CHG: a message..

[proxmark3-svn] / client / cmdlfem4x.c

diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c
index 5a263bf690e6398f2575dc3fd99a77510528a188..88d292ff61ec14c3f167e990f5b329fd105054db 100644 (file)
--- a/client/cmdlfem4x.c
+++ b/client/cmdlfem4x.c
@@ -8,31 +8,17 @@
 // Low frequency EM4x commands
 //-----------------------------------------------------------------------------
 
 // 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"
 #include "cmdlfem4x.h"

-#include "lfdemod.h"

 
 

-#define llx PRIx64
-
-char *global_em410xId;
+uint64_t g_em410xid = 0;

 
 static int CmdHelp(const char *Cmd);
 
 int CmdEMdemodASK(const char *Cmd)
 {
        char cmdp = param_getchar(Cmd, 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;
+       uint8_t findone = (cmdp == '1') ? 1 : 0;
+       UsbCommand c = {CMD_EM410X_DEMOD, {findone, 0, 0}};

        SendCommand(&c);
        return 0;
 }
        SendCommand(&c);
        return 0;
 }


@@ -57,78 +43,86 @@ int CmdEM410xRead(const char *Cmd)
                PrintAndLog ("EM410x XL pattern found");
                return 0;
        }
                PrintAndLog ("EM410x XL pattern found");
                return 0;
        }

-       char id[12] = {0x00};
-       sprintf(id, "%010llx",lo);
-       
-       global_em410xId = id;
+       g_em410xid = lo;

        return 1;
 }
 
        return 1;
 }
 

+
+int usage_lf_em410x_sim(void) {
+       PrintAndLog("Simulating EM410x tag");
+       PrintAndLog("");
+       PrintAndLog("Usage:  lf em4x em410xsim [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 em4x em410xsim 0F0368568B");
+       PrintAndLog("      lf em4x em410xsim 0F0368568B 32");
+       return 0;
+}
+

 // emulate an EM410X tag
 int CmdEM410xSim(const char *Cmd)
 {
        int i, n, j, binary[4], parity[4];
 // emulate an EM410X tag
 int CmdEM410xSim(const char *Cmd)
 {
        int i, n, j, binary[4], parity[4];

+       uint8_t uid[5] = {0x00};

 
        char cmdp = param_getchar(Cmd, 0);
 
        char cmdp = param_getchar(Cmd, 0);

-       uint8_t uid[5] = {0x00};
+       if (cmdp == 'h' || cmdp == 'H') return usage_lf_em410x_sim();

 
 

-       if (cmdp == 'h' || cmdp == 'H') {
-               PrintAndLog("Usage:  lf em4x em410xsim <UID>");
-               PrintAndLog("");
-               PrintAndLog("     sample: lf em4x em410xsim 0F0368568B");
-               return 0;
-       }
+       /* 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;
        }
        
 
        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]);
+       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");
 
        PrintAndLog("Press pm3-button to about simulation");
 

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

        /* clear our graph */
        ClearGraph(0);
 
        /* 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];
-               }
+       /* 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]);
+       /* parity columns */
+       AppendGraph(0, clock, parity[0]);
+       AppendGraph(0, clock, parity[1]);
+       AppendGraph(0, clock, parity[2]);
+       AppendGraph(0, clock, parity[3]);

 
 

-               /* stop bit */
+       /* stop bit */

        AppendGraph(1, clock, 0);
  
        CmdLFSim("0"); //240 start_gap.
        AppendGraph(1, clock, 0);
  
        CmdLFSim("0"); //240 start_gap.


@@ -160,10 +154,12 @@ int CmdEM410xWatch(const char *Cmd)
 }
 
 //currently only supports manchester modulations
 }
 
 //currently only supports manchester modulations

+// todo: helptext

 int CmdEM410xWatchnSpoof(const char *Cmd)
 {
 int CmdEM410xWatchnSpoof(const char *Cmd)
 {

+       // loops if the captured ID was in XL-format.

        CmdEM410xWatch(Cmd);
        CmdEM410xWatch(Cmd);

-       PrintAndLog("# Replaying captured ID: %s",global_em410xId);
+       PrintAndLog("# Replaying captured ID: %llu", g_em410xid);

        CmdLFaskSim("");
        return 0;
 }
        CmdLFaskSim("");
        return 0;
 }


@@ -172,7 +168,7 @@ int CmdEM410xWrite(const char *Cmd)
 {
        uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
        int card = 0xFF; // invalid card value
 {
        uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
        int card = 0xFF; // invalid card value

-       unsigned int clock = 0; // invalid clock value
+       uint32_t clock = 0; // invalid clock value

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


@@ -197,21 +193,13 @@ int CmdEM410xWrite(const char *Cmd)
        }
 
        // Check Clock
        }
 
        // Check Clock

-       if (card == 1)
-       {

                // Default: 64
                // Default: 64

-               if (clock == 0)
-                       clock = 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");
+       // 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;
        }
 
                return 0;
        }
 


@@ -221,11 +209,11 @@ int CmdEM410xWrite(const char *Cmd)
                //   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
                //   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)
+               card = (card & 0xFF) | ((clock << 8) & 0xFF00);
+       }       else if (card == 0) {

                PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
                PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);

-       else {
+               card = (card & 0xFF) | ((clock << 8) & 0xFF00);
+       } else {

                PrintAndLog("Error! Bad card type selected.\n");
                return 0;
        }
                PrintAndLog("Error! Bad card type selected.\n");
                return 0;
        }


@@ -266,10 +254,12 @@ bool EM_ByteParityTest(uint8_t *BitStream, size_t size, uint8_t rows, uint8_t co
 uint32_t OutputEM4x50_Block(uint8_t *BitStream, size_t size, bool verbose, bool pTest)
 {
        if (size<45) return 0;
 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);
        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
        if (verbose || g_debugMode){
                for (uint8_t i = 0; i<5; i++){
                        if (i == 4) PrintAndLog(""); //parity byte spacer


@@ -293,7 +283,7 @@ uint32_t OutputEM4x50_Block(uint8_t *BitStream, size_t size, bool verbose, bool
        }
        return code;
 }
        }
        return code;
 }

-/* Read the transmitted data of an EM4x50 tag
+/* Read the transmitted data of an EM4x50 tag from the graphbuffer

  * Format:
  *
  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
  * Format:
  *
  *  XXXXXXXX [row parity bit (even)] <- 8 bits plus parity


@@ -380,7 +370,10 @@ int EM4x50Read(const char *Cmd, bool verbose)
                                break;
                        }
                }
                                break;
                        }
                }

-               if (!clk) return 0;
+               if (!clk) {
+                       PrintAndLog("ERROR: EM4x50 - didn't find a clock");
+                       return 0;
+               }

        } else tol = clk/8;
 
        // look for data start - should be 2 pairs of LW (pulses of clk*3,clk*2)
        } else tol = clk/8;
 
        // look for data start - should be 2 pairs of LW (pulses of clk*3,clk*2)


@@ -501,132 +494,284 @@ int EM4x50Read(const char *Cmd, bool verbose)
        return (int)AllPTest;
 }
 
        return (int)AllPTest;
 }
 

-int CmdEM4x50Read(const char *Cmd)
-{
+int CmdEM4x50Read(const char *Cmd) {

        return EM4x50Read(Cmd, true);
 }
 
        return EM4x50Read(Cmd, true);
 }
 

-int CmdReadWord(const char *Cmd)
-{
-       int Word = -1; //default to invalid word
-       UsbCommand c;
+int usage_lf_em_read(void) {
+       PrintAndLog("Read EM 4x05/4x50/EM4x69.  Tag must be on antenna. ");
+       PrintAndLog("");
+       PrintAndLog("Usage:  lf em readword [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 readword 1");
+       PrintAndLog("      lf em readword 1 11223344");
+       return 0;
+}
+
+int usage_lf_em_write(void) {
+       PrintAndLog("Write EM 4x05/4x50/4x69.  Tag must be on antenna. ");
+       PrintAndLog("");
+       PrintAndLog("Usage:  lf em writeword [h] <address> <data> <pwd>");
+       PrintAndLog("Options:");
+       PrintAndLog("       h         - this help");
+       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 writeword 1");
+       PrintAndLog("      lf em writeword 1 deadc0de 11223344");
+       return 0;
+}
+
+#define EM_PREAMBLE_LEN 6
+// download samples from device
+// and copy them to Graphbuffer
+bool downloadSamplesEM(){

        
        

-       sscanf(Cmd, "%d", &Word);
+       // 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, 2500) ) {
+               PrintAndLog("command execution time out");
+               return FALSE;
+       }
+       setGraphBuf(got, sizeof(got));
+       return TRUE;
+}
+//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex
+bool doPreambleSearch(size_t *startIdx){

        
        

-       if ( (Word > 15) | (Word < 0) ) {
-               PrintAndLog("Word must be between 0 and 15");
-               return 1;
+       // sanity check
+       if ( DemodBufferLen < EM_PREAMBLE_LEN) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 demodbuffer too small");
+               return FALSE;

        }
        
        }
        

-       PrintAndLog("Reading word %d", Word);
+       // skip first two 0 bits as they might have been missed in the demod 
+       uint8_t preamble[EM_PREAMBLE_LEN] = {0,0,1,0,1,0};

        
        

-       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;
+       // set size to 10 to only test first 4 positions for the preamble
+       size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+       *startIdx = 0; 
+       uint8_t found = 0;

        
        

-       sscanf(Cmd, "%d %x", &Word, &Password);
+       // em only sends preamble once, so look for it once in the first x bits
+       for (int idx = 0; idx < size - EM_PREAMBLE_LEN; idx++){
+               if (memcmp(DemodBuffer+idx, preamble, EM_PREAMBLE_LEN) == 0){
+                       //first index found
+                       *startIdx = idx;
+                       found = 1;
+                       break;
+               }
+       }

        
        

-       if ( (Word > 15) | (Word < 0) ) {
-               PrintAndLog("Word must be between 0 and 15");
+       if ( !found) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", *startIdx);
+               return FALSE;
+       } 
+       return TRUE;
+}
+
+bool detectFSK(){
+       // detect fsk clock
+       if (!GetFskClock("", FALSE, FALSE)) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK clock failed");
+               return FALSE;
+       }
+       // demod
+       int ans = FSKrawDemod("0 0", FALSE);
+       if (!ans) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK Demod failed");
+               return FALSE;
+       }
+       return TRUE;
+}
+// PSK clocks should be easy to detect ( but difficult to demod a non-repeating pattern... )
+bool detectPSK(){      
+       int     ans = GetPskClock("", FALSE, FALSE);
+       if (ans <= 0) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: PSK clock failed");
+               return FALSE;
+       }
+       PrintAndLog("PSK response possibly found, run `data rawd p1` to attempt to demod");
+       return TRUE;
+}
+// try manchester - NOTE: ST only applies to T55x7 tags.
+bool detectASK_MAN(){
+       bool stcheck = FALSE;
+       int ans = ASKDemod_ext("0 0 0", FALSE, FALSE, 1, &stcheck);
+       if (!ans) {
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed");
+               return FALSE;
+       } 
+       return TRUE;
+}
+bool detectASK_BI(){
+       int ans = ASKbiphaseDemod("0 0 1", FALSE);
+       if (!ans) { 
+               if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase normal demod failed");
+               
+               ans = ASKbiphaseDemod("0 1 1", FALSE);
+               if (!ans) {
+                       if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase inverted demod failed");
+                       return FALSE;
+               }
+       }
+       return TRUE;
+}
+
+// param: idx - start index in demoded data.
+int setDemodBufferEM(uint8_t bitsNeeded, size_t idx){
+       if ( bitsNeeded < DemodBufferLen) {
+               setDemodBuf(DemodBuffer + idx + EM_PREAMBLE_LEN, bitsNeeded, 0);
+               CmdPrintDemodBuff("x");

                return 1;
        }
                return 1;
        }

+       return -1;
+}
+
+// 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(uint8_t bitsNeeded) {
+       size_t startIdx = 0;    

        
        

-       PrintAndLog("Reading word %d with password %08X", Word, Password);
+       if (detectASK_MAN() && doPreambleSearch( &startIdx ))
+               return setDemodBufferEM(bitsNeeded, startIdx);

        
        

-       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;
+       if (detectASK_BI() && doPreambleSearch( &startIdx ))
+               return setDemodBufferEM(bitsNeeded, startIdx);
+       
+       if (detectFSK() && doPreambleSearch( &startIdx ))
+               return setDemodBufferEM(bitsNeeded, startIdx);
+       
+       if (detectPSK() && doPreambleSearch( &startIdx )) 
+               return setDemodBufferEM(bitsNeeded, startIdx);
+
+       return -1;

 }
 
 }
 

-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);
+int CmdReadWord(const char *Cmd) {
+       int addr, 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, -1, 10);
+       pwd =  param_get32ex(Cmd, 1, -1, 16);

        
        

-       if (Word > 15) {
-               PrintAndLog("Word must be between 0 and 15");
+       if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
+               PrintAndLog("Address must be between 0 and 15");

                return 1;
        }
                return 1;
        }

+       if ( pwd == -1 )
+               PrintAndLog("Reading address %d", addr);
+       else {
+               usePwd = true;
+               PrintAndLog("Reading address %d | password %08X", addr, pwd);
+       }

        
        

-       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;
+       UsbCommand c = {CMD_EM4X_READ_WORD, {addr, pwd, usePwd}};
+       clearCommandBuffer();

        SendCommand(&c);
        SendCommand(&c);

-       return 0;
+       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("Tag not found");
+               return -1;
+       }
+
+       //attempt demod:
+       //need 32 bits from a read word
+       int result = demodEM4x05resp(44);
+       if (result == -1)
+               PrintAndLog("Read failed");
+       
+       return result;

 }
 
 }
 

-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;
+int CmdWriteWord(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;            
+       int addr = 16; // default to invalid address
+       int data = 0xFFFFFFFF; // default to blank data
+       int pwd = 0xFFFFFFFF; // default to blank password

        
        

-       sscanf(Cmd, "%x %d %x", &Data, &Word, &Password);
+       addr = param_get8ex(Cmd, 0, -1, 10);
+       data = param_get32ex(Cmd, 1, -1, 16);
+       pwd =  param_get32ex(Cmd, 2, -1, 16);

        
        

-       if (Word > 15) {
-               PrintAndLog("Word must be between 0 and 15");
+       if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
+               PrintAndLog("Address must be between 0 and 15");

                return 1;
        }
                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);               
+       }

        
        

-       PrintAndLog("Writing word %d with data %08X and password %08X", Word, Data, Password);
+       uint16_t flag = (addr << 8 ) | usePwd;

        
        

-       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;
+       UsbCommand c = {CMD_EM4X_WRITE_WORD, {flag, data, pwd}};
+       clearCommandBuffer();

        SendCommand(&c);
        SendCommand(&c);

-       return 0;
+       UsbCommand resp;        
+       if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
+               PrintAndLog("Error occurred, device did not respond during write operation.");
+               return -1;
+       }
+       
+       if (!downloadSamplesEM())
+               return -1;
+
+       //todo: check response for 00001010 then write data for write confirmation!
+       
+       //attempt demod:
+       //need 0 bits demoded (after preamble) to verify write cmd
+       int result = demodEM4x05resp(0);
+       if (result == 1)
+               PrintAndLog("Write Verified");
+
+       return result;

 }
 
 }
 

-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 in GraphBuffer"},
-       {"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, 0, "<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"},
+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 in GraphBuffer"},
+       {"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,         0, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
+       {"em4x50read",  CmdEM4x50Read,          1, "demod data from EM4x50 tag from the graphbuffer"},
+       {"readword",    CmdReadWord,            1, "read EM4x05/4x69 data"},
+       {"writeword",   CmdWriteWord,           1, "write EM405/4x69 data"},

        {NULL, NULL, 0, NULL}
 };
 
        {NULL, NULL, 0, NULL}
 };
 

-int CmdLFEM4X(const char *Cmd)
-{
+int CmdLFEM4X(const char *Cmd) {
+       clearCommandBuffer();

        CmdsParse(CommandTable, Cmd);
        return 0;
 }
 
        CmdsParse(CommandTable, Cmd);
        return 0;
 }
 

-int CmdHelp(const char *Cmd)
-{
+int CmdHelp(const char *Cmd) {

        CmdsHelp(CommandTable);
        return 0;
 }
        CmdsHelp(CommandTable);
        return 0;
 }