Refactoring for HomeKit client

pkg/hap/README.md

@@ -0,0 +1,33 @@
+# Home Accessory Protocol
+
+> PS. Character = Characteristic
+
+**Device** - HomeKit end device (swith, camera, etc)
+
+- mDNS name: `MyCamera._hap._tcp.local.`
+- DeviceID - mac-like: `0E:AA:CE:2B:35:71`
+- HomeKit device is described by:
+  - one or more `Accessories` - has `AID` and `Services`  
+  - `Services` - has `IID`, `Type` and `Characters`  
+  - `Characters` - has `IID`, `Type`, `Format` and `Value`
+
+**Client** - HomeKit client (iPhone, iPad, MacBook or opensource library)
+
+- ClientID - static random UUID
+- ClientPublic/ClientPrivate - static random 32 byte keypair
+- can pair with Device (exchange ClientID/ClientPublic, ServerID/ServerPublic using Pin)
+- can auth to Device using ClientPrivate
+- holding persistant Secure connection to device
+- can read device Accessories
+- can read and write device Characters
+- can subscribe on device Characters change (Event)
+
+**Server** - HomeKit server (soft on end device or opensource library)
+
+- ServerID - same as DeviceID (using for Client auth)
+- ServerPublic/ServerPrivate - static random 32 byte keypair
+
+## Useful links
+
+- [Extracting HomeKit Pairing Keys](https://pvieito.com/2019/12/extract-homekit-pairing-keys)
+- [HAP in AirPlay2 receiver](https://github.com/openairplay/airplay2-receiver/blob/master/ap2/pairing/hap.py)

pkg/hap/accessory.go

@@ -0,0 +1,62 @@
+package hap
+
+type Accessory struct {
+	AID      int        `json:"aid"`
+	Services []*Service `json:"services"`
+}
+
+type Accessories struct {
+	Accessories []*Accessory `json:"accessories"`
+}
+
+type Characters struct {
+	Characters []*Character `json:"characteristics"`
+}
+
+func (a *Accessory) GetService(servType string) *Service {
+	for _, serv := range a.Services {
+		if serv.Type == servType {
+			return serv
+		}
+	}
+	return nil
+}
+
+func (a *Accessory) GetCharacter(charType string) *Character {
+	for _, serv := range a.Services {
+		for _, char := range serv.Characters {
+			if char.Type == charType {
+				return char
+			}
+		}
+	}
+	return nil
+}
+
+func (a *Accessory) GetCharacterByID(iid int) *Character {
+	for _, serv := range a.Services {
+		for _, char := range serv.Characters {
+			if char.IID == iid {
+				return char
+			}
+		}
+	}
+	return nil
+}
+
+type Service struct {
+	IID         int          `json:"iid"`
+	Type        string       `json:"type"`
+	Primary     bool         `json:"primary,omitempty"`
+	Hidden      bool         `json:"hidden,omitempty"`
+	Characters  []*Character `json:"characteristics"`
+}
+
+func (s *Service) GetCharacter(charType string) *Character {
+	for _, char := range s.Characters {
+		if char.Type == charType {
+			return char
+		}
+	}
+	return nil
+}

pkg/hap/camera/client.go

@@ -0,0 +1,100 @@
+package camera
+
+import (
+	"errors"
+	"github.com/AlexxIT/go2rtc/pkg/hap"
+	"github.com/brutella/hap/characteristic"
+	"github.com/brutella/hap/rtp"
+)
+
+type Client struct {
+	client *hap.Conn
+}
+
+func NewClient(client *hap.Conn) *Client {
+	return &Client{client: client}
+}
+
+func (c *Client) StartStream(ses *Session) (err error) {
+	// Step 1. Check if camera ready (free) to stream
+	var srv *hap.Service
+	if srv, err = c.GetFreeStream(); err != nil {
+		return err
+	}
+	if srv == nil {
+		return errors.New("no free streams")
+	}
+
+	if ses.Answer, err = c.SetupEndpoins(srv, ses.Offer); err != nil {
+		return
+	}
+
+	return c.SetConfig(srv, ses.Config)
+}
+
+// GetFreeStream search free streaming service.
+// Usual every HomeKit camera can stream only to two clients simultaniosly.
+// So it has two similar services for streaming.
+func (c *Client) GetFreeStream() (srv *hap.Service, err error) {
+	var accs []*hap.Accessory
+	if accs, err = c.client.GetAccessories(); err != nil {
+		return
+	}
+
+	for _, srv = range accs[0].Services {
+		for _, char := range srv.Characters {
+			if char.Type == characteristic.TypeStreamingStatus {
+				status := rtp.StreamingStatus{}
+				if err = char.ReadTLV8(&status); err != nil {
+					return
+				}
+
+				if status.Status == rtp.SessionStatusSuccess {
+					return
+				}
+			}
+		}
+	}
+
+	return nil, nil
+}
+
+func (c *Client) SetupEndpoins(
+	srv *hap.Service, req *rtp.SetupEndpoints,
+) (res *rtp.SetupEndpointsResponse, err error) {
+	// get setup endpoint character ID
+	char := srv.GetCharacter(characteristic.TypeSetupEndpoints)
+	char.Event = nil
+	// encode new character value
+	if err = char.Write(req); err != nil {
+		return
+	}
+	// write (put) new endpoint value to device
+	if err = c.client.PutCharacters(char); err != nil {
+		return
+	}
+
+	// get new endpoint value from device (response)
+	if err = c.client.GetCharacter(char); err != nil {
+		return
+	}
+	// decode new endpoint value
+	res = &rtp.SetupEndpointsResponse{}
+	if err = char.ReadTLV8(res); err != nil {
+		return
+	}
+
+	return
+}
+
+func (c *Client) SetConfig(srv *hap.Service, config *rtp.StreamConfiguration) (err error) {
+	// get setup endpoint character ID
+	char := srv.GetCharacter(characteristic.TypeSelectedStreamConfiguration)
+	char.Event = nil
+	// encode new character value
+	if err = char.Write(config); err != nil {
+		panic(err)
+	}
+	// write (put) new character value to device
+	return c.client.PutCharacters(char)
+}

pkg/hap/camera/session.go

@@ -0,0 +1,75 @@
+package camera
+
+import (
+	cryptorand "crypto/rand"
+	"encoding/binary"
+	"github.com/brutella/hap/rtp"
+)
+
+type Session struct {
+	Offer  *rtp.SetupEndpoints
+	Answer *rtp.SetupEndpointsResponse
+	Config *rtp.StreamConfiguration
+}
+
+func NewSession(vp *rtp.VideoParameters, ap *rtp.AudioParameters) *Session {
+	vp.RTP = rtp.RTPParams{
+		PayloadType: 99,
+		Ssrc:        RandomUint32(),
+		Bitrate:     2048,
+		Interval:    10,
+		MTU:         1200, // like WebRTC
+	}
+	ap.RTP = rtp.RTPParams{
+		PayloadType:             110,
+		Ssrc:                    RandomUint32(),
+		Bitrate:                 32,
+		Interval:                10,
+		ComfortNoisePayloadType: 98,
+		MTU:                     0,
+	}
+
+	sessionID := RandomBytes(16)
+	s := &Session{
+		Offer: &rtp.SetupEndpoints{
+			SessionId: sessionID,
+			Video: rtp.CryptoSuite{
+				MasterKey:  RandomBytes(16),
+				MasterSalt: RandomBytes(14),
+			},
+			Audio: rtp.CryptoSuite{
+				MasterKey:  RandomBytes(16),
+				MasterSalt: RandomBytes(14),
+			},
+		},
+		Config: &rtp.StreamConfiguration{
+			Command: rtp.SessionControlCommand{
+				Identifier: sessionID,
+				Type:       rtp.SessionControlCommandTypeStart,
+			},
+			Video: *vp,
+			Audio: *ap,
+		},
+	}
+	return s
+}
+
+func (s *Session) SetLocalEndpoint(host string, port uint16) {
+	s.Offer.ControllerAddr = rtp.Addr{
+		IPAddr:       host,
+		VideoRtpPort: port,
+		AudioRtpPort: port,
+	}
+}
+
+func RandomBytes(size int) []byte {
+	data := make([]byte, size)
+	_, _ = cryptorand.Read(data)
+	return data
+}
+
+func RandomUint32() uint32 {
+	data := make([]byte, 4)
+	_, _ = cryptorand.Read(data)
+	return binary.BigEndian.Uint32(data)
+}

pkg/hap/character.go

@@ -0,0 +1,133 @@
+package hap
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"github.com/brutella/hap/characteristic"
+	"github.com/brutella/hap/tlv8"
+	"io"
+	"net/http"
+)
+
+type Character struct {
+	AID         int         `json:"aid,omitempty"`
+	IID         int         `json:"iid"`
+	Type        string      `json:"type,omitempty"`
+	Format      string      `json:"format,omitempty"`
+	Value       interface{} `json:"value,omitempty"`
+	Event       interface{} `json:"ev,omitempty"`
+	Perms       []string    `json:"perms,omitempty"`
+	Description string      `json:"description,omitempty"`
+	//MaxDataLen int      `json:"maxDataLen"`
+
+	listeners map[io.Writer]bool
+}
+
+func (c *Character) AddListener(w io.Writer) {
+	// TODO: sync.Mutex
+	if c.listeners == nil {
+		c.listeners = map[io.Writer]bool{}
+	}
+	c.listeners[w] = true
+}
+
+func (c *Character) RemoveListener(w io.Writer) {
+	delete(c.listeners, w)
+
+	if len(c.listeners) == 0 {
+		c.listeners = nil
+	}
+}
+
+func (c *Character) NotifyListeners(ignore io.Writer) error {
+	if c.listeners == nil {
+		return nil
+	}
+
+	data, err := c.GenerateEvent()
+	if err != nil {
+		return err
+	}
+
+	for w, _ := range c.listeners {
+		if w == ignore {
+			continue
+		}
+		if _, err = w.Write(data); err != nil {
+			// error not a problem - just remove listener
+			c.RemoveListener(w)
+		}
+	}
+
+	return nil
+}
+
+// GenerateEvent with raw HTTP headers
+func (c *Character) GenerateEvent() (data []byte, err error) {
+	chars := Characters{
+		Characters: []*Character{{AID: DeviceAID, IID: c.IID, Value: c.Value}},
+	}
+	if data, err = json.Marshal(chars); err != nil {
+		return
+	}
+
+	res := http.Response{
+		StatusCode:    http.StatusOK,
+		ProtoMajor:    1,
+		ProtoMinor:    0,
+		Header:        http.Header{"Content-Type": []string{MimeJSON}},
+		ContentLength: int64(len(data)),
+		Body:          io.NopCloser(bytes.NewReader(data)),
+	}
+
+	buf := bytes.NewBuffer([]byte{0})
+	if err = res.Write(buf); err != nil {
+		return
+	}
+	copy(buf.Bytes(), "EVENT")
+
+	return buf.Bytes(), err
+}
+
+// Set new value and NotifyListeners
+func (c *Character) Set(v interface{}) (err error) {
+	if err = c.Write(v); err != nil {
+		return
+	}
+	return c.NotifyListeners(nil)
+}
+
+// Write new value with right format
+func (c *Character) Write(v interface{}) (err error) {
+	switch c.Format {
+	case characteristic.FormatTLV8:
+		var data []byte
+		if data, err = tlv8.Marshal(v); err != nil {
+			return
+		}
+		c.Value = base64.StdEncoding.EncodeToString(data)
+
+	case characteristic.FormatBool:
+		switch v.(type) {
+		case bool:
+			c.Value = v.(bool)
+		case float64:
+			c.Value = v.(float64) != 0
+		}
+	}
+	return
+}
+
+// ReadTLV8 value to right struct
+func (c *Character) ReadTLV8(v interface{}) (err error) {
+	var data []byte
+	if data, err = base64.StdEncoding.DecodeString(c.Value.(string)); err != nil {
+		return
+	}
+	return tlv8.Unmarshal(data, v)
+}
+
+func (c *Character) ReadBool() bool {
+	return c.Value.(bool)
+}

pkg/hap/conn.go

@@ -0,0 +1,733 @@
+package hap
+
+import (
+	"bufio"
+	"crypto/sha512"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/AlexxIT/go2rtc/pkg/hap/mdns"
+	"github.com/AlexxIT/go2rtc/pkg/streamer"
+	"github.com/brutella/hap"
+	"github.com/brutella/hap/chacha20poly1305"
+	"github.com/brutella/hap/curve25519"
+	"github.com/brutella/hap/ed25519"
+	"github.com/brutella/hap/hkdf"
+	"github.com/brutella/hap/tlv8"
+	"github.com/tadglines/go-pkgs/crypto/srp"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// Conn for HomeKit. DevicePublic can be null.
+type Conn struct {
+	streamer.Element
+
+	DeviceAddress string // including port
+	DeviceID      string
+	DevicePublic  []byte
+	ClientID      string
+	ClientPrivate []byte
+
+	OnEvent func(res *http.Response)
+	Output  func(msg interface{})
+
+	conn         net.Conn
+	secure       *Secure
+	httpResponse chan *bufio.Reader
+}
+
+func NewConn(rawURL string) (*Conn, error) {
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		return nil, err
+	}
+
+	query := u.Query()
+	c := &Conn{
+		DeviceAddress: u.Host,
+		DeviceID:      query.Get("device_id"),
+		DevicePublic:  DecodeKey(query.Get("device_public")),
+		ClientID:      query.Get("client_id"),
+		ClientPrivate: DecodeKey(query.Get("client_private")),
+	}
+
+	return c, nil
+}
+
+func Pair(deviceID, pin string) (*Conn, error) {
+	entry := mdns.GetEntry(deviceID)
+	if entry == nil {
+		return nil, errors.New("can't find device via mDNS")
+	}
+
+	c := &Conn{
+		DeviceAddress: fmt.Sprintf("%s:%d", entry.AddrV4.String(), entry.Port),
+		DeviceID:      deviceID,
+		ClientID:      GenerateUUID(),
+		ClientPrivate: GenerateKey(),
+	}
+
+	var mfi bool
+	for _, field := range entry.InfoFields {
+		if field[:2] == "ff" {
+			if field[3] == '1' {
+				mfi = true
+			}
+			break
+		}
+	}
+
+	return c, c.Pair(mfi, pin)
+}
+
+func (c *Conn) ClientPublic() []byte {
+	return c.ClientPrivate[32:]
+}
+
+func (c *Conn) URL() string {
+	return fmt.Sprintf(
+		"homekit://%s?device_id=%s&device_public=%16x&client_id=%s&client_private=%32x",
+		c.DeviceAddress, c.DeviceID, c.DevicePublic, c.ClientID, c.ClientPrivate,
+	)
+}
+
+func (c *Conn) DialAndServe() error {
+	if err := c.Dial(); err != nil {
+		return err
+	}
+	return c.Handle()
+}
+
+func (c *Conn) Dial() error {
+	// update device host before dial
+	if host := mdns.GetAddress(c.DeviceID); host != "" {
+		c.DeviceAddress = host
+	}
+
+	var err error
+	c.conn, err = net.DialTimeout("tcp", c.DeviceAddress, time.Second*5)
+	if err != nil {
+		return err
+	}
+
+	// STEP M1: send our session public to device
+	sessionPublic, sessionPrivate := curve25519.GenerateKeyPair()
+
+	// 1. generate payload
+	// important not include other fields
+	requestM1 := struct {
+		State     byte   `tlv8:"6"`
+		PublicKey []byte `tlv8:"3"`
+	}{
+		State:     hap.M1,
+		PublicKey: sessionPublic[:],
+	}
+	// 2. pack payload to TLV8
+	buf, err := tlv8.Marshal(requestM1)
+	if err != nil {
+		return err
+	}
+
+	// 3. send request
+	resp, err := c.Post(UriPairVerify, buf)
+	if err != nil {
+		return err
+	}
+
+	// STEP M2: unpack deviceID from response
+	responseM2 := PairVerifyPayload{}
+	if err = tlv8.UnmarshalReader(resp.Body, &responseM2); err != nil {
+		return err
+	}
+
+	// 1. generate session shared key
+	var deviceSessionPublic [32]byte
+	copy(deviceSessionPublic[:], responseM2.PublicKey)
+	sessionShared := curve25519.SharedSecret(sessionPrivate, deviceSessionPublic)
+	sessionKey, err := hkdf.Sha512(
+		sessionShared[:], []byte("Pair-Verify-Encrypt-Salt"),
+		[]byte("Pair-Verify-Encrypt-Info"),
+	)
+
+	// 2. decrypt M2 response with session key
+	msg := responseM2.EncryptedData[:len(responseM2.EncryptedData)-16]
+	var mac [16]byte
+	copy(mac[:], responseM2.EncryptedData[len(msg):]) // 16 byte (MAC)
+
+	buf, err = chacha20poly1305.DecryptAndVerify(
+		sessionKey[:], []byte("PV-Msg02"), msg, mac, nil,
+	)
+
+	// 3. unpack payload from TLV8
+	payloadM2 := PairVerifyPayload{}
+	if err = tlv8.Unmarshal(buf, &payloadM2); err != nil {
+		return err
+	}
+
+	// 4. verify signature for M2 response with device public
+	// device session + device id + our session
+	if c.DevicePublic != nil {
+		buf = nil
+		buf = append(buf, responseM2.PublicKey[:]...)
+		buf = append(buf, []byte(payloadM2.Identifier)...)
+		buf = append(buf, sessionPublic[:]...)
+		if !ed25519.ValidateSignature(
+			c.DevicePublic[:], buf, payloadM2.Signature,
+		) {
+			return errors.New("device public signature invalid")
+		}
+	}
+
+	// STEP M3: send our clientID to device
+	// 1. generate signature with our private key
+	// (our session + our ID + device session)
+	buf = nil
+	buf = append(buf, sessionPublic[:]...)
+	buf = append(buf, []byte(c.ClientID)...)
+	buf = append(buf, responseM2.PublicKey[:]...)
+	signature, err := ed25519.Signature(c.ClientPrivate[:], buf)
+	if err != nil {
+		return err
+	}
+
+	// 2. generate payload
+	payloadM3 := struct {
+		Identifier string `tlv8:"1"`
+		Signature  []byte `tlv8:"10"`
+	}{
+		Identifier: c.ClientID,
+		Signature:  signature,
+	}
+	// 3. pack payload to TLV8
+	buf, err = tlv8.Marshal(payloadM3)
+	if err != nil {
+		return err
+	}
+
+	// 4. encrypt payload with session key
+	msg, mac, _ = chacha20poly1305.EncryptAndSeal(
+		sessionKey[:], []byte("PV-Msg03"), buf, nil,
+	)
+
+	// 4. generate request
+	requestM3 := struct {
+		EncryptedData []byte `tlv8:"5"`
+		State         byte   `tlv8:"6"`
+	}{
+		State:         hap.M3,
+		EncryptedData: append(msg, mac[:]...),
+	}
+	// 5. pack payload to TLV8
+	buf, err = tlv8.Marshal(requestM3)
+	if err != nil {
+		return err
+	}
+
+	resp, err = c.Post(UriPairVerify, buf)
+	if err != nil {
+		return err
+	}
+
+	// STEP M4. Read response
+	responseM4 := PairVerifyPayload{}
+	if err = tlv8.UnmarshalReader(resp.Body, &responseM4); err != nil {
+		return err
+	}
+
+	// 1. check response state
+	if responseM4.State != 4 || responseM4.Status != 0 {
+		return fmt.Errorf("wrong M4 response: %+v", responseM4)
+	}
+
+	c.secure, err = NewSecure(sessionShared, false)
+	//c.secure.Buffer = bytes.NewBuffer(nil)
+	c.secure.Conn = c.conn
+
+	c.httpResponse = make(chan *bufio.Reader, 10)
+
+	return err
+}
+
+// https://github.com/apple/HomeKitADK/blob/master/HAP/HAPPairingPairSetup.c
+func (c *Conn) Pair(mfi bool, pin string) (err error) {
+	pin = strings.ReplaceAll(pin, "-", "")
+	if len(pin) != 8 {
+		return fmt.Errorf("wrong PIN format: %s", pin)
+	}
+	pin = pin[:3] + "-" + pin[3:5] + "-" + pin[5:]
+
+	c.conn, err = net.Dial("tcp", c.DeviceAddress)
+	if err != nil {
+		return
+	}
+
+	// STEP M1. Generate request
+	reqM1 := struct {
+		Method byte `tlv8:"0"`
+		State  byte `tlv8:"6"`
+	}{
+		State: hap.M1,
+	}
+	if mfi {
+		reqM1.Method = 1 // ff=1 => method=1, ff=2 => method=0
+	}
+	buf, err := tlv8.Marshal(reqM1)
+	if err != nil {
+		return
+	}
+
+	// STEP M1. Send request
+	res, err := c.Post(UriPairSetup, buf)
+	if err != nil {
+		return
+	}
+
+	// STEP M2. Read response
+	resM2 := struct {
+		Salt      []byte `tlv8:"2"`
+		PublicKey []byte `tlv8:"3"` // server public key, aka session.B
+		State     byte   `tlv8:"6"`
+		Error     byte   `tlv8:"7"`
+	}{}
+	if err = tlv8.UnmarshalReader(res.Body, &resM2); err != nil {
+		return
+	}
+	if resM2.State != 2 || resM2.Error > 0 {
+		return fmt.Errorf("wrong M2: %+v", resM2)
+	}
+
+	// STEP M3. Generate session using pin
+	username := []byte("Pair-Setup")
+
+	SRP, err := srp.NewSRP(
+		"rfc5054.3072", sha512.New, keyDerivativeFuncRFC2945(username),
+	)
+	if err != nil {
+		return
+	}
+
+	SRP.SaltLength = 16
+
+	// username: "Pair-Setup"
+	// password: PIN (with dashes)
+	session := SRP.NewClientSession(username, []byte(pin))
+	sessionShared, err := session.ComputeKey(resM2.Salt, resM2.PublicKey)
+	if err != nil {
+		return
+	}
+
+	// STEP M3. Generate request
+	reqM3 := struct {
+		PublicKey []byte `tlv8:"3"`
+		Proof     []byte `tlv8:"4"`
+		State     byte   `tlv8:"6"`
+	}{
+		PublicKey: session.GetA(), // client public key, aka session.A
+		Proof:     session.ComputeAuthenticator(),
+		State:     hap.M3,
+	}
+	buf, err = tlv8.Marshal(reqM3)
+	if err != nil {
+		return err
+	}
+
+	// STEP M3. Send request
+	res, err = c.Post(UriPairSetup, buf)
+	if err != nil {
+		return
+	}
+
+	// STEP M4. Read response
+	resM4 := struct {
+		Proof []byte `tlv8:"4"` // server proof
+		State byte   `tlv8:"6"`
+		Error byte   `tlv8:"7"`
+	}{}
+	if err = tlv8.UnmarshalReader(res.Body, &resM4); err != nil {
+		return
+	}
+	if resM4.Error == 2 {
+		return fmt.Errorf("wrong PIN: %s", pin)
+	}
+	if resM4.State != 4 || resM4.Error > 0 {
+		return fmt.Errorf("wrong M4: %+v", resM4)
+	}
+
+	// STEP M4. Verify response
+	if !session.VerifyServerAuthenticator(resM4.Proof) {
+		return errors.New("verify server auth fail")
+	}
+
+	// STEP M5. Generate signature
+	saltKey, err := hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Controller-Sign-Salt"),
+		[]byte("Pair-Setup-Controller-Sign-Info"),
+	)
+	if err != nil {
+		return
+	}
+
+	buf = nil
+	buf = append(buf, saltKey[:]...)
+	buf = append(buf, []byte(c.ClientID)...)
+	buf = append(buf, c.ClientPublic()...)
+
+	signature, err := ed25519.Signature(c.ClientPrivate, buf)
+	if err != nil {
+		return
+	}
+
+	// STEP M5. Generate payload
+	msgM5 := struct {
+		Identifier string `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Signature  []byte `tlv8:"10"`
+	}{
+		Identifier: c.ClientID,
+		PublicKey:  c.ClientPublic(),
+		Signature:  signature,
+	}
+	buf, err = tlv8.Marshal(msgM5)
+	if err != nil {
+		return
+	}
+
+	// STEP M5. Encrypt payload
+	sessionKey, err := hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Encrypt-Salt"),
+		[]byte("Pair-Setup-Encrypt-Info"),
+	)
+	if err != nil {
+		return
+	}
+	buf, mac, _ := chacha20poly1305.EncryptAndSeal(
+		sessionKey[:], []byte("PS-Msg05"), buf, nil,
+	)
+
+	// STEP M5. Generate request
+	reqM5 := struct {
+		EncryptedData []byte `tlv8:"5"`
+		State         byte   `tlv8:"6"`
+	}{
+		EncryptedData: append(buf, mac[:]...),
+		State:         hap.M5,
+	}
+	buf, err = tlv8.Marshal(reqM5)
+	if err != nil {
+		return err
+	}
+
+	// STEP M5. Send request
+	res, err = c.Post(UriPairSetup, buf)
+	if err != nil {
+		return
+	}
+
+	// STEP M6. Read response
+	resM6 := struct {
+		EncryptedData []byte `tlv8:"5"`
+		State         byte   `tlv8:"6"`
+		Error         byte   `tlv8:"7"`
+	}{}
+	if err = tlv8.UnmarshalReader(res.Body, &resM6); err != nil {
+		return
+	}
+	if resM6.State != 6 || resM6.Error > 0 {
+		return fmt.Errorf("wrong M6: %+v", resM2)
+	}
+
+	// STEP M6. Decrypt payload
+	msg := resM6.EncryptedData[:len(resM6.EncryptedData)-16]
+	copy(mac[:], resM6.EncryptedData[len(msg):]) // 16 byte (MAC)
+
+	buf, err = chacha20poly1305.DecryptAndVerify(
+		sessionKey[:], []byte("PS-Msg06"), msg, mac, nil,
+	)
+	if err != nil {
+		return
+	}
+
+	msgM6 := struct {
+		Identifier []byte `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Signature  []byte `tlv8:"10"`
+	}{}
+	if err = tlv8.Unmarshal(buf, &msgM6); err != nil {
+		return
+	}
+
+	// STEP M6. Verify payload
+	if saltKey, err = hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Accessory-Sign-Salt"),
+		[]byte("Pair-Setup-Accessory-Sign-Info"),
+	); err != nil {
+		return
+	}
+
+	buf = nil
+	buf = append(buf, saltKey[:]...)
+	buf = append(buf, msgM6.Identifier...)
+	buf = append(buf, msgM6.PublicKey...)
+
+	if !ed25519.ValidateSignature(
+		msgM6.PublicKey[:], buf, msgM6.Signature,
+	) {
+		return errors.New("wrong server signature")
+	}
+
+	if c.DeviceID != string(msgM6.Identifier) {
+		return fmt.Errorf("wrong Device ID: %s", msgM6.Identifier)
+	}
+
+	c.DevicePublic = msgM6.PublicKey
+
+	return nil
+}
+
+func (c *Conn) Close() error {
+	if c.conn == nil {
+		return nil
+	}
+	conn := c.conn
+	c.conn = nil
+	return conn.Close()
+}
+
+func (c *Conn) GetAccessories() ([]*Accessory, error) {
+	res, err := c.Get("/accessories")
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	p := Accessories{}
+	if err = json.Unmarshal(data, &p); err != nil {
+		return nil, err
+	}
+
+	for _, accs := range p.Accessories {
+		for _, serv := range accs.Services {
+			for _, char := range serv.Characters {
+				char.AID = accs.AID
+			}
+		}
+	}
+
+	return p.Accessories, nil
+}
+
+func (c *Conn) GetCharacters(query string) ([]*Character, error) {
+	res, err := c.Get("/characteristics?id=" + query)
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	ch := Characters{}
+	if err = json.Unmarshal(data, &ch); err != nil {
+		return nil, err
+	}
+	return ch.Characters, nil
+}
+
+func (c *Conn) GetCharacter(char *Character) error {
+	query := fmt.Sprintf("%d.%d", char.AID, char.IID)
+	chars, err := c.GetCharacters(query)
+	if err != nil {
+		return err
+	}
+	char.Value = chars[0].Value
+	return nil
+}
+
+func (c *Conn) PutCharacters(characters ...*Character) (err error) {
+	for i, char := range characters {
+		if char.Event != nil {
+			char = &Character{AID: char.AID, IID: char.IID, Event: char.Event}
+		} else {
+			char = &Character{AID: char.AID, IID: char.IID, Value: char.Value}
+		}
+		characters[i] = char
+	}
+	var data []byte
+	if data, err = json.Marshal(Characters{characters}); err != nil {
+		return
+	}
+
+	var res *http.Response
+	if res, err = c.Put("/characteristics", data); err != nil {
+		return
+	}
+
+	if res.StatusCode >= 400 {
+		return errors.New("wrong response status")
+	}
+
+	return
+}
+
+func (c *Conn) GetImage(width, height int) ([]byte, error) {
+	res, err := c.Post(
+		"/resource", []byte(fmt.Sprintf(
+			`{"image-width":%d,"image-height":%d,"resource-type":"image","reason":0}`,
+			width, height,
+		)),
+	)
+	if err != nil {
+		return nil, err
+	}
+	return io.ReadAll(res.Body)
+}
+
+//func (c *Client) onEventData(r io.Reader) error {
+//	if c.OnEvent == nil {
+//		return nil
+//	}
+//
+//	data, err := io.ReadAll(r)
+//
+//	ch := Characters{}
+//	if err = json.Unmarshal(data, &ch); err != nil {
+//		return err
+//	}
+//
+//	c.OnEvent(ch.Characters)
+//
+//	return nil
+//}
+
+func (c *Conn) ListPairings() error {
+	pReq := struct {
+		Method byte `tlv8:"0"`
+		State  byte `tlv8:"6"`
+	}{
+		Method: hap.MethodListPairings,
+		State:  hap.M1,
+	}
+	data, err := tlv8.Marshal(pReq)
+	if err != nil {
+		return err
+	}
+
+	res, err := c.Post("/pairings", data)
+	if err != nil {
+		return err
+	}
+
+	data, err = io.ReadAll(res.Body)
+	// TODO: don't know how to fix array of items
+	var pRes struct {
+		State      byte   `tlv8:"6"`
+		Identifier string `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Permission byte   `tlv8:"11"`
+	}
+	if err = tlv8.Unmarshal(data, &pRes); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *Conn) PairingsAdd(clientID string, clientPublic []byte, admin bool) error {
+	pReq := struct {
+		Method     byte   `tlv8:"0"`
+		Identifier string `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		State      byte   `tlv8:"6"`
+		Permission byte   `tlv8:"11"`
+	}{
+		Method:     hap.MethodAddPairing,
+		Identifier: clientID,
+		PublicKey:  clientPublic,
+		State:      hap.M1,
+		Permission: hap.PermissionUser,
+	}
+	if admin {
+		pReq.Permission = hap.PermissionAdmin
+	}
+
+	data, err := tlv8.Marshal(pReq)
+	if err != nil {
+		return err
+	}
+
+	res, err := c.Post("/pairings", data)
+	if err != nil {
+		return err
+	}
+
+	data, err = io.ReadAll(res.Body)
+	var pRes struct {
+		State   byte `tlv8:"6"`
+		Unknown byte `tlv8:"7"`
+	}
+	if err = tlv8.Unmarshal(data, &pRes); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *Conn) DeletePairing(id string) error {
+	reqM1 := struct {
+		State      byte   `tlv8:"6"`
+		Method     byte   `tlv8:"0"`
+		Identifier string `tlv8:"1"`
+	}{
+		State:      hap.M1,
+		Method:     hap.MethodDeletePairing,
+		Identifier: id,
+	}
+	data, err := tlv8.Marshal(reqM1)
+	if err != nil {
+		return err
+	}
+
+	res, err := c.Post("/pairings", data)
+	if err != nil {
+		return err
+	}
+
+	data, err = io.ReadAll(res.Body)
+	var resM2 struct {
+		State byte `tlv8:"6"`
+	}
+	if err = tlv8.Unmarshal(data, &resM2); err != nil {
+		return err
+	}
+	if resM2.State != hap.M2 {
+		return errors.New("wrong state")
+	}
+
+	return nil
+}
+
+func (c *Conn) LocalAddr() string {
+	return c.conn.LocalAddr().String()
+}
+
+func DecodeKey(s string) []byte {
+	if s == "" {
+		return nil
+	}
+	data, err := hex.DecodeString(s)
+	if err != nil {
+		return nil
+	}
+	return data
+}

pkg/hap/helpers.go

@@ -0,0 +1,90 @@
+package hap
+
+import (
+	"crypto/rand"
+	"crypto/sha512"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+const DeviceAID = 1 // TODO: fix someday
+
+func GenerateID(name string) string {
+	sum := sha512.Sum512([]byte(name))
+	return fmt.Sprintf(
+		"%02X:%02X:%02X:%02X:%02X:%02X",
+		sum[0], sum[1], sum[2], sum[3], sum[4], sum[5],
+	)
+}
+
+func GenerateUUID() string {
+	//12345678-9012-3456-7890-123456789012
+	data := make([]byte, 16)
+	_, _ = rand.Read(data)
+	s := hex.EncodeToString(data)
+	return s[:8] + "-" + s[8:12] + "-" + s[12:16] + "-" + s[16:20] + "-" + s[20:]
+}
+
+type PairVerifyPayload struct {
+	Method        byte   `tlv8:"0,optional"`
+	Identifier    string `tlv8:"1,optional"`
+	PublicKey     []byte `tlv8:"3,optional"`
+	EncryptedData []byte `tlv8:"5,optional"`
+	State         byte   `tlv8:"6,optional"`
+	Status        byte   `tlv8:"7,optional"`
+	Signature     []byte `tlv8:"10,optional"`
+}
+
+//func (c *Character) Unmarshal(value interface{}) error {
+//	switch c.Format {
+//	case characteristic.FormatTLV8:
+//		data, err := base64.StdEncoding.DecodeString(c.Value.(string))
+//		if err != nil {
+//			return err
+//		}
+//		return tlv8.Unmarshal(data, value)
+//	}
+//	return nil
+//}
+
+//func (c *Character) Marshal(value interface{}) error {
+//	switch c.Format {
+//	case characteristic.FormatTLV8:
+//		data, err := tlv8.Marshal(value)
+//		if err != nil {
+//			return err
+//		}
+//		c.Value = base64.StdEncoding.EncodeToString(data)
+//	}
+//	return nil
+//}
+
+func (c *Character) String() string {
+	data, err := json.Marshal(c)
+	if err != nil {
+		return "ERROR"
+	}
+	return string(data)
+}
+
+func UnmarshalEvent(res *http.Response) (char *Character, err error) {
+	var data []byte
+	if data, err = io.ReadAll(res.Body); err != nil {
+		return
+	}
+
+	ch := Characters{}
+	if err = json.Unmarshal(data, &ch); err != nil {
+		return
+	}
+
+	if len(ch.Characters) > 1 {
+		panic("not implemented")
+	}
+
+	char = ch.Characters[0]
+	return
+}

pkg/hap/http.go

@@ -0,0 +1,246 @@
+package hap
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/textproto"
+	"strconv"
+)
+
+const (
+	MimeTLV8 = "application/pairing+tlv8"
+	MimeJSON = "application/hap+json"
+
+	UriPairSetup       = "/pair-setup"
+	UriPairVerify      = "/pair-verify"
+	UriPairings        = "/pairings"
+	UriAccessories     = "/accessories"
+	UriCharacteristics = "/characteristics"
+	UriResource        = "/resource"
+)
+
+func (c *Conn) Write(p []byte) (r io.Reader, err error) {
+	if c.secure == nil {
+		if _, err = c.conn.Write(p); err == nil {
+			r = bufio.NewReader(c.conn)
+		}
+	} else {
+		if _, err = c.secure.Write(p); err == nil {
+			r = <-c.httpResponse
+		}
+	}
+	return
+}
+
+func (c *Conn) Do(req *http.Request) (*http.Response, error) {
+	if c.secure == nil {
+		// insecure requests
+		if err := req.Write(c.conn); err != nil {
+			return nil, err
+		}
+		return http.ReadResponse(bufio.NewReader(c.conn), req)
+	}
+
+	// secure support write interface to connection
+	if err := req.Write(c.secure); err != nil {
+		return nil, err
+	}
+
+	// get decrypted buffer from connection
+	buf := <-c.httpResponse
+
+	return http.ReadResponse(buf, req)
+}
+
+func (c *Conn) Get(uri string) (*http.Response, error) {
+	req, err := http.NewRequest(
+		"GET", "http://"+c.DeviceAddress+uri, nil,
+	)
+	if err != nil {
+		return nil, err
+	}
+	return c.Do(req)
+}
+
+func (c *Conn) Post(uri string, data []byte) (*http.Response, error) {
+	req, err := http.NewRequest(
+		"POST", "http://"+c.DeviceAddress+uri,
+		bytes.NewReader(data),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	switch uri {
+	case "/pair-verify", "/pairings":
+		req.Header.Set("Content-Type", MimeTLV8)
+	case UriResource:
+		req.Header.Set("Content-Type", MimeJSON)
+	}
+
+	return c.Do(req)
+}
+
+func (c *Conn) Put(uri string, data []byte) (*http.Response, error) {
+	req, err := http.NewRequest(
+		"PUT", "http://"+c.DeviceAddress+uri,
+		bytes.NewReader(data),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	switch uri {
+	case UriCharacteristics:
+		req.Header.Set("Content-Type", MimeJSON)
+	}
+
+	return c.Do(req)
+}
+
+func (c *Conn) Handle() (err error) {
+	defer func() {
+		if c.conn == nil {
+			err = nil
+		}
+	}()
+
+	b := make([]byte, 512000)
+	for {
+		var total, content int
+		header := -1
+
+		for {
+			var n1 int
+			n1, err = c.secure.Read(b[total:])
+			if err != nil {
+				return err
+			}
+
+			if n1 == 0 {
+				return io.EOF
+			}
+
+			total += n1
+
+			// TODO: rewrite
+			if header == -1 {
+				// step 1. wait whole header
+				header = bytes.Index(b[:total], []byte("\r\n\r\n"))
+				if header < 0 {
+					continue
+				}
+				header += 4
+
+				// step 2. check content-length
+				i1 := bytes.Index(b[:total], []byte("Content-Length: "))
+				if i1 < 0 {
+					break
+				}
+				i1 += 16
+				i2 := bytes.IndexByte(b[i1:total], '\r')
+				content, err = strconv.Atoi(string(b[i1 : i1+i2]))
+				if err != nil {
+					break
+				}
+			}
+
+			if total >= header+content {
+				break
+			}
+		}
+
+		// copy slice to buffer
+		buf := bytes.NewBuffer(make([]byte, 0, total))
+		buf.Write(b[:total])
+		r := bufio.NewReader(buf)
+
+		// EVENT/1.0 200 OK
+		if b[0] == 'E' {
+			if c.OnEvent == nil {
+				continue
+			}
+
+			tp := textproto.NewReader(r)
+
+			var s string
+			if s, err = tp.ReadLine(); err != nil {
+				return err
+			}
+			if s != "EVENT/1.0 200 OK" {
+				return errors.New("wrong response")
+			}
+
+			var mimeHeader textproto.MIMEHeader
+			if mimeHeader, err = tp.ReadMIMEHeader(); err != nil {
+				return err
+			}
+
+			var cl int
+			if cl, err = strconv.Atoi(
+				mimeHeader.Get("Content-Length"),
+			); err != nil {
+				return err
+			}
+
+			res := http.Response{
+				StatusCode:    200,
+				Proto:         "EVENT/1.0",
+				ProtoMajor:    1,
+				ProtoMinor:    0,
+				Header:        http.Header(mimeHeader),
+				ContentLength: int64(cl),
+				Body:          io.NopCloser(r),
+			}
+			c.OnEvent(&res)
+			continue
+		}
+
+		//if bytes.Index(b, []byte("image/jpeg")) > 0 {
+		//	if total, err = c.secure.Read(b); err != nil {
+		//		return
+		//	}
+		//	buf.Write(b[:total])
+		//}
+
+		c.httpResponse <- r
+	}
+}
+
+func WriteStatusCode(w io.Writer, statusCode int) (err error) {
+	body := []byte(fmt.Sprintf(
+		"HTTP/1.1 %d %s\n\n", statusCode, http.StatusText(statusCode),
+	))
+	//print("<<<", string(body), "<<<\n")
+	_, err = w.Write(body)
+	return
+}
+
+func WriteResponse(
+	w io.Writer, statusCode int, contentType string, body []byte,
+) (err error) {
+	header := fmt.Sprintf(
+		"HTTP/1.1 %d %s\nContent-Type: %s\nContent-Length: %d\n\n",
+		statusCode, http.StatusText(statusCode), contentType, len(body),
+	)
+	body = append([]byte(header), body...)
+	//print("<<<", string(body), "<<<\n")
+	_, err = w.Write(body)
+	return
+}
+
+func WriteChunked(w io.Writer, contentType string, body []byte) (err error) {
+	header := fmt.Sprintf(
+		"HTTP/1.1 200 OK\nContent-Type: %s\nTransfer-Encoding: chunked\n\n%x\n",
+		contentType, len(body),
+	)
+	body = append([]byte(header), body...)
+	body = append(body, "\n0\n\n"...)
+	//print("<<<", string(body), "<<<\n")
+	_, err = w.Write(body)
+	return
+}

pkg/hap/mdns/client.go

@@ -0,0 +1,42 @@
+package mdns
+
+import (
+	"fmt"
+	"github.com/hashicorp/mdns"
+	"strings"
+)
+
+const Suffix = "._hap._tcp.local."
+
+func GetAll() chan *mdns.ServiceEntry {
+	entries := make(chan *mdns.ServiceEntry)
+	params := &mdns.QueryParam{
+		Service: "_hap._tcp", Entries: entries, DisableIPv6: true,
+	}
+
+	go func() {
+		_ = mdns.Query(params)
+		close(entries)
+	}()
+
+	return entries
+}
+
+func GetAddress(deviceID string) string {
+	for entry := range GetAll() {
+		if strings.Contains(entry.Info, deviceID) {
+			return fmt.Sprintf("%s:%d", entry.AddrV4.String(), entry.Port)
+		}
+	}
+
+	return ""
+}
+
+func GetEntry(deviceID string) *mdns.ServiceEntry {
+	for entry := range GetAll() {
+		if strings.Contains(entry.Info, deviceID) {
+			return entry
+		}
+	}
+	return nil
+}

pkg/hap/mdns/server.go

@@ -0,0 +1,53 @@
+package mdns
+
+import (
+	"github.com/hashicorp/mdns"
+	"net"
+)
+
+const HostHeaderTail = "._hap._tcp.local"
+
+func NewServer(name string, port int, ips []net.IP, txt []string) (*mdns.Server, error) {
+	if ips == nil || ips[0] == nil {
+		ips = LocalIPs()
+	}
+
+	// important to set hostName manually with any value and `.local.` tail
+	// important to set ips manually
+	service, _ := mdns.NewMDNSService(
+		name, "_hap._tcp", "", name+".local.", port, ips, txt,
+	)
+
+	return mdns.NewServer(&mdns.Config{Zone: service})
+}
+
+func LocalIPs() []net.IP {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil
+	}
+
+	var ips []net.IP
+	for _, iface := range ifaces {
+		if iface.Flags&net.FlagUp == 0 {
+			continue // interface down
+		}
+		if iface.Flags&net.FlagLoopback != 0 {
+			continue // loopback interface
+		}
+
+		var addrs []net.Addr
+		if addrs, err = iface.Addrs(); err != nil {
+			continue
+		}
+		for _, addr := range addrs {
+			switch addr := addr.(type) {
+			case *net.IPNet:
+				ips = append(ips, addr.IP)
+			case *net.IPAddr:
+				ips = append(ips, addr.IP)
+			}
+		}
+	}
+	return ips
+}

pkg/hap/pairing.go

@@ -0,0 +1,410 @@
+package hap
+
+import (
+	"bufio"
+	"crypto/sha512"
+	"errors"
+	"github.com/brutella/hap"
+	"github.com/brutella/hap/chacha20poly1305"
+	"github.com/brutella/hap/curve25519"
+	"github.com/brutella/hap/ed25519"
+	"github.com/brutella/hap/hkdf"
+	"github.com/brutella/hap/tlv8"
+	"github.com/tadglines/go-pkgs/crypto/srp"
+	"net"
+	"net/http"
+)
+
+type pairSetupPayload struct {
+	Method        byte   `tlv8:"0"`
+	Identifier    string `tlv8:"1"`
+	Salt          []byte `tlv8:"2"`
+	PublicKey     []byte `tlv8:"3"`
+	Proof         []byte `tlv8:"4"`
+	EncryptedData []byte `tlv8:"5"`
+	State         byte   `tlv8:"6"`
+	Error         byte   `tlv8:"7"`
+	RetryDelay    byte   `tlv8:"8"`
+	Certificate   []byte `tlv8:"9"`
+	Signature     []byte `tlv8:"10"`
+	Permissions   byte   `tlv8:"11"`
+	FragmentData  []byte `tlv8:"13"`
+	FragmentLast  []byte `tlv8:"14"`
+}
+
+func (s *Server) PairSetupHandler(
+	conn net.Conn, req *http.Request,
+) (clientID string, err error) {
+	// STEP 1. Request from iPhone
+	payloadM1 := pairSetupPayload{}
+	if err = tlv8.UnmarshalReader(req.Body, &payloadM1); err != nil {
+		return
+	}
+	if payloadM1.State != hap.M1 {
+		err = errors.New("wrong state")
+		return
+	}
+
+	// generate our session public and salt using PIN
+	username := []byte("Pair-Setup")
+
+	var SRP *srp.SRP
+	if SRP, err = srp.NewSRP(
+		"rfc5054.3072", sha512.New,
+		keyDerivativeFuncRFC2945(username),
+	); err != nil {
+		return
+	}
+
+	SRP.SaltLength = 16
+	var salt, verifier []byte
+	if salt, verifier, err = SRP.ComputeVerifier([]byte(s.Pin)); err != nil {
+		return
+	}
+	session := SRP.NewServerSession(username, salt, verifier)
+
+	// STEP 2. Response to iPhone
+	payloadM2 := struct {
+		Salt      []byte `tlv8:"2"`
+		PublicKey []byte `tlv8:"3"`
+		State     byte   `tlv8:"6"`
+	}{
+		State:     hap.M2,
+		PublicKey: session.GetB(),
+		Salt:      salt,
+	}
+	var buf []byte
+	if buf, err = tlv8.Marshal(payloadM2); err != nil {
+		return
+	}
+	if err = WriteResponse(conn, http.StatusOK, MimeTLV8, buf); err != nil {
+		return
+	}
+
+	// STEP 3. Request from iPhone
+	r := bufio.NewReader(conn)
+	if req, err = http.ReadRequest(r); err != nil {
+		return
+	}
+	payloadM3 := pairSetupPayload{}
+	if err = tlv8.UnmarshalReader(req.Body, &payloadM3); err != nil {
+		return
+	}
+	if payloadM3.State != hap.M3 {
+		err = errors.New("wrong state")
+		return
+	}
+
+	// important to compute key before verify client
+	var sessionShared []byte
+	if sessionShared, err = session.ComputeKey(payloadM3.PublicKey); err != nil {
+		return
+	}
+
+	// support skip pin verify (any pin accepted)
+	if s.Pin != "" && !session.VerifyClientAuthenticator(payloadM3.Proof) {
+		err = errors.New("client proof is invalid")
+		return
+	}
+
+	serverProof := session.ComputeAuthenticator(payloadM3.Proof)
+
+	// STEP 4. Response to iPhone
+	payloadM4 := struct {
+		Proof []byte `tlv8:"4"`
+		State byte   `tlv8:"6"`
+	}{
+		State: hap.M4, Proof: serverProof,
+	}
+	if buf, err = tlv8.Marshal(payloadM4); err != nil {
+		return
+	}
+	if err = WriteResponse(conn, http.StatusOK, MimeTLV8, buf); err != nil {
+		return
+	}
+
+	// STEP 5. Request from iPhone
+	if req, err = http.ReadRequest(r); err != nil {
+		return
+	}
+	encryptedM5 := pairSetupPayload{}
+	if err = tlv8.UnmarshalReader(req.Body, &encryptedM5); err != nil {
+		return
+	}
+	if encryptedM5.State != hap.M5 {
+		err = errors.New("wrong state")
+		return
+	}
+
+	msg := encryptedM5.EncryptedData[:len(encryptedM5.EncryptedData)-16]
+	var mac [16]byte
+	copy(mac[:], encryptedM5.EncryptedData[len(msg):]) // 16 byte (MAC)
+
+	// decrypt message using session shared
+	var sessionKey [32]byte
+	if sessionKey, err = hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Encrypt-Salt"),
+		[]byte("Pair-Setup-Encrypt-Info"),
+	); err != nil {
+		return
+	}
+
+	if buf, err = chacha20poly1305.DecryptAndVerify(
+		sessionKey[:], []byte("PS-Msg05"), msg, mac, nil,
+	); err != nil {
+		return
+	}
+
+	// unpack message from TLV8
+	payloadM5 := struct {
+		Identifier string `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Signature  []byte `tlv8:"10"`
+	}{}
+	if err = tlv8.Unmarshal(buf, &payloadM5); err != nil {
+		return
+	}
+
+	// 3. verify client ID and Public
+	var saltKey [32]byte
+	if saltKey, err = hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Controller-Sign-Salt"),
+		[]byte("Pair-Setup-Controller-Sign-Info"),
+	); err != nil {
+		return
+	}
+
+	buf = nil
+	buf = append(buf, saltKey[:]...)
+	buf = append(buf, payloadM5.Identifier...)
+	buf = append(buf, payloadM5.PublicKey[:]...)
+
+	if !ed25519.ValidateSignature(
+		payloadM5.PublicKey[:], buf, payloadM5.Signature,
+	) {
+		err = errors.New("wrong client signature")
+		return
+	}
+
+	// 4. generate signature to our ID adn Public
+	if saltKey, err = hkdf.Sha512(
+		sessionShared, []byte("Pair-Setup-Accessory-Sign-Salt"),
+		[]byte("Pair-Setup-Accessory-Sign-Info"),
+	); err != nil {
+		return
+	}
+
+	buf = nil
+	buf = append(buf, saltKey[:]...)
+	buf = append(buf, []byte(s.ServerID)...)
+	buf = append(buf, s.ServerPrivate[32:]...) // ServerPublic
+
+	var signature []byte
+	if signature, err = ed25519.Signature(s.ServerPrivate, buf); err != nil {
+		return
+	}
+
+	// 5. pack our ID and Public
+	payloadM6 := struct {
+		Identifier []byte `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Signature  []byte `tlv8:"10"`
+	}{
+		Identifier: []byte(s.ServerID),
+		PublicKey:  s.ServerPrivate[32:],
+		Signature:  signature,
+	}
+	if buf, err = tlv8.Marshal(payloadM6); err != nil {
+		return
+	}
+
+	// 6. encrypt message
+	buf, mac, _ = chacha20poly1305.EncryptAndSeal(
+		sessionKey[:], []byte("PS-Msg06"), buf, nil,
+	)
+
+	// STEP 6. Response to iPhone
+	encryptedM6 := struct {
+		EncryptedData []byte `tlv8:"5"`
+		State         byte   `tlv8:"6"`
+	}{
+		State:         hap.M6,
+		EncryptedData: append(buf, mac[:]...),
+	}
+	if buf, err = tlv8.Marshal(encryptedM6); err != nil {
+		return
+	}
+	if err = WriteResponse(conn, http.StatusOK, MimeTLV8, buf); err != nil {
+		return
+	}
+
+	if s.Pairings != nil {
+		s.Pairings[payloadM5.Identifier] = append(
+			payloadM5.PublicKey, 1, // adds admin (1) flag
+		)
+	}
+
+	clientID = payloadM5.Identifier
+
+	return
+}
+
+func keyDerivativeFuncRFC2945(username []byte) srp.KeyDerivationFunc {
+	return func(salt, pin []byte) []byte {
+		h := sha512.New()
+		h.Write(username)
+		h.Write([]byte(":"))
+		h.Write(pin)
+		t2 := h.Sum(nil)
+		h.Reset()
+		h.Write(salt)
+		h.Write(t2)
+		return h.Sum(nil)
+	}
+}
+
+type pairVerifyPayload struct {
+	Method        byte   `tlv8:"0"`
+	Identifier    string `tlv8:"1"`
+	PublicKey     []byte `tlv8:"3"`
+	EncryptedData []byte `tlv8:"5"`
+	State         byte   `tlv8:"6"`
+	Signature     []byte `tlv8:"10"`
+}
+
+func (s *Server) PairVerifyHandler(
+	conn net.Conn, req *http.Request,
+) (secure *Secure, err error) {
+	// STEP M1. Request from iPhone
+	payloadM1 := pairVerifyPayload{}
+	if err = tlv8.UnmarshalReader(req.Body, &payloadM1); err != nil {
+		return
+	}
+	if payloadM1.State != hap.M1 {
+		err = errors.New("wrong state")
+		return
+	}
+
+	var clientPublic [32]byte
+	copy(clientPublic[:], payloadM1.PublicKey)
+
+	// Generate the key pair.
+	sessionPublic, sessionPrivate := curve25519.GenerateKeyPair()
+	sessionShared := curve25519.SharedSecret(sessionPrivate, clientPublic)
+
+	var sessionKey [32]byte
+	if sessionKey, err = hkdf.Sha512(
+		sessionShared[:], []byte("Pair-Verify-Encrypt-Salt"),
+		[]byte("Pair-Verify-Encrypt-Info"),
+	); err != nil {
+		return
+	}
+
+	var buf []byte
+	buf = append(buf, sessionPublic[:]...)
+	buf = append(buf, s.ServerID...)
+	buf = append(buf, clientPublic[:]...)
+
+	var signature []byte
+	if signature, err = ed25519.Signature(s.ServerPrivate[:], buf); err != nil {
+		return
+	}
+
+	// STEP M2. Response to iPhone
+	payloadM2 := struct {
+		Identifier string `tlv8:"1"`
+		Signature  []byte `tlv8:"10"`
+	}{
+		Identifier: s.ServerID,
+		Signature:  signature,
+	}
+	if buf, err = tlv8.Marshal(payloadM2); err != nil {
+		return
+	}
+
+	var mac [16]byte
+	buf, mac, _ = chacha20poly1305.EncryptAndSeal(
+		sessionKey[:], []byte("PV-Msg02"), buf, nil,
+	)
+	encryptedM2 := struct {
+		State         byte   `tlv8:"6"`
+		PublicKey     []byte `tlv8:"3"`
+		EncryptedData []byte `tlv8:"5"`
+	}{
+		State:         hap.M2,
+		PublicKey:     sessionPublic[:],
+		EncryptedData: append(buf, mac[:]...),
+	}
+	if buf, err = tlv8.Marshal(encryptedM2); err != nil {
+		return
+	}
+	if err = WriteResponse(conn, http.StatusOK, MimeTLV8, buf); err != nil {
+		return
+	}
+
+	// STEP M3. Request from iPhone
+	r := bufio.NewReader(conn)
+	if req, err = http.ReadRequest(r); err != nil {
+		return
+	}
+	encryptedM3 := pairSetupPayload{}
+	if err = tlv8.UnmarshalReader(req.Body, &encryptedM3); err != nil {
+		return
+	}
+	if encryptedM3.State != hap.M3 {
+		err = errors.New("wrong state")
+		return
+	}
+
+	buf = encryptedM3.EncryptedData[:len(encryptedM3.EncryptedData)-16]
+	copy(mac[:], encryptedM3.EncryptedData[len(buf):]) // 16 byte (MAC)
+
+	if buf, err = chacha20poly1305.DecryptAndVerify(
+		sessionKey[:], []byte("PV-Msg03"), buf, mac, nil,
+	); err != nil {
+		return
+	}
+
+	payloadM3 := pairVerifyPayload{}
+	if err = tlv8.Unmarshal(buf, &payloadM3); err != nil {
+		return
+	}
+
+	if s.Pairings != nil {
+		pairing := s.Pairings[payloadM3.Identifier]
+		if pairing == nil {
+			err = errors.New("not paired yet")
+			return
+		}
+
+		buf = nil
+		buf = append(buf, clientPublic[:]...)
+		buf = append(buf, []byte(payloadM3.Identifier)...)
+		buf = append(buf, sessionPublic[:]...)
+
+		if !ed25519.ValidateSignature(
+			pairing[:32], buf, payloadM3.Signature,
+		) {
+			err = errors.New("signature invalid")
+			return
+		}
+	}
+
+	// STEP M4. Response to iPhone
+	payloadM4 := struct {
+		State byte `tlv8:"6"`
+	}{
+		State: hap.M4,
+	}
+	if buf, err = tlv8.Marshal(payloadM4); err != nil {
+		return
+	}
+	err = WriteResponse(conn, http.StatusOK, MimeTLV8, buf)
+
+	if secure, err = NewSecure(sessionShared, true); err != nil {
+		return
+	}
+	secure.Conn = conn
+
+	return
+}

pkg/hap/secure.go

@@ -0,0 +1,137 @@
+package hap
+
+import (
+	"encoding/binary"
+	"github.com/brutella/hap/chacha20poly1305"
+	"github.com/brutella/hap/hkdf"
+	"net"
+	"sync"
+)
+
+type Secure struct {
+	Conn net.Conn
+
+	encryptKey   [32]byte
+	decryptKey   [32]byte
+	encryptCount uint64
+	decryptCount uint64
+
+	mx sync.Mutex
+}
+
+func NewSecure(sharedKey [32]byte, isServer bool) (*Secure, error) {
+	salt := []byte("Control-Salt")
+
+	key1, err := hkdf.Sha512(
+		sharedKey[:], salt, []byte("Control-Read-Encryption-Key"),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	key2, err := hkdf.Sha512(
+		sharedKey[:], salt, []byte("Control-Write-Encryption-Key"),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	if isServer {
+		return &Secure{encryptKey: key1, decryptKey: key2}, nil
+	} else {
+		return &Secure{encryptKey: key2, decryptKey: key1}, nil
+	}
+}
+
+func (s *Secure) Read(b []byte) (n int, err error) {
+	for {
+		var length uint16
+		if err = binary.Read(s.Conn, binary.LittleEndian, &length); err != nil {
+			return
+		}
+
+		var enc = make([]byte, length)
+		if err = binary.Read(s.Conn, binary.LittleEndian, &enc); err != nil {
+			return
+		}
+
+		var mac [16]byte
+		if err = binary.Read(s.Conn, binary.LittleEndian, &mac); err != nil {
+			return
+		}
+
+		var nonce [8]byte
+		binary.LittleEndian.PutUint64(nonce[:], s.decryptCount)
+		s.decryptCount++
+
+		bLength := make([]byte, 2)
+		binary.LittleEndian.PutUint16(bLength, length)
+
+		var msg []byte
+		if msg, err = chacha20poly1305.DecryptAndVerify(
+			s.decryptKey[:], nonce[:], enc, mac, bLength,
+		); err != nil {
+			return
+		}
+
+		n += copy(b[n:], msg)
+
+		// Finish when all bytes fit in b
+		if length < packetLengthMax {
+			//fmt.Printf(">>>%s>>>\n", b[:n])
+			return
+		}
+	}
+}
+
+func (s *Secure) Write(b []byte) (n int, err error) {
+	s.mx.Lock()
+	defer s.mx.Unlock()
+
+	var packetLen = len(b)
+	for {
+		if packetLen > packetLengthMax {
+			packetLen = packetLengthMax
+		}
+
+		//fmt.Printf("<<<%s<<<\n", b[:packetLen])
+
+		var nonce [8]byte
+		binary.LittleEndian.PutUint64(nonce[:], s.encryptCount)
+		s.encryptCount++
+
+		bLength := make([]byte, 2)
+		binary.LittleEndian.PutUint16(bLength, uint16(packetLen))
+
+		var enc []byte
+		var mac [16]byte
+		enc, mac, err = chacha20poly1305.EncryptAndSeal(
+			s.encryptKey[:], nonce[:], b[:packetLen], bLength[:],
+		)
+		if err != nil {
+			return
+		}
+
+		enc = append(bLength, enc...)
+		enc = append(enc, mac[:]...)
+		if _, err = s.Conn.Write(enc); err != nil {
+			return
+		}
+
+		n += packetLen
+
+		if packetLen == packetLengthMax {
+			b = b[packetLengthMax:]
+			packetLen = len(b)
+		} else {
+			break
+		}
+	}
+
+	return
+}
+
+const (
+	// packetLengthMax is the max length of encrypted packets
+	packetLengthMax = 0x400
+)

pkg/hap/server.go

@@ -0,0 +1,155 @@
+package hap
+
+import (
+	"bufio"
+	"crypto/ed25519"
+	"github.com/brutella/hap"
+	"github.com/brutella/hap/tlv8"
+	"io"
+	"net"
+	"net/http"
+)
+
+type Server struct {
+	// Pin can't be null because server proof will be wrong
+	Pin string `json:"-"`
+
+	ServerID string `json:"server_id"`
+	// 32 bytes private key + 32 bytes public key
+	ServerPrivate []byte `json:"server_private"`
+
+	// Pairings can be nil for disable pair verify check
+	// ClientID: 32 bytes client public + 1 byte (isAdmin)
+	Pairings map[string][]byte `json:"pairings"`
+
+	DefaultPlainHandler  func(w io.Writer, r *http.Request) error
+	DefaultSecureHandler func(w io.Writer, r *http.Request) error
+
+	OnPairChange func(clientID string, clientPublic []byte) `json:"-"`
+	OnRequest    func(w io.Writer, r *http.Request)         `json:"-"`
+}
+
+func GenerateKey() []byte {
+	_, key, _ := ed25519.GenerateKey(nil)
+	return key
+}
+
+func NewServer(name string) *Server {
+	return &Server{
+		ServerID:      GenerateID(name),
+		ServerPrivate: GenerateKey(),
+		Pairings:      map[string][]byte{},
+	}
+}
+
+func (s *Server) Serve(address string) (err error) {
+	var ln net.Listener
+	if ln, err = net.Listen("tcp", address); err != nil {
+		return
+	}
+
+	for {
+		var conn net.Conn
+		if conn, err = ln.Accept(); err != nil {
+			continue
+		}
+		go func() {
+			//fmt.Printf("[%s] new connection\n", conn.RemoteAddr().String())
+			s.Accept(conn)
+			//fmt.Printf("[%s] close connection\n", conn.RemoteAddr().String())
+		}()
+	}
+}
+
+func (s *Server) Accept(conn net.Conn) (err error) {
+	defer conn.Close()
+
+	var req *http.Request
+	r := bufio.NewReader(conn)
+	if req, err = http.ReadRequest(r); err != nil {
+		return
+	}
+
+	return s.HandleRequest(conn, req)
+}
+
+func (s *Server) HandleRequest(conn net.Conn, req *http.Request) (err error) {
+	if s.OnRequest != nil {
+		s.OnRequest(conn, req)
+	}
+
+	switch req.URL.Path {
+	case UriPairSetup:
+		if _, err = s.PairSetupHandler(conn, req); err != nil {
+			return
+		}
+
+	case UriPairVerify:
+		var secure *Secure
+		if secure, err = s.PairVerifyHandler(conn, req); err != nil {
+			return
+		}
+
+		err = s.HandleSecure(secure)
+
+	default:
+		if s.DefaultPlainHandler != nil {
+			err = s.DefaultPlainHandler(conn, req)
+		}
+	}
+
+	return
+}
+
+func (s *Server) HandleSecure(secure *Secure) (err error) {
+	r := bufio.NewReader(secure)
+	for {
+		var req *http.Request
+		if req, err = http.ReadRequest(r); err != nil {
+			return
+		}
+
+		if s.OnRequest != nil {
+			s.OnRequest(secure, req)
+		}
+
+		switch req.URL.Path {
+		case UriPairings:
+			s.HandlePairings(secure, req)
+		default:
+			if err = s.DefaultSecureHandler(secure, req); err != nil {
+				return
+			}
+		}
+	}
+}
+
+func (s *Server) HandlePairings(w io.Writer, r *http.Request) {
+	req := struct {
+		Method     byte   `tlv8:"0"`
+		Identifier string `tlv8:"1"`
+		PublicKey  []byte `tlv8:"3"`
+		Permission byte   `tlv8:"11"`
+		State      byte   `tlv8:"6"`
+	}{}
+
+	if err := tlv8.UnmarshalReader(r.Body, &req); err != nil {
+		panic(err)
+	}
+
+	switch req.Method {
+	case hap.MethodAddPairing, hap.MethodDeletePairing:
+		res := struct {
+			State byte `tlv8:"6"`
+		}{
+			State: hap.M2,
+		}
+		data, err := tlv8.Marshal(res)
+		if err != nil {
+			panic(err)
+		}
+		if err = WriteResponse(w, http.StatusOK, MimeJSON, data); err != nil {
+			panic(err)
+		}
+	}
+}