+#include "pcf7931.h"
+
+#define T0_PCF 8 //period for the pcf7931 in us
+#define ALLOC 16
+
+#define abs(x) ( ((x)<0) ? -(x) : (x) )
+#define max(x,y) ( x<y ? y:x)
+
+int 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;
+ int pmc, block_done;
+ int lc, warnings = 0;
+ int num_blocks = 0;
+ int lmin=128, lmax=128;
+ uint8_t dir;
+
+ LFSetupFPGAForADC(95, true);
+ DoAcquisition_default(0, true);
+
+ lmin = 64;
+ lmax = 192;
+
+ i = 2;
+
+ /* Find first local max/min */
+ if(dest[1] > dest[0]) {
+ while(i < GraphTraceLen) {
+ if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
+ break;
+ i++;
+ }
+ dir = 0;
+ }
+ else {
+ while(i < GraphTraceLen) {
+ if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
+ break;
+ i++;
+ }
+ dir = 1;
+ }
+
+ lastval = i++;
+ half_switch = 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))
+ {
+ lc = i - lastval;
+ lastval = i;
+
+ // Switch depending on lc length:
+ // Tolerance is 1/8 of clock rate (arbitrary)
+ if (abs(lc-clock/4) < tolerance) {
+ // 16T0
+ if((i - pmc) == lc) { /* 16T0 was previous one */
+ /* It's a PMC ! */
+ i += (128+127+16+32+33+16)-1;
+ lastval = i;
+ pmc = 0;
+ block_done = 1;
+ }
+ else {
+ pmc = i;
+ }
+ } else if (abs(lc-clock/2) < tolerance) {
+ // 32TO
+ if((i - pmc) == lc) { /* 16T0 was previous one */
+ /* It's a PMC ! */
+ i += (128+127+16+32+33)-1;
+ lastval = i;
+ pmc = 0;
+ block_done = 1;
+ }
+ else if(half_switch == 1) {
+ bits[bitidx++] = 0;
+ half_switch = 0;
+ }
+ else
+ half_switch++;
+ } else if (abs(lc-clock) < tolerance) {
+ // 64TO
+ bits[bitidx++] = 1;
+ } else {
+ // Error
+ warnings++;
+ if (warnings > 10)
+ {
+ Dbprintf("Error: too many detection errors, aborting.");
+ return 0;
+ }
+ }
+
+ 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];
+
+ }
+ num_blocks++;
+ }
+ bitidx = 0;
+ block_done = 0;
+ half_switch = 0;
+ }
+ if(i < GraphTraceLen)
+ dir =(dest[i-1] > dest[i]) ? 0 : 1;
+ }
+ if(bitidx==255)
+ bitidx=0;
+ warnings = 0;
+ if(num_blocks == 4) break;
+ }
+ memcpy(outBlocks, blocks, 16*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;
+}
+
+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;
+
+ return 0;
+}
+
+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;
+
+ memset(Blocks, 0, 8*17*sizeof(uint8_t));
+
+ do {
+ memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
+ n = DemodPCF7931((uint8_t**)tmpBlocks);
+ if(!n)
+ error++;
+ if(error==10 && num_blocks == 0) {
+ Dbprintf("Error, no tag or bad tag");
+ return;
+ }
+ else if (tries==20 || error==10) {
+ 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;
+ }
+ break;
+ }
+ }
+ }
+ }
+ 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++;
+ if (BUTTON_PRESS()) return;
+ } while (num_blocks != max_blocks);
+ 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]);
+ else
+ Dbprintf("<missing block %d>", i);
+ }
+ Dbprintf("-----------------------------------------");
+
+ return ;
+}
+
+
+/* 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)
+{
+
+ 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);
+
+ //PMC
+ Dbprintf("Initialization delay : %d us", init_delay);
+ 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 (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);
+
+
+ //programming mode (0 or 1)
+ AddBitPCF7931(0, tab, l, p);
+
+ //block adress on 6 bits
+ Dbprintf("Block address : %02x", address);
+ for (u=0; u<6; u++)
+ {
+ if (address&(1<<u)) { // bit 1
+ parity++;
+ AddBitPCF7931(1, tab, l, p);
+ } else{ // bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+ //byte address on 4 bits
+ Dbprintf("Byte address : %02x", byte);
+ for (u=0; u<4; u++)
+ {
+ if (byte&(1<<u)) { // bit 1
+ parity++;
+ AddBitPCF7931(1, tab, l, p);
+ } else{ // bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+ //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);
+ } else{ //bit 0
+ AddBitPCF7931(0, tab, l, p);
+ }
+ }
+
+
+ //parity bit
+ if((parity%2)==0){
+ AddBitPCF7931(0, tab, l, p); //even parity
+ }else{
+ AddBitPCF7931(1, tab, l, p);//odd parity
+ }
+
+ //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;
+ }
+
+
+ //compennsation of the counter reload
+ while (!comp){
+ comp = 1;
+ for(u=0;tab[u]!=0;u++){
+ if(tab[u] > 0xFFFF){
+ tab[u] -= 0xFFFF;
+ comp = 0;
+ }
+ }
+ }
+
+ SendCmdPCF7931(tab);
+}
+
+
+
+/* Send a trame to a PCF7931 tags
+ * @param tab : array of the data frame
+ */
+
+void SendCmdPCF7931(uint32_t * tab){
+ uint16_t u=0;
+ uint16_t tempo=0;
+
+ Dbprintf("SENDING DATA FRAME...");
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
+
+ LED_A_ON();
+
+ // steal this pin from the SSP and use it to control the modulation
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+ AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+
+ //initialization of the timer
+ AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14);
+ AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE;
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; //clock at 48/32 MHz
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
+ AT91C_BASE_TCB->TCB_BCR = 1;
+
+
+ tempo = AT91C_BASE_TC0->TC_CV;
+ for(u=0;tab[u]!= 0;u+=3){
+
+
+ // modulate antenna
+ 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]){
+ tempo = AT91C_BASE_TC0->TC_CV;
+ }
+
+
+ // modulate antenna
+ HIGH(GPIO_SSC_DOUT);
+ while(tempo != tab[u+2]){
+ tempo = AT91C_BASE_TC0->TC_CV;
+ }
+
+
+ }
+
+ LED_A_OFF();
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+ SpinDelay(200);
+
+
+ AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
+ DbpString("FINISH !");
+ DbpString("(Could be usefull to send the same trame many times)");
+ LED(0xFFFF, 1000);
+}
+
+
+/* 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
+ * @param p : offset on low pulse positioning
+ */
+
+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 à 1
+ if(AddBitPCF7931(1, tab, l, p)==1)return 1;
+ } else { //bit à 0
+ if(AddBitPCF7931(0, tab, l, p)==1)return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* 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
+ * @param p : offset on low pulse positioning
+ */
+bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
+ uint8_t u = 0;
+
+ 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;
+
+ 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
+
+ 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;
+}
+
+/* Add a custom pattern in the data frame
+ * @param a : delay of the first high pulse
+ * @param b : delay of the low pulse
+ * @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){
+ 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];
+
+ tab[u+1] = b+tab[u];
+ tab[u+2] = c+tab[u+1];
+
+ return 0;
+}
\ No newline at end of file
projects / proxmark3-svn / commitdiff