Re: [PATCH v5 2/4] dpp: add DPP authentication protocol

[James Prestwood <prestwoj at gmail.com>]

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On Fri, 2021-12-17 at 14:19 -0600, Denis Kenzior wrote:
> Hi James,
> 
> On 12/17/21 13:14, James Prestwood wrote:
> > This implements the DPP protocol used to authenticate to a
> > DPP configurator.
> > 
> > Note this is not a full implementation of the protocol and
> > there are a few missing features which will be added as
> > needed:
> > 
> >   - Mutual authentication (needed for BLE bootstrapping)
> >   - Configurator support
> >   - Initiator role
> > ---
> >   src/dpp.c | 491
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 491 insertions(+)
> > 
> > v5:
> >   * Updated use of wrap/unwrap APIs.
> >   * Better commented how AAD is used with wrapping/unwrapping
> > 
> 
> <snip>
> 
> > +static void dpp_free_auth_data(struct dpp_sm *dpp)
> > +{
> > +       if (dpp->proto_public) {
> > +               l_ecc_point_free(dpp->proto_public);
> > +               dpp->proto_public = NULL;
> > +       }
> > +
> > +       if (dpp->proto_private) {
> > +               l_ecc_scalar_free(dpp->proto_private);
> > +               dpp->proto_private = NULL;
> > +       }
> > +
> > +       if (dpp->i_proto_public) {
> > +               l_ecc_point_free(dpp->i_proto_public);
> > +               dpp->i_proto_public = NULL;
> > +       }
> 
> Should we be paranoid and explicit_bzero the nonces and keys?

Yes, for keys/nonces we can do this. I'm thinking we should also add
explicit_bzero to the l_ecc_point_free, as well as for scalars.

> 
> Applied, thanks.
> 
> Regards,
> -Denis