X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/be2cf126bf74c3e0c60706dd2620c8a6d742e396..60034782f92e3f8d59a2a56b32663ca16cc59524:/armsrc/iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index b73495a3..5c7367a1 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -20,10 +20,9 @@
 #include "iso14443a.h"
 #include "crapto1.h"
 #include "mifareutil.h"
-
+#include "BigBuf.h"
 static uint32_t iso14a_timeout;
 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;
@@ -142,25 +141,40 @@ const uint8_t OddByteParity[256] = {
   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
 };
 
+
 void iso14a_set_trigger(bool enable) {
 	trigger = enable;
 }
 
-void iso14a_clear_trace() {
-	uint8_t *trace = BigBuf_get_addr();
-	uint16_t max_traceLen = BigBuf_max_traceLen();
-	memset(trace, 0x44, max_traceLen);
-	traceLen = 0;
-}
-
-void iso14a_set_tracing(bool enable) {
-	tracing = enable;
-}
 
 void iso14a_set_timeout(uint32_t timeout) {
 	iso14a_timeout = timeout;
+	if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 }
 
+
+void iso14a_set_ATS_timeout(uint8_t *ats) {
+
+	uint8_t tb1;
+	uint8_t fwi; 
+	uint32_t fwt;
+	
+	if (ats[0] > 1) {							// there is a format byte T0
+		if ((ats[1] & 0x20) == 0x20) {			// there is an interface byte TB(1)
+			if ((ats[1] & 0x10) == 0x10) {		// there is an interface byte TA(1) preceding TB(1)
+				tb1 = ats[3];
+			} else {
+				tb1 = ats[2];
+			}
+			fwi = (tb1 & 0xf0) >> 4;			// frame waiting indicator (FWI)
+			fwt = 256 * 16 * (1 << fwi);		// frame waiting time (FWT) in 1/fc
+			
+			iso14a_set_timeout(fwt/(8*16));
+		}
+	}
+}
+
+
 //-----------------------------------------------------------------------------
 // Generate the parity value for a byte sequence
 //
@@ -199,63 +213,6 @@ void AppendCrc14443a(uint8_t* data, int len)
 	ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 }
 
-// The function LogTrace() is also used by the iClass implementation in iClass.c
-bool RAMFUNC LogTrace(const uint8_t *btBytes, uint16_t iLen, uint32_t timestamp_start, uint32_t timestamp_end, uint8_t *parity, bool readerToTag)
-{
-	if (!tracing) return FALSE;
-	
-	uint8_t *trace = BigBuf_get_addr();
-	uint16_t num_paritybytes = (iLen-1)/8 + 1;	// number of valid paritybytes in *parity
-	uint16_t duration = timestamp_end - timestamp_start;
-
-	// Return when trace is full
-	uint16_t max_traceLen = BigBuf_max_traceLen();
-	if (traceLen + sizeof(iLen) + sizeof(timestamp_start) + sizeof(duration) + num_paritybytes + iLen >= max_traceLen) {
-		tracing = FALSE;	// don't trace any more
-		return FALSE;
-	}
-	
-	// Traceformat:
-	// 32 bits timestamp (little endian)
-	// 16 bits duration (little endian)
-	// 16 bits data length (little endian, Highest Bit used as readerToTag flag)
-	// y Bytes data
-	// x Bytes parity (one byte per 8 bytes data)
-	
-	// timestamp (start)
-	trace[traceLen++] = ((timestamp_start >> 0) & 0xff);
-	trace[traceLen++] = ((timestamp_start >> 8) & 0xff);
-	trace[traceLen++] = ((timestamp_start >> 16) & 0xff);
-	trace[traceLen++] = ((timestamp_start >> 24) & 0xff);
-	
-	// duration
-	trace[traceLen++] = ((duration >> 0) & 0xff);
-	trace[traceLen++] = ((duration >> 8) & 0xff);
-
-	// data length
-	trace[traceLen++] = ((iLen >> 0) & 0xff);
-	trace[traceLen++] = ((iLen >> 8) & 0xff);
-
-	// readerToTag flag
-	if (!readerToTag) {
-		trace[traceLen - 1] |= 0x80;
-	}
-
-	// data bytes
-	if (btBytes != NULL && iLen != 0) {
-		memcpy(trace + traceLen, btBytes, iLen);
-	}
-	traceLen += iLen;
-
-	// parity bytes
-	if (parity != NULL && iLen != 0) {
-		memcpy(trace + traceLen, parity, num_paritybytes);
-	}
-	traceLen += num_paritybytes;
-
-	return TRUE;
-}
-
 //=============================================================================
 // ISO 14443 Type A - Miller decoder
 //=============================================================================
@@ -310,26 +267,27 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 
 	Uart.twoBits = (Uart.twoBits << 8) | bit;
 	
-	if (Uart.state == STATE_UNSYNCD) {												// not yet synced
+	if (Uart.state == STATE_UNSYNCD) {											// not yet synced
 	
-		if (Uart.highCnt < 7) {													// wait for a stable unmodulated signal
+		if (Uart.highCnt < 2) {													// wait for a stable unmodulated signal
 			if (Uart.twoBits == 0xffff) {
 				Uart.highCnt++;
 			} else {
 				Uart.highCnt = 0;
 			}
 		} else {	
-			Uart.syncBit = 0xFFFF; // not set
-			// look for 00xx1111 (the start bit)
-			if 		((Uart.twoBits & 0x6780) == 0x0780) Uart.syncBit = 7; 
-			else if ((Uart.twoBits & 0x33C0) == 0x03C0) Uart.syncBit = 6;
-			else if ((Uart.twoBits & 0x19E0) == 0x01E0) Uart.syncBit = 5;
-			else if ((Uart.twoBits & 0x0CF0) == 0x00F0) Uart.syncBit = 4;
-			else if ((Uart.twoBits & 0x0678) == 0x0078) Uart.syncBit = 3;
-			else if ((Uart.twoBits & 0x033C) == 0x003C) Uart.syncBit = 2;
-			else if ((Uart.twoBits & 0x019E) == 0x001E) Uart.syncBit = 1;
-			else if ((Uart.twoBits & 0x00CF) == 0x000F) Uart.syncBit = 0;
-			if (Uart.syncBit != 0xFFFF) {
+			Uart.syncBit = 0xFFFF; 												// not set
+																				// we look for a ...1111111100x11111xxxxxx pattern (the start bit)
+			if 		((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8;   	// mask is   11x11111 xxxxxxxx, 
+																				// check for 00x11111 xxxxxxxx
+			else if	((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7;		// both masks shifted right one bit, left padded with '1'
+			else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6;		// ...
+			else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5;
+			else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4;
+			else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3;
+			else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2;
+			else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1;
+			if (Uart.syncBit != 0xFFFF) {										// found a sync bit
 				Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 				Uart.startTime -= Uart.syncBit;
 				Uart.endTime = Uart.startTime;
@@ -342,11 +300,9 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 		if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) {			
 			if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) {		// Modulation in both halves - error
 				UartReset();
-				Uart.highCnt = 6;
 			} else {															// Modulation in first half = Sequence Z = logic "0"
 				if (Uart.state == STATE_MILLER_X) {								// error - must not follow after X
 					UartReset();
-					Uart.highCnt = 6;
 				} else {
 					Uart.bitCount++;
 					Uart.shiftReg = (Uart.shiftReg >> 1);						// add a 0 to the shiftreg
@@ -401,12 +357,13 @@ static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 					if (Uart.len) {
 						return TRUE;											// we are finished with decoding the raw data sequence
 					} else {
-						UartReset();					// Nothing receiver - start over
+						UartReset();											// Nothing received - start over
+						Uart.highCnt = 1;
 					}
 				}
 				if (Uart.state == STATE_START_OF_COMMUNICATION) {				// error - must not follow directly after SOC
 					UartReset();
-					Uart.highCnt = 6;
+					Uart.highCnt = 1;
 				} else {														// a logic "0"
 					Uart.bitCount++;
 					Uart.shiftReg = (Uart.shiftReg >> 1);						// add a 0 to the shiftreg
@@ -594,12 +551,8 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 	
 	LEDsoff();
 
-	// 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
-	bool triggered = !(param & 0x03); 
-	
+	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
 	// Allocate memory from BigBuf for some buffers
 	// free all previous allocations first
 	BigBuf_free();
@@ -616,8 +569,8 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 	uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
 
 	// init trace buffer
-	iso14a_clear_trace();
-	iso14a_set_tracing(TRUE);
+	clear_trace();
+	set_tracing(TRUE);
 
 	uint8_t *data = dmaBuf;
 	uint8_t previous_data = 0;
@@ -626,8 +579,6 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 	bool TagIsActive = FALSE;
 	bool ReaderIsActive = FALSE;
 	
-	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
-
 	// Set up the demodulator for tag -> reader responses.
 	DemodInit(receivedResponse, receivedResponsePar);
 	
@@ -637,6 +588,12 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 	// Setup and start DMA.
 	FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 	
+	// 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
+	bool triggered = !(param & 0x03); 
+	
 	// And now we loop, receiving samples.
 	for(uint32_t rsamples = 0; TRUE; ) {
 
@@ -741,7 +698,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 
 	FpgaDisableSscDma();
 	Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
-	Dbprintf("traceLen=%d, Uart.output[0]=%08x", traceLen, (uint32_t)Uart.output[0]);
+	Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
 	LEDsoff();
 }
 
@@ -1069,6 +1026,9 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
 		.modulation_n = 0
 	};
   
+	// We need to listen to the high-frequency, peak-detected path.
+	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
 	BigBuf_free_keep_EM();
 
 	// allocate buffers:
@@ -1077,8 +1037,8 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
 	free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
 
 	// clear trace
-    iso14a_clear_trace();
-	iso14a_set_tracing(TRUE);
+	clear_trace();
+	set_tracing(TRUE);
 
 	// Prepare the responses of the anticollision phase
 	// there will be not enough time to do this at the moment the reader sends it REQA
@@ -1097,9 +1057,6 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
 	int happened2 = 0;
 	int cmdsRecvd = 0;
 
-	// We need to listen to the high-frequency, peak-detected path.
-	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
 	cmdsRecvd = 0;
 	tag_response_info_t* p_response;
 
@@ -1425,6 +1382,7 @@ void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *p
   CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
 }
 
+
 //-----------------------------------------------------------------------------
 // Wait for commands from reader
 // Stop when button is pressed (return 1) or field was gone (return 2)
@@ -1447,9 +1405,9 @@ static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
 	// 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);
+				ADC_MODE_PRESCALE(63) |
+				ADC_MODE_STARTUP_TIME(1) |
+				ADC_MODE_SAMPLE_HOLD_TIME(15);
 	AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
 	// start ADC
 	AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
@@ -1459,7 +1417,7 @@ static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
 
 	// Clear RXRDY:
     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-
+	
 	for(;;) {
 		WDT_HIT();
 
@@ -1471,7 +1429,7 @@ static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
 			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) {
+				if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
 					vtime = GetTickCount();
 					if (!timer) timer = vtime;
 					// 50ms no field --> card to idle state
@@ -1546,14 +1504,15 @@ static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNe
 	}
 
 	// Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
-	for (i = 0; i < 2 ; ) {
+	uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
+	for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
 		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
 			AT91C_BASE_SSC->SSC_THR = SEC_F;
 			FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 			i++;
 		}
 	}
-	
+
 	LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
 
 	return 0;
@@ -1655,7 +1614,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receive
 
 	// clear RXRDY:
     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-	
+
 	c = 0;
 	for(;;) {
 		WDT_HIT();
@@ -1665,7 +1624,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receive
 			if(ManchesterDecoding(b, offset, 0)) {
 				NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
 				return TRUE;
-			} else if (c++ > iso14a_timeout) {
+			} else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
 				return FALSE; 
 			}
 		}
@@ -1863,6 +1822,10 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
 
 	// reset the PCB block number
 	iso14_pcb_blocknum = 0;
+
+	// set default timeout based on ATS
+	iso14a_set_ATS_timeout(resp);
+
 	return 1;	
 }
 
@@ -1927,17 +1890,18 @@ void ReaderIso14443a(UsbCommand *c)
 {
 	iso14a_command_t param = c->arg[0];
 	uint8_t *cmd = c->d.asBytes;
-	size_t len = c->arg[1];
-	size_t lenbits = c->arg[2];
+	size_t len = c->arg[1] & 0xffff;
+	size_t lenbits = c->arg[1] >> 16;
+	uint32_t timeout = c->arg[2];
 	uint32_t arg0 = 0;
 	byte_t buf[USB_CMD_DATA_SIZE];
 	uint8_t par[MAX_PARITY_SIZE];
   
 	if(param & ISO14A_CONNECT) {
-		iso14a_clear_trace();
+		clear_trace();
 	}
 
-	iso14a_set_tracing(TRUE);
+	set_tracing(TRUE);
 
 	if(param & ISO14A_REQUEST_TRIGGER) {
 		iso14a_set_trigger(TRUE);
@@ -1953,7 +1917,7 @@ void ReaderIso14443a(UsbCommand *c)
 	}
 
 	if(param & ISO14A_SET_TIMEOUT) {
-		iso14a_set_timeout(c->arg[2]);
+		iso14a_set_timeout(timeout);
 	}
 
 	if(param & ISO14A_APDU) {
@@ -2007,7 +1971,7 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
 		nttmp1 = prng_successor(nttmp1, 1);
 		if (nttmp1 == nt2) return i;
 		nttmp2 = prng_successor(nttmp2, 1);
-			if (nttmp2 == nt1) return -i;
+		if (nttmp2 == nt1) return -i;
 		}
 	
 	return(-99999); // either nt1 or nt2 are invalid nonces
@@ -2030,11 +1994,15 @@ void ReaderMifare(bool first_try)
 	uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
 	uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
 
+	if (first_try) { 
+		iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+	}
+	
 	// free eventually allocated BigBuf memory. We want all for tracing.
 	BigBuf_free();
 	
-	iso14a_clear_trace();
-	iso14a_set_tracing(TRUE);
+	clear_trace();
+	set_tracing(TRUE);
 
 	byte_t nt_diff = 0;
 	uint8_t par[1] = {0};	// maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
@@ -2058,7 +2026,6 @@ void ReaderMifare(bool first_try)
 
 	if (first_try) { 
 		mf_nr_ar3 = 0;
-		iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
 		sync_time = GetCountSspClk() & 0xfffffff8;
 		sync_cycles = 65536;									// theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
 		nt_attacked = 0;
@@ -2076,18 +2043,21 @@ void ReaderMifare(bool first_try)
 	LED_B_OFF();
 	LED_C_OFF();
 	
-  
+
+	#define DARKSIDE_MAX_TRIES	32		// number of tries to sync on PRNG cycle. Then give up.
+	uint16_t unsuccessfull_tries = 0;
+	
 	for(uint16_t i = 0; TRUE; i++) {
 		
+		LED_C_ON();
 		WDT_HIT();
 
 		// Test if the action was cancelled
 		if(BUTTON_PRESS()) {
+			isOK = -1;
 			break;
 		}
 		
-		LED_C_ON();
-
 		if(!iso14443a_select_card(uid, NULL, &cuid)) {
 			if (MF_DBGLEVEL >= 1)	Dbprintf("Mifare: Can't select card");
 			continue;
@@ -2122,8 +2092,14 @@ void ReaderMifare(bool first_try)
 				nt_attacked = nt;
 			}
 			else {
-				if (nt_distance == -99999) { // invalid nonce received, try again
-					continue;
+				if (nt_distance == -99999) { // invalid nonce received
+					unsuccessfull_tries++;
+					if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) {
+						isOK = -3;		// Card has an unpredictable PRNG. Give up	
+						break;
+					} else {
+						continue;		// continue trying...
+					}
 				}
 				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);
@@ -2185,6 +2161,10 @@ void ReaderMifare(bool first_try)
 			if (nt_diff == 0 && first_try)
 			{
 				par[0]++;
+				if (par[0] == 0x00) {		// tried all 256 possible parities without success. Card doesn't send NACK.
+					isOK = -2;
+					break;
+				}
 			} else {
 				par[0] = ((par[0] & 0x1F) + 1) | par_low;
 			}
@@ -2201,13 +2181,13 @@ void ReaderMifare(bool first_try)
 	memcpy(buf + 16, ks_list, 8);
 	memcpy(buf + 24, mf_nr_ar, 4);
 		
-	cmd_send(CMD_ACK,isOK,0,0,buf,28);
+	cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
 
 	// Thats it...
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 	LEDsoff();
 
-	iso14a_set_tracing(FALSE);
+	set_tracing(FALSE);
 }
 
 /**
@@ -2262,12 +2242,6 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 	uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
 	uint8_t ar_nr_collected = 0;
 
-	// free eventually allocated BigBuf memory but keep Emulator Memory
-	BigBuf_free_keep_EM();
-	// clear trace
-    iso14a_clear_trace();
-	iso14a_set_tracing(TRUE);
-
 	// Authenticate response - nonce
 	uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
 	
@@ -2305,13 +2279,10 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 	if (_7BUID) {
 		rATQA[0] = 0x44;
 		rUIDBCC1[0] = 0x88;
+		rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
 		rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
 	}
 
-	// We need to listen to the high-frequency, peak-detected path.
-	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
-
 	if (MF_DBGLEVEL >= 1)	{
 		if (!_7BUID) {
 			Dbprintf("4B UID: %02x%02x%02x%02x", 
@@ -2323,15 +2294,24 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 		}
 	}
 
+	// We need to listen to the high-frequency, peak-detected path.
+	iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+	// free eventually allocated BigBuf memory but keep Emulator Memory
+	BigBuf_free_keep_EM();
+
+	// clear trace
+	clear_trace();
+	set_tracing(TRUE);
+
+
 	bool finished = FALSE;
 	while (!BUTTON_PRESS() && !finished) {
 		WDT_HIT();
 
 		// 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;
+			vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
 			if (vHf > MF_MINFIELDV) {
 				cardSTATE_TO_IDLE();
 				LED_A_ON();
@@ -2406,6 +2386,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 					LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 					break;
 				}
+
 				uint32_t ar = bytes_to_num(receivedCmd, 4);
 				uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
 
@@ -2512,6 +2493,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 						ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); 
 						num_to_bytes(ans, 4, rAUTH_AT);
 					}
+
 					EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
 					//Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
 					cardSTATE = MFEMUL_AUTH1;
@@ -2544,13 +2526,13 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 						|| receivedCmd[0] == 0xB0) { // transfer
 					if (receivedCmd[1] >= 16 * 4) {
 						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
-						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
 						break;
 					}
 
 					if (receivedCmd[1] / 4 != cardAUTHSC) {
 						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
-						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
 						break;
 					}
 				}
@@ -2692,7 +2674,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 		if(ar_nr_collected > 1) {
 			Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
 			Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
-					 ar_nr_responses[0], // UID
+					ar_nr_responses[0], // UID
 					ar_nr_responses[1], //NT
 					ar_nr_responses[2], //AR1
 					ar_nr_responses[3], //NR1
@@ -2711,7 +2693,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
 			}
 		}
 	}
-	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, traceLen);
+	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, BigBuf_get_traceLen());
+	
 }
 
 
@@ -2728,8 +2711,8 @@ void RAMFUNC SniffMifare(uint8_t param) {
 	// C(red) A(yellow) B(green)
 	LEDsoff();
 	// init trace buffer
-	iso14a_clear_trace();
-	iso14a_set_tracing(TRUE);
+	clear_trace();
+	set_tracing(TRUE);
 
 	// The command (reader -> tag) that we're receiving.
 	// The length of a received command will in most cases be no more than 18 bytes.
@@ -2740,10 +2723,8 @@ void RAMFUNC SniffMifare(uint8_t param) {
 	uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
 	uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
 
-	// 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;
-	
+	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
 	// free eventually allocated BigBuf memory
 	BigBuf_free();
 	// allocate the DMA buffer, used to stream samples from the FPGA
@@ -2755,8 +2736,6 @@ void RAMFUNC SniffMifare(uint8_t param) {
 	bool ReaderIsActive = FALSE;
 	bool TagIsActive = FALSE;
 
-	iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
-
 	// Set up the demodulator for tag -> reader responses.
 	DemodInit(receivedResponse, receivedResponsePar);