Re: private algorithms and the DS record

[Samuel Weiler <weiler@tislabs.com>]

Ed writes:

> 1) If the private alg name is one not understood, there's no way to
> validate that the received DNSKEY set for X is genuine.

I'm confused.  Doesn't the DS hash already cover the name of the
algorithm, which is carried in the DNSKEY?  The validator doesn't need
to check the RRSIG(DNSKEY), just match the DNSKEY to the DS.  Yes,
someone could substitute in a DNSKEY with a different private
algorithm name, but, unless these cryptographic hashes aren't worth
the money we're paying for them, the DS won't match whatever the
attackers generate, right?

In other words, I think Ed's validator todo list is sufficient (which
adds the "if it's a private algorithm, get the DNSKEY and see if you
understand it" steps).

> maybe there's a way to squeeze the private alg name into the hash
> in the DS for private algorithms before it's too late.

I don't think this is needed.

As for updating the docs, I also prefer an RFC Editor note rather than
a separate doc.

-- Sam

--
to unsubscribe send a message to namedroppers-request@ops.ietf.org with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/namedroppers/>