I'm extremely puzzled by the following paragraph from RFC 1421:
4.6.4.2 Key-Info Field
One "Key-Info:" field is included for each of a message's named
recipients. In addition, it is recommended that PEM implementations
support (as a locally-selectable option) the ability to include a
"Key-Info:" field corresponding to a PEM message's originator,
following an Originator-ID or "Originator-Certificate:" field and
before any associated Recipient-ID fields, but inclusion of such a
field is not a requirement for conformance with this RFC.
Does anyone know what the semantics of this locally-selectable option are?
That is, if you see a Key-Info field immediately following an Originator-
Certificate, what do you do with its contents and what does this tell you
about the message?
Mike