Re: [Bluez PATCH 1/3] adapter: Use PeripheralLongTermKey to store LTK

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

Hi Archie,

On Sun, Oct 31, 2021 at 11:06 PM Archie Pusaka <apusaka@google.com> wrote:
>
> From: Archie Pusaka <apusaka@chromium.org>
>
> Introducing PeripheralLongTermKey group for storing LTK info to
> replace the less inclusive term. Currently we still need to write/read
> from both to ensure smooth transition, but later we should deprecate
> the old term.
>
> Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
> ---
>
>  src/adapter.c | 41 ++++++++++++++++++++++++++++++++---------
>  1 file changed, 32 insertions(+), 9 deletions(-)
>
> diff --git a/src/adapter.c b/src/adapter.c
> index d0d38621b8..6b12c9e793 100644
> --- a/src/adapter.c
> +++ b/src/adapter.c
> @@ -3868,7 +3868,11 @@ static struct smp_ltk_info *get_peripheral_ltk_info(GKeyFile *key_file,
>
>         DBG("%s", peer);
>
> -       ltk = get_ltk(key_file, peer, bdaddr_type, "SlaveLongTermKey");
> +       /* Read from both entries. Later we should deprecate Slave. */
> +       ltk = get_ltk(key_file, peer, bdaddr_type, "PeripheralLongTermKey");
> +       if (!ltk)
> +               ltk = get_ltk(key_file, peer, bdaddr_type, "SlaveLongTermKey");

If you find the old name being used you better replace it with the new
one and erase the old.

>         if (ltk)
>                 ltk->central = false;
>
> @@ -8415,13 +8419,12 @@ static void new_link_key_callback(uint16_t index, uint16_t length,
>         bonding_complete(adapter, &addr->bdaddr, addr->type, 0);
>  }
>
> -static void store_longtermkey(struct btd_adapter *adapter, const bdaddr_t *peer,
> +static void store_ltk_group(struct btd_adapter *adapter, const bdaddr_t *peer,
>                                 uint8_t bdaddr_type, const unsigned char *key,
> -                               uint8_t central, uint8_t authenticated,
> +                               const char *group, uint8_t authenticated,
>                                 uint8_t enc_size, uint16_t ediv,
>                                 uint64_t rand)
>  {
> -       const char *group = central ? "LongTermKey" : "SlaveLongTermKey";
>         char device_addr[18];
>         char filename[PATH_MAX];
>         GKeyFile *key_file;
> @@ -8431,11 +8434,6 @@ static void store_longtermkey(struct btd_adapter *adapter, const bdaddr_t *peer,
>         char *str;
>         int i;
>
> -       if (central != 0x00 && central != 0x01) {
> -               error("Unsupported LTK type %u", central);
> -               return;
> -       }
> -
>         ba2str(peer, device_addr);
>
>         snprintf(filename, PATH_MAX, STORAGEDIR "/%s/%s/info",
> @@ -8475,6 +8473,31 @@ static void store_longtermkey(struct btd_adapter *adapter, const bdaddr_t *peer,
>         g_key_file_free(key_file);
>  }
>
> +static void store_longtermkey(struct btd_adapter *adapter, const bdaddr_t *peer,
> +                               uint8_t bdaddr_type, const unsigned char *key,
> +                               uint8_t central, uint8_t authenticated,
> +                               uint8_t enc_size, uint16_t ediv,
> +                               uint64_t rand)
> +{
> +       if (central != 0x00 && central != 0x01) {
> +               error("Unsupported LTK type %u", central);
> +               return;
> +       }
> +
> +       if (central) {
> +               store_ltk_group(adapter, peer, bdaddr_type, key, "LongTermKey",
> +                               authenticated, enc_size, ediv, rand);
> +       } else {
> +               /* Store duplicates for now. Later we should deprecate Slave. */
> +               store_ltk_group(adapter, peer, bdaddr_type, key,
> +                               "PeripheralLongTermKey", authenticated,
> +                               enc_size, ediv, rand);
> +               store_ltk_group(adapter, peer, bdaddr_type, key,
> +                               "SlaveLongTermKey", authenticated,
> +                               enc_size, ediv, rand);

In not following why you want to keep duplicate entries?

> +       }
> +}
> +
>  static void new_long_term_key_callback(uint16_t index, uint16_t length,
>                                         const void *param, void *user_data)
>  {
> --
> 2.33.1.1089.g2158813163f-goog
>


-- 
Luiz Augusto von Dentz