* [PATCH-v7 0/2] Bluetooth: Add MITM protection to LE-SMP @ 2011-12-21 1:04 Brian Gix 2011-12-21 1:04 ` [PATCH-v7 1/2] Bluetooth: Add MITM mechanism " Brian Gix 2011-12-21 1:04 ` [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm Brian Gix 0 siblings, 2 replies; 8+ messages in thread From: Brian Gix @ 2011-12-21 1:04 UTC (permalink / raw) To: linux-bluetooth These patches are identical to Version 6 of the same patchset, except that they have been rebased onto the latest code, including the new work queue patches. -- Brian Gix bgix@codeaurora.org Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH-v7 1/2] Bluetooth: Add MITM mechanism to LE-SMP 2011-12-21 1:04 [PATCH-v7 0/2] Bluetooth: Add MITM protection to LE-SMP Brian Gix @ 2011-12-21 1:04 ` Brian Gix 2011-12-21 2:22 ` Marcel Holtmann 2011-12-21 10:28 ` Andrei Emeltchenko 2011-12-21 1:04 ` [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm Brian Gix 1 sibling, 2 replies; 8+ messages in thread From: Brian Gix @ 2011-12-21 1:04 UTC (permalink / raw) To: linux-bluetooth; +Cc: Brian Gix To achive Man-In-The-Middle (MITM) level security with Low Energy, we have to enable User Passkey Comparison. This commit modifies the hard-coded JUST-WORKS pairing mechanism to support query via the MGMT interface of Passkey comparison and User Confirmation. Signed-off-by: Brian Gix <bgix@codeaurora.org> --- include/net/bluetooth/hci_core.h | 1 + include/net/bluetooth/smp.h | 5 + net/bluetooth/smp.c | 227 ++++++++++++++++++++++++++++++++++---- 3 files changed, 211 insertions(+), 22 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index e34cd71..39bcd50 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -316,6 +316,7 @@ struct hci_conn { struct hci_dev *hdev; void *l2cap_data; void *sco_data; + void *smp_conn; struct hci_conn *link; diff --git a/include/net/bluetooth/smp.h b/include/net/bluetooth/smp.h index 15b97d5..5cbcd05 100644 --- a/include/net/bluetooth/smp.h +++ b/include/net/bluetooth/smp.h @@ -115,6 +115,9 @@ struct smp_cmd_security_req { #define SMP_MIN_ENC_KEY_SIZE 7 #define SMP_MAX_ENC_KEY_SIZE 16 +#define SMP_FLAG_TK_VALID 1 +#define SMP_FLAG_CFM_PENDING 2 + struct smp_chan { struct l2cap_conn *conn; u8 preq[7]; /* SMP Pairing Request */ @@ -124,6 +127,7 @@ struct smp_chan { u8 pcnf[16]; /* SMP Pairing Confirm */ u8 tk[16]; /* SMP Temporary Key */ u8 smp_key_size; + unsigned long smp_flags; struct crypto_blkcipher *tfm; struct work_struct confirm; struct work_struct random; @@ -134,6 +138,7 @@ struct smp_chan { int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level); int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb); int smp_distribute_keys(struct l2cap_conn *conn, __u8 force); +int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey); void smp_chan_destroy(struct l2cap_conn *conn); diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 0b96737..42ca847 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -23,6 +23,7 @@ #include <net/bluetooth/bluetooth.h> #include <net/bluetooth/hci_core.h> #include <net/bluetooth/l2cap.h> +#include <net/bluetooth/mgmt.h> #include <net/bluetooth/smp.h> #include <linux/crypto.h> #include <linux/scatterlist.h> @@ -188,24 +189,45 @@ static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) msecs_to_jiffies(SMP_TIMEOUT)); } +static __u8 authreq_to_seclevel(__u8 authreq) +{ + if (authreq & SMP_AUTH_MITM) + return BT_SECURITY_HIGH; + else + return BT_SECURITY_MEDIUM; +} + +static __u8 seclevel_to_authreq(__u8 sec_level) +{ + switch (sec_level) { + case BT_SECURITY_HIGH: + return SMP_AUTH_MITM | SMP_AUTH_BONDING; + case BT_SECURITY_MEDIUM: + return SMP_AUTH_BONDING; + default: + return SMP_AUTH_NONE; + } +} + static void build_pairing_cmd(struct l2cap_conn *conn, struct smp_cmd_pairing *req, struct smp_cmd_pairing *rsp, __u8 authreq) { - u8 dist_keys; + u8 dist_keys = 0; - dist_keys = 0; if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->flags)) { dist_keys = SMP_DIST_ENC_KEY; authreq |= SMP_AUTH_BONDING; + } else { + 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->init_key_dist = 0; req->resp_key_dist = dist_keys; req->auth_req = authreq; return; @@ -214,7 +236,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn, 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 & dist_keys; + rsp->init_key_dist = 0; rsp->resp_key_dist = req->resp_key_dist & dist_keys; rsp->auth_req = authreq; } @@ -244,6 +266,93 @@ static void smp_failure(struct l2cap_conn *conn, u8 reason, u8 send) smp_chan_destroy(conn); } +#define JUST_WORKS 0x00 +#define JUST_CFM 0x01 +#define REQ_PASSKEY 0x02 +#define CFM_PASSKEY 0x03 +#define REQ_OOB 0x04 +#define OVERLAP 0xFF + +static const u8 gen_method[5][5] = { + {JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY}, + {JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY}, + {CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY}, + {JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM}, + {CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP} +}; + +static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, + u8 local_io, u8 remote_io) +{ + struct hci_conn *hcon = conn->hcon; + struct smp_chan *smp = conn->smp_chan; + u8 method; + u32 passkey = 0; + int ret = 0; + + /* Initialize key to JUST WORKS */ + memset(smp->tk, 0, sizeof(smp->tk)); + clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); + + BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); + + /* If neither side wants MITM, use JUST WORKS */ + /* If either side has unknown io_caps, use JUST_WORKS */ + if (!(auth & SMP_AUTH_MITM) || + local_io > SMP_IO_KEYBOARD_DISPLAY || + remote_io > SMP_IO_KEYBOARD_DISPLAY) { + auth &= ~SMP_AUTH_MITM; + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); + return 0; + } + + /* MITM is now officially requested, but not required */ + /* Determine what we need (if anything) from the agent */ + method = gen_method[local_io][remote_io]; + + if (method == JUST_WORKS || method == JUST_CFM) + auth &= ~SMP_AUTH_MITM; + + /* Don't bother confirming unbonded JUST_WORKS */ + if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM) { + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); + return 0; + } else if (method == JUST_WORKS) { + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); + return 0; + } else if (method == OVERLAP) { + if (hcon->link_mode & HCI_LM_MASTER) + method = CFM_PASSKEY; + else + method = REQ_PASSKEY; + } + + if (method == CFM_PASSKEY) { + u8 key[16]; + /* Generate a passkey for display. It is not valid until + * confirmed. + */ + memset(key, 0, sizeof(key)); + get_random_bytes(&passkey, sizeof(passkey)); + passkey %= 1000000; + put_unaligned_le32(passkey, key); + swap128(key, smp->tk); + BT_DBG("PassKey: %d", passkey); + } + + hci_dev_lock(hcon->hdev); + + if (method == REQ_PASSKEY) + ret = mgmt_user_passkey_request(hcon->hdev, conn->dst); + else + ret = mgmt_user_confirm_request(hcon->hdev, conn->dst, + cpu_to_le32(passkey), 0); + + hci_dev_unlock(hcon->hdev); + + return ret; +} + static void confirm_work(struct work_struct *work) { struct smp_chan *smp = container_of(work, struct smp_chan, confirm); @@ -276,6 +385,8 @@ static void confirm_work(struct work_struct *work) goto error; } + clear_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); + swap128(res, cp.confirm_val); smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); @@ -381,6 +492,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) smp->conn = conn; conn->smp_chan = smp; + conn->hcon->smp_conn = conn; hci_conn_hold(conn->hcon); @@ -398,18 +510,67 @@ void smp_chan_destroy(struct l2cap_conn *conn) kfree(smp); conn->smp_chan = NULL; + conn->hcon->smp_conn = NULL; hci_conn_put(conn->hcon); } +int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) +{ + struct l2cap_conn *conn = hcon->smp_conn; + struct smp_chan *smp; + u32 value; + u8 key[16]; + u8 reason = 0; + int ret = 0; + + BT_DBG(""); + + if (!conn) + return -ENOTCONN; + + smp = conn->smp_chan; + + switch (mgmt_op) { + case MGMT_OP_USER_PASSKEY_REPLY: + value = le32_to_cpu(passkey); + memset(key, 0, sizeof(key)); + BT_DBG("PassKey: %d", value); + put_unaligned_le32(value, key); + swap128(key, smp->tk); + /* Fall Through */ + case MGMT_OP_USER_CONFIRM_REPLY: + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); + break; + default: + ret = -EOPNOTSUPP; + /* Fall Through */ + case MGMT_OP_USER_PASSKEY_NEG_REPLY: + case MGMT_OP_USER_CONFIRM_NEG_REPLY: + reason = SMP_PASSKEY_ENTRY_FAILED; + break; + } + + if (reason) + smp_failure(conn, reason, 1); + else if (test_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags)) + queue_work(hcon->hdev->workqueue, &smp->confirm); + + return ret; +} + static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) { struct smp_cmd_pairing rsp, *req = (void *) skb->data; struct smp_chan *smp; u8 key_size; + u8 auth = SMP_AUTH_NONE; int ret; BT_DBG("conn %p", conn); + if (conn->hcon->link_mode & HCI_LM_MASTER) + return SMP_CMD_NOTSUPP; + if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend)) smp = smp_chan_create(conn); @@ -419,19 +580,16 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) memcpy(&smp->preq[1], req, sizeof(*req)); skb_pull(skb, sizeof(*req)); - if (req->oob_flag) - return SMP_OOB_NOT_AVAIL; + /* We didn't start the pairing, so match remote */ + if (req->auth_req & SMP_AUTH_BONDING) + auth = req->auth_req; - /* We didn't start the pairing, so no requirements */ - build_pairing_cmd(conn, req, &rsp, SMP_AUTH_NONE); + build_pairing_cmd(conn, req, &rsp, auth); key_size = min(req->max_key_size, rsp.max_key_size); if (check_enc_key_size(conn, key_size)) return SMP_ENC_KEY_SIZE; - /* Just works */ - memset(smp->tk, 0, sizeof(smp->tk)); - ret = smp_rand(smp->prnd); if (ret) return SMP_UNSPECIFIED; @@ -441,6 +599,11 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); + /* Request setup of TK */ + ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); + if (ret) + return SMP_UNSPECIFIED; + return 0; } @@ -449,11 +612,14 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) struct smp_cmd_pairing *req, *rsp = (void *) skb->data; struct smp_chan *smp = conn->smp_chan; struct hci_dev *hdev = conn->hcon->hdev; - u8 key_size; + u8 key_size, auth = SMP_AUTH_NONE; int ret; BT_DBG("conn %p", conn); + if (!(conn->hcon->link_mode & HCI_LM_MASTER)) + return SMP_CMD_NOTSUPP; + skb_pull(skb, sizeof(*rsp)); req = (void *) &smp->preq[1]; @@ -462,12 +628,6 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) if (check_enc_key_size(conn, key_size)) return SMP_ENC_KEY_SIZE; - if (rsp->oob_flag) - return SMP_OOB_NOT_AVAIL; - - /* Just works */ - memset(smp->tk, 0, sizeof(smp->tk)); - ret = smp_rand(smp->prnd); if (ret) return SMP_UNSPECIFIED; @@ -475,6 +635,22 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) smp->prsp[0] = SMP_CMD_PAIRING_RSP; memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); + if ((req->auth_req & SMP_AUTH_BONDING) && + (rsp->auth_req & SMP_AUTH_BONDING)) + auth = SMP_AUTH_BONDING; + + auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM; + + ret = tk_request(conn, 0, auth, rsp->io_capability, req->io_capability); + if (ret) + return SMP_UNSPECIFIED; + + set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); + + /* Can't compose response until we have been confirmed */ + if (!test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) + return 0; + queue_work(hdev->workqueue, &smp->confirm); return 0; @@ -496,8 +672,10 @@ static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) swap128(smp->prnd, random); smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random), random); - } else { + } else if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) { queue_work(hdev->workqueue, &smp->confirm); + } else { + set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); } return 0; @@ -550,7 +728,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) BT_DBG("conn %p", conn); - hcon->pending_sec_level = BT_SECURITY_MEDIUM; + hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req); if (smp_ltk_encrypt(conn)) return 0; @@ -577,6 +755,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) { struct hci_conn *hcon = conn->hcon; struct smp_chan *smp = conn->smp_chan; + __u8 authreq; BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); @@ -597,18 +776,22 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) return 0; smp = smp_chan_create(conn); + if (!smp) + return 1; + + authreq = seclevel_to_authreq(sec_level); if (hcon->link_mode & HCI_LM_MASTER) { struct smp_cmd_pairing cp; - build_pairing_cmd(conn, &cp, NULL, SMP_AUTH_NONE); + build_pairing_cmd(conn, &cp, NULL, authreq); smp->preq[0] = SMP_CMD_PAIRING_REQ; memcpy(&smp->preq[1], &cp, sizeof(cp)); smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); } else { struct smp_cmd_security_req cp; - cp.auth_req = SMP_AUTH_NONE; + cp.auth_req = authreq; smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); } -- 1.7.8 -- Brian Gix bgix@codeaurora.org Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH-v7 1/2] Bluetooth: Add MITM mechanism to LE-SMP 2011-12-21 1:04 ` [PATCH-v7 1/2] Bluetooth: Add MITM mechanism " Brian Gix @ 2011-12-21 2:22 ` Marcel Holtmann 2011-12-21 10:28 ` Andrei Emeltchenko 1 sibling, 0 replies; 8+ messages in thread From: Marcel Holtmann @ 2011-12-21 2:22 UTC (permalink / raw) To: Brian Gix; +Cc: linux-bluetooth Hi Brian, > To achive Man-In-The-Middle (MITM) level security with Low Energy, > we have to enable User Passkey Comparison. This commit modifies the > hard-coded JUST-WORKS pairing mechanism to support query via the MGMT > interface of Passkey comparison and User Confirmation. > > Signed-off-by: Brian Gix <bgix@codeaurora.org> > --- > include/net/bluetooth/hci_core.h | 1 + > include/net/bluetooth/smp.h | 5 + > net/bluetooth/smp.c | 227 ++++++++++++++++++++++++++++++++++---- > 3 files changed, 211 insertions(+), 22 deletions(-) > > diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h > index e34cd71..39bcd50 100644 > --- a/include/net/bluetooth/hci_core.h > +++ b/include/net/bluetooth/hci_core.h > @@ -316,6 +316,7 @@ struct hci_conn { > struct hci_dev *hdev; > void *l2cap_data; > void *sco_data; > + void *smp_conn; > > struct hci_conn *link; > > diff --git a/include/net/bluetooth/smp.h b/include/net/bluetooth/smp.h > index 15b97d5..5cbcd05 100644 > --- a/include/net/bluetooth/smp.h > +++ b/include/net/bluetooth/smp.h > @@ -115,6 +115,9 @@ struct smp_cmd_security_req { > #define SMP_MIN_ENC_KEY_SIZE 7 > #define SMP_MAX_ENC_KEY_SIZE 16 > > +#define SMP_FLAG_TK_VALID 1 > +#define SMP_FLAG_CFM_PENDING 2 > + > struct smp_chan { > struct l2cap_conn *conn; > u8 preq[7]; /* SMP Pairing Request */ > @@ -124,6 +127,7 @@ struct smp_chan { > u8 pcnf[16]; /* SMP Pairing Confirm */ > u8 tk[16]; /* SMP Temporary Key */ > u8 smp_key_size; > + unsigned long smp_flags; > struct crypto_blkcipher *tfm; > struct work_struct confirm; > struct work_struct random; > @@ -134,6 +138,7 @@ struct smp_chan { > int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level); > int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb); > int smp_distribute_keys(struct l2cap_conn *conn, __u8 force); > +int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey); > > void smp_chan_destroy(struct l2cap_conn *conn); > > diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c > index 0b96737..42ca847 100644 > --- a/net/bluetooth/smp.c > +++ b/net/bluetooth/smp.c > @@ -23,6 +23,7 @@ > #include <net/bluetooth/bluetooth.h> > #include <net/bluetooth/hci_core.h> > #include <net/bluetooth/l2cap.h> > +#include <net/bluetooth/mgmt.h> > #include <net/bluetooth/smp.h> > #include <linux/crypto.h> > #include <linux/scatterlist.h> > @@ -188,24 +189,45 @@ static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) > msecs_to_jiffies(SMP_TIMEOUT)); > } > > +static __u8 authreq_to_seclevel(__u8 authreq) > +{ > + if (authreq & SMP_AUTH_MITM) > + return BT_SECURITY_HIGH; > + else > + return BT_SECURITY_MEDIUM; > +} > + > +static __u8 seclevel_to_authreq(__u8 sec_level) > +{ > + switch (sec_level) { > + case BT_SECURITY_HIGH: > + return SMP_AUTH_MITM | SMP_AUTH_BONDING; > + case BT_SECURITY_MEDIUM: > + return SMP_AUTH_BONDING; > + default: > + return SMP_AUTH_NONE; > + } > +} > + > static void build_pairing_cmd(struct l2cap_conn *conn, > struct smp_cmd_pairing *req, > struct smp_cmd_pairing *rsp, > __u8 authreq) > { > - u8 dist_keys; > + u8 dist_keys = 0; > > - dist_keys = 0; > if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->flags)) { > dist_keys = SMP_DIST_ENC_KEY; > authreq |= SMP_AUTH_BONDING; > + } else { > + 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->init_key_dist = 0; > req->resp_key_dist = dist_keys; > req->auth_req = authreq; > return; > @@ -214,7 +236,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn, > 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 & dist_keys; > + rsp->init_key_dist = 0; > rsp->resp_key_dist = req->resp_key_dist & dist_keys; > rsp->auth_req = authreq; > } > @@ -244,6 +266,93 @@ static void smp_failure(struct l2cap_conn *conn, u8 reason, u8 send) > smp_chan_destroy(conn); > } > > +#define JUST_WORKS 0x00 > +#define JUST_CFM 0x01 > +#define REQ_PASSKEY 0x02 > +#define CFM_PASSKEY 0x03 > +#define REQ_OOB 0x04 > +#define OVERLAP 0xFF > + > +static const u8 gen_method[5][5] = { some style nitpicks here. Please remove the tab in between. It does not really help to make this more visual. > + {JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY}, > + {JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY}, > + {CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY}, > + {JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM}, > + {CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP} And here please do { JUST_WORKS and close with REQ_PASSKEY } and just make sure that all } align. Also for the last one do }, even it is not strictly speaking necessary. > +}; > + > +static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, > + u8 local_io, u8 remote_io) > +{ > + struct hci_conn *hcon = conn->hcon; > + struct smp_chan *smp = conn->smp_chan; > + u8 method; > + u32 passkey = 0; > + int ret = 0; > + > + /* Initialize key to JUST WORKS */ > + memset(smp->tk, 0, sizeof(smp->tk)); > + clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + > + BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); > + > + /* If neither side wants MITM, use JUST WORKS */ > + /* If either side has unknown io_caps, use JUST_WORKS */ > + if (!(auth & SMP_AUTH_MITM) || > + local_io > SMP_IO_KEYBOARD_DISPLAY || > + remote_io > SMP_IO_KEYBOARD_DISPLAY) { > + auth &= ~SMP_AUTH_MITM; > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; > + } > + > + /* MITM is now officially requested, but not required */ > + /* Determine what we need (if anything) from the agent */ > + method = gen_method[local_io][remote_io]; > + > + if (method == JUST_WORKS || method == JUST_CFM) > + auth &= ~SMP_AUTH_MITM; > + > + /* Don't bother confirming unbonded JUST_WORKS */ > + if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM) { > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; Since we do return 0 here, whey not just do another if we an empty line in between instead of else if. I think it helps a bit with making clear what to code does. I would also not mind some extra small comments on top of every if statement. > + } else if (method == JUST_WORKS) { > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; > + } else if (method == OVERLAP) { > + if (hcon->link_mode & HCI_LM_MASTER) > + method = CFM_PASSKEY; > + else > + method = REQ_PASSKEY; > + } > + > + if (method == CFM_PASSKEY) { > + u8 key[16]; > + /* Generate a passkey for display. It is not valid until > + * confirmed. > + */ > + memset(key, 0, sizeof(key)); > + get_random_bytes(&passkey, sizeof(passkey)); > + passkey %= 1000000; > + put_unaligned_le32(passkey, key); > + swap128(key, smp->tk); > + BT_DBG("PassKey: %d", passkey); > + } > + > + hci_dev_lock(hcon->hdev); > + > + if (method == REQ_PASSKEY) > + ret = mgmt_user_passkey_request(hcon->hdev, conn->dst); > + else > + ret = mgmt_user_confirm_request(hcon->hdev, conn->dst, > + cpu_to_le32(passkey), 0); > + > + hci_dev_unlock(hcon->hdev); > + > + return ret; > +} > + > static void confirm_work(struct work_struct *work) > { > struct smp_chan *smp = container_of(work, struct smp_chan, confirm); > @@ -276,6 +385,8 @@ static void confirm_work(struct work_struct *work) > goto error; > } > > + clear_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); > + > swap128(res, cp.confirm_val); > smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); > > @@ -381,6 +492,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) > > smp->conn = conn; > conn->smp_chan = smp; > + conn->hcon->smp_conn = conn; > > hci_conn_hold(conn->hcon); > > @@ -398,18 +510,67 @@ void smp_chan_destroy(struct l2cap_conn *conn) > > kfree(smp); > conn->smp_chan = NULL; > + conn->hcon->smp_conn = NULL; > hci_conn_put(conn->hcon); > } > > +int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) > +{ > + struct l2cap_conn *conn = hcon->smp_conn; > + struct smp_chan *smp; > + u32 value; > + u8 key[16]; > + u8 reason = 0; > + int ret = 0; > + > + BT_DBG(""); > + > + if (!conn) > + return -ENOTCONN; > + > + smp = conn->smp_chan; > + > + switch (mgmt_op) { > + case MGMT_OP_USER_PASSKEY_REPLY: > + value = le32_to_cpu(passkey); > + memset(key, 0, sizeof(key)); > + BT_DBG("PassKey: %d", value); > + put_unaligned_le32(value, key); > + swap128(key, smp->tk); > + /* Fall Through */ > + case MGMT_OP_USER_CONFIRM_REPLY: > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + break; > + default: > + ret = -EOPNOTSUPP; > + /* Fall Through */ > + case MGMT_OP_USER_PASSKEY_NEG_REPLY: > + case MGMT_OP_USER_CONFIRM_NEG_REPLY: > + reason = SMP_PASSKEY_ENTRY_FAILED; > + break; > + } So I do not like the labels after default at all. I prefer that we have default at really the last one and just duplicate the one line. > + > + if (reason) > + smp_failure(conn, reason, 1); > + else if (test_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags)) > + queue_work(hcon->hdev->workqueue, &smp->confirm); And then looking here, why do we bother with assigning reason while in reality right now it is constant anyway. Could we just not feed that into the switch statement and just return in that case? Maybe some future patches use this, but then you need to give me head up here. Right now this looks too complicated for what it is actually doing. > + > + return ret; > +} > + > static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) > { > struct smp_cmd_pairing rsp, *req = (void *) skb->data; > struct smp_chan *smp; > u8 key_size; > + u8 auth = SMP_AUTH_NONE; > int ret; > > BT_DBG("conn %p", conn); > > + if (conn->hcon->link_mode & HCI_LM_MASTER) > + return SMP_CMD_NOTSUPP; > + > if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend)) > smp = smp_chan_create(conn); > > @@ -419,19 +580,16 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) > memcpy(&smp->preq[1], req, sizeof(*req)); > skb_pull(skb, sizeof(*req)); > > - if (req->oob_flag) > - return SMP_OOB_NOT_AVAIL; > + /* We didn't start the pairing, so match remote */ > + if (req->auth_req & SMP_AUTH_BONDING) > + auth = req->auth_req; > > - /* We didn't start the pairing, so no requirements */ > - build_pairing_cmd(conn, req, &rsp, SMP_AUTH_NONE); > + build_pairing_cmd(conn, req, &rsp, auth); > > key_size = min(req->max_key_size, rsp.max_key_size); > if (check_enc_key_size(conn, key_size)) > return SMP_ENC_KEY_SIZE; > > - /* Just works */ > - memset(smp->tk, 0, sizeof(smp->tk)); > - > ret = smp_rand(smp->prnd); > if (ret) > return SMP_UNSPECIFIED; > @@ -441,6 +599,11 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) > > smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); > > + /* Request setup of TK */ > + ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); > + if (ret) > + return SMP_UNSPECIFIED; > + > return 0; > } > > @@ -449,11 +612,14 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) > struct smp_cmd_pairing *req, *rsp = (void *) skb->data; > struct smp_chan *smp = conn->smp_chan; > struct hci_dev *hdev = conn->hcon->hdev; > - u8 key_size; > + u8 key_size, auth = SMP_AUTH_NONE; > int ret; > > BT_DBG("conn %p", conn); > > + if (!(conn->hcon->link_mode & HCI_LM_MASTER)) > + return SMP_CMD_NOTSUPP; > + > skb_pull(skb, sizeof(*rsp)); > > req = (void *) &smp->preq[1]; > @@ -462,12 +628,6 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) > if (check_enc_key_size(conn, key_size)) > return SMP_ENC_KEY_SIZE; > > - if (rsp->oob_flag) > - return SMP_OOB_NOT_AVAIL; > - > - /* Just works */ > - memset(smp->tk, 0, sizeof(smp->tk)); > - > ret = smp_rand(smp->prnd); > if (ret) > return SMP_UNSPECIFIED; > @@ -475,6 +635,22 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) > smp->prsp[0] = SMP_CMD_PAIRING_RSP; > memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); > > + if ((req->auth_req & SMP_AUTH_BONDING) && > + (rsp->auth_req & SMP_AUTH_BONDING)) > + auth = SMP_AUTH_BONDING; > + > + auth |= (req->auth_req | rsp->auth_req) & SMP_AUTH_MITM; > + > + ret = tk_request(conn, 0, auth, rsp->io_capability, req->io_capability); > + if (ret) > + return SMP_UNSPECIFIED; > + > + set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); > + > + /* Can't compose response until we have been confirmed */ > + if (!test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) > + return 0; > + > queue_work(hdev->workqueue, &smp->confirm); > > return 0; > @@ -496,8 +672,10 @@ static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) > swap128(smp->prnd, random); > smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random), > random); > - } else { > + } else if (test_bit(SMP_FLAG_TK_VALID, &smp->smp_flags)) { > queue_work(hdev->workqueue, &smp->confirm); > + } else { > + set_bit(SMP_FLAG_CFM_PENDING, &smp->smp_flags); > } > > return 0; > @@ -550,7 +728,7 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) > > BT_DBG("conn %p", conn); > > - hcon->pending_sec_level = BT_SECURITY_MEDIUM; > + hcon->pending_sec_level = authreq_to_seclevel(rp->auth_req); > > if (smp_ltk_encrypt(conn)) > return 0; > @@ -577,6 +755,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) > { > struct hci_conn *hcon = conn->hcon; > struct smp_chan *smp = conn->smp_chan; > + __u8 authreq; > > BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); > > @@ -597,18 +776,22 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) > return 0; > > smp = smp_chan_create(conn); > + if (!smp) > + return 1; > + > + authreq = seclevel_to_authreq(sec_level); > > if (hcon->link_mode & HCI_LM_MASTER) { > struct smp_cmd_pairing cp; > > - build_pairing_cmd(conn, &cp, NULL, SMP_AUTH_NONE); > + build_pairing_cmd(conn, &cp, NULL, authreq); > smp->preq[0] = SMP_CMD_PAIRING_REQ; > memcpy(&smp->preq[1], &cp, sizeof(cp)); > > smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); > } else { > struct smp_cmd_security_req cp; > - cp.auth_req = SMP_AUTH_NONE; > + cp.auth_req = authreq; > smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); > } > Someone might need to have a second look over this, but from what I can tell, the rest looks all fine to me. Regards Marcel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH-v7 1/2] Bluetooth: Add MITM mechanism to LE-SMP 2011-12-21 1:04 ` [PATCH-v7 1/2] Bluetooth: Add MITM mechanism " Brian Gix 2011-12-21 2:22 ` Marcel Holtmann @ 2011-12-21 10:28 ` Andrei Emeltchenko 2011-12-21 18:11 ` Brian Gix 1 sibling, 1 reply; 8+ messages in thread From: Andrei Emeltchenko @ 2011-12-21 10:28 UTC (permalink / raw) To: Brian Gix; +Cc: linux-bluetooth Hi Brian, On Tue, Dec 20, 2011 at 05:04:41PM -0800, Brian Gix wrote: > To achive Man-In-The-Middle (MITM) level security with Low Energy, > we have to enable User Passkey Comparison. This commit modifies the > hard-coded JUST-WORKS pairing mechanism to support query via the MGMT > interface of Passkey comparison and User Confirmation. > > Signed-off-by: Brian Gix <bgix@codeaurora.org> > --- > include/net/bluetooth/hci_core.h | 1 + > include/net/bluetooth/smp.h | 5 + > net/bluetooth/smp.c | 227 ++++++++++++++++++++++++++++++++++---- > 3 files changed, 211 insertions(+), 22 deletions(-) ... > +static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, > + u8 local_io, u8 remote_io) > +{ > + struct hci_conn *hcon = conn->hcon; > + struct smp_chan *smp = conn->smp_chan; > + u8 method; > + u32 passkey = 0; > + int ret = 0; > + > + /* Initialize key to JUST WORKS */ > + memset(smp->tk, 0, sizeof(smp->tk)); > + clear_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + > + BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); > + > + /* If neither side wants MITM, use JUST WORKS */ > + /* If either side has unknown io_caps, use JUST_WORKS */ > + if (!(auth & SMP_AUTH_MITM) || > + local_io > SMP_IO_KEYBOARD_DISPLAY || > + remote_io > SMP_IO_KEYBOARD_DISPLAY) { > + auth &= ~SMP_AUTH_MITM; > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; > + } > + > + /* MITM is now officially requested, but not required */ > + /* Determine what we need (if anything) from the agent */ > + method = gen_method[local_io][remote_io]; > + > + if (method == JUST_WORKS || method == JUST_CFM) > + auth &= ~SMP_AUTH_MITM; > + > + /* Don't bother confirming unbonded JUST_WORKS */ > + if (!(auth & SMP_AUTH_BONDING) && method == JUST_CFM) { > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; > + } else if (method == JUST_WORKS) { > + set_bit(SMP_FLAG_TK_VALID, &smp->smp_flags); > + return 0; > + } else if (method == OVERLAP) { > + if (hcon->link_mode & HCI_LM_MASTER) > + method = CFM_PASSKEY; > + else > + method = REQ_PASSKEY; > + } > + > + if (method == CFM_PASSKEY) { > + u8 key[16]; > + /* Generate a passkey for display. It is not valid until > + * confirmed. > + */ > + memset(key, 0, sizeof(key)); > + get_random_bytes(&passkey, sizeof(passkey)); > + passkey %= 1000000; > + put_unaligned_le32(passkey, key); > + swap128(key, smp->tk); > + BT_DBG("PassKey: %d", passkey); > + } Would it make sense to use switch(method) instead of [if/else/else if] ? Best regards Andrei Emeltchenko ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH-v7 1/2] Bluetooth: Add MITM mechanism to LE-SMP 2011-12-21 10:28 ` Andrei Emeltchenko @ 2011-12-21 18:11 ` Brian Gix 2011-12-21 19:50 ` Marcel Holtmann 0 siblings, 1 reply; 8+ messages in thread From: Brian Gix @ 2011-12-21 18:11 UTC (permalink / raw) To: Andrei Emeltchenko, linux-bluetooth Hi Andrei, On 12/21/2011 2:28 AM, Andrei Emeltchenko wrote: > Hi Brian, > > On Tue, Dec 20, 2011 at 05:04:41PM -0800, Brian Gix wrote: >> To achive Man-In-The-Middle (MITM) level security with Low Energy, >> we have to enable User Passkey Comparison. This commit modifies the >> hard-coded JUST-WORKS pairing mechanism to support query via the MGMT >> interface of Passkey comparison and User Confirmation. >> >> Signed-off-by: Brian Gix<bgix@codeaurora.org> >> --- >> include/net/bluetooth/hci_core.h | 1 + >> include/net/bluetooth/smp.h | 5 + >> net/bluetooth/smp.c | 227 ++++++++++++++++++++++++++++++++++---- >> 3 files changed, 211 insertions(+), 22 deletions(-) > > ... > >> +static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, >> + u8 local_io, u8 remote_io) >> +{ >> + struct hci_conn *hcon = conn->hcon; >> + struct smp_chan *smp = conn->smp_chan; >> + u8 method; >> + u32 passkey = 0; >> + int ret = 0; >> + >> + /* Initialize key to JUST WORKS */ >> + memset(smp->tk, 0, sizeof(smp->tk)); >> + clear_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); >> + >> + BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); >> + >> + /* If neither side wants MITM, use JUST WORKS */ >> + /* If either side has unknown io_caps, use JUST_WORKS */ >> + if (!(auth& SMP_AUTH_MITM) || >> + local_io> SMP_IO_KEYBOARD_DISPLAY || >> + remote_io> SMP_IO_KEYBOARD_DISPLAY) { >> + auth&= ~SMP_AUTH_MITM; >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); >> + return 0; >> + } >> + >> + /* MITM is now officially requested, but not required */ >> + /* Determine what we need (if anything) from the agent */ >> + method = gen_method[local_io][remote_io]; >> + >> + if (method == JUST_WORKS || method == JUST_CFM) >> + auth&= ~SMP_AUTH_MITM; >> + >> + /* Don't bother confirming unbonded JUST_WORKS */ >> + if (!(auth& SMP_AUTH_BONDING)&& method == JUST_CFM) { >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); >> + return 0; >> + } else if (method == JUST_WORKS) { >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); >> + return 0; >> + } else if (method == OVERLAP) { >> + if (hcon->link_mode& HCI_LM_MASTER) >> + method = CFM_PASSKEY; >> + else >> + method = REQ_PASSKEY; >> + } >> + >> + if (method == CFM_PASSKEY) { >> + u8 key[16]; >> + /* Generate a passkey for display. It is not valid until >> + * confirmed. >> + */ >> + memset(key, 0, sizeof(key)); >> + get_random_bytes(&passkey, sizeof(passkey)); >> + passkey %= 1000000; >> + put_unaligned_le32(passkey, key); >> + swap128(key, smp->tk); >> + BT_DBG("PassKey: %d", passkey); >> + } > > Would it make sense to use switch(method) instead of [if/else/else if] ? I can use a simpler "method" switch at the end, to determine which mgmt call to make to get the passkey or confirmation. However, the "truth table" is a bit too complex for a switch, with the method being tweaked based on rules coming from the Core Spec, and then later clarified in erratum 4249. I also wanted to avoid putting the random passkey generation inside of the hci_dev_lock block. -- Brian Gix bgix@codeaurora.org Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH-v7 1/2] Bluetooth: Add MITM mechanism to LE-SMP 2011-12-21 18:11 ` Brian Gix @ 2011-12-21 19:50 ` Marcel Holtmann 0 siblings, 0 replies; 8+ messages in thread From: Marcel Holtmann @ 2011-12-21 19:50 UTC (permalink / raw) To: Brian Gix; +Cc: Andrei Emeltchenko, linux-bluetooth Hi Brian, > > On Tue, Dec 20, 2011 at 05:04:41PM -0800, Brian Gix wrote: > >> To achive Man-In-The-Middle (MITM) level security with Low Energy, > >> we have to enable User Passkey Comparison. This commit modifies the > >> hard-coded JUST-WORKS pairing mechanism to support query via the MGMT > >> interface of Passkey comparison and User Confirmation. > >> > >> Signed-off-by: Brian Gix<bgix@codeaurora.org> > >> --- > >> include/net/bluetooth/hci_core.h | 1 + > >> include/net/bluetooth/smp.h | 5 + > >> net/bluetooth/smp.c | 227 ++++++++++++++++++++++++++++++++++---- > >> 3 files changed, 211 insertions(+), 22 deletions(-) > > > > ... > > > >> +static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, > >> + u8 local_io, u8 remote_io) > >> +{ > >> + struct hci_conn *hcon = conn->hcon; > >> + struct smp_chan *smp = conn->smp_chan; > >> + u8 method; > >> + u32 passkey = 0; > >> + int ret = 0; > >> + > >> + /* Initialize key to JUST WORKS */ > >> + memset(smp->tk, 0, sizeof(smp->tk)); > >> + clear_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); > >> + > >> + BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); > >> + > >> + /* If neither side wants MITM, use JUST WORKS */ > >> + /* If either side has unknown io_caps, use JUST_WORKS */ > >> + if (!(auth& SMP_AUTH_MITM) || > >> + local_io> SMP_IO_KEYBOARD_DISPLAY || > >> + remote_io> SMP_IO_KEYBOARD_DISPLAY) { > >> + auth&= ~SMP_AUTH_MITM; > >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); > >> + return 0; > >> + } > >> + > >> + /* MITM is now officially requested, but not required */ > >> + /* Determine what we need (if anything) from the agent */ > >> + method = gen_method[local_io][remote_io]; > >> + > >> + if (method == JUST_WORKS || method == JUST_CFM) > >> + auth&= ~SMP_AUTH_MITM; > >> + > >> + /* Don't bother confirming unbonded JUST_WORKS */ > >> + if (!(auth& SMP_AUTH_BONDING)&& method == JUST_CFM) { > >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); > >> + return 0; > >> + } else if (method == JUST_WORKS) { > >> + set_bit(SMP_FLAG_TK_VALID,&smp->smp_flags); > >> + return 0; > >> + } else if (method == OVERLAP) { > >> + if (hcon->link_mode& HCI_LM_MASTER) > >> + method = CFM_PASSKEY; > >> + else > >> + method = REQ_PASSKEY; > >> + } > >> + > >> + if (method == CFM_PASSKEY) { > >> + u8 key[16]; > >> + /* Generate a passkey for display. It is not valid until > >> + * confirmed. > >> + */ > >> + memset(key, 0, sizeof(key)); > >> + get_random_bytes(&passkey, sizeof(passkey)); > >> + passkey %= 1000000; > >> + put_unaligned_le32(passkey, key); > >> + swap128(key, smp->tk); > >> + BT_DBG("PassKey: %d", passkey); > >> + } > > > > Would it make sense to use switch(method) instead of [if/else/else if] ? > > I can use a simpler "method" switch at the end, to determine which mgmt > call to make to get the passkey or confirmation. However, the "truth > table" is a bit too complex for a switch, with the method being tweaked > based on rules coming from the Core Spec, and then later clarified in > erratum 4249. I also wanted to avoid putting the random passkey > generation inside of the hci_dev_lock block. I am fine with if statements as long as you just return and do not bother with else if. Regards Marcel ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm 2011-12-21 1:04 [PATCH-v7 0/2] Bluetooth: Add MITM protection to LE-SMP Brian Gix 2011-12-21 1:04 ` [PATCH-v7 1/2] Bluetooth: Add MITM mechanism " Brian Gix @ 2011-12-21 1:04 ` Brian Gix 2011-12-21 2:26 ` Marcel Holtmann 1 sibling, 1 reply; 8+ messages in thread From: Brian Gix @ 2011-12-21 1:04 UTC (permalink / raw) To: linux-bluetooth; +Cc: Brian Gix Low Energy pairing is performed through the SMP (Security Manager Protocol) mechanism rather than HCI. Signed-off-by: Brian Gix <bgix@codeaurora.org> --- net/bluetooth/mgmt.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 7a23f21..4e05e24 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -29,6 +29,7 @@ #include <net/bluetooth/bluetooth.h> #include <net/bluetooth/hci_core.h> #include <net/bluetooth/mgmt.h> +#include <net/bluetooth/smp.h> #define MGMT_VERSION 0 #define MGMT_REVISION 1 @@ -1606,8 +1607,15 @@ static int user_pairing_resp(struct sock *sk, u16 index, bdaddr_t *bdaddr, } /* Continue with pairing via SMP */ + err = smp_user_confirm_reply(conn, mgmt_op, passkey); + + if (!err) + err = cmd_status(sk, index, mgmt_op, + MGMT_STATUS_SUCCESS); + else + err = cmd_status(sk, index, mgmt_op, + MGMT_STATUS_FAILED); - err = cmd_status(sk, index, mgmt_op, MGMT_STATUS_SUCCESS); goto done; } -- 1.7.8 -- Brian Gix bgix@codeaurora.org Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm 2011-12-21 1:04 ` [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm Brian Gix @ 2011-12-21 2:26 ` Marcel Holtmann 0 siblings, 0 replies; 8+ messages in thread From: Marcel Holtmann @ 2011-12-21 2:26 UTC (permalink / raw) To: Brian Gix; +Cc: linux-bluetooth Hi Brain, > Low Energy pairing is performed through the SMP (Security Manager Protocol) > mechanism rather than HCI. > > Signed-off-by: Brian Gix <bgix@codeaurora.org> > --- > net/bluetooth/mgmt.c | 10 +++++++++- > 1 files changed, 9 insertions(+), 1 deletions(-) Acked-by: Marcel Holtmann <marcel@holtmann.org> Regards Marcel ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2011-12-21 19:50 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-12-21 1:04 [PATCH-v7 0/2] Bluetooth: Add MITM protection to LE-SMP Brian Gix 2011-12-21 1:04 ` [PATCH-v7 1/2] Bluetooth: Add MITM mechanism " Brian Gix 2011-12-21 2:22 ` Marcel Holtmann 2011-12-21 10:28 ` Andrei Emeltchenko 2011-12-21 18:11 ` Brian Gix 2011-12-21 19:50 ` Marcel Holtmann 2011-12-21 1:04 ` [PATCH-v7 2/2] Bluetooth: Add SMP to User Passkey and Confirm Brian Gix 2011-12-21 2:26 ` Marcel Holtmann
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