Function shs_core::client_to_server_key

pub fn client_to_server_key(
    server_pk: &ServerPublicKey, 
    net_key: &NetworkKey, 
    shared_a: &SharedA, 
    shared_b: &SharedB, 
    shared_c: &SharedC
) -> Key

Final shared key used to seal and open secret boxes (client to server)