Fix for swapped parity when using lf_bulk_program.lua (#591)

[proxmark3-svn] / armsrc / iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 6703cc65c7286cd041e19fda40b29e02604e16a2..a8273e5e1bc1fda9d4ea358d15258ab49f070611 100644 (file)
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -2151,9 +2151,7 @@ void ReaderMifare(bool first_try)
        uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
        uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
 
-       if (first_try) { 
-               iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
-       }
+       iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
        
        // free eventually allocated BigBuf memory. We want all for tracing.
        BigBuf_free();
@@ -2161,9 +2159,9 @@ void ReaderMifare(bool first_try)
        clear_trace();
        set_tracing(true);
 
-       byte_t nt_diff = 0;
+       uint8_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;
+       static uint8_t par_low = 0;
        bool led_on = true;
        uint8_t uid[10]  ={0};
        uint32_t cuid;
@@ -2171,11 +2169,11 @@ void ReaderMifare(bool first_try)
        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};
+       uint8_t par_list[8] = {0x00};
+       uint8_t ks_list[8] = {0x00};
 
        #define PRNG_SEQUENCE_LENGTH  (1 << 16);
-       static uint32_t sync_time;
+       uint32_t sync_time = GetCountSspClk() & 0xfffffff8;
        static int32_t sync_cycles;
        int catch_up_cycles = 0;
        int last_catch_up = 0;
@@ -2185,10 +2183,9 @@ void ReaderMifare(bool first_try)
 
        if (first_try) { 
                mf_nr_ar3 = 0;
-               sync_time = GetCountSspClk() & 0xfffffff8;
+               par[0] = par_low = 0;
                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;
-               par[0] = 0;
        }
        else {
                // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
@@ -2204,6 +2201,7 @@ void ReaderMifare(bool first_try)
 
        #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 SYNC_TIME_BUFFER                16              // if there is only SYNC_TIME_BUFFER left before next planned sync, wait for next PRNG cycle
        #define NUM_DEBUG_INFOS                 8               // per strategy
        #define MAX_STRATEGY                    3
        uint16_t unexpected_random = 0;
@@ -2253,8 +2251,8 @@ void ReaderMifare(bool first_try)
                        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) {
+                       // if we missed the sync time already or are about to miss it, advance to the next nonce repeat
+                       while(sync_time < GetCountSspClk() + SYNC_TIME_BUFFER) {
                                elapsed_prng_sequences++;
                                sync_time = (sync_time & 0xfffffff8) + sync_cycles;
                        }
@@ -2410,14 +2408,14 @@ void ReaderMifare(bool first_try)
                }
        }
        
-       byte_t buf[28];
+       uint8_t buf[32];
        memcpy(buf + 0,  uid, 4);
        num_to_bytes(nt, 4, buf + 4);
        memcpy(buf + 8,  par_list, 8);
        memcpy(buf + 16, ks_list, 8);
-       memcpy(buf + 24, mf_nr_ar, 4);
+       memcpy(buf + 24, mf_nr_ar, 8);
                
-       cmd_send(CMD_ACK, isOK, 0, 0, buf, 28);
+       cmd_send(CMD_ACK, isOK, 0, 0, buf, 32);
 
        // Thats it...
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);