[PATCH v2] Bluetooth: Double check sec req for pre 2.1 device

[PATCH v2] Bluetooth: Double check sec req for pre 2.1 device

[Waldemar Rymarkiewicz]

In case of pre v2.1 devices authentication request will return
success immediately if the link key already exists without any
authentication process.

That means, it's not possible to re-authenticate the link if you
already have combination key and for instance want to re-authenticate
to get the high security (use 16 digit pin).

Therefore, it's necessary to check security requirements on auth
complete event to prevent not enough secure connection.

Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
---
 include/net/bluetooth/hci_core.h |    1 +
 net/bluetooth/hci_conn.c         |   17 +++++++++++++++++
 net/bluetooth/rfcomm/core.c      |    2 +-
 3 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 14cc324..6c994c0 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -422,6 +422,7 @@ void hci_conn_check_pending(struct hci_dev *hdev);
 
 struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 sec_level, __u8 auth_type);
 int hci_conn_check_link_mode(struct hci_conn *conn);
+int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level);
 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type);
 int hci_conn_change_link_key(struct hci_conn *conn);
 int hci_conn_switch_role(struct hci_conn *conn, __u8 role);
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 7f5ad8a..3163330 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -623,6 +623,23 @@ encrypt:
 }
 EXPORT_SYMBOL(hci_conn_security);
 
+/* Check secure link requirement */
+int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
+{
+	BT_DBG("conn %p", conn);
+
+	if (sec_level != BT_SECURITY_HIGH)
+		return 1; /* Accept if non-secure is required */
+
+	if (conn->key_type == HCI_LK_AUTH_COMBINATION ||
+			(conn->key_type == HCI_LK_COMBINATION &&
+			conn->pin_length == 16))
+		return 1;
+
+	return 0; /* Reject not secure link */
+}
+EXPORT_SYMBOL(hci_conn_check_secure);
+
 /* Change link key */
 int hci_conn_change_link_key(struct hci_conn *conn)
 {
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 121a5c1..5759bb7 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -2096,7 +2096,7 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 		if (!test_and_clear_bit(RFCOMM_AUTH_PENDING, &d->flags))
 			continue;
 
-		if (!status)
+		if (!status && hci_conn_check_secure(conn, d->sec_level))
 			set_bit(RFCOMM_AUTH_ACCEPT, &d->flags);
 		else
 			set_bit(RFCOMM_AUTH_REJECT, &d->flags);
-- 
1.7.1

Re: [PATCH v2] Bluetooth: Double check sec req for pre 2.1 device

[Gustavo F. Padovan]

Hi Waldemar,

* Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com> [2011-05-06 09:42:31 +0200]:

> In case of pre v2.1 devices authentication request will return
> success immediately if the link key already exists without any
> authentication process.
> 
> That means, it's not possible to re-authenticate the link if you
> already have combination key and for instance want to re-authenticate
> to get the high security (use 16 digit pin).
> 
> Therefore, it's necessary to check security requirements on auth
> complete event to prevent not enough secure connection.
> 
> Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
> ---
>  include/net/bluetooth/hci_core.h |    1 +
>  net/bluetooth/hci_conn.c         |   17 +++++++++++++++++
>  net/bluetooth/rfcomm/core.c      |    2 +-
>  3 files changed, 19 insertions(+), 1 deletions(-)

Patch has been applied. Thanks.

-- 
Gustavo F. Padovan
http://profusion.mobi