X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/f89c705002842291e39d000f27dbaea1ddd78917..42daa759c16328607aff6ab35ef97656ad2050da:/armsrc/iso14443a.c?ds=sidebyside

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 7b709ab0..bd7e758d 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1,5 +1,5 @@
 //-----------------------------------------------------------------------------
-// Merlok - June 2011
+// Merlok - June 2011, 2012
 // Gerhard de Koning Gans - May 2008
 // Hagen Fritsch - June 2010
 //
@@ -14,23 +14,27 @@
 #include "apps.h"
 #include "util.h"
 #include "string.h"
+#include "cmd.h"
 
 #include "iso14443crc.h"
 #include "iso14443a.h"
 #include "crapto1.h"
 #include "mifareutil.h"
 
-static uint8_t *trace = (uint8_t *) BigBuf;
-static int traceLen = 0;
-static int rsamples = 0;
-static int tracing = TRUE;
 static uint32_t iso14a_timeout;
+uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
+int traceLen = 0;
+int rsamples = 0;
+int tracing = TRUE;
+uint8_t trigger = 0;
+// the block number for the ISO14443-4 PCB
+static uint8_t iso14_pcb_blocknum = 0;
 
-// CARD TO READER
+// CARD TO READER - manchester
 // 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
+// READER TO CARD - miller
 // Sequence X: 00001100 drop after half a period
 // Sequence Y: 00000000 no drop
 // Sequence Z: 11000000 drop at start
@@ -41,7 +45,7 @@ static uint32_t iso14a_timeout;
 #define	SEC_Y 0x00
 #define	SEC_Z 0xc0
 
-static const uint8_t OddByteParity[256] = {
+const uint8_t OddByteParity[256] = {
   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
@@ -60,18 +64,24 @@ static const uint8_t OddByteParity[256] = {
   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
 };
 
-// BIG CHANGE - UNDERSTAND THIS BEFORE WE COMMIT
-#define RECV_CMD_OFFSET   3032
-#define RECV_RES_OFFSET   3096
-#define DMA_BUFFER_OFFSET 3160
-#define DMA_BUFFER_SIZE   4096
-#define TRACE_LENGTH      3000
 
-uint8_t trigger = 0;
-void iso14a_set_trigger(int enable) {
+void iso14a_set_trigger(bool enable) {
 	trigger = enable;
 }
 
+void iso14a_clear_trace() {
+  memset(trace, 0x44, TRACE_SIZE);
+	traceLen = 0;
+}
+
+void iso14a_set_tracing(bool enable) {
+	tracing = enable;
+}
+
+void iso14a_set_timeout(uint32_t timeout) {
+	iso14a_timeout = timeout;
+}
+
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //
@@ -99,10 +109,11 @@ void AppendCrc14443a(uint8_t* data, int len)
   ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 }
 
-int LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader)
+// The function LogTrace() is also used by the iClass implementation in iClass.c
+int RAMFUNC LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader)
 {
   // Return when trace is full
-  if (traceLen >= TRACE_LENGTH) return FALSE;
+  if (traceLen >= TRACE_SIZE) return FALSE;
 
   // Trace the random, i'm curious
   rsamples += iSamples;
@@ -127,36 +138,11 @@ int LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity,
 // The software UART that receives commands from the reader, and its state
 // variables.
 //-----------------------------------------------------------------------------
-static struct {
-    enum {
-        STATE_UNSYNCD,
-        STATE_START_OF_COMMUNICATION,
-		STATE_MILLER_X,
-		STATE_MILLER_Y,
-		STATE_MILLER_Z,
-        STATE_ERROR_WAIT
-    }       state;
-    uint16_t    shiftReg;
-    int     bitCnt;
-    int     byteCnt;
-    int     byteCntMax;
-    int     posCnt;
-    int     syncBit;
-	int     parityBits;
-	int     samples;
-    int     highCnt;
-    int     bitBuffer;
-	enum {
-		DROP_NONE,
-		DROP_FIRST_HALF,
-		DROP_SECOND_HALF
-	}		drop;
-    uint8_t   *output;
-} Uart;
+static tUart Uart;
 
 static RAMFUNC int MillerDecoding(int bit)
 {
-	int error = 0;
+	//int error = 0;
 	int bitright;
 
 	if(!Uart.bitBuffer) {
@@ -202,7 +188,7 @@ static RAMFUNC int MillerDecoding(int bit)
 				// measured a drop in first and second half
 				// which should not be possible
 				Uart.state = STATE_ERROR_WAIT;
-				error = 0x01;
+				//error = 0x01;
 			}
 
 			Uart.posCnt = 0;
@@ -213,7 +199,7 @@ static RAMFUNC int MillerDecoding(int bit)
 					if(Uart.drop == DROP_SECOND_HALF) {
 						// error, should not happen in SOC
 						Uart.state = STATE_ERROR_WAIT;
-						error = 0x02;
+						//error = 0x02;
 					}
 					else {
 						// correct SOC
@@ -251,7 +237,7 @@ static RAMFUNC int MillerDecoding(int bit)
 						// Would be STATE_MILLER_Z
 						// but Z does not follow X, so error
 						Uart.state = STATE_ERROR_WAIT;
-						error = 0x03;
+						//error = 0x03;
 					}
 					if(Uart.drop == DROP_SECOND_HALF) {
 						// We see a '1' and stay in state X
@@ -372,7 +358,7 @@ static RAMFUNC int MillerDecoding(int bit)
 				Uart.bitCnt = 0;
 				Uart.byteCnt = 0;
 				Uart.parityBits = 0;
-				error = 0;
+				//error = 0;
 			}
 			else {
 				Uart.highCnt = 0;
@@ -391,38 +377,13 @@ static RAMFUNC int MillerDecoding(int bit)
 //=============================================================================
 // ISO 14443 Type A - Manchester
 //=============================================================================
-
-static struct {
-    enum {
-        DEMOD_UNSYNCD,
-		DEMOD_START_OF_COMMUNICATION,
-		DEMOD_MANCHESTER_D,
-		DEMOD_MANCHESTER_E,
-		DEMOD_MANCHESTER_F,
-        DEMOD_ERROR_WAIT
-    }       state;
-    int     bitCount;
-    int     posCount;
-	int     syncBit;
-	int     parityBits;
-    uint16_t    shiftReg;
-	int     buffer;
-	int     buff;
-	int     samples;
-    int     len;
-	enum {
-		SUB_NONE,
-		SUB_FIRST_HALF,
-		SUB_SECOND_HALF
-	}		sub;
-    uint8_t   *output;
-} Demod;
+static tDemod Demod;
 
 static RAMFUNC int ManchesterDecoding(int v)
 {
 	int bit;
 	int modulation;
-	int error = 0;
+	//int error = 0;
 
 	if(!Demod.buff) {
 		Demod.buff = 1;
@@ -479,7 +440,7 @@ static RAMFUNC int ManchesterDecoding(int v)
 					case 0x01: Demod.samples = 0; break;
 				}
 			}
-			error = 0;
+			//error = 0;
 		}
 	}
 	else {
@@ -503,7 +464,7 @@ static RAMFUNC int ManchesterDecoding(int v)
 				if(Demod.state!=DEMOD_ERROR_WAIT) {
 					Demod.state = DEMOD_ERROR_WAIT;
 					Demod.output[Demod.len] = 0xaa;
-					error = 0x01;
+					//error = 0x01;
 				}
 			}
 			else if(modulation) {
@@ -518,7 +479,7 @@ static RAMFUNC int ManchesterDecoding(int v)
 					else {
 						Demod.output[Demod.len] = 0xab;
 						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x02;
+						//error = 0x02;
 					}
 					break;
 
@@ -556,7 +517,7 @@ static RAMFUNC int ManchesterDecoding(int v)
 					else {
 						Demod.output[Demod.len] = 0xad;
 						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x03;
+						//error = 0x03;
 					}
 					break;
 
@@ -616,180 +577,157 @@ static RAMFUNC int ManchesterDecoding(int v)
 // triggering so that we start recording at the point that the tag is moved
 // near the reader.
 //-----------------------------------------------------------------------------
-void RAMFUNC SnoopIso14443a(void)
-{
-//	#define RECV_CMD_OFFSET 	2032	// original (working as of 21/2/09) values
-//	#define RECV_RES_OFFSET		2096	// original (working as of 21/2/09) values
-//	#define DMA_BUFFER_OFFSET	2160	// original (working as of 21/2/09) values
-//	#define DMA_BUFFER_SIZE 	4096	// original (working as of 21/2/09) values
-//	#define TRACE_LENGTH	 	2000	// original (working as of 21/2/09) values
-
-    // 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
-    // response from the tag.
-    int triggered = FALSE; // FALSE to wait first for card
-
-    // The command (reader -> tag) that we're receiving.
+void RAMFUNC SnoopIso14443a(uint8_t param) {
+	// param:
+	// bit 0 - trigger from first card answer
+	// bit 1 - trigger from first reader 7-bit request
+	
+	LEDsoff();
+	// init trace buffer
+    iso14a_clear_trace();
+
+	// 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
+	// response from the tag.
+	// triggered == FALSE -- to wait first for card
+	int triggered = !(param & 0x03); 
+
+	// 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);
-    // The response (tag -> reader) that we're receiving.
-    uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
+	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	// 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;
-    
-    traceLen = 0; // uncommented to fix ISSUE 15 - gerhard - jan2011
-
-    // 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 smpl;
-    int maxBehindBy = 0;
-
-    // Count of samples received so far, so that we can include timing
-    // information in the trace buffer.
-    int samples = 0;
-    int rsamples = 0;
-
-    memset(trace, 0x44, RECV_CMD_OFFSET);
-
-    // Set up the demodulator for tag -> reader responses.
-    Demod.output = receivedResponse;
-    Demod.len = 0;
-    Demod.state = DEMOD_UNSYNCD;
-
-    // Setup for the DMA.
-    FpgaSetupSsc();
-    upTo = dmaBuf;
-    lastRxCounter = DMA_BUFFER_SIZE;
-    FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
-
-    // And the reader -> tag commands
-    memset(&Uart, 0, sizeof(Uart));
-    Uart.output = receivedCmd;
-    Uart.byteCntMax = 32; // was 100 (greg)////////////////////////////////////////////////////////////////////////
-    Uart.state = STATE_UNSYNCD;
+	// 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;
+	
+	// The DMA buffer, used to stream samples from the FPGA
+	int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
+	int8_t *data = dmaBuf;
+	int maxDataLen = 0;
+	int dataLen = 0;
 
-    // And put the FPGA in the appropriate mode
-    // Signal field is off with the appropriate LED
-    LED_D_OFF();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
-    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	// Set up the demodulator for tag -> reader responses.
+	Demod.output = receivedResponse;
+	Demod.len = 0;
+	Demod.state = DEMOD_UNSYNCD;
 
+	// Set up the demodulator for the reader -> tag commands
+	memset(&Uart, 0, sizeof(Uart));
+	Uart.output = receivedCmd;
+	Uart.byteCntMax = 32;                        // was 100 (greg)//////////////////
+	Uart.state = STATE_UNSYNCD;
 
-    // And now we loop, receiving samples.
-    for(;;) {
-        LED_A_ON();
-        WDT_HIT();
-        int behindBy = (lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR) &
-                                (DMA_BUFFER_SIZE-1);
-        if(behindBy > maxBehindBy) {
-            maxBehindBy = behindBy;
-            if(behindBy > 400) {
-                Dbprintf("blew circular buffer! behindBy=0x%x", behindBy);
-                goto done;
-            }
-        }
-        if(behindBy < 1) continue;
+	// Setup for the DMA.
+	FpgaSetupSsc();
+	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 
-	LED_A_OFF();
-        smpl = upTo[0];
-        upTo++;
-        lastRxCounter -= 1;
-        if(upTo - dmaBuf > DMA_BUFFER_SIZE) {
-            upTo -= DMA_BUFFER_SIZE;
-            lastRxCounter += DMA_BUFFER_SIZE;
-            AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo;
-            AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
-        }
+	// And put the FPGA in the appropriate mode
+	// Signal field is off with the appropriate LED
+	LED_D_OFF();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-        samples += 4;
-        if(MillerDecoding((smpl & 0xF0) >> 4)) {
-            rsamples = samples - Uart.samples;
-            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_LENGTH) break;
-            }
-            /* 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();
-        }
+	// Count of samples received so far, so that we can include timing
+	// information in the trace buffer.
+	rsamples = 0;
+	// And now we loop, receiving samples.
+	while(true) {
+		if(BUTTON_PRESS()) {
+			DbpString("cancelled by button");
+			goto done;
+		}
 
-        if(ManchesterDecoding(smpl & 0x0F)) {
-            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_LENGTH) break;
-
-            triggered = TRUE;
-
-            // And ready to receive another response.
-            memset(&Demod, 0, sizeof(Demod));
-            Demod.output = receivedResponse;
-            Demod.state = DEMOD_UNSYNCD;
-            LED_C_OFF();
-        }
+		LED_A_ON();
+		WDT_HIT();
 
-        if(BUTTON_PRESS()) {
-            DbpString("cancelled_a");
-            goto done;
-        }
-    }
+		int register readBufDataP = data - dmaBuf;
+		int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
+		if (readBufDataP <= dmaBufDataP){
+			dataLen = dmaBufDataP - readBufDataP;
+		} else {
+			dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
+		}
+		// test for length of buffer
+		if(dataLen > maxDataLen) {
+			maxDataLen = dataLen;
+			if(dataLen > 400) {
+				Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
+				goto done;
+			}
+		}
+		if(dataLen < 1) continue;
+
+		// primary buffer was stopped( <-- we lost data!
+		if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+			AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+		}
+		// secondary buffer sets as primary, secondary buffer was stopped
+		if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+		}
+
+		LED_A_OFF();
+		
+		rsamples += 4;
+		if(MillerDecoding((data[0] & 0xF0) >> 4)) {
+			LED_C_ON();
 
-    DbpString("COMMAND FINISHED");
+			// check - if there is a short 7bit request from reader
+			if ((!triggered) && (param & 0x02) && (Uart.byteCnt == 1) && (Uart.bitCnt = 9)) triggered = TRUE;
 
-    Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+			if(triggered) {
+				if (!LogTrace(receivedCmd, Uart.byteCnt, 0 - Uart.samples, Uart.parityBits, TRUE)) break;
+			}
+			/* 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();
+		}
+
+		if(ManchesterDecoding(data[0] & 0x0F)) {
+			LED_B_ON();
+
+			if (!LogTrace(receivedResponse, Demod.len, 0 - Demod.samples, Demod.parityBits, FALSE)) break;
+
+			if ((!triggered) && (param & 0x01)) triggered = TRUE;
+
+			// And ready to receive another response.
+			memset(&Demod, 0, sizeof(Demod));
+			Demod.output = receivedResponse;
+			Demod.state = DEMOD_UNSYNCD;
+			LED_C_OFF();
+		}
+
+		data++;
+		if(data > dmaBuf + DMA_BUFFER_SIZE) {
+			data = dmaBuf;
+		}
+	} // main cycle
+
+	DbpString("COMMAND FINISHED");
 
 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]);
-    LED_A_OFF();
-    LED_B_OFF();
-	LED_C_OFF();
-	LED_D_OFF();
+	AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
+	Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x", maxDataLen, Uart.state, Uart.byteCnt);
+	Dbprintf("Uart.byteCntMax=%x, traceLen=%x, Uart.output[0]=%08x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+	LEDsoff();
 }
 
 //-----------------------------------------------------------------------------
 // Prepare tag messages
 //-----------------------------------------------------------------------------
-static void CodeIso14443aAsTag(const uint8_t *cmd, int len)
+static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
 {
-    int i;
-	int oddparity;
+	int i;
 
-    ToSendReset();
+	ToSendReset();
 
 	// Correction bit, might be removed when not needed
 	ToSendStuffBit(0);
@@ -800,55 +738,47 @@ static void CodeIso14443aAsTag(const uint8_t *cmd, int len)
 	ToSendStuffBit(0);
 	ToSendStuffBit(0);
 	ToSendStuffBit(0);
-
+	
 	// Send startbit
 	ToSend[++ToSendMax] = SEC_D;
 
-    for(i = 0; i < len; i++) {
-        int j;
-        uint8_t b = cmd[i];
+	for(i = 0; i < len; i++) {
+		int j;
+		uint8_t b = cmd[i];
 
 		// Data bits
-        oddparity = 0x01;
 		for(j = 0; j < 8; j++) {
-            oddparity ^= (b & 1);
 			if(b & 1) {
 				ToSend[++ToSendMax] = SEC_D;
 			} else {
 				ToSend[++ToSendMax] = SEC_E;
-            }
-            b >>= 1;
-        }
+			}
+			b >>= 1;
+		}
 
-        // Parity bit
-        if(oddparity) {
-        	ToSend[++ToSendMax] = SEC_D;
+		// Get the parity bit
+		if ((dwParity >> i) & 0x01) {
+			ToSend[++ToSendMax] = SEC_D;
 		} else {
 			ToSend[++ToSendMax] = SEC_E;
 		}
-    }
-
-    // Send stopbit
-    ToSend[++ToSendMax] = SEC_F;
-
-	// Flush the buffer in FPGA!!
-	for(i = 0; i < 5; i++) {
-		ToSend[++ToSendMax] = SEC_F;
 	}
 
-    // Convert from last byte pos to length
-    ToSendMax++;
+	// Send stopbit
+	ToSend[++ToSendMax] = SEC_F;
+
+	// Convert from last byte pos to length
+	ToSendMax++;
+}
 
-    // Add a few more for slop
-    ToSend[ToSendMax++] = 0x00;
-	ToSend[ToSendMax++] = 0x00;
-    //ToSendMax += 2;
+static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
+	CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
 }
 
 //-----------------------------------------------------------------------------
 // This is to send a NACK kind of answer, its only 3 bits, I know it should be 4
 //-----------------------------------------------------------------------------
-static void CodeStrangeAnswer()
+static void CodeStrangeAnswerAsTag()
 {
 	int i;
 
@@ -886,11 +816,47 @@ static void CodeStrangeAnswer()
 
     // Convert from last byte pos to length
     ToSendMax++;
+}
+
+static void Code4bitAnswerAsTag(uint8_t cmd)
+{
+	int i;
+
+    ToSendReset();
+
+	// Correction bit, might be removed when not needed
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(1);  // 1
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+	ToSendStuffBit(0);
+
+	// Send startbit
+	ToSend[++ToSendMax] = SEC_D;
+
+	uint8_t b = cmd;
+	for(i = 0; i < 4; i++) {
+		if(b & 1) {
+			ToSend[++ToSendMax] = SEC_D;
+		} else {
+			ToSend[++ToSendMax] = SEC_E;
+		}
+		b >>= 1;
+	}
+
+	// Send stopbit
+	ToSend[++ToSendMax] = SEC_F;
+
+	// Flush the buffer in FPGA!!
+	for(i = 0; i < 5; i++) {
+		ToSend[++ToSendMax] = SEC_F;
+	}
 
-    // Add a few more for slop
-    ToSend[ToSendMax++] = 0x00;
-	ToSend[ToSendMax++] = 0x00;
-    //ToSendMax += 2;
+    // Convert from last byte pos to length
+    ToSendMax++;
 }
 
 //-----------------------------------------------------------------------------
@@ -933,49 +899,104 @@ static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen
     }
 }
 
+static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded);
+int EmSend4bitEx(uint8_t resp, int correctionNeeded);
+int EmSend4bit(uint8_t resp);
+int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
+int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
+int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded);
+int EmSendCmd(uint8_t *resp, int respLen);
+int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
+
 //-----------------------------------------------------------------------------
 // Main loop of simulated tag: receive commands from reader, decide what
 // response to send, and send it.
 //-----------------------------------------------------------------------------
-void SimulateIso14443aTag(int tagType, int TagUid)
+void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
 {
-	// This function contains the tag emulation
-
-	// Prepare protocol messages
-    // static const uint8_t cmd1[] = { 0x26 };
-//     static const uint8_t response1[] = { 0x02, 0x00 }; // Says: I am Mifare 4k - original line - greg
-//
-	static const uint8_t response1[] = { 0x44, 0x03 }; // Says: I am a DESFire Tag, ph33r me
-//	static const uint8_t response1[] = { 0x44, 0x00 }; // Says: I am a ULTRALITE Tag, 0wn me
-
-	// UID response
-    // static const uint8_t cmd2[] = { 0x93, 0x20 };
-    //static const uint8_t response2[] = { 0x9a, 0xe5, 0xe4, 0x43, 0xd8 }; // original value - greg
+  // Enable and clear the trace
+	tracing = TRUE;
+  iso14a_clear_trace();
 
-// my desfire
-    static const uint8_t response2[] = { 0x88, 0x04, 0x21, 0x3f, 0x4d }; // known uid - note cascade (0x88), 2nd byte (0x04) = NXP/Phillips
+	// This function contains the tag emulation
+	uint8_t sak;
 
+	// The first response contains the ATQA (note: bytes are transmitted in reverse order).
+	uint8_t response1[2];
+	
+	switch (tagType) {
+		case 1: { // MIFARE Classic
+			// Says: I am Mifare 1k - original line
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x08;
+		} break;
+		case 2: { // MIFARE Ultralight
+			// Says: I am a stupid memory tag, no crypto
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x00;
+		} break;
+		case 3: { // MIFARE DESFire
+			// Says: I am a DESFire tag, ph33r me
+			response1[0] = 0x04;
+			response1[1] = 0x03;
+			sak = 0x20;
+		} break;
+		case 4: { // ISO/IEC 14443-4
+			// Says: I am a javacard (JCOP)
+			response1[0] = 0x04;
+			response1[1] = 0x00;
+			sak = 0x28;
+		} break;
+		default: {
+			Dbprintf("Error: unkown tagtype (%d)",tagType);
+			return;
+		} break;
+	}
+	
+	// The second response contains the (mandatory) first 24 bits of the UID
+	uint8_t response2[5];
+
+	// Check if the uid uses the (optional) part
+	uint8_t response2a[5];
+	if (uid_2nd) {
+		response2[0] = 0x88;
+		num_to_bytes(uid_1st,3,response2+1);
+		num_to_bytes(uid_2nd,4,response2a);
+		response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
+
+		// Configure the ATQA and SAK accordingly
+		response1[0] |= 0x40;
+		sak |= 0x04;
+	} else {
+		num_to_bytes(uid_1st,4,response2);
+		// Configure the ATQA and SAK accordingly
+		response1[0] &= 0xBF;
+		sak &= 0xFB;
+	}
 
-// When reader selects us during cascade1 it will send cmd3
-//uint8_t response3[] = { 0x04, 0x00, 0x00 }; // SAK Select (cascade1) successful response (ULTRALITE)
-uint8_t response3[] = { 0x24, 0x00, 0x00 }; // SAK Select (cascade1) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
+	// Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
+	response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
 
-// send cascade2 2nd half of UID
-static const uint8_t response2a[] = { 0x51, 0x48, 0x1d, 0x80, 0x84 }; //  uid - cascade2 - 2nd half (4 bytes) of UID+ BCCheck
-// NOTE : THE CRC on the above may be wrong as I have obfuscated the actual UID
+	// Prepare the mandatory SAK (for 4 and 7 byte UID)
+	uint8_t response3[3];
+	response3[0] = sak;
+	ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
 
-// When reader selects us during cascade2 it will send cmd3a
-//uint8_t response3a[] = { 0x00, 0x00, 0x00 }; // SAK Select (cascade2) successful response (ULTRALITE)
-uint8_t response3a[] = { 0x20, 0x00, 0x00 }; // SAK Select (cascade2) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
+	// Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
+	uint8_t response3a[3];
+	response3a[0] = sak & 0xFB;
+	ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 
-    static const uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
+	uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
+	uint8_t response6[] = { 0x03, 0x3B, 0x00, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
+	ComputeCrc14443(CRC_14443_A, response6, 3, &response6[3], &response6[4]);
 
-    uint8_t *resp;
-    int respLen;
+	uint8_t *resp = NULL;
+	int respLen;
 
-    // Longest possible response will be 16 bytes + 2 CRC = 18 bytes
+  // Longest possible response will be 16 bytes + 2 CRC = 18 bytes
 	// This will need
 	//    144        data bits (18 * 8)
 	//     18        parity bits
@@ -988,41 +1009,41 @@ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 	// 166 bytes, since every bit that needs to be send costs us a byte
 	//
 
-    // Respond with card type
-    uint8_t *resp1 = (((uint8_t *)BigBuf) + 800);
-    int resp1Len;
+	// Respond with card type
+	uint8_t *resp1 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+	int resp1Len;
 
-    // Anticollision cascade1 - respond with uid
-    uint8_t *resp2 = (((uint8_t *)BigBuf) + 970);
-    int resp2Len;
+	// Anticollision cascade1 - respond with uid
+	uint8_t *resp2 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 166);
+	int resp2Len;
 
-    // Anticollision cascade2 - respond with 2nd half of uid if asked
-    // we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88
-    uint8_t *resp2a = (((uint8_t *)BigBuf) + 1140);
-    int resp2aLen;
+	// Anticollision cascade2 - respond with 2nd half of uid if asked
+	// we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88
+	uint8_t *resp2a = (((uint8_t *)BigBuf) + 1140);
+	int resp2aLen;
 
-    // Acknowledge select - cascade 1
-    uint8_t *resp3 = (((uint8_t *)BigBuf) + 1310);
-    int resp3Len;
+	// Acknowledge select - cascade 1
+	uint8_t *resp3 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*2));
+	int resp3Len;
 
-    // Acknowledge select - cascade 2
-    uint8_t *resp3a = (((uint8_t *)BigBuf) + 1480);
-    int resp3aLen;
+	// Acknowledge select - cascade 2
+	uint8_t *resp3a = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*3));
+	int resp3aLen;
 
-    // Response to a read request - not implemented atm
-    uint8_t *resp4 = (((uint8_t *)BigBuf) + 1550);
-    int resp4Len;
+	// Response to a read request - not implemented atm
+	uint8_t *resp4 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*4));
+//	int resp4Len;
 
-    // Authenticate response - nonce
-    uint8_t *resp5 = (((uint8_t *)BigBuf) + 1720);
-    int resp5Len;
+	// Authenticate response - nonce
+	uint8_t *resp5 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*5));
+	int resp5Len;
 
-    uint8_t *receivedCmd = (uint8_t *)BigBuf;
-    int len;
+	// Authenticate response - nonce
+	uint8_t *resp6 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*6));
+	int resp6Len;
 
-    int i;
-	int u;
-	uint8_t b;
+	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
+	int len;
 
 	// To control where we are in the protocol
 	int order = 0;
@@ -1032,130 +1053,130 @@ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 	int happened = 0;
 	int happened2 = 0;
 
-    int cmdsRecvd = 0;
-
-	int fdt_indicator;
+	int cmdsRecvd = 0;
+	uint8_t* respdata = NULL;
+	int respsize = 0;
+//	uint8_t nack = 0x04;
 
-    memset(receivedCmd, 0x44, 400);
+	memset(receivedCmd, 0x44, RECV_CMD_SIZE);
 
 	// Prepare the responses of the anticollision phase
 	// there will be not enough time to do this at the moment the reader sends it REQA
 
 	// Answer to request
 	CodeIso14443aAsTag(response1, sizeof(response1));
-    memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
+	memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
 
 	// Send our UID (cascade 1)
 	CodeIso14443aAsTag(response2, sizeof(response2));
-    memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax;
+	memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax;
 
 	// Answer to select (cascade1)
 	CodeIso14443aAsTag(response3, sizeof(response3));
-    memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax;
+	memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax;
 
 	// Send the cascade 2 2nd part of the uid
 	CodeIso14443aAsTag(response2a, sizeof(response2a));
-    memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax;
+	memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax;
 
 	// Answer to select (cascade 2)
 	CodeIso14443aAsTag(response3a, sizeof(response3a));
-    memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax;
+	memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax;
 
 	// Strange answer is an example of rare message size (3 bits)
-	CodeStrangeAnswer();
-	memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
+	CodeStrangeAnswerAsTag();
+	memcpy(resp4, ToSend, ToSendMax);// resp4Len = ToSendMax;
 
 	// Authentication answer (random nonce)
 	CodeIso14443aAsTag(response5, sizeof(response5));
-    memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax;
+	memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax;
 
-    // We need to listen to the high-frequency, peak-detected path.
-    SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-    FpgaSetupSsc();
+	// dummy ATS (pseudo-ATR), answer to RATS
+	CodeIso14443aAsTag(response6, sizeof(response6));
+	memcpy(resp6, ToSend, ToSendMax); resp6Len = ToSendMax;
+
+	// We need to listen to the high-frequency, peak-detected path.
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaSetupSsc();
 
-    cmdsRecvd = 0;
+	cmdsRecvd = 0;
 
-    LED_A_ON();
+	LED_A_ON();
 	for(;;) {
-
-		if(!GetIso14443aCommandFromReader(receivedCmd, &len, 100)) {
-            DbpString("button press");
-            break;
-        }
-	// doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
-        // Okay, look at the command now.
-        lastorder = order;
-		i = 1; // first byte transmitted
-        if(receivedCmd[0] == 0x26) {
-			// Received a REQUEST
+	
+		if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
+			DbpString("button press");
+			break;
+		}
+    
+    if (tracing) {
+			LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE);
+    }
+    
+		// doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
+		// Okay, look at the command now.
+		lastorder = order;
+		if(receivedCmd[0] == 0x26) { // Received a REQUEST
 			resp = resp1; respLen = resp1Len; order = 1;
-			//DbpString("Hello request from reader:");
-		} else if(receivedCmd[0] == 0x52) {
-			// Received a WAKEUP
+			respdata = response1;
+			respsize = sizeof(response1);
+		} else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
 			resp = resp1; respLen = resp1Len; order = 6;
-//			//DbpString("Wakeup request from reader:");
-
-		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {	// greg - cascade 1 anti-collision
-			// Received request for UID (cascade 1)
+			respdata = response1;
+			respsize = sizeof(response1);
+		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {	// Received request for UID (cascade 1)
 			resp = resp2; respLen = resp2Len; order = 2;
-//			DbpString("UID (cascade 1) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] ==0x95) {	// greg - cascade 2 anti-collision
-			// Received request for UID (cascade 2)
+			respdata = response2;
+			respsize = sizeof(response2);
+		} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
 			resp = resp2a; respLen = resp2aLen; order = 20;
-//			DbpString("UID (cascade 2) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x93) {	// greg - cascade 1 select
-			// Received a SELECT
+			respdata = response2a;
+			respsize = sizeof(response2a);
+		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {	// Received a SELECT (cascade 1)
 			resp = resp3; respLen = resp3Len; order = 3;
-//			DbpString("Select (cascade 1) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x95) {	// greg - cascade 2 select
-			// Received a SELECT
+			respdata = response3;
+			respsize = sizeof(response3);
+		} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {	// Received a SELECT (cascade 2)
 			resp = resp3a; respLen = resp3aLen; order = 30;
-//			DbpString("Select (cascade 2) request from reader:");
-//			DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[0] == 0x30) {
-			// Received a READ
-			resp = resp4; respLen = resp4Len; order = 4; // Do nothing
-			Dbprintf("Read request from reader: %x %x %x",
-				receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
-		} else if(receivedCmd[0] == 0x50) {
-			// Received a HALT
-			resp = resp1; respLen = 0; order = 5; // Do nothing
-			DbpString("Reader requested we HALT!:");
-
-		} else if(receivedCmd[0] == 0x60) {
-			// Received an authentication request
-			resp = resp5; respLen = resp5Len; order = 7;
-			Dbprintf("Authenticate request from reader: %x %x %x",
-				receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-		} else if(receivedCmd[0] == 0xE0) {
-			// Received a RATS request
-			resp = resp1; respLen = 0;order = 70;
-			Dbprintf("RATS request from reader: %x %x %x",
-				receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-        } else {
-            // Never seen this command before
-		Dbprintf("Unknown command received from reader (len=%d): %x %x %x %x %x %x %x %x %x",
-			len,
-			receivedCmd[0], receivedCmd[1], receivedCmd[2],
-			receivedCmd[3], receivedCmd[4], receivedCmd[5],
-			receivedCmd[6], receivedCmd[7], receivedCmd[8]);
+			respdata = response3a;
+			respsize = sizeof(response3a);
+		} else if(receivedCmd[0] == 0x30) {	// Received a (plain) READ
+//			resp = resp4; respLen = resp4Len; order = 4; // Do nothing
+//			respdata = &nack;
+//			respsize = sizeof(nack); // 4-bit answer
+      EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
+			Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
+      // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
+      respLen = 0;
+		} else if(receivedCmd[0] == 0x50) {	// Received a HALT
+//			DbpString("Reader requested we HALT!:");
 			// Do not respond
 			resp = resp1; respLen = 0; order = 0;
-        }
+			respdata = NULL;
+			respsize = 0;
+		} else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {	// Received an authentication request
+			resp = resp5; respLen = resp5Len; order = 7;
+			respdata = response5;
+			respsize = sizeof(response5);
+		} else if(receivedCmd[0] == 0xE0) {	// Received a RATS request
+			resp = resp6; respLen = resp6Len; order = 70;
+			respdata = response6;
+			respsize = sizeof(response6);
+		} else {
+      if (order == 7 && len ==8) {
+        uint32_t nr = bytes_to_num(receivedCmd,4);
+        uint32_t ar = bytes_to_num(receivedCmd+4,4);
+        Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
+      } else {
+        // Never seen this command before
+        Dbprintf("Received unknown command (len=%d):",len);
+        Dbhexdump(len,receivedCmd,false);
+      }
+      // Do not respond
+      resp = resp1; respLen = 0; order = 0;
+      respdata = NULL;
+      respsize = 0;
+		}
 
 		// Count number of wakeups received after a halt
 		if(order == 6 && lastorder == 5) { happened++; }
@@ -1166,166 +1187,112 @@ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 		// Look at last parity bit to determine timing of answer
 		if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) {
 			// 1236, so correction bit needed
-			i = 0;
+			//i = 0;
 		}
 
-        memset(receivedCmd, 0x44, 32);
-
 		if(cmdsRecvd > 999) {
 			DbpString("1000 commands later...");
-            break;
-        }
-		else {
+			break;
+		} else {
 			cmdsRecvd++;
 		}
 
-        if(respLen <= 0) continue;
-
-        // Modulate Manchester
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
-        AT91C_BASE_SSC->SSC_THR = 0x00;
-        FpgaSetupSsc();
-
-		// ### Transmit the response ###
-		u = 0;
-		b = 0x00;
-		fdt_indicator = FALSE;
-        for(;;) {
-            if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-				volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-                (void)b;
-            }
-            if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-				if(i > respLen) {
-					b = 0x00;
-					u++;
-				} else {
-					b = resp[i];
-					i++;
-				}
-				AT91C_BASE_SSC->SSC_THR = b;
-
-                if(u > 4) {
-                    break;
-                }
-            }
-			if(BUTTON_PRESS()) {
-			    break;
+		if(respLen > 0) {
+			EmSendCmd14443aRaw(resp, respLen, receivedCmd[0] == 0x52);
+		}
+		
+		if (tracing) {
+			if (respdata != NULL) {
+				LogTrace(respdata,respsize, 0, SwapBits(GetParity(respdata,respsize),respsize), FALSE);
 			}
-        }
+			if(traceLen > TRACE_SIZE) {
+				DbpString("Trace full");
+				break;
+			}
+		}
 
-    }
+		memset(receivedCmd, 0x44, RECV_CMD_SIZE);
+  }
 
 	Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
 	LED_A_OFF();
 }
 
-//-----------------------------------------------------------------------------
-// Transmit the command (to the tag) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait)
-{
-  int c;
 
-  FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+// prepare a delayed transfer. This simply shifts ToSend[] by a number
+// of bits specified in the delay parameter.
+void PrepareDelayedTransfer(uint16_t delay)
+{
+	uint8_t bitmask = 0;
+	uint8_t bits_to_shift = 0;
+	uint8_t bits_shifted = 0;
+	
+	delay &= 0x07;
+	if (delay) {
+		for (uint16_t i = 0; i < delay; i++) {
+			bitmask |= (0x01 << i);
+		}
+		ToSend[++ToSendMax] = 0x00;
+		for (uint16_t i = 0; i < ToSendMax; i++) {
+			bits_to_shift = ToSend[i] & bitmask;
+			ToSend[i] = ToSend[i] >> delay;
+			ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
+			bits_shifted = bits_to_shift;
+		}
+	}
+}
 
-	if (wait)
-    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();
-  }
 
-  c = 0;
-  for(;;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-      AT91C_BASE_SSC->SSC_THR = cmd[c];
-      c++;
-      if(c >= len) {
-        break;
-      }
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
-	if (samples) *samples = (c + *wait) << 3;
-}
 
 //-----------------------------------------------------------------------------
-// Code a 7-bit command without parity bit
-// This is especially for 0x26 and 0x52 (REQA and WUPA)
+// Transmit the command (to the tag) that was placed in ToSend[].
+// Parameter timing:
+// if NULL: ignored
+// if == 0:	return time of transfer
+// if != 0: delay transfer until time specified
 //-----------------------------------------------------------------------------
-void ShortFrameFromReader(const uint8_t bt)
+static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
 {
-	int j;
-	int last;
-  uint8_t b;
+	int c;
 
-	ToSendReset();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
 
-	// Start of Communication (Seq. Z)
-	ToSend[++ToSendMax] = SEC_Z;
-	last = 0;
 
-	b = bt;
-	for(j = 0; j < 7; j++) {
-		if(b & 1) {
-			// Sequence X
-			ToSend[++ToSendMax] = SEC_X;
-			last = 1;
+	if (timing) {
+		if(*timing == 0) {										// Measure time
+			*timing = (GetCountMifare() + 8) & 0xfffffff8;
 		} else {
-			if(last == 0) {
-				// Sequence Z
-				ToSend[++ToSendMax] = SEC_Z;
-			}
-			else {
-				// Sequence Y
-				ToSend[++ToSendMax] = SEC_Y;
-				last = 0;
-			}
+			PrepareDelayedTransfer(*timing & 0x00000007);		// Delay transfer (fine tuning - up to 7 MF clock ticks)
 		}
-		b >>= 1;
+		if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+		while(GetCountMifare() < (*timing & 0xfffffff8));		// Delay transfer (multiple of 8 MF clock ticks)
 	}
 
-	// End of Communication
-	if(last == 0) {
-		// Sequence Z
-		ToSend[++ToSendMax] = SEC_Z;
+	for(c = 0; c < 10;) {	// standard delay for each transfer (allow tag to be ready after last transmission)
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			AT91C_BASE_SSC->SSC_THR = 0x00;	
+			c++;
+		}
 	}
-	else {
-		// Sequence Y
-		ToSend[++ToSendMax] = SEC_Y;
-		last = 0;
+	
+	c = 0;
+	for(;;) {
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			AT91C_BASE_SSC->SSC_THR = cmd[c];
+			c++;
+			if(c >= len) {
+				break;
+			}
+		}
 	}
-	// Sequence Y
-	ToSend[++ToSendMax] = SEC_Y;
-
-	// Just to be sure!
-	ToSend[++ToSendMax] = SEC_Y;
-	ToSend[++ToSendMax] = SEC_Y;
-	ToSend[++ToSendMax] = SEC_Y;
 
-    // Convert from last character reference to length
-    ToSendMax++;
 }
 
 //-----------------------------------------------------------------------------
-// Prepare reader command to send to FPGA
-//
+// Prepare reader command (in bits, support short frames) to send to FPGA
 //-----------------------------------------------------------------------------
-void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
+void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
 {
   int i, j;
   int last;
@@ -1337,12 +1304,14 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
   ToSend[++ToSendMax] = SEC_Z;
   last = 0;
 
+  size_t bytecount = nbytes(bits);
   // Generate send structure for the data bits
-  for (i = 0; i < len; i++) {
+  for (i = 0; i < bytecount; i++) {
     // Get the current byte to send
     b = cmd[i];
+    size_t bitsleft = MIN((bits-(i*8)),8);
 
-    for (j = 0; j < 8; j++) {
+    for (j = 0; j < bitsleft; j++) {
       if (b & 1) {
         // Sequence X
     	  ToSend[++ToSendMax] = SEC_X;
@@ -1360,19 +1329,22 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
       b >>= 1;
     }
 
-    // Get the parity bit
-    if ((dwParity >> i) & 0x01) {
-      // Sequence X
-    	ToSend[++ToSendMax] = SEC_X;
-      last = 1;
-    } else {
-      if (last == 0) {
-        // Sequence Z
-    	  ToSend[++ToSendMax] = SEC_Z;
+    // Only transmit (last) parity bit if we transmitted a complete byte
+    if (j == 8) {
+      // Get the parity bit
+      if ((dwParity >> i) & 0x01) {
+        // Sequence X
+        ToSend[++ToSendMax] = SEC_X;
+        last = 1;
       } else {
-        // Sequence Y
-    	  ToSend[++ToSendMax] = SEC_Y;
-        last = 0;
+        if (last == 0) {
+          // Sequence Z
+          ToSend[++ToSendMax] = SEC_Z;
+        } else {
+          // Sequence Y
+          ToSend[++ToSendMax] = SEC_Y;
+          last = 0;
+        }
       }
     }
   }
@@ -1399,89 +1371,233 @@ void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
 }
 
 //-----------------------------------------------------------------------------
-// Wait a certain time for tag response
-//  If a response is captured return TRUE
-//  If it takes to long return FALSE
+// Prepare reader command to send to FPGA
 //-----------------------------------------------------------------------------
-static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer
+void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
 {
-	// buffer needs to be 512 bytes
-	int c;
+  CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
+}
 
-	// Set FPGA mode to "reader listen mode", no modulation (listen
-	// only, since we are receiving, not transmitting).
-	// Signal field is on with the appropriate LED
-	LED_D_ON();
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
+//-----------------------------------------------------------------------------
+// Wait for commands from reader
+// Stop when button is pressed (return 1) or field was gone (return 2)
+// Or return 0 when command is captured
+//-----------------------------------------------------------------------------
+static int EmGetCmd(uint8_t *received, int *len, int maxLen)
+{
+	*len = 0;
 
-	// Now get the answer from the card
-	Demod.output = receivedResponse;
-	Demod.len = 0;
-	Demod.state = DEMOD_UNSYNCD;
+	uint32_t timer = 0, vtime = 0;
+	int analogCnt = 0;
+	int analogAVG = 0;
 
-	uint8_t b;
-	if (elapsed) *elapsed = 0;
+	// Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
+	// only, since we are receiving, not transmitting).
+	// Signal field is off with the appropriate LED
+	LED_D_OFF();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+	// Set ADC to read field strength
+	AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
+	AT91C_BASE_ADC->ADC_MR =
+				ADC_MODE_PRESCALE(32) |
+				ADC_MODE_STARTUP_TIME(16) |
+				ADC_MODE_SAMPLE_HOLD_TIME(8);
+	AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
+	// start ADC
+	AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+	
+	// Now run a 'software UART' on the stream of incoming samples.
+	Uart.output = received;
+	Uart.byteCntMax = maxLen;
+	Uart.state = STATE_UNSYNCD;
 
-	c = 0;
 	for(;;) {
 		WDT_HIT();
 
+		if (BUTTON_PRESS()) return 1;
+
+		// test if the field exists
+		if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
+			analogCnt++;
+			analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
+			AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+			if (analogCnt >= 32) {
+				if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
+					vtime = GetTickCount();
+					if (!timer) timer = vtime;
+					// 50ms no field --> card to idle state
+					if (vtime - timer > 50) return 2;
+				} else
+					if (timer) timer = 0;
+				analogCnt = 0;
+				analogAVG = 0;
+			}
+		}
+		// transmit none
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
-			if (elapsed) (*elapsed)++;
+			AT91C_BASE_SSC->SSC_THR = 0x00;
 		}
+		// receive and test the miller decoding
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			if(c < iso14a_timeout) { c++; } else { return FALSE; }
-			b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			if(ManchesterDecoding((b>>4) & 0xf)) {
-				*samples = ((c - 1) << 3) + 4;
-				return TRUE;
+			volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			if(MillerDecoding((b & 0xf0) >> 4)) {
+				*len = Uart.byteCnt;
+				if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
+				return 0;
 			}
-			if(ManchesterDecoding(b & 0x0f)) {
-				*samples = c << 3;
-				return TRUE;
+			if(MillerDecoding(b & 0x0f)) {
+				*len = Uart.byteCnt;
+				if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
+				return 0;
 			}
 		}
 	}
 }
 
-void ReaderTransmitShort(const uint8_t* bt)
+static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded)
 {
-  int wait = 0;
-  int samples = 0;
+	int i, u = 0;
+	uint8_t b = 0;
 
-  ShortFrameFromReader(*bt);
+	// Modulate Manchester
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
+	AT91C_BASE_SSC->SSC_THR = 0x00;
+	FpgaSetupSsc();
+	
+	// include correction bit
+	i = 1;
+	if((Uart.parityBits & 0x01) || correctionNeeded) {
+		// 1236, so correction bit needed
+		i = 0;
+	}
+	
+	// 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;
+		}
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			if(i > respLen) {
+				b = 0xff; // was 0x00
+				u++;
+			} else {
+				b = resp[i];
+				i++;
+			}
+			AT91C_BASE_SSC->SSC_THR = b;
 
-  // Select the card
-  TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
+			if(u > 4) break;
+		}
+		if(BUTTON_PRESS()) {
+			break;
+		}
+	}
 
-  // Store reader command in buffer
-  if (tracing) LogTrace(bt,1,0,GetParity(bt,1),TRUE);
+	return 0;
+}
+
+int EmSend4bitEx(uint8_t resp, int correctionNeeded){
+  Code4bitAnswerAsTag(resp);
+	int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
+  if (tracing) LogTrace(&resp, 1, GetDeltaCountUS(), GetParity(&resp, 1), FALSE);
+	return res;
+}
+
+int EmSend4bit(uint8_t resp){
+	return EmSend4bitEx(resp, 0);
+}
+
+int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par){
+  CodeIso14443aAsTagPar(resp, respLen, par);
+	int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
+  if (tracing) LogTrace(resp, respLen, GetDeltaCountUS(), par, FALSE);
+	return res;
 }
 
-void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par)
+int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded){
+	return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
+}
+
+int EmSendCmd(uint8_t *resp, int respLen){
+	return EmSendCmdExPar(resp, respLen, 0, GetParity(resp, respLen));
+}
+
+int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
+	return EmSendCmdExPar(resp, respLen, 0, par);
+}
+
+//-----------------------------------------------------------------------------
+// Wait a certain time for tag response
+//  If a response is captured return TRUE
+//  If it takes to long return FALSE
+//-----------------------------------------------------------------------------
+static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer
 {
-  int wait = 0;
-  int samples = 0;
+	// buffer needs to be 512 bytes
+	int c;
+
+	// Set FPGA mode to "reader listen mode", no modulation (listen
+	// only, since we are receiving, not transmitting).
+	// Signal field is on with the appropriate LED
+	LED_D_ON();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
+	
+	// Now get the answer from the card
+	Demod.output = receivedResponse;
+	Demod.len = 0;
+	Demod.state = DEMOD_UNSYNCD;
 
-  // This is tied to other size changes
-  // 	uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
-  CodeIso14443aAsReaderPar(frame,len,par);
+	uint8_t b;
+	if (elapsed) *elapsed = 0;
+
+	c = 0;
+	for(;;) {
+		WDT_HIT();
 
+		// if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+			// AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
+			// if (elapsed) (*elapsed)++;
+		// }
+		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+			if(c < iso14a_timeout) { c++; } else { return FALSE; }
+			b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+			if(ManchesterDecoding((b>>4) & 0xf)) {
+				*samples = ((c - 1) << 3) + 4;
+				return TRUE;
+			}
+			if(ManchesterDecoding(b & 0x0f)) {
+				*samples = c << 3;
+				return TRUE;
+			}
+		}
+	}
+}
+
+void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
+{
+ 
+  CodeIso14443aBitsAsReaderPar(frame,bits,par);
+  
   // Select the card
-  TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
+  TransmitFor14443a(ToSend, ToSendMax, timing);
   if(trigger)
   	LED_A_ON();
-
+  
   // Store reader command in buffer
-  if (tracing) LogTrace(frame,len,0,par,TRUE);
+  if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
 }
 
+void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
+{
+  ReaderTransmitBitsPar(frame,len*8,par, timing);
+}
 
-void ReaderTransmit(uint8_t* frame, int len)
+void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
 {
   // Generate parity and redirect
-  ReaderTransmitPar(frame,len,GetParity(frame,len));
+  ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
 }
 
 int ReaderReceive(uint8_t* receivedAnswer)
@@ -1506,90 +1622,117 @@ int ReaderReceivePar(uint8_t* receivedAnswer, uint32_t * parptr)
 /* performs iso14443a anticolision procedure
  * fills the uid pointer unless NULL
  * fills resp_data unless NULL */
-int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, uint32_t * cuid_ptr) {
-	uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
-	uint8_t sel_all[]    = { 0x93,0x20 };
-	uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
-	uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
-
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
-
-	uint8_t sak = 0x04; // cascade uid
-	int cascade_level = 0;
-
-	int len;
+int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
+  uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
+  uint8_t sel_all[]    = { 0x93,0x20 };
+  uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+  uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
+  uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);	// was 3560 - tied to other size changes
+  byte_t uid_resp[4];
+  size_t uid_resp_len;
+
+  uint8_t sak = 0x04; // cascade uid
+  int cascade_level = 0;
+  int len;
+	 
+  // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+    ReaderTransmitBitsPar(wupa,7,0, NULL);
+  // Receive the ATQA
+  if(!ReaderReceive(resp)) return 0;
+//  Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
+
+  if(p_hi14a_card) {
+    memcpy(p_hi14a_card->atqa, resp, 2);
+    p_hi14a_card->uidlen = 0;
+    memset(p_hi14a_card->uid,0,10);
+  }
 	
-	// clear uid
-	memset(uid_ptr, 0, 8);
-
-	// Broadcast for a card, WUPA (0x52) will force response from all cards in the field
-	ReaderTransmitShort(wupa);
-	// Receive the ATQA
-	if(!ReaderReceive(resp)) return 0;
+  // clear uid
+  if (uid_ptr) {
+    memset(uid_ptr,0,10);
+  }
 
-	if(resp_data)
-		memcpy(resp_data->atqa, resp, 2);
-	
-	// OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
-	// which case we need to make a cascade 2 request and select - this is a long UID
-	// While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
-	for(; sak & 0x04; cascade_level++)
-	{
-		// SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
-		sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
+  // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
+  // which case we need to make a cascade 2 request and select - this is a long UID
+  // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
+  for(; sak & 0x04; cascade_level++) {
+    // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
+    sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
 
-		// SELECT_ALL
-		ReaderTransmit(sel_all,sizeof(sel_all));
-		if (!ReaderReceive(resp)) return 0;
-		if(uid_ptr) memcpy(uid_ptr + cascade_level*4, resp, 4);
-		
-		// calculate crypto UID
-		if(cuid_ptr) *cuid_ptr = bytes_to_num(resp, 4);
+    // SELECT_ALL
+    ReaderTransmit(sel_all,sizeof(sel_all), NULL);
+    if (!ReaderReceive(resp)) return 0;
+    
+    // First backup the current uid
+    memcpy(uid_resp,resp,4);
+    uid_resp_len = 4;
+    //    Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
+    
+	// calculate crypto UID. Always use last 4 Bytes.
+	if(cuid_ptr) {
+		*cuid_ptr = bytes_to_num(uid_resp, 4);
+    }
 
-		// Construct SELECT UID command
+    // Construct SELECT UID command
 		memcpy(sel_uid+2,resp,5);
-		AppendCrc14443a(sel_uid,7);
-		ReaderTransmit(sel_uid,sizeof(sel_uid));
+    AppendCrc14443a(sel_uid,7);
+    ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
+
+    // Receive the SAK
+    if (!ReaderReceive(resp)) return 0;
+    sak = resp[0];
+
+    // Test if more parts of the uid are comming
+    if ((sak & 0x04) && uid_resp[0] == 0x88) {
+      // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
+      // http://www.nxp.com/documents/application_note/AN10927.pdf
+      memcpy(uid_resp, uid_resp + 1, 3);
+      uid_resp_len = 3;
+    }
+    
+    if(uid_ptr) {
+      memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
+    }
+    
+    if(p_hi14a_card) {
+      memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
+      p_hi14a_card->uidlen += uid_resp_len;
+    }
+  }
 
-		// Receive the SAK
-		if (!ReaderReceive(resp)) return 0;
-		sak = resp[0];
-	}
-	if(resp_data) {
-		resp_data->sak = sak;
-		resp_data->ats_len = 0;
-	}
-	//--  this byte not UID, it CT.  http://www.nxp.com/documents/application_note/AN10927.pdf  page 3
-	if (uid_ptr[0] == 0x88) {  
-		memcpy(uid_ptr, uid_ptr + 1, 7);
-		uid_ptr[7] = 0;
-	}
+  if(p_hi14a_card) {
+    p_hi14a_card->sak = sak;
+    p_hi14a_card->ats_len = 0;
+  }
 
-	if( (sak & 0x20) == 0)
-		return 2; // non iso14443a compliant tag
+  if( (sak & 0x20) == 0) {
+    return 2; // non iso14443a compliant tag
+  }
 
-	// Request for answer to select
-	if(resp_data) {  // JCOP cards - if reader sent RATS then there is no MIFARE session at all!!!
-		AppendCrc14443a(rats, 2);
-		ReaderTransmit(rats, sizeof(rats));
-		
-		if (!(len = ReaderReceive(resp))) return 0;
-		
-		memcpy(resp_data->ats, resp, sizeof(resp_data->ats));
-		resp_data->ats_len = len;
-	}
+  // Request for answer to select
+  AppendCrc14443a(rats, 2);
+  ReaderTransmit(rats, sizeof(rats), NULL);
+
+  if (!(len = ReaderReceive(resp))) return 0;
+
+  if(p_hi14a_card) {
+    memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
+    p_hi14a_card->ats_len = len;
+  }
 	
-	return 1;
+  // reset the PCB block number
+  iso14_pcb_blocknum = 0;
+  return 1;
 }
 
 void iso14443a_setup() {
-	// Setup SSC
+	// Set up the synchronous serial port
 	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);
+//	LED_D_OFF();
+//	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	// SpinDelay(50);
 
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
@@ -1597,7 +1740,7 @@ void iso14443a_setup() {
 	// Signal field is on with the appropriate LED
 	LED_D_ON();
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-	SpinDelay(200);
+	SpinDelay(7); // iso14443-3 specifies 5ms max.
 
 	iso14a_timeout = 2048; //default
 }
@@ -1605,35 +1748,53 @@ void iso14443a_setup() {
 int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
 	uint8_t real_cmd[cmd_len+4];
 	real_cmd[0] = 0x0a; //I-Block
+	// put block number into the PCB
+	real_cmd[0] |= iso14_pcb_blocknum;
 	real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
 	memcpy(real_cmd+2, cmd, cmd_len);
 	AppendCrc14443a(real_cmd,cmd_len+2);
  
-	ReaderTransmit(real_cmd, cmd_len+4);
+	ReaderTransmit(real_cmd, cmd_len+4, NULL);
 	size_t len = ReaderReceive(data);
-	if(!len)
-		return -1; //DATA LINK ERROR
-	
+	uint8_t * data_bytes = (uint8_t *) data;
+	if (!len)
+		return 0; //DATA LINK ERROR
+	// if we received an I- or R(ACK)-Block with a block number equal to the
+	// current block number, toggle the current block number
+	else if (len >= 4 // PCB+CID+CRC = 4 bytes
+	         && ((data_bytes[0] & 0xC0) == 0 // I-Block
+	             || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
+	         && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
+	{
+		iso14_pcb_blocknum ^= 1;
+	}
+
 	return len;
 }
 
-
 //-----------------------------------------------------------------------------
 // Read an ISO 14443a tag. Send out commands and store answers.
 //
 //-----------------------------------------------------------------------------
-void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
+void ReaderIso14443a(UsbCommand * c)
 {
 	iso14a_command_t param = c->arg[0];
 	uint8_t * cmd = c->d.asBytes;
 	size_t len = c->arg[1];
-
-	if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(1);
+	uint32_t arg0 = 0;
+	byte_t buf[USB_CMD_DATA_SIZE];
+  
+	iso14a_clear_trace();
+	iso14a_set_tracing(true);
+
+	if(param & ISO14A_REQUEST_TRIGGER) {
+		iso14a_set_trigger(1);
+	}
 
 	if(param & ISO14A_CONNECT) {
 		iso14443a_setup();
-		ack->arg[0] = iso14443a_select_card(ack->d.asBytes, (iso14a_card_select_t *) (ack->d.asBytes+12), NULL);
-		UsbSendPacket((void *)ack, sizeof(UsbCommand));
+		arg0 = iso14443a_select_card(NULL, (iso14a_card_select_t*)buf, NULL);
+		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(iso14a_card_select_t));
 	}
 
 	if(param & ISO14A_SET_TIMEOUT) {
@@ -1645,8 +1806,8 @@ void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
 	}
 
 	if(param & ISO14A_APDU) {
-		ack->arg[0] = iso14_apdu(cmd, len, ack->d.asBytes);
-		UsbSendPacket((void *)ack, sizeof(UsbCommand));
+		arg0 = iso14_apdu(cmd, len, buf);
+		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
 	}
 
 	if(param & ISO14A_RAW) {
@@ -1654,94 +1815,208 @@ void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
 			AppendCrc14443a(cmd,len);
 			len += 2;
 		}
-		ReaderTransmit(cmd,len);
-		ack->arg[0] = ReaderReceive(ack->d.asBytes);
-		UsbSendPacket((void *)ack, sizeof(UsbCommand));
+		ReaderTransmit(cmd,len, NULL);
+		arg0 = ReaderReceive(buf);
+		cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
 	}
 
-	if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(0);
+	if(param & ISO14A_REQUEST_TRIGGER) {
+		iso14a_set_trigger(0);
+	}
 
-	if(param & ISO14A_NO_DISCONNECT)
+	if(param & ISO14A_NO_DISCONNECT) {
 		return;
+	}
 
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 	LEDsoff();
 }
+
+
+// Determine the distance between two nonces.
+// Assume that the difference is small, but we don't know which is first.
+// Therefore try in alternating directions.
+int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
+
+	uint16_t i;
+	uint32_t nttmp1, nttmp2;
+
+	if (nt1 == nt2) return 0;
+
+	nttmp1 = nt1;
+	nttmp2 = nt2;
+	
+	for (i = 1; i < 32768; i++) {
+		nttmp1 = prng_successor(nttmp1, 1);
+		if (nttmp1 == nt2) return i;
+		nttmp2 = prng_successor(nttmp2, 1);
+			if (nttmp2 == nt1) return -i;
+		}
+	
+	return(-99999); // either nt1 or nt2 are invalid nonces
+}
+
+
 //-----------------------------------------------------------------------------
-// Read an ISO 14443a tag. Send out commands and store answers.
-//
+// Recover several bits of the cypher stream. This implements (first stages of)
+// the algorithm described in "The Dark Side of Security by Obscurity and
+// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
+// (article by Nicolas T. Courtois, 2009)
 //-----------------------------------------------------------------------------
-void ReaderMifare(uint32_t parameter)
+void ReaderMifare(bool first_try)
 {
 	// Mifare AUTH
 	uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
 	uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+	static uint8_t mf_nr_ar3;
 
-	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
+	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
 	traceLen = 0;
 	tracing = false;
 
-	iso14443a_setup();
-
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
-
 	byte_t nt_diff = 0;
-	LED_A_OFF();
 	byte_t par = 0;
-	byte_t par_mask = 0xff;
-	byte_t par_low = 0;
-	int led_on = TRUE;
-	uint8_t uid[7];
+	//byte_t par_mask = 0xff;
+	static byte_t par_low = 0;
+	bool led_on = TRUE;
+	uint8_t uid[10];
 	uint32_t cuid;
 
-	tracing = FALSE;
-	byte_t nt[4] = {0,0,0,0};
-	byte_t nt_attacked[4];
+	uint32_t nt, previous_nt;
+	static uint32_t nt_attacked = 0;
 	byte_t par_list[8] = {0,0,0,0,0,0,0,0};
 	byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
-	num_to_bytes(parameter, 4, nt_attacked);
+
+	static uint32_t sync_time;
+	static uint32_t sync_cycles;
+	int catch_up_cycles = 0;
+	int last_catch_up = 0;
+	uint16_t consecutive_resyncs = 0;
 	int isOK = 0;
+
+
+
+	if (first_try) { 
+		StartCountMifare();
+		mf_nr_ar3 = 0;
+		iso14443a_setup();
+		while((GetCountMifare() & 0xffff0000) != 0x10000);		// wait for counter to reset and "warm up" 
+		sync_time = GetCountMifare() & 0xfffffff8;
+		sync_cycles = 65536;									// theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+		nt_attacked = 0;
+		nt = 0;
+		par = 0;
+	}
+	else {
+		// we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
+		// nt_attacked = prng_successor(nt_attacked, 1);
+		mf_nr_ar3++;
+		mf_nr_ar[3] = mf_nr_ar3;
+		par = par_low;
+	}
+
+	LED_A_ON();
+	LED_B_OFF();
+	LED_C_OFF();
 	
-	while(TRUE)
-	{
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-		SpinDelay(200);
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+  
+	for(uint16_t i = 0; TRUE; i++) {
+		
+		WDT_HIT();
 
 		// Test if the action was cancelled
 		if(BUTTON_PRESS()) {
 			break;
 		}
+		
+		LED_C_ON();
+
+		if(!iso14443a_select_card(uid, NULL, &cuid)) {
+			if (MF_DBGLEVEL >= 1)	Dbprintf("Mifare: Can't select card");
+			continue;
+		}
+
+		//keep the card active
+		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
 
-		if(!iso14443a_select_card(uid, NULL, &cuid)) continue;
+		// CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));
 
-		// Transmit MIFARE_CLASSIC_AUTH
-		ReaderTransmit(mf_auth, sizeof(mf_auth));
+		sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+		catch_up_cycles = 0;
 
-		// Receive the (16 bit) "random" nonce
-		if (!ReaderReceive(receivedAnswer)) continue;
-		memcpy(nt, receivedAnswer, 4);
+		// if we missed the sync time already, advance to the next nonce repeat
+		while(GetCountMifare() > sync_time) {
+			sync_time = (sync_time & 0xfffffff8) + sync_cycles;
+		}
 
-		// Transmit reader nonce and reader answer
-		ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar),par);
+		// Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) 
+		ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
 
-		// Receive 4 bit answer
+		// Receive the (4 Byte) "random" nonce
+		if (!ReaderReceive(receivedAnswer)) {
+			if (MF_DBGLEVEL >= 1)	Dbprintf("Mifare: Couldn't receive tag nonce");
+			continue;
+		  }
+
+		previous_nt = nt;
+		nt = bytes_to_num(receivedAnswer, 4);
+
+		// Transmit reader nonce with fake par
+		ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
+
+		if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
+			int nt_distance = dist_nt(previous_nt, nt);
+			if (nt_distance == 0) {
+				nt_attacked = nt;
+			}
+			else {
+				if (nt_distance == -99999) { // invalid nonce received, try again
+					continue;
+				}
+				sync_cycles = (sync_cycles - nt_distance);
+				if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
+				continue;
+			}
+		}
+
+		if ((nt != nt_attacked) && nt_attacked) { 	// we somehow lost sync. Try to catch up again...
+			catch_up_cycles = -dist_nt(nt_attacked, nt);
+			if (catch_up_cycles == 99999) {			// invalid nonce received. Don't resync on that one.
+				catch_up_cycles = 0;
+				continue;
+			}
+			if (catch_up_cycles == last_catch_up) {
+				consecutive_resyncs++;
+			}
+			else {
+				last_catch_up = catch_up_cycles;
+			    consecutive_resyncs = 0;
+			}
+			if (consecutive_resyncs < 3) {
+				if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
+			}
+			else {	
+				sync_cycles = sync_cycles + catch_up_cycles;
+				if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
+			}
+			continue;
+		}
+ 
+		consecutive_resyncs = 0;
+		
+		// Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
 		if (ReaderReceive(receivedAnswer))
 		{
+			catch_up_cycles = 8; 	// the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
+	
 			if (nt_diff == 0)
 			{
-				LED_A_ON();
-				memcpy(nt_attacked, nt, 4);
-				par_mask = 0xf8;
-				par_low = par & 0x07;
+				par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
 			}
 
-			if (memcmp(nt, nt_attacked, 4) != 0) continue;
-
 			led_on = !led_on;
 			if(led_on) LED_B_ON(); else LED_B_OFF();
+
 			par_list[nt_diff] = par;
 			ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
 
@@ -1752,10 +2027,10 @@ void ReaderMifare(uint32_t parameter)
 			}
 
 			nt_diff = (nt_diff + 1) & 0x07;
-			mf_nr_ar[3] = nt_diff << 5;
+			mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
 			par = par_low;
 		} else {
-			if (nt_diff == 0)
+			if (nt_diff == 0 && first_try)
 			{
 				par++;
 			} else {
@@ -1764,546 +2039,601 @@ void ReaderMifare(uint32_t parameter)
 		}
 	}
 
-	LogTrace(nt, 4, 0, GetParity(nt, 4), TRUE);
+	LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE);
 	LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE);
 	LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE);
 
-	UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
-	memcpy(ack.d.asBytes + 0,  uid, 4);
-	memcpy(ack.d.asBytes + 4,  nt, 4);
-	memcpy(ack.d.asBytes + 8,  par_list, 8);
-	memcpy(ack.d.asBytes + 16, ks_list, 8);
+	mf_nr_ar[3] &= 0x1F;
+	
+	byte_t buf[28];
+	memcpy(buf + 0,  uid, 4);
+	num_to_bytes(nt, 4, buf + 4);
+	memcpy(buf + 8,  par_list, 8);
+	memcpy(buf + 16, ks_list, 8);
+	memcpy(buf + 24, mf_nr_ar, 4);
 		
-	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-	LED_B_OFF();	
+	cmd_send(CMD_ACK,isOK,0,0,buf,28);
 
 	// Thats it...
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 	LEDsoff();
 	tracing = TRUE;
-	
-//	DbpString("COMMAND mifare FINISHED");
 }
 
 //-----------------------------------------------------------------------------
-// Select, Authenticaate, Read an MIFARE tag. 
-// read block
+// MIFARE 1K simulate. 
+// 
 //-----------------------------------------------------------------------------
-void MifareReadBlock(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
+void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 {
-  // params
-	uint8_t blockNo = arg0;
-	uint8_t keyType = arg1;
-	uint64_t ui64Key = 0;
-	ui64Key = bytes_to_num(datain, 6);
-	
-	// variables
-	byte_t isOK = 0;
-	byte_t dataoutbuf[16];
-	uint8_t uid[7];
-	uint32_t cuid;
+	int cardSTATE = MFEMUL_NOFIELD;
+	int _7BUID = 0;
+	int vHf = 0;	// in mV
+	//int nextCycleTimeout = 0;
+	int res;
+//	uint32_t timer = 0;
+	uint32_t selTimer = 0;
+	uint32_t authTimer = 0;
+	uint32_t par = 0;
+	int len = 0;
+	uint8_t cardWRBL = 0;
+	uint8_t cardAUTHSC = 0;
+	uint8_t cardAUTHKEY = 0xff;  // no authentication
+	//uint32_t cardRn = 0;
+	uint32_t cardRr = 0;
+	uint32_t cuid = 0;
+	//uint32_t rn_enc = 0;
+	uint32_t ans = 0;
+	uint32_t cardINTREG = 0;
+	uint8_t cardINTBLOCK = 0;
 	struct Crypto1State mpcs = {0, 0};
 	struct Crypto1State *pcs;
 	pcs = &mpcs;
-
-	// clear trace
-	traceLen = 0;
-//	tracing = false;
-
-	iso14443a_setup();
-
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
-
-	while (true) {
-		if(!iso14443a_select_card(uid, NULL, &cuid)) {
-			Dbprintf("Can't select card");
-			break;
-		};
-
-		if(mifare_classic_auth(pcs, cuid, blockNo, keyType, ui64Key, AUTH_FIRST)) {
-			Dbprintf("Auth error");
-			break;
-		};
-		
-		if(mifare_classic_readblock(pcs, cuid, blockNo, dataoutbuf)) {
-			Dbprintf("Read block error");
-			break;
-		};
-
-		if(mifare_classic_halt(pcs, cuid)) {
-			Dbprintf("Halt error");
-			break;
-		};
-		
-		isOK = 1;
-		break;
-	}
-	
-	//  ----------------------------- crypto1 destroy
-	crypto1_destroy(pcs);
 	
-//    DbpString("READ BLOCK FINISHED");
-
-	// add trace trailer
-	uid[0] = 0xff;
-	uid[1] = 0xff;
-	uid[2] = 0xff;
-	uid[3] = 0xff;
-	LogTrace(uid, 4, 0, 0, TRUE);
-
-	UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
-	memcpy(ack.d.asBytes, dataoutbuf, 16);
+	uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
+	uint8_t *response = eml_get_bigbufptr_sendbuf();
 	
-	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-	LED_B_OFF();
+	static uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
 
+	static uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; 
+	static uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
+		
+	static uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
+	static uint8_t rSAK1[] = {0x04, 0xda, 0x17};
 
-  // Thats it...
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	LEDsoff();
-//  tracing = TRUE;
+	static uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
+//	static uint8_t rAUTH_NT[] = {0x1a, 0xac, 0xff, 0x4f};
+	static uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
 
-}
+	// clear trace
+	traceLen = 0;
+	tracing = true;
 
-//-----------------------------------------------------------------------------
-// Select, Authenticaate, Read an MIFARE tag. 
-// read sector (data = 4 x 16 bytes = 64 bytes)
-//-----------------------------------------------------------------------------
-void MifareReadSector(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
-{
-  // params
-	uint8_t sectorNo = arg0;
-	uint8_t keyType = arg1;
-	uint64_t ui64Key = 0;
-	ui64Key = bytes_to_num(datain, 6);
+  // Authenticate response - nonce
+	uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
 	
-	// variables
-	byte_t isOK = 0;
-	byte_t dataoutbuf[16 * 4];
-	uint8_t uid[8];
-	uint32_t cuid;
-	struct Crypto1State mpcs = {0, 0};
-	struct Crypto1State *pcs;
-	pcs = &mpcs;
+	// get UID from emul memory
+	emlGetMemBt(receivedCmd, 7, 1);
+	_7BUID = !(receivedCmd[0] == 0x00);
+	if (!_7BUID) {                     // ---------- 4BUID
+		rATQA[0] = 0x04;
+
+		emlGetMemBt(rUIDBCC1, 0, 4);
+		rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
+	} else {                           // ---------- 7BUID
+		rATQA[0] = 0x44;
+
+		rUIDBCC1[0] = 0x88;
+		emlGetMemBt(&rUIDBCC1[1], 0, 3);
+		rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
+		emlGetMemBt(rUIDBCC2, 3, 4);
+		rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
+	}
 
-	// clear trace
-	traceLen = 0;
-//	tracing = false;
+// --------------------------------------	test area
 
-	iso14443a_setup();
+// --------------------------------------	END test area
+	// start mkseconds counter
+	StartCountUS();
 
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
+	// We need to listen to the high-frequency, peak-detected path.
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaSetupSsc();
 
+  FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+	SpinDelay(200);
+
+	if (MF_DBGLEVEL >= 1)	Dbprintf("Started. 7buid=%d", _7BUID);
+	// calibrate mkseconds counter
+	GetDeltaCountUS();
 	while (true) {
-		if(!iso14443a_select_card(uid, NULL, &cuid)) {
-			Dbprintf("Can't select card");
-			break;
-		};
+		WDT_HIT();
 
-		if(mifare_classic_auth(pcs, cuid, sectorNo * 4, keyType, ui64Key, AUTH_FIRST)) {
-			Dbprintf("Auth error");
+		if(BUTTON_PRESS()) {
 			break;
-		};
+		}
+
+		// find reader field
+		// Vref = 3300mV, and an 10:1 voltage divider on the input
+		// can measure voltages up to 33000 mV
+		if (cardSTATE == MFEMUL_NOFIELD) {
+			vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
+			if (vHf > MF_MINFIELDV) {
+				cardSTATE_TO_IDLE();
+				LED_A_ON();
+			}
+		} 
+
+		if (cardSTATE != MFEMUL_NOFIELD) {
+			res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
+			if (res == 2) {
+				cardSTATE = MFEMUL_NOFIELD;
+				LEDsoff();
+				continue;
+			}
+			if(res) break;
+		}
 		
-		if(mifare_classic_readblock(pcs, cuid, sectorNo * 4 + 0, dataoutbuf + 16 * 0)) {
-			Dbprintf("Read block 0 error");
-			break;
-		};
-		if(mifare_classic_readblock(pcs, cuid, sectorNo * 4 + 1, dataoutbuf + 16 * 1)) {
-			Dbprintf("Read block 1 error");
-			break;
-		};
-		if(mifare_classic_readblock(pcs, cuid, sectorNo * 4 + 2, dataoutbuf + 16 * 2)) {
-			Dbprintf("Read block 2 error");
-			break;
-		};
-		if(mifare_classic_readblock(pcs, cuid, sectorNo * 4 + 3, dataoutbuf + 16 * 3)) {
-			Dbprintf("Read block 3 error");
-			break;
-		};
+		//nextCycleTimeout = 0;
 		
-		if(mifare_classic_halt(pcs, cuid)) {
-			Dbprintf("Halt error");
-			break;
-		};
-
-		isOK = 1;
-		break;
-	}
-	
-	//  ----------------------------- crypto1 destroy
-	crypto1_destroy(pcs);
-	
-//    DbpString("READ BLOCK FINISHED");
-
-	// add trace trailer
-	uid[0] = 0xff;
-	uid[1] = 0xff;
-	uid[2] = 0xff;
-	uid[3] = 0xff;
-	LogTrace(uid, 4, 0, 0, TRUE);
-
-	UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
-	memcpy(ack.d.asBytes, dataoutbuf, 16 * 2);
-	
-	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-
-	SpinDelay(100);
-	
-	memcpy(ack.d.asBytes, dataoutbuf + 16 * 2, 16 * 2);
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-	LED_B_OFF();	
-
-	// Thats it...
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	LEDsoff();
-//  tracing = TRUE;
-
-}
-
-//-----------------------------------------------------------------------------
-// Select, Authenticaate, Read an MIFARE tag. 
-// read block
-//-----------------------------------------------------------------------------
-void MifareWriteBlock(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
-{
-	// params
-	uint8_t blockNo = arg0;
-	uint8_t keyType = arg1;
-	uint64_t ui64Key = 0;
-	byte_t blockdata[16];
-
-	ui64Key = bytes_to_num(datain, 6);
-	memcpy(blockdata, datain + 10, 16);
-	
-	// variables
-	byte_t isOK = 0;
-	uint8_t uid[8];
-	uint32_t cuid;
-	struct Crypto1State mpcs = {0, 0};
-	struct Crypto1State *pcs;
-	pcs = &mpcs;
+//		if (len) Dbprintf("len:%d cmd: %02x %02x %02x %02x", len, receivedCmd[0], receivedCmd[1], receivedCmd[2], receivedCmd[3]);
+
+		if (len != 4 && cardSTATE != MFEMUL_NOFIELD) { // len != 4 <---- speed up the code 4 authentication
+			// REQ or WUP request in ANY state and WUP in HALTED state
+			if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
+				selTimer = GetTickCount();
+				EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
+				cardSTATE = MFEMUL_SELECT1;
+
+				// init crypto block
+				LED_B_OFF();
+				LED_C_OFF();
+				crypto1_destroy(pcs);
+				cardAUTHKEY = 0xff;
+			}
+		}
+		
+		switch (cardSTATE) {
+			case MFEMUL_NOFIELD:{
+				break;
+			}
+			case MFEMUL_HALTED:{
+				break;
+			}
+			case MFEMUL_IDLE:{
+				break;
+			}
+			case MFEMUL_SELECT1:{
+				// select all
+				if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
+					EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
+					break;
+				}
 
-	// clear trace
-	traceLen = 0;
-//  tracing = false;
+				// select card
+				if (len == 9 && 
+						(receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
+					if (!_7BUID) 
+						EmSendCmd(rSAK, sizeof(rSAK));
+					else
+						EmSendCmd(rSAK1, sizeof(rSAK1));
+
+					cuid = bytes_to_num(rUIDBCC1, 4);
+					if (!_7BUID) {
+						cardSTATE = MFEMUL_WORK;
+						LED_B_ON();
+						if (MF_DBGLEVEL >= 4)	Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
+						break;
+					} else {
+						cardSTATE = MFEMUL_SELECT2;
+						break;
+					}
+				}
+				
+				break;
+			}
+			case MFEMUL_SELECT2:{
+				if (!len) break;
+			
+				if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
+					EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
+					break;
+				}
 
-	iso14443a_setup();
+				// select 2 card
+				if (len == 9 && 
+						(receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
+					EmSendCmd(rSAK, sizeof(rSAK));
 
-	LED_A_ON();
-	LED_B_OFF();
-	LED_C_OFF();
+					cuid = bytes_to_num(rUIDBCC2, 4);
+					cardSTATE = MFEMUL_WORK;
+					LED_B_ON();
+					if (MF_DBGLEVEL >= 4)	Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
+					break;
+				}
+				
+				// i guess there is a command). go into the work state.
+				if (len != 4) break;
+				cardSTATE = MFEMUL_WORK;
+				goto lbWORK;
+			}
+			case MFEMUL_AUTH1:{
+				if (len == 8) {
+					// --- crypto
+					//rn_enc = bytes_to_num(receivedCmd, 4);
+					//cardRn = rn_enc ^ crypto1_word(pcs, rn_enc , 1);
+					cardRr = bytes_to_num(&receivedCmd[4], 4) ^ crypto1_word(pcs, 0, 0);
+					// test if auth OK
+					if (cardRr != prng_successor(nonce, 64)){
+						if (MF_DBGLEVEL >= 4)	Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x", cardRr, prng_successor(nonce, 64));
+						cardSTATE_TO_IDLE();
+						break;
+					}
+					ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
+					num_to_bytes(ans, 4, rAUTH_AT);
+					// --- crypto
+					EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
+					cardSTATE = MFEMUL_AUTH2;
+				} else {
+					cardSTATE_TO_IDLE();
+				}
+				if (cardSTATE != MFEMUL_AUTH2) break;
+			}
+			case MFEMUL_AUTH2:{
+				LED_C_ON();
+				cardSTATE = MFEMUL_WORK;
+				if (MF_DBGLEVEL >= 4)	Dbprintf("AUTH COMPLETED. sec=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
+				break;
+			}
+			case MFEMUL_WORK:{
+lbWORK:	if (len == 0) break;
+				
+				if (cardAUTHKEY == 0xff) {
+					// first authentication
+					if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
+						authTimer = GetTickCount();
+
+						cardAUTHSC = receivedCmd[1] / 4;  // received block num
+						cardAUTHKEY = receivedCmd[0] - 0x60;
+
+						// --- crypto
+						crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
+						ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
+						num_to_bytes(nonce, 4, rAUTH_AT);
+						EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
+						// --- crypto
+						
+//   last working revision 
+//						EmSendCmd14443aRaw(resp1, resp1Len, 0);
+//						LogTrace(NULL, 0, GetDeltaCountUS(), 0, true);
+
+						cardSTATE = MFEMUL_AUTH1;
+						//nextCycleTimeout = 10;
+						break;
+					}
+				} else {
+					// decrypt seqence
+					mf_crypto1_decrypt(pcs, receivedCmd, len);
+					
+					// nested authentication
+					if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
+						authTimer = GetTickCount();
+
+						cardAUTHSC = receivedCmd[1] / 4;  // received block num
+						cardAUTHKEY = receivedCmd[0] - 0x60;
+
+						// --- crypto
+						crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
+						ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
+						num_to_bytes(ans, 4, rAUTH_AT);
+						EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
+						// --- crypto
+
+						cardSTATE = MFEMUL_AUTH1;
+						//nextCycleTimeout = 10;
+						break;
+					}
+				}
+				
+				// rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
+				// BUT... ACK --> NACK
+				if (len == 1 && receivedCmd[0] == CARD_ACK) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					break;
+				}
+				
+				// rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
+				if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					break;
+				}
+				
+				// read block
+				if (len == 4 && receivedCmd[0] == 0x30) {
+					if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						break;
+					}
+					emlGetMem(response, receivedCmd[1], 1);
+					AppendCrc14443a(response, 16);
+					mf_crypto1_encrypt(pcs, response, 18, &par);
+					EmSendCmdPar(response, 18, par);
+					break;
+				}
+				
+				// write block
+				if (len == 4 && receivedCmd[0] == 0xA0) {
+					if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						break;
+					}
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					//nextCycleTimeout = 50;
+					cardSTATE = MFEMUL_WRITEBL2;
+					cardWRBL = receivedCmd[1];
+					break;
+				}
+			
+				// works with cardINTREG
+				
+				// increment, decrement, restore
+				if (len == 4 && (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2)) {
+					if (receivedCmd[1] >= 16 * 4 || 
+							receivedCmd[1] / 4 != cardAUTHSC || 
+							emlCheckValBl(receivedCmd[1])) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						break;
+					}
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					if (receivedCmd[0] == 0xC1)
+						cardSTATE = MFEMUL_INTREG_INC;
+					if (receivedCmd[0] == 0xC0)
+						cardSTATE = MFEMUL_INTREG_DEC;
+					if (receivedCmd[0] == 0xC2)
+						cardSTATE = MFEMUL_INTREG_REST;
+					cardWRBL = receivedCmd[1];
+					
+					break;
+				}
+				
 
-	while (true) {
-		if(!iso14443a_select_card(uid, NULL, &cuid)) {
-			Dbprintf("Can't select card");
-			break;
-		};
+				// transfer
+				if (len == 4 && receivedCmd[0] == 0xB0) {
+					if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) {
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+						break;
+					}
+					
+					if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					else
+						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+						
+					break;
+				}
 
-		if(mifare_classic_auth(pcs, cuid, blockNo, keyType, ui64Key, AUTH_FIRST)) {
-			Dbprintf("Auth error");
-			break;
-		};
-		
-		if(mifare_classic_writeblock(pcs, cuid, blockNo, blockdata)) {
-			Dbprintf("Write block error");
-			break;
-		};
+				// halt
+				if (len == 4 && (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00)) {
+					LED_B_OFF();
+					LED_C_OFF();
+					cardSTATE = MFEMUL_HALTED;
+					if (MF_DBGLEVEL >= 4)	Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
+					break;
+				}
+				
+				// command not allowed
+				if (len == 4) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					break;
+				}
 
-		if(mifare_classic_halt(pcs, cuid)) {
-			Dbprintf("Halt error");
-			break;
-		};
-		
-		isOK = 1;
-		break;
+				// case break
+				break;
+			}
+			case MFEMUL_WRITEBL2:{
+				if (len == 18){
+					mf_crypto1_decrypt(pcs, receivedCmd, len);
+					emlSetMem(receivedCmd, cardWRBL, 1);
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
+					cardSTATE = MFEMUL_WORK;
+					break;
+				} else {
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				break;
+			}
+			
+			case MFEMUL_INTREG_INC:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				cardINTREG = cardINTREG + ans;
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+			case MFEMUL_INTREG_DEC:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				cardINTREG = cardINTREG - ans;
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+			case MFEMUL_INTREG_REST:{
+				mf_crypto1_decrypt(pcs, receivedCmd, len);
+				memcpy(&ans, receivedCmd, 4);
+				if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
+					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				cardSTATE = MFEMUL_WORK;
+				break;
+			}
+		}
 	}
-	
-	//  ----------------------------- crypto1 destroy
-	crypto1_destroy(pcs);
-	
-//  DbpString("WRITE BLOCK FINISHED");
 
-	// add trace trailer
-	uid[0] = 0xff;
-	uid[1] = 0xff;
-	uid[2] = 0xff;
-	uid[3] = 0xff;
-	LogTrace(uid, 4, 0, 0, TRUE);
-
-	UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
-	
-	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-	LED_B_OFF();	
-
-
-	// Thats it...
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 	LEDsoff();
-//  tracing = TRUE;
 
-}
+	// add trace trailer
+	memset(rAUTH_NT, 0x44, 4);
+	LogTrace(rAUTH_NT, 4, 0, 0, TRUE);
 
-// Return 1 if the nonce is invalid else return 0
-int valid_nonce(uint32_t Nt, uint32_t NtEnc, uint32_t Ks1, byte_t * parity) {
-	return ((oddparity((Nt >> 24) & 0xFF) == ((parity[0]) ^ oddparity((NtEnc >> 24) & 0xFF) ^ BIT(Ks1,16))) & \
-	(oddparity((Nt >> 16) & 0xFF) == ((parity[1]) ^ oddparity((NtEnc >> 16) & 0xFF) ^ BIT(Ks1,8))) & \
-	(oddparity((Nt >> 8) & 0xFF) == ((parity[2]) ^ oddparity((NtEnc >> 8) & 0xFF) ^ BIT(Ks1,0)))) ? 1 : 0;
+	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, traceLen);
 }
 
-
 //-----------------------------------------------------------------------------
-// MIFARE nested authentication. 
+// MIFARE sniffer. 
 // 
 //-----------------------------------------------------------------------------
-void MifareNested(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
-{
-	// params
-	uint8_t blockNo = arg0;
-	uint8_t keyType = arg1;
-	uint64_t ui64Key = 0;
-
-	ui64Key = bytes_to_num(datain, 6);
-	
-	// variables
-	uint8_t targetBlockNo = blockNo + 1;
-	int rtr, i, m, len;
-	int davg, dmin, dmax;
-	uint8_t uid[8];
-	uint32_t cuid, nt1, nt2, nttmp, nttest, par, ks1;
-	uint8_t par_array[4];
-	nestedVector nvector[3][10];
-	int nvectorcount[3] = {10, 10, 10};
-	int ncount = 0;
-	struct Crypto1State mpcs = {0, 0};
-	struct Crypto1State *pcs;
-	pcs = &mpcs;
-	uint8_t* receivedAnswer = mifare_get_bigbufptr();
+void RAMFUNC SniffMifare(uint8_t param) {
+	// param:
+	// bit 0 - trigger from first card answer
+	// bit 1 - trigger from first reader 7-bit request
 
-	// clear trace
-	traceLen = 0;
-  tracing = false;
-
-	iso14443a_setup();
+	// C(red) A(yellow) B(green)
+	LEDsoff();
+	// init trace buffer
+    iso14a_clear_trace();
 
-	LED_A_ON();
-	LED_B_ON();
-	LED_C_OFF();
+	// 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);
+	// The response (tag -> reader) that we're receiving.
+	uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
 
-  FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-  SpinDelay(200);
+	// 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;
 	
-	davg = dmax = 0;
-	dmin = 2000;
-
-	// test nonce distance
-	for (rtr = 0; rtr < 10; rtr++) {
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    SpinDelay(100);
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-
-    // Test if the action was cancelled
-    if(BUTTON_PRESS()) {
-      break;
-    }
-
-		if(!iso14443a_select_card(uid, NULL, &cuid)) {
-			Dbprintf("Can't select card");
-			break;
-		};
-		
-		if(mifare_classic_authex(pcs, cuid, blockNo, keyType, ui64Key, AUTH_FIRST, &nt1)) {
-			Dbprintf("Auth1 error");
-			break;
-		};
+	// The DMA buffer, used to stream samples from the FPGA
+	int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
+	int8_t *data = dmaBuf;
+	int maxDataLen = 0;
+	int dataLen = 0;
 
-		if(mifare_classic_authex(pcs, cuid, blockNo, keyType, ui64Key, AUTH_NESTED, &nt2)) {
-			Dbprintf("Auth2 error");
-			break;
-		};
-		
-		nttmp = prng_successor(nt1, 500);
-		for (i = 501; i < 2000; i++) {
-			nttmp = prng_successor(nttmp, 1);
-			if (nttmp == nt2) break;
-		}
-		
-		if (i != 2000) {
-			davg += i;
-			if (dmin > i) dmin = i;
-			if (dmax < i) dmax = i;
-//			Dbprintf("r=%d nt1=%08x nt2=%08x distance=%d", rtr, nt1, nt2, i);
-		}
-	}
-	
-	if (rtr == 0)	return;
+	// Set up the demodulator for tag -> reader responses.
+	Demod.output = receivedResponse;
+	Demod.len = 0;
+	Demod.state = DEMOD_UNSYNCD;
 
-	davg = davg / rtr;
-	Dbprintf("distance: min=%d max=%d avg=%d", dmin, dmax, davg);
+	// Set up the demodulator for the reader -> tag commands
+	memset(&Uart, 0, sizeof(Uart));
+	Uart.output = receivedCmd;
+	Uart.byteCntMax = 32; // was 100 (greg)//////////////////
+	Uart.state = STATE_UNSYNCD;
 
-	LED_B_OFF();
+	// Setup for the DMA.
+	FpgaSetupSsc();
+	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 
-  tracing = true;
+	// And put the FPGA in the appropriate mode
+	// Signal field is off with the appropriate LED
+	LED_D_OFF();
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 	
-	LED_C_ON();
-
-	//  get crypted nonces for target sector
-	for (rtr = 0; rtr < 4; rtr++) {
-		Dbprintf("------------------------------");
-
-		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    SpinDelay(100);
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+	// init sniffer
+	MfSniffInit();
+	int sniffCounter = 0;
 
-    // Test if the action was cancelled
-    if(BUTTON_PRESS()) {
-      break;
-    }
-
-		if(!iso14443a_select_card(uid, NULL, &cuid)) {
-			Dbprintf("Can't select card");
-			break;
-		};
-		
-		if(mifare_classic_authex(pcs, cuid, blockNo, keyType, ui64Key, AUTH_FIRST, &nt1)) {
-			Dbprintf("Auth1 error");
-			break;
-		};
+	// And now we loop, receiving samples.
+	while(true) {
+		if(BUTTON_PRESS()) {
+			DbpString("cancelled by button");
+			goto done;
+		}
 
-		// nested authentication
-		len = mifare_sendcmd_shortex(pcs, AUTH_NESTED, 0x60 + (keyType & 0x01), targetBlockNo, receivedAnswer, &par);
-		if (len != 4) {
-			Dbprintf("Auth2 error len=%d", len);
-			break;
-		};
-	
-		nt2 = bytes_to_num(receivedAnswer, 4);		
-		Dbprintf("r=%d nt1=%08x nt2enc=%08x nt2par=%08x", rtr, nt1, nt2, par);
+		LED_A_ON();
+		WDT_HIT();
 		
-// -----------------------  test		
-/*	uint32_t d_nt, d_ks1, d_ks2, d_ks3, reader_challenge;
-	byte_t ar[4];
-
-	ar[0] = 0x55;
-	ar[1] = 0x41;
-	ar[2] = 0x49;
-	ar[3] = 0x92; 
-
-	crypto1_destroy(pcs);
-	crypto1_create(pcs, ui64Key);
+		if (++sniffCounter > 65) {
+			if (MfSniffSend(2000)) {
+				FpgaEnableSscDma();
+			}
+			sniffCounter = 0;
+		}
 
-	// decrypt nt with help of new key 
-	d_nt = crypto1_word(pcs, nt2 ^ cuid, 1) ^ nt2;
-	
-	reader_challenge = d_nt;//(uint32_t)bytes_to_num(ar, 4); 
-	d_ks1 = crypto1_word(pcs, reader_challenge, 0);
-	d_ks2 = crypto1_word(pcs, 0, 0);
-	d_ks3 = crypto1_word(pcs, 0,0);
-		
-	Dbprintf("TST: ks1=%08x nt=%08x", d_ks1, d_nt);*/
-// -----------------------  test		
-		
-		// Parity validity check
-		for (i = 0; i < 4; i++) {
-			par_array[i] = (oddparity(receivedAnswer[i]) != ((par & 0x08) >> 3));
-			par = par << 1;
+		int register readBufDataP = data - dmaBuf;
+		int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
+		if (readBufDataP <= dmaBufDataP){
+			dataLen = dmaBufDataP - readBufDataP;
+		} else {
+			dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
 		}
-		
-		ncount = 0;
-		for (m = dmin - 10; m < dmax + 10; m++) {
-			nttest = prng_successor(nt1, m);
-			ks1 = nt2 ^ nttest;
-
-//--------------------------------------  test
-/*			if (nttest == d_nt){
-				Dbprintf("nttest=d_nt!  m=%d ks1=%08x nttest=%08x", m, ks1, nttest);
-			}*/
-//--------------------------------------  test
-			if (valid_nonce(nttest, nt2, ks1, par_array) && (ncount < 11)){
-				
-				nvector[2][ncount].nt = nttest;
-				nvector[2][ncount].ks1 = ks1;
-				ncount++;
-				nvectorcount[2] = ncount;
-				
-				Dbprintf("valid m=%d ks1=%08x nttest=%08x", m, ks1, nttest);
+		// test for length of buffer
+		if(dataLen > maxDataLen) {
+			maxDataLen = dataLen;
+			if(dataLen > 400) {
+				Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
+				goto done;
 			}
+		}
+		if(dataLen < 1) continue;
 
+		// primary buffer was stopped( <-- we lost data!
+		if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+			AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+			Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
 		}
-		
-		// select vector with length less than got
-		m = 2;
-		if (nvectorcount[2] < nvectorcount[1]) m = 1;
-		if (nvectorcount[2] < nvectorcount[0]) m = 0;
-		if (m != 2) {
-			for (i = 0; i < nvectorcount[m]; i++) {
-				nvector[m][i] = nvector[2][i];
-			}
-			nvectorcount[m] = nvectorcount[2];
+		// secondary buffer sets as primary, secondary buffer was stopped
+		if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+			AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+			AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
 		}
+
+		LED_A_OFF();
 		
-		Dbprintf("vector count: 1=%d 2=%d 3=%d", nvectorcount[0], nvectorcount[1], nvectorcount[2]);
-	}
+		if(MillerDecoding((data[0] & 0xF0) >> 4)) {
+			LED_C_INV();
+			// check - if there is a short 7bit request from reader
+			if (MfSniffLogic(receivedCmd, Uart.byteCnt, Uart.parityBits, Uart.bitCnt, TRUE)) break;
+
+			/* And ready to receive another command. */
+			Uart.state = STATE_UNSYNCD;
+			
+			/* And also reset the demod code */
+			Demod.state = DEMOD_UNSYNCD;
+		}
 
-	LED_C_OFF();
+		if(ManchesterDecoding(data[0] & 0x0F)) {
+			LED_C_INV();
 
-	
-	//  ----------------------------- crypto1 destroy
-	crypto1_destroy(pcs);
-	
-	// add trace trailer
-	uid[0] = 0xff;
-	uid[1] = 0xff;
-	uid[2] = 0xff;
-	uid[3] = 0xff;
-	LogTrace(uid, 4, 0, 0, TRUE);
-
-	for (i = 0; i < 2; i++) {
-		ncount = nvectorcount[i];
-		if (ncount > 5) ncount = 5; //!!!!!  needs to be 2 packets x 5 pairs (nt,ks1)
-
-		// isEOF = 0
-		UsbCommand ack = {CMD_ACK, {0, ncount, targetBlockNo}};
-		memcpy(ack.d.asBytes, &cuid, 4);
-		for (m = 0; m < 5; m++) {
-			memcpy(ack.d.asBytes + 4 + m * 8 + 0, &nvector[i][m].nt, 4);
-			memcpy(ack.d.asBytes + 4 + m * 8 + 4, &nvector[i][m].ks1, 4);
-		}
-	
-		LED_B_ON();
-		UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-		LED_B_OFF();	
-	}
+			if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
 
-	// finalize list
-	// isEOF = 1
-	UsbCommand ack = {CMD_ACK, {1, 0, 0}};
-	
-	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
-	LED_B_OFF();	
+			// And ready to receive another response.
+			memset(&Demod, 0, sizeof(Demod));
+			Demod.output = receivedResponse;
+			Demod.state = DEMOD_UNSYNCD;
 
-	DbpString("NESTED FINISHED");
+			/* And also reset the uart code */
+			Uart.state = STATE_UNSYNCD;
+		}
 
-	// Thats it...
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	LEDsoff();
-//  tracing = TRUE;
+		data++;
+		if(data > dmaBuf + DMA_BUFFER_SIZE) {
+			data = dmaBuf;
+		}
+	} // main cycle
 
-}
+	DbpString("COMMAND FINISHED");
 
-//-----------------------------------------------------------------------------
-// MIFARE 1K simulate. 
-// 
-//-----------------------------------------------------------------------------
-void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
-{
+done:
+	FpgaDisableSscDma();
+	MfSniffEnd();
+	
+	Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax);
+	LEDsoff();
 }