chore: fix: resolve golangci-lint errcheck and govet/shadow warnings

client/main.go

@@ -384,7 +384,7 @@ func ParseVkCaptchaError(errData map[string]interface{}) *VkCaptchaError {
 	}
 	// Fallback to top-level session_token field if not in redirect_uri
 	if sessionToken == "" {
-		if st, ok := errData["session_token"].(string); ok {
+		if st, stOk := errData["session_token"].(string); stOk {
 			sessionToken = st
 		}
 	}

client/manual_captcha.go

@@ -562,7 +562,11 @@ func (t *loggingTransport) RoundTrip(req *http.Request) (*http.Response, error)
 	isCaptchaRequest := req.Body != nil && (strings.Contains(req.URL.Path, "captchaNotRobot.check") || strings.Contains(req.URL.Path, "captchaNotRobot.componentDone"))
 
 	if isCaptchaRequest {
-		b, _ := io.ReadAll(req.Body)
+		b, err := io.ReadAll(req.Body)
+		if err != nil {
+			log.Printf("[Captcha Proxy] Failed to read request body: %v", err)
+			b = nil
+		}
 		req.Body = io.NopCloser(bytes.NewReader(b))
 
 		if isDebug {
@@ -573,7 +577,10 @@ func (t *loggingTransport) RoundTrip(req *http.Request) (*http.Response, error)
 		}
 
 		if strings.Contains(req.URL.Path, "captchaNotRobot.componentDone") || strings.Contains(req.URL.Path, "captchaNotRobot.check") {
-			parsedBody, _ := neturl.ParseQuery(string(b))
+			parsedBody, err := neturl.ParseQuery(string(b))
+			if err != nil {
+				log.Printf("[Captcha Proxy] Failed to parse request body: %v", err)
+			}
 			device := parsedBody.Get("device")
 			browserFp := parsedBody.Get("browser_fp")
 

client/slider_captcha.go

@@ -170,8 +170,8 @@ func (s *captchaNotRobotSession) requestComponentDone() error {
 
 	respObj, ok := resp["response"].(map[string]interface{})
 	if ok {
-		if status, _ := respObj["status"].(string); status != "" && status != "OK" {
+		if statusVal, ok := respObj["status"].(string); ok && statusVal != "" && statusVal != "OK" {
-			return fmt.Errorf("componentDone status: %s", status)
+			return fmt.Errorf("componentDone status: %s", statusVal)
 		}
 	}
 
@@ -294,7 +294,8 @@ func callCaptchaNotRobotWithSliderPOC(
 	time.Sleep(200 * time.Millisecond)
 
 	log.Printf("[STREAM %d] [Captcha] Step 2/4: componentDone", streamID)
-	if err := session.requestComponentDone(); err != nil {
+	err = session.requestComponentDone()
+	if err != nil {
 		return "", err
 	}
 
@@ -337,7 +338,8 @@ func callCaptchaNotRobotWithSliderPOC(
 	// VK refuses getContent with ERROR because it expects the widget lifecycle.
 	log.Printf("[STREAM %d] [Captcha] Re-registering slider component before getContent...", streamID)
 	time.Sleep(300 * time.Millisecond)
-	if err := session.requestComponentDone(); err != nil {
+	err = session.requestComponentDone()
+	if err != nil {
 		// Non-fatal: log and continue — getContent may still succeed.
 		log.Printf("[STREAM %d] [Captcha] Warning: slider componentDone failed: %v", streamID, err)
 	}
@@ -401,7 +403,7 @@ func parseCaptchaSettingsResponse(resp map[string]interface{}) (*captchaSettings
 	settings := &captchaSettingsResponse{
 		SettingsByType: make(map[string]string),
 	}
-	settings.ShowCaptchaType, _ = respObj["show_captcha_type"].(string)
+	settings.ShowCaptchaType, _ = respObj["show_captcha_type"].(string) //nolint:errcheck
 
 	rawSettings, ok := expandCaptchaSettings(respObj["captcha_settings"])
 	if !ok {
@@ -414,7 +416,7 @@ func parseCaptchaSettingsResponse(resp map[string]interface{}) (*captchaSettings
 			continue
 		}
 
-		captchaType, _ := item["type"].(string)
+		captchaType, _ := item["type"].(string) //nolint:errcheck
 		if captchaType == "" {
 			continue
 		}
@@ -580,9 +582,9 @@ func parseCaptchaCheckResult(resp map[string]interface{}) (*captchaCheckResult,
 	}
 
 	result := &captchaCheckResult{}
-	result.Status, _ = respObj["status"].(string)
+	result.Status, _ = respObj["status"].(string)                     //nolint:errcheck
-	result.SuccessToken, _ = respObj["success_token"].(string)
+	result.SuccessToken, _ = respObj["success_token"].(string)        //nolint:errcheck
-	result.ShowCaptchaType, _ = respObj["show_captcha_type"].(string)
+	result.ShowCaptchaType, _ = respObj["show_captcha_type"].(string) //nolint:errcheck
 	if result.Status == "" {
 		return nil, fmt.Errorf("check status missing: %v", resp)
 	}
@@ -596,7 +598,7 @@ func parseSliderCaptchaContentResponse(resp map[string]interface{}) (*sliderCapt
 		return nil, fmt.Errorf("invalid slider content response: %v", resp)
 	}
 
-	status, _ := respObj["status"].(string)
+	status, _ := respObj["status"].(string) //nolint:errcheck
 	if status != "OK" {
 		// Log all fields from the response to help diagnose why VK rejected getContent.
 		var debugFields []string
@@ -610,13 +612,13 @@ func parseSliderCaptchaContentResponse(resp map[string]interface{}) (*sliderCapt
 		return nil, fmt.Errorf("slider getContent status: %s", status)
 	}
 
-	extension, _ := respObj["extension"].(string)
+	extension, _ := respObj["extension"].(string) //nolint:errcheck
 	extension = strings.ToLower(extension)
 	if extension != "jpeg" && extension != "jpg" {
 		return nil, fmt.Errorf("unsupported slider image format: %s", extension)
 	}
 
-	rawImage, _ := respObj["image"].(string)
+	rawImage, _ := respObj["image"].(string) //nolint:errcheck
 	if rawImage == "" {
 		return nil, fmt.Errorf("slider image missing")
 	}

server/main.go

@@ -224,8 +224,8 @@ func handleVLESSConnection(ctx context.Context, dtlsConn net.Conn, connectAddr s
 		return
 	}
 	defer func() {
-		if err := kcpSess.Close(); err != nil {
+		if closeErr := kcpSess.Close(); closeErr != nil {
-			log.Printf("failed to close KCP session: %v", err)
+			log.Printf("failed to close KCP session: %v", closeErr)
 		}
 	}()
 	log.Printf("KCP session established (server)")
@@ -318,7 +318,11 @@ func pipeConn(ctx context.Context, c1, c2 net.Conn) {
 
 	wg.Wait()
 
-	// Reset deadlines
+	// Reset deadlines (best-effort; connection may already be closed)
-	_ = c1.SetDeadline(time.Time{})
+	if err := c1.SetDeadline(time.Time{}); err != nil {
-	_ = c2.SetDeadline(time.Time{})
+		log.Printf("pipeConn: failed to reset deadline c1: %v", err)
+	}
+	if err := c2.SetDeadline(time.Time{}); err != nil {
+		log.Printf("pipeConn: failed to reset deadline c2: %v", err)
+	}
 }