private boolean isLetterOrDigit(char c) {
		if (c < '0') {
			return false;
		}
		if (c > '9' && c < 'A') {
			return false;
		}
		if (c > 'Z' && c < 'a') {
			return false;
		}
		return c <= 'z';
	}
Sets the X500 distinguished name for a user
@param username user name/SID
@param x500User X500 distinguished name
@return true if successful, false if user not found
@throws IOException if error occurs while updating user file
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/UserManager.java