X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/1604d0a2909a6ae1a5b615d280671d867c1028a4..01aa068b6ff34d86dd5d9d9e962aba20cd490050:/armsrc/iclass.c?ds=sidebyside

diff --git a/armsrc/iclass.c b/armsrc/iclass.c
index d5cd366d..afe1a607 100644
--- a/armsrc/iclass.c
+++ b/armsrc/iclass.c
@@ -3,6 +3,7 @@
 // Hagen Fritsch - June 2010
 // Gerhard de Koning Gans - May 2011
 // Gerhard de Koning Gans - June 2012 - Added iClass card and reader emulation
+// piwi - 2019
 //
 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
 // at your option, any later version. See the LICENSE.txt file for the text of
@@ -10,1524 +11,927 @@
 //-----------------------------------------------------------------------------
 // Routines to support iClass.
 //-----------------------------------------------------------------------------
-// Based on ISO14443a implementation. Still in experimental phase.
 // Contribution made during a security research at Radboud University Nijmegen
-// 
-// Please feel free to contribute and extend iClass support!!
-//-----------------------------------------------------------------------------
-//
-// FIX:
-// ====
-// We still have sometimes a demodulation error when snooping iClass communication.
-// The resulting trace of a read-block-03 command may look something like this:
-//
-//  +  22279:    :     0c  03  e8  01    
-//
-//    ...with an incorrect answer...
-//
-//  +     85:   0: TAG ff! ff! ff! ff! ff! ff! ff! ff! bb  33  bb  00  01! 0e! 04! bb     !crc
-//
-// We still left the error signalling bytes in the traces like 0xbb
-//
-// A correct trace should look like this:
-//
-// +  21112:    :     0c  03  e8  01    
-// +     85:   0: TAG ff  ff  ff  ff  ff  ff  ff  ff  ea  f5    
 //
+// Please feel free to contribute and extend iClass support!!
 //-----------------------------------------------------------------------------
 
+#include "iclass.h"
+
 #include "proxmark3.h"
 #include "apps.h"
 #include "util.h"
 #include "string.h"
+#include "printf.h"
 #include "common.h"
+#include "usb_cdc.h"
+#include "iso14443a.h"
+#include "iso15693.h"
 // Needed for CRC in emulation mode;
 // same construction as in ISO 14443;
 // different initial value (CRC_ICLASS)
 #include "iso14443crc.h"
+#include "iso15693tools.h"
+#include "protocols.h"
+#include "optimized_cipher.h"
+#include "fpgaloader.h"
+
+// iCLASS has a slightly different timing compared to ISO15693. According to the picopass data sheet the tag response is expected 330us after
+// the reader command. This is measured from end of reader EOF to first modulation of the tag's SOF which starts with a 56,64us unmodulated period.
+// 330us = 140 ssp_clk cycles @ 423,75kHz when simulating.
+// 56,64us = 24 ssp_clk_cycles
+#define DELAY_ICLASS_VCD_TO_VICC_SIM     (140 - 24)
+// times in ssp_clk_cycles @ 3,3625MHz when acting as reader
+#define DELAY_ICLASS_VICC_TO_VCD_READER  DELAY_ISO15693_VICC_TO_VCD_READER
+// times in samples @ 212kHz when acting as reader
+#define ICLASS_READER_TIMEOUT_ACTALL     330 // 1558us, nominal 330us + 7slots*160us = 1450us
+#define ICLASS_READER_TIMEOUT_UPDATE    3390 // 16000us, nominal 4-15ms
+#define ICLASS_READER_TIMEOUT_OTHERS      80 // 380us, nominal 330us
+
+#define ICLASS_BUFFER_SIZE 34                // we expect max 34 bytes as tag answer (response to READ4)
 
-static int timeout = 4096;
-
-
-static int SendIClassAnswer(uint8_t *resp, int respLen, int delay);
-
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
-//-----------------------------------------------------------------------------
-static struct {
-    enum {
-        STATE_UNSYNCD,
-        STATE_START_OF_COMMUNICATION,
-	STATE_RECEIVING
-    }       state;
-    uint16_t    shiftReg;
-    int     bitCnt;
-    int     byteCnt;
-    int     byteCntMax;
-    int     posCnt;
-    int     nOutOfCnt;
-    int     OutOfCnt;
-    int     syncBit;
-    int     parityBits;
-    int     samples;
-    int     highCnt;
-    int     swapper;
-    int     counter;
-    int     bitBuffer;
-    int     dropPosition;
-    uint8_t   *output;
-} Uart;
-
-static RAMFUNC int OutOfNDecoding(int bit)
-{
-	//int error = 0;
-	int bitright;
-
-	if(!Uart.bitBuffer) {
-		Uart.bitBuffer = bit ^ 0xFF0;
-		return FALSE;
-	}
-	else {
-		Uart.bitBuffer <<= 4;
-		Uart.bitBuffer ^= bit;
-	}
-	
-	/*if(Uart.swapper) {
-		Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
-		Uart.byteCnt++;
-		Uart.swapper = 0;
-		if(Uart.byteCnt > 15) { return TRUE; }
-	}
-	else {
-		Uart.swapper = 1;
-	}*/
-
-	if(Uart.state != STATE_UNSYNCD) {
-		Uart.posCnt++;
-
-		if((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit) {
-			bit = 0x00;
-		}
-		else {
-			bit = 0x01;
-		}
-		if(((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit) {
-			bitright = 0x00;
-		}
-		else {
-			bitright = 0x01;
-		}
-		if(bit != bitright) { bit = bitright; }
-
-		
-		// So, now we only have to deal with *bit*, lets see...
-		if(Uart.posCnt == 1) {
-			// measurement first half bitperiod
-			if(!bit) {
-				// Drop in first half means that we are either seeing
-				// an SOF or an EOF.
-
-				if(Uart.nOutOfCnt == 1) {
-					// End of Communication
-					Uart.state = STATE_UNSYNCD;
-					Uart.highCnt = 0;
-					if(Uart.byteCnt == 0) {
-						// Its not straightforward to show single EOFs
-						// So just leave it and do not return TRUE
-						Uart.output[Uart.byteCnt] = 0xf0;
-						Uart.byteCnt++;
-
-						// Calculate the parity bit for the client...
-						Uart.parityBits = 1;
-					}
-					else {
-						return TRUE;
-					}
-				}
-				else if(Uart.state != STATE_START_OF_COMMUNICATION) {
-					// When not part of SOF or EOF, it is an error
-					Uart.state = STATE_UNSYNCD;
-					Uart.highCnt = 0;
-					//error = 4;
-				}
-			}
-		}
-		else {
-			// measurement second half bitperiod
-			// Count the bitslot we are in... (ISO 15693)
-			Uart.nOutOfCnt++;
-			
-			if(!bit) {
-				if(Uart.dropPosition) {
-					if(Uart.state == STATE_START_OF_COMMUNICATION) {
-						//error = 1;
-					}
-					else {
-						//error = 7;
-					}
-					// It is an error if we already have seen a drop in current frame
-					Uart.state = STATE_UNSYNCD;
-					Uart.highCnt = 0;
-				}
-				else {
-					Uart.dropPosition = Uart.nOutOfCnt;
-				}
-			}
-
-			Uart.posCnt = 0;
-
-			
-			if(Uart.nOutOfCnt == Uart.OutOfCnt && Uart.OutOfCnt == 4) {
-				Uart.nOutOfCnt = 0;
-				
-				if(Uart.state == STATE_START_OF_COMMUNICATION) {
-					if(Uart.dropPosition == 4) {
-						Uart.state = STATE_RECEIVING;
-						Uart.OutOfCnt = 256;
-					}
-					else if(Uart.dropPosition == 3) {
-						Uart.state = STATE_RECEIVING;
-						Uart.OutOfCnt = 4;
-						//Uart.output[Uart.byteCnt] = 0xdd;
-						//Uart.byteCnt++;
-					}
-					else {
-						Uart.state = STATE_UNSYNCD;
-						Uart.highCnt = 0;
-					}
-					Uart.dropPosition = 0;
-				}
-				else {
-					// RECEIVING DATA
-					// 1 out of 4
-					if(!Uart.dropPosition) {
-						Uart.state = STATE_UNSYNCD;
-						Uart.highCnt = 0;
-						//error = 9;
-					}
-					else {
-						Uart.shiftReg >>= 2;
-						
-						// Swap bit order
-						Uart.dropPosition--;
-						//if(Uart.dropPosition == 1) { Uart.dropPosition = 2; }
-						//else if(Uart.dropPosition == 2) { Uart.dropPosition = 1; }
-						
-						Uart.shiftReg ^= ((Uart.dropPosition & 0x03) << 6);
-						Uart.bitCnt += 2;
-						Uart.dropPosition = 0;
-
-						if(Uart.bitCnt == 8) {
-							Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
-							Uart.byteCnt++;
-
-							// Calculate the parity bit for the client...
-							Uart.parityBits <<= 1;
-							Uart.parityBits ^= OddByteParity[(Uart.shiftReg & 0xff)];
-
-							Uart.bitCnt = 0;
-							Uart.shiftReg = 0;
-						}
-					}
-				}
-			}
-			else if(Uart.nOutOfCnt == Uart.OutOfCnt) {
-				// RECEIVING DATA
-				// 1 out of 256
-				if(!Uart.dropPosition) {
-					Uart.state = STATE_UNSYNCD;
-					Uart.highCnt = 0;
-					//error = 3;
-				}
-				else {
-					Uart.dropPosition--;
-					Uart.output[Uart.byteCnt] = (Uart.dropPosition & 0xff);
-					Uart.byteCnt++;
-
-					// Calculate the parity bit for the client...
-					Uart.parityBits <<= 1;
-					Uart.parityBits ^= OddByteParity[(Uart.dropPosition & 0xff)];
-
-					Uart.bitCnt = 0;
-					Uart.shiftReg = 0;
-					Uart.nOutOfCnt = 0;
-					Uart.dropPosition = 0;
-				}
-			}
-
-			/*if(error) {
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = error & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = (Uart.bitBuffer >> 8) & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = (Uart.syncBit >> 3) & 0xFF;
-				Uart.byteCnt++;
-				Uart.output[Uart.byteCnt] = 0xAA;
-				Uart.byteCnt++;
-				return TRUE;
-			}*/
-		}
-
-	}
-	else {
-		bit = Uart.bitBuffer & 0xf0;
-		bit >>= 4;
-		bit ^= 0x0F; // drops become 1s ;-)
-		if(bit) {
-			// should have been high or at least (4 * 128) / fc
-			// according to ISO this should be at least (9 * 128 + 20) / fc
-			if(Uart.highCnt == 8) {
-				// we went low, so this could be start of communication
-				// it turns out to be safer to choose a less significant
-				// syncbit... so we check whether the neighbour also represents the drop
-				Uart.posCnt = 1;   // apparently we are busy with our first half bit period
-				Uart.syncBit = bit & 8;
-				Uart.samples = 3;
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 4; Uart.samples = 2; }
-				else if(bit & 4)	{ Uart.syncBit = bit & 4; Uart.samples = 2; bit <<= 2; }
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 2; Uart.samples = 1; }
-				else if(bit & 2)	{ Uart.syncBit = bit & 2; Uart.samples = 1; bit <<= 1; }
-				if(!Uart.syncBit)	{ Uart.syncBit = bit & 1; Uart.samples = 0;
-					if(Uart.syncBit && (Uart.bitBuffer & 8)) {
-						Uart.syncBit = 8;
-
-						// the first half bit period is expected in next sample
-						Uart.posCnt = 0;
-						Uart.samples = 3;
-					}
-				}
-				else if(bit & 1)	{ Uart.syncBit = bit & 1; Uart.samples = 0; }
-
-				Uart.syncBit <<= 4;
-				Uart.state = STATE_START_OF_COMMUNICATION;
-				Uart.bitCnt = 0;
-				Uart.byteCnt = 0;
-				Uart.parityBits = 0;
-				Uart.nOutOfCnt = 0;
-				Uart.OutOfCnt = 4; // Start at 1/4, could switch to 1/256
-				Uart.dropPosition = 0;
-				Uart.shiftReg = 0;
-				//error = 0;
-			}
-			else {
-				Uart.highCnt = 0;
-			}
-		}
-		else {
-			if(Uart.highCnt < 8) {
-				Uart.highCnt++;
-			}
-		}
-	}
-
-    return FALSE;
-}
 
 //=============================================================================
-// Manchester
+// A `sniffer' for iClass communication
+// Both sides of communication!
 //=============================================================================
+void SnoopIClass(uint8_t jam_search_len, uint8_t *jam_search_string) {
+	SnoopIso15693(jam_search_len, jam_search_string);
+}
+
 
-static struct {
-    enum {
-        DEMOD_UNSYNCD,
-		DEMOD_START_OF_COMMUNICATION,
-		DEMOD_START_OF_COMMUNICATION2,
-		DEMOD_START_OF_COMMUNICATION3,
-		DEMOD_SOF_COMPLETE,
-		DEMOD_MANCHESTER_D,
-		DEMOD_MANCHESTER_E,
-		DEMOD_END_OF_COMMUNICATION,
-		DEMOD_END_OF_COMMUNICATION2,
-		DEMOD_MANCHESTER_F,
-        DEMOD_ERROR_WAIT
-    }       state;
-    int     bitCount;
-    int     posCount;
-	int     syncBit;
-	int     parityBits;
-    uint16_t    shiftReg;
-	int     buffer;
-	int     buffer2;
-	int	buffer3;
-	int     buff;
-	int     samples;
-    int     len;
-	enum {
-		SUB_NONE,
-		SUB_FIRST_HALF,
-		SUB_SECOND_HALF,
-		SUB_BOTH
-	}		sub;
-    uint8_t   *output;
-} Demod;
-
-static RAMFUNC int ManchesterDecoding(int v)
-{
-	int bit;
-	int modulation;
-	int error = 0;
-
-	bit = Demod.buffer;
-	Demod.buffer = Demod.buffer2;
-	Demod.buffer2 = Demod.buffer3;
-	Demod.buffer3 = v;
-
-	if(Demod.buff < 3) {
-		Demod.buff++;
-		return FALSE;
+void rotateCSN(uint8_t* originalCSN, uint8_t* rotatedCSN) {
+	int i;
+	for (i = 0; i < 8; i++) {
+		rotatedCSN[i] = (originalCSN[i] >> 3) | (originalCSN[(i+1)%8] << 5);
 	}
+}
 
-	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
 
-		if(bit & 0x08) {
-			Demod.syncBit = 0x08;
-		}
+// Encode SOF only
+static void CodeIClassTagSOF() {
+	ToSendReset();
+	ToSend[++ToSendMax] = 0x1D;
+	ToSendMax++;
+}
 
-		if(bit & 0x04) {
-			if(Demod.syncBit) {
-				bit <<= 4;
-			}
-			Demod.syncBit = 0x04;
-		}
 
-		if(bit & 0x02) {
-			if(Demod.syncBit) {
-				bit <<= 2;
-			}
-			Demod.syncBit = 0x02;
-		}
+static void AppendCrc(uint8_t *data, int len) {
+	ComputeCrc14443(CRC_ICLASS, data, len, data+len, data+len+1);
+}
 
-		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();  // Not useful in this case...
-				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;
-				}
-				// SOF must be long burst... otherwise stay unsynced!!!
-				if(!(Demod.buffer & Demod.syncBit) || !(Demod.buffer2 & Demod.syncBit)) {
-					Demod.state = DEMOD_UNSYNCD;
-				}
-			}
-			else {
-				// SOF must be long burst... otherwise stay unsynced!!!
-				if(!(Demod.buffer2 & Demod.syncBit) || !(Demod.buffer3 & Demod.syncBit)) {
-					Demod.state = DEMOD_UNSYNCD;
-					error = 0x88;
-				}
 
-			}
-			error = 0;
+/**
+ * @brief Does the actual simulation
+ */
+int doIClassSimulation(int simulationMode, uint8_t *reader_mac_buf) {
 
-		}
-	}
-	else {
-		modulation = bit & Demod.syncBit;
-		modulation |= ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
-		//modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
+	// free eventually allocated BigBuf memory
+	BigBuf_free_keep_EM();
 
-		Demod.samples += 4;
+	uint16_t page_size = 32 * 8;
+	uint8_t current_page = 0;
 
-		if(Demod.posCount==0) {
-			Demod.posCount = 1;
-			if(modulation) {
-				Demod.sub = SUB_FIRST_HALF;
-			}
-			else {
-				Demod.sub = SUB_NONE;
-			}
-		}
-		else {
-			Demod.posCount = 0;
-			/*(modulation && (Demod.sub == SUB_FIRST_HALF)) {
-				if(Demod.state!=DEMOD_ERROR_WAIT) {
-					Demod.state = DEMOD_ERROR_WAIT;
-					Demod.output[Demod.len] = 0xaa;
-					error = 0x01;
-				}
-			}*/
-			//else if(modulation) {
-			if(modulation) {
-				if(Demod.sub == SUB_FIRST_HALF) {
-					Demod.sub = SUB_BOTH;
-				}
-				else {
-					Demod.sub = SUB_SECOND_HALF;
-				}
-			}
-			else if(Demod.sub == SUB_NONE) {
-				if(Demod.state == DEMOD_SOF_COMPLETE) {
-					Demod.output[Demod.len] = 0x0f;
-					Demod.len++;
-					Demod.parityBits <<= 1;
-					Demod.parityBits ^= OddByteParity[0x0f];
-					Demod.state = DEMOD_UNSYNCD;
-//					error = 0x0f;
-					return TRUE;
-				}
-				else {
-					Demod.state = DEMOD_ERROR_WAIT;
-					error = 0x33;
-				}
-				/*if(Demod.state!=DEMOD_ERROR_WAIT) {
-					Demod.state = DEMOD_ERROR_WAIT;
-					Demod.output[Demod.len] = 0xaa;
-					error = 0x01;
-				}*/
-			}
+	// maintain cipher states for both credit and debit key for each page
+	State cipher_state_KC[8];
+	State cipher_state_KD[8];
+	State *cipher_state = &cipher_state_KD[0];
 
-			switch(Demod.state) {
-				case DEMOD_START_OF_COMMUNICATION:
-					if(Demod.sub == SUB_BOTH) {
-						//Demod.state = DEMOD_MANCHESTER_D;
-						Demod.state = DEMOD_START_OF_COMMUNICATION2;
-						Demod.posCount = 1;
-						Demod.sub = SUB_NONE;
-					}
-					else {
-						Demod.output[Demod.len] = 0xab;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0xd2;
-					}
-					break;
-				case DEMOD_START_OF_COMMUNICATION2:
-					if(Demod.sub == SUB_SECOND_HALF) {
-						Demod.state = DEMOD_START_OF_COMMUNICATION3;
-					}
-					else {
-						Demod.output[Demod.len] = 0xab;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0xd3;
-					}
-					break;
-				case DEMOD_START_OF_COMMUNICATION3:
-					if(Demod.sub == SUB_SECOND_HALF) {
-//						Demod.state = DEMOD_MANCHESTER_D;
-						Demod.state = DEMOD_SOF_COMPLETE;
-						//Demod.output[Demod.len] = Demod.syncBit & 0xFF;
-						//Demod.len++;
-					}
-					else {
-						Demod.output[Demod.len] = 0xab;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0xd4;
-					}
-					break;
-				case DEMOD_SOF_COMPLETE:
-				case DEMOD_MANCHESTER_D:
-				case DEMOD_MANCHESTER_E:
-					// OPPOSITE FROM ISO14443 - 11110000 = 0 (1 in 14443)
-					//                          00001111 = 1 (0 in 14443)
-					if(Demod.sub == SUB_SECOND_HALF) { // SUB_FIRST_HALF
-						Demod.bitCount++;
-						Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100;
-						Demod.state = DEMOD_MANCHESTER_D;
-					}
-					else if(Demod.sub == SUB_FIRST_HALF) { // SUB_SECOND_HALF
-						Demod.bitCount++;
-						Demod.shiftReg >>= 1;
-						Demod.state = DEMOD_MANCHESTER_E;
-					}
-					else if(Demod.sub == SUB_BOTH) {
-						Demod.state = DEMOD_MANCHESTER_F;
-					}
-					else {
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x55;
-					}
-					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 > 1) {  // was > 0, do not interpret last closing bit, is part of EOF
-							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;
-						}
+	uint8_t *emulator = BigBuf_get_EM_addr();
+	uint8_t *csn = emulator;
 
-						Demod.state = DEMOD_UNSYNCD;
-						return TRUE;
-					}
-					else {
-						Demod.output[Demod.len] = 0xad;
-						Demod.state = DEMOD_ERROR_WAIT;
-						error = 0x03;
-					}
-					break;
+	// CSN followed by two CRC bytes
+	uint8_t anticoll_data[10];
+	uint8_t csn_data[10];
+	memcpy(csn_data, csn, sizeof(csn_data));
+	Dbprintf("Simulating CSN %02x%02x%02x%02x%02x%02x%02x%02x", csn[0], csn[1], csn[2], csn[3], csn[4], csn[5], csn[6], csn[7]);
 
-				case DEMOD_ERROR_WAIT:
-					Demod.state = DEMOD_UNSYNCD;
-					break;
+	// Construct anticollision-CSN
+	rotateCSN(csn_data, anticoll_data);
 
-				default:
-					Demod.output[Demod.len] = 0xdd;
-					Demod.state = DEMOD_UNSYNCD;
-					break;
-			}
+	// Compute CRC on both CSNs
+	AppendCrc(anticoll_data, 8);
+	AppendCrc(csn_data, 8);
 
-			/*if(Demod.bitCount>=9) {
-				Demod.output[Demod.len] = Demod.shiftReg & 0xff;
-				Demod.len++;
+	uint8_t diversified_key_d[8] = { 0x00 };
+	uint8_t diversified_key_c[8] = { 0x00 };
+	uint8_t *diversified_key = diversified_key_d;
 
-				Demod.parityBits <<= 1;
-				Demod.parityBits ^= ((Demod.shiftReg >> 8) & 0x01);
+	// configuration block
+	uint8_t conf_block[10] = {0x12, 0xFF, 0xFF, 0xFF, 0x7F, 0x1F, 0xFF, 0x3C, 0x00, 0x00};
 
-				Demod.bitCount = 0;
-				Demod.shiftReg = 0;
-			}*/
-			if(Demod.bitCount>=8) {
-				Demod.shiftReg >>= 1;
-				Demod.output[Demod.len] = (Demod.shiftReg & 0xff);
-				Demod.len++;
+	// e-Purse
+	uint8_t card_challenge_data[8] = { 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
+	if (simulationMode == ICLASS_SIM_MODE_FULL) {
+		// initialize from page 0
+		memcpy(conf_block, emulator + 8 * 1, 8);
+		memcpy(card_challenge_data, emulator + 8 * 2, 8); // e-purse
+		memcpy(diversified_key_d, emulator + 8 * 3, 8);   // Kd
+		memcpy(diversified_key_c, emulator + 8 * 4, 8);   // Kc
+	}
 
-				// FOR ISO15639 PARITY NOT SEND OTA, JUST CALCULATE IT FOR THE CLIENT
-				Demod.parityBits <<= 1;
-				Demod.parityBits ^= OddByteParity[(Demod.shiftReg & 0xff)];
+	AppendCrc(conf_block, 8);
 
-				Demod.bitCount = 0;
-				Demod.shiftReg = 0;
-			}
+	// save card challenge for sim2,4 attack
+	if (reader_mac_buf != NULL) {
+		memcpy(reader_mac_buf, card_challenge_data, 8);
+	}
 
-			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++;
-				// Look harder ;-)
-				Demod.output[Demod.len] = Demod.buffer2 & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = Demod.syncBit & 0xFF;
-				Demod.len++;
-				Demod.output[Demod.len] = 0xBB;
-				Demod.len++;
-				return TRUE;
-			}
+	if (conf_block[5] & 0x80) {
+		page_size = 256 * 8;
+	}
 
+	// From PicoPass DS:
+	// When the page is in personalization mode this bit is equal to 1.
+	// Once the application issuer has personalized and coded its dedicated areas, this bit must be set to 0:
+	// the page is then "in application mode".
+	bool personalization_mode = conf_block[7] & 0x80;
+
+	// chip memory may be divided in 8 pages
+	uint8_t max_page = conf_block[4] & 0x10 ? 0 : 7;
+
+	// Precalculate the cipher states, feeding it the CC
+	cipher_state_KD[0] = opt_doTagMAC_1(card_challenge_data, diversified_key_d);
+	cipher_state_KC[0] = opt_doTagMAC_1(card_challenge_data, diversified_key_c);
+	if (simulationMode == ICLASS_SIM_MODE_FULL) {
+		for (int i = 1; i < max_page; i++) {
+			uint8_t *epurse = emulator + i*page_size + 8*2;
+			uint8_t *Kd = emulator + i*page_size + 8*3;
+			uint8_t *Kc = emulator + i*page_size + 8*4;
+			cipher_state_KD[i] = opt_doTagMAC_1(epurse, Kd);
+			cipher_state_KC[i] = opt_doTagMAC_1(epurse, Kc);
 		}
+	}
 
-	} // end (state != UNSYNCED)
+	int exitLoop = 0;
+	// Reader 0a
+	// Tag    0f
+	// Reader 0c
+	// Tag    anticoll. CSN
+	// Reader 81 anticoll. CSN
+	// Tag    CSN
 
-    return FALSE;
-}
+	uint8_t *modulated_response;
+	int modulated_response_size = 0;
+	uint8_t *trace_data = NULL;
+	int trace_data_size = 0;
 
-//=============================================================================
-// Finally, a `sniffer' for iClass communication
-// Both sides of communication!
-//=============================================================================
+	// Respond SOF -- takes 1 bytes
+	uint8_t *resp_sof = BigBuf_malloc(1);
+	int resp_sof_Len;
 
-//-----------------------------------------------------------------------------
-// Record the sequence of commands sent by the reader to the tag, with
-// triggering so that we start recording at the point that the tag is moved
-// near the reader.
-//-----------------------------------------------------------------------------
-void RAMFUNC SnoopIClass(void)
-{
-
-
-    // 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.
-	// The length of a received command will in most cases be no more than 18 bytes.
-	// So 32 should be enough!
-	uint8_t *readerToTagCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
-    // The response (tag -> reader) that we're receiving.
-	uint8_t *tagToReaderResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
-
-    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
- 
-    // reset traceLen to 0
-    iso14a_set_tracing(TRUE);
-    iso14a_clear_trace();
-    iso14a_set_trigger(FALSE);
-
-    // The DMA buffer, used to stream samples from the FPGA
-    int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
-    int lastRxCounter;
-    int8_t *upTo;
-    int smpl;
-    int maxBehindBy = 0;
-
-    // Count of samples received so far, so that we can include timing
-    // information in the trace buffer.
-    int samples = 0;
-    rsamples = 0;
-
-    // Set up the demodulator for tag -> reader responses.
-	Demod.output = tagToReaderResponse;
-    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 = readerToTagCmd;
-    Uart.byteCntMax = 32; // was 100 (greg)////////////////////////////////////////////////////////////////////////
-    Uart.state = STATE_UNSYNCD;
-
-    // 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);
-
-	uint32_t time_0 = GetCountSspClk();
-
-
-    int div = 0;
-    //int div2 = 0;
-    int decbyte = 0;
-    int decbyter = 0;
-
-    // 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;
+	// Anticollision CSN (rotated CSN)
+	// 22: Takes 2 bytes for SOF/EOF and 10 * 2 = 20 bytes (2 bytes/byte)
+	uint8_t *resp_anticoll = BigBuf_malloc(22);
+	int resp_anticoll_len;
+
+	// CSN (block 0)
+	// 22: Takes 2 bytes for SOF/EOF and 10 * 2 = 20 bytes (2 bytes/byte)
+	uint8_t *resp_csn = BigBuf_malloc(22);
+	int resp_csn_len;
+
+	// configuration (block 1) picopass 2ks
+	uint8_t *resp_conf = BigBuf_malloc(22);
+	int resp_conf_len;
+
+	// e-Purse (block 2)
+	// 18: Takes 2 bytes for SOF/EOF and 8 * 2 = 16 bytes (2 bytes/bit)
+	uint8_t *resp_cc = BigBuf_malloc(18);
+	int resp_cc_len;
+
+	// Kd, Kc (blocks 3 and 4). Cannot be read. Always respond with 0xff bytes only
+	uint8_t *resp_ff = BigBuf_malloc(22);
+	int resp_ff_len;
+	uint8_t ff_data[10] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00};
+	AppendCrc(ff_data, 8);
+
+	// Application Issuer Area (block 5)
+	uint8_t *resp_aia = BigBuf_malloc(22);
+	int resp_aia_len;
+	uint8_t aia_data[10] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00};
+	AppendCrc(aia_data, 8);
+
+	uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+	int len;
 
-	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;
-        }
-
-        //samples += 4;
-	samples += 1;
-
-	if(smpl & 0xF) {
-		decbyte ^= (1 << (3 - div));
-	}
-	
-	// FOR READER SIDE COMMUMICATION...
+	// Prepare card messages
 
-	decbyter <<= 2;
-	decbyter ^= (smpl & 0x30);
+	// First card answer: SOF only
+	CodeIClassTagSOF();
+	memcpy(resp_sof, ToSend, ToSendMax);
+	resp_sof_Len = ToSendMax;
 
-	div++;
-	
-	if((div + 1) % 2 == 0) {
-		smpl = decbyter;	
-		if(OutOfNDecoding((smpl & 0xF0) >> 4)) {
-		    rsamples = samples - Uart.samples;
-		    LED_C_ON();
-
-			//if(!LogTrace(Uart.output,Uart.byteCnt, rsamples, Uart.parityBits,TRUE)) break;
-			//if(!LogTrace(NULL, 0, Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, 0, TRUE)) break;
-			if(tracing)
-			{
-				LogTrace(Uart.output,Uart.byteCnt, (GetCountSspClk()-time_0) << 4, Uart.parityBits,TRUE);
-				LogTrace(NULL, 0, (GetCountSspClk()-time_0) << 4, 0, TRUE);
-			}
+	// Anticollision CSN
+	CodeIso15693AsTag(anticoll_data, sizeof(anticoll_data));
+	memcpy(resp_anticoll, ToSend, ToSendMax);
+	resp_anticoll_len = ToSendMax;
+
+	// CSN (block 0)
+	CodeIso15693AsTag(csn_data, sizeof(csn_data));
+	memcpy(resp_csn, ToSend, ToSendMax);
+	resp_csn_len = ToSendMax;
+
+	// Configuration (block 1)
+	CodeIso15693AsTag(conf_block, sizeof(conf_block));
+	memcpy(resp_conf, ToSend, ToSendMax);
+	resp_conf_len = ToSendMax;
+
+	// e-Purse (block 2)
+	CodeIso15693AsTag(card_challenge_data, sizeof(card_challenge_data));
+	memcpy(resp_cc, ToSend, ToSendMax);
+	resp_cc_len = ToSendMax;
+
+	// Kd, Kc (blocks 3 and 4)
+	CodeIso15693AsTag(ff_data, sizeof(ff_data));
+	memcpy(resp_ff, ToSend, ToSendMax);
+	resp_ff_len = ToSendMax;
+
+	// Application Issuer Area (block 5)
+	CodeIso15693AsTag(aia_data, sizeof(aia_data));
+	memcpy(resp_aia, ToSend, ToSendMax);
+	resp_aia_len = ToSendMax;
+
+	//This is used for responding to READ-block commands or other data which is dynamically generated
+	uint8_t *data_generic_trace = BigBuf_malloc(32 + 2); // 32 bytes data + 2byte CRC is max tag answer
+	uint8_t *data_response = BigBuf_malloc( (32 + 2) * 2 + 2);
+
+	bool buttonPressed = false;
+	enum { IDLE, ACTIVATED, SELECTED, HALTED } chip_state = IDLE;
 
+	while (!exitLoop) {
+		WDT_HIT();
 
-			/* And ready to receive another command. */
-		    Uart.state = STATE_UNSYNCD;
-		    /* And also reset the demod code, which might have been */
-		    /* false-triggered by the commands from the reader. */
-		    Demod.state = DEMOD_UNSYNCD;
-		    LED_B_OFF();
-		    Uart.byteCnt = 0;
+		uint32_t reader_eof_time = 0;
+		len = GetIso15693CommandFromReader(receivedCmd, MAX_FRAME_SIZE, &reader_eof_time);
+		if (len < 0) {
+			buttonPressed = true;
+			break;
 		}
-		decbyter = 0;
-	}
 
-	if(div > 3) {
-		smpl = decbyte;
-		if(ManchesterDecoding(smpl & 0x0F)) {
-		    rsamples = samples - Demod.samples;
-		    LED_B_ON();
+		// Now look at the reader command and provide appropriate responses
+		// default is no response:
+		modulated_response = NULL;
+		modulated_response_size = 0;
+		trace_data = NULL;
+		trace_data_size = 0;
 
-			if(tracing)
-			{
-				LogTrace(Demod.output,Demod.len, (GetCountSspClk()-time_0) << 4 , Demod.parityBits,FALSE);
-				LogTrace(NULL, 0, (GetCountSspClk()-time_0) << 4, 0, FALSE);
+		if (receivedCmd[0] == ICLASS_CMD_ACTALL && len == 1) {
+			// Reader in anticollision phase
+			if (chip_state != HALTED) {
+				modulated_response = resp_sof;
+				modulated_response_size = resp_sof_Len;
+				chip_state = ACTIVATED;
 			}
 
+		} else if (receivedCmd[0] == ICLASS_CMD_READ_OR_IDENTIFY && len == 1) { // identify
+			// Reader asks for anticollision CSN
+			if (chip_state == SELECTED || chip_state == ACTIVATED) {
+				modulated_response = resp_anticoll;
+				modulated_response_size = resp_anticoll_len;
+				trace_data = anticoll_data;
+				trace_data_size = sizeof(anticoll_data);
+			}
 
-		    // And ready to receive another response.
-		    memset(&Demod, 0, sizeof(Demod));
-			Demod.output = tagToReaderResponse;
-		    Demod.state = DEMOD_UNSYNCD;
-		    LED_C_OFF();
-		}
-		
-		div = 0;
-		decbyte = 0x00;
-	}
-	//}
-
-        if(BUTTON_PRESS()) {
-            DbpString("cancelled_a");
-            goto done;
-        }
-    }
-
-    DbpString("COMMAND FINISHED");
-
-    Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
-
-done:
-    AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
-    Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
-    Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
-    LED_A_OFF();
-    LED_B_OFF();
-    LED_C_OFF();
-    LED_D_OFF();
-}
+		} else if (receivedCmd[0] == ICLASS_CMD_SELECT && len == 9) {
+			// Reader selects anticollision CSN.
+			// Tag sends the corresponding real CSN
+			if (chip_state == ACTIVATED || chip_state == SELECTED) {
+				if (!memcmp(receivedCmd+1, anticoll_data, 8)) {
+					modulated_response = resp_csn;
+					modulated_response_size = resp_csn_len;
+					trace_data = csn_data;
+					trace_data_size = sizeof(csn_data);
+					chip_state = SELECTED;
+				} else {
+					chip_state = IDLE;
+				}
+			} else if (chip_state == HALTED) {
+				// RESELECT with CSN
+				if (!memcmp(receivedCmd+1, csn_data, 8)) {
+					modulated_response = resp_csn;
+					modulated_response_size = resp_csn_len;
+					trace_data = csn_data;
+					trace_data_size = sizeof(csn_data);
+					chip_state = SELECTED;
+				}
+			}
 
-void rotateCSN(uint8_t* originalCSN, uint8_t* rotatedCSN) {
-	int i; 
-	for(i = 0; i < 8; i++) {
-		rotatedCSN[i] = (originalCSN[i] >> 3) | (originalCSN[(i+1)%8] << 5);
-	}
-}
+		} else if (receivedCmd[0] == ICLASS_CMD_READ_OR_IDENTIFY && len == 4) { // read block
+			uint16_t blockNo = receivedCmd[1];
+			if (chip_state == SELECTED) {
+				if (simulationMode == ICLASS_SIM_MODE_EXIT_AFTER_MAC) {
+					// provide defaults for blocks 0 ... 5
+					switch (blockNo) {
+						case 0: // csn (block 00)
+							modulated_response = resp_csn;
+							modulated_response_size = resp_csn_len;
+							trace_data = csn_data;
+							trace_data_size = sizeof(csn_data);
+							break;
+						case 1: // configuration (block 01)
+							modulated_response = resp_conf;
+							modulated_response_size = resp_conf_len;
+							trace_data = conf_block;
+							trace_data_size = sizeof(conf_block);
+							break;
+						case 2: // e-purse (block 02)
+							modulated_response = resp_cc;
+							modulated_response_size = resp_cc_len;
+							trace_data = card_challenge_data;
+							trace_data_size = sizeof(card_challenge_data);
+							// set epurse of sim2,4 attack
+							if (reader_mac_buf != NULL) {
+								memcpy(reader_mac_buf, card_challenge_data, 8);
+							}
+							break;
+						case 3:
+						case 4: // Kd, Kc, always respond with 0xff bytes
+							modulated_response = resp_ff;
+							modulated_response_size = resp_ff_len;
+							trace_data = ff_data;
+							trace_data_size = sizeof(ff_data);
+							break;
+						case 5: // Application Issuer Area (block 05)
+							modulated_response = resp_aia;
+							modulated_response_size = resp_aia_len;
+							trace_data = aia_data;
+							trace_data_size = sizeof(aia_data);
+							break;
+						// default: don't respond
+					}
+				} else if (simulationMode == ICLASS_SIM_MODE_FULL) {
+					if (blockNo == 3 || blockNo == 4) { // Kd, Kc, always respond with 0xff bytes
+						modulated_response = resp_ff;
+						modulated_response_size = resp_ff_len;
+						trace_data = ff_data;
+						trace_data_size = sizeof(ff_data);
+					} else { // use data from emulator memory
+						memcpy(data_generic_trace, emulator + current_page*page_size + 8*blockNo, 8);
+						AppendCrc(data_generic_trace, 8);
+						trace_data = data_generic_trace;
+						trace_data_size = 10;
+						CodeIso15693AsTag(trace_data, trace_data_size);
+						memcpy(data_response, ToSend, ToSendMax);
+						modulated_response = data_response;
+						modulated_response_size = ToSendMax;
+					}
+				}
+			}
 
-//-----------------------------------------------------------------------------
-// Wait for commands from reader
-// Stop when button is pressed
-// Or return TRUE when command is captured
-//-----------------------------------------------------------------------------
-static int GetIClassCommandFromReader(uint8_t *received, int *len, int maxLen)
-{
-    // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
-    // only, since we are receiving, not transmitting).
-    // Signal field is off with the appropriate LED
-    LED_D_OFF();
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
-    // Now run a `software UART' on the stream of incoming samples.
-    Uart.output = received;
-    Uart.byteCntMax = maxLen;
-    Uart.state = STATE_UNSYNCD;
-
-    for(;;) {
-        WDT_HIT();
-
-        if(BUTTON_PRESS()) return FALSE;
-
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-            AT91C_BASE_SSC->SSC_THR = 0x00;
-        }
-        if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			/*if(OutOfNDecoding((b & 0xf0) >> 4)) {
-				*len = Uart.byteCnt;
-				return TRUE;
-			}*/
-			if(OutOfNDecoding(b & 0x0f)) {
-				*len = Uart.byteCnt;
-				return TRUE;
+		} else if ((receivedCmd[0] == ICLASS_CMD_READCHECK_KD
+					|| receivedCmd[0] == ICLASS_CMD_READCHECK_KC) && receivedCmd[1] == 0x02 && len == 2) {
+			// Read e-purse (88 02 || 18 02)
+			if (chip_state == SELECTED) {
+				if(receivedCmd[0] == ICLASS_CMD_READCHECK_KD){
+					cipher_state = &cipher_state_KD[current_page];
+					diversified_key = diversified_key_d;
+				} else {
+					cipher_state = &cipher_state_KC[current_page];
+					diversified_key = diversified_key_c;
+				}
+				modulated_response = resp_cc;
+				modulated_response_size = resp_cc_len;
+				trace_data = card_challenge_data;
+				trace_data_size = sizeof(card_challenge_data);
 			}
-        }
-    }
-}
 
+		} else if ((receivedCmd[0] == ICLASS_CMD_CHECK_KC
+					|| receivedCmd[0] == ICLASS_CMD_CHECK_KD) && len == 9) {
+			// Reader random and reader MAC!!!
+			if (chip_state == SELECTED) {
+				if (simulationMode == ICLASS_SIM_MODE_FULL) {
+					//NR, from reader, is in receivedCmd+1
+					opt_doTagMAC_2(*cipher_state, receivedCmd+1, data_generic_trace, diversified_key);
+					trace_data = data_generic_trace;
+					trace_data_size = 4;
+					CodeIso15693AsTag(trace_data, trace_data_size);
+					memcpy(data_response, ToSend, ToSendMax);
+					modulated_response = data_response;
+					modulated_response_size = ToSendMax;
+					//exitLoop = true;
+				} else { // Not fullsim, we don't respond
+					// We do not know what to answer, so lets keep quiet
+					if (simulationMode == ICLASS_SIM_MODE_EXIT_AFTER_MAC) {
+						if (reader_mac_buf != NULL) {
+							// save NR and MAC for sim 2,4
+							memcpy(reader_mac_buf + 8, receivedCmd + 1, 8);
+						}
+						exitLoop = true;
+					}
+				}
+			}
 
-//-----------------------------------------------------------------------------
-// Prepare tag messages
-//-----------------------------------------------------------------------------
-static void CodeIClassTagAnswer(const uint8_t *cmd, int len)
-{
-	//So far a dummy implementation, not used
-	//int lastProxToAirDuration =0;
-	int i;
+		} else if (receivedCmd[0] == ICLASS_CMD_HALT && len == 1) {
+			if (chip_state == SELECTED) {
+				// Reader ends the session
+				modulated_response = resp_sof;
+				modulated_response_size = resp_sof_Len;
+				chip_state = HALTED;
+			}
+
+		} else if (simulationMode == ICLASS_SIM_MODE_FULL && receivedCmd[0] == ICLASS_CMD_READ4 && len == 4) {  // 0x06
+			//Read 4 blocks
+			if (chip_state == SELECTED) {
+				uint8_t blockNo = receivedCmd[1];
+				memcpy(data_generic_trace, emulator + current_page*page_size + blockNo*8, 8 * 4);
+				AppendCrc(data_generic_trace, 8 * 4);
+				trace_data = data_generic_trace;
+				trace_data_size = 8 * 4 + 2;
+				CodeIso15693AsTag(trace_data, trace_data_size);
+				memcpy(data_response, ToSend, ToSendMax);
+				modulated_response = data_response;
+				modulated_response_size = ToSendMax;
+			}
+
+		} else if (receivedCmd[0] == ICLASS_CMD_UPDATE && (len == 12 || len == 14)) {
+			// We're expected to respond with the data+crc, exactly what's already in the receivedCmd
+			// receivedCmd is now UPDATE 1b | ADDRESS 1b | DATA 8b | Signature 4b or CRC 2b
+			if (chip_state == SELECTED) {
+				uint8_t blockNo = receivedCmd[1];
+				if (blockNo == 2) { // update e-purse
+					memcpy(card_challenge_data, receivedCmd+2, 8);
+					CodeIso15693AsTag(card_challenge_data, sizeof(card_challenge_data));
+					memcpy(resp_cc, ToSend, ToSendMax);
+					resp_cc_len = ToSendMax;
+					cipher_state_KD[current_page] = opt_doTagMAC_1(card_challenge_data, diversified_key_d);
+					cipher_state_KC[current_page] = opt_doTagMAC_1(card_challenge_data, diversified_key_c);
+					if (simulationMode == ICLASS_SIM_MODE_FULL) {
+						memcpy(emulator + current_page*page_size + 8*2, card_challenge_data, 8);
+					}
+				} else if (blockNo == 3) { // update Kd
+					for (int i = 0; i < 8; i++) {
+						if (personalization_mode) {
+							diversified_key_d[i] = receivedCmd[2 + i];
+						} else {
+							diversified_key_d[i] ^= receivedCmd[2 + i];
+						}
+					}
+					cipher_state_KD[current_page] = opt_doTagMAC_1(card_challenge_data, diversified_key_d);
+					if (simulationMode == ICLASS_SIM_MODE_FULL) {
+						memcpy(emulator + current_page*page_size + 8*3, diversified_key_d, 8);
+					}
+				} else if (blockNo == 4) { // update Kc
+					for (int i = 0; i < 8; i++) {
+						if (personalization_mode) {
+							diversified_key_c[i] = receivedCmd[2 + i];
+						} else {
+							diversified_key_c[i] ^= receivedCmd[2 + i];
+						}
+					}
+					cipher_state_KC[current_page] = opt_doTagMAC_1(card_challenge_data, diversified_key_c);
+					if (simulationMode == ICLASS_SIM_MODE_FULL) {
+						memcpy(emulator + current_page*page_size + 8*4, diversified_key_c, 8);
+					}
+				} else if (simulationMode == ICLASS_SIM_MODE_FULL) { // update any other data block
+						memcpy(emulator + current_page*page_size + 8*blockNo, receivedCmd+2, 8);
+				}
+				memcpy(data_generic_trace, receivedCmd + 2, 8);
+				AppendCrc(data_generic_trace, 8);
+				trace_data = data_generic_trace;
+				trace_data_size = 10;
+				CodeIso15693AsTag(trace_data, trace_data_size);
+				memcpy(data_response, ToSend, ToSendMax);
+				modulated_response = data_response;
+				modulated_response_size = ToSendMax;
+			}
+
+		} else if (receivedCmd[0] == ICLASS_CMD_PAGESEL && len == 4) {
+			// Pagesel
+			// Chips with a single page will not answer to this command
+			// Otherwise, we should answer 8bytes (conf block 1) + 2bytes CRC
+			if (chip_state == SELECTED) {
+				if (simulationMode == ICLASS_SIM_MODE_FULL && max_page > 0) {
+					current_page = receivedCmd[1];
+					memcpy(data_generic_trace, emulator + current_page*page_size + 8*1, 8);
+					memcpy(diversified_key_d, emulator + current_page*page_size + 8*3, 8);
+					memcpy(diversified_key_c, emulator + current_page*page_size + 8*4, 8);
+					cipher_state = &cipher_state_KD[current_page];
+					personalization_mode = data_generic_trace[7] & 0x80;
+					AppendCrc(data_generic_trace, 8);
+					trace_data = data_generic_trace;
+					trace_data_size = 10;
+					CodeIso15693AsTag(trace_data, trace_data_size);
+					memcpy(data_response, ToSend, ToSendMax);
+					modulated_response = data_response;
+					modulated_response_size = ToSendMax;
+				}
+			}
 
-	ToSendReset();
+		} else if (receivedCmd[0] == 0x26 && len == 5) {
+			// standard ISO15693 INVENTORY command. Ignore.
 
-	// Send SOF
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;//Proxtoair duration starts here
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-
-	for(i = 0; i < len; i++) {
-		int j;
-		uint8_t b = cmd[i];
-
-		// Data bits
-		for(j = 0; j < 8; j++) {
-			if(b & 1) {
-				ToSend[++ToSendMax] = 0x00;
-				ToSend[++ToSendMax] = 0xff;
-			} else {
-				ToSend[++ToSendMax] = 0xff;
-				ToSend[++ToSendMax] = 0x00;
+		} else {
+			// don't know how to handle this command
+			char debug_message[250]; // should be enough
+			sprintf(debug_message, "Unhandled command (len = %d) received from reader:", len);
+			for (int i = 0; i < len && strlen(debug_message) < sizeof(debug_message) - 3 - 1; i++) {
+				sprintf(debug_message + strlen(debug_message), " %02x", receivedCmd[i]);
 			}
-			b >>= 1;
+			Dbprintf("%s", debug_message);
+			// Do not respond
 		}
-	}
 
-	// Send EOF
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;	
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
+		/**
+		A legit tag has about 273,4us delay between reader EOT and tag SOF.
+		**/
+		if (modulated_response_size > 0) {
+			uint32_t response_time = reader_eof_time + DELAY_ICLASS_VCD_TO_VICC_SIM;
+			TransmitTo15693Reader(modulated_response, modulated_response_size, &response_time, 0, false);
+			LogTrace_ISO15693(trace_data, trace_data_size, response_time*32, response_time*32 + modulated_response_size/2, NULL, false);
+		}
 
-	//lastProxToAirDuration  = 8*ToSendMax - 3*8 - 3*8;//Not counting zeroes in the beginning or end
+	}
 
-	// Convert from last byte pos to length
-	ToSendMax++;
+	if (buttonPressed)
+	{
+		DbpString("Button pressed");
+	}
+	return buttonPressed;
 }
 
-// Only SOF 
-static void CodeIClassTagSOF()
-{
-	//So far a dummy implementation, not used
-	//int lastProxToAirDuration =0;
-
-	ToSendReset();
-	// Send SOF
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0xff;
-	ToSend[++ToSendMax] = 0x00;
-	ToSend[++ToSendMax] = 0xff;
-
-//	lastProxToAirDuration  = 8*ToSendMax - 3*8;//Not counting zeroes in the beginning
-
-	
-	// Convert from last byte pos to length
-	ToSendMax++;
-}
-int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived, uint8_t *reader_mac_buf);
 /**
  * @brief SimulateIClass simulates an iClass card.
  * @param arg0 type of simulation
- *			- 0 uses the first 8 bytes in usb data as CSN
- *			- 2 "dismantling iclass"-attack. This mode iterates through all CSN's specified
- *			in the usb data. This mode collects MAC from the reader, in order to do an offline
- *			attack on the keys. For more info, see "dismantling iclass" and proxclone.com.
- *			- Other : Uses the default CSN (031fec8af7ff12e0)
+ *          - 0 uses the first 8 bytes in usb data as CSN
+ *          - 2 "dismantling iclass"-attack. This mode iterates through all CSN's specified
+ *          in the usb data. This mode collects MAC from the reader, in order to do an offline
+ *          attack on the keys. For more info, see "dismantling iclass" and proxclone.com.
+ *          - Other : Uses the default CSN (031fec8af7ff12e0)
  * @param arg1 - number of CSN's contained in datain (applicable for mode 2 only)
  * @param arg2
  * @param datain
  */
-void SimulateIClass(uint32_t arg0, uint32_t arg1, uint32_t arg2, uint8_t *datain)
-{
+void SimulateIClass(uint32_t arg0, uint32_t arg1, uint32_t arg2, uint8_t *datain) {
+
+	LED_A_ON();
+
 	uint32_t simType = arg0;
 	uint32_t numberOfCSNS = arg1;
+
+	// setup hardware for simulation:
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
+	LED_D_OFF();
+	FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR);
+	StartCountSspClk();
 
 	// Enable and clear the trace
-	iso14a_set_tracing(TRUE);
-	iso14a_clear_trace();
+	set_tracing(true);
+	clear_trace();
+	//Use the emulator memory for SIM
+	uint8_t *emulator = BigBuf_get_EM_addr();
 
-	uint8_t csn_crc[] = { 0x03, 0x1f, 0xec, 0x8a, 0xf7, 0xff, 0x12, 0xe0, 0x00, 0x00 };
-	if(simType == 0) {
+	if (simType == ICLASS_SIM_MODE_CSN) {
 		// Use the CSN from commandline
-		memcpy(csn_crc, datain, 8);
-		doIClassSimulation(csn_crc,0,NULL);
-	}else if(simType == 1)
-	{
-		doIClassSimulation(csn_crc,0,NULL);
-	}
-	else if(simType == 2)
-	{
-
-		uint8_t mac_responses[64] = { 0 };
-		Dbprintf("Going into attack mode");
+		memcpy(emulator, datain, 8);
+		doIClassSimulation(ICLASS_SIM_MODE_CSN, NULL);
+	} else if (simType == ICLASS_SIM_MODE_CSN_DEFAULT) {
+		//Default CSN
+		uint8_t csn_crc[] = { 0x03, 0x1f, 0xec, 0x8a, 0xf7, 0xff, 0x12, 0xe0, 0x00, 0x00 };
+		// Use the CSN from commandline
+		memcpy(emulator, csn_crc, 8);
+		doIClassSimulation(ICLASS_SIM_MODE_CSN, NULL);
+	} else if (simType == ICLASS_SIM_MODE_READER_ATTACK) {
+		uint8_t mac_responses[USB_CMD_DATA_SIZE] = { 0 };
+		Dbprintf("Going into attack mode, %d CSNS sent", numberOfCSNS);
 		// In this mode, a number of csns are within datain. We'll simulate each one, one at a time
-		// in order to collect MAC's from the reader. This can later be used in an offlne-attack
+		// in order to collect MAC's from the reader. This can later be used in an offline-attack
 		// in order to obtain the keys, as in the "dismantling iclass"-paper.
-		int i = 0;
-		for( ; i < numberOfCSNS && i*8+8 < USB_CMD_DATA_SIZE; i++)
-		{
-			// The usb data is 512 bytes, fitting 65 8-byte CSNs in there.
-
-			memcpy(csn_crc, datain+(i*8), 8);
-			if(doIClassSimulation(csn_crc,1,mac_responses))
-			{
-				return; // Button pressed
-			}
+		int i;
+		for (i = 0; i < numberOfCSNS && i*16+16 <= USB_CMD_DATA_SIZE; i++) {
+			// The usb data is 512 bytes, fitting 32 responses (8 byte CC + 4 Byte NR + 4 Byte MAC = 16 Byte response).
+			memcpy(emulator, datain+(i*8), 8);
+			if (doIClassSimulation(ICLASS_SIM_MODE_EXIT_AFTER_MAC, mac_responses+i*16)) {
+				 // Button pressed
+				 break;
+			}
+			Dbprintf("CSN: %02x %02x %02x %02x %02x %02x %02x %02x",
+					datain[i*8+0], datain[i*8+1], datain[i*8+2], datain[i*8+3],
+					datain[i*8+4], datain[i*8+5], datain[i*8+6], datain[i*8+7]);
+			Dbprintf("NR,MAC: %02x %02x %02x %02x %02x %02x %02x %02x",
+					mac_responses[i*16+ 8], mac_responses[i*16+ 9], mac_responses[i*16+10], mac_responses[i*16+11],
+					mac_responses[i*16+12], mac_responses[i*16+13], mac_responses[i*16+14], mac_responses[i*16+15]);
+			SpinDelay(100); // give the reader some time to prepare for next CSN
 		}
-		cmd_send(CMD_ACK,CMD_SIMULATE_TAG_ICLASS,i,0,mac_responses,i*8);
-
-	}
-	else{
+		cmd_send(CMD_ACK, CMD_SIMULATE_TAG_ICLASS, i, 0, mac_responses, i*16);
+	} else if (simType == ICLASS_SIM_MODE_FULL) {
+		//This is 'full sim' mode, where we use the emulator storage for data.
+		doIClassSimulation(ICLASS_SIM_MODE_FULL, NULL);
+	} else {
 		// We may want a mode here where we hardcode the csns to use (from proxclone).
 		// That will speed things up a little, but not required just yet.
 		Dbprintf("The mode is not implemented, reserved for future use");
 	}
+
 	Dbprintf("Done...");
 
+	LED_A_OFF();
 }
-/**
- * @brief Does the actual simulation
- * @param csn - csn to use
- * @param breakAfterMacReceived if true, returns after reader MAC has been received.
- */
-int doIClassSimulation(uint8_t csn[], int breakAfterMacReceived, uint8_t *reader_mac_buf)
-{
 
 
-	// CSN followed by two CRC bytes
-	uint8_t response2[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-	uint8_t response3[] = { 0,0,0,0,0,0,0,0,0,0};
-	memcpy(response3,csn,sizeof(response3));
-	Dbprintf("Simulating CSN %02x%02x%02x%02x%02x%02x%02x%02x",csn[0],csn[1],csn[2],csn[3],csn[4],csn[5],csn[6],csn[7]);
-	// e-Purse
-	uint8_t response4[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-
-	// Construct anticollision-CSN
-	rotateCSN(response3,response2);
-
-	// Compute CRC on both CSNs
-	ComputeCrc14443(CRC_ICLASS, response2, 8, &response2[8], &response2[9]);
-	ComputeCrc14443(CRC_ICLASS, response3, 8, &response3[8], &response3[9]);
+/// THE READER CODE
 
-	int exitLoop = 0;
-	// Reader 0a
-	// Tag    0f
-	// Reader 0c
-	// Tag    anticoll. CSN
-	// Reader 81 anticoll. CSN
-	// Tag    CSN
+static void ReaderTransmitIClass(uint8_t *frame, int len, uint32_t *start_time) {
 
-	uint8_t *resp;
-	int respLen;
-	uint8_t* respdata = NULL;
-	int respsize = 0;
-	uint8_t sof = 0x0f;
+	CodeIso15693AsReader(frame, len);
 
-	// Respond SOF -- takes 8 bytes
-	uint8_t *resp1 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
-	int resp1Len;
+	TransmitTo15693Tag(ToSend, ToSendMax, start_time);
 
-	// Anticollision CSN (rotated CSN)
-	// 176: Takes 16 bytes for SOF/EOF and 10 * 16 = 160 bytes (2 bytes/bit)
-	uint8_t *resp2 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 10);
-	int resp2Len;
+	uint32_t end_time = *start_time + 32*(8*ToSendMax-4); // substract the 4 padding bits after EOF
+	LogTrace_ISO15693(frame, len, *start_time*4, end_time*4, NULL, true);
+}
 
-	// CSN
-	// 176: Takes 16 bytes for SOF/EOF and 10 * 16 = 160 bytes (2 bytes/bit)
-	uint8_t *resp3 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 190);
-	int resp3Len;
 
-	// e-Purse
-	// 144: Takes 16 bytes for SOF/EOF and 8 * 16 = 128 bytes (2 bytes/bit)
-	uint8_t *resp4 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 370);
-	int resp4Len;
-
-	// + 1720..
-	uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
-	memset(receivedCmd, 0x44, RECV_CMD_SIZE);
-	int len;
+static bool sendCmdGetResponseWithRetries(uint8_t* command, size_t cmdsize, uint8_t* resp, size_t max_resp_size,
+										  uint8_t expected_size, uint8_t tries, uint32_t start_time, uint32_t timeout, uint32_t *eof_time) {
+	while (tries-- > 0) {
+		ReaderTransmitIClass(command, cmdsize, &start_time);
+		if (expected_size == GetIso15693AnswerFromTag(resp, max_resp_size, timeout, eof_time)) {
+			return true;
+		}
+	}
+	return false;//Error
+}
 
-	// Prepare card messages
-	ToSendMax = 0;
 
-	// First card answer: SOF
-	CodeIClassTagSOF();
-	memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
+/**
+ * @brief Selects an iclass tag
+ * @param card_data where the CSN is stored for return
+ * @return false = fail
+ *         true = success
+ */
+static bool selectIclassTag(uint8_t *card_data, uint32_t *eof_time) {
+	uint8_t act_all[]      = { 0x0a };
+	uint8_t identify[]     = { 0x0c };
+	uint8_t select[]       = { 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+	uint8_t resp[ICLASS_BUFFER_SIZE];
+
+	uint32_t start_time = GetCountSspClk();
+
+	// Send act_all
+	ReaderTransmitIClass(act_all, 1, &start_time);
+	// Card present?
+	if (GetIso15693AnswerFromTag(resp, sizeof(resp), ICLASS_READER_TIMEOUT_ACTALL, eof_time) < 0) return false; //Fail
+
+	//Send Identify
+	start_time = *eof_time + DELAY_ICLASS_VICC_TO_VCD_READER;
+	ReaderTransmitIClass(identify, 1, &start_time);
+	//We expect a 10-byte response here, 8 byte anticollision-CSN and 2 byte CRC
+	uint8_t len = GetIso15693AnswerFromTag(resp, sizeof(resp), ICLASS_READER_TIMEOUT_OTHERS, eof_time);
+	if (len != 10) return false; //Fail
+
+	//Copy the Anti-collision CSN to our select-packet
+	memcpy(&select[1], resp, 8);
+	//Select the card
+	start_time = *eof_time + DELAY_ICLASS_VICC_TO_VCD_READER;
+	ReaderTransmitIClass(select, sizeof(select), &start_time);
+	//We expect a 10-byte response here, 8 byte CSN and 2 byte CRC
+	len = GetIso15693AnswerFromTag(resp, sizeof(resp), ICLASS_READER_TIMEOUT_OTHERS, eof_time);
+	if (len != 10) return false; //Fail
+
+	//Success - we got CSN
+	//Save CSN in response data
+	memcpy(card_data, resp, 8);
+
+	return true;
+}
 
-	// Anticollision CSN
-	CodeIClassTagAnswer(response2, sizeof(response2));
-	memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax;
 
-	// CSN
-	CodeIClassTagAnswer(response3, sizeof(response3));
-	memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax;
+// Select an iClass tag and read all blocks which are always readable without authentication
+void ReaderIClass(uint8_t flags) {
 
-	// e-Purse
-	CodeIClassTagAnswer(response4, sizeof(response4));
-	memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
+	LED_A_ON();
 
+	uint8_t card_data[6 * 8] = {0};
+	memset(card_data, 0xFF, sizeof(card_data));
+	uint8_t resp[ICLASS_BUFFER_SIZE];
+	//Read conf block CRC(0x01) => 0xfa 0x22
+	uint8_t readConf[] = {ICLASS_CMD_READ_OR_IDENTIFY, 0x01, 0xfa, 0x22};
+	//Read e-purse block CRC(0x02) => 0x61 0x10
+	uint8_t readEpurse[] = {ICLASS_CMD_READ_OR_IDENTIFY, 0x02, 0x61, 0x10};
+	//Read App Issuer Area block CRC(0x05) => 0xde  0x64
+	uint8_t readAA[] = {ICLASS_CMD_READ_OR_IDENTIFY, 0x05, 0xde, 0x64};
 
-	// Start from off (no field generated)
-	//FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	//SpinDelay(200);
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-	SpinDelay(100);
-	StartCountSspClk();
-	// We need to listen to the high-frequency, peak-detected path.
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
-	FpgaSetupSsc();
+	uint8_t result_status = 0;
 
-	// To control where we are in the protocol
-	int cmdsRecvd = 0;
-	uint32_t time_0 = GetCountSspClk();
-	uint32_t t2r_time =0;
-	uint32_t r2t_time =0;
+	if (flags & FLAG_ICLASS_READER_INIT) {
+		Iso15693InitReader();
+	}
 
-	LED_A_ON();
-	bool buttonPressed = false;
+	if (flags & FLAG_ICLASS_READER_CLEARTRACE) {
+		set_tracing(true);
+		clear_trace();
+		StartCountSspClk();
+	}
 
-	/** Hack  for testing
-	memcpy(reader_mac_buf,csn,8);
-	exitLoop = true;
-	end hack **/
+	uint32_t start_time = 0;
+	uint32_t eof_time = 0;
 
-	while(!exitLoop) {
+	if (selectIclassTag(resp, &eof_time)) {
+		result_status = FLAG_ICLASS_READER_CSN;
+		memcpy(card_data, resp, 8);
 
-		LED_B_OFF();
-		//Signal tracer
-		// Can be used to get a trigger for an oscilloscope..
-		LED_C_OFF();
+		start_time = eof_time + DELAY_ICLASS_VICC_TO_VCD_READER;
 
-		if(!GetIClassCommandFromReader(receivedCmd, &len, 100)) {
-			buttonPressed = true;
-			break;
-		}
-		r2t_time = GetCountSspClk();
-		//Signal tracer
-		LED_C_ON();
-
-		// Okay, look at the command now.
-		if(receivedCmd[0] == 0x0a ) {
-			// Reader in anticollission phase
-			resp = resp1; respLen = resp1Len; //order = 1;
-			respdata = &sof;
-			respsize = sizeof(sof);
-		} else if(receivedCmd[0] == 0x0c) {
-			// Reader asks for anticollission CSN
-			resp = resp2; respLen = resp2Len; //order = 2;
-			respdata = response2;
-			respsize = sizeof(response2);
-			//DbpString("Reader requests anticollission CSN:");
-		} else if(receivedCmd[0] == 0x81) {
-			// Reader selects anticollission CSN.
-			// Tag sends the corresponding real CSN
-			resp = resp3; respLen = resp3Len; //order = 3;
-			respdata = response3;
-			respsize = sizeof(response3);
-			//DbpString("Reader selects anticollission CSN:");
-		} else if(receivedCmd[0] == 0x88) {
-			// Read e-purse (88 02)
-			resp = resp4; respLen = resp4Len; //order = 4;
-			respdata = response4;
-			respsize = sizeof(response4);
-			LED_B_ON();
-		} else if(receivedCmd[0] == 0x05) {
-			// Reader random and reader MAC!!!
-			// Do not respond
-			// We do not know what to answer, so lets keep quit
-			resp = resp1; respLen = 0; //order = 5;
-			respdata = NULL;
-			respsize = 0;
-			if (breakAfterMacReceived){
-				// TODO, actually return this to the caller instead of just
-				// dbprintf:ing ...
-				Dbprintf("CSN: %02x %02x %02x %02x %02x %02x %02x %02x",csn[0],csn[1],csn[2],csn[3],csn[4],csn[5],csn[6],csn[7]);
-				Dbprintf("RDR:  (len=%02d): %02x %02x %02x %02x %02x %02x %02x %02x %02x",len,
-						 receivedCmd[0], receivedCmd[1], receivedCmd[2],
-						receivedCmd[3], receivedCmd[4], receivedCmd[5],
-						receivedCmd[6], receivedCmd[7], receivedCmd[8]);
-				if (reader_mac_buf != NULL)
-				{
-					memcpy(reader_mac_buf,receivedCmd+1,8);
-				}
-				exitLoop = true;
+		//Read block 1, config
+		if (flags & FLAG_ICLASS_READER_CONF) {
+			if (sendCmdGetResponseWithRetries(readConf, sizeof(readConf), resp, sizeof(resp), 10, 10, start_time, ICLASS_READER_TIMEOUT_OTHERS, &eof_time)) {
+				result_status |= FLAG_ICLASS_READER_CONF;
+				memcpy(card_data+8, resp, 8);
+			} else {
+				Dbprintf("Failed to read config block");
 			}
-		} else if(receivedCmd[0] == 0x00 && len == 1) {
-			// Reader ends the session
-			resp = resp1; respLen = 0; //order = 0;
-			respdata = NULL;
-			respsize = 0;
-		} else {
-			//#db# Unknown command received from reader (len=5): 26 1 0 f6 a 44 44 44 44
-			// Never seen this command before
-			Dbprintf("Unknown command received from reader (len=%d): %x %x %x %x %x %x %x %x %x",
-			len,
-			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;
-		}
-
-		if(cmdsRecvd >  100) {
-			//DbpString("100 commands later...");
-			//break;
-		}
-		else {
-			cmdsRecvd++;
+			start_time = eof_time + DELAY_ICLASS_VICC_TO_VCD_READER;
 		}
 
-		if(respLen > 0) {
-			SendIClassAnswer(resp, respLen, 21);
-			t2r_time = GetCountSspClk();
+		//Read block 2, e-purse
+		if (flags & FLAG_ICLASS_READER_CC) {
+			if (sendCmdGetResponseWithRetries(readEpurse, sizeof(readEpurse), resp, sizeof(resp), 10, 10, start_time, ICLASS_READER_TIMEOUT_OTHERS, &eof_time)) {
+				result_status |= FLAG_ICLASS_READER_CC;
+				memcpy(card_data + (8*2), resp, 8);
+			} else {
+				Dbprintf("Failed to read e-purse");
+			}
+			start_time = eof_time + DELAY_ICLASS_VICC_TO_VCD_READER;
 		}
 
-		if (tracing) {
-			LogTrace(receivedCmd,len, (r2t_time-time_0)<< 4, Uart.parityBits,TRUE);
-			LogTrace(NULL,0, (r2t_time-time_0) << 4, 0,TRUE);
-
-			if (respdata != NULL) {
-				LogTrace(respdata,respsize, (t2r_time-time_0) << 4,SwapBits(GetParity(respdata,respsize),respsize),FALSE);
-				LogTrace(NULL,0, (t2r_time-time_0) << 4,0,FALSE);
-
-
-			}
-			if(!tracing) {
-				DbpString("Trace full");
-				//break;
+		//Read block 5, AA
+		if (flags & FLAG_ICLASS_READER_AA) {
+			if (sendCmdGetResponseWithRetries(readAA, sizeof(readAA), resp, sizeof(resp), 10, 10, start_time, ICLASS_READER_TIMEOUT_OTHERS, &eof_time)) {
+				result_status |= FLAG_ICLASS_READER_AA;
+				memcpy(card_data + (8*5), resp, 8);
+			} else {
+				Dbprintf("Failed to read AA block");
 			}
-
 		}
-		memset(receivedCmd, 0x44, RECV_CMD_SIZE);
 	}
+	
+	cmd_send(CMD_ACK, result_status, 0, 0, card_data, sizeof(card_data));
 
-	//Dbprintf("%x", cmdsRecvd);
 	LED_A_OFF();
-	LED_B_OFF();
-	if(buttonPressed)
-	{
-		DbpString("Button pressed");
-	}
-	return buttonPressed;
 }
 
-static int SendIClassAnswer(uint8_t *resp, int respLen, int delay)
-{
-	int i = 0, d=0;//, u = 0, d = 0;
-	uint8_t b = 0;
 
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR|FPGA_HF_SIMULATOR_MODULATE_424K);
+void iClass_Check(uint8_t *NRMAC) {
+	uint8_t check[9] = {ICLASS_CMD_CHECK_KD, 0x00};
+	uint8_t resp[4];
+	memcpy(check+1, NRMAC, 8);
+	uint32_t eof_time;
+	bool isOK = sendCmdGetResponseWithRetries(check, sizeof(check), resp, sizeof(resp), 4, 3, 0, ICLASS_READER_TIMEOUT_OTHERS, &eof_time);
+	cmd_send(CMD_ACK, isOK, 0, 0, resp, sizeof(resp));
+}
 
-	AT91C_BASE_SSC->SSC_THR = 0x00;
-	FpgaSetupSsc();
-	while(!BUTTON_PRESS()) {
-		if((AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)){
-			b = AT91C_BASE_SSC->SSC_RHR; (void) b;
-		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)){
-			b = 0x00;
-			if(d < delay) {
-				d++;
-			}
-			else {
-				if( i < respLen){
-					b = resp[i];
-					//Hack
-					//b = 0xAC;
-				}
-				i++;
-			}
-			AT91C_BASE_SSC->SSC_THR = b;
-		}
 
-		if (i > respLen +4) break;
+void iClass_Readcheck(uint8_t block, bool use_credit_key) {
+	uint8_t readcheck[2] = {ICLASS_CMD_READCHECK_KD, block};
+	if (use_credit_key) {
+		readcheck[0] = ICLASS_CMD_READCHECK_KC;
 	}
-
-	return 0;
+	uint8_t resp[8];
+	uint32_t eof_time;
+	bool isOK = sendCmdGetResponseWithRetries(readcheck, sizeof(readcheck), resp, sizeof(resp), 8, 3, 0, ICLASS_READER_TIMEOUT_OTHERS, &eof_time);
+	cmd_send(CMD_ACK, isOK, 0, 0, resp, sizeof(resp));
 }
 
-/// THE READER CODE
 
-//-----------------------------------------------------------------------------
-// Transmit the command (to the tag) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitIClassCommand(const uint8_t *cmd, int len, int *samples, int *wait)
-{
-  int c;
-  FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-  AT91C_BASE_SSC->SSC_THR = 0x00;
-  FpgaSetupSsc();
-
-   if (wait)
-    if(*wait < 10)
-      *wait = 10;
-
-  for(c = 0; c < *wait;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-      AT91C_BASE_SSC->SSC_THR = 0x00;		// For exact timing!
-      c++;
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
-
-  uint8_t sendbyte;
-  bool firstpart = TRUE;
-  c = 0;
-  for(;;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-
-      // DOUBLE THE SAMPLES!
-      if(firstpart) {
-	sendbyte = (cmd[c] & 0xf0) | (cmd[c] >> 4); 
-      }
-      else {
-	sendbyte = (cmd[c] & 0x0f) | (cmd[c] << 4);
-        c++;
-      }
-      if(sendbyte == 0xff) {
-	sendbyte = 0xfe;
-      }
-      AT91C_BASE_SSC->SSC_THR = sendbyte;
-      firstpart = !firstpart;
-
-      if(c >= len) {
-        break;
-      }
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
-  if (samples) *samples = (c + *wait) << 3;
-}
+static bool iClass_ReadBlock(uint8_t blockNo, uint8_t *readdata) {
+	uint8_t readcmd[] = {ICLASS_CMD_READ_OR_IDENTIFY, blockNo, 0x00, 0x00}; //0x88, 0x00 // can i use 0C?
+	uint8_t bl = blockNo;
+	uint16_t rdCrc = iclass_crc16(&bl, 1);
+	readcmd[2] = rdCrc >> 8;
+	readcmd[3] = rdCrc & 0xff;
+	uint8_t resp[10];
+	uint32_t eof_time;
 
+	bool isOK = sendCmdGetResponseWithRetries(readcmd, sizeof(readcmd), resp, sizeof(resp), 10, 10, 0, ICLASS_READER_TIMEOUT_OTHERS, &eof_time);
+	memcpy(readdata, resp, sizeof(resp));
 
-//-----------------------------------------------------------------------------
-// Prepare iClass reader command to send to FPGA
-//-----------------------------------------------------------------------------
-void CodeIClassCommand(const uint8_t * cmd, int len)
-{
-  int i, j, k;
-  uint8_t b;
-
-  ToSendReset();
-
-  // Start of Communication: 1 out of 4
-  ToSend[++ToSendMax] = 0xf0;
-  ToSend[++ToSendMax] = 0x00;
-  ToSend[++ToSendMax] = 0x0f;
-  ToSend[++ToSendMax] = 0x00;
-
-  // Modulate the bytes 
-  for (i = 0; i < len; i++) {
-    b = cmd[i];
-    for(j = 0; j < 4; j++) {
-      for(k = 0; k < 4; k++) {
-			if(k == (b & 3)) {
-				ToSend[++ToSendMax] = 0x0f;
-			}
-			else {
-				ToSend[++ToSendMax] = 0x00;
-			}
-      }
-      b >>= 2;
-    }
-  }
-
-  // End of Communication
-  ToSend[++ToSendMax] = 0x00;
-  ToSend[++ToSendMax] = 0x00;
-  ToSend[++ToSendMax] = 0xf0;
-  ToSend[++ToSendMax] = 0x00;
-
-  // Convert from last character reference to length
-  ToSendMax++;
+	return isOK;
 }
 
-void ReaderTransmitIClass(uint8_t* frame, int len)
-{
-  int wait = 0;
-  int samples = 0;
-  int par = 0;
 
-  // This is tied to other size changes
-  // 	uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
-  CodeIClassCommand(frame,len);
+void iClass_ReadBlk(uint8_t blockno) {
 
-  // Select the card
-  TransmitIClassCommand(ToSend, ToSendMax, &samples, &wait);
-  if(trigger)
-  	LED_A_ON();
+	LED_A_ON();
 
-  // Store reader command in buffer
-  if (tracing) LogTrace(frame,len,rsamples,par,TRUE);
+	uint8_t readblockdata[10];
+	bool isOK = iClass_ReadBlock(blockno, readblockdata);
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+	cmd_send(CMD_ACK, isOK, 0, 0, readblockdata, 8);
+
+	LED_A_OFF();
 }
 
-//-----------------------------------------------------------------------------
-// Wait a certain time for tag response
-//  If a response is captured return TRUE
-//  If it takes too long return FALSE
-//-----------------------------------------------------------------------------
-static int GetIClassAnswer(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer
-{
-	// 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).
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
+void iClass_Dump(uint8_t startblock, uint8_t numblks) {
 
-	// Now get the answer from the card
-	Demod.output = receivedResponse;
-	Demod.len = 0;
-	Demod.state = DEMOD_UNSYNCD;
+	LED_A_ON();
 
-	uint8_t b;
-	if (elapsed) *elapsed = 0;
+	uint8_t readblockdata[USB_CMD_DATA_SIZE+2] = {0};
+	bool isOK = false;
+	uint16_t blkCnt = 0;
 
-	bool skip = FALSE;
+	if (numblks > USB_CMD_DATA_SIZE / 8) {
+		numblks = USB_CMD_DATA_SIZE / 8;
+	}
 
-	c = 0;
-	for(;;) {
-		WDT_HIT();
+	for (blkCnt = 0; blkCnt < numblks; blkCnt++) {
+		isOK = iClass_ReadBlock(startblock+blkCnt, readblockdata+8*blkCnt);
+		if (!isOK) {
+			Dbprintf("Block %02X failed to read", startblock+blkCnt);
+			break;
+		}
+	}
 
-	        if(BUTTON_PRESS()) return FALSE;
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+
+	cmd_send(CMD_ACK, isOK, blkCnt, 0, readblockdata, blkCnt*8);
+
+	LED_A_OFF();
+}
 
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-			AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
-			if (elapsed) (*elapsed)++;
+
+static bool iClass_WriteBlock_ext(uint8_t blockNo, uint8_t *data) {
+
+	uint8_t write[16] = {ICLASS_CMD_UPDATE, blockNo};
+	memcpy(write+2, data, 12); // data + mac
+	AppendCrc(write+1, 13);
+	uint8_t resp[10];
+	bool isOK = false;
+	uint32_t eof_time = 0;
+
+	isOK = sendCmdGetResponseWithRetries(write, sizeof(write), resp, sizeof(resp), 10, 3, 0, ICLASS_READER_TIMEOUT_UPDATE, &eof_time);
+	if (!isOK) {
+		return false;
+	}
+	
+	uint8_t all_ff[8] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+	if (blockNo == 2) {
+		if (memcmp(data+4, resp, 4) || memcmp(data, resp+4, 4)) { // check response. e-purse update swaps first and second half
+			return false;
 		}
-		if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-			if(c < timeout) { c++; } else { return FALSE; }
-			b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
-			skip = !skip;
-			if(skip) continue;
-			/*if(ManchesterDecoding((b>>4) & 0xf)) {
-				*samples = ((c - 1) << 3) + 4;
-				return TRUE;
-			}*/
-			if(ManchesterDecoding(b & 0x0f)) {
-				*samples = c << 3;
-				return  TRUE;
-			}
+	} else if (blockNo == 3 || blockNo == 4) {
+		if (memcmp(all_ff, resp, 8)) { // check response. Key updates always return 0xffffffffffffffff
+			return false;
+		}
+	} else {
+		if (memcmp(data, resp, 8)) { // check response. All other updates return unchanged data
+			return false;
 		}
 	}
-}
 
-int ReaderReceiveIClass(uint8_t* receivedAnswer)
-{
-  int samples = 0;
-  if (!GetIClassAnswer(receivedAnswer,160,&samples,0)) return FALSE;
-  rsamples += samples;
-  if (tracing) LogTrace(receivedAnswer,Demod.len,rsamples,Demod.parityBits,FALSE);
-  if(samples == 0) return FALSE;
-  return Demod.len;
+	return true;
 }
 
-// Reader iClass Anticollission
-void ReaderIClass(uint8_t arg0) {
-	uint8_t act_all[]     = { 0x0a };
-	uint8_t identify[]    = { 0x0c };
-	uint8_t select[]      = { 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
-
-	uint8_t* resp = (((uint8_t *)BigBuf) + 3560);	// was 3560 - tied to other size changes
 
-    FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+void iClass_WriteBlock(uint8_t blockNo, uint8_t *data) {
 
-	// Reset trace buffer
-	memset(trace, 0x44, RECV_CMD_OFFSET);
-	traceLen = 0;
+	LED_A_ON();
 
-	// Setup SSC
-	FpgaSetupSsc();
-	// Start from off (no field generated)
-	// Signal field is off with the appropriate LED
-	LED_D_OFF();
+	bool isOK = iClass_WriteBlock_ext(blockNo, data);
+	if (isOK) {
+		Dbprintf("Write block [%02x] successful", blockNo);
+	} else {
+		Dbprintf("Write block [%02x] failed", blockNo);
+	}
 	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-	SpinDelay(200);
+	LED_D_OFF();
+
+	cmd_send(CMD_ACK, isOK, 0, 0, 0, 0);
+	LED_A_OFF();
+}
 
-	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-	// Now give it time to spin up.
-	// Signal field is on with the appropriate LED
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-	SpinDelay(200);
+void iClass_Clone(uint8_t startblock, uint8_t endblock, uint8_t *data) {
 
 	LED_A_ON();
 
-	for(;;) {
-	
-		if(traceLen > TRACE_SIZE) {
-			DbpString("Trace full");
-			break;
-		}
-		
-		if (BUTTON_PRESS()) break;
-
-		// Send act_all
-		ReaderTransmitIClass(act_all, 1);
-		// Card present?
-		if(ReaderReceiveIClass(resp)) {
-			ReaderTransmitIClass(identify, 1);
-			if(ReaderReceiveIClass(resp) == 10) {
-				// Select card          
-				memcpy(&select[1],resp,8);
-				ReaderTransmitIClass(select, sizeof(select));
-
-				if(ReaderReceiveIClass(resp) == 10) {
-					Dbprintf("     Selected CSN: %02x %02x %02x %02x %02x %02x %02x %02x",
-					resp[0], resp[1], resp[2],
-					resp[3], resp[4], resp[5],
-					resp[6], resp[7]);
-				}
-				// Card selected, whats next... ;-)
-			}
+	int written = 0;
+	int total_blocks = (endblock - startblock) + 1;
+
+	for (uint8_t block = startblock; block <= endblock; block++) {
+		// block number
+		if (iClass_WriteBlock_ext(block, data + (block-startblock)*12)) {
+			Dbprintf("Write block [%02x] successful", block);
+			written++;
+		} else {
+			Dbprintf("Write block [%02x] failed", block);
 		}
-		WDT_HIT();
 	}
-	
-	LED_A_OFF();
-}
 
+	if (written == total_blocks)
+		Dbprintf("Clone complete");
+	else
+		Dbprintf("Clone incomplete");
 
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+	LED_D_OFF();
+
+	cmd_send(CMD_ACK, 1, 0, 0, 0, 0);
+	LED_A_OFF();
+}