hf mf mifare:

* prevent WDT crash on repeated tries
* comes with faster execution as side effect
* use uint8_t instead of byte_t
* populate ar instead of (correctly) assuming that it is zero
* remove the "will take a few seconds longer" message because it is no longer true

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);

diff --git a/client/mifarehost.c b/client/mifarehost.c
index 2bd21077e9b6ba5cd23c276445cccc809f3dbf04..471fbc4231745dc4a436995ae26e284d05e86488 100644 (file)
--- a/client/mifarehost.c
+++ b/client/mifarehost.c
@@ -73,13 +73,12 @@ static uint32_t intersection(uint64_t *list1, uint64_t *list2)
 \r
 \r
 // Darkside attack (hf mf mifare)\r
-static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {\r
+static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint32_t ar, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {\r
        struct Crypto1State *states;\r
-       uint32_t i, pos, rr; //nr_diff;\r
+       uint32_t i, pos;\r
        uint8_t bt, ks3x[8], par[8][8];\r
        uint64_t key_recovered;\r
-       static uint64_t *keylist;\r
-       rr = 0;\r
+       uint64_t *keylist;\r
 \r
        // Reset the last three significant bits of the reader nonce\r
        nr &= 0xffffff1f;\r
@@ -92,7 +91,7 @@ static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_i
                }\r
        }\r
 \r
-       states = lfsr_common_prefix(nr, rr, ks3x, par, (par_info == 0));\r
+       states = lfsr_common_prefix(nr, ar, ks3x, par, (par_info == 0));\r
 \r
        if (states == NULL) {\r
                *keys = NULL;\r
@@ -116,7 +115,7 @@ static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint64_t par_i
 int mfDarkside(uint64_t *key)\r
 {\r
        uint32_t uid = 0;\r
-       uint32_t nt = 0, nr = 0;\r
+       uint32_t nt = 0, nr = 0, ar = 0;\r
        uint64_t par_list = 0, ks_list = 0;\r
        uint64_t *keylist = NULL, *last_keylist = NULL;\r
        uint32_t keycount = 0;\r
@@ -159,18 +158,18 @@ int mfDarkside(uint64_t *key)
                                nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);\r
                                par_list = bytes_to_num(resp.d.asBytes +  8, 8);\r
                                ks_list = bytes_to_num(resp.d.asBytes +  16, 8);\r
-                               nr = bytes_to_num(resp.d.asBytes + 24, 4);\r
+                               nr = (uint32_t)bytes_to_num(resp.d.asBytes + 24, 4);\r
+                               ar = (uint32_t)bytes_to_num(resp.d.asBytes + 28, 4);\r
                                break;\r
                        }\r
                }\r
 \r
                if (par_list == 0 && c.arg[0] == true) {\r
                        PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");\r
-                       PrintAndLog("Attack will take a few seconds longer because we need two consecutive successful runs.");\r
                }\r
                c.arg[0] = false;\r
 \r
-               keycount = nonce2key(uid, nt, nr, par_list, ks_list, &keylist);\r
+               keycount = nonce2key(uid, nt, nr, ar, par_list, ks_list, &keylist);\r
 \r
                if (keycount == 0) {\r
                        PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);\r