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.
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..21b19faf88f1 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 mode has been enabled,
+ * 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 mode has been enabled,
+ * 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,
--
2.1.0
--
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