VMess AEAD based packet length

(cherry picked from commit 08221600082a79376bdc262f2ffec1a3129ae98d)

proxy/vmess/encoding/auth.go

@@ -7,6 +7,8 @@ import (
 
 	"github.com/xtls/xray-core/common"
 
+	"github.com/xtls/xray-core/common/crypto"
+
 	"golang.org/x/crypto/sha3"
 )
 
@@ -116,3 +118,11 @@ func (s *ShakeSizeParser) NextPaddingLen() uint16 {
 func (s *ShakeSizeParser) MaxPaddingLen() uint16 {
 	return 64
 }
+
+type AEADSizeParser struct {
+	crypto.AEADChunkSizeParser
+}
+
+func NewAEADSizeParser(auth *crypto.AEADAuthenticator) *AEADSizeParser {
+	return &AEADSizeParser{crypto.AEADChunkSizeParser{Auth: auth}}
+}