I have read that, but they used tcpdump only to detect what kind of traffic Siri sends after failing to use a normal HTTP proxy. Setting up a custom SSL certification authority is exactly what sshmitm does - but it does not (yet) support transparent proxying. Somehow they have redirected traffic for guzzoni.apple.com to a fake server that acts as a man in the middle (probably simply by using their own DNS), but what I wanted to know is what software they used to fake that server.