Developing DKIM using GNUtls

[Alessandro Vesely]

Hi all,
I have little crypto experience.  However, I've been using a dkim
library (OpenDKIM) based on OpenSSL to write a mail filter.  I'd like
to compile that library with GNUtls instead.  Is that possible?

I've browsed GNUtls' API page and found gnutls_fingerprint() can
produce required hashes, but haven't been able to find functions to
produce/verify RSA signatures using just the keys.  (DKIM does not use
x509 certificates.)

TIA
Ale