Re: [saag] A case against algorithm agility (long)

[Yoav Nir <[e-mail]>]

On May 4, 2014, at 2:46 PM, ianG <[e-mail]> wrote:

> On 4/05/2014 04:10 am, Benjamin Kaduk wrote:
> 
>> That there is even a
>> commercial market for it suggests that they are in use, and not just by
>> people who could by pass the crypto.
> 
> 
> Yes, this is fascinating.  There's also the SSL-interceptor boxes which
> allegedly will take your commercially provided sub-Root.  Who uses those
> machines and why?

These boxes are used for whatever purpose people want access to the plaintext for. Uses range from running so-called "next generation firewall”([1]) policy on them, to looking for dissidents in certain countries.

Commercial CAs rarely give sub-root certificates, and when they do, they have  name constraints ([2]), so they can’t be used for generating fake certificates for mail.google.com.  These boxes generally either generate their own self-signed CA, or get a corporate sub-CA. Either way, it requires clients to be configured with the interception CA.

Yoav 

[1] “next generation firewall” is a marketing term, but in general classic firewall can block addresses, protocols and ports, whereas “next generation” looks at higher layers as well. So a classic firewall can block your access to Facebook, a next-generation firewall can block your access to Farmville.
[2] Yes, there were cases where this was not followed.