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ADD: added the 'max frame size' parameter set, valid sizes: 16|24|32|…
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…40|48|64|96|128|256

it can be verified by setting debuglevel to 3 or more.
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@iceman1001
iceman1001 committed Aug 7, 2016
1 parent b62cbad commit 29f8c2c
Showing 1 changed file with 90 additions and 60 deletions.
150 changes: 90 additions & 60 deletions armsrc/iso14443b.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,8 @@
#include "iso14443b.h"

#ifndef FWT_TIMEOUT_14B
# define FWT_TIMEOUT_14B 60000
// defaults to 2000ms
# define FWT_TIMEOUT_14B 35312
#endif
#ifndef ISO14443B_DMA_BUFFER_SIZE
# define ISO14443B_DMA_BUFFER_SIZE 256
Expand All @@ -37,29 +38,19 @@
// 4sample
#define SEND4STUFFBIT(x) ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);ToSendStuffBit(x);
//#define SEND4STUFFBIT(x) ToSendStuffBit(x);
// iceman, this threshold value, what makes 8 a good amplituted for this IQ values?
#ifndef SUBCARRIER_DETECT_THRESHOLD
# define SUBCARRIER_DETECT_THRESHOLD 6
#endif

static void iso14b_set_timeout(uint32_t timeout);
static void iso14b_set_maxframesize(uint16_t size);
static void switch_off(void);

// the block number for the ISO14443-4 PCB (used with APDUs)
static uint8_t pcb_blocknum = 0;

static uint32_t iso14b_timeout = FWT_TIMEOUT_14B;
// param timeout is in ftw_
void iso14b_set_timeout(uint32_t timeout) {
// 9.4395us = 1etu.
// clock is about 1.5 us
iso14b_timeout = timeout;
if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443B Timeout set to %ld fwt", iso14b_timeout);
}

static void switch_off(void){
if (MF_DBGLEVEL > 3) Dbprintf("switch_off");
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(100);
FpgaDisableSscDma();
set_tracing(FALSE);
LEDsoff();
}

//=============================================================================
// An ISO 14443 Type B tag. We listen for commands from the reader, using
Expand Down Expand Up @@ -150,6 +141,44 @@ static void DemodInit(uint8_t *data) {
// memset(Demod.output, 0x00, MAX_FRAME_SIZE);
}


/*
* 9.4395 us = 1 ETU and clock is about 1.5 us
* 13560000Hz
* 1000ms/s
* timeout in ETUs (time to transfer 1 bit, 9.4395 us)
*
* Formula to calculate FWT (in ETUs) by timeout (in ms):
* fwt = 13560000 * 1000 / (8*16) * timeout;
* Sample: 3sec == 3000ms
* 13560000 * 1000 / (8*16) * 3000 ==
* 13560000000 / 384000 = 35312 FWT
* @param timeout is in frame wait time, fwt, measured in ETUs
*/
static void iso14b_set_timeout(uint32_t timeout) {
#define MAX_TIMEOUT 40542464 // 13560000Hz * 1000ms / (2^32-1) * (8*16)
if(timeout > MAX_TIMEOUT)
timeout = MAX_TIMEOUT;

iso14b_timeout = timeout;
if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443B Timeout set to %ld fwt", iso14b_timeout);
}
static void iso14b_set_maxframesize(uint16_t size) {
if (size > 256)
size = MAX_FRAME_SIZE;

Uart.byteCntMax = size;
if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443B Max frame size set to %d bytes", Uart.byteCntMax);
}
static void switch_off(void){
if (MF_DBGLEVEL > 3) Dbprintf("switch_off");
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(100);
FpgaDisableSscDma();
set_tracing(FALSE);
LEDsoff();
}

void AppendCrc14443b(uint8_t* data, int len) {
ComputeCrc14443(CRC_14443_B, data, len, data+len, data+len+1);
}
Expand Down Expand Up @@ -298,9 +327,9 @@ static void CodeIso14443bAsTag(const uint8_t *cmd, int len) {
* false if we are still waiting for some more
*/
static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
switch(Uart.state) {
switch (Uart.state) {
case STATE_UNSYNCD:
if(!bit) {
if (!bit) {
// we went low, so this could be the beginning of an SOF
Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF;
Uart.posCnt = 0;
Expand All @@ -310,40 +339,37 @@ static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {

case STATE_GOT_FALLING_EDGE_OF_SOF:
Uart.posCnt++;
if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
if(bit) {
if(Uart.bitCnt > 9) {
if (Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit
if (bit) {
if (Uart.bitCnt > 9) {
// we've seen enough consecutive
// zeros that it's a valid SOF
Uart.posCnt = 0;
Uart.byteCnt = 0;
Uart.state = STATE_AWAITING_START_BIT;
LED_A_ON(); // Indicate we got a valid SOF
} else {
// didn't stay down long enough
// before going high, error
// didn't stay down long enough before going high, error
Uart.state = STATE_UNSYNCD;
}
} else {
// do nothing, keep waiting
}
Uart.bitCnt++;
}
if(Uart.posCnt >= 4) Uart.posCnt = 0;
if(Uart.bitCnt > 12) {
// Give up if we see too many zeros without
// a one, too.
if (Uart.posCnt >= 4) Uart.posCnt = 0;
if (Uart.bitCnt > 12) {
// Give up if we see too many zeros without a one, too.
LED_A_OFF();
Uart.state = STATE_UNSYNCD;
}
break;

case STATE_AWAITING_START_BIT:
Uart.posCnt++;
if(bit) {
if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
// stayed high for too long between
// characters, error
if (bit) {
if (Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs
// stayed high for too long between characters, error
Uart.state = STATE_UNSYNCD;
}
} else {
Expand All @@ -357,26 +383,26 @@ static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {

case STATE_RECEIVING_DATA:
Uart.posCnt++;
if(Uart.posCnt == 2) {
if (Uart.posCnt == 2) {
// time to sample a bit
Uart.shiftReg >>= 1;
if(bit) {
if (bit) {
Uart.shiftReg |= 0x200;
}
Uart.bitCnt++;
}
if(Uart.posCnt >= 4) {
if (Uart.posCnt >= 4) {
Uart.posCnt = 0;
}
if(Uart.bitCnt == 10) {
if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
if (Uart.bitCnt == 10) {
if ((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001))
{
// this is a data byte, with correct
// start and stop bits
Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff;
Uart.byteCnt++;

if(Uart.byteCnt >= Uart.byteCntMax) {
if (Uart.byteCnt >= Uart.byteCntMax) {
// Buffer overflowed, give up
LED_A_OFF();
Uart.state = STATE_UNSYNCD;
Expand All @@ -389,9 +415,9 @@ static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
// this is an EOF byte
LED_A_OFF(); // Finished receiving
Uart.state = STATE_UNSYNCD;
if (Uart.byteCnt != 0) {
return TRUE;
}
if (Uart.byteCnt != 0)
return TRUE;

} else {
// this is an error
LED_A_OFF();
Expand All @@ -405,7 +431,6 @@ static RAMFUNC int Handle14443bReaderUartBit(uint8_t bit) {
Uart.state = STATE_UNSYNCD;
break;
}

return FALSE;
}

Expand Down Expand Up @@ -716,13 +741,9 @@ void SimulateIso14443bTag(uint32_t pupi) {
* false if we are still waiting for some more
*
*/
// iceman, this threshold value, what makes 8 a good amplituted for this IQ values?
#ifndef SUBCARRIER_DETECT_THRESHOLD
# define SUBCARRIER_DETECT_THRESHOLD 6
#endif

static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
int v = 0, myI = 0, myQ = 0;
int v = 0, myI = ABS(ci), myQ = ABS(cq);

// The soft decision on the bit uses an estimate of just the
// quadrant of the reference angle, not the exact angle.
#define MAKE_SOFT_DECISION() { \
Expand Down Expand Up @@ -774,8 +795,6 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {

//note: couldn't we just use MAX(ABS(ci),ABS(cq)) + (MIN(ABS(ci),ABS(cq))/2) from common.h - marshmellow
#define CHECK_FOR_SUBCARRIER() { \
myI = ABS(ci); \
myQ = ABS(cq); \
v = MAX(myI, myQ) + (MIN(myI, myQ) >> 1); \
}

Expand Down Expand Up @@ -895,18 +914,19 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
uint16_t s = Demod.shiftReg;

// stop bit == '1', start bit == '0'
if((s & 0x200) && !(s & 0x001)) {
uint8_t b = (s >> 1);
Demod.output[Demod.len] = b;
if ((s & 0x200) && (s & 0x001) == 0 ) {
// left shift to drop the startbit
Demod.output[Demod.len] = (s >> 1) & 0xFF;
++Demod.len;
Demod.state = DEMOD_AWAITING_START_BIT;
} else {
// this one is a bit hard, either its a correc byte or its unsynced.
Demod.state = DEMOD_UNSYNCD;
Demod.endTime = GetCountSspClk();
LED_C_OFF();

// This is EOF (start, stop and all data bits == '0'
if(s == 0) return TRUE;
if (s == 0) return TRUE;
}
}
Demod.posCount = 0;
Expand All @@ -929,7 +949,7 @@ static RAMFUNC int Handle14443bTagSamplesDemod(int ci, int cq) {
static void GetTagSamplesFor14443bDemod() {
bool gotFrame = FALSE, finished = FALSE;
int lastRxCounter = ISO14443B_DMA_BUFFER_SIZE;
int ci = 0, cq = 0, samples = 0;
int ci = 0, cq = 0;
uint32_t time_0 = 0, time_stop = 0;

BigBuf_free();
Expand Down Expand Up @@ -963,8 +983,6 @@ static void GetTagSamplesFor14443bDemod() {
ci = upTo[0] >> 1;
cq = upTo[1] >> 1;
upTo += 2;
samples += 2;

lastRxCounter -= 2;

// restart DMA buffer to receive again.
Expand All @@ -976,7 +994,6 @@ static void GetTagSamplesFor14443bDemod() {
}

// https://github.com/Proxmark/proxmark3/issues/103
//gotFrame = Handle14443bTagSamplesDemod(ci & 0xfe, cq & 0xfe);
gotFrame = Handle14443bTagSamplesDemod(ci, cq);
time_stop = GetCountSspClk() - time_0;

Expand Down Expand Up @@ -1285,10 +1302,23 @@ uint8_t iso14443b_select_card(iso14b_card_select_t *card )
ComputeCrc14443(CRC_14443_B, Demod.output, Demod.len-2, &crc[0], &crc[1]);
if ( crc[0] != Demod.output[1] || crc[1] != Demod.output[2] )
return 3;

// CID

if (card) {

// CID
card->cid = Demod.output[0];

// MAX FRAME
uint16_t maxFrame = card->atqb[5] >> 4;
if (maxFrame < 5) maxFrame = 8 * maxFrame + 16;
else if (maxFrame == 5) maxFrame = 64;
else if (maxFrame == 6) maxFrame = 96;
else if (maxFrame == 7) maxFrame = 128;
else if (maxFrame == 8) maxFrame = 256;
else maxFrame = 257;
iso14b_set_maxframesize(maxFrame);

// FWT
uint8_t fwt = card->atqb[6] >> 4;
if ( fwt < 16 ){
uint32_t fwt_time = (302 << fwt);
Expand Down

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