[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 "cmdlfem4x.h"
#include "proxmark3.h"
#include "ui.h"
#include "util.h"
#include "data.h"
#include "graph.h"
#include "cmdparser.h"
#include "cmddata.h"
#include "cmdlf.h"
#include "cmdmain.h"
#include "lfdemod.h"

uint64_t g_em410xId=0;

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;
}

//by marshmellow
//print 64 bit EM410x ID in multiple formats
void printEM410x(uint32_t hi, uint64_t id)
{
        if (id || hi){
                uint64_t iii=1;
                uint64_t id2lo=0;
                uint32_t ii=0;
                uint32_t i=0;
                for (ii=5; ii>0;ii--){
                        for (i=0;i<8;i++){
                                id2lo=(id2lo<<1LL) | ((id & (iii << (i+((ii-1)*8)))) >> (i+((ii-1)*8)));
                        }
                }
                if (hi){
                        //output 88 bit em id
                        PrintAndLog("\nEM TAG ID      : %06X%016" PRIX64, hi, id);
                } else{
                        //output 40 bit em id
                        PrintAndLog("\nEM TAG ID      : %010" PRIX64, id);
                        PrintAndLog("\nPossible de-scramble patterns");
                        PrintAndLog("Unique TAG ID  : %010" PRIX64,  id2lo);
                        PrintAndLog("HoneyWell IdentKey {");
                        PrintAndLog("DEZ 8          : %08" PRIu64,id & 0xFFFFFF);
                        PrintAndLog("DEZ 10         : %010" PRIu64,id & 0xFFFFFFFF);
                        PrintAndLog("DEZ 5.5        : %05lld.%05" PRIu64,(id>>16LL) & 0xFFFF,(id & 0xFFFF));
                        PrintAndLog("DEZ 3.5A       : %03lld.%05" PRIu64,(id>>32ll),(id & 0xFFFF));
                        PrintAndLog("DEZ 3.5B       : %03lld.%05" PRIu64,(id & 0xFF000000) >> 24,(id & 0xFFFF));
                        PrintAndLog("DEZ 3.5C       : %03lld.%05" PRIu64,(id & 0xFF0000) >> 16,(id & 0xFFFF));
                        PrintAndLog("DEZ 14/IK2     : %014" PRIu64,id);
                        PrintAndLog("DEZ 15/IK3     : %015" PRIu64,id2lo);
                        PrintAndLog("DEZ 20/ZK      : %02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64 "%02" PRIu64,
                            (id2lo & 0xf000000000) >> 36,
                            (id2lo & 0x0f00000000) >> 32,
                            (id2lo & 0x00f0000000) >> 28,
                            (id2lo & 0x000f000000) >> 24,
                            (id2lo & 0x0000f00000) >> 20,
                            (id2lo & 0x00000f0000) >> 16,
                            (id2lo & 0x000000f000) >> 12,
                            (id2lo & 0x0000000f00) >> 8,
                            (id2lo & 0x00000000f0) >> 4,
                            (id2lo & 0x000000000f)
                        );
                        uint64_t paxton = (((id>>32) << 24) | (id & 0xffffff))  + 0x143e00;
                        PrintAndLog("}\nOther          : %05" PRIu64 "_%03" PRIu64 "_%08" PRIu64 "",(id&0xFFFF),((id>>16LL) & 0xFF),(id & 0xFFFFFF));  
                        PrintAndLog("Pattern Paxton : %" PRIu64 " [0x%" PRIX64 "]", paxton, paxton);

                        uint32_t p1id = (id & 0xFFFFFF);
                        uint8_t arr[32] = {0x00};
                        int i =0; 
                        int j = 23;
                        for (; i < 24; ++i, --j ){
                                arr[i] = (p1id >> i) & 1;
                        }

                        uint32_t p1  = 0;

                        p1 |= arr[23] << 21;
                        p1 |= arr[22] << 23;
                        p1 |= arr[21] << 20;
                        p1 |= arr[20] << 22;
                                
                        p1 |= arr[19] << 18;
                        p1 |= arr[18] << 16;
                        p1 |= arr[17] << 19;
                        p1 |= arr[16] << 17;
                                
                        p1 |= arr[15] << 13;
                        p1 |= arr[14] << 15;
                        p1 |= arr[13] << 12;
                        p1 |= arr[12] << 14;

                        p1 |= arr[11] << 6;
                        p1 |= arr[10] << 2;
                        p1 |= arr[9]  << 7;
                        p1 |= arr[8]  << 1;

                        p1 |= arr[7]  << 0;
                        p1 |= arr[6]  << 8;
                        p1 |= arr[5]  << 11;
                        p1 |= arr[4]  << 3;

                        p1 |= arr[3]  << 10;
                        p1 |= arr[2]  << 4;
                        p1 |= arr[1]  << 5;
                        p1 |= arr[0]  << 9;
                        PrintAndLog("Pattern 1      : %d [0x%X]", p1, p1);

                        uint16_t sebury1 = id & 0xFFFF;
                        uint8_t  sebury2 = (id >> 16) & 0x7F;
                        uint32_t sebury3 = id & 0x7FFFFF;
                        PrintAndLog("Pattern Sebury : %d %d %d  [0x%X 0x%X 0x%X]", sebury1, sebury2, sebury3, sebury1, sebury2, sebury3);
                }
        }
        return;
}

/* 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 AskEm410xDecode(bool verbose, uint32_t *hi, uint64_t *lo )
{
        size_t idx = 0;
        size_t BitLen = DemodBufferLen;
        uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
        memcpy(BitStream, DemodBuffer, BitLen); 
        if (Em410xDecode(BitStream, &BitLen, &idx, hi, lo)){
                //set GraphBuffer for clone or sim command
                setDemodBuf(BitStream, BitLen, idx);
                if (g_debugMode){
                        PrintAndLog("DEBUG: idx: %d, Len: %d, Printing Demod Buffer:", idx, BitLen);
                        printDemodBuff();
                }
                if (verbose){
                        PrintAndLog("EM410x pattern found: ");
                        printEM410x(*hi, *lo);
                        g_em410xId = *lo;
                }
                return 1;
        }
        return 0;
}

//askdemod then call Em410xdecode
int AskEm410xDemod(const char *Cmd, uint32_t *hi, uint64_t *lo, bool verbose)
{
        bool st = true;
        if (!ASKDemod_ext(Cmd, false, false, 1, &st)) return 0;
        return AskEm410xDecode(verbose, hi, lo);
}

//by marshmellow
//takes 3 arguments - clock, invert and maxErr as integers
//attempts to demodulate ask while decoding manchester
//prints binary found and saves in graphbuffer for further commands
int CmdAskEM410xDemod(const char *Cmd)
{
        char cmdp = param_getchar(Cmd, 0);
        if (strlen(Cmd) > 10 || cmdp == 'h' || cmdp == 'H') {
                PrintAndLog("Usage:  lf em 410xdemod [clock] <0|1> [maxError]");
                PrintAndLog("     [set clock as integer] optional, if not set, autodetect.");
                PrintAndLog("     <invert>, 1 for invert output");
                PrintAndLog("     [set maximum allowed errors], default = 100.");
                PrintAndLog("");
                PrintAndLog("    sample: lf em 410xdemod        = demod an EM410x Tag ID from GraphBuffer");
                PrintAndLog("          : lf em 410xdemod 32     = demod an EM410x Tag ID from GraphBuffer using a clock of RF/32");
                PrintAndLog("          : lf em 410xdemod 32 1   = demod an EM410x Tag ID from GraphBuffer using a clock of RF/32 and inverting data");
                PrintAndLog("          : lf em 410xdemod 1      = demod an EM410x Tag ID from GraphBuffer while inverting data");
                PrintAndLog("          : lf em 410xdemod 64 1 0 = demod an EM410x Tag ID from GraphBuffer using a clock of RF/64 and inverting data and allowing 0 demod errors");
                return 0;
        }
        uint64_t lo = 0;
        uint32_t hi = 0;
        return AskEm410xDemod(Cmd, &hi, &lo, true);
}

int usage_lf_em410x_sim(void) {
        PrintAndLog("Simulating EM410x tag");
        PrintAndLog("");
        PrintAndLog("Usage:  lf em 410xsim [h] <uid> <clock>");
        PrintAndLog("Options:");
        PrintAndLog("       h         - this help");
        PrintAndLog("       uid       - uid (10 HEX symbols)");
        PrintAndLog("       clock     - clock (32|64) (optional)");
        PrintAndLog("samples:");
        PrintAndLog("      lf em 410xsim 0F0368568B");
        PrintAndLog("      lf em 410xsim 0F0368568B 32");
        return 0;
}

// emulate an EM410X 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') return usage_lf_em410x_sim();
        /* clock is 64 in EM410x tags */
        uint8_t clock = 64;

        if (param_gethex(Cmd, 0, uid, 10)) {
                PrintAndLog("UID must include 10 HEX symbols");
                return 0;
        }
        param_getdec(Cmd,1, &clock);

        PrintAndLog("Starting simulating UID %02X%02X%02X%02X%02X  clock: %d", uid[0],uid[1],uid[2],uid[3],uid[4],clock);
        PrintAndLog("Press pm3-button to about simulation");


        /* 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("0"); //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
 *
 *  EDIT -- capture enough to get 2 complete preambles at the slowest data rate known to be used (rf/64) (64*64*2+9 = 8201)     marshmellow
*/
int CmdEM410xWatch(const char *Cmd)
{
        do {
                if (ukbhit()) {
                        printf("\naborted via keyboard!\n");
                        break;
                }
                
                CmdLFRead("s");
                getSamples("8201",true); 
        } while (!CmdAskEM410xDemod(""));

        return 0;
}

//currently only supports manchester modulations
int CmdEM410xWatchnSpoof(const char *Cmd)
{
        CmdEM410xWatch(Cmd);
        PrintAndLog("# Replaying captured ID: %010"PRIx64, g_em410xId);
        CmdLFaskSim("");
        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, "%" SCNx64 " %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
        // Default: 64
        if (clock == 0)
                clock = 64;

        // Allowed clock rates: 16, 32, 40 and 64
        if ((clock != 16) && (clock != 32) && (clock != 64) && (clock != 40)) {
                PrintAndLog("Error! Clock rate %d not valid. Supported clock rates are 16, 32, 40 and 64.\n", clock);
                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) | ((clock << 8) & 0xFF00);
        }       else if (card == 0) {
                PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
                card = (card & 0xFF) | ((clock << 8) & 0xFF00);
        } 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;
}

//**************** Start of EM4x50 Code ************************
bool EM_EndParityTest(uint8_t *BitStream, size_t size, uint8_t rows, uint8_t cols, uint8_t pType)
{
        if (rows*cols>size) return false;
        uint8_t colP=0;
        //assume last col is a parity and do not test
        for (uint8_t colNum = 0; colNum < cols-1; colNum++) {
                for (uint8_t rowNum = 0; rowNum < rows; rowNum++) {
                        colP ^= BitStream[(rowNum*cols)+colNum];
                }
                if (colP != pType) return false;
        }
        return true;
}

bool EM_ByteParityTest(uint8_t *BitStream, size_t size, uint8_t rows, uint8_t cols, uint8_t pType)
{
        if (rows*cols>size) return false;
        uint8_t rowP=0;
        //assume last row is a parity row and do not test
        for (uint8_t rowNum = 0; rowNum < rows-1; rowNum++) {
                for (uint8_t colNum = 0; colNum < cols; colNum++) {
                        rowP ^= BitStream[(rowNum*cols)+colNum];
                }
                if (rowP != pType) return false;
        }
        return true;
}

uint32_t OutputEM4x50_Block(uint8_t *BitStream, size_t size, bool verbose, bool pTest)
{
        if (size<45) return 0;
        uint32_t code = bytebits_to_byte(BitStream,8);
        code = code<<8 | bytebits_to_byte(BitStream+9,8);
        code = code<<8 | bytebits_to_byte(BitStream+18,8);
        code = code<<8 | bytebits_to_byte(BitStream+27,8);
        if (verbose || g_debugMode){
                for (uint8_t i = 0; i<5; i++){
                        if (i == 4) PrintAndLog(""); //parity byte spacer
                        PrintAndLog("%d%d%d%d%d%d%d%d %d -> 0x%02x",
                            BitStream[i*9],
                            BitStream[i*9+1],
                            BitStream[i*9+2],
                            BitStream[i*9+3],
                            BitStream[i*9+4],
                            BitStream[i*9+5],
                            BitStream[i*9+6],
                            BitStream[i*9+7],
                            BitStream[i*9+8],
                            bytebits_to_byte(BitStream+i*9,8)
                        );
                }
                if (pTest)
                        PrintAndLog("Parity Passed");
                else
                        PrintAndLog("Parity Failed");
        }
        return code;
}
/* Read the transmitted data of an EM4x50 tag from the graphbuffer
 * 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.
 */
 //completed by Marshmellow
int EM4x50Read(const char *Cmd, bool verbose)
{
        uint8_t fndClk[] = {8,16,32,40,50,64,128};
        int clk = 0; 
        int invert = 0;
        int tol = 0;
        int i, j, startblock, skip, block, start, end, low, high, minClk;
        bool complete = false;
        int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
        uint32_t Code[6];
        char tmp[6];
        char tmp2[20];
        int phaseoff;
        high = low = 0;
        memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);

        // get user entry if any
        sscanf(Cmd, "%i %i", &clk, &invert);
        
        // save GraphBuffer - to restore it later       
        save_restoreGB(1);

        // 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];
        }

        i = 0;
        j = 0;
        minClk = 255;
        // get to first full low to prime loop and skip incomplete first pulse
        while ((GraphBuffer[i] < high) && (i < GraphTraceLen))
                ++i;
        while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
                ++i;
        skip = i;

        // populate tmpbuff buffer with pulse lengths
        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;
                if (i-start < minClk && i < GraphTraceLen) {
                        minClk = i - start;
                }
        }
        // set clock
        if (!clk) {
                for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
                        tol = fndClk[clkCnt]/8;
                        if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) { 
                                clk=fndClk[clkCnt];
                                break;
                        }
                }
                if (!clk) return 0;
        } else tol = clk/8;

        // look for data start - should be 2 pairs of LW (pulses of clk*3,clk*2)
        start = -1;
        for (i= 0; i < j - 4 ; ++i) {
                skip += tmpbuff[i];
                if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)  //3 clocks
                        if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol)  //2 clocks
                                if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
                                        if (tmpbuff[i+3] >= clk-tol)  //1.5 to 2 clocks - depends on bit following
                                        {
                                                start= i + 4;
                                                break;
                                        }
        }
        startblock = i + 4;

        // skip over the remainder of LW
        skip += tmpbuff[i+1] + tmpbuff[i+2] + clk;
        if (tmpbuff[i+3]>clk) 
                phaseoff = tmpbuff[i+3]-clk;
        else
                phaseoff = 0;
        // now do it again to find the end
        end = skip;
        for (i += 3; i < j - 4 ; ++i) {
                end += tmpbuff[i];
                if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)  //3 clocks
                        if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol)  //2 clocks
                                if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
                                        if (tmpbuff[i+3] >= clk-tol)  //1.5 to 2 clocks - depends on bit following
                                        {
                                                complete= true;
                                                break;
                                        }
        }
        end = i;
        // report back
        if (verbose || g_debugMode) {
                if (start >= 0) {
                        PrintAndLog("\nNote: one block = 50 bits (32 data, 12 parity, 6 marker)");
                }       else {
                        PrintAndLog("No data found!, clock tried:%d",clk);
                        PrintAndLog("Try again with more samples.");
                        PrintAndLog("  or after a 'data askedge' command to clean up the read");
                        return 0;
                }
        } else if (start < 0) return 0;
        start = skip;
        snprintf(tmp2, sizeof(tmp2),"%d %d 1000 %d", clk, invert, clk*47);
        // get rid of leading crap 
        snprintf(tmp, sizeof(tmp), "%i", skip);
        CmdLtrim(tmp);
        bool pTest;
        bool AllPTest = true;
        // now work through remaining buffer printing out data blocks
        block = 0;
        i = startblock;
        while (block < 6) {
                if (verbose || g_debugMode) PrintAndLog("\nBlock %i:", block);
                skip = phaseoff;
                
                // look for LW before start of next block
                for ( ; i < j - 4 ; ++i) {
                        skip += tmpbuff[i];
                        if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)
                                if (tmpbuff[i+1] >= clk-tol)
                                        break;
                }
                if (i >= j-4) break; //next LW not found
                skip += clk;
                if (tmpbuff[i+1]>clk)
                        phaseoff = tmpbuff[i+1]-clk;
                else
                        phaseoff = 0;
                i += 2;
                if (ASKDemod(tmp2, false, false, 1) < 1) {
                        save_restoreGB(0);
                        return 0;
                }
                //set DemodBufferLen to just one block
                DemodBufferLen = skip/clk;
                //test parities
                pTest = EM_ByteParityTest(DemodBuffer,DemodBufferLen,5,9,0);    
                pTest &= EM_EndParityTest(DemodBuffer,DemodBufferLen,5,9,0);
                AllPTest &= pTest;
                //get output
                Code[block] = OutputEM4x50_Block(DemodBuffer,DemodBufferLen,verbose, pTest);
                if (g_debugMode) PrintAndLog("\nskipping %d samples, bits:%d", skip, skip/clk);
                //skip to start of next block
                snprintf(tmp,sizeof(tmp),"%i",skip);
                CmdLtrim(tmp);
                block++;
                if (i >= end) break; //in case chip doesn't output 6 blocks
        }
        //print full code:
        if (verbose || g_debugMode || AllPTest){
                if (!complete) {
                        PrintAndLog("*** Warning!");
                        PrintAndLog("Partial data - no end found!");
                        PrintAndLog("Try again with more samples.");
                }
                PrintAndLog("Found data at sample: %i - using clock: %i", start, clk);    
                end = block;
                for (block=0; block < end; block++){
                        PrintAndLog("Block %d: %08x",block,Code[block]);
                }
                if (AllPTest) {
                        PrintAndLog("Parities Passed");
                } else {
                        PrintAndLog("Parities Failed");
                        PrintAndLog("Try cleaning the read samples with 'data askedge'");
                }
        }

        //restore GraphBuffer
        save_restoreGB(0);
        return (int)AllPTest;
}

int CmdEM4x50Read(const char *Cmd)
{
        return EM4x50Read(Cmd, true);
}

//**************** Start of EM4x05/EM4x69 Code ************************
int usage_lf_em_read(void) {
        PrintAndLog("Read EM4x05/EM4x69.  Tag must be on antenna. ");
        PrintAndLog("");
        PrintAndLog("Usage:  lf em 4x05readword [h] <address> <pwd>");
        PrintAndLog("Options:");
        PrintAndLog("       h         - this help");
        PrintAndLog("       address   - memory address to read. (0-15)");
        PrintAndLog("       pwd       - password (hex) (optional)");
        PrintAndLog("samples:");
        PrintAndLog("      lf em 4x05readword 1");
        PrintAndLog("      lf em 4x05readword 1 11223344");
        return 0;
}

// for command responses from em4x05 or em4x69
// download samples from device and copy them to the Graphbuffer
bool downloadSamplesEM() {
        // 8 bit preamble + 32 bit word response (max clock (128) * 40bits = 5120 samples)
        uint8_t got[6000]; 
        GetFromBigBuf(got, sizeof(got), 0);
        if ( !WaitForResponseTimeout(CMD_ACK, NULL, 4000) ) {
                PrintAndLog("command execution time out");
                return false;
        }
        setGraphBuf(got, sizeof(got));
        return true;
}

bool EM4x05testDemodReadData(uint32_t *word, bool readCmd) {
        // em4x05/em4x69 command response preamble is 00001010
        // skip first two 0 bits as they might have been missed in the demod
        uint8_t preamble[] = {0,0,1,0,1,0};
        size_t startIdx = 0;

        // set size to 20 to only test first 14 positions for the preamble or less if not a read command
        size_t size = (readCmd) ? 20 : 11;
        // sanity check
        size = (size > DemodBufferLen) ? DemodBufferLen : size;
        // test preamble
        if ( !preambleSearchEx(DemodBuffer, preamble, sizeof(preamble), &size, &startIdx, true) ) {
                if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
                return false;
        }
        // if this is a readword command, get the read bytes and test the parities
        if (readCmd) {
                if (!EM_EndParityTest(DemodBuffer + startIdx + sizeof(preamble), 45, 5, 9, 0)) {
                        if (g_debugMode) PrintAndLog("DEBUG: Error - End Parity check failed");
                        return false;
                }
                // test for even parity bits and remove them. (leave out the end row of parities so 36 bits)
                if ( removeParity(DemodBuffer, startIdx + sizeof(preamble),9,0,36) == 0 ) {             
                        if (g_debugMode) PrintAndLog("DEBUG: Error - Parity not detected");
                        return false;
                }

                setDemodBuf(DemodBuffer, 32, 0);
                *word = bytebits_to_byteLSBF(DemodBuffer, 32);
        }
        return true;
}

// FSK, PSK, ASK/MANCHESTER, ASK/BIPHASE, ASK/DIPHASE 
// should cover 90% of known used configs
// the rest will need to be manually demoded for now...
int demodEM4x05resp(uint32_t *word, bool readCmd) {
        int ans = 0;

        // test for FSK wave (easiest to 99% ID)
        if (GetFskClock("", false, false)) {
                //valid fsk clocks found
                ans = FSKrawDemod("0 0", false);
                if (!ans) {
                        if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK Demod failed, ans: %d", ans);
                } else {
                        if (EM4x05testDemodReadData(word, readCmd)) {
                                return 1;
                        }
                }
        }
        // PSK clocks should be easy to detect ( but difficult to demod a non-repeating pattern... )
        ans = GetPskClock("", false, false);
        if (ans>0) {
                //try psk1
                ans = PSKDemod("0 0 6", false);
                if (!ans) {
                        if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: PSK1 Demod failed, ans: %d", ans);
                } else {
                        if (EM4x05testDemodReadData(word, readCmd)) {
                                return 1;
                        } else {
                                //try psk2
                                psk1TOpsk2(DemodBuffer, DemodBufferLen);
                                if (EM4x05testDemodReadData(word, readCmd)) {
                                        return 1;
                                }
                        }
                        //try psk1 inverted
                        ans = PSKDemod("0 1 6", false);
                        if (!ans) {
                                if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: PSK1 Demod failed, ans: %d", ans);
                        } else {
                                if (EM4x05testDemodReadData(word, readCmd)) {
                                        return 1;
                                } else {
                                        //try psk2
                                        psk1TOpsk2(DemodBuffer, DemodBufferLen);
                                        if (EM4x05testDemodReadData(word, readCmd)) {
                                                return 1;
                                        }
                                }
                        }
                }
        }

        // manchester is more common than biphase... try first
        bool stcheck = false;
        // try manchester - NOTE: ST only applies to T55x7 tags.
        ans = ASKDemod_ext("0,0,1", false, false, 1, &stcheck);
        if (!ans) {
                if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed, ans: %d", ans);
        } else {
                if (EM4x05testDemodReadData(word, readCmd)) {
                        return 1;
                }
        }

        //try biphase
        ans = ASKbiphaseDemod("0 0 1", false);
        if (!ans) { 
                if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed, ans: %d", ans);
        } else {
                if (EM4x05testDemodReadData(word, readCmd)) {
                        return 1;
                }
        }

        //try diphase (differential biphase or inverted)
        ans = ASKbiphaseDemod("0 1 1", false);
        if (!ans) { 
                if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed, ans: %d", ans);
        } else {
                if (EM4x05testDemodReadData(word, readCmd)) {
                        return 1;
                }
        }

        return -1;
}

int EM4x05ReadWord_ext(uint8_t addr, uint32_t pwd, bool usePwd, uint32_t *wordData) {
        UsbCommand c = {CMD_EM4X_READ_WORD, {addr, pwd, usePwd}};
        clearCommandBuffer();
        SendCommand(&c);
        UsbCommand resp;        
        if (!WaitForResponseTimeout(CMD_ACK, &resp, 2500)){
                PrintAndLog("Command timed out");
                return -1;
        }
        if ( !downloadSamplesEM() ) {
                return -1;
        }
        int testLen = (GraphTraceLen < 1000) ? GraphTraceLen : 1000;
        if (graphJustNoise(GraphBuffer, testLen)) {
                PrintAndLog("no tag not found");
                return -1;
        }
        //attempt demod:
        return demodEM4x05resp(wordData, true);
}

int EM4x05ReadWord(uint8_t addr, uint32_t pwd, bool usePwd) {
        uint32_t wordData = 0;
        int success = EM4x05ReadWord_ext(addr, pwd, usePwd, &wordData);
        if (success == 1)
                PrintAndLog("%s Address %02d | %08X", (addr>13) ? "Lock":" Got",addr,wordData);
        else
                PrintAndLog("Read Address %02d | failed",addr);

        return success;
}

int CmdEM4x05ReadWord(const char *Cmd) {
        uint8_t addr;
        uint32_t pwd;
        bool usePwd = false;
        uint8_t ctmp = param_getchar(Cmd, 0);
        if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_read();

        addr = param_get8ex(Cmd, 0, 50, 10);
        // for now use default input of 1 as invalid (unlikely 1 will be a valid password...)
        pwd =  param_get32ex(Cmd, 1, 1, 16);
        
        if ( (addr > 15) ) {
                PrintAndLog("Address must be between 0 and 15");
                return 1;
        }
        if ( pwd == 1 ) {
                PrintAndLog("Reading address %02u", addr);
        }       else {
                usePwd = true;
                PrintAndLog("Reading address %02u | password %08X", addr, pwd);
        }

        return EM4x05ReadWord(addr, pwd, usePwd);
}

int usage_lf_em_dump(void) {
        PrintAndLog("Dump EM4x05/EM4x69.  Tag must be on antenna. ");
        PrintAndLog("");
        PrintAndLog("Usage:  lf em 4x05dump [h] <pwd>");
        PrintAndLog("Options:");
        PrintAndLog("       h         - this help");
        PrintAndLog("       pwd       - password (hex) (optional)");
        PrintAndLog("samples:");
        PrintAndLog("      lf em 4x05dump");
        PrintAndLog("      lf em 4x05dump 11223344");
        return 0;
}

int CmdEM4x05dump(const char *Cmd) {
        uint8_t addr = 0;
        uint32_t pwd;
        bool usePwd = false;
        uint8_t ctmp = param_getchar(Cmd, 0);
        if ( ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_dump();

        // for now use default input of 1 as invalid (unlikely 1 will be a valid password...)
        pwd = param_get32ex(Cmd, 0, 1, 16);
        
        if ( pwd != 1 ) {
                usePwd = true;
        }
        int success = 1;
        for (; addr < 16; addr++) {
                if (addr == 2) {
                        if (usePwd) {
                                PrintAndLog(" PWD Address %02u | %08X",addr,pwd);
                        } else {
                                PrintAndLog(" PWD Address 02 | cannot read");
                        }
                } else {
                        success &= EM4x05ReadWord(addr, pwd, usePwd);
                }
        }

        return success;
}


int usage_lf_em_write(void) {
        PrintAndLog("Write EM4x05/EM4x69.  Tag must be on antenna. ");
        PrintAndLog("");
        PrintAndLog("Usage:  lf em 4x05writeword [h] [s] <address> <data> <pwd>");
        PrintAndLog("Options:");
        PrintAndLog("       h         - this help");
        PrintAndLog("       s         - swap data bit order before write");
        PrintAndLog("       address   - memory address to write to. (0-15)");
        PrintAndLog("       data      - data to write (hex)");  
        PrintAndLog("       pwd       - password (hex) (optional)");
        PrintAndLog("samples:");
        PrintAndLog("      lf em 4x05writeword 1");
        PrintAndLog("      lf em 4x05writeword 1 deadc0de 11223344");
        return 0;
}

int CmdEM4x05WriteWord(const char *Cmd) {
        uint8_t ctmp = param_getchar(Cmd, 0);
        if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_write();

        bool usePwd = false;

        uint8_t addr = 16; // default to invalid address
        uint32_t data = 0xFFFFFFFF; // default to blank data
        uint32_t pwd = 0xFFFFFFFF; // default to blank password
        char swap = 0;

        int p = 0;
        swap = param_getchar(Cmd, 0);
        if (swap == 's' || swap=='S') p++;
        addr = param_get8ex(Cmd, p++, 16, 10);
        data = param_get32ex(Cmd, p++, 0, 16);
        pwd  = param_get32ex(Cmd, p++, 1, 16);

        if (swap == 's' || swap=='S') data = SwapBits(data, 32);

        if ( (addr > 15) ) {
                PrintAndLog("Address must be between 0 and 15");
                return 1;
        }
        if ( pwd == 1 )
                PrintAndLog("Writing address %d data %08X", addr, data);        
        else {
                usePwd = true;
                PrintAndLog("Writing address %d data %08X using password %08X", addr, data, pwd);
        }

        uint16_t flag = (addr << 8 ) | usePwd;

        UsbCommand c = {CMD_EM4X_WRITE_WORD, {flag, data, pwd}};
        clearCommandBuffer();
        SendCommand(&c);
        UsbCommand resp;
        if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)){
                PrintAndLog("Error occurred, device did not respond during write operation.");
                return -1;
        }
        if ( !downloadSamplesEM() ) {
                return -1;
        }
        //check response for 00001010 for write confirmation!
        //attempt demod:
        uint32_t dummy = 0;
        int result = demodEM4x05resp(&dummy,false);
        if (result == 1) {
                PrintAndLog("Write Verified");
        } else {
                PrintAndLog("Write could not be verified");
        }
        return result;
}

void printEM4x05config(uint32_t wordData) {
        uint16_t datarate = (((wordData & 0x3F)+1)*2);
        uint8_t encoder = ((wordData >> 6) & 0xF);
        char enc[14];
        memset(enc,0,sizeof(enc));

        uint8_t PSKcf = (wordData >> 10) & 0x3;
        char cf[10];
        memset(cf,0,sizeof(cf));
        uint8_t delay = (wordData >> 12) & 0x3;
        char cdelay[33];
        memset(cdelay,0,sizeof(cdelay));
        uint8_t LWR = (wordData >> 14) & 0xF; //last word read

        switch (encoder) {
                case 0: snprintf(enc,sizeof(enc),"NRZ"); break;
                case 1: snprintf(enc,sizeof(enc),"Manchester"); break;
                case 2: snprintf(enc,sizeof(enc),"Biphase"); break;
                case 3: snprintf(enc,sizeof(enc),"Miller"); break;
                case 4: snprintf(enc,sizeof(enc),"PSK1"); break;
                case 5: snprintf(enc,sizeof(enc),"PSK2"); break;
                case 6: snprintf(enc,sizeof(enc),"PSK3"); break;
                case 7: snprintf(enc,sizeof(enc),"Unknown"); break;
                case 8: snprintf(enc,sizeof(enc),"FSK1"); break;
                case 9: snprintf(enc,sizeof(enc),"FSK2"); break;
                default: snprintf(enc,sizeof(enc),"Unknown"); break;
        }

        switch (PSKcf) {
                case 0: snprintf(cf,sizeof(cf),"RF/2"); break;
                case 1: snprintf(cf,sizeof(cf),"RF/8"); break;
                case 2: snprintf(cf,sizeof(cf),"RF/4"); break;
                case 3: snprintf(cf,sizeof(cf),"unknown"); break;
        }

        switch (delay) {
                case 0: snprintf(cdelay, sizeof(cdelay),"no delay"); break;
                case 1: snprintf(cdelay, sizeof(cdelay),"BP/8 or 1/8th bit period delay"); break;
                case 2: snprintf(cdelay, sizeof(cdelay),"BP/4 or 1/4th bit period delay"); break;
                case 3: snprintf(cdelay, sizeof(cdelay),"no delay"); break;
        }
        PrintAndLog("ConfigWord: %08X (Word 4)\n", wordData);
        PrintAndLog("Config Breakdown:", wordData);
        PrintAndLog(" Data Rate:  %02u | RF/%u", wordData & 0x3F, datarate);
        PrintAndLog("   Encoder:   %u | %s", encoder, enc);
        PrintAndLog("    PSK CF:   %u | %s", PSKcf, cf);
        PrintAndLog("     Delay:   %u | %s", delay, cdelay);
        PrintAndLog(" LastWordR:  %02u | Address of last word for default read", LWR);
        PrintAndLog(" ReadLogin:   %u | Read Login is %s", (wordData & 0x40000)>>18, (wordData & 0x40000) ? "Required" : "Not Required");       
        PrintAndLog("   ReadHKL:   %u | Read Housekeeping Words Login is %s", (wordData & 0x80000)>>19, (wordData & 0x80000) ? "Required" : "Not Required");    
        PrintAndLog("WriteLogin:   %u | Write Login is %s", (wordData & 0x100000)>>20, (wordData & 0x100000) ? "Required" : "Not Required");    
        PrintAndLog("  WriteHKL:   %u | Write Housekeeping Words Login is %s", (wordData & 0x200000)>>21, (wordData & 0x200000) ? "Required" : "Not Required"); 
        PrintAndLog("    R.A.W.:   %u | Read After Write is %s", (wordData & 0x400000)>>22, (wordData & 0x400000) ? "On" : "Off");
        PrintAndLog("   Disable:   %u | Disable Command is %s", (wordData & 0x800000)>>23, (wordData & 0x800000) ? "Accepted" : "Not Accepted");
        PrintAndLog("    R.T.F.:   %u | Reader Talk First is %s", (wordData & 0x1000000)>>24, (wordData & 0x1000000) ? "Enabled" : "Disabled");
        PrintAndLog("    Pigeon:   %u | Pigeon Mode is %s\n", (wordData & 0x4000000)>>26, (wordData & 0x4000000) ? "Enabled" : "Disabled");
}

void printEM4x05info(uint8_t chipType, uint8_t cap, uint16_t custCode, uint32_t serial) {
        switch (chipType) {
                case 9: PrintAndLog("\n Chip Type:   %u | EM4305", chipType); break;
                case 4: PrintAndLog(" Chip Type:   %u | Unknown", chipType); break;
                case 2: PrintAndLog(" Chip Type:   %u | EM4469", chipType); break;
                //add more here when known
                default: PrintAndLog(" Chip Type:   %u Unknown", chipType); break;
        }

        switch (cap) {
                case 3: PrintAndLog("  Cap Type:   %u | 330pF",cap); break;
                case 2: PrintAndLog("  Cap Type:   %u | %spF",cap, (chipType==2)? "75":"210"); break;
                case 1: PrintAndLog("  Cap Type:   %u | 250pF",cap); break;
                case 0: PrintAndLog("  Cap Type:   %u | no resonant capacitor",cap); break;
                default: PrintAndLog("  Cap Type:   %u | unknown",cap); break;
        }

        PrintAndLog(" Cust Code: %03u | %s", custCode, (custCode == 0x200) ? "Default": "Unknown");
        if (serial != 0) {
                PrintAndLog("\n  Serial #: %08X\n", serial);
        }
}

void printEM4x05ProtectionBits(uint32_t wordData) {
        for (uint8_t i = 0; i < 15; i++) {
                PrintAndLog("      Word:  %02u | %s", i, (((1 << i) & wordData ) || i < 2) ? "Is Write Locked" : "Is Not Write Locked");
                if (i==14) {
                        PrintAndLog("      Word:  %02u | %s", i+1, (((1 << i) & wordData ) || i < 2) ? "Is Write Locked" : "Is Not Write Locked");
                }
        }
}

//quick test for EM4x05/EM4x69 tag
bool EM4x05Block0Test(uint32_t *wordData) {
        if (EM4x05ReadWord_ext(0,0,false,wordData) == 1) {
                return true;
        }
        return false;
}

int CmdEM4x05info(const char *Cmd) {
        //uint8_t addr = 0;
        uint32_t pwd;
        uint32_t wordData = 0;
        bool usePwd = false;
        uint8_t ctmp = param_getchar(Cmd, 0);
        if ( ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_dump();

        // for now use default input of 1 as invalid (unlikely 1 will be a valid password...)
        pwd = param_get32ex(Cmd, 0, 1, 16);
        
        if ( pwd != 1 ) {
                usePwd = true;
        }

        // read word 0 (chip info)
        // block 0 can be read even without a password.
        if ( !EM4x05Block0Test(&wordData) ) 
                return -1;
        
        uint8_t chipType = (wordData >> 1) & 0xF;
        uint8_t cap = (wordData >> 5) & 3;
        uint16_t custCode = (wordData >> 9) & 0x3FF;
        
        // read word 1 (serial #) doesn't need pwd
        wordData = 0;
        if (EM4x05ReadWord_ext(1, 0, false, &wordData) != 1) {
                //failed, but continue anyway...
        }
        printEM4x05info(chipType, cap, custCode, wordData);

        // read word 4 (config block) 
        // needs password if one is set
        wordData = 0;
        if ( EM4x05ReadWord_ext(4, pwd, usePwd, &wordData) != 1 ) {
                //failed
                return 0;
        }
        printEM4x05config(wordData);

        // read word 14 and 15 to see which is being used for the protection bits
        wordData = 0;
        if ( EM4x05ReadWord_ext(14, pwd, usePwd, &wordData) != 1 ) {
                //failed
                return 0;
        }
        // if status bit says this is not the used protection word
        if (!(wordData & 0x8000)) {
                if ( EM4x05ReadWord_ext(15, pwd, usePwd, &wordData) != 1 ) {
                        //failed
                        return 0;
                }
        }
        if (!(wordData & 0x8000)) {
                //something went wrong
                return 0;
        }
        printEM4x05ProtectionBits(wordData);

        return 1;
}


static command_t CommandTable[] =
{
        {"help",      CmdHelp, 1, "This help"},
        {"410xread",  CmdEMdemodASK, 0, "[findone] -- Extract ID from EM410x tag (option 0 for continuous loop, 1 for only 1 tag)"},  
        {"410xdemod", CmdAskEM410xDemod,  1, "[clock] [invert<0|1>] [maxErr] -- Demodulate an EM410x tag from GraphBuffer (args optional)"},
        {"410xsim",   CmdEM410xSim, 0, "<UID> [clock rate] -- Simulate EM410x tag"},
        {"410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
        {"410xspoof", CmdEM410xWatchnSpoof, 0, "['h'] --- Watches for EM410x 125/134 kHz tags, and replays them. (option 'h' for 134)" },
        {"410xwrite", CmdEM410xWrite, 0, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
        {"4x05dump",  CmdEM4x05dump, 0, "(pwd) -- Read EM4x05/EM4x69 all word data"},
        {"4x05info",  CmdEM4x05info, 0, "(pwd) -- Get info from EM4x05/EM4x69 tag"},
        {"4x05readword",  CmdEM4x05ReadWord, 0, "<Word> (pwd) -- Read EM4x05/EM4x69 word data"},
        {"4x05writeword", CmdEM4x05WriteWord, 0, "<Word> <data> (pwd) -- Write EM4x05/EM4x69 word data"},
        {"4x50read",  CmdEM4x50Read, 1, "demod data from EM4x50 tag from the graph buffer"},
        {NULL, NULL, 0, NULL}
};

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

int CmdHelp(const char *Cmd)
{
        CmdsHelp(CommandTable);
        return 0;
}