git.zerfleddert.de Git - proxmark3-svn/blob - client/cmdlfnexwatch.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 Honeywell NexWatch tag commands
   8 // PSK1 RF/16, RF/2, 128 bits long (known)
   9 //-----------------------------------------------------------------------------
  10
  11 #include "cmdlfnexwatch.h"
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <inttypes.h>
  16 #include <stdbool.h>
  17 #include "comms.h"
  18 #include "ui.h"
  19 #include "util.h"
  20 #include "graph.h"
  21 #include "cmdparser.h"
  22 #include "cmddata.h"
  23 #include "cmdlf.h"
  24 #include "lfdemod.h"
  25
  26 static int CmdHelp(const char *Cmd);
  27
  28 int CmdPSKNexWatch(const char *Cmd)
  29 {
  30         if (!PSKDemod("", false)) return 0;
  31         uint8_t preamble[28] = {0,0,0,0,0,1,0,1,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
  32         size_t startIdx = 0, size = DemodBufferLen;
  33         bool invert = false;
  34         if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)){
  35                 // if didn't find preamble try again inverting
  36                 if (!PSKDemod("1", false)) return 0;
  37                 size = DemodBufferLen;
  38                 if (!preambleSearch(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx)) return 0;
  39                 invert = true;
  40         }
  41         if (size != 128) return 0;
  42         setDemodBuf(DemodBuffer, size, startIdx+4);
  43         setClockGrid(g_DemodClock, g_DemodStartIdx + ((startIdx+4)*g_DemodClock));
  44         startIdx = 8+32; // 8 = preamble, 32 = reserved bits (always 0)
  45         //get ID
  46         uint32_t ID = 0;
  47         for (uint8_t wordIdx=0; wordIdx<4; wordIdx++){
  48                 for (uint8_t idx=0; idx<8; idx++){
  49                         ID = (ID << 1) | DemodBuffer[startIdx+wordIdx+(idx*4)];
  50                 }
  51         }
  52         //parity check (TBD)
  53
  54         //checksum check (TBD)
  55
  56         //output
  57         PrintAndLog("NexWatch ID: %d", ID);
  58         if (invert){
  59                 PrintAndLog("Had to Invert - probably NexKey");
  60                 for (uint8_t idx=0; idx<size; idx++)
  61                         DemodBuffer[idx] ^= 1;
  62         }
  63
  64         CmdPrintDemodBuff("x");
  65         return 1;
  66 }
  67
  68 //by marshmellow
  69 //see ASKDemod for what args are accepted
  70 int CmdNexWatchRead(const char *Cmd) {
  71         // read lf silently
  72         lf_read(true, 10000);
  73         // demod and output viking ID
  74         return CmdPSKNexWatch(Cmd);
  75 }
  76
  77 static command_t CommandTable[] = {
  78         {"help",  CmdHelp,          1, "This help"},
  79         {"demod", CmdPSKNexWatch,   1, "Demodulate a NexWatch tag (nexkey, quadrakey) from the GraphBuffer"},
  80         {"read",  CmdNexWatchRead,  0, "Attempt to Read and Extract tag data from the antenna"},
  81         {NULL, NULL, 0, NULL}
  82 };
  83
  84 int CmdLFNexWatch(const char *Cmd) {
  85         CmdsParse(CommandTable, Cmd);
  86         return 0;
  87 }
  88
  89 int CmdHelp(const char *Cmd) {
  90         CmdsHelp(CommandTable);
  91         return 0;
  92 }