From 49c25bf1e4eab98bc204afc7956f3fb591eb120c Mon Sep 17 00:00:00 2001
From: e1732a364fed <75717694+e1732a364fed@users.noreply.github.com>
Date: Sat, 1 Jan 2000 00:00:00 +0000
Subject: [PATCH] =?UTF-8?q?=E4=BB=A4trojan=E8=AF=BB=E5=88=B0crlf=E5=90=8E?=
 =?UTF-8?q?=E5=86=8D=E7=BB=93=E6=9D=9F;=E4=BF=AE=E8=AE=A2=E4=BB=A3?=
 =?UTF-8?q?=E7=A0=81,=E6=B7=BB=E5=8A=A0read=5Ftimeout=E7=9A=84app=E9=85=8D?=
 =?UTF-8?q?=E7=BD=AE;?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

根据 https://www.ihcblog.com/a-better-tls-obfs-proxy/
trojan的crlf是模仿http协议，令服务端具有和真实http服务器一样的响应特征
---
 cmd/verysimple/config.go |  8 ++++++++
 proxy/proxy.go           |  4 +++-
 proxy/trojan/server.go   | 32 ++++++++++++++++++++++++++------
 3 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/cmd/verysimple/config.go b/cmd/verysimple/config.go
index 42d01a1..cfd20c1 100644
--- a/cmd/verysimple/config.go
+++ b/cmd/verysimple/config.go
@@ -41,6 +41,7 @@ type AppConf struct {
 	UDP_timeout *int `toml:"udp_timeout"`
 
 	DialTimeoutSeconds *int `toml:"dial_timeout"`
+	ReadTimeoutSeconds *int `toml:"read_timeout"`
 
 	GeoipFile     *string `toml:"geoip_file"`
 	GeositeFolder *string `toml:"geosite_folder"`
@@ -75,6 +76,13 @@ func setupByAppConf(ac *AppConf) {
 
 			}
 		}
+
+		if ac.ReadTimeoutSeconds != nil {
+			if s := *ac.ReadTimeoutSeconds; s > 0 {
+				proxy.CommonReadTimeout = time.Duration(s) * time.Second
+			}
+		}
+
 		if ac.GeoipFile != nil {
 			netLayer.GeoipFileName = *ac.GeoipFile
 		}
diff --git a/proxy/proxy.go b/proxy/proxy.go
index 146e90c..8617bfd 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -13,7 +13,9 @@ import (
 )
 
 // default recommended handshake read timeout
-const CommonReadTimeout = time.Second * 4
+const DefaultCommonReadTimeout = time.Second * 4
+
+var CommonReadTimeout = DefaultCommonReadTimeout
 
 // set read timeout after CommonReadTimeout
 func SetCommonReadTimeout(c net.Conn) error {
diff --git a/proxy/trojan/server.go b/proxy/trojan/server.go
index b4737d1..ede517e 100644
--- a/proxy/trojan/server.go
+++ b/proxy/trojan/server.go
@@ -90,14 +90,33 @@ func (s *Server) Handshake(underlay net.Conn) (result net.Conn, msgConn netLayer
 
 	readbs := utils.GetBytes(utils.MTU)
 
-	wholeReadLen, err := underlay.Read(readbs)
-	if err != nil {
-		returnErr = utils.ErrInErr{ErrDesc: "read underlay failed", ErrDetail: err, Data: wholeReadLen}
-		return
-	}
-	//todo: 根据 https://www.ihcblog.com/a-better-tls-obfs-proxy/
+	var wholeReadLen int
+
+	//根据 https://www.ihcblog.com/a-better-tls-obfs-proxy/
 	//trojan的 CRLF 是为了模拟http服务器的行为, 所以此时不要一次性Read，而是要Read到CRLF为止
 
+	// wholeReadLen, err := underlay.Read(readbs)
+	// if err != nil {
+	// 	returnErr = utils.ErrInErr{ErrDesc: "read underlay failed", ErrDetail: err, Data: wholeReadLen}
+	// 	return
+	// }
+
+	for {
+		thislen, e := underlay.Read(readbs[wholeReadLen:])
+		if e != nil {
+			returnErr = utils.ErrInErr{ErrDesc: "read underlay failed", ErrDetail: e, Data: wholeReadLen}
+			return
+		}
+		lastTail := wholeReadLen
+		wholeReadLen += thislen
+
+		index_crlf := bytes.Index(readbs[lastTail:wholeReadLen], crlf)
+
+		if index_crlf > 0 {
+			break
+		}
+	}
+
 	if wholeReadLen < 17 {
 		//根据下面回答，HTTP的最小长度恰好是16字节，但是是0.9版本。1.0是18字节，1.1还要更长。总之我们可以直接不返回fallback地址
 		//https://stackoverflow.com/questions/25047905/http-request-minimum-size-in-bytes/25065089
@@ -173,6 +192,7 @@ realPart:
 		//关于 trojan实现多路复用的方式，可参考 https://p4gefau1t.github.io/trojan-go/developer/mux/  (该链接只是泛泛提了一下而已，没有制定具体实现的标准)
 		ismux = true
 	}
+	var err error
 
 	targetAddr, err = GetAddrFrom(readbuf, ismux)
 	if err != nil {