Re: More on KEKIdentifiers, and a suggested addition to CMS

[[e-mail] (John Pawling)]

John,

You stated:
>I agree with Peter, CMS should allow the extension of the Choice syntax
> i.e. in text using  the old ASN.1 rules), which gives a good pointer to the
>implementors that they should not object if the they receive an extended
>choice.

I agree that the CMS RecipientInfo CHOICE syntax could be modified in future
versions of CMS through the addition of well-defined ASN.1 syntaxes, but I
disagree that adding "..." in the current CMS RecipientInfo syntax adds any
value.  If your use of "extended choice" refers to a RecipientInfo including
a CHOICE alternative not specified in the CMS document, then I object to
your statement that implementors "should not object if the they receive an
extended choice."  Please see my previous message for the explanation of why
I object to the premise that it is straightforward for recipient software to
ignore undefined CHOICE alternatives. 

- John Pawling