relayd as transparent HTTPS proxy

[Gianfranco Gallizia]

Hello everyone, I have a question regarding relayd(8) in OpenBSD 5.3

I was playing a little with relayd as a transparent proxy with URL
filtering using this relayd.conf:

        
        http protocol httpfilter {
                # Return HTML error pages
                return error

                header change "Connection" to "close"

                # Block requests to unwated hosts
                request url filter file "/etc/blacklist.txt"
        }

        relay httpproxy {
                listen on 127.0.0.1 port 8080
                protocol "httpfilter"
                forward to destination
        }

then I've added this line to my pf.conf:

pass quick inet proto tcp to port http divert-to 127.0.0.1 port 8080

So far everything is working fine: pf redirects all the HTTP traffic on
the standard TCP port and relayd takes care of the rest filtering out
anything I place in /etc/blacklist.txt

Is it possible to do so for HTTPS connections too? I've found a lot of
tutorial/documentation aiming at SSL accelleration but none about
transparent SSL proxy. As far as I know "forward to destination" doesn't
have a ssl option like "forward with ssl to $address".

I fear I am looking at the problem from the wrong side, so I've
decided to ask for advice before messing with the conf files and/or
looking at the source code of relayd.

Thanks for your time,

Gianfranco Gallizia