[PATCH] Cygwin: add secure_getenv

[Eric Blake]

On 2/19/19 11:21 AM, Corinna Vinschen wrote:

>> That said, while it is ideal to avoid squashing to NULL in situations
>> that are not security boundaries (as with your STC displaying HOME even
>> after seteuid() on Linux), I'm also okay if we filter too aggressively
>> (the way gnulib's fallback implementation does when neither
>> __secure_getenv() nor issetugid() available).
> 
> In fact, gnulib's implementation would chose the
> 
>    if (issetugid ())
>      return NULL;
>    return getenv (name);
> 
> branch on Cygwin right now, just as on BSDs.  If that's the right thing
> to do for BSD, it's not... *really* wrong for Cygwin either, regardless
> what Linux is doing.
> 
> That in turn means Yaakov's patch is perfeclty fine since it's equivalent
> to the above gnulib code.
> 
> Agreed?

Yes.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
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