Method ConsumeMessageInitiation

device/noise-protocol.go:340–442

(msg *MessageInitiation)

}

func (device *Device) ConsumeMessageInitiation(msg *MessageInitiation) *Peer {
	var (
		hash     [blake2s.Size]byte
		chainKey [blake2s.Size]byte
	)

	if msg.Type != MessageInitiationType {
		return nil
	}

	device.staticIdentity.RLock()
	defer device.staticIdentity.RUnlock()

	mixHash(&hash, &InitialHash, device.staticIdentity.publicKey[:])
	mixHash(&hash, &hash, msg.Ephemeral[:])
	mixKey(&chainKey, &InitialChainKey, msg.Ephemeral[:])

	// decrypt static key
	var peerPK NoisePublicKey
	var key [chacha20poly1305.KeySize]byte
	ss, err := device.staticIdentity.privateKey.sharedSecret(msg.Ephemeral)
	if err != nil {
		return nil
	}
	KDF2(&chainKey, &key, chainKey[:], ss[:])
	aead, _ := chacha20poly1305.New(key[:])
	_, err = aead.Open(peerPK[:0], ZeroNonce[:], msg.Static[:], hash[:])
	if err != nil {
		return nil
	}
	mixHash(&hash, &hash, msg.Static[:])

	// lookup peer

	peer := device.LookupPeer(peerPK)
	if peer == nil || !peer.isRunning.Load() {
		return nil
	}

	handshake := &peer.handshake

	// verify identity

	var timestamp tai64n.Timestamp

	handshake.mutex.RLock()

	if isZero(handshake.precomputedStaticStatic[:]) {
		handshake.mutex.RUnlock()
		return nil
	}
	KDF2(
		&chainKey,
		&key,
		chainKey[:],
		handshake.precomputedStaticStatic[:],
	)
	aead, _ = chacha20poly1305.New(key[:])