fix: resolve remaining errcheck and gosec lint failures

Author: TMHSDigital

internal/dns/simulate.go

@@ -8,6 +8,10 @@ import (
 	"time"
 )
 
+// seededRand is a package-level random source seeded at startup.
+// math/rand is appropriate here — simulation output is not security-sensitive.
+var seededRand = rand.New(rand.NewSource(time.Now().UnixNano())) //nolint:gosec
+
 // SimulateResolution returns a synthetic DNS result without performing any
 // network I/O. Common subdomain prefixes resolve ~90% of the time; everything
 // else uses the supplied hitRate (0-100).
@@ -21,20 +25,20 @@ func SimulateResolution(domain string, hitRate int, verbose bool) bool {
 	for _, sub := range commonSubdomains {
 		if strings.HasPrefix(domain, sub+".") {
 			if verbose {
-				fakeTiming := time.Duration(50+rand.Intn(200)) * time.Millisecond
-				fakeIP := fmt.Sprintf("192.168.%d.%d", rand.Intn(255), 1+rand.Intn(254))
+				fakeTiming := time.Duration(50+seededRand.Intn(200)) * time.Millisecond
+				fakeIP := fmt.Sprintf("192.168.%d.%d", seededRand.Intn(255), 1+seededRand.Intn(254))
 				fmt.Fprintf(os.Stderr, "Resolved (SIMULATED): %s (IP: %s) in %s\n", domain, fakeIP, fakeTiming)
 			}
-			return rand.Intn(100) < 90
+			return seededRand.Intn(100) < 90
 		}
 	}
 
-	result := rand.Intn(100) < hitRate
+	result := seededRand.Intn(100) < hitRate
 
 	if verbose {
-		fakeTiming := time.Duration(100+rand.Intn(500)) * time.Millisecond
+		fakeTiming := time.Duration(100+seededRand.Intn(500)) * time.Millisecond
 		if result {
-			fakeIP := fmt.Sprintf("10.%d.%d.%d", rand.Intn(255), rand.Intn(255), 1+rand.Intn(254))
+			fakeIP := fmt.Sprintf("10.%d.%d.%d", seededRand.Intn(255), seededRand.Intn(255), 1+seededRand.Intn(254))
 			fmt.Fprintf(os.Stderr, "Resolved (SIMULATED): %s (IP: %s) in %s\n", domain, fakeIP, fakeTiming)
 		} else {
 			fmt.Fprintf(os.Stderr, "Failed to resolve (SIMULATED): %s (Error: no such host) in %s\n", domain, fakeTiming)

main.go

@@ -165,10 +165,16 @@ func main() {
 			out.Error("creating output file: %v", err)
 			os.Exit(1)
 		}
-		defer f.Close()
 		outWriter = bufio.NewWriter(f)
-		defer outWriter.Flush()
 		out = output.New(outWriter, *testMode)
+		defer func() {
+			if flushErr := outWriter.Flush(); flushErr != nil {
+				out.Error("flushing output: %v", flushErr)
+			}
+			if closeErr := f.Close(); closeErr != nil {
+				out.Error("closing output file: %v", closeErr)
+			}
+		}()
 	}
 
 	if *verbose {

tools/wordlist-gen.go

@@ -33,10 +33,16 @@ func main() {
 		fmt.Printf("Error creating output file: %v\n", err)
 		os.Exit(1)
 	}
-	defer file.Close()
 
 	writer := bufio.NewWriter(file)
-	defer writer.Flush()
+	defer func() {
+		if flushErr := writer.Flush(); flushErr != nil {
+			fmt.Printf("Error flushing writer: %v\n", flushErr)
+		}
+		if closeErr := file.Close(); closeErr != nil {
+			fmt.Printf("Error closing file: %v\n", closeErr)
+		}
+	}()
 
 	// Track added words to avoid duplicates
 	addedWords := make(map[string]bool)