Playing around with this half-baked feature that has somehow made it to the GA release of vSphere 6.0, you’ll notice that capability to publish the library for future use. As such a URL is presented like so:
Clicking the URL presents the following authentication box, which is also a given since “Password Protected” is set to yes. Anyways, the authentication box says:
A username and password are being requested by https://vcenter60.domain.local. The site says: “VCSP Authentication”
Searched high and low for an answer to this and then stumbled upon a VMware vCloud kb article here. Basically, the username will be vcsp and the password will be what was created at the time the library was being published.