From 399701df33e62674eee9330121326b949ee37adb Mon Sep 17 00:00:00 2001
From: Oscar Linderholm <osm@recv.se>
Date: Fri, 6 Sep 2024 16:00:30 +0200
Subject: [PATCH] Do not share the XOR key offset between the send and receive
 threads

---
 CHANGELOG.md                                   |  6 ++++++
 proxy/xorv2/xorv2.go                           | 10 +++++-----
 vendor/github.com/mullvad/proxy/xorv2/xorv2.go | 10 +++++-----
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e460597..9887820 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,10 +19,16 @@ Line wrap the file at 100 chars.                                              Th
 * **Fixed**: for any bug fixes.
 * **Security**: in case of vulnerabilities.
 
+## [1.1.1] - 2024-09-06
+### Fixed
+- Do not share the XOR key offset between the send and receive threads.
+
+
 ## [1.1.0] - 2024-09-05
 ### Added
 - Add XOR v2.
 
+
 ## [1.0.4] - 2024-07-04
 ### Changed
 - Upgrade to use Go 1.22.5
diff --git a/proxy/xorv2/xorv2.go b/proxy/xorv2/xorv2.go
index ed72c9a..2015ce0 100644
--- a/proxy/xorv2/xorv2.go
+++ b/proxy/xorv2/xorv2.go
@@ -9,9 +9,8 @@ import (
 )
 
 type xor struct {
-	addrPort     string
-	xorKey       []byte
-	xorKeyOffset int
+	addrPort string
+	xorKey   []byte
 }
 
 func New(ip net.IP) (*xor, error) {
@@ -33,6 +32,7 @@ func (x *xor) ToPeer(dst io.Writer, src io.Reader)   { x.forward(dst, src) }
 
 func (x *xor) forward(dst io.Writer, src io.Reader) {
 	buf := make([]byte, 1024*64)
+	offset := 0
 
 	for {
 		nr, err := src.Read(buf)
@@ -41,8 +41,8 @@ func (x *xor) forward(dst io.Writer, src io.Reader) {
 		}
 
 		for i := 0; i < nr; i++ {
-			buf[i] ^= x.xorKey[x.xorKeyOffset]
-			x.xorKeyOffset = (x.xorKeyOffset + 1) % len(x.xorKey)
+			buf[i] ^= x.xorKey[offset]
+			offset = (offset + 1) % len(x.xorKey)
 		}
 
 		nw, err := dst.Write(buf[0:nr])
diff --git a/vendor/github.com/mullvad/proxy/xorv2/xorv2.go b/vendor/github.com/mullvad/proxy/xorv2/xorv2.go
index ed72c9a..2015ce0 100644
--- a/vendor/github.com/mullvad/proxy/xorv2/xorv2.go
+++ b/vendor/github.com/mullvad/proxy/xorv2/xorv2.go
@@ -9,9 +9,8 @@ import (
 )
 
 type xor struct {
-	addrPort     string
-	xorKey       []byte
-	xorKeyOffset int
+	addrPort string
+	xorKey   []byte
 }
 
 func New(ip net.IP) (*xor, error) {
@@ -33,6 +32,7 @@ func (x *xor) ToPeer(dst io.Writer, src io.Reader)   { x.forward(dst, src) }
 
 func (x *xor) forward(dst io.Writer, src io.Reader) {
 	buf := make([]byte, 1024*64)
+	offset := 0
 
 	for {
 		nr, err := src.Read(buf)
@@ -41,8 +41,8 @@ func (x *xor) forward(dst io.Writer, src io.Reader) {
 		}
 
 		for i := 0; i < nr; i++ {
-			buf[i] ^= x.xorKey[x.xorKeyOffset]
-			x.xorKeyOffset = (x.xorKeyOffset + 1) % len(x.xorKey)
+			buf[i] ^= x.xorKey[offset]
+			offset = (offset + 1) % len(x.xorKey)
 		}
 
 		nw, err := dst.Write(buf[0:nr])