mirror of
https://github.com/SagerNet/sing-box.git
synced 2024-11-23 17:11:29 +00:00
378 lines
9.7 KiB
Go
378 lines
9.7 KiB
Go
package sniff
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"crypto"
|
|
"crypto/aes"
|
|
"crypto/tls"
|
|
"encoding/binary"
|
|
"io"
|
|
"os"
|
|
|
|
"github.com/sagernet/sing-box/adapter"
|
|
"github.com/sagernet/sing-box/common/ja3"
|
|
"github.com/sagernet/sing-box/common/sniff/internal/qtls"
|
|
C "github.com/sagernet/sing-box/constant"
|
|
"github.com/sagernet/sing/common/buf"
|
|
E "github.com/sagernet/sing/common/exceptions"
|
|
|
|
"golang.org/x/crypto/hkdf"
|
|
)
|
|
|
|
var ErrClientHelloFragmented = E.New("need more packet for chromium QUIC connection")
|
|
|
|
func QUICClientHello(ctx context.Context, metadata *adapter.InboundContext, packet []byte) error {
|
|
reader := bytes.NewReader(packet)
|
|
typeByte, err := reader.ReadByte()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if typeByte&0x40 == 0 {
|
|
return E.New("bad type byte")
|
|
}
|
|
var versionNumber uint32
|
|
err = binary.Read(reader, binary.BigEndian, &versionNumber)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if versionNumber != qtls.VersionDraft29 && versionNumber != qtls.Version1 && versionNumber != qtls.Version2 {
|
|
return E.New("bad version")
|
|
}
|
|
packetType := (typeByte & 0x30) >> 4
|
|
if packetType == 0 && versionNumber == qtls.Version2 || packetType == 2 && versionNumber != qtls.Version2 || packetType > 2 {
|
|
return E.New("bad packet type")
|
|
}
|
|
|
|
destConnIDLen, err := reader.ReadByte()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if destConnIDLen == 0 || destConnIDLen > 20 {
|
|
return E.New("bad destination connection id length")
|
|
}
|
|
|
|
destConnID := make([]byte, destConnIDLen)
|
|
_, err = io.ReadFull(reader, destConnID)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
srcConnIDLen, err := reader.ReadByte()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
_, err = io.CopyN(io.Discard, reader, int64(srcConnIDLen))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
tokenLen, err := qtls.ReadUvarint(reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
_, err = io.CopyN(io.Discard, reader, int64(tokenLen))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
packetLen, err := qtls.ReadUvarint(reader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
hdrLen := int(reader.Size()) - reader.Len()
|
|
if hdrLen+int(packetLen) > len(packet) {
|
|
return os.ErrInvalid
|
|
}
|
|
|
|
_, err = io.CopyN(io.Discard, reader, 4)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
pnBytes := make([]byte, aes.BlockSize)
|
|
_, err = io.ReadFull(reader, pnBytes)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var salt []byte
|
|
switch versionNumber {
|
|
case qtls.Version1:
|
|
salt = qtls.SaltV1
|
|
case qtls.Version2:
|
|
salt = qtls.SaltV2
|
|
default:
|
|
salt = qtls.SaltOld
|
|
}
|
|
var hkdfHeaderProtectionLabel string
|
|
switch versionNumber {
|
|
case qtls.Version2:
|
|
hkdfHeaderProtectionLabel = qtls.HKDFLabelHeaderProtectionV2
|
|
default:
|
|
hkdfHeaderProtectionLabel = qtls.HKDFLabelHeaderProtectionV1
|
|
}
|
|
initialSecret := hkdf.Extract(crypto.SHA256.New, destConnID, salt)
|
|
secret := qtls.HKDFExpandLabel(crypto.SHA256, initialSecret, []byte{}, "client in", crypto.SHA256.Size())
|
|
hpKey := qtls.HKDFExpandLabel(crypto.SHA256, secret, []byte{}, hkdfHeaderProtectionLabel, 16)
|
|
block, err := aes.NewCipher(hpKey)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
mask := make([]byte, aes.BlockSize)
|
|
block.Encrypt(mask, pnBytes)
|
|
newPacket := make([]byte, len(packet))
|
|
copy(newPacket, packet)
|
|
newPacket[0] ^= mask[0] & 0xf
|
|
for i := range newPacket[hdrLen : hdrLen+4] {
|
|
newPacket[hdrLen+i] ^= mask[i+1]
|
|
}
|
|
packetNumberLength := newPacket[0]&0x3 + 1
|
|
if hdrLen+int(packetNumberLength) > int(packetLen)+hdrLen {
|
|
return os.ErrInvalid
|
|
}
|
|
var packetNumber uint32
|
|
switch packetNumberLength {
|
|
case 1:
|
|
packetNumber = uint32(newPacket[hdrLen])
|
|
case 2:
|
|
packetNumber = uint32(binary.BigEndian.Uint16(newPacket[hdrLen:]))
|
|
case 3:
|
|
packetNumber = uint32(newPacket[hdrLen+2]) | uint32(newPacket[hdrLen+1])<<8 | uint32(newPacket[hdrLen])<<16
|
|
case 4:
|
|
packetNumber = binary.BigEndian.Uint32(newPacket[hdrLen:])
|
|
default:
|
|
return E.New("bad packet number length")
|
|
}
|
|
extHdrLen := hdrLen + int(packetNumberLength)
|
|
copy(newPacket[extHdrLen:hdrLen+4], packet[extHdrLen:])
|
|
data := newPacket[extHdrLen : int(packetLen)+hdrLen]
|
|
|
|
var keyLabel string
|
|
var ivLabel string
|
|
switch versionNumber {
|
|
case qtls.Version2:
|
|
keyLabel = qtls.HKDFLabelKeyV2
|
|
ivLabel = qtls.HKDFLabelIVV2
|
|
default:
|
|
keyLabel = qtls.HKDFLabelKeyV1
|
|
ivLabel = qtls.HKDFLabelIVV1
|
|
}
|
|
|
|
key := qtls.HKDFExpandLabel(crypto.SHA256, secret, []byte{}, keyLabel, 16)
|
|
iv := qtls.HKDFExpandLabel(crypto.SHA256, secret, []byte{}, ivLabel, 12)
|
|
cipher := qtls.AEADAESGCMTLS13(key, iv)
|
|
nonce := make([]byte, int32(cipher.NonceSize()))
|
|
binary.BigEndian.PutUint64(nonce[len(nonce)-8:], uint64(packetNumber))
|
|
decrypted, err := cipher.Open(newPacket[extHdrLen:extHdrLen], nonce, data, newPacket[:extHdrLen])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var frameType byte
|
|
var fragments []qCryptoFragment
|
|
decryptedReader := bytes.NewReader(decrypted)
|
|
const (
|
|
frameTypePadding = 0x00
|
|
frameTypePing = 0x01
|
|
frameTypeAck = 0x02
|
|
frameTypeAck2 = 0x03
|
|
frameTypeCrypto = 0x06
|
|
frameTypeConnectionClose = 0x1c
|
|
)
|
|
var frameTypeList []uint8
|
|
for {
|
|
frameType, err = decryptedReader.ReadByte()
|
|
if err == io.EOF {
|
|
break
|
|
}
|
|
frameTypeList = append(frameTypeList, frameType)
|
|
switch frameType {
|
|
case frameTypePadding:
|
|
continue
|
|
case frameTypePing:
|
|
continue
|
|
case frameTypeAck, frameTypeAck2:
|
|
_, err = qtls.ReadUvarint(decryptedReader) // Largest Acknowledged
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // ACK Delay
|
|
if err != nil {
|
|
return err
|
|
}
|
|
ackRangeCount, err := qtls.ReadUvarint(decryptedReader) // ACK Range Count
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // First ACK Range
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for i := 0; i < int(ackRangeCount); i++ {
|
|
_, err = qtls.ReadUvarint(decryptedReader) // Gap
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // ACK Range Length
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
if frameType == 0x03 {
|
|
_, err = qtls.ReadUvarint(decryptedReader) // ECT0 Count
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // ECT1 Count
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // ECN-CE Count
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
case frameTypeCrypto:
|
|
var offset uint64
|
|
offset, err = qtls.ReadUvarint(decryptedReader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var length uint64
|
|
length, err = qtls.ReadUvarint(decryptedReader)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
index := len(decrypted) - decryptedReader.Len()
|
|
fragments = append(fragments, qCryptoFragment{offset, length, decrypted[index : index+int(length)]})
|
|
_, err = decryptedReader.Seek(int64(length), io.SeekCurrent)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
case frameTypeConnectionClose:
|
|
_, err = qtls.ReadUvarint(decryptedReader) // Error Code
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = qtls.ReadUvarint(decryptedReader) // Frame Type
|
|
if err != nil {
|
|
return err
|
|
}
|
|
var length uint64
|
|
length, err = qtls.ReadUvarint(decryptedReader) // Reason Phrase Length
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = decryptedReader.Seek(int64(length), io.SeekCurrent) // Reason Phrase
|
|
if err != nil {
|
|
return err
|
|
}
|
|
default:
|
|
return os.ErrInvalid
|
|
}
|
|
}
|
|
if metadata.SniffContext != nil {
|
|
fragments = append(fragments, metadata.SniffContext.([]qCryptoFragment)...)
|
|
metadata.SniffContext = nil
|
|
}
|
|
var frameLen uint64
|
|
for _, fragment := range fragments {
|
|
frameLen += fragment.length
|
|
}
|
|
buffer := buf.NewSize(5 + int(frameLen))
|
|
defer buffer.Release()
|
|
buffer.WriteByte(0x16)
|
|
binary.Write(buffer, binary.BigEndian, uint16(0x0303))
|
|
binary.Write(buffer, binary.BigEndian, uint16(frameLen))
|
|
var index uint64
|
|
var length int
|
|
find:
|
|
for {
|
|
for _, fragment := range fragments {
|
|
if fragment.offset == index {
|
|
buffer.Write(fragment.payload)
|
|
index = fragment.offset + fragment.length
|
|
length++
|
|
continue find
|
|
}
|
|
}
|
|
break
|
|
}
|
|
metadata.Protocol = C.ProtocolQUIC
|
|
fingerprint, err := ja3.Compute(buffer.Bytes())
|
|
if err != nil {
|
|
metadata.Protocol = C.ProtocolQUIC
|
|
metadata.Client = C.ClientChromium
|
|
metadata.SniffContext = fragments
|
|
return ErrClientHelloFragmented
|
|
}
|
|
metadata.Domain = fingerprint.ServerName
|
|
for metadata.Client == "" {
|
|
if len(frameTypeList) == 1 {
|
|
metadata.Client = C.ClientFirefox
|
|
break
|
|
}
|
|
if frameTypeList[0] == frameTypeCrypto && isZero(frameTypeList[1:]) {
|
|
if len(fingerprint.Versions) == 2 && fingerprint.Versions[0]&ja3.GreaseBitmask == 0x0A0A &&
|
|
len(fingerprint.EllipticCurves) == 5 && fingerprint.EllipticCurves[0]&ja3.GreaseBitmask == 0x0A0A {
|
|
metadata.Client = C.ClientSafari
|
|
break
|
|
}
|
|
if len(fingerprint.CipherSuites) == 1 && fingerprint.CipherSuites[0] == tls.TLS_AES_256_GCM_SHA384 &&
|
|
len(fingerprint.EllipticCurves) == 1 && fingerprint.EllipticCurves[0] == uint16(tls.X25519) &&
|
|
len(fingerprint.SignatureAlgorithms) == 1 && fingerprint.SignatureAlgorithms[0] == uint16(tls.ECDSAWithP256AndSHA256) {
|
|
metadata.Client = C.ClientSafari
|
|
break
|
|
}
|
|
}
|
|
|
|
if frameTypeList[len(frameTypeList)-1] == frameTypeCrypto && isZero(frameTypeList[:len(frameTypeList)-1]) {
|
|
metadata.Client = C.ClientQUICGo
|
|
break
|
|
}
|
|
|
|
if count(frameTypeList, frameTypeCrypto) > 1 || count(frameTypeList, frameTypePing) > 0 {
|
|
if maybeUQUIC(fingerprint) {
|
|
metadata.Client = C.ClientQUICGo
|
|
} else {
|
|
metadata.Client = C.ClientChromium
|
|
}
|
|
break
|
|
}
|
|
|
|
metadata.Client = C.ClientUnknown
|
|
//nolint:staticcheck
|
|
break
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func isZero(slices []uint8) bool {
|
|
for _, slice := range slices {
|
|
if slice != 0 {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func count(slices []uint8, value uint8) int {
|
|
var times int
|
|
for _, slice := range slices {
|
|
if slice == value {
|
|
times++
|
|
}
|
|
}
|
|
return times
|
|
}
|
|
|
|
type qCryptoFragment struct {
|
|
offset uint64
|
|
length uint64
|
|
payload []byte
|
|
}
|