From a20eb4660bb364bd2078b5db78f09d9de1bf915e Mon Sep 17 00:00:00 2001
From: luyuhuang <luyu_huang@foxmail.com>
Date: Sat, 5 Sep 2020 11:52:33 +0800
Subject: [PATCH] certificate pinning for servers without domain

---
 cmd/gost/route.go | 27 +++++++++++++++++++++
 tls.go            | 61 +++++++++++++++++++++++++----------------------
 2 files changed, 59 insertions(+), 29 deletions(-)

diff --git a/cmd/gost/route.go b/cmd/gost/route.go
index f64056b..0db5b2e 100644
--- a/cmd/gost/route.go
+++ b/cmd/gost/route.go
@@ -3,12 +3,14 @@ package main
 import (
 	"crypto/sha256"
 	"crypto/tls"
+	"crypto/x509"
 	"encoding/base64"
 	"fmt"
 	"net"
 	"net/url"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/ginuerzh/gost"
 	"github.com/go-log/log"
@@ -128,6 +130,31 @@ func parseChainNode(ns string) (nodes []gost.Node, err error) {
 		InsecureSkipVerify: !node.GetBool("secure"),
 		RootCAs:            rootCAs,
 	}
+
+	// If the argument `ca` is given, but not open `secure`, we verify the
+	// certificate manually.
+	if rootCAs != nil && !node.GetBool("secure") {
+		tlsCfg.VerifyConnection = func(state tls.ConnectionState) error {
+			opts := x509.VerifyOptions{
+				Roots:         rootCAs,
+				CurrentTime:   time.Now(),
+				DNSName:       "",
+				Intermediates: x509.NewCertPool(),
+			}
+
+			certs := state.PeerCertificates
+			for i, cert := range certs {
+				if i == 0 {
+					continue
+				}
+				opts.Intermediates.AddCert(cert)
+			}
+
+			_, err = certs[0].Verify(opts)
+			return err
+		}
+	}
+
 	if cert, err := tls.LoadX509KeyPair(node.Get("cert"), node.Get("key")); err == nil {
 		tlsCfg.Certificates = []tls.Certificate{cert}
 	}
diff --git a/tls.go b/tls.go
index 44faff6..c1b9684 100644
--- a/tls.go
+++ b/tls.go
@@ -2,7 +2,6 @@ package gost
 
 import (
 	"crypto/tls"
-	"crypto/x509"
 	"errors"
 	"net"
 	"sync"
@@ -290,36 +289,40 @@ func wrapTLSClient(conn net.Conn, tlsConfig *tls.Config, timeout time.Duration)
 		return nil, err
 	}
 
-	// If crypto/tls is doing verification, there's no need to do our own.
-	if tlsConfig.InsecureSkipVerify == false {
-		return tlsConn, nil
-	}
-
-	// Similarly if we use host's CA, we can do full handshake
-	if tlsConfig.RootCAs == nil {
-		return tlsConn, nil
-	}
-
-	opts := x509.VerifyOptions{
-		Roots:         tlsConfig.RootCAs,
-		CurrentTime:   time.Now(),
-		DNSName:       "",
-		Intermediates: x509.NewCertPool(),
-	}
-
-	certs := tlsConn.ConnectionState().PeerCertificates
-	for i, cert := range certs {
-		if i == 0 {
-			continue
+	// We can do this in `tls.Config.VerifyConnection`, which effective for
+	// other TLS protocols such as WebSocket. See `route.go:parseChainNode`
+	/*
+		// If crypto/tls is doing verification, there's no need to do our own.
+		if tlsConfig.InsecureSkipVerify == false {
+			return tlsConn, nil
 		}
-		opts.Intermediates.AddCert(cert)
-	}
 
-	_, err = certs[0].Verify(opts)
-	if err != nil {
-		tlsConn.Close()
-		return nil, err
-	}
+		// Similarly if we use host's CA, we can do full handshake
+		if tlsConfig.RootCAs == nil {
+			return tlsConn, nil
+		}
+
+		opts := x509.VerifyOptions{
+			Roots:         tlsConfig.RootCAs,
+			CurrentTime:   time.Now(),
+			DNSName:       "",
+			Intermediates: x509.NewCertPool(),
+		}
+
+		certs := tlsConn.ConnectionState().PeerCertificates
+		for i, cert := range certs {
+			if i == 0 {
+				continue
+			}
+			opts.Intermediates.AddCert(cert)
+		}
+
+		_, err = certs[0].Verify(opts)
+		if err != nil {
+			tlsConn.Close()
+			return nil, err
+		}
+	*/
 
 	return tlsConn, err
 }