mihomo/transport/shadowtls/shadowtls.go
2023-11-03 21:58:21 +08:00

151 lines
3.1 KiB
Go

package shadowtls
import (
"context"
"crypto/hmac"
"crypto/sha1"
"crypto/tls"
"encoding/binary"
"fmt"
"hash"
"io"
"net"
"github.com/metacubex/mihomo/common/pool"
C "github.com/metacubex/mihomo/constant"
)
const (
chunkSize = 1 << 13
Mode string = "shadow-tls"
hashLen int = 8
tlsHeaderLen int = 5
)
var (
DefaultALPN = []string{"h2", "http/1.1"}
)
// ShadowTLS is shadow-tls implementation
type ShadowTLS struct {
net.Conn
password []byte
remain int
firstRequest bool
tlsConfig *tls.Config
}
type HashedConn struct {
net.Conn
hasher hash.Hash
}
func newHashedStream(conn net.Conn, password []byte) HashedConn {
return HashedConn{
Conn: conn,
hasher: hmac.New(sha1.New, password),
}
}
func (h HashedConn) Read(b []byte) (n int, err error) {
n, err = h.Conn.Read(b)
h.hasher.Write(b[:n])
return
}
func (s *ShadowTLS) read(b []byte) (int, error) {
var buf [tlsHeaderLen]byte
_, err := io.ReadFull(s.Conn, buf[:])
if err != nil {
return 0, fmt.Errorf("shadowtls read failed %w", err)
}
if buf[0] != 0x17 || buf[1] != 0x3 || buf[2] != 0x3 {
return 0, fmt.Errorf("invalid shadowtls header %v", buf)
}
length := int(binary.BigEndian.Uint16(buf[3:]))
if length > len(b) {
n, err := s.Conn.Read(b)
if err != nil {
return n, err
}
s.remain = length - n
return n, nil
}
return io.ReadFull(s.Conn, b[:length])
}
func (s *ShadowTLS) Read(b []byte) (int, error) {
if s.remain > 0 {
length := s.remain
if length > len(b) {
length = len(b)
}
n, err := io.ReadFull(s.Conn, b[:length])
if err != nil {
return n, fmt.Errorf("shadowtls Read failed with %w", err)
}
s.remain -= n
return n, nil
}
return s.read(b)
}
func (s *ShadowTLS) Write(b []byte) (int, error) {
length := len(b)
for i := 0; i < length; i += chunkSize {
end := i + chunkSize
if end > length {
end = length
}
n, err := s.write(b[i:end])
if err != nil {
return n, fmt.Errorf("shadowtls Write failed with %w, i=%d, end=%d, n=%d", err, i, end, n)
}
}
return length, nil
}
func (s *ShadowTLS) write(b []byte) (int, error) {
var hashVal []byte
if s.firstRequest {
hashedConn := newHashedStream(s.Conn, s.password)
tlsConn := tls.Client(hashedConn, s.tlsConfig)
// fix tls handshake not timeout
ctx, cancel := context.WithTimeout(context.Background(), C.DefaultTLSTimeout)
defer cancel()
if err := tlsConn.HandshakeContext(ctx); err != nil {
return 0, fmt.Errorf("tls connect failed with %w", err)
}
hashVal = hashedConn.hasher.Sum(nil)[:hashLen]
s.firstRequest = false
}
buf := pool.GetBuffer()
defer pool.PutBuffer(buf)
buf.Write([]byte{0x17, 0x03, 0x03})
binary.Write(buf, binary.BigEndian, uint16(len(b)+len(hashVal)))
buf.Write(hashVal)
buf.Write(b)
_, err := s.Conn.Write(buf.Bytes())
if err != nil {
// return 0 because errors occur here make the
// whole situation irrecoverable
return 0, err
}
return len(b), nil
}
// NewShadowTLS return a ShadowTLS
func NewShadowTLS(conn net.Conn, password string, tlsConfig *tls.Config) net.Conn {
return &ShadowTLS{
Conn: conn,
password: []byte(password),
firstRequest: true,
tlsConfig: tlsConfig,
}
}