Re: Firewall best practices

Sorry - read the paper.  It boils down to included "already trusted CA's" on the browser and a complicit CA cooperating with a nefarious entity to issue another cert for a targeted domain.

The hardware device the paper refers to can have this cert installed and proceed to impersonate the targeted domain thus decrypting all traffic destined for that destination.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Cian Brennan
Sent: Wednesday, April 28, 2010 4:14 AM
To: Firewall Wizards Security Mailing List
Cc: [email protected]; Firewall Wizards Security Mailing List
Subject: Re: [fw-wiz] Firewall best practices

On Tue, Apr 27, 2010 at 11:12:40AM -0500, Fetch, Brandon wrote:
> Too late:
> http://files.cloudprivacy.net/ssl-mitm.pdf
> 
> And these devices are already in deployment...now, imagine one of these with a wildcard certificate running at a coffee house, or at the aggregation point within a provider's CO POP...
> 
Where it would generate cert errors for every user?

These only make sense where you can install the proxy's wildcard cert on all of
the client machines. Neither coffee houes, nor ISPs can do this.

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of John Morrison
> Sent: Tuesday, April 27, 2010 5:45 AM
> To: Firewall Wizards Security Mailing List
> Cc: [email protected]; Firewall Wizards Security Mailing List
> Subject: Re: [fw-wiz] Firewall best practices
> 
> 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.
> 
> On 23 April 2010 20:18,  <[email protected]> wrote:
> > On Fri, 23 Apr 2010, Martin Barry wrote:
> >
> >> $quoted_author = "Marcus J. Ranum" ;
> >>>
> >>> That's why firewalls need to go back to doing what they
> >>> originally did, and parsing/analyzying the traffic that
> >>> flows through them, rather than "stateful packet
> >>> inspection" (which, as far as I can tell, means that
> >>> there's a state-table entry saying "I saw SYN!")
> >>
> >> Marcus, are you referring to DPI or proxies or both or something else
> >> entirely?
> >>
> >>
> >>> If the firewall doesn't understand the data it's passing,
> >>> it's not a firewall, it's a hub.
> >>
> >> If an application emulates HTTPS traffic and is proxy aware, how do you
> >> tell
> >> the difference?
> >
> > There are firewalls on the market that can decrypt HTTPS traffic (and I
> > believe be configured to block any traffic that they can't decrypt)
> >
> > David Lang
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> >
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