X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/9f6939303570569bf4bc050a9b82c79b1927a814..902cb3c00b49535f0de9a3b6d5ba0c54260ccac1:/armsrc/iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 54fbb246..d2ebb0c6 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
 //
@@ -14,17 +14,21 @@
 #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 - manchester
 // Sequence D: 11110000 modulation with subcarrier during first half
@@ -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
 };
 
-uint8_t trigger = 0;
-void iso14a_set_trigger(int enable) {
+
+void iso14a_set_trigger(bool enable) {
 	trigger = enable;
 }
 
-void iso14a_clear_tracelen(void) {
+void iso14a_clear_trace() {
+  memset(trace, 0x44, TRACE_SIZE);
 	traceLen = 0;
 }
-void iso14a_set_tracing(int enable) {
+
+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;
@@ -127,32 +138,7 @@ 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)
 {
@@ -391,32 +377,7 @@ 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)
 {
@@ -616,166 +577,147 @@ 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);
-
-    // 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;
+	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);
 
-    // 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);
+	// 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;
 
+	// Set up the demodulator for tag -> reader responses.
+	Demod.output = receivedResponse;
+	Demod.len = 0;
+	Demod.state = DEMOD_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;
+	// 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_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;
-        }
+	// Setup for the DMA.
+	FpgaSetupSsc();
+	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 
-        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();
-        }
+	// 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);
 
-        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();
-        }
+	// 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(BUTTON_PRESS()) {
-            DbpString("cancelled_a");
-            goto done;
-        }
-    }
+		LED_A_ON();
+		WDT_HIT();
+
+		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();
+
+			// check - if there is a short 7bit request from reader
+			if ((!triggered) && (param & 0x02) && (Uart.byteCnt == 1) && (Uart.bitCnt = 9)) triggered = TRUE;
+
+			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");
+	DbpString("COMMAND FINISHED");
 
 done:
-    AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
-    Dbprintf("maxBehindBy=%x, Uart.state=%x, Uart.byteCnt=%x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("Uart.byteCntMax=%x, traceLen=%x, Uart.output[0]=%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();
 }
 
 //-----------------------------------------------------------------------------
@@ -962,45 +904,91 @@ static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded);
 // 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)
 {
-	// 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;
+	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
@@ -1013,41 +1001,41 @@ 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;
@@ -1057,34 +1045,35 @@ 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)
 	CodeStrangeAnswerAsTag();
@@ -1092,95 +1081,83 @@ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 
 	// 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;
 
-    cmdsRecvd = 0;
+	// We need to listen to the high-frequency, peak-detected path.
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaSetupSsc();
 
-    LED_A_ON();
-	for(;;) {
+	cmdsRecvd = 0;
 
-		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
+	LED_A_ON();
+	for(;;) {
+	
+		if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
+			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;
+		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
+			respdata = response3a;
+			respsize = sizeof(response3a);
+		} else if(receivedCmd[0] == 0x30) {	// Received a (plain) 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
+			Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
+			respdata = &nack;
+			respsize = sizeof(nack); // 4-bit answer
+		} else if(receivedCmd[0] == 0x50) {	// Received a HALT
 			DbpString("Reader requested we HALT!:");
-
-		} else if(receivedCmd[0] == 0x60) {
-			// Received an authentication request
+			// 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;
-			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",
+			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 {
+			// Never seen this command before
+			Dbprintf("Received (len=%d): %02x %02x %02x %02x %02x %02x %02x %02x %02x",
 			len,
 			receivedCmd[0], receivedCmd[1], receivedCmd[2],
 			receivedCmd[3], receivedCmd[4], receivedCmd[5],
 			receivedCmd[6], receivedCmd[7], receivedCmd[8]);
 			// Do not respond
 			resp = resp1; respLen = 0; order = 0;
-        }
+			respdata = NULL;
+			respsize = 0;
+		}
 
 		// Count number of wakeups received after a halt
 		if(order == 6 && lastorder == 5) { happened++; }
@@ -1194,57 +1171,30 @@ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 			//i = 0;
 		}
 
-        memset(receivedCmd, 0x44, 32);
-
 		if(cmdsRecvd > 999) {
 			DbpString("1000 commands later...");
-            break;
-        }
-		else {
+			break;
+		} else {
 			cmdsRecvd++;
 		}
 
-        if(respLen <= 0) continue;
-		//----------------------------
-		//u = 0;
-		//b = 0x00;
-		//fdt_indicator = FALSE;
-
-		EmSendCmd14443aRaw(resp, respLen, receivedCmd[0] == 0x52);
-/*        // 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) {
+			LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE);
+			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();
@@ -1692,7 +1642,7 @@ int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, u
 	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* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);	// was 3560 - tied to other size changes
 
 	uint8_t sak = 0x04; // cascade uid
 	int cascade_level = 0;
@@ -1700,13 +1650,14 @@ int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, u
 	int len;
 	
 	// clear uid
-	memset(uid_ptr, 0, 8);
+	memset(uid_ptr, 0, 12);
 
 	// 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;
-
+//  Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
+  
 	if(resp_data)
 		memcpy(resp_data->atqa, resp, 2);
 	
@@ -1721,6 +1672,8 @@ int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, u
 		// SELECT_ALL
 		ReaderTransmit(sel_all,sizeof(sel_all));
 		if (!ReaderReceive(resp)) return 0;
+//    Dbprintf("uid: %02x %02x %02x %02x",resp[0],resp[1],resp[2],resp[3]);
+
 		if(uid_ptr) memcpy(uid_ptr + cascade_level*4, resp, 4);
 		
 		// calculate crypto UID
@@ -1759,17 +1712,20 @@ int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, u
 		resp_data->ats_len = len;
 	}
 	
+	// reset the PCB block number
+	iso14_pcb_blocknum = 0;
+	
 	return 1;
 }
 
 void iso14443a_setup() {
-	// Setup SSC
-	FpgaSetupSsc();
+  // 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);
+	SpinDelay(50);
 
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
@@ -1777,7 +1733,7 @@ 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(50);
 
 	iso14a_timeout = 2048; //default
 }
@@ -1785,35 +1741,52 @@ 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);
 	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];
+  uint32_t arg0;
+  byte_t buf[48];
+  
+  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(buf, (iso14a_card_select_t *)(buf+12), NULL);
+		cmd_send(CMD_ACK,arg0,0,0,buf,48);
+//    UsbSendPacket((void *)ack, sizeof(UsbCommand));
 	}
 
 	if(param & ISO14A_SET_TIMEOUT) {
@@ -1825,8 +1798,9 @@ 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,48);
+//		UsbSendPacket((void *)ack, sizeof(UsbCommand));
 	}
 
 	if(param & ISO14A_RAW) {
@@ -1835,8 +1809,9 @@ void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
 			len += 2;
 		}
 		ReaderTransmit(cmd,len);
-		ack->arg[0] = ReaderReceive(ack->d.asBytes);
-		UsbSendPacket((void *)ack, sizeof(UsbCommand));
+		arg0 = ReaderReceive(buf);
+//		UsbSendPacket((void *)ack, sizeof(UsbCommand));
+    cmd_send(CMD_ACK,arg0,0,0,buf,48);
 	}
 
 	if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(0);
@@ -1847,6 +1822,7 @@ void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 	LEDsoff();
 }
+
 //-----------------------------------------------------------------------------
 // Read an ISO 14443a tag. Send out commands and store answers.
 //
@@ -1857,7 +1833,7 @@ void ReaderMifare(uint32_t parameter)
 	uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
 	uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
 
-	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
+	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);	// was 3560 - tied to other size changes
 	traceLen = 0;
 	tracing = false;
 
@@ -1886,11 +1862,12 @@ void ReaderMifare(uint32_t parameter)
 
 	while(TRUE)
 	{
-		LED_C_ON();
+		LED_C_OFF();
 		FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-		SpinDelay(200);
+		SpinDelay(50);
 		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-		LED_C_OFF();
+		LED_C_ON();
+		SpinDelay(2);
 
 		// Test if the action was cancelled
 		if(BUTTON_PRESS()) {
@@ -1914,7 +1891,7 @@ void ReaderMifare(uint32_t parameter)
 		{
 			if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue;
 
-			isNULL = (nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0);
+			isNULL = !(nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0);
 			if ( (isNULL != 0 ) && (memcmp(nt, nt_attacked, 4) != 0) ) continue;
 
 			if (nt_diff == 0)
@@ -1953,14 +1930,16 @@ void ReaderMifare(uint32_t parameter)
 	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);
+  byte_t buf[48];
+//	UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
+	memcpy(buf + 0,  uid, 4);
+	memcpy(buf + 4,  nt, 4);
+	memcpy(buf + 8,  par_list, 8);
+	memcpy(buf + 16, ks_list, 8);
 		
 	LED_B_ON();
-	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
+  cmd_send(CMD_ACK,isOK,0,0,buf,48);
+//	UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
 	LED_B_OFF();	
 
 	// Thats it...
@@ -2077,7 +2056,7 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 		} 
 
 		if (cardSTATE != MFEMUL_NOFIELD) {
-			res = EmGetCmd(receivedCmd, &len, 100); // (+ nextCycleTimeout)
+			res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
 			if (res == 2) {
 				cardSTATE = MFEMUL_NOFIELD;
 				LEDsoff();
@@ -2391,9 +2370,7 @@ lbWORK:	if (len == 0) break;
 				cardSTATE = MFEMUL_WORK;
 				break;
 			}
-		
 		}
-	
 	}
 
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
@@ -2405,3 +2382,149 @@ lbWORK:	if (len == 0) break;
 
 	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, traceLen);
 }
+
+//-----------------------------------------------------------------------------
+// MIFARE sniffer. 
+// 
+//-----------------------------------------------------------------------------
+void RAMFUNC SniffMifare(uint8_t param) {
+	// param:
+	// bit 0 - trigger from first card answer
+	// bit 1 - trigger from first reader 7-bit request
+
+	// C(red) A(yellow) B(green)
+	LEDsoff();
+	// init trace buffer
+    iso14a_clear_trace();
+
+	// 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);
+
+	// 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;
+
+	// 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;
+
+	// Setup for the DMA.
+	FpgaSetupSsc();
+	FpgaSetupSscDma((uint8_t *)dmaBuf, 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);
+	
+	// init sniffer
+	MfSniffInit();
+	int sniffCounter = 0;
+
+	// And now we loop, receiving samples.
+	while(true) {
+		if(BUTTON_PRESS()) {
+			DbpString("cancelled by button");
+			goto done;
+		}
+
+		LED_A_ON();
+		WDT_HIT();
+		
+		if (++sniffCounter > 65) {
+			if (MfSniffSend(2000)) {
+				FpgaEnableSscDma();
+			}
+			sniffCounter = 0;
+		}
+
+		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;
+			Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
+		}
+		// 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();
+		
+		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;
+		}
+
+		if(ManchesterDecoding(data[0] & 0x0F)) {
+			LED_C_INV();
+
+			if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
+
+			// And ready to receive another response.
+			memset(&Demod, 0, sizeof(Demod));
+			Demod.output = receivedResponse;
+			Demod.state = DEMOD_UNSYNCD;
+
+			/* And also reset the uart code */
+			Uart.state = STATE_UNSYNCD;
+		}
+
+		data++;
+		if(data > dmaBuf + DMA_BUFFER_SIZE) {
+			data = dmaBuf;
+		}
+	} // main cycle
+
+	DbpString("COMMAND FINISHED");
+
+done:
+	FpgaDisableSscDma();
+	MfSniffEnd();
+	
+	Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax);
+	LEDsoff();
+}
\ No newline at end of file