[proxmark3-svn] / client / cmdlfem4x.c

//-----------------------------------------------------------------------------
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Low frequency EM4x commands
//-----------------------------------------------------------------------------

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include "proxmark3.h"
#include "ui.h"
#include "util.h"
#include "graph.h"
#include "cmdparser.h"
#include "cmddata.h"
#include "cmdlf.h"
#include "cmdlfem4x.h"
char *global_em410xId;

static int CmdHelp(const char *Cmd);

int CmdEMdemodASK(const char *Cmd)
{
	char cmdp = param_getchar(Cmd, 0);
	int findone = (cmdp == '1') ? 1 : 0;	
  UsbCommand c={CMD_EM410X_DEMOD};
  c.arg[0]=findone;
  SendCommand(&c);
  return 0;
}

/* Read the ID of an EM410x tag.
 * Format:
 *   1111 1111 1           <-- standard non-repeatable header
 *   XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
 *   ....
 *   CCCC                  <-- each bit here is parity for the 10 bits above in corresponding column
 *   0                     <-- stop bit, end of tag
 */
int CmdEM410xRead(const char *Cmd)
{
  int i, j, clock, header, rows, bit, hithigh, hitlow, first, bit2idx, high, low;
  int parity[4];
  char id[11] = {0x00};
  char id2[11] = {0x00};
  int retested = 0;
  uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
  high = low = 0;

  /* Detect high and lows and clock */
  for (i = 0; i < GraphTraceLen; i++)
  {
    if (GraphBuffer[i] > high)
      high = GraphBuffer[i];
    else if (GraphBuffer[i] < low)
      low = GraphBuffer[i];
  }

  /* get clock */
  clock = GetClock(Cmd, high, 0);

  /* parity for our 4 columns */
  parity[0] = parity[1] = parity[2] = parity[3] = 0;
  header = rows = 0;

  // manchester demodulate
  bit = bit2idx = 0;
  for (i = 0; i < (int)(GraphTraceLen / clock); i++)
  {
    hithigh = 0;
    hitlow = 0;
    first = 1;

    /* Find out if we hit both high and low peaks */
    for (j = 0; j < clock; j++)
    {
      if (GraphBuffer[(i * clock) + j] >= high)
        hithigh = 1;
      else if (GraphBuffer[(i * clock) + j] <= low)
        hitlow = 1;

      /* it doesn't count if it's the first part of our read
       because it's really just trailing from the last sequence */
      if (first && (hithigh || hitlow))
        hithigh = hitlow = 0;
      else
        first = 0;

      if (hithigh && hitlow)
        break;
    }

    /* If we didn't hit both high and low peaks, we had a bit transition */
    if (!hithigh || !hitlow)
      bit ^= 1;

    BitStream[bit2idx++] = bit;
  }

retest:
  /* We go till 5 before the graph ends because we'll get that far below */
  for (i = 1; i < bit2idx - 5; i++)
  {
    /* Step 2: We have our header but need our tag ID */
    if (header == 9 && rows < 10)
    {
      /* Confirm parity is correct */
      if ((BitStream[i] ^ BitStream[i+1] ^ BitStream[i+2] ^ BitStream[i+3]) == BitStream[i+4])
      {
        /* Read another byte! */
        sprintf(id+rows, "%x", (8 * BitStream[i]) + (4 * BitStream[i+1]) + (2 * BitStream[i+2]) + (1 * BitStream[i+3]));
        sprintf(id2+rows, "%x", (8 * BitStream[i+3]) + (4 * BitStream[i+2]) + (2 * BitStream[i+1]) + (1 * BitStream[i]));
        rows++;

        /* Keep parity info */
        parity[0] ^= BitStream[i];
        parity[1] ^= BitStream[i+1];
        parity[2] ^= BitStream[i+2];
        parity[3] ^= BitStream[i+3];

        /* Move 4 bits ahead */
        i += 4;
      }

      /* Damn, something wrong! reset */
      else
      {
        PrintAndLog("Thought we had a valid tag but failed at word %d (i=%d)", rows + 1, i);

        /* Start back rows * 5 + 9 header bits, -1 to not start at same place */
        i -= 9 + (5 * rows) - 5;

        rows = header = 0;
      }
    }

    /* Step 3: Got our 40 bits! confirm column parity */
    else if (rows == 10)
    {
      /* We need to make sure our 4 bits of parity are correct and we have a stop bit */
      if (BitStream[i] == parity[0] && BitStream[i+1] == parity[1] &&
        BitStream[i+2] == parity[2] && BitStream[i+3] == parity[3] &&
        BitStream[i+4] == 0)
      {
        /* Sweet! */
        PrintAndLog("EM410x Tag ID: %s", id);
        PrintAndLog("Unique Tag ID: %s", id2);

		global_em410xId = id;
		
        /* Stop any loops */
        return 1;
      }

      /* Crap! Incorrect parity or no stop bit, start all over */
      else
      {
        rows = header = 0;

        /* Go back 59 bits (9 header bits + 10 rows at 4+1 parity) */
        i -= 59;
      }
    }

    /* Step 1: get our header */
    else if (header < 9)
    {
      /* Need 9 consecutive 1's */
      if (BitStream[i] == 1)
        header++;

      /* We don't have a header, not enough consecutive 1 bits */
      else
        header = 0;
    }
  }

  /* if we've already retested after flipping bits, return */
	if (retested++){
		PrintAndLog("Failed to decode");
    return 0;
	}

  /* if this didn't work, try flipping bits */
  for (i = 0; i < bit2idx; i++)
    BitStream[i] ^= 1;

  goto retest;
}

/* emulate an EM410X tag
 * Format:
 *   1111 1111 1           <-- standard non-repeatable header
 *   XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
 *   ....
 *   CCCC                  <-- each bit here is parity for the 10 bits above in corresponding column
 *   0                     <-- stop bit, end of tag
 */
int CmdEM410xSim(const char *Cmd)
{
	int i, n, j, binary[4], parity[4];

	char cmdp = param_getchar(Cmd, 0);
	uint8_t uid[5] = {0x00};

	if (cmdp == 'h' || cmdp == 'H') {
		PrintAndLog("Usage:  lf em4x 410xsim <UID>");
		PrintAndLog("");
		PrintAndLog("     sample: lf em4x 410xsim 0F0368568B");
		return 0;
	}

	if (param_gethex(Cmd, 0, uid, 10)) {
		PrintAndLog("UID must include 10 HEX symbols");
		return 0;
	}
	
	PrintAndLog("Starting simulating UID %02X%02X%02X%02X%02X", uid[0],uid[1],uid[2],uid[3],uid[4]);
	PrintAndLog("Press pm3-button to about simulation");

  /* clock is 64 in EM410x tags */
  int clock = 64;

  /* clear our graph */
  ClearGraph(0);

    /* write 9 start bits */
    for (i = 0; i < 9; i++)
      AppendGraph(0, clock, 1);

    /* for each hex char */
    parity[0] = parity[1] = parity[2] = parity[3] = 0;
    for (i = 0; i < 10; i++)
    {
      /* read each hex char */
      sscanf(&Cmd[i], "%1x", &n);
      for (j = 3; j >= 0; j--, n/= 2)
        binary[j] = n % 2;

      /* append each bit */
      AppendGraph(0, clock, binary[0]);
      AppendGraph(0, clock, binary[1]);
      AppendGraph(0, clock, binary[2]);
      AppendGraph(0, clock, binary[3]);

      /* append parity bit */
      AppendGraph(0, clock, binary[0] ^ binary[1] ^ binary[2] ^ binary[3]);

      /* keep track of column parity */
      parity[0] ^= binary[0];
      parity[1] ^= binary[1];
      parity[2] ^= binary[2];
      parity[3] ^= binary[3];
    }

    /* parity columns */
    AppendGraph(0, clock, parity[0]);
    AppendGraph(0, clock, parity[1]);
    AppendGraph(0, clock, parity[2]);
    AppendGraph(0, clock, parity[3]);

    /* stop bit */
  AppendGraph(1, clock, 0);
 
  CmdLFSim("240"); //240 start_gap.
  return 0;
}

/* Function is equivalent of lf read + data samples + em410xread
 * looped until an EM410x tag is detected 
 * 
 * Why is CmdSamples("16000")?
 *  TBD: Auto-grow sample size based on detected sample rate.  IE: If the
 *       rate gets lower, then grow the number of samples
 *  Changed by martin, 4000 x 4 = 16000, 
 *  see http://www.proxmark.org/forum/viewtopic.php?pid=7235#p7235

*/
int CmdEM410xWatch(const char *Cmd)
{
	char cmdp = param_getchar(Cmd, 0);
	int read_h = (cmdp == 'h');
	do {
		if (ukbhit()) {
			printf("\naborted via keyboard!\n");
			break;
		}
		
		CmdLFRead(read_h ? "h" : "");
		CmdSamples("6000");		
	} while (
		!CmdEM410xRead("") 
	);
	return 0;
}

int CmdEM410xWatchnSpoof(const char *Cmd)
{
	CmdEM410xWatch(Cmd);
    PrintAndLog("# Replaying : %s",global_em410xId);
    CmdEM410xSim(global_em410xId);
  return 0;
}

/* Read the transmitted data of an EM4x50 tag
 * Format:
 *
 *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
 *  CCCCCCCC                         <- column parity bits
 *  0                                <- stop bit
 *  LW                               <- Listen Window
 *
 * This pattern repeats for every block of data being transmitted.
 * Transmission starts with two Listen Windows (LW - a modulated
 * pattern of 320 cycles each (32/32/128/64/64)).
 *
 * Note that this data may or may not be the UID. It is whatever data
 * is stored in the blocks defined in the control word First and Last
 * Word Read values. UID is stored in block 32.
 */
int CmdEM4x50Read(const char *Cmd)
{
  int i, j, startblock, skip, block, start, end, low, high;
  bool complete= false;
  int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
  char tmp[6];

  high= low= 0;
  memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);

  /* first get high and low values */
  for (i = 0; i < GraphTraceLen; i++)
  {
    if (GraphBuffer[i] > high)
      high = GraphBuffer[i];
    else if (GraphBuffer[i] < low)
      low = GraphBuffer[i];
  }

  /* populate a buffer with pulse lengths */
  i= 0;
  j= 0;
  while (i < GraphTraceLen)
  {
    // measure from low to low
    while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
      ++i;
    start= i;
    while ((GraphBuffer[i] < high) && (i<GraphTraceLen))
      ++i;
    while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
      ++i;
    if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
      break;
    }
    tmpbuff[j++]= i - start;
  }

  /* look for data start - should be 2 pairs of LW (pulses of 192,128) */
  start= -1;
  skip= 0;
  for (i= 0; i < j - 4 ; ++i)
  {
    skip += tmpbuff[i];
    if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
      if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
        if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
          if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
          {
            start= i + 3;
            break;
          }
  }
  startblock= i + 3;

  /* skip over the remainder of the LW */
  skip += tmpbuff[i+1]+tmpbuff[i+2];
  while (skip < MAX_GRAPH_TRACE_LEN && GraphBuffer[skip] > low)
    ++skip;
  skip += 8;

  /* now do it again to find the end */
  end= start;
  for (i += 3; i < j - 4 ; ++i)
  {
    end += tmpbuff[i];
    if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
      if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
        if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
          if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
          {
            complete= true;
            break;
          }
  }

  if (start >= 0)
    PrintAndLog("Found data at sample: %i",skip);
  else
  {
    PrintAndLog("No data found!");
    PrintAndLog("Try again with more samples.");
    return 0;
  }

  if (!complete)
  {
    PrintAndLog("*** Warning!");
    PrintAndLog("Partial data - no end found!");
    PrintAndLog("Try again with more samples.");
  }

  /* get rid of leading crap */
  sprintf(tmp,"%i",skip);
  CmdLtrim(tmp);

  /* now work through remaining buffer printing out data blocks */
  block= 0;
  i= startblock;
  while (block < 6)
  {
    PrintAndLog("Block %i:", block);
    // mandemod routine needs to be split so we can call it for data
    // just print for now for debugging
    CmdManchesterDemod("i 64");
    skip= 0;
    /* look for LW before start of next block */
    for ( ; i < j - 4 ; ++i)
    {
      skip += tmpbuff[i];
      if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
        if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
          break;
    }
    while (GraphBuffer[skip] > low)
      ++skip;
    skip += 8;
    sprintf(tmp,"%i",skip);
    CmdLtrim(tmp);
    start += skip;
    block++;
  }
  return 0;
}

int CmdEM410xWrite(const char *Cmd)
{
  uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
  int card = 0xFF; // invalid card value
	unsigned int clock = 0; // invalid clock value

	sscanf(Cmd, "%" PRIx64 " %d %d", &id, &card, &clock);

	// Check ID
	if (id == 0xFFFFFFFFFFFFFFFF) {
		PrintAndLog("Error! ID is required.\n");
		return 0;
	}
	if (id >= 0x10000000000) {
		PrintAndLog("Error! Given EM410x ID is longer than 40 bits.\n");
		return 0;
	}

	// Check Card
	if (card == 0xFF) {
		PrintAndLog("Error! Card type required.\n");
		return 0;
	}
	if (card < 0) {
		PrintAndLog("Error! Bad card type selected.\n");
		return 0;
	}

	// Check Clock
	if (card == 1)
	{
		// Default: 64
		if (clock == 0)
			clock = 64;

		// Allowed clock rates: 16, 32 and 64
		if ((clock != 16) && (clock != 32) && (clock != 64)) {
			PrintAndLog("Error! Clock rate %d not valid. Supported clock rates are 16, 32 and 64.\n", clock);
			return 0;
		}
	}
	else if (clock != 0)
	{
		PrintAndLog("Error! Clock rate is only supported on T55x7 tags.\n");
		return 0;
	}

	if (card == 1) {
		PrintAndLog("Writing %s tag with UID 0x%010" PRIx64 " (clock rate: %d)", "T55x7", id, clock);
		// NOTE: We really should pass the clock in as a separate argument, but to
		//   provide for backwards-compatibility for older firmware, and to avoid
		//   having to add another argument to CMD_EM410X_WRITE_TAG, we just store
		//   the clock rate in bits 8-15 of the card value
		card = (card & 0xFF) | (((uint64_t)clock << 8) & 0xFF00);
	}
	else if (card == 0)
		PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
	else {
		PrintAndLog("Error! Bad card type selected.\n");
		return 0;
	}

  UsbCommand c = {CMD_EM410X_WRITE_TAG, {card, (uint32_t)(id >> 32), (uint32_t)id}};
  SendCommand(&c);

  return 0;
}

int CmdReadWord(const char *Cmd)
{
	int Word = -1; //default to invalid word
  UsbCommand c;
  
  sscanf(Cmd, "%d", &Word);
  
	if ( (Word > 15) | (Word < 0) ) {
    PrintAndLog("Word must be between 0 and 15");
    return 1;
  }
  
  PrintAndLog("Reading word %d", Word);
  
  c.cmd = CMD_EM4X_READ_WORD;
  c.d.asBytes[0] = 0x0; //Normal mode
  c.arg[0] = 0;
  c.arg[1] = Word;
  c.arg[2] = 0;
  SendCommand(&c);
  return 0;
}

int CmdReadWordPWD(const char *Cmd)
{
	int Word = -1; //default to invalid word
  int Password = 0xFFFFFFFF; //default to blank password
  UsbCommand c;
  
  sscanf(Cmd, "%d %x", &Word, &Password);
  
	if ( (Word > 15) | (Word < 0) ) {
    PrintAndLog("Word must be between 0 and 15");
    return 1;
  }
  
  PrintAndLog("Reading word %d with password %08X", Word, Password);
  
  c.cmd = CMD_EM4X_READ_WORD;
  c.d.asBytes[0] = 0x1; //Password mode
  c.arg[0] = 0;
  c.arg[1] = Word;
  c.arg[2] = Password;
  SendCommand(&c);
  return 0;
}

int CmdWriteWord(const char *Cmd)
{
  int Word = 16; //default to invalid block
  int Data = 0xFFFFFFFF; //default to blank data
  UsbCommand c;
  
  sscanf(Cmd, "%x %d", &Data, &Word);
  
  if (Word > 15) {
    PrintAndLog("Word must be between 0 and 15");
    return 1;
  }
  
  PrintAndLog("Writing word %d with data %08X", Word, Data);
  
  c.cmd = CMD_EM4X_WRITE_WORD;
  c.d.asBytes[0] = 0x0; //Normal mode
  c.arg[0] = Data;
  c.arg[1] = Word;
  c.arg[2] = 0;
  SendCommand(&c);
  return 0;
}

int CmdWriteWordPWD(const char *Cmd)
{
  int Word = 16; //default to invalid word
  int Data = 0xFFFFFFFF; //default to blank data
  int Password = 0xFFFFFFFF; //default to blank password
  UsbCommand c;
  
  sscanf(Cmd, "%x %d %x", &Data, &Word, &Password);
  
  if (Word > 15) {
    PrintAndLog("Word must be between 0 and 15");
    return 1;
  }
  
  PrintAndLog("Writing word %d with data %08X and password %08X", Word, Data, Password);
  
  c.cmd = CMD_EM4X_WRITE_WORD;
  c.d.asBytes[0] = 0x1; //Password mode
  c.arg[0] = Data;
  c.arg[1] = Word;
  c.arg[2] = Password;
  SendCommand(&c);
  return 0;
}

static command_t CommandTable[] =
{
  {"help", CmdHelp, 1, "This help"},
  {"em410xdemod", CmdEMdemodASK, 0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},  
  {"em410xread", CmdEM410xRead, 1, "[clock rate] -- Extract ID from EM410x tag"},
  {"em410xsim", CmdEM410xSim, 0, "<UID> -- Simulate EM410x tag"},
  {"em410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
  {"em410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
  {"em410xwrite", CmdEM410xWrite, 1, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
  {"em4x50read", CmdEM4x50Read, 1, "Extract data from EM4x50 tag"},
  {"readword", CmdReadWord, 1, "<Word> -- Read EM4xxx word data"},
  {"readwordPWD", CmdReadWordPWD, 1, "<Word> <Password> -- Read EM4xxx word data in password mode"},
  {"writeword", CmdWriteWord, 1, "<Data> <Word> -- Write EM4xxx word data"},
  {"writewordPWD", CmdWriteWordPWD, 1, "<Data> <Word> <Password> -- Write EM4xxx word data in password mode"},
  {NULL, NULL, 0, NULL}
};

int CmdLFEM4X(const char *Cmd)
{
  CmdsParse(CommandTable, Cmd);
  return 0;
}

int CmdHelp(const char *Cmd)
{
  CmdsHelp(CommandTable);
  return 0;
}
Commit	Line	Data
a553f267	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	// Low frequency EM4x commands
	9	//-----------------------------------------------------------------------------
	10
7fe9b0b7	11	#include <stdio.h>
9e13f875	12	#include <string.h>
ec564290	13	#include <inttypes.h>
902cb3c0	14	#include "proxmark3.h"
7fe9b0b7	15	#include "ui.h"
3fe4ff4f	16	#include "util.h"
7fe9b0b7	17	#include "graph.h"
	18	#include "cmdparser.h"
	19	#include "cmddata.h"
	20	#include "cmdlf.h"
	21	#include "cmdlfem4x.h"
c3bfb9c7	22	char *global_em410xId;
7fe9b0b7	23
	24	static int CmdHelp(const char *Cmd);
	25
66707a3b	26	int CmdEMdemodASK(const char *Cmd)
66707a3b	27	{
3fe4ff4f	28	char cmdp = param_getchar(Cmd, 0);
3fe4ff4f	29	int findone = (cmdp == '1') ? 1 : 0;
66707a3b	30	UsbCommand c={CMD_EM410X_DEMOD};
66707a3b	31	c.arg[0]=findone;
	32	SendCommand(&c);
	33	return 0;
	34	}
	35
7fe9b0b7	36	/* Read the ID of an EM410x tag.
	37	* Format:
	38	* 1111 1111 1 <-- standard non-repeatable header
	39	* XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
	40	* ....
	41	* CCCC <-- each bit here is parity for the 10 bits above in corresponding column
	42	* 0 <-- stop bit, end of tag
	43	*/
	44	int CmdEM410xRead(const char *Cmd)
	45	{
	46	int i, j, clock, header, rows, bit, hithigh, hitlow, first, bit2idx, high, low;
	47	int parity[4];
3fe4ff4f	48	char id[11] = {0x00};
3fe4ff4f	49	char id2[11] = {0x00};
7fe9b0b7	50	int retested = 0;
15cdabd4	51	uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
7fe9b0b7	52	high = low = 0;
	53
	54	/* Detect high and lows and clock */
	55	for (i = 0; i < GraphTraceLen; i++)
	56	{
	57	if (GraphBuffer[i] > high)
	58	high = GraphBuffer[i];
	59	else if (GraphBuffer[i] < low)
	60	low = GraphBuffer[i];
	61	}
	62
	63	/* get clock */
	64	clock = GetClock(Cmd, high, 0);
	65
	66	/* parity for our 4 columns */
	67	parity[0] = parity[1] = parity[2] = parity[3] = 0;
	68	header = rows = 0;
	69
c3bfb9c7	70	// manchester demodulate
7fe9b0b7	71	bit = bit2idx = 0;
	72	for (i = 0; i < (int)(GraphTraceLen / clock); i++)
	73	{
	74	hithigh = 0;
	75	hitlow = 0;
	76	first = 1;
	77
	78	/* Find out if we hit both high and low peaks */
	79	for (j = 0; j < clock; j++)
	80	{
c3bfb9c7	81	if (GraphBuffer[(i * clock) + j] >= high)
7fe9b0b7	82	hithigh = 1;
c3bfb9c7	83	else if (GraphBuffer[(i * clock) + j] <= low)
7fe9b0b7	84	hitlow = 1;
	85
	86	/* it doesn't count if it's the first part of our read
	87	because it's really just trailing from the last sequence */
	88	if (first && (hithigh \|\| hitlow))
	89	hithigh = hitlow = 0;
	90	else
	91	first = 0;
	92
	93	if (hithigh && hitlow)
	94	break;
	95	}
	96
	97	/* If we didn't hit both high and low peaks, we had a bit transition */
	98	if (!hithigh \|\| !hitlow)
	99	bit ^= 1;
	100
	101	BitStream[bit2idx++] = bit;
	102	}
	103
	104	retest:
	105	/* We go till 5 before the graph ends because we'll get that far below */
	106	for (i = 1; i < bit2idx - 5; i++)
	107	{
	108	/* Step 2: We have our header but need our tag ID */
	109	if (header == 9 && rows < 10)
	110	{
	111	/* Confirm parity is correct */
	112	if ((BitStream[i] ^ BitStream[i+1] ^ BitStream[i+2] ^ BitStream[i+3]) == BitStream[i+4])
	113	{
	114	/* Read another byte! */
	115	sprintf(id+rows, "%x", (8 * BitStream[i]) + (4 * BitStream[i+1]) + (2 * BitStream[i+2]) + (1 * BitStream[i+3]));
cb967ea9	116	sprintf(id2+rows, "%x", (8 * BitStream[i+3]) + (4 * BitStream[i+2]) + (2 * BitStream[i+1]) + (1 * BitStream[i]));
7fe9b0b7	117	rows++;
	118
	119	/* Keep parity info */
	120	parity[0] ^= BitStream[i];
	121	parity[1] ^= BitStream[i+1];
	122	parity[2] ^= BitStream[i+2];
	123	parity[3] ^= BitStream[i+3];
	124
	125	/* Move 4 bits ahead */
	126	i += 4;
	127	}
	128
	129	/* Damn, something wrong! reset */
	130	else
	131	{
	132	PrintAndLog("Thought we had a valid tag but failed at word %d (i=%d)", rows + 1, i);
	133
	134	/* Start back rows * 5 + 9 header bits, -1 to not start at same place */
	135	i -= 9 + (5 * rows) - 5;
	136
	137	rows = header = 0;
	138	}
	139	}
	140
	141	/* Step 3: Got our 40 bits! confirm column parity */
	142	else if (rows == 10)
	143	{
	144	/* We need to make sure our 4 bits of parity are correct and we have a stop bit */
	145	if (BitStream[i] == parity[0] && BitStream[i+1] == parity[1] &&
	146	BitStream[i+2] == parity[2] && BitStream[i+3] == parity[3] &&
	147	BitStream[i+4] == 0)
	148	{
	149	/* Sweet! */
	150	PrintAndLog("EM410x Tag ID: %s", id);
cb967ea9	151	PrintAndLog("Unique Tag ID: %s", id2);
7fe9b0b7	152
c3bfb9c7	153	global_em410xId = id;
c3bfb9c7	154
7fe9b0b7	155	/* Stop any loops */
	156	return 1;
	157	}
	158
	159	/* Crap! Incorrect parity or no stop bit, start all over */
	160	else
	161	{
	162	rows = header = 0;
	163
	164	/* Go back 59 bits (9 header bits + 10 rows at 4+1 parity) */
	165	i -= 59;
	166	}
	167	}
	168
	169	/* Step 1: get our header */
	170	else if (header < 9)
	171	{
	172	/* Need 9 consecutive 1's */
	173	if (BitStream[i] == 1)
	174	header++;
	175
	176	/* We don't have a header, not enough consecutive 1 bits */
	177	else
	178	header = 0;
	179	}
	180	}
	181
	182	/* if we've already retested after flipping bits, return */
c3bfb9c7	183	if (retested++){
c3bfb9c7	184	PrintAndLog("Failed to decode");
7fe9b0b7	185	return 0;
c3bfb9c7	186	}
7fe9b0b7	187
	188	/* if this didn't work, try flipping bits */
	189	for (i = 0; i < bit2idx; i++)
	190	BitStream[i] ^= 1;
	191
	192	goto retest;
	193	}
	194
	195	/* emulate an EM410X tag
	196	* Format:
	197	* 1111 1111 1 <-- standard non-repeatable header
	198	* XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
	199	* ....
	200	* CCCC <-- each bit here is parity for the 10 bits above in corresponding column
	201	* 0 <-- stop bit, end of tag
	202	*/
	203	int CmdEM410xSim(const char *Cmd)
	204	{
3fe4ff4f	205	int i, n, j, binary[4], parity[4];
	206
	207	char cmdp = param_getchar(Cmd, 0);
	208	uint8_t uid[5] = {0x00};
	209
	210	if (cmdp == 'h' \|\| cmdp == 'H') {
	211	PrintAndLog("Usage: lf em4x 410xsim <UID>");
	212	PrintAndLog("");
	213	PrintAndLog(" sample: lf em4x 410xsim 0F0368568B");
	214	return 0;
	215	}
	216
	217	if (param_gethex(Cmd, 0, uid, 10)) {
	218	PrintAndLog("UID must include 10 HEX symbols");
	219	return 0;
	220	}
	221
	222	PrintAndLog("Starting simulating UID %02X%02X%02X%02X%02X", uid[0],uid[1],uid[2],uid[3],uid[4]);
	223	PrintAndLog("Press pm3-button to about simulation");
7fe9b0b7	224
	225	/* clock is 64 in EM410x tags */
	226	int clock = 64;
	227
	228	/* clear our graph */
	229	ClearGraph(0);
	230
7fe9b0b7	231	/* write 9 start bits */
	232	for (i = 0; i < 9; i++)
	233	AppendGraph(0, clock, 1);
	234
	235	/* for each hex char */
	236	parity[0] = parity[1] = parity[2] = parity[3] = 0;
	237	for (i = 0; i < 10; i++)
	238	{
	239	/* read each hex char */
	240	sscanf(&Cmd[i], "%1x", &n);
	241	for (j = 3; j >= 0; j--, n/= 2)
	242	binary[j] = n % 2;
	243
	244	/* append each bit */
	245	AppendGraph(0, clock, binary[0]);
	246	AppendGraph(0, clock, binary[1]);
	247	AppendGraph(0, clock, binary[2]);
	248	AppendGraph(0, clock, binary[3]);
	249
	250	/* append parity bit */
	251	AppendGraph(0, clock, binary[0] ^ binary[1] ^ binary[2] ^ binary[3]);
	252
	253	/* keep track of column parity */
	254	parity[0] ^= binary[0];
	255	parity[1] ^= binary[1];
	256	parity[2] ^= binary[2];
	257	parity[3] ^= binary[3];
	258	}
	259
	260	/* parity columns */
	261	AppendGraph(0, clock, parity[0]);
	262	AppendGraph(0, clock, parity[1]);
	263	AppendGraph(0, clock, parity[2]);
	264	AppendGraph(0, clock, parity[3]);
	265
	266	/* stop bit */
3fe4ff4f	267	AppendGraph(1, clock, 0);
	268
	269	CmdLFSim("240"); //240 start_gap.
7fe9b0b7	270	return 0;
	271	}
	272
3fe4ff4f	273	/* Function is equivalent of lf read + data samples + em410xread
	274	* looped until an EM410x tag is detected
	275	*
	276	* Why is CmdSamples("16000")?
	277	* TBD: Auto-grow sample size based on detected sample rate. IE: If the
	278	* rate gets lower, then grow the number of samples
	279	* Changed by martin, 4000 x 4 = 16000,
	280	* see http://www.proxmark.org/forum/viewtopic.php?pid=7235#p7235
	281
	282	*/
7fe9b0b7	283	int CmdEM410xWatch(const char *Cmd)
7fe9b0b7	284	{
3fe4ff4f	285	char cmdp = param_getchar(Cmd, 0);
	286	int read_h = (cmdp == 'h');
	287	do {
	288	if (ukbhit()) {
	289	printf("\naborted via keyboard!\n");
	290	break;
	291	}
	292
	293	CmdLFRead(read_h ? "h" : "");
	294	CmdSamples("6000");
	295	} while (
	296	!CmdEM410xRead("")
	297	);
	298	return 0;
7fe9b0b7	299	}
7fe9b0b7	300
c3bfb9c7	301	int CmdEM410xWatchnSpoof(const char *Cmd)
	302	{
	303	CmdEM410xWatch(Cmd);
	304	PrintAndLog("# Replaying : %s",global_em410xId);
	305	CmdEM410xSim(global_em410xId);
	306	return 0;
	307	}
	308
7fe9b0b7	309	/* Read the transmitted data of an EM4x50 tag
	310	* Format:
	311	*
	312	* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
	313	* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
	314	* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
	315	* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
	316	* CCCCCCCC <- column parity bits
	317	* 0 <- stop bit
	318	* LW <- Listen Window
	319	*
	320	* This pattern repeats for every block of data being transmitted.
	321	* Transmission starts with two Listen Windows (LW - a modulated
	322	* pattern of 320 cycles each (32/32/128/64/64)).
	323	*
	324	* Note that this data may or may not be the UID. It is whatever data
	325	* is stored in the blocks defined in the control word First and Last
	326	* Word Read values. UID is stored in block 32.
	327	*/
	328	int CmdEM4x50Read(const char *Cmd)
	329	{
31b6e9af	330	int i, j, startblock, skip, block, start, end, low, high;
7fe9b0b7	331	bool complete= false;
	332	int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
	333	char tmp[6];
	334
	335	high= low= 0;
913d23c6	336	memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);
7fe9b0b7	337
	338	/* first get high and low values */
	339	for (i = 0; i < GraphTraceLen; i++)
	340	{
	341	if (GraphBuffer[i] > high)
	342	high = GraphBuffer[i];
	343	else if (GraphBuffer[i] < low)
	344	low = GraphBuffer[i];
	345	}
	346
	347	/* populate a buffer with pulse lengths */
	348	i= 0;
	349	j= 0;
	350	while (i < GraphTraceLen)
	351	{
	352	// measure from low to low
	353	while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
	354	++i;
	355	start= i;
	356	while ((GraphBuffer[i] < high) && (i<GraphTraceLen))
	357	++i;
	358	while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
	359	++i;
90e278d3	360	if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
7fe9b0b7	361	break;
	362	}
	363	tmpbuff[j++]= i - start;
	364	}
	365
	366	/* look for data start - should be 2 pairs of LW (pulses of 192,128) */
	367	start= -1;
	368	skip= 0;
	369	for (i= 0; i < j - 4 ; ++i)
	370	{
	371	skip += tmpbuff[i];
	372	if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
	373	if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
	374	if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
	375	if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
	376	{
	377	start= i + 3;
	378	break;
	379	}
	380	}
	381	startblock= i + 3;
	382
	383	/* skip over the remainder of the LW */
	384	skip += tmpbuff[i+1]+tmpbuff[i+2];
	385	while (skip < MAX_GRAPH_TRACE_LEN && GraphBuffer[skip] > low)
	386	++skip;
	387	skip += 8;
	388
	389	/* now do it again to find the end */
	390	end= start;
	391	for (i += 3; i < j - 4 ; ++i)
	392	{
	393	end += tmpbuff[i];
	394	if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
	395	if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
	396	if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
	397	if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
	398	{
	399	complete= true;
	400	break;
	401	}
	402	}
	403
	404	if (start >= 0)
	405	PrintAndLog("Found data at sample: %i",skip);
	406	else
	407	{
	408	PrintAndLog("No data found!");
	409	PrintAndLog("Try again with more samples.");
	410	return 0;
	411	}
	412
	413	if (!complete)
	414	{
	415	PrintAndLog("*** Warning!");
	416	PrintAndLog("Partial data - no end found!");
	417	PrintAndLog("Try again with more samples.");
	418	}
	419
	420	/* get rid of leading crap */
	421	sprintf(tmp,"%i",skip);
	422	CmdLtrim(tmp);
	423
	424	/* now work through remaining buffer printing out data blocks */
425	block= 0;
426	i= startblock;
427	while (block < 6)
428	{
429	PrintAndLog("Block %i:", block);
430	// mandemod routine needs to be split so we can call it for data
431	// just print for now for debugging
432	CmdManchesterDemod("i 64");
433	skip= 0;
434	/* look for LW before start of next block */
435	for ( ; i < j - 4 ; ++i)
436	{
437	skip += tmpbuff[i];
438	if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
439	if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
440	break;
441	}
442	while (GraphBuffer[skip] > low)
443	++skip;
444	skip += 8;
445	sprintf(tmp,"%i",skip);
446	CmdLtrim(tmp);
447	start += skip;
448	block++;
449	}
450	return 0;
451	}
452
2d4eae76	453	int CmdEM410xWrite(const char *Cmd)
2d4eae76	454	{
e67b06b7	455	uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
7bb9d33e	456	int card = 0xFF; // invalid card value
e67b06b7	457	unsigned int clock = 0; // invalid clock value
	458
	459	sscanf(Cmd, "%" PRIx64 " %d %d", &id, &card, &clock);
	460
	461	// Check ID
	462	if (id == 0xFFFFFFFFFFFFFFFF) {
	463	PrintAndLog("Error! ID is required.\n");
	464	return 0;
	465	}
	466	if (id >= 0x10000000000) {
	467	PrintAndLog("Error! Given EM410x ID is longer than 40 bits.\n");
	468	return 0;
	469	}
	470
	471	// Check Card
	472	if (card == 0xFF) {
	473	PrintAndLog("Error! Card type required.\n");
	474	return 0;
	475	}
	476	if (card < 0) {
	477	PrintAndLog("Error! Bad card type selected.\n");
	478	return 0;
	479	}
	480
	481	// Check Clock
	482	if (card == 1)
	483	{
	484	// Default: 64
	485	if (clock == 0)
	486	clock = 64;
	487
	488	// Allowed clock rates: 16, 32 and 64
	489	if ((clock != 16) && (clock != 32) && (clock != 64)) {
	490	PrintAndLog("Error! Clock rate %d not valid. Supported clock rates are 16, 32 and 64.\n", clock);
	491	return 0;
	492	}
	493	}
	494	else if (clock != 0)
	495	{
	496	PrintAndLog("Error! Clock rate is only supported on T55x7 tags.\n");
	497	return 0;
	498	}
	499
	500	if (card == 1) {
	501	PrintAndLog("Writing %s tag with UID 0x%010" PRIx64 " (clock rate: %d)", "T55x7", id, clock);
	502	// NOTE: We really should pass the clock in as a separate argument, but to
	503	// provide for backwards-compatibility for older firmware, and to avoid
	504	// having to add another argument to CMD_EM410X_WRITE_TAG, we just store
	505	// the clock rate in bits 8-15 of the card value
	506	card = (card & 0xFF) \| (((uint64_t)clock << 8) & 0xFF00);
	507	}
	508	else if (card == 0)
	509	PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
	510	else {
	511	PrintAndLog("Error! Bad card type selected.\n");
	512	return 0;
	513	}
2d4eae76	514
2d4eae76	515	UsbCommand c = {CMD_EM410X_WRITE_TAG, {card, (uint32_t)(id >> 32), (uint32_t)id}};
	516	SendCommand(&c);
	517
	518	return 0;
	519	}
	520
54a942b0	521	int CmdReadWord(const char *Cmd)
54a942b0	522	{
b915fda3	523	int Word = -1; //default to invalid word
54a942b0	524	UsbCommand c;
	525
	526	sscanf(Cmd, "%d", &Word);
	527
b915fda3	528	if ( (Word > 15) \| (Word < 0) ) {
54a942b0	529	PrintAndLog("Word must be between 0 and 15");
	530	return 1;
	531	}
	532
	533	PrintAndLog("Reading word %d", Word);
	534
	535	c.cmd = CMD_EM4X_READ_WORD;
	536	c.d.asBytes[0] = 0x0; //Normal mode
	537	c.arg[0] = 0;
	538	c.arg[1] = Word;
	539	c.arg[2] = 0;
	540	SendCommand(&c);
	541	return 0;
	542	}
	543
	544	int CmdReadWordPWD(const char *Cmd)
	545	{
b915fda3	546	int Word = -1; //default to invalid word
54a942b0	547	int Password = 0xFFFFFFFF; //default to blank password
	548	UsbCommand c;
	549
	550	sscanf(Cmd, "%d %x", &Word, &Password);
	551
b915fda3	552	if ( (Word > 15) \| (Word < 0) ) {
54a942b0	553	PrintAndLog("Word must be between 0 and 15");
	554	return 1;
	555	}
	556
	557	PrintAndLog("Reading word %d with password %08X", Word, Password);
	558
	559	c.cmd = CMD_EM4X_READ_WORD;
	560	c.d.asBytes[0] = 0x1; //Password mode
	561	c.arg[0] = 0;
	562	c.arg[1] = Word;
	563	c.arg[2] = Password;
	564	SendCommand(&c);
	565	return 0;
	566	}
	567
	568	int CmdWriteWord(const char *Cmd)
	569	{
	570	int Word = 16; //default to invalid block
	571	int Data = 0xFFFFFFFF; //default to blank data
	572	UsbCommand c;
	573
	574	sscanf(Cmd, "%x %d", &Data, &Word);
	575
	576	if (Word > 15) {
	577	PrintAndLog("Word must be between 0 and 15");
	578	return 1;
	579	}
	580
b915fda3	581	PrintAndLog("Writing word %d with data %08X", Word, Data);
54a942b0	582
	583	c.cmd = CMD_EM4X_WRITE_WORD;
	584	c.d.asBytes[0] = 0x0; //Normal mode
	585	c.arg[0] = Data;
	586	c.arg[1] = Word;
	587	c.arg[2] = 0;
	588	SendCommand(&c);
	589	return 0;
	590	}
	591
	592	int CmdWriteWordPWD(const char *Cmd)
	593	{
b915fda3	594	int Word = 16; //default to invalid word
54a942b0	595	int Data = 0xFFFFFFFF; //default to blank data
	596	int Password = 0xFFFFFFFF; //default to blank password
	597	UsbCommand c;
	598
	599	sscanf(Cmd, "%x %d %x", &Data, &Word, &Password);
	600
	601	if (Word > 15) {
	602	PrintAndLog("Word must be between 0 and 15");
	603	return 1;
	604	}
	605
b915fda3	606	PrintAndLog("Writing word %d with data %08X and password %08X", Word, Data, Password);
54a942b0	607
	608	c.cmd = CMD_EM4X_WRITE_WORD;
	609	c.d.asBytes[0] = 0x1; //Password mode
	610	c.arg[0] = Data;
	611	c.arg[1] = Word;
	612	c.arg[2] = Password;
	613	SendCommand(&c);
	614	return 0;
	615	}
	616
2d4eae76	617	static command_t CommandTable[] =
7fe9b0b7	618	{
54a942b0	619	{"help", CmdHelp, 1, "This help"},
4118b74d	620	{"em410xdemod", CmdEMdemodASK, 0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},
54a942b0	621	{"em410xread", CmdEM410xRead, 1, "[clock rate] -- Extract ID from EM410x tag"},
54a942b0	622	{"em410xsim", CmdEM410xSim, 0, "<UID> -- Simulate EM410x tag"},
e67b06b7	623	{"em410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
c3bfb9c7	624	{"em410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
e67b06b7	625	{"em410xwrite", CmdEM410xWrite, 1, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
54a942b0	626	{"em4x50read", CmdEM4x50Read, 1, "Extract data from EM4x50 tag"},
	627	{"readword", CmdReadWord, 1, "<Word> -- Read EM4xxx word data"},
	628	{"readwordPWD", CmdReadWordPWD, 1, "<Word> <Password> -- Read EM4xxx word data in password mode"},
	629	{"writeword", CmdWriteWord, 1, "<Data> <Word> -- Write EM4xxx word data"},
	630	{"writewordPWD", CmdWriteWordPWD, 1, "<Data> <Word> <Password> -- Write EM4xxx word data in password mode"},
7fe9b0b7	631	{NULL, NULL, 0, NULL}
	632	};
	633
	634	int CmdLFEM4X(const char *Cmd)
	635	{
	636	CmdsParse(CommandTable, Cmd);
	637	return 0;
	638	}
	639
	640	int CmdHelp(const char *Cmd)
	641	{
	642	CmdsHelp(CommandTable);
	643	return 0;
	644	}