Secure connections

[Leiradella, Andre V Matos Da Cunha]

Does anybody can point me the functions I need to:

. Generate a key pair;
. Encrypt/Decrypt a data buffer using one of the keys.

I'm gonna use gnupg to start a secure client-server connection to exchange a
DES (does DES do the job?) key that will be used to encrypt/decrypt all data
that passes over the connection. I know automatic generation of keys suck
because random number generators suck too, but I'll probably by using an
external hardware to generate true (?) random numbers.

Thanks in advance,

Andre de Leiradella