Java Security

Colleagues,

I need to transmit a formatted text file to a government agency using HTTP protocol (SMTP is not permitted) and for the life of me I cannot get this to work ... I can transmit fine but their server cannot decrypt my files. I must use multipart/signed with a syntax similar to this:

Content-type: multipart/signed;
protocol="application/pkcs7-signature";
micalg=<hash symbol>;
boundary="---------------------------9723347566394"

---------------------------9723347566394
Content-Type: Application/edi-consent
+<Formatted Text File/Object>+

-----------------------------9723347566394
Content-Type: application/pkcs7-signature
Cryptographic signature of EDI Object and associated headers+

-----------------------------9723347566394--

I need to digitally sign the Format Text/Object with PKCS#7 and put the output of that in the section of "*Cryptographic signature of EDI Object and associated headers*". How can I do that? Digitally Sign the file and then open it in a text editor and cut and paste the ASCII text?

Once I populate "*Cryptographic signature of EDI Object and associated headers*", I am then suppose the encrypt the whole file (headers and message body parts one & two) and then send it off via HTTP .

Can anyone point me to a working example of this? Or shed some light on how to accomplish this. The technical document that they gave me is useless.

Thanks in advance