Single point login

Don't know what to call this, but single sign on seems to be close, but i'll break it down.

Can nginx provide me with a solution to allow people to access a variety of services on a server, on a single port?

For example,

plex is on 36400
deluge is on 8117
http is on 80 and 8080

the first two are restricted to allow access to local network clients only, and plex goes even further by allowing full access to anyone on the local network. What i'm trying to do is provide a login point on a single port that can then access all the other services. This allows me to connect to the services via remote locations and still provide security in the form of a login.

Only other solution i've come across is a socks proxy, which does the trick, but i have some other ideas i want to implement which i think nginx will be able to help with. the main one is, the first page after login would offer a set of links to all the individual services, meaning i don't have to remember every port.

I reckon in terms of security, this might be better too, as i only have to manage security for one application (nginx) and can limit what ip's can access it. the firewall would reject every other port other than nginx's.

I hope this makes sense.