X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/6c283951062aaad9d0d1ba8670b02895047be438..f2ba788536822f03dea834cd3310d9915e3b2b35:/common/crc.c?ds=sidebyside

diff --git a/common/crc.c b/common/crc.c
index 311a676c..540ae668 100644
--- a/common/crc.c
+++ b/common/crc.c
@@ -29,6 +29,7 @@ void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, u
 }
 
 void crc_clear(crc_t *crc) {
+	
 	crc->state = crc->initial_value & crc->mask;
 	if (crc->refin) 
 		crc->state = reflect(crc->state, crc->order);
@@ -36,21 +37,46 @@ void crc_clear(crc_t *crc) {
 
 void crc_update(crc_t *crc, uint32_t indata, int data_width){
 
+	uint32_t poly = crc->polynom;	
+
+	// if requested, return the initial CRC */
+    if (indata == 0)
+        return crc->initial_value;
+		
 	//reflected
-	if (crc->refin) indata = reflect(indata, data_width);
+	if (crc->refin) 
+		indata = reflect(indata, data_width);
 	
 	// Bring the next byte into the remainder.
 	crc->state ^= indata << (crc->order - data_width);
 	
-	for( uint8_t bit = data_width; bit > 0; --bit) {
+	for( uint8_t bit = data_width; bit > 0; --bit) {		
 		 // Try to divide the current data bit.
 		if (crc->state & crc->topbit)
-			crc->state = (crc->state << 1) ^ crc->polynom;
+			crc->state = (crc->state << 1) ^ poly;
 		else
 			crc->state = (crc->state << 1);
 	}
+    return crc ^ model->xorout;
 }
 
+void crc_update2(crc_t *crc, uint32_t data, int data_width)
+{
+	if (crc->refin) 
+		data = reflect(data, data_width);
+	
+	int i;
+	for(i=0; i<data_width; i++) {
+		int oldstate = crc->state;
+		crc->state = crc->state >> 1;
+		if( (oldstate^data) & 1 ) {
+			crc->state ^= crc->polynom;
+		}
+		data >>= 1;
+	}
+}
+
+
 uint32_t crc_finish(crc_t *crc) {
 	uint32_t val = crc->state;
 	if (crc->refout) val = reflect(val, crc->order);
@@ -82,8 +108,15 @@ uint32_t CRC8Maxim(uint8_t *buff, size_t size) {
 	return crc_finish(&crc);
 }
 
-
 // width=4  poly=0xC, reversed poly=0x7  init=0x5   refin=true  refout=true  xorout=0x0000  check=  name="CRC-4/LEGIC"
+uint32_t CRC4Legic(uint8_t *cmd, size_t size) {
+ 	crc_t crc;
+ 	crc_init_ref(&crc, 4, 0x19 >> 1, 0x5, 0, TRUE, TRUE);
+	crc_update2(&crc, 1, 1); /* CMD_READ */
+	crc_update2(&crc, cmd[0], 8);
+	crc_update2(&crc, cmd[1], 8);
+	return reflect(crc_finish(&crc), 4);	
+}
 // width=8  poly=0x63, reversed poly=0x8D  init=0x55  refin=true  refout=true  xorout=0x0000  check=0xC6  name="CRC-8/LEGIC"
 // the CRC needs to be reversed before returned.
 uint32_t CRC8Legic(uint8_t *buff, size_t size) {
@@ -99,8 +132,8 @@ uint32_t CRC8Legic(uint8_t *buff, size_t size) {
 uint32_t CRC16Legic(uint8_t *buff, size_t size, uint8_t uidcrc) {
 
 	#define CRC16_POLY_LEGIC 0xB400
-	//uint8_t initial = reflect(uidcrc, 8);
-	uint16_t initial = uidcrc;
+	uint16_t initial = reflect(uidcrc, 8);
+	//uint16_t initial = uidcrc;
 	initial |= initial << 8;
 	crc_t crc;
 	crc_init_ref(&crc, 16, CRC16_POLY_LEGIC, initial, 0, TRUE, TRUE);
@@ -126,4 +159,21 @@ uint32_t CRC16_CCITT(uint8_t *buff, size_t size) {
 	for ( int i=0; i < size; ++i)
 		crc_update(&crc, buff[i], 8);
 	return  crc_finish(&crc);
+}
+//width=16  poly=0x8408  init=0xffff  refin=false  refout=true  xorout=0xffff  check=0xF0B8  name="CRC-16/ISO/IEC 13239"
+uint32_t CRC16_Iso15693(uint8_t *buff, size_t size) {
+	crc_t crc;
+	crc_init_ref(&crc, 16, 0x8408, 0xFFFF, 0xFFFF, true, false);	
+	for ( int i=0; i < size; ++i)
+		crc_update(&crc, buff[i], 8);
+	return reflect(crc_finish(&crc), 16);
+}
+//width=16  poly=0x8408  init=0xffff  refin=true  refout=true  xorout=0x0BC3  check=0xF0B8  name="CRC-16/ICLASS"
+uint32_t CRC16_ICLASS(uint8_t *buff, size_t size) {
+
+	crc_t crc;
+	crc_init_ref(&crc, 16, 0x8408, 0xFFFF, 0x0BC3, false, false);	
+	for ( int i=0; i < size; ++i)
+		crc_update(&crc, buff[i], 8);
+	return  crc_finish(&crc);
 }
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