eburet-oss/wireguard-go-awg2-lx
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

lx: re-graft AmneziaWG 2.0 obfuscation onto sagernet/wireguard-go v0.0.5

Browse source 
Rebase of the AWG obf graft (was e5feca7 on v0.0.3) onto v0.0.5
(2c27bbf4f9, 'Add L3 forwarding support'). 15 of 16 graft files
applied clean via 3-way; only send.go conflicted, on a single line
(upstream queuedOutboundPackets backpressure decrement vs a graft
blank line — took upstream).

Key invariant preserved: MessageEncapsulatingTransportSize=0 (graft
zeroes the sagernet encapsulating headroom; AWG obfuscation composes
the prefix itself via SendBuffers, not Bind.Send prepend). Upstream's
InputPacket/InputPackets and the new size-based outbound buffer pool
(GetOutboundBuffer/PutOutboundBuffer) are taken verbatim; the graft's
RoutineEncryption (header at buffer start) and transport-padding shift
in RoutineSequentialSender re-woven around them.

Builds clean on linux/android/windows/darwin (device/conn/tun).
This commit is contained in:
Leadaxe 2026-07-08 14:41:07 +03:00
parent f39689ad35
commit 831d483366
16 changed files with 1001 additions and 45 deletions
Download patch file Download diff file Expand all files Collapse all files

108
device/send.go
View file

@ -6,9 +6,12 @@
package device
import (
"bytes"
"crypto/rand"
"encoding/binary"
"errors"
"fmt"
"math/big"
"net"
"net/netip"
"os"
@ -199,15 +202,48 @@ func (peer *Peer) SendHandshakeInitiation(isRetry bool) error {
return err
}
buf := make([]byte, MessageEncapsulatingTransportSize+MessageInitiationSize)
packet := buf[MessageEncapsulatingTransportSize:]
_ = msg.marshal(packet)
var sendBuffer [][]byte
for _, ipacket := range peer.device.ipackets {
if ipacket != nil {
buf := make([]byte, ipacket.ObfuscatedLen(0))
ipacket.Obfuscate(buf, nil)
sendBuffer = append(sendBuffer, buf)
}
}
jc := peer.device.junk.count
jmin := peer.device.junk.min
jmax := peer.device.junk.max
for i := 0; i < jc; i++ {
nBig, _ := rand.Int(rand.Reader, big.NewInt(int64(jmax-jmin+1)))
n := int(nBig.Int64()) + jmin
buf := make([]byte, n)
rand.Read(buf)
sendBuffer = append(sendBuffer, buf)
}
var buf [MessageInitiationSize]byte
writer := bytes.NewBuffer(buf[:0])
binary.Write(writer, binary.LittleEndian, msg)
packet := writer.Bytes()
peer.cookieGenerator.AddMacs(packet)
peer.timersAnyAuthenticatedPacketTraversal()
peer.timersAnyAuthenticatedPacketSent()
err = peer.SendBuffers([][]byte{buf})
if padding := peer.device.paddings.init; padding > 0 {
buf := make([]byte, padding+len(packet))
rand.Read(buf[:padding])
copy(buf[padding:], packet)
packet = buf
}
sendBuffer = append(sendBuffer, packet)
err = peer.SendBuffers(sendBuffer)
if err != nil {
peer.device.log.Errorf("%v - Failed to send handshake initiation: %v", peer, err)
}
@ -229,9 +265,11 @@ func (peer *Peer) SendHandshakeResponse() error {
return err
}
buf := make([]byte, MessageEncapsulatingTransportSize+MessageResponseSize)
packet := buf[MessageEncapsulatingTransportSize:]
_ = response.marshal(packet)
var buf [MessageResponseSize]byte
writer := bytes.NewBuffer(buf[:0])
binary.Write(writer, binary.LittleEndian, response)
packet := writer.Bytes()
peer.cookieGenerator.AddMacs(packet)
err = peer.BeginSymmetricSession()
@ -244,8 +282,15 @@ func (peer *Peer) SendHandshakeResponse() error {
peer.timersAnyAuthenticatedPacketTraversal()
peer.timersAnyAuthenticatedPacketSent()
if padding := peer.device.paddings.response; padding > 0 {
buf := make([]byte, padding+len(packet))
rand.Read(buf[:padding])
copy(buf[padding:], packet)
packet = buf
}
// TODO: allocation could be avoided
err = peer.SendBuffers([][]byte{buf})
err = peer.SendBuffers([][]byte{packet})
if err != nil {
peer.device.log.Errorf("%v - Failed to send handshake response: %v", peer, err)
}
@ -256,18 +301,33 @@ func (device *Device) SendHandshakeCookie(initiatingElem *QueueHandshakeElement)
device.log.Verbosef("Sending cookie response for denied handshake message for %v", initiatingElem.endpoint.DstToString())
sender := binary.LittleEndian.Uint32(initiatingElem.packet[4:8])
reply, err := device.cookieChecker.CreateReply(initiatingElem.packet, sender, initiatingElem.endpoint.DstToBytes())
msgType := device.headers.cookie.Generate()
reply, err := device.cookieChecker.CreateReply(
initiatingElem.packet,
sender,
initiatingElem.endpoint.DstToBytes(),
msgType,
)
if err != nil {
device.log.Errorf("Failed to create cookie reply: %v", err)
return err
}
buf := make([]byte, MessageEncapsulatingTransportSize+MessageCookieReplySize)
packet := buf[MessageEncapsulatingTransportSize:]
_ = reply.marshal(packet)
// TODO: allocation could be avoided
device.net.bind.Send([][]byte{buf}, initiatingElem.endpoint, MessageEncapsulatingTransportSize)
var buf [MessageCookieReplySize]byte
writer := bytes.NewBuffer(buf[:0])
binary.Write(writer, binary.LittleEndian, reply)
packet := writer.Bytes()
if padding := device.paddings.cookie; padding > 0 {
buf := make([]byte, padding+len(packet))
rand.Read(buf[:padding])
copy(buf[padding:], packet)
packet = buf
}
// TODO: allocation could be avoided
device.net.bind.Send([][]byte{packet}, initiatingElem.endpoint, 0)
return nil
}
@ -687,7 +747,9 @@ func (device *Device) RoutineEncryption(id int) {
fieldReceiver := header[4:8]
fieldNonce := header[8:16]
binary.LittleEndian.PutUint32(fieldType, MessageTransportType)
msgType := device.headers.transport.Generate()
binary.LittleEndian.PutUint32(fieldType, msgType)
binary.LittleEndian.PutUint32(fieldReceiver, elem.keypair.remoteIndex)
binary.LittleEndian.PutUint64(fieldNonce, elem.nonce)
@ -704,9 +766,6 @@ func (device *Device) RoutineEncryption(id int) {
elem.packet,
nil,
)
// re-slice packet to include encapsulating transport space
elem.packet = elem.buffer[:MessageEncapsulatingTransportSize+len(elem.packet)]
}
elemsContainer.filling.Done()
}
@ -775,6 +834,19 @@ func (peer *Peer) processOutboundContainer(elemsContainer *QueueOutboundElements
if len(elem.packet[MessageEncapsulatingTransportSize:]) != MessageKeepaliveSize {
dataSent = true
}
// lx:begin awg (SPEC 025 — AmneziaWG transport padding, S4)
// Prepend `transport` random bytes ahead of the transport header. The AWG
// path zeroes MessageEncapsulatingTransportSize (see noise-protocol.go), so
// elem.packet starts at buffer offset 0 and this shift is what creates the
// prefix; the buffer is allocated with PaddingMultiple headroom.
if padding := device.paddings.transport; padding > 0 {
for i := len(elem.packet) - 1; i >= 0; i-- {
elem.buffer[i+padding] = elem.buffer[i]
}
rand.Read(elem.buffer[:padding])
elem.packet = elem.buffer[:padding+len(elem.packet)]
}
// lx:end awg
scratch = append(scratch, elem.packet)
}