static uint32_t LastTimeProxToAirStart;
static uint32_t LastProxToAirDuration;
-
-
// CARD TO READER - manchester
// Sequence D: 11110000 modulation with subcarrier during first half
// Sequence E: 00001111 modulation with subcarrier during second half
trigger = enable;
}
-
void iso14a_set_timeout(uint32_t timeout) {
iso14a_timeout = timeout;
if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
}
-
void iso14a_set_ATS_timeout(uint8_t *ats) {
uint8_t tb1;
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)
+
+ if ((ats[1] & 0x10) == 0x10) // there is an interface byte TA(1) preceding TB(1)
tb1 = ats[3];
- } else {
+ else
tb1 = ats[2];
- }
+
fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
- fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
+ //fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
+ fwt = 4096 * (1 << fwi);
- iso14a_set_timeout(fwt/(8*16));
+ //iso14a_set_timeout(fwt/(8*16));
+ iso14a_set_timeout(fwt/128);
}
}
}
-
//-----------------------------------------------------------------------------
// Generate the parity value for a byte sequence
//
{ .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
- //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
+
{ .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response
+ };
+ //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
//{ .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
- };
+
// 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
LED_A_ON();
for(;;) {
+
+ WDT_HIT();
+
// Clean receive command buffer
if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
DbpString("Button press");
delay &= 0x07;
if (delay) {
for (uint16_t i = 0; i < delay; i++) {
- bitmask |= (0x01 << i);
+ bitmask |= (1 << i);
}
- ToSend[ToSendMax++] = 0x00;
+ ToSend[++ToSendMax] = 0x00;
for (uint16_t i = 0; i < ToSendMax; i++) {
bits_to_shift = ToSend[i] & bitmask;
ToSend[i] = ToSend[i] >> delay;
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 {
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = cmd[c];
- c++;
+ ++c;
if(c >= len)
break;
}
ToSend[++ToSendMax] = SEC_Y;
// Convert to length of command:
- ToSendMax++;
+ ++ToSendMax;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
{
- CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
+ //CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
+ CodeIso14443aBitsAsReaderPar(cmd, len<<3, parity);
}
}
// Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
- uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;
+ uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; // twich /8 ?? >>3,
for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = SEC_F;
LED_A_ON();
// Log reader command in trace buffer
- LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
+ //LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
+ LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
}
void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
{
- ReaderTransmitBitsPar(frame, len*8, par, timing);
+ //ReaderTransmitBitsPar(frame, len*8, par, timing);
+ ReaderTransmitBitsPar(frame, len<<3, par, timing);
}
void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
{
// Generate parity and redirect
uint8_t par[MAX_PARITY_SIZE] = {0x00};
- GetParity(frame, len/8, par);
+ //GetParity(frame, len/8, par);
+ GetParity(frame, len >> 3, par);
ReaderTransmitBitsPar(frame, len, par, timing);
}
// Generate parity and redirect
uint8_t par[MAX_PARITY_SIZE] = {0x00};
GetParity(frame, len, par);
- ReaderTransmitBitsPar(frame, len*8, par, timing);
+ //ReaderTransmitBitsPar(frame, len*8, par, timing);
+ ReaderTransmitBitsPar(frame, len<<3, par, timing);
}
int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
return FALSE;
- LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+ //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+ LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
return Demod.len;
}
if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
return FALSE;
- LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+ //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
+ LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
return Demod.len;
}
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[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 resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
+ uint8_t resp_par[MAX_PARITY_SIZE] = {0};
+ byte_t uid_resp[4] = {0};
+ size_t uid_resp_len = 0;
uint8_t sak = 0x04; // cascade uid
int cascade_level = 0;
}
if (anticollision) {
- // clear uid
- if (uid_ptr) {
- memset(uid_ptr,0,10);
- }
+ // clear uid
+ if (uid_ptr)
+ memset(uid_ptr,0,10);
}
// check for proprietary anticollision:
- if ((resp[0] & 0x1F) == 0) {
- return 3;
- }
+ 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
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);
+ 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;
}
- 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];
+ // 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);
}
- 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 { // 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;
uid_resp_len = 4;
// calculate crypto UID. Always use last 4 Bytes.
- if(cuid_ptr) {
+ if(cuid_ptr)
*cuid_ptr = bytes_to_num(uid_resp, 4);
- }
// Construct SELECT UID command
sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
// Receive the SAK
if (!ReaderReceive(resp, resp_par)) return 0;
+
sak = resp[0];
// Test if more parts of the uid are coming
uid_resp_len = 3;
}
- if(uid_ptr && anticollision) {
+ 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);
ReaderTransmit(rats, sizeof(rats), NULL);
if (!(len = ReaderReceive(resp, resp_par))) return 0;
-
if(p_hi14a_card) {
memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
if (nt1 == nt2) return 0;
-
- uint16_t i;
+
uint32_t nttmp1 = nt1;
uint32_t nttmp2 = nt2;
- for (i = 1; i < 0xFFFF; ++i) {
- nttmp1 = prng_successor(nttmp1, 1);
- if (nttmp1 == nt2) return i;
+ for (uint16_t i = 1; i < 0xFFFF; i += 8) {
+ nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i;
+ nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i;
+
+ nttmp1 = prng_successor(nttmp1, 2); if (nttmp1 == nt2) return i+1;
+ nttmp2 = prng_successor(nttmp2, 2); if (nttmp2 == nt1) return -i-1;
+
+ nttmp1 = prng_successor(nttmp1, 3); if (nttmp1 == nt2) return i+2;
+ nttmp2 = prng_successor(nttmp2, 3); if (nttmp2 == nt1) return -i-2;
+
+ nttmp1 = prng_successor(nttmp1, 4); if (nttmp1 == nt2) return i+3;
+ nttmp2 = prng_successor(nttmp2, 4); if (nttmp2 == nt1) return -i-3;
- nttmp2 = prng_successor(nttmp2, 1);
- if (nttmp2 == nt1) return -i;
+ nttmp1 = prng_successor(nttmp1, 5); if (nttmp1 == nt2) return i+4;
+ nttmp2 = prng_successor(nttmp2, 5); if (nttmp2 == nt1) return -i-4;
+
+ nttmp1 = prng_successor(nttmp1, 6); if (nttmp1 == nt2) return i+5;
+ nttmp2 = prng_successor(nttmp2, 6); if (nttmp2 == nt1) return -i-5;
+
+ nttmp1 = prng_successor(nttmp1, 7); if (nttmp1 == nt2) return i+6;
+ nttmp2 = prng_successor(nttmp2, 7); if (nttmp2 == nt1) return -i-6;
+
+ nttmp1 = prng_successor(nttmp1, 8); if (nttmp1 == nt2) return i+7;
+ nttmp2 = prng_successor(nttmp2, 8); if (nttmp2 == nt1) return -i-7;
}
return(-99999); // either nt1 or nt2 are invalid nonces
//uint8_t mf_auth[] = { 0x60,0x05, 0x58, 0x2c };
uint8_t mf_auth[] = { 0x60,0x00, 0x00, 0x00 };
uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
- static uint8_t mf_nr_ar3;
+ static uint8_t mf_nr_ar3 = 0;
mf_auth[1] = block;
AppendCrc14443a(mf_auth, 2);
uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
- 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 = 0;
+ //uint32_t cuid = 0;
uint32_t nt = 0;
uint32_t previous_nt = 0;
byte_t par_list[8] = {0x00};
byte_t ks_list[8] = {0x00};
- #define PRNG_SEQUENCE_LENGTH (1 << 16);
static uint32_t sync_time = 0;
static int32_t sync_cycles = 0;
int catch_up_cycles = 0;
int last_catch_up = 0;
- uint16_t elapsed_prng_sequences = 0;
+ uint16_t elapsed_prng_sequences = 1;
uint16_t consecutive_resyncs = 0;
int isOK = 0;
+ #define PRNG_SEQUENCE_LENGTH (1 << 16);
+ #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;
+ uint16_t strategy = 0;
+ uint32_t halt_time = 0;
+
+ clear_trace();
+ set_tracing(TRUE);
+
+ LED_A_ON();
+ LED_B_OFF();
+ LED_C_OFF();
+
+ if (first_try)
+ iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+
+ // free eventually allocated BigBuf memory. We want all for tracing.
+ BigBuf_free();
+
if (first_try) {
- mf_nr_ar3 = 0;
sync_time = GetCountSspClk() & 0xfffffff8;
sync_cycles = PRNG_SEQUENCE_LENGTH; //65536; //0x10000 // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+ mf_nr_ar3 = 0;
nt_attacked = 0;
par[0] = 0;
- }
- else {
+ } 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();
-
-
- #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 = 0;
- uint32_t halt_time = 0;
-
- for(uint16_t i = 0; TRUE; ++i) {
- LED_C_ON();
+ LED_C_ON();
+ for(uint16_t i = 0; TRUE; ++i) {
+
WDT_HIT();
// Test if the action was cancelled
}
if (strategy == 2) {
- // test with additional hlt command
+ // test with additional halt 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 (len && MF_DBGLEVEL >= 3)
+ Dbprintf("Unexpected response of %d bytes to halt command.", len);
}
if (strategy == 3) {
SpinDelay(200);
iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
SpinDelay(100);
+ sync_time = GetCountSspClk() & 0xfffffff8;
WDT_HIT();
}
- if(!iso14443a_select_card(uid, NULL, &cuid, true, 0)) {
- if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
+ if (!iso14443a_select_card(uid, NULL, NULL, true, 0)) {
+ if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card\n");
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);
- }
+
+ 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);
// Receive the (4 Byte) "random" nonce
- if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
- if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
+ if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
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);
+ previous_nt = nt;
+ nt = bytes_to_num(receivedAnswer, 4);
+
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) {
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_nr;
- debug_info[strategy][debug_info_nr] = nt_distance;
- if (debug_info_nr == NUM_DEBUG_INFOS) {
- ++strategy;
- debug_info_nr = 0;
- }
+ } else {
continue;
}
}
- sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences);
- if (sync_cycles <= 0) {
+
+ sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
+ if (sync_cycles <= 0)
sync_cycles += PRNG_SEQUENCE_LENGTH;
- }
- if (MF_DBGLEVEL >= 3) {
+
+ 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;
}
+
+ // average?
catch_up_cycles /= elapsed_prng_sequences;
+
if (catch_up_cycles == last_catch_up) {
++consecutive_resyncs;
- }
- else {
+ } 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);
+ 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 += 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;
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]++;
par[0] = ((par[0] & 0x1F) + 1) | par_low;
}
}
+
+ consecutive_resyncs = 0;
}
mf_nr_ar[3] &= 0x1F;
WDT_HIT();
-
- 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]);
- }
- }
- }
+
+ // reset sync_time.
+ if ( isOK == 1) {
+ sync_time = 0;
+ sync_cycles = 0;
+ mf_nr_ar3 = 0;
+ nt_attacked = 0;
+ par[0] = 0;
}
byte_t buf[28] = {0x00};
cmd_send(CMD_ACK,isOK,0,0,buf,28);
- // Thats it...
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
-
set_tracing(FALSE);
}
projects / proxmark3-svn / blobdiff