fixed bug in ASKbiphaseDemod()

[proxmark3-svn] / armsrc / pcf7931.c

diff --git a/armsrc/pcf7931.c b/armsrc/pcf7931.c
index e4ba1da5e9a709d7660a33bc0c1da64b47c28736..9aa0d9bea7e9e5d56ec86dc3bab2d2667feed766 100644 (file)
--- a/armsrc/pcf7931.c
+++ b/armsrc/pcf7931.c
@@ -4,27 +4,26 @@
 #include "pcf7931.h"
 #include "util.h"
 #include "string.h"
 #include "pcf7931.h"
 #include "util.h"
 #include "string.h"

+#include "fpgaloader.h"

 
 #define T0_PCF 8 //period for the pcf7931 in us
 #define ALLOC 16
 
 
 #define T0_PCF 8 //period for the pcf7931 in us
 #define ALLOC 16
 

-int DemodPCF7931(uint8_t **outBlocks) {
-
-    uint8_t bits[256] = {0x00};
+size_t DemodPCF7931(uint8_t **outBlocks) {
+       uint8_t bits[256] = {0x00};

        uint8_t blocks[8][16];
        uint8_t blocks[8][16];

-    uint8_t *dest = BigBuf_get_addr();
+       uint8_t *dest = BigBuf_get_addr();

     
        int GraphTraceLen = BigBuf_max_traceLen();
     
        int GraphTraceLen = BigBuf_max_traceLen();

-       if (  GraphTraceLen > 18000 )
+       if (GraphTraceLen > 18000)

                GraphTraceLen = 18000;
        
                GraphTraceLen = 18000;
        

-       

        int i, j, lastval, bitidx, half_switch;
        int clock = 64;
        int tolerance = clock / 8;
        int pmc, block_done;
        int lc, warnings = 0;
        int i, j, lastval, bitidx, half_switch;
        int clock = 64;
        int tolerance = clock / 8;
        int pmc, block_done;
        int lc, warnings = 0;

-       int num_blocks = 0;
+       size_t num_blocks = 0;

        int lmin=128, lmax=128;
        uint8_t dir;
        //clear read buffer
        int lmin=128, lmax=128;
        uint8_t dir;
        //clear read buffer


@@ -39,17 +38,16 @@ int DemodPCF7931(uint8_t **outBlocks) {
        i = 2;
 
        /* Find first local max/min */
        i = 2;
 
        /* Find first local max/min */

-    if(dest[1] > dest[0]) {
+       if(dest[1] > dest[0]) {

                while(i < GraphTraceLen) {
                while(i < GraphTraceLen) {

-            if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
+                       if( !(dest[i] > dest[i-1]) && dest[i] > lmax)

                                break;
                        i++;
                }
                dir = 0;
                                break;
                        i++;
                }
                dir = 0;

-       }
-       else {
+       } else {

                while(i < GraphTraceLen) {
                while(i < GraphTraceLen) {

-            if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
+                       if( !(dest[i] < dest[i-1]) && dest[i] < lmin)

                                break;
                        i++;
                }
                                break;
                        i++;
                }


@@ -61,10 +59,8 @@ int DemodPCF7931(uint8_t **outBlocks) {
        pmc = 0;
        block_done = 0;
 
        pmc = 0;
        block_done = 0;
 

-       for (bitidx = 0; i < GraphTraceLen; i++)
-       {
-        if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
-               {
+       for (bitidx = 0; i < GraphTraceLen; i++) {
+               if ((dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin)) {

                        lc = i - lastval;
                        lastval = i;
 
                        lc = i - lastval;
                        lastval = i;
 


@@ -78,8 +74,7 @@ int DemodPCF7931(uint8_t **outBlocks) {
                                        lastval = i;
                                        pmc = 0;
                                        block_done = 1;
                                        lastval = i;
                                        pmc = 0;
                                        block_done = 1;

-                               }
-                               else {
+                               } else {

                                        pmc = i;
                                }
                        } else if (ABS(lc-clock/2) < tolerance) {
                                        pmc = i;
                                }
                        } else if (ABS(lc-clock/2) < tolerance) {


@@ -90,21 +85,18 @@ int DemodPCF7931(uint8_t **outBlocks) {
                                        lastval = i;
                                        pmc = 0;
                                        block_done = 1;
                                        lastval = i;
                                        pmc = 0;
                                        block_done = 1;

-                               }
-                               else if(half_switch == 1) {
-                    bits[bitidx++] = 0;
+                               } else if(half_switch == 1) {
+                                       bits[bitidx++] = 0;

                                        half_switch = 0;
                                }
                                else
                                        half_switch++;
                        } else if (ABS(lc-clock) < tolerance) {
                                // 64TO
                                        half_switch = 0;
                                }
                                else
                                        half_switch++;
                        } else if (ABS(lc-clock) < tolerance) {
                                // 64TO

-                bits[bitidx++] = 1;
+                               bits[bitidx++] = 1;

                        } else {
                                // Error
                        } else {
                                // Error

-                               warnings++;
-                               if (warnings > 10)
-                               {
+                               if (++warnings > 10) {

                                        Dbprintf("Error: too many detection errors, aborting.");
                                        return 0;
                                }
                                        Dbprintf("Error: too many detection errors, aborting.");
                                        return 0;
                                }


@@ -112,16 +104,17 @@ int DemodPCF7931(uint8_t **outBlocks) {
 
                        if(block_done == 1) {
                                if(bitidx == 128) {
 
                        if(block_done == 1) {
                                if(bitidx == 128) {

-                                       for(j=0; j<16; j++) {
-                        blocks[num_blocks][j] = 128*bits[j*8+7]+
-                                64*bits[j*8+6]+
-                                32*bits[j*8+5]+
-                                16*bits[j*8+4]+
-                                8*bits[j*8+3]+
-                                4*bits[j*8+2]+
-                                2*bits[j*8+1]+
-                                bits[j*8];
-                                               
+                                       for(j = 0; j < 16; ++j) {
+                                               blocks[num_blocks][j] =
+                                                       128 * bits[j*8 + 7]+
+                                                       64 * bits[j*8 + 6] +
+                                                       32 * bits[j*8 + 5] +
+                                                       16 * bits[j*8 + 4] +
+                                                       8 * bits[j*8 + 3] +
+                                                       4 * bits[j*8 + 2] +
+                                                       2 * bits[j*8 + 1] +
+                                                       bits[j*8]
+                                               ;

                                        }
                                        num_blocks++;
                                }
                                        }
                                        num_blocks++;
                                }


@@ -130,272 +123,349 @@ int DemodPCF7931(uint8_t **outBlocks) {
                                half_switch = 0;
                        }
                        if(i < GraphTraceLen)
                                half_switch = 0;
                        }
                        if(i < GraphTraceLen)

-                dir =(dest[i-1] > dest[i]) ? 0 : 1;
+                               dir = (dest[i-1] > dest[i]) ? 0 : 1;

                }
                if(bitidx==255)
                        bitidx=0;
                warnings = 0;
                if(num_blocks == 4) break;
        }
                }
                if(bitidx==255)
                        bitidx=0;
                warnings = 0;
                if(num_blocks == 4) break;
        }

-    memcpy(outBlocks, blocks, 16*num_blocks);
+       memcpy(outBlocks, blocks, 16 * num_blocks);

        return num_blocks;
 }
 
        return num_blocks;
 }
 

-int IsBlock0PCF7931(uint8_t *Block) {
-       // Assume RFU means 0 :)
-       if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
-               return 1;
-       if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
-               return 1;
-       return 0;
+bool IsBlock0PCF7931(uint8_t *block) {
+       // assuming all RFU bits are set to 0
+       // if PAC is enabled password is set to 0
+       if (block[7] == 0x01)
+       {
+               if (!memcmp(block, "\x00\x00\x00\x00\x00\x00\x00", 7) && !memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
+                       return true;
+       }
+       else if (block[7] == 0x00)
+       {
+               if (!memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
+                       return true;
+       }
+       return false;

 }
 
 }
 

-int IsBlock1PCF7931(uint8_t *Block) {
-       // Assume RFU means 0 :)
-       if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
-               if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
-                       return 1;
+bool IsBlock1PCF7931(uint8_t *block) {
+       // assuming all RFU bits are set to 0
+       if (block[10] == 0 && block[11] == 0 && block[12] == 0 && block[13] == 0)
+               if((block[14] & 0x7f) <= 9 && block[15] <= 9)
+                       return true;

 
 

-       return 0;
+       return false;

 }
 
 void ReadPCF7931() {
 }
 
 void ReadPCF7931() {

-       uint8_t Blocks[8][17];
-       uint8_t tmpBlocks[4][16];
-       int i, j, ind, ind2, n;
-       int num_blocks = 0;
-       int max_blocks = 8;
-       int ident = 0;
-       int error = 0;
-       int tries = 0;
+       int found_blocks = 0; // successfully read blocks
+       int max_blocks = 8;     // readable blocks      
+       uint8_t memory_blocks[8][17]; // PCF content
+       
+       uint8_t single_blocks[8][17]; // PFC blocks with unknown position
+       int single_blocks_cnt = 0;

 
 

-       memset(Blocks, 0, 8*17*sizeof(uint8_t));
+       size_t n = 0; // transmitted blocks     
+       uint8_t tmp_blocks[4][16]; // temporary read buffer
+       
+       uint8_t found_0_1 = 0; // flag: blocks 0 and 1 were found
+       int errors = 0; // error counter
+       int tries = 0; // tries counter
+       
+       memset(memory_blocks, 0, 8*17*sizeof(uint8_t));
+       memset(single_blocks, 0, 8*17*sizeof(uint8_t));
+       
+       int i = 0, j = 0;

 
        do {
 
        do {

-               memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
-               n = DemodPCF7931((uint8_t**)tmpBlocks);
+               i = 0;
+               
+               memset(tmp_blocks, 0, 4*16*sizeof(uint8_t));
+               n = DemodPCF7931((uint8_t**)tmp_blocks);

                if(!n)
                if(!n)

-                       error++;
-               if(error==10 && num_blocks == 0) {
+                       ++errors;
+               
+               // exit if no block is received 
+               if (errors >= 10 && found_blocks == 0 && single_blocks_cnt == 0) {

                        Dbprintf("Error, no tag or bad tag");
                        return;
                }
                        Dbprintf("Error, no tag or bad tag");
                        return;
                }

-               else if (tries==20 || error==10) {
+               // exit if too many errors during reading 
+               if (tries > 50 && (2*errors > tries)) {

                        Dbprintf("Error reading the tag");
                        Dbprintf("Here is the partial content");
                        goto end;
                }
                        Dbprintf("Error reading the tag");
                        Dbprintf("Here is the partial content");
                        goto end;
                }

-
-               for(i=0; i<n; i++)
-                       Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
-                                        tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
-                                       tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
-               if(!ident) {
-                       for(i=0; i<n; i++) {
-                               if(IsBlock0PCF7931(tmpBlocks[i])) {
-                                       // Found block 0 ?
-                                       if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
-                                               // Found block 1!
-                                               // \o/
-                                               ident = 1;
-                                               memcpy(Blocks[0], tmpBlocks[i], 16);
-                                               Blocks[0][ALLOC] = 1;
-                                               memcpy(Blocks[1], tmpBlocks[i+1], 16);
-                                               Blocks[1][ALLOC] = 1;
-                                               max_blocks = MAX((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
-                                               // Debug print
-                                               Dbprintf("(dbg) Max blocks: %d", max_blocks);
-                                               num_blocks = 2;
-                                               // Handle following blocks
-                                               for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
-                                                       if(j==n) j=0;
-                                                       if(j==i) break;
-                                                       memcpy(Blocks[ind2], tmpBlocks[j], 16);
-                                                       Blocks[ind2][ALLOC] = 1;
-                                               }
+               
+               // our logic breaks if we don't get at least two blocks
+               if (n < 2) {
+                       if (n == 0 || !memcmp(tmp_blocks[0], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16))
+                               continue;
+
+                       if (single_blocks_cnt < max_blocks) {
+                               for (i = 0; i < single_blocks_cnt; ++i) {
+                                       if (!memcmp(single_blocks[i], tmp_blocks[0], 16)) {
+                                               j = 1;

                                                break;
                                        }
                                }
                                                break;
                                        }
                                }

+                               if (j != 1) {
+                                       memcpy(single_blocks[single_blocks_cnt], tmp_blocks[0], 16);
+                                       single_blocks_cnt++;
+                               }
+                               j = 0;

                        }
                        }

-               }
-               else {
-                       for(i=0; i<n; i++) { // Look for identical block in known blocks
-                               if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
-                                       for(j=0; j<max_blocks; j++) {
-                                               if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
-                                                       // Found an identical block
-                                                       for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
-                                                               if(ind2 < 0)
-                                                                       ind2 = max_blocks;
-                                                               if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
-                                                                       // Dbprintf("Tmp %d -> Block %d", ind, ind2);
-                                                                       memcpy(Blocks[ind2], tmpBlocks[ind], 16);
-                                                                       Blocks[ind2][ALLOC] = 1;
-                                                                       num_blocks++;
-                                                                       if(num_blocks == max_blocks) goto end;
-                                                               }
-                                                       }
-                                                       for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
-                                                               if(ind2 > max_blocks)
-                                                                       ind2 = 0;
-                                                               if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
-                                                                       // Dbprintf("Tmp %d -> Block %d", ind, ind2);
-                                                                       memcpy(Blocks[ind2], tmpBlocks[ind], 16);
-                                                                       Blocks[ind2][ALLOC] = 1;
-                                                                       num_blocks++;
-                                                                       if(num_blocks == max_blocks) goto end;
-                                                               }
+                       ++tries;
+                       continue;
+               }
+               
+               Dbprintf("(dbg) got %d blocks (%d/%d found) (%d tries, %d errors)", n, found_blocks, (max_blocks == 0 ? found_blocks : max_blocks), tries, errors);
+
+               i = 0;
+               if(!found_0_1) {                        
+                       while (i < n - 1) {
+                               if (IsBlock0PCF7931(tmp_blocks[i]) && IsBlock1PCF7931(tmp_blocks[i+1])) {
+                                       found_0_1 = 1;
+                                       memcpy(memory_blocks[0], tmp_blocks[i], 16);
+                                       memcpy(memory_blocks[1], tmp_blocks[i+1], 16);
+                                       memory_blocks[0][ALLOC] = memory_blocks[1][ALLOC] = 1;
+                                       // block 1 tells how many blocks are going to be sent
+                                       max_blocks = MAX((memory_blocks[1][14] & 0x7f), memory_blocks[1][15]) + 1;
+                                       found_blocks = 2;
+                                       
+                                       Dbprintf("Found blocks 0 and 1. PCF is transmitting %d blocks.", max_blocks);
+                                       
+                                       // handle the following blocks
+                                       for (j = i + 2; j < n; ++j) {
+                                               memcpy(memory_blocks[found_blocks], tmp_blocks[j], 16);
+                                               memory_blocks[found_blocks][ALLOC] = 1;
+                                               ++found_blocks;
+                                       }
+                                       break;
+                               }
+                               ++i;
+                       }
+               } else {
+                       // Trying to re-order blocks
+                       // Look for identical block in memory blocks
+                       while (i < n-1) {
+                               // skip all zeroes blocks
+                               if (memcmp(tmp_blocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
+                                       for (j = 1; j < max_blocks - 1; ++j) {
+                                               if (!memcmp(tmp_blocks[i], memory_blocks[j], 16) && !memory_blocks[j+1][ALLOC]) {
+                                                       memcpy(memory_blocks[j+1], tmp_blocks[i+1], 16);
+                                                       memory_blocks[j+1][ALLOC] = 1;
+                                                       if (++found_blocks >= max_blocks) goto end;
+                                               }
+                                       }
+                               }
+                               if (memcmp(tmp_blocks[i+1], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
+                                       for (j = 0; j < max_blocks; ++j) {
+                                               if (!memcmp(tmp_blocks[i+1], memory_blocks[j], 16) && !memory_blocks[(j == 0 ? max_blocks : j) -1][ALLOC]) {
+                                                       if (j == 0) {
+                                                               memcpy(memory_blocks[max_blocks - 1], tmp_blocks[i], 16);
+                                                               memory_blocks[max_blocks - 1][ALLOC] = 1;
+                                                       } else {
+                                                               memcpy(memory_blocks[j-1], tmp_blocks[i], 16);
+                                                               memory_blocks[j-1][ALLOC] = 1;

                                                        }
                                                        }

+                                                       if (++found_blocks >= max_blocks) goto end;

                                                }
                                        }
                                }
                                                }
                                        }
                                }

+                               ++i;

                        }
                }
                        }
                }

-               tries++;
-               if (BUTTON_PRESS()) return;
-       } while (num_blocks != max_blocks);
+               ++tries;
+               if (BUTTON_PRESS()) {
+                       Dbprintf("Button pressed, stopping.");
+                       goto end;
+               }
+       }
+       while (found_blocks != max_blocks);
+

  end:
        Dbprintf("-----------------------------------------");
        Dbprintf("Memory content:");
        Dbprintf("-----------------------------------------");
  end:
        Dbprintf("-----------------------------------------");
        Dbprintf("Memory content:");
        Dbprintf("-----------------------------------------");

-       for(i=0; i<max_blocks; i++) {
-               if(Blocks[i][ALLOC]==1)
-                       Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
-                                        Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
-                                       Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
+       for (i = 0; i < max_blocks; ++i) {
+               if (memory_blocks[i][ALLOC])
+                       print_result("Block", memory_blocks[i], 16);

                else
                        Dbprintf("<missing block %d>", i);
        }
        Dbprintf("-----------------------------------------");
                else
                        Dbprintf("<missing block %d>", i);
        }
        Dbprintf("-----------------------------------------");

-
+       
+       if (found_blocks < max_blocks) {
+               Dbprintf("-----------------------------------------");
+               Dbprintf("Blocks with unknown position:");
+               Dbprintf("-----------------------------------------");
+               for (i = 0; i < single_blocks_cnt; ++i)
+                       print_result("Block", single_blocks[i], 16);
+               
+               Dbprintf("-----------------------------------------");
+       }

        cmd_send(CMD_ACK,0,0,0,0,0);
 }
 
        cmd_send(CMD_ACK,0,0,0,0,0);
 }
 

-
-/* Write on a byte of a PCF7931 tag
- * @param address : address of the block to write
-   @param byte : address of the byte to write
-    @param data : data to write
- */
-void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
-{
-
+static void RealWritePCF7931(uint8_t *pass, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data) {

        uint32_t tab[1024]={0}; // data times frame
        uint32_t u = 0;
        uint8_t parity = 0;
        bool comp = 0;
 
        //BUILD OF THE DATA FRAME
        uint32_t tab[1024]={0}; // data times frame
        uint32_t u = 0;
        uint8_t parity = 0;
        bool comp = 0;
 
        //BUILD OF THE DATA FRAME

-

        //alimentation of the tag (time for initializing)
        AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
        //alimentation of the tag (time for initializing)
        AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);

-
-       //PMC
-       Dbprintf("Initialization delay : %d us", init_delay);

        AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
        AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);

-
-       Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
-

        //password indication bit
        AddBitPCF7931(1, tab, l, p);
        //password indication bit
        AddBitPCF7931(1, tab, l, p);

-
-
-       //password (on 56 bits)
-       Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
-       AddBytePCF7931(pass1, tab, l, p);
-       AddBytePCF7931(pass2, tab, l, p);
-       AddBytePCF7931(pass3, tab, l, p);
-       AddBytePCF7931(pass4, tab, l, p);
-       AddBytePCF7931(pass5, tab, l, p);
-       AddBytePCF7931(pass6, tab, l, p);
-       AddBytePCF7931(pass7, tab, l, p);
-
+       // password (on 56 bits)
+       AddBytePCF7931(pass[0], tab, l, p);
+       AddBytePCF7931(pass[1], tab, l, p);
+       AddBytePCF7931(pass[2], tab, l, p);
+       AddBytePCF7931(pass[3], tab, l, p);
+       AddBytePCF7931(pass[4], tab, l, p);
+       AddBytePCF7931(pass[5], tab, l, p);
+       AddBytePCF7931(pass[6], tab, l, p);

        //programming mode (0 or 1)
        AddBitPCF7931(0, tab, l, p);
        //programming mode (0 or 1)
        AddBitPCF7931(0, tab, l, p);

-
+       

        //block adress on 6 bits
        //block adress on 6 bits

-       Dbprintf("Block address : %02x", address);
-       for (u=0; u<6; u++)
-       {
-               if (address&(1<<u)) {   // bit 1
-                        parity++;
+       for (u = 0; u < 6; ++u) {
+               if (address & (1 << u)) {       // bit 1
+                        ++parity;

                         AddBitPCF7931(1, tab, l, p);
                         AddBitPCF7931(1, tab, l, p);

-               } else{                                 // bit 0
+               } else {                                        // bit 0

                         AddBitPCF7931(0, tab, l, p);
                }
        }
                         AddBitPCF7931(0, tab, l, p);
                }
        }

-
+       

        //byte address on 4 bits
        //byte address on 4 bits

-       Dbprintf("Byte address : %02x", byte);
-       for (u=0; u<4; u++)
+       for (u = 0; u < 4; ++u)

        {
        {

-               if (byte&(1<<u)) {      // bit 1
+               if (byte & (1 << u)) {  // bit 1

                         parity++;
                         AddBitPCF7931(1, tab, l, p);
                         parity++;
                         AddBitPCF7931(1, tab, l, p);

-               } else{                         // bit 0
-                        AddBitPCF7931(0, tab, l, p);

                }
                }

+               else                            // bit 0
+                        AddBitPCF7931(0, tab, l, p);

        }
        }

-
+       

        //data on 8 bits
        //data on 8 bits

-       Dbprintf("Data : %02x", data);

        for (u=0; u<8; u++)
        {
                if (data&(1<<u)) {      // bit 1
                         parity++;
                         AddBitPCF7931(1, tab, l, p);
        for (u=0; u<8; u++)
        {
                if (data&(1<<u)) {      // bit 1
                         parity++;
                         AddBitPCF7931(1, tab, l, p);

-               } else{                         //bit 0
+               } 
+               else                            //bit 0

                         AddBitPCF7931(0, tab, l, p);
                         AddBitPCF7931(0, tab, l, p);

-               }

        }
 
        }
 

-

        //parity bit
        //parity bit

-       if((parity%2)==0){
+       if ((parity % 2) == 0)

                AddBitPCF7931(0, tab, l, p); //even parity
                AddBitPCF7931(0, tab, l, p); //even parity

-       }else{
+       else

                AddBitPCF7931(1, tab, l, p);//odd parity
                AddBitPCF7931(1, tab, l, p);//odd parity

-       }

 
        //time access memory
        AddPatternPCF7931(5120+2680, 0, 0, tab);
 
        //conversion of the scale time
 
        //time access memory
        AddPatternPCF7931(5120+2680, 0, 0, tab);
 
        //conversion of the scale time

-       for(u=0;u<500;u++){
-               tab[u]=(tab[u] * 3)/2;
-       }
-
+       for (u = 0; u < 500; ++u)
+               tab[u] = (tab[u] * 3) / 2;

 
        //compennsation of the counter reload
 
        //compennsation of the counter reload

-       while (!comp){
+       while (!comp) {

                comp = 1;
                comp = 1;

-               for(u=0;tab[u]!=0;u++){
-                       if(tab[u] > 0xFFFF){
+               for (u = 0; tab[u] != 0; ++u)
+                       if(tab[u] > 0xFFFF) {

                          tab[u] -= 0xFFFF;
                          comp = 0;
                        }
                          tab[u] -= 0xFFFF;
                          comp = 0;
                        }

-               }

        }
 
        SendCmdPCF7931(tab);
 }
 
        }
 
        SendCmdPCF7931(tab);
 }
 

+void BruteForcePCF7931(uint64_t password, uint8_t tries, uint16_t init_delay, int32_t l, int32_t p) {
+       uint8_t i = 0;
+       uint8_t pass_array[7];
+       
+       while (password < 0x00FFFFFFFFFFFFFF) {
+               if (BUTTON_PRESS()) {
+                       Dbprintf("Button pressed, stopping bruteforce ...");
+                       return;
+               }
+               
+               pass_array[0] = password & 0xFF;
+               pass_array[1] = (password >> 8) & 0xFF;
+               pass_array[2] = (password >> 16) & 0xFF;
+               pass_array[3] = (password >> 24) & 0xFF;
+               pass_array[4] = (password >> 32) & 0xFF;
+               pass_array[5] = (password >> 40) & 0xFF;
+               pass_array[6] = (password >> 48) & 0xFF;
+
+               Dbprintf("Trying: %02x %02x %02x %02x %02x %02x %02x ...",
+                       pass_array[0],
+                       pass_array[1],
+                       pass_array[2],
+                       pass_array[3],
+                       pass_array[4],
+                       pass_array[5],
+                       pass_array[6]);
+               
+               for (i = 0; i < tries; ++i)
+                       RealWritePCF7931
+                       (
+                               pass_array,
+                               init_delay,
+                               l,
+                               p,
+                               0,
+                               7,
+                               0x01
+                       );
+       
+               ++password;     
+       }
+}
+
+/* Write on a byte of a PCF7931 tag
+ * @param address : address of the block to write
+   @param byte : address of the byte to write
+    @param data : data to write
+ */
+void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data) {
+       Dbprintf("Initialization delay : %d us", init_delay);
+       Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
+       Dbprintf("Password (LSB first on each byte): %02x %02x %02x %02x %02x %02x %02x", pass1, pass2, pass3, pass4, pass5, pass6, pass7);
+       Dbprintf("Block address : %02x", address);
+       Dbprintf("Byte address : %02x", byte);
+       Dbprintf("Data : %02x", data);
+       
+       uint8_t password[7] = {pass1, pass2, pass3, pass4, pass5, pass6, pass7};
+       
+       RealWritePCF7931 (password, init_delay, l, p, address, byte, data);
+}
+

 
 
 /* Send a trame to a PCF7931 tags
  * @param tab : array of the data frame
  */
 
 
 
 /* Send a trame to a PCF7931 tags
  * @param tab : array of the data frame
  */
 

-void SendCmdPCF7931(uint32_t * tab){
+void SendCmdPCF7931(uint32_t * tab) {

        uint16_t u=0;
        uint16_t tempo=0;
 
        uint16_t u=0;
        uint16_t tempo=0;
 

-       Dbprintf("SENDING DATA FRAME...");
+       Dbprintf("Sending data frame ...");

 
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
 
        FpgaDownloadAndGo(FPGA_BITSTREAM_LF);

-

        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz

-

        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
 
        LED_A_ON();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
 
        LED_A_ON();


@@ -412,41 +482,30 @@ void SendCmdPCF7931(uint32_t * tab){
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
        AT91C_BASE_TCB->TCB_BCR = 1;
 
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
        AT91C_BASE_TCB->TCB_BCR = 1;
 

-

        tempo = AT91C_BASE_TC0->TC_CV;
        tempo = AT91C_BASE_TC0->TC_CV;

-       for(u=0;tab[u]!= 0;u+=3){
-
-
+       for (u = 0; tab[u] !=  0; u += 3) {

                // modulate antenna
                HIGH(GPIO_SSC_DOUT);
                // modulate antenna
                HIGH(GPIO_SSC_DOUT);

-               while(tempo !=  tab[u]){
+               while(tempo !=  tab[u])

                        tempo = AT91C_BASE_TC0->TC_CV;
                        tempo = AT91C_BASE_TC0->TC_CV;

-               }
-
+                       

                // stop modulating antenna
                LOW(GPIO_SSC_DOUT);
                // stop modulating antenna
                LOW(GPIO_SSC_DOUT);

-               while(tempo !=  tab[u+1]){
+               while(tempo !=  tab[u+1])

                        tempo = AT91C_BASE_TC0->TC_CV;
                        tempo = AT91C_BASE_TC0->TC_CV;

-               }
-

 
                // modulate antenna
                HIGH(GPIO_SSC_DOUT);
 
                // modulate antenna
                HIGH(GPIO_SSC_DOUT);

-               while(tempo !=  tab[u+2]){
+               while(tempo !=  tab[u+2])

                        tempo = AT91C_BASE_TC0->TC_CV;
                        tempo = AT91C_BASE_TC0->TC_CV;

-               }
-
-

        }
 
        LED_A_OFF();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        SpinDelay(200);
 
        }
 
        LED_A_OFF();
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
        SpinDelay(200);
 

-

        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
        AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable

-       DbpString("FINISH !");
-       DbpString("(Could be usefull to send the same trame many times)");
+       DbpString("Data frame sent (multiple sends may be needed)");

        LED(0xFFFF, 1000);
 }
 
        LED(0xFFFF, 1000);
 }
 


@@ -457,15 +516,12 @@ void SendCmdPCF7931(uint32_t * tab){
  * @param l : offset on low pulse width
  * @param p : offset on low pulse positioning
  */
  * @param l : offset on low pulse width
  * @param p : offset on low pulse positioning
  */

-
-bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
-
+bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p) {

        uint32_t u;
        uint32_t u;

-       for (u=0; u<8; u++)
-       {
-               if (byte&(1<<u)) {      //bit à 1
+       for (u = 0; u < 8; ++u) {
+               if (byte & (1 << u)) {  //bit is 1

                        if(AddBitPCF7931(1, tab, l, p)==1)return 1;
                        if(AddBitPCF7931(1, tab, l, p)==1)return 1;

-               } else { //bit à 0
+               } else { //bit is 0

                        if(AddBitPCF7931(0, tab, l, p)==1)return 1;
                }
        }
                        if(AddBitPCF7931(0, tab, l, p)==1)return 1;
                }
        }


@@ -479,29 +535,27 @@ bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
  * @param l : offset on low pulse width
  * @param p : offset on low pulse positioning
  */
  * @param l : offset on low pulse width
  * @param p : offset on low pulse positioning
  */

-bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
+bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p) {

        uint8_t u = 0;
 
        uint8_t u = 0;
 

-       for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
-       
+       for (u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array

 
 

-       if(b==1){       //add a bit 1
-               if(u==0) tab[u] = 34*T0_PCF+p;
-               else     tab[u] = 34*T0_PCF+tab[u-1]+p;
+       if (b == 1) {   //add a bit 1
+               if (u == 0)     tab[u] = 34 * T0_PCF + p;
+               else            tab[u] = 34 * T0_PCF + tab[u-1] + p;

 
 

-               tab[u+1] = 6*T0_PCF+tab[u]+l;
-               tab[u+2] = 88*T0_PCF+tab[u+1]-l-p;
+               tab[u+1] = 6 * T0_PCF+tab[u] + l;
+               tab[u+2] = 88 * T0_PCF+tab[u + 1] - l - p;

                return 0;
                return 0;

-       }else{          //add a bit 0
+       } else {                //add a bit 0

 
 

-               if(u==0) tab[u] = 98*T0_PCF+p;
-               else     tab[u] = 98*T0_PCF+tab[u-1]+p;
+               if (u == 0)     tab[u] = 98 * T0_PCF + p;
+               else            tab[u] = 98 * T0_PCF + tab[u-1] + p;

 
 

-               tab[u+1] = 6*T0_PCF+tab[u]+l;
-               tab[u+2] = 24*T0_PCF+tab[u+1]-l-p;
+               tab[u + 1] = 6 * T0_PCF + tab[u] + l;
+               tab[u + 2] = 24 * T0_PCF + tab[u + 1] - l - p;

                return 0;
        }
                return 0;
        }

-

        
        return 1;
 }
        
        return 1;
 }


@@ -512,15 +566,15 @@ bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
  * @param c : delay of the last high pulse
  * @param tab : array of the data frame
  */
  * @param c : delay of the last high pulse
  * @param tab : array of the data frame
  */

-bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
+bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab) {

        uint32_t u = 0;
        uint32_t u = 0;

-       for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
+       for(u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array

 
 

-       if(u==0) tab[u] = a;
-       else tab[u] = a + tab[u-1];
+       if (u == 0)     tab[u] = a;
+       else            tab[u] = a + tab[u - 1];

 
 

-       tab[u+1] = b+tab[u];
-       tab[u+2] = c+tab[u+1];
+       tab[u + 1] = b + tab[u];
+       tab[u + 2] = c + tab[u + 1];

 
        return 0;
 }
 
        return 0;
 }