Replace deprecated ioutil.ReadFile with new func from os

main.go

@@ -6,11 +6,9 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net"
 	"os"
-	"strings"
 	"sync"
 	"time"
 
@@ -89,7 +87,7 @@ func startAccepting(listener net.Listener, serverConfig ssh.ServerConfig) {
 
 func getKey(path string) []byte {
 	if path != "" {
-		privateBytes, err := ioutil.ReadFile(path)
+		privateBytes, err := os.ReadFile(path)
 		if err != nil {
 			log.Fatalf("Failed to load private key: %s", path)
 		}
@@ -119,7 +117,12 @@ func connectionHandler(con net.Conn, serverConfig ssh.ServerConfig) {
 }
 
 func printConnectionData(conn ssh.ConnMetadata, password []byte) (*ssh.Permissions, error) {
-	ip := getIPWithoutPort(conn.RemoteAddr().String())
+	responseErr := fmt.Errorf("password rejected for %s", conn.User())
+	ip, _, err := net.SplitHostPort(conn.RemoteAddr().String())
+	if err != nil {
+		fmt.Println(err)
+		return nil, responseErr
+	}
 
 	if isJson {
 		fmt.Printf(
@@ -133,7 +136,7 @@ func printConnectionData(conn ssh.ConnMetadata, password []byte) (*ssh.Permissio
 		log.Printf("SRC=%s USERNAME=%s PASSWORD=%s\n", ip, conn.User(), string(password))
 	}
 
-	return nil, fmt.Errorf("password rejected for %s", conn.User())
+	return nil, responseErr
 }
 
 func printHelp() {
@@ -145,10 +148,3 @@ USAGE:
 FLAGS:`)
 	flags.PrintDefaults()
 }
-
-func getIPWithoutPort(address string) string {
-	if strings.Contains(address, "]") { // Is IPv6
-		return strings.ReplaceAll(strings.Split(address, "]")[0], "[", "")
-	}
-	return strings.Split(address, ":")[0]
-}

main_test.go

@@ -1,23 +0,0 @@
-package main
-
-import "testing"
-
-func TestGetIPWithoutPort(t *testing.T) {
-	t.Run("IPv6", func(t *testing.T) {
-		got := getIPWithoutPort("[::1]:2222")
-		want := "::1"
-
-		if want != got {
-			t.Fatalf("Want '%s' but got '%s'", want, got)
-		}
-	})
-
-	t.Run("IPv4", func(t *testing.T) {
-		got := getIPWithoutPort("127.0.0.1:2222")
-		want := "127.0.0.1"
-
-		if want != got {
-			t.Fatalf("Want '%s' but got '%s'", want, got)
-		}
-	})
-}