]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/iso14443a.c
CHG: Added calling clear bigbuff to zero out it also, instead of just "free" it.
[proxmark3-svn] / armsrc / iso14443a.c
index 8dbe9e81f714fb21c4cff3d43ca43086bfc0ce27..be16447cf8b4096013dca1d809b234c75a6920c7 100644 (file)
@@ -546,7 +546,7 @@ void RAMFUNC SniffIso14443a(uint8_t param) {
        
        // Allocate memory from BigBuf for some buffers
        // free all previous allocations first
-       BigBuf_free();
+       BigBuf_free(); BigBuf_Clear_ext(false);
        
        // init trace buffer
        clear_trace();
@@ -750,7 +750,7 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *par
 
 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
 {
-       uint8_t par[MAX_PARITY_SIZE];
+       uint8_t par[MAX_PARITY_SIZE] = {0};
        
        GetParity(cmd, len, par);
        CodeIso14443aAsTagPar(cmd, len, par);
@@ -1167,20 +1167,12 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                                p_response = NULL;
                                
                } else if(receivedCmd[0] == 0x3C && tagType == 7) {     // Received a READ SIGNATURE -- 
-                               // ECC data,  taken from a NTAG215 amiibo token. might work. LEN: 32, + 2 crc
                                //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
                                uint16_t start = 4 * 4;
                                uint8_t emdata[34];
                                emlGetMemBt( emdata, start, 32);
                                AppendCrc14443a(emdata, 32);
                                EmSendCmdEx(emdata, sizeof(emdata), false);
-                               //uint8_t data[] = {0x56,0x06,0xa6,0x4f,0x43,0x32,0x53,0x6f,
-                               //                                0x43,0xda,0x45,0xd6,0x61,0x38,0xaa,0x1e,
-                               //                                0xcf,0xd3,0x61,0x36,0xca,0x5f,0xbb,0x05,
-                               //                                0xce,0x21,0x24,0x5b,0xa6,0x7a,0x79,0x07,
-                               //                                0x00,0x00};
-                               //AppendCrc14443a(data, sizeof(data)-2);
-                               //EmSendCmdEx(data,sizeof(data),false);
                                p_response = NULL;                                      
                } else if (receivedCmd[0] == 0x39 && tagType == 7) {    // Received a READ COUNTER -- 
                        uint8_t index = receivedCmd[1];
@@ -1210,9 +1202,7 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                        emlGetMemBt( emdata, 10+counter, 1);
                        AppendCrc14443a(emdata, sizeof(emdata)-2);
                        EmSendCmdEx(emdata, sizeof(emdata), false);     
-                       p_response = NULL;
-                       //p_response = &responses[9];                           
-               
+                       p_response = NULL;              
                } else if(receivedCmd[0] == 0x50) {     // Received a HALT
                        LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
                        p_response = NULL;
@@ -1224,7 +1214,6 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                                AppendCrc14443a(emdata, sizeof(emdata)-2);
                                EmSendCmdEx(emdata, sizeof(emdata), false);     
                                p_response = NULL;
-                               //p_response = &responses[7];
                        } else {
                                p_response = &responses[5]; order = 7;
                        }
@@ -1299,7 +1288,6 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                                AppendCrc14443a(emdata, 2);
                                EmSendCmdEx(emdata, sizeof(emdata), false);
                                p_response = NULL;
-                               //p_response =  &responses[8]; // PACK response
                                uint32_t pwd = bytes_to_num(receivedCmd+1,4);
                                
                                if ( MF_DBGLEVEL >= 3)  Dbprintf("Auth attempt: %08x", pwd);    
@@ -1428,24 +1416,26 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
 // of bits specified in the delay parameter.
 void PrepareDelayedTransfer(uint16_t delay)
 {
+       delay &= 0x07;
+       if (!delay) return;
+
        uint8_t bitmask = 0;
        uint8_t bits_to_shift = 0;
        uint8_t bits_shifted = 0;
+       uint16_t i = 0;
+
+       for (i = 0; i < delay; ++i)
+               bitmask |= (0x01 << i);
 
-       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++) {
+
+       for (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;
                }
        }
-}
 
 
 //-------------------------------------------------------------------------------------
@@ -1463,18 +1453,27 @@ static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing
        uint32_t ThisTransferTime = 0;
 
        if (timing) {
-               if(*timing == 0) {                                                                              // Measure time
+
+               if (*timing != 0)
+                       // Delay transfer (fine tuning - up to 7 MF clock ticks)
+                       PrepareDelayedTransfer(*timing & 0x00000007);   
+               else
+                       // Measure time
                        *timing = (GetCountSspClk() + 8) & 0xfffffff8;
-               } else {
-                       PrepareDelayedTransfer(*timing & 0x00000007);           // Delay transfer (fine tuning - up to 7 MF clock ticks)
-               }
-               if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+
+               
+               if (MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) 
+                       Dbprintf("TransmitFor14443a: Missed timing");
                
-               while(GetCountSspClk() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
+               // Delay transfer (multiple of 8 MF clock ticks)
+               while (GetCountSspClk() < (*timing & 0xfffffff8));      
+
                LastTimeProxToAirStart = *timing;
        } else {
                ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
+
                while(GetCountSspClk() < ThisTransferTime);
+
                LastTimeProxToAirStart = ThisTransferTime;
        }
        
@@ -1572,7 +1571,7 @@ void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8
        ToSend[++ToSendMax] = SEC_Y;
 
        // Convert to length of command:
-       ToSendMax++;
+       ++ToSendMax;
 }
 
 //-----------------------------------------------------------------------------
@@ -1580,7 +1579,8 @@ void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8
 //-----------------------------------------------------------------------------
 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);
 }
 
 
@@ -1703,7 +1703,7 @@ static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNe
        }
 
        // 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;
@@ -1838,19 +1838,22 @@ void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t
                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);
 }
 
@@ -1859,7 +1862,8 @@ void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *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)
@@ -1867,7 +1871,8 @@ int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parit
        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;
 }
 
@@ -1876,7 +1881,8 @@ int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
        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;
 }
 
@@ -2189,17 +2195,57 @@ void ReaderIso14443a(UsbCommand *c)
 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 (i = 1; i < 0xFFFF; i += 8) {
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+1;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-1;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+2;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-2;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+3;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-3;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+4;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-4;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+5;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-5;
+
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+6;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-6;
 
-               nttmp2 = prng_successor(nttmp2, 1);
-               if (nttmp2 == nt1) return -i;
+               nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+7;
+               nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-7;
+/*
+               if ( prng_successor(nttmp1, i) == nt2) return i;
+               if ( prng_successor(nttmp2, i) == nt1) return -i;
+
+               if ( prng_successor(nttmp1, i+2) == nt2) return i+2;
+               if ( prng_successor(nttmp2, i+2) == nt1) return -(i+2);
+
+               if ( prng_successor(nttmp1, i+3) == nt2) return i+3;
+               if ( prng_successor(nttmp2, i+3) == nt1) return -(i+3);
+
+               if ( prng_successor(nttmp1, i+4) == nt2) return i+4;
+               if ( prng_successor(nttmp2, i+4) == nt1) return -(i+4);
+
+               if ( prng_successor(nttmp1, i+5) == nt2) return i+5;
+               if ( prng_successor(nttmp2, i+5) == nt1) return -(i+5);
+
+               if ( prng_successor(nttmp1, i+6) == nt2) return i+6;
+               if ( prng_successor(nttmp2, i+6) == nt1) return -(i+6);
+
+               if ( prng_successor(nttmp1, i+7) == nt2) return i+7;
+               if ( prng_successor(nttmp2, i+7) == nt1) return -(i+7);
+*/
        }
        
        return(-99999); // either nt1 or nt2 are invalid nonces
@@ -2217,82 +2263,72 @@ void ReaderMifare(bool first_try, uint8_t block )
        // Mifare AUTH
        //uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
        //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 = 0;
-
-       mf_auth[1] = block;
-       AppendCrc14443a(mf_auth, 2);
-       
+       uint8_t mf_auth[]       = { 0x60,0x00, 0x00, 0x00 };
+       uint8_t mf_nr_ar[]      = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+       uint8_t uid[10]         = {0,0,0,0,0,0,0,0,0,0};
+       uint8_t par_list[8]     = {0,0,0,0,0,0,0,0};
+       uint8_t ks_list[8]      = {0,0,0,0,0,0,0,0};
        uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
        uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
+       uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
+       
+       mf_auth[1] = block;
+       AppendCrc14443a(mf_auth, 2);
 
        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 nt = 0;
-       uint32_t previous_nt = 0;
-       static uint32_t nt_attacked = 0;
-       byte_t par_list[8] = {0x00};
-       byte_t ks_list[8] = {0x00};
-
-       static uint32_t sync_time = 0;
-       static int32_t sync_cycles = 0;
+       uint32_t previous_nt = 0;       
+       uint32_t halt_time = 0;
+       uint32_t cuid = 0;
+       
        int catch_up_cycles = 0;
        int last_catch_up = 0;
+       int isOK = 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;
-       int16_t debug_info_nr = -1;
        uint16_t strategy = 0;
-       int32_t debug_info[MAX_STRATEGY+1][NUM_DEBUG_INFOS];
-       uint32_t select_time = 0;
-       uint32_t halt_time = 0;
-       //uint8_t caller[7] = {0};      
 
-       // init to zero.
-       for (uint16_t i = 0; i < MAX_STRATEGY+1; ++i)
-               for(uint16_t j = 0; j < NUM_DEBUG_INFOS; ++j)
-                       debug_info[i][j] = 0;
+       static uint32_t nt_attacked = 0;
+       static uint32_t sync_time = 0;
+       static int32_t sync_cycles = 0;
+       static uint8_t par_low = 0;
+       static uint8_t mf_nr_ar3 = 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 MAX_STRATEGY            3
+
+       // free eventually allocated BigBuf memory
+       BigBuf_free(); BigBuf_Clear_ext(false);
+       
+       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();
-       clear_trace();
-       set_tracing(TRUE);
 
        if (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).
+               sync_cycles = PRNG_SEQUENCE_LENGTH + 1100; //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 {
-               // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
-               mf_nr_ar3++;
+               // 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_C_ON(); 
        for(uint16_t i = 0; TRUE; ++i) {
 
@@ -2310,7 +2346,7 @@ void ReaderMifare(bool first_try, uint8_t block )
                        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 halt command (additional debugging).\n", len);
+                               Dbprintf("Unexpected response of %d bytes to halt command.", len);
                }
 
                if (strategy == 3) {
@@ -2323,61 +2359,36 @@ void ReaderMifare(bool first_try, uint8_t block )
                        WDT_HIT();
                }
                
-               if (!iso14443a_select_card(uid, NULL, &cuid, true, 0)) {
-                       if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card\n");
+               if (!iso14443a_select_card(uid, NULL,  &cuid, true, 0)) {
+                       if (MF_DBGLEVEL >= 2) Dbprintf("Mifare: Can't select card\n");
                        continue;
                }
 
-               select_time = GetCountSspClk() & 0xfffffff8;
-               elapsed_prng_sequences = 1;
+               // Sending timeslot of ISO14443a frame
                
-               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
-                       WDT_HIT();
-                       while(GetCountSspClk() > sync_time) {
-                               ++elapsed_prng_sequences;
-                               sync_time = (sync_time & 0xfffffff8) + sync_cycles;
-                               //sync_time += sync_cycles;
-                               //sync_time &= 0xfffffff8;
-                       }
-                       WDT_HIT();
-                       // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) 
-                       ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);                   
-                       if (MF_DBGLEVEL == 2) Dbprintf("sync_time %d \n", 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;
+               
+               //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))
                        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) {
@@ -2397,22 +2408,16 @@ void ReaderMifare(bool first_try, uint8_t block )
                                        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-1) {
-                                                       ++strategy;
-                                                       debug_info_nr = 0;
-                                               }
+                                       } else {
                                                continue;
-                                       }
+                               }
                                }
                                
-                               sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences);
+                               sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
                                if (sync_cycles <= 0)
                                        sync_cycles += PRNG_SEQUENCE_LENGTH;
                                
-                               if (MF_DBGLEVEL >= 2)
+                               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;
@@ -2435,8 +2440,7 @@ void ReaderMifare(bool first_try, uint8_t block )
                        } else {
                                last_catch_up = catch_up_cycles;
                            consecutive_resyncs = 0;
-                       }
-                       sync_cycles += catch_up_cycles;
+                       }               
                        
                        if (consecutive_resyncs < 3) {
                                if (MF_DBGLEVEL >= 3)
@@ -2454,8 +2458,6 @@ void ReaderMifare(bool first_try, uint8_t block )
                        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
@@ -2463,9 +2465,6 @@ void ReaderMifare(bool first_try, uint8_t block )
                        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;
 
@@ -2478,7 +2477,9 @@ void ReaderMifare(bool first_try, uint8_t block )
                        nt_diff = (nt_diff + 1) & 0x07;
                        mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
                        par[0] = par_low;
+                       
                } else {
+                       // No NACK.     
                        if (nt_diff == 0 && first_try) {
                                par[0]++;
                                if (par[0] == 0x00) {   // tried all 256 possible parities without success. Card doesn't send NACK.
@@ -2486,20 +2487,17 @@ void ReaderMifare(bool first_try, uint8_t block )
                                        break;
                                }
                        } else {
+                               // Why this?
                                par[0] = ((par[0] & 0x1F) + 1) | par_low;
                        }
                }
+               
+               consecutive_resyncs = 0;
        }
 
        mf_nr_ar[3] &= 0x1F;
 
        WDT_HIT();
-
-       if (isOK == -4) {
-               for (uint16_t i = 0; i < MAX_STRATEGY+1; ++i)
-                       for(uint16_t j = 0; j < NUM_DEBUG_INFOS; ++j)
-                               Dbprintf("info[%d][%d] = %d", i, j, debug_info[i][j]);
-       }
        
        // reset sync_time.
        if ( isOK == 1) {
@@ -2510,8 +2508,8 @@ void ReaderMifare(bool first_try, uint8_t block )
                par[0] = 0;
        }
        
-       byte_t buf[28] = {0x00};
-       memcpy(buf + 0,  uid, 4);
+       uint8_t buf[28] = {0x00};
+       num_to_bytes(cuid, 4, buf);
        num_to_bytes(nt, 4, buf + 4);
        memcpy(buf + 8,  par_list, 8);
        memcpy(buf + 16, ks_list, 8);
@@ -3070,6 +3068,9 @@ void RAMFUNC SniffMifare(uint8_t param) {
        // bit 1 - trigger from first reader 7-bit request
        LEDsoff();
 
+       // free eventually allocated BigBuf memory
+       BigBuf_free(); BigBuf_Clear_ext(false);
+       
        // init trace buffer
        clear_trace();
        set_tracing(TRUE);
@@ -3086,9 +3087,6 @@ void RAMFUNC SniffMifare(uint8_t param) {
 
        iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 
-       // free eventually allocated BigBuf memory
-       BigBuf_free();
-       
        // allocate the DMA buffer, used to stream samples from the FPGA
        uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
        uint8_t *data = dmaBuf;
Impressum, Datenschutz