msg validation error

Author: makiuchi-d

server/auth/mackey.go

@@ -69,13 +69,17 @@ func EncryptMACKey(appKey, macKey string) (string, error) {
 }
 
 // ValidateMsgHMAC validates the hmac of a websocket message.
-func ValidateMsgHMAC(mac hash.Hash, data []byte) ([]byte, bool) {
+func ValidateMsgHMAC(mac hash.Hash, data []byte) ([]byte, error) {
 	dlen := len(data) - mac.Size()
 	if dlen < 0 {
-		return nil, false
+		return nil, xerrors.Errorf("data=%v", data)
 	}
 	data, h := data[:dlen], data[dlen:]
-	return data, hmac.Equal(h, CalculateMsgHMAC(mac, data))
+	hash := CalculateMsgHMAC(mac, data)
+	if !hmac.Equal(h, hash) {
+		return nil, xerrors.Errorf("hash=(%v, %v)", h, hash)
+	}
+	return data, nil
 }
 
 func CalculateMsgHMAC(mac hash.Hash, data []byte) []byte {

server/binary/msg.go

@@ -136,10 +136,10 @@ func BuildRegularMsgFrame(t MsgType, seq int, payload []byte, hmac hash.Hash) []
 }
 
 // ParseMsg parse binary data to Msg struct
-func UnmarshalMsg(hmac hash.Hash, alldata []byte) (Msg, error) {
-	data, ok := auth.ValidateMsgHMAC(hmac, alldata)
-	if !ok {
-		return nil, xerrors.Errorf("invalid msg hmac (len=%v)", len(alldata))
+func UnmarshalMsg(hmac hash.Hash, data []byte) (Msg, error) {
+	data, err := auth.ValidateMsgHMAC(hmac, data)
+	if err != nil {
+		return nil, xerrors.Errorf("invalid msg hmac: %w", err)
 	}
 
 	if len(data) < 1 {