X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/9455b51c2a0554ea2bd55a28dee5a5c2a6707fc6..be09ea86035044f67e0419b067ac54ee055ad9ee:/common/iso15693tools.c

diff --git a/common/iso15693tools.c b/common/iso15693tools.c
index 6d8ae5b1..2da6c7f9 100644
--- a/common/iso15693tools.c
+++ b/common/iso15693tools.c
@@ -7,26 +7,36 @@
 //-----------------------------------------------------------------------------
 
 
+#include "iso15693tools.h"
+
 #include "proxmark3.h"
 #include <stdint.h>
 #include <stdlib.h>
-//#include "iso15693tools.h"
+#ifdef ON_DEVICE
+#include "printf.h"
+#else
+#include <stdio.h>
+#endif
+
+
+#define ISO15693_CRC_PRESET  (uint16_t)0xFFFF
+#define ISO15693_CRC_POLY    (uint16_t)0x8408
+
 
 // The CRC as described in ISO 15693-Part 3-Annex C
-// 	v	buffer with data
-//		n	length
-//	returns crc as 16bit value
-uint16_t Iso15693Crc(uint8_t *v, int n)
-{
+//    v   buffer with data
+//    n   length
+//  returns crc as 16bit value
+uint16_t Iso15693Crc(uint8_t *v, int n) {
 	uint32_t reg;
 	int i, j;
 
-	reg = 0xffff;
-	for(i = 0; i < n; i++) {
+	reg = ISO15693_CRC_PRESET;
+	for (i = 0; i < n; i++) {
 		reg = reg ^ ((uint32_t)v[i]);
 		for (j = 0; j < 8; j++) {
 			if (reg & 0x0001) {
-				reg = (reg >> 1) ^ 0x8408;
+				reg = (reg >> 1) ^ ISO15693_CRC_POLY;
 			} else {
 				reg = (reg >> 1);
 			}
@@ -37,31 +47,50 @@ uint16_t Iso15693Crc(uint8_t *v, int n)
 }
 
 // adds a CRC to a dataframe
-// 	req[]   iso15963 frame without crc
-//		n       length without crc
+//    req[]   iso15963 frame without crc
+//    n       length without crc
 // returns the new length of the dataframe.
 int Iso15693AddCrc(uint8_t *req, int n) {
-	uint16_t crc=Iso15693Crc(req,n);
+	uint16_t crc = Iso15693Crc(req, n);
 	req[n] = crc & 0xff;
 	req[n+1] = crc >> 8;
-	return n+2;
+	return n + 2;
 }
 
 
-int sprintf(char *str, const char *format, ...);
-
 // returns a string representation of the UID
 // UID is transmitted and stored LSB first, displayed MSB first
-//		target    char* buffer, where to put the UID, if NULL a static buffer is returned
-//		uid[]		the UID in transmission order
-//	return: ptr to string
-char* Iso15693sprintUID(char *target,uint8_t *uid) {
-  static char tempbuf[9]="";
-  if (target==NULL) target=tempbuf;
-  sprintf(target,"%02hX%02hX%02hX%02hX%02hX%02hX%02hX%02hX",
-  				uid[7],uid[6],uid[5],uid[4],uid[3],uid[2],uid[1],uid[0]);
-  return target;
+//    target    char* buffer, where to put the UID, if NULL a static buffer is returned
+//    uid[]     the UID in transmission order
+//    return:   ptr to string
+char* Iso15693sprintUID(char *target, uint8_t *uid) {
+	static char tempbuf[2*8+1] = "";
+	if (target == NULL) target = tempbuf;
+	sprintf(target, "%02X%02X%02X%02X%02X%02X%02X%02X", uid[7], uid[6], uid[5], uid[4], uid[3], uid[2], uid[1], uid[0]);
+	return target;
 }
 
 
+uint16_t iclass_crc16(char *data_p, unsigned short length) {
+	unsigned char i;
+	unsigned int data;
+	uint16_t crc = ISO15693_CRC_PRESET;
+
+	if (length == 0)
+		return (~crc);
+
+	do {
+		for (i = 0, data = (unsigned int)0xff & *data_p++; i < 8; i++, data >>= 1) {
+			if ((crc & 0x0001) ^ (data & 0x0001))
+				crc = (crc >> 1) ^ ISO15693_CRC_POLY;
+			else  crc >>= 1;
+		}
+	} while (--length);
+
+	crc = ~crc;
+	data = crc;
+	crc = (crc << 8) | (data >> 8 & 0xff);
+	crc = crc ^ 0xBC3;
+	return (crc);
+}