Currently to add an SSL cert to use the web interface with https enabled a rather involved and error prone procedure, partly described here, needs to be performed. This involves logging in to the console of the router, uploading the SSL cert and editing the configuration of uhttpd.
Accessing the router via https at its hostname e.g. 'https://my-rutx11.my-domain.com' will cause the browser to warn about an invalid SSL cert for my-rutx11.my-domain.com. Adding the cert to the browser as an exception is not, I feel, a viable solution, nor is using an SSH tunnel as suggested else where.
It would be nice to be able to use the Web Interface to upload and install a self signed or issued SSL cert for uhttpd to use to properly secure the Web Interface.
I believe this feature is a necessary and would make the RUTX11(and siblings) more secure and only enhance an already feature rich product.
N.B. This doesn't seem to be solved with "System->Administration->Root CA".