Function tsproto::algorithms::compute_iv_mac

pub fn compute_iv_mac(
    alpha: &[u8; 10], 
    beta: &[u8; 54], 
    our_key: &EccKeyPrivEd25519, 
    other_key: &EdwardsPoint
) -> ([u8; 64], [u8; 8])

Compute shared iv and shared mac.