Problem with signatures

Hi

I am trying to compose S/MIME messages with signed and encrypted data.
My question is:  what exactly is the input for the signing procedure? For
example(below), should
all the pkcs#7-mime headers(and the blank lines) be included when the signature
is calculated or is it only the base 64 encrypted data?
When this example is opened in Netscape Messenger the decryption works fine but
the signature is invalid, I am quite sure that I use the right certificates.

please advise

Andreas Rehn


Message-ID: <941020533(_at_)random-pc>
Date: Wednesday, 27/10/1999 12:35:33 +0200
From: Anders(_dot_)Jalm(_at_)sth(_dot_)frontec(_dot_)se
To: Anders(_dot_)Jalm(_at_)sth(_dot_)frontec(_dot_)se
Subject: encrypted to be signed
MIME-Version: 1.0
Content-Type: multipart/signed;  protocol="application/pkcs7-signature";
      micalg="sha1"; boundary="BOUNDARY"

--BOUNDARY
Content-Type: application/pkcs7-mime; name="test"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test"
Content-Description: S/MIME Encrypted Message

MIAGCSqGSIb...
...
...qVSnAAAAAA==

--BOUNDARY
Content-Type: application/pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature

MIAGCSqGSIb3D...
...UB2KZ9RcTbkAAAAAA==
--BOUNDARY--
.