From 13d39315c22b128f4796fc008b04914a7c32bb1a Mon Sep 17 00:00:00 2001 From: Waldemar Rymarkiewicz Date: Thu, 28 Apr 2011 12:07:55 +0200 Subject: [PATCH] Bluetooth: Map sec_level to link key requirements 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 Signed-off-by: Gustavo F. Padovan --- 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 69967e540c9..2da2eb9f53a 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 7a6f56b2f49..74cd755b38a 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 35f98980070..655af8bc60e 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); } -- 2.39.5