pub fn derive_wrap_key(
our_secret: &StaticSecret,
their_pub: &PublicKey,
) -> [u8; 32]Expand description
Derive the 32-byte wrap key both sides compute: HKDF-SHA256 over the raw
X25519 ECDH shared secret of our_secret and their_pub. The owner uses it
to passphrase::wrap the session key; the joiner uses it to unwrap.