LEDsoff();
- // 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);
-
+ iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
// Allocate memory from BigBuf for some buffers
// free all previous allocations first
BigBuf_free();
bool TagIsActive = FALSE;
bool ReaderIsActive = FALSE;
- iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
-
// Set up the demodulator for tag -> reader responses.
DemodInit(receivedResponse, receivedResponsePar);
// 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; ) {
.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:
int happened2 = 0;
int cmdsRecvd = 0;
- // We need to listen to the high-frequency, peak-detected path.
- iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
cmdsRecvd = 0;
tag_response_info_t* p_response;
LED_A_ON();
for(;;) {
// Clean receive command buffer
-
if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
DbpString("Button press");
break;
nttmp1 = prng_successor(nttmp1, 1);
if (nttmp1 == nt2) return i;
nttmp2 = prng_successor(nttmp2, 1);
- if (nttmp2 == nt1) return -i;
+ if (nttmp2 == nt1) return -i;
}
return(-99999); // either nt1 or nt2 are invalid nonces
uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
+ if (first_try) {
+ iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
+ }
+
// free eventually allocated BigBuf memory. We want all for tracing.
BigBuf_free();
byte_t par_list[8] = {0x00};
byte_t ks_list[8] = {0x00};
+ #define PRNG_SEQUENCE_LENGTH (1 << 16);
static uint32_t sync_time;
- static uint32_t sync_cycles;
+ 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;
- iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
sync_time = GetCountSspClk() & 0xfffffff8;
- sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+ 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;
- nt = 0;
par[0] = 0;
}
else {
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;
+ uint32_t halt_time;
+
for(uint16_t i = 0; TRUE; i++) {
+ LED_C_ON();
WDT_HIT();
// Test if the action was cancelled
if(BUTTON_PRESS()) {
+ isOK = -1;
break;
}
- LED_C_ON();
+ 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)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
continue;
}
+ select_time = GetCountSspClk();
- sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
- catch_up_cycles = 0;
+ 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) {
- sync_time = (sync_time & 0xfffffff8) + sync_cycles;
- }
+ // 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);
+ // 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)) {
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;
+ } 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);
}
- 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;
}
}
catch_up_cycles = 0;
continue;
}
+ catch_up_cycles /= elapsed_prng_sequences;
if (catch_up_cycles == last_catch_up) {
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))
- {
+ 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)
- {
+ 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
}
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);
memcpy(buf + 16, ks_list, 8);
memcpy(buf + 24, mf_nr_ar, 4);
- cmd_send(CMD_ACK,isOK,0,0,buf,28);
+ cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
// Thats it...
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
uint8_t ar_nr_collected = 0;
- // free eventually allocated BigBuf memory but keep Emulator Memory
- BigBuf_free_keep_EM();
-
- // clear trace
- clear_trace();
- set_tracing(TRUE);
-
// Authenticate response - nonce
uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
if (_7BUID) {
rATQA[0] = 0x44;
rUIDBCC1[0] = 0x88;
+ rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
}
- // We need to listen to the high-frequency, peak-detected path.
- iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
-
-
if (MF_DBGLEVEL >= 1) {
if (!_7BUID) {
Dbprintf("4B UID: %02x%02x%02x%02x",
}
}
+ // We need to listen to the high-frequency, peak-detected path.
+ iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
+
+ // free eventually allocated BigBuf memory but keep Emulator Memory
+ BigBuf_free_keep_EM();
+
+ // clear trace
+ clear_trace();
+ set_tracing(TRUE);
+
+
bool finished = FALSE;
while (!BUTTON_PRESS() && !finished) {
WDT_HIT();
|| receivedCmd[0] == 0xB0) { // transfer
if (receivedCmd[1] >= 16 * 4) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
- if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
+ if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
break;
}
if (receivedCmd[1] / 4 != cardAUTHSC) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
- if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
+ if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02x) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
break;
}
}
uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
- // 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;
-
+ iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
+
// free eventually allocated BigBuf memory
BigBuf_free();
// allocate the DMA buffer, used to stream samples from the FPGA
bool ReaderIsActive = FALSE;
bool TagIsActive = FALSE;
- iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
-
// Set up the demodulator for tag -> reader responses.
DemodInit(receivedResponse, receivedResponsePar);
projects / proxmark3-svn / blobdiff