Re: [Cbor] [COSE] CBOR magic number, file format and tags

[John Mattsson <[e-mail]>]

Hi,

It seems like there is agreement to specify a CBOR tag for a CBOR certificate. I stated specifying this for the next -07 version, se below.

I started to specify a tag based on Laurance suggestion to tag an array wrapping the CBOR Sequence. I don't know how to best specify this data item. It would have been easy before when the CBOR Sequence was specified as a CDDL group. Now when CBORCertificate is specified as an array with human-readable text specifying that it is really a CBOR sequence, both CBORCertificate and [ CBORCertificate ] seems wrong....

Would a tag for a chain/bag or both be needed as well? If a tag for COSE_X509 with CBOR certificates is specified, that could potentially be used to tag a single certificate as well.

Maybe it is confusing to use the COSE_X509 CDDL for CBOR certificates? A new structure for CBOR certificates could then also be more compact by wrapping the certs in arrays instead of bstr.

---------

## CBOR Tags Registry {#tags}

This document registers the following entries in the "CBOR Tags" registry under the "Concise Binary Object Representation (CBOR) Tags" heading.

~~~~~~~~~~~
+------+------------------------------------------------------------+
|  Tag | X.509 Public Key Algorithms                                |
+======+============================================================+
| TDB6 | Data Item: [ CBORCertificate ]                             |
|      | Semantics: The CBORCertificate CBOR sequence wrapped in an |
|      |            array.                                          |
|      | Reference: This document                                   |
+------+------------------------------------------------------------+
| TDB7 | Data Item: COSE_X509                                       |
|      | Semantics: The content of each bstr is the bytes of a CBOR |
|      |            Certificate.                                    |
|      | Reference: This document                                   |
+------+------------------------------------------------------------+
~~~~~~~~~~~