From 5378bc5622a9c221cb472ce86a5024290d6353c2 Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Thu, 29 May 2014 14:00:39 +0300 Subject: [PATCH] Bluetooth: Update LTK lookup to correctly deal with SC LTKs LTKs derived from Secure Connections based pairing are symmetric, i.e. they should match both master and slave role. This patch updates the LTK lookup functions to ignore the desired role when dealing with SC LTKs. Furthermore, with Secure Connections the EDiv and Rand values are not used and should always be set to zero. This patch updates the LTK lookup to first use the bdaddr as key and then do the necessary verifications of EDiv and Rand based on whether the found LTK is for SC or not. Signed-off-by: Johan Hedberg Signed-off-by: Marcel Holtmann --- net/bluetooth/hci_core.c | 30 +++++++++++++++++++++++------- net/bluetooth/hci_event.c | 15 +++++++++++++-- 2 files changed, 36 insertions(+), 9 deletions(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 2586e405adb3..e091e8ffeb8e 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3195,11 +3195,18 @@ struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, __le64 rand, if (k->ediv != ediv || k->rand != rand) continue; - if (ltk_role(k->type) != role) - continue; + if (smp_ltk_is_sc(k)) { + if (k->type == SMP_LTK_P256_DEBUG && + !test_bit(HCI_KEEP_DEBUG_KEYS, &hdev->dev_flags)) + continue; + rcu_read_unlock(); + return k; + } - rcu_read_unlock(); - return k; + if (ltk_role(k->type) == role) { + rcu_read_unlock(); + return k; + } } rcu_read_unlock(); @@ -3213,9 +3220,18 @@ struct smp_ltk *hci_find_ltk_by_addr(struct hci_dev *hdev, bdaddr_t *bdaddr, rcu_read_lock(); list_for_each_entry_rcu(k, &hdev->long_term_keys, list) { - if (addr_type == k->bdaddr_type && - bacmp(bdaddr, &k->bdaddr) == 0 && - ltk_role(k->type) == role) { + if (addr_type != k->bdaddr_type || bacmp(bdaddr, &k->bdaddr)) + continue; + + if (smp_ltk_is_sc(k)) { + if (k->type == SMP_LTK_P256_DEBUG && + !test_bit(HCI_KEEP_DEBUG_KEYS, &hdev->dev_flags)) + continue; + rcu_read_unlock(); + return k; + } + + if (ltk_role(k->type) == role) { rcu_read_unlock(); return k; } diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index f980fc46ea5e..0058b545c5ed 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4590,10 +4590,21 @@ static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb) if (conn == NULL) goto not_found; - ltk = hci_find_ltk(hdev, ev->ediv, ev->rand, conn->role); - if (ltk == NULL) + ltk = hci_find_ltk_by_addr(hdev, &conn->dst, conn->dst_type, + conn->role); + if (!ltk) goto not_found; + if (smp_ltk_is_sc(ltk)) { + /* With SC both EDiv and Rand are set to zero */ + if (ev->ediv || ev->rand) + goto not_found; + } else { + /* For non-SC keys check that EDiv and Rand match */ + if (ev->ediv != ltk->ediv || ev->rand != ltk->rand) + goto not_found; + } + memcpy(cp.ltk, ltk->val, sizeof(ltk->val)); cp.handle = cpu_to_le16(conn->handle); -- 2.34.1