Hi Szymon,
>> 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)?
most likely it should. However that can be a separate patch.
I think actually any change to SSP or SC setting should cause the remote OOB information to be flushed.
>>
>> 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
Johan can make that change before applying the patch. However good catch.
>
>> + * 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
Same here, Johan, please fix this before applying.
>> + * 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,
Regards
Marcel
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