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Commit 13d39315 authored by Waldemar Rymarkiewicz's avatar Waldemar Rymarkiewicz Committed by Gustavo Padovan
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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: default avatarWaldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: default avatarGustavo F. Padovan <padovan@profusion.mobi>
parent 9003c4e2

include/net/bluetooth/hci_core.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

net/bluetooth/hci_conn.c

+51 −10
Original line number Diff line number Diff line
@@ -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);

net/bluetooth/hci_event.c

+4 −0
Original line number Diff line number Diff line
@@ -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);

	}