Return-Path: From: Vinicius Costa Gomes To: linux-bluetooth@vger.kernel.org Cc: Vinicius Costa Gomes Subject: [RFC 07/15] Bluetooth: Fix SM pairing parameters negotiation Date: Tue, 5 Apr 2011 23:11:20 -0300 Message-Id: <1302055888-28177-8-git-send-email-vinicius.gomes@openbossa.org> In-Reply-To: <1302055888-28177-1-git-send-email-vinicius.gomes@openbossa.org> References: <1302055888-28177-1-git-send-email-vinicius.gomes@openbossa.org> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Before implementing SM key distribution, the pairing features exchange must be better negotiated, taking into account some features of the host and connection requirements. Signed-off-by: Vinicius Costa Gomes --- net/bluetooth/smp.c | 42 ++++++++++++++++++++++++++++++++---------- 1 files changed, 32 insertions(+), 10 deletions(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 1f1b318..3d2fb13 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -201,14 +201,36 @@ static __u8 seclevel_to_authreq(__u8 level) } static void build_pairing_cmd(struct l2cap_conn *conn, - struct smp_cmd_pairing *cmd, __u8 authreq) + struct smp_cmd_pairing *req, + struct smp_cmd_pairing *rsp, + __u8 authreq) { - cmd->io_capability = conn->hcon->io_capability; - cmd->oob_flag = SMP_OOB_NOT_PRESENT; - cmd->max_key_size = SMP_MAX_ENC_KEY_SIZE; - cmd->init_key_dist = SMP_DIST_ENC_KEY | SMP_DIST_ID_KEY | SMP_DIST_SIGN; - cmd->resp_key_dist = SMP_DIST_ENC_KEY | SMP_DIST_ID_KEY | SMP_DIST_SIGN; - cmd->auth_req = authreq; + u8 all_keys = SMP_DIST_ENC_KEY | SMP_DIST_ID_KEY | + SMP_DIST_SIGN; + u8 dist_keys; + + dist_keys = 0; + if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->flags)) { + dist_keys = SMP_DIST_ENC_KEY; + authreq |= SMP_AUTH_BONDING; + } + + if (rsp == NULL) { + req->io_capability = conn->hcon->io_capability; + req->oob_flag = SMP_OOB_NOT_PRESENT; + req->max_key_size = SMP_MAX_ENC_KEY_SIZE; + req->init_key_dist = dist_keys; + req->resp_key_dist = all_keys; + req->auth_req = authreq; + return; + } + + rsp->io_capability = conn->hcon->io_capability; + rsp->oob_flag = SMP_OOB_NOT_PRESENT; + rsp->max_key_size = SMP_MAX_ENC_KEY_SIZE; + rsp->init_key_dist = req->init_key_dist & all_keys; + rsp->resp_key_dist = req->resp_key_dist & dist_keys; + rsp->auth_req = authreq; } static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) @@ -237,7 +259,7 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) return SMP_OOB_NOT_AVAIL; /* We didn't start the pairing, so no requirements */ - build_pairing_cmd(conn, &rsp, SMP_AUTH_NONE); + build_pairing_cmd(conn, req, &rsp, SMP_AUTH_NONE); key_size = min(req->max_key_size, rsp.max_key_size); if (check_enc_key_size(conn, key_size)) @@ -422,7 +444,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) skb_pull(skb, sizeof(*rp)); memset(&cp, 0, sizeof(cp)); - build_pairing_cmd(conn, &cp, rp->auth_req); + build_pairing_cmd(conn, &cp, NULL, rp->auth_req); conn->preq[0] = SMP_CMD_PAIRING_REQ; memcpy(&conn->preq[1], &cp, sizeof(cp)); @@ -461,7 +483,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) if (hcon->link_mode & HCI_LM_MASTER) { struct smp_cmd_pairing cp; - build_pairing_cmd(conn, &cp, authreq); + build_pairing_cmd(conn, &cp, NULL, authreq); conn->preq[0] = SMP_CMD_PAIRING_REQ; memcpy(&conn->preq[1], &cp, sizeof(cp)); -- 1.7.4.1