Re: [RFC] [PATCH] Support explicit_bzero, memset_s, memzero_explicit, or similar.

[Paul Eggert <eggert at cs dot ucla dot edu>]

Rich Felker wrote:

> Only if you also wrap your device in tinfoil.

Perhaps; but if the original request is for a tinfoil beanie, it's not 
unreasonable to suggest getting the full hat.

> these measures are about preventing information disclosure in the event of
> subsequent compromise of the process (or possibly even normal behavior
> following setuid() to drop privs), not defending against physical
> attacks to recover previous state of memory/disks.

If only things were so simple!  With virtual machines, there's not always a 
clean distinction between a compromise and a physical attack.

> If you agree with
> my assessment of the scope, it's solvable purely at the compiler level
> without any special OS or hardware level support.

Possibly, but there might be some assumptions involved that do require some 
support from lower levels.  It's something that would have to be vetted.  (As 
far as I know this has not been done for C.)

Anyway, I think we're in agreement that the suggested (library-only) approach 
does not suffice.