Keep the link key type together with connection and use it to
map security level to link key requirements. Authenticate and/or
encrypt connection if the link is insufficiently secure.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@xxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_conn.c | 61 +++++++++++++++++++++++++++++++------
net/bluetooth/hci_event.c | 4 ++
3 files changed, 56 insertions(+), 10 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 69967e5..2da2eb9 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -226,6 +226,7 @@ struct hci_conn {
__u16 pkt_type;
__u16 link_policy;
__u32 link_mode;
+ __u8 key_type;
__u8 auth_type;
__u8 sec_level;
__u8 pending_sec_level;
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 7a6f56b..74cd755 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -287,6 +287,7 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
conn->auth_type = HCI_AT_GENERAL_BONDING;
conn->io_capability = hdev->io_capability;
conn->remote_auth = 0xff;
+ conn->key_type = 0xff;
conn->power_save = 1;
conn->disc_timeout = HCI_DISCONN_TIMEOUT;
@@ -535,32 +536,72 @@ static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
return 0;
}
+/* Encrypt the the link */
+static void hci_conn_encrypt(struct hci_conn *conn)
+{
+ BT_DBG("conn %p", conn);
+
+ if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend)) {
+ struct hci_cp_set_conn_encrypt cp;
+ cp.handle = cpu_to_le16(conn->handle);
+ cp.encrypt = 0x01;
+ hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
+ &cp);
+ }
+}
+
/* Enable security */
int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
{
BT_DBG("conn %p", conn);
+ /* For sdp we don't need the link key. */
if (sec_level == BT_SECURITY_SDP)
return 1;
+ /* For non 2.1 devices and low security level we don't need the link
+ key. */
if (sec_level == BT_SECURITY_LOW &&
(!conn->ssp_mode || !conn->hdev->ssp_mode))
return 1;
- if (conn->link_mode & HCI_LM_ENCRYPT)
- return hci_conn_auth(conn, sec_level, auth_type);
-
+ /* For other security levels we need the link key. */
+ if (!(conn->link_mode & HCI_LM_AUTH))
+ goto auth;
+
+ /* An authenticated combination key has sufficient security for any
+ security level. */
+ if (conn->key_type == HCI_LK_AUTH_COMBINATION)
+ goto encrypt;
+
+ /* An unauthenticated combination key has sufficient security for
+ security level 1 and 2. */
+ if (conn->key_type == HCI_LK_UNAUTH_COMBINATION &&
+ (sec_level == BT_SECURITY_MEDIUM ||
+ sec_level == BT_SECURITY_LOW))
+ goto encrypt;
+
+ /* A combination key has always sufficient security for the security
+ levels 1 or 2. High security level requires the combination key
+ is generated using maximum PIN code length (16).
+ For pre 2.1 units. */
+ if (conn->key_type == HCI_LK_COMBINATION &&
+ (sec_level != BT_SECURITY_HIGH ||
+ conn->pin_length == 16))
+ goto encrypt;
+
+auth:
if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend))
return 0;
- if (hci_conn_auth(conn, sec_level, auth_type)) {
- struct hci_cp_set_conn_encrypt cp;
- cp.handle = cpu_to_le16(conn->handle);
- cp.encrypt = 1;
- hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT,
- sizeof(cp), &cp);
- }
+ hci_conn_auth(conn, sec_level, auth_type);
+ return 0;
+
+encrypt:
+ if (conn->link_mode & HCI_LM_ENCRYPT)
+ return 1;
+ hci_conn_encrypt(conn);
return 0;
}
EXPORT_SYMBOL(hci_conn_security);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 35f9898..655af8b 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2095,6 +2095,10 @@ static inline void hci_link_key_notify_evt(struct hci_dev *hdev, struct sk_buff
hci_conn_hold(conn);
conn->disc_timeout = HCI_DISCONN_TIMEOUT;
pin_len = conn->pin_length;
+
+ if (ev->key_type != HCI_LK_CHANGED_COMBINATION)
+ conn->key_type = ev->key_type;
+
hci_conn_put(conn);
}
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
