NaCl support for Emacs (was: GnuTLS for W32)

[Ted Zlatanov <tzz@lifelogs.com>]

Speaking of security libraries...

I'm interested in bringing in support for the NaCl cryptographic library
for Emacs, after 24.1 is out.  There is info on NaCl here:

http://nacl.cr.yp.to/index.html

The library is in the public domain, with no usage or distribution
restrictions.  I'm not sure if that means we can or can't include the
support.

My rationale for supporting this library is that it's fast, very simple
on the client side, and provides good security for arbitrary binary
payloads.  There are many places within Emacs where that's appropriate,
whereas heavyweight network-oriented security like GnuTLS is either not
appropriate or not usable.  An example is EPA/EPG, which currently
relies on the external GPG utility.  Emacs could provide similar
functionality (perhaps integrated with EPA/EPG, perhaps standalone)
without relying on external utilities if it has NaCl support.

NaCl can't replace GnuTLS for many reasons, but I think by itself it
would be a good addition to Emacs.  The C API is really simple compared
to GnuTLS, so the actual C support will not take long to write.

Thanks
Ted