From 8771fa5c17e8eb430739eb125bc283f3dc0b32df Mon Sep 17 00:00:00 2001
From: H1JK <106379370+h1jk@users.noreply.github.com>
Date: Sat, 4 Mar 2023 21:47:06 +0800
Subject: [PATCH] chore: Vision padding upgrade

---
 transport/vless/conn.go   | 28 ++++++++++++++--------------
 transport/vless/vision.go | 23 +++++++++++++++++------
 2 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/transport/vless/conn.go b/transport/vless/conn.go
index c8477090..1f7d2cb3 100644
--- a/transport/vless/conn.go
+++ b/transport/vless/conn.go
@@ -241,7 +241,7 @@ func (vc *Conn) WriteBuffer(buffer *buf.Buffer) error {
 			command = commandPaddingEnd
 
 			// disable XTLS
-			vc.readProcess = false
+			//vc.readProcess = false
 			vc.writeFilterApplicationData = false
 			vc.packetsToFilter = 0
 		} else if buffer.Len() > 6 && bytes.Equal(buffer.To(3), tlsApplicationDataStart) || vc.packetsToFilter <= 0 {
@@ -252,7 +252,7 @@ func (vc *Conn) WriteBuffer(buffer *buf.Buffer) error {
 			}
 			vc.writeFilterApplicationData = false
 		}
-		ApplyPadding(buffer, command, nil)
+		ApplyPadding(buffer, command, nil, vc.isTLS)
 		err := vc.ExtendedWriter.WriteBuffer(buffer)
 		if err != nil {
 			return err
@@ -276,7 +276,7 @@ func (vc *Conn) WriteBuffer(buffer *buf.Buffer) error {
 				}
 				vc.writeFilterApplicationData = false
 			}
-			ApplyPadding(buffer2, command, nil)
+			ApplyPadding(buffer2, command, nil, vc.isTLS)
 			err = vc.ExtendedWriter.WriteBuffer(buffer2)
 			if vc.writeDirect {
 				vc.ExtendedWriter = N.NewExtendedWriter(vc.Conn)
@@ -352,19 +352,19 @@ func (vc *Conn) sendRequest(p []byte) bool {
 
 	if isVision && !vc.dst.UDP && !vc.dst.Mux {
 		if len(p) == 0 {
-			WriteWithPadding(buffer, nil, commandPaddingContinue, vc.id)
+			WriteWithPadding(buffer, nil, commandPaddingContinue, vc.id, vc.isTLS)
 		} else {
 			vc.FilterTLS(p)
-			if vc.isTLS {
-				WriteWithPadding(buffer, p, commandPaddingContinue, vc.id)
-			} else {
-				buf.Must(buf.Error(buffer.Write(p)))
-
-				// disable XTLS
-				vc.readProcess = false
-				vc.writeFilterApplicationData = false
-				vc.packetsToFilter = 0
-			}
+			//if vc.isTLS {
+			WriteWithPadding(buffer, p, commandPaddingContinue, vc.id, vc.isTLS)
+			//} else {
+			//	buf.Must(buf.Error(buffer.Write(p)))
+			//
+			//	// disable XTLS
+			//	vc.readProcess = false
+			//	vc.writeFilterApplicationData = false
+			//	vc.packetsToFilter = 0
+			//}
 		}
 	} else {
 		buf.Must(buf.Error(buffer.Write(p)))
diff --git a/transport/vless/vision.go b/transport/vless/vision.go
index f87a6870..14d701b4 100644
--- a/transport/vless/vision.go
+++ b/transport/vless/vision.go
@@ -19,16 +19,22 @@ const (
 	commandPaddingDirect   byte = 0x02
 )
 
-func WriteWithPadding(buffer *buf.Buffer, p []byte, command byte, userUUID *uuid.UUID) {
+func WriteWithPadding(buffer *buf.Buffer, p []byte, command byte, userUUID *uuid.UUID, paddingTLS bool) {
 	contentLen := int32(len(p))
 	var paddingLen int32
-	if contentLen < 900 {
+	if contentLen < 900 && paddingTLS {
+		log.Debugln("long padding")
 		paddingLen = rand.Int31n(500) + 900 - contentLen
+	} else {
+		paddingLen = rand.Int31n(256)
+	}
+	if paddingLen > buf.BufferSize-21-contentLen {
+		paddingLen = buf.BufferSize - 21 - contentLen
 	}
-
 	if userUUID != nil { // unnecessary, but keep the same with Xray
 		buffer.Write(userUUID.Bytes())
 	}
+
 	buffer.WriteByte(command)
 	binary.BigEndian.PutUint16(buffer.Extend(2), uint16(contentLen))
 	binary.BigEndian.PutUint16(buffer.Extend(2), uint16(paddingLen))
@@ -37,13 +43,18 @@ func WriteWithPadding(buffer *buf.Buffer, p []byte, command byte, userUUID *uuid
 	log.Debugln("XTLS Vision write padding1: command=%v, payloadLen=%v, paddingLen=%v", command, contentLen, paddingLen)
 }
 
-func ApplyPadding(buffer *buf.Buffer, command byte, userUUID *uuid.UUID) {
+func ApplyPadding(buffer *buf.Buffer, command byte, userUUID *uuid.UUID, paddingTLS bool) {
 	contentLen := int32(buffer.Len())
 	var paddingLen int32
-	if contentLen < 900 {
+	if contentLen < 900 && paddingTLS {
+		log.Debugln("long padding")
 		paddingLen = rand.Int31n(500) + 900 - contentLen
+	} else {
+		paddingLen = rand.Int31n(256)
+	}
+	if paddingLen > buf.BufferSize-21-contentLen {
+		paddingLen = buf.BufferSize - 21 - contentLen
 	}
-
 	binary.BigEndian.PutUint16(buffer.ExtendHeader(2), uint16(paddingLen))
 	binary.BigEndian.PutUint16(buffer.ExtendHeader(2), uint16(contentLen))
 	buffer.ExtendHeader(1)[0] = command