X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/fecd8202a5ad638db4c1ba088842390e78ef52db..19a700a8b54f948623cb35f6f297dc03601f9950:/armsrc/iclass.c?ds=sidebyside

diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index 9971b670..41c9b8b5 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -50,17 +50,6 @@
 
 static int timeout = 4096;
 
-// CARD TO READER
-// Sequence D: 11110000 modulation with subcarrier during first half
-// Sequence E: 00001111 modulation with subcarrier during second half
-// Sequence F: 00000000 no modulation with subcarrier
-// READER TO CARD
-// Sequence X: 00001100 drop after half a period
-// Sequence Y: 00000000 no drop
-// Sequence Z: 11000000 drop at start
-#define	SEC_X 0x0c
-#define	SEC_Y 0x00
-#define	SEC_Z 0xc0
 
 static int SendIClassAnswer(uint8_t *resp, int respLen, int delay);
 
@@ -82,14 +71,13 @@ static struct {
     int     nOutOfCnt;
     int     OutOfCnt;
     int     syncBit;
-    int     parityBits;
     int     samples;
     int     highCnt;
     int     swapper;
     int     counter;
     int     bitBuffer;
     int     dropPosition;
-    uint8_t   *output;
+    uint8_t *output;
 } Uart;
 
 static RAMFUNC int OutOfNDecoding(int bit)
@@ -148,11 +136,8 @@ static RAMFUNC int OutOfNDecoding(int bit)
 					if(Uart.byteCnt == 0) {
 						// Its not straightforward to show single EOFs
 						// So just leave it and do not return TRUE
-						Uart.output[Uart.byteCnt] = 0xf0;
+						Uart.output[0] = 0xf0;
 						Uart.byteCnt++;
-
-						// Calculate the parity bit for the client...
-						Uart.parityBits = 1;
 					}
 					else {
 						return TRUE;
@@ -234,11 +219,6 @@ static RAMFUNC int OutOfNDecoding(int bit)
 						if(Uart.bitCnt == 8) {
 							Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
 							Uart.byteCnt++;
-
-							// Calculate the parity bit for the client...
-							Uart.parityBits <<= 1;
-							Uart.parityBits ^= OddByteParity[(Uart.shiftReg & 0xff)];
-
 							Uart.bitCnt = 0;
 							Uart.shiftReg = 0;
 						}
@@ -257,11 +237,6 @@ static RAMFUNC int OutOfNDecoding(int bit)
 					Uart.dropPosition--;
 					Uart.output[Uart.byteCnt] = (Uart.dropPosition & 0xff);
 					Uart.byteCnt++;
-
-					// Calculate the parity bit for the client...
-					Uart.parityBits <<= 1;
-					Uart.parityBits ^= OddByteParity[(Uart.dropPosition & 0xff)];
-
 					Uart.bitCnt = 0;
 					Uart.shiftReg = 0;
 					Uart.nOutOfCnt = 0;
@@ -322,7 +297,6 @@ static RAMFUNC int OutOfNDecoding(int bit)
 				Uart.state = STATE_START_OF_COMMUNICATION;
 				Uart.bitCnt = 0;
 				Uart.byteCnt = 0;
-				Uart.parityBits = 0;
 				Uart.nOutOfCnt = 0;
 				Uart.OutOfCnt = 4; // Start at 1/4, could switch to 1/256
 				Uart.dropPosition = 0;
@@ -364,7 +338,6 @@ static struct {
     int     bitCount;
     int     posCount;
 	int     syncBit;
-	int     parityBits;
     uint16_t    shiftReg;
 	int     buffer;
 	int     buffer2;
@@ -378,7 +351,7 @@ static struct {
 		SUB_SECOND_HALF,
 		SUB_BOTH
 	}		sub;
-    uint8_t   *output;
+    uint8_t *output;
 } Demod;
 
 static RAMFUNC int ManchesterDecoding(int v)
@@ -431,7 +404,6 @@ static RAMFUNC int ManchesterDecoding(int v)
 			Demod.sub = SUB_FIRST_HALF;
 			Demod.bitCount = 0;
 			Demod.shiftReg = 0;
-			Demod.parityBits = 0;
 			Demod.samples = 0;
 			if(Demod.posCount) {
 				//if(trigger) LED_A_OFF();  // Not useful in this case...
@@ -461,7 +433,6 @@ static RAMFUNC int ManchesterDecoding(int v)
 	else {
 		modulation = bit & Demod.syncBit;
 		modulation |= ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
-		//modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
 
 		Demod.samples += 4;
 
@@ -496,8 +467,6 @@ static RAMFUNC int ManchesterDecoding(int v)
 				if(Demod.state == DEMOD_SOF_COMPLETE) {
 					Demod.output[Demod.len] = 0x0f;
 					Demod.len++;
-					Demod.parityBits <<= 1;
-					Demod.parityBits ^= OddByteParity[0x0f];
 					Demod.state = DEMOD_UNSYNCD;
 //					error = 0x0f;
 					return TRUE;
@@ -578,11 +547,9 @@ static RAMFUNC int ManchesterDecoding(int v)
 					// Tag response does not need to be a complete byte!
 					if(Demod.len > 0 || Demod.bitCount > 0) {
 						if(Demod.bitCount > 1) {  // was > 0, do not interpret last closing bit, is part of EOF
-							Demod.shiftReg >>= (9 - Demod.bitCount);
+							Demod.shiftReg >>= (9 - Demod.bitCount);	// right align data
 							Demod.output[Demod.len] = Demod.shiftReg & 0xff;
 							Demod.len++;
-							// No parity bit, so just shift a 0
-							Demod.parityBits <<= 1;
 						}
 
 						Demod.state = DEMOD_UNSYNCD;
@@ -619,11 +586,6 @@ static RAMFUNC int ManchesterDecoding(int v)
 				Demod.shiftReg >>= 1;
 				Demod.output[Demod.len] = (Demod.shiftReg & 0xff);
 				Demod.len++;
-
-				// FOR ISO15639 PARITY NOT SEND OTA, JUST CALCULATE IT FOR THE CLIENT
-				Demod.parityBits <<= 1;
-				Demod.parityBits ^= OddByteParity[(Demod.shiftReg & 0xff)];
-
 				Demod.bitCount = 0;
 				Demod.shiftReg = 0;
 			}
@@ -668,12 +630,7 @@ static RAMFUNC int ManchesterDecoding(int v)
 //-----------------------------------------------------------------------------
 void RAMFUNC SnoopIClass(void)
 {
-// DEFINED ABOVE
-// #define RECV_CMD_OFFSET   3032
-// #define RECV_RES_OFFSET   3096
-// #define DMA_BUFFER_OFFSET 3160
-// #define DMA_BUFFER_SIZE   4096
-// #define TRACE_SIZE        3000
+
 
     // We won't start recording the frames that we acquire until we trigger;
     // a good trigger condition to get started is probably when we see a
@@ -683,23 +640,24 @@ void RAMFUNC SnoopIClass(void)
     // The command (reader -> tag) that we're receiving.
 	// The length of a received command will in most cases be no more than 18 bytes.
 	// So 32 should be enough!
-    uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	#define ICLASS_BUFFER_SIZE 32
+	uint8_t readerToTagCmd[ICLASS_BUFFER_SIZE];
     // The response (tag -> reader) that we're receiving.
-    uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
-
-    // As we receive stuff, we copy it from receivedCmd or receivedResponse
-    // into trace, along with its length and other annotations.
-    //uint8_t *trace = (uint8_t *)BigBuf;
-    
-    // reset traceLen to 0
-    iso14a_set_tracing(TRUE);
-    iso14a_clear_trace();
+	uint8_t tagToReaderResponse[ICLASS_BUFFER_SIZE];
+	
+    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+ 
+ 	// free all BigBuf memory
+	BigBuf_free();
+    // The DMA buffer, used to stream samples from the FPGA
+    uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
+ 
+	set_tracing(TRUE);
+	clear_trace();
     iso14a_set_trigger(FALSE);
 
-    // The DMA buffer, used to stream samples from the FPGA
-    int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
-    int lastRxCounter;
-    int8_t *upTo;
+	int lastRxCounter;
+    uint8_t *upTo;
     int smpl;
     int maxBehindBy = 0;
 
@@ -708,10 +666,8 @@ void RAMFUNC SnoopIClass(void)
     int samples = 0;
     rsamples = 0;
 
-    memset(trace, 0x44, RECV_CMD_OFFSET);
-
     // Set up the demodulator for tag -> reader responses.
-    Demod.output = receivedResponse;
+	Demod.output = tagToReaderResponse;
     Demod.len = 0;
     Demod.state = DEMOD_UNSYNCD;
 
@@ -723,7 +679,7 @@ void RAMFUNC SnoopIClass(void)
 
     // And the reader -> tag commands
     memset(&Uart, 0, sizeof(Uart));
-    Uart.output = receivedCmd;
+	Uart.output = readerToTagCmd;
     Uart.byteCntMax = 32; // was 100 (greg)////////////////////////////////////////////////////////////////////////
     Uart.state = STATE_UNSYNCD;
 
@@ -733,6 +689,10 @@ void RAMFUNC SnoopIClass(void)
     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
     SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
+	uint32_t time_0 = GetCountSspClk();
+	uint32_t time_start = 0;
+	uint32_t time_stop  = 0;
+
     int div = 0;
     //int div2 = 0;
     int decbyte = 0;
@@ -746,7 +706,7 @@ void RAMFUNC SnoopIClass(void)
                                 (DMA_BUFFER_SIZE-1);
         if(behindBy > maxBehindBy) {
             maxBehindBy = behindBy;
-            if(behindBy > 400) {
+            if(behindBy > (9 * DMA_BUFFER_SIZE / 10)) {
                 Dbprintf("blew circular buffer! behindBy=0x%x", behindBy);
                 goto done;
             }
@@ -766,20 +726,13 @@ void RAMFUNC SnoopIClass(void)
 
         //samples += 4;
 	samples += 1;
-	//div2++;	
 
-	//if(div2 > 3) {
-		//div2 = 0;
-	//decbyte ^= ((smpl & 0x01) << (3 - div));
-	//decbyte ^= (((smpl & 0x01) | ((smpl & 0x02) >> 1)) << (3 - div)); // better already...
-	//decbyte ^= (((smpl & 0x01) | ((smpl & 0x02) >> 1) | ((smpl & 0x04) >> 2)) << (3 - div)); // even better...
 	if(smpl & 0xF) {
 		decbyte ^= (1 << (3 - div));
 	}
-	//decbyte ^= (MajorityNibble[(smpl & 0x0F)] << (3 - div));
 	
 	// FOR READER SIDE COMMUMICATION...
-	//decbyte ^=  ((smpl & 0x10) << (3 - div));
+
 	decbyter <<= 2;
 	decbyter ^= (smpl & 0x30);
 
@@ -789,28 +742,27 @@ void RAMFUNC SnoopIClass(void)
 		smpl = decbyter;	
 		if(OutOfNDecoding((smpl & 0xF0) >> 4)) {
 		    rsamples = samples - Uart.samples;
+			time_stop = (GetCountSspClk()-time_0) << 4;
 		    LED_C_ON();
-		    //if(triggered) {
-			trace[traceLen++] = ((rsamples >>  0) & 0xff);
-			trace[traceLen++] = ((rsamples >>  8) & 0xff);
-			trace[traceLen++] = ((rsamples >> 16) & 0xff);
-			trace[traceLen++] = ((rsamples >> 24) & 0xff);
-			trace[traceLen++] = ((Uart.parityBits >>  0) & 0xff);
-			trace[traceLen++] = ((Uart.parityBits >>  8) & 0xff);
-			trace[traceLen++] = ((Uart.parityBits >> 16) & 0xff);
-			trace[traceLen++] = ((Uart.parityBits >> 24) & 0xff);
-			trace[traceLen++] = Uart.byteCnt;
-			memcpy(trace+traceLen, receivedCmd, Uart.byteCnt);
-			traceLen += Uart.byteCnt;
-			if(traceLen > TRACE_SIZE) break;
-		    //}
-		    /* And ready to receive another command. */
+
+			//if(!LogTrace(Uart.output,Uart.byteCnt, rsamples, Uart.parityBits,TRUE)) break;
+			//if(!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
+			if(tracing)	{
+				uint8_t parity[MAX_PARITY_SIZE];
+				GetParity(Uart.output, Uart.byteCnt, parity);
+				LogTrace(Uart.output,Uart.byteCnt, time_start, time_stop, parity, TRUE);
+			}
+
+
+			/* And ready to receive another command. */
 		    Uart.state = STATE_UNSYNCD;
 		    /* And also reset the demod code, which might have been */
 		    /* false-triggered by the commands from the reader. */
 		    Demod.state = DEMOD_UNSYNCD;
 		    LED_B_OFF();
 		    Uart.byteCnt = 0;
+		}else{
+			time_start = (GetCountSspClk()-time_0) << 4;
 		}
 		decbyter = 0;
 	}
@@ -818,31 +770,24 @@ void RAMFUNC SnoopIClass(void)
 	if(div > 3) {
 		smpl = decbyte;
 		if(ManchesterDecoding(smpl & 0x0F)) {
-		    rsamples = samples - Demod.samples;
+			time_stop = (GetCountSspClk()-time_0) << 4;
+
+			rsamples = samples - Demod.samples;
 		    LED_B_ON();
 
-		    // timestamp, as a count of samples
-		    trace[traceLen++] = ((rsamples >>  0) & 0xff);
-		    trace[traceLen++] = ((rsamples >>  8) & 0xff);
-		    trace[traceLen++] = ((rsamples >> 16) & 0xff);
-		    trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff);
-		    trace[traceLen++] = ((Demod.parityBits >>  0) & 0xff);
-		    trace[traceLen++] = ((Demod.parityBits >>  8) & 0xff);
-		    trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff);
-		    trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff);
-		    // length
-		    trace[traceLen++] = Demod.len;
-		    memcpy(trace+traceLen, receivedResponse, Demod.len);
-		    traceLen += Demod.len;
-		    if(traceLen > TRACE_SIZE) break;
-
-		    //triggered = TRUE;
+			if(tracing)	{
+				uint8_t parity[MAX_PARITY_SIZE];
+				GetParity(Demod.output, Demod.len, parity);
+				LogTrace(Demod.output, Demod.len, time_start, time_stop, parity, FALSE);
+			}
 
 		    // And ready to receive another response.
 		    memset(&Demod, 0, sizeof(Demod));
-		    Demod.output = receivedResponse;
+			Demod.output = tagToReaderResponse;
 		    Demod.state = DEMOD_UNSYNCD;
 		    LED_C_OFF();
+		}else{
+			time_start = (GetCountSspClk()-time_0) << 4;
 		}
 		
 		div = 0;
@@ -859,12 +804,12 @@ void RAMFUNC SnoopIClass(void)
     DbpString("COMMAND FINISHED");
 
     Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+	Dbprintf("%x %x %x", Uart.byteCntMax, BigBuf_get_traceLen(), (int)Uart.output[0]);
 
 done:
     AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
     Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+	Dbprintf("%x %x %x", Uart.byteCntMax, BigBuf_get_traceLen(), (int)Uart.output[0]);
     LED_A_OFF();
     LED_B_OFF();
     LED_C_OFF();
@@ -906,10 +851,7 @@ static int GetIClassCommandFromReader(uint8_t *received, int *len, int maxLen)
         }
         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
             uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			/*if(OutOfNDecoding((b & 0xf0) >> 4)) {
-				*len = Uart.byteCnt;
-				return TRUE;
-			}*/
+
 			if(OutOfNDecoding(b & 0x0f)) {
 				*len = Uart.byteCnt;
 				return TRUE;
@@ -918,53 +860,93 @@ static int GetIClassCommandFromReader(uint8_t *received, int *len, int maxLen)
     }
 }
 
+static uint8_t encode4Bits(const uint8_t b)
+{
+	uint8_t c = b & 0xF;
+	// OTA, the least significant bits first
+	//         The columns are
+	//               1 - Bit value to send
+	//               2 - Reversed (big-endian)
+	//               3 - Encoded
+	//               4 - Hex values
+
+	switch(c){
+	//                          1       2         3         4
+	  case 15: return 0x55; // 1111 -> 1111 -> 01010101 -> 0x55
+	  case 14: return 0x95; // 1110 -> 0111 -> 10010101 -> 0x95
+	  case 13: return 0x65; // 1101 -> 1011 -> 01100101 -> 0x65
+	  case 12: return 0xa5; // 1100 -> 0011 -> 10100101 -> 0xa5
+	  case 11: return 0x59; // 1011 -> 1101 -> 01011001 -> 0x59
+	  case 10: return 0x99; // 1010 -> 0101 -> 10011001 -> 0x99
+	  case 9:  return 0x69; // 1001 -> 1001 -> 01101001 -> 0x69
+	  case 8:  return 0xa9; // 1000 -> 0001 -> 10101001 -> 0xa9
+	  case 7:  return 0x56; // 0111 -> 1110 -> 01010110 -> 0x56
+	  case 6:  return 0x96; // 0110 -> 0110 -> 10010110 -> 0x96
+	  case 5:  return 0x66; // 0101 -> 1010 -> 01100110 -> 0x66
+	  case 4:  return 0xa6; // 0100 -> 0010 -> 10100110 -> 0xa6
+	  case 3:  return 0x5a; // 0011 -> 1100 -> 01011010 -> 0x5a
+	  case 2:  return 0x9a; // 0010 -> 0100 -> 10011010 -> 0x9a
+	  case 1:  return 0x6a; // 0001 -> 1000 -> 01101010 -> 0x6a
+	  default: return 0xaa; // 0000 -> 0000 -> 10101010 -> 0xaa
+
+	}
+}
 
 //-----------------------------------------------------------------------------
 // Prepare tag messages
 //-----------------------------------------------------------------------------
 static void CodeIClassTagAnswer(const uint8_t *cmd, int len)
 {
+
+	/*
+	 * SOF comprises 3 parts;
+	 * * An unmodulated time of 56.64 us
+	 * * 24 pulses of 423.75 KHz (fc/32)
+	 * * A logic 1, which starts with an unmodulated time of 18.88us
+	 *   followed by 8 pulses of 423.75kHz (fc/32)
+	 *
+	 *
+	 * EOF comprises 3 parts:
+	 * - A logic 0 (which starts with 8 pulses of fc/32 followed by an unmodulated
+	 *   time of 18.88us.
+	 * - 24 pulses of fc/32
+	 * - An unmodulated time of 56.64 us
+	 *
+	 *
+	 * A logic 0 starts with 8 pulses of fc/32
+	 * followed by an unmodulated time of 256/fc (~18,88us).
+	 *
+	 * A logic 0 starts with unmodulated time of 256/fc (~18,88us) followed by
+	 * 8 pulses of fc/32 (also 18.88us)
+	 *
+	 * The mode FPGA_HF_SIMULATOR_MODULATE_424K_8BIT which we use to simulate tag,
+	 * works like this.
+	 * - A 1-bit input to the FPGA becomes 8 pulses on 423.5kHz (fc/32) (18.88us).
+	 * - A 0-bit inptu to the FPGA becomes an unmodulated time of 18.88us
+	 *
+	 * In this mode the SOF can be written as 00011101 = 0x1D
+	 * The EOF can be written as 10111000 = 0xb8
+	 * A logic 1 is 01
+	 * A logic 0 is 10
+	 *
+	 * */
+
 	int i;
 
 	ToSendReset();
 
 	// Send SOF
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
+	ToSend[++ToSendMax] = 0x1D;
 
 	for(i = 0; i < len; i++) {
-		int j;
 		uint8_t b = cmd[i];
-
-		// Data bits
-		for(j = 0; j < 8; j++) {
-			if(b & 1) {
-				ToSend[++ToSendMax] = 0x00;
-				ToSend[++ToSendMax] = 0xff;
-			} else {
-				ToSend[++ToSendMax] = 0xff;
-				ToSend[++ToSendMax] = 0x00;
-			}
-			b >>= 1;
-		}
+		ToSend[++ToSendMax] = encode4Bits(b & 0xF); //Least significant half
+		ToSend[++ToSendMax] = encode4Bits((b >>4) & 0xF);//Most significant half
 	}
 
 	// Send EOF
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-
+	ToSend[++ToSendMax] = 0xB8;
+	//lastProxToAirDuration  = 8*ToSendMax - 3*8 - 3*8;//Not counting zeroes in the beginning or end
 	// Convert from last byte pos to length
 	ToSendMax++;
 }
@@ -972,48 +954,98 @@ static void CodeIClassTagAnswer(const uint8_t *cmd, int len)
 // Only SOF 
 static void CodeIClassTagSOF()
 {
-	ToSendReset();
+	//So far a dummy implementation, not used
+	//int lastProxToAirDuration =0;
 
+	ToSendReset();
 	// Send SOF
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	
+	ToSend[++ToSendMax] = 0x1D;
+//	lastProxToAirDuration  = 8*ToSendMax - 3*8;//Not counting zeroes in the beginning
+
 	// Convert from last byte pos to length
 	ToSendMax++;
 }
 
-//-----------------------------------------------------------------------------
-// Simulate iClass Card
-// Only CSN (Card Serial Number)
-// 
-//-----------------------------------------------------------------------------
-void SimulateIClass(uint8_t arg0, uint8_t *datain)
+int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived, uint8_t *reader_mac_buf);
+/**
+ * @brief SimulateIClass simulates an iClass card.
+ * @param arg0 type of simulation
+ *			- 0 uses the first 8 bytes in usb data as CSN
+ *			- 2 "dismantling iclass"-attack. This mode iterates through all CSN's specified
+ *			in the usb data. This mode collects MAC from the reader, in order to do an offline
+ *			attack on the keys. For more info, see "dismantling iclass" and proxclone.com.
+ *			- Other : Uses the default CSN (031fec8af7ff12e0)
+ * @param arg1 - number of CSN's contained in datain (applicable for mode 2 only)
+ * @param arg2
+ * @param datain
+ */
+void SimulateIClass(uint32_t arg0, uint32_t arg1, uint32_t arg2, uint8_t *datain)
 {
-	uint8_t simType = arg0;
+	uint32_t simType = arg0;
+	uint32_t numberOfCSNS = arg1;
+	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 
-  // Enable and clear the trace
-	tracing = TRUE;
-	traceLen = 0;
-  memset(trace, 0x44, TRACE_SIZE);
+	// Enable and clear the trace
+	set_tracing(TRUE);
+	clear_trace();
+
+	uint8_t csn_crc[] = { 0x03, 0x1f, 0xec, 0x8a, 0xf7, 0xff, 0x12, 0xe0, 0x00, 0x00 };
+	if(simType == 0) {
+		// Use the CSN from commandline
+		memcpy(csn_crc, datain, 8);
+		doIClassSimulation(csn_crc,0,NULL);
+	}else if(simType == 1)
+	{
+		doIClassSimulation(csn_crc,0,NULL);
+	}
+	else if(simType == 2)
+	{
+
+		uint8_t mac_responses[USB_CMD_DATA_SIZE] = { 0 };
+		Dbprintf("Going into attack mode, %d CSNS sent", numberOfCSNS);
+		// In this mode, a number of csns are within datain. We'll simulate each one, one at a time
+		// in order to collect MAC's from the reader. This can later be used in an offlne-attack
+		// in order to obtain the keys, as in the "dismantling iclass"-paper.
+		int i = 0;
+		for( ; i < numberOfCSNS && i*8+8 < USB_CMD_DATA_SIZE; i++)
+		{
+			// The usb data is 512 bytes, fitting 65 8-byte CSNs in there.
+
+			memcpy(csn_crc, datain+(i*8), 8);
+			if(doIClassSimulation(csn_crc,1,mac_responses+i*8))
+			{
+				cmd_send(CMD_ACK,CMD_SIMULATE_TAG_ICLASS,i,0,mac_responses,i*8);
+				return; // Button pressed
+			}
+		}
+		cmd_send(CMD_ACK,CMD_SIMULATE_TAG_ICLASS,i,0,mac_responses,i*8);
+
+	}
+	else{
+		// We may want a mode here where we hardcode the csns to use (from proxclone).
+		// That will speed things up a little, but not required just yet.
+		Dbprintf("The mode is not implemented, reserved for future use");
+	}
+	Dbprintf("Done...");
+
+}
+/**
+ * @brief Does the actual simulation
+ * @param csn - csn to use
+ * @param breakAfterMacReceived if true, returns after reader MAC has been received.
+ */
+int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived, uint8_t *reader_mac_buf)
+{
 
 	// CSN followed by two CRC bytes
+	uint8_t response1[] = { 0x0F} ;
 	uint8_t response2[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-	uint8_t response3[] = { 0x03, 0x1f, 0xec, 0x8a, 0xf7, 0xff, 0x12, 0xe0, 0x00, 0x00 };
-
+	uint8_t response3[] = { 0,0,0,0,0,0,0,0,0,0};
+	memcpy(response3,csn,sizeof(response3));
+	Dbprintf("Simulating CSN %02x%02x%02x%02x%02x%02x%02x%02x",csn[0],csn[1],csn[2],csn[3],csn[4],csn[5],csn[6],csn[7]);
 	// e-Purse
 	uint8_t response4[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 
-	if(simType == 0) {
-		// Use the CSN from commandline
-		memcpy(response3, datain, 8);
-	}
-
 	// Construct anticollision-CSN
 	rotateCSN(response3,response2);
 
@@ -1021,6 +1053,7 @@ void SimulateIClass(uint8_t arg0, uint8_t *datain)
 	ComputeCrc14443(CRC_ICLASS, response2, 8, &response2[8], &response2[9]);
 	ComputeCrc14443(CRC_ICLASS, response3, 8, &response3[8], &response3[9]);
 
+	int exitLoop = 0;
 	// Reader 0a
 	// Tag    0f
 	// Reader 0c
@@ -1028,34 +1061,35 @@ void SimulateIClass(uint8_t arg0, uint8_t *datain)
 	// Reader 81 anticoll. CSN
 	// Tag    CSN
 
-	uint8_t *resp;
-	int respLen;
-	uint8_t* respdata = NULL;
-	int respsize = 0;
-	uint8_t sof = 0x0f;
+	uint8_t *modulated_response;
+	int modulated_response_size;
+	uint8_t* trace_data = NULL;
+	int trace_data_size = 0;
+	//uint8_t sof = 0x0f;
 
-	// Respond SOF -- takes 8 bytes
-	uint8_t *resp1 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+	// free eventually allocated BigBuf memory
+	BigBuf_free();
+	// Respond SOF -- takes 1 bytes
+	uint8_t *resp1 = BigBuf_malloc(2);
 	int resp1Len;
 
 	// Anticollision CSN (rotated CSN)
-	// 176: Takes 16 bytes for SOF/EOF and 10 * 16 = 160 bytes (2 bytes/bit)
-	uint8_t *resp2 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 10);
+	// 22: Takes 2 bytes for SOF/EOF and 10 * 2 = 20 bytes (2 bytes/byte)
+	uint8_t *resp2 = BigBuf_malloc(28);
 	int resp2Len;
 
 	// CSN
-	// 176: Takes 16 bytes for SOF/EOF and 10 * 16 = 160 bytes (2 bytes/bit)
-	uint8_t *resp3 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 190);
+	// 22: Takes 2 bytes for SOF/EOF and 10 * 2 = 20 bytes (2 bytes/byte)
+	uint8_t *resp3 = BigBuf_malloc(30);
 	int resp3Len;
 
 	// e-Purse
-	// 144: Takes 16 bytes for SOF/EOF and 8 * 16 = 128 bytes (2 bytes/bit)
-	uint8_t *resp4 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 370);
+	// 18: Takes 2 bytes for SOF/EOF and 8 * 2 = 16 bytes (2 bytes/bit)
+	uint8_t *resp4 = BigBuf_malloc(20);
 	int resp4Len;
 
-	// + 1720..
-  uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
-	memset(receivedCmd, 0x44, RECV_CMD_SIZE);
+	uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+	memset(receivedCmd, 0x44, MAX_FRAME_SIZE);
 	int len;
 
 	// Prepare card messages
@@ -1077,74 +1111,94 @@ void SimulateIClass(uint8_t arg0, uint8_t *datain)
 	CodeIClassTagAnswer(response4, sizeof(response4));
 	memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
 
+
+	// Start from off (no field generated)
+	//FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	//SpinDelay(200);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+	SpinDelay(100);
+	StartCountSspClk();
 	// We need to listen to the high-frequency, peak-detected path.
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 	FpgaSetupSsc();
 
 	// To control where we are in the protocol
 	int cmdsRecvd = 0;
+	uint32_t time_0 = GetCountSspClk();
+	uint32_t t2r_time =0;
+	uint32_t r2t_time =0;
 
 	LED_A_ON();
-	for(;;) {
+	bool buttonPressed = false;
+
+	while(!exitLoop) {
+
 		LED_B_OFF();
+		//Signal tracer
+		// Can be used to get a trigger for an oscilloscope..
+		LED_C_OFF();
+
 		if(!GetIClassCommandFromReader(receivedCmd, &len, 100)) {
-			DbpString("button press");
+			buttonPressed = true;
 			break;
 		}
+		r2t_time = GetCountSspClk();
+		//Signal tracer
+		LED_C_ON();
 
 		// Okay, look at the command now.
-		if(receivedCmd[0] == 0x0a) {
+		if(receivedCmd[0] == 0x0a ) {
 			// Reader in anticollission phase
-			resp = resp1; respLen = resp1Len; //order = 1;
-			respdata = &sof;
-			respsize = sizeof(sof);
-			//resp = resp2; respLen = resp2Len; order = 2;
-			//DbpString("Hello request from reader:");
+			modulated_response = resp1; modulated_response_size = resp1Len; //order = 1;
+			trace_data = response1;
+			trace_data_size = sizeof(response1);
 		} else if(receivedCmd[0] == 0x0c) {
 			// Reader asks for anticollission CSN
-			resp = resp2; respLen = resp2Len; //order = 2;
-			respdata = response2;
-			respsize = sizeof(response2);
+			modulated_response = resp2; modulated_response_size = resp2Len; //order = 2;
+			trace_data = response2;
+			trace_data_size = sizeof(response2);
 			//DbpString("Reader requests anticollission CSN:");
 		} else if(receivedCmd[0] == 0x81) {
 			// Reader selects anticollission CSN.
 			// Tag sends the corresponding real CSN
-			resp = resp3; respLen = resp3Len; //order = 3;
-			respdata = response3;
-			respsize = sizeof(response3);
+			modulated_response = resp3; modulated_response_size = resp3Len; //order = 3;
+			trace_data = response3;
+			trace_data_size = sizeof(response3);
 			//DbpString("Reader selects anticollission CSN:");
 		} else if(receivedCmd[0] == 0x88) {
 			// Read e-purse (88 02)
-			resp = resp4; respLen = resp4Len; //order = 4;
-			respdata = response4;
-			respsize = sizeof(response4);
+			modulated_response = resp4; modulated_response_size = resp4Len; //order = 4;
+			trace_data = response4;
+			trace_data_size = sizeof(response4);
 			LED_B_ON();
 		} else if(receivedCmd[0] == 0x05) {
 			// Reader random and reader MAC!!!
-			// Lets store this ;-)
-/*
-			Dbprintf("                CSN: %02x %02x %02x %02x %02x %02x %02x %02x",
-			response3[0], response3[1], response3[2],
-			response3[3], response3[4], response3[5],
-			response3[6], response3[7]);
-*/			
-			Dbprintf("READER AUTH (len=%02d): %02x %02x %02x %02x %02x %02x %02x %02x %02x",
-			len,
-			receivedCmd[0], receivedCmd[1], receivedCmd[2],
-			receivedCmd[3], receivedCmd[4], receivedCmd[5],
-			receivedCmd[6], receivedCmd[7], receivedCmd[8]);
-
 			// Do not respond
-			// We do not know what to answer, so lets keep quit
-			resp = resp1; respLen = 0; //order = 5;
-			respdata = NULL;
-			respsize = 0;
+            // We do not know what to answer, so lets keep quiet
+			modulated_response = resp1; modulated_response_size = 0; //order = 5;
+			trace_data = NULL;
+			trace_data_size = 0;
+			if (breakAfterMacReceived){
+				// dbprintf:ing ...
+				Dbprintf("CSN: %02x %02x %02x %02x %02x %02x %02x %02x"
+						   ,csn[0],csn[1],csn[2],csn[3],csn[4],csn[5],csn[6],csn[7]);
+				Dbprintf("RDR:  (len=%02d): %02x %02x %02x %02x %02x %02x %02x %02x %02x",len,
+						receivedCmd[0], receivedCmd[1], receivedCmd[2],
+						receivedCmd[3], receivedCmd[4], receivedCmd[5],
+						receivedCmd[6], receivedCmd[7], receivedCmd[8]);
+				if (reader_mac_buf != NULL)
+				{
+					memcpy(reader_mac_buf,receivedCmd+1,8);
+				}
+				exitLoop = true;
+			}
 		} else if(receivedCmd[0] == 0x00 && len == 1) {
 			// Reader ends the session
-			resp = resp1; respLen = 0; //order = 0;
-			respdata = NULL;
-			respsize = 0;
+			modulated_response = resp1; modulated_response_size = 0; //order = 0;
+			trace_data = NULL;
+			trace_data_size = 0;
 		} else {
+			//#db# Unknown command received from reader (len=5): 26 1 0 f6 a 44 44 44 44
 			// Never seen this command before
 			Dbprintf("Unknown command received from reader (len=%d): %x %x %x %x %x %x %x %x %x",
 			len,
@@ -1152,79 +1206,88 @@ void SimulateIClass(uint8_t arg0, uint8_t *datain)
 			receivedCmd[3], receivedCmd[4], receivedCmd[5],
 			receivedCmd[6], receivedCmd[7], receivedCmd[8]);
 			// Do not respond
-			resp = resp1; respLen = 0; //order = 0;
-			respdata = NULL;
-			respsize = 0;
+			modulated_response = resp1; modulated_response_size = 0; //order = 0;
+			trace_data = NULL;
+			trace_data_size = 0;
 		}
 
-		if(cmdsRecvd > 999) {
-			DbpString("1000 commands later...");
-			break;
+		if(cmdsRecvd >  100) {
+			//DbpString("100 commands later...");
+			//break;
 		}
 		else {
 			cmdsRecvd++;
 		}
-
-		if(respLen > 0) {
-			SendIClassAnswer(resp, respLen, 21);
+		/**
+		A legit tag has about 380us delay between reader EOT and tag SOF.
+		**/
+		if(modulated_response_size > 0) {
+			SendIClassAnswer(modulated_response, modulated_response_size, 1);
+			t2r_time = GetCountSspClk();
 		}
-		
+
 		if (tracing) {
-			LogTrace(receivedCmd,len, rsamples, Uart.parityBits, TRUE);
-			if (respdata != NULL) {
-				LogTrace(respdata,respsize, rsamples, SwapBits(GetParity(respdata,respsize),respsize), FALSE);
+			uint8_t parity[MAX_PARITY_SIZE];
+			GetParity(receivedCmd, len, parity);
+			LogTrace(receivedCmd,len, (r2t_time-time_0)<< 4, (r2t_time-time_0) << 4, parity, TRUE);
+
+			if (trace_data != NULL) {
+				GetParity(trace_data, trace_data_size, parity);
+				LogTrace(trace_data, trace_data_size, (t2r_time-time_0) << 4, (t2r_time-time_0) << 4, parity, FALSE);
 			}
-			if(traceLen > TRACE_SIZE) {
+			if(!tracing) {
 				DbpString("Trace full");
-				break;
+				//break;
 			}
-		}
 
-		memset(receivedCmd, 0x44, RECV_CMD_SIZE);
+		}
+		memset(receivedCmd, 0x44, MAX_FRAME_SIZE);
 	}
 
-	Dbprintf("%x", cmdsRecvd);
+	//Dbprintf("%x", cmdsRecvd);
 	LED_A_OFF();
 	LED_B_OFF();
+	LED_C_OFF();
+
+	if(buttonPressed)
+	{
+		DbpString("Button pressed");
+	}
+	return buttonPressed;
 }
 
 static int SendIClassAnswer(uint8_t *resp, int respLen, int delay)
 {
-	int i = 0, u = 0, d = 0;
+	int i = 0, d=0;//, u = 0, d = 0;
 	uint8_t b = 0;
-	// return 0;
-	// Modulate Manchester
-	// FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD424);
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
+
+	//FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR|FPGA_HF_SIMULATOR_MODULATE_424K);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR|FPGA_HF_SIMULATOR_MODULATE_424K_8BIT);
+
 	AT91C_BASE_SSC->SSC_THR = 0x00;
 	FpgaSetupSsc();
-	
-	// send cycle
-	for(;;) {
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			(void)b;
+	while(!BUTTON_PRESS()) {
+		if((AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)){
+			b = AT91C_BASE_SSC->SSC_RHR; (void) b;
 		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)){
+			b = 0x00;
 			if(d < delay) {
-				b = 0x00;
 				d++;
 			}
-			else if(i >= respLen) {
-				b = 0x00;
-				u++;
-			} else {
-				b = resp[i];
-				u++;
-				if(u > 1) { i++; u = 0; }
+			else {
+				if( i < respLen){
+					b = resp[i];
+					//Hack
+					//b = 0xAC;
+				}
+				i++;
 			}
 			AT91C_BASE_SSC->SSC_THR = b;
-
-			if(u > 4) break;
-		}
-		if(BUTTON_PRESS()) {
-			break;
 		}
+
+//		if (i > respLen +4) break;
+		if (i > respLen +1) break;
 	}
 
 	return 0;
@@ -1238,26 +1301,28 @@ static int SendIClassAnswer(uint8_t *resp, int respLen, int delay)
 static void TransmitIClassCommand(const uint8_t *cmd, int len, int *samples, int *wait)
 {
   int c;
-
   FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
   AT91C_BASE_SSC->SSC_THR = 0x00;
   FpgaSetupSsc();
 
    if (wait)
-    if(*wait < 10)
-      *wait = 10;
+   {
+     if(*wait < 10) *wait = 10;
+     
+     for(c = 0; c < *wait;) {
+       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+         AT91C_BASE_SSC->SSC_THR = 0x00;		// For exact timing!
+         c++;
+       }
+       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+         volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
+         (void)r;
+       }
+       WDT_HIT();
+     }
+
+   }
 
-  for(c = 0; c < *wait;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-      AT91C_BASE_SSC->SSC_THR = 0x00;		// For exact timing!
-      c++;
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
 
   uint8_t sendbyte;
   bool firstpart = TRUE;
@@ -1314,12 +1379,12 @@ void CodeIClassCommand(const uint8_t * cmd, int len)
     b = cmd[i];
     for(j = 0; j < 4; j++) {
       for(k = 0; k < 4; k++) {
-	if(k == (b & 3)) {
-	    ToSend[++ToSendMax] = 0x0f;
-	}
-	else {
-	    ToSend[++ToSendMax] = 0x00;
-	}
+			if(k == (b & 3)) {
+				ToSend[++ToSendMax] = 0x0f;
+			}
+			else {
+				ToSend[++ToSendMax] = 0x00;
+			}
       }
       b >>= 2;
     }
@@ -1337,21 +1402,23 @@ void CodeIClassCommand(const uint8_t * cmd, int len)
 
 void ReaderTransmitIClass(uint8_t* frame, int len)
 {
-  int wait = 0;
-  int samples = 0;
-  int par = 0;
-
-  // This is tied to other size changes
-  // 	uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
-  CodeIClassCommand(frame,len);
-
-  // Select the card
-  TransmitIClassCommand(ToSend, ToSendMax, &samples, &wait);
-  if(trigger)
-  	LED_A_ON();
-
-  // Store reader command in buffer
-  if (tracing) LogTrace(frame,len,rsamples,par,TRUE);
+	int wait = 0;
+	int samples = 0;
+
+	// This is tied to other size changes
+	CodeIClassCommand(frame,len);
+
+	// Select the card
+	TransmitIClassCommand(ToSend, ToSendMax, &samples, &wait);
+	if(trigger)
+		LED_A_ON();
+
+	// Store reader command in buffer
+	if (tracing) {
+		uint8_t par[MAX_PARITY_SIZE];
+		GetParity(frame, len, par);
+		LogTrace(frame, len, rsamples, rsamples, par, TRUE);
+	}
 }
 
 //-----------------------------------------------------------------------------
@@ -1393,10 +1460,7 @@ static int GetIClassAnswer(uint8_t *receivedResponse, int maxLen, int *samples,
 			b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 			skip = !skip;
 			if(skip) continue;
-			/*if(ManchesterDecoding((b>>4) & 0xf)) {
-				*samples = ((c - 1) << 3) + 4;
-				return TRUE;
-			}*/
+		
 			if(ManchesterDecoding(b & 0x0f)) {
 				*samples = c << 3;
 				return  TRUE;
@@ -1410,85 +1474,176 @@ int ReaderReceiveIClass(uint8_t* receivedAnswer)
   int samples = 0;
   if (!GetIClassAnswer(receivedAnswer,160,&samples,0)) return FALSE;
   rsamples += samples;
-  if (tracing) LogTrace(receivedAnswer,Demod.len,rsamples,Demod.parityBits,FALSE);
+  if (tracing) {
+	uint8_t parity[MAX_PARITY_SIZE];
+	GetParity(receivedAnswer, Demod.len, parity);
+	LogTrace(receivedAnswer,Demod.len,rsamples,rsamples,parity,FALSE);
+  }
   if(samples == 0) return FALSE;
   return Demod.len;
 }
 
-// Reader iClass Anticollission
-void ReaderIClass(uint8_t arg0) {
-	uint8_t act_all[]     = { 0x0a };
-	uint8_t identify[]    = { 0x0c };
-	uint8_t select[]      = { 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+void setupIclassReader()
+{
+    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+    // Reset trace buffer
+	set_tracing(TRUE);
+	clear_trace();
 
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
+    // 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);
 
-	// Reset trace buffer
-    	memset(trace, 0x44, RECV_CMD_OFFSET);
-	traceLen = 0;
+    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-	// 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);
+    // 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();
 
-	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);
+size_t sendCmdGetResponseWithRetries(uint8_t* command, size_t cmdsize, uint8_t* resp, uint8_t expected_size, uint8_t retries)
+{
+	while(retries-- > 0)
+	{
+		ReaderTransmitIClass(command, cmdsize);
+		if(expected_size == ReaderReceiveIClass(resp)){
+			return 0;
+		}
+	}
+	return 1;//Error
+}
 
-	LED_A_ON();
+/**
+ * @brief Talks to an iclass tag, sends the commands to get CSN and CC.
+ * @param card_data where the CSN and CC are stored for return
+ * @return 0 = fail
+ *         1 = Got CSN
+ *         2 = Got CSN and CC
+ */
+uint8_t handshakeIclassTag(uint8_t *card_data)
+{
+	static uint8_t act_all[]     = { 0x0a };
+	static uint8_t identify[]    = { 0x0c };
+	static uint8_t select[]      = { 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+	static uint8_t readcheck_cc[]= { 0x88, 0x02 };
+	uint8_t resp[ICLASS_BUFFER_SIZE];
+
+	uint8_t read_status = 0;
+
+	// Send act_all
+	ReaderTransmitIClass(act_all, 1);
+	// Card present?
+	if(!ReaderReceiveIClass(resp)) return read_status;//Fail
+	//Send Identify
+	ReaderTransmitIClass(identify, 1);
+	//We expect a 10-byte response here, 8 byte anticollision-CSN and 2 byte CRC
+	uint8_t len  = ReaderReceiveIClass(resp);
+	if(len != 10) return read_status;//Fail
+
+	//Copy the Anti-collision CSN to our select-packet
+	memcpy(&select[1],resp,8);
+	//Select the card
+	ReaderTransmitIClass(select, sizeof(select));
+	//We expect a 10-byte response here, 8 byte CSN and 2 byte CRC
+	len  = ReaderReceiveIClass(resp);
+	if(len != 10) return read_status;//Fail
+
+	//Success - level 1, we got CSN
+	//Save CSN in response data
+	memcpy(card_data,resp,8);
+
+	//Flag that we got to at least stage 1, read CSN
+	read_status = 1;
+
+	// Card selected, now read e-purse (cc)
+	ReaderTransmitIClass(readcheck_cc, sizeof(readcheck_cc));
+	if(ReaderReceiveIClass(resp) == 8) {
+		//Save CC (e-purse) in response data
+		memcpy(card_data+8,resp,8);
+
+		//Got both
+		read_status = 2;
+	}
 
-	for(;;) {
+	return read_status;
+}
+
+// Reader iClass Anticollission
+void ReaderIClass(uint8_t arg0) {
+
+    uint8_t card_data[24]={0};
+    uint8_t last_csn[8]={0};
 	
-		if(traceLen > TRACE_SIZE) {
+    int read_status= 0;
+    bool abort_after_read = arg0 & FLAG_ICLASS_READER_ONLY_ONCE;
+	bool get_cc = arg0 & FLAG_ICLASS_READER_GET_CC;
+	set_tracing(TRUE);
+    setupIclassReader();
+
+    size_t datasize = 0;
+    while(!BUTTON_PRESS())
+    {
+
+		if(!tracing) {
 			DbpString("Trace full");
 			break;
 		}
-		
-		if (BUTTON_PRESS()) break;
+		WDT_HIT();
 
-		// 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));
+		read_status = handshakeIclassTag(card_data);
 
-				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]);
+		if(read_status == 0) continue;
+		if(read_status == 1) datasize = 8;
+		if(read_status == 2) datasize = 16;
+
+		LED_B_ON();
+		//Send back to client, but don't bother if we already sent this
+		if(memcmp(last_csn, card_data, 8) != 0)
+		{
+
+			if(!get_cc || (get_cc && read_status == 2))
+			{
+				cmd_send(CMD_ACK,read_status,0,0,card_data,datasize);
+				if(abort_after_read) {
+					LED_A_OFF();
+					return;
 				}
-				// Card selected, whats next... ;-)
+				//Save that we already sent this....
+				memcpy(last_csn, card_data, 8);
 			}
+			//If 'get_cc' was specified and we didn't get a CC, we'll just keep trying...
 		}
-		WDT_HIT();
-	}
-	
-	LED_A_OFF();
+		LED_B_OFF();
+    }
+    cmd_send(CMD_ACK,0,0,0,card_data, 0);
+    LED_A_OFF();
 }
 
 void ReaderIClass_Replay(uint8_t arg0, 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 card_data[USB_CMD_DATA_SIZE]={0};
+	uint16_t block_crc_LUT[255] = {0};
+
+	{//Generate a lookup table for block crc
+		for(int block = 0; block < 255; block++){
+			char bl = block;
+			block_crc_LUT[block] = iclass_crc16(&bl ,1);
+		}
+	}
+	//Dbprintf("Lookup table: %02x %02x %02x" ,block_crc_LUT[0],block_crc_LUT[1],block_crc_LUT[2]);
+
 	uint8_t check[]       = { 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 	uint8_t read[]        = { 0x0c, 0x00, 0x00, 0x00 };
 	
     uint16_t crc = 0;
 	uint8_t cardsize=0;
-	bool read_success=false;
 	uint8_t mem=0;
 	
 	static struct memory_t{
@@ -1499,223 +1654,114 @@ void ReaderIClass_Replay(uint8_t arg0, uint8_t *MAC) {
 	  int keyaccess;
 	} memory;
 	
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
-
-	// 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();
+	uint8_t resp[ICLASS_BUFFER_SIZE];
+	
+    setupIclassReader();
+	set_tracing(TRUE);
 
-	for(int i=0;i<1;i++) {
+	while(!BUTTON_PRESS()) {
 	
-		if(traceLen > TRACE_SIZE) {
+		WDT_HIT();
+
+		if(!tracing) {
 			DbpString("Trace full");
 			break;
 		}
 		
-		if (BUTTON_PRESS()) break;
+		uint8_t read_status = handshakeIclassTag(card_data);
+		if(read_status < 2) continue;
 
-		// 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("Dump Contents");
-				//first get configuration block
-				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);
+		//for now replay captured auth (as cc not updated)
+		memcpy(check+5,MAC,4);
 
-				      }
-				}
-				if (memory.k16){
-				  cardsize=255;
-				}else cardsize=32;
-				//then loop around remaining blocks
-				for(uint8_t j=0; j<cardsize; j++){
-				    read_success=false;
-				    uint8_t *blockno=&j;
-				    //crc_data[0]=j;
-				    read[1]=j;
-				    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;
-				         Dbprintf("     %02x: %02x %02x %02x %02x %02x %02x %02x %02x",
-					  j, resp[0], resp[1], resp[2],
-					  resp[3], resp[4], resp[5],
-					  resp[6], resp[7]);
-				      }
-				    }
-				}
-			}
+		if(sendCmdGetResponseWithRetries(check, sizeof(check),resp, 4, 5))
+		{
+			Dbprintf("Error: Authentication Fail!");
+			continue;
 		}
-		WDT_HIT();
-	}
-	
-	LED_A_OFF();
-}
-
-//1. Create Method to Read sectors/blocks 0,1,2 and Send to client
-void IClass_iso14443A_GetPublic(uint8_t arg0) {
-	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 read[]        = { 0x0c, 0x00, 0x00, 0x00 };	
-	uint8_t card_data[24]={0};
-	
-	//bool read_success=false;
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
-
-	// 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();
+		//first get configuration block (block 1)
+		crc = block_crc_LUT[1];
+		read[1]=1;
+		read[2] = crc >> 8;
+		read[3] = crc & 0xff;
 
-	for(int i=0;i<1;i++) {
-	
-		if(traceLen > TRACE_SIZE) {
-			DbpString("Trace full");
-			break;
+		if(sendCmdGetResponseWithRetries(read, sizeof(read),resp, 10, 10))
+		{
+			Dbprintf("Dump config (block 1) failed");
+			continue;
 		}
-		
-		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));
+		mem=resp[5];
+		memory.k16= (mem & 0x80);
+		memory.book= (mem & 0x20);
+		memory.k2= (mem & 0x8);
+		memory.lockauth= (mem & 0x2);
+		memory.keyaccess= (mem & 0x1);
 
-				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]);
-				}
-				memcpy(card_data,resp,8);
-				// 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]);
+		cardsize = memory.k16 ? 255 : 32;
+		WDT_HIT();
+		//Set card_data to all zeroes, we'll fill it with data
+		memset(card_data,0x0,USB_CMD_DATA_SIZE);
+		uint8_t failedRead =0;
+		uint8_t stored_data_length =0;
+		//then loop around remaining blocks
+		for(int block=0; block < cardsize; block++){
+
+			read[1]= block;
+			crc = block_crc_LUT[block];
+			read[2] = crc >> 8;
+			read[3] = crc & 0xff;
+
+			if(!sendCmdGetResponseWithRetries(read, sizeof(read), resp, 10, 10))
+			{
+				Dbprintf("     %02x: %02x %02x %02x %02x %02x %02x %02x %02x",
+						 block, resp[0], resp[1], resp[2],
+						resp[3], resp[4], resp[5],
+						resp[6], resp[7]);
+
+				//Fill up the buffer
+				memcpy(card_data+stored_data_length,resp,8);
+				stored_data_length += 8;
+
+				if(stored_data_length +8 > USB_CMD_DATA_SIZE)
+				{//Time to send this off and start afresh
+					cmd_send(CMD_ACK,
+							 stored_data_length,//data length
+							 failedRead,//Failed blocks?
+							 0,//Not used ATM
+							 card_data, stored_data_length);
+					//reset
+					stored_data_length = 0;
+					failedRead = 0;
 				}
-				memcpy(card_data+8,resp,8);
-				//prep to read config block
-				/*  read card configuration block
-				  while(!read_success){
-				  uint8_t sector_config=0x01;
-				  memcpy(read+1,&sector_config,1);
-				  ReaderTransmitIClass(read, sizeof(read));
-				  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]);
-					read_success=true;
-                    memcpy(card_data+16,resp,8);
-				  }
-				}*/
+
+			}else{
+				failedRead = 1;
+				stored_data_length +=8;//Otherwise, data becomes misaligned
+				Dbprintf("Failed to dump block %d", block);
 			}
 		}
-		WDT_HIT();
+		//Send off any remaining data
+		if(stored_data_length > 0)
+		{
+			cmd_send(CMD_ACK,
+					 stored_data_length,//data length
+					 failedRead,//Failed blocks?
+					 0,//Not used ATM
+					 card_data, stored_data_length);
+		}
+		//If we got here, let's break
+		break;
 	}
-	//Dbprintf("DEBUG: %02x%02x%02x%02x%02x%02x%02x%02x",card_data[0],card_data[1],card_data[2],card_data[3],card_data[4],card_data[5],card_data[6],card_data[7]);
-	//Dbprintf("DEBUG: %02x%02x%02x%02x%02x%02x%02x%02x",card_data[8],card_data[9],card_data[10],card_data[11],card_data[12],card_data[13],card_data[14],card_data[15]);
+	//Signal end of transmission
+	cmd_send(CMD_ACK,
+			 0,//data length
+			 0,//Failed blocks?
+			 0,//Not used ATM
+			 card_data, 0);
+
 	LED_A_OFF();
-	LED_B_ON();
-	//send data back to the client
-    cmd_send(CMD_ACK,0,0,0,card_data,16);
-	LED_B_OFF();
 }
 
 //2. Create Read method (cut-down from above) based off responses from 1. 
@@ -1733,7 +1779,7 @@ void IClass_iso14443A_write(uint8_t arg0, uint8_t blockNo, uint8_t *data, uint8_
 	
     uint16_t crc = 0;
 	
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
+	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);
 
 	// Reset trace buffer
     memset(trace, 0x44, RECV_CMD_OFFSET);