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