S/MIME “application/pkcs7-mime”
MIME “application” content type is intended for data that does not fit into other media types
- especially data to be processed by a program
S/MIME defines “pkcs7-mime” subtype to carry CMS enveloped-data and signed-data objects
CMS objects are binary data that need special application processing that is not in basic MIME
- defined using ASN.1
- encoded using BER and DER
- usually need transfer encoding, such as “base64”