats for every block of data being transmitted.
 298  * Transmission starts with two Listen Windows (LW - a modulated
 299  * pattern of 320 cycles each (32/32/128/64/64)).
 300  *
 301  * Note that this data may or may not be the UID. It is whatever data
 302  * is stored in the blocks defined in the control word First and Last
 303  * Word Read values. UID is stored in block 32.
 304  */
 305  //completed by Marshmellow
 306 int EM4x50Read(const char *Cmd, bool verbose)
 307 {
 308
 309         uint8_t fndClk[] = {8,16,32,40,50,64,128};
 310         int clk = 0;
 311         int invert = 0;
 312         int tol = 0;
 313         int i, j, startblock, skip, block, start, end, low, high, minClk;
 314         bool complete = false;
 315         int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
 316         uint32_t Code[6];
 317         char tmp[6];
 318         char tmp2[20];
 319         int phaseoff;
 320         high = low = 0;
 321         memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);
 322
 323         // get user entry if any
 324         sscanf(Cmd, "%i %i", &clk, &invert);
 325
 326         // save GraphBuffer - to restore it later
 327         save_restoreGB(1);
 328
 329         // first get high and low values
 330         for (i = 0; i < GraphTraceLen; i++) {
 331                 if (GraphBuffer[i] > high)
 332                         high = GraphBuffer[i];
 333                 else if (GraphBuffer[i] < low)
 334                         low = GraphBuffer[i];
 335         }
 336
 337         i = 0;
 338         j = 0;
 339         minClk = 255;
 340         // get to first full low to prime loop and skip incomplete first pulse
 341         while ((GraphBuffer[i] < high) && (i < GraphTraceLen))
 342                 ++i;
 343         while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
 344                 ++i;
 345         skip = i;
 346
 347         // populate tmpbuff buffer with pulse lengths
 348         while (i < GraphTraceLen) {
 349                 // measure from low to low
 350                 while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
 351                         ++i;
 352                 start= i;
 353                 while ((GraphBuffer[i] < high) && (i < GraphTraceLen))
 354                         ++i;
 355                 while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
 356                         ++i;
 357                 if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
 358                         break;
 359                 }
 360                 tmpbuff[j++]= i - start;
 361                 if (i-start < minClk && i < GraphTraceLen) {
 362                         minClk = i - start;
 363                 }
 364         }
 365         // set clock
 366         if (!clk) {
 367                 for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
 368                         tol = fndClk[clkCnt]/8;
 369                         if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
 370                                 clk=fndClk[clkCnt];
 371                                 break;
 372                         }
 373                 }
 374                 if (!clk) {
 375                         PrintAndLog("ERROR: EM4x50 - didn't find a clock");
 376                         return 0;
 377                 }
 378         } else tol = clk/8;
 379
 380         // look for data start - should be 2 pairs of LW (pulses of clk*3,clk*2)
 381         start = -1;
 382         for (i= 0; i < j - 4 ; ++i) {
 383                 skip += tmpbuff[i];
 384                 if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)  //3 clocks
 385                         if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol)  //2 clocks
 386                                 if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
 387                                         if (tmpbuff[i+3] >= clk-tol)  //1.5 to 2 clocks - depends on bit following
 388                                         {
 389                                                 start= i + 4;
 390                                                 break;
 391                                         }
 392         }
 393         startblock = i + 4;
 394
 395         // skip over the remainder of LW
 396         skip += tmpbuff[i+1] + tmpbuff[i+2] + clk;
 397         if (tmpbuff[i+3]>clk)
 398                 phaseoff = tmpbuff[i+3]-clk;
 399         else
 400                 phaseoff = 0;
 401         // now do it again to find the end
 402         end = skip;
 403         for (i += 3; i < j - 4 ; ++i) {
 404                 end += tmpbuff[i];
 405                 if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)  //3 clocks
 406                         if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol)  //2 clocks
 407                                 if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
 408                                         if (tmpbuff[i+3] >= clk-tol)  //1.5 to 2 clocks - depends on bit following
 409                                         {
 410                                                 complete= true;
 411                                                 break;
 412                                         }
 413         }
 414         end = i;
 415         // report back
 416         if (verbose || g_debugMode) {
 417                 if (start >= 0) {
 418                         PrintAndLog("\nNote: one block = 50 bits (32 data, 12 parity, 6 marker)");
 419                 }       else {
 420                         PrintAndLog("No data found!, clock tried:%d",clk);
 421                         PrintAndLog("Try again with more samples.");
 422                         PrintAndLog("  or after a 'data askedge' command to clean up the read");
 423                         return 0;
 424                 }
 425         } else if (start < 0) return 0;
 426         start = skip;
 427         snprintf(tmp2, sizeof(tmp2),"%d %d 1000 %d", clk, invert, clk*47);
 428         // get rid of leading crap
 429         snprintf(tmp, sizeof(tmp), "%i", skip);
 430         CmdLtrim(tmp);
 431         bool pTest;
 432         bool AllPTest = true;
 433         // now work through remaining buffer printing out data blocks
 434         block = 0;
 435         i = startblock;
 436         while (block < 6) {
 437                 if (verbose || g_debugMode) PrintAndLog("\nBlock %i:", block);
 438                 skip = phaseoff;
 439
 440                 // look for LW before start of next block
 441                 for ( ; i < j - 4 ; ++i) {
 442                         skip += tmpbuff[i];
 443                         if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)
 444                                 if (tmpbuff[i+1] >= clk-tol)
 445                                         break;
 446                 }
 447                 if (i >= j-4) break; //next LW not found
 448                 skip += clk;
 449                 if (tmpbuff[i+1]>clk)
 450                         phaseoff = tmpbuff[i+1]-clk;
 451                 else
 452                         phaseoff = 0;
 453                 i += 2;
 454                 if (ASKDemod(tmp2, false, false, 1) < 1) {
 455                         save_restoreGB(0);
 456                         return 0;
 457                 }
 458                 //set DemodBufferLen to just one block
 459                 DemodBufferLen = skip/clk;
 460                 //test parities
 461                 pTest = EM_ByteParityTest(DemodBuffer,DemodBufferLen,5,9,0);
 462                 pTest &= EM_EndParityTest(DemodBuffer,DemodBufferLen,5,9,0);
 463                 AllPTest &= pTest;
 464                 //get output
 465                 Code[block] = OutputEM4x50_Block(DemodBuffer,DemodBufferLen,verbose, pTest);
 466                 if (g_debugMode) PrintAndLog("\nskipping %d samples, bits:%d", skip, skip/clk);
 467                 //skip to start of next block
 468                 snprintf(tmp,sizeof(tmp),"%i",skip);
 469                 CmdLtrim(tmp);
 470                 block++;
 471                 if (i >= end) break; //in case chip doesn't output 6 blocks
 472         }
 473         //print full code:
 474         if (verbose || g_debugMode || AllPTest){
 475                 if (!complete) {
 476                         PrintAndLog("*** Warning!");
 477                         PrintAndLog("Partial data - no end found!");
 478                         PrintAndLog("Try again with more samples.");
 479                 }
 480                 PrintAndLog("Found data at sample: %i - using clock: %i", start, clk);
 481                 end = block;
 482                 for (block=0; block < end; block++){
 483                         PrintAndLog("Block %d: %08x",block,Code[block]);
 484                 }
 485                 if (AllPTest) {
 486                         PrintAndLog("Parities Passed");
 487                 } else {
 488                         PrintAndLog("Parities Failed");
 489                         PrintAndLog("Try cleaning the read samples with 'data askedge'");
 490                 }
 491         }
 492
 493         //restore GraphBuffer
 494         save_restoreGB(0);
 495         return (int)AllPTest;
 496 }
 497
 498 int CmdEM4x50Read(const char *Cmd) {
 499         return EM4x50Read(Cmd, true);
 500 }
 501
 502 int usage_lf_em_read(void) {
 503         PrintAndLog("Read EM4x50.  Tag must be on antenna. ");
 504         PrintAndLog("");
 505         PrintAndLog("Usage:  lf em readword [h] <address> <pwd>");
 506         PrintAndLog("Options:");
 507         PrintAndLog("       h         - this help");
 508         PrintAndLog("       address   - memory address to read. (0-15)");
 509         PrintAndLog("       pwd       - password (hex) (optional)");
 510         PrintAndLog("samples:");
 511         PrintAndLog("      lf em readword 1");
 512         PrintAndLog("      lf em readword 1 11223344");
 513         return 0;
 514 }
 515 int CmdReadWord(const char *Cmd) {
 516         int addr, pwd;
 517         bool usePwd = false;
 518         uint8_t ctmp = param_getchar(Cmd, 0);
 519         if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_read();
 520
 521         addr = param_get8ex(Cmd, 0, -1, 10);
 522         pwd =  param_get32ex(Cmd, 1, -1, 16);
 523
 524         if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
 525                 PrintAndLog("Address must be between 0 and 15");
 526                 return 1;
 527         }
 528         if ( pwd == -1 )
 529                 PrintAndLog("Reading address %d", addr);
 530         else {
 531                 usePwd = true;
 532                 PrintAndLog("Reading address %d | password %08X", addr, pwd);
 533         }
 534
 535         UsbCommand c = {CMD_EM4X_READ_WORD, {addr, pwd, usePwd}};
 536         clearCommandBuffer();
 537         SendCommand(&c);
 538         UsbCommand resp;
 539         if (!WaitForResponseTimeout(CMD_ACK, &resp, 2500)){
 540                 PrintAndLog("Command timed out");
 541                 return -1;
 542         }
 543
 544         uint8_t got[6000];
 545         GetFromBigBuf(got, sizeof(got), 0);
 546         if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2500) ) {
 547                 PrintAndLog("command execution time out");
 548                 return -1;
 549         }
 550         setGraphBuf(got, sizeof(got));
 551
 552
 553         int ans = 0;
 554         //bool ST = true;
 555         DemodBufferLen = 0x00;
 556
 557         //ans = ASKDemod_ext("0 0 1", FALSE, FALSE, 1, &ST);
 558         ans = ASKbiphaseDemod("0 0 1", FALSE);
 559         if (!ans) {
 560                 if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed");
 561                 return -1;
 562         }
 563
 564         size_t startIdx = 0, size = DemodBufferLen;
 565
 566         PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size);
 567
 568
 569         uint8_t preamble[8] = {0,0,0,0,1,0,1,0};
 570         uint8_t errChk = !preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx);
 571         if ( errChk == 0) {
 572                 if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
 573                 return -1;
 574         }
 575
 576         // sanity check.
 577         if (size != 32) {
 578                 if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 incorrect data length found,  %u", size );
 579                 return -1;
 580         }
 581
 582         //setDemodBuf(BitStream, 32, preambleIndex);
 583
 584         return 1;
 585 }
 586
 587 int usage_lf_em_write(void) {
 588         PrintAndLog("Write EM4x50.  Tag must be on antenna. ");
 589         PrintAndLog("");
 590         PrintAndLog("Usage:  lf em writeword [h] <address> <data> <pwd>");
 591         PrintAndLog("Options:");
 592         PrintAndLog("       h         - this help");
 593         PrintAndLog("       address   - memory address to write to. (0-15)");
 594         PrintAndLog("       data      - data to write (hex)");
 595         PrintAndLog("       pwd       - password (hex) (optional)");
 596         PrintAndLog("samples:");
 597         PrintAndLog("      lf em writeword 1");
 598         PrintAndLog("      lf em writeword 1 deadc0de 11223344");
 599         return 0;
 600 }
 601 int CmdWriteWord(const char *Cmd) {
 602         uint8_t ctmp = param_getchar(Cmd, 0);
 603         if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_write();
 604
 605         bool usePwd = false;
 606
 607         int addr = 16; // default to invalid address
 608         int data = 0xFFFFFFFF; // default to blank data
 609         int pwd = 0xFFFFFFFF; // default to blank password
 610
 611         addr = param_get8ex(Cmd, 0, -1, 10);
 612         data = param_get32ex(Cmd, 1, -1, 16);
 613         pwd =  param_get32ex(Cmd, 2, -1, 16);
 614
 615
 616         if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
 617                 PrintAndLog("Address must be between 0 and 15");
 618                 return 1;
 619         }
 620         if ( pwd == -1 )
 621                 PrintAndLog("Writing address %d data %08X", addr, data);
 622         else {
 623                 usePwd = true;
 624                 PrintAndLog("Writing address %d data %08X using password %08X", addr, data, pwd);
 625         }
 626
 627         uint16_t flag = (addr << 8 ) | usePwd;
 628
 629         UsbCommand c = {CMD_EM4X_WRITE_WORD, {flag, data, pwd}};
 630         clearCommandBuffer();
 631         SendCommand(&c);
 632         UsbCommand resp;
 633         if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
 634                 PrintAndLog("Error occurred, device did not respond during write operation.");
 635                 return -1;
 636         }
 637
 638         //get response if there is one
 639         uint8_t got[6000]; // 8 bit preamble + 32 bit word response (max clock (128) * 40bits = 5120 samples)
 640         GetFromBigBuf(got, sizeof(got), 0);
 641         if ( !WaitForResponseTimeout(CMD_ACK, NULL, 8000) ) {
 642                 PrintAndLog("command execution time out");
 643                 return -2;
 644         }
 645         setGraphBuf(got, sizeof(got));
 646
 647         int ans = 0;
 648         //bool ST = true;
 649         DemodBufferLen = 0x00;
 650
 651         //ans = ASKDemod_ext("0 0 1", FALSE, FALSE, 1, &ST);
 652         ans = ASKbiphaseDemod("0 0 1", FALSE);
 653         if (!ans) {
 654                 if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed");
 655                 return -3;
 656         }
 657         PrintAndLog("ANS: %d", ans);
 658
 659         //todo: check response for 00001010 then write data for write confirmation!
 660         size_t startIdx = 0, size = DemodBufferLen;
 661
 662         uint8_t preamble[8] = {0,0,0,0,1,0,1,0};
 663         if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)){
 664                 if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
 665                 return -4;
 666         }
 667         PrintAndLog("Write OK");
 668         return 0;
 669 }
 670
 671 static command_t CommandTable[] = {
 672         {"help",                CmdHelp,                        1, "This help"},
 673         {"em410xdemod", CmdEMdemodASK,          0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},
 674         {"em410xread",  CmdEM410xRead,          1, "[clock rate] -- Extract ID from EM410x tag in GraphBuffer"},
 675         {"em410xsim",   CmdEM410xSim,           0, "<UID> -- Simulate EM410x tag"},
 676         {"em410xwatch", CmdEM410xWatch,         0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
 677         {"em410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
 678         {"em410xwrite", CmdEM410xWrite,         0, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
 679         {"em4x50read",  CmdEM4x50Read,          1, "demod data from EM4x50 tag from the graphbuffer"},
 680         {"readword",    CmdReadWord,            1, "read EM4x05/4x69 data"},
 681         {"writeword",   CmdWriteWord,           1, "write EM405/4x69 data"},
 682         {NULL, NULL, 0, NULL}
 683 };
 684
 685 int CmdLFEM4X(const char *Cmd) {
 686         clearCommandBuffer();
 687         CmdsParse(CommandTable, Cmd);
 688         return 0;
 689 }
 690
 691 int CmdHelp(const char *Cmd) {
 692         CmdsHelp(CommandTable);
 693         return 0;
 694 }