hat tip to .gov hostmasters

David Conrad drc at virtualized.org
Mon Sep 22 12:16:09 CDT 2008


On Sep 22, 2008, at 8:11 AM, Keith Medcalf wrote:
>> Correct, you need a validating, security-aware stub resolver, or the
>> ISP needs to validate the records for you.
>
> That would defeat the entire purpose of using DNSSEC.  In order for  
> DNSSEC to actually provide any improvement in security whatsoever,  
> the ROOT ZONE (.) needs to be signed, and every delegation up the  
> chain needs to be signed.

The root does not need to be signed to provide security improvement.   
If you have configured the (say) .SE trust anchor in your validating  
resolver, you greatly reduce the chances that any lookup for a name  
in .SE can be spoofed.  The downside of not having the root signed is  
that you need to maintain multiple trust anchors.

> And EVERY resolver (whether recursive or local on host) needs to  
> understand and enforce DNSSEC.

I personally believe it is more-or-less safe to trust communications  
local to the machine.  As such, running a validating resolver on your  
local host would suffice.  Having a stub resolver also validate in  
this scenario would be overkill.

> If even one delegation is unsigned or even one resolver does not  
> enforce DNSSEC, then, from an actual security perspective, you will  
> be far worse off than you are now.

In what way?  I'm running a validating resolver on my laptop (using  
the signed root zone and trust anchor available from ns.iana.org so I  
only have to deal with one trust anchor).  If someone tries to spoof a  
name in the root, .SE, .BG, .PR, .BR, .CZ, their efforts will fail.   
How is this worse off than before I configured my resolver?

> Until such time as EVERY SINGLE DOMAIN including the root is signed  
> and every single DNS Server and resolver (including the local host  
> resolvers) understand and enforce DNSSEC you should realize that  
> DNSSEC does nothing for you whatsoever except give the uneducated a  
> false sense of "security".

If this were true, DNSSEC would be a complete waste of time.   
Fortunately, it isn't true.

Regards,
-drc





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