[RFC 19/20] Bluetooth: Add support for LE Start Encryption

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This adds support for starting SMP Phase 2 Encryption, when the initial
SMP negotiation is successful. This adds the LE Start Encryption and LE
Long Term Key Request commands and related events.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxxxxxx>
---
 include/net/bluetooth/hci.h      |   34 +++++++++++++++++++
 include/net/bluetooth/hci_core.h |    5 +++
 net/bluetooth/hci_conn.c         |   47 ++++++++++++++++++++++++++
 net/bluetooth/hci_event.c        |   67 ++++++++++++++++++++++++++++++++++++++
 net/bluetooth/smp.c              |   10 +++++-
 5 files changed, 162 insertions(+), 1 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 2103731..036fdae 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -626,6 +626,33 @@ struct hci_cp_le_create_conn {
 
 #define HCI_OP_LE_CREATE_CONN_CANCEL	0x200e
 
+#define HCI_OP_LE_START_ENC		0x2019
+struct hci_cp_le_start_enc {
+	__le16	handle;
+	__u8	rand[8];
+	__le16	ediv;
+	__u8	ltk[16];
+} __packed;
+
+#define HCI_OP_LE_LTK_REPLY		0x201a
+struct hci_cp_le_ltk_reply {
+	__le16	handle;
+	__u8	ltk[16];
+} __packed;
+struct hci_rp_le_ltk_reply {
+	__u8	status;
+	__le16	handle;
+} __packed;
+
+#define HCI_OP_LE_LTK_NEG_REPLY		0x201b
+struct hci_cp_le_ltk_neg_reply {
+	__le16	handle;
+} __packed;
+struct hci_rp_le_ltk_neg_reply {
+	__u8	status;
+	__le16	handle;
+} __packed;
+
 /* ---- HCI Events ---- */
 #define HCI_EV_INQUIRY_COMPLETE		0x01
 
@@ -897,6 +924,13 @@ struct hci_ev_le_conn_complete {
 	__u8     clk_accurancy;
 } __packed;
 
+#define HCI_EV_LE_LTK_REQ		0x05
+struct hci_ev_le_ltk_req {
+	__le16	handle;
+	__u8	random[8];
+	__le16	ediv;
+} __packed;
+
 /* Internal events generated by Bluetooth stack */
 #define HCI_EV_STACK_INTERNAL	0xfd
 struct hci_ev_stack_internal {
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index ee5efa8..cfbe56c 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -192,6 +192,7 @@ struct hci_conn {
 	__u8             sec_level;
 	__u8             power_save;
 	__u16            disc_timeout;
+	__u8		 ltk[16];
 	unsigned long	 pend;
 
 	unsigned int	 sent;
@@ -713,4 +714,8 @@ struct hci_sec_filter {
 
 void hci_req_complete(struct hci_dev *hdev, int result);
 
+void hci_le_start_enc(struct hci_conn *conn, u8 ltk[16]);
+void hci_le_ltk_reply(struct hci_conn *conn, u8 ltk[16]);
+void hci_le_ltk_neg_reply(struct hci_conn *conn);
+
 #endif /* __HCI_CORE_H */
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index d9a31b6..674829d 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -182,6 +182,53 @@ void hci_setup_sync(struct hci_conn *conn, __u16 handle)
 	hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp);
 }
 
+void hci_le_start_enc(struct hci_conn *conn, u8 ltk[16])
+{
+	struct hci_dev *hdev = conn->hdev;
+	struct hci_cp_le_start_enc cp;
+
+	BT_DBG("%p", conn);
+
+	memset(&cp, 0, sizeof(cp));
+
+	cp.handle = cpu_to_le16(conn->handle);
+	memcpy(cp.ltk, ltk, 16);
+
+	hci_send_cmd(hdev, HCI_OP_LE_START_ENC, sizeof(cp), &cp);
+}
+EXPORT_SYMBOL(hci_le_start_enc);
+
+void hci_le_ltk_reply(struct hci_conn *conn, u8 ltk[16])
+{
+	struct hci_dev *hdev = conn->hdev;
+	struct hci_cp_le_ltk_reply cp;
+
+	BT_DBG("%p", conn);
+
+	memset(&cp, 0, sizeof(cp));
+
+	cp.handle = cpu_to_le16(conn->handle);
+	memcpy(&cp.ltk, ltk, sizeof(ltk));
+
+	hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp);
+}
+EXPORT_SYMBOL(hci_le_ltk_reply);
+
+void hci_le_ltk_neg_reply(struct hci_conn *conn)
+{
+	struct hci_dev *hdev = conn->hdev;
+	struct hci_cp_le_ltk_neg_reply cp;
+
+	BT_DBG("%p", conn);
+
+	memset(&cp, 0, sizeof(cp));
+
+	cp.handle = cpu_to_le16(conn->handle);
+
+	hci_send_cmd(hdev, HCI_OP_LE_LTK_NEG_REPLY, sizeof(cp), &cp);
+}
+EXPORT_SYMBOL(hci_le_ltk_neg_reply);
+
 /* Device _must_ be locked */
 void hci_sco_setup(struct hci_conn *conn, __u8 status)
 {
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index df6eaa1..57560fb 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -559,6 +559,30 @@ static void hci_cc_le_read_buffer_size(struct hci_dev *hdev,
 	hci_req_complete(hdev, rp->status);
 }
 
+static void hci_cc_le_ltk_reply(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_rp_le_ltk_reply *rp = (void *) skb->data;
+
+	BT_DBG("%s status 0x%x", hdev->name, rp->status);
+
+	if (rp->status)
+		return;
+
+	hci_req_complete(hdev, rp->status);
+}
+
+static void hci_cc_le_ltk_neg_reply(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_rp_le_ltk_neg_reply *rp = (void *) skb->data;
+
+	BT_DBG("%s status 0x%x", hdev->name, rp->status);
+
+	if (rp->status)
+		return;
+
+	hci_req_complete(hdev, rp->status);
+}
+
 static inline void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
 {
 	BT_DBG("%s status 0x%x", hdev->name, status);
@@ -920,6 +944,11 @@ static void hci_cs_le_create_conn(struct hci_dev *hdev, __u8 status)
 	hci_dev_unlock(hdev);
 }
 
+static void hci_cs_le_start_enc(struct hci_dev *hdev, u8 status)
+{
+	BT_DBG("%s status 0x%x", hdev->name, status);
+}
+
 static inline void hci_inquiry_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	__u8 status = *((__u8 *) skb->data);
@@ -1440,6 +1469,14 @@ static inline void hci_cmd_complete_evt(struct hci_dev *hdev, struct sk_buff *sk
 		hci_cc_le_read_buffer_size(hdev, skb);
 		break;
 
+	case HCI_OP_LE_LTK_REPLY:
+		hci_cc_le_ltk_reply(hdev, skb);
+		break;
+
+	case HCI_OP_LE_LTK_NEG_REPLY:
+		hci_cc_le_ltk_neg_reply(hdev, skb);
+		break;
+
 	default:
 		BT_DBG("%s opcode 0x%x", hdev->name, opcode);
 		break;
@@ -1510,6 +1547,10 @@ static inline void hci_cmd_status_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		hci_cs_le_create_conn(hdev, ev->status);
 		break;
 
+	case HCI_OP_LE_START_ENC:
+		hci_cs_le_start_enc(hdev, ev->status);
+		break;
+
 	default:
 		BT_DBG("%s opcode 0x%x", hdev->name, opcode);
 		break;
@@ -2013,6 +2054,28 @@ unlock:
 	hci_dev_unlock(hdev);
 }
 
+static inline void hci_le_ltk_request_evt(struct hci_dev *hdev,
+						struct sk_buff *skb)
+{
+	struct hci_ev_le_ltk_req *ev = (void *) skb->data;
+	struct hci_cp_le_ltk_reply cp;
+	struct hci_conn *conn;
+
+	BT_DBG("%s handle %d", hdev->name, cpu_to_le16(ev->handle));
+
+	hci_dev_lock(hdev);
+
+	conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(ev->handle));
+
+	memset(&cp, 0, sizeof(cp));
+	cp.handle = cpu_to_le16(conn->handle);
+	memcpy(cp.ltk, conn->ltk, sizeof(conn->ltk));
+
+	hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp);
+
+	hci_dev_unlock(hdev);
+}
+
 static inline void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_le_meta *le_ev = (void *) skb->data;
@@ -2024,6 +2087,10 @@ static inline void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		hci_le_conn_complete_evt(hdev, skb);
 		break;
 
+	case HCI_EV_LE_LTK_REQ:
+		hci_le_ltk_request_evt(hdev, skb);
+		break;
+
 	default:
 		break;
 	}
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index a8d2e12..6cfd088 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -287,7 +287,8 @@ static void smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb
 
 static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 {
-	struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
+	struct hci_conn *hcon = conn->hcon;
+	struct crypto_blkcipher *tfm = hcon->hdev->tfm;
 	int ret;
 	u8 k[16], key[16], res[16], random[16], confirm[16], buf[128];
 
@@ -295,6 +296,7 @@ static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	skb_pull(skb, 16);
 
 	memset(k, 0, sizeof(k));
+	memset(hcon->ltk, 0, sizeof(hcon->ltk));
 
 	if (conn->hcon->out)
 		ret = smp_c1(tfm, k, random, conn->preq, conn->pres, 0,
@@ -319,6 +321,10 @@ static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 	if (conn->hcon->out) {
 		smp_s1(tfm, k, random, conn->prnd, key);
 
+		swap128(key, hcon->ltk);
+
+		hci_le_start_enc(conn->hcon, hcon->ltk);
+
 		hex_dump_to_buffer(key, sizeof(key), 16, 1, buf, sizeof(buf), 0);
 
 		BT_DBG("key %s", buf);
@@ -331,6 +337,8 @@ static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 
 		smp_s1(tfm, k, conn->prnd, random, key);
 
+		swap128(key, hcon->ltk);
+
 		hex_dump_to_buffer(key, sizeof(key), 16, 1, buf, sizeof(buf), 0);
 
 		BT_DBG("key %s", buf);
-- 
1.7.3.2

--
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


[Index of Archives]     [Bluez Devel]     [Linux Wireless Networking]     [Linux Wireless Personal Area Networking]     [Linux ATH6KL]     [Linux USB Devel]     [Linux Media Drivers]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Big List of Linux Books]

  Powered by Linux