Optimization: use client session cache for TLS connection (#26)

adapters/outbound/socks5.go

@@ -32,6 +32,7 @@ type Socks5 struct {
 	name           string
 	tls            bool
 	skipCertVerify bool
+	tlsConfig      *tls.Config
 }
 
 type Socks5Option struct {
@@ -54,11 +55,9 @@ func (ss *Socks5) Generator(metadata *C.Metadata) (adapter C.ProxyAdapter, err e
 	c, err := net.DialTimeout("tcp", ss.addr, tcpTimeout)
 
 	if err == nil && ss.tls {
-		tlsConfig := tls.Config{
-			InsecureSkipVerify: ss.skipCertVerify,
-			MaxVersion:         tls.VersionTLS12,
-		}
-		c = tls.Client(c, &tlsConfig)
+		cc := tls.Client(c, ss.tlsConfig)
+		err = cc.Handshake()
+		c = cc
 	}
 
 	if err != nil {
@@ -103,10 +102,22 @@ func (ss *Socks5) shakeHand(metadata *C.Metadata, rw io.ReadWriter) error {
 }
 
 func NewSocks5(option Socks5Option) *Socks5 {
+	var tlsConfig *tls.Config
+	if option.TLS {
+		tlsConfig = &tls.Config{
+			InsecureSkipVerify: option.SkipCertVerify,
+			ClientSessionCache: getClientSessionCache(),
+			MinVersion:         tls.VersionTLS11,
+			MaxVersion:         tls.VersionTLS12,
+			ServerName:         option.Server,
+		}
+	}
+
 	return &Socks5{
 		addr:           fmt.Sprintf("%s:%d", option.Server, option.Port),
 		name:           option.Name,
 		tls:            option.TLS,
 		skipCertVerify: option.SkipCertVerify,
+		tlsConfig:      tlsConfig,
 	}
 }

adapters/outbound/util.go

@@ -1,10 +1,12 @@
 package adapters
 
 import (
+	"crypto/tls"
 	"fmt"
 	"net"
 	"net/http"
 	"net/url"
+	"sync"
 	"time"
 
 	C "github.com/Dreamacro/clash/constant"
@@ -14,6 +16,11 @@ const (
 	tcpTimeout = 5 * time.Second
 )
 
+var (
+	globalClientSessionCache tls.ClientSessionCache
+	once                     sync.Once
+)
+
 // DelayTest get the delay for the specified URL
 func DelayTest(proxy C.Proxy, url string) (t int16, err error) {
 	addr, err := urlToMetadata(url)
@@ -95,3 +102,10 @@ func tcpKeepAlive(c net.Conn) {
 		tcp.SetKeepAlivePeriod(30 * time.Second)
 	}
 }
+
+func getClientSessionCache() tls.ClientSessionCache {
+	once.Do(func() {
+		globalClientSessionCache = tls.NewLRUClientSessionCache(128)
+	})
+	return globalClientSessionCache
+}

adapters/outbound/vmess.go

@@ -72,6 +72,7 @@ func NewVmess(option VmessOption) (*Vmess, error) {
 		NetWork:        option.Network,
 		WebSocketPath:  option.WSPath,
 		SkipCertVerify: option.SkipCertVerify,
+		SessionCacahe:  getClientSessionCache(),
 	})
 	if err != nil {
 		return nil, err