add socks5s:// upstream proxy handler

Author: Snawoot

dialer/dialer.go

@@ -22,6 +22,8 @@ func init() {
 	xproxy.RegisterDialerType("h2c", H2ProxyDialerFromURL)
 	xproxy.RegisterDialerType("set-src-hints", NewHintsSettingDialerFromURL)
 	xproxy.RegisterDialerType("cached", GetCachedDialer)
+	xproxy.RegisterDialerType("socks5s", SOCKS5SDialerFromURL)
+	xproxy.RegisterDialerType("socks5hs", SOCKS5SDialerFromURL)
 }
 
 type LegacyDialer interface {

dialer/socks5s.go

@@ -0,0 +1,57 @@
+package dialer
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"net"
+	"net/url"
+
+	"github.com/SenseUnit/dumbproxy/tlsutil"
+	xproxy "golang.org/x/net/proxy"
+)
+
+func SOCKS5SDialerFromURL(u *url.URL, next xproxy.Dialer) (xproxy.Dialer, error) {
+	var (
+		tlsConfig  *tls.Config
+		tlsFactory func(net.Conn, *tls.Config) net.Conn
+		err        error
+	)
+	tlsConfig, err = tlsutil.TLSConfigFromURL(u)
+	if err != nil {
+		return nil, fmt.Errorf("TLS configuration failed: %w", err)
+	}
+	tlsFactory, err = tlsutil.TLSFactoryFromURL(u)
+	if err != nil {
+		return nil, fmt.Errorf("TLS configuration failed: %w", err)
+	}
+	u.Scheme = "socks5"
+	u.RawQuery = ""
+	return xproxy.FromURL(u, NewTLSWrappingDialer(tlsConfig, tlsFactory, MaybeWrapWithContextDialer(next)))
+}
+
+type TLSWrappingDialer struct {
+	next       Dialer
+	tlsConfig  *tls.Config
+	tlsFactory func(net.Conn, *tls.Config) net.Conn
+}
+
+func NewTLSWrappingDialer(tlsConfig *tls.Config, tlsFactory func(net.Conn, *tls.Config) net.Conn, next Dialer) *TLSWrappingDialer {
+	return &TLSWrappingDialer{
+		next:       next,
+		tlsConfig:  tlsConfig,
+		tlsFactory: tlsFactory,
+	}
+}
+
+func (d *TLSWrappingDialer) Dial(network, address string) (net.Conn, error) {
+	return d.DialContext(context.Background(), network, address)
+}
+
+func (d *TLSWrappingDialer) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	conn, err := d.next.DialContext(ctx, network, address)
+	if err != nil {
+		return nil, err
+	}
+	return d.tlsFactory(conn, d.tlsConfig), nil
+}