Re: Firewall best practices

Carson Gaspar <[email protected]> Tue, 27 Apr 2010 16:34:16 -0500
Newsgroups gmane.comp.security.firewalls.wizards
Message-ID <[email protected]>
John Morrison wrote:
> My understanding of https (and other PKI-based encryption) is that
> only the holder of the private key can decrypt the data encrypted with
> the other (public) key in the pair. My view is that the firewall can
> only decrypt and inspect https traffic if it is acting as the server
> to the external client. It can't intercept and decrypt https traffic
> destined for another device - the real server. If it did https would
> be worthless. Any hacker could buy such a firewall to sniff and
> decrypt all https traffic.

Not entirely true. Way back when (1995/96) when I was hacking on 
firewall proxies I postulated a benevolent dictator MITM proxy for HTTPS 
(or other SSL services). This requires that you have your own signing CA 
and install its key as trusted in your users' browsers (or other 
software). The proxy can then impersonate the server and examine the 
traffic.

Since then, several implementations of such a beast have been created, 
some of which are open source.

-- 
Carson