I need to inspect a part of the HTTPS traffic passing through my Linux (CentOS 6.5) router. In particular I need to know which destination web site host is being requested by the user. The user can be a guest browser / device over which I have no control (i.e. can't deploy certificates). I don't care about the contents / payload, I just need to log the destination URL into a log file :-)
It's open in terms of technology, I'm not limited and can therefore use iptables, squid, or any other filter that runs on Linux (preferably not a commercial one - some of those are licensed by device). Or even a combination of the above.
I am pretty sure this can be done because if I can install Fiddler on my windows machine and browse HTTPS web sites using Chrome without certificate warnings and see the "host" in Fiddler.
I have spent some time searching to see how this can be done, but so far have hit limitations with certificates needing to be installed on client browsers. That, and I could only find string matching for iptables but from what I understand that won't work with HTTPS packets as they are encrypted (I wrongly thought that the destination would not be encrypted ?)
Any help with this would be appreciated, hope I've covered the requirements in enough details.