[saag] OCB does not have an OID specified, that is a general problem

[Phillip Hallam-Baker <[e-mail]>]

Raising this in SAAG because this raises a policy issue and CFRG because
that is where the policy should be enforced. It is also relevant to LAMPS
but trying to avoid cross posting as everyone on the LAMPS list is likely
on SAAG.


rfc7253 specifies OCB mode. But there is no OID specified to use OCB with
CMS, nor are there identifiers for use with JOSE.

This is problematic to say the least. If an algorithm is worth publishing
as an RFC, there should be definitive identifiers for general purpose
packaging formats specified in that RFC.

I would like to propose that in future assignment of relevant OIDs and JOSE
identifiers be considered a requirement for similar work. If a spec for a
symmetric mode isn't sufficiently specified to enable interoperable
implementation in CMS and JOSE, it is not sufficiently specified to be an
RFC.

This would not cover TLS, IPSEC etc. since they have rather different
considerations. Algorithms are curated and selected as suites for TLS for a
start.

I am not a fan of having multiple registries for specifying identifiers for
algorithms. In fact if I had my way, there would be a single IANA text
registry because while we could write a spec for a cryptographic algorithm
and call it SMTP, that would be silly.

It seems to me that one registry for the ASN.1 identifiers and one for text
based identifiers is sufficient for all reasonable purposes. To the extent
that XML signature and encryption are still a thing, well why don't we just
specify a generic URN scheme for IANA registries and have done.