git.zerfleddert.de Git - proxmark3-svn/blob - client/cmdhf15.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 // High frequency ISO15693 commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <stdint.h>
  15 #include "proxusb.h"
  16 #include "data.h"
  17 #include "graph.h"
  18 #include "ui.h"
  19 #include "cmdparser.h"
  20 #include "cmdhf15.h"
  21
  22 static int CmdHelp(const char *Cmd);
  23
  24 static uint16_t Iso15693Crc(uint8_t *v, int n)
  25 {
  26   uint32_t reg;
  27   int i, j;
  28
  29   reg = 0xffff;
  30   for (i = 0; i < n; i++) {
  31     reg = reg ^ ((uint32_t)v[i]);
  32     for (j = 0; j < 8; j++) {
  33       if (reg & 0x0001) {
  34         reg = (reg >> 1) ^ 0x8408;
  35       } else {
  36         reg = (reg >> 1);
  37       }
  38     }
  39   }
  40
  41   return (uint16_t)~reg;
  42 }
  43
  44 int CmdHF15Demod(const char *Cmd)
  45 {
  46   // The sampling rate is 106.353 ksps/s, for T = 18.8 us
  47
  48   // SOF defined as
  49   // 1) Unmodulated time of 56.64us
  50   // 2) 24 pulses of 423.75khz
  51   // 3) logic '1' (unmodulated for 18.88us followed by 8 pulses of 423.75khz)
  52
  53   static const int FrameSOF[] = {
  54     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  55     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  56      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
  57      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
  58     -1, -1, -1, -1,
  59     -1, -1, -1, -1,
  60      1,  1,  1,  1,
  61      1,  1,  1,  1
  62   };
  63   static const int Logic0[] = {
  64      1,  1,  1,  1,
  65      1,  1,  1,  1,
  66     -1, -1, -1, -1,
  67     -1, -1, -1, -1
  68   };
  69   static const int Logic1[] = {
  70     -1, -1, -1, -1,
  71     -1, -1, -1, -1,
  72      1,  1,  1,  1,
  73      1,  1,  1,  1
  74   };
  75
  76   // EOF defined as
  77   // 1) logic '0' (8 pulses of 423.75khz followed by unmodulated for 18.88us)
  78   // 2) 24 pulses of 423.75khz
  79   // 3) Unmodulated time of 56.64us
  80
  81   static const int FrameEOF[] = {
  82      1,  1,  1,  1,
  83      1,  1,  1,  1,
  84     -1, -1, -1, -1,
  85     -1, -1, -1, -1,
  86      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
  87      1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
  88     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  89     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
  90   };
  91
  92   int i, j;
  93   int max = 0, maxPos = 0;
  94
  95   int skip = 4;
  96
  97   if (GraphTraceLen < 1000) return 0;
  98
  99   // First, correlate for SOF
 100   for (i = 0; i < 100; i++) {
 101     int corr = 0;
 102     for (j = 0; j < arraylen(FrameSOF); j += skip) {
 103       corr += FrameSOF[j] * GraphBuffer[i + (j / skip)];
 104     }
 105     if (corr > max) {
 106       max = corr;
 107       maxPos = i;
 108     }
 109   }
 110   PrintAndLog("SOF at %d, correlation %d", maxPos,
 111     max / (arraylen(FrameSOF) / skip));
 112
 113   i = maxPos + arraylen(FrameSOF) / skip;
 114   int k = 0;
 115   uint8_t outBuf[20];
 116   memset(outBuf, 0, sizeof(outBuf));
 117   uint8_t mask = 0x01;
 118   for (;;) {
 119     int corr0 = 0, corr1 = 0, corrEOF = 0;
 120     for (j = 0; j < arraylen(Logic0); j += skip) {
 121       corr0 += Logic0[j] * GraphBuffer[i + (j / skip)];
 122     }
 123     for (j = 0; j < arraylen(Logic1); j += skip) {
 124       corr1 += Logic1[j] * GraphBuffer[i + (j / skip)];
 125     }
 126     for (j = 0; j < arraylen(FrameEOF); j += skip) {
 127       corrEOF += FrameEOF[j] * GraphBuffer[i + (j / skip)];
 128     }
 129     // Even things out by the length of the target waveform.
 130     corr0 *= 4;
 131     corr1 *= 4;
 132
 133     if (corrEOF > corr1 && corrEOF > corr0) {
 134       PrintAndLog("EOF at %d", i);
 135       break;
 136     } else if (corr1 > corr0) {
 137       i += arraylen(Logic1) / skip;
 138       outBuf[k] |= mask;
 139     } else {
 140       i += arraylen(Logic0) / skip;
 141     }
 142     mask <<= 1;
 143     if (mask == 0) {
 144       k++;
 145       mask = 0x01;
 146     }
 147     if ((i + (int)arraylen(FrameEOF)) >= GraphTraceLen) {
 148       PrintAndLog("ran off end!");
 149       break;
 150     }
 151   }
 152   if (mask != 0x01) {
 153     PrintAndLog("error, uneven octet! (discard extra bits!)");
 154     PrintAndLog("   mask=%02x", mask);
 155   }
 156   PrintAndLog("%d octets", k);
 157
 158   for (i = 0; i < k; i++) {
 159     PrintAndLog("# %2d: %02x ", i, outBuf[i]);
 160   }
 161   PrintAndLog("CRC=%04x", Iso15693Crc(outBuf, k - 2));
 162   return 0;
 163 }
 164
 165 int CmdHF15Read(const char *Cmd)
 166 {
 167   UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_15693};
 168   SendCommand(&c);
 169   return 0;
 170 }
 171
 172 int CmdHF15Reader(const char *Cmd)
 173 {
 174   UsbCommand c = {CMD_READER_ISO_15693, {strtol(Cmd, NULL, 0), 0, 0}};
 175   SendCommand(&c);
 176   return 0;
 177 }
 178
 179 int CmdHF15Sim(const char *Cmd)
 180 {
 181   UsbCommand c = {CMD_SIMTAG_ISO_15693, {strtol(Cmd, NULL, 0), 0, 0}};
 182   SendCommand(&c);
 183   return 0;
 184 }
 185
 186 static command_t CommandTable[] =
 187 {
 188   {"help",    CmdHelp,        1, "This help"},
 189   {"demod",   CmdHF15Demod,   1, "Demodulate ISO15693 from tag"},
 190   {"read",    CmdHF15Read,    0, "Read HF tag (ISO 15693)"},
 191   {"reader",  CmdHF15Reader,  0, "Act like an ISO15693 reader"},
 192   {"sim",     CmdHF15Sim,     0, "Fake an ISO15693 tag"},
 193   {NULL, NULL, 0, NULL}
 194 };
 195
 196 int CmdHF15(const char *Cmd)
 197 {
 198   CmdsParse(CommandTable, Cmd);
 199   return 0;
 200 }
 201
 202 int CmdHelp(const char *Cmd)
 203 {
 204   CmdsHelp(CommandTable);
 205   return 0;
 206 }