This patch implements a simple version of the SMP Pairing Features exchange procedure (Vol. 3 Part H, Section 2.3.5.1). For now, everything that would cause a Pairing Method different of Just Works to be chosen is rejected. Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxxxxxx> --- net/bluetooth/hci_event.c | 1 + net/bluetooth/smp.c | 106 ++++++++++++++++++++++---------------------- 2 files changed, 54 insertions(+), 53 deletions(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 21d6055..ac2c5e8 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -1622,6 +1622,7 @@ static inline void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff * /* Encryption implies authentication */ conn->link_mode |= HCI_LM_AUTH; conn->link_mode |= HCI_LM_ENCRYPT; + conn->sec_level = conn->pending_sec_level; } else conn->link_mode &= ~HCI_LM_ENCRYPT; } diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index d29700d..dfd6891 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -181,6 +181,18 @@ static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) hci_send_acl(conn->hcon, skb, 0); } +static __u8 seclevel_to_authreq(__u8 level) +{ + switch (level) { + case BT_SECURITY_HIGH: + /* Right now we don't support bonding */ + return SMP_AUTH_MITM; + + default: + return SMP_AUTH_NONE; + } +} + static void build_pairing_cmd(struct l2cap_conn *conn, struct smp_cmd_pairing *cmd, __u8 authreq) { @@ -192,7 +204,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn, cmd->auth_req = authreq; } -static void smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) +static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) { struct smp_cmd_pairing *rp = (void *) skb->data; @@ -202,12 +214,11 @@ static void smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) memcpy(&conn->preq[1], rp, sizeof(*rp)); skb_pull(skb, sizeof(*rp)); - rp->io_capability = 0x00; - rp->oob_flag = 0x00; - rp->max_key_size = 16; - rp->init_key_dist = 0x00; - rp->resp_key_dist = 0x00; - rp->auth_req &= (SMP_AUTH_BONDING | SMP_AUTH_MITM); + if (rp->oob_flag) + return SMP_OOB_NOT_AVAIL; + + /* We didn't start the pairing, so no requirements */ + build_pairing_cmd(conn, rp, SMP_AUTH_NONE); /* Just works */ memset(conn->tk, 0, sizeof(conn->tk)); @@ -216,9 +227,11 @@ static void smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) memcpy(&conn->prsp[1], rp, sizeof(*rp)); smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(*rp), rp); + + return 0; } -static void smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) +static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) { struct smp_cmd_pairing *rp = (void *) skb->data; struct smp_cmd_pairing_confirm cp; @@ -228,29 +241,34 @@ static void smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) BT_DBG("conn %p", conn); + skb_pull(skb, sizeof(*rp)); + + if (rp->oob_flag) + return SMP_OOB_NOT_AVAIL; + /* Just works */ memset(conn->tk, 0, sizeof(conn->tk)); conn->prsp[0] = SMP_CMD_PAIRING_RSP; memcpy(&conn->prsp[1], rp, sizeof(*rp)); - skb_pull(skb, sizeof(*rp)); ret = smp_rand(conn->prnd); if (ret) - return; + return SMP_UNSPECIFIED; ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp, 0, conn->src, conn->hcon->dst_type, conn->dst, res); if (ret) - return; + return SMP_UNSPECIFIED; swap128(res, cp.confirm_val); smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); + + return 0; } -static void smp_cmd_pairing_confirm(struct l2cap_conn *conn, - struct sk_buff *skb) +static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) { struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm; @@ -272,21 +290,23 @@ static void smp_cmd_pairing_confirm(struct l2cap_conn *conn, ret = smp_rand(conn->prnd); if (ret) - return; + return SMP_UNSPECIFIED; ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp, conn->hcon->dst_type, conn->dst, 0, conn->src, res); if (ret) - return; + return SMP_CONFIRM_FAILED; swap128(res, cp.confirm_val); smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); } + + return 0; } -static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) +static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) { struct hci_conn *hcon = conn->hcon; struct crypto_blkcipher *tfm = hcon->hdev->tfm; @@ -307,19 +327,15 @@ static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) conn->hcon->dst_type, conn->dst, 0, conn->src, res); if (ret) - return; + return SMP_UNSPECIFIED; BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); swap128(res, confirm); if (memcmp(conn->pcnf, confirm, sizeof(conn->pcnf)) != 0) { - struct smp_cmd_pairing_fail cp; - BT_ERR("Pairing failed (confirmation values mismatch)"); - cp.reason = SMP_CONFIRM_FAILED; - smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(cp), &cp); - return; + return SMP_CONFIRM_FAILED; } if (conn->hcon->out) { @@ -341,9 +357,11 @@ static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) smp_s1(tfm, conn->tk, conn->prnd, random, key); swap128(key, hcon->ltk); } + + return 0; } -static void smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) +static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) { struct smp_cmd_security_req *rp = (void *) skb->data; struct smp_cmd_pairing cp; @@ -352,17 +370,12 @@ static void smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) BT_DBG("conn %p", conn); if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend)) - return; + return 0; skb_pull(skb, sizeof(*rp)); - memset(&cp, 0, sizeof(cp)); - cp.io_capability = 0x00; - cp.oob_flag = 0x00; - cp.max_key_size = 16; - cp.init_key_dist = 0x00; - cp.resp_key_dist = 0x00; - cp.auth_req = rp->auth_req & (SMP_AUTH_BONDING | SMP_AUTH_MITM); + memset(&cp, 0, sizeof(cp)); + build_pairing_cmd(conn, &cp, rp->auth_req); conn->preq[0] = SMP_CMD_PAIRING_REQ; memcpy(&conn->preq[1], &cp, sizeof(cp)); @@ -370,18 +383,8 @@ static void smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend); -} -static __u8 seclevel_to_authreq(__u8 level) -{ - switch (level) { - case BT_SECURITY_HIGH: - /* For now we don't support bonding */ - return SMP_AUTH_MITM; - - default: - return SMP_AUTH_NONE; - } + return 0; } int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) @@ -407,13 +410,8 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) if (hcon->link_mode & HCI_LM_MASTER) { struct smp_cmd_pairing cp; - cp.io_capability = 0x00; - cp.oob_flag = 0x00; - cp.max_key_size = 16; - cp.init_key_dist = 0x00; - cp.resp_key_dist = 0x00; - cp.auth_req = authreq; + build_pairing_cmd(conn, &cp, authreq); conn->preq[0] = SMP_CMD_PAIRING_REQ; memcpy(&conn->preq[1], &cp, sizeof(cp)); @@ -446,26 +444,28 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb) switch (code) { case SMP_CMD_PAIRING_REQ: - smp_cmd_pairing_req(conn, skb); + reason = smp_cmd_pairing_req(conn, skb); break; case SMP_CMD_PAIRING_FAIL: + reason = 0; + err = -EPERM; break; case SMP_CMD_PAIRING_RSP: - smp_cmd_pairing_rsp(conn, skb); + reason = smp_cmd_pairing_rsp(conn, skb); break; case SMP_CMD_SECURITY_REQ: - smp_cmd_security_req(conn, skb); + reason = smp_cmd_security_req(conn, skb); break; case SMP_CMD_PAIRING_CONFIRM: - smp_cmd_pairing_confirm(conn, skb); + reason = smp_cmd_pairing_confirm(conn, skb); break; case SMP_CMD_PAIRING_RANDOM: - smp_cmd_pairing_random(conn, skb); + reason = smp_cmd_pairing_random(conn, skb); break; case SMP_CMD_ENCRYPT_INFO: -- 1.7.5.4 -- 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