diff --git a/client/util.c b/client/util.c
index 3e6c7cdc6..5ae4ab862 100644
--- a/client/util.c
+++ b/client/util.c
@@ -23,6 +23,7 @@ uint8_t g_debugMode = 0;
 #include <termios.h>
 #include <sys/ioctl.h> 
 #include <unistd.h>
+#include <stdarg.h>
 
 int ukbhit(void) {
 	int cnt = 0;
@@ -120,6 +121,35 @@ void FillFileNameByUID(char *filenamePrefix, uint8_t *uid, const char *ext, int
 	strcat(filenamePrefix, ext); 
 }
 
+// fill buffer from structure [{uint8_t data, size_t length},...]
+int FillBuffer(uint8_t *data, size_t maxDataLength, size_t *dataLength, ...) {
+	*dataLength = 0;
+	va_list valist;
+	va_start(valist, dataLength);
+	
+	uint8_t *vdata = NULL;
+	size_t vlength = 0;
+	do{
+		vdata = va_arg(valist, uint8_t *);
+		if (!vdata)
+			break;
+		
+		vlength = va_arg(valist, size_t);
+		if (*dataLength + vlength >  maxDataLength) {
+			va_end(valist);
+			return 1;
+		}
+		
+		memcpy(&data[*dataLength], vdata, vlength);
+		*dataLength += vlength;
+		
+	} while (vdata);
+	
+	va_end(valist);
+
+	return 0;
+}
+
 void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex_len, const size_t hex_max_len, 
 	const size_t min_str_len, const size_t spaces_between, bool uppercase) {
 		
diff --git a/client/util.h b/client/util.h
index 637bfb3ca..a069b5012 100644
--- a/client/util.h
+++ b/client/util.h
@@ -187,6 +187,9 @@ extern void AddLogUint64(char *fileName, char *extData, const uint64_t data);
 extern void AddLogCurrentDT(char *fileName);
 extern void FillFileNameByUID(char *filenamePrefix, uint8_t * uid, const char *ext, int uidlen);
 
+// fill buffer from structure [{uint8_t data, size_t length},...]
+extern int FillBuffer(uint8_t *data, size_t maxDataLength, size_t *dataLength, ...);
+
 extern void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex_len, 
 						  const size_t hex_max_len, const size_t min_str_len, const size_t spaces_between,
 						  bool uppercase);