Return-Path: From: Claudio Takahasi To: linux-bluetooth@vger.kernel.org Cc: Claudio Takahasi Subject: [PATCH] Bluetooth: Fix removing Long Term Key Date: Thu, 25 Jul 2013 16:34:24 -0300 Message-Id: <1374780864-8529-1-git-send-email-claudio.takahasi@openbossa.org> In-Reply-To: <1374776057-2618-1-git-send-email-claudio.takahasi@openbossa.org> References: <1374776057-2618-1-git-send-email-claudio.takahasi@openbossa.org> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: This patch fixes authentication failure on LE link re-connection when BlueZ acts as slave (peripheral). LTK is removed from the internal list after its first use causing PIN or Key missing reply when re-connecting the link. The LE Long Term Key Request event indicates that the master is attempting to encrypt or re-encrypt the link. Pre-condition: BlueZ host paired and running as slave. How to reproduce(master): 1) Establish an ACL LE encrypted link 2) Disconnect the link 3) Try to re-establish the ACL LE encrypted link (fails) > HCI Event: LE Meta Event (0x3e) plen 19 LE Connection Complete (0x01) Status: Success (0x00) Handle: 64 Role: Slave (0x01) ... @ Device Connected: 00:02:72:DC:29:C9 (1) flags 0x0000 > HCI Event: LE Meta Event (0x3e) plen 13 LE Long Term Key Request (0x05) Handle: 64 Random number: 875be18439d9aa37 Encryption diversifier: 0x76ed < HCI Command: LE Long Term Key Request Reply (0x08|0x001a) plen 18 Handle: 64 Long term key: 2aa531db2fce9f00a0569c7d23d17409 > HCI Event: Command Complete (0x0e) plen 6 LE Long Term Key Request Reply (0x08|0x001a) ncmd 1 Status: Success (0x00) Handle: 64 > HCI Event: Encryption Change (0x08) plen 4 Status: Success (0x00) Handle: 64 Encryption: Enabled with AES-CCM (0x01) ... @ Device Disconnected: 00:02:72:DC:29:C9 (1) reason 3 < HCI Command: LE Set Advertise Enable (0x08|0x000a) plen 1 Advertising: Enabled (0x01) > HCI Event: Command Complete (0x0e) plen 4 LE Set Advertise Enable (0x08|0x000a) ncmd 1 Status: Success (0x00) > HCI Event: LE Meta Event (0x3e) plen 19 LE Connection Complete (0x01) Status: Success (0x00) Handle: 64 Role: Slave (0x01) ... @ Device Connected: 00:02:72:DC:29:C9 (1) flags 0x0000 > HCI Event: LE Meta Event (0x3e) plen 13 LE Long Term Key Request (0x05) Handle: 64 Random number: 875be18439d9aa37 Encryption diversifier: 0x76ed < HCI Command: LE Long Term Key Request Neg Reply (0x08|0x001b) plen 2 Handle: 64 > HCI Event: Command Complete (0x0e) plen 6 LE Long Term Key Request Neg Reply (0x08|0x001b) ncmd 1 Status: Success (0x00) Handle: 64 > HCI Event: Disconnect Complete (0x05) plen 4 Status: Success (0x00) Handle: 64 Reason: Authentication Failure (0x05) @ Device Disconnected: 00:02:72:DC:29:C9 (1) reason 0 Signed-off-by: Claudio Takahasi --- net/bluetooth/hci_event.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index ae78738..124a5e2 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3558,7 +3558,13 @@ static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb) hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp); - if (ltk->type & HCI_SMP_STK) { + /* + * Ref. Bluetooth Core SPEC pages 1975 and 2004. STK is a temporary + * key used to encrypt a connection following pairing. It is used + * during the Encrypted Session Setup to distribute the keys. Later, + * security can be re-established using a distributed LTK. + */ + if (ltk->type == HCI_SMP_STK_SLAVE) { list_del(<k->list); kfree(ltk); } -- 1.7.11.7