mirror of
https://github.com/SagerNet/sing-box.git
synced 2024-11-25 18:11:28 +00:00
295 lines
7.1 KiB
Go
295 lines
7.1 KiB
Go
package shadowtls
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/hmac"
|
|
"crypto/rand"
|
|
"crypto/sha1"
|
|
"crypto/sha256"
|
|
"encoding/binary"
|
|
"hash"
|
|
"io"
|
|
"net"
|
|
|
|
"github.com/sagernet/sing/common"
|
|
"github.com/sagernet/sing/common/buf"
|
|
"github.com/sagernet/sing/common/bufio"
|
|
E "github.com/sagernet/sing/common/exceptions"
|
|
N "github.com/sagernet/sing/common/network"
|
|
)
|
|
|
|
const (
|
|
tlsRandomSize = 32
|
|
tlsHeaderSize = 5
|
|
tlsSessionIDSize = 32
|
|
|
|
clientHello = 1
|
|
serverHello = 2
|
|
|
|
changeCipherSpec = 20
|
|
alert = 21
|
|
handshake = 22
|
|
applicationData = 23
|
|
|
|
serverRandomIndex = tlsHeaderSize + 1 + 3 + 2
|
|
sessionIDLengthIndex = tlsHeaderSize + 1 + 3 + 2 + tlsRandomSize
|
|
tlsHmacHeaderSize = tlsHeaderSize + hmacSize
|
|
hmacSize = 4
|
|
)
|
|
|
|
func generateSessionID(password string) func(clientHello []byte, sessionID []byte) error {
|
|
return func(clientHello []byte, sessionID []byte) error {
|
|
const sessionIDStart = 1 + 3 + 2 + tlsRandomSize + 1
|
|
if len(clientHello) < sessionIDStart+tlsSessionIDSize {
|
|
return E.New("unexpected client hello length")
|
|
}
|
|
_, err := rand.Read(sessionID[:tlsSessionIDSize-hmacSize])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
hmacSHA1Hash := hmac.New(sha1.New, []byte(password))
|
|
hmacSHA1Hash.Write(clientHello[:sessionIDStart])
|
|
hmacSHA1Hash.Write(sessionID)
|
|
hmacSHA1Hash.Write(clientHello[sessionIDStart+tlsSessionIDSize:])
|
|
copy(sessionID[tlsSessionIDSize-hmacSize:], hmacSHA1Hash.Sum(nil)[:hmacSize])
|
|
return nil
|
|
}
|
|
}
|
|
|
|
type StreamWrapper struct {
|
|
net.Conn
|
|
password string
|
|
buffer *buf.Buffer
|
|
serverRandom []byte
|
|
readHMAC hash.Hash
|
|
readHMACKey []byte
|
|
authorized bool
|
|
}
|
|
|
|
func NewStreamWrapper(conn net.Conn, password string) *StreamWrapper {
|
|
return &StreamWrapper{
|
|
Conn: conn,
|
|
password: password,
|
|
}
|
|
}
|
|
|
|
func (w *StreamWrapper) Authorized() (bool, []byte, hash.Hash) {
|
|
return w.authorized, w.serverRandom, w.readHMAC
|
|
}
|
|
|
|
func (w *StreamWrapper) Read(p []byte) (n int, err error) {
|
|
if w.buffer != nil {
|
|
if !w.buffer.IsEmpty() {
|
|
return w.buffer.Read(p)
|
|
}
|
|
w.buffer.Release()
|
|
w.buffer = nil
|
|
}
|
|
var tlsHeader [tlsHeaderSize]byte
|
|
_, err = io.ReadFull(w.Conn, tlsHeader[:])
|
|
if err != nil {
|
|
return
|
|
}
|
|
length := int(binary.BigEndian.Uint16(tlsHeader[3:tlsHeaderSize]))
|
|
w.buffer = buf.NewSize(tlsHeaderSize + length)
|
|
common.Must1(w.buffer.Write(tlsHeader[:]))
|
|
_, err = w.buffer.ReadFullFrom(w.Conn, length)
|
|
if err != nil {
|
|
return
|
|
}
|
|
buffer := w.buffer.Bytes()
|
|
switch tlsHeader[0] {
|
|
case handshake:
|
|
if len(buffer) > serverRandomIndex+tlsRandomSize && buffer[5] == serverHello {
|
|
w.serverRandom = make([]byte, tlsRandomSize)
|
|
copy(w.serverRandom, buffer[serverRandomIndex:serverRandomIndex+tlsRandomSize])
|
|
w.readHMAC = hmac.New(sha1.New, []byte(w.password))
|
|
w.readHMAC.Write(w.serverRandom)
|
|
w.readHMACKey = kdf(w.password, w.serverRandom)
|
|
}
|
|
case applicationData:
|
|
w.authorized = false
|
|
if len(buffer) > tlsHmacHeaderSize && w.readHMAC != nil {
|
|
w.readHMAC.Write(buffer[tlsHmacHeaderSize:])
|
|
if hmac.Equal(w.readHMAC.Sum(nil)[:hmacSize], buffer[tlsHeaderSize:tlsHmacHeaderSize]) {
|
|
xorSlice(buffer[tlsHmacHeaderSize:], w.readHMACKey)
|
|
copy(buffer[hmacSize:], buffer[:tlsHeaderSize])
|
|
binary.BigEndian.PutUint16(buffer[hmacSize+3:], uint16(len(buffer)-tlsHmacHeaderSize))
|
|
w.buffer.Advance(hmacSize)
|
|
w.authorized = true
|
|
}
|
|
}
|
|
}
|
|
return w.buffer.Read(p)
|
|
}
|
|
|
|
func kdf(password string, serverRandom []byte) []byte {
|
|
hasher := sha256.New()
|
|
hasher.Write([]byte(password))
|
|
hasher.Write(serverRandom)
|
|
return hasher.Sum(nil)
|
|
}
|
|
|
|
func xorSlice(data []byte, key []byte) {
|
|
for i := range data {
|
|
data[i] ^= key[i%len(key)]
|
|
}
|
|
}
|
|
|
|
var _ N.VectorisedWriter = (*VerifiedConn)(nil)
|
|
|
|
type VerifiedConn struct {
|
|
net.Conn
|
|
writer N.VectorisedWriter
|
|
hmacAdd hash.Hash
|
|
hmacVerify hash.Hash
|
|
hmacIgnore hash.Hash
|
|
|
|
buffer *buf.Buffer
|
|
}
|
|
|
|
func NewVerifiedConn(
|
|
conn net.Conn,
|
|
hmacAdd hash.Hash,
|
|
hmacVerify hash.Hash,
|
|
hmacIgnore hash.Hash,
|
|
) *VerifiedConn {
|
|
return &VerifiedConn{
|
|
Conn: conn,
|
|
writer: bufio.NewVectorisedWriter(conn),
|
|
hmacAdd: hmacAdd,
|
|
hmacVerify: hmacVerify,
|
|
hmacIgnore: hmacIgnore,
|
|
}
|
|
}
|
|
|
|
func (c *VerifiedConn) Read(b []byte) (n int, err error) {
|
|
if c.buffer != nil {
|
|
if !c.buffer.IsEmpty() {
|
|
return c.buffer.Read(b)
|
|
}
|
|
c.buffer.Release()
|
|
c.buffer = nil
|
|
}
|
|
for {
|
|
var tlsHeader [tlsHeaderSize]byte
|
|
_, err = io.ReadFull(c.Conn, tlsHeader[:])
|
|
if err != nil {
|
|
sendAlert(c.Conn)
|
|
return
|
|
}
|
|
length := int(binary.BigEndian.Uint16(tlsHeader[3:tlsHeaderSize]))
|
|
c.buffer = buf.NewSize(tlsHeaderSize + length)
|
|
common.Must1(c.buffer.Write(tlsHeader[:]))
|
|
_, err = c.buffer.ReadFullFrom(c.Conn, length)
|
|
if err != nil {
|
|
return
|
|
}
|
|
buffer := c.buffer.Bytes()
|
|
switch buffer[0] {
|
|
case alert:
|
|
err = E.Cause(net.ErrClosed, "remote alert")
|
|
return
|
|
case applicationData:
|
|
if c.hmacIgnore != nil {
|
|
if verifyApplicationData(buffer, c.hmacIgnore, false) {
|
|
c.buffer.Release()
|
|
c.buffer = nil
|
|
continue
|
|
} else {
|
|
c.hmacIgnore = nil
|
|
}
|
|
}
|
|
if !verifyApplicationData(buffer, c.hmacVerify, true) {
|
|
sendAlert(c.Conn)
|
|
err = E.New("application data verification failed")
|
|
return
|
|
}
|
|
c.buffer.Advance(tlsHmacHeaderSize)
|
|
default:
|
|
sendAlert(c.Conn)
|
|
err = E.New("unexpected TLS record type: ", buffer[0])
|
|
return
|
|
}
|
|
return c.buffer.Read(b)
|
|
}
|
|
}
|
|
|
|
func (c *VerifiedConn) Write(p []byte) (n int, err error) {
|
|
pTotal := len(p)
|
|
for len(p) > 0 {
|
|
var pWrite []byte
|
|
if len(p) > 16384 {
|
|
pWrite = p[:16384]
|
|
p = p[16384:]
|
|
} else {
|
|
pWrite = p
|
|
p = nil
|
|
}
|
|
_, err = c.write(pWrite)
|
|
}
|
|
if err == nil {
|
|
n = pTotal
|
|
}
|
|
return
|
|
}
|
|
|
|
func (c *VerifiedConn) write(p []byte) (n int, err error) {
|
|
var header [tlsHmacHeaderSize]byte
|
|
header[0] = applicationData
|
|
header[1] = 3
|
|
header[2] = 3
|
|
binary.BigEndian.PutUint16(header[3:tlsHeaderSize], hmacSize+uint16(len(p)))
|
|
c.hmacAdd.Write(p)
|
|
hmacHash := c.hmacAdd.Sum(nil)[:hmacSize]
|
|
c.hmacAdd.Write(hmacHash)
|
|
copy(header[tlsHeaderSize:], hmacHash)
|
|
_, err = bufio.WriteVectorised(c.writer, [][]byte{common.Dup(header[:]), p})
|
|
if err == nil {
|
|
n = len(p)
|
|
}
|
|
return
|
|
}
|
|
|
|
func (c *VerifiedConn) WriteVectorised(buffers []*buf.Buffer) error {
|
|
var header [tlsHmacHeaderSize]byte
|
|
header[0] = applicationData
|
|
header[1] = 3
|
|
header[2] = 3
|
|
binary.BigEndian.PutUint16(header[3:tlsHeaderSize], hmacSize+uint16(buf.LenMulti(buffers)))
|
|
for _, buffer := range buffers {
|
|
c.hmacAdd.Write(buffer.Bytes())
|
|
}
|
|
c.hmacAdd.Write(c.hmacAdd.Sum(nil)[:hmacSize])
|
|
copy(header[tlsHeaderSize:], c.hmacAdd.Sum(nil)[:hmacSize])
|
|
return c.writer.WriteVectorised(append([]*buf.Buffer{buf.As(header[:])}, buffers...))
|
|
}
|
|
|
|
func verifyApplicationData(frame []byte, hmac hash.Hash, update bool) bool {
|
|
if frame[1] != 3 || frame[2] != 3 || len(frame) < tlsHmacHeaderSize {
|
|
return false
|
|
}
|
|
hmac.Write(frame[tlsHmacHeaderSize:])
|
|
hmacHash := hmac.Sum(nil)[:hmacSize]
|
|
if update {
|
|
hmac.Write(hmacHash)
|
|
}
|
|
return bytes.Equal(frame[tlsHeaderSize:tlsHeaderSize+hmacSize], hmacHash)
|
|
}
|
|
|
|
func sendAlert(writer io.Writer) {
|
|
const recordSize = 31
|
|
record := [recordSize]byte{
|
|
alert,
|
|
3,
|
|
3,
|
|
0,
|
|
recordSize - tlsHeaderSize,
|
|
}
|
|
_, err := rand.Read(record[tlsHeaderSize:])
|
|
if err != nil {
|
|
return
|
|
}
|
|
writer.Write(record[:])
|
|
}
|