Using an RSA GnuPG key for RSA ?

[Leo Gaspard]

On Fri, Apr 04, 2014 at 01:32:47PM -0400, vedaal at nym.hush.com wrote:
> I trust them to encrypt to my public key, and was planning to work out
> a system where I could decrypt on my own without it going through
> them.
> (they could have my public key, and verify my RSA signature).
> 
> [All this is in the theoretical planning stage ;-)  
> first I would need to be able to isolate my RSA part of my GnuPG key
> and see if it can be used with an open source simple RSA program
> offline.
> 
> That was my original question.]
> vedaal

Well... As this seems not documented (otherwise I guess someone else would have
answered you), I'm going to assume there is no such function available in gnupg.

So, this (and the reasons explained by Sam) explains the reason why I'm trying
to figure out what you actually want to do, in order to perhaps propose you
another solution, instead of merely answering you to write your own extractor.

So, if you forgive my bluntness... With what closed program are you trying to
interface? Why would you want to use your pgp keypair for this program, and not
a key generated for this use?