git.zerfleddert.de Git - proxmark3-svn/blob - client/cmdlf.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 commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <limits.h>
  15 #include "proxusb.h"
  16 #include "data.h"
  17 #include "graph.h"
  18 #include "ui.h"
  19 #include "cmdparser.h"
  20 #include "cmdmain.h"
  21 #include "cmddata.h"
  22 #include "cmdlf.h"
  23 #include "cmdlfhid.h"
  24 #include "cmdlfti.h"
  25 #include "cmdlfem4x.h"
  26
  27 static int CmdHelp(const char *Cmd);
  28
  29 /* send a command before reading */
  30 int CmdLFCommandRead(const char *Cmd)
  31 {
  32   static char dummy[3];
  33
  34   dummy[0]= ' ';
  35
  36   UsbCommand c = {CMD_MOD_THEN_ACQUIRE_RAW_ADC_SAMPLES_125K};
  37   sscanf(Cmd, "%i %i %i %s %s", &c.arg[0], &c.arg[1], &c.arg[2], (char *) &c.d.asBytes,(char *) &dummy+1);
  38   // in case they specified 'h'
  39   strcpy((char *)&c.d.asBytes + strlen((char *)c.d.asBytes), dummy);
  40   SendCommand(&c);
  41   return 0;
  42 }
  43
  44 int CmdFlexdemod(const char *Cmd)
  45 {
  46   int i;
  47   for (i = 0; i < GraphTraceLen; ++i) {
  48     if (GraphBuffer[i] < 0) {
  49       GraphBuffer[i] = -1;
  50     } else {
  51       GraphBuffer[i] = 1;
  52     }
  53   }
  54
  55 #define LONG_WAIT 100
  56   int start;
  57   for (start = 0; start < GraphTraceLen - LONG_WAIT; start++) {
  58     int first = GraphBuffer[start];
  59     for (i = start; i < start + LONG_WAIT; i++) {
  60       if (GraphBuffer[i] != first) {
  61         break;
  62       }
  63     }
  64     if (i == (start + LONG_WAIT)) {
  65       break;
  66     }
  67   }
  68   if (start == GraphTraceLen - LONG_WAIT) {
  69     PrintAndLog("nothing to wait for");
  70     return 0;
  71   }
  72
  73   GraphBuffer[start] = 2;
  74   GraphBuffer[start+1] = -2;
  75
  76   uint8_t bits[64];
  77
  78   int bit;
  79   i = start;
  80   for (bit = 0; bit < 64; bit++) {
  81     int j;
  82     int sum = 0;
  83     for (j = 0; j < 16; j++) {
  84       sum += GraphBuffer[i++];
  85     }
  86     if (sum > 0) {
  87       bits[bit] = 1;
  88     } else {
  89       bits[bit] = 0;
  90     }
  91     PrintAndLog("bit %d sum %d", bit, sum);
  92   }
  93
  94   for (bit = 0; bit < 64; bit++) {
  95     int j;
  96     int sum = 0;
  97     for (j = 0; j < 16; j++) {
  98       sum += GraphBuffer[i++];
  99     }
 100     if (sum > 0 && bits[bit] != 1) {
 101       PrintAndLog("oops1 at %d", bit);
 102     }
 103     if (sum < 0 && bits[bit] != 0) {
 104       PrintAndLog("oops2 at %d", bit);
 105     }
 106   }
 107
 108   GraphTraceLen = 32*64;
 109   i = 0;
 110   int phase = 0;
 111   for (bit = 0; bit < 64; bit++) {
 112     if (bits[bit] == 0) {
 113       phase = 0;
 114     } else {
 115       phase = 1;
 116     }
 117     int j;
 118     for (j = 0; j < 32; j++) {
 119       GraphBuffer[i++] = phase;
 120       phase = !phase;
 121     }
 122   }
 123
 124   RepaintGraphWindow();
 125   return 0;
 126 }
 127
 128 int CmdIndalaDemod(const char *Cmd)
 129 {
 130   // Usage: recover 64bit UID by default, specify "224" as arg to recover a 224bit UID
 131
 132   int state = -1;
 133   int count = 0;
 134   int i, j;
 135   // worst case with GraphTraceLen=64000 is < 4096
 136   // under normal conditions it's < 2048
 137   uint8_t rawbits[4096];
 138   int rawbit = 0;
 139   int worst = 0, worstPos = 0;
 140   PrintAndLog("Expecting a bit less than %d raw bits", GraphTraceLen / 32);
 141   for (i = 0; i < GraphTraceLen-1; i += 2) {
 142     count += 1;
 143     if ((GraphBuffer[i] > GraphBuffer[i + 1]) && (state != 1)) {
 144       if (state == 0) {
 145         for (j = 0; j <  count - 8; j += 16) {
 146           rawbits[rawbit++] = 0;
 147         }
 148         if ((abs(count - j)) > worst) {
 149           worst = abs(count - j);
 150           worstPos = i;
 151         }
 152       }
 153       state = 1;
 154       count = 0;
 155     } else if ((GraphBuffer[i] < GraphBuffer[i + 1]) && (state != 0)) {
 156       if (state == 1) {
 157         for (j = 0; j <  count - 8; j += 16) {
 158           rawbits[rawbit++] = 1;
 159         }
 160         if ((abs(count - j)) > worst) {
 161           worst = abs(count - j);
 162           worstPos = i;
 163         }
 164       }
 165       state = 0;
 166       count = 0;
 167     }
 168   }
 169   PrintAndLog("Recovered %d raw bits", rawbit);
 170   PrintAndLog("worst metric (0=best..7=worst): %d at pos %d", worst, worstPos);
 171
 172   // Finding the start of a UID
 173   int uidlen, long_wait;
 174   if (strcmp(Cmd, "224") == 0) {
 175     uidlen = 224;
 176     long_wait = 30;
 177   } else {
 178     uidlen = 64;
 179     long_wait = 29;
 180   }
 181   int start;
 182   int first = 0;
 183   for (start = 0; start <= rawbit - uidlen; start++) {
 184     first = rawbits[start];
 185     for (i = start; i < start + long_wait; i++) {
 186       if (rawbits[i] != first) {
 187         break;
 188       }
 189     }
 190     if (i == (start + long_wait)) {
 191       break;
 192     }
 193   }
 194   if (start == rawbit - uidlen + 1) {
 195     PrintAndLog("nothing to wait for");
 196     return 0;
 197   }
 198
 199   // Inverting signal if needed
 200   if (first == 1) {
 201     for (i = start; i < rawbit; i++) {
 202       rawbits[i] = !rawbits[i];
 203     }
 204   }
 205
 206   // Dumping UID
 207   uint8_t bits[224];
 208   char showbits[225];
 209   showbits[uidlen]='\0';
 210   int bit;
 211   i = start;
 212   int times = 0;
 213   if (uidlen > rawbit) {
 214     PrintAndLog("Warning: not enough raw bits to get a full UID");
 215     for (bit = 0; bit < rawbit; bit++) {
 216       bits[bit] = rawbits[i++];
 217       // As we cannot know the parity, let's use "." and "/"
 218       showbits[bit] = '.' + bits[bit];
 219     }
 220     showbits[bit+1]='\0';
 221     PrintAndLog("Partial UID=%s", showbits);
 222     return 0;
 223   } else {
 224     for (bit = 0; bit < uidlen; bit++) {
 225       bits[bit] = rawbits[i++];
 226       showbits[bit] = '0' + bits[bit];
 227     }
 228     times = 1;
 229   }
 230   PrintAndLog("UID=%s", showbits);
 231
 232   // Checking UID against next occurences
 233   for (; i + uidlen <= rawbit;) {
 234     int failed = 0;
 235     for (bit = 0; bit < uidlen; bit++) {
 236       if (bits[bit] != rawbits[i++]) {
 237         failed = 1;
 238         break;
 239       }
 240     }
 241     if (failed == 1) {
 242       break;
 243     }
 244     times += 1;
 245   }
 246   PrintAndLog("Occurences: %d (expected %d)", times, (rawbit - start) / uidlen);
 247
 248   // Remodulating for tag cloning
 249   GraphTraceLen = 32*uidlen;
 250   i = 0;
 251   int phase = 0;
 252   for (bit = 0; bit < uidlen; bit++) {
 253     if (bits[bit] == 0) {
 254       phase = 0;
 255     } else {
 256       phase = 1;
 257     }
 258     int j;
 259     for (j = 0; j < 32; j++) {
 260       GraphBuffer[i++] = phase;
 261       phase = !phase;
 262     }
 263   }
 264
 265   RepaintGraphWindow();
 266   return 0;
 267 }
 268
 269 int CmdLFRead(const char *Cmd)
 270 {
 271   UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_125K};
 272   // 'h' means higher-low-frequency, 134 kHz
 273   if(*Cmd == 'h') {
 274     c.arg[0] = 1;
 275   } else if (*Cmd == '\0') {
 276     c.arg[0] = 0;
 277   } else {
 278     PrintAndLog("use 'read' or 'read h'");
 279     return 0;
 280   }
 281   SendCommand(&c);
 282   WaitForResponse(CMD_ACK);
 283   return 0;
 284 }
 285
 286 static void ChkBitstream(const char *str)
 287 {
 288   int i;
 289
 290   /* convert to bitstream if necessary */
 291   for (i = 0; i < (int)(GraphTraceLen / 2); i++)
 292   {
 293     if (GraphBuffer[i] > 1 || GraphBuffer[i] < 0)
 294     {
 295       CmdBitstream(str);
 296       break;
 297     }
 298   }
 299 }
 300
 301 int CmdLFSim(const char *Cmd)
 302 {
 303   int i;
 304   static int gap;
 305
 306   sscanf(Cmd, "%i", &gap);
 307
 308   /* convert to bitstream if necessary */
 309   ChkBitstream(Cmd);
 310
 311   PrintAndLog("Sending data, please wait...");
 312   for (i = 0; i < GraphTraceLen; i += 48) {
 313     UsbCommand c={CMD_DOWNLOADED_SIM_SAMPLES_125K, {i, 0, 0}};
 314     int j;
 315     for (j = 0; j < 48; j++) {
 316       c.d.asBytes[j] = GraphBuffer[i+j];
 317     }
 318     SendCommand(&c);
 319     WaitForResponse(CMD_ACK);
 320   }
 321
 322   PrintAndLog("Starting simulator...");
 323   UsbCommand c = {CMD_SIMULATE_TAG_125K, {GraphTraceLen, gap, 0}};
 324   SendCommand(&c);
 325   return 0;
 326 }
 327
 328 int CmdLFSimBidir(const char *Cmd)
 329 {
 330   /* Set ADC to twice the carrier for a slight supersampling */
 331   UsbCommand c = {CMD_LF_SIMULATE_BIDIR, {47, 384, 0}};
 332   SendCommand(&c);
 333   return 0;
 334 }
 335
 336 /* simulate an LF Manchester encoded tag with specified bitstream, clock rate and inter-id gap */
 337 int CmdLFSimManchester(const char *Cmd)
 338 {
 339   static int clock, gap;
 340   static char data[1024], gapstring[8];
 341
 342   /* get settings/bits */
 343   sscanf(Cmd, "%i %s %i", &clock, &data[0], &gap);
 344
 345   /* clear our graph */
 346   ClearGraph(0);
 347
 348   /* fill it with our bitstream */
 349   for (int i = 0; i < strlen(data) ; ++i)
 350     AppendGraph(0, clock, data[i]- '0');
 351
 352   /* modulate */
 353   CmdManchesterMod("");
 354
 355   /* show what we've done */
 356   RepaintGraphWindow();
 357
 358   /* simulate */
 359   sprintf(&gapstring[0], "%i", gap);
 360   CmdLFSim(gapstring);
 361   return 0;
 362 }
 363
 364 int CmdVchDemod(const char *Cmd)
 365 {
 366   // Is this the entire sync pattern, or does this also include some
 367   // data bits that happen to be the same everywhere? That would be
 368   // lovely to know.
 369   static const int SyncPattern[] = {
 370     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
 371     1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 372     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
 373     1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 374     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
 375     1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 376     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
 377     1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 378     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
 379     1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 380   };
 381
 382   // So first, we correlate for the sync pattern, and mark that.
 383   int bestCorrel = 0, bestPos = 0;
 384   int i;
 385   // It does us no good to find the sync pattern, with fewer than
 386   // 2048 samples after it...
 387   for (i = 0; i < (GraphTraceLen-2048); i++) {
 388     int sum = 0;
 389     int j;
 390     for (j = 0; j < arraylen(SyncPattern); j++) {
 391       sum += GraphBuffer[i+j]*SyncPattern[j];
 392     }
 393     if (sum > bestCorrel) {
 394       bestCorrel = sum;
 395       bestPos = i;
 396     }
 397   }
 398   PrintAndLog("best sync at %d [metric %d]", bestPos, bestCorrel);
 399
 400   char bits[257];
 401   bits[256] = '\0';
 402
 403   int worst = INT_MAX;
 404   int worstPos;
 405
 406   for (i = 0; i < 2048; i += 8) {
 407     int sum = 0;
 408     int j;
 409     for (j = 0; j < 8; j++) {
 410       sum += GraphBuffer[bestPos+i+j];
 411     }
 412     if (sum < 0) {
 413       bits[i/8] = '.';
 414     } else {
 415       bits[i/8] = '1';
 416     }
 417     if(abs(sum) < worst) {
 418       worst = abs(sum);
 419       worstPos = i;
 420     }
 421   }
 422   PrintAndLog("bits:");
 423   PrintAndLog("%s", bits);
 424   PrintAndLog("worst metric: %d at pos %d", worst, worstPos);
 425
 426   if (strcmp(Cmd, "clone")==0) {
 427     GraphTraceLen = 0;
 428     char *s;
 429     for(s = bits; *s; s++) {
 430       int j;
 431       for(j = 0; j < 16; j++) {
 432         GraphBuffer[GraphTraceLen++] = (*s == '1') ? 1 : 0;
 433       }
 434     }
 435     RepaintGraphWindow();
 436   }
 437   return 0;
 438 }
 439
 440 static command_t CommandTable[] =
 441 {
 442   {"help",        CmdHelp,            1, "This help"},
 443   {"cmdread",     CmdLFCommandRead,   0, "<off period> <'0' period> <'1' period> <command> ['h'] -- Modulate LF reader field to send command before read (all periods in microseconds) (option 'h' for 134)"},
 444   {"em4x",        CmdLFEM4X,          1, "{ EM4X RFIDs... }"},
 445   {"flexdemod",   CmdFlexdemod,       1, "Demodulate samples for FlexPass"},
 446   {"hid",         CmdLFHID,           1, "{ HID RFIDs... }"},
 447   {"indalademod", CmdIndalaDemod,     1, "['224'] -- Demodulate samples for Indala 64 bit UID (option '224' for 224 bit)"},
 448   {"read",        CmdLFRead,          0, "['h'] -- Read 125/134 kHz LF ID-only tag (option 'h' for 134)"},
 449   {"sim",         CmdLFSim,           0, "[GAP] -- Simulate LF tag from buffer with optional GAP (in microseconds)"},
 450   {"simbidir",    CmdLFSimBidir,      0, "Simulate LF tag (with bidirectional data transmission between reader and tag)"},
 451   {"simman",      CmdLFSimManchester, 0, "<Clock> <Bitstream> [GAP] Simulate arbitrary Manchester LF tag"},
 452   {"ti",          CmdLFTI,            1, "{ TI RFIDs... }"},
 453   {"vchdemod",    CmdVchDemod,        1, "['clone'] -- Demodulate samples for VeriChip"},
 454   {NULL, NULL, 0, NULL}
 455 };
 456
 457 int CmdLF(const char *Cmd)
 458 {
 459   CmdsParse(CommandTable, Cmd);
 460   return 0;
 461 }
 462
 463 int CmdHelp(const char *Cmd)
 464 {
 465   CmdsHelp(CommandTable);
 466   return 0;
 467 }