]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/iso14443a.c
ADD: @marshmellow42's decrypt crypto-1 method,
[proxmark3-svn] / armsrc / iso14443a.c
index 862594e9c483293a7824184cd6385d8921f49788..492e2d6dc13598db95d213f76fa59aa5f5864047 100644 (file)
@@ -947,10 +947,10 @@ 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
@@ -1047,7 +1047,7 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
        response3a[0] = sak & 0xFB;
        ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 
-       uint8_t response5[] = { 0x01, 0x01, 0x01, 0x01 }; // Very random tag nonce
+       uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
        uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS: 
        // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present, 
        // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
@@ -1151,9 +1151,9 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                } else if(receivedCmd[0] == 0x30) {     // Received a (plain) READ
                        uint8_t block = receivedCmd[1];
                        if ( tagType == 7 ) {
-                               uint8_t start = 4 * block;
+                               uint16_t start = 4 * block;
                                
-                               if ( block < 4 ) {
+                               /*if ( block < 4 ) {
                                    //NTAG 215
                                        uint8_t blockdata[50] = {
                                        data[0],data[1],data[2], 0x88 ^ data[0] ^ data[1] ^ data[2],
@@ -1167,12 +1167,12 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
                                        0x00,0x00};
                                        AppendCrc14443a(blockdata+start, 16);
                                        EmSendCmdEx( blockdata+start, MAX_MIFARE_FRAME_SIZE, false);
-                               } else {        
+                               } else {*/      
                                        uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
                                        emlGetMemBt( emdata, start, 16);
                                        AppendCrc14443a(emdata, 16);
                                        EmSendCmdEx(emdata, sizeof(emdata), false);                             
-                               }
+                               //}
                                p_response = NULL;
                                
                        } else {                        
@@ -1299,7 +1299,8 @@ 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 {
@@ -1417,9 +1418,11 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
        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);
+       }
 }
 
 
@@ -2194,7 +2197,7 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
        nttmp1 = nt1;
        nttmp2 = nt2;
        
-       for (i = 1; i < 32768; i++) {
+       for (i = 1; i < 0xFFFF; i++) {
                nttmp1 = prng_successor(nttmp1, 1);
                if (nttmp1 == nt2) return i;
                nttmp2 = prng_successor(nttmp2, 1);
@@ -2244,19 +2247,20 @@ void ReaderMifare(bool first_try)
        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 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;
 
        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; //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 {
@@ -2271,8 +2275,17 @@ void ReaderMifare(bool first_try)
        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++) {
                
@@ -2285,21 +2298,60 @@ 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();
 
-               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)) {
@@ -2317,19 +2369,37 @@ void ReaderMifare(bool first_try)
                        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;
                        }
                }
@@ -2340,6 +2410,7 @@ 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++;
                        }
@@ -2353,6 +2424,9 @@ 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;
                }
@@ -2360,12 +2434,10 @@ 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
                        }
 
@@ -2401,8 +2473,17 @@ void ReaderMifare(bool first_try)
 
        mf_nr_ar[3] &= 0x1F;
        
-       byte_t buf[28] = {0x00};
+       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);
        num_to_bytes(nt, 4, buf + 4);
        memcpy(buf + 8,  par_list, 8);
@@ -2418,8 +2499,7 @@ void ReaderMifare(bool first_try)
        set_tracing(FALSE);
 }
 
-
- /*
+/**
   *MIFARE 1K simulate.
   *
   *@param flags :
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