git.zerfleddert.de Git - proxmark3-svn/blob - client/cmdhf15.c

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