ADD: num_to_bytebitsLSBF function.

ADD: lf guard clone - works...  needs some checking.
ADD: added a option to "addparity" to set zero on fixed pos.

client/cmddata.c

@@ -619,13 +619,13 @@ int CmdG_Prox_II_Demod(const char *Cmd)
 			continue;
 		} 
 		if (keyCnt<8){ //lsb first
-			xorKey = xorKey | (DemodBuffer[startIdx+idx]<<keyCnt);
+			xorKey |=  (DemodBuffer[startIdx+idx]<<keyCnt);
 			keyCnt++;
 			if (keyCnt==8 && g_debugMode) PrintAndLog("xorKey Found: %02x", xorKey);
 			continue;
 		}
 		//lsb first
-		ByteStream[ByteCnt] = ByteStream[ByteCnt] | (DemodBuffer[startIdx+idx]<<bitCnt);
+		ByteStream[ByteCnt] |=  (DemodBuffer[startIdx+idx]<<bitCnt);
 		bitCnt++;
 		if (bitCnt % 8 == 0){
 			if (g_debugMode) PrintAndLog("byte %u: %02x", (unsigned int)ByteCnt, ByteStream[ByteCnt]);

client/cmdlfguard.c

@@ -47,40 +47,14 @@ int GetGuardBits(uint32_t fc, uint32_t cn, uint8_t *guardBits) {
 	// Intializes random number generator
 	time_t t;
 	srand((unsigned) time(&t));
-
+	//uint8_t xorKey = rand() % 0xFF;
+	uint8_t xorKey = 0x6b;
+	uint8_t i;
+	
+	
 	uint8_t pre[96];
 	memset(pre, 0x00, sizeof(pre));
 
-	uint8_t index = 8;
-	
-	// preamble  6bits
-	pre[0] = 1;
-	pre[1] = 1;
-	pre[2] = 1;
-	pre[3] = 1;
-	pre[4] = 1;
-	//pre[5] = 0;
-
-	// add xor key
-	uint8_t xorKey = rand() % 0xFF;
-	num_to_bytebits(xorKey, 8, pre+index);
-	index += 8;
-	
-	// add format length
-	// len | hex | bin  wiegand pos fc/cn   
-	//  26 | 1A  | 0001 1010
-	num_to_bytebits(26, 8, pre+index);
-	//  36 | 24  | 0010 0100
-	//num_to_bytebits(36, 8, pre+index);
-	//  40 | 28  | 0010 1000
-	//num_to_bytebits(40, 8, pre+index);
-
-	index += 8;
-	
-	// 2bit checksum
-	// unknown today.
-	index += 2;
-	
 	// Get 26 wiegand from FacilityCode, CardNumber	
 	uint8_t wiegand[24];
 	memset(wiegand, 0x00, sizeof(wiegand));
@@ -88,26 +62,71 @@ int GetGuardBits(uint32_t fc, uint32_t cn, uint8_t *guardBits) {
 	num_to_bytebits(cn, 16, wiegand+8);
 
 	// add wiegand parity bits (dest, source, len)
-	wiegand_add_parity(pre+index, wiegand, 24);
+	wiegand_add_parity(pre, wiegand, 24);
 
-	uint8_t tmp = 0, i = 0;
+	// lets start. 12bytes of data to be produced.
-	for (i = 2; i < 12; ++i) {
+	uint8_t rawbytes[12];
-		// // xor all bytes
+	memset(rawbytes, 0x00, sizeof(rawbytes));
-		// tmp = xorKey ^ bytebits_to_byte(pre + (i*8), 8);
-		
-		// // copy to out..
-		// num_to_bytebits(tmp, 8, pre + (i*8) );
-	}
 
-	// add spacer bit 0 every 5
+	// xor key
+	rawbytes[0] = xorKey;
+
+	// add format length (decimal)
+	// len | hex | bin
+	//  26 | 1A  | 0001 1010
+	rawbytes[1] = (26 << 2);
+	//  36 | 24  | 0010 0100
+	//rawbytes[1] = (36 << 2);
+	//  40 | 28  | 0010 1000
+	//rawbytes[1] = (40 << 2);
 	
-	// swap nibbles
+	// 2bit checksum, unknown today, 
+	// these two bits are the last ones of rawbyte[1], hence the LSHIFT above.
+	rawbytes[2] = 1;
+	rawbytes[3] = 0;
 	
+	// add wiegand to rawbytes
+	for (i = 0; i < 4; ++i)
+		rawbytes[i+4] = bytebits_to_byte( pre + (i*8), 8);
 	
-	// copy to outarray
+	if (g_debugMode) printf(" WIE | %s\n", sprint_hex(rawbytes, sizeof(rawbytes)));	
-	memcpy(guardBits, pre, sizeof(pre));
 	
-	printf(" | %s\n", sprint_bin(guardBits, 96) );
+	// NIBBLE_SWAP (works on all data)
+	// for (i = 0; i < 12; ++i)
+		// rawbytes[i] = SWAP_NIBBLE( rawbytes[i] );
+
+	// printf("SWAP | %s\n", sprint_hex(rawbytes, sizeof(rawbytes)));
+	
+	// XOR (only works on wiegand stuff)
+	for (i = 1; i < 12; ++i)
+		rawbytes[i] ^= xorKey ;
+	
+	if (g_debugMode) printf(" XOR | %s \n", sprint_hex(rawbytes, sizeof(rawbytes)));
+
+	// convert rawbytes to bits in pre
+	for (i = 0; i < 12; ++i)
+		num_to_bytebitsLSBF( rawbytes[i], 8, pre + (i*8));
+
+	if (g_debugMode) printf("\n Raw | %s \n", sprint_hex(rawbytes, sizeof(rawbytes)));
+	if (g_debugMode) printf(" Raw | %s\n", sprint_bin(pre, 64) );
+	
+	// add spacer bit 0 every 4 bits, starting with index 0,
+	// 12 bytes, 24 nibbles.  24+1 extra bites. 3bytes.  Ie 9bytes | 1byte xorkey, 8bytes rawdata (64bits, should be enough for a 40bit wiegand)
+	addParity(pre, guardBits+6, 64, 5, 3);
+
+	// preamble
+	guardBits[0] = 1;
+	guardBits[1] = 1;
+	guardBits[2] = 1;
+	guardBits[3] = 1;
+	guardBits[4] = 1;
+	guardBits[5] = 0;
+/*               6      B      
+PRE |          0110   1101   0101   1110   0001   1101   1101   0111   1101011011010110110101101101011
+FIN | 111110 0 0110 0 1101 0 0101 0 1110 0 0001 0 1101 0 1101 0 0111 0 110100110011010011001101001100110100110000000000
+*/
+	
+	if (g_debugMode) printf(" FIN | %s\n", sprint_bin(guardBits, 96) );
 	return 1;
 }
 
@@ -153,19 +172,19 @@ int CmdGuardClone(const char *Cmd) {
 	for ( i = 0; i<4; ++i )
 		PrintAndLog(" %02d | %08x", i, blocks[i]);
 
-	// UsbCommand resp;
+	UsbCommand resp;
-	// UsbCommand c = {CMD_T55XX_WRITE_BLOCK, {0,0,0}};
+	UsbCommand c = {CMD_T55XX_WRITE_BLOCK, {0,0,0}};
 
-	// for ( i = 0; i<5; ++i ) {
+	for ( i = 0; i<4; ++i ) {
-		// c.arg[0] = blocks[i];
+		c.arg[0] = blocks[i];
-		// c.arg[1] = i;
+		c.arg[1] = i;
-		// clearCommandBuffer();
+		clearCommandBuffer();
-		// SendCommand(&c);
+		SendCommand(&c);
-		// if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
+		if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
-			// PrintAndLog("Error occurred, device did not respond during write operation.");
+			PrintAndLog("Error occurred, device did not respond during write operation.");
-			// return -1;
+			return -1;
-		// }
+		}
-	// }
+	}
     return 0;
 }
 
@@ -207,7 +226,7 @@ int CmdGuardSim(const char *Cmd) {
 static command_t CommandTable[] = {
     {"help",	CmdHelp,		1, "This help"},
 	{"read",	CmdGuardRead,  0, "Attempt to read and extract tag data"},
-//	{"clone",	CmdGuardClone, 0, "<Facility-Code> <Card Number>  clone Guardall tag"},
+	{"clone",	CmdGuardClone, 0, "<Facility-Code> <Card Number>  clone Guardall tag"},
 //	{"sim",		CmdGuardSim,   0, "<Facility-Code> <Card Number>  simulate Guardall tag"},
     {NULL, NULL, 0, NULL}
 };

client/util.c

@@ -103,6 +103,7 @@ void print_hex(const uint8_t * data, const size_t len) {
 		printf("%02x ", data[i]);
 	printf("\n");
 }
+
 void print_hex_break(const uint8_t *data, const size_t len, uint8_t breaks) {
 
 	int rownum = 0;
@@ -178,6 +179,7 @@ char *sprint_hex_ascii(const uint8_t *data, const size_t len) {
 	sprintf(tmp, "%s| %s", sprint_hex(data, max_len) , data);	
 	return buf;
 }
+
 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
 {
 	while (len--) {
@@ -197,12 +199,22 @@ uint64_t bytes_to_num(uint8_t* src, size_t len)
 	return num;
 }
 
-void num_to_bytebits(uint64_t	n, size_t len, uint8_t *dest) {
+// takes a number (uint64_t) and creates a binarray in dest.
+void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest) {
 	while (len--) {
 		dest[len] = n & 1;
 		n >>= 1;
 	}
 }
+//least significant bit first
+void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest)
+{
+	for(int i = 0 ; i < len ; ++i) {
+		dest[i] =  n & 1;
+		n >>= 1;
+	}
+}
+
 
 // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp
 // to
@@ -220,6 +232,8 @@ uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockS
 	return tmp;
 }
 
+// takes a uint8_t src array, for len items and reverses the byte order in blocksizes (8,16,32,64), 
+// returns: the dest array contains the reordered src array.
 void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSize, uint8_t *dest){
 	for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 		for (size_t i = 0; i < blockSize; i++){
@@ -228,7 +242,6 @@ void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSiz
 	}
 }
 
-
 //  -------------------------------------------------------------------------
 //  string parameters lib
 //  -------------------------------------------------------------------------
@@ -493,6 +506,7 @@ void wiegand_add_parity(uint8_t *target, uint8_t *source, uint8_t length)
     *(target)= GetParity(source + length / 2, ODD, length / 2);
 }
 
+// xor two arrays together for len items.  The dst array contains the new xored values.
 void xor(unsigned char * dst, unsigned char * src, size_t len) {
    for( ; len > 0; len--,dst++,src++)
        *dst ^= *src;
@@ -502,6 +516,7 @@ int32_t le24toh (uint8_t data[3]) {
     return (data[2] << 16) | (data[1] << 8) | data[0];
 }
 
+// Pack a bitarray into a uint32_t.  
 uint32_t PackBits(uint8_t start, uint8_t len, uint8_t* bits) {
 
 	if (len > 32) return 0;
@@ -526,6 +541,7 @@ void rol(uint8_t *data, const size_t len){
     data[len-1] = first;
 }
 
+// Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
 uint32_t SwapBits(uint32_t value, int nrbits) {
 	uint32_t newvalue = 0;
 	for(int i = 0; i < nrbits; i++) {

client/util.h

@@ -36,6 +36,18 @@
 #define EVEN                        0
 #define ODD                         1
 
+#ifndef NIBBLE_HIGH
+# define NIBBLE_HIGH(b) ( (b & 0xF0) >> 4 )
+#endif
+#ifndef NIBBLE_LOW
+# define NIBBLE_LOW(b)  ( b & 0x0F )
+#endif
+#ifndef CRUMB
+# define CRUMB(b,p)    (((b & (0x3 << p) ) >> p ) & 0xF)
+#endif
+#ifndef SWAP_NIBBLE
+# define SWAP_NIBBLE(b)  ( (NIBBLE_LOW(b)<< 4) | NIBBLE_HIGH(b))
+#endif
 int ukbhit(void);
 
 void AddLogLine(char *fileName, char *extData, char *c);
@@ -53,7 +65,8 @@ char *sprint_hex_ascii(const uint8_t *data, const size_t len);
 
 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest);
 uint64_t bytes_to_num(uint8_t* src, size_t len);
-void num_to_bytebits(uint64_t	n, size_t len, uint8_t *dest);
+void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest);
+void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest);
 uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockSize);
 void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSize, uint8_t *dest);
 

common/lfdemod.c

@@ -95,7 +95,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
 
 // by marshmellow
 // takes a array of binary values, length of bits per parity (includes parity bit),
-//   Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+//   Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
 size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
 {
 	uint32_t parityWd = 0;
@@ -105,12 +105,16 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
 			parityWd = (parityWd << 1) | BitSource[word+bit];
 			dest[j++] = (BitSource[word+bit]);
 		}
+		
 		// if parity fails then return 0
-		if (pType == 2) { // then marker bit which should be a 1
+		switch (pType) {
-			dest[j++]=1;
+			case 3: dest[j++]=0; break; // marker bit which should be a 0
-		} else {
+			case 2: dest[j++]=1; break; // marker bit which should be a 1
-			dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+			default: 
+				dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+				break;
 		}
+		
 		bitCnt += pLen;
 		parityWd = 0;
 	}
@@ -122,8 +126,7 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
 uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
 {
 	uint32_t num = 0;
-	for(int i = 0 ; i < numbits ; i++)
+	for(int i = 0 ; i < numbits ; i++) {
-	{
 		num = (num << 1) | (*src);
 		src++;
 	}