X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/6982ac2612c12af9fa65437bf4279007d734cc59..7fe9b0b742d7dae9c5af1d292d11840b5c3cbfae:/client/cmdlfti.c?ds=sidebyside

diff --git a/client/cmdlfti.c b/client/cmdlfti.c
new file mode 100644
index 00000000..a0e2bb84
--- /dev/null
+++ b/client/cmdlfti.c
@@ -0,0 +1,293 @@
+#include <stdio.h>
+#include "crc16.h"
+#include "proxusb.h"
+#include "data.h"
+#include "ui.h"
+#include "graph.h"
+#include "cmdparser.h"
+#include "cmdlfti.h"
+
+static int CmdHelp(const char *Cmd);
+
+int CmdTIDemod(const char *Cmd)
+{
+  /* MATLAB as follows:
+    f_s = 2000000;  % sampling frequency
+    f_l = 123200;   % low FSK tone
+    f_h = 134200;   % high FSK tone
+
+    T_l = 119e-6;   % low bit duration
+    T_h = 130e-6;   % high bit duration
+
+    l = 2*pi*ones(1, floor(f_s*T_l))*(f_l/f_s);
+    h = 2*pi*ones(1, floor(f_s*T_h))*(f_h/f_s);
+
+    l = sign(sin(cumsum(l)));
+    h = sign(sin(cumsum(h)));
+  */
+
+  // 2M*16/134.2k = 238
+  static const int LowTone[] = {
+    1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,    -1, -1
+  };
+  // 2M*16/123.2k = 260
+  static const int HighTone[] = {
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1,   -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1,      -1, -1, -1, -1, -1, -1, -1,
+    1, 1, 1, 1, 1, 1, 1, 1
+  };
+  int lowLen = sizeof(LowTone)/sizeof(int);
+  int highLen = sizeof(HighTone)/sizeof(int);
+  int convLen = (highLen>lowLen)?highLen:lowLen;
+  uint16_t crc;
+  int i, j, TagType;
+  int lowSum = 0, highSum = 0;;
+  int lowTot = 0, highTot = 0;
+
+  for (i = 0; i < GraphTraceLen - convLen; i++) {
+    lowSum = 0;
+    highSum = 0;;
+
+    for (j = 0; j < lowLen; j++) {
+      lowSum += LowTone[j]*GraphBuffer[i+j];
+    }
+    for (j = 0; j < highLen; j++) {
+      highSum += HighTone[j]*GraphBuffer[i+j];
+    }
+    lowSum = abs((100*lowSum) / lowLen);
+    highSum = abs((100*highSum) / highLen);
+    lowSum = (lowSum<0)?-lowSum:lowSum;
+    highSum = (highSum<0)?-highSum:highSum;
+
+    GraphBuffer[i] = (highSum << 16) | lowSum;
+  }
+
+  for (i = 0; i < GraphTraceLen - convLen - 16; i++) {
+    lowTot = 0;
+    highTot = 0;
+    // 16 and 15 are f_s divided by f_l and f_h, rounded
+    for (j = 0; j < 16; j++) {
+      lowTot += (GraphBuffer[i+j] & 0xffff);
+    }
+    for (j = 0; j < 15; j++) {
+      highTot += (GraphBuffer[i+j] >> 16);
+    }
+    GraphBuffer[i] = lowTot - highTot;
+  }
+
+  GraphTraceLen -= (convLen + 16);
+
+  RepaintGraphWindow();
+
+  // TI tag data format is 16 prebits, 8 start bits, 64 data bits,
+  // 16 crc CCITT bits, 8 stop bits, 15 end bits
+
+  // the 16 prebits are always low
+  // the 8 start and stop bits of a tag must match
+  // the start/stop prebits of a ro tag are 01111110
+  // the start/stop prebits of a rw tag are 11111110
+  // the 15 end bits of a ro tag are all low
+  // the 15 end bits of a rw tag match bits 15-1 of the data bits
+
+  // Okay, so now we have unsliced soft decisions;
+  // find bit-sync, and then get some bits.
+  // look for 17 low bits followed by 6 highs (common pattern for ro and rw tags)
+  int max = 0, maxPos = 0;
+  for (i = 0; i < 6000; i++) {
+    int j;
+    int dec = 0;
+    // searching 17 consecutive lows
+    for (j = 0; j < 17*lowLen; j++) {
+      dec -= GraphBuffer[i+j];
+    }
+    // searching 7 consecutive highs
+    for (; j < 17*lowLen + 6*highLen; j++) {
+      dec += GraphBuffer[i+j];
+    }
+    if (dec > max) {
+      max = dec;
+      maxPos = i;
+    }
+  }
+
+  // place a marker in the buffer to visually aid location
+  // of the start of sync
+  GraphBuffer[maxPos] = 800;
+  GraphBuffer[maxPos+1] = -800;
+
+  // advance pointer to start of actual data stream (after 16 pre and 8 start bits)
+  maxPos += 17*lowLen;
+  maxPos += 6*highLen;
+
+  // place a marker in the buffer to visually aid location
+  // of the end of sync
+  GraphBuffer[maxPos] = 800;
+  GraphBuffer[maxPos+1] = -800;
+
+  PrintAndLog("actual data bits start at sample %d", maxPos);
+
+  PrintAndLog("length %d/%d", highLen, lowLen);
+
+  uint8_t bits[1+64+16+8+16];
+  bits[sizeof(bits)-1] = '\0';
+
+  uint32_t shift3 = 0x7e000000, shift2 = 0, shift1 = 0, shift0 = 0;
+
+  for (i = 0; i < arraylen(bits)-1; i++) {
+    int high = 0;
+    int low = 0;
+    int j;
+    for (j = 0; j < lowLen; j++) {
+      low -= GraphBuffer[maxPos+j];
+    }
+    for (j = 0; j < highLen; j++) {
+      high += GraphBuffer[maxPos+j];
+    }
+
+    if (high > low) {
+      bits[i] = '1';
+      maxPos += highLen;
+      // bitstream arrives lsb first so shift right
+      shift3 |= (1<<31);
+    } else {
+      bits[i] = '.';
+      maxPos += lowLen;
+    }
+
+    // 128 bit right shift register
+    shift0 = (shift0>>1) | (shift1 << 31);
+    shift1 = (shift1>>1) | (shift2 << 31);
+    shift2 = (shift2>>1) | (shift3 << 31);
+    shift3 >>= 1;
+
+    // place a marker in the buffer between bits to visually aid location
+    GraphBuffer[maxPos] = 800;
+    GraphBuffer[maxPos+1] = -800;
+  }
+  PrintAndLog("Info: raw tag bits = %s", bits);
+
+  TagType = (shift3>>8)&0xff;
+  if ( TagType != ((shift0>>16)&0xff) ) {
+    PrintAndLog("Error: start and stop bits do not match!");
+    return 0;
+  }
+  else if (TagType == 0x7e) {
+    PrintAndLog("Info: Readonly TI tag detected.");
+    return 0;
+  }
+  else if (TagType == 0xfe) {
+    PrintAndLog("Info: Rewriteable TI tag detected.");
+
+    // put 64 bit data into shift1 and shift0
+    shift0 = (shift0>>24) | (shift1 << 8);
+    shift1 = (shift1>>24) | (shift2 << 8);
+
+    // align 16 bit crc into lower half of shift2
+    shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+
+    // align 16 bit "end bits" or "ident" into lower half of shift3
+    shift3 >>= 16;
+
+    // only 15 bits compare, last bit of ident is not valid
+    if ( (shift3^shift0)&0x7fff ) {
+      PrintAndLog("Error: Ident mismatch!");
+    }
+    // WARNING the order of the bytes in which we calc crc below needs checking
+    // i'm 99% sure the crc algorithm is correct, but it may need to eat the
+    // bytes in reverse or something
+    // calculate CRC
+    crc=0;
+    crc = update_crc16(crc, (shift0)&0xff);
+    crc = update_crc16(crc, (shift0>>8)&0xff);
+    crc = update_crc16(crc, (shift0>>16)&0xff);
+    crc = update_crc16(crc, (shift0>>24)&0xff);
+    crc = update_crc16(crc, (shift1)&0xff);
+    crc = update_crc16(crc, (shift1>>8)&0xff);
+    crc = update_crc16(crc, (shift1>>16)&0xff);
+    crc = update_crc16(crc, (shift1>>24)&0xff);
+    PrintAndLog("Info: Tag data = %08X%08X", shift1, shift0);
+    if (crc != (shift2&0xffff)) {
+      PrintAndLog("Error: CRC mismatch, calculated %04X, got ^04X", crc, shift2&0xffff);
+    } else {
+      PrintAndLog("Info: CRC %04X is good", crc);
+    }
+  }
+  else {
+    PrintAndLog("Unknown tag type.");
+    return 0;
+  }
+  return 0;
+}
+
+// read a TI tag and return its ID
+int CmdTIRead(const char *Cmd)
+{
+  UsbCommand c = {CMD_READ_TI_TYPE};
+  SendCommand(&c);
+  return 0;
+}
+
+// write new data to a r/w TI tag
+int CmdTIWrite(const char *Cmd)
+{
+  UsbCommand c = {CMD_WRITE_TI_TYPE};
+  int res = 0;
+
+  res = sscanf(Cmd, "0x%x 0x%x 0x%x ", &c.arg[0], &c.arg[1], &c.arg[2]);
+  if (res == 2) c.arg[2]=0;
+  if (res < 2)
+    PrintAndLog("Please specify the data as two hex strings, optionally the CRC as a third");
+  else
+    SendCommand(&c);
+  return 0;
+}
+
+static command_t CommandTable[] = 
+{
+  {"help",      CmdHelp,        1, "This help"},
+  {"demod",     CmdTIDemod,     1, "Demodulate raw bits for TI-type LF tag"},
+  {"read",      CmdTIRead,      0, "Read and decode a TI 134 kHz tag"},
+  {"write",     CmdTIWrite,     0, "Write new data to a r/w TI 134 kHz tag"},
+  {NULL, NULL, 0, NULL}
+};
+
+int CmdLFTI(const char *Cmd)
+{
+  CmdsParse(CommandTable, Cmd);
+  return 0;
+}
+
+int CmdHelp(const char *Cmd)
+{
+  CmdsHelp(CommandTable);
+  return 0;
+}