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

3
device/cookie.go
View file

@ -118,6 +118,7 @@ func (st *CookieChecker) CreateReply(
msg []byte,
recv uint32,
src []byte,
msgType uint32,
) (*MessageCookieReply, error) {
st.RLock()
@ -153,7 +154,7 @@ func (st *CookieChecker) CreateReply(
smac1 := smac2 - blake2s.Size128
reply := new(MessageCookieReply)
reply.Type = MessageCookieReplyType
reply.Type = msgType
reply.Receiver = recv
_, err := rand.Read(reply.Nonce[:])

31
device/device.go
View file

@ -99,6 +99,29 @@ type Device struct {
closed chan struct{}
log *Logger
pauseManager pause.Manager
// lx: AmneziaWG obfuscation state (grafted from amneziawg-go).
junk struct {
min int
max int
count int
}
headers struct {
init *magicHeader
cookie *magicHeader
response *magicHeader
transport *magicHeader
}
paddings struct {
init int
response int
cookie int
transport int
}
ipackets [5]*obfChain
}
// deviceState represents the state of a Device.
@ -172,7 +195,8 @@ func (device *Device) changeState(want deviceState) (err error) {
err = errDown
}
}
device.log.Verbosef("Interface state was %s, requested %s, now %s", old, want, device.deviceState())
device.log.Verbosef(
"Interface state was %s, requested %s, now %s", old, want, device.deviceState())
return
}
@ -317,6 +341,11 @@ func NewDevice(ctx context.Context, tunDevice tun.Device, bind conn.Bind, logger
device.rate.limiter.Init()
device.indexTable.Init()
device.headers.init = &magicHeader{start: MessageInitiationType, end: MessageInitiationType}
device.headers.response = &magicHeader{start: MessageResponseType, end: MessageResponseType}
device.headers.cookie = &magicHeader{start: MessageCookieReplyType, end: MessageCookieReplyType}
device.headers.transport = &magicHeader{start: MessageTransportType, end: MessageTransportType}
device.PopulatePools()
// create queues

63
device/magic-header.go Normal file
View file

@ -0,0 +1,63 @@
package device
import (
"crypto/rand"
"errors"
"fmt"
"math/big"
"strconv"
"strings"
)
type magicHeader struct {
start uint32
end uint32
}
func newMagicHeader(spec string) (*magicHeader, error) {
parts := strings.Split(spec, "-")
if len(parts) < 1 || len(parts) > 2 {
return nil, errors.New("bad format")
}
start, err := strconv.ParseUint(parts[0], 10, 32)
if err != nil {
return nil, fmt.Errorf("failed to parse %s: %w", parts[0], err)
}
var end uint64
if len(parts) > 1 {
end, err = strconv.ParseUint(parts[1], 10, 32)
if err != nil {
return nil, fmt.Errorf("failed to parse %s: %w", parts[1], err)
}
} else {
end = start
}
if end < start {
return nil, errors.New("wrong range specified")
}
return &magicHeader{
start: uint32(start),
end: uint32(end),
}, nil
}
func (h *magicHeader) GenSpec() string {
if h.start == h.end {
return fmt.Sprintf("%d", h.start)
}
return fmt.Sprintf("%d-%d", h.start, h.end)
}
func (h *magicHeader) Validate(val uint32) bool {
return h.start <= val && val <= h.end
}
func (h *magicHeader) Generate() uint32 {
high := int64(h.end - h.start + 1)
r, _ := rand.Int(rand.Reader, big.NewInt(high))
return h.start + uint32(r.Int64())
}

19
device/noise-protocol.go
View file

@ -54,10 +54,11 @@ const (
)
const (
MessageInitiationType = 1
MessageResponseType = 2
MessageCookieReplyType = 3
MessageTransportType = 4
MessageUnknownType uint32 = 0
MessageInitiationType uint32 = 1
MessageResponseType uint32 = 2
MessageCookieReplyType uint32 = 3
MessageTransportType uint32 = 4
)
const (
@ -65,7 +66,7 @@ const (
MessageResponseSize = 92 // size of response message
MessageCookieReplySize = 64 // size of cookie reply message
MessageTransportHeaderSize = 16 // size of data preceding content in transport message
MessageEncapsulatingTransportSize = 8 // size of optional, free (for use by conn.Bind.Send()) space preceding the transport header
MessageEncapsulatingTransportSize = 0 // lx: zeroed so AmneziaWG obfuscation composes without sagernet headroom (AWG path doesn't use the Bind.Send prepend)
MessageTransportSize = MessageTransportHeaderSize + poly1305.TagSize // size of empty transport
MessageKeepaliveSize = MessageTransportSize // size of keepalive
MessageHandshakeSize = MessageInitiationSize // size of largest handshake related message
@ -218,7 +219,7 @@ type Handshake struct {
localEphemeral NoisePrivateKey // ephemeral secret key
localIndex uint32 // used to clear hash-table
remoteIndex uint32 // index for sending
remoteStatic NoisePublicKey // long term key
remoteStatic NoisePublicKey // long term key, never changes, can be accessed without mutex
remoteEphemeral NoisePublicKey // ephemeral public key
precomputedStaticStatic [NoisePublicKeySize]byte // precomputed shared secret
lastTimestamp tai64n.Timestamp
@ -287,8 +288,10 @@ func (device *Device) CreateMessageInitiation(peer *Peer) (*MessageInitiation, e
handshake.mixHash(handshake.remoteStatic[:])
msgType := device.headers.init.Generate()
msg := MessageInitiation{
Type: MessageInitiationType,
Type: msgType,
Ephemeral: handshake.localEphemeral.publicKey(),
}
@ -471,7 +474,7 @@ func (device *Device) CreateMessageResponse(peer *Peer) (*MessageResponse, error
}
var msg MessageResponse
msg.Type = MessageResponseType
msg.Type = device.headers.response.Generate()
msg.Sender = handshake.localIndex
msg.Receiver = handshake.remoteIndex

140
device/obf.go Normal file
View file

@ -0,0 +1,140 @@
package device
import (
"errors"
"fmt"
"strings"
)
type obfBuilder func(val string) (obf, error)
var obfBuilders = map[string]obfBuilder{
"b": newBytesObf,
"t": newTimestampObf,
"r": newRandObf,
"rc": newRandCharObf,
"rd": newRandDigitsObf,
"d": newDataObf,
"ds": newDataStringObf,
"dz": newDataSizeObf,
}
type obf interface {
Obfuscate(dst, src []byte)
Deobfuscate(dst, src []byte) bool
ObfuscatedLen(srcLen int) int
DeobfuscatedLen(srcLen int) int
}
type obfChain struct {
Spec string
obfs []obf
}
func newObfChain(spec string) (*obfChain, error) {
var (
obfs []obf
errs []error
)
remaining := spec[:]
for {
start := strings.IndexByte(remaining, '<')
if start == -1 {
break
}
end := strings.IndexByte(remaining[start:], '>')
if end == -1 {
return nil, errors.New("missing enclosing >")
}
end += start
tag := remaining[start+1 : end]
parts := strings.Fields(tag)
if len(parts) == 0 {
errs = append(errs, errors.New("empty tag"))
remaining = remaining[end+1:]
continue
}
key := parts[0]
builder, ok := obfBuilders[key]
if !ok {
errs = append(errs, fmt.Errorf("unknown tag <%s>", key))
remaining = remaining[end+1:]
continue
}
val := ""
if len(parts) > 1 {
val = parts[1]
}
o, err := builder(val)
if err != nil {
errs = append(errs, fmt.Errorf("failed to build <%s>: %w", key, err))
remaining = remaining[end+1:]
continue
}
obfs = append(obfs, o)
remaining = remaining[end+1:]
}
if len(errs) > 0 {
return nil, errors.Join(errs...)
}
return &obfChain{
Spec: spec,
obfs: obfs,
}, nil
}
func (c *obfChain) Obfuscate(dst, src []byte) {
written := 0
for _, o := range c.obfs {
obfLen := o.ObfuscatedLen(len(src))
o.Obfuscate(dst[written:written+obfLen], src)
written += obfLen
}
}
func (c *obfChain) Deobfuscate(dst, src []byte) bool {
dynamicLen := len(src) - c.ObfuscatedLen(0)
written, read := 0, 0
for _, o := range c.obfs {
deobfLen := o.DeobfuscatedLen(dynamicLen)
obfLen := o.ObfuscatedLen(deobfLen)
if !o.Deobfuscate(dst[written:written+deobfLen], src[read:read+obfLen]) {
return false
}
written += deobfLen
read += obfLen
}
return true
}
func (c *obfChain) ObfuscatedLen(n int) int {
total := 0
for _, o := range c.obfs {
total += o.ObfuscatedLen(n)
}
return total
}
func (c *obfChain) DeobfuscatedLen(n int) int {
dynamicLen := n - c.ObfuscatedLen(0)
total := 0
for _, o := range c.obfs {
total += o.DeobfuscatedLen(dynamicLen)
}
return total
}

47
device/obf_bytes.go Normal file
View file

@ -0,0 +1,47 @@
package device
import (
"bytes"
"encoding/hex"
"errors"
"strings"
)
func newBytesObf(val string) (obf, error) {
val = strings.TrimPrefix(val, "0x")
if len(val) == 0 {
return nil, errors.New("empty argument")
}
if len(val)%2 != 0 {
return nil, errors.New("odd amount of symbols")
}
bytes, err := hex.DecodeString(val)
if err != nil {
return nil, err
}
return &bytesObf{data: bytes}, nil
}
type bytesObf struct {
data []byte
}
func (o *bytesObf) Obfuscate(dst, src []byte) {
copy(dst, o.data)
}
func (o *bytesObf) Deobfuscate(dst, src []byte) bool {
return bytes.Equal(o.data, src[:o.ObfuscatedLen(0)])
}
func (o *bytesObf) ObfuscatedLen(srcLen int) int {
return len(o.data)
}
func (o *bytesObf) DeobfuscatedLen(srcLen int) int {
return 0
}

25
device/obf_data.go Normal file
View file

@ -0,0 +1,25 @@
package device
func newDataObf(val string) (obf, error) {
return &dataObf{}, nil
}
type dataObf struct {
}
func (obf *dataObf) Obfuscate(dst, src []byte) {
copy(dst, src)
}
func (obf *dataObf) Deobfuscate(dst, src []byte) bool {
copy(dst, src)
return true
}
func (o *dataObf) ObfuscatedLen(n int) int {
return n
}
func (o *dataObf) DeobfuscatedLen(n int) int {
return n
}

38
device/obf_datasize.go Normal file
View file

@ -0,0 +1,38 @@
package device
import "strconv"
func newDataSizeObf(val string) (obf, error) {
length, err := strconv.Atoi(val)
if err != nil {
return nil, err
}
return &dataSizeObf{
length: length,
}, nil
}
type dataSizeObf struct {
length int
}
func (o *dataSizeObf) Obfuscate(dst, src []byte) {
srcLen := len(src)
for i := o.length - 1; i >= 0; i-- {
dst[i] = byte(srcLen & 0xFF)
srcLen >>= 8
}
}
func (o *dataSizeObf) Deobfuscate(dst, src []byte) bool {
return true
}
func (o *dataSizeObf) ObfuscatedLen(srcLen int) int {
return o.length
}
func (o *dataSizeObf) DeobfuscatedLen(srcLen int) int {
return 0
}

29
device/obf_datastring.go Normal file
View file

@ -0,0 +1,29 @@
package device
import (
"encoding/base64"
)
func newDataStringObf(val string) (obf, error) {
return &dataStringObf{}, nil
}
type dataStringObf struct {
}
func (o *dataStringObf) Obfuscate(dst, src []byte) {
base64.RawStdEncoding.Encode(dst, src)
}
func (o *dataStringObf) Deobfuscate(dst, src []byte) bool {
base64.RawStdEncoding.Decode(dst, src)
return true
}
func (o *dataStringObf) ObfuscatedLen(n int) int {
return base64.RawStdEncoding.EncodedLen(n)
}
func (o *dataStringObf) DeobfuscatedLen(n int) int {
return base64.RawStdEncoding.DecodedLen(n)
}

39
device/obf_rand.go Normal file
View file

@ -0,0 +1,39 @@
package device
import (
"crypto/rand"
"strconv"
)
func newRandObf(val string) (obf, error) {
length, err := strconv.Atoi(val)
if err != nil {
return nil, err
}
return &randObf{
length: length,
}, nil
}
type randObf struct {
length int
}
func (o *randObf) Obfuscate(dst, src []byte) {
rand.Read(dst[:o.length])
}
func (o *randObf) Deobfuscate(dst, src []byte) bool {
// there is no way to validate randomness :)
// assume that it is always true
return true
}
func (o *randObf) ObfuscatedLen(n int) int {
return o.length
}
func (o *randObf) DeobfuscatedLen(n int) int {
return 0
}

48
device/obf_randchars.go Normal file
View file

@ -0,0 +1,48 @@
package device
import (
"crypto/rand"
"strconv"
"unicode"
)
const chars52 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
func newRandCharObf(val string) (obf, error) {
length, err := strconv.Atoi(val)
if err != nil {
return nil, err
}
return &randCharObf{
length: length,
}, nil
}
type randCharObf struct {
length int
}
func (o *randCharObf) Obfuscate(dst, src []byte) {
rand.Read(dst[:o.length])
for i := range dst[:o.length] {
dst[i] = chars52[dst[i]%52]
}
}
func (o *randCharObf) Deobfuscate(dst, src []byte) bool {
for _, b := range src[:o.length] {
if !unicode.IsLetter(rune(b)) {
return false
}
}
return true
}
func (o *randCharObf) ObfuscatedLen(n int) int {
return o.length
}
func (o *randCharObf) DeobfuscatedLen(n int) int {
return 0
}

48
device/obf_randdigits.go Normal file
View file

@ -0,0 +1,48 @@
package device
import (
"crypto/rand"
"strconv"
"unicode"
)
const digits10 = "0123456789"
func newRandDigitsObf(val string) (obf, error) {
length, err := strconv.Atoi(val)
if err != nil {
return nil, err
}
return &randDigitObf{
length: length,
}, nil
}
type randDigitObf struct {
length int
}
func (o *randDigitObf) Obfuscate(dst, src []byte) {
rand.Read(dst[:o.length])
for i := range dst[:o.length] {
dst[i] = digits10[dst[i]%10]
}
}
func (o *randDigitObf) Deobfuscate(dst, src []byte) bool {
for _, b := range src[:o.length] {
if !unicode.IsDigit(rune(b)) {
return false
}
}
return true
}
func (o *randDigitObf) ObfuscatedLen(n int) int {
return o.length
}
func (o *randDigitObf) DeobfuscatedLen(n int) int {
return 0
}

31
device/obf_timestamp.go Normal file
View file

@ -0,0 +1,31 @@
package device
import (
"encoding/binary"
"time"
)
func newTimestampObf(_ string) (obf, error) {
return &timestampObf{}, nil
}
type timestampObf struct{}
func (o *timestampObf) Obfuscate(dst, src []byte) {
t := uint32(time.Now().Unix())
binary.BigEndian.PutUint32(dst, t)
}
func (o *timestampObf) Deobfuscate(dst, src []byte) bool {
// replay attack check?
// requires time to be always synchronized
return true
}
func (o *timestampObf) ObfuscatedLen(n int) int {
return 4
}
func (o *timestampObf) DeobfuscatedLen(n int) int {
return 0
}

86
device/receive.go
View file

@ -76,7 +76,10 @@ func (peer *Peer) keepKeyFreshReceiving() {
* Every time the bind is updated a new routine is started for
* IPv4 and IPv6 (separately)
*/
func (device *Device) RoutineReceiveIncoming(maxBatchSize int, recv conn.ReceiveFunc) {
func (device *Device) RoutineReceiveIncoming(
maxBatchSize int,
recv conn.ReceiveFunc,
) {
recvName := recv.PrettyName()
defer func() {
device.log.Verbosef("Routine: receive incoming %s - stopped", recvName)
@ -139,9 +142,14 @@ func (device *Device) RoutineReceiveIncoming(maxBatchSize int, recv conn.Receive
}
// check size of packet
packet := bufsArrs[i][:size]
msgType := binary.LittleEndian.Uint32(packet[:4])
// get message padding and type based on information from S1-S4 and H1-H4
msgType, padding := device.DeterminePacketTypeAndPadding(packet, MessageUnknownType)
if padding > 0 {
copy(packet, packet[padding:])
packet = packet[:len(packet)-padding]
}
switch msgType {
@ -283,7 +291,6 @@ func (device *Device) RoutineHandshake(id int) {
device.log.Verbosef("Routine: handshake worker %d - started", id)
for elem := range device.queue.handshake.c {
// handle cookie fields and ratelimiting
switch elem.msgType {
@ -310,9 +317,14 @@ func (device *Device) RoutineHandshake(id int) {
// consume reply
if peer := entry.peer; peer.isRunning.Load() {
device.log.Verbosef("Receiving cookie response from %s", elem.endpoint.DstToString())
device.log.Verbosef(
"Receiving cookie response from %s",
elem.endpoint.DstToString(),
)
if !peer.cookieGenerator.ConsumeReply(&reply) {
device.log.Verbosef("Could not decrypt invalid cookie response")
device.log.Verbosef(
"Could not decrypt invalid cookie response",
)
}
}
@ -354,9 +366,7 @@ func (device *Device) RoutineHandshake(id int) {
switch elem.msgType {
case MessageInitiationType:
// unmarshal
var msg MessageInitiation
err := msg.unmarshal(elem.packet)
if err != nil {
@ -364,7 +374,8 @@ func (device *Device) RoutineHandshake(id int) {
goto skip
}
// consume initiation
// have to reassign msgType for ranged msgType to work
msg.Type = elem.msgType
peer := device.ConsumeMessageInitiation(&msg, elem.endpoint)
if peer == nil {
@ -396,6 +407,9 @@ func (device *Device) RoutineHandshake(id int) {
goto skip
}
// have to reassign msgType for ranged msgType to work
msg.Type = elem.msgType
// consume response
peer := device.ConsumeMessageResponse(&msg)
@ -573,3 +587,57 @@ func (peer *Peer) processInboundContainer(elemsContainer *QueueInboundElementsCo
device.PutInboundElement(elem)
}
}
func (device *Device) DeterminePacketTypeAndPadding(packet []byte, expectedType uint32) (uint32, int) {
size := len(packet)
if expectedType == MessageUnknownType || expectedType == MessageInitiationType {
padding := device.paddings.init
header := device.headers.init
if size == padding+MessageInitiationSize {
data := packet[padding:]
if header.Validate(binary.LittleEndian.Uint32(data)) {
return MessageInitiationType, padding
}
}
}
if expectedType == MessageUnknownType || expectedType == MessageResponseType {
padding := device.paddings.response
header := device.headers.response
if size == padding+MessageResponseSize {
data := packet[padding:]
if header.Validate(binary.LittleEndian.Uint32(data)) {
return MessageResponseType, padding
}
}
}
if expectedType == MessageUnknownType || expectedType == MessageCookieReplyType {
padding := device.paddings.cookie
header := device.headers.cookie
if size == padding+MessageCookieReplySize {
data := packet[padding:]
if header.Validate(binary.LittleEndian.Uint32(data)) {
return MessageCookieReplyType, padding
}
}
}
if expectedType == MessageUnknownType || expectedType == MessageTransportType {
padding := device.paddings.transport
header := device.headers.transport
if size >= padding+MessageTransportHeaderSize {
data := packet[padding:]
if header.Validate(binary.LittleEndian.Uint32(data)) {
return MessageTransportType, padding
}
}
}
return MessageUnknownType, 0
}

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)
}

291
device/uapi.go
View file

@ -97,6 +97,56 @@ func (device *Device) IpcGetOperation(w io.Writer) error {
sendf("fwmark=%d", device.net.fwmark)
}
if device.junk.count != 0 {
sendf("jc=%d", device.junk.count)
}
if device.junk.min != 0 {
sendf("jmin=%d", device.junk.min)
}
if device.junk.max != 0 {
sendf("jmax=%d", device.junk.max)
}
if device.paddings.init != 0 {
sendf("s1=%d", device.paddings.init)
}
if device.paddings.response != 0 {
sendf("s2=%d", device.paddings.response)
}
if device.paddings.cookie != 0 {
sendf("s3=%d", device.paddings.cookie)
}
if device.paddings.transport != 0 {
sendf("s4=%d", device.paddings.transport)
}
if device.headers.init != nil {
sendf("h1=%s", device.headers.init.GenSpec())
}
if device.headers.response != nil {
sendf("h2=%s", device.headers.response.GenSpec())
}
if device.headers.cookie != nil {
sendf("h3=%s", device.headers.cookie.GenSpec())
}
if device.headers.transport != nil {
sendf("h4=%s", device.headers.transport.GenSpec())
}
for i, ipacket := range device.ipackets {
if ipacket != nil {
sendf("i%d=%s", i+1, ipacket.Spec)
}
}
for _, peer := range device.peers.keyMap {
// Serialize peer state.
peer.handshake.mutex.RLock()
@ -147,6 +197,7 @@ func (device *Device) IpcSetOperation(r io.Reader) (err error) {
}
}()
ipcDev := new(ipcSetDevice)
peer := new(ipcSetPeer)
deviceConfig := true
@ -155,12 +206,20 @@ func (device *Device) IpcSetOperation(r io.Reader) (err error) {
line := scanner.Text()
if line == "" {
// Blank line means terminate operation.
err := ipcDev.mergeWithDevice(device)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to merge with device: %w", err)
}
peer.handlePostConfig()
return nil
}
key, value, ok := strings.Cut(line, "=")
if !ok {
return ipcErrorf(ipc.IpcErrorProtocol, "failed to parse line %q", line)
return ipcErrorf(
ipc.IpcErrorProtocol,
"failed to parse line %q",
line,
)
}
if key == "public_key" {
@ -186,6 +245,10 @@ func (device *Device) IpcSetOperation(r io.Reader) (err error) {
return err
}
}
err = ipcDev.mergeWithDevice(device)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to merge with device: %w", err)
}
peer.handlePostConfig()
if err := scanner.Err(); err != nil {
@ -235,11 +298,155 @@ func (device *Device) handleDeviceLine(key, value string) error {
case "replace_peers":
if value != "true" {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to set replace_peers, invalid value: %v", value)
return ipcErrorf(
ipc.IpcErrorInvalid,
"failed to set replace_peers, invalid value: %v",
value,
)
}
device.log.Verbosef("UAPI: Removing all peers")
device.RemoveAllPeers()
case "jc":
jc, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse jc: %w", err)
}
if jc <= 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "jc must be a positive value")
}
device.log.Verbosef("UAPI: Updating junk count")
device.junk.count = jc
case "jmin":
jmin, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse jmin: %w", err)
}
if jmin <= 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "jmin must be a positive value")
}
device.log.Verbosef("UAPI: Updating junk min")
device.junk.min = jmin
case "jmax":
jmax, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse jmax: %w", err)
}
if jmax <= 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "jmax must be a positive value")
}
device.log.Verbosef("UAPI: Updating junk max")
device.junk.max = jmax
case "s1":
padding, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse s1: %w", err)
}
if padding < 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "s1 must be non-negative")
}
device.log.Verbosef("UAPI: Updating s1 padding")
device.paddings.init = padding
case "s2":
padding, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse s2: %w", err)
}
if padding < 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "s2 must be non-negative")
}
device.log.Verbosef("UAPI: Updating s2 padding")
device.paddings.response = padding
case "s3":
padding, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse s3: %w", err)
}
if padding < 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "s3 must be non-negative")
}
device.log.Verbosef("UAPI: Updating s3 padding")
device.paddings.cookie = padding
case "s4":
padding, err := strconv.Atoi(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse s4: %w", err)
}
if padding < 0 {
return ipcErrorf(ipc.IpcErrorInvalid, "s4 must be non-negative")
}
device.log.Verbosef("UAPI: Updating s4 padding")
device.paddings.transport = padding
case "h1":
header, err := newMagicHeader(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse H1: %w", err)
}
device.headers.init = header
case "h2":
header, err := newMagicHeader(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse H2: %w", err)
}
device.headers.response = header
case "h3":
header, err := newMagicHeader(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse H3: %w", err)
}
device.headers.cookie = header
case "h4":
header, err := newMagicHeader(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse H4: %w", err)
}
device.headers.transport = header
case "i1":
chain, err := newObfChain(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse I1: %w", err)
}
device.ipackets[0] = chain
case "i2":
chain, err := newObfChain(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse I2: %w", err)
}
device.ipackets[1] = chain
case "i3":
chain, err := newObfChain(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse I3: %w", err)
}
device.ipackets[2] = chain
case "i4":
chain, err := newObfChain(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse I4: %w", err)
}
device.ipackets[3] = chain
case "i5":
chain, err := newObfChain(value)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to parse I5: %w", err)
}
device.ipackets[4] = chain
default:
return ipcErrorf(ipc.IpcErrorInvalid, "invalid UAPI device key: %v", key)
}
@ -271,7 +478,10 @@ func (peer *ipcSetPeer) handlePostConfig() {
}
}
func (device *Device) handlePublicKeyLine(peer *ipcSetPeer, value string) error {
func (device *Device) handlePublicKeyLine(
peer *ipcSetPeer,
value string,
) error {
// Load/create the peer we are configuring.
var publicKey NoisePublicKey
err := publicKey.FromHex(value)
@ -301,12 +511,19 @@ func (device *Device) handlePublicKeyLine(peer *ipcSetPeer, value string) error
return nil
}
func (device *Device) handlePeerLine(peer *ipcSetPeer, key, value string) error {
func (device *Device) handlePeerLine(
peer *ipcSetPeer,
key, value string,
) error {
switch key {
case "update_only":
// allow disabling of creation
if value != "true" {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to set update only, invalid value: %v", value)
return ipcErrorf(
ipc.IpcErrorInvalid,
"failed to set update only, invalid value: %v",
value,
)
}
if peer.created && !peer.dummy {
device.RemovePeer(peer.handshake.remoteStatic)
@ -352,7 +569,11 @@ func (device *Device) handlePeerLine(peer *ipcSetPeer, key, value string) error
secs, err := strconv.ParseUint(value, 10, 16)
if err != nil {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to set persistent keepalive interval: %w", err)
return ipcErrorf(
ipc.IpcErrorInvalid,
"failed to set persistent keepalive interval: %w",
err,
)
}
old := peer.persistentKeepaliveInterval.Swap(uint32(secs))
@ -363,7 +584,11 @@ func (device *Device) handlePeerLine(peer *ipcSetPeer, key, value string) error
case "replace_allowed_ips":
device.log.Verbosef("%v - UAPI: Removing all allowedips", peer.Peer)
if value != "true" {
return ipcErrorf(ipc.IpcErrorInvalid, "failed to replace allowedips, invalid value: %v", value)
return ipcErrorf(
ipc.IpcErrorInvalid,
"failed to replace allowedips, invalid value: %v",
value,
)
}
if peer.dummy {
return nil
@ -442,7 +667,11 @@ func (device *Device) IpcHandle(socket net.Conn) {
return
}
if nextByte != '\n' {
err = ipcErrorf(ipc.IpcErrorInvalid, "trailing character in UAPI get: %q", nextByte)
err = ipcErrorf(
ipc.IpcErrorInvalid,
"trailing character in UAPI get: %q",
nextByte,
)
break
}
err = device.IpcGetOperation(buffered.Writer)
@ -466,3 +695,49 @@ func (device *Device) IpcHandle(socket net.Conn) {
buffered.Flush()
}
}
type ipcSetDevice struct {
headers struct {
init *magicHeader
response *magicHeader
cookie *magicHeader
transport *magicHeader
}
}
func (d *ipcSetDevice) mergeWithDevice(device *Device) error {
if d.headers.init == nil {
d.headers.init = device.headers.init
}
if d.headers.response == nil {
d.headers.response = device.headers.response
}
if d.headers.cookie == nil {
d.headers.cookie = device.headers.cookie
}
if d.headers.transport == nil {
d.headers.transport = device.headers.transport
}
headers := []*magicHeader{d.headers.init, d.headers.response, d.headers.cookie, d.headers.transport}
for i := 0; i < len(headers); i++ {
for j := i + 1; j < len(headers); j++ {
left := headers[i]
right := headers[j]
if left.start <= right.end && right.start <= left.end {
return errors.New("headers must not overlap")
}
}
}
device.headers.init = d.headers.init
device.headers.response = d.headers.response
device.headers.cookie = d.headers.cookie
device.headers.transport = d.headers.transport
return nil
}