Refactor code and fix linter warnings (#3627)

* refactor: use any instead of empty interface

* refactor: code cleanup

util/crypto/crypto.go

@@ -13,6 +13,5 @@ func HashPasswordAsBcrypt(password string) (string, error) {
 
 // CheckPasswordHash verifies if the given password matches the bcrypt hash.
 func CheckPasswordHash(hash, password string) bool {
-	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
-	return err == nil
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password)) == nil
 }

util/ldap/ldap.go

@@ -24,13 +24,22 @@ type Config struct {
 // FetchVlessFlags returns map[email]enabled
 func FetchVlessFlags(cfg Config) (map[string]bool, error) {
 	addr := fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
-	var conn *ldap.Conn
-	var err error
+
+	scheme := "ldap"
 	if cfg.UseTLS {
-		conn, err = ldap.DialTLS("tcp", addr, &tls.Config{InsecureSkipVerify: false})
-	} else {
-		conn, err = ldap.Dial("tcp", addr)
+		scheme = "ldaps"
 	}
+
+	ldapURL := fmt.Sprintf("%s://%s", scheme, addr)
+
+	var opts []ldap.DialOpt
+	if cfg.UseTLS {
+		opts = append(opts, ldap.DialWithTLSConfig(&tls.Config{
+			InsecureSkipVerify: false,
+		}))
+	}
+
+	conn, err := ldap.DialURL(ldapURL, opts...)
 	if err != nil {
 		return nil, err
 	}
@@ -91,13 +100,22 @@ func FetchVlessFlags(cfg Config) (map[string]bool, error) {
 // AuthenticateUser searches user by cfg.UserAttr and attempts to bind with provided password.
 func AuthenticateUser(cfg Config, username, password string) (bool, error) {
 	addr := fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
-	var conn *ldap.Conn
-	var err error
+
+	scheme := "ldap"
 	if cfg.UseTLS {
-		conn, err = ldap.DialTLS("tcp", addr, &tls.Config{InsecureSkipVerify: false})
-	} else {
-		conn, err = ldap.Dial("tcp", addr)
+		scheme = "ldaps"
 	}
+
+	ldapURL := fmt.Sprintf("%s://%s", scheme, addr)
+
+	var opts []ldap.DialOpt
+	if cfg.UseTLS {
+		opts = append(opts, ldap.DialWithTLSConfig(&tls.Config{
+			InsecureSkipVerify: false,
+		}))
+	}
+
+	conn, err := ldap.DialURL(ldapURL, opts...)
 	if err != nil {
 		return false, err
 	}

util/random/random.go

@@ -18,10 +18,10 @@ var (
 // init initializes the character sequences used for random string generation.
 // It sets up arrays for numbers, lowercase letters, uppercase letters, and combinations.
 func init() {
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		numSeq[i] = rune('0' + i)
 	}
-	for i := 0; i < 26; i++ {
+	for i := range 26 {
 		lowerSeq[i] = rune('a' + i)
 		upperSeq[i] = rune('A' + i)
 	}
@@ -40,7 +40,7 @@ func init() {
 // Seq generates a random string of length n containing alphanumeric characters (numbers, lowercase and uppercase letters).
 func Seq(n int) string {
 	runes := make([]rune, n)
-	for i := 0; i < n; i++ {
+	for i := range n {
 		idx, err := rand.Int(rand.Reader, big.NewInt(int64(len(allSeq))))
 		if err != nil {
 			panic("crypto/rand failed: " + err.Error())

util/reflect_util/reflect.go

@@ -7,7 +7,7 @@ import "reflect"
 func GetFields(t reflect.Type) []reflect.StructField {
 	num := t.NumField()
 	fields := make([]reflect.StructField, 0, num)
-	for i := 0; i < num; i++ {
+	for i := range num {
 		fields = append(fields, t.Field(i))
 	}
 	return fields
@@ -17,7 +17,7 @@ func GetFields(t reflect.Type) []reflect.StructField {
 func GetFieldValues(v reflect.Value) []reflect.Value {
 	num := v.NumField()
 	fields := make([]reflect.Value, 0, num)
-	for i := 0; i < num; i++ {
+	for i := range num {
 		fields = append(fields, v.Field(i))
 	}
 	return fields

util/sys/sys_darwin.go

@@ -47,11 +47,11 @@ func CPUPercentRaw() (float64, error) {
 	var out [5]uint64
 	switch len(raw) {
 	case 5 * 8:
-		for i := 0; i < 5; i++ {
+		for i := range 5 {
 			out[i] = binary.LittleEndian.Uint64(raw[i*8 : (i+1)*8])
 		}
 	case 5 * 4:
-		for i := 0; i < 5; i++ {
+		for i := range 5 {
 			out[i] = uint64(binary.LittleEndian.Uint32(raw[i*4 : (i+1)*4]))
 		}
 	default: