well firstly there appears to be a linux ssl client more than readily available from Nokia, how this works and where you actually get it from i wouldn't know, back to your vendor or such. Additionally an existing SSL client may well work with the VPN concentrator or firewall on the server side. So primarily i'd encourage you to explore a formal solution but....
SSH tunnels are normally created client side and so you'd want to be able to point your ssh client on linux at a port on a remote firewall that will either forward you to the box itself or another suitable box. in terms of actually setting it up, the puTTY docs give a nice friendly guide on what tunneling is, just ignore the puTTY / Windows specific stuff: http://people.hmdc.harvard.edu/~mathpre/vnc/putty/
and also a number of other docs help you understand what tunneling is all about
Seems that it is also possible to set up a server initiated tunnel though, which means that you should preumably have much less problems with firewalling as such, as you say you can already reach your home machine from work. have a look here, may be all you need to know... http://www.brandonhutchinson.com/ssh_tunnelling.html
It ends up being a little cryptic, but the benefits are huge for a minute overhead.