1 files changed, 100 insertions, 13 deletions

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 7b61be73650f..32363c2b7f83 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2603,6 +2603,63 @@ unlock:
 	hci_dev_unlock(hdev);
 }
 
+static void read_enc_key_size_complete(struct hci_dev *hdev, u8 status,
+				       u16 opcode, struct sk_buff *skb)
+{
+	const struct hci_rp_read_enc_key_size *rp;
+	struct hci_conn *conn;
+	u16 handle;
+
+	BT_DBG("%s status 0x%02x", hdev->name, status);
+
+	if (!skb || skb->len < sizeof(*rp)) {
+		BT_ERR("%s invalid HCI Read Encryption Key Size response",
+		       hdev->name);
+		return;
+	}
+
+	rp = (void *)skb->data;
+	handle = le16_to_cpu(rp->handle);
+
+	hci_dev_lock(hdev);
+
+	conn = hci_conn_hash_lookup_handle(hdev, handle);
+	if (!conn)
+		goto unlock;
+
+	/* If we fail to read the encryption key size, assume maximum
+	 * (which is the same we do also when this HCI command isn't
+	 * supported.
+	 */
+	if (rp->status) {
+		BT_ERR("%s failed to read key size for handle %u", hdev->name,
+		       handle);
+		conn->enc_key_size = HCI_LINK_KEY_SIZE;
+	} else {
+		conn->enc_key_size = rp->key_size;
+	}
+
+	if (conn->state == BT_CONFIG) {
+		conn->state = BT_CONNECTED;
+		hci_connect_cfm(conn, 0);
+		hci_conn_drop(conn);
+	} else {
+		u8 encrypt;
+
+		if (!test_bit(HCI_CONN_ENCRYPT, &conn->flags))
+			encrypt = 0x00;
+		else if (test_bit(HCI_CONN_AES_CCM, &conn->flags))
+			encrypt = 0x02;
+		else
+			encrypt = 0x01;
+
+		hci_encrypt_cfm(conn, 0, encrypt);
+	}
+
+unlock:
+	hci_dev_unlock(hdev);
+}
+
 static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_encrypt_change *ev = (void *) skb->data;
@@ -2650,22 +2707,51 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
 		goto unlock;
 	}
 
-	if (conn->state == BT_CONFIG) {
-		if (!ev->status)
-			conn->state = BT_CONNECTED;
+	/* In Secure Connections Only mode, do not allow any connections
+	 * that are not encrypted with AES-CCM using a P-256 authenticated
+	 * combination key.
+	 */
+	if (hci_dev_test_flag(hdev, HCI_SC_ONLY) &&
+	    (!test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
+	     conn->key_type != HCI_LK_AUTH_COMBINATION_P256)) {
+		hci_connect_cfm(conn, HCI_ERROR_AUTH_FAILURE);
+		hci_conn_drop(conn);
+		goto unlock;
+	}
+
+	/* Try reading the encryption key size for encrypted ACL links */
+	if (!ev->status && ev->encrypt && conn->type == ACL_LINK) {
+		struct hci_cp_read_enc_key_size cp;
+		struct hci_request req;
 
-		/* In Secure Connections Only mode, do not allow any
-		 * connections that are not encrypted with AES-CCM
-		 * using a P-256 authenticated combination key.
+		/* Only send HCI_Read_Encryption_Key_Size if the
+		 * controller really supports it. If it doesn't, assume
+		 * the default size (16).
 		 */
-		if (hci_dev_test_flag(hdev, HCI_SC_ONLY) &&
-		    (!test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
-		     conn->key_type != HCI_LK_AUTH_COMBINATION_P256)) {
-			hci_connect_cfm(conn, HCI_ERROR_AUTH_FAILURE);
-			hci_conn_drop(conn);
-			goto unlock;
+		if (!(hdev->commands[20] & 0x10)) {
+			conn->enc_key_size = HCI_LINK_KEY_SIZE;
+			goto notify;
 		}
 
+		hci_req_init(&req, hdev);
+
+		cp.handle = cpu_to_le16(conn->handle);
+		hci_req_add(&req, HCI_OP_READ_ENC_KEY_SIZE, sizeof(cp), &cp);
+
+		if (hci_req_run_skb(&req, read_enc_key_size_complete)) {
+			BT_ERR("Sending HCI Read Encryption Key Size failed");
+			conn->enc_key_size = HCI_LINK_KEY_SIZE;
+			goto notify;
+		}
+
+		goto unlock;
+	}
+
+notify:
+	if (conn->state == BT_CONFIG) {
+		if (!ev->status)
+			conn->state = BT_CONNECTED;
+
 		hci_connect_cfm(conn, ev->status);
 		hci_conn_drop(conn);
 	} else
@@ -4955,7 +5041,8 @@ static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
 			goto not_found;
 	}
 
-	memcpy(cp.ltk, ltk->val, sizeof(ltk->val));
+	memcpy(cp.ltk, ltk->val, ltk->enc_size);
+	memset(cp.ltk + ltk->enc_size, 0, sizeof(cp.ltk) - ltk->enc_size);
 	cp.handle = cpu_to_le16(conn->handle);
 
 	conn->pending_sec_level = smp_ltk_sec_level(ltk);