From 35dc6f834c9dc888391c7b700130d0831a907ca1 Mon Sep 17 00:00:00 2001 From: Johan Hedberg Date: Thu, 13 Nov 2014 10:55:18 +0200 Subject: Bluetooth: Add key preference parameter to smp_sufficient_security So far smp_sufficient_security() has returned false if we're encrypted with an STK but do have an LTK available. However, for the sake of LE CoC servers we do want to let the incoming connection through even though we're only encrypted with the STK. This patch adds a key preference parameter to smp_sufficient_security() with two possible values (enum used instead of bool for readability). Signed-off-by: Johan Hedberg Signed-off-by: Marcel Holtmann --- net/bluetooth/smp.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'net/bluetooth/smp.c') diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 3b63c7f09dd5..3dc5f0e66405 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -1122,18 +1122,20 @@ static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) return true; } -bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level) +bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, + enum smp_key_pref key_pref) { if (sec_level == BT_SECURITY_LOW) return true; - /* If we're encrypted with an STK always claim insufficient - * security. This way we allow the connection to be re-encrypted - * with an LTK, even if the LTK provides the same level of - * security. Only exception is if we don't have an LTK (e.g. - * because of key distribution bits). + /* If we're encrypted with an STK but the caller prefers using + * LTK claim insufficient security. This way we allow the + * connection to be re-encrypted with an LTK, even if the LTK + * provides the same level of security. Only exception is if we + * don't have an LTK (e.g. because of key distribution bits). */ - if (test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && + if (key_pref == SMP_USE_LTK && + test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) return false; @@ -1167,7 +1169,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) else sec_level = authreq_to_seclevel(auth); - if (smp_sufficient_security(hcon, sec_level)) + if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) return 0; if (sec_level > hcon->pending_sec_level) @@ -1217,7 +1219,7 @@ int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) return 1; - if (smp_sufficient_security(hcon, sec_level)) + if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) return 1; if (sec_level > hcon->pending_sec_level) -- cgit v1.2.3