Feature: support trojan

README.md

@@ -243,6 +243,19 @@ proxies:
       # mode: http # or tls
       # host: bing.com
 
+  # trojan
+  - name: "trojan"
+    type: trojan
+    server: server
+    port: 443
+    password: yourpsk
+    # udp: true
+    # sni: example.com # aka server name
+    # alpn:
+    #   - h2
+    #   - http/1.1
+    # skip-cert-verify: true
+
 proxy-groups:
   # url-test select which proxy will be used by benchmarking speed to a URL.
   - name: "auto"

adapters/outbound/parser.go

@@ -52,6 +52,13 @@ func ParseProxy(mapping map[string]interface{}) (C.Proxy, error) {
 			break
 		}
 		proxy, err = NewSnell(*snellOption)
+	case "trojan":
+		trojanOption := &TrojanOption{}
+		err = decoder.Decode(mapping, trojanOption)
+		if err != nil {
+			break
+		}
+		proxy, err = NewTrojan(*trojanOption)
 	default:
 		return nil, fmt.Errorf("Unsupport proxy type: %s", proxyType)
 	}

adapters/outbound/trojan.go

@@ -0,0 +1,107 @@
+package outbound
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net"
+	"strconv"
+
+	"github.com/Dreamacro/clash/component/dialer"
+	"github.com/Dreamacro/clash/component/trojan"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type Trojan struct {
+	*Base
+	server   string
+	instance *trojan.Trojan
+}
+
+type TrojanOption struct {
+	Name           string   `proxy:"name"`
+	Server         string   `proxy:"server"`
+	Port           int      `proxy:"port"`
+	Password       string   `proxy:"password"`
+	ALPN           []string `proxy:"alpn,omitempty"`
+	SNI            string   `proxy:"sni,omitempty"`
+	SkipCertVerify bool     `proxy:"skip-cert-verify,omitempty"`
+	UDP            bool     `proxy:"udp,omitempty"`
+}
+
+func (t *Trojan) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialer.DialContext(ctx, "tcp", t.server)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %w", t.server, err)
+	}
+	tcpKeepAlive(c)
+	c, err = t.instance.StreamConn(c)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %w", t.server, err)
+	}
+
+	err = t.instance.WriteHeader(c, trojan.CommandTCP, serializesSocksAddr(metadata))
+	return newConn(c, t), err
+}
+
+func (t *Trojan) DialUDP(metadata *C.Metadata) (C.PacketConn, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	c, err := dialer.DialContext(ctx, "tcp", t.server)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %w", t.server, err)
+	}
+	tcpKeepAlive(c)
+	c, err = t.instance.StreamConn(c)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %w", t.server, err)
+	}
+
+	err = t.instance.WriteHeader(c, trojan.CommandUDP, serializesSocksAddr(metadata))
+	if err != nil {
+		return nil, err
+	}
+
+	pc := t.instance.PacketConn(c)
+	return newPacketConn(&trojanPacketConn{pc, c}, t), err
+}
+
+func (t *Trojan) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]string{
+		"type": t.Type().String(),
+	})
+}
+
+func NewTrojan(option TrojanOption) (*Trojan, error) {
+	server := net.JoinHostPort(option.Server, strconv.Itoa(option.Port))
+
+	tOption := &trojan.Option{
+		Password:       option.Password,
+		ALPN:           option.ALPN,
+		ServerName:     option.Server,
+		SkipCertVerify: option.SkipCertVerify,
+	}
+
+	if option.SNI != "" {
+		tOption.ServerName = option.SNI
+	}
+
+	return &Trojan{
+		Base: &Base{
+			name: option.Name,
+			tp:   C.Trojan,
+			udp:  option.UDP,
+		},
+		server:   server,
+		instance: trojan.New(tOption),
+	}, nil
+}
+
+type trojanPacketConn struct {
+	net.PacketConn
+	conn net.Conn
+}
+
+func (tpc *trojanPacketConn) WriteWithMetadata(p []byte, metadata *C.Metadata) (n int, err error) {
+	return trojan.WritePacket(tpc.conn, serializesSocksAddr(metadata), p)
+}

component/trojan/trojan.go

@@ -0,0 +1,144 @@
+package trojan
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"crypto/tls"
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"net"
+	"sync"
+
+	"github.com/Dreamacro/clash/component/socks5"
+)
+
+var (
+	defaultALPN = []string{"h2", "http/1.1"}
+	crlf        = []byte{'\r', '\n'}
+
+	bufPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
+)
+
+type Command = byte
+
+var (
+	CommandTCP byte = 1
+	CommandUDP byte = 3
+)
+
+type Option struct {
+	Password       string
+	ALPN           []string
+	ServerName     string
+	SkipCertVerify bool
+}
+
+type Trojan struct {
+	option      *Option
+	hexPassword []byte
+}
+
+func (t *Trojan) StreamConn(conn net.Conn) (net.Conn, error) {
+	alpn := defaultALPN
+	if len(t.option.ALPN) != 0 {
+		alpn = t.option.ALPN
+	}
+
+	tlsConfig := &tls.Config{
+		NextProtos:         alpn,
+		MinVersion:         tls.VersionTLS12,
+		InsecureSkipVerify: t.option.SkipCertVerify,
+		ServerName:         t.option.ServerName,
+	}
+
+	tlsConn := tls.Client(conn, tlsConfig)
+	if err := tlsConn.Handshake(); err != nil {
+		return nil, err
+	}
+
+	return tlsConn, nil
+}
+
+func (t *Trojan) WriteHeader(conn net.Conn, command Command, socks5Addr []byte) error {
+	buf := bufPool.Get().(*bytes.Buffer)
+	defer buf.Reset()
+	defer bufPool.Put(buf)
+
+	buf.Write(t.hexPassword)
+	buf.Write(crlf)
+
+	buf.WriteByte(command)
+	buf.Write(socks5Addr)
+	buf.Write(crlf)
+
+	_, err := conn.Write(buf.Bytes())
+	return err
+}
+
+func (t *Trojan) PacketConn(conn net.Conn) net.PacketConn {
+	return &PacketConn{conn}
+}
+
+func WritePacket(conn net.Conn, socks5Addr, payload []byte) (int, error) {
+	buf := bufPool.Get().(*bytes.Buffer)
+	defer buf.Reset()
+	defer bufPool.Put(buf)
+
+	buf.Write(socks5Addr)
+	binary.Write(buf, binary.BigEndian, uint16(len(payload)))
+	buf.Write(crlf)
+	buf.Write(payload)
+
+	return conn.Write(buf.Bytes())
+}
+
+func DecodePacket(payload []byte) (net.Addr, []byte, error) {
+	addr := socks5.SplitAddr(payload)
+	if addr == nil {
+		return nil, nil, errors.New("split addr error")
+	}
+
+	buf := payload[len(addr):]
+	if len(buf) <= 4 {
+		return nil, nil, errors.New("packet invalid")
+	}
+
+	length := binary.BigEndian.Uint16(buf[:2])
+	if len(buf) < 4+int(length) {
+		return nil, nil, errors.New("packet invalid")
+	}
+
+	return addr.UDPAddr(), buf[4 : 4+length], nil
+}
+
+func New(option *Option) *Trojan {
+	return &Trojan{option, hexSha224([]byte(option.Password))}
+}
+
+type PacketConn struct {
+	net.Conn
+}
+
+func (pc *PacketConn) WriteTo(b []byte, addr net.Addr) (int, error) {
+	return WritePacket(pc, socks5.ParseAddr(addr.String()), b)
+}
+
+func (pc *PacketConn) ReadFrom(b []byte) (int, net.Addr, error) {
+	n, err := pc.Conn.Read(b)
+	addr, payload, err := DecodePacket(b)
+	if err != nil {
+		return n, nil, err
+	}
+
+	copy(b, payload)
+	return len(payload), addr, nil
+}
+
+func hexSha224(data []byte) []byte {
+	buf := make([]byte, 56)
+	hash := sha256.New224()
+	hash.Write(data)
+	hex.Encode(buf, hash.Sum(nil))
+	return buf
+}

constant/adapters.go

@@ -10,15 +10,18 @@ import (
 // Adapter Type
 const (
 	Direct AdapterType = iota
-	Fallback
 	Reject
-	Selector
+
 	Shadowsocks
 	Snell
 	Socks5
 	Http
-	URLTest
 	Vmess
+	Trojan
+
+	Selector
+	Fallback
+	URLTest
 	LoadBalance
 )
 
@@ -86,12 +89,9 @@ func (at AdapterType) String() string {
 	switch at {
 	case Direct:
 		return "Direct"
-	case Fallback:
-		return "Fallback"
 	case Reject:
 		return "Reject"
-	case Selector:
-		return "Selector"
+
 	case Shadowsocks:
 		return "Shadowsocks"
 	case Snell:
@@ -100,12 +100,20 @@ func (at AdapterType) String() string {
 		return "Socks5"
 	case Http:
 		return "Http"
-	case URLTest:
-		return "URLTest"
 	case Vmess:
 		return "Vmess"
+	case Trojan:
+		return "Trojan"
+
+	case Selector:
+		return "Selector"
+	case Fallback:
+		return "Fallback"
+	case URLTest:
+		return "URLTest"
 	case LoadBalance:
 		return "LoadBalance"
+
 	default:
 		return "Unknown"
 	}