//-----------------------------------------------------------------------------
+// Merlok - June 2011, 2012
// Gerhard de Koning Gans - May 2008
// Hagen Fritsch - June 2010
//
// Routines to support ISO 14443 type A.
//-----------------------------------------------------------------------------
+#include "iso14443a.h"
+
+#include <stdio.h>
+#include <string.h>
#include "proxmark3.h"
#include "apps.h"
#include "util.h"
-#include "string.h"
-
+#include "cmd.h"
#include "iso14443crc.h"
-#include "iso14443a.h"
+#include "crapto1/crapto1.h"
+#include "mifareutil.h"
+#include "mifaresniff.h"
+#include "BigBuf.h"
+#include "protocols.h"
+#include "parity.h"
+
+typedef struct {
+ enum {
+ DEMOD_UNSYNCD,
+ // DEMOD_HALF_SYNCD,
+ // DEMOD_MOD_FIRST_HALF,
+ // DEMOD_NOMOD_FIRST_HALF,
+ DEMOD_MANCHESTER_DATA
+ } state;
+ uint16_t twoBits;
+ uint16_t highCnt;
+ uint16_t bitCount;
+ uint16_t collisionPos;
+ uint16_t syncBit;
+ uint8_t parityBits;
+ uint8_t parityLen;
+ uint16_t shiftReg;
+ uint16_t samples;
+ uint16_t len;
+ uint32_t startTime, endTime;
+ uint8_t *output;
+ uint8_t *parity;
+} tDemod;
+
+typedef enum {
+ MOD_NOMOD = 0,
+ MOD_SECOND_HALF,
+ MOD_FIRST_HALF,
+ MOD_BOTH_HALVES
+ } Modulation_t;
+
+typedef struct {
+ enum {
+ STATE_UNSYNCD,
+ STATE_START_OF_COMMUNICATION,
+ STATE_MILLER_X,
+ STATE_MILLER_Y,
+ STATE_MILLER_Z,
+ // DROP_NONE,
+ // DROP_FIRST_HALF,
+ } state;
+ uint16_t shiftReg;
+ int16_t bitCount;
+ uint16_t len;
+ uint16_t byteCntMax;
+ uint16_t posCnt;
+ uint16_t syncBit;
+ uint8_t parityBits;
+ uint8_t parityLen;
+ uint32_t fourBits;
+ uint32_t startTime, endTime;
+ uint8_t *output;
+ uint8_t *parity;
+} tUart;
-static uint8_t *trace = (uint8_t *) BigBuf;
-static int traceLen = 0;
-static int rsamples = 0;
-static int tracing = TRUE;
static uint32_t iso14a_timeout;
+#define MAX_ISO14A_TIMEOUT 524288
+
+int rsamples = 0;
+uint8_t trigger = 0;
+// the block number for the ISO14443-4 PCB
+static uint8_t iso14_pcb_blocknum = 0;
+
+//
+// ISO14443 timing:
+//
+// minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
+#define REQUEST_GUARD_TIME (7000/16 + 1)
+// minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
+#define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
+// bool LastCommandWasRequest = false;
+
+//
+// Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
+//
+// When the PM acts as reader and is receiving tag data, it takes
+// 3 ticks delay in the AD converter
+// 16 ticks until the modulation detector completes and sets curbit
+// 8 ticks until bit_to_arm is assigned from curbit
+// 8*16 ticks for the transfer from FPGA to ARM
+// 4*16 ticks until we measure the time
+// - 8*16 ticks because we measure the time of the previous transfer
+#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
+
+// When the PM acts as a reader and is sending, it takes
+// 4*16 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks until the first transfer starts
+// 8 ticks later the FPGA samples the data
+// 1 tick to assign mod_sig_coil
+#define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
+
+// When the PM acts as tag and is receiving it takes
+// 2 ticks delay in the RF part (for the first falling edge),
+// 3 ticks for the A/D conversion,
+// 8 ticks on average until the start of the SSC transfer,
+// 8 ticks until the SSC samples the first data
+// 7*16 ticks to complete the transfer from FPGA to ARM
+// 8 ticks until the next ssp_clk rising edge
+// 4*16 ticks until we measure the time
+// - 8*16 ticks because we measure the time of the previous transfer
+#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
+
+// The FPGA will report its internal sending delay in
+uint16_t FpgaSendQueueDelay;
+// the 5 first bits are the number of bits buffered in mod_sig_buf
+// the last three bits are the remaining ticks/2 after the mod_sig_buf shift
+#define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
+
+// When the PM acts as tag and is sending, it takes
+// 4*16 + 8 ticks until we can write data to the sending hold register
+// 8*16 ticks until the SHR is transferred to the Sending Shift Register
+// 8 ticks later the FPGA samples the first data
+// + 16 ticks until assigned to mod_sig
+// + 1 tick to assign mod_sig_coil
+// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
+#define DELAY_ARM2AIR_AS_TAG (4*16 + 8 + 8*16 + 8 + 16 + 1 + DELAY_FPGA_QUEUE)
+
+// When the PM acts as sniffer and is receiving tag data, it takes
+// 3 ticks A/D conversion
+// 14 ticks to complete the modulation detection
+// 8 ticks (on average) until the result is stored in to_arm
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
+
+// When the PM acts as sniffer and is receiving reader data, it takes
+// 2 ticks delay in analogue RF receiver (for the falling edge of the
+// start bit, which marks the start of the communication)
+// 3 ticks A/D conversion
+// 8 ticks on average until the data is stored in to_arm.
+// + the delays in transferring data - which is the same for
+// sniffing reader and tag data and therefore not relevant
+#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
+
+//variables used for timing purposes:
+//these are in ssp_clk cycles:
+static uint32_t NextTransferTime;
+static uint32_t LastTimeProxToAirStart;
+static uint32_t LastProxToAirDuration;
-// CARD TO READER
+
+
+// CARD TO READER - manchester
// Sequence D: 11110000 modulation with subcarrier during first half
// Sequence E: 00001111 modulation with subcarrier during second half
// Sequence F: 00000000 no modulation with subcarrier
-// READER TO CARD
+// READER TO CARD - miller
// Sequence X: 00001100 drop after half a period
// Sequence Y: 00000000 no drop
// Sequence Z: 11000000 drop at start
#define SEC_Y 0x00
#define SEC_Z 0xc0
-static const uint8_t OddByteParity[256] = {
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
- 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
-};
+void iso14a_set_trigger(bool enable) {
+ trigger = enable;
+}
-// BIG CHANGE - UNDERSTAND THIS BEFORE WE COMMIT
-#define RECV_CMD_OFFSET 3032
-#define RECV_RES_OFFSET 3096
-#define DMA_BUFFER_OFFSET 3160
-#define DMA_BUFFER_SIZE 4096
-#define TRACE_LENGTH 3000
-uint8_t trigger = 0;
-void iso14a_set_trigger(int enable) {
- trigger = enable;
+void iso14a_set_timeout(uint32_t timeout) {
+ iso14a_timeout = timeout - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8);
+ if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", timeout, timeout / 106);
+}
+
+
+uint32_t iso14a_get_timeout(void) {
+ return iso14a_timeout + (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/(16*8);
}
//-----------------------------------------------------------------------------
// Generate the parity value for a byte sequence
//
//-----------------------------------------------------------------------------
-uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
+void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
{
- int i;
- uint32_t dwPar = 0;
+ uint16_t paritybit_cnt = 0;
+ uint16_t paritybyte_cnt = 0;
+ uint8_t parityBits = 0;
+
+ for (uint16_t i = 0; i < iLen; i++) {
+ // Generate the parity bits
+ parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
+ if (paritybit_cnt == 7) {
+ par[paritybyte_cnt] = parityBits; // save 8 Bits parity
+ parityBits = 0; // and advance to next Parity Byte
+ paritybyte_cnt++;
+ paritybit_cnt = 0;
+ } else {
+ paritybit_cnt++;
+ }
+ }
- // Generate the encrypted data
- for (i = 0; i < iLen; i++) {
- // Save the encrypted parity bit
- dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
- }
- return dwPar;
+ // save remaining parity bits
+ par[paritybyte_cnt] = parityBits;
+
}
void AppendCrc14443a(uint8_t* data, int len)
{
- ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
+ ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
}
-int LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader)
+static void AppendCrc14443b(uint8_t* data, int len)
{
- // Return when trace is full
- if (traceLen >= TRACE_LENGTH) return FALSE;
-
- // Trace the random, i'm curious
- rsamples += iSamples;
- trace[traceLen++] = ((rsamples >> 0) & 0xff);
- trace[traceLen++] = ((rsamples >> 8) & 0xff);
- trace[traceLen++] = ((rsamples >> 16) & 0xff);
- trace[traceLen++] = ((rsamples >> 24) & 0xff);
- if (!bReader) {
- trace[traceLen - 1] |= 0x80;
- }
- trace[traceLen++] = ((dwParity >> 0) & 0xff);
- trace[traceLen++] = ((dwParity >> 8) & 0xff);
- trace[traceLen++] = ((dwParity >> 16) & 0xff);
- trace[traceLen++] = ((dwParity >> 24) & 0xff);
- trace[traceLen++] = iLen;
- memcpy(trace + traceLen, btBytes, iLen);
- traceLen += iLen;
- return TRUE;
+ ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
}
-//-----------------------------------------------------------------------------
-// The software UART that receives commands from the reader, and its state
-// variables.
-//-----------------------------------------------------------------------------
-static struct {
- enum {
- STATE_UNSYNCD,
- STATE_START_OF_COMMUNICATION,
- STATE_MILLER_X,
- STATE_MILLER_Y,
- STATE_MILLER_Z,
- STATE_ERROR_WAIT
- } state;
- uint16_t shiftReg;
- int bitCnt;
- int byteCnt;
- int byteCntMax;
- int posCnt;
- int syncBit;
- int parityBits;
- int samples;
- int highCnt;
- int bitBuffer;
- enum {
- DROP_NONE,
- DROP_FIRST_HALF,
- DROP_SECOND_HALF
- } drop;
- uint8_t *output;
-} Uart;
-
-static RAMFUNC int MillerDecoding(int bit)
-{
- int error = 0;
- int bitright;
- if(!Uart.bitBuffer) {
- Uart.bitBuffer = bit ^ 0xFF0;
- return FALSE;
- }
- else {
- Uart.bitBuffer <<= 4;
- Uart.bitBuffer ^= bit;
- }
+//=============================================================================
+// ISO 14443 Type A - Miller decoder
+//=============================================================================
+// Basics:
+// This decoder is used when the PM3 acts as a tag.
+// The reader will generate "pauses" by temporarily switching of the field.
+// At the PM3 antenna we will therefore measure a modulated antenna voltage.
+// The FPGA does a comparison with a threshold and would deliver e.g.:
+// ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 .......
+// The Miller decoder needs to identify the following sequences:
+// 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
+// 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
+// 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
+// Note 1: the bitstream may start at any time. We therefore need to sync.
+// Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
+//-----------------------------------------------------------------------------
+static tUart Uart;
+
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept the following:
+// 0001 - a 3 tick wide pause
+// 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
+// 0111 - a 2 tick wide pause shifted left
+// 1001 - a 2 tick wide pause shifted right
+const bool Mod_Miller_LUT[] = {
+ false, true, false, true, false, false, false, true,
+ false, true, false, false, false, false, false, false
+};
+#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
+#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
- int EOC = FALSE;
+static void UartReset()
+{
+ Uart.state = STATE_UNSYNCD;
+ Uart.bitCount = 0;
+ Uart.len = 0; // number of decoded data bytes
+ Uart.parityLen = 0; // number of decoded parity bytes
+ Uart.shiftReg = 0; // shiftreg to hold decoded data bits
+ Uart.parityBits = 0; // holds 8 parity bits
+ Uart.startTime = 0;
+ Uart.endTime = 0;
+}
- if(Uart.state != STATE_UNSYNCD) {
- Uart.posCnt++;
+static void UartInit(uint8_t *data, uint8_t *parity)
+{
+ Uart.output = data;
+ Uart.parity = parity;
+ Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
+ UartReset();
+}
- 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; }
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
+{
- if(Uart.posCnt == 1) {
- // measurement first half bitperiod
- if(!bit) {
- Uart.drop = DROP_FIRST_HALF;
- }
+ Uart.fourBits = (Uart.fourBits << 8) | bit;
+
+ if (Uart.state == STATE_UNSYNCD) { // not yet synced
+
+ Uart.syncBit = 9999; // not set
+ // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
+ // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
+ // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern
+ // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
+ #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00000111 11111111 11101111 10000000
+ #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00000111 11111111 10001111 10000000
+ if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
+ else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
+
+ if (Uart.syncBit != 9999) { // found a sync bit
+ Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+ Uart.startTime -= Uart.syncBit;
+ Uart.endTime = Uart.startTime;
+ Uart.state = STATE_START_OF_COMMUNICATION;
}
- else {
- // measurement second half bitperiod
- if(!bit & (Uart.drop == DROP_NONE)) {
- Uart.drop = DROP_SECOND_HALF;
- }
- else if(!bit) {
- // measured a drop in first and second half
- // which should not be possible
- Uart.state = STATE_ERROR_WAIT;
- error = 0x01;
- }
- Uart.posCnt = 0;
+ } else {
- switch(Uart.state) {
- case STATE_START_OF_COMMUNICATION:
- Uart.shiftReg = 0;
- if(Uart.drop == DROP_SECOND_HALF) {
- // error, should not happen in SOC
- Uart.state = STATE_ERROR_WAIT;
- error = 0x02;
- }
- else {
- // correct SOC
- Uart.state = STATE_MILLER_Z;
- }
- break;
-
- case STATE_MILLER_Z:
- Uart.bitCnt++;
- Uart.shiftReg >>= 1;
- if(Uart.drop == DROP_NONE) {
- // logic '0' followed by sequence Y
- // end of communication
- Uart.state = STATE_UNSYNCD;
- EOC = TRUE;
- }
- // if(Uart.drop == DROP_FIRST_HALF) {
- // Uart.state = STATE_MILLER_Z; stay the same
- // we see a logic '0' }
- if(Uart.drop == DROP_SECOND_HALF) {
- // we see a logic '1'
- Uart.shiftReg |= 0x100;
- Uart.state = STATE_MILLER_X;
- }
- break;
-
- case STATE_MILLER_X:
- Uart.shiftReg >>= 1;
- if(Uart.drop == DROP_NONE) {
- // sequence Y, we see a '0'
- Uart.state = STATE_MILLER_Y;
- Uart.bitCnt++;
- }
- if(Uart.drop == DROP_FIRST_HALF) {
- // Would be STATE_MILLER_Z
- // but Z does not follow X, so error
- Uart.state = STATE_ERROR_WAIT;
- error = 0x03;
- }
- if(Uart.drop == DROP_SECOND_HALF) {
- // We see a '1' and stay in state X
- Uart.shiftReg |= 0x100;
- Uart.bitCnt++;
- }
- break;
-
- case STATE_MILLER_Y:
- Uart.bitCnt++;
- Uart.shiftReg >>= 1;
- if(Uart.drop == DROP_NONE) {
- // logic '0' followed by sequence Y
- // end of communication
- Uart.state = STATE_UNSYNCD;
- EOC = TRUE;
+ if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
+ if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
+ UartReset();
+ } else { // Modulation in first half = Sequence Z = logic "0"
+ if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
+ UartReset();
+ } else {
+ Uart.bitCount++;
+ Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
+ Uart.state = STATE_MILLER_Z;
+ Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
+ if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
+ Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+ Uart.parityBits <<= 1; // make room for the parity bit
+ Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
+ Uart.bitCount = 0;
+ Uart.shiftReg = 0;
+ if((Uart.len&0x0007) == 0) { // every 8 data bytes
+ Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
+ Uart.parityBits = 0;
+ }
}
- if(Uart.drop == DROP_FIRST_HALF) {
- // we see a '0'
- Uart.state = STATE_MILLER_Z;
+ }
+ }
+ } else {
+ if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
+ Uart.bitCount++;
+ Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
+ Uart.state = STATE_MILLER_X;
+ Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
+ if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
+ Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+ Uart.parityBits <<= 1; // make room for the new parity bit
+ Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
+ Uart.bitCount = 0;
+ Uart.shiftReg = 0;
+ if ((Uart.len&0x0007) == 0) { // every 8 data bytes
+ Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
+ Uart.parityBits = 0;
}
- if(Uart.drop == DROP_SECOND_HALF) {
- // We see a '1' and go to state X
- Uart.shiftReg |= 0x100;
- Uart.state = STATE_MILLER_X;
+ }
+ } else { // no modulation in both halves - Sequence Y
+ if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
+ Uart.state = STATE_UNSYNCD;
+ Uart.bitCount--; // last "0" was part of EOC sequence
+ Uart.shiftReg <<= 1; // drop it
+ if(Uart.bitCount > 0) { // if we decoded some bits
+ Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
+ Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
+ Uart.parityBits <<= 1; // add a (void) parity bit
+ Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
+ Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
+ return true;
+ } else if (Uart.len & 0x0007) { // there are some parity bits to store
+ Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
+ Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
}
- break;
-
- case STATE_ERROR_WAIT:
- // That went wrong. Now wait for at least two bit periods
- // and try to sync again
- if(Uart.drop == DROP_NONE) {
- Uart.highCnt = 6;
- Uart.state = STATE_UNSYNCD;
+ if (Uart.len) {
+ return true; // we are finished with decoding the raw data sequence
+ } else {
+ UartReset(); // Nothing received - start over
}
- break;
-
- default:
- Uart.state = STATE_UNSYNCD;
- Uart.highCnt = 0;
- break;
- }
-
- Uart.drop = DROP_NONE;
-
- // should have received at least one whole byte...
- if((Uart.bitCnt == 2) && EOC && (Uart.byteCnt > 0)) {
- return TRUE;
- }
-
- if(Uart.bitCnt == 9) {
- Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
- Uart.byteCnt++;
-
- Uart.parityBits <<= 1;
- Uart.parityBits ^= ((Uart.shiftReg >> 8) & 0x01);
-
- if(EOC) {
- // when End of Communication received and
- // all data bits processed..
- return TRUE;
}
- Uart.bitCnt = 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;
- 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;
+ if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
+ UartReset();
+ } else { // a logic "0"
+ Uart.bitCount++;
+ Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
+ Uart.state = STATE_MILLER_Y;
+ if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
+ Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
+ Uart.parityBits <<= 1; // make room for the parity bit
+ Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
+ Uart.bitCount = 0;
+ Uart.shiftReg = 0;
+ if ((Uart.len&0x0007) == 0) { // every 8 data bytes
+ Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
+ Uart.parityBits = 0;
+ }
}
}
- else if(bit & 1) { Uart.syncBit = bit & 1; Uart.samples = 0; }
-
- Uart.syncBit <<= 4;
- Uart.state = STATE_START_OF_COMMUNICATION;
- Uart.drop = DROP_FIRST_HALF;
- Uart.bitCnt = 0;
- Uart.byteCnt = 0;
- Uart.parityBits = 0;
- error = 0;
- }
- else {
- Uart.highCnt = 0;
}
}
- else {
- if(Uart.highCnt < 8) {
- Uart.highCnt++;
- }
- }
- }
+
+ }
- return FALSE;
+ return false; // not finished yet, need more data
}
+
+
//=============================================================================
-// ISO 14443 Type A - Manchester
+// ISO 14443 Type A - Manchester decoder
//=============================================================================
+// Basics:
+// This decoder is used when the PM3 acts as a reader.
+// 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. 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;
+
+// Lookup-Table to decide if 4 raw bits are a modulation.
+// We accept three or four "1" in any position
+const bool Mod_Manchester_LUT[] = {
+ false, false, false, false, false, false, false, true,
+ false, false, false, true, false, true, true, true
+};
-static struct {
- enum {
- DEMOD_UNSYNCD,
- DEMOD_START_OF_COMMUNICATION,
- DEMOD_MANCHESTER_D,
- DEMOD_MANCHESTER_E,
- DEMOD_MANCHESTER_F,
- DEMOD_ERROR_WAIT
- } state;
- int bitCount;
- int posCount;
- int syncBit;
- int parityBits;
- uint16_t shiftReg;
- int buffer;
- int buff;
- int samples;
- int len;
- enum {
- SUB_NONE,
- SUB_FIRST_HALF,
- SUB_SECOND_HALF
- } sub;
- uint8_t *output;
-} Demod;
-
-static RAMFUNC int ManchesterDecoding(int v)
-{
- 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;
- }
+#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
+#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
- 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; }
- if(!Demod.syncBit) {
- if(bit & 0x04) { Demod.syncBit = 0x04; }
- }
- else if(bit & 0x04) { Demod.syncBit = 0x04; bit <<= 4; }
- if(!Demod.syncBit) {
- if(bit & 0x02) { Demod.syncBit = 0x02; }
- }
- else if(bit & 0x02) { Demod.syncBit = 0x02; bit <<= 4; }
- if(!Demod.syncBit) {
- if(bit & 0x01) { Demod.syncBit = 0x01; }
- if(Demod.syncBit & (Demod.buffer & 0x08)) {
- Demod.syncBit = 0x08;
+static void DemodReset()
+{
+ Demod.state = DEMOD_UNSYNCD;
+ Demod.len = 0; // number of decoded data bytes
+ Demod.parityLen = 0;
+ Demod.shiftReg = 0; // shiftreg to hold decoded data bits
+ Demod.parityBits = 0; //
+ Demod.collisionPos = 0; // Position of collision bit
+ Demod.twoBits = 0xffff; // buffer for 2 Bits
+ Demod.highCnt = 0;
+ Demod.startTime = 0;
+ Demod.endTime = 0;
+}
- // The first half bitperiod is expected in next sample
- Demod.posCount = 0;
- Demod.output[Demod.len] = 0xfb;
- }
- }
- else if(bit & 0x01) { 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;
- }
- }
- error = 0;
- }
- }
- else {
- //modulation = bit & Demod.syncBit;
- modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
+static void DemodInit(uint8_t *data, uint8_t *parity)
+{
+ Demod.output = data;
+ Demod.parity = parity;
+ DemodReset();
+}
+
+// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
+static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
+{
- Demod.samples += 4;
+ Demod.twoBits = (Demod.twoBits << 8) | bit;
+
+ if (Demod.state == DEMOD_UNSYNCD) {
- if(Demod.posCount==0) {
- Demod.posCount = 1;
- if(modulation) {
- Demod.sub = SUB_FIRST_HALF;
+ if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
+ if (Demod.twoBits == 0x0000) {
+ Demod.highCnt++;
+ } else {
+ Demod.highCnt = 0;
}
- else {
- Demod.sub = SUB_NONE;
+ } else {
+ Demod.syncBit = 0xFFFF; // not set
+ if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
+ else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
+ else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
+ else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
+ else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
+ else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
+ else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
+ else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
+ if (Demod.syncBit != 0xFFFF) {
+ Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
+ Demod.startTime -= Demod.syncBit;
+ Demod.bitCount = offset; // number of decoded data bits
+ Demod.state = DEMOD_MANCHESTER_DATA;
}
}
- 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;
- }
- }
- else if(modulation) {
- Demod.sub = SUB_SECOND_HALF;
- }
-
- 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;
- }
- 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;
- }
- else {
- Demod.output[Demod.len] = 0xad;
- Demod.state = DEMOD_ERROR_WAIT;
- error = 0x03;
- }
- 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);
+ } else {
+ if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
+ if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision
+ if (!Demod.collisionPos) {
+ Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
+ }
+ } // 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.output[Demod.len++] = (Demod.shiftReg & 0xff);
+ Demod.parityBits <<= 1; // make room for the parity bit
+ Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
+ if((Demod.len&0x0007) == 0) { // every 8 data bytes
+ Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
+ Demod.parityBits = 0;
+ }
+ }
+ Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
+ } else { // no modulation in first half
+ if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // 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.output[Demod.len++] = (Demod.shiftReg & 0xff);
+ Demod.parityBits <<= 1; // make room for the new parity bit
+ Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
+ Demod.bitCount = 0;
+ Demod.shiftReg = 0;
+ if ((Demod.len&0x0007) == 0) { // every 8 data bytes
+ Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
+ Demod.parityBits = 0;
+ }
+ }
+ Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
+ } else { // no modulation in both halves - End of communication
+ if(Demod.bitCount > 0) { // there are some remaining data bits
+ Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
+ Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
+ Demod.parityBits <<= 1; // add a (void) parity bit
+ Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
+ Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
+ return true;
+ } else if (Demod.len & 0x0007) { // there are some parity bits to store
+ Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
+ Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
+ }
+ if (Demod.len) {
+ return true; // we are finished with decoding the raw data sequence
+ } else { // nothing received. Start over
+ DemodReset();
+ }
}
-
- /*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
}
//=============================================================================
// triggering so that we start recording at the point that the tag is moved
// near the reader.
//-----------------------------------------------------------------------------
-void RAMFUNC SnoopIso14443a(void)
-{
-// #define RECV_CMD_OFFSET 2032 // original (working as of 21/2/09) values
-// #define RECV_RES_OFFSET 2096 // original (working as of 21/2/09) values
-// #define DMA_BUFFER_OFFSET 2160 // original (working as of 21/2/09) values
-// #define DMA_BUFFER_SIZE 4096 // original (working as of 21/2/09) values
-// #define TRACE_LENGTH 2000 // original (working as of 21/2/09) values
-
- // We won't start recording the frames that we acquire until we trigger;
- // a good trigger condition to get started is probably when we see a
- // response from the tag.
- int triggered = FALSE; // FALSE to wait first for card
-
- // The command (reader -> tag) that we're receiving.
- // The length of a received command will in most cases be no more than 18 bytes.
- // So 32 should be enough!
- uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
- // The response (tag -> reader) that we're receiving.
- uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
-
- // As we receive stuff, we copy it from receivedCmd or receivedResponse
- // into trace, along with its length and other annotations.
- //uint8_t *trace = (uint8_t *)BigBuf;
-
- traceLen = 0; // uncommented to fix ISSUE 15 - gerhard - jan2011
-
- // The DMA buffer, used to stream samples from the FPGA
- int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
- int lastRxCounter;
- int8_t *upTo;
- int smpl;
- int maxBehindBy = 0;
-
- // Count of samples received so far, so that we can include timing
- // information in the trace buffer.
- int samples = 0;
- int rsamples = 0;
-
- memset(trace, 0x44, RECV_CMD_OFFSET);
-
- // Set up the demodulator for tag -> reader responses.
- Demod.output = receivedResponse;
- Demod.len = 0;
- Demod.state = DEMOD_UNSYNCD;
-
- // Setup for the DMA.
- FpgaSetupSsc();
- upTo = dmaBuf;
- lastRxCounter = DMA_BUFFER_SIZE;
- FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
-
- // And the reader -> tag commands
- memset(&Uart, 0, sizeof(Uart));
- Uart.output = receivedCmd;
- Uart.byteCntMax = 32; // was 100 (greg)////////////////////////////////////////////////////////////////////////
- Uart.state = STATE_UNSYNCD;
-
- // 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);
+void RAMFUNC SnoopIso14443a(uint8_t param) {
+ // param:
+ // bit 0 - trigger from first card answer
+ // bit 1 - trigger from first reader 7-bit request
+
+ LEDsoff();
+ iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
- // 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;
+ // Allocate memory from BigBuf for some buffers
+ // free all previous allocations first
+ BigBuf_free();
- 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;
- }
+ // The command (reader -> tag) that we're receiving.
+ uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+ uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
+
+ // The response (tag -> reader) that we're receiving.
+ uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
+ uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
+
+ // The DMA buffer, used to stream samples from the FPGA
+ uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
+
+ // init trace buffer
+ clear_trace();
+ set_tracing(true);
+
+ uint8_t *data = dmaBuf;
+ uint8_t previous_data = 0;
+ int maxDataLen = 0;
+ int dataLen = 0;
+ bool TagIsActive = false;
+ bool ReaderIsActive = false;
+
+ // Set up the demodulator for tag -> reader responses.
+ DemodInit(receivedResponse, receivedResponsePar);
+
+ // Set up the demodulator for the reader -> tag commands
+ UartInit(receivedCmd, receivedCmdPar);
+
+ // Setup and start DMA.
+ FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
+
+ // We won't start recording the frames that we acquire until we trigger;
+ // a good trigger condition to get started is probably when we see a
+ // response from the tag.
+ // triggered == false -- to wait first for card
+ bool triggered = !(param & 0x03);
+
+ // And now we loop, receiving samples.
+ for(uint32_t rsamples = 0; true; ) {
- samples += 4;
- if(MillerDecoding((smpl & 0xF0) >> 4)) {
- rsamples = samples - Uart.samples;
- LED_C_ON();
- if(triggered) {
- trace[traceLen++] = ((rsamples >> 0) & 0xff);
- trace[traceLen++] = ((rsamples >> 8) & 0xff);
- trace[traceLen++] = ((rsamples >> 16) & 0xff);
- trace[traceLen++] = ((rsamples >> 24) & 0xff);
- trace[traceLen++] = ((Uart.parityBits >> 0) & 0xff);
- trace[traceLen++] = ((Uart.parityBits >> 8) & 0xff);
- trace[traceLen++] = ((Uart.parityBits >> 16) & 0xff);
- trace[traceLen++] = ((Uart.parityBits >> 24) & 0xff);
- trace[traceLen++] = Uart.byteCnt;
- memcpy(trace+traceLen, receivedCmd, Uart.byteCnt);
- traceLen += Uart.byteCnt;
- if(traceLen > TRACE_LENGTH) break;
- }
- /* And ready to receive another command. */
- Uart.state = STATE_UNSYNCD;
- /* And also reset the demod code, which might have been */
- /* false-triggered by the commands from the reader. */
- Demod.state = DEMOD_UNSYNCD;
- LED_B_OFF();
- }
+ if(BUTTON_PRESS()) {
+ DbpString("cancelled by button");
+ break;
+ }
- if(ManchesterDecoding(smpl & 0x0F)) {
- rsamples = samples - Demod.samples;
- LED_B_ON();
-
- // timestamp, as a count of samples
- trace[traceLen++] = ((rsamples >> 0) & 0xff);
- trace[traceLen++] = ((rsamples >> 8) & 0xff);
- trace[traceLen++] = ((rsamples >> 16) & 0xff);
- trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff);
- trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff);
- trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff);
- trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff);
- trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff);
- // length
- trace[traceLen++] = Demod.len;
- memcpy(trace+traceLen, receivedResponse, Demod.len);
- traceLen += Demod.len;
- if(traceLen > TRACE_LENGTH) break;
-
- triggered = TRUE;
-
- // And ready to receive another response.
- memset(&Demod, 0, sizeof(Demod));
- Demod.output = receivedResponse;
- Demod.state = DEMOD_UNSYNCD;
- LED_C_OFF();
- }
+ LED_A_ON();
+ WDT_HIT();
- if(BUTTON_PRESS()) {
- DbpString("cancelled_a");
- goto done;
- }
- }
+ int register readBufDataP = data - dmaBuf;
+ int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
+ if (readBufDataP <= dmaBufDataP){
+ dataLen = dmaBufDataP - readBufDataP;
+ } else {
+ dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
+ }
+ // test for length of buffer
+ if(dataLen > maxDataLen) {
+ maxDataLen = dataLen;
+ if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
+ Dbprintf("blew circular buffer! dataLen=%d", dataLen);
+ break;
+ }
+ }
+ if(dataLen < 1) continue;
- DbpString("COMMAND FINISHED");
+ // primary buffer was stopped( <-- we lost data!
+ if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+ AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+ AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+ Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
+ }
+ // secondary buffer sets as primary, secondary buffer was stopped
+ if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+ AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+ }
- Dbprintf("%x %x %x", maxBehindBy, Uart.state, Uart.byteCnt);
- Dbprintf("%x %x %x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
+ LED_A_OFF();
+
+ if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
+
+ if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
+ uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+ if (MillerDecoding(readerdata, (rsamples-1)*4)) {
+ LED_C_ON();
+
+ // check - if there is a short 7bit request from reader
+ if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = true;
+
+ if(triggered) {
+ if (!LogTrace(receivedCmd,
+ Uart.len,
+ Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
+ Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
+ Uart.parity,
+ true)) break;
+ }
+ /* And ready to receive another command. */
+ UartReset();
+ /* And also reset the demod code, which might have been */
+ /* false-triggered by the commands from the reader. */
+ DemodReset();
+ LED_B_OFF();
+ }
+ ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+ }
-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();
+ if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
+ uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+ if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
+ LED_B_ON();
+
+ if (!LogTrace(receivedResponse,
+ Demod.len,
+ Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
+ Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
+ Demod.parity,
+ false)) break;
+
+ if ((!triggered) && (param & 0x01)) triggered = true;
+
+ // And ready to receive another response.
+ DemodReset();
+ // And reset the Miller decoder including itS (now outdated) input buffer
+ UartInit(receivedCmd, receivedCmdPar);
+
+ LED_C_OFF();
+ }
+ TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+ }
+ }
+
+ previous_data = *data;
+ rsamples++;
+ data++;
+ if(data == dmaBuf + DMA_BUFFER_SIZE) {
+ data = dmaBuf;
+ }
+ } // main cycle
+
+ DbpString("COMMAND FINISHED");
+
+ FpgaDisableSscDma();
+ Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
+ Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
+ LEDsoff();
}
//-----------------------------------------------------------------------------
// Prepare tag messages
//-----------------------------------------------------------------------------
-static void CodeIso14443aAsTag(const uint8_t *cmd, int len)
+static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
{
- int i;
- int oddparity;
-
- ToSendReset();
+ ToSendReset();
// Correction bit, might be removed when not needed
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
-
+
// Send startbit
ToSend[++ToSendMax] = SEC_D;
+ LastProxToAirDuration = 8 * ToSendMax - 4;
- for(i = 0; i < len; i++) {
- int j;
- uint8_t b = cmd[i];
+ for(uint16_t i = 0; i < len; i++) {
+ uint8_t b = cmd[i];
// Data bits
- oddparity = 0x01;
- for(j = 0; j < 8; j++) {
- oddparity ^= (b & 1);
+ for(uint16_t j = 0; j < 8; j++) {
if(b & 1) {
ToSend[++ToSendMax] = SEC_D;
} else {
ToSend[++ToSendMax] = SEC_E;
- }
- b >>= 1;
- }
+ }
+ b >>= 1;
+ }
- // Parity bit
- if(oddparity) {
- ToSend[++ToSendMax] = SEC_D;
+ // Get the parity bit
+ if (parity[i>>3] & (0x80>>(i&0x0007))) {
+ ToSend[++ToSendMax] = SEC_D;
+ LastProxToAirDuration = 8 * ToSendMax - 4;
} else {
ToSend[++ToSendMax] = SEC_E;
+ LastProxToAirDuration = 8 * ToSendMax;
}
- }
-
- // Send stopbit
- ToSend[++ToSendMax] = SEC_F;
-
- // Flush the buffer in FPGA!!
- for(i = 0; i < 5; i++) {
- ToSend[++ToSendMax] = SEC_F;
}
- // Convert from last byte pos to length
- ToSendMax++;
+ // Send stopbit
+ ToSend[++ToSendMax] = SEC_F;
- // Add a few more for slop
- ToSend[ToSendMax++] = 0x00;
- ToSend[ToSendMax++] = 0x00;
- //ToSendMax += 2;
+ // Convert from last byte pos to length
+ ToSendMax++;
}
-//-----------------------------------------------------------------------------
-// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4
-//-----------------------------------------------------------------------------
-static void CodeStrangeAnswer()
+
+static void Code4bitAnswerAsTag(uint8_t cmd)
{
int i;
- ToSendReset();
+ ToSendReset();
// Correction bit, might be removed when not needed
ToSendStuffBit(0);
// Send startbit
ToSend[++ToSendMax] = SEC_D;
- // 0
- ToSend[++ToSendMax] = SEC_E;
+ uint8_t b = cmd;
+ for(i = 0; i < 4; i++) {
+ if(b & 1) {
+ ToSend[++ToSendMax] = SEC_D;
+ LastProxToAirDuration = 8 * ToSendMax - 4;
+ } else {
+ ToSend[++ToSendMax] = SEC_E;
+ LastProxToAirDuration = 8 * ToSendMax;
+ }
+ b >>= 1;
+ }
+
+ // Send stopbit
+ ToSend[++ToSendMax] = SEC_F;
- // 0
- ToSend[++ToSendMax] = SEC_E;
+ // Convert from last byte pos to length
+ ToSendMax++;
+}
- // 1
- ToSend[++ToSendMax] = SEC_D;
- // Send stopbit
- ToSend[++ToSendMax] = SEC_F;
+static uint8_t *LastReaderTraceTime = NULL;
- // Flush the buffer in FPGA!!
- for(i = 0; i < 5; i++) {
- ToSend[++ToSendMax] = SEC_F;
- }
+static void EmLogTraceReader(void) {
+ // remember last reader trace start to fix timing info later
+ LastReaderTraceTime = BigBuf_get_addr() + BigBuf_get_traceLen();
+ LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, true);
+}
- // Convert from last byte pos to length
- ToSendMax++;
- // Add a few more for slop
- ToSend[ToSendMax++] = 0x00;
- ToSend[ToSendMax++] = 0x00;
- //ToSendMax += 2;
+static void FixLastReaderTraceTime(uint32_t tag_StartTime) {
+ uint32_t reader_EndTime = Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG;
+ uint32_t reader_StartTime = Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG;
+ uint16_t reader_modlen = reader_EndTime - reader_StartTime;
+ uint16_t approx_fdt = tag_StartTime - reader_EndTime;
+ uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
+ reader_StartTime = tag_StartTime - exact_fdt - reader_modlen;
+ LastReaderTraceTime[0] = (reader_StartTime >> 0) & 0xff;
+ LastReaderTraceTime[1] = (reader_StartTime >> 8) & 0xff;
+ LastReaderTraceTime[2] = (reader_StartTime >> 16) & 0xff;
+ LastReaderTraceTime[3] = (reader_StartTime >> 24) & 0xff;
}
+
+static void EmLogTraceTag(uint8_t *tag_data, uint16_t tag_len, uint8_t *tag_Parity, uint32_t ProxToAirDuration) {
+ uint32_t tag_StartTime = LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG;
+ uint32_t tag_EndTime = (LastTimeProxToAirStart + ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG;
+ LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, false);
+ FixLastReaderTraceTime(tag_StartTime);
+}
+
+
//-----------------------------------------------------------------------------
// Wait for commands from reader
// Stop when button is pressed
-// Or return TRUE when command is captured
+// Or return true when command is captured
//-----------------------------------------------------------------------------
-static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen)
+static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
{
// Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
// only, since we are receiving, not transmitting).
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;
+ UartInit(received, parity);
+
+ // clear RXRDY:
+ uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
for(;;) {
WDT_HIT();
- if(BUTTON_PRESS()) return FALSE;
-
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = 0x00;
- }
+ if(BUTTON_PRESS()) return false;
+
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
- uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- if(MillerDecoding((b & 0xf0) >> 4)) {
- *len = Uart.byteCnt;
- return TRUE;
+ b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+ if(MillerDecoding(b, 0)) {
+ *len = Uart.len;
+ EmLogTraceReader();
+ return true;
}
- if(MillerDecoding(b & 0x0f)) {
- *len = Uart.byteCnt;
- return TRUE;
- }
- }
+ }
}
}
-//-----------------------------------------------------------------------------
-// Main loop of simulated tag: receive commands from reader, decide what
-// response to send, and send it.
-//-----------------------------------------------------------------------------
-void SimulateIso14443aTag(int tagType, int TagUid)
-{
- // This function contains the tag emulation
-
- // Prepare protocol messages
- // static const uint8_t cmd1[] = { 0x26 };
-// static const uint8_t response1[] = { 0x02, 0x00 }; // Says: I am Mifare 4k - original line - greg
-//
- static const uint8_t response1[] = { 0x44, 0x03 }; // Says: I am a DESFire Tag, ph33r me
-// static const uint8_t response1[] = { 0x44, 0x00 }; // Says: I am a ULTRALITE Tag, 0wn me
-
- // UID response
- // static const uint8_t cmd2[] = { 0x93, 0x20 };
- //static const uint8_t response2[] = { 0x9a, 0xe5, 0xe4, 0x43, 0xd8 }; // original value - greg
-
-// my desfire
- static const uint8_t response2[] = { 0x88, 0x04, 0x21, 0x3f, 0x4d }; // known uid - note cascade (0x88), 2nd byte (0x04) = NXP/Phillips
-
-
-// When reader selects us during cascade1 it will send cmd3
-//uint8_t response3[] = { 0x04, 0x00, 0x00 }; // SAK Select (cascade1) successful response (ULTRALITE)
-uint8_t response3[] = { 0x24, 0x00, 0x00 }; // SAK Select (cascade1) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
-
-// send cascade2 2nd half of UID
-static const uint8_t response2a[] = { 0x51, 0x48, 0x1d, 0x80, 0x84 }; // uid - cascade2 - 2nd half (4 bytes) of UID+ BCCheck
-// NOTE : THE CRC on the above may be wrong as I have obfuscated the actual UID
-// When reader selects us during cascade2 it will send cmd3a
-//uint8_t response3a[] = { 0x00, 0x00, 0x00 }; // SAK Select (cascade2) successful response (ULTRALITE)
-uint8_t response3a[] = { 0x20, 0x00, 0x00 }; // SAK Select (cascade2) successful response (DESFire)
-ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
+static int EmSend4bitEx(uint8_t resp);
+int EmSend4bit(uint8_t resp);
+static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
+int EmSendCmdEx(uint8_t *resp, uint16_t respLen);
+int EmSendPrecompiledCmd(tag_response_info_t *response_info);
- static const uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
- uint8_t *resp;
- int respLen;
-
- // Longest possible response will be 16 bytes + 2 CRC = 18 bytes
- // This will need
+static bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
+ // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
+ // This will need the following byte array for a modulation sequence
// 144 data bits (18 * 8)
// 18 parity bits
// 2 Start and stop
// 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
// 1 just for the case
// ----------- +
- // 166
- //
- // 166 bytes, since every bit that needs to be send costs us a byte
+ // 166 bytes, since every bit that needs to be send costs us a byte
//
+
+
+ // Prepare the tag modulation bits from the message
+ GetParity(response_info->response, response_info->response_n, &(response_info->par));
+ CodeIso14443aAsTagPar(response_info->response,response_info->response_n, &(response_info->par));
+
+ // Make sure we do not exceed the free buffer space
+ if (ToSendMax > max_buffer_size) {
+ Dbprintf("Out of memory, when modulating bits for tag answer:");
+ Dbhexdump(response_info->response_n, response_info->response, false);
+ return false;
+ }
+
+ // Copy the byte array, used for this modulation to the buffer position
+ memcpy(response_info->modulation, ToSend, ToSendMax);
+
+ // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
+ response_info->modulation_n = ToSendMax;
+ response_info->ProxToAirDuration = LastProxToAirDuration;
+
+ return true;
+}
- // Respond with card type
- uint8_t *resp1 = (((uint8_t *)BigBuf) + 800);
- int resp1Len;
- // Anticollision cascade1 - respond with uid
- uint8_t *resp2 = (((uint8_t *)BigBuf) + 970);
- int resp2Len;
+// "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
+// Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
+// 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits for the modulation
+// -> need 273 bytes buffer
+#define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273
- // Anticollision cascade2 - respond with 2nd half of uid if asked
- // we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88
- uint8_t *resp2a = (((uint8_t *)BigBuf) + 1140);
- int resp2aLen;
+bool prepare_allocated_tag_modulation(tag_response_info_t* response_info, uint8_t **buffer, size_t *max_buffer_size) {
- // Acknowledge select - cascade 1
- uint8_t *resp3 = (((uint8_t *)BigBuf) + 1310);
- int resp3Len;
+ // Retrieve and store the current buffer index
+ response_info->modulation = *buffer;
+
+ // Forward the prepare tag modulation function to the inner function
+ if (prepare_tag_modulation(response_info, *max_buffer_size)) {
+ // Update the free buffer offset and the remaining buffer size
+ *buffer += ToSendMax;
+ *max_buffer_size -= ToSendMax;
+ return true;
+ } else {
+ return false;
+ }
+}
- // Acknowledge select - cascade 2
- uint8_t *resp3a = (((uint8_t *)BigBuf) + 1480);
- int resp3aLen;
+//-----------------------------------------------------------------------------
+// Main loop of simulated tag: receive commands from reader, decide what
+// response to send, and send it.
+//-----------------------------------------------------------------------------
+void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
+{
+ uint8_t sak;
- // Response to a read request - not implemented atm
- uint8_t *resp4 = (((uint8_t *)BigBuf) + 1550);
- int resp4Len;
+ // The first response contains the ATQA (note: bytes are transmitted in reverse order).
+ uint8_t response1[2];
+
+ switch (tagType) {
+ case 1: { // MIFARE Classic
+ // Says: I am Mifare 1k - original line
+ response1[0] = 0x04;
+ response1[1] = 0x00;
+ sak = 0x08;
+ } break;
+ case 2: { // MIFARE Ultralight
+ // Says: I am a stupid memory tag, no crypto
+ response1[0] = 0x04;
+ response1[1] = 0x00;
+ sak = 0x00;
+ } break;
+ case 3: { // MIFARE DESFire
+ // Says: I am a DESFire tag, ph33r me
+ response1[0] = 0x04;
+ response1[1] = 0x03;
+ sak = 0x20;
+ } break;
+ case 4: { // ISO/IEC 14443-4
+ // Says: I am a javacard (JCOP)
+ response1[0] = 0x04;
+ response1[1] = 0x00;
+ sak = 0x28;
+ } break;
+ case 5: { // MIFARE TNP3XXX
+ // Says: I am a toy
+ response1[0] = 0x01;
+ response1[1] = 0x0f;
+ sak = 0x01;
+ } break;
+ default: {
+ Dbprintf("Error: unkown tagtype (%d)",tagType);
+ return;
+ } break;
+ }
+
+ // The second response contains the (mandatory) first 24 bits of the UID
+ uint8_t response2[5] = {0x00};
- // Authenticate response - nonce
- uint8_t *resp5 = (((uint8_t *)BigBuf) + 1720);
- int resp5Len;
+ // Check if the uid uses the (optional) part
+ uint8_t response2a[5] = {0x00};
+
+ if (uid_2nd) {
+ response2[0] = 0x88;
+ num_to_bytes(uid_1st,3,response2+1);
+ num_to_bytes(uid_2nd,4,response2a);
+ response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
+
+ // Configure the ATQA and SAK accordingly
+ response1[0] |= 0x40;
+ sak |= 0x04;
+ } else {
+ num_to_bytes(uid_1st,4,response2);
+ // Configure the ATQA and SAK accordingly
+ response1[0] &= 0xBF;
+ sak &= 0xFB;
+ }
- uint8_t *receivedCmd = (uint8_t *)BigBuf;
- int len;
+ // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
+ response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
+
+ // Prepare the mandatory SAK (for 4 and 7 byte UID)
+ uint8_t response3[3] = {0x00};
+ response3[0] = sak;
+ ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
+
+ // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
+ uint8_t response3a[3] = {0x00};
+ response3a[0] = sak & 0xFB;
+ ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
+
+ uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
+ uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
+ // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
+ // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
+ // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us)
+ // TC(1) = 0x02: CID supported, NAD not supported
+ ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
+
+ #define TAG_RESPONSE_COUNT 7
+ tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
+ { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
+ { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
+ { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
+ { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
+ { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
+ { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
+ { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
+ };
+
+ // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
+ // Such a response is less time critical, so we can prepare them on the fly
+ #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
+ #define DYNAMIC_MODULATION_BUFFER_SIZE 512
+ uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
+ uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
+ tag_response_info_t dynamic_response_info = {
+ .response = dynamic_response_buffer,
+ .response_n = 0,
+ .modulation = dynamic_modulation_buffer,
+ .modulation_n = 0
+ };
+
+ // We need to listen to the high-frequency, peak-detected path.
+ iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+ BigBuf_free_keep_EM();
+
+ // allocate buffers:
+ uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
+ uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
+ uint8_t *free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
+ size_t free_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
+ // clear trace
+ clear_trace();
+ set_tracing(true);
- int i;
- int u;
- uint8_t b;
+ // Prepare the responses of the anticollision phase
+ // there will be not enough time to do this at the moment the reader sends it REQA
+ for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
+ prepare_allocated_tag_modulation(&responses[i], &free_buffer_pointer, &free_buffer_size);
+ }
+
+ int len = 0;
// To control where we are in the protocol
int order = 0;
// Just to allow some checks
int happened = 0;
int happened2 = 0;
+ int cmdsRecvd = 0;
- int cmdsRecvd = 0;
-
- int fdt_indicator;
+ cmdsRecvd = 0;
+ tag_response_info_t* p_response;
- memset(receivedCmd, 0x44, 400);
-
- // Prepare the responses of the anticollision phase
- // there will be not enough time to do this at the moment the reader sends it REQA
-
- // Answer to request
- CodeIso14443aAsTag(response1, sizeof(response1));
- memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax;
-
- // Send our UID (cascade 1)
- CodeIso14443aAsTag(response2, sizeof(response2));
- memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax;
-
- // Answer to select (cascade1)
- CodeIso14443aAsTag(response3, sizeof(response3));
- memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax;
-
- // Send the cascade 2 2nd part of the uid
- CodeIso14443aAsTag(response2a, sizeof(response2a));
- memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax;
-
- // Answer to select (cascade 2)
- CodeIso14443aAsTag(response3a, sizeof(response3a));
- memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax;
-
- // Strange answer is an example of rare message size (3 bits)
- CodeStrangeAnswer();
- memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax;
-
- // Authentication answer (random nonce)
- CodeIso14443aAsTag(response5, sizeof(response5));
- memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax;
-
- // We need to listen to the high-frequency, peak-detected path.
- SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
- FpgaSetupSsc();
-
- cmdsRecvd = 0;
-
- LED_A_ON();
+ LED_A_ON();
for(;;) {
+ // Clean receive command buffer
+ if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
+ DbpString("Button press");
+ break;
+ }
- if(!GetIso14443aCommandFromReader(receivedCmd, &len, 100)) {
- DbpString("button press");
- break;
- }
- // doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
- // Okay, look at the command now.
- lastorder = order;
- i = 1; // first byte transmitted
- if(receivedCmd[0] == 0x26) {
- // Received a REQUEST
- resp = resp1; respLen = resp1Len; order = 1;
- //DbpString("Hello request from reader:");
- } else if(receivedCmd[0] == 0x52) {
- // Received a WAKEUP
- resp = resp1; respLen = resp1Len; order = 6;
-// //DbpString("Wakeup request from reader:");
-
- } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // greg - cascade 1 anti-collision
- // Received request for UID (cascade 1)
- resp = resp2; respLen = resp2Len; order = 2;
-// DbpString("UID (cascade 1) request from reader:");
-// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
- } else if(receivedCmd[1] == 0x20 && receivedCmd[0] ==0x95) { // greg - cascade 2 anti-collision
- // Received request for UID (cascade 2)
- resp = resp2a; respLen = resp2aLen; order = 20;
-// DbpString("UID (cascade 2) request from reader:");
-// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
- } else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x93) { // greg - cascade 1 select
- // Received a SELECT
- resp = resp3; respLen = resp3Len; order = 3;
-// DbpString("Select (cascade 1) request from reader:");
-// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
- } else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x95) { // greg - cascade 2 select
- // Received a SELECT
- resp = resp3a; respLen = resp3aLen; order = 30;
-// DbpString("Select (cascade 2) request from reader:");
-// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
- } else if(receivedCmd[0] == 0x30) {
- // Received a READ
- resp = resp4; respLen = resp4Len; order = 4; // Do nothing
- Dbprintf("Read request from reader: %x %x %x",
- receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
-
- } else if(receivedCmd[0] == 0x50) {
- // Received a HALT
- resp = resp1; respLen = 0; order = 5; // Do nothing
- DbpString("Reader requested we HALT!:");
-
- } else if(receivedCmd[0] == 0x60) {
- // Received an authentication request
- resp = resp5; respLen = resp5Len; order = 7;
- Dbprintf("Authenticate request from reader: %x %x %x",
- receivedCmd[0], receivedCmd[1], receivedCmd[2]);
-
- } else if(receivedCmd[0] == 0xE0) {
- // Received a RATS request
- resp = resp1; respLen = 0;order = 70;
- Dbprintf("RATS request from reader: %x %x %x",
- receivedCmd[0], receivedCmd[1], receivedCmd[2]);
- } else {
- // Never seen this command before
- Dbprintf("Unknown command received from reader: %x %x %x %x %x %x %x %x %x",
- receivedCmd[0], receivedCmd[1], receivedCmd[2],
- receivedCmd[3], receivedCmd[3], receivedCmd[4],
- receivedCmd[5], receivedCmd[6], receivedCmd[7]);
- // Do not respond
- resp = resp1; respLen = 0; order = 0;
- }
+ p_response = NULL;
+
+ // Okay, look at the command now.
+ lastorder = order;
+ if(receivedCmd[0] == 0x26) { // Received a REQUEST
+ p_response = &responses[0]; order = 1;
+ } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
+ p_response = &responses[0]; order = 6;
+ } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
+ p_response = &responses[1]; order = 2;
+ } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
+ p_response = &responses[2]; order = 20;
+ } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
+ p_response = &responses[3]; order = 3;
+ } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
+ p_response = &responses[4]; order = 30;
+ } else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
+ EmSendCmdEx(data+(4*receivedCmd[1]),16);
+ // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
+ // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
+ p_response = NULL;
+ } else if(receivedCmd[0] == 0x50) { // Received a HALT
+ p_response = NULL;
+ } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
+ p_response = &responses[5]; order = 7;
+ } else if(receivedCmd[0] == 0xE0) { // Received a RATS request
+ if (tagType == 1 || tagType == 2) { // RATS not supported
+ EmSend4bit(CARD_NACK_NA);
+ p_response = NULL;
+ } else {
+ p_response = &responses[6]; order = 70;
+ }
+ } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
+ uint32_t nr = bytes_to_num(receivedCmd,4);
+ uint32_t ar = bytes_to_num(receivedCmd+4,4);
+ Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
+ } else {
+ // Check for ISO 14443A-4 compliant commands, look at left nibble
+ switch (receivedCmd[0]) {
+
+ case 0x0B:
+ case 0x0A: { // IBlock (command)
+ dynamic_response_info.response[0] = receivedCmd[0];
+ dynamic_response_info.response[1] = 0x00;
+ dynamic_response_info.response[2] = 0x90;
+ dynamic_response_info.response[3] = 0x00;
+ dynamic_response_info.response_n = 4;
+ } break;
+
+ case 0x1A:
+ case 0x1B: { // Chaining command
+ dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
+ dynamic_response_info.response_n = 2;
+ } break;
+
+ case 0xaa:
+ case 0xbb: {
+ dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
+ dynamic_response_info.response_n = 2;
+ } break;
+
+ case 0xBA: { //
+ memcpy(dynamic_response_info.response,"\xAB\x00",2);
+ dynamic_response_info.response_n = 2;
+ } break;
+
+ case 0xCA:
+ case 0xC2: { // Readers sends deselect command
+ memcpy(dynamic_response_info.response,"\xCA\x00",2);
+ dynamic_response_info.response_n = 2;
+ } break;
+
+ default: {
+ // Never seen this command before
+ Dbprintf("Received unknown command (len=%d):",len);
+ Dbhexdump(len,receivedCmd,false);
+ // Do not respond
+ dynamic_response_info.response_n = 0;
+ } break;
+ }
+
+ if (dynamic_response_info.response_n > 0) {
+ // Copy the CID from the reader query
+ dynamic_response_info.response[1] = receivedCmd[1];
+
+ // Add CRC bytes, always used in ISO 14443A-4 compliant cards
+ AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
+ dynamic_response_info.response_n += 2;
+
+ if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
+ Dbprintf("Error preparing tag response");
+ break;
+ }
+ p_response = &dynamic_response_info;
+ }
+ }
// Count number of wakeups received after a halt
if(order == 6 && lastorder == 5) { happened++; }
// Count number of other messages after a halt
if(order != 6 && lastorder == 5) { happened2++; }
- // Look at last parity bit to determine timing of answer
- if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) {
- // 1236, so correction bit needed
- i = 0;
- }
-
- memset(receivedCmd, 0x44, 32);
-
if(cmdsRecvd > 999) {
DbpString("1000 commands later...");
- break;
- }
- else {
- cmdsRecvd++;
+ break;
}
+ cmdsRecvd++;
- if(respLen <= 0) continue;
-
- // Modulate Manchester
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
- AT91C_BASE_SSC->SSC_THR = 0x00;
- FpgaSetupSsc();
-
- // ### Transmit the response ###
- u = 0;
- b = 0x00;
- fdt_indicator = FALSE;
- for(;;) {
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
- volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- (void)b;
- }
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- if(i > respLen) {
- b = 0x00;
- u++;
- } else {
- b = resp[i];
- i++;
- }
- AT91C_BASE_SSC->SSC_THR = b;
-
- if(u > 4) {
- break;
- }
- }
- if(BUTTON_PRESS()) {
- break;
- }
- }
-
- }
+ if (p_response != NULL) {
+ EmSendPrecompiledCmd(p_response);
+ }
+
+ if (!tracing) {
+ Dbprintf("Trace Full. Simulation stopped.");
+ break;
+ }
+ }
Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
LED_A_OFF();
+ BigBuf_free_keep_EM();
}
-//-----------------------------------------------------------------------------
-// Transmit the command (to the tag) that was placed in ToSend[].
-//-----------------------------------------------------------------------------
-static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait)
+
+// prepare a delayed transfer. This simply shifts ToSend[] by a number
+// of bits specified in the delay parameter.
+static void PrepareDelayedTransfer(uint16_t delay)
{
- int c;
+ uint8_t bitmask = 0;
+ uint8_t bits_to_shift = 0;
+ uint8_t bits_shifted = 0;
+
+ delay &= 0x07;
+ if (delay) {
+ for (uint16_t i = 0; i < delay; i++) {
+ bitmask |= (0x01 << i);
+ }
+ ToSend[ToSendMax++] = 0x00;
+ for (uint16_t i = 0; i < ToSendMax; i++) {
+ bits_to_shift = ToSend[i] & bitmask;
+ ToSend[i] = ToSend[i] >> delay;
+ ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
+ bits_shifted = bits_to_shift;
+ }
+ }
+}
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- if (wait)
- if(*wait < 10)
- *wait = 10;
+//-------------------------------------------------------------------------------------
+// Transmit the command (to the tag) that was placed in ToSend[].
+// Parameter timing:
+// if NULL: transfer at next possible time, taking into account
+// request guard time, startup frame guard time and frame delay time
+// if == 0: transfer immediately and return time of transfer
+// if != 0: delay transfer until time specified
+//-------------------------------------------------------------------------------------
+static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
+{
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- 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();
- }
+ uint32_t ThisTransferTime = 0;
- c = 0;
- for(;;) {
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = cmd[c];
- c++;
- if(c >= len) {
- break;
- }
- }
- 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;
+ if (timing) {
+ if(*timing == 0) { // Measure time
+ *timing = (GetCountSspClk() + 8) & 0xfffffff8;
+ } else {
+ PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
+ }
+ if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+ while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
+ LastTimeProxToAirStart = *timing;
+ } else {
+ ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
+ while(GetCountSspClk() < ThisTransferTime);
+ LastTimeProxToAirStart = ThisTransferTime;
+ }
+
+ // clear TXRDY
+ AT91C_BASE_SSC->SSC_THR = SEC_Y;
+
+ uint16_t c = 0;
+ for(;;) {
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+ AT91C_BASE_SSC->SSC_THR = cmd[c];
+ c++;
+ if(c >= len) {
+ break;
+ }
+ }
+ }
+
+ NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
}
+
//-----------------------------------------------------------------------------
-// Code a 7-bit command without parity bit
-// This is especially for 0x26 and 0x52 (REQA and WUPA)
+// Prepare reader command (in bits, support short frames) to send to FPGA
//-----------------------------------------------------------------------------
-void ShortFrameFromReader(const uint8_t bt)
+static void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
{
- int j;
+ int i, j;
int last;
- uint8_t b;
+ uint8_t b;
ToSendReset();
// Start of Communication (Seq. Z)
ToSend[++ToSendMax] = SEC_Z;
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
last = 0;
- b = bt;
- for(j = 0; j < 7; j++) {
- if(b & 1) {
- // Sequence X
- ToSend[++ToSendMax] = SEC_X;
- last = 1;
- } else {
- if(last == 0) {
+ size_t bytecount = nbytes(bits);
+ // Generate send structure for the data bits
+ for (i = 0; i < bytecount; i++) {
+ // Get the current byte to send
+ b = cmd[i];
+ size_t bitsleft = MIN((bits-(i*8)),8);
+
+ for (j = 0; j < bitsleft; j++) {
+ if (b & 1) {
+ // Sequence X
+ ToSend[++ToSendMax] = SEC_X;
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+ last = 1;
+ } else {
+ if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+ } else {
+ // Sequence Y
+ ToSend[++ToSendMax] = SEC_Y;
+ last = 0;
+ }
}
- else {
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
- last = 0;
+ b >>= 1;
+ }
+
+ // Only transmit parity bit if we transmitted a complete byte
+ if (j == 8 && parity != NULL) {
+ // Get the parity bit
+ if (parity[i>>3] & (0x80 >> (i&0x0007))) {
+ // Sequence X
+ ToSend[++ToSendMax] = SEC_X;
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
+ last = 1;
+ } else {
+ if (last == 0) {
+ // Sequence Z
+ ToSend[++ToSendMax] = SEC_Z;
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+ } else {
+ // Sequence Y
+ ToSend[++ToSendMax] = SEC_Y;
+ last = 0;
+ }
}
}
- b >>= 1;
}
- // End of Communication
- if(last == 0) {
+ // End of Communication: Logic 0 followed by Sequence Y
+ if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
- }
- else {
+ LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
+ } else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
-
- // Just to be sure!
- ToSend[++ToSendMax] = SEC_Y;
- ToSend[++ToSendMax] = SEC_Y;
ToSend[++ToSendMax] = SEC_Y;
- // Convert from last character reference to length
- ToSendMax++;
+ // Convert to length of command:
+ ToSendMax++;
}
+
//-----------------------------------------------------------------------------
-// Prepare reader command to send to FPGA
-//
+// Wait for commands from reader
+// Stop when button is pressed (return 1) or field was gone (return 2)
+// Or return 0 when command is captured
//-----------------------------------------------------------------------------
-void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
+int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
{
- int i, j;
- int last;
- uint8_t b;
-
- ToSendReset();
-
- // Start of Communication (Seq. Z)
- ToSend[++ToSendMax] = SEC_Z;
- last = 0;
-
- // Generate send structure for the data bits
- for (i = 0; i < len; i++) {
- // Get the current byte to send
- b = cmd[i];
-
- for (j = 0; j < 8; j++) {
- if (b & 1) {
- // Sequence X
- ToSend[++ToSendMax] = SEC_X;
- last = 1;
- } else {
- if (last == 0) {
- // Sequence Z
- ToSend[++ToSendMax] = SEC_Z;
- } else {
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
- last = 0;
+ *len = 0;
+
+ uint32_t timer = 0, vtime = 0;
+ int analogCnt = 0;
+ int analogAVG = 0;
+
+ // Set ADC to read field strength
+ AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
+ AT91C_BASE_ADC->ADC_MR =
+ ADC_MODE_PRESCALE(63) |
+ ADC_MODE_STARTUP_TIME(1) |
+ ADC_MODE_SAMPLE_HOLD_TIME(15);
+ AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
+ // start ADC
+ AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+
+ // Run a 'software UART' on the stream of incoming samples.
+ UartInit(received, parity);
+
+ // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN
+ do {
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+ AT91C_BASE_SSC->SSC_THR = SEC_F;
+ uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; (void) b;
+ }
+ } while (GetCountSspClk() < LastTimeProxToAirStart + LastProxToAirDuration + (FpgaSendQueueDelay>>3));
+
+ // 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);
+
+ for(;;) {
+ WDT_HIT();
+
+ if (BUTTON_PRESS()) return 1;
+
+ // test if the field exists
+ if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
+ analogCnt++;
+ analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
+ AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
+ if (analogCnt >= 32) {
+ if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
+ vtime = GetTickCount();
+ if (!timer) timer = vtime;
+ // 50ms no field --> card to idle state
+ if (vtime - timer > 50) return 2;
+ } else
+ if (timer) timer = 0;
+ analogCnt = 0;
+ analogAVG = 0;
+ }
+ }
+
+ // receive and test the miller decoding
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
+ uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+ if(MillerDecoding(b, 0)) {
+ *len = Uart.len;
+ EmLogTraceReader();
+ return 0;
+ }
}
- }
- b >>= 1;
- }
- // Get the parity bit
- if ((dwParity >> i) & 0x01) {
- // Sequence X
- ToSend[++ToSendMax] = SEC_X;
- last = 1;
- } else {
- if (last == 0) {
- // Sequence Z
- ToSend[++ToSendMax] = SEC_Z;
- } else {
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
- last = 0;
- }
- }
- }
+ }
+}
- // End of Communication
- if (last == 0) {
- // Sequence Z
- ToSend[++ToSendMax] = SEC_Z;
- } else {
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
- last = 0;
- }
- // Sequence Y
- ToSend[++ToSendMax] = SEC_Y;
- // Just to be sure!
- ToSend[++ToSendMax] = SEC_Y;
- ToSend[++ToSendMax] = SEC_Y;
- ToSend[++ToSendMax] = SEC_Y;
+static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen)
+{
+ uint8_t b;
+ uint16_t i = 0;
+ bool correctionNeeded;
+
+ // Modulate Manchester
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
+
+ // include correction bit if necessary
+ if (Uart.bitCount == 7)
+ {
+ // Short tags (7 bits) don't have parity, determine the correct value from MSB
+ correctionNeeded = Uart.output[0] & 0x40;
+ }
+ else
+ {
+ // Look at the last parity bit
+ correctionNeeded = Uart.parity[(Uart.len-1)/8] & (0x80 >> ((Uart.len-1) & 7));
+ }
+
+ if(correctionNeeded) {
+ // 1236, so correction bit needed
+ i = 0;
+ } else {
+ i = 1;
+ }
- // Convert from last character reference to length
- ToSendMax++;
+ // clear receiving shift register and holding register
+ while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+ b = AT91C_BASE_SSC->SSC_RHR; (void) b;
+ while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+ b = AT91C_BASE_SSC->SSC_RHR; (void) b;
+
+ // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
+ for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
+ while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
+ if (AT91C_BASE_SSC->SSC_RHR) break;
+ }
+
+ LastTimeProxToAirStart = (GetCountSspClk() & 0xfffffff8) + (correctionNeeded?8:0);
+
+ // send cycle
+ for(; i < respLen; ) {
+ if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+ AT91C_BASE_SSC->SSC_THR = resp[i++];
+ FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
+ }
+
+ if(BUTTON_PRESS()) {
+ break;
+ }
+ }
+
+ return 0;
+}
+
+
+static int EmSend4bitEx(uint8_t resp){
+ Code4bitAnswerAsTag(resp);
+ int res = EmSendCmd14443aRaw(ToSend, ToSendMax);
+ // do the tracing for the previous reader request and this tag answer:
+ EmLogTraceTag(&resp, 1, NULL, LastProxToAirDuration);
+ return res;
+}
+
+
+int EmSend4bit(uint8_t resp){
+ return EmSend4bitEx(resp);
+}
+
+
+static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
+ CodeIso14443aAsTagPar(resp, respLen, par);
+ int res = EmSendCmd14443aRaw(ToSend, ToSendMax);
+ // do the tracing for the previous reader request and this tag answer:
+ EmLogTraceTag(resp, respLen, par, LastProxToAirDuration);
+ return res;
+}
+
+
+int EmSendCmdEx(uint8_t *resp, uint16_t respLen){
+ uint8_t par[MAX_PARITY_SIZE];
+ GetParity(resp, respLen, par);
+ return EmSendCmdExPar(resp, respLen, par);
+}
+
+
+int EmSendCmd(uint8_t *resp, uint16_t respLen){
+ uint8_t par[MAX_PARITY_SIZE];
+ GetParity(resp, respLen, par);
+ return EmSendCmdExPar(resp, respLen, par);
+}
+
+
+int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
+ return EmSendCmdExPar(resp, respLen, par);
+}
+
+
+int EmSendPrecompiledCmd(tag_response_info_t *response_info) {
+ int ret = EmSendCmd14443aRaw(response_info->modulation, response_info->modulation_n);
+ // do the tracing for the previous reader request and this tag answer:
+ EmLogTraceTag(response_info->response, response_info->response_n, &(response_info->par), response_info->ProxToAirDuration);
+ return ret;
}
+
//-----------------------------------------------------------------------------
// Wait a certain time for tag response
-// If a response is captured return TRUE
-// If it takes to long return FALSE
+// If a response is captured return true
+// 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, uint8_t *receivedResponsePar, uint16_t offset)
{
- // buffer needs to be 512 bytes
- int c;
-
+ uint32_t c;
+
// Set FPGA mode to "reader listen mode", no modulation (listen
// only, since we are receiving, not transmitting).
// Signal field is on with the appropriate LED
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
-
+
// Now get the answer from the card
- Demod.output = receivedResponse;
- Demod.len = 0;
- Demod.state = DEMOD_UNSYNCD;
+ DemodInit(receivedResponse, receivedResponsePar);
- uint8_t b;
- if (elapsed) *elapsed = 0;
+ // clear RXRDY:
+ uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
c = 0;
for(;;) {
WDT_HIT();
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = 0x00; // To make use of exact timing of next command from reader!!
- if (elapsed) (*elapsed)++;
- }
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
- if(c < iso14a_timeout) { c++; } else { return FALSE; }
b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- if(ManchesterDecoding((b>>4) & 0xf)) {
- *samples = ((c - 1) << 3) + 4;
- return TRUE;
- }
- if(ManchesterDecoding(b & 0x0f)) {
- *samples = c << 3;
- return TRUE;
+ if(ManchesterDecoding(b, offset, 0)) {
+ NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
+ return true;
+ } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
+ return false;
}
}
}
}
-void ReaderTransmitShort(const uint8_t* bt)
-{
- int wait = 0;
- int samples = 0;
- ShortFrameFromReader(*bt);
+void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
+{
+ CodeIso14443aBitsAsReaderPar(frame, bits, par);
+
+ // Send command to tag
+ TransmitFor14443a(ToSend, ToSendMax, timing);
+ if(trigger)
+ LED_A_ON();
+
+ // Log reader command in trace buffer
+ if (tracing) {
+ LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, true);
+ }
+}
- // Select the card
- TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
- // Store reader command in buffer
- if (tracing) LogTrace(bt,1,0,GetParity(bt,1),TRUE);
+void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
+{
+ ReaderTransmitBitsPar(frame, len*8, par, timing);
}
-void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par)
-{
- int wait = 0;
- int samples = 0;
- // This is tied to other size changes
- // uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
- CodeIso14443aAsReaderPar(frame,len,par);
+static void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
+{
+ // Generate parity and redirect
+ uint8_t par[MAX_PARITY_SIZE];
+ GetParity(frame, len/8, par);
+ ReaderTransmitBitsPar(frame, len, par, timing);
+}
- // Select the card
- TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
- if(trigger)
- LED_A_ON();
- // Store reader command in buffer
- if (tracing) LogTrace(frame,len,0,par,TRUE);
+void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
+{
+ // Generate parity and redirect
+ uint8_t par[MAX_PARITY_SIZE];
+ GetParity(frame, len, par);
+ ReaderTransmitBitsPar(frame, len*8, par, timing);
}
-void ReaderTransmit(uint8_t* frame, int len)
+static int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
{
- // Generate parity and redirect
- ReaderTransmitPar(frame,len,GetParity(frame,len));
+ if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return false;
+ if (tracing) {
+ LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, false);
+ }
+ return Demod.len;
}
-int ReaderReceive(uint8_t* receivedAnswer)
+
+int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
{
- int samples = 0;
- if (!GetIso14443aAnswerFromTag(receivedAnswer,100,&samples,0)) return FALSE;
- if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
- if(samples == 0) return FALSE;
- return Demod.len;
+ if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return false;
+ if (tracing) {
+ LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, false);
+ }
+ return Demod.len;
+}
+
+
+static void iso14a_set_ATS_times(uint8_t *ats) {
+
+ uint8_t tb1;
+ uint8_t fwi, sfgi;
+ uint32_t fwt, sfgt;
+
+ if (ats[0] > 1) { // there is a format byte T0
+ if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
+ if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1)
+ tb1 = ats[3];
+ } else {
+ tb1 = ats[2];
+ }
+ fwi = (tb1 & 0xf0) >> 4; // frame waiting time integer (FWI)
+ if (fwi != 15) {
+ fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
+ iso14a_set_timeout(fwt/(8*16));
+ }
+ sfgi = tb1 & 0x0f; // startup frame guard time integer (SFGI)
+ if (sfgi != 0 && sfgi != 15) {
+ sfgt = 256 * 16 * (1 << sfgi); // startup frame guard time (SFGT) in 1/fc
+ NextTransferTime = MAX(NextTransferTime, Demod.endTime + (sfgt - DELAY_AIR2ARM_AS_READER - DELAY_ARM2AIR_AS_READER)/16);
+ }
+ }
+ }
+}
+
+
+static int GetATQA(uint8_t *resp, uint8_t *resp_par) {
+
+#define WUPA_RETRY_TIMEOUT 10 // 10ms
+ uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
+
+ uint32_t save_iso14a_timeout = iso14a_get_timeout();
+ iso14a_set_timeout(1236/(16*8)+1); // response to WUPA is expected at exactly 1236/fc. No need to wait longer.
+
+ uint32_t start_time = GetTickCount();
+ int len;
+
+ // we may need several tries if we did send an unknown command or a wrong authentication before...
+ do {
+ // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+ ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
+ // Receive the ATQA
+ len = ReaderReceive(resp, resp_par);
+ } while (len == 0 && GetTickCount() <= start_time + WUPA_RETRY_TIMEOUT);
+
+ iso14a_set_timeout(save_iso14a_timeout);
+ return len;
}
-/* performs iso14443a anticolision procedure
- * fills the uid pointer unless NULL
- * fills resp_data unless NULL */
-int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data) {
- uint8_t wupa[] = { 0x52 };
+
+// performs iso14443a anticollision (optional) and card select procedure
+// fills the uid and cuid pointer unless NULL
+// fills the card info record unless NULL
+// if anticollision is false, then the UID must be provided in uid_ptr[]
+// and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
+// requests ATS unless no_rats is true
+int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades, bool no_rats) {
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) + 3560); // was 3560 - tied to other size changes
- uint8_t* uid = resp + 7;
+ uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
+ uint8_t resp_par[MAX_PARITY_SIZE];
+ byte_t uid_resp[4];
+ size_t uid_resp_len;
uint8_t sak = 0x04; // cascade uid
int cascade_level = 0;
-
int len;
- // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
- ReaderTransmitShort(wupa);
- // Receive the ATQA
- if(!ReaderReceive(resp)) return 0;
+ // init card struct
+ if(p_hi14a_card) {
+ p_hi14a_card->uidlen = 0;
+ memset(p_hi14a_card->uid, 0, 10);
+ p_hi14a_card->ats_len = 0;
+ }
- if(resp_data)
- memcpy(resp_data->atqa, resp, 2);
-
- ReaderTransmit(sel_all,sizeof(sel_all));
- if(!ReaderReceive(uid)) return 0;
+ if (!GetATQA(resp, resp_par)) {
+ return 0;
+ }
+ if(p_hi14a_card) {
+ memcpy(p_hi14a_card->atqa, resp, 2);
+ }
+
+ if (anticollision) {
+ // clear uid
+ if (uid_ptr) {
+ memset(uid_ptr,0,10);
+ }
+ }
+
+ // check for proprietary anticollision:
+ if ((resp[0] & 0x1F) == 0) {
+ return 3;
+ }
+
// OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
// which case we need to make a cascade 2 request and select - this is a long UID
// While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
- for(; sak & 0x04; cascade_level++)
- {
+ for(; sak & 0x04; cascade_level++) {
// SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
- // SELECT_ALL
- ReaderTransmit(sel_all,sizeof(sel_all));
- if (!ReaderReceive(resp)) return 0;
- if(uid_ptr) memcpy(uid_ptr + cascade_level*4, resp, 4);
+ if (anticollision) {
+ // SELECT_ALL
+ ReaderTransmit(sel_all, sizeof(sel_all), NULL);
+ if (!ReaderReceive(resp, resp_par)) return 0;
+
+ 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 / 8] |= 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, resp_par)) 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);
+ }
+ } else {
+ if (cascade_level < num_cascades - 1) {
+ uid_resp[0] = 0x88;
+ memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
+ } else {
+ memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
+ }
+ }
+ uid_resp_len = 4;
+
+ // 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);
- ReaderTransmit(sel_uid,sizeof(sel_uid));
+ 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 received during anticollision, or the provided 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
- if (!ReaderReceive(resp)) return 0;
+ if (!ReaderReceive(resp, resp_par)) return 0;
sak = resp[0];
+
+ // Test if more parts of the uid are coming
+ 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
+ uid_resp[0] = uid_resp[1];
+ uid_resp[1] = uid_resp[2];
+ uid_resp[2] = uid_resp[3];
+ uid_resp_len = 3;
+ }
+
+ if(uid_ptr && anticollision) {
+ memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
+ }
+
+ if(p_hi14a_card) {
+ memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
+ p_hi14a_card->uidlen += uid_resp_len;
+ }
}
- if(resp_data) {
- resp_data->sak = sak;
- resp_data->ats_len = 0;
+
+ if(p_hi14a_card) {
+ p_hi14a_card->sak = sak;
}
- if( (sak & 0x20) == 0)
- return 2; // non iso14443a compliant tag
+ // PICC compilant with iso14443a-4 ---> (SAK & 0x20 != 0)
+ if( (sak & 0x20) == 0) return 2;
- // Request for answer to select
- AppendCrc14443a(rats, 2);
- ReaderTransmit(rats, sizeof(rats));
- if (!(len = ReaderReceive(resp))) return 0;
- if(resp_data) {
- memcpy(resp_data->ats, resp, sizeof(resp_data->ats));
- resp_data->ats_len = len;
- }
+ if (!no_rats) {
+ // Request for answer to select
+ AppendCrc14443a(rats, 2);
+ ReaderTransmit(rats, sizeof(rats), NULL);
+
+ if (!(len = ReaderReceive(resp, resp_par))) return 0;
+
+ if(p_hi14a_card) {
+ memcpy(p_hi14a_card->ats, resp, len);
+ p_hi14a_card->ats_len = len;
+ }
- return 1;
+ // reset the PCB block number
+ iso14_pcb_blocknum = 0;
+
+ // set default timeout and delay next transfer based on ATS
+ iso14a_set_ATS_times(resp);
+
+ }
+ return 1;
}
-void iso14443a_setup() {
- // Setup SSC
- FpgaSetupSsc();
- // Start from off (no field generated)
- // Signal field is off with the appropriate LED
- LED_D_OFF();
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
- SpinDelay(200);
+void iso14443a_setup(uint8_t fpga_minor_mode) {
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+ // Set up the synchronous serial port
+ FpgaSetupSsc();
+ // connect Demodulated Signal to ADC:
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
- // Now give it time to spin up.
// Signal field is on with the appropriate LED
- LED_D_ON();
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- SpinDelay(200);
+ if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
+ || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
+ LED_D_ON();
+ } else {
+ LED_D_OFF();
+ }
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
- iso14a_timeout = 2048; //default
+ // Start the timer
+ StartCountSspClk();
+
+ DemodReset();
+ UartReset();
+ NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
+ iso14a_set_timeout(1060); // 10ms default
}
-int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
- uint8_t real_cmd[cmd_len+4];
- real_cmd[0] = 0x0a; //I-Block
- real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
- memcpy(real_cmd+2, cmd, cmd_len);
- AppendCrc14443a(real_cmd,cmd_len+2);
+/* Peter Fillmore 2015
+Added card id field to the function
+ info from ISO14443A standard
+b1 = Block Number
+b2 = RFU (always 1)
+b3 = depends on block
+b4 = Card ID following if set to 1
+b5 = depends on block type
+b6 = depends on block type
+b7,b8 = block type.
+Coding of I-BLOCK:
+b8 b7 b6 b5 b4 b3 b2 b1
+0 0 0 x x x 1 x
+b5 = chaining bit
+Coding of R-block:
+b8 b7 b6 b5 b4 b3 b2 b1
+1 0 1 x x 0 1 x
+b5 = ACK/NACK
+Coding of S-block:
+b8 b7 b6 b5 b4 b3 b2 b1
+1 1 x x x 0 1 0
+b5,b6 = 00 - DESELECT
+ 11 - WTX
+*/
+int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
+ uint8_t parity[MAX_PARITY_SIZE];
+ uint8_t real_cmd[cmd_len + 4];
+
+ // ISO 14443 APDU frame: PCB [CID] [NAD] APDU CRC PCB=0x02
+ real_cmd[0] = 0x02; // bnr,nad,cid,chn=0; i-block(0x00)
+ // put block number into the PCB
+ real_cmd[0] |= iso14_pcb_blocknum;
+ memcpy(real_cmd + 1, cmd, cmd_len);
+ AppendCrc14443a(real_cmd, cmd_len + 1);
- ReaderTransmit(real_cmd, cmd_len+4);
- size_t len = ReaderReceive(data);
- if(!len)
- return -1; //DATA LINK ERROR
+ ReaderTransmit(real_cmd, cmd_len + 3, NULL);
+
+ size_t len = ReaderReceive(data, parity);
+ uint8_t *data_bytes = (uint8_t *) data;
+
+ if (!len) {
+ return 0; //DATA LINK ERROR
+ } else{
+ // S-Block WTX
+ while((data_bytes[0] & 0xF2) == 0xF2) {
+ uint32_t save_iso14a_timeout = iso14a_timeout;
+ // temporarily increase timeout
+ iso14a_timeout = MAX((data_bytes[1] & 0x3f) * iso14a_timeout, MAX_ISO14A_TIMEOUT);
+ // Transmit WTX back
+ // byte1 - WTXM [1..59]. command FWT=FWT*WTXM
+ data_bytes[1] = data_bytes[1] & 0x3f; // 2 high bits mandatory set to 0b
+ // now need to fix CRC.
+ AppendCrc14443a(data_bytes, len - 2);
+ // transmit S-Block
+ ReaderTransmit(data_bytes, len, NULL);
+ // retrieve the result again (with increased timeout)
+ len = ReaderReceive(data, parity);
+ data_bytes = data;
+ // restore timeout
+ iso14a_timeout = save_iso14a_timeout;
+ }
+
+ // if we received an I- or R(ACK)-Block with a block number equal to the
+ // current block number, toggle the current block number
+ if (len >= 3 // PCB+CRC = 3 bytes
+ && ((data_bytes[0] & 0xC0) == 0 // I-Block
+ || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
+ && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
+ {
+ iso14_pcb_blocknum ^= 1;
+ }
+
+ // crc check
+ if (len >=3 && !CheckCrc14443(CRC_14443_A, data_bytes, len)) {
+ return -1;
+ }
+
+ }
+
+ // cut frame byte
+ len -= 1;
+ // memmove(data_bytes, data_bytes + 1, len);
+ for (int i = 0; i < len; i++)
+ data_bytes[i] = data_bytes[i + 1];
return len;
}
// Read an ISO 14443a tag. Send out commands and store answers.
//
//-----------------------------------------------------------------------------
-void ReaderIso14443a(UsbCommand * c, UsbCommand * ack)
+void ReaderIso14443a(UsbCommand *c)
{
iso14a_command_t param = c->arg[0];
- uint8_t * cmd = c->d.asBytes;
- size_t len = c->arg[1];
-
- if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(1);
+ uint8_t *cmd = c->d.asBytes;
+ size_t len = c->arg[1] & 0xffff;
+ size_t lenbits = c->arg[1] >> 16;
+ uint32_t timeout = c->arg[2];
+ uint32_t arg0 = 0;
+ byte_t buf[USB_CMD_DATA_SIZE] = {0};
+ uint8_t par[MAX_PARITY_SIZE];
+ bool cantSELECT = false;
+
+ set_tracing(true);
+
+ if(param & ISO14A_CLEAR_TRACE) {
+ clear_trace();
+ }
- if(param & ISO14A_CONNECT) {
- iso14443a_setup();
- ack->arg[0] = iso14443a_select_card(ack->d.asBytes, (iso14a_card_select_t *) (ack->d.asBytes+12));
- UsbSendPacket((void *)ack, sizeof(UsbCommand));
+ if(param & ISO14A_REQUEST_TRIGGER) {
+ iso14a_set_trigger(true);
}
- if(param & ISO14A_SET_TIMEOUT) {
- iso14a_timeout = c->arg[2];
+ if(param & ISO14A_CONNECT) {
+ LED_A_ON();
+ iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
+ if(!(param & ISO14A_NO_SELECT)) {
+ iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
+ arg0 = iso14443a_select_card(NULL, card, NULL, true, 0, param & ISO14A_NO_RATS);
+
+ // if we cant select then we cant send data
+ if (arg0 != 1 && arg0 != 2) {
+ // 1 - all is OK with ATS, 2 - without ATS
+ cantSELECT = true;
+ }
+
+ LED_B_ON();
+ cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
+ LED_B_OFF();
+ }
}
if(param & ISO14A_SET_TIMEOUT) {
- iso14a_timeout = c->arg[2];
+ iso14a_set_timeout(timeout);
}
- if(param & ISO14A_APDU) {
- ack->arg[0] = iso14_apdu(cmd, len, ack->d.asBytes);
- UsbSendPacket((void *)ack, sizeof(UsbCommand));
+ if(param & ISO14A_APDU && !cantSELECT) {
+ arg0 = iso14_apdu(cmd, len, buf);
+ LED_B_ON();
+ cmd_send(CMD_ACK, arg0, 0, 0, buf, sizeof(buf));
+ LED_B_OFF();
}
- if(param & ISO14A_RAW) {
+ if(param & ISO14A_RAW && !cantSELECT) {
if(param & ISO14A_APPEND_CRC) {
- AppendCrc14443a(cmd,len);
+ if(param & ISO14A_TOPAZMODE) {
+ AppendCrc14443b(cmd,len);
+ } else {
+ AppendCrc14443a(cmd,len);
+ }
len += 2;
+ if (lenbits) lenbits += 16;
+ }
+ if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
+ if(param & ISO14A_TOPAZMODE) {
+ int bits_to_send = lenbits;
+ uint16_t i = 0;
+ ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
+ bits_to_send -= 7;
+ while (bits_to_send > 0) {
+ ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
+ bits_to_send -= 8;
+ }
+ } else {
+ GetParity(cmd, lenbits/8, par);
+ ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
+ }
+ } else { // want to send complete bytes only
+ if(param & ISO14A_TOPAZMODE) {
+ uint16_t i = 0;
+ ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
+ while (i < len) {
+ ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
+ }
+ } else {
+ ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
+ }
}
- ReaderTransmit(cmd,len);
- ack->arg[0] = ReaderReceive(ack->d.asBytes);
- UsbSendPacket((void *)ack, sizeof(UsbCommand));
+ arg0 = ReaderReceive(buf, par);
+
+ LED_B_ON();
+ cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
+ LED_B_OFF();
}
- if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(0);
+ if(param & ISO14A_REQUEST_TRIGGER) {
+ iso14a_set_trigger(false);
+ }
- if(param & ISO14A_NO_DISCONNECT)
+ if(param & ISO14A_NO_DISCONNECT) {
return;
+ }
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
}
+
+
+// Determine the distance between two nonces.
+// Assume that the difference is small, but we don't know which is first.
+// Therefore try in alternating directions.
+static int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
+
+ uint16_t i;
+ uint32_t nttmp1, nttmp2;
+
+ if (nt1 == nt2) return 0;
+
+ nttmp1 = nt1;
+ nttmp2 = nt2;
+
+ for (i = 1; i < 32768; i++) {
+ nttmp1 = prng_successor(nttmp1, 1);
+ if (nttmp1 == nt2) return i;
+ nttmp2 = prng_successor(nttmp2, 1);
+ if (nttmp2 == nt1) return -i;
+ }
+
+ return(-99999); // either nt1 or nt2 are invalid nonces
+}
+
+
//-----------------------------------------------------------------------------
-// Read an ISO 14443a tag. Send out commands and store answers.
-//
+// Recover several bits of the cypher stream. This implements (first stages of)
+// the algorithm described in "The Dark Side of Security by Obscurity and
+// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
+// (article by Nicolas T. Courtois, 2009)
//-----------------------------------------------------------------------------
-void ReaderMifare(uint32_t parameter)
+void ReaderMifare(bool first_try)
{
// Mifare AUTH
uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
- uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+ uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+ static uint8_t mf_nr_ar3;
- uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + 3560); // was 3560 - tied to other size changes
- traceLen = 0;
- tracing = false;
+ uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
+ uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
- iso14443a_setup();
+ if (first_try) {
+ iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+ }
+
+ // free eventually allocated BigBuf memory. We want all for tracing.
+ BigBuf_free();
+
+ clear_trace();
+ set_tracing(true);
+
+ byte_t nt_diff = 0;
+ uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
+ static byte_t par_low = 0;
+ bool led_on = true;
+ uint8_t uid[10] ={0};
+ uint32_t cuid;
+
+ uint32_t nt = 0;
+ uint32_t previous_nt = 0;
+ static uint32_t nt_attacked = 0;
+ byte_t par_list[8] = {0x00};
+ byte_t ks_list[8] = {0x00};
+
+ #define PRNG_SEQUENCE_LENGTH (1 << 16);
+ static uint32_t sync_time;
+ static int32_t sync_cycles;
+ int catch_up_cycles = 0;
+ int last_catch_up = 0;
+ uint16_t elapsed_prng_sequences;
+ uint16_t consecutive_resyncs = 0;
+ int isOK = 0;
+
+ if (first_try) {
+ mf_nr_ar3 = 0;
+ sync_time = GetCountSspClk() & 0xfffffff8;
+ sync_cycles = PRNG_SEQUENCE_LENGTH; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the tag nonces).
+ nt_attacked = 0;
+ par[0] = 0;
+ }
+ else {
+ // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
+ mf_nr_ar3++;
+ mf_nr_ar[3] = mf_nr_ar3;
+ par[0] = par_low;
+ }
LED_A_ON();
LED_B_OFF();
LED_C_OFF();
+
- byte_t nt_diff = 0;
- LED_A_OFF();
- byte_t par = 0;
- byte_t par_mask = 0xff;
- byte_t par_low = 0;
- int led_on = TRUE;
-
- tracing = FALSE;
- byte_t nt[4];
- byte_t nt_attacked[4];
- byte_t par_list[8];
- byte_t ks_list[8];
- num_to_bytes(parameter,4,nt_attacked);
-
- while(TRUE)
- {
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
- SpinDelay(200);
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-
- // Test if the action was cancelled
- if(BUTTON_PRESS()) {
- break;
- }
+ #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
+ #define MAX_SYNC_TRIES 32
+ #define NUM_DEBUG_INFOS 8 // per strategy
+ #define MAX_STRATEGY 3
+ uint16_t unexpected_random = 0;
+ uint16_t sync_tries = 0;
+ int16_t debug_info_nr = -1;
+ uint16_t strategy = 0;
+ int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS];
+ uint32_t select_time;
+ uint32_t halt_time;
+
+ for(uint16_t i = 0; true; i++) {
+
+ LED_C_ON();
+ WDT_HIT();
- if(!iso14443a_select_card(NULL, NULL)) continue;
-
- // Transmit MIFARE_CLASSIC_AUTH
- ReaderTransmit(mf_auth,sizeof(mf_auth));
-
- // Receive the (16 bit) "random" nonce
- if (!ReaderReceive(receivedAnswer)) continue;
- memcpy(nt,receivedAnswer,4);
-
- // Transmit reader nonce and reader answer
- ReaderTransmitPar(mf_nr_ar,sizeof(mf_nr_ar),par);
-
- // Receive 4 bit answer
- if (ReaderReceive(receivedAnswer))
- {
- if (nt_diff == 0)
- {
- LED_A_ON();
- memcpy(nt_attacked,nt,4);
- par_mask = 0xf8;
- par_low = par & 0x07;
- }
-
- if (memcmp(nt,nt_attacked,4) != 0) continue;
-
- led_on = !led_on;
- if(led_on) LED_B_ON(); else LED_B_OFF();
- par_list[nt_diff] = par;
- ks_list[nt_diff] = receivedAnswer[0]^0x05;
-
- // Test if the information is complete
- if (nt_diff == 0x07) break;
-
- nt_diff = (nt_diff+1) & 0x07;
- mf_nr_ar[3] = nt_diff << 5;
- par = par_low;
- } else {
- if (nt_diff == 0)
- {
- par++;
- } else {
- par = (((par>>3)+1) << 3) | par_low;
- }
- }
- }
+ // Test if the action was cancelled
+ if(BUTTON_PRESS()) {
+ isOK = -1;
+ break;
+ }
+
+ if (strategy == 2) {
+ // test with additional hlt command
+ halt_time = 0;
+ int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
+ if (len && MF_DBGLEVEL >= 3) {
+ Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len);
+ }
+ }
+
+ if (strategy == 3) {
+ // test with FPGA power off/on
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ SpinDelay(200);
+ iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+ SpinDelay(100);
+ }
+
+ if(!iso14443a_select_card(uid, NULL, &cuid, true, 0, true)) {
+ if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
+ continue;
+ }
+ select_time = GetCountSspClk();
+
+ elapsed_prng_sequences = 1;
+ if (debug_info_nr == -1) {
+ sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+ catch_up_cycles = 0;
+
+ // if we missed the sync time already, advance to the next nonce repeat
+ while(GetCountSspClk() > sync_time) {
+ elapsed_prng_sequences++;
+ sync_time = (sync_time & 0xfffffff8) + sync_cycles;
+ }
+
+ // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
+ ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+ } else {
+ // collect some information on tag nonces for debugging:
+ #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH
+ if (strategy == 0) {
+ // nonce distances at fixed time after card select:
+ sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES;
+ } else if (strategy == 1) {
+ // nonce distances at fixed time between authentications:
+ sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES;
+ } else if (strategy == 2) {
+ // nonce distances at fixed time after halt:
+ sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES;
+ } else {
+ // nonce_distances at fixed time after power on
+ sync_time = DEBUG_FIXED_SYNC_CYCLES;
+ }
+ ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
+ }
+
+ // Receive the (4 Byte) "random" nonce
+ if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
+ if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
+ continue;
+ }
+
+ previous_nt = nt;
+ nt = bytes_to_num(receivedAnswer, 4);
- LogTrace(nt,4,0,GetParity(nt,4),TRUE);
- LogTrace(par_list,8,0,GetParity(par_list,8),TRUE);
- LogTrace(ks_list,8,0,GetParity(ks_list,8),TRUE);
+ // Transmit reader nonce with fake par
+ ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
- // Thats it...
+ if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
+ int nt_distance = dist_nt(previous_nt, nt);
+ if (nt_distance == 0) {
+ nt_attacked = nt;
+ } else {
+ if (nt_distance == -99999) { // invalid nonce received
+ unexpected_random++;
+ if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
+ isOK = -3; // Card has an unpredictable PRNG. Give up
+ break;
+ } else {
+ continue; // continue trying...
+ }
+ }
+ if (++sync_tries > MAX_SYNC_TRIES) {
+ if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
+ isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
+ break;
+ } else { // continue for a while, just to collect some debug info
+ debug_info[strategy][debug_info_nr] = nt_distance;
+ debug_info_nr++;
+ if (debug_info_nr == NUM_DEBUG_INFOS) {
+ strategy++;
+ debug_info_nr = 0;
+ }
+ continue;
+ }
+ }
+ sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences);
+ if (sync_cycles <= 0) {
+ sync_cycles += PRNG_SEQUENCE_LENGTH;
+ }
+ if (MF_DBGLEVEL >= 3) {
+ Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles);
+ }
+ continue;
+ }
+ }
+
+ if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
+ catch_up_cycles = -dist_nt(nt_attacked, nt);
+ if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
+ catch_up_cycles = 0;
+ continue;
+ }
+ catch_up_cycles /= elapsed_prng_sequences;
+ if (catch_up_cycles == last_catch_up) {
+ consecutive_resyncs++;
+ }
+ else {
+ last_catch_up = catch_up_cycles;
+ consecutive_resyncs = 0;
+ }
+ if (consecutive_resyncs < 3) {
+ if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
+ }
+ else {
+ sync_cycles = sync_cycles + catch_up_cycles;
+ if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
+ last_catch_up = 0;
+ catch_up_cycles = 0;
+ consecutive_resyncs = 0;
+ }
+ continue;
+ }
+
+ consecutive_resyncs = 0;
+
+ // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
+ if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
+ catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
+
+ if (nt_diff == 0) {
+ par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
+ }
+
+ led_on = !led_on;
+ if(led_on) LED_B_ON(); else LED_B_OFF();
+
+ par_list[nt_diff] = SwapBits(par[0], 8);
+ ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
+
+ // Test if the information is complete
+ if (nt_diff == 0x07) {
+ isOK = 1;
+ break;
+ }
+
+ nt_diff = (nt_diff + 1) & 0x07;
+ mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
+ par[0] = par_low;
+ } else {
+ if (nt_diff == 0 && first_try)
+ {
+ par[0]++;
+ if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
+ isOK = -2;
+ break;
+ }
+ } else {
+ par[0] = ((par[0] & 0x1F) + 1) | par_low;
+ }
+ }
+ }
+
+
+ mf_nr_ar[3] &= 0x1F;
+
+ if (isOK == -4) {
+ if (MF_DBGLEVEL >= 3) {
+ for (uint16_t i = 0; i <= MAX_STRATEGY; i++) {
+ for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) {
+ Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]);
+ }
+ }
+ }
+ }
+
+ byte_t buf[28];
+ memcpy(buf + 0, uid, 4);
+ num_to_bytes(nt, 4, buf + 4);
+ memcpy(buf + 8, par_list, 8);
+ memcpy(buf + 16, ks_list, 8);
+ memcpy(buf + 24, mf_nr_ar, 4);
+
+ cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
+
+ // Thats it...
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
- tracing = TRUE;
+
+ set_tracing(false);
+}
+
+
+//-----------------------------------------------------------------------------
+// MIFARE sniffer.
+//
+//-----------------------------------------------------------------------------
+void RAMFUNC SniffMifare(uint8_t param) {
+ // param:
+ // bit 0 - trigger from first card answer
+ // bit 1 - trigger from first reader 7-bit request
+
+ // C(red) A(yellow) B(green)
+ LEDsoff();
+ // init trace buffer
+ clear_trace();
+ set_tracing(true);
+
+ // The command (reader -> tag) that we're receiving.
+ // The length of a received command will in most cases be no more than 18 bytes.
+ // So 32 should be enough!
+ uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
+ uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
+ // The response (tag -> reader) that we're receiving.
+ uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
+ uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
+
+ iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
+ // free eventually allocated BigBuf memory
+ BigBuf_free();
+ // allocate the DMA buffer, used to stream samples from the FPGA
+ uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
+ uint8_t *data = dmaBuf;
+ uint8_t previous_data = 0;
+ int maxDataLen = 0;
+ int dataLen = 0;
+ bool ReaderIsActive = false;
+ bool TagIsActive = false;
+
+ // Set up the demodulator for tag -> reader responses.
+ DemodInit(receivedResponse, receivedResponsePar);
+
+ // Set up the demodulator for the reader -> tag commands
+ UartInit(receivedCmd, receivedCmdPar);
+
+ // Setup for the DMA.
+ FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
+
+ LED_D_OFF();
+
+ // init sniffer
+ MfSniffInit();
+
+ // And now we loop, receiving samples.
+ for(uint32_t sniffCounter = 0; true; ) {
+
+ if(BUTTON_PRESS()) {
+ DbpString("cancelled by button");
+ break;
+ }
+
+ LED_A_ON();
+ WDT_HIT();
+
+ if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
+ // check if a transaction is completed (timeout after 2000ms).
+ // if yes, stop the DMA transfer and send what we have so far to the client
+ if (MfSniffSend(2000)) {
+ // Reset everything - we missed some sniffed data anyway while the DMA was stopped
+ sniffCounter = 0;
+ data = dmaBuf;
+ maxDataLen = 0;
+ ReaderIsActive = false;
+ TagIsActive = false;
+ FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
+ }
+ }
+
+ int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
+ int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
+ if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred
+ dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
+ } else {
+ dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
+ }
+ // test for length of buffer
+ if(dataLen > maxDataLen) { // we are more behind than ever...
+ maxDataLen = dataLen;
+ if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
+ Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
+ break;
+ }
+ }
+ if(dataLen < 1) continue;
+
+ // primary buffer was stopped ( <-- we lost data!
+ if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
+ AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
+ AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
+ Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
+ }
+ // secondary buffer sets as primary, secondary buffer was stopped
+ if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
+ AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
+ AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
+ }
+
+ LED_A_OFF();
+
+ if (sniffCounter & 0x01) {
+
+ if(!TagIsActive) { // no need to try decoding tag data if the reader is sending
+ uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
+ if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
+ LED_C_INV();
+ if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, true)) break;
+
+ /* And ready to receive another command. */
+ UartInit(receivedCmd, receivedCmdPar);
+
+ /* And also reset the demod code */
+ DemodReset();
+ }
+ ReaderIsActive = (Uart.state != STATE_UNSYNCD);
+ }
+
+ if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending
+ uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
+ if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
+ LED_C_INV();
+
+ if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, false)) break;
+
+ // And ready to receive another response.
+ DemodReset();
+ // And reset the Miller decoder including its (now outdated) input buffer
+ UartInit(receivedCmd, receivedCmdPar);
+ }
+ TagIsActive = (Demod.state != DEMOD_UNSYNCD);
+ }
+ }
+
+ previous_data = *data;
+ sniffCounter++;
+ data++;
+ if(data == dmaBuf + DMA_BUFFER_SIZE) {
+ data = dmaBuf;
+ }
+
+ } // main cycle
+
+ DbpString("COMMAND FINISHED");
+
+ FpgaDisableSscDma();
+ MfSniffEnd();
+
+ Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
+ LEDsoff();
}
projects / proxmark3-svn / blobdiff