"******@****.***", gcm256CipherID,
	chacha20Poly1305ID,
	"aes128-ctr", "aes192-ctr", "aes256-ctr",
}

// supportedMACs specifies a default set of MAC algorithms in preference order.
// This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed
// because they have reached the end of their useful life.
// https://cs.opensource.google/go/x/crypto/+/refs/tags/v0.22.0:ssh/common.go;l=85
var supportedMACs = []string{

// return true if the string includes a port.
func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }

// removeEmptyPort strips the empty port in ":port" to ""
// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

// objectAPIHandler implements and provides http handlers for S3 API.
type objectAPIHandlers struct {
	ObjectAPI func() ObjectLayer
}

// getHost tries its best to return the request host.
// According to section 14.23 of RFC 2616 the Host header
// can include the port number if the default value of 80 is not used.
func getHost(r *http.Request) string {
	if r.URL.IsAbs() {
		return r.URL.Host
	}
	return r.Host
}

	if err != nil {
		return err
	}
	// While AWS documentation mentions that the date specified
	// must be present in ISO 8601 format, in reality they allow
	// users to provide RFC 3339 compliant dates.
	retDate, err := amztime.ISO8601Parse(dateStr)
	if err != nil {
		return ErrInvalidRetentionDate
	}

	*rDate = RetentionDate{retDate}
	return nil
}

```

If you set an empty lookup bind password, the lookup bind will use the unauthenticated authentication mechanism, as described in [RFC 4513 Section 5.1.2](https://tools.ietf.org/html/rfc4513#section-5.1.2).

### User lookup