+
+/*
+The following methods comes from Rfidler sourcecode.
+https://github.com/ApertureLabsLtd/RFIDler/blob/master/firmware/Pic32/RFIDler.X/src/
+*/
+
+// convert hex to sequence of 0/1 bit values
+// returns number of bits converted
+int hextobinarray(char *target, char *source)
+{
+ int length, i, count= 0;
+ char x;
+
+ length = strlen(source);
+ // process 4 bits (1 hex digit) at a time
+ while(length--)
+ {
+ x= *(source++);
+ // capitalize
+ if (x >= 'a' && x <= 'f')
+ x -= 32;
+ // convert to numeric value
+ if (x >= '0' && x <= '9')
+ x -= '0';
+ else if (x >= 'A' && x <= 'F')
+ x -= 'A' - 10;
+ else
+ return 0;
+ // output
+ for(i= 0 ; i < 4 ; ++i, ++count)
+ *(target++)= (x >> (3 - i)) & 1;
+ }
+
+ return count;
+}
+
+// convert hex to human readable binary string
+int hextobinstring(char *target, char *source)
+{
+ int length;
+
+ if(!(length= hextobinarray(target, source)))
+ return 0;
+ binarraytobinstring(target, target, length);
+ return length;
+}
+
+// convert binary array of 0x00/0x01 values to hex (safe to do in place as target will always be shorter than source)
+// return number of bits converted
+int binarraytohex(char *target,char *source, int length)
+{
+ unsigned char i, x;
+ int j = length;
+
+ if(j % 4)
+ return 0;
+
+ while(j)
+ {
+ for(i= x= 0 ; i < 4 ; ++i)
+ x += ( source[i] << (3 - i));
+ sprintf(target,"%X", (unsigned int)x);
+ ++target;
+ source += 4;
+ j -= 4;
+ }
+ return length;
+}
+
+// convert binary array to human readable binary
+void binarraytobinstring(char *target, char *source, int length)
+{
+ int i;
+
+ for(i= 0 ; i < length ; ++i)
+ *(target++)= *(source++) + '0';
+ *target= '\0';
+}
+
+// return parity bit required to match type
+uint8_t GetParity( uint8_t *bits, uint8_t type, int length)
+{
+ int x;
+
+ for(x= 0 ; length > 0 ; --length)
+ x += bits[length - 1];
+ x %= 2;
+
+ return x ^ type;
+}
+
+// add HID parity to binary array: EVEN prefix for 1st half of ID, ODD suffix for 2nd half
+void wiegand_add_parity(uint8_t *target, uint8_t *source, uint8_t length)
+{
+ *(target++)= GetParity(source, EVEN, length / 2);
+ memcpy(target, source, length);
+ target += 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;
+}
+
+int32_t le24toh (uint8_t data[3]) {
+ return (data[2] << 16) | (data[1] << 8) | data[0];
+}
+uint32_t le32toh (uint8_t *data) {
+ return (uint32_t)( (data[3]<<24) | (data[2]<<16) | (data[1]<<8) | data[0]);
+}
+
+// RotateLeft - Ultralight, Desfire, works on byte level
+// 00-01-02 >> 01-02-00
+void rol(uint8_t *data, const size_t len){
+ uint8_t first = data[0];
+ for (size_t i = 0; i < len-1; i++) {
+ data[i] = data[i+1];
+ }
+ data[len-1] = first;
+}
+
+
+// Replace unprintable characters with a dot in char buffer
+void clean_ascii(unsigned char *buf, size_t len) {
+ for (size_t i = 0; i < len; i++) {
+ if (!isprint(buf[i]))
+ buf[i] = '.';
+ }
+}
+
+
+// Timer functions
+#if !defined (_WIN32)
+#include <errno.h>
+
+static void nsleep(uint64_t n) {
+ struct timespec timeout;
+ timeout.tv_sec = n/1000000000;
+ timeout.tv_nsec = n%1000000000;
+ while (nanosleep(&timeout, &timeout) && errno == EINTR);
+}
+
+void msleep(uint32_t n) {
+ nsleep(1000000 * n);
+}
+
+#endif // _WIN32
+
+// a milliseconds timer for performance measurement
+uint64_t msclock() {
+#if defined(_WIN32)
+#include <sys/types.h>
+ struct _timeb t;
+ if (_ftime_s(&t)) {
+ return 0;
+ } else {
+ return 1000 * t.time + t.millitm;
+ }
+#else
+ struct timespec t;
+ clock_gettime(CLOCK_MONOTONIC, &t);
+ return (t.tv_sec * 1000 + t.tv_nsec / 1000000);
+#endif
+}