Re: [PATCH v6 01/12] luks2: Add slot_key member to struct grub_luks2_keyslot/segment/digest

[Daniel Kiper]

On Thu, Dec 03, 2020 at 01:23:17AM -0600, Glenn Washburn wrote:
> On Wed, 2 Dec 2020 18:01:47 +0100
> Daniel Kiper <dkiper@net-space.pl> wrote:
>
> > On Fri, Nov 27, 2020 at 03:03:33AM -0600, Glenn Washburn wrote:
> > > This allows code using these structs to know the named key
> > > associated with these json data structures. In the future we can
> > > use these to provide better error messages to the user.
> > >
> > > Get rid of idx variable in luks2_get_keyslot which was overloaded
> > > to be used
> >
> > I prefer if you add "()" to the function names, i.e.
> > luks2_get_keyslot(), in the comments and commit messages. This way it
> > is easier to understand what you mean.
>
> Ok.
>
> > > for both keyslot and segment slot keys.
> > >
> > > Signed-off-by: Glenn Washburn <development@efficientek.com>
> > > ---
> > >  grub-core/disk/luks2.c | 13 ++++++++-----
> > >  1 file changed, 8 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
> > > index d96764a02..ab2c31dcd 100644
> > > --- a/grub-core/disk/luks2.c
> > > +++ b/grub-core/disk/luks2.c
> > > @@ -65,6 +65,7 @@ typedef struct grub_luks2_header
> > > grub_luks2_header_t;
> > >
> > >  struct grub_luks2_keyslot
> > >  {
> > > +  grub_uint64_t slot_key;
> >
> > Could you be more consistent and use keyslot instead of slot_key here?
>
> I intentionally chose not to use keyslot because I thought it was
> confusing.  slot_key is not a keyslot in the sense of a slot for a
> cryptographic key or key material as in the usage keyslot in the struct
> named "grub_luks2_keyslot".  Its the key value of a "slot" in a json
> associative array which is modeling a sparse array.  Perhaps just "key"
> might be more to your liking?

IMO "key" is more confusing in this context and it would require at
least a comment to clarify what it means. Is not json_slot_key better
then? Probably with some comment what is it too...

> > >    grub_int64_t key_size;
> > >    grub_int64_t priority;
> > >    struct
> > > @@ -103,6 +104,7 @@ typedef struct grub_luks2_keyslot
> > > grub_luks2_keyslot_t;
> > >
> > >  struct grub_luks2_segment
> > >  {
> > > +  grub_uint64_t slot_key;
> >
> > Ditto. The code below uses keyslot instead...
> >
> > >    grub_uint64_t offset;
> > >    const char     *size;
> > >    const char     *encryption;
> > > @@ -112,6 +114,7 @@ typedef struct grub_luks2_segment
> > > grub_luks2_segment_t;
> > >
> > >  struct grub_luks2_digest
> > >  {
> > > +  grub_uint64_t slot_key;
> > >    /* Both keyslots and segments are interpreted as bitfields here
> > > */ grub_uint64_t  keyslots;
> > >    grub_uint64_t  segments;
> > > @@ -259,12 +262,11 @@ luks2_get_keyslot (grub_luks2_keyslot_t *k,
> > > grub_luks2_digest_t *d, grub_luks2_s {
> > >    grub_json_t keyslots, keyslot, digests, digest, segments,
> > > segment; grub_size_t i, size;
> > > -  grub_uint64_t idx;
> > >
> > >    /* Get nth keyslot */
> > >    if (grub_json_getvalue (&keyslots, root, "keyslots") ||
> > >        grub_json_getchild (&keyslot, &keyslots, keyslot_idx) ||
> > > -      grub_json_getuint64 (&idx, &keyslot, NULL) ||
> > > +      grub_json_getuint64 (&k->slot_key, &keyslot, NULL) ||

Should not keyslot be renamed to json_slot_key too?

Daniel