make it more intuitive for tls proxy

client.go

@@ -274,15 +274,17 @@ func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader h
 			return nil, nil, err
 		}
 		if proxyURL != nil {
+			proxyDialer := &netDialerFunc{fn: netDial}
 			if proxyURL.Scheme == "https" {
-				netDial = func(network, addr string) (net.Conn, error) {
+				proxyDialer.usesTLS = true
+				proxyDialer.fn = func(network, addr string) (net.Conn, error) {
 					t := tls.Dialer{}
 					t.Config = d.TLSClientConfig
 					t.NetDialer = &net.Dialer{}
 					return t.DialContext(ctx, network, addr)
 				}
 			}
-			dialer, err := proxy_FromURL(proxyURL, netDialerFunc(netDial))
+			dialer, err := proxy_FromURL(proxyURL, proxyDialer)
 			if err != nil {
 				return nil, nil, err
 			}

proxy.go

@@ -6,6 +6,7 @@ package websocket
 
 import (
 	"bufio"
+	"crypto/tls"
 	"encoding/base64"
 	"errors"
 	"net"
@@ -14,24 +15,40 @@ import (
 	"strings"
 )
 
-type netDialerFunc func(network, addr string) (net.Conn, error)
+type netDialerFunc struct {
+	fn      func(network, addr string) (net.Conn, error)
+	usesTLS bool
+}
 
-func (fn netDialerFunc) Dial(network, addr string) (net.Conn, error) {
+func (ndf *netDialerFunc) Dial(network, addr string) (net.Conn, error) {
-	return fn(network, addr)
+	return ndf.fn(network, addr)
+}
+
+func (ndf *netDialerFunc) UsesTLS() bool {
+	return ndf.usesTLS
 }
 
 func init() {
 	proxy_RegisterDialerType("http", func(proxyURL *url.URL, forwardDialer proxy_Dialer) (proxy_Dialer, error) {
-		return &httpProxyDialer{proxyURL: proxyURL, forwardDial: forwardDialer.Dial}, nil
+		return &httpProxyDialer{proxyURL: proxyURL, forwardDial: forwardDialer.Dial, usesTLS: forwardDialer.UsesTLS()}, nil
 	})
 	proxy_RegisterDialerType("https", func(proxyURL *url.URL, forwardDialer proxy_Dialer) (proxy_Dialer, error) {
-		return &httpProxyDialer{proxyURL: proxyURL, forwardDial: forwardDialer.Dial}, nil
+		fwd := forwardDialer.Dial
+		if !forwardDialer.UsesTLS() {
+			tlsDialer := &tls.Dialer{
+				Config:    &tls.Config{},
+				NetDialer: &net.Dialer{},
+			}
+			fwd = tlsDialer.Dial
+		}
+		return &httpProxyDialer{proxyURL: proxyURL, forwardDial: fwd, usesTLS: true}, nil
 	})
 }
 
 type httpProxyDialer struct {
 	proxyURL    *url.URL
 	forwardDial func(network, addr string) (net.Conn, error)
+	usesTLS     bool
 }
 
 func (hpd *httpProxyDialer) Dial(network string, addr string) (net.Conn, error) {
@@ -78,3 +95,7 @@ func (hpd *httpProxyDialer) Dial(network string, addr string) (net.Conn, error)
 	}
 	return conn, nil
 }
+
+func (hpd *httpProxyDialer) UsesTLS() bool {
+	return hpd.usesTLS
+}

x_net_proxy.go

@@ -27,6 +27,10 @@ func (proxy_direct) Dial(network, addr string) (net.Conn, error) {
 	return net.Dial(network, addr)
 }
 
+func (proxy_direct) UsesTLS() bool {
+	return false
+}
+
 // A PerHost directs connections to a default Dialer unless the host name
 // requested matches one of a number of exceptions.
 type proxy_PerHost struct {
@@ -59,6 +63,10 @@ func (p *proxy_PerHost) Dial(network, addr string) (c net.Conn, err error) {
 	return p.dialerForRequest(host).Dial(network, addr)
 }
 
+func (p *proxy_PerHost) UsesTLS() bool {
+	return p.def.UsesTLS() || p.bypass.UsesTLS()
+}
+
 func (p *proxy_PerHost) dialerForRequest(host string) proxy_Dialer {
 	if ip := net.ParseIP(host); ip != nil {
 		for _, net := range p.bypassNetworks {
@@ -161,6 +169,8 @@ func (p *proxy_PerHost) AddHost(host string) {
 type proxy_Dialer interface {
 	// Dial connects to the given address via the proxy.
 	Dial(network, addr string) (c net.Conn, err error)
+	// UsesTLS indicates whether we expect to dial to a TLS proxy
+	UsesTLS() bool
 }
 
 // Auth contains authentication parameters that specific Dialers may require.
@@ -338,6 +348,10 @@ func (s *proxy_socks5) Dial(network, addr string) (net.Conn, error) {
 	return conn, nil
 }
 
+func (s *proxy_socks5) UsesTLS() bool {
+	return s.forward.UsesTLS()
+}
+
 // connect takes an existing connection to a socks5 proxy server,
 // and commands the server to extend that connection to target,
 // which must be a canonical address with a host and port.