Feature: add shadowsocks simple-obfs support

adapters/remote/shadowsocks.go

@@ -9,6 +9,7 @@ import (
 
 	C "github.com/Dreamacro/clash/constant"
 
+	"github.com/Dreamacro/clash/common/simple-obfs"
 	"github.com/riobard/go-shadowsocks2/core"
 	"github.com/riobard/go-shadowsocks2/socks"
 )
@@ -28,9 +29,11 @@ func (ss *ShadowsocksAdapter) Conn() net.Conn {
 }
 
 type ShadowSocks struct {
-	server string
+	server   string
-	name   string
+	name     string
-	cipher core.Cipher
+	obfs     string
+	obfsHost string
+	cipher   core.Cipher
 }
 
 func (ss *ShadowSocks) Name() string {
@@ -47,22 +50,42 @@ func (ss *ShadowSocks) Generator(addr *C.Addr) (adapter C.ProxyAdapter, err erro
 		return nil, fmt.Errorf("%s connect error", ss.server)
 	}
 	tcpKeepAlive(c)
+	switch ss.obfs {
+	case "tls":
+		c = obfs.NewTLSObfs(c, ss.obfsHost)
+	case "http":
+		_, port, _ := net.SplitHostPort(ss.server)
+		c = obfs.NewHTTPObfs(c, ss.obfsHost, port)
+	}
 	c = ss.cipher.StreamConn(c)
 	_, err = c.Write(serializesSocksAddr(addr))
 	return &ShadowsocksAdapter{conn: c}, err
 }
 
-func NewShadowSocks(name string, ssURL string) (*ShadowSocks, error) {
+func NewShadowSocks(name string, ssURL string, option map[string]string) (*ShadowSocks, error) {
 	var key []byte
 	server, cipher, password, _ := parseURL(ssURL)
 	ciph, err := core.PickCipher(cipher, key, password)
 	if err != nil {
 		return nil, fmt.Errorf("ss %s initialize error: %s", server, err.Error())
 	}
+
+	obfs := ""
+	obfsHost := "bing.com"
+	if value, ok := option["obfs"]; ok {
+		obfs = value
+	}
+
+	if value, ok := option["obfs-host"]; ok {
+		obfsHost = value
+	}
+
 	return &ShadowSocks{
-		server: server,
+		server:   server,
-		name:   name,
+		name:     name,
-		cipher: ciph,
+		cipher:   ciph,
+		obfs:     obfs,
+		obfsHost: obfsHost,
 	}, nil
 }
 

common/simple-obfs/http.go

@@ -0,0 +1,88 @@
+package obfs
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math/rand"
+	"net"
+	"net/http"
+)
+
+// HTTPObfs is shadowsocks http simple-obfs implementation
+type HTTPObfs struct {
+	net.Conn
+	host          string
+	port          string
+	buf           []byte
+	offset        int
+	firstRequest  bool
+	firstResponse bool
+}
+
+func (ho *HTTPObfs) Read(b []byte) (int, error) {
+	if ho.buf != nil {
+		n := copy(b, ho.buf[ho.offset:])
+		ho.offset += n
+		if ho.offset == len(ho.buf) {
+			ho.buf = nil
+		}
+		return n, nil
+	}
+
+	if ho.firstResponse {
+		buf := bufPool.Get().([]byte)
+		n, err := ho.Conn.Read(buf)
+		if err != nil {
+			bufPool.Put(buf[:cap(buf)])
+			return 0, err
+		}
+		idx := bytes.Index(buf[:n], []byte("\r\n\r\n"))
+		if idx == -1 {
+			bufPool.Put(buf[:cap(buf)])
+			return 0, io.EOF
+		}
+		ho.firstResponse = false
+		length := n - (idx + 4)
+		n = copy(b, buf[idx+4:n])
+		if length > n {
+			ho.buf = buf[:idx+4+length]
+			ho.offset = idx + 4 + n
+		} else {
+			bufPool.Put(buf[:cap(buf)])
+		}
+		return n, nil
+	}
+	return ho.Conn.Read(b)
+}
+
+func (ho *HTTPObfs) Write(b []byte) (int, error) {
+	if ho.firstRequest {
+		randBytes := make([]byte, 16)
+		rand.Read(randBytes)
+		req, _ := http.NewRequest("GET", fmt.Sprintf("http://%s/", ho.host), bytes.NewBuffer(b[:]))
+		req.Header.Set("User-Agent", fmt.Sprintf("curl/7.%d.%d", rand.Int()%54, rand.Int()%2))
+		req.Header.Set("Upgrade", "websocket")
+		req.Header.Set("Connection", "Upgrade")
+		req.Host = fmt.Sprintf("%s:%s", ho.host, ho.port)
+		req.Header.Set("Sec-WebSocket-Key", base64.URLEncoding.EncodeToString(randBytes))
+		req.ContentLength = int64(len(b))
+		err := req.Write(ho.Conn)
+		ho.firstRequest = false
+		return len(b), err
+	}
+
+	return ho.Conn.Write(b)
+}
+
+// NewHTTPObfs return a HTTPObfs
+func NewHTTPObfs(conn net.Conn, host string, port string) net.Conn {
+	return &HTTPObfs{
+		Conn:          conn,
+		firstRequest:  true,
+		firstResponse: true,
+		host:          host,
+		port:          port,
+	}
+}

common/simple-obfs/tls.go

@@ -0,0 +1,190 @@
+package obfs
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"math/rand"
+	"net"
+	"sync"
+	"time"
+)
+
+func init() {
+	rand.Seed(time.Now().Unix())
+}
+
+var bufPool = sync.Pool{New: func() interface{} { return make([]byte, 2048) }}
+
+// TLSObfs is shadowsocks tls simple-obfs implementation
+type TLSObfs struct {
+	net.Conn
+	server        string
+	remain        int
+	firstRequest  bool
+	firstResponse bool
+}
+
+func (to *TLSObfs) read(b []byte, discardN int) (int, error) {
+	buf := bufPool.Get().([]byte)
+	_, err := io.ReadFull(to.Conn, buf[:discardN])
+	if err != nil {
+		return 0, err
+	}
+	bufPool.Put(buf[:cap(buf)])
+
+	sizeBuf := make([]byte, 2)
+	_, err = io.ReadFull(to.Conn, sizeBuf)
+	if err != nil {
+		return 0, nil
+	}
+
+	length := int(binary.BigEndian.Uint16(sizeBuf))
+	if length > len(b) {
+		n, err := to.Conn.Read(b)
+		if err != nil {
+			return n, err
+		}
+		to.remain = length - n
+		return n, nil
+	}
+
+	return io.ReadFull(to.Conn, b[:length])
+}
+
+func (to *TLSObfs) Read(b []byte) (int, error) {
+	if to.remain > 0 {
+		length := to.remain
+		if length > len(b) {
+			length = len(b)
+		}
+
+		n, err := io.ReadFull(to.Conn, b[:length])
+		to.remain -= n
+		return n, err
+	}
+
+	if to.firstResponse {
+		// type + ver + lensize + 91 = 96
+		// type + ver + lensize + 1 = 6
+		// type + ver = 3
+		to.firstResponse = false
+		return to.read(b, 105)
+	}
+
+	// type + ver = 3
+	return to.read(b, 3)
+}
+
+func (to *TLSObfs) Write(b []byte) (int, error) {
+	if to.firstRequest {
+		helloMsg := makeClientHelloMsg(b, to.server)
+		_, err := to.Conn.Write(helloMsg)
+		to.firstRequest = false
+		return len(b), err
+	}
+
+	size := bufPool.Get().([]byte)
+	binary.BigEndian.PutUint16(size[:2], uint16(len(b)))
+
+	buf := &bytes.Buffer{}
+	buf.Write([]byte{0x17, 0x03, 0x03})
+	buf.Write(size[:2])
+	buf.Write(b)
+	_, err := to.Conn.Write(buf.Bytes())
+	bufPool.Put(size[:cap(size)])
+	return len(b), err
+}
+
+// NewTLSObfs return a SimpleObfs
+func NewTLSObfs(conn net.Conn, server string) net.Conn {
+	return &TLSObfs{
+		Conn:          conn,
+		server:        server,
+		firstRequest:  true,
+		firstResponse: true,
+	}
+}
+
+func makeClientHelloMsg(data []byte, server string) []byte {
+	random := make([]byte, 32)
+	sessionID := make([]byte, 32)
+	size := make([]byte, 2)
+	rand.Read(random)
+	rand.Read(sessionID)
+
+	buf := &bytes.Buffer{}
+
+	// handshake, TLS 1.0 version, length
+	buf.WriteByte(22)
+	buf.Write([]byte{0x03, 0x01})
+	length := uint16(212 + len(data) + len(server))
+	buf.WriteByte(byte(length >> 8))
+	buf.WriteByte(byte(length & 0xff))
+
+	// clientHello, length, TLS 1.2 version
+	buf.WriteByte(1)
+	binary.BigEndian.PutUint16(size, uint16(208+len(data)+len(server)))
+	buf.WriteByte(0)
+	buf.Write(size)
+	buf.Write([]byte{0x03, 0x03})
+
+	// random, sid len, sid
+	buf.Write(random)
+	buf.WriteByte(32)
+	buf.Write(sessionID)
+
+	// cipher suites
+	buf.Write([]byte{0x00, 0x38})
+	buf.Write([]byte{
+		0xc0, 0x2c, 0xc0, 0x30, 0x00, 0x9f, 0xcc, 0xa9, 0xcc, 0xa8, 0xcc, 0xaa, 0xc0, 0x2b, 0xc0, 0x2f,
+		0x00, 0x9e, 0xc0, 0x24, 0xc0, 0x28, 0x00, 0x6b, 0xc0, 0x23, 0xc0, 0x27, 0x00, 0x67, 0xc0, 0x0a,
+		0xc0, 0x14, 0x00, 0x39, 0xc0, 0x09, 0xc0, 0x13, 0x00, 0x33, 0x00, 0x9d, 0x00, 0x9c, 0x00, 0x3d,
+		0x00, 0x3c, 0x00, 0x35, 0x00, 0x2f, 0x00, 0xff,
+	})
+
+	// compression
+	buf.Write([]byte{0x01, 0x00})
+
+	// extension length
+	binary.BigEndian.PutUint16(size, uint16(79+len(data)+len(server)))
+	buf.Write(size)
+
+	// session ticket
+	buf.Write([]byte{0x00, 0x23})
+	binary.BigEndian.PutUint16(size, uint16(len(data)))
+	buf.Write(size)
+	buf.Write(data)
+
+	// server name
+	buf.Write([]byte{0x00, 0x00})
+	binary.BigEndian.PutUint16(size, uint16(len(server)+5))
+	buf.Write(size)
+	binary.BigEndian.PutUint16(size, uint16(len(server)+3))
+	buf.Write(size)
+	buf.WriteByte(0)
+	binary.BigEndian.PutUint16(size, uint16(len(server)))
+	buf.Write(size)
+	buf.Write([]byte(server))
+
+	// ec_point
+	buf.Write([]byte{0x00, 0x0b, 0x00, 0x04, 0x03, 0x01, 0x00, 0x02})
+
+	// groups
+	buf.Write([]byte{0x00, 0x0a, 0x00, 0x0a, 0x00, 0x08, 0x00, 0x1d, 0x00, 0x17, 0x00, 0x19, 0x00, 0x18})
+
+	// signature
+	buf.Write([]byte{
+		0x00, 0x0d, 0x00, 0x20, 0x00, 0x1e, 0x06, 0x01, 0x06, 0x02, 0x06, 0x03, 0x05,
+		0x01, 0x05, 0x02, 0x05, 0x03, 0x04, 0x01, 0x04, 0x02, 0x04, 0x03, 0x03, 0x01,
+		0x03, 0x02, 0x03, 0x03, 0x02, 0x01, 0x02, 0x02, 0x02, 0x03,
+	})
+
+	// encrypt then mac
+	buf.Write([]byte{0x00, 0x16, 0x00, 0x00})
+
+	// extended master secret
+	buf.Write([]byte{0x00, 0x17, 0x00, 0x00})
+
+	return buf.Bytes()
+}

config/config.go

@@ -223,7 +223,8 @@ func (c *Config) parseProxies(cfg *ini.File) error {
 				continue
 			}
 			ssURL := fmt.Sprintf("ss://%s:%s@%s:%s", proxy[3], proxy[4], proxy[1], proxy[2])
-			ss, err := adapters.NewShadowSocks(key.Name(), ssURL)
+			option := parseOptions(5, proxy...)
+			ss, err := adapters.NewShadowSocks(key.Name(), ssURL, option)
 			if err != nil {
 				return err
 			}