dh: Rename variables for DH key exchange
Rename and refactor how some variables are held in ssh_crypto_struct.
Refactor allocation of dh exchange public keys.
This is in preparation for switching the code to use openssl native DH
handling and allowed to better reason about the code and the overall API.
Signed-off-by: Simo Sorce <firstname.lastname@example.org>
Reviewed-by: Anderson Toshiyuki Sasaki <email@example.com>
Reviewed-by: Andreas Schneider <firstname.lastname@example.org>