X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/be6250d31b5cc1ebb9ab0bece84c6691220a8e0d..d10e08ae6e5a113f88daeeaa59fd352fc35d478d:/armsrc/pcf7931.c

diff --git a/armsrc/pcf7931.c b/armsrc/pcf7931.c
new file mode 100644
index 00000000..290cffef
--- /dev/null
+++ b/armsrc/pcf7931.c
@@ -0,0 +1,526 @@
+#include "proxmark3.h"
+#include "apps.h"
+#include "lfsampling.h"
+#include "pcf7931.h"
+#include "string.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;
+}