Geodata: Apply uTLS Chrome fingerprint when downloading (#6371)

Closes https://github.com/XTLS/Xray-core/issues/6369

app/geodata/download.go

@@ -2,6 +2,7 @@ package geodata
 
 import (
 	"context"
+	"crypto/tls"
 	go_errors "errors"
 	"io"
 	"net/http"
@@ -9,6 +10,7 @@ import (
 	"path/filepath"
 	"time"
 
+	utls "github.com/refraction-networking/utls"
 	"github.com/xtls/xray-core/common/errors"
 	"github.com/xtls/xray-core/common/net"
 	"github.com/xtls/xray-core/common/platform/filesystem"
@@ -16,6 +18,7 @@ import (
 	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/features/routing"
 	"github.com/xtls/xray-core/transport/internet/tagged"
+	"golang.org/x/net/http2"
 )
 
 const idleTimeout = 30 * time.Second
@@ -26,8 +29,9 @@ type stage struct {
 }
 
 type downloader struct {
-	ctx    context.Context
-	client *http.Client
+	ctx         context.Context
+	httpClient  *http.Client
+	httpsClient *http.Client
 }
 
 type idleConn struct {
@@ -53,52 +57,84 @@ func (c *idleConn) Write(b []byte) (int, error) {
 
 func newDownloader(ctx context.Context, dispatcher routing.Dispatcher, outbound string) *downloader {
 	return &downloader{
-		ctx:    ctx,
-		client: newClient(ctx, dispatcher, outbound),
+		ctx:         ctx,
+		httpClient:  newClient(ctx, dispatcher, outbound, false),
+		httpsClient: newClient(ctx, dispatcher, outbound, true),
 	}
 }
 
-func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound string) *http.Client {
-	return &http.Client{
-		Transport: &http.Transport{
-			Proxy:             nil,
-			DisableKeepAlives: true,
-			DialContext: func(ctx context.Context, network, address string) (net.Conn, error) {
-				var conn net.Conn
-				err := task.Run(ctx, func() error {
-					if tagged.Dialer == nil {
-						return errors.New("tagged dialer is not initialized")
-					}
-					dest, err := net.ParseDestination(network + ":" + address)
-					if err != nil {
-						return errors.New("cannot understand address").Base(err)
-					}
-					c, err := tagged.Dialer(baseCtx, dispatcher, dest, outbound)
-					if err != nil {
-						return errors.New("cannot dial remote address ", dest).Base(err)
-					}
-					conn = c
-					return nil
-				})
-				if err != nil {
-					return nil, errors.New("cannot finish connection").Base(err)
-				}
-				return &idleConn{
-					Conn: conn,
-				}, nil
-			},
-			TLSHandshakeTimeout:   idleTimeout,
-			ResponseHeaderTimeout: idleTimeout,
-		},
-		CheckRedirect: func(req *http.Request, via []*http.Request) error {
-			if req.URL.Scheme != "https" {
-				return errors.New("redirected to non-https URL: ", req.URL.String())
+func newClient(baseCtx context.Context, dispatcher routing.Dispatcher, outbound string, isHTTPS bool) *http.Client {
+	dial := func(ctx context.Context, network, address string) (net.Conn, error) {
+		var conn net.Conn
+		err := task.Run(ctx, func() error {
+			if tagged.Dialer == nil {
+				return errors.New("tagged dialer is not initialized")
 			}
-			if len(via) >= 10 {
-				return errors.New("stopped after 10 redirects")
+			dest, err := net.ParseDestination(network + ":" + address)
+			if err != nil {
+				return errors.New("cannot understand address").Base(err)
 			}
+			c, err := tagged.Dialer(baseCtx, dispatcher, dest, outbound)
+			if err != nil {
+				return errors.New("cannot dial remote address ", dest).Base(err)
+			}
+			conn = c
 			return nil
-		},
+		})
+		if err != nil {
+			return nil, errors.New("cannot finish connection").Base(err)
+		}
+		return &idleConn{
+			Conn: conn,
+		}, nil
+	}
+	if isHTTPS {
+		return &http.Client{
+			Transport: &http2.Transport{
+				DialTLSContext: func(ctx context.Context, network string, address string, cfg *tls.Config) (net.Conn, error) {
+					conn, err := dial(ctx, network, address)
+					if err != nil {
+						return nil, err
+					}
+					host, _, _ := net.SplitHostPort(address)
+					tlsConn := utls.UClient(conn, &utls.Config{ServerName: host}, utls.HelloChrome_Auto)
+					handshakeCtx, cancel := context.WithTimeout(ctx, idleTimeout)
+					defer cancel()
+					if err := tlsConn.HandshakeContext(handshakeCtx); err != nil {
+						conn.Close()
+						return nil, err
+					}
+					return tlsConn, nil
+				},
+			},
+			CheckRedirect: func(req *http.Request, via []*http.Request) error {
+				if req.URL.Scheme != "https" {
+					return errors.New("redirected to non-https URL: ", req.URL.String())
+				}
+				if len(via) >= 10 {
+					return errors.New("stopped after 10 redirects")
+				}
+				return nil
+			},
+		}
+	} else {
+		return &http.Client{
+			Transport: &http.Transport{
+				Proxy:                 nil,
+				DisableKeepAlives:     true,
+				DialContext:           dial,
+				ResponseHeaderTimeout: idleTimeout,
+			},
+			CheckRedirect: func(req *http.Request, via []*http.Request) error {
+				if req.URL.Scheme != "https" {
+					return errors.New("redirected to non-https URL: ", req.URL.String())
+				}
+				if len(via) >= 10 {
+					return errors.New("stopped after 10 redirects")
+				}
+				return nil
+			},
+		}
 	}
 }
 
@@ -160,7 +196,13 @@ func (d *downloader) fetch(rawURL string, writer io.Writer) error {
 	}
 	utils.TryDefaultHeadersWith(req.Header, "nav")
 
-	resp, err := d.client.Do(req)
+	var client *http.Client
+	if req.URL.Scheme == "https" {
+		client = d.httpsClient
+	} else {
+		client = d.httpClient
+	}
+	resp, err := client.Do(req)
 	if err != nil {
 		return err
 	}