I wrote:
In other words in the 20-odd years that ASN.1 has been around, this pressing
need to save a handful of bytes in time encodings has never been an issue.
This suggests a simple solution...
Thinking about this a bit more, if the goal is to save space, why not combine
all of the mandatory attributes into a single meta-attribute:
compactAttributes ::= SEQUENCE {
signingTime GeneralisedTime,
contentType OBJECT IDENTIFIER,
messageDigest OCTET STRING
}
This would save many, many times as much space as binaryTime, and considerably
simplify decoding, since there's only one meta-attribute that contains all of
the signing attributes, so you eliminate all of the extra OIDs and several
layers of encoding wrappers around the invidual attributes.
(And I'd still have this as Experimental, pending any actual user demand for
it).
Peter.