git.zerfleddert.de Git - proxmark3-svn/blob - client/cmdhf14b.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 ISO14443B commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <stdbool.h>
  14 #include <string.h>
  15 #include <stdint.h>
  16 #include "iso14443crc.h"
  17 #include "proxusb.h"
  18 #include "proxmark3.h"
  19 #include "data.h"
  20 #include "graph.h"
  21 #include "ui.h"
  22 #include "cmdparser.h"
  23 #include "cmdhf14b.h"
  24
  25 static int CmdHelp(const char *Cmd);
  26
  27 int CmdHF14BDemod(const char *Cmd)
  28 {
  29   int i, j, iold;
  30   int isum, qsum;
  31   int outOfWeakAt;
  32   bool negateI, negateQ;
  33
  34   uint8_t data[256];
  35   int dataLen = 0;
  36
  37   // As received, the samples are pairs, correlations against I and Q
  38   // square waves. So estimate angle of initial carrier (or just
  39   // quadrant, actually), and then do the demod.
  40
  41   // First, estimate where the tag starts modulating.
  42   for (i = 0; i < GraphTraceLen; i += 2) {
  43     if (abs(GraphBuffer[i]) + abs(GraphBuffer[i + 1]) > 40) {
  44       break;
  45     }
  46   }
  47   if (i >= GraphTraceLen) {
  48     PrintAndLog("too weak to sync");
  49     return 0;
  50   }
  51   PrintAndLog("out of weak at %d", i);
  52   outOfWeakAt = i;
  53
  54   // Now, estimate the phase in the initial modulation of the tag
  55   isum = 0;
  56   qsum = 0;
  57   for (; i < (outOfWeakAt + 16); i += 2) {
  58     isum += GraphBuffer[i + 0];
  59     qsum += GraphBuffer[i + 1];
  60   }
  61   negateI = (isum < 0);
  62   negateQ = (qsum < 0);
  63
  64   // Turn the correlation pairs into soft decisions on the bit.
  65   j = 0;
  66   for (i = 0; i < GraphTraceLen / 2; i++) {
  67     int si = GraphBuffer[j];
  68     int sq = GraphBuffer[j + 1];
  69     if (negateI) si = -si;
  70     if (negateQ) sq = -sq;
  71     GraphBuffer[i] = si + sq;
  72     j += 2;
  73   }
  74   GraphTraceLen = i;
  75
  76   i = outOfWeakAt / 2;
  77   while (GraphBuffer[i] > 0 && i < GraphTraceLen)
  78     i++;
  79   if (i >= GraphTraceLen) goto demodError;
  80
  81   iold = i;
  82   while (GraphBuffer[i] < 0 && i < GraphTraceLen)
  83     i++;
  84   if (i >= GraphTraceLen) goto demodError;
  85   if ((i - iold) > 23) goto demodError;
  86
  87   PrintAndLog("make it to demod loop");
  88
  89   for (;;) {
  90     iold = i;
  91     while (GraphBuffer[i] >= 0 && i < GraphTraceLen)
  92       i++;
  93     if (i >= GraphTraceLen) goto demodError;
  94     if ((i - iold) > 6) goto demodError;
  95
  96     uint16_t shiftReg = 0;
  97     if (i + 20 >= GraphTraceLen) goto demodError;
  98
  99     for (j = 0; j < 10; j++) {
 100       int soft = GraphBuffer[i] + GraphBuffer[i + 1];
 101
 102       if (abs(soft) < (abs(isum) + abs(qsum)) / 20) {
 103         PrintAndLog("weak bit");
 104       }
 105
 106       shiftReg >>= 1;
 107       if(GraphBuffer[i] + GraphBuffer[i+1] >= 0) {
 108         shiftReg |= 0x200;
 109       }
 110
 111       i+= 2;
 112     }
 113
 114     if ((shiftReg & 0x200) && !(shiftReg & 0x001))
 115     {
 116       // valid data byte, start and stop bits okay
 117       PrintAndLog("   %02x", (shiftReg >> 1) & 0xff);
 118       data[dataLen++] = (shiftReg >> 1) & 0xff;
 119       if (dataLen >= sizeof(data)) {
 120         return 0;
 121       }
 122     } else if (shiftReg == 0x000) {
 123       // this is EOF
 124       break;
 125     } else {
 126       goto demodError;
 127     }
 128   }
 129
 130   uint8_t first, second;
 131   ComputeCrc14443(CRC_14443_B, data, dataLen-2, &first, &second);
 132   PrintAndLog("CRC: %02x %02x (%s)\n", first, second,
 133     (first == data[dataLen-2] && second == data[dataLen-1]) ?
 134       "ok" : "****FAIL****");
 135
 136   RepaintGraphWindow();
 137   return 0;
 138
 139 demodError:
 140   PrintAndLog("demod error");
 141   RepaintGraphWindow();
 142   return 0;
 143 }
 144
 145 int CmdHF14BList(const char *Cmd)
 146 {
 147   uint8_t got[960];
 148   GetFromBigBuf(got,sizeof(got),0);
 149
 150   PrintAndLog("recorded activity:");
 151   PrintAndLog(" time  :rssi: who bytes");
 152   PrintAndLog("---------+----+----+-----------");
 153
 154   int i = 0;
 155   int prev = -1;
 156
 157   for(;;) {
 158     if(i >= 900) {
 159       break;
 160     }
 161
 162     bool isResponse;
 163     int timestamp = *((uint32_t *)(got+i));
 164     if(timestamp & 0x80000000) {
 165       timestamp &= 0x7fffffff;
 166       isResponse = 1;
 167     } else {
 168       isResponse = 0;
 169     }
 170     int metric = *((uint32_t *)(got+i+4));
 171
 172     int len = got[i+8];
 173
 174     if(len > 100) {
 175       break;
 176     }
 177     if(i + len >= 900) {
 178       break;
 179     }
 180
 181     uint8_t *frame = (got+i+9);
 182
 183     char line[1000] = "";
 184     int j;
 185     for(j = 0; j < len; j++) {
 186       sprintf(line+(j*3), "%02x  ", frame[j]);
 187     }
 188
 189     char *crc;
 190     if(len > 2) {
 191       uint8_t b1, b2;
 192       ComputeCrc14443(CRC_14443_B, frame, len-2, &b1, &b2);
 193       if(b1 != frame[len-2] || b2 != frame[len-1]) {
 194         crc = "**FAIL CRC**";
 195       } else {
 196         crc = "";
 197       }
 198     } else {
 199       crc = "(SHORT)";
 200     }
 201
 202     char metricString[100];
 203     if(isResponse) {
 204       sprintf(metricString, "%3d", metric);
 205     } else {
 206       strcpy(metricString, "   ");
 207     }
 208
 209     PrintAndLog(" +%7d: %s: %s %s %s",
 210       (prev < 0 ? 0 : timestamp - prev),
 211       metricString,
 212       (isResponse ? "TAG" : "   "), line, crc);
 213
 214     prev = timestamp;
 215     i += (len + 9);
 216   }
 217   return 0;
 218 }
 219
 220 int CmdHF14BRead(const char *Cmd)
 221 {
 222   UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_ISO_14443, {strtol(Cmd, NULL, 0), 0, 0}};
 223   SendCommand(&c);
 224   return 0;
 225 }
 226
 227 int CmdHF14Sim(const char *Cmd)
 228 {
 229   UsbCommand c={CMD_SIMULATE_TAG_ISO_14443};
 230   SendCommand(&c);
 231   return 0;
 232 }
 233
 234 int CmdHFSimlisten(const char *Cmd)
 235 {
 236   UsbCommand c = {CMD_SIMULATE_TAG_HF_LISTEN};
 237   SendCommand(&c);
 238   return 0;
 239 }
 240
 241 int CmdHF14BSnoop(const char *Cmd)
 242 {
 243   UsbCommand c = {CMD_SNOOP_ISO_14443};
 244   SendCommand(&c);
 245   return 0;
 246 }
 247
 248 /* New command to read the contents of a SRI512 tag
 249  * SRI512 tags are ISO14443-B modulated memory tags,
 250  * this command just dumps the contents of the memory
 251  */
 252 int CmdSri512Read(const char *Cmd)
 253 {
 254   UsbCommand c = {CMD_READ_SRI512_TAG, {strtol(Cmd, NULL, 0), 0, 0}};
 255   SendCommand(&c);
 256   return 0;
 257 }
 258
 259 /* New command to read the contents of a SRIX4K tag
 260  * SRIX4K tags are ISO14443-B modulated memory tags,
 261  * this command just dumps the contents of the memory/
 262  */
 263 int CmdSrix4kRead(const char *Cmd)
 264 {
 265   UsbCommand c = {CMD_READ_SRIX4K_TAG, {strtol(Cmd, NULL, 0), 0, 0}};
 266   SendCommand(&c);
 267   return 0;
 268 }
 269
 270 static command_t CommandTable[] =
 271 {
 272   {"help",        CmdHelp,        1, "This help"},
 273   {"demod",       CmdHF14BDemod,  1, "Demodulate ISO14443 Type B from tag"},
 274   {"list",        CmdHF14BList,   0, "List ISO 14443 history"},
 275   {"read",        CmdHF14BRead,   0, "Read HF tag (ISO 14443)"},
 276   {"sim",         CmdHF14Sim,     0, "Fake ISO 14443 tag"},
 277   {"simlisten",   CmdHFSimlisten, 0, "Get HF samples as fake tag"},
 278   {"snoop",       CmdHF14BSnoop,  0, "Eavesdrop ISO 14443"},
 279   {"sri512read",  CmdSri512Read,  0, "<int> -- Read contents of a SRI512 tag"},
 280   {"srix4kread",  CmdSrix4kRead,  0, "<int> -- Read contents of a SRIX4K tag"},
 281   {NULL, NULL, 0, NULL}
 282 };
 283
 284 int CmdHF14B(const char *Cmd)
 285 {
 286   CmdsParse(CommandTable, Cmd);
 287   return 0;
 288 }
 289
 290 int CmdHelp(const char *Cmd)
 291 {
 292   CmdsHelp(CommandTable);
 293   return 0;
 294 }