install go2rtc on bob

installs_on_host/go2rtc/pkg/tcp/websocket/client.go

@@ -0,0 +1,130 @@
+package websocket
+
+import (
+	cryptorand "crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"time"
+)
+
+const BinaryMessage = 2
+
+type Client struct {
+	conn   net.Conn
+	remain int
+}
+
+func NewClient(conn net.Conn) *Client {
+	return &Client{conn: conn}
+}
+
+const finalBit = 0x80
+const maskBit = 0x80
+
+func (w *Client) Read(b []byte) (n int, err error) {
+	if w.remain == 0 {
+		b2 := make([]byte, 2)
+		if _, err = io.ReadFull(w.conn, b2); err != nil {
+			return 0, err
+		}
+
+		frameType := b2[0] & 0xF
+		w.remain = int(b2[1] & 0x7F)
+
+		switch frameType {
+		case BinaryMessage:
+		default:
+			return 0, fmt.Errorf("unsupported frame type: %d", frameType)
+		}
+
+		switch w.remain {
+		case 126:
+			if _, err = io.ReadFull(w.conn, b2); err != nil {
+				return 0, err
+			}
+			w.remain = int(binary.BigEndian.Uint16(b2))
+		case 127:
+			b8 := make([]byte, 8)
+			if _, err = io.ReadFull(w.conn, b8); err != nil {
+				return 0, err
+			}
+			w.remain = int(binary.BigEndian.Uint64(b8))
+		}
+	}
+
+	if w.remain > len(b) {
+		n, err = io.ReadFull(w.conn, b)
+		w.remain -= n
+		return
+	}
+
+	n, err = io.ReadFull(w.conn, b[:w.remain])
+	w.remain = 0
+
+	return
+}
+
+func (w *Client) Write(b []byte) (n int, err error) {
+	var data []byte
+	var start byte
+
+	size := len(b)
+
+	switch {
+	case size > 65535:
+		start = 10
+		data = make([]byte, size+14)
+		data[1] = maskBit | 127
+		binary.BigEndian.PutUint64(data[2:], uint64(size))
+	case size > 125:
+		start = 4
+		data = make([]byte, size+8)
+		data[1] = maskBit | 126
+		binary.BigEndian.PutUint16(data[2:], uint16(size))
+	default:
+		start = 2
+		data = make([]byte, size+6)
+		data[1] = maskBit | byte(size)
+	}
+
+	data[0] = BinaryMessage | finalBit
+
+	mask := data[start : start+4]
+	msg := data[start+4:]
+
+	if _, err = cryptorand.Read(mask); err != nil {
+		return 0, err
+	}
+
+	for i := 0; i < len(b); i++ {
+		msg[i] = b[i] ^ mask[i%4]
+	}
+
+	return w.conn.Write(data)
+}
+
+func (w *Client) Close() error {
+	return w.conn.Close()
+}
+
+func (w *Client) LocalAddr() net.Addr {
+	return w.conn.LocalAddr()
+}
+
+func (w *Client) RemoteAddr() net.Addr {
+	return w.conn.RemoteAddr()
+}
+
+func (w *Client) SetDeadline(t time.Time) error {
+	return w.conn.SetDeadline(t)
+}
+
+func (w *Client) SetReadDeadline(t time.Time) error {
+	return w.conn.SetReadDeadline(t)
+}
+
+func (w *Client) SetWriteDeadline(t time.Time) error {
+	return w.conn.SetWriteDeadline(t)
+}

installs_on_host/go2rtc/pkg/tcp/websocket/dial.go

@@ -0,0 +1,65 @@
+package websocket
+
+import (
+	cryptorand "crypto/rand"
+	"crypto/sha1"
+	"encoding/base64"
+	"errors"
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/pkg/tcp"
+)
+
+func Dial(address string) (net.Conn, error) {
+	if strings.HasPrefix(address, "ws") {
+		address = "http" + address[2:] // support http and https
+	}
+
+	// using custom client for support Digest Auth
+	// https://github.com/AlexxIT/go2rtc/issues/415
+	ctx, pconn := tcp.WithConn()
+
+	req, err := http.NewRequestWithContext(ctx, "GET", address, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	key, accept := GetKeyAccept()
+
+	// Version, Key, Protocol important for Axis cameras
+	req.Header.Set("Connection", "Upgrade")
+	req.Header.Set("Upgrade", "websocket")
+	req.Header.Set("Sec-WebSocket-Version", "13")
+	req.Header.Set("Sec-WebSocket-Key", key)
+	req.Header.Set("Sec-WebSocket-Protocol", "binary")
+
+	res, err := tcp.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	if res.StatusCode != http.StatusSwitchingProtocols {
+		return nil, errors.New("wrong status: " + res.Status)
+	}
+
+	if res.Header.Get("Sec-Websocket-Accept") != accept {
+		return nil, errors.New("wrong websocket accept")
+	}
+
+	return NewClient(*pconn), nil
+}
+
+func GetKeyAccept() (key, accept string) {
+	b := make([]byte, 16)
+	_, _ = cryptorand.Read(b)
+	key = base64.StdEncoding.EncodeToString(b)
+
+	h := sha1.New()
+	h.Write([]byte(key))
+	h.Write([]byte("258EAFA5-E914-47DA-95CA-C5AB0DC85B11"))
+	accept = base64.StdEncoding.EncodeToString(h.Sum(nil))
+
+	return
+}