X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/981bd4292e1f6d898453479c7bad86480d0c959f..3be2a5ae0b3f153a60a04ff83b7c3f864d716371:/armsrc/iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 63cc32ae..3f775de5 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -96,9 +96,9 @@ uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
 	int i;
 	uint32_t dwPar = 0;
 
-	// Generate the encrypted data
+	// Generate the parity bits
 	for (i = 0; i < iLen; i++) {
-		// Save the encrypted parity bit
+		// and save them to a 32Bit word
 		dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
 	}
 	return dwPar;
@@ -375,196 +375,176 @@ static RAMFUNC int MillerDecoding(int bit)
 }
 
 //=============================================================================
-// ISO 14443 Type A - Manchester
+// ISO 14443 Type A - Manchester decoder
 //=============================================================================
+// Basics:
+// The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
+// at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
+// ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .......
+// The Manchester decoder needs to identify the following sequences:
+// 4 ticks modulated followed by 4 ticks unmodulated: 	Sequence D = 1 (also used as "start of communication")
+// 4 ticks unmodulated followed by 4 ticks modulated: 	Sequence E = 0
+// 8 ticks unmodulated:									Sequence F = end of communication
+// 8 ticks modulated:									A collision. Save the collision position and treat as Sequence D
+// Note 1: the bitstream may start at any time (either in first or second nibble within the parameter bit). We therefore need to sync.
+// Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 static tDemod Demod;
 
-static RAMFUNC int ManchesterDecoding(int v)
+inline RAMFUNC bool IsModulation(byte_t b)
 {
-	int bit;
-	int modulation;
-	//int error = 0;
-
-	if(!Demod.buff) {
-		Demod.buff = 1;
-		Demod.buffer = v;
-		return FALSE;
-	}
-	else {
-		bit = Demod.buffer;
-		Demod.buffer = v;
-	}
+	if (b >= 5 || b == 3)		// majority decision: 2 or more bits are set
+		return true;
+	else
+		return false;
+	
+}
 
-	if(Demod.state==DEMOD_UNSYNCD) {
-		Demod.output[Demod.len] = 0xfa;
-		Demod.syncBit = 0;
-		//Demod.samples = 0;
-		Demod.posCount = 1;		// This is the first half bit period, so after syncing handle the second part
+inline RAMFUNC bool IsModulationNibble1(byte_t b)
+{
+	return IsModulation((b & 0xE0) >> 5);
+}
 
-		if(bit & 0x08) {
-			Demod.syncBit = 0x08;
-		}
+inline RAMFUNC bool IsModulationNibble2(byte_t b)
+{
+	return IsModulation((b & 0x0E) >> 1);
+}
 
-		if(bit & 0x04) {
-			if(Demod.syncBit) {
-				bit <<= 4;
+static RAMFUNC int ManchesterDecoding(int bit, uint16_t offset)
+{
+	
+	switch (Demod.state) {
+
+		case DEMOD_UNSYNCD:						// not yet synced
+			Demod.len = 0;						// initialize number of decoded data bytes
+			Demod.bitCount = offset;			// initialize number of decoded data bits
+			Demod.shiftReg = 0;					// initialize shiftreg to hold decoded data bits
+			Demod.parityBits = 0;				// initialize parity bits
+			Demod.collisionPos = 0;				// Position of collision bit
+			
+			if (IsModulationNibble1(bit) 
+				&& !IsModulationNibble2(bit)) { 	 						// this is the start bit
+				Demod.samples = 8;
+				if(trigger) LED_A_OFF();
+				Demod.state = DEMOD_MANCHESTER_DATA;
+			} else if (!IsModulationNibble1(bit) && IsModulationNibble2(bit)) { // this may be the first half of the start bit
+					Demod.samples = 4;
+					Demod.state = DEMOD_HALF_SYNCD;
 			}
-			Demod.syncBit = 0x04;
-		}
+			break;
 
-		if(bit & 0x02) {
-			if(Demod.syncBit) {
-				bit <<= 2;
-			}
-			Demod.syncBit = 0x02;
-		}
 
-		if(bit & 0x01 && Demod.syncBit) {
-			Demod.syncBit = 0x01;
-		}
-		
-		if(Demod.syncBit) {
-			Demod.len = 0;
-			Demod.state = DEMOD_START_OF_COMMUNICATION;
-			Demod.sub = SUB_FIRST_HALF;
-			Demod.bitCount = 0;
-			Demod.shiftReg = 0;
-			Demod.parityBits = 0;
-			Demod.samples = 0;
-			if(Demod.posCount) {
-				if(trigger) LED_A_OFF();
-				switch(Demod.syncBit) {
-					case 0x08: Demod.samples = 3; break;
-					case 0x04: Demod.samples = 2; break;
-					case 0x02: Demod.samples = 1; break;
-					case 0x01: Demod.samples = 0; break;
+		case DEMOD_HALF_SYNCD:
+			Demod.samples += 8;
+			if (IsModulationNibble1(bit)) {								// error: this was not a start bit.
+				Demod.state = DEMOD_UNSYNCD;
+			} else {
+				if (IsModulationNibble2(bit)) {							// modulation in first half
+					Demod.state = DEMOD_MOD_FIRST_HALF;
+				} else {												// no modulation in first half
+					Demod.state = DEMOD_NOMOD_FIRST_HALF;
 				}
 			}
-			//error = 0;
-		}
-	}
-	else {
-		//modulation = bit & Demod.syncBit;
-		modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
-
-		Demod.samples += 4;
-
-		if(Demod.posCount==0) {
-			Demod.posCount = 1;
-			if(modulation) {
-				Demod.sub = SUB_FIRST_HALF;
+			break;
+			
+			
+		case DEMOD_MOD_FIRST_HALF:
+			Demod.samples += 8;
+			Demod.bitCount++;
+			if (IsModulationNibble1(bit)) {								// modulation in both halfs - collision
+				if (!Demod.collisionPos) {
+					Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
+				}
+			}															// modulation in first half only - Sequence D = 1
+			Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;				// add a 1 to the shiftreg
+			if(Demod.bitCount >= 9) {									// if we decoded a full byte (including parity)
+				Demod.parityBits <<= 1;									// make room for the parity bit
+				Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+				Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); 	// store parity bit
+				Demod.bitCount = 0;
+				Demod.shiftReg = 0;
 			}
-			else {
-				Demod.sub = SUB_NONE;
+			if (IsModulationNibble2(bit)) {								// modulation in first half
+				Demod.state = DEMOD_MOD_FIRST_HALF;
+			} else {													// no modulation in first half
+				Demod.state = DEMOD_NOMOD_FIRST_HALF;
 			}
-		}
-		else {
-			Demod.posCount = 0;
-			if(modulation && (Demod.sub == SUB_FIRST_HALF)) {
-				if(Demod.state!=DEMOD_ERROR_WAIT) {
-					Demod.state = DEMOD_ERROR_WAIT;
-					Demod.output[Demod.len] = 0xaa;
-					//error = 0x01;
+			break;
+
+
+		case DEMOD_NOMOD_FIRST_HALF:
+			if (IsModulationNibble1(bit)) {								// modulation in second half only - Sequence E = 0
+				Demod.bitCount++;
+				Demod.samples += 8;
+				Demod.shiftReg = (Demod.shiftReg >> 1);		 			// add a 0 to the shiftreg
+				if(Demod.bitCount >= 9) {								// if we decoded a full byte (including parity)
+					Demod.parityBits <<= 1;								// make room for the new parity bit
+					Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+					Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
+					Demod.bitCount = 0;
+					Demod.shiftReg = 0;
+				}
+			} else {													// no modulation in both halves - End of communication
+				Demod.samples += 4;
+				if(Demod.bitCount > 0) {								// if we decoded bits
+					Demod.shiftReg >>= (9 - Demod.bitCount);			// add the remaining decoded bits to the output
+					Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
+					// No parity bit, so just shift a 0
+					Demod.parityBits <<= 1;
 				}
+				Demod.state = DEMOD_UNSYNCD;							// start from the beginning
+				return TRUE;											// we are finished with decoding the raw data sequence
 			}
-			else if(modulation) {
-				Demod.sub = SUB_SECOND_HALF;
+			if (IsModulationNibble2(bit)) {								// modulation in first half
+				Demod.state = DEMOD_MOD_FIRST_HALF;
+			} else {													// no modulation in first half
+				Demod.state = DEMOD_NOMOD_FIRST_HALF;
 			}
+			break;
+			
 
-			switch(Demod.state) {
-				case DEMOD_START_OF_COMMUNICATION:
-					if(Demod.sub == SUB_FIRST_HALF) {
-						Demod.state = DEMOD_MANCHESTER_D;
-					}
-					else {
-						Demod.output[Demod.len] = 0xab;
-						Demod.state = DEMOD_ERROR_WAIT;
-						//error = 0x02;
-					}
-					break;
-
-				case DEMOD_MANCHESTER_D:
-				case DEMOD_MANCHESTER_E:
-					if(Demod.sub == SUB_FIRST_HALF) {
-						Demod.bitCount++;
-						Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100;
-						Demod.state = DEMOD_MANCHESTER_D;
-					}
-					else if(Demod.sub == SUB_SECOND_HALF) {
-						Demod.bitCount++;
-						Demod.shiftReg >>= 1;
-						Demod.state = DEMOD_MANCHESTER_E;
-					}
-					else {
-						Demod.state = DEMOD_MANCHESTER_F;
+		case DEMOD_MANCHESTER_DATA:
+			Demod.samples += 8;
+			if (IsModulationNibble1(bit)) {									// modulation in first half
+				if (IsModulationNibble2(bit) & 0x0f) {						// ... and in second half = collision
+					if (!Demod.collisionPos) {
+						Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
 					}
-					break;
-
-				case DEMOD_MANCHESTER_F:
-					// Tag response does not need to be a complete byte!
-					if(Demod.len > 0 || Demod.bitCount > 0) {
-						if(Demod.bitCount > 0) {
-							Demod.shiftReg >>= (9 - Demod.bitCount);
-							Demod.output[Demod.len] = Demod.shiftReg & 0xff;
-							Demod.len++;
-							// No parity bit, so just shift a 0
-							Demod.parityBits <<= 1;
-						}
-
-						Demod.state = DEMOD_UNSYNCD;
-						return TRUE;
+				}														// modulation in first half only - Sequence D = 1
+				Demod.bitCount++;
+				Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;			// in both cases, add a 1 to the shiftreg
+				if(Demod.bitCount >= 9) {								// if we decoded a full byte (including parity)
+					Demod.parityBits <<= 1;								// make room for the parity bit
+					Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+					Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
+					Demod.bitCount = 0;
+					Demod.shiftReg = 0;
+				}
+			} else {													// no modulation in first half
+				if (IsModulationNibble2(bit)) {							// and modulation in second half = Sequence E = 0
+					Demod.bitCount++;
+					Demod.shiftReg = (Demod.shiftReg >> 1);				// add a 0 to the shiftreg
+					if(Demod.bitCount >= 9) {							// if we decoded a full byte (including parity)
+						Demod.parityBits <<= 1;							// make room for the new parity bit
+						Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
+						Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
+						Demod.bitCount = 0;
+						Demod.shiftReg = 0;
 					}
-					else {
-						Demod.output[Demod.len] = 0xad;
-						Demod.state = DEMOD_ERROR_WAIT;
-						//error = 0x03;
+				} else {												// no modulation in both halves - End of communication
+					if(Demod.bitCount > 0) {							// if we decoded bits
+						Demod.shiftReg >>= (9 - Demod.bitCount);		// add the remaining decoded bits to the output
+						Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
+						// No parity bit, so just shift a 0
+						Demod.parityBits <<= 1;
 					}
-					break;
-
-				case DEMOD_ERROR_WAIT:
-					Demod.state = DEMOD_UNSYNCD;
-					break;
-
-				default:
-					Demod.output[Demod.len] = 0xdd;
-					Demod.state = DEMOD_UNSYNCD;
-					break;
-			}
-
-			if(Demod.bitCount>=9) {
-				Demod.output[Demod.len] = Demod.shiftReg & 0xff;
-				Demod.len++;
-
-				Demod.parityBits <<= 1;
-				Demod.parityBits ^= ((Demod.shiftReg >> 8) & 0x01);
-
-				Demod.bitCount = 0;
-				Demod.shiftReg = 0;
+					Demod.state = DEMOD_UNSYNCD;						// start from the beginning
+					return TRUE;										// we are finished with decoding the raw data sequence
+				}
 			}
+			
+	} 
 
-			/*if(error) {
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				Demod.output[Demod.len] = error & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				Demod.output[Demod.len] = bit & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = Demod.buffer & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = Demod.syncBit & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				return TRUE;
-			}*/
-
-		}
-
-	} // end (state != UNSYNCED)
-
-    return FALSE;
+    return FALSE;	// not finished yet, need more data
 }
 
 //=============================================================================
@@ -672,7 +652,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 		}
 
 		LED_A_OFF();
-		
+
 		rsamples += 4;
 		if(MillerDecoding((data[0] & 0xF0) >> 4)) {
 			LED_C_ON();
@@ -691,7 +671,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) {
 			LED_B_OFF();
 		}
 
-		if(ManchesterDecoding(data[0] & 0x0F)) {
+		if(ManchesterDecoding(data[0], 0)) {
 			LED_B_ON();
 
 			if (!LogTrace(receivedResponse, Demod.len, 0 - Demod.samples, Demod.parityBits, FALSE)) break;
@@ -1296,7 +1276,7 @@ static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
 		while(GetCountMifare() < (*timing & 0xfffffff8));		// Delay transfer (multiple of 8 MF clock ticks)
 	}
 
-	for(c = 0; c < 10;) {	// standard delay for each transfer (allow tag to be ready after last transmission)
+	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++;
@@ -1558,13 +1538,12 @@ int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
 //-----------------------------------------------------------------------------
 // Wait a certain time for tag response
 //  If a response is captured return TRUE
-//  If it takes to long return FALSE
+//  If it takes too long return FALSE
 //-----------------------------------------------------------------------------
-static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer
+static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen, int *samples)
 {
-	// 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
@@ -1577,7 +1556,6 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
 	Demod.state = DEMOD_UNSYNCD;
 
 	uint8_t b;
-	if (elapsed) *elapsed = 0;
 
 	c = 0;
 	for(;;) {
@@ -1590,12 +1568,8 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
 		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;
+			if(ManchesterDecoding(b, offset)) {
+				*samples = Demod.samples;
 				return TRUE;
 			}
 		}
@@ -1607,12 +1581,12 @@ void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *tim
 
   CodeIso14443aBitsAsReaderPar(frame,bits,par);
   
-  // Select the card
+  // Send command to tag
   TransmitFor14443a(ToSend, ToSendMax, timing);
   if(trigger)
   	LED_A_ON();
   
-  // Store reader command in buffer
+  // Log reader command in trace buffer
   if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
 }
 
@@ -1621,38 +1595,49 @@ void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
   ReaderTransmitBitsPar(frame,len*8,par, timing);
 }
 
+void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
+{
+  // Generate parity and redirect
+  ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
+}
+
 void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
 {
   // Generate parity and redirect
   ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
 }
 
+int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
+{
+	int samples = 0;
+	if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160,&samples)) return FALSE;
+	if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
+	if(samples == 0) return FALSE;
+	return Demod.len;
+}
+
 int ReaderReceive(uint8_t* receivedAnswer)
 {
-  int samples = 0;
-  if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE;
-  if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
-  if(samples == 0) return FALSE;
-  return Demod.len;
+	return ReaderReceiveOffset(receivedAnswer, 0);
 }
 
-int ReaderReceivePar(uint8_t* receivedAnswer, uint32_t * parptr)
+int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
 {
-  int samples = 0;
-  if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE;
-  if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
+	int samples = 0;
+	if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160,&samples)) return FALSE;
+	if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
 	*parptr = Demod.parityBits;
-  if(samples == 0) return FALSE;
-  return Demod.len;
+	if(samples == 0) return FALSE;
+	return Demod.len;
 }
 
-/* performs iso14443a anticolision procedure
+/* performs iso14443a anticollision procedure
  * fills the uid pointer unless NULL
  * fills resp_data unless NULL */
 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 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];
@@ -1666,7 +1651,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
     ReaderTransmitBitsPar(wupa,7,0, NULL);
   // Receive the ATQA
   if(!ReaderReceive(resp)) return 0;
-//  Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
+  // Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
 
   if(p_hi14a_card) {
     memcpy(p_hi14a_card->atqa, resp, 2);
@@ -1690,19 +1675,50 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
     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;
+	if (Demod.collisionPos) {			// we had a collision and need to construct the UID bit by bit
+		memset(uid_resp, 0, 4);
+		uint16_t uid_resp_bits = 0;
+		uint16_t collision_answer_offset = 0;
+		// anti-collision-loop:
+		while (Demod.collisionPos) {
+			Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
+			for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {	// add valid UID bits before collision point
+				uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
+				uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
+			}
+			uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);					// next time select the card(s) with a 1 in the collision position
+			uid_resp_bits++;
+			// construct anticollosion command:
+			sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);  	// length of data in bytes and bits
+			for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
+				sel_uid[2+i] = uid_resp[i];
+			}
+			collision_answer_offset = uid_resp_bits%8;
+			ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
+			if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
+		}
+		// finally, add the last bits and BCC of the UID
+		for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
+			uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
+			uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
+		}
+
+	} else {		// no collision, use the response to SELECT_ALL as 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.
+    // calculate crypto UID. Always use last 4 Bytes.
     if(cuid_ptr) {
         *cuid_ptr = bytes_to_num(uid_resp, 4);
     }
 
     // Construct SELECT UID command
-    memcpy(sel_uid+2,resp,5);
-    AppendCrc14443a(sel_uid,7);
+	sel_uid[1] = 0x70;													// transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
+    memcpy(sel_uid+2,uid_resp,4);										// the UID
+	sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];  	// calculate and add BCC
+    AppendCrc14443a(sel_uid,7);											// calculate and add CRC
     ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
 
     // Receive the SAK
@@ -1710,7 +1726,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
     sak = resp[0];
 
     // Test if more parts of the uid are comming
-    if ((sak & 0x04) && uid_resp[0] == 0x88) {
+    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);
@@ -1769,6 +1785,7 @@ void iso14443a_setup() {
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
 	SpinDelay(7); // iso14443-3 specifies 5ms max.
 
+	Demod.state = DEMOD_UNSYNCD;
 	iso14a_timeout = 2048; //default
 }
 
@@ -1815,6 +1832,7 @@ void ReaderIso14443a(UsbCommand * c)
 	if(param & ISO14A_CONNECT) {
 		iso14a_clear_trace();
 	}
+
 	iso14a_set_tracing(true);
 
 	if(param & ISO14A_REQUEST_TRIGGER) {
@@ -1908,7 +1926,7 @@ void ReaderMifare(bool first_try)
 	static uint8_t mf_nr_ar3;
 
 	uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
-	traceLen = 0;
+	iso14a_clear_trace();
 	tracing = false;
 
 	byte_t nt_diff = 0;
@@ -1956,7 +1974,7 @@ void ReaderMifare(bool first_try)
 	LED_B_OFF();
 	LED_C_OFF();
 	
-  
+
 	for(uint16_t i = 0; TRUE; i++) {
 		
 		WDT_HIT();
@@ -1976,8 +1994,6 @@ void ReaderMifare(bool first_try)
 		//keep the card active
 		FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
 
-		// CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));
-
 		sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
 		catch_up_cycles = 0;
 
@@ -2097,18 +2113,22 @@ void ReaderMifare(bool first_try)
 	tracing = TRUE;
 }
 
-//-----------------------------------------------------------------------------
-// MIFARE 1K simulate. 
-// 
-//-----------------------------------------------------------------------------
-void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
+/**
+  *MIFARE 1K simulate.
+  *
+  *@param flags :
+  *	FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
+  * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
+  * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
+  *	FLAG_NR_AR_ATTACK  - means we should collect NR_AR responses for bruteforcing later
+  *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
+  */
+void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
 {
 	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;
@@ -2116,7 +2136,6 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 	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;
@@ -2126,50 +2145,74 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 	struct Crypto1State mpcs = {0, 0};
 	struct Crypto1State *pcs;
 	pcs = &mpcs;
-	
+	uint32_t numReads = 0;//Counts numer of times reader read a block
 	uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
 	uint8_t *response = eml_get_bigbufptr_sendbuf();
 	
-	static uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
+	uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
+	uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
+	uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
+	uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
+	uint8_t rSAK1[] = {0x04, 0xda, 0x17};
 
-	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};
+	uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
+	uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
 
-	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};
+	//Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
+	// This can be used in a reader-only attack.
+	// (it can also be retrieved via 'hf 14a list', but hey...
+	uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
+	uint8_t ar_nr_collected = 0;
 
 	// clear trace
-	traceLen = 0;
+	iso14a_clear_trace();
+
 	tracing = true;
 
   // Authenticate response - nonce
 	uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
-	
-	// get UID from emul memory
-	emlGetMemBt(receivedCmd, 7, 1);
-	_7BUID = !(receivedCmd[0] == 0x00);
-	if (!_7BUID) {                     // ---------- 4BUID
-		rATQA[0] = 0x04;
 
-		emlGetMemBt(rUIDBCC1, 0, 4);
+	//-- Determine the UID
+	// Can be set from emulator memory, incoming data
+	// and can be 7 or 4 bytes long
+	if(flags & FLAG_4B_UID_IN_DATA)
+	{
+		// 4B uid comes from data-portion of packet
+		memcpy(rUIDBCC1,datain,4);
 		rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
-	} else {                           // ---------- 7BUID
-		rATQA[0] = 0x44;
 
+	}else if(flags & FLAG_7B_UID_IN_DATA)
+	{
+		// 7B uid comes from data-portion of packet
+		memcpy(&rUIDBCC1[1],datain,3);
+		memcpy(rUIDBCC2, datain+3, 4);
+		_7BUID = true;
+	}
+	else
+	{
+		// get UID from emul memory
+		emlGetMemBt(receivedCmd, 7, 1);
+		_7BUID = !(receivedCmd[0] == 0x00);
+		if (!_7BUID) {                     // ---------- 4BUID
+			emlGetMemBt(rUIDBCC1, 0, 4);
+		} else {                           // ---------- 7BUID
+			emlGetMemBt(&rUIDBCC1[1], 0, 3);
+			emlGetMemBt(rUIDBCC2, 3, 4);
+		}
+	}
+	/*
+	 * Regardless of what method was used to set the UID, set fifth byte and modify
+	 * the ATQA for 4 or 7-byte UID
+	 */
+
+	rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
+	if(_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];
 	}
 
-// --------------------------------------	test area
-
-// --------------------------------------	END test area
 	// start mkseconds counter
 	StartCountUS();
 
@@ -2177,19 +2220,23 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 	FpgaSetupSsc();
 
-  FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 	SpinDelay(200);
 
-	if (MF_DBGLEVEL >= 1)	Dbprintf("Started. 7buid=%d", _7BUID);
+	if (MF_DBGLEVEL >= 1)	{
+		if (!_7BUID) {
+			Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
+		}else
+		{
+			Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
+		}
+	}
 	// calibrate mkseconds counter
 	GetDeltaCountUS();
-	while (true) {
+	bool finished = false;
+	while (!BUTTON_PRESS() && !finished) {
 		WDT_HIT();
 
-		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
@@ -2200,56 +2247,54 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 				LED_A_ON();
 			}
 		} 
+		if(cardSTATE == MFEMUL_NOFIELD) continue;
 
-		if (cardSTATE != MFEMUL_NOFIELD) {
-			res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
-			if (res == 2) {
-				cardSTATE = MFEMUL_NOFIELD;
-				LEDsoff();
-				continue;
-			}
-			if(res) break;
-		}
-		
-		//nextCycleTimeout = 0;
-		
-//		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;
-			}
+		//Now, get data
+
+		res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
+		if (res == 2) { //Field is off!
+			cardSTATE = MFEMUL_NOFIELD;
+			LEDsoff();
+			continue;
+		}else if(res == 1) break;//return value 1 means button press
+
+
+		// 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;
+			continue;
 		}
-		
+
 		switch (cardSTATE) {
-			case MFEMUL_NOFIELD:{
-				break;
-			}
-			case MFEMUL_HALTED:{
-				break;
-			}
+			case MFEMUL_NOFIELD:
+			case MFEMUL_HALTED:
 			case MFEMUL_IDLE:{
 				break;
 			}
 			case MFEMUL_SELECT1:{
 				// select all
 				if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
+					if (MF_DBGLEVEL >= 4)	Dbprintf("SELECT ALL received");
 					EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
 					break;
 				}
 
+				if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
+				{
+					Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
+				}
 				// select card
 				if (len == 9 && 
 						(receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
+
 					if (!_7BUID) 
 						EmSendCmd(rSAK, sizeof(rSAK));
 					else
@@ -2269,6 +2314,51 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 				
 				break;
 			}
+			case MFEMUL_AUTH1:{
+				if( len != 8)
+				{
+					cardSTATE_TO_IDLE();
+					break;
+				}
+				uint32_t ar = bytes_to_num(receivedCmd, 4);
+				uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
+
+				//Collect AR/NR
+				if(ar_nr_collected < 2){
+					if(ar_nr_responses[2] != ar)
+					{// Avoid duplicates... probably not necessary, ar should vary. 
+						ar_nr_responses[ar_nr_collected*4] = cuid;
+						ar_nr_responses[ar_nr_collected*4+1] = nonce;
+						ar_nr_responses[ar_nr_collected*4+2] = ar;
+						ar_nr_responses[ar_nr_collected*4+3] = nr;
+						ar_nr_collected++;
+					}
+				}
+
+				// --- crypto
+				crypto1_word(pcs, ar , 1);
+				cardRr = nr ^ crypto1_word(pcs, 0, 0);
+
+				// test if auth OK
+				if (cardRr != prng_successor(nonce, 64)){
+					if (MF_DBGLEVEL >= 2)	Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
+					//Shouldn't we respond anything here?
+					// Right now, we don't nack or anything, which causes the
+					// reader to do a WUPA after a while. /Martin
+					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));
+				LED_C_ON();
+				cardSTATE = MFEMUL_WORK;
+				if (MF_DBGLEVEL >= 4)	Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
+				break;
+			}
 			case MFEMUL_SELECT2:{
 				if (!len) break;
 			
@@ -2292,86 +2382,44 @@ void Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain)
 				// 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;
+				//goto lbWORK;
+				//intentional fall-through to the next case-stmt
 			}
 			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);
+				if (len == 0) break;
 
-						cardSTATE = MFEMUL_AUTH1;
-						//nextCycleTimeout = 10;
-						break;
-					}
-				} else {
+				bool encrypted_data = (cardAUTHKEY != 0xFF) ;
+
+				if(encrypted_data)
+				{
 					// 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;
+				if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
+					authTimer = GetTickCount();
+					cardAUTHSC = receivedCmd[1] / 4;  // received block num
+					cardAUTHKEY = receivedCmd[0] - 0x60;
+					crypto1_destroy(pcs);//Added by martin
+					crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
 
-						// --- 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
+					if (!encrypted_data) { // first authentication
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
 
-						cardSTATE = MFEMUL_AUTH1;
-						//nextCycleTimeout = 10;
-						break;
+						crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
+						num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
+					}
+					else{ // nested authentication
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
+						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;
+					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) {
@@ -2385,39 +2433,63 @@ lbWORK:	if (len == 0) break;
 					break;
 				}
 				
-				// read block
-				if (len == 4 && receivedCmd[0] == 0x30) {
-					if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) {
+				if(len != 4) break;
+
+				if(receivedCmd[0] == 0x30 // read block
+						|| receivedCmd[0] == 0xA0 // write block
+						|| receivedCmd[0] == 0xC0
+						|| receivedCmd[0] == 0xC1
+						|| receivedCmd[0] == 0xC2 // inc dec restore
+						|| 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]);
 						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);
+						break;
+					}
+				}
+				// read block
+				if (receivedCmd[0] == 0x30) {
+					if (MF_DBGLEVEL >= 2) {
+						Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
+					}
 					emlGetMem(response, receivedCmd[1], 1);
 					AppendCrc14443a(response, 16);
 					mf_crypto1_encrypt(pcs, response, 18, &par);
 					EmSendCmdPar(response, 18, par);
+					numReads++;
+					if(exitAfterNReads > 0 && numReads == exitAfterNReads)
+					{
+						Dbprintf("%d reads done, exiting", numReads);
+						finished = true;
+					}
 					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;
-					}
+				if (receivedCmd[0] == 0xA0) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
+
 					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])) {
+				if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+
+					if (emlCheckValBl(receivedCmd[1])) {
+						if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
 						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
 						break;
 					}
@@ -2429,17 +2501,13 @@ lbWORK:	if (len == 0) break;
 					if (receivedCmd[0] == 0xC2)
 						cardSTATE = MFEMUL_INTREG_REST;
 					cardWRBL = receivedCmd[1];
-					
+
 					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 (receivedCmd[0] == 0xB0) {
+					if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
 					
 					if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
 						EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
@@ -2450,20 +2518,23 @@ lbWORK:	if (len == 0) break;
 				}
 
 				// halt
-				if (len == 4 && (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00)) {
+				if (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) {
+				// RATS
+				if (receivedCmd[0] == 0xe0) {//RATS
 					EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
 					break;
 				}
 
+				// command not allowed
+				if (MF_DBGLEVEL >= 4)	Dbprintf("Received command not allowed, nacking");
+				EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
+
 				// case break
 				break;
 			}
@@ -2525,10 +2596,43 @@ lbWORK:	if (len == 0) break;
 	// add trace trailer
 	memset(rAUTH_NT, 0x44, 4);
 	LogTrace(rAUTH_NT, 4, 0, 0, TRUE);
-
+	if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
+	{
+		//May just aswell send the collected ar_nr in the response aswell
+		cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
+	}
+	if(flags & FLAG_NR_AR_ATTACK)
+	{
+		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",
+					 ar_nr_responses[0], // UID
+					ar_nr_responses[1], //NT
+					ar_nr_responses[2], //AR1
+					ar_nr_responses[3], //NR1
+					ar_nr_responses[6], //AR2
+					ar_nr_responses[7] //NR2
+					);
+		}else
+		{
+			Dbprintf("Failed to obtain two AR/NR pairs!");
+			if(ar_nr_collected >0)
+			{
+				Dbprintf("Only got these: UID=%08d, nonce=%08d, AR1=%08d, NR1=%08d",
+						ar_nr_responses[0], // UID
+						ar_nr_responses[1], //NT
+						ar_nr_responses[2], //AR1
+						ar_nr_responses[3] //NR1
+						);
+			}
+		}
+	}
 	if (MF_DBGLEVEL >= 1)	Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ",	tracing, traceLen);
 }
 
+
+
 //-----------------------------------------------------------------------------
 // MIFARE sniffer. 
 // 
@@ -2645,7 +2749,7 @@ void RAMFUNC SniffMifare(uint8_t param) {
 			Demod.state = DEMOD_UNSYNCD;
 		}
 
-		if(ManchesterDecoding(data[0] & 0x0F)) {
+		if(ManchesterDecoding(data[0], 0)) {
 			LED_C_INV();
 
 			if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;