1//go:build go1.21

2

3// From go1.21 and onwards.

4

5package tlsrpt

6

7import (

8 "crypto/tls"

9 "fmt"

10 "strings"

11)

12

13// FormatAlert formats a TLS alert in the form "alert-<num>" or "alert-<num>-<shortcode>".

14func FormatAlert(alert uint8) string {

15 s := fmt.Sprintf("alert-%d", alert)

16 err := tls.AlertError(alert) // Since go1.21.0

17 // crypto/tls returns messages like "tls: short message" or "tls: alert(321)".

18 if str := err.Error(); !strings.Contains(str, "alert(") {

19 s += "-" + strings.ReplaceAll(strings.TrimPrefix(str, "tls: "), " ", "-")

20 }

21 return s

22}

23