mirror of
https://github.com/Proxmark/proxmark3.git
synced 2025-08-14 10:36:58 -07:00
Major rework of hf mf nested:
- PM: used GetCountMifare in MifareNested() for improved timing accuracy and to deliver better quality nonces - PM: MifareNested now delivers exactly two different nonces to avoid time consuming multiple lfsr_recovery32() on client side - Client: replaced quicksort by bucketsort in crapto1.c which is faster - Client: use multithreading (two parallel calls to lfsr_recovery32()) - Client: fixed a small bug in mfnested() (always showed trgkey=0) - Client: introduced a mutex for PrintAndLog() to avoid interlaced printing Minor rework of hf mf chk: - Avoid time consuming off/on cycles. Send a "halt" instead.
This commit is contained in:
micki.held@gmx.de
parent
babfcaa0f3
commit
9492e0b098
14 changed files with 728 additions and 630 deletions
|
|
@ -1218,47 +1218,75 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
|
|||
LED_A_OFF();
|
||||
}
|
||||
|
||||
|
||||
// prepare a delayed transfer. This simply shifts ToSend[] by a number
|
||||
// of bits specified in the delay parameter.
|
||||
void PrepareDelayedTransfer(uint16_t delay)
|
||||
{
|
||||
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;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// Transmit the command (to the tag) that was placed in ToSend[].
|
||||
// Parameter timing:
|
||||
// if NULL: ignored
|
||||
// if == 0: return time of transfer
|
||||
// if != 0: delay transfer until time specified
|
||||
//-----------------------------------------------------------------------------
|
||||
static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait)
|
||||
static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
|
||||
{
|
||||
int c;
|
||||
int c;
|
||||
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
|
||||
|
||||
if (wait)
|
||||
if(*wait < 10)
|
||||
*wait = 10;
|
||||
|
||||
for(c = 0; c < *wait;) {
|
||||
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
|
||||
AT91C_BASE_SSC->SSC_THR = 0x00; // For exact timing!
|
||||
c++;
|
||||
}
|
||||
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
|
||||
volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
|
||||
(void)r;
|
||||
}
|
||||
WDT_HIT();
|
||||
}
|
||||
if (timing) {
|
||||
if(*timing == 0) { // Measure time
|
||||
*timing = (GetCountMifare() + 8) & 0xfffffff8;
|
||||
} else {
|
||||
PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
|
||||
}
|
||||
if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
|
||||
while(GetCountMifare() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
|
||||
}
|
||||
|
||||
for(c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission)
|
||||
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
|
||||
AT91C_BASE_SSC->SSC_THR = 0x00;
|
||||
c++;
|
||||
}
|
||||
}
|
||||
|
||||
c = 0;
|
||||
for(;;) {
|
||||
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
|
||||
AT91C_BASE_SSC->SSC_THR = cmd[c];
|
||||
c++;
|
||||
if(c >= len) {
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
|
|
@ -1528,10 +1556,10 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
|
|||
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_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;
|
||||
|
|
@ -1547,17 +1575,13 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
|
|||
}
|
||||
}
|
||||
|
||||
void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par)
|
||||
void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
|
||||
{
|
||||
int wait = 0;
|
||||
int samples = 0;
|
||||
|
||||
// This is tied to other size changes
|
||||
// uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
|
||||
|
||||
CodeIso14443aBitsAsReaderPar(frame,bits,par);
|
||||
|
||||
// Select the card
|
||||
TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
|
||||
TransmitFor14443a(ToSend, ToSendMax, timing);
|
||||
if(trigger)
|
||||
LED_A_ON();
|
||||
|
||||
|
|
@ -1565,15 +1589,15 @@ void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par)
|
|||
if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
|
||||
}
|
||||
|
||||
void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par)
|
||||
void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
|
||||
{
|
||||
ReaderTransmitBitsPar(frame,len*8,par);
|
||||
ReaderTransmitBitsPar(frame,len*8,par, timing);
|
||||
}
|
||||
|
||||
void ReaderTransmit(uint8_t* frame, int len)
|
||||
void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
|
||||
{
|
||||
// Generate parity and redirect
|
||||
ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len));
|
||||
ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
|
||||
}
|
||||
|
||||
int ReaderReceive(uint8_t* receivedAnswer)
|
||||
|
|
@ -1612,7 +1636,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
|
|||
int len;
|
||||
|
||||
// Broadcast for a card, WUPA (0x52) will force response from all cards in the field
|
||||
ReaderTransmitBitsPar(wupa,7,0);
|
||||
ReaderTransmitBitsPar(wupa,7,0, NULL);
|
||||
// Receive the ATQA
|
||||
if(!ReaderReceive(resp)) return 0;
|
||||
// Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
|
||||
|
|
@ -1636,7 +1660,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
|
|||
sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
|
||||
|
||||
// SELECT_ALL
|
||||
ReaderTransmit(sel_all,sizeof(sel_all));
|
||||
ReaderTransmit(sel_all,sizeof(sel_all), NULL);
|
||||
if (!ReaderReceive(resp)) return 0;
|
||||
|
||||
// First backup the current uid
|
||||
|
|
@ -1644,15 +1668,15 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
|
|||
uid_resp_len = 4;
|
||||
// Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
|
||||
|
||||
// calculate crypto UID
|
||||
if(cuid_ptr) {
|
||||
*cuid_ptr = bytes_to_num(uid_resp, 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));
|
||||
ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
|
||||
|
||||
// Receive the SAK
|
||||
if (!ReaderReceive(resp)) return 0;
|
||||
|
|
@ -1687,7 +1711,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
|
|||
|
||||
// Request for answer to select
|
||||
AppendCrc14443a(rats, 2);
|
||||
ReaderTransmit(rats, sizeof(rats));
|
||||
ReaderTransmit(rats, sizeof(rats), NULL);
|
||||
|
||||
if (!(len = ReaderReceive(resp))) return 0;
|
||||
|
||||
|
|
@ -1702,13 +1726,13 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
|
|||
}
|
||||
|
||||
void iso14443a_setup() {
|
||||
// Set up the synchronous serial port
|
||||
FpgaSetupSsc();
|
||||
// Set up the synchronous serial port
|
||||
FpgaSetupSsc();
|
||||
// Start from off (no field generated)
|
||||
// Signal field is off with the appropriate LED
|
||||
LED_D_OFF();
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
|
||||
SpinDelay(50);
|
||||
// LED_D_OFF();
|
||||
// FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
|
||||
// SpinDelay(50);
|
||||
|
||||
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
|
||||
|
||||
|
|
@ -1716,7 +1740,7 @@ void iso14443a_setup() {
|
|||
// Signal field is on with the appropriate LED
|
||||
LED_D_ON();
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
|
||||
SpinDelay(50);
|
||||
SpinDelay(7); // iso14443-3 specifies 5ms max.
|
||||
|
||||
iso14a_timeout = 2048; //default
|
||||
}
|
||||
|
|
@ -1730,7 +1754,7 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
|
|||
memcpy(real_cmd+2, cmd, cmd_len);
|
||||
AppendCrc14443a(real_cmd,cmd_len+2);
|
||||
|
||||
ReaderTransmit(real_cmd, cmd_len+4);
|
||||
ReaderTransmit(real_cmd, cmd_len+4, NULL);
|
||||
size_t len = ReaderReceive(data);
|
||||
uint8_t * data_bytes = (uint8_t *) data;
|
||||
if (!len)
|
||||
|
|
@ -1757,21 +1781,20 @@ void ReaderIso14443a(UsbCommand * c)
|
|||
iso14a_command_t param = c->arg[0];
|
||||
uint8_t * cmd = c->d.asBytes;
|
||||
size_t len = c->arg[1];
|
||||
uint32_t arg0 = 0;
|
||||
byte_t buf[USB_CMD_DATA_SIZE];
|
||||
uint32_t arg0 = 0;
|
||||
byte_t buf[USB_CMD_DATA_SIZE];
|
||||
|
||||
iso14a_clear_trace();
|
||||
iso14a_set_tracing(true);
|
||||
iso14a_clear_trace();
|
||||
iso14a_set_tracing(true);
|
||||
|
||||
if(param & ISO14A_REQUEST_TRIGGER) {
|
||||
iso14a_set_trigger(1);
|
||||
}
|
||||
iso14a_set_trigger(1);
|
||||
}
|
||||
|
||||
if(param & ISO14A_CONNECT) {
|
||||
iso14443a_setup();
|
||||
arg0 = iso14443a_select_card(NULL,(iso14a_card_select_t*)buf,NULL);
|
||||
arg0 = iso14443a_select_card(NULL, (iso14a_card_select_t*)buf, NULL);
|
||||
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(iso14a_card_select_t));
|
||||
// UsbSendPacket((void *)ack, sizeof(UsbCommand));
|
||||
}
|
||||
|
||||
if(param & ISO14A_SET_TIMEOUT) {
|
||||
|
|
@ -1785,7 +1808,6 @@ void ReaderIso14443a(UsbCommand * c)
|
|||
if(param & ISO14A_APDU) {
|
||||
arg0 = iso14_apdu(cmd, len, buf);
|
||||
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
|
||||
// UsbSendPacket((void *)ack, sizeof(UsbCommand));
|
||||
}
|
||||
|
||||
if(param & ISO14A_RAW) {
|
||||
|
|
@ -1793,50 +1815,24 @@ void ReaderIso14443a(UsbCommand * c)
|
|||
AppendCrc14443a(cmd,len);
|
||||
len += 2;
|
||||
}
|
||||
ReaderTransmit(cmd,len);
|
||||
ReaderTransmit(cmd,len, NULL);
|
||||
arg0 = ReaderReceive(buf);
|
||||
// UsbSendPacket((void *)ack, sizeof(UsbCommand));
|
||||
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
|
||||
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
|
||||
}
|
||||
|
||||
if(param & ISO14A_REQUEST_TRIGGER) {
|
||||
iso14a_set_trigger(0);
|
||||
}
|
||||
iso14a_set_trigger(0);
|
||||
}
|
||||
|
||||
if(param & ISO14A_NO_DISCONNECT) {
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
|
||||
LEDsoff();
|
||||
}
|
||||
|
||||
|
||||
// prepare the Mifare AUTH transfer with an added necessary delay.
|
||||
void PrepareDelayedAuthTransfer(uint8_t* frame, int len, uint16_t delay)
|
||||
{
|
||||
CodeIso14443aBitsAsReaderPar(frame, len*8, GetParity(frame,len));
|
||||
|
||||
uint8_t bitmask = 0;
|
||||
uint8_t bits_to_shift = 0;
|
||||
uint8_t bits_shifted = 0;
|
||||
|
||||
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;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
// 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.
|
||||
|
|
@ -1904,11 +1900,8 @@ void ReaderMifare(bool first_try)
|
|||
StartCountMifare();
|
||||
mf_nr_ar3 = 0;
|
||||
iso14443a_setup();
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); // resets some FPGA internal registers
|
||||
while((GetCountMifare() & 0xffff0000) != 0x10000); // wait for counter to reset and "warm up"
|
||||
while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME); // wait for ssp_frame to be low
|
||||
while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_FRAME)); // sync on rising edge of ssp_frame
|
||||
sync_time = GetCountMifare();
|
||||
sync_time = GetCountMifare() & 0xfffffff8;
|
||||
sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
|
||||
nt_attacked = 0;
|
||||
nt = 0;
|
||||
|
|
@ -1939,41 +1932,37 @@ void ReaderMifare(bool first_try)
|
|||
LED_C_ON();
|
||||
|
||||
if(!iso14443a_select_card(uid, NULL, &cuid)) {
|
||||
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
|
||||
continue;
|
||||
}
|
||||
|
||||
//keep the card active
|
||||
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
|
||||
|
||||
PrepareDelayedAuthTransfer(mf_auth, sizeof(mf_auth), (sync_cycles + catch_up_cycles) & 0x00000007);
|
||||
// CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));
|
||||
|
||||
sync_time = sync_time + ((sync_cycles + catch_up_cycles) & 0xfffffff8);
|
||||
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(GetCountMifare() > sync_time) {
|
||||
sync_time = sync_time + (sync_cycles & 0xfffffff8);
|
||||
sync_time = (sync_time & 0xfffffff8) + sync_cycles;
|
||||
}
|
||||
|
||||
// now sync. After syncing, the following Classic Auth will return the same tag nonce (mostly)
|
||||
while(GetCountMifare() < sync_time);
|
||||
|
||||
// Transmit MIFARE_CLASSIC_AUTH
|
||||
int samples = 0;
|
||||
int wait = 0;
|
||||
TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
|
||||
// Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
|
||||
ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
|
||||
|
||||
// Receive the (4 Byte) "random" nonce
|
||||
if (!ReaderReceive(receivedAnswer)) {
|
||||
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
|
||||
continue;
|
||||
}
|
||||
|
||||
|
||||
previous_nt = nt;
|
||||
nt = bytes_to_num(receivedAnswer, 4);
|
||||
|
||||
// Transmit reader nonce with fake par
|
||||
ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par);
|
||||
ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
|
||||
|
||||
if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
|
||||
int nt_distance = dist_nt(previous_nt, nt);
|
||||
|
|
@ -1985,7 +1974,7 @@ void ReaderMifare(bool first_try)
|
|||
continue;
|
||||
}
|
||||
sync_cycles = (sync_cycles - nt_distance);
|
||||
// Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
|
||||
if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
|
||||
continue;
|
||||
}
|
||||
}
|
||||
|
|
@ -2004,11 +1993,11 @@ void ReaderMifare(bool first_try)
|
|||
consecutive_resyncs = 0;
|
||||
}
|
||||
if (consecutive_resyncs < 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);
|
||||
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;
|
||||
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);
|
||||
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);
|
||||
}
|
||||
continue;
|
||||
}
|
||||
|
|
@ -2018,7 +2007,7 @@ void ReaderMifare(bool first_try)
|
|||
// Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
|
||||
if (ReaderReceive(receivedAnswer))
|
||||
{
|
||||
catch_up_cycles = 8; // the PRNG doesn't run during data transfers. 4 Bit = 8 cycles
|
||||
catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
|
||||
|
||||
if (nt_diff == 0)
|
||||
{
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue