Re fixed panic len out of range in rcon.Dial #5

Author: outdead

CHANGELOG.md

@@ -3,11 +3,18 @@ All notable changes to this project will be documented in this file.
 
 **ATTN**: This project uses [semantic versioning](http://semver.org/).
 
-## [Unreleased
+## [Unreleased]
+
+## [v1.3.3] - 2022-05-16
+### Fixed
+- Added "response from not rcon server" error on auth request (Re fixed panic: runtime error: makeslice: len out of range in rcon.Dial #5).
 
 ## [v1.3.2] - 2022-05-16
 ### Fixed
-- Fixed panic: runtime error: makeslice: len out of range in rcon.Dial #5
+- Fixed panic: runtime error: makeslice: len out of range in rcon.Dial
+
+### Updated
+- Updated golangci linter to 1.42.1 version
 
 ## [v1.3.1] - 2021-01-06
 ### Updated
@@ -78,7 +85,8 @@ changed.
 ### Added
 - Initial implementation.
 
-[Unreleased]: https://github.com/gorcon/rcon/compare/v1.3.2...HEAD
+[Unreleased]: https://github.com/gorcon/rcon/compare/v1.3.3...HEAD
+[v1.3.3]: https://github.com/gorcon/rcon/compare/v1.3.2...v1.3.3
 [v1.3.2]: https://github.com/gorcon/rcon/compare/v1.3.1...v1.3.2
 [v1.3.1]: https://github.com/gorcon/rcon/compare/v1.3.0...v1.3.1
 [v1.3.0]: https://github.com/gorcon/rcon/compare/v1.2.4...v1.3.0

rcon.go

@@ -54,6 +54,9 @@ const (
 )
 
 var (
+	// ErrAuthNotRCON is returned when got auth response with negative size.
+	ErrAuthNotRCON = errors.New("response from not rcon server")
+
 	// ErrInvalidAuthResponse is returned when we didn't get an auth packet
 	// back for second read try after discard empty SERVERDATA_RESPONSE_VALUE
 	// from authentication response.
@@ -184,8 +187,8 @@ func (c *Conn) auth(password string) error {
 	}
 
 	size := response.Size - PacketHeaderSize
-	if size <= 0 {
-		size = response.Size
+	if size < 0 {
+		return ErrAuthNotRCON
 	}
 
 	// When the server receives an auth request, it will respond with an empty

rcon_test.go

@@ -22,20 +22,15 @@ func authHandler(c *rcontest.Context) {
 	case "another":
 		rcon.NewPacket(rcon.SERVERDATA_AUTH_RESPONSE, 42, "").WriteTo(c.Conn())
 	case "makeslice":
-		size := int32(len([]byte("")) + int(rcon.PacketPaddingSize)) // Some minecraft servers does not add header size
+		size := int32(len([]byte("")))
 
 		buffer := bytes.NewBuffer(make([]byte, 0, size+4))
 
 		_ = binary.Write(buffer, binary.LittleEndian, size)
 		_ = binary.Write(buffer, binary.LittleEndian, c.Request().ID)
 		_ = binary.Write(buffer, binary.LittleEndian, rcon.SERVERDATA_RESPONSE_VALUE)
 
-		// Write command body, null terminated ASCII string and an empty ASCIIZ string.
-		buffer.Write(append([]byte(""), 0x00, 0x00))
-
 		buffer.WriteTo(c.Conn())
-
-		rcon.NewPacket(rcon.SERVERDATA_AUTH_RESPONSE, c.Request().ID, "").WriteTo(c.Conn())
 	case c.Server().Settings.Password:
 		rcon.NewPacket(rcon.SERVERDATA_RESPONSE_VALUE, c.Request().ID, "").WriteTo(c.Conn())
 		rcon.NewPacket(rcon.SERVERDATA_AUTH_RESPONSE, c.Request().ID, "").WriteTo(c.Conn())
@@ -135,31 +130,27 @@ func TestDial(t *testing.T) {
 		}
 	})
 
-	t.Run("auth success", func(t *testing.T) {
-		conn, err := rcon.Dial(server.Addr(), "password")
-		if err != nil {
-			t.Errorf("got err %q, want %v", err, nil)
-			return
-		}
-
-		conn.Close()
-	})
-
 	t.Run("makeslice", func(t *testing.T) {
 		server := rcontest.NewServer(
 			rcontest.SetSettings(rcontest.Settings{Password: "makeslice"}),
 			rcontest.SetAuthHandler(authHandler),
 		)
+		defer server.Close()
 
-		conn, err := rcon.Dial(server.Addr(), "makeslice")
+		_, err := rcon.Dial(server.Addr(), "makeslice")
+		if !errors.Is(err, rcon.ErrAuthNotRCON) {
+			t.Errorf("got err %q, want %q", err, rcon.ErrAuthNotRCON)
+		}
+	})
+
+	t.Run("auth success", func(t *testing.T) {
+		conn, err := rcon.Dial(server.Addr(), "password")
 		if err != nil {
 			t.Errorf("got err %q, want %v", err, nil)
-			server.Close()
 			return
 		}
 
 		conn.Close()
-		server.Close()
 	})
 }