package protocol import ( "bytes" "crypto/aes" "crypto/cipher" "encoding/base64" "encoding/binary" "math/rand" "sync" "time" "github.com/Dreamacro/clash/common/pool" "github.com/Dreamacro/clash/transport/shadowsocks/core" ) type Base struct { Key []byte Overhead int Param string } type userData struct { userKey []byte userID [4]byte } type authData struct { clientID [4]byte connectionID uint32 mutex sync.Mutex } func (a *authData) next() *authData { r := &authData{} a.mutex.Lock() defer a.mutex.Unlock() if a.connectionID > 0xff000000 || a.connectionID == 0 { rand.Read(a.clientID[:]) a.connectionID = rand.Uint32() & 0xffffff } a.connectionID++ copy(r.clientID[:], a.clientID[:]) r.connectionID = a.connectionID return r } func (a *authData) putAuthData(buf *bytes.Buffer) { binary.Write(buf, binary.LittleEndian, uint32(time.Now().Unix())) buf.Write(a.clientID[:]) binary.Write(buf, binary.LittleEndian, a.connectionID) } func (a *authData) putEncryptedData(b *bytes.Buffer, userKey []byte, paddings [2]int, salt string) error { encrypt := pool.Get(16) defer pool.Put(encrypt) binary.LittleEndian.PutUint32(encrypt, uint32(time.Now().Unix())) copy(encrypt[4:], a.clientID[:]) binary.LittleEndian.PutUint32(encrypt[8:], a.connectionID) binary.LittleEndian.PutUint16(encrypt[12:], uint16(paddings[0])) binary.LittleEndian.PutUint16(encrypt[14:], uint16(paddings[1])) cipherKey := core.Kdf(base64.StdEncoding.EncodeToString(userKey)+salt, 16) block, err := aes.NewCipher(cipherKey) if err != nil { return err } iv := bytes.Repeat([]byte{0}, 16) cbcCipher := cipher.NewCBCEncrypter(block, iv) cbcCipher.CryptBlocks(encrypt, encrypt) b.Write(encrypt) return nil }