Re: clearenv(3): implies that it's a security tool

["Stéphane Aulery" <saulery-GANU6spQydw@public.gmane.org>]

Hello Michael and Matt,

----- Michael Kerrisk (man-pages) <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> a écrit :
> On 18 February 2016 at 21:34, Matt Zimmerman <mdz-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org> wrote:
> > Thanks for following up.  My recommendation is to say something like:
> >
> > This function DOES NOT securely erase the contents of the environment.
> > Security-conscious applications which need to do this should use ....
> > instead.
> 
> So, I think this report is a little confused, but mainly because of
> the poor description in the man page.
> 
> The security-conscious applications in this context are those that
> want to precisely control the environment passed to an exec()ed
> program. clearenv() cannot, indeed must not, try to erase the buffers
> containing the environment definitions. (See putenv(3) to understand
> why.) I've adjusted the man page in away that I hope explains things
> better:
> 
>        The  clearenv()  function  may  be  useful  in security-conscious
>        applications that want to precisely control the environment  that
>        is  passed  to  programs executed using exec(3).  The application
>        would do this by first clearing the environment and  then  adding
>        select environment variables.
> 
>        Note that the main effect of clearenv() is to adjust the value of
>        the pointer environ(7); this function does not erase the contents
>        of the buffers containing the environment definitions.


It's much better that I can do.
If no objection Matt,
I pass the bug report in fixed-upstream.


Regards,

-- 
Stéphane Aulery
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