add local HTTPS reverse proxy

cmd/telebit/telebit.go

@@ -47,9 +47,10 @@ var (
 )
 
 type Forward struct {
-	scheme  string
-	pattern string
-	port    string
+	scheme   string
+	pattern  string
+	port     string
+	localTLS bool
 }
 
 var authorizer telebit.Authorizer
@@ -83,6 +84,7 @@ func main() {
 	secret := flag.String("secret", "", "the same secret used by telebit-relay (used for JWT authentication)")
 	token := flag.String("token", "", "a pre-generated token to give the server (instead of generating one with --secret)")
 	bindAddrsStr := flag.String("listen", "", "list of bind addresses on which to listen, such as localhost:80, or :443")
+	tlsLocals := flag.String("tls-locals", "", "like --locals, but TLS will be used to connect to the local port")
 	locals := flag.String("locals", "", "a list of <from-domain>:<to-port>")
 	portToPorts := flag.String("port-forward", "", "a list of <from-port>:<to-port> for raw port-forwarding")
 	verbose := flag.Bool("verbose", false, "log excessively")
@@ -147,6 +149,32 @@ func main() {
 		domains = append(domains, domain)
 	}
 
+	if 0 == len(*tlsLocals) {
+		*tlsLocals = os.Getenv("TLS_LOCALS")
+	}
+	for _, cfg := range strings.Fields(strings.ReplaceAll(*tlsLocals, ",", " ")) {
+		parts := strings.Split(cfg, ":")
+		last := len(parts) - 1
+		port := parts[last]
+		domain := parts[last-1]
+		scheme := ""
+		if len(parts) > 2 {
+			scheme = parts[0]
+		}
+		forwards = append(forwards, Forward{
+			scheme:   scheme,
+			pattern:  domain,
+			port:     port,
+			localTLS: true,
+		})
+
+		// don't load wildcard into jwt domains
+		if "*" == domain {
+			continue
+		}
+		domains = append(domains, domain)
+	}
+
 	if 0 == len(*portToPorts) {
 		*portToPorts = os.Getenv("PORT_FORWARDS")
 	}
@@ -467,7 +495,12 @@ func muxAll(
 	for _, fwd := range forwards {
 		//mux.ForwardTCP("*", "localhost:"+fwd.port, 120*time.Second)
 		if "https" == fwd.scheme {
-			mux.ReverseProxyHTTP(fwd.pattern, "localhost:"+fwd.port, 120*time.Second, "[Servername Reverse Proxy]")
+			if fwd.localTLS {
+				// this doesn't make much sense, but... security theatre
+				mux.ReverseProxyHTTPS(fwd.pattern, "localhost:"+fwd.port, 120*time.Second, "[Servername Reverse Proxy TLS]")
+			} else {
+				mux.ReverseProxyHTTP(fwd.pattern, "localhost:"+fwd.port, 120*time.Second, "[Servername Reverse Proxy]")
+			}
 		}
 		mux.ForwardTCP(fwd.pattern, "localhost:"+fwd.port, 120*time.Second, "[Servername Forward]")
 	}

examples/run-as-client.sh

@@ -42,6 +42,7 @@ VERBOSE_RAW=${VERBOSE_RAW:-}
     --secret "$CLIENT_SECRET" \
     --tunnel-relay-url $TUNNEL_RELAY_URL \
     --listen "$LISTEN" \
+    --tls-locals "$TLS_LOCALS" \
     --locals "$LOCALS" \
     --acme-agree=${ACME_AGREE} \
     --acme-email "$ACME_EMAIL" \

routemux.go

@@ -158,6 +158,16 @@ func (m *RouteMux) ForwardTCP(servername string, target string, timeout time.Dur
 	return nil
 }
 
+func (m *RouteMux) ReverseProxyHTTPS(servername string, target string, timeout time.Duration, comment ...string) error {
+	m.routes = append(m.routes, meta{
+		addr:      servername,
+		terminate: false,
+		handler:   NewTheatricalProxier(target, timeout),
+		comment:   append(comment, "")[0],
+	})
+	return nil
+}
+
 func (m *RouteMux) ReverseProxyHTTP(servername string, target string, timeout time.Duration, comment ...string) error {
 	m.routes = append(m.routes, meta{
 		addr:      servername,

telebit.go

@@ -69,15 +69,72 @@ func NewForwarder(target string, timeout time.Duration) HandlerFunc {
 	}
 }
 
+// NewTheatricalProxier exists because... reasons... but should not be used
+func NewTheatricalProxier(target string, timeout time.Duration) HandlerFunc {
+	return newReverseProxier(target, timeout, true)
+}
+
 func NewReverseProxier(target string, timeout time.Duration) HandlerFunc {
+	return newReverseProxier(target, timeout, false)
+}
+
+func newReverseProxier(target string, timeout time.Duration, theatre bool) HandlerFunc {
 	// TODO accept listener?
 	proxyListener := httpshim.NewListener()
-	myURL, err := url.Parse("http://" + target)
+	scheme := "http://"
+	if theatre {
+		scheme = "https://"
+	}
+	targetURL, err := url.Parse(scheme + target)
 	if nil != err {
 		panic(err)
 	}
-	// TODO headers
-	proxyHandler := httputil.NewSingleHostReverseProxy(myURL)
+	//proxyHandler := httputil.NewSingleHostReverseProxy(targetURL)
+	proxyHandler := &httputil.ReverseProxy{
+		Director: func(req *http.Request) {
+			req.Header.Del("X-Forwarded-For")
+			req.Header.Del("X-Forwarded-Proto")
+			req.Header.Del("X-Forwarded-Port")
+
+			targetQuery := targetURL.RawQuery
+			req.URL.Scheme = targetURL.Scheme
+			req.URL.Host = targetURL.Host
+			req.URL.Path, req.URL.RawPath = joinURLPath(targetURL, req.URL)
+			if targetQuery == "" || req.URL.RawQuery == "" {
+				req.URL.RawQuery = targetQuery + req.URL.RawQuery
+			} else {
+				req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+			}
+			if _, ok := req.Header["User-Agent"]; !ok {
+				// explicitly disable User-Agent so it's not set to default value
+				req.Header.Set("User-Agent", "")
+			}
+		},
+	}
+	if theatre {
+		/*
+			// TODO we could take control of the SNI here
+			proxyHandler.Transport = &http.Transport{
+				DialTLSContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+					// would need timeout
+					dialer := tls.Dialer{
+						Config: &tls.Config{
+							ServerName:         "localhost",
+							InsecureSkipVerify: true,
+							TLSHandshakeTimeout: 10 * time.Second,
+						},
+					}
+					return dialer.DialContext(ctx, network, addr)
+				},
+			}
+			//*/
+		///*
+		proxyHandler.Transport = &http.Transport{
+			TLSClientConfig:     &tls.Config{InsecureSkipVerify: true},
+			TLSHandshakeTimeout: 10 * time.Second,
+		}
+		//*/
+	}
 	proxyServer := &http.Server{
 		Handler: proxyHandler,
 	}
@@ -92,6 +149,40 @@ func NewReverseProxier(target string, timeout time.Duration) HandlerFunc {
 	}
 }
 
+// Taken from https://golang.org/src/net/http/httputil/reverseproxy.go
+func joinURLPath(a, b *url.URL) (path, rawpath string) {
+	if a.RawPath == "" && b.RawPath == "" {
+		return singleJoiningSlash(a.Path, b.Path), ""
+	}
+	// Same as singleJoiningSlash, but uses EscapedPath to determine
+	// whether a slash should be added
+	apath := a.EscapedPath()
+	bpath := b.EscapedPath()
+
+	aslash := strings.HasSuffix(apath, "/")
+	bslash := strings.HasPrefix(bpath, "/")
+
+	switch {
+	case aslash && bslash:
+		return a.Path + b.Path[1:], apath + bpath[1:]
+	case !aslash && !bslash:
+		return a.Path + "/" + b.Path, apath + "/" + bpath
+	}
+	return a.Path + b.Path, apath + bpath
+}
+
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}
+
 // Forward port-forwards a relay (websocket) client to a target (local) server
 func Forward(client net.Conn, target net.Conn, timeout time.Duration) error {