Improve: refactor ssr and fix #995 (#1189)

Co-authored-by: goomada <madao@DESKTOP-IOEBS0C.localdomain>

component/ssr/protocol/base.go

@@ -1,10 +1,77 @@
 package protocol
 
-// Base information for 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/log"
+	"github.com/Dreamacro/go-shadowsocks2/core"
+)
+
 type Base struct {
-	IV       []byte
 	Key      []byte
-	TCPMss   int
 	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 {
+		log.Warnln("New cipher error: %s", err.Error())
+		return err
+	}
+	iv := bytes.Repeat([]byte{0}, 16)
+	cbcCipher := cipher.NewCBCEncrypter(block, iv)
+
+	cbcCipher.CryptBlocks(encrypt, encrypt)
+
+	b.Write(encrypt)
+	return nil
+}