Hi Marcel,
On Tuesday 27 of January 2015 11:21:52 Marcel Holtmann wrote:
> When using Secure Connection Only mode, the P-192 hash and rand values
> for BR/EDR and the TK value for LE are not valid. The Secure Connections
> Only mode limits the encryption keys to P-256 derived values for both
> transports. To avoid accidentally loading weak values for pairing just
> restrict it to P-256 values.
If so, shouldn't enabling Secure Connection Only mode result in clearing OOB
data (or at least removing legacy ones)?
>
> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> ---
> net/bluetooth/mgmt.c | 30 ++++++++++++++++++++++++++----
> 1 file changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 8417ab387d1a..5c7340b1cd66 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -3660,6 +3660,21 @@ static int add_remote_oob_data(struct sock *sk,
> struct hci_dev *hdev, goto unlock;
> }
>
> + /* In case Secure Connections Only made has been enabled,
typo: made -> mode
> + * do not allow providing P-192 hash and rand values.
> + *
> + * This actually means that in Secure Connections Only
> + * mode this command with the legacy parameter list
> + * is not supported at all.
> + */
> + if (test_bit(HCI_SC_ONLY, &hdev->dev_flags)) {
> + err = cmd_complete(sk, hdev->id,
> + MGMT_OP_ADD_REMOTE_OOB_DATA,
> + MGMT_STATUS_INVALID_PARAMS,
> + addr, sizeof(*addr));
> + goto unlock;
> + }
> +
> err = hci_add_remote_oob_data(hdev, &cp->addr.bdaddr,
> cp->addr.type, cp->hash,
> cp->rand, NULL, NULL);
> @@ -3675,10 +3690,17 @@ static int add_remote_oob_data(struct sock *sk,
> struct hci_dev *hdev, u8 *rand192, *hash192;
> u8 status;
>
> - if (bdaddr_type_is_le(cp->addr.type)) {
> - /* Enforce zero-valued 192-bit parameters as
> - * long as legacy SMP OOB isn't implemented.
> - */
> + /* For Bluetooth LE, currently only P-256 hash and rand
> + * values are allowed. The P-192 hash and rand values
> + * are required to be zero. This is required since Legacy
> + * Pairing for LE with OOB is not implemented yet.
> + *
> + * In case Secure Connections Only made has been enabled,
same typo
> + * do not allow providing P-192 hash and rand values. It
> + * is required that the values are zero here as well.
> + */
> + if (bdaddr_type_is_le(cp->addr.type) ||
> + test_bit(HCI_SC_ONLY, &hdev->dev_flags)) {
> if (memcmp(cp->rand192, ZERO_KEY, 16) ||
> memcmp(cp->hash192, ZERO_KEY, 16)) {
> err = cmd_complete(sk, hdev->id,
--
BR
Szymon Janc
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