Refactor: Fragmentation

5f5ae37571
9122d0f056
This commit is contained in:
RPRX 2023-07-06 16:30:39 +00:00 committed by GitHub
parent 6d4194415d
commit f0f3b417f7
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4 changed files with 161 additions and 218 deletions

View File

@ -39,91 +39,89 @@ func (c *FreedomConfig) Build() (proto.Message, error) {
}
if c.Fragment != nil {
if len(c.Fragment.Interval) == 0 || len(c.Fragment.Length) == 0 {
return nil, newError("Invalid interval or length")
}
intervalMinMax := strings.Split(c.Fragment.Interval, "-")
var minInterval, maxInterval int64
config.Fragment = new(freedom.Fragment)
var err, err2 error
if len(intervalMinMax) == 2 {
minInterval, err = strconv.ParseInt(intervalMinMax[0], 10, 64)
maxInterval, err2 = strconv.ParseInt(intervalMinMax[1], 10, 64)
} else {
minInterval, err = strconv.ParseInt(intervalMinMax[0], 10, 64)
maxInterval = minInterval
}
if err != nil {
return nil, newError("Invalid minimum interval: ", err).Base(err)
}
if err2 != nil {
return nil, newError("Invalid maximum interval: ", err2).Base(err2)
}
lengthMinMax := strings.Split(c.Fragment.Length, "-")
var minLength, maxLength int64
if len(lengthMinMax) == 2 {
minLength, err = strconv.ParseInt(lengthMinMax[0], 10, 64)
maxLength, err2 = strconv.ParseInt(lengthMinMax[1], 10, 64)
} else {
minLength, err = strconv.ParseInt(lengthMinMax[0], 10, 64)
maxLength = minLength
}
if err != nil {
return nil, newError("Invalid minimum length: ", err).Base(err)
}
if err2 != nil {
return nil, newError("Invalid maximum length: ", err2).Base(err2)
}
if minInterval > maxInterval {
minInterval, maxInterval = maxInterval, minInterval
}
if minLength > maxLength {
minLength, maxLength = maxLength, minLength
}
config.Fragment = &freedom.Fragment{
MinInterval: int32(minInterval),
MaxInterval: int32(maxInterval),
MinLength: int32(minLength),
MaxLength: int32(maxLength),
}
switch strings.ToLower(c.Fragment.Packets) {
case "tlshello":
// TLS Hello Fragmentation (into multiple handshake messages)
config.Fragment.StartPacket = 0
config.Fragment.EndPacket = 1
config.Fragment.PacketsFrom = 0
config.Fragment.PacketsTo = 1
case "":
// TCP Segmentation (all packets)
config.Fragment.StartPacket = 0
config.Fragment.EndPacket = 0
config.Fragment.PacketsFrom = 0
config.Fragment.PacketsTo = 0
default:
// TCP Segmentation (range)
packetRange := strings.Split(c.Fragment.Packets, "-")
var startPacket, endPacket int64
if len(packetRange) == 2 {
startPacket, err = strconv.ParseInt(packetRange[0], 10, 64)
endPacket, err2 = strconv.ParseInt(packetRange[1], 10, 64)
packetsFromTo := strings.Split(c.Fragment.Packets, "-")
if len(packetsFromTo) == 2 {
config.Fragment.PacketsFrom, err = strconv.ParseUint(packetsFromTo[0], 10, 64)
config.Fragment.PacketsTo, err2 = strconv.ParseUint(packetsFromTo[1], 10, 64)
} else {
startPacket, err = strconv.ParseInt(packetRange[0], 10, 64)
endPacket = startPacket
config.Fragment.PacketsFrom, err = strconv.ParseUint(packetsFromTo[0], 10, 64)
config.Fragment.PacketsTo = config.Fragment.PacketsFrom
}
if err != nil {
return nil, newError("Invalid start packet: ", err).Base(err)
return nil, newError("Invalid PacketsFrom").Base(err)
}
if err2 != nil {
return nil, newError("Invalid end packet: ", err2).Base(err2)
return nil, newError("Invalid PacketsTo").Base(err2)
}
if startPacket > endPacket {
return nil, newError("Invalid packet range: ", c.Fragment.Packets)
if config.Fragment.PacketsFrom > config.Fragment.PacketsTo {
config.Fragment.PacketsFrom, config.Fragment.PacketsTo = config.Fragment.PacketsTo, config.Fragment.PacketsFrom
}
if startPacket < 1 {
return nil, newError("Cannot start from packet 0")
if config.Fragment.PacketsFrom == 0 {
return nil, newError("PacketsFrom can't be 0")
}
}
{
if c.Fragment.Length == "" {
return nil, newError("Length can't be empty")
}
lengthMinMax := strings.Split(c.Fragment.Length, "-")
if len(lengthMinMax) == 2 {
config.Fragment.LengthMin, err = strconv.ParseUint(lengthMinMax[0], 10, 64)
config.Fragment.LengthMax, err2 = strconv.ParseUint(lengthMinMax[1], 10, 64)
} else {
config.Fragment.LengthMin, err = strconv.ParseUint(lengthMinMax[0], 10, 64)
config.Fragment.LengthMax = config.Fragment.LengthMin
}
if err != nil {
return nil, newError("Invalid LengthMin").Base(err)
}
if err2 != nil {
return nil, newError("Invalid LengthMax").Base(err2)
}
if config.Fragment.LengthMin > config.Fragment.LengthMax {
config.Fragment.LengthMin, config.Fragment.LengthMax = config.Fragment.LengthMax, config.Fragment.LengthMin
}
if config.Fragment.LengthMin == 0 {
return nil, newError("LengthMin can't be 0")
}
}
{
if c.Fragment.Interval == "" {
return nil, newError("Interval can't be empty")
}
intervalMinMax := strings.Split(c.Fragment.Interval, "-")
if len(intervalMinMax) == 2 {
config.Fragment.IntervalMin, err = strconv.ParseUint(intervalMinMax[0], 10, 64)
config.Fragment.IntervalMax, err2 = strconv.ParseUint(intervalMinMax[1], 10, 64)
} else {
config.Fragment.IntervalMin, err = strconv.ParseUint(intervalMinMax[0], 10, 64)
config.Fragment.IntervalMax = config.Fragment.IntervalMin
}
if err != nil {
return nil, newError("Invalid IntervalMin").Base(err)
}
if err2 != nil {
return nil, newError("Invalid IntervalMax").Base(err2)
}
if config.Fragment.IntervalMin > config.Fragment.IntervalMax {
config.Fragment.IntervalMin, config.Fragment.IntervalMax = config.Fragment.IntervalMax, config.Fragment.IntervalMin
}
config.Fragment.StartPacket = int32(startPacket)
config.Fragment.EndPacket = int32(endPacket)
}
}

View File

@ -125,12 +125,12 @@ type Fragment struct {
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
MinInterval int32 `protobuf:"varint,1,opt,name=min_interval,json=minInterval,proto3" json:"min_interval,omitempty"`
MaxInterval int32 `protobuf:"varint,2,opt,name=max_interval,json=maxInterval,proto3" json:"max_interval,omitempty"`
MinLength int32 `protobuf:"varint,3,opt,name=min_length,json=minLength,proto3" json:"min_length,omitempty"`
MaxLength int32 `protobuf:"varint,4,opt,name=max_length,json=maxLength,proto3" json:"max_length,omitempty"`
StartPacket int32 `protobuf:"varint,5,opt,name=start_packet,json=startPacket,proto3" json:"start_packet,omitempty"`
EndPacket int32 `protobuf:"varint,6,opt,name=end_packet,json=endPacket,proto3" json:"end_packet,omitempty"`
PacketsFrom uint64 `protobuf:"varint,1,opt,name=packets_from,json=packetsFrom,proto3" json:"packets_from,omitempty"`
PacketsTo uint64 `protobuf:"varint,2,opt,name=packets_to,json=packetsTo,proto3" json:"packets_to,omitempty"`
LengthMin uint64 `protobuf:"varint,3,opt,name=length_min,json=lengthMin,proto3" json:"length_min,omitempty"`
LengthMax uint64 `protobuf:"varint,4,opt,name=length_max,json=lengthMax,proto3" json:"length_max,omitempty"`
IntervalMin uint64 `protobuf:"varint,5,opt,name=interval_min,json=intervalMin,proto3" json:"interval_min,omitempty"`
IntervalMax uint64 `protobuf:"varint,6,opt,name=interval_max,json=intervalMax,proto3" json:"interval_max,omitempty"`
}
func (x *Fragment) Reset() {
@ -165,44 +165,44 @@ func (*Fragment) Descriptor() ([]byte, []int) {
return file_proxy_freedom_config_proto_rawDescGZIP(), []int{1}
}
func (x *Fragment) GetMinInterval() int32 {
func (x *Fragment) GetPacketsFrom() uint64 {
if x != nil {
return x.MinInterval
return x.PacketsFrom
}
return 0
}
func (x *Fragment) GetMaxInterval() int32 {
func (x *Fragment) GetPacketsTo() uint64 {
if x != nil {
return x.MaxInterval
return x.PacketsTo
}
return 0
}
func (x *Fragment) GetMinLength() int32 {
func (x *Fragment) GetLengthMin() uint64 {
if x != nil {
return x.MinLength
return x.LengthMin
}
return 0
}
func (x *Fragment) GetMaxLength() int32 {
func (x *Fragment) GetLengthMax() uint64 {
if x != nil {
return x.MaxLength
return x.LengthMax
}
return 0
}
func (x *Fragment) GetStartPacket() int32 {
func (x *Fragment) GetIntervalMin() uint64 {
if x != nil {
return x.StartPacket
return x.IntervalMin
}
return 0
}
func (x *Fragment) GetEndPacket() int32 {
func (x *Fragment) GetIntervalMax() uint64 {
if x != nil {
return x.EndPacket
return x.IntervalMax
}
return 0
}
@ -302,19 +302,19 @@ var file_proxy_freedom_config_proto_rawDesc = []byte{
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View File

@ -13,12 +13,12 @@ message DestinationOverride {
}
message Fragment {
int32 min_interval = 1;
int32 max_interval = 2;
int32 min_length = 3;
int32 max_length = 4;
int32 start_packet = 5;
int32 end_packet = 6;
uint64 packets_from = 1;
uint64 packets_to = 2;
uint64 length_min = 3;
uint64 length_max = 4;
uint64 interval_min = 5;
uint64 interval_max = 6;
}
message Config {

View File

@ -5,7 +5,6 @@ package freedom
import (
"context"
"crypto/rand"
"encoding/binary"
"io"
"math/big"
"time"
@ -13,7 +12,6 @@ import (
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/buf"
"github.com/xtls/xray-core/common/dice"
"github.com/xtls/xray-core/common/errors"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-core/common/retry"
"github.com/xtls/xray-core/common/session"
@ -175,28 +173,12 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
var writer buf.Writer
if destination.Network == net.Network_TCP {
if h.config.Fragment != nil {
if h.config.Fragment.StartPacket == 0 && h.config.Fragment.EndPacket == 1 {
newError("FRAGMENT", int(h.config.Fragment.MaxLength)).WriteToLog(session.ExportIDToError(ctx))
writer = buf.NewWriter(
&FragmentedClientHelloConn{
Conn: conn,
maxLength: int(h.config.Fragment.MaxLength),
minInterval: time.Duration(h.config.Fragment.MinInterval) * time.Millisecond,
maxInterval: time.Duration(h.config.Fragment.MaxInterval) * time.Millisecond,
})
} else {
writer = buf.NewWriter(
&FragmentWriter{
Writer: conn,
minLength: int(h.config.Fragment.MinLength),
maxLength: int(h.config.Fragment.MaxLength),
minInterval: time.Duration(h.config.Fragment.MinInterval) * time.Millisecond,
maxInterval: time.Duration(h.config.Fragment.MaxInterval) * time.Millisecond,
startPacket: int(h.config.Fragment.StartPacket),
endPacket: int(h.config.Fragment.EndPacket),
PacketCount: 0,
})
}
newError("FRAGMENT", h.config.Fragment.PacketsFrom, h.config.Fragment.PacketsTo, h.config.Fragment.LengthMin, h.config.Fragment.LengthMax,
h.config.Fragment.IntervalMin, h.config.Fragment.IntervalMax).AtDebug().WriteToLog(session.ExportIDToError(ctx))
writer = buf.NewWriter(&FragmentWriter{
fragment: h.config.Fragment,
writer: conn,
})
} else {
writer = buf.NewWriter(conn)
}
@ -356,40 +338,66 @@ func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
}
type FragmentWriter struct {
io.Writer
minLength int
maxLength int
minInterval time.Duration
maxInterval time.Duration
startPacket int
endPacket int
PacketCount int
fragment *Fragment
writer io.Writer
count uint64
}
func (w *FragmentWriter) Write(buf []byte) (int, error) {
w.PacketCount += 1
if (w.startPacket != 0 && (w.PacketCount < w.startPacket || w.PacketCount > w.endPacket)) || len(buf) <= w.minLength {
return w.Writer.Write(buf)
func (f *FragmentWriter) Write(b []byte) (int, error) {
f.count++
if f.fragment.PacketsFrom == 0 && f.fragment.PacketsTo == 1 {
if f.count != 1 || len(b) <= 5 || b[0] != 22 {
return f.writer.Write(b)
}
recordLen := 5 + ((int(b[3]) << 8) | int(b[4]))
data := b[5:recordLen]
buf := make([]byte, 1024)
for from := 0; ; {
to := from + int(randBetween(int64(f.fragment.LengthMin), int64(f.fragment.LengthMax)))
if to > len(data) {
to = len(data)
}
copy(buf[:3], b)
copy(buf[5:], data[from:to])
l := to - from
from = to
buf[3] = byte(l >> 8)
buf[4] = byte(l)
_, err := f.writer.Write(buf[:5+l])
time.Sleep(time.Duration(randBetween(int64(f.fragment.IntervalMin), int64(f.fragment.IntervalMax))) * time.Millisecond)
if err != nil {
return 0, err
}
if from == len(data) {
if len(b) > recordLen {
n, err := f.writer.Write(b[recordLen:])
if err != nil {
return recordLen + n, err
}
}
return len(b), nil
}
}
}
nTotal := 0
for {
randomBytesTo := int(randBetween(int64(w.minLength), int64(w.maxLength))) + nTotal
if randomBytesTo > len(buf) {
randomBytesTo = len(buf)
if f.fragment.PacketsFrom != 0 && (f.count < f.fragment.PacketsFrom || f.count > f.fragment.PacketsTo) {
return f.writer.Write(b)
}
for from := 0; ; {
to := from + int(randBetween(int64(f.fragment.LengthMin), int64(f.fragment.LengthMax)))
if to > len(b) {
to = len(b)
}
n, err := w.Writer.Write(buf[nTotal:randomBytesTo])
n, err := f.writer.Write(b[from:to])
from += n
time.Sleep(time.Duration(randBetween(int64(f.fragment.IntervalMin), int64(f.fragment.IntervalMax))) * time.Millisecond)
if err != nil {
return nTotal + n, err
return from, err
}
nTotal += n
if nTotal >= len(buf) {
return nTotal, nil
if from >= len(b) {
return from, nil
}
randomInterval := randBetween(int64(w.minInterval), int64(w.maxInterval))
time.Sleep(time.Duration(randomInterval))
}
}
@ -401,66 +409,3 @@ func randBetween(left int64, right int64) int64 {
bigInt, _ := rand.Int(rand.Reader, big.NewInt(right-left))
return left + bigInt.Int64()
}
type FragmentedClientHelloConn struct {
net.Conn
PacketCount int
minLength int
maxLength int
minInterval time.Duration
maxInterval time.Duration
}
func (c *FragmentedClientHelloConn) Write(b []byte) (n int, err error) {
if len(b) >= 5 && b[0] == 22 && c.PacketCount == 0 {
n, err = sendFragmentedClientHello(c, b, c.minLength, c.maxLength)
if err == nil {
c.PacketCount++
return n, err
}
}
return c.Conn.Write(b)
}
func sendFragmentedClientHello(conn *FragmentedClientHelloConn, clientHello []byte, minFragmentSize, maxFragmentSize int) (n int, err error) {
if len(clientHello) < 5 || clientHello[0] != 22 {
return 0, errors.New("not a valid TLS ClientHello message")
}
clientHelloLen := (int(clientHello[3]) << 8) | int(clientHello[4])
clientHelloData := clientHello[5:]
for i := 0; i < clientHelloLen; {
fragmentEnd := i + int(randBetween(int64(minFragmentSize), int64(maxFragmentSize)))
if fragmentEnd > clientHelloLen {
fragmentEnd = clientHelloLen
}
fragment := clientHelloData[i:fragmentEnd]
i = fragmentEnd
err = writeFragmentedRecord(conn, 22, fragment, clientHello)
if err != nil {
return 0, err
}
}
return len(clientHello), nil
}
func writeFragmentedRecord(c *FragmentedClientHelloConn, contentType uint8, data []byte, clientHello []byte) error {
header := make([]byte, 5)
header[0] = byte(clientHello[0])
tlsVersion := (int(clientHello[1]) << 8) | int(clientHello[2])
binary.BigEndian.PutUint16(header[1:], uint16(tlsVersion))
binary.BigEndian.PutUint16(header[3:], uint16(len(data)))
_, err := c.Conn.Write(append(header, data...))
randomInterval := randBetween(int64(c.minInterval), int64(c.maxInterval))
time.Sleep(time.Duration(randomInterval))
return err
}