How does one use the openssl lib to establish a session in the
following way:

Alice (client) loads the trusted public key of Bob (server), from a
cached file. Bob's server gets a connection from
Alice, and negotiates a session without any certificate signing.

All the howto I've read assume the public key must be sent to ALice on
an insecure channel. This project can assume Alice already has Bob's
public keys. (PEM format.)

How do you prepare the SSL struct for SSL_connect(..) and
SSL_accept(..)?

c code or the url of a good how-to would be appreciated. Thanks in
advance.