Handling of boundary values in digest and encryption

Hi

I am developing a prototype SMIME application. I have a doubt regarding
the creation of digests and encrypting them. I would like to know what
exactly becomes the input for these operations. I have a multipart
message body. If I want to create a digest do I also include each and
every boundary delimiter line or just the boundary parameter value
defined at the content-type header field. I am slifgtly confused here.
If I am only doing encryption, does the input to the encryption
fucntion  include only the boundary parameter value and each boundary
delimiter line within a message or just the boundary parameter  value
defined at the header level?  I would be grateful if someone could help
me in this regard. Thank you very much for the time. I am eagerly
awaiting a reply.

cheers
Kasi Viswanathan