On Tue, Nov 12, 2013 at 4:56 PM, Niels Möller <[email protected]> wrote:
>> Attached is a patch that allows overwriting values (points and
>> scalars) in the ECC API.
> What's the use case? Just to clear sensitive memory, or do you do any
> operations on these values after zeroize?
> In the former case, maybe it's better to just let the ecc_*_clear
> functions do that? Cost should be negligible, compared to doing any real
> ecc operation.
I've checked it a bit further. Would the following on top of nettle be
equivalent?
void ecc_point_zeroize (struct ecc_point *p)
{
memset(p->p, 0, 2*ecc_size(p->ecc)*sizeof(mp_limb_t));
/* or using ecc_size_a() be better here? */
}
void ecc_scalar_zeroize (struct ecc_scalar *s);
{
memset(s->p, 0, ecc_size(s->ecc)*sizeof(mp_limb_t));
}
Then the only change needed in nettle would be for those sizes to be documented.
regards,
Nikos
_______________________________________________
nettle-bugs mailing list
[email protected]
http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
