+
+// -------------------------------------------------------------------------
+// string parameters lib
+// -------------------------------------------------------------------------
+
+// -------------------------------------------------------------------------
+// line - param line
+// bg, en - symbol numbers in param line of beginning an ending parameter
+// paramnum - param number (from 0)
+// -------------------------------------------------------------------------
+int param_getptr(const char *line, int *bg, int *en, int paramnum)
+{
+ int i;
+ int len = strlen(line);
+
+ *bg = 0;
+ *en = 0;
+
+ // skip spaces
+ while (line[*bg] ==' ' || line[*bg]=='\t') (*bg)++;
+ if (*bg >= len) {
+ return 1;
+ }
+
+ for (i = 0; i < paramnum; i++) {
+ while (line[*bg]!=' ' && line[*bg]!='\t' && line[*bg] != '\0') (*bg)++;
+ while (line[*bg]==' ' || line[*bg]=='\t') (*bg)++;
+
+ if (line[*bg] == '\0') return 1;
+ }
+
+ *en = *bg;
+ while (line[*en] != ' ' && line[*en] != '\t' && line[*en] != '\0') (*en)++;
+
+ (*en)--;
+
+ return 0;
+}
+
+
+char param_getchar(const char *line, int paramnum)
+{
+ int bg, en;
+
+ if (param_getptr(line, &bg, &en, paramnum)) return 0x00;
+
+ return line[bg];
+}
+
+uint8_t param_get8(const char *line, int paramnum)
+{
+ return param_get8ex(line, paramnum, 0, 10);
+}
+
+/**
+ * @brief Reads a decimal integer (actually, 0-254, not 255)
+ * @param line
+ * @param paramnum
+ * @return -1 if error
+ */
+uint8_t param_getdec(const char *line, int paramnum, uint8_t *destination)
+{
+ uint8_t val = param_get8ex(line, paramnum, 255, 10);
+ if( (int8_t) val == -1) return 1;
+ (*destination) = val;
+ return 0;
+}
+/**
+ * @brief Checks if param is decimal
+ * @param line
+ * @param paramnum
+ * @return
+ */
+uint8_t param_isdec(const char *line, int paramnum)
+{
+ int bg, en;
+ //TODO, check more thorougly
+ if (!param_getptr(line, &bg, &en, paramnum)) return 1;
+ // return strtoul(&line[bg], NULL, 10) & 0xff;
+
+ return 0;
+}
+
+uint8_t param_get8ex(const char *line, int paramnum, int deflt, int base)
+{
+ int bg, en;
+
+ if (!param_getptr(line, &bg, &en, paramnum))
+ return strtoul(&line[bg], NULL, base) & 0xff;
+ else
+ return deflt;
+}
+
+uint32_t param_get32ex(const char *line, int paramnum, int deflt, int base)
+{
+ int bg, en;
+
+ if (!param_getptr(line, &bg, &en, paramnum))
+ return strtoul(&line[bg], NULL, base);
+ else
+ return deflt;
+}
+
+uint64_t param_get64ex(const char *line, int paramnum, int deflt, int base)
+{
+ int bg, en;
+
+ if (!param_getptr(line, &bg, &en, paramnum))
+ return strtoull(&line[bg], NULL, base);
+ else
+ return deflt;
+
+ return 0;
+}
+
+int param_gethex(const char *line, int paramnum, uint8_t * data, int hexcnt)
+{
+ int bg, en, temp, i;
+
+ if (hexcnt % 2)
+ return 1;
+
+ if (param_getptr(line, &bg, &en, paramnum)) return 1;
+
+ if (en - bg + 1 != hexcnt)
+ return 1;
+
+ for(i = 0; i < hexcnt; i += 2) {
+ if (!(isxdigit(line[bg + i]) && isxdigit(line[bg + i + 1])) ) return 1;
+
+ sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
+ data[i / 2] = temp & 0xff;
+ }
+
+ return 0;
+}
+int param_gethex_ex(const char *line, int paramnum, uint8_t * data, int *hexcnt)
+{
+ int bg, en, temp, i;
+
+ //if (hexcnt % 2)
+ // return 1;
+
+ if (param_getptr(line, &bg, &en, paramnum)) return 1;
+
+ *hexcnt = en - bg + 1;
+ if (*hexcnt % 2) //error if not complete hex bytes
+ return 1;
+
+ for(i = 0; i < *hexcnt; i += 2) {
+ if (!(isxdigit(line[bg + i]) && isxdigit(line[bg + i + 1])) ) return 1;
+
+ sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
+ data[i / 2] = temp & 0xff;
+ }
+
+ return 0;
+}
+int param_getstr(const char *line, int paramnum, char * str)
+{
+ int bg, en;
+
+ if (param_getptr(line, &bg, &en, paramnum)) return 0;
+
+ memcpy(str, line + bg, en - bg + 1);
+ str[en - bg + 1] = 0;
+
+ return en - bg + 1;
+}
+
+/*
+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);
+}
+
+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;
+}