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authorMarcel Holtmann <marcel@holtmann.org>2009-01-15 21:58:04 +0100
committerMarcel Holtmann <marcel@holtmann.org>2009-02-27 06:14:25 +0100
commit8c1b235594fbab9a13240a1dac12ea9fd99b6440 (patch)
treeeb137a23e0fd8199144a4c3e36902af411e44269 /net/bluetooth
parentc89b6e6bda4c8021195778f47567d0cc9dbfe7ec (diff)
Bluetooth: Add enhanced security model for Simple Pairing
The current security model is based around the flags AUTH, ENCRYPT and SECURE. Starting with support for the Bluetooth 2.1 specification this is no longer sufficient. The different security levels are now defined as SDP, LOW, MEDIUM and SECURE. Previously it was possible to set each security independently, but this actually doesn't make a lot of sense. For Bluetooth the encryption depends on a previous successful authentication. Also you can only update your existing link key if you successfully created at least one before. And of course the update of link keys without having proper encryption in place is a security issue. The new security levels from the Bluetooth 2.1 specification are now used internally. All old settings are mapped to the new values and this way it ensures that old applications still work. The only limitation is that it is no longer possible to set authentication without also enabling encryption. No application should have done this anyway since this is actually a security issue. Without encryption the integrity of the authentication can't be guaranteed. As default for a new L2CAP or RFCOMM connection, the LOW security level is used. The only exception here are the service discovery sessions on PSM 1 where SDP level is used. To have similar security strength as with a Bluetooth 2.0 and before combination key, the MEDIUM level should be used. This is according to the Bluetooth specification. The MEDIUM level will not require any kind of man-in-the-middle (MITM) protection. Only the HIGH security level will require this. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/hci_conn.c45
-rw-r--r--net/bluetooth/hci_event.c3
-rw-r--r--net/bluetooth/l2cap.c134
-rw-r--r--net/bluetooth/rfcomm/core.c81
-rw-r--r--net/bluetooth/sco.c2
5 files changed, 97 insertions, 168 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index a4a789f24c8d..98f97a1e9bbb 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -325,7 +325,7 @@ EXPORT_SYMBOL(hci_get_route);
/* Create SCO or ACL connection.
* Device _must_ be locked */
-struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 auth_type)
+struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 sec_level, __u8 auth_type)
{
struct hci_conn *acl;
struct hci_conn *sco;
@@ -340,6 +340,7 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
hci_conn_hold(acl);
if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
+ acl->sec_level = sec_level;
acl->auth_type = auth_type;
hci_acl_connect(acl);
}
@@ -385,16 +386,17 @@ int hci_conn_check_link_mode(struct hci_conn *conn)
EXPORT_SYMBOL(hci_conn_check_link_mode);
/* Authenticate remote device */
-int hci_conn_auth(struct hci_conn *conn)
+static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level)
{
BT_DBG("conn %p", conn);
- if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0) {
- if (!(conn->auth_type & 0x01)) {
- conn->auth_type |= 0x01;
- conn->link_mode &= ~HCI_LM_AUTH;
- }
- }
+ if (sec_level > conn->sec_level)
+ conn->link_mode &= ~HCI_LM_AUTH;
+
+ conn->sec_level = sec_level;
+
+ if (sec_level == BT_SECURITY_HIGH)
+ conn->auth_type |= 0x01;
if (conn->link_mode & HCI_LM_AUTH)
return 1;
@@ -405,31 +407,42 @@ int hci_conn_auth(struct hci_conn *conn)
hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
sizeof(cp), &cp);
}
+
return 0;
}
-EXPORT_SYMBOL(hci_conn_auth);
-/* Enable encryption */
-int hci_conn_encrypt(struct hci_conn *conn)
+/* Enable security */
+int hci_conn_security(struct hci_conn *conn, __u8 sec_level)
{
BT_DBG("conn %p", conn);
+ if (sec_level == BT_SECURITY_SDP)
+ return 1;
+
+ if (sec_level == BT_SECURITY_LOW) {
+ if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0)
+ return hci_conn_auth(conn, sec_level);
+ else
+ return 1;
+ }
+
if (conn->link_mode & HCI_LM_ENCRYPT)
- return hci_conn_auth(conn);
+ return hci_conn_auth(conn, sec_level);
if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend))
return 0;
- if (hci_conn_auth(conn)) {
+ if (hci_conn_auth(conn, sec_level)) {
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);
}
+
return 0;
}
-EXPORT_SYMBOL(hci_conn_encrypt);
+EXPORT_SYMBOL(hci_conn_security);
/* Change link key */
int hci_conn_change_link_key(struct hci_conn *conn)
@@ -442,12 +455,13 @@ int hci_conn_change_link_key(struct hci_conn *conn)
hci_send_cmd(conn->hdev, HCI_OP_CHANGE_CONN_LINK_KEY,
sizeof(cp), &cp);
}
+
return 0;
}
EXPORT_SYMBOL(hci_conn_change_link_key);
/* Switch role */
-int hci_conn_switch_role(struct hci_conn *conn, uint8_t role)
+int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
{
BT_DBG("conn %p", conn);
@@ -460,6 +474,7 @@ int hci_conn_switch_role(struct hci_conn *conn, uint8_t role)
cp.role = role;
hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
}
+
return 0;
}
EXPORT_SYMBOL(hci_conn_switch_role);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index beea9dbb6562..014fc8b320ba 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1601,7 +1601,8 @@ static inline void hci_remote_ext_features_evt(struct hci_dev *hdev, struct sk_b
if (conn->state == BT_CONFIG) {
if (!ev->status && hdev->ssp_mode > 0 &&
- conn->ssp_mode > 0 && conn->out) {
+ conn->ssp_mode > 0 && conn->out &&
+ conn->sec_level != BT_SECURITY_SDP) {
struct hci_cp_auth_requested cp;
cp.handle = ev->handle;
hci_send_cmd(hdev, HCI_OP_AUTH_REQUESTED,
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 123efb46d3f5..eadf09231866 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -263,12 +263,17 @@ static inline int l2cap_check_link_mode(struct sock *sk)
{
struct l2cap_conn *conn = l2cap_pi(sk)->conn;
- if ((l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT) ||
- (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE))
- return hci_conn_encrypt(conn->hcon);
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE)
+ return hci_conn_security(conn->hcon, BT_SECURITY_HIGH);
+
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT)
+ return hci_conn_security(conn->hcon, BT_SECURITY_MEDIUM);
if (l2cap_pi(sk)->link_mode & L2CAP_LM_AUTH)
- return hci_conn_auth(conn->hcon);
+ return hci_conn_security(conn->hcon, BT_SECURITY_LOW);
+
+ if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001))
+ return hci_conn_security(conn->hcon, BT_SECURITY_SDP);
return 1;
}
@@ -803,6 +808,7 @@ static int l2cap_do_connect(struct sock *sk)
struct l2cap_conn *conn;
struct hci_conn *hcon;
struct hci_dev *hdev;
+ __u8 sec_level;
__u8 auth_type;
int err = 0;
@@ -815,21 +821,37 @@ static int l2cap_do_connect(struct sock *sk)
err = -ENOMEM;
- if (l2cap_pi(sk)->link_mode & L2CAP_LM_AUTH ||
- l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT ||
- l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE) {
- if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001))
- auth_type = HCI_AT_NO_BONDING_MITM;
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE)
+ sec_level = BT_SECURITY_HIGH;
+ else if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001))
+ sec_level = BT_SECURITY_SDP;
+ else if (l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT)
+ sec_level = BT_SECURITY_MEDIUM;
+ else
+ sec_level = BT_SECURITY_LOW;
+
+ if (sk->sk_type == SOCK_RAW) {
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE)
+ auth_type = HCI_AT_DEDICATED_BONDING_MITM;
+ else if (l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT)
+ auth_type = HCI_AT_DEDICATED_BONDING;
else
- auth_type = HCI_AT_GENERAL_BONDING_MITM;
- } else {
- if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001))
auth_type = HCI_AT_NO_BONDING;
+ } else if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001)) {
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE)
+ auth_type = HCI_AT_NO_BONDING_MITM;
else
+ auth_type = HCI_AT_NO_BONDING;
+ } else {
+ if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE)
+ auth_type = HCI_AT_GENERAL_BONDING_MITM;
+ else if (l2cap_pi(sk)->link_mode & L2CAP_LM_ENCRYPT)
auth_type = HCI_AT_GENERAL_BONDING;
+ else
+ auth_type = HCI_AT_NO_BONDING;
}
- hcon = hci_connect(hdev, ACL_LINK, dst, auth_type);
+ hcon = hci_connect(hdev, ACL_LINK, dst, sec_level, auth_type);
if (!hcon)
goto done;
@@ -1402,11 +1424,6 @@ static void l2cap_chan_ready(struct sock *sk)
*/
parent->sk_data_ready(parent, 0);
}
-
- if (l2cap_pi(sk)->link_mode & L2CAP_LM_SECURE) {
- struct l2cap_conn *conn = l2cap_pi(sk)->conn;
- hci_conn_change_link_key(conn->hcon);
- }
}
/* Copy frame to all raw sockets on that connection */
@@ -2323,77 +2340,7 @@ static int l2cap_disconn_ind(struct hci_conn *hcon, u8 reason)
return 0;
}
-static int l2cap_auth_cfm(struct hci_conn *hcon, u8 status)
-{
- struct l2cap_chan_list *l;
- struct l2cap_conn *conn = hcon->l2cap_data;
- struct sock *sk;
-
- if (!conn)
- return 0;
-
- l = &conn->chan_list;
-
- BT_DBG("conn %p", conn);
-
- read_lock(&l->lock);
-
- for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
- struct l2cap_pinfo *pi = l2cap_pi(sk);
-
- bh_lock_sock(sk);
-
- if ((pi->link_mode & (L2CAP_LM_ENCRYPT | L2CAP_LM_SECURE)) &&
- !(hcon->link_mode & HCI_LM_ENCRYPT) &&
- !status) {
- bh_unlock_sock(sk);
- continue;
- }
-
- if (sk->sk_state == BT_CONNECT) {
- if (!status) {
- struct l2cap_conn_req req;
- req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
- req.psm = l2cap_pi(sk)->psm;
-
- l2cap_pi(sk)->ident = l2cap_get_ident(conn);
-
- l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
- L2CAP_CONN_REQ, sizeof(req), &req);
- } else {
- l2cap_sock_clear_timer(sk);
- l2cap_sock_set_timer(sk, HZ / 10);
- }
- } else if (sk->sk_state == BT_CONNECT2) {
- struct l2cap_conn_rsp rsp;
- __u16 result;
-
- if (!status) {
- sk->sk_state = BT_CONFIG;
- result = L2CAP_CR_SUCCESS;
- } else {
- sk->sk_state = BT_DISCONN;
- l2cap_sock_set_timer(sk, HZ / 10);
- result = L2CAP_CR_SEC_BLOCK;
- }
-
- rsp.scid = cpu_to_le16(l2cap_pi(sk)->dcid);
- rsp.dcid = cpu_to_le16(l2cap_pi(sk)->scid);
- rsp.result = cpu_to_le16(result);
- rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
- l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
- L2CAP_CONN_RSP, sizeof(rsp), &rsp);
- }
-
- bh_unlock_sock(sk);
- }
-
- read_unlock(&l->lock);
-
- return 0;
-}
-
-static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
+static int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
{
struct l2cap_chan_list *l;
struct l2cap_conn *conn = hcon->l2cap_data;
@@ -2413,10 +2360,10 @@ static int l2cap_encrypt_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
bh_lock_sock(sk);
- if ((pi->link_mode & (L2CAP_LM_ENCRYPT | L2CAP_LM_SECURE)) &&
+ if (!status && encrypt == 0x00 &&
+ (pi->link_mode & L2CAP_LM_SECURE) &&
(sk->sk_state == BT_CONNECTED ||
- sk->sk_state == BT_CONFIG) &&
- !status && encrypt == 0x00) {
+ sk->sk_state == BT_CONFIG)) {
__l2cap_sock_close(sk, ECONNREFUSED);
bh_unlock_sock(sk);
continue;
@@ -2608,8 +2555,7 @@ static struct hci_proto l2cap_hci_proto = {
.connect_ind = l2cap_connect_ind,
.connect_cfm = l2cap_connect_cfm,
.disconn_ind = l2cap_disconn_ind,
- .auth_cfm = l2cap_auth_cfm,
- .encrypt_cfm = l2cap_encrypt_cfm,
+ .security_cfm = l2cap_security_cfm,
.recv_acldata = l2cap_recv_acldata
};
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index edee49e00fbf..68f70c5270c6 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -226,16 +226,18 @@ static int rfcomm_l2sock_create(struct socket **sock)
static inline int rfcomm_check_link_mode(struct rfcomm_dlc *d)
{
struct sock *sk = d->session->sock->sk;
+ struct l2cap_conn *conn = l2cap_pi(sk)->conn;
- if (d->link_mode & (RFCOMM_LM_ENCRYPT | RFCOMM_LM_SECURE)) {
- if (!hci_conn_encrypt(l2cap_pi(sk)->conn->hcon))
- return 1;
- } else if (d->link_mode & RFCOMM_LM_AUTH) {
- if (!hci_conn_auth(l2cap_pi(sk)->conn->hcon))
- return 1;
- }
+ if (d->link_mode & RFCOMM_LM_SECURE)
+ return hci_conn_security(conn->hcon, BT_SECURITY_HIGH);
- return 0;
+ if (d->link_mode & RFCOMM_LM_ENCRYPT)
+ return hci_conn_security(conn->hcon, BT_SECURITY_MEDIUM);
+
+ if (d->link_mode & RFCOMM_LM_AUTH)
+ return hci_conn_security(conn->hcon, BT_SECURITY_LOW);
+
+ return 1;
}
/* ---- RFCOMM DLCs ---- */
@@ -389,9 +391,9 @@ static int __rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst,
if (s->state == BT_CONNECTED) {
if (rfcomm_check_link_mode(d))
- set_bit(RFCOMM_AUTH_PENDING, &d->flags);
- else
rfcomm_send_pn(s, 1, d);
+ else
+ set_bit(RFCOMM_AUTH_PENDING, &d->flags);
}
rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT);
@@ -1199,14 +1201,14 @@ void rfcomm_dlc_accept(struct rfcomm_dlc *d)
static void rfcomm_check_accept(struct rfcomm_dlc *d)
{
if (rfcomm_check_link_mode(d)) {
- set_bit(RFCOMM_AUTH_PENDING, &d->flags);
- rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
- } else {
if (d->defer_setup) {
set_bit(RFCOMM_DEFER_SETUP, &d->flags);
rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
} else
rfcomm_dlc_accept(d);
+ } else {
+ set_bit(RFCOMM_AUTH_PENDING, &d->flags);
+ rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
}
}
@@ -1659,10 +1661,11 @@ static void rfcomm_process_connect(struct rfcomm_session *s)
if (d->state == BT_CONFIG) {
d->mtu = s->mtu;
if (rfcomm_check_link_mode(d)) {
+ rfcomm_send_pn(s, 1, d);
+ } else {
set_bit(RFCOMM_AUTH_PENDING, &d->flags);
rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
- } else
- rfcomm_send_pn(s, 1, d);
+ }
}
}
}
@@ -1973,42 +1976,7 @@ static int rfcomm_run(void *unused)
return 0;
}
-static void rfcomm_auth_cfm(struct hci_conn *conn, u8 status)
-{
- struct rfcomm_session *s;
- struct rfcomm_dlc *d;
- struct list_head *p, *n;
-
- BT_DBG("conn %p status 0x%02x", conn, status);
-
- s = rfcomm_session_get(&conn->hdev->bdaddr, &conn->dst);
- if (!s)
- return;
-
- rfcomm_session_hold(s);
-
- list_for_each_safe(p, n, &s->dlcs) {
- d = list_entry(p, struct rfcomm_dlc, list);
-
- if ((d->link_mode & (RFCOMM_LM_ENCRYPT | RFCOMM_LM_SECURE)) &&
- !(conn->link_mode & HCI_LM_ENCRYPT) && !status)
- continue;
-
- if (!test_and_clear_bit(RFCOMM_AUTH_PENDING, &d->flags))
- continue;
-
- if (!status)
- set_bit(RFCOMM_AUTH_ACCEPT, &d->flags);
- else
- set_bit(RFCOMM_AUTH_REJECT, &d->flags);
- }
-
- rfcomm_session_put(s);
-
- rfcomm_schedule(RFCOMM_SCHED_AUTH);
-}
-
-static void rfcomm_encrypt_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
+static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
{
struct rfcomm_session *s;
struct rfcomm_dlc *d;
@@ -2025,10 +1993,10 @@ static void rfcomm_encrypt_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
list_for_each_safe(p, n, &s->dlcs) {
d = list_entry(p, struct rfcomm_dlc, list);
- if ((d->link_mode & (RFCOMM_LM_ENCRYPT | RFCOMM_LM_SECURE)) &&
+ if (!status && encrypt == 0x00 &&
+ (d->link_mode & RFCOMM_LM_ENCRYPT) &&
(d->state == BT_CONNECTED ||
- d->state == BT_CONFIG) &&
- !status && encrypt == 0x00) {
+ d->state == BT_CONFIG)) {
__rfcomm_dlc_close(d, ECONNREFUSED);
continue;
}
@@ -2036,7 +2004,7 @@ static void rfcomm_encrypt_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
if (!test_and_clear_bit(RFCOMM_AUTH_PENDING, &d->flags))
continue;
- if (!status && encrypt)
+ if (!status)
set_bit(RFCOMM_AUTH_ACCEPT, &d->flags);
else
set_bit(RFCOMM_AUTH_REJECT, &d->flags);
@@ -2049,8 +2017,7 @@ static void rfcomm_encrypt_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
static struct hci_cb rfcomm_cb = {
.name = "RFCOMM",
- .auth_cfm = rfcomm_auth_cfm,
- .encrypt_cfm = rfcomm_encrypt_cfm
+ .security_cfm = rfcomm_security_cfm
};
static ssize_t rfcomm_dlc_sysfs_show(struct class *dev, char *buf)
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 71df982c09c9..7f10f97cd697 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -195,7 +195,7 @@ static int sco_connect(struct sock *sk)
else
type = SCO_LINK;
- hcon = hci_connect(hdev, type, dst, HCI_AT_NO_BONDING);
+ hcon = hci_connect(hdev, type, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
if (!hcon)
goto done;