Hi CBOR/COSE enthusiasts! During the design of the (in)famous Embedded Signature specification and associated implementations [*}, I stumbled over the type of the COSE algorithm ID, in CDDL defined as "tstr/int". A problem is that my CBOR implementations do not really support "int" since this effectively translates to a 65-bit integer. A quick consultation with the associated IANA Designated Expert (Carsten Bormann) revealed that IANA would not accept COSE algorithm IDs even above the JavaScript 53-bit level.
A similar issue arose with "iat" in CWT. Although it might be cool with timestamps spanning billions of years forward and backward, this is not particularly interoperable with current time APIs. To cope with such issues, my primary project (creating a cross-platform profile for CBOR), defines a set of "standardized", presumably portable, CBOR protocol primitives: https://www.ietf.org/archive/id/draft-rundgren-cbor-core-24.html#name-protocol-primitives For the COSE-derived solutions, the type of "alg" was set to int32 while limiting "iat" to the range defined by the I-D: 0 ("1970‑01‑01T00:00:00Z") to 253402300799 ("9999‑12‑31T23:59:59Z"). Anders *] https://test.webpki.org/csf-lab _______________________________________________ COSE mailing list -- [email protected] To unsubscribe send an email to [email protected]
