1package mox

2

3import (

4 "errors"

5 "net"

6 "reflect"

7)

8

9func AsTLSAlert(err error) (alert uint8, ok bool) {

10 // If the remote client aborts the connection, it can send an alert indicating why.

11 // crypto/tls gives us a net.OpError with "Op" set to "remote error", an an Err

12 // with the unexported type "alert", a uint8. So we try to read it.

13

14 var opErr *net.OpError

15 if !errors.As(err, &opErr) || opErr.Op != "remote error" || opErr.Err == nil {

16 return

17 }

18 v := reflect.ValueOf(opErr.Err)

19 if v.Kind() != reflect.Uint8 || v.Type().Name() != "alert" {

20 return

21 }

22 return uint8(v.Uint()), true

23}

24