Refactor return value of decryption

cmd/ck-server/ck-server.go

@@ -52,14 +52,14 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 		go util.Pipe(conn, webConn)
 	}
 
-	UID, sessionID, proxyMethod, encryptionMethod, finishHandshake, err := server.PrepareConnection(data, sta, conn)
+	ci, finishHandshake, err := server.PrepareConnection(data, sta, conn)
 	if err != nil {
 		log.WithFields(log.Fields{
 			"remoteAddr":       remoteAddr,
-			"UID":              b64(UID),
+			"UID":              b64(ci.UID),
-			"sessionId":        sessionID,
+			"sessionId":        ci.SessionId,
-			"proxyMethod":      proxyMethod,
+			"proxyMethod":      ci.ProxyMethod,
-			"encryptionMethod": encryptionMethod,
+			"encryptionMethod": ci.EncryptionMethod,
 		}).Warn(err)
 		goWeb()
 		return
@@ -67,7 +67,7 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 
 	sessionKey := make([]byte, 32)
 	rand.Read(sessionKey)
-	obfuscator, err := mux.GenerateObfs(encryptionMethod, sessionKey)
+	obfuscator, err := mux.GenerateObfs(ci.EncryptionMethod, sessionKey)
 	if err != nil {
 		log.Error(err)
 		goWeb()
@@ -77,7 +77,7 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 	// adminUID can use the server as normal with unlimited QoS credits. The adminUID is not
 	// added to the userinfo database. The distinction between going into the admin mode
 	// and normal proxy mode is that sessionID needs == 0 for admin mode
-	if bytes.Equal(UID, sta.AdminUID) && sessionID == 0 {
+	if bytes.Equal(ci.UID, sta.AdminUID) && ci.SessionId == 0 {
 		err = finishHandshake(sessionKey)
 		if err != nil {
 			log.Error(err)
@@ -101,14 +101,14 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 	}
 
 	var user *server.ActiveUser
-	if sta.IsBypass(UID) {
+	if sta.IsBypass(ci.UID) {
-		user, err = sta.Panel.GetBypassUser(UID)
+		user, err = sta.Panel.GetBypassUser(ci.UID)
 	} else {
-		user, err = sta.Panel.GetUser(UID)
+		user, err = sta.Panel.GetUser(ci.UID)
 	}
 	if err != nil {
 		log.WithFields(log.Fields{
-			"UID":        b64(UID),
+			"UID":        b64(ci.UID),
 			"remoteAddr": remoteAddr,
 			"error":      err,
 		}).Warn("+1 unauthorised UID")
@@ -121,9 +121,9 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 		Valve:      nil,
 		UnitRead:   util.ReadTLS,
 	}
-	sesh, existing, err := user.GetSession(sessionID, seshConfig)
+	sesh, existing, err := user.GetSession(ci.SessionId, seshConfig)
 	if err != nil {
-		user.DeleteSession(sessionID, "")
+		user.DeleteSession(ci.SessionId, "")
 		log.Error(err)
 		return
 	}
@@ -147,8 +147,8 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 	log.Trace("finished handshake")
 
 	log.WithFields(log.Fields{
-		"UID":       b64(UID),
+		"UID":       b64(ci.UID),
-		"sessionID": sessionID,
+		"sessionID": ci.SessionId,
 	}).Info("New session")
 	sesh.AddConnection(conn)
 
@@ -157,20 +157,20 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 		if err != nil {
 			if err == mux.ErrBrokenSession {
 				log.WithFields(log.Fields{
-					"UID":       b64(UID),
+					"UID":       b64(ci.UID),
-					"sessionID": sessionID,
+					"sessionID": ci.SessionId,
 					"reason":    sesh.TerminalMsg(),
 				}).Info("Session closed")
-				user.DeleteSession(sessionID, "")
+				user.DeleteSession(ci.SessionId, "")
 				return
 			} else {
 				continue
 			}
 		}
-		localConn, err := net.Dial("tcp", sta.ProxyBook[proxyMethod])
+		localConn, err := net.Dial("tcp", sta.ProxyBook[ci.ProxyMethod])
 		if err != nil {
-			log.Errorf("Failed to connect to %v: %v", proxyMethod, err)
+			log.Errorf("Failed to connect to %v: %v", ci.ProxyMethod, err)
-			user.DeleteSession(sessionID, "Failed to connect to proxy server")
+			user.DeleteSession(ci.SessionId, "Failed to connect to proxy server")
 			continue
 		}
 		go util.Pipe(localConn, newStream)

internal/server/TLS.go

@@ -218,7 +218,7 @@ var ErrBadClientHello = errors.New("non (or malformed) ClientHello")
 var ErrNotCloak = errors.New("TLS but non-Cloak ClientHello")
 var ErrBadProxyMethod = errors.New("invalid proxy method")
 
-func PrepareConnection(firstPacket []byte, sta *State, conn net.Conn) (UID []byte, sessionID uint32, proxyMethod string, encryptionMethod byte, finisher func([]byte) error, err error) {
+func PrepareConnection(firstPacket []byte, sta *State, conn net.Conn) (info *ClientInfo, finisher func([]byte) error, err error) {
 	ch, err := parseClientHello(firstPacket)
 	if err != nil {
 		log.Debug(err)
@@ -227,13 +227,13 @@ func PrepareConnection(firstPacket []byte, sta *State, conn net.Conn) (UID []byt
 	}
 
 	var sharedSecret []byte
-	UID, sessionID, proxyMethod, encryptionMethod, sharedSecret, err = TouchStone(ch, sta)
+	info, sharedSecret, err = TouchStone(ch, sta)
 	if err != nil {
 		log.Debug(err)
 		err = ErrNotCloak
 		return
 	}
-	if _, ok := sta.ProxyBook[proxyMethod]; !ok {
+	if _, ok := sta.ProxyBook[info.ProxyMethod]; !ok {
 		err = ErrBadProxyMethod
 		return
 	}

internal/server/auth.go

@@ -10,12 +10,19 @@ import (
 	"time"
 )
 
+type ClientInfo struct {
+	UID              []byte
+	SessionId        uint32
+	ProxyMethod      string
+	EncryptionMethod byte
+}
+
 var ErrReplay = errors.New("duplicate random")
 var ErrInvalidPubKey = errors.New("public key has invalid format")
 var ErrCiphertextLength = errors.New("ciphertext has the wrong length")
 var ErrTimestampOutOfWindow = errors.New("timestamp is outside of the accepting window")
 
-func TouchStone(ch *ClientHello, sta *State) (UID []byte, sessionID uint32, proxyMethod string, encryptionMethod byte, sharedSecret []byte, err error) {
+func TouchStone(ch *ClientHello, sta *State) (info *ClientInfo, sharedSecret []byte, err error) {
 
 	if sta.registerRandom(ch.random) {
 		err = ErrReplay
@@ -47,9 +54,13 @@ func TouchStone(ch *ClientHello, sta *State) (UID []byte, sessionID uint32, prox
 		return
 	}
 
-	UID = plaintext[0:16]
+	info = &ClientInfo{
-	proxyMethod = string(bytes.Trim(plaintext[16:28], "\x00"))
+		UID:              plaintext[0:16],
-	encryptionMethod = plaintext[28]
+		SessionId:        0,
+		ProxyMethod:      string(bytes.Trim(plaintext[16:28], "\x00")),
+		EncryptionMethod: plaintext[28],
+	}
+
 	timestamp := int64(binary.BigEndian.Uint64(plaintext[29:37]))
 	clientTime := time.Unix(timestamp, 0)
 	serverTime := sta.Now()
@@ -57,6 +68,6 @@ func TouchStone(ch *ClientHello, sta *State) (UID []byte, sessionID uint32, prox
 		err = fmt.Errorf("%v: received timestamp %v", ErrTimestampOutOfWindow, timestamp)
 		return
 	}
-	sessionID = binary.BigEndian.Uint32(plaintext[37:41])
+	info.SessionId = binary.BigEndian.Uint32(plaintext[37:41])
 	return
 }