Add Snell protocol. Refactor MASQUE HTTP/2, Fair Queue. Update XHTTP, OpenVPN, Sudoku, Fallback. Fixes

transport/simple-obfs/http_server.go

@@ -0,0 +1,100 @@
+package obfs
+
+import (
+	"bufio"
+	cryptorand "crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math/rand/v2"
+	"net"
+	"net/http"
+	"time"
+)
+
+// HTTPObfsServer is the server side of the shadowsocks http simple-obfs implementation.
+type HTTPObfsServer struct {
+	net.Conn
+	buf           []byte
+	bio           *bufio.Reader
+	offset        int
+	firstRequest  bool
+	firstResponse bool
+}
+
+func (hos *HTTPObfsServer) Read(b []byte) (int, error) {
+	if hos.buf != nil {
+		n := copy(b, hos.buf[hos.offset:])
+		hos.offset += n
+		if hos.offset == len(hos.buf) {
+			hos.offset = 0
+			hos.buf = nil
+		}
+		return n, nil
+	}
+	if hos.firstRequest {
+		bio := bufio.NewReader(hos.Conn)
+		req, err := http.ReadRequest(bio)
+		if err != nil {
+			return 0, err
+		}
+		if req.Method != "GET" || req.Header.Get("Connection") != "Upgrade" {
+			return 0, io.EOF
+		}
+		buf, err := io.ReadAll(req.Body)
+		if err != nil {
+			return 0, err
+		}
+		n := copy(b, buf)
+		if n < len(buf) {
+			hos.buf = buf
+			hos.offset = n
+		}
+		req.Body.Close()
+		hos.bio = bio
+		hos.firstRequest = false
+		return n, nil
+	}
+	return hos.bio.Read(b)
+}
+
+func (hos *HTTPObfsServer) Write(b []byte) (int, error) {
+	if hos.firstResponse {
+		randBytes := make([]byte, 16)
+		cryptorand.Read(randBytes)
+		date := time.Now().Format(time.RFC1123)
+		resp := fmt.Sprintf(httpResponseTemplate, vMajor, vMinor, date, base64.URLEncoding.EncodeToString(randBytes))
+		_, err := hos.Conn.Write([]byte(resp))
+		if err != nil {
+			return 0, err
+		}
+		hos.firstResponse = false
+	}
+	return hos.Conn.Write(b)
+}
+
+func (hos *HTTPObfsServer) Upstream() any {
+	return hos.Conn
+}
+
+// NewHTTPObfsServer returns a server-side HTTPObfs.
+func NewHTTPObfsServer(conn net.Conn) net.Conn {
+	return &HTTPObfsServer{
+		Conn:          conn,
+		firstRequest:  true,
+		firstResponse: true,
+	}
+}
+
+const httpResponseTemplate = "HTTP/1.1 101 Switching Protocols\r\n" +
+	"Server: nginx/1.%d.%d\r\n" +
+	"Date: %s\r\n" +
+	"Upgrade: websocket\r\n" +
+	"Connection: Upgrade\r\n" +
+	"Sec-WebSocket-Accept: %s\r\n" +
+	"\r\n"
+
+var (
+	vMajor = rand.IntN(11)
+	vMinor = rand.IntN(12)
+)