On Fri, Dec 04, 2020 at 10:43:34AM -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 for both keyslot and segment slot keys.
> 
> Signed-off-by: Glenn Washburn <development@efficientek.com>

Personally, I'd have named them `json_slot_idx`. But you've already done
so much work on improving the code that I don't want this to be the
reason to not give an SOB, especially considering that it's a strict
improvement anyway. So:

Signed-off-by: Patrick Steinhardt <ps@pks.im>

> ---
>  grub-core/disk/luks2.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/grub-core/disk/luks2.c b/grub-core/disk/luks2.c
> index eadd529e9..437c1da07 100644
> --- a/grub-core/disk/luks2.c
> +++ b/grub-core/disk/luks2.c
> @@ -65,6 +65,8 @@ typedef struct grub_luks2_header grub_luks2_header_t;
>  
>  struct grub_luks2_keyslot
>  {
> +  /* The integer key to the associative array of keyslots */
> +  grub_uint64_t json_slot_key;
>    grub_int64_t key_size;
>    grub_int64_t priority;
>    struct
> @@ -103,6 +105,7 @@ typedef struct grub_luks2_keyslot grub_luks2_keyslot_t;
>  
>  struct grub_luks2_segment
>  {
> +  grub_uint64_t json_slot_key;
>    grub_uint64_t offset;
>    const char	*size;
>    const char	*encryption;
> @@ -112,6 +115,7 @@ typedef struct grub_luks2_segment grub_luks2_segment_t;
>  
>  struct grub_luks2_digest
>  {
> +  grub_uint64_t json_slot_key;
>    /* Both keyslots and segments are interpreted as bitfields here */
>    grub_uint64_t	keyslots;
>    grub_uint64_t	segments;
> @@ -261,12 +265,11 @@ 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->json_slot_key, &keyslot, NULL) ||
>        grub_json_getchild (&keyslot, &keyslot, 0) ||
>        luks2_parse_keyslot (k, &keyslot))
>      return grub_error (GRUB_ERR_BAD_ARGUMENT, "Could not parse keyslot %"PRIuGRUB_SIZE, keyslot_idx);
> @@ -278,11 +281,12 @@ luks2_get_keyslot (grub_luks2_keyslot_t *k, grub_luks2_digest_t *d, grub_luks2_s
>    for (i = 0; i < size; i++)
>      {
>        if (grub_json_getchild (&digest, &digests, i) ||
> +	  grub_json_getuint64 (&d->json_slot_key, &digest, NULL) ||
>            grub_json_getchild (&digest, &digest, 0) ||
>            luks2_parse_digest (d, &digest))
>  	return grub_error (GRUB_ERR_BAD_ARGUMENT, "Could not parse digest %"PRIuGRUB_SIZE, i);
>  
> -      if ((d->keyslots & (1 << idx)))
> +      if ((d->keyslots & (1 << k->json_slot_key)))
>  	break;
>      }
>    if (i == size)
> @@ -295,12 +299,12 @@ luks2_get_keyslot (grub_luks2_keyslot_t *k, grub_luks2_digest_t *d, grub_luks2_s
>    for (i = 0; i < size; i++)
>      {
>        if (grub_json_getchild (&segment, &segments, i) ||
> -	  grub_json_getuint64 (&idx, &segment, NULL) ||
> +	  grub_json_getuint64 (&s->json_slot_key, &segment, NULL) ||
>  	  grub_json_getchild (&segment, &segment, 0) ||
>            luks2_parse_segment (s, &segment))
>  	return grub_error (GRUB_ERR_BAD_ARGUMENT, "Could not parse segment %"PRIuGRUB_SIZE, i);
>  
> -      if ((d->segments & (1 << idx)))
> +      if ((d->segments & (1 << s->json_slot_key)))
>  	break;
>      }
>    if (i == size)
> -- 
> 2.27.0
>