Different security options while invoking external rest services from Business Console gadget

while invoking rest services using rest connector wizard from designer to invoke external services from gadget , we have option to choose either IS or Other server details.
if you select others , then we have option to give usename and password. but if we provide credentials we can see those use name and password in auto-generated controller.js file in encrypted format.

How can we dynamically pass user name and pass word to call rest service in gadget to call rest service ? is anyone already did this in their project? need some help to do