RFC 5272, "Certificate Management over CMS (CMC)", June 2008Source of RFC: pkix (sec)
Errata ID: 4186
Reported By: Pierce Leonberger
Date Reported: 2014-11-18
Rejected by: Kathleen Moriarty
Date Rejected: 2015-03-31
Section 220.127.116.11.2 says:
The Data content type allows for general transport of unstructured data. The Data content type is used by this document for: Holding the encrypted random value y for POP proof in the encrypted POP control (see Section 6.7).
It should say:
It's invalid for the encoding of an ANY or OpenType to have "unstructured" data. See X.690 section 8.15:
8.15 Encoding of an open type
The value of an open type is also a value of some (other) ASN.1 type. The encoding of such a value shall be the complete encoding herein specified for the value considered as being of that other type.
Note there's similar wording in X.209 section 21 for ANY:
21 Encoding of a value of the ANY type
The encoding of an ANY type shall be the complete encoding specified in this Recommendation for the type of the value of the ANY type.
The Data content type being referenced here is the Data content type from CMS. This type is defined as using an OCTET STRING wrapper around the data. Therefore unstructured data is not being placed at the ASN.1 level and the referenced text does not apply.