From 4c516367886014ce98fa17cd8b0f20bd434c6e92 Mon Sep 17 00:00:00 2001
From: yuhan6665 <1588741+yuhan6665@users.noreply.github.com>
Date: Sat, 6 Jul 2024 15:06:58 -0400
Subject: [PATCH] Relax server HTTP host check

---
 transport/internet/http/config.go     | 4 +++-
 transport/internet/httpupgrade/hub.go | 2 +-
 transport/internet/splithttp/hub.go   | 2 +-
 transport/internet/websocket/hub.go   | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/transport/internet/http/config.go b/transport/internet/http/config.go
index cfcc8c08..990c2680 100644
--- a/transport/internet/http/config.go
+++ b/transport/internet/http/config.go
@@ -1,6 +1,8 @@
 package http
 
 import (
+	"strings"
+
 	"github.com/xtls/xray-core/common"
 	"github.com/xtls/xray-core/common/dice"
 	"github.com/xtls/xray-core/transport/internet"
@@ -18,7 +20,7 @@ func (c *Config) getHosts() []string {
 func (c *Config) isValidHost(host string) bool {
 	hosts := c.getHosts()
 	for _, h := range hosts {
-		if h == host {
+		if strings.Contains(strings.ToLower(host), strings.ToLower(h)) {
 			return true
 		}
 	}
diff --git a/transport/internet/httpupgrade/hub.go b/transport/internet/httpupgrade/hub.go
index 52e260a4..5be9240f 100644
--- a/transport/internet/httpupgrade/hub.go
+++ b/transport/internet/httpupgrade/hub.go
@@ -39,7 +39,7 @@ func (s *server) Handle(conn net.Conn) (stat.Connection, error) {
 
 	if s.config != nil {
 		host := req.Host
-		if len(s.config.Host) > 0 && host != s.config.Host {
+		if len(s.config.Host) > 0 && !strings.Contains(strings.ToLower(host), strings.ToLower(s.config.Host)) {
 			return nil, errors.New("bad host: ", host)
 		}
 		path := s.config.GetNormalizedPath()
diff --git a/transport/internet/splithttp/hub.go b/transport/internet/splithttp/hub.go
index 3dee0b9e..8fe4951f 100644
--- a/transport/internet/splithttp/hub.go
+++ b/transport/internet/splithttp/hub.go
@@ -72,7 +72,7 @@ func (h *requestHandler) upsertSession(sessionId string) *httpSession {
 }
 
 func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
-	if len(h.host) > 0 && request.Host != h.host {
+	if len(h.host) > 0 && !strings.Contains(strings.ToLower(request.Host), strings.ToLower(h.host)) {
 		errors.LogInfo(context.Background(), "failed to validate host, request:", request.Host, ", config:", h.host)
 		writer.WriteHeader(http.StatusNotFound)
 		return
diff --git a/transport/internet/websocket/hub.go b/transport/internet/websocket/hub.go
index 2fb893b2..1d86be1d 100644
--- a/transport/internet/websocket/hub.go
+++ b/transport/internet/websocket/hub.go
@@ -38,7 +38,7 @@ var upgrader = &websocket.Upgrader{
 }
 
 func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
-	if len(h.host) > 0 && request.Host != h.host {
+	if len(h.host) > 0 && !strings.Contains(strings.ToLower(request.Host), strings.ToLower(h.host)) {
 		errors.LogInfo(context.Background(), "failed to validate host, request:", request.Host, ", config:", h.host)
 		writer.WriteHeader(http.StatusNotFound)
 		return