I am currently attempting to determine if there is anything in the S/MIME
standard that would allow me to determine if a message was, for example,
signed then encrypted, without processing any of the security layers.
My understanding of the smime-type parameter is that it only applies to the
current layer of security, so for example, a message that was signed and
then encrypted will have an outer smime-type of enveloped-data with no clue
that there is a signature layer within.
Any insight into this is much appreciated.