[DNSOP] threat model for draft-ietf-dnsop-domain-verification-techniques

[Erik Nygren <[e-mail]>]

I've written up a first pass PR for a threat model for DCV
(draft-ietf-dnsop-domain-verification-techniques):

https://github.com/ietf-wg-dnsop/draft-ietf-dnsop-domain-verification-techniques/pull/206

There aren't many precedents for including a threat model in an IETF draft
so it's possible that we will need to iterate on this some. Most other
threat models appear to be stand-alone RFCs. I drew from STAMP terminology
here, but rather than incorporating this as an analysis I list the
Unacceptable Losses and Hazards up-front and then reference them throughout
from the sections intended to mitigate them.

Placement and length of the threat model is also a trade-off here, but
given that this draft's purpose is to mitigate the threats it seemed worth
including it early on (but not so early as to lack context for the reader).
Feedback is welcome.  If it looks good we'll fold it in and make a few of
the other changes queued up and then publish a new draft.

Best, Erik