]> cvs.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/iso14443a.c
FIX: a suggested fix for #136 where the "lf t55x7 read" command when called with...
[proxmark3-svn] / armsrc / iso14443a.c
index a723f50266285287aaceca26c248375be6a79af2..06b6d32f46a78291c0fe540868f53f7336ad2ae4 100644 (file)
@@ -718,6 +718,8 @@ void RAMFUNC SniffIso14443a(uint8_t param) {
 
        Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
        Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
+       
+       set_tracing(FALSE);     
 }
 
 //-----------------------------------------------------------------------------
@@ -937,7 +939,6 @@ bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 //-----------------------------------------------------------------------------
 void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
 {
-
        //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
        // This can be used in a reader-only attack.
        // (it can also be retrieved via 'hf 14a list', but hey...
@@ -947,10 +948,10 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
        uint8_t sak;
                                        
        // PACK response to PWD AUTH for EV1/NTAG
-       uint8_t response8[4];
+       uint8_t response8[4] =  {0,0,0,0};
        
        // The first response contains the ATQA (note: bytes are transmitted in reverse order).
-       uint8_t response1[2];
+       uint8_t response1[2] =  {0,0};
        
        switch (tagType) {
                case 1: { // MIFARE Classic
@@ -1299,7 +1300,8 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                        if ( tagType == 7 ) {
                                p_response =  &responses[8]; // PACK response
                                uint32_t pwd = bytes_to_num(receivedCmd+1,4);
-                               Dbprintf("Auth attempt: %08x", pwd);    
+                               
+                               if ( MF_DBGLEVEL >= 3)  Dbprintf("Auth attempt: %08x", pwd);    
                        }
                }
                else {
@@ -1414,13 +1416,14 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
        }
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       set_tracing(FALSE);
        BigBuf_free_keep_EM();
        LED_A_OFF();
        
        if (MF_DBGLEVEL >= 4){
-       Dbprintf("-[ Wake ups after halt [%d]", happened);
-       Dbprintf("-[ Messages after halt [%d]", happened2);
-       Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
+               Dbprintf("-[ Wake ups after halt [%d]", happened);
+               Dbprintf("-[ Messages after halt [%d]", happened2);
+               Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
        }
 }
 
@@ -1432,7 +1435,7 @@ 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++) {
@@ -2179,6 +2182,7 @@ void ReaderIso14443a(UsbCommand *c)
        }
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       set_tracing(FALSE);
        LEDsoff();
 }
 
@@ -2206,28 +2210,6 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
        return(-99999); // either nt1 or nt2 are invalid nonces
 }
 
-int32_t dist_nt_ex32(uint32_t nt1, uint32_t nt2, bool *result) {
-
-       uint16_t i;
-       uint32_t nttmp1, nttmp2;
-
-       if (nt1 == nt2) return 0;
-
-       nttmp1 = nt1;
-       nttmp2 = nt2;
-       
-       *result = true;
-       for (i = 1; i < 0xFFFFFFFF; i++) {
-               nttmp1 = prng_successor(nttmp1, 1);
-               if (nttmp1 == nt2) return i;
-                       
-               nttmp2 = prng_successor(nttmp2, 1);
-                       if (nttmp2 == nt1) return -i;
-               }
-       
-       *result = false;
-       return(-99999); // either nt1 or nt2 are invalid nonces
-}
 
 //-----------------------------------------------------------------------------
 // Recover several bits of the cypher stream. This implements (first stages of)
@@ -2270,9 +2252,10 @@ void ReaderMifare(bool first_try)
 
    #define PRNG_SEQUENCE_LENGTH  (1 << 16);
        static uint32_t sync_time = 0;
-       static uint32_t sync_cycles = 0;
+       static int32_t sync_cycles = 0;
        int catch_up_cycles = 0;
        int last_catch_up = 0;
+       uint16_t elapsed_prng_sequences;
        uint16_t consecutive_resyncs = 0;
        int isOK = 0;
 
@@ -2281,7 +2264,6 @@ void ReaderMifare(bool first_try)
                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).
                nt_attacked = 0;
-               nt = 0;
                par[0] = 0;
        }
        else {
@@ -2296,12 +2278,17 @@ void ReaderMifare(bool first_try)
        LED_C_OFF();
        
 
-       #define MAX_UNEXPECTED_RANDOM   5               // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
-       #define MAX_SYNC_TRIES                  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;
        int16_t debug_info_nr = -1;
-       uint32_t debug_info[MAX_SYNC_TRIES];
+       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++) {
                
@@ -2314,24 +2301,59 @@ void ReaderMifare(bool first_try)
                        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();
 
+               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 {
-                       ReaderTransmit(mf_auth, sizeof(mf_auth), NULL);
+                       // 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
@@ -2353,7 +2375,7 @@ void ReaderMifare(bool first_try)
                        } else {
                                if (nt_distance == -99999) { // invalid nonce received
                                        unexpected_random++;
-                                       if (!nt_attacked && unexpected_random > MAX_UNEXPECTED_RANDOM) {
+                                       if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
                                                isOK = -3;              // Card has an unpredictable PRNG. Give up      
                                                break;
                                        } else {
@@ -2361,20 +2383,25 @@ void ReaderMifare(bool first_try)
                                        }
                                }
                                if (++sync_tries > MAX_SYNC_TRIES) {
-                                       if (sync_tries > 2 * 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[++debug_info_nr] = nt_distance;
+                                               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);
+                               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, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
+                                       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;
                        }
@@ -2386,6 +2413,7 @@ void ReaderMifare(bool first_try)
                                catch_up_cycles = 0;
                                continue;
                        }
+                       catch_up_cycles /= elapsed_prng_sequences;
                        if (catch_up_cycles == last_catch_up) {
                                consecutive_resyncs++;
                        }
@@ -2399,6 +2427,9 @@ void ReaderMifare(bool first_try)
                        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;
                }
@@ -2406,12 +2437,10 @@ void ReaderMifare(bool first_try)
                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
                        }
 
@@ -2449,8 +2478,10 @@ void ReaderMifare(bool first_try)
        
        if (isOK == -4) {
                if (MF_DBGLEVEL >= 3) {
-                       for(uint16_t i = 0; i < MAX_SYNC_TRIES; i++) {
-                               Dbprintf("collected debug info[%d] = %d\n", i, debug_info[i]);
+                       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]);
+                               }
                        }
                }
        }
@@ -3001,6 +3032,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *
                }
        }
        if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
+       
+       set_tracing(FALSE);
 }
 
 
@@ -3159,4 +3192,5 @@ void RAMFUNC SniffMifare(uint8_t param) {
        MfSniffEnd();
        LEDsoff();
        Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
+       set_tracing(FALSE);
 }
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