Update README.md

[proxmark3-svn] / armsrc / legicrf.c

diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c
index 68d4e7600356df9f6520cd9809deb14c6ebadde6..5ad1fdf1f0c31895328f089847186405c2fec2cd 100644 (file)
--- a/armsrc/legicrf.c
+++ b/armsrc/legicrf.c
@@ -81,38 +81,39 @@ static void setup_timer(void)
 /* Generate Keystream */
 static uint32_t get_key_stream(int skip, int count)
 {
-  uint32_t key=0; int i;
-
-  /* Use int to enlarge timer tc to 32bit */
-  legic_prng_bc += prng_timer->TC_CV;
-  prng_timer->TC_CCR = AT91C_TC_SWTRG;
-
-  /* If skip == -1, forward prng time based */
-  if(skip == -1) {
-     i  = (legic_prng_bc+SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */
-     i -= legic_prng_count(); /* substract cycles of finished frames */
-     i -= count; /* substract current frame length, rewidn to bedinning */
-     legic_prng_forward(i);
-  } else {
-     legic_prng_forward(skip);
-  }
+       uint32_t key=0; int i;
+
+       /* Use int to enlarge timer tc to 32bit */
+       legic_prng_bc += prng_timer->TC_CV;
+       prng_timer->TC_CCR = AT91C_TC_SWTRG;
+
+       /* If skip == -1, forward prng time based */
+       if(skip == -1) {
+               i  = (legic_prng_bc+SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */
+               i -= legic_prng_count(); /* substract cycles of finished frames */
+               i -= count; /* substract current frame length, rewidn to bedinning */
+               legic_prng_forward(i);
+       } else {
+               legic_prng_forward(skip);
+       }
 
-  /* Write Time Data into LOG */
-  uint8_t *BigBuf = BigBuf_get_addr();
-  if(count == 6) { i = -1; } else { i = legic_read_count; }
-  BigBuf[OFFSET_LOG+128+i] = legic_prng_count();
-  BigBuf[OFFSET_LOG+256+i*4]   = (legic_prng_bc >> 0) & 0xff;
-  BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff;
-  BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff;
-  BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff;
-  BigBuf[OFFSET_LOG+384+i] = count;
-
-  /* Generate KeyStream */
-  for(i=0; i<count; i++) {
-    key |= legic_prng_get_bit() << i;
-    legic_prng_forward(1);
-  }
-  return key;
+       /* Write Time Data into LOG */
+       uint8_t *BigBuf = BigBuf_get_addr();
+       i = (count == 6) ? -1 : legic_read_count;
+
+       BigBuf[OFFSET_LOG+128+i] = legic_prng_count();
+       BigBuf[OFFSET_LOG+256+i*4]   = (legic_prng_bc >> 0) & 0xff;
+       BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff;
+       BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff;
+       BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff;
+       BigBuf[OFFSET_LOG+384+i] = count;
+
+       /* Generate KeyStream */
+       for(i=0; i<count; i++) {
+               key |= legic_prng_get_bit() << i;
+               legic_prng_forward(1);
+       }
+       return key;
 }
 
 /* Send a frame in tag mode, the FPGA must have been set up by
@@ -145,11 +146,11 @@ static void frame_send_tag(uint16_t response, int bits, int crypt)
       int nextbit = timer->TC_CV + TAG_TIME_BIT;
       int bit = response & 1;
       response = response >> 1;
-      if(bit) {
+      if(bit)
          AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
-      } else {
+      else
          AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
-      }
+      
       while(timer->TC_CV < nextbit) ;
    }
    AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
@@ -171,11 +172,11 @@ static void frame_send_rwd(uint32_t data, int bits)
                int bit = data & 1;
                data = data >> 1;
 
-               if(bit ^ legic_prng_get_bit()) {
+               if(bit ^ legic_prng_get_bit())
                        bit_end = starttime + RWD_TIME_1;
-               } else {
+               else
                        bit_end = starttime + RWD_TIME_0;
-               }
+               
 
                /* RWD_TIME_PAUSE time off, then some time on, so that the complete bit time is
                 * RWD_TIME_x, where x is the bit to be transmitted */
@@ -184,16 +185,15 @@ static void frame_send_rwd(uint32_t data, int bits)
                AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
                legic_prng_forward(1); /* bit duration is longest. use this time to forward the lfsr */
 
-               while(timer->TC_CV < bit_end) ;
+               while(timer->TC_CV < bit_end);
        }
 
-       {
-               /* One final pause to mark the end of the frame */
-               int pause_end = timer->TC_CV + RWD_TIME_PAUSE;
-               AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
-               while(timer->TC_CV < pause_end) ;
-               AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
-       }
+       /* One final pause to mark the end of the frame */
+       int pause_end = timer->TC_CV + RWD_TIME_PAUSE;
+       AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
+       while(timer->TC_CV < pause_end) ;
+       AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
+
 
        /* Reset the timer, to measure time until the start of the tag frame */
        timer->TC_CCR = AT91C_TC_SWTRG;
@@ -239,8 +239,7 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt)
      * since we cannot compute it on the fly while reading */
        legic_prng_forward(2);
 
-       if(crypt)
-       {
+       if(crypt) {
                for(i=0; i<bits; i++) {
                        data |= legic_prng_get_bit() << i;
                        legic_prng_forward(1);
@@ -277,10 +276,10 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt)
 
 static void frame_append_bit(struct legic_frame * const f, int bit)
 {
-   if(f->bits >= 31) {
+   if (f->bits >= 31)
        return; /* Overflow, won't happen */
-   }
-   f->data |= (bit<<f->bits);
+  
+   f->data |= (bit << f->bits);
    f->bits++;
 }
 
@@ -355,9 +354,11 @@ int legic_read_byte(int byte_index, int cmd_sz) {
        frame_receive_rwd(&current_frame, 12, 1);
 
        byte = current_frame.data & 0xff;
+
        if( LegicCRC(byte_index, byte, cmd_sz) != (current_frame.data >> 8) ) {
                Dbprintf("!!! crc mismatch: expected %x but got %x !!!", 
-           LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), current_frame.data >> 8);
+                       LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz),
+                       current_frame.data >> 8);
                return -1;
        }
 
@@ -373,9 +374,8 @@ int legic_read_byte(int byte_index, int cmd_sz) {
  */
 int legic_write_byte(int byte, int addr, int addr_sz) {
     //do not write UID, CRC, DCF
-    if(addr <= 0x06) { 
+    if(addr <= 0x06)
                return 0;
-       }
 
        //== send write command ==============================
        crc_clear(&legic_crc);
@@ -448,12 +448,11 @@ int LegicRfReader(int offset, int bytes) {
                        Dbprintf("Unknown card format: %x",tag_type);
                        return -1;
        }
-       if(bytes == -1) {
+       if(bytes == -1)
                bytes = card_sz;
-       }
-       if(bytes+offset >= card_sz) {
+
+       if(bytes+offset >= card_sz)
                bytes = card_sz-offset;
-       }
 
        perform_setup_phase_rwd(SESSION_IV);