http://www.iykpqm7jiradoeezzkhj7c4b33g4hbgfwelht2evxxeicbpjy44c7ead.onion/deeplinks/2012/03/https-and-tor-working-together-protect-your-privacy-and-security-online
If the Global Network Adversary (GNA) controls the relay through which you enter the Tor network and the relay through which you exit, the GNA can correlate the size and timing of your traffic to identify you on the Tor network. In this scenario, the GNA will have the origin and destination of your traffic, but if you are using HTTPS, they will not be able to read the content.