GPGME - signing binary (PDF) files

[Razvan Deaconescu]

Hi!

I am sorry for posting this message both on the devel and users mailing
lists but I am not sure where a question related to GPGME should be
posted.

I am involved in a project that (on top of other things) has to sign PDF
documents. We are trying to sign PDF documents using gpg. It's very easy
to do that in the command line (using --sign, --detach-sig, --verify),
but we weren't able to do that with GPGME. We want to sign PDF documents
from within a C program.

The documentation mentions signing text files[1] but has no mention of
binary data.

Can a binary (PDF) file be signed using GPGME? If yes, could you point
the functions that should be called to enable this? We are interested in
something similar to the following command:
---
gpg --output doc.sig --detach-sig doc
---

Razvan

[1] http://www.fifi.org/cgi-bin/info2www?(gpgme)Creating+a+Signature