Fixed UTF-8 passwords for DeviceCommunicationControl to hold up to 20 UTF-8 characters (#767)

src/bacnet/basic/service/h_dcc.c

@@ -24,7 +24,13 @@
 #include "bacnet/basic/services.h"
 #include "bacnet/datalink/datalink.h"
 
-static char My_Password[32] = "filister";
+/* The byte length of a UTF-8 character can vary.
+ * In UTF-8, the number of bytes used to represent a character can range from 1
+ * to 4 bytes. Commonly used characters in the ASCII set are represented by 1
+ * byte,xi while other Unicode characters may require 2, 3, or 4 bytes. Let's
+ * add space for the null '\0' termination byte.
+ * */
+static char My_Password[20 * 4 + 1] = "filister";
 
 /** Sets (non-volatile hold) the password to be used for DCC requests.
  * @param new_password [in] The new DCC password, of up to 31 characters.