Hi Luiz,
ti 9. maalisk. 2021 klo 20.42 Luiz Augusto von Dentz
(luiz.dentz@xxxxxxxxx) kirjoitti:
>
> From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
>
> This fails the pairing procedure when both remote and local non-debug
> public keys are identical.
Would you mind elaborating why we need to disallow identical public keys?
Do you have some specific attack scenario in your mind?
>
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> ---
> net/bluetooth/smp.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
> index b0c1ee110eff..9e7e3655e4ec 100644
> --- a/net/bluetooth/smp.c
> +++ b/net/bluetooth/smp.c
> @@ -2732,6 +2732,15 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb)
> if (skb->len < sizeof(*key))
> return SMP_INVALID_PARAMS;
>
> + /* Check if remote and local public keys are the same and debug key is
> + * not in use.
> + */
> + if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) &&
> + !memcmp(key, smp->local_pk, 64)) {
> + BT_ERR("Remote and local public keys are identical");
> + return SMP_UNSPECIFIED;
> + }
> +
> memcpy(smp->remote_pk, key, 64);
>
> if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
> --
> 2.29.2
>
Best regards,
Matias Karhumaa
