ADD: a TEA crypto algorithm implemention.

[proxmark3-svn] / client / cmdhf14b.c

diff --git a/client/cmdhf14b.c b/client/cmdhf14b.c
index 71c640fe1c4d5358d39d04f06da43f894ec639d7..39232a0a9006adb209ffe4d79fb5be55fc99b37a 100644 (file)
--- a/client/cmdhf14b.c
+++ b/client/cmdhf14b.c
@@ -11,7 +11,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>

-//#include <string.h>

 #include <stdint.h>
 #include "iso14443crc.h"
 #include "proxmark3.h"
 #include <stdint.h>
 #include "iso14443crc.h"
 #include "proxmark3.h"


@@ -35,7 +34,7 @@ int CmdHF14BList(const char *Cmd)
 
 int CmdHF14BSim(const char *Cmd)
 {
 
 int CmdHF14BSim(const char *Cmd)
 {

-       UsbCommand c={CMD_SIMULATE_TAG_ISO_14443B};
+       UsbCommand c = {CMD_SIMULATE_TAG_ISO_14443B};

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


@@ -43,7 +42,7 @@ int CmdHF14BSim(const char *Cmd)
 
 int CmdHF14BSnoop(const char *Cmd)
 {
 
 int CmdHF14BSnoop(const char *Cmd)
 {

-  UsbCommand c = {CMD_SNOOP_ISO_14443B};
+       UsbCommand c = {CMD_SNOOP_ISO_14443B};

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


@@ -73,11 +72,16 @@ int CmdSrix4kRead(const char *Cmd)
        return 0;
 }
 
        return 0;
 }
 

+

 int rawClose(void){
 int rawClose(void){

+       UsbCommand resp;

        UsbCommand c = {CMD_ISO_14443B_COMMAND, {0, 0, 0}};
        clearCommandBuffer();
        SendCommand(&c);
        UsbCommand c = {CMD_ISO_14443B_COMMAND, {0, 0, 0}};
        clearCommandBuffer();
        SendCommand(&c);

+       if (!WaitForResponseTimeout(CMD_ACK,&resp,1000)) {

        return 0;       
        return 0;       

+       }
+       return 0;

 }
 
 int HF14BCmdRaw(bool reply, bool *crc, bool power, uint8_t *data, uint8_t *datalen, bool verbose){
 }
 
 int HF14BCmdRaw(bool reply, bool *crc, bool power, uint8_t *data, uint8_t *datalen, bool verbose){


@@ -104,7 +108,8 @@ int HF14BCmdRaw(bool reply, bool *crc, bool power, uint8_t *data, uint8_t *datal
        }
 
        *datalen = resp.arg[0];
        }
 
        *datalen = resp.arg[0];

-       if ( *datalen < 3 ) return 0;
+       if (verbose) PrintAndLog("received %u octets", *datalen);
+       if(*datalen<3) return 0;

 
        memcpy(data, resp.d.asBytes, *datalen);
        
 
        memcpy(data, resp.d.asBytes, *datalen);
        


@@ -128,16 +133,20 @@ int CmdHF14BCmdRaw (const char *Cmd) {
     bool reply = true;
     bool crc = false;
        bool power = false;
     bool reply = true;
     bool crc = false;
        bool power = false;

+       bool select = false;
+       bool SRx = false;

     char buf[5]="";
     uint8_t data[USB_CMD_DATA_SIZE] = {0x00};
     uint8_t datalen = 0;
     unsigned int temp;
     int i = 0;
     if (strlen(Cmd)<3) {
     char buf[5]="";
     uint8_t data[USB_CMD_DATA_SIZE] = {0x00};
     uint8_t datalen = 0;
     unsigned int temp;
     int i = 0;
     if (strlen(Cmd)<3) {

-        PrintAndLog("Usage: hf 14b raw [-r] [-c] [-p] <0A 0B 0C ... hex>");
+               PrintAndLog("Usage: hf 14b raw [-r] [-c] [-p] [-s || -ss] <0A 0B 0C ... hex>");

         PrintAndLog("       -r    do not read response");
         PrintAndLog("       -c    calculate and append CRC");
         PrintAndLog("       -p    leave the field on after receive");
         PrintAndLog("       -r    do not read response");
         PrintAndLog("       -c    calculate and append CRC");
         PrintAndLog("       -p    leave the field on after receive");

+               PrintAndLog("       -s    active signal field ON with select");
+               PrintAndLog("       -ss   active signal field ON with select for SRx ST Microelectronics tags");

         return 0;    
     }
 
         return 0;    
     }
 


@@ -160,6 +169,14 @@ int CmdHF14BCmdRaw (const char *Cmd) {
                 case 'P': 
                                        power = true;
                     break;
                 case 'P': 
                                        power = true;
                     break;

+                               case 's':
+                               case 'S':
+                                       select = true;
+                                       if (Cmd[i+2]=='s' || Cmd[i+2]=='S') {
+                                               SRx = true;
+                                               i++;
+                                       }
+                                       break;

                 default:
                     PrintAndLog("Invalid option");
                     return 0;
                 default:
                     PrintAndLog("Invalid option");
                     return 0;


@@ -178,11 +195,12 @@ int CmdHF14BCmdRaw (const char *Cmd) {
                 sscanf(buf,"%x",&temp);
                 data[datalen++]=(uint8_t)(temp & 0xff);
                 *buf=0;
                 sscanf(buf,"%x",&temp);
                 data[datalen++]=(uint8_t)(temp & 0xff);
                 *buf=0;

+                               memset(buf, 0x00, sizeof(buf));

             }
             continue;
         }
         PrintAndLog("Invalid char on input");
             }
             continue;
         }
         PrintAndLog("Invalid char on input");

-        return 1;
+               return 0;

     }
     if (datalen == 0)
     {
     }
     if (datalen == 0)
     {


@@ -190,12 +208,65 @@ int CmdHF14BCmdRaw (const char *Cmd) {
       return 0;
     }
 
       return 0;
     }
 

+       if (select){ //auto select 14b tag
+               uint8_t cmd2[16];
+               bool crc2 = true;
+               uint8_t cmdLen;
+
+               if (SRx) {
+                       // REQ SRx
+                       cmdLen = 2;
+                       cmd2[0] = 0x06;
+                       cmd2[1] = 0x00;
+               } else {
+                       // REQB
+                       cmdLen = 3;
+                       cmd2[0] = 0x05;
+                       cmd2[1] = 0x00;
+                       cmd2[2] = 0x08;
+               }
+               
+               // REQB
+               if (HF14BCmdRaw(true, &crc2, true, cmd2, &cmdLen, false)==0) return rawClose();
+                                                                         
+               PrintAndLog("REQB   : %s", sprint_hex(cmd2, cmdLen));
+               
+               if ( SRx && (cmdLen != 3 || !crc2) ) return rawClose();
+               else if (cmd2[0] != 0x50 || cmdLen != 14 || !crc2) return rawClose();
+               
+               uint8_t chipID = 0;
+               if (SRx) {
+                       // select
+                       chipID = cmd2[0];
+                       cmd2[0] = 0x0E;
+                       cmd2[1] = chipID;
+                       cmdLen = 2;
+               } else {
+                       // attrib
+                       cmd2[0] = 0x1D; 
+                       // UID from cmd2[1 - 4]
+                       cmd2[5] = 0x00;
+                       cmd2[6] = 0x08;
+                       cmd2[7] = 0x01;
+                       cmd2[8] = 0x00;
+                       cmdLen = 9;
+               }
+               // wait         
+               
+               // attrib
+               if (HF14BCmdRaw(true, &crc2, true, cmd2, &cmdLen, false)==0) return rawClose();
+               PrintAndLog("ATTRIB : %s", sprint_hex(cmd2, cmdLen));
+               
+               if (cmdLen != 3 || !crc2) return rawClose();            
+               if (SRx && cmd2[0] != chipID) return rawClose();
+       
+       }

        return HF14BCmdRaw(reply, &crc, power, data, &datalen, true);
 }
 
 // print full atqb info
 static void print_atqb_resp(uint8_t *data){
        return HF14BCmdRaw(reply, &crc, power, data, &datalen, true);
 }
 
 // print full atqb info
 static void print_atqb_resp(uint8_t *data){

-       PrintAndLog ("           UID: %s", sprint_hex(data+1,4));
+       //PrintAndLog ("           UID: %s", sprint_hex(data+1,4));

        PrintAndLog ("      App Data: %s", sprint_hex(data+5,4));
        PrintAndLog ("      Protocol: %s", sprint_hex(data+9,3));
        uint8_t BitRate = data[9];
        PrintAndLog ("      App Data: %s", sprint_hex(data+5,4));
        PrintAndLog ("      Protocol: %s", sprint_hex(data+9,3));
        uint8_t BitRate = data[9];


@@ -216,14 +287,15 @@ static void print_atqb_resp(uint8_t *data){
        else if (maxFrame == 8) maxFrame = 256;
        else maxFrame = 257;
 
        else if (maxFrame == 8) maxFrame = 256;
        else maxFrame = 257;
 

-       PrintAndLog ("Max Frame Size: %d%s", maxFrame, (maxFrame == 257) ? "+ RFU" : "");
+       PrintAndLog ("Max Frame Size: %u%s",maxFrame, (maxFrame == 257) ? "+ RFU" : "");

 
        uint8_t protocolT = data[10] & 0xF;
        PrintAndLog (" Protocol Type: Protocol is %scompliant with ISO/IEC 14443-4",(protocolT) ? "" : "not " );
 
        uint8_t protocolT = data[10] & 0xF;
        PrintAndLog (" Protocol Type: Protocol is %scompliant with ISO/IEC 14443-4",(protocolT) ? "" : "not " );

-       PrintAndLog ("Frame Wait Int: %d", data[11]>>4);
+       PrintAndLog ("Frame Wait Int: %u", data[11]>>4);

        PrintAndLog (" App Data Code: Application is %s",(data[11]&4) ? "Standard" : "Proprietary");
        PrintAndLog (" Frame Options: NAD is %ssupported",(data[11]&2) ? "" : "not ");
        PrintAndLog (" Frame Options: CID is %ssupported",(data[11]&1) ? "" : "not ");
        PrintAndLog (" App Data Code: Application is %s",(data[11]&4) ? "Standard" : "Proprietary");
        PrintAndLog (" Frame Options: NAD is %ssupported",(data[11]&2) ? "" : "not ");
        PrintAndLog (" Frame Options: CID is %ssupported",(data[11]&1) ? "" : "not ");

+       PrintAndLog ("Max Buf Length: %u (MBLI) %s",data[14]>>4, (data[14] & 0xF0) ? "" : "not supported");

 
        return;
 }
 
        return;
 }


@@ -242,11 +314,76 @@ char *get_ST_Chip_Model(uint8_t data){
                case 0x6: sprintf(retStr, "SRI512"); break;
                case 0x7: sprintf(retStr, "SRI4K"); break;
                case 0xC: sprintf(retStr, "SRT512"); break;
                case 0x6: sprintf(retStr, "SRI512"); break;
                case 0x7: sprintf(retStr, "SRI4K"); break;
                case 0xC: sprintf(retStr, "SRT512"); break;

-               default: sprintf(retStr, "Unknown"); break;
+               default : sprintf(retStr, "Unknown"); break;

        }
        return retStr;
 }
 
        }
        return retStr;
 }
 

+int print_ST_Lock_info(uint8_t model){
+       //assume connection open and tag selected...
+       uint8_t data[16] = {0x00};
+       uint8_t datalen = 2;
+       bool crc = true;
+       uint8_t resplen;
+       uint8_t blk1;
+       data[0] = 0x08;
+
+       if (model == 0x2) { //SR176 has special command:
+               data[1] = 0xf;
+               resplen = 4;                    
+       } else {
+               data[1] = 0xff;
+               resplen = 6;
+       }
+
+       //std read cmd
+       if (HF14BCmdRaw(true, &crc, true, data, &datalen, false)==0) return rawClose();
+
+       if (datalen != resplen || !crc) return rawClose();
+
+       PrintAndLog("Chip Write Protection Bits:");
+       // now interpret the data
+       switch (model){
+               case 0x0: //fall through (SRIX4K special)
+               case 0x3: //fall through (SRIx4K)
+               case 0x7: //             (SRI4K)
+                       //only need data[3]
+                       blk1 = 9;
+                       PrintAndLog("   raw: %s",printBits(1,data+3));
+                       PrintAndLog(" 07/08:%slocked", (data[3] & 1) ? " not " : " " );
+                       for (uint8_t i = 1; i<8; i++){
+                               PrintAndLog("    %02u:%slocked", blk1, (data[3] & (1 << i)) ? " not " : " " );
+                               blk1++;
+                       }
+                       break;
+               case 0x4: //fall through (SRIX512)
+               case 0x6: //fall through (SRI512)
+               case 0xC: //             (SRT512)
+                       //need data[2] and data[3]
+                       blk1 = 0;
+                       PrintAndLog("   raw: %s",printBits(2,data+2));
+                       for (uint8_t b=2; b<4; b++){
+                               for (uint8_t i=0; i<8; i++){
+                                       PrintAndLog("    %02u:%slocked", blk1, (data[b] & (1 << i)) ? " not " : " " );
+                                       blk1++;
+                               }
+                       }
+                       break;
+               case 0x2: //             (SR176)
+                       //need data[2]
+                       blk1 = 0;
+                       PrintAndLog("   raw: %s",printBits(1,data+2));
+                       for (uint8_t i = 0; i<8; i++){
+                               PrintAndLog(" %02u/%02u:%slocked", blk1, blk1+1, (data[2] & (1 << i)) ? " " : " not " );
+                               blk1+=2;
+                       }
+                       break;
+               default:
+                       return rawClose();
+       }
+       return 1;
+}
+

 // print UID info from SRx chips (ST Microelectronics)
 static void print_st_general_info(uint8_t *data){
        //uid = first 8 bytes in data
 // print UID info from SRx chips (ST Microelectronics)
 static void print_st_general_info(uint8_t *data){
        //uid = first 8 bytes in data


@@ -259,9 +396,9 @@ static void print_st_general_info(uint8_t *data){
 // 14b get and print UID only (general info)
 int HF14BStdReader(uint8_t *data, uint8_t *datalen){
        //05 00 00 = find one tag in field
 // 14b get and print UID only (general info)
 int HF14BStdReader(uint8_t *data, uint8_t *datalen){
        //05 00 00 = find one tag in field

-       //1d xx xx xx xx 20 00 08 01 00 = attrib xx=crc
-       //a3 = ?  (resp 03 e2 c2)
-       //02 = ?  (resp 02 6a d3)
+       //1d xx xx xx xx 00 08 01 00 = attrib xx=UID (resp 10 [f9 e0])
+       //a3 = ?  (resp 03 [e2 c2])
+       //02 = ?  (resp 02 [6a d3])

        // 022b (resp 02 67 00 [29  5b])
        // 0200a40400 (resp 02 67 00 [29 5b])
        // 0200a4040c07a0000002480300 (resp 02 67 00 [29 5b])
        // 022b (resp 02 67 00 [29  5b])
        // 0200a40400 (resp 02 67 00 [29 5b])
        // 0200a4040c07a0000002480300 (resp 02 67 00 [29 5b])


@@ -274,6 +411,7 @@ int HF14BStdReader(uint8_t *data, uint8_t *datalen){
        //03 = ?  (resp 03 [e3 c2])
        //c2 = ?  (resp c2 [66 15])
        //b2 = ?  (resp a3 [e9 67])             
        //03 = ?  (resp 03 [e3 c2])
        //c2 = ?  (resp c2 [66 15])
        //b2 = ?  (resp a3 [e9 67])             

+       //a2 = ?  (resp 02 [6a d3])

        bool crc = true;
        *datalen = 3;
        //std read cmd
        bool crc = true;
        *datalen = 3;
        //std read cmd


@@ -281,14 +419,36 @@ int HF14BStdReader(uint8_t *data, uint8_t *datalen){
        data[1] = 0x00;
        data[2] = 0x08;
 
        data[1] = 0x00;
        data[2] = 0x08;
 

-       // response, crc, powerfield, data, len, verbose
-       if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return 0;
+       if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return rawClose();

 
 

-       if (data[0] != 0x50  || *datalen != 14 || !crc) return 0;
+       if (data[0] != 0x50 || *datalen != 14 || !crc) return rawClose();

 
        PrintAndLog ("\n14443-3b tag found:");
        PrintAndLog ("           UID: %s", sprint_hex(data+1,4));
 
 
        PrintAndLog ("\n14443-3b tag found:");
        PrintAndLog ("           UID: %s", sprint_hex(data+1,4));
 

+       uint8_t cmd2[16];
+       uint8_t cmdLen = 3;
+       bool crc2 = true;
+
+       cmd2[0] = 0x1D; 
+       // UID from data[1 - 4]
+       cmd2[1] = data[1];
+       cmd2[2] = data[2];
+       cmd2[3] = data[3];
+       cmd2[4] = data[4];
+       cmd2[5] = 0x00;
+       cmd2[6] = 0x08;
+       cmd2[7] = 0x01;
+       cmd2[8] = 0x00;
+       cmdLen = 9;
+
+       // attrib
+       if (HF14BCmdRaw(true, &crc2, true, cmd2, &cmdLen, false)==0) return rawClose();
+
+       if (cmdLen != 3 || !crc2) return rawClose();
+       // add attrib responce to data
+       data[14] = cmd2[0];
+       rawClose();

        return 1;
 }
 
        return 1;
 }
 


@@ -298,12 +458,11 @@ int HF14BStdInfo(uint8_t *data, uint8_t *datalen){
 
        //add more info here
        print_atqb_resp(data);
 
        //add more info here
        print_atqb_resp(data);

-

        return 1;
 }
 
 // SRx get and print general info about SRx chip from UID
        return 1;
 }
 
 // SRx get and print general info about SRx chip from UID

-int HF14B_ST_Reader(uint8_t *data, uint8_t *datalen){
+int HF14B_ST_Reader(uint8_t *data, uint8_t *datalen, bool closeCon){

        bool crc = true;
        *datalen = 2;
        //wake cmd
        bool crc = true;
        *datalen = 2;
        //wake cmd


@@ -323,7 +482,6 @@ int HF14B_ST_Reader(uint8_t *data, uint8_t *datalen){
        *datalen = 2;
 
        //leave power on
        *datalen = 2;
 
        //leave power on

-       // verbose on for now for testing - turn off when functional

        if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return rawClose();
 
        if (*datalen != 3 || !crc || data[0] != chipID) return rawClose();
        if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return rawClose();
 
        if (*datalen != 3 || !crc || data[0] != chipID) return rawClose();


@@ -332,11 +490,13 @@ int HF14B_ST_Reader(uint8_t *data, uint8_t *datalen){
        data[0] = 0x0B;
        *datalen = 1;
 
        data[0] = 0x0B;
        *datalen = 1;
 

-       //power off
-       // verbose on for now for testing - turn off when functional
-       if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return 0;
-       rawClose();
-       if (*datalen != 10 || !crc) return 0;
+       //leave power on
+       if (HF14BCmdRaw(true, &crc, true, data, datalen, false)==0) return rawClose();
+
+       if (*datalen != 10 || !crc) return rawClose();
+
+       //power off ?
+       if (closeCon) rawClose();

 
        PrintAndLog("\n14443-3b ST tag found:");
        print_st_general_info(data);
 
        PrintAndLog("\n14443-3b ST tag found:");
        print_st_general_info(data);


@@ -345,10 +505,11 @@ int HF14B_ST_Reader(uint8_t *data, uint8_t *datalen){
 
 // SRx get and print full info (needs more info...)
 int HF14B_ST_Info(uint8_t *data, uint8_t *datalen){
 
 // SRx get and print full info (needs more info...)
 int HF14B_ST_Info(uint8_t *data, uint8_t *datalen){

-       if (!HF14B_ST_Reader(data, datalen)) return 0;
+       if (!HF14B_ST_Reader(data, datalen, false)) return 0;

        
        //add locking bit information here.
        
        //add locking bit information here.

-
+       if (print_ST_Lock_info(data[5]>>2)) 
+               rawClose();

 
        return 1;
 }
 
        return 1;
 }


@@ -368,6 +529,7 @@ int HF14B_Other_Reader(uint8_t *data, uint8_t *datalen){
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x000b3f80 command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x000b3f80 command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));

+                       rawClose();

                        return 1;
                }
        }
                        return 1;
                }
        }


@@ -381,6 +543,7 @@ int HF14B_Other_Reader(uint8_t *data, uint8_t *datalen){
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x0A command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x0A command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));

+                       rawClose();

                        return 1;
                }
        }
                        return 1;
                }
        }


@@ -394,6 +557,7 @@ int HF14B_Other_Reader(uint8_t *data, uint8_t *datalen){
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x0C command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));
                        PrintAndLog ("\n14443-3b tag found:");
                        PrintAndLog ("Unknown tag type answered to a 0x0C command ans:");
                        PrintAndLog ("%s",sprint_hex(data,*datalen));

+                       rawClose();

                        return 1;
                }
        }
                        return 1;
                }
        }


@@ -434,7 +598,7 @@ int HF14BReader(bool verbose){
        if (HF14BStdReader(data, &datalen)) return 1;
 
        // try st 14b
        if (HF14BStdReader(data, &datalen)) return 1;
 
        // try st 14b

-       if (HF14B_ST_Reader(data, &datalen)) return 1;
+       if (HF14B_ST_Reader(data, &datalen, true)) return 1;

 
        // try unknown 14b read commands (to be identified later)
        //   could be read of calypso, CEPAS, moneo, or pico pass.
 
        // try unknown 14b read commands (to be identified later)
        //   could be read of calypso, CEPAS, moneo, or pico pass.


@@ -516,6 +680,84 @@ int CmdSriWrite( const char *Cmd){
        return 0;
 }
 
        return 0;
 }
 

+int srix4kChecksum(uint32_t value) {
+/*
+// vv = value
+// pp = position
+//                vv vv vv pp 
+4 bytes                        : 00 1A 20 01
+*/
+
+#define NibbleHigh(b) ( (b & 0xF0) >> 4 )
+#define NibbleLow(b)  ( b & 0x0F )
+#define Crumb(b,p)    (((b & (0x3 << p) ) >> p ) & 0xF) 
+
+       // only the lower crumbs.
+       uint8_t block = (value & 0xFF);
+       uint8_t i = 0;
+       uint8_t valuebytes[] = {0,0,0};
+               
+       // if ( strlen(Cmd) > 0){
+               // value = param_get32ex(Cmd, 0, 0, 16);
+       
+               // block = value & 0xFF;
+               
+               // value &= 0xFFFFFF00;
+               // value >>=8;
+       // }
+
+       num_to_bytes(value, 3, valuebytes);
+       
+       // Scrambled part
+       // Crumb swapping of value.
+       uint8_t temp[] = {0,0};
+       temp[0] = (Crumb(value, 22) << 4 | Crumb(value, 14 ) << 2 | Crumb(value, 6)) << 4;
+       temp[0] |= Crumb(value, 20) << 4 | Crumb(value, 12 ) << 2 | Crumb(value, 4);
+       temp[1] = (Crumb(value, 18) << 4 | Crumb(value, 10 ) << 2 | Crumb(value, 2)) << 4;
+       temp[1] |= Crumb(value, 16) << 4 | Crumb(value, 8  ) << 2 | Crumb(value, 0);
+
+       // chksum part
+       uint32_t chksum = 0xFF - block;
+       
+       // chksum is reduced by each nibbles of value.
+       for (i = 0; i < 3; ++i){
+               chksum -= NibbleHigh(valuebytes[i]);
+               chksum -= NibbleLow(valuebytes[i]);
+       }
+
+       // base4 conversion
+       // and left shift twice
+       i = 3;
+       uint8_t base4[] = {0,0,0,0};    
+       while( chksum !=0 ){
+        base4[i--] = (chksum % 4 << 2);
+               chksum /= 4;
+    }
+       
+       // merge scambled and chksum parts
+       uint32_t encvalue = 
+               ( NibbleLow ( base4[0]) << 28 ) |
+               ( NibbleHigh( temp[0])  << 24 ) |
+               
+               ( NibbleLow ( base4[1]) << 20 ) |
+               ( NibbleLow ( temp[0])  << 16 ) |
+               
+               ( NibbleLow ( base4[2]) << 12 ) |
+               ( NibbleHigh( temp[1])  << 8 ) |
+               
+               ( NibbleLow ( base4[3]) << 4 ) |
+                 NibbleLow ( temp[1] );
+
+       PrintAndLog("ICE | %08X", encvalue);
+       return 0;
+}
+int srix4kMagicbytes(){
+       return 0;
+}
+int srix4kValid(){
+       return 0;
+}
+

 static command_t CommandTable[] = 
 {
        {"help",        CmdHelp,        1, "This help"},
 static command_t CommandTable[] = 
 {
        {"help",        CmdHelp,        1, "This help"},


@@ -528,6 +770,7 @@ static command_t CommandTable[] =
        {"srix4kread",  CmdSrix4kRead,  0, "Read contents of a SRIX4K tag"},
        {"sriwrite",    CmdSriWrite,    0, "Write data to a SRI512 | SRIX4K tag"},
        {"raw",         CmdHF14BCmdRaw, 0, "Send raw hex data to tag"},
        {"srix4kread",  CmdSrix4kRead,  0, "Read contents of a SRIX4K tag"},
        {"sriwrite",    CmdSriWrite,    0, "Write data to a SRI512 | SRIX4K tag"},
        {"raw",         CmdHF14BCmdRaw, 0, "Send raw hex data to tag"},

+       //{"calcSrix4",   srix4kchksum, 1, "a srix4k checksum test"},

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