]> git.zerfleddert.de Git - proxmark3-svn/blobdiff - armsrc/pcf7931.c
PCF7931: Print found single/consecutive block(s), fixes to block 1 check
[proxmark3-svn] / armsrc / pcf7931.c
index 16b7912dbc672a9e407441cf81b8f503615ca88f..147f6fb8d215441b47c1447455c4317774b612c2 100644 (file)
@@ -4,6 +4,7 @@
 #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
@@ -12,11 +13,11 @@ size_t DemodPCF7931(uint8_t **outBlocks) {
        uint8_t bits[256] = {0x00};
        uint8_t blocks[8][16];
        uint8_t *dest = BigBuf_get_addr();
-    
+
        int GraphTraceLen = BigBuf_max_traceLen();
        if (GraphTraceLen > 18000)
                GraphTraceLen = 18000;
-       
+
        int i, j, lastval, bitidx, half_switch;
        int clock = 64;
        int tolerance = clock / 8;
@@ -106,7 +107,7 @@ size_t DemodPCF7931(uint8_t **outBlocks) {
                                        for(j = 0; j < 16; ++j) {
                                                blocks[num_blocks][j] =
                                                        128 * bits[j*8 + 7]+
-                                                       64 * bits[j*8 + 6] +
+                                                                                       64 * bits[j*8 + 6] +
                                                        32 * bits[j*8 + 5] +
                                                        16 * bits[j*8 + 4] +
                                                        8 * bits[j*8 + 3] +
@@ -151,8 +152,14 @@ bool IsBlock0PCF7931(uint8_t *block) {
 
 bool IsBlock1PCF7931(uint8_t *block) {
        // assuming all RFU bits are set to 0
+
+       uint8_t rb1 = block[14] & 0x80;
+       uint8_t rfb = block[14] & 0x7f;
+       uint8_t rlb = block[15];
+
        if (block[10] == 0 && block[11] == 0 && block[12] == 0 && block[13] == 0)
-               if((block[14] & 0x7f) <= 9 && block[15] <= 9)
+               // block 1 is sent only if (RLB >= 1 && RFB <= 1) or RB1 enabled
+               if(rfb <= rlb && rfb <= 9 && rlb <= 9 && ((rfb <= 1 && rlb >= 1) || rb1))
                        return true;
 
        return false;
@@ -160,49 +167,52 @@ bool IsBlock1PCF7931(uint8_t *block) {
 
 void ReadPCF7931() {
        int found_blocks = 0; // successfully read blocks
-       int max_blocks = 8;     // readable 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;
 
-       size_t n = 0; // transmitted blocks     
+       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 {
                i = 0;
-               
+
                memset(tmp_blocks, 0, 4*16*sizeof(uint8_t));
                n = DemodPCF7931((uint8_t**)tmp_blocks);
                if(!n)
                        ++errors;
-               
-               // exit if no block is received 
+
+               // exit if no block is received
                if (errors >= 10 && found_blocks == 0 && single_blocks_cnt == 0) {
                        Dbprintf("Error, no tag or bad tag");
                        return;
                }
-               // exit if too many errors during reading 
+
+               // 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;
                }
-               
+
                // our logic breaks if we don't get at least two blocks
                if (n < 2) {
+                       // skip if all 0s block or no blocks
                        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;
 
+                       // add block to single blocks list
                        if (single_blocks_cnt < max_blocks) {
                                for (i = 0; i < single_blocks_cnt; ++i) {
                                        if (!memcmp(single_blocks[i], tmp_blocks[0], 16)) {
@@ -212,18 +222,23 @@ void ReadPCF7931() {
                                }
                                if (j != 1) {
                                        memcpy(single_blocks[single_blocks_cnt], tmp_blocks[0], 16);
+                                       print_result("got single block", single_blocks[single_blocks_cnt], 16);
                                        single_blocks_cnt++;
                                }
                                j = 0;
                        }
                        ++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);
+               }
+
+               Dbprintf("(dbg) got %d blocks (%d/%d found) (%d tries, %d errors)", n, found_blocks, (max_blocks == 0 ? found_blocks : max_blocks), tries, errors);
+               for (i = 0; i < n; ++i)
+               {
+                       print_result("got consecutive blocks", tmp_blocks[i], 16);
+               }
 
                i = 0;
-               if(!found_0_1) {                        
+               if(!found_0_1) {
                        while (i < n - 1) {
                                if (IsBlock0PCF7931(tmp_blocks[i]) && IsBlock1PCF7931(tmp_blocks[i+1])) {
                                        found_0_1 = 1;
@@ -233,9 +248,9 @@ void ReadPCF7931() {
                                        // 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);
@@ -283,7 +298,7 @@ void ReadPCF7931() {
                        goto end;
                }
        }
-       while (found_blocks != max_blocks);
+       while (found_blocks < max_blocks);
 
  end:
        Dbprintf("-----------------------------------------");
@@ -296,14 +311,14 @@ void ReadPCF7931() {
                        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);
@@ -331,42 +346,42 @@ static void RealWritePCF7931(uint8_t *pass, uint16_t init_delay, int32_t l, int3
        AddBytePCF7931(pass[6], tab, l, p);
        //programming mode (0 or 1)
        AddBitPCF7931(0, tab, l, p);
-       
+
        //block adress on 6 bits
        for (u = 0; u < 6; ++u) {
-               if (address & (1 << u)) {       // bit 1
+               if (address & (1 << u)) {   // bit 1
                         ++parity;
                         AddBitPCF7931(1, tab, l, p);
-               } else {                                        // bit 0
+               } else {                    // bit 0
                         AddBitPCF7931(0, tab, l, p);
                }
        }
-       
+
        //byte address on 4 bits
        for (u = 0; u < 4; ++u)
        {
-               if (byte & (1 << u)) {  // bit 1
+               if (byte & (1 << u)) {  // bit 1
                         parity++;
                         AddBitPCF7931(1, tab, l, p);
                }
-               else                            // bit 0
+               else                // bit 0
                         AddBitPCF7931(0, tab, l, p);
        }
-       
+
        //data on 8 bits
        for (u=0; u<8; u++)
        {
-               if (data&(1<<u)) {      // bit 1
+               if (data&(1<<u)) {  // bit 1
                         parity++;
                         AddBitPCF7931(1, tab, l, p);
-               } 
-               else                            //bit 0
+               }
+               else                //bit 0
                         AddBitPCF7931(0, tab, l, p);
        }
 
        //parity bit
        if ((parity % 2) == 0)
-               AddBitPCF7931(0, tab, l, p); //even parity
+               AddBitPCF7931(0, tab, l, p); //even parity
        else
                AddBitPCF7931(1, tab, l, p);//odd parity
 
@@ -393,20 +408,14 @@ static void RealWritePCF7931(uint8_t *pass, uint16_t init_delay, int32_t l, int3
 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;
+
+               num_to_bytes(password, 7, pass_array);
 
                Dbprintf("Trying: %02x %02x %02x %02x %02x %02x %02x ...",
                        pass_array[0],
@@ -416,7 +425,7 @@ void BruteForcePCF7931(uint64_t password, uint8_t tries, uint16_t init_delay, in
                        pass_array[4],
                        pass_array[5],
                        pass_array[6]);
-               
+
                for (i = 0; i < tries; ++i)
                        RealWritePCF7931
                        (
@@ -428,15 +437,15 @@ void BruteForcePCF7931(uint64_t password, uint8_t tries, uint16_t init_delay, in
                                7,
                                0x01
                        );
-       
-               ++password;     
+
+               ++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
+       @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);
@@ -445,9 +454,9 @@ void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, ui
        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);
 }
 
@@ -487,7 +496,7 @@ void SendCmdPCF7931(uint32_t * tab) {
                HIGH(GPIO_SSC_DOUT);
                while(tempo !=  tab[u])
                        tempo = AT91C_BASE_TC0->TC_CV;
-                       
+
                // stop modulating antenna
                LOW(GPIO_SSC_DOUT);
                while(tempo !=  tab[u+1])
@@ -509,7 +518,7 @@ void SendCmdPCF7931(uint32_t * tab) {
 }
 
 
-/* Add a byte for building the data frame of PCF7931 tags 
+/* Add a byte for building the data frame of PCF7931 tags
  * @param b : byte to add
  * @param tab : array of the data frame
  * @param l : offset on low pulse width
@@ -518,7 +527,7 @@ void SendCmdPCF7931(uint32_t * tab) {
 bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p) {
        uint32_t u;
        for (u = 0; u < 8; ++u) {
-               if (byte & (1 << u)) {  //bit is 1
+               if (byte & (1 << u)) {  //bit is 1
                        if(AddBitPCF7931(1, tab, l, p)==1)return 1;
                } else { //bit is 0
                        if(AddBitPCF7931(0, tab, l, p)==1)return 1;
@@ -528,7 +537,7 @@ bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p) {
        return 0;
 }
 
-/* Add a bits for building the data frame of PCF7931 tags 
+/* Add a bits for building the data frame of PCF7931 tags
  * @param b : bit to add
  * @param tab : array of the data frame
  * @param l : offset on low pulse width
@@ -539,23 +548,23 @@ bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p) {
 
        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;
                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;
                return 0;
        }
-       
+
        return 1;
 }
 
@@ -569,8 +578,8 @@ bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab) {
        uint32_t u = 0;
        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];
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