Using GPGME

[David Anderson]

Hi all

First of all, apologies if this is not the right group to ask about 
GPGME. It seemed to be the best...

I am currently working on a projet which requires both authentication 
through signature verification and encryption of a session key.

I believe, through exploration of the texinfo manual, that I have 
managed to initialise libgpgme, create a working context. I also 
understand how to shuffle data through signature/verification and 
encryption/decryption. My only remaining obstable is how to retrieve the 
  keys!

Right now, our program is given the KeyID to use, and it must first look 
for it in the local keyring (with private section if required by the 
specific task), then search on a keyserver for the public part if all 
else fails. How would I implement this using gpgme functions? I can see 
that I must set the key location mode to either local or external, but 
the workings of the browsing/selection of a key elude me...

Thanks in advance for any help you can give me
David Anderson