On 8/9/18, 20:24, "DNSOP on behalf of Paul Wouters" <dnsop-boun...@ietf.org on 
behalf of p...@nohats.ca> wrote:

>The point was to allow redistribution and to not depend on a trusted source 

That, FWIW, is the heart of DNSSEC.  Source authentication and data integrity 
for data sets is the advertised goal (as well as provable non-existence) of the 
extensions.  The DNS is not a strict client-server protocol, there is no 
telling what path a resource record (set) would take from the zone 
administrator to the would-be validating receiver.

Originally the set of paths included authoritative servers, forwarding servers, 
recursive servers, iterative servers, and such down to the point where DNSSEC 
validation could no longer be done.  (Originally, CPU horsepower and reliable 
libraries weren't assumed to me on end devices, hence the stub resolvers aren't 
included.  No reason they couldn't, no reason applications can't validate, 
except for performance/trust anchor management concerns.)

Now we are envisioning the transfer of zones in bulk, not just single datasets, 
via non-port 53 means.  But is that any different?  Does it really matter 
whether RSYNC of a zone was used to get a dataset from A to B?

There is a concern I can see.  When a server is loaded from disk (secondary 
storage), it does not validate the DNSSEC records to save time.  There's a risk 
that a maliciously inserted zone version be loaded and served, possible if the 
channel security is defeated.  But, if that happens, validating recipients of 
data sets will fail the data sets that are altered.  While this could be a 
denial of service for the server, but DNS provides fallback to other servers so 
relying parties are just as protected as they ordinarily are (including, no 
DNSSEC, no protection...).

How realistic is it that a forged zone could defeat all of the channel security 
for a zone?  How likely would it be for someone to load a false zone on all the 
places a recursive server would look for it?  Answering that would be a crucial 
step in deciding whether to add a zone hash mechanism.

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