Feature: Trojan XTLS

README.md

@@ -127,11 +127,14 @@ rules:
 ```
 
 ### Proxies configuration
-Support outbound transport protocol `VLESS`.
+Support outbound protocol `VLESS`.
 
-The XTLS only support TCP transport by the XRAY-CORE.
+Support `Trojan` with XTLS.
+
+Currently XTLS only supports TCP transport.
 ```yaml
 proxies:
+  # VLESS
   - name: "vless-tls"
     type: vless
     server: server
@@ -149,9 +152,22 @@ proxies:
     network: tcp
     servername: example.com
     flow: xtls-rprx-direct # or xtls-rprx-origin
-    # flow-show: true # print the XTLS direct log
+    # flow-show: true # print the XTLS direction log
     # udp: true
     # skip-cert-verify: true
+
+  # Trojan
+  - name: "trojan-xtls"
+    type: trojan
+    server: server
+    port: 443
+    password: yourpsk
+    network: tcp
+    flow: xtls-rprx-direct # or xtls-rprx-origin
+    # flow-show: true # print the XTLS direction log
+    # udp: true
+    # sni: example.com # aka server name
+    # skip-cert-verify: true
 ```
 
 ### IPTABLES configuration

adapter/outbound/trojan.go

@@ -12,6 +12,7 @@ import (
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/transport/gun"
 	"github.com/Dreamacro/clash/transport/trojan"
+	"github.com/Dreamacro/clash/transport/vless"
 
 	"golang.org/x/net/http2"
 )
@@ -40,6 +41,8 @@ type TrojanOption struct {
 	Network        string      `proxy:"network,omitempty"`
 	GrpcOpts       GrpcOptions `proxy:"grpc-opts,omitempty"`
 	WSOpts         WSOptions   `proxy:"ws-opts,omitempty"`
+	Flow           string      `proxy:"flow,omitempty"`
+	FlowShow       bool        `proxy:"flow-show,omitempty"`
 }
 
 func (t *Trojan) plainStream(c net.Conn) (net.Conn, error) {
@@ -82,6 +85,11 @@ func (t *Trojan) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error)
 		return nil, fmt.Errorf("%s connect error: %w", t.addr, err)
 	}
 
+	c, err = t.instance.PresetXTLSConn(c)
+	if err != nil {
+		return nil, err
+	}
+
 	err = t.instance.WriteHeader(c, trojan.CommandTCP, serializesSocksAddr(metadata))
 	return c, err
 }
@@ -95,6 +103,12 @@ func (t *Trojan) DialContext(ctx context.Context, metadata *C.Metadata, opts ...
 			return nil, err
 		}
 
+		c, err = t.instance.PresetXTLSConn(c)
+		if err != nil {
+			c.Close()
+			return nil, err
+		}
+
 		if err = t.instance.WriteHeader(c, trojan.CommandTCP, serializesSocksAddr(metadata)); err != nil {
 			c.Close()
 			return nil, err
@@ -160,6 +174,17 @@ func NewTrojan(option TrojanOption) (*Trojan, error) {
 		ALPN:           option.ALPN,
 		ServerName:     option.Server,
 		SkipCertVerify: option.SkipCertVerify,
+		FlowShow:       option.FlowShow,
+	}
+
+	if option.Network != "ws" && len(option.Flow) >= 16 {
+		option.Flow = option.Flow[:16]
+		switch option.Flow {
+		case vless.XRO, vless.XRD, vless.XRS:
+			tOption.Flow = option.Flow
+		default:
+			return nil, fmt.Errorf("unsupported xtls flow type: %s", option.Flow)
+		}
 	}
 
 	if option.SNI != "" {
@@ -196,7 +221,12 @@ func NewTrojan(option TrojanOption) (*Trojan, error) {
 			ServerName:         tOption.ServerName,
 		}
 
+		if t.option.Flow != "" {
+			t.transport = gun.NewHTTP2XTLSClient(dialFn, tlsConfig)
+		} else {
 			t.transport = gun.NewHTTP2Client(dialFn, tlsConfig)
+		}
+
 		t.gunTLSConfig = tlsConfig
 		t.gunConfig = &gun.Config{
 			ServiceName: option.GrpcOpts.GrpcServiceName,

test/config/trojan-xtls.json

@@ -0,0 +1,39 @@
+{
+    "inbounds": [
+        {
+            "port": 10002,
+            "listen": "0.0.0.0",
+            "protocol": "trojan",
+            "settings": {
+                "clients": [
+                    {
+                        "password": "example",
+                        "email": "xtls@example.com",
+                        "flow": "xtls-rprx-direct",
+                        "level": 0
+                    }
+                ]
+            },
+            "streamSettings": {
+                "network": "tcp",
+                "security": "xtls",
+                "xtlsSettings": {
+                    "certificates": [
+                        {
+                            "certificateFile": "/etc/ssl/v2ray/fullchain.pem",
+                            "keyFile": "/etc/ssl/v2ray/privkey.pem"
+                        }
+                    ]
+                }
+            }
+        }
+    ],
+    "outbounds": [
+        {
+            "protocol": "freedom"
+        }
+    ],
+    "log": {
+        "loglevel": "debug"
+    }
+}

test/trojan_test.go

@@ -131,6 +131,46 @@ func TestClash_TrojanWebsocket(t *testing.T) {
 	testSuit(t, proxy)
 }
 
+func TestClash_TrojanXTLS(t *testing.T) {
+	cfg := &container.Config{
+		Image:        ImageXray,
+		ExposedPorts: defaultExposedPorts,
+	}
+	hostCfg := &container.HostConfig{
+		PortBindings: defaultPortBindings,
+		Binds: []string{
+			fmt.Sprintf("%s:/etc/xray/config.json", C.Path.Resolve("trojan-xtls.json")),
+			fmt.Sprintf("%s:/etc/ssl/v2ray/fullchain.pem", C.Path.Resolve("example.org.pem")),
+			fmt.Sprintf("%s:/etc/ssl/v2ray/privkey.pem", C.Path.Resolve("example.org-key.pem")),
+		},
+	}
+
+	id, err := startContainer(cfg, hostCfg, "trojan-xtls")
+	if err != nil {
+		assert.FailNow(t, err.Error())
+	}
+	defer cleanContainer(id)
+
+	proxy, err := outbound.NewTrojan(outbound.TrojanOption{
+		Name:           "trojan",
+		Server:         localIP.String(),
+		Port:           10002,
+		Password:       "example",
+		SNI:            "example.org",
+		SkipCertVerify: true,
+		UDP:            true,
+		Network:        "tcp",
+		Flow:           "xtls-rprx-direct",
+		FlowShow:       true,
+	})
+	if err != nil {
+		assert.FailNow(t, err.Error())
+	}
+
+	time.Sleep(waitTime)
+	testSuit(t, proxy)
+}
+
 func Benchmark_Trojan(b *testing.B) {
 	cfg := &container.Config{
 		Image:        ImageTrojan,

transport/trojan/trojan.go

@@ -7,6 +7,7 @@ import (
 	"encoding/binary"
 	"encoding/hex"
 	"errors"
+	"fmt"
 	"io"
 	"net"
 	"net/http"
@@ -15,7 +16,10 @@ import (
 	"github.com/Dreamacro/clash/common/pool"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/transport/socks5"
+	"github.com/Dreamacro/clash/transport/vless"
 	"github.com/Dreamacro/clash/transport/vmess"
+
+	xtls "github.com/xtls/go"
 )
 
 const (
@@ -32,9 +36,13 @@ var (
 
 type Command = byte
 
-var (
+const (
 	CommandTCP byte = 1
 	CommandUDP byte = 3
+
+	// for XTLS
+	commandXRD byte = 0xf0 // XTLS direct mode
+	commandXRO byte = 0xf1 // XTLS origin mode
 )
 
 type Option struct {
@@ -42,6 +50,8 @@ type Option struct {
 	ALPN           []string
 	ServerName     string
 	SkipCertVerify bool
+	Flow           string
+	FlowShow       bool
 }
 
 type WebsocketOption struct {
@@ -62,6 +72,24 @@ func (t *Trojan) StreamConn(conn net.Conn) (net.Conn, error) {
 		alpn = t.option.ALPN
 	}
 
+	if t.option.Flow != "" {
+		xtlsConfig := &xtls.Config{
+			NextProtos:         alpn,
+			MinVersion:         xtls.VersionTLS12,
+			InsecureSkipVerify: t.option.SkipCertVerify,
+			ServerName:         t.option.ServerName,
+		}
+
+		xtlsConn := xtls.Client(conn, xtlsConfig)
+
+		ctx, cancel := context.WithTimeout(context.Background(), C.DefaultTLSTimeout)
+		defer cancel()
+		if err := xtlsConn.HandshakeContext(ctx); err != nil {
+			return nil, err
+		}
+
+		return xtlsConn, nil
+	} else {
 		tlsConfig := &tls.Config{
 			NextProtos:         alpn,
 			MinVersion:         tls.VersionTLS12,
@@ -80,6 +108,7 @@ func (t *Trojan) StreamConn(conn net.Conn) (net.Conn, error) {
 
 		return tlsConn, nil
 	}
+}
 
 func (t *Trojan) StreamWebsocketConn(conn net.Conn, wsOptions *WebsocketOption) (net.Conn, error) {
 	alpn := defaultWebsocketALPN
@@ -104,7 +133,37 @@ func (t *Trojan) StreamWebsocketConn(conn net.Conn, wsOptions *WebsocketOption)
 	})
 }
 
+func (t *Trojan) PresetXTLSConn(conn net.Conn) (net.Conn, error) {
+	switch t.option.Flow {
+	case vless.XRO, vless.XRD, vless.XRS:
+		if xtlsConn, ok := conn.(*xtls.Conn); ok {
+			xtlsConn.RPRX = true
+			xtlsConn.SHOW = t.option.FlowShow
+			xtlsConn.MARK = "XTLS"
+			if t.option.Flow == vless.XRS {
+				t.option.Flow = vless.XRD
+			}
+
+			if t.option.Flow == vless.XRD {
+				xtlsConn.DirectMode = true
+			}
+		} else {
+			return nil, fmt.Errorf("failed to use %s, maybe \"security\" is not \"xtls\"", t.option.Flow)
+		}
+	}
+
+	return conn, nil
+}
+
 func (t *Trojan) WriteHeader(w io.Writer, command Command, socks5Addr []byte) error {
+	if command == CommandTCP {
+		if t.option.Flow == vless.XRD {
+			command = commandXRD
+		} else if t.option.Flow == vless.XRO {
+			command = commandXRO
+		}
+	}
+
 	buf := pool.GetBuffer()
 	defer pool.PutBuffer(buf)