diff --git a/armsrc/appmain.c b/armsrc/appmain.c
index 37899f57..ca727644 100644
--- a/armsrc/appmain.c
+++ b/armsrc/appmain.c
@@ -683,7 +683,12 @@ void UsbPacketReceived(uint8_t *packet, int len)
 			break;
 		case CMD_AWID_DEMOD_FSK: // Set realtime AWID demodulation
 			CmdAWIDdemodFSK(c->arg[0], 0, 0, 1);
-                        break;
+            break;
+        case CMD_VIKING_CLONE_TAG:
+            CopyViKingtoT55x7(c->arg[0],c->arg[1]);
+            break;
+
+    
 #endif
 
 #ifdef WITH_HITAG
@@ -865,9 +870,19 @@ void UsbPacketReceived(uint8_t *packet, int len)
 		case CMD_READER_ICLASS_REPLAY:
 		    ReaderIClass_Replay(c->arg[0], c->d.asBytes);
 			break;
-	case CMD_ICLASS_EML_MEMSET:
+        case CMD_ICLASS_EML_MEMSET:
 			emlSet(c->d.asBytes,c->arg[0], c->arg[1]);
 			break;
+        case CMD_ICLASS_ISO14443A_WRITE:
+            IClass_iso14443A_write(c->arg[0],c->d.asBytes);
+            break;
+        case CMD_ICLASS_AUTHENTICATION:
+            IClass_Authentication(c->d.asBytes);
+            break;
+        case CMD_ICLASS_CLONE:
+            IClass_Clone(c->arg[0],c->arg[1],c->d.asBytes);
+            break;
+            
 #endif
 
 		case CMD_BUFF_CLEAR:
diff --git a/armsrc/apps.h b/armsrc/apps.h
index b5638ee1..e517c680 100644
--- a/armsrc/apps.h
+++ b/armsrc/apps.h
@@ -168,7 +168,10 @@ void SimulateIClass(uint32_t arg0, uint32_t arg1, uint32_t arg2, uint8_t *datain
 void ReaderIClass(uint8_t arg0);
 void ReaderIClass_Replay(uint8_t arg0,uint8_t *MAC);
 void IClass_iso14443A_GetPublic(uint8_t arg0);
-
+void IClass_Authentication(uint8_t *MAC);
+void IClass_iso14443A_write(uint8_t blockno,uint8_t *data);
+void IClass_Clone(uint8_t startblock,uint8_t endblock,uint8_t *data);
+void CopyViKingtoT55x7(uint32_t block1,uint32_t block2);
 // hitag2.h
 void SnoopHitag(uint32_t type);
 void SimulateHitagTag(bool tag_mem_supplied, byte_t* data);
diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index 97c62bb6..9f7dfa87 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -1903,131 +1903,57 @@ void ReaderIClass_Replay(uint8_t arg0, uint8_t *MAC) {
 
 	LED_A_OFF();
 }
-
-//2. Create Read method (cut-down from above) based off responses from 1. 
-//   Since we have the MAC could continue to use replay function.
-//3. Create Write method
-/*
-void IClass_iso14443A_write(uint8_t arg0, uint8_t blockNo, uint8_t *data, uint8_t *MAC) {
-	uint8_t act_all[]     = { 0x0a };
-	uint8_t identify[]    = { 0x0c };
-	uint8_t select[]      = { 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-	uint8_t readcheck_cc[]= { 0x88, 0x02 };
-	uint8_t check[]       = { 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-	uint8_t read[]        = { 0x0c, 0x00, 0x00, 0x00 };
-	uint8_t write[]       = { 0x87, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-	
-    uint16_t crc = 0;
-	
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);
-
-	// Reset trace buffer
-    memset(trace, 0x44, RECV_CMD_OFFSET);
-	traceLen = 0;
-
-	// Setup SSC
-	FpgaSetupSsc();
-	// Start from off (no field generated)
-	// Signal field is off with the appropriate LED
-	LED_D_OFF();
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	SpinDelay(200);
-
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-
-	// Now give it time to spin up.
-	// Signal field is on with the appropriate LED
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-	SpinDelay(200);
-
-	LED_A_ON();
-
-	for(int i=0;i<1;i++) {
-	
-		if(traceLen > TRACE_SIZE) {
-			DbpString("Trace full");
-			break;
-		}
-		
-		if (BUTTON_PRESS()) break;
-
-		// Send act_all
-		ReaderTransmitIClass(act_all, 1);
-		// Card present?
-		if(ReaderReceiveIClass(resp)) {
-			ReaderTransmitIClass(identify, 1);
-			if(ReaderReceiveIClass(resp) == 10) {
-				// Select card          
-				memcpy(&select[1],resp,8);
-				ReaderTransmitIClass(select, sizeof(select));
-
-				if(ReaderReceiveIClass(resp) == 10) {
-					Dbprintf("     Selected CSN: %02x %02x %02x %02x %02x %02x %02x %02x",
-					resp[0], resp[1], resp[2],
-					resp[3], resp[4], resp[5],
-					resp[6], resp[7]);
-				}
-				// Card selected
-				Dbprintf("Readcheck on Sector 2");
-				ReaderTransmitIClass(readcheck_cc, sizeof(readcheck_cc));
-				if(ReaderReceiveIClass(resp) == 8) {
-				   Dbprintf("     CC: %02x %02x %02x %02x %02x %02x %02x %02x",
-					resp[0], resp[1], resp[2],
-					resp[3], resp[4], resp[5],
-					resp[6], resp[7]);
-				}else return;
-				Dbprintf("Authenticate");
-				//for now replay captured auth (as cc not updated)
-				memcpy(check+5,MAC,4);
-				Dbprintf("     AA: %02x %02x %02x %02x",
-					check[5], check[6], check[7],check[8]);
-				ReaderTransmitIClass(check, sizeof(check));
-				if(ReaderReceiveIClass(resp) == 4) {
-				   Dbprintf("     AR: %02x %02x %02x %02x",
-					resp[0], resp[1], resp[2],resp[3]);
-				}else {
-				  Dbprintf("Error: Authentication Fail!");
-				  return;
-				}
-				Dbprintf("Write Block");
-				
-				//read configuration for max block number
-				read_success=false;
-				read[1]=1;
-				uint8_t *blockno=&read[1];
-				crc = iclass_crc16((char *)blockno,1);
-				read[2] = crc >> 8;
-				read[3] = crc & 0xff;
-				while(!read_success){
-				      ReaderTransmitIClass(read, sizeof(read));
-				      if(ReaderReceiveIClass(resp) == 10) {
-					 read_success=true;
-					 mem=resp[5];
-					 memory.k16= (mem & 0x80);
-					 memory.book= (mem & 0x20);
-					 memory.k2= (mem & 0x8);
-					 memory.lockauth= (mem & 0x2);
-					 memory.keyaccess= (mem & 0x1);
-
-				      }
-				}
-				if (memory.k16){
-				  cardsize=255;
-				}else cardsize=32;
-				//check card_size
-				
-				memcpy(write+1,blockNo,1);
-				memcpy(write+2,data,8);
-				memcpy(write+10,mac,4);
-				while(!send_success){
-				  ReaderTransmitIClass(write, sizeof(write));
-				  if(ReaderReceiveIClass(resp) == 10) {
-				    write_success=true;
-				}
-			}//
-		}
-		WDT_HIT();
-	}
-	
-	LED_A_OFF();
-}*/
+void IClass_Authentication(uint8_t *MAC){
+    uint8_t check[]       = { 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+    uint8_t resp[ICLASS_BUFFER_SIZE];
+    memcpy(check+5,MAC,4);
+    
+    sendCmdGetResponseWithRetries(check, sizeof(check),resp, 8, 5);
+    // successful
+}
+void IClass_iso14443A_write(uint8_t blockNo, uint8_t *data) {
+    uint8_t write[]       = { 0x87, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+    
+    write[1] = blockNo;
+    memcpy(write + 2,data,8); // data
+    memcpy(write+10,data + 8,4); // mac no
+    uint8_t r[12];
+    
+    // 0x87
+    sendCmdGetResponseWithRetries(write,sizeof(write),r,sizeof(r),5);
+    Dbprintf("reply [%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x]",r[0],r[1],r[2],r[3],r[4],r[5],r[6],r[7],r[8],r[9],r[10],r[11]);
+    
+    if (memcmp(data,r,8) == 0)
+        Dbprintf("Write block [%02x] ok",blockNo);
+    else
+        Dbprintf("Write block [%02x] fail",blockNo);
+}
+void IClass_Clone(uint8_t startblock,uint8_t endblock,uint8_t *data){
+    uint8_t write[]       = { 0x87, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+    uint8_t r[12];
+    int i;
+    int written = 0;
+    int total_block = (endblock - startblock) + 1;
+    for (i = 0; i < total_block;i++){
+        // block number
+        write[0] = 0x87;
+        write[1] = i + startblock;
+        // data
+        memcpy(write + 2,data + (i * 12),8);
+        // mac number
+        memcpy(write + 10,data + ((i * 12) + 8), 4);
+        sendCmdGetResponseWithRetries(write,sizeof(write),r,sizeof(r),5);
+        
+        if (memcmp(write + 2,r,8) == 0){
+            Dbprintf("Write block [%02x] ok",i + 6);
+            written++;
+        }
+        else
+            Dbprintf("Write block [%02x] fail",i + 6);
+    }
+    if (written == total_block)
+        Dbprintf("Clone complete");
+    else
+        Dbprintf("Clone incomplete");
+    
+}
diff --git a/armsrc/lfops.c b/armsrc/lfops.c
index 188d7280..75eaaa86 100644
--- a/armsrc/lfops.c
+++ b/armsrc/lfops.c
@@ -2062,3 +2062,14 @@ void EM4xWriteWord(uint32_t Data, uint8_t Address, uint32_t Pwd, uint8_t PwdMode
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
 	LED_D_OFF();
 }
+void CopyViKingtoT55x7(uint32_t block1,uint32_t block2)
+{
+    LED_D_ON();
+    T55xxWriteBlock(block1,1,0,0);
+    T55xxWriteBlock(block2,2,0,0);
+
+    T55xxWriteBlock(T55x7_MODULATION_MANCHESTER | T55x7_BITRATE_RF_32 | 2 << T5555_MAXBLOCK_SHIFT,0,0,1);
+    LED_D_OFF();
+    DbpString("DONE!");
+}
+
diff --git a/client/.history b/client/.history
new file mode 100644
index 00000000..66787acd
--- /dev/null
+++ b/client/.history
@@ -0,0 +1 @@
+lf
diff --git a/client/Makefile b/client/Makefile
index 15b1cbca..bee9a336 100644
--- a/client/Makefile
+++ b/client/Makefile
@@ -93,6 +93,7 @@ CMDSRCS = 	nonce2key/crapto1.c\
 			cmdlfem4x.c \
 			cmdlfhitag.c \
 			cmdlfti.c \
+			cmdlfviking.c\
 			cmdparser.c \
 			cmdmain.c \
 			cmdlft55xx.c \
@@ -104,7 +105,7 @@ CMDSRCS = 	nonce2key/crapto1.c\
 			aes.c\
 			protocols.c\
 			sha1.c\
-
+			
 ZLIBSRCS = deflate.c adler32.c trees.c zutil.c inflate.c inffast.c inftrees.c
 ZLIB_FLAGS = -DZ_SOLO -DZ_PREFIX -DNO_GZIP -DZLIB_PM3_TUNED 
 #-DDEBUG -Dverbose=1
diff --git a/client/cmddata.c b/client/cmddata.c
index bec1b5aa..c4bae05f 100644
--- a/client/cmddata.c
+++ b/client/cmddata.c
@@ -1870,6 +1870,53 @@ int CmdRawDemod(const char *Cmd)
 	return ans;
 }
 
+int AmVikingDecode(const uint8_t *id){
+    // searching the buffer for the id
+    uint8_t id_bits[32];
+    // convert 4 bytes of id to 32 bits present in 32 bytes data;
+    bytes_to_bits(id,4,id_bits,sizeof(id_bits));
+    printf("binary : ");
+    print_arraybinary(id_bits,sizeof(id_bits));
+    printf("\n");
+    size_t idx = 0;
+    size_t BitLen = DemodBufferLen;
+    uint8_t BitStream[MAX_GRAPH_TRACE_LEN]={0};
+    memcpy(BitStream, DemodBuffer, BitLen);
+    
+    if (VikingDecode(BitStream,BitLen,&idx,id_bits,sizeof(id_bits)) ==  1)
+    {
+        setDemodBuf(BitStream,64, idx);
+        printf("Found Viking tag\n");
+        CmdPrintDemodBuff("x");
+    }
+    else
+    {
+        printf("Not found Viking tag\n");
+    }
+    return 0;
+}
+int AMVikingDemod(const uint8_t *id){
+    // demod am clock 32 fail
+    if (!ASKDemod("32",g_debugMode,false,1))
+        return 0;
+    // search for the card id from bitstream.
+    return AmVikingDecode(id);
+}
+//by Gusto
+// takes 1 argument <8 bytes of Hex number on the card
+// print binary found and saves in grapbuffer for further commands
+int CmdAMVikingDemod(const char *Cmd){
+    uint8_t id[4];
+    if (param_gethex(Cmd,0,id,8) == 1)
+    {
+        PrintAndLog("Usage:  data vikingdemod CardID 8 bytes of hex number");
+        return 0;
+    }
+    printf("Card ID : %02X%02X%02X%02X\n",id[0],id[1],id[2],id[3]);
+    // try to demod AMViking
+    return AMVikingDemod(id);
+}
+
 int CmdGrid(const char *Cmd)
 {
 	sscanf(Cmd, "%i %i", &PlotGridX, &PlotGridY);
@@ -2279,6 +2326,7 @@ static command_t CommandTable[] =
 	{"detectclock",     CmdDetectClockRate, 1, "[modulation] Detect clock rate of wave in GraphBuffer (options: 'a','f','n','p' for ask, fsk, nrz, psk respectively)"},
 	{"fdxbdemod",       CmdFDXBdemodBI    , 1, "Demodulate a FDX-B ISO11784/85 Biphase tag from GraphBuffer"},
 	{"fskawiddemod",    CmdFSKdemodAWID,    1, "Demodulate an AWID FSK tag from GraphBuffer"},
+    {"vikingdemod",     CmdAMVikingDemod,   1, "Demodulate a Viking AM tag from GraphBuffer"},
 	//{"fskfcdetect",   CmdFSKfcDetect,     1, "Try to detect the Field Clock of an FSK wave"},
 	{"fskhiddemod",     CmdFSKdemodHID,     1, "Demodulate a HID FSK tag from GraphBuffer"},
 	{"fskiodemod",      CmdFSKdemodIO,      1, "Demodulate an IO Prox FSK tag from GraphBuffer"},
diff --git a/client/cmddata.h b/client/cmddata.h
index fcc51a6b..c70f938e 100644
--- a/client/cmddata.h
+++ b/client/cmddata.h
@@ -67,7 +67,8 @@ int PSKDemod(const char *Cmd, bool verbose);
 int NRZrawDemod(const char *Cmd, bool verbose);
 void printEM410x(uint32_t hi, uint64_t id);
 int getSamples(const char *Cmd, bool silent);
-
+int AMVikingDemod(const uint8_t *cardid);
+int CmdAMVikingDemod(const char *cmd);
 
 #define MAX_DEMOD_BUF_LEN (1024*128)
 extern uint8_t DemodBuffer[MAX_DEMOD_BUF_LEN];
diff --git a/client/cmdhficlass.c b/client/cmdhficlass.c
old mode 100644
new mode 100755
index 824aaa36..5ee25144
--- a/client/cmdhficlass.c
+++ b/client/cmdhficlass.c
@@ -31,9 +31,14 @@
 #include "loclass/fileutils.h"
 #include "protocols.h"
 #include "usb_cmd.h"
-
+typedef struct iclass_block {
+    uint8_t d[8];
+} iclass_block_t;
 static int CmdHelp(const char *Cmd);
-
+static uint8_t GLOBAL_KEY[8] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+static uint8_t HS_KEY[8]     = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+static uint8_t BLANK_KEY[8]  = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+static bool    HS_KEY_LOAD   = false;
 int xorbits_8(uint8_t val)
 {
 	uint8_t res = val ^ (val >> 1); //1st pass
@@ -42,7 +47,117 @@ int xorbits_8(uint8_t val)
 	res = res ^ (res >> 4); 			// 4th pass
 	return res & 1;
 }
+void CmdHFiClass_printkey(const char* keyname,const uint8_t *key){
+    printf("%s : %02X%02X%02X%02X%02X%02X%02X%02X\n",keyname,key[0],key[1],key[2],key[3],key[4],key[5],key[6],key[7]);
+}
+int readKeyfile(const char *filename, size_t len, uint8_t* buffer)
+{
+    FILE *f = fopen(filename, "rb");
+    if(!f) {
+        PrintAndLog("Failed to read from file '%s'", filename);
+        return 1;
+    }
+    fseek(f, 0, SEEK_END);
+    long fsize = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    size_t bytes_read = fread(buffer, 1, len, f);
+    fclose(f);
+    if(fsize != len)
+    {
+        PrintAndLog("Warning, file size is %d, expected %d", fsize, len);
+        return 1;
+    }
+    if(bytes_read != len)
+    {
+        PrintAndLog("Warning, could only read %d bytes, expected %d" ,bytes_read, len);
+        return 1;
+    }
+    return 0;
+}
 
+int usage_iclass_readkeyfile(){
+    printf("usage: hf iclass readkeyfile <filename>\n");
+    return 0;
+}
+int CmdHFiClassReadKeyFile(const char *Cmd){
+    uint8_t key[8];
+    if ( (strlen(Cmd) < 1) || (readKeyfile(Cmd,sizeof(key),key) != 0)) {
+        return usage_iclass_readkeyfile();
+    }
+    CmdHFiClass_printkey("Key ",key);
+    return 0;
+}
+int usage_iclass_savekeyfile(){
+    printf("usage: hf iclass writekeyfile <KEY> filename\n");
+    return 0;
+}
+int CmdHFiClassSaveKeyFile(const char *Cmd){
+    char filename[50];
+    uint8_t key[8];
+    FILE *file;
+    if (param_gethex(Cmd, 0, key, 16))
+    {
+        PrintAndLog("KEY must include 16 HEX symbols");
+        return 1;
+    }
+    if (param_getstr(Cmd,1,filename) < 1)
+        return usage_iclass_savekeyfile();
+
+    file = fopen(filename,"wb");
+    
+    if (file == NULL) {
+        printf("error opening file %s\n",filename);
+        return 0;
+    }
+    if (fwrite(&key,sizeof(key),1,file))
+    printf("write key to file was successful\n");
+    else
+    printf("write key to file was fail\n");
+    fclose(file);
+    return 0;
+}
+
+int CmdHFiClass_SendAuthentication(uint8_t *MAC){
+    UsbCommand d = {CMD_ICLASS_AUTHENTICATION, {0}};
+    memcpy(d.d.asBytes,MAC, 4);
+    SendCommand(&d);
+    return 0;
+
+}
+int CmdHFiClass_SendACK(uint8_t *CSN,uint8_t *CCNR) {
+
+    UsbCommand resp;
+    UsbCommand c = {CMD_READER_ICLASS, {0}};
+    c.arg[0] = FLAG_ICLASS_READER_ONLY_ONCE| FLAG_ICLASS_READER_CC;
+    SendCommand(&c);
+    
+    if (!WaitForResponseTimeout(CMD_ACK,&resp,4500))
+    {
+        PrintAndLog("Command execute timeout");
+        return 1;
+    }
+    
+    uint8_t isOK    = resp.arg[0] & 0xff;
+    uint8_t * data  = resp.d.asBytes;
+    
+    memcpy(CSN,data,8);
+    memcpy(CCNR,data+16,8);
+
+    if(isOK <= 1){
+        PrintAndLog("Failed to obtain CC! Aborting");
+        return 1;
+    }
+    
+    PrintAndLog("CSN: %s",sprint_hex(CSN,8));
+    return 0;
+}
+int CmdHFiClass_SendReadBlock(uint8_t blockno,uint8_t *rdata){
+    UsbCommand d = {CMD_ICLASS_READBLOCK, {blockno}};
+    memcpy(d.d.asBytes,rdata,sizeof(uint8_t *));
+    SendCommand(&d);
+    
+    return 0;
+}
 int CmdHFiClassList(const char *Cmd)
 {
 	PrintAndLog("Deprecated command, use 'hf list iclass' instead");
@@ -230,162 +345,124 @@ int CmdHFiClassReader_Replay(const char *Cmd)
 
 	return 0;
 }
-
+int usage_hf_iclass_dump(){
+    PrintAndLog("Usage:  hf iclass dump [e]");
+    PrintAndLog("        Key    - A 16 byte master key");
+    PrintAndLog("        e      - If 'e' is specified, HS_KEY will be used otherwise standard key");
+    return 0;
+}
 int CmdHFiClassReader_Dump(const char *Cmd)
 {
-	uint8_t readerType = 0;
-	uint8_t MAC[4]={0x00,0x00,0x00,0x00};
-	uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	//uint8_t CC_temp[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t keytable[128] = {0};
-	int elite = 0;
-	uint8_t *used_key;
-	int i;
-	if (strlen(Cmd)<1)
-	{
-		PrintAndLog("Usage:  hf iclass dump <Key> [e]");
-		PrintAndLog("        Key    - A 16 byte master key");
-		PrintAndLog("        e      - If 'e' is specified, the key is interpreted as the 16 byte");
-		PrintAndLog("                 Custom Key (KCus), which can be obtained via reader-attack");
-		PrintAndLog("                 See 'hf iclass sim 2'. This key should be on iclass-format");
-		PrintAndLog("        sample: hf iclass dump 0011223344556677");
+    uint8_t readerType = 0;
+    uint8_t MAC[4]={0x00,0x00,0x00,0x00};
+    uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    //uint8_t CC_temp[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t keytable[128] = {0};
+    int elite = 0;
+    uint8_t *used_key;
+    int i;
+    
+    if (param_getchar(Cmd, 0) == 'e')
+    {
+        PrintAndLog("Elite switch on");
+        elite = 1;
+        memcpy(KEY,HS_KEY,sizeof(KEY));
+        //calc h2
+        hash2(KEY, keytable);
+        //printarr_human_readable("keytable", keytable, 128);
+    }
+    else
+        memcpy(KEY,GLOBAL_KEY,sizeof(KEY));
+    
+    UsbCommand resp;
+    uint8_t key_sel[8] = {0};
+    uint8_t key_sel_p[8] = { 0 };
+    // send ACK
+    if (CmdHFiClass_SendACK(CSN,CCNR) != 0)
+    return 1;
 
 
-		return 0;
-	}
-
-	if (param_gethex(Cmd, 0, KEY, 16))
-	{
-		PrintAndLog("KEY must include 16 HEX symbols");
-		return 1;
-	}
-
-	if (param_getchar(Cmd, 1) == 'e')
-	{
-		PrintAndLog("Elite switch on");
-		elite = 1;
-
-		//calc h2
-		hash2(KEY, keytable);
-		printarr_human_readable("keytable", keytable, 128);
-
-	}
-
-	UsbCommand resp;
-	uint8_t key_sel[8] = {0};
-	uint8_t key_sel_p[8] = { 0 };
-
-	UsbCommand c = {CMD_READER_ICLASS, {0}};
-	c.arg[0] = FLAG_ICLASS_READER_ONLY_ONCE| FLAG_ICLASS_READER_CC;
-	SendCommand(&c);
-
-
-
-	if (!WaitForResponseTimeout(CMD_ACK,&resp,4500))
-	{
-		PrintAndLog("Command execute timeout");
-		return 0;
-	}
-
-	uint8_t isOK    = resp.arg[0] & 0xff;
-	uint8_t * data  = resp.d.asBytes;
-
-	memcpy(CSN,data,8);
-	memcpy(CCNR,data+16,8);
-
-	PrintAndLog("isOk:%02x", isOK);
-
-	if(isOK > 0)
-	{
-		PrintAndLog("CSN: %s",sprint_hex(CSN,8));
-	}
-	if(isOK <= 1){
-		PrintAndLog("Failed to obtain CC! Aborting");
-		return 0;
-	}
-	//Status 2 or higher
-
-	if(elite)
-	{
-		//Get the key index (hash1)
-		uint8_t key_index[8] = {0};
-
-		hash1(CSN, key_index);
-		printvar("hash1", key_index,8);
-		for(i = 0; i < 8 ; i++)
-			key_sel[i] = keytable[key_index[i]] & 0xFF;
-		PrintAndLog("Pre-fortified 'permuted' HS key that would be needed by an iclass reader to talk to above CSN:");
-		printvar("k_sel", key_sel,8);
-		//Permute from iclass format to standard format
-		permutekey_rev(key_sel,key_sel_p);
-		used_key = key_sel_p;
-	}else{
-		used_key = KEY;
-	}
-
-	PrintAndLog("Pre-fortified key that would be needed by the OmniKey reader to talk to above CSN:");
-	printvar("Used key",used_key,8);
-	diversifyKey(CSN,used_key, div_key);
-	PrintAndLog("Hash0, a.k.a diversified key, that is computed using Ksel and stored in the card (Block 3):");
-	printvar("Div key", div_key, 8);
-	printvar("CC_NR:",CCNR,12);
-	doMAC(CCNR,div_key, MAC);
-	printvar("MAC", MAC, 4);
-
-	uint8_t iclass_data[32000] = {0};
-	uint32_t iclass_datalen = 0;
-	uint32_t iclass_blocksFailed = 0;//Set to 1 if dump was incomplete
-
-	UsbCommand d = {CMD_READER_ICLASS_REPLAY, {readerType}};
-	memcpy(d.d.asBytes, MAC, 4);
-	clearCommandBuffer();
-	SendCommand(&d);
-	PrintAndLog("Waiting for device to dump data. Press button on device and key on keyboard to abort...");
-	while (true) {
-		printf(".");
-		if (ukbhit()) {
-			getchar();
-			printf("\naborted via keyboard!\n");
-			break;
-		}
-		if(WaitForResponseTimeout(CMD_ACK,&resp,4500))
-		{
-			uint32_t dataLength = resp.arg[0];
-			iclass_blocksFailed |= resp.arg[1];
-			if(dataLength > 0)
-			{
-				PrintAndLog("Got %d bytes data (total so far %d)" ,dataLength,iclass_datalen);
-				memcpy(iclass_data+iclass_datalen, resp.d.asBytes,dataLength);
-				iclass_datalen += dataLength;
-			}else
-			{//Last transfer, datalength 0 means the dump is finished
-				PrintAndLog("Dumped %d bytes of data from tag. ", iclass_datalen);
-				if(iclass_blocksFailed)
-				{
-					PrintAndLog("OBS! Some blocks failed to be dumped correctly!");
-				}
-				if(iclass_datalen > 0)
-				{
-					char filename[100] = {0};
-					//create a preferred filename
-					snprintf(filename, 100,"iclass_tagdump-%02x%02x%02x%02x%02x%02x%02x%02x",
-							 CSN[0],CSN[1],CSN[2],CSN[3],
-							CSN[4],CSN[5],CSN[6],CSN[7]);
-					//Place the div_key in block 3
-					memcpy(iclass_data+(3*8), div_key, 8);
-					saveFile(filename,"bin",iclass_data, iclass_datalen );
-				}
-				//Aaaand we're finished
-				return 0;
-			}
-		}
-	}
-
-
-	return 0;
+    //Status 2 or higher
+    
+    if(elite)
+    {
+        //Get the key index (hash1)
+        uint8_t key_index[8] = {0};
+        
+        hash1(CSN, key_index);
+        //printvar("hash1", key_index,8);
+        for(i = 0; i < 8 ; i++)
+            key_sel[i] = keytable[key_index[i]] & 0xFF;
+        //PrintAndLog("Pre-fortified 'permuted' HS key that would be needed by an iclass reader to talk to above CSN:");
+        //printvar("k_sel", key_sel,8);
+        //Permute from iclass format to standard format
+        permutekey_rev(key_sel,key_sel_p);
+        used_key = key_sel_p;
+    }else{
+        used_key = KEY;
+    }
+    
+    //PrintAndLog("Pre-fortified key that would be needed by the OmniKey reader to talk to above CSN:");
+    //printvar("Used key",used_key,8);
+    diversifyKey(CSN,used_key, div_key);
+    //PrintAndLog("Hash0, a.k.a diversified key, that is computed using Ksel and stored in the card (Block 3):");
+    //printvar("Div key", div_key, 8);
+    //printvar("CC_NR:",CCNR,12);
+    doMAC(CCNR,div_key, MAC);
+    //printvar("MAC", MAC, 4);
+    
+    uint8_t iclass_data[32000] = {0};
+    uint32_t iclass_datalen = 0;
+    uint32_t iclass_blocksFailed = 0;//Set to 1 if dump was incomplete
+    
+    UsbCommand d = {CMD_READER_ICLASS_REPLAY, {readerType}};
+    memcpy(d.d.asBytes, MAC, 4);
+    clearCommandBuffer();
+    SendCommand(&d);
+    PrintAndLog("Waiting for device to dump data. Press button on device and key on keyboard to abort...");
+    while (true) {
+        printf(".");
+        if (ukbhit()) {
+            getchar();
+            printf("\naborted via keyboard!\n");
+            break;
+        }
+        if(WaitForResponseTimeout(CMD_ACK,&resp,4500))
+        {
+            uint32_t dataLength = resp.arg[0];
+            iclass_blocksFailed |= resp.arg[1];
+            if(dataLength > 0)
+            {
+                PrintAndLog("Got %d bytes data (total so far %d)" ,dataLength,iclass_datalen);
+                memcpy(iclass_data+iclass_datalen, resp.d.asBytes,dataLength);
+                iclass_datalen += dataLength;
+            }else
+            {//Last transfer, datalength 0 means the dump is finished
+                PrintAndLog("Dumped %d bytes of data from tag. ", iclass_datalen);
+                if(iclass_blocksFailed)
+                {
+                    PrintAndLog("OBS! Some blocks failed to be dumped correctly!");
+                }
+                if(iclass_datalen > 0)
+                {
+                    char filename[100] = {0};
+                    //create a preferred filename
+                    snprintf(filename, 100,"iclass_tagdump-%02x%02x%02x%02x%02x%02x%02x%02x",
+                             CSN[0],CSN[1],CSN[2],CSN[3],
+                             CSN[4],CSN[5],CSN[6],CSN[7]);
+                    //Place the div_key in block 3
+                    memcpy(iclass_data+(3*8), div_key, 8);
+                    saveFile(filename,"bin",iclass_data, iclass_datalen );
+                }
+                //Aaaand we're finished
+                return 0;
+            }
+        }
+    }
+    return 0;
 }
 
 int hf_iclass_eload_usage()
@@ -477,31 +554,6 @@ int usage_hf_iclass_decrypt()
 	return 1;
 }
 
-int readKeyfile(const char *filename, size_t len, uint8_t* buffer)
-{
-	FILE *f = fopen(filename, "rb");
-	if(!f) {
-		PrintAndLog("Failed to read from file '%s'", filename);
-		return 1;
-	}
-	fseek(f, 0, SEEK_END);
-	long fsize = ftell(f);
-	fseek(f, 0, SEEK_SET);
-	size_t bytes_read = fread(buffer, 1, len, f);
-	fclose(f);
-	if(fsize != len)
-	{
-		PrintAndLog("Warning, file size is %d, expected %d", fsize, len);
-		return 1;
-	}
-	if(bytes_read != len)
-	{
-		PrintAndLog("Warning, could only read %d bytes, expected %d" ,bytes_read, len);
-		return 1;
-	}
-	return 0;
-}
-
 int CmdHFiClassDecrypt(const char *Cmd)
 {
 	uint8_t key[16] = { 0 };
@@ -559,83 +611,51 @@ int CmdHFiClassDecrypt(const char *Cmd)
 
 	return 0;
 }
-
+void Calc_wb_mac(uint8_t blockno,uint8_t *data,uint8_t *div_key,uint8_t MAC[4]){
+    uint8_t WB[9];
+    WB[0] = blockno;
+    memcpy(WB + 1,data,8);
+    // do mac 9 bytes
+    doMAC_N(WB,sizeof(WB),div_key,MAC);
+}
 int CmdHFiClass_iso14443A_write(const char *Cmd)
 {
-	uint8_t readerType = 0;
-	uint8_t MAC[4]={0x00,0x00,0x00,0x00};
-	uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-	uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
-
-	uint8_t blockNo=0;
+	uint8_t blockno=0;
 	uint8_t bldata[8]={0};
+    uint8_t MAC[4]={0x00,0x00,0x00,0x00};
 
-	if (strlen(Cmd)<3)
-	{
-		PrintAndLog("Usage:  hf iclass write <Key> <Block> <Data>");
-		PrintAndLog("        sample: hf iclass write 0011223344556677 10 AAAAAAAAAAAAAAAA");
-		return 0;
-	}
+    uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
 
-	if (param_gethex(Cmd, 0, KEY, 16))
-	{
-		PrintAndLog("KEY must include 16 HEX symbols");
-		return 1;
-	}
+    if (param_gethex(Cmd, 0,&blockno, 2))
+    {
+        PrintAndLog("Block No must include 2 HEX symbols");
+        return 1;
+    }
+    if (param_gethex(Cmd, 1, bldata, 16))
+    {
+        PrintAndLog("Block data must include 16 HEX symbols");
+        return 1;
+    }
+    // tell the reader to send ACK and get CSN + CCNR
+    if (CmdHFiClass_SendACK(CSN,CCNR) != 0)
+    return 1;
+    
+    memcpy(KEY,GLOBAL_KEY,sizeof(KEY));
+    diversifyKey(CSN,KEY, div_key);
+    doMAC(CCNR,div_key, MAC);
+    // send authentication
+    CmdHFiClass_SendAuthentication(MAC);
+    // send write command
+    Calc_wb_mac(blockno,bldata,div_key,MAC);
+    UsbCommand w = {CMD_ICLASS_ISO14443A_WRITE, {blockno}};
+    memcpy(w.d.asBytes, bldata, 8);
+    memcpy(w.d.asBytes + 8,MAC, 4);
 
-	blockNo = param_get8(Cmd, 1);
-	if (blockNo>32)
-	{
-		PrintAndLog("Error: Maximum number of blocks is 32 for iClass 2K Cards!");
-		return 1;
-	}
-	if (param_gethex(Cmd, 2, bldata, 8))
-	{
-		PrintAndLog("Block data must include 8 HEX symbols");
-		return 1;
-	}
-
-	UsbCommand c = {CMD_ICLASS_ISO14443A_WRITE, {0}};
-	SendCommand(&c);
-	UsbCommand resp;
-
-	if (WaitForResponseTimeout(CMD_ACK,&resp,4500)) {
-		uint8_t isOK    = resp.arg[0] & 0xff;
-		uint8_t * data  = resp.d.asBytes;
-
-		memcpy(CSN,data,8);
-		memcpy(CCNR,data+8,8);
-		PrintAndLog("DEBUG: %s",sprint_hex(CSN,8));
-		PrintAndLog("DEBUG: %s",sprint_hex(CCNR,8));
-		PrintAndLog("isOk:%02x", isOK);
-	} else {
-		PrintAndLog("Command execute timeout");
-	}
-
-	diversifyKey(CSN,KEY, div_key);
-
-	PrintAndLog("Div Key: %s",sprint_hex(div_key,8));
-	doMAC(CCNR, div_key, MAC);
-
-	UsbCommand c2 = {CMD_ICLASS_ISO14443A_WRITE, {readerType,blockNo}};
-	memcpy(c2.d.asBytes, bldata, 8);
-	memcpy(c2.d.asBytes+8, MAC, 4);
-	SendCommand(&c2);
-
-	if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
-		uint8_t isOK    = resp.arg[0] & 0xff;
-		uint8_t * data  = resp.d.asBytes;
-
-		if (isOK)
-			PrintAndLog("isOk:%02x data:%s", isOK, sprint_hex(data, 4));
-		else
-			PrintAndLog("isOk:%02x", isOK);
-	} else {
-		PrintAndLog("Command execute timeout");
-	}
-	return 0;
+    SendCommand(&w);
+    return 0;
 }
 int CmdHFiClass_loclass(const char *Cmd)
 {
@@ -682,23 +702,406 @@ int CmdHFiClass_loclass(const char *Cmd)
 
 	return 0;
 }
-
-static command_t CommandTable[] = 
+int usage_hf_iclass_readtagfile(){
+    PrintAndLog("Usage: hf iclass readtagfile <filename>");
+    return 1;
+}
+void printIclassDumpContents(uint8_t* iclass_dump,uint8_t startblock,uint8_t endblock,size_t filesize){
+    uint8_t blockdata[8];
+    uint8_t mem_config;
+    memcpy(&mem_config, iclass_dump + 13,1);
+    uint8_t maxmemcount;
+    uint8_t filemaxblock = filesize / 8;
+    if (mem_config == 0x80)
+        maxmemcount = 255;
+    else
+        maxmemcount = 32;
+    
+    if (startblock == 0)
+        startblock = 6;
+    if ((endblock > maxmemcount) || (endblock == 0))
+        endblock = maxmemcount;
+    if (endblock > filemaxblock)
+        endblock = filemaxblock;
+    int i = startblock;
+    int j;
+    while (i < endblock){
+        printf("block[%02x]: ",i);
+        memcpy(blockdata,iclass_dump + (i * 8),8);
+        for (j = 0;j < 8;j++)
+            printf("%02x",blockdata[j]);
+        printf("\n");
+        i++;
+    }
+    if ((i < filemaxblock) && (i < maxmemcount)){
+        printf("block[%02x]: ",i);
+        memcpy(blockdata,iclass_dump + (i * 8),8);
+        for (j = 0;j < 8;j++)
+            printf("%02x",blockdata[j]);
+        printf("\n");
+    }
+}
+int CmdHFiClassReadTagFile(const char *Cmd)
 {
-	{"help",	CmdHelp,			1,	"This help"},
-	{"list",	CmdHFiClassList,	0,	"[Deprecated] List iClass history"},
-	{"snoop",	CmdHFiClassSnoop,	0,	"Eavesdrop iClass communication"},
-	{"sim",	CmdHFiClassSim,		0,	"Simulate iClass tag"},
-	{"reader",CmdHFiClassReader,	0,	"Read an iClass tag"},
-	{"replay",CmdHFiClassReader_Replay,	0,	"Read an iClass tag via Reply Attack"},
-	{"dump",	CmdHFiClassReader_Dump,	0,		"Authenticate and Dump iClass tag"},
-//	{"write",	CmdHFiClass_iso14443A_write,	0,	"Authenticate and Write iClass block"},
-	{"loclass",	CmdHFiClass_loclass,	1,	"Use loclass to perform bruteforce of reader attack dump"},
-	{"eload",   CmdHFiClassELoad,    0,     "[experimental] Load data into iclass emulator memory"},
-	{"decrypt", CmdHFiClassDecrypt,  1,     "Decrypt tagdump" },
-	{NULL, NULL, 0, NULL}
-};
+    int startblock = 0;
+    int endblock = 0;
+    char tempnum[5];
+    FILE *f;
+    char filename[FILE_PATH_SIZE];
+    if (param_getstr(Cmd, 0, filename) < 1)
+        return usage_hf_iclass_readtagfile();
+    if (param_getstr(Cmd,1,(char *)&tempnum) < 1)
+        startblock = 0;
+    else
+        sscanf(tempnum,"%d",&startblock);
+    
+    if (param_getstr(Cmd,2,(char *)&tempnum) < 1)
+        endblock = 0;
+    else
+        sscanf(tempnum,"%d",&endblock);
+    // file handling and reading
+    f = fopen(filename,"rb");
+    if(!f) {
+        PrintAndLog("Failed to read from file '%s'", filename);
+        return 1;
+    }
+    fseek(f, 0, SEEK_END);
+    long fsize = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    
+    uint8_t *dump = malloc(fsize);
+    
+    
+    size_t bytes_read = fread(dump, 1, fsize, f);
+    fclose(f);
+    uint8_t *csn = dump;
+    printf("CSN :      %02x %02x %02x %02x %02x %02x %02x %02x\n",csn[0],csn[1],csn[2],csn[3],csn[4],csn[5],csn[6],csn[7]);
+//    printIclassDumpInfo(dump);
+    printIclassDumpContents(dump,startblock,endblock,bytes_read);
+    free(dump);
+    return 0;
+}
+int usage_hf_iclass_calckey(){
+    PrintAndLog("error please load ekey");
+    return 1;
+}
+uint64_t xorcheck(uint64_t sdiv,uint64_t hdiv){
+    uint64_t new_div = 0x00;
+    new_div ^= sdiv;
+    new_div ^= hdiv;
+    return new_div;
+}
+uint64_t hexarray_to_uint64(uint8_t *key){
+    char temp[17];
+    uint64_t uint_key;
+    for (int i = 0;i < 8;i++)
+        sprintf(&temp[(i *2)],"%02X",key[i]);
+    temp[16] = '\0';
+    if (sscanf(temp,"%016llX",&uint_key) < 1)
+        return 0;
+    return uint_key;
+}
+int CmdHFiClassCalcEKey(const char *Cmd){
+    
+    uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t std_div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t elite_div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t keytable[128] = {0};
+    uint8_t key_index[8] = {0};
+    uint64_t new_div_key;
+    uint64_t i_elite_div_key;
+    uint64_t i_std_div_key;
+    int i;
+    if (!HS_KEY_LOAD)
+        return usage_hf_iclass_calckey();
+    
+    hash2(HS_KEY, keytable);
+    
+    UsbCommand resp;
+    uint8_t key_sel[8] = {0};
+    uint8_t key_sel_p[8] = { 0 };
+    
+    UsbCommand c = {CMD_READER_ICLASS, {0}};
+    c.arg[0] = FLAG_ICLASS_READER_ONLY_ONCE| FLAG_ICLASS_READER_CC;
+    SendCommand(&c);
+    
+    if (!WaitForResponseTimeout(CMD_ACK,&resp,4500))
+    {
+        PrintAndLog("Command execute timeout");
+        return 0;
+    }
+    
+    uint8_t isOK    = resp.arg[0] & 0xff;
+    uint8_t * data  = resp.d.asBytes;
+    
+    memcpy(CSN,data,8);
+    
+//    PrintAndLog("isOk:%02x", isOK);
+    
+    if(isOK > 0)
+    {
+        PrintAndLog("CSN: %s",sprint_hex(CSN,8));
+    }
+    if(isOK <= 1){
+        PrintAndLog("Failed to obtain CC! Aborting");
+        return 0;
+    }
+    diversifyKey(CSN, GLOBAL_KEY, std_div_key);
+    
+//    printvar("(S)Div key", std_div_key, 8);
+    hash1(CSN, key_index);
+    for(i = 0; i < 8 ; i++)
+        key_sel[i] = keytable[key_index[i]] & 0xFF;
+    
+    //Permute from iclass format to standard format
+    permutekey_rev(key_sel,key_sel_p);
+    diversifyKey(CSN,key_sel_p, elite_div_key);
+//    printvar("(E)Div key", elite_div_key, 8);
+    i_elite_div_key = hexarray_to_uint64(elite_div_key);
+    i_std_div_key = hexarray_to_uint64(std_div_key);
+    new_div_key = xorcheck(i_std_div_key,i_elite_div_key);
+    printf("(E)Div key : %016llx\n",new_div_key);
+    return 0;
+    
+}
+int usage_hf_iclass_load(){
+    PrintAndLog("Usage:  hf iclass load <tagfile.bin> <start block> <end block>");
+    PrintAndLog("        sample: hf iclass write iclass_tagdump-121345.bin 6 19");
+    return -1;
+}
+// load data from tag file and write to another iclass tag
+int CmdHFiClass_load(const char *Cmd){
+    
+    if (strlen(Cmd) < 3)
+        return usage_hf_iclass_load();
+    int startblock = 0;
+    int endblock = 0;
+    char tempnum[5];
+    uint8_t mem_config;
+    FILE *f;
+    char filename[FILE_PATH_SIZE];
+    if (param_getstr(Cmd, 0, filename) < 1)
+        return usage_hf_iclass_load();
+    
+    if (param_getstr(Cmd,1,(char *)&tempnum) < 1)
+        startblock = 6;
+    else
+        sscanf(tempnum,"%d",&startblock);
+    
+    if (param_getstr(Cmd,2,(char *)&tempnum) < 1)
+        endblock = 0;
+    else
+        sscanf(tempnum,"%d",&endblock);
+    
+    // file handling and reading
+    f = fopen(filename,"rb");
+    if(!f) {
+        PrintAndLog("Failed to read from file '%s'", filename);
+        return 1;
+    }
+    fseek(f, 0, SEEK_END);
+    long fsize = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    
+    uint8_t *dump = malloc(fsize);
+    
+    size_t bytes_read = fread(dump, 1, fsize, f);
+    fclose(f);
+    
+    memcpy(&mem_config,dump + 13,1);
+    uint8_t maxmemcount;
+    
+    uint8_t filemaxblock = bytes_read / 8;
+    if (mem_config == 0x80)
+        maxmemcount = 255;
+    else
+        maxmemcount = 32;
+    
+    if (startblock == 0)
+        startblock = 6;
+    if ((endblock > maxmemcount) || (endblock == 0))
+        endblock = maxmemcount;
+    if (endblock > filemaxblock)
+        endblock = filemaxblock;
+    
+    return 0;
+}
+int CmdHFIClassReadBlock(const char *Cmd){
+    uint8_t blockno=0;
+    uint8_t MAC[4]={0x00,0x00,0x00,0x00};
+    uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    
+    if (param_gethex(Cmd, 0,&blockno, 2))
+    {
+        PrintAndLog("Block No must include 2 HEX symbols");
+        return 1;
+    }
+    // tell the reader to send ACK and get CSN + CCNR
+    if (CmdHFiClass_SendACK(CSN,CCNR) != 0)
+    return 1;
+    
+    memcpy(KEY,GLOBAL_KEY,sizeof(KEY));
+    //    PrintAndLog("Pre-fortified key that would be needed by the OmniKey reader to talk to above CSN:");
+    //    printvar("Used key",KEY,8);
+    diversifyKey(CSN,KEY, div_key);
+    //    PrintAndLog("Hash0, a.k.a diversified key, that is computed using Ksel and stored in the card (Block 3):");
+    //    printvar("Div key", div_key, 8);
+    //    printvar("CC_NR:",CCNR,8);
+    doMAC(CCNR,div_key, MAC);
+    //    printvar("MAC", MAC, 4);
+    CmdHFiClass_SendAuthentication(MAC);
+    
+    // not yet implement
+    
+    return 0;
+}
 
+
+
+int CmdHFiClassCloneTag_Usage(){
+    PrintAndLog("Usage:  hf iclass clone <tagfile.bin> <start block> <end block> -e <KEY>");
+    PrintAndLog("        sample: hf iclass clone iclass_tagdump-121345.bin 6 19 -e 1122334455667788");
+    return -1;
+}
+int CmdHFiClassCloneTag(const char *Cmd){
+    if (strlen(Cmd) < 3)
+        return CmdHFiClassCloneTag_Usage();
+
+    int startblock = 0;
+    int endblock = 0;
+    char tempnum[5];
+    FILE *f;
+
+    iclass_block_t tag_data[26];
+    uint8_t MAC[4]={0x00,0x00,0x00,0x00};
+    uint8_t KEY[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CSN[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t CCNR[12]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+    uint8_t div_key[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
+   
+    char filename[FILE_PATH_SIZE];
+    // get tagfile parameter
+    if (param_getstr(Cmd, 0, filename) < 1)
+        return usage_hf_iclass_load();
+    // get start block parameter
+    if (param_getstr(Cmd,1,(char *)&tempnum) < 1)
+        startblock = 6;
+    else
+        sscanf(tempnum,"%x",&startblock);
+    // get end block parameter
+    if (param_getstr(Cmd,2,(char *)&tempnum) < 1)
+        endblock = 0;
+    else
+        sscanf(tempnum,"%x",&endblock);
+    
+    
+    // file handling and reading
+    f = fopen(filename,"rb");
+    if(!f) {
+        PrintAndLog("Failed to read from file '%s'", filename);
+        return 1;
+    }
+    
+   // now read data from the file from block 6 --- 19
+    // ok we will use this struct [data 8 bytes][MAC 4 bytes] for each block calculate all mac number for each data
+    // then copy to usbcommand->asbytes; the max is 32 - 6 = 24 block 12 bytes each block 288 bytes then we can only accept to clone 21 blocks at the time,
+    // else we have to create a share memory
+    int i;
+    fseek(f,6*8,SEEK_SET);
+    fread(tag_data,sizeof(iclass_block_t),32 - 6,f);
+    for (i = 0;i < 32 - 6; i++){
+        printf("block [%02x] [%02x%02x%02x%02x%02x%02x%02x%02x]\n",i + 6,tag_data[i].d[0],tag_data[i].d[1],tag_data[i].d[2],tag_data[i].d[3],tag_data[i].d[4],tag_data[i].d[5],tag_data[i].d[6],tag_data[i].d[7]);
+    }
+    
+    // tell the reader to send ACK and get CSN + CCNR
+    if (CmdHFiClass_SendACK(CSN,CCNR) != 0)
+        return 1;
+    
+    memcpy(KEY,GLOBAL_KEY,sizeof(KEY));
+    //    PrintAndLog("Pre-fortified key that would be needed by the OmniKey reader to talk to above CSN:");
+    //    printvar("Used key",KEY,8);
+    diversifyKey(CSN,KEY, div_key);
+    //    PrintAndLog("Hash0, a.k.a diversified key, that is computed using Ksel and stored in the card (Block 3):");
+    //    printvar("Div key", div_key, 8);
+    //    printvar("CC_NR:",CCNR,8);
+    doMAC(CCNR,div_key, MAC);
+    //    printvar("MAC", MAC, 4);
+    
+    // now authentication with the card
+    CmdHFiClass_SendAuthentication(MAC);
+    
+
+    // everythings is ready now
+    UsbCommand w = {CMD_ICLASS_CLONE,{startblock,endblock}};
+    uint8_t *ptr;
+    // calculate all mac for every the block we will write
+    for (i = startblock;i <= endblock;i++){
+        Calc_wb_mac(i,tag_data[i - 6].d,div_key,MAC);
+        // usb command d start pointer = d + (i - 6) * 12
+        // memcpy(pointer,tag_data[i - 6],8) 8 bytes
+        // memcpy(pointer + 8,mac,sizoof(mac) 4 bytes;
+        // next one
+        ptr = w.d.asBytes + (i - 6) * 12;
+        memcpy(ptr, &(tag_data[i - 6].d[0]), 8);
+        memcpy(ptr + 8,MAC, 4);
+    }
+    uint8_t p[12];
+    for (i = 0; i <= endblock - startblock;i++){
+        memcpy(p,w.d.asBytes + (i * 12),12);
+        printf("block [%02x]",i + 6);
+        printf(" [%02x%02x%02x%02x%02x%02x%02x%02x]",p[0],p[1],p[2],p[3],p[4],p[5],p[6],p[7]);
+        printf(" MAC [%02x%02x%02x%02x]\n",p[8],p[9],p[10],p[11]);
+    }
+    SendCommand(&w);
+    return 0;
+}
+int CmdHFiClassEKey_usage(){
+    PrintAndLog(" Usage: hf iclass ekey [filename] to load the key");
+    PrintAndLog("Sample: hf iclass ekey helloworld.key [load key from file]");
+    PrintAndLog("Sample: hf iclass ekey [show the current ekey]");
+    return -1;
+}
+int CmdHFiClassEKey(const char *Cmd){
+    if (strlen(Cmd) > 1)
+    {
+        if (readKeyfile(Cmd,sizeof(HS_KEY),HS_KEY) != 0)
+        {
+            HS_KEY_LOAD = false;
+            memcpy(HS_KEY,BLANK_KEY,sizeof(BLANK_KEY));
+            return CmdHFiClassEKey_usage();
+        }
+        HS_KEY_LOAD = true;
+    }
+    else
+    CmdHFiClass_printkey("HS Key",HS_KEY);
+    return 0;
+}
+static command_t CommandTable[] =
+{
+    {"help",        CmdHelp,                    	1,	"This help"},
+    {"list",        CmdHFiClassList,            	0,	"[Deprecated] List iClass history"},
+    {"snoop",       CmdHFiClassSnoop,           	0,	"Eavesdrop iClass communication"},
+    {"sim",         CmdHFiClassSim,             	0,	"Simulate iClass tag"},
+    {"reader",      CmdHFiClassReader,          	0,	"Read an iClass tag"},
+    {"replay",      CmdHFiClassReader_Replay,       0,	"Read an iClass tag via Reply Attack"},
+    {"dump",        CmdHFiClassReader_Dump,         0,	"Authenticate and Dump iClass tag"},
+    {"write",       CmdHFiClass_iso14443A_write,	0,	"Authenticate and Write iClass block"},
+    {"read",        CmdHFIClassReadBlock,           0,  "Authenticate and Read iClass block"},
+    {"load",        CmdHFiClass_load,           	0,	"Load from tagfile to iclass card"},
+    {"loclass",     CmdHFiClass_loclass,            1,	"Use loclass to perform bruteforce of reader attack dump"},
+    {"eload",   	CmdHFiClassELoad,               0,  "[experimental] Load data into iclass emulator memory"},
+    {"decrypt", 	CmdHFiClassDecrypt,             1,  "Decrypt tagdump" },
+    {"readtagfile",	CmdHFiClassReadTagFile,         1,	"Display Content from tagfile"},
+    {"ediv",        CmdHFiClassCalcEKey,            0,	"Give Diversify key for this card to write to block 3"},
+    {"readkey",     CmdHFiClassReadKeyFile,         1,	"Read and display key from file"},
+    {"savekey",     CmdHFiClassSaveKeyFile,         1,	"Write key to file"},
+    {"clone",       CmdHFiClassCloneTag,            0,  "Clone tag"},
+    {"ekey",        CmdHFiClassEKey,                1,  "Load HS key from file or show current HS Key"},
+    {NULL,          NULL,                           0,  NULL}
+};
 int CmdHFiClass(const char *Cmd)
 {
 	CmdsParse(CommandTable, Cmd);
diff --git a/client/cmdhficlass.h b/client/cmdhficlass.h
old mode 100644
new mode 100755
index 30c6a8a7..abcb48a9
--- a/client/cmdhficlass.h
+++ b/client/cmdhficlass.h
@@ -1,3 +1,5 @@
+// version 2.1.0
+// add readkeyfile,writekeyfile,modify dump,iso write and calcEkey functions.
 //-----------------------------------------------------------------------------
 // Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
 // Copyright (C) 2011 Gerhard de Koning Gans
@@ -20,5 +22,10 @@ int CmdHFiClassList(const char *Cmd);
 int HFiClassReader(const char *Cmd, bool loop, bool verbose);
 int CmdHFiClassReader(const char *Cmd);
 int CmdHFiClassReader_Replay(const char *Cmd);
-
+int CmdHFiClassReadKeyFile(const char *filename);
+int CmdHFiClassWriteKeyFile(const char *Cmd);
+int CmdHFiClass_iso14443A_write(const char *Cmd);
+int CmdHFiClassCalcEKey(const char *Cmd);
+int CmdHFiClassRestore(const char *cmd);
+int CmdHFiClass_TestMac(const char *Cmd);
 #endif
diff --git a/client/cmdlf.c b/client/cmdlf.c
index 6dae5164..0569ea85 100644
--- a/client/cmdlf.c
+++ b/client/cmdlf.c
@@ -30,7 +30,7 @@
 #include "cmdlfpcf7931.h"
 #include "cmdlfio.h"
 #include "lfdemod.h"
-
+#include "cmdlfviking.h"
 static int CmdHelp(const char *Cmd);
 
 /* send a command before reading */
@@ -1148,6 +1148,7 @@ static command_t CommandTable[] =
 	{"vchdemod",    CmdVchDemod,        1, "['clone'] -- Demodulate samples for VeriChip"},
 	{"t55xx",       CmdLFT55XX,         1, "{ T55xx RFIDs... }"},
 	{"pcf7931",     CmdLFPCF7931,       1, "{PCF7931 RFIDs...}"},
+    {"viking",      CmdLFViking,        1, "{Viking RFIDs..}"},
 	{NULL, NULL, 0, NULL}
 };
 
diff --git a/client/cmdlfviking.c b/client/cmdlfviking.c
new file mode 100755
index 00000000..d20f2560
--- /dev/null
+++ b/client/cmdlfviking.c
@@ -0,0 +1,64 @@
+#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 "cmdlfviking.h"
+#include "lfdemod.h"
+static int CmdHelp(const char *Cmd);
+int CmdVikingDemod(const char *Cmd)
+{
+    uint8_t id[4];
+    if (param_gethex(Cmd,0,id,8) == 1)
+    {
+        PrintAndLog("Usage: lf viking demod <CardID 8 bytes of hex number>");
+        return 0;
+    }
+    UsbCommand c = {CMD_ACQUIRE_RAW_ADC_SAMPLES_125K, {false,0,0}};
+    SendCommand(&c);
+    WaitForResponse(CMD_ACK,NULL);
+    getSamples("40000",true);
+    // try to demod AMViking
+    return AMVikingDemod(id);
+}
+int CmdVikingClone(const char *Cmd)
+{
+    uint32_t b1,b2;
+    // get the tag number 64 bits (8 bytes) in hex
+    uint8_t id[8];
+    if (param_gethex(Cmd,0,id,16) == 1)
+    {
+        PrintAndLog("Usage: lf viking clone <Card ID 16 bytes of hex number>");
+        return 0;
+    }
+    b1 = bytes_to_num(id,sizeof(uint32_t));
+    b2 = bytes_to_num(id + sizeof(uint32_t),sizeof(uint32_t));
+    UsbCommand c = {CMD_VIKING_CLONE_TAG,{b1,b2}};
+    SendCommand(&c);   
+    return 0;
+}
+
+static command_t CommandTable[] =
+{
+    {"help", CmdHelp, 1, "This help"},
+    {"demod",CmdVikingDemod ,1, "<8 digits tag id> -- Extract tag data"},
+    {"clone", CmdVikingClone, 1, "<16 digits card data>  clone viking tag"},
+    {NULL, NULL, 0, NULL}
+};
+
+int CmdLFViking(const char *Cmd)
+{
+    CmdsParse(CommandTable, Cmd);
+    return 0;
+}
+
+int CmdHelp(const char *Cmd)
+{
+    CmdsHelp(CommandTable);
+    return 0;
+}
diff --git a/client/cmdlfviking.h b/client/cmdlfviking.h
new file mode 100755
index 00000000..469a2b7b
--- /dev/null
+++ b/client/cmdlfviking.h
@@ -0,0 +1,7 @@
+#ifndef CMDLFVIKING_H__
+#define CMDLFVIKING_H__
+int CmdLFViking(const char *Cmd);
+int CmdVikingDemod(const char *Cmd);
+int CmdVikingClone(const char *Cmd);
+#endif
+
diff --git a/client/loclass/cipher.c b/client/loclass/cipher.c
index 7c9cc873..2aae093d 100644
--- a/client/loclass/cipher.c
+++ b/client/loclass/cipher.c
@@ -241,6 +241,27 @@ void doMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4])
 	//free(cc_nr);
     return;
 }
+void doMAC_N(uint8_t *cc_nr_p,uint8_t cc_nr_size, uint8_t *div_key_p, uint8_t mac[4])
+{
+    uint8_t *cc_nr;
+    uint8_t div_key[8];
+    cc_nr = (uint8_t*) malloc(cc_nr_size);
+    
+    memcpy(cc_nr,cc_nr_p,cc_nr_size);
+    memcpy(div_key,div_key_p,8);
+    
+    reverse_arraybytes(cc_nr,cc_nr_size);
+    BitstreamIn bitstream = {cc_nr,cc_nr_size * 8,0};
+    uint8_t dest []= {0,0,0,0,0,0,0,0};
+    BitstreamOut out = { dest, sizeof(dest)*8, 0 };
+    MAC(div_key,bitstream, out);
+    //The output MAC must also be reversed
+    reverse_arraybytes(dest, sizeof(dest));
+    memcpy(mac, dest, 4);
+    free(cc_nr);
+    return;
+}
+
 #ifndef ON_DEVICE
 int testMAC()
 {
diff --git a/client/loclass/cipher.h b/client/loclass/cipher.h
index bdea9432..24e86851 100644
--- a/client/loclass/cipher.h
+++ b/client/loclass/cipher.h
@@ -42,6 +42,8 @@
 #include <stdint.h>
 
 void doMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);
+void doMAC_N(uint8_t *cc_nr_p,uint8_t cc_nr_size, uint8_t *div_key_p, uint8_t mac[4]);
+
 #ifndef ON_DEVICE
 int testMAC();
 #endif
diff --git a/client/util.c b/client/util.c
index 9f2142c6..1660715e 100644
--- a/client/util.c
+++ b/client/util.c
@@ -453,3 +453,32 @@ void xor(unsigned char *dst, unsigned char *src, size_t len) {
 int32_t le24toh (uint8_t data[3]) {
     return (data[2] << 16) | (data[1] << 8) | data[0];
 }
+size_t bytes_to_bits(const uint8_t *src,size_t src_size,uint8_t *des,size_t des_size){
+    int i,j,k;
+    int count = 0;
+    // check src_size and des_size
+    if ((src_size * 8) > des_size)
+        return -1;
+    // convert 1 bytes to 8 bits at the time
+    for (j = 0;j < src_size;j++){
+        for (i = 0;i < 8;i++){
+            k = src[j] >> i;
+            if (k & 1)
+                *(des + (j * 8) + (7 - i)) = 1;
+            else
+                *(des + (j * 8) + (7 - i)) = 0;
+            count++;
+        }
+    }
+    return count;
+}
+void print_arraybinary(const uint8_t *b,size_t c){
+    int i;
+    for (i = 0;i < c;i++){
+        if (*(b + i) == 0)
+            printf("0");
+        else
+            printf("1");
+    }
+    printf("\n");
+}
diff --git a/client/util.h b/client/util.h
index 2d2beaf4..5d9d6cb5 100644
--- a/client/util.h
+++ b/client/util.h
@@ -65,3 +65,4 @@ void wiegand_add_parity(char *target, char *source, char length);
 
 void xor(unsigned char *dst, unsigned char *src, size_t len);
 int32_t le24toh(uint8_t data[3]);
+size_t bytes_to_bits(const uint8_t *src,size_t src_size,uint8_t *des,size_t des_size);
\ No newline at end of file
diff --git a/common/lfdemod.c b/common/lfdemod.c
index f13a567c..d883ed9d 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -1482,3 +1482,26 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
 	*size = numBits;
 	return errCnt;
 }
+// on successful return 1 otherwise return 0
+int VikingDecode(uint8_t *BitStream, size_t size, size_t *startIdx,uint8_t *id_bits,size_t id_bits_size)
+{
+    //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+    //  otherwise could be a void with no arguments
+    //set defaults
+    uint32_t i = 0;
+    uint32_t lastcheckindex = size - (id_bits_size * 2);
+    int found = 0;
+    while (i < lastcheckindex)
+    {
+        if (memcmp(BitStream + i,id_bits,id_bits_size) == 0)
+        {
+            *startIdx = i;
+            found = 1;
+            break;
+        }
+        i++;
+    }
+    return found;
+}
+
+
diff --git a/common/lfdemod.h b/common/lfdemod.h
index d16aab9e..3b807b56 100644
--- a/common/lfdemod.h
+++ b/common/lfdemod.h
@@ -49,5 +49,6 @@ int IOdemodFSK(uint8_t *dest, size_t size);
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert);
 int PyramiddemodFSK(uint8_t *dest, size_t *size);
 int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo);
+int  VikingDecode(uint8_t *BitStream, size_t size, size_t *startIdx,uint8_t *id_bit,size_t id_bits_size);
 
 #endif
diff --git a/include/usb_cmd.h b/include/usb_cmd.h
index e45bf35e..5fa38ee2 100644
--- a/include/usb_cmd.h
+++ b/include/usb_cmd.h
@@ -96,6 +96,8 @@ typedef struct{
 #define CMD_ASK_SIM_TAG                                                   0x021F
 #define CMD_PSK_SIM_TAG                                                   0x0220
 #define CMD_AWID_DEMOD_FSK                                                0x0221
+#define CMD_VIKING_CLONE_TAG                                              0x0222
+
 
 /* CMD_SET_ADC_MUX: ext1 is 0 for lopkd, 1 for loraw, 2 for hipkd, 3 for hiraw */
 
@@ -135,6 +137,9 @@ typedef struct{
 #define CMD_READER_ICLASS_REPLAY                                          0x0395
 #define CMD_ICLASS_ISO14443A_WRITE                                        0x0397
 #define CMD_ICLASS_EML_MEMSET                                             0x0398
+#define CMD_ICLASS_AUTHENTICATION                                         0x0399
+#define CMD_ICLASS_READBLOCK                                              0x039A
+#define CMD_ICLASS_CLONE                                                  0x039B
 
 // For measurements of the antenna tuning
 #define CMD_MEASURE_ANTENNA_TUNING                                        0x0400