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

   1 //-----------------------------------------------------------------------------
   2 //
   3 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   4 // at your option, any later version. See the LICENSE.txt file for the text of
   5 // the license.
   6 //-----------------------------------------------------------------------------
   7 // Low frequency Stanley/PAC tag commands
   8 // NRZ, RF/32, 128 bits long (unknown cs)
   9 //-----------------------------------------------------------------------------
  10 #include "cmdlfpac.h"
  11 #include <string.h>
  12 #include <inttypes.h>
  13 #include "proxmark3.h"
  14 #include "ui.h"
  15 #include "util.h"
  16 #include "graph.h"
  17 #include "cmdparser.h"
  18 #include "cmddata.h"
  19 #include "cmdmain.h"
  20 #include "cmdlf.h"
  21 #include "lfdemod.h"    // preamble test
  22
  23 static int CmdHelp(const char *Cmd);
  24
  25 // by marshmellow
  26 // find PAC preamble in already demoded data
  27 int PacFind(uint8_t *dest, size_t *size) {
  28         if (*size < 128) return -1; //make sure buffer has data
  29         size_t startIdx = 0;
  30         uint8_t preamble[] = {1,1,1,1,1,1,1,1,0,0,1,0,0,0,0,0,0,1,0};
  31         if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
  32                 return -2; //preamble not found
  33         if (*size != 128) return -3; //wrong demoded size
  34         //return start position
  35         return (int)startIdx;
  36 }
  37
  38 //see NRZDemod for what args are accepted
  39 int CmdPacDemod(const char *Cmd) {
  40
  41         //NRZ
  42         if (!NRZrawDemod(Cmd, false)) {
  43                 if (g_debugMode) PrintAndLog("DEBUG: Error - PAC: NRZ Demod failed");
  44                 return 0;
  45         }
  46         size_t size = DemodBufferLen;
  47         int ans = PacFind(DemodBuffer, &size);
  48         if (ans < 0) {
  49                 if (g_debugMode) {
  50                         if (ans == -1)
  51                                 PrintAndLog("DEBUG: Error - PAC: too few bits found");
  52                         else if (ans == -2)
  53                                 PrintAndLog("DEBUG: Error - PAC: preamble not found");
  54                         else if (ans == -3)
  55                                 PrintAndLog("DEBUG: Error - PAC: Size not correct: %d", size);
  56                         else
  57                                 PrintAndLog("DEBUG: Error - PAC: ans: %d", ans);
  58                 }
  59                 return 0;
  60         }
  61         setDemodBuf(DemodBuffer, 128, ans);
  62         setClockGrid(g_DemodClock, g_DemodStartIdx + (ans*g_DemodClock));
  63
  64         //got a good demod
  65         uint32_t raw1 = bytebits_to_byte(DemodBuffer   , 32);
  66         uint32_t raw2 = bytebits_to_byte(DemodBuffer+32, 32);
  67         uint32_t raw3 = bytebits_to_byte(DemodBuffer+64, 32);
  68         uint32_t raw4 = bytebits_to_byte(DemodBuffer+96, 32);
  69
  70         // preamble     then appears to have marker bits of "10"                                                                                                                                       CS?
  71         // 11111111001000000 10 01001100 10 00001101 10 00001101 10 00001101 10 00001101 10 00001101 10 00001101 10 00001101 10 00001101 10 10001100 10 100000001
  72         // unknown checksum 9 bits at the end
  73
  74         PrintAndLog("PAC/Stanley Tag Found -- Raw: %08X%08X%08X%08X", raw1 ,raw2, raw3, raw4);
  75         PrintAndLog("\nHow the Raw ID is translated by the reader is unknown");
  76         return 1;
  77 }
  78
  79 int CmdPacRead(const char *Cmd) {
  80         lf_read(true, 4096*2 + 20);
  81         return CmdPacDemod(Cmd);
  82 }
  83
  84 static command_t CommandTable[] = {
  85         {"help",  CmdHelp,    1, "This help"},
  86         {"demod", CmdPacDemod,1, "Attempt to read and extract tag data from the GraphBuffer"},
  87         {"read",  CmdPacRead, 0, "Attempt to read and extract tag data from the antenna"},
  88         {NULL, NULL, 0, NULL}
  89 };
  90
  91 int CmdLFPac(const char *Cmd) {
  92         clearCommandBuffer();
  93         CmdsParse(CommandTable, Cmd);
  94         return 0;
  95 }
  96
  97 int CmdHelp(const char *Cmd) {
  98         CmdsHelp(CommandTable);
  99         return 0;
 100 }