| /* |
| BlueZ - Bluetooth protocol stack for Linux |
| Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License version 2 as |
| published by the Free Software Foundation; |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. |
| IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY |
| CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS, |
| COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS |
| SOFTWARE IS DISCLAIMED. |
| */ |
| |
| #include <linux/crypto.h> |
| #include <linux/scatterlist.h> |
| #include <crypto/b128ops.h> |
| |
| #include <net/bluetooth/bluetooth.h> |
| #include <net/bluetooth/hci_core.h> |
| #include <net/bluetooth/l2cap.h> |
| #include <net/bluetooth/mgmt.h> |
| |
| #include "smp.h" |
| |
| #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) |
| |
| #define SMP_TIMEOUT msecs_to_jiffies(30000) |
| |
| #define AUTH_REQ_MASK 0x07 |
| #define KEY_DIST_MASK 0x07 |
| |
| enum { |
| SMP_FLAG_TK_VALID, |
| SMP_FLAG_CFM_PENDING, |
| SMP_FLAG_MITM_AUTH, |
| SMP_FLAG_COMPLETE, |
| SMP_FLAG_INITIATOR, |
| }; |
| |
| struct smp_chan { |
| struct l2cap_conn *conn; |
| struct delayed_work security_timer; |
| unsigned long allow_cmd; /* Bitmask of allowed commands */ |
| |
| u8 preq[7]; /* SMP Pairing Request */ |
| u8 prsp[7]; /* SMP Pairing Response */ |
| u8 prnd[16]; /* SMP Pairing Random (local) */ |
| u8 rrnd[16]; /* SMP Pairing Random (remote) */ |
| u8 pcnf[16]; /* SMP Pairing Confirm */ |
| u8 tk[16]; /* SMP Temporary Key */ |
| u8 enc_key_size; |
| u8 remote_key_dist; |
| bdaddr_t id_addr; |
| u8 id_addr_type; |
| u8 irk[16]; |
| struct smp_csrk *csrk; |
| struct smp_csrk *slave_csrk; |
| struct smp_ltk *ltk; |
| struct smp_ltk *slave_ltk; |
| struct smp_irk *remote_irk; |
| unsigned long flags; |
| |
| struct crypto_blkcipher *tfm_aes; |
| }; |
| |
| static inline void swap_buf(const u8 *src, u8 *dst, size_t len) |
| { |
| size_t i; |
| |
| for (i = 0; i < len; i++) |
| dst[len - 1 - i] = src[i]; |
| } |
| |
| static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r) |
| { |
| struct blkcipher_desc desc; |
| struct scatterlist sg; |
| uint8_t tmp[16], data[16]; |
| int err; |
| |
| if (tfm == NULL) { |
| BT_ERR("tfm %p", tfm); |
| return -EINVAL; |
| } |
| |
| desc.tfm = tfm; |
| desc.flags = 0; |
| |
| /* The most significant octet of key corresponds to k[0] */ |
| swap_buf(k, tmp, 16); |
| |
| err = crypto_blkcipher_setkey(tfm, tmp, 16); |
| if (err) { |
| BT_ERR("cipher setkey failed: %d", err); |
| return err; |
| } |
| |
| /* Most significant octet of plaintextData corresponds to data[0] */ |
| swap_buf(r, data, 16); |
| |
| sg_init_one(&sg, data, 16); |
| |
| err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16); |
| if (err) |
| BT_ERR("Encrypt data error %d", err); |
| |
| /* Most significant octet of encryptedData corresponds to data[0] */ |
| swap_buf(data, r, 16); |
| |
| return err; |
| } |
| |
| static int smp_ah(struct crypto_blkcipher *tfm, u8 irk[16], u8 r[3], u8 res[3]) |
| { |
| u8 _res[16]; |
| int err; |
| |
| /* r' = padding || r */ |
| memcpy(_res, r, 3); |
| memset(_res + 3, 0, 13); |
| |
| err = smp_e(tfm, irk, _res); |
| if (err) { |
| BT_ERR("Encrypt error"); |
| return err; |
| } |
| |
| /* The output of the random address function ah is: |
| * ah(h, r) = e(k, r') mod 2^24 |
| * The output of the security function e is then truncated to 24 bits |
| * by taking the least significant 24 bits of the output of e as the |
| * result of ah. |
| */ |
| memcpy(res, _res, 3); |
| |
| return 0; |
| } |
| |
| bool smp_irk_matches(struct hci_dev *hdev, u8 irk[16], bdaddr_t *bdaddr) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| struct crypto_blkcipher *tfm; |
| u8 hash[3]; |
| int err; |
| |
| if (!chan || !chan->data) |
| return false; |
| |
| tfm = chan->data; |
| |
| BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk); |
| |
| err = smp_ah(tfm, irk, &bdaddr->b[3], hash); |
| if (err) |
| return false; |
| |
| return !memcmp(bdaddr->b, hash, 3); |
| } |
| |
| int smp_generate_rpa(struct hci_dev *hdev, u8 irk[16], bdaddr_t *rpa) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| struct crypto_blkcipher *tfm; |
| int err; |
| |
| if (!chan || !chan->data) |
| return -EOPNOTSUPP; |
| |
| tfm = chan->data; |
| |
| get_random_bytes(&rpa->b[3], 3); |
| |
| rpa->b[5] &= 0x3f; /* Clear two most significant bits */ |
| rpa->b[5] |= 0x40; /* Set second most significant bit */ |
| |
| err = smp_ah(tfm, irk, &rpa->b[3], rpa->b); |
| if (err < 0) |
| return err; |
| |
| BT_DBG("RPA %pMR", rpa); |
| |
| return 0; |
| } |
| |
| static int smp_c1(struct crypto_blkcipher *tfm_aes, u8 k[16], u8 r[16], |
| u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia, u8 _rat, |
| bdaddr_t *ra, u8 res[16]) |
| { |
| u8 p1[16], p2[16]; |
| int err; |
| |
| memset(p1, 0, 16); |
| |
| /* p1 = pres || preq || _rat || _iat */ |
| p1[0] = _iat; |
| p1[1] = _rat; |
| memcpy(p1 + 2, preq, 7); |
| memcpy(p1 + 9, pres, 7); |
| |
| /* p2 = padding || ia || ra */ |
| memcpy(p2, ra, 6); |
| memcpy(p2 + 6, ia, 6); |
| memset(p2 + 12, 0, 4); |
| |
| /* res = r XOR p1 */ |
| u128_xor((u128 *) res, (u128 *) r, (u128 *) p1); |
| |
| /* res = e(k, res) */ |
| err = smp_e(tfm_aes, k, res); |
| if (err) { |
| BT_ERR("Encrypt data error"); |
| return err; |
| } |
| |
| /* res = res XOR p2 */ |
| u128_xor((u128 *) res, (u128 *) res, (u128 *) p2); |
| |
| /* res = e(k, res) */ |
| err = smp_e(tfm_aes, k, res); |
| if (err) |
| BT_ERR("Encrypt data error"); |
| |
| return err; |
| } |
| |
| static int smp_s1(struct crypto_blkcipher *tfm_aes, u8 k[16], u8 r1[16], |
| u8 r2[16], u8 _r[16]) |
| { |
| int err; |
| |
| /* Just least significant octets from r1 and r2 are considered */ |
| memcpy(_r, r2, 8); |
| memcpy(_r + 8, r1, 8); |
| |
| err = smp_e(tfm_aes, k, _r); |
| if (err) |
| BT_ERR("Encrypt data error"); |
| |
| return err; |
| } |
| |
| static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp; |
| struct kvec iv[2]; |
| struct msghdr msg; |
| |
| if (!chan) |
| return; |
| |
| BT_DBG("code 0x%2.2x", code); |
| |
| iv[0].iov_base = &code; |
| iv[0].iov_len = 1; |
| |
| iv[1].iov_base = data; |
| iv[1].iov_len = len; |
| |
| memset(&msg, 0, sizeof(msg)); |
| |
| msg.msg_iov = (struct iovec *) &iv; |
| msg.msg_iovlen = 2; |
| |
| l2cap_chan_send(chan, &msg, 1 + len); |
| |
| if (!chan->data) |
| return; |
| |
| smp = chan->data; |
| |
| cancel_delayed_work_sync(&smp->security_timer); |
| schedule_delayed_work(&smp->security_timer, 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) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| u8 local_dist = 0, remote_dist = 0; |
| |
| if (test_bit(HCI_BONDABLE, &conn->hcon->hdev->dev_flags)) { |
| local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| authreq |= SMP_AUTH_BONDING; |
| } else { |
| authreq &= ~SMP_AUTH_BONDING; |
| } |
| |
| if (test_bit(HCI_RPA_RESOLVING, &hdev->dev_flags)) |
| remote_dist |= SMP_DIST_ID_KEY; |
| |
| if (test_bit(HCI_PRIVACY, &hdev->dev_flags)) |
| local_dist |= SMP_DIST_ID_KEY; |
| |
| 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 = local_dist; |
| req->resp_key_dist = remote_dist; |
| req->auth_req = (authreq & AUTH_REQ_MASK); |
| |
| smp->remote_key_dist = remote_dist; |
| 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 & remote_dist; |
| rsp->resp_key_dist = req->resp_key_dist & local_dist; |
| rsp->auth_req = (authreq & AUTH_REQ_MASK); |
| |
| smp->remote_key_dist = rsp->init_key_dist; |
| } |
| |
| static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) || |
| (max_key_size < SMP_MIN_ENC_KEY_SIZE)) |
| return SMP_ENC_KEY_SIZE; |
| |
| smp->enc_key_size = max_key_size; |
| |
| return 0; |
| } |
| |
| static void smp_chan_destroy(struct l2cap_conn *conn) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| bool complete; |
| |
| BUG_ON(!smp); |
| |
| cancel_delayed_work_sync(&smp->security_timer); |
| |
| complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); |
| mgmt_smp_complete(conn->hcon, complete); |
| |
| kfree(smp->csrk); |
| kfree(smp->slave_csrk); |
| |
| crypto_free_blkcipher(smp->tfm_aes); |
| |
| /* If pairing failed clean up any keys we might have */ |
| if (!complete) { |
| if (smp->ltk) { |
| list_del_rcu(&smp->ltk->list); |
| kfree_rcu(smp->ltk, rcu); |
| } |
| |
| if (smp->slave_ltk) { |
| list_del_rcu(&smp->slave_ltk->list); |
| kfree_rcu(smp->slave_ltk, rcu); |
| } |
| |
| if (smp->remote_irk) { |
| list_del_rcu(&smp->remote_irk->list); |
| kfree_rcu(smp->remote_irk, rcu); |
| } |
| } |
| |
| chan->data = NULL; |
| kfree(smp); |
| hci_conn_drop(conn->hcon); |
| } |
| |
| static void smp_failure(struct l2cap_conn *conn, u8 reason) |
| { |
| struct hci_conn *hcon = conn->hcon; |
| struct l2cap_chan *chan = conn->smp; |
| |
| if (reason) |
| smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), |
| &reason); |
| |
| clear_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags); |
| mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); |
| |
| if (chan->data) |
| 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 u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) |
| { |
| /* If either side has unknown io_caps, use JUST_CFM (which gets |
| * converted later to JUST_WORKS if we're initiators. |
| */ |
| if (local_io > SMP_IO_KEYBOARD_DISPLAY || |
| remote_io > SMP_IO_KEYBOARD_DISPLAY) |
| return JUST_CFM; |
| |
| return gen_method[remote_io][local_io]; |
| } |
| |
| 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 l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| u8 method; |
| u32 passkey = 0; |
| int ret = 0; |
| |
| /* Initialize key for JUST WORKS */ |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| clear_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| |
| BT_DBG("tk_request: auth:%d lcl:%d rem:%d", auth, local_io, remote_io); |
| |
| /* If neither side wants MITM, either "just" confirm an incoming |
| * request or use just-works for outgoing ones. The JUST_CFM |
| * will be converted to JUST_WORKS if necessary later in this |
| * function. If either side has MITM look up the method from the |
| * table. |
| */ |
| if (!(auth & SMP_AUTH_MITM)) |
| method = JUST_CFM; |
| else |
| method = get_auth_method(smp, local_io, remote_io); |
| |
| /* Don't confirm locally initiated pairing attempts */ |
| if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) |
| method = JUST_WORKS; |
| |
| /* Don't bother user space with no IO capabilities */ |
| if (method == JUST_CFM && hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| method = JUST_WORKS; |
| |
| /* If Just Works, Continue with Zero TK */ |
| if (method == JUST_WORKS) { |
| set_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| return 0; |
| } |
| |
| /* Not Just Works/Confirm results in MITM Authentication */ |
| if (method != JUST_CFM) { |
| set_bit(SMP_FLAG_MITM_AUTH, &smp->flags); |
| if (hcon->pending_sec_level < BT_SECURITY_HIGH) |
| hcon->pending_sec_level = BT_SECURITY_HIGH; |
| } |
| |
| /* If both devices have Keyoard-Display I/O, the master |
| * Confirms and the slave Enters the passkey. |
| */ |
| if (method == OVERLAP) { |
| if (hcon->role == HCI_ROLE_MASTER) |
| method = CFM_PASSKEY; |
| else |
| method = REQ_PASSKEY; |
| } |
| |
| /* Generate random passkey. */ |
| if (method == CFM_PASSKEY) { |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| get_random_bytes(&passkey, sizeof(passkey)); |
| passkey %= 1000000; |
| put_unaligned_le32(passkey, smp->tk); |
| BT_DBG("PassKey: %d", passkey); |
| set_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| } |
| |
| if (method == REQ_PASSKEY) |
| ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type); |
| else if (method == JUST_CFM) |
| ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type, |
| passkey, 1); |
| else |
| ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type, |
| passkey, 0); |
| |
| return ret; |
| } |
| |
| static u8 smp_confirm(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct smp_cmd_pairing_confirm cp; |
| int ret; |
| |
| BT_DBG("conn %p", conn); |
| |
| ret = smp_c1(smp->tfm_aes, smp->tk, smp->prnd, smp->preq, smp->prsp, |
| conn->hcon->init_addr_type, &conn->hcon->init_addr, |
| conn->hcon->resp_addr_type, &conn->hcon->resp_addr, |
| cp.confirm_val); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); |
| |
| if (conn->hcon->out) |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| else |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| return 0; |
| } |
| |
| static u8 smp_random(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| u8 confirm[16]; |
| int ret; |
| |
| if (IS_ERR_OR_NULL(smp->tfm_aes)) |
| return SMP_UNSPECIFIED; |
| |
| BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); |
| |
| ret = smp_c1(smp->tfm_aes, smp->tk, smp->rrnd, smp->preq, smp->prsp, |
| hcon->init_addr_type, &hcon->init_addr, |
| hcon->resp_addr_type, &hcon->resp_addr, confirm); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) { |
| BT_ERR("Pairing failed (confirmation values mismatch)"); |
| return SMP_CONFIRM_FAILED; |
| } |
| |
| if (hcon->out) { |
| u8 stk[16]; |
| __le64 rand = 0; |
| __le16 ediv = 0; |
| |
| smp_s1(smp->tfm_aes, smp->tk, smp->rrnd, smp->prnd, stk); |
| |
| memset(stk + smp->enc_key_size, 0, |
| SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size); |
| |
| if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) |
| return SMP_UNSPECIFIED; |
| |
| hci_le_start_enc(hcon, ediv, rand, stk); |
| hcon->enc_key_size = smp->enc_key_size; |
| set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); |
| } else { |
| u8 stk[16], auth; |
| __le64 rand = 0; |
| __le16 ediv = 0; |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), |
| smp->prnd); |
| |
| smp_s1(smp->tfm_aes, smp->tk, smp->prnd, smp->rrnd, stk); |
| |
| memset(stk + smp->enc_key_size, 0, |
| SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size); |
| |
| if (hcon->pending_sec_level == BT_SECURITY_HIGH) |
| auth = 1; |
| else |
| auth = 0; |
| |
| /* Even though there's no _SLAVE suffix this is the |
| * slave STK we're adding for later lookup (the master |
| * STK never needs to be stored). |
| */ |
| hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, |
| SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); |
| } |
| |
| return 0; |
| } |
| |
| static void smp_notify_keys(struct l2cap_conn *conn) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| struct smp_cmd_pairing *req = (void *) &smp->preq[1]; |
| struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; |
| bool persistent; |
| |
| if (smp->remote_irk) { |
| mgmt_new_irk(hdev, smp->remote_irk); |
| /* Now that user space can be considered to know the |
| * identity address track the connection based on it |
| * from now on. |
| */ |
| bacpy(&hcon->dst, &smp->remote_irk->bdaddr); |
| hcon->dst_type = smp->remote_irk->addr_type; |
| queue_work(hdev->workqueue, &conn->id_addr_update_work); |
| |
| /* When receiving an indentity resolving key for |
| * a remote device that does not use a resolvable |
| * private address, just remove the key so that |
| * it is possible to use the controller white |
| * list for scanning. |
| * |
| * Userspace will have been told to not store |
| * this key at this point. So it is safe to |
| * just remove it. |
| */ |
| if (!bacmp(&smp->remote_irk->rpa, BDADDR_ANY)) { |
| list_del_rcu(&smp->remote_irk->list); |
| kfree_rcu(smp->remote_irk, rcu); |
| smp->remote_irk = NULL; |
| } |
| } |
| |
| /* The LTKs and CSRKs should be persistent only if both sides |
| * had the bonding bit set in their authentication requests. |
| */ |
| persistent = !!((req->auth_req & rsp->auth_req) & SMP_AUTH_BONDING); |
| |
| if (smp->csrk) { |
| smp->csrk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->csrk->bdaddr, &hcon->dst); |
| mgmt_new_csrk(hdev, smp->csrk, persistent); |
| } |
| |
| if (smp->slave_csrk) { |
| smp->slave_csrk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->slave_csrk->bdaddr, &hcon->dst); |
| mgmt_new_csrk(hdev, smp->slave_csrk, persistent); |
| } |
| |
| if (smp->ltk) { |
| smp->ltk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->ltk->bdaddr, &hcon->dst); |
| mgmt_new_ltk(hdev, smp->ltk, persistent); |
| } |
| |
| if (smp->slave_ltk) { |
| smp->slave_ltk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->slave_ltk->bdaddr, &hcon->dst); |
| mgmt_new_ltk(hdev, smp->slave_ltk, persistent); |
| } |
| } |
| |
| static void smp_allow_key_dist(struct smp_chan *smp) |
| { |
| /* Allow the first expected phase 3 PDU. The rest of the PDUs |
| * will be allowed in each PDU handler to ensure we receive |
| * them in the correct order. |
| */ |
| if (smp->remote_key_dist & SMP_DIST_ENC_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_ID_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| } |
| |
| static void smp_distribute_keys(struct smp_chan *smp) |
| { |
| struct smp_cmd_pairing *req, *rsp; |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| __u8 *keydist; |
| |
| BT_DBG("conn %p", conn); |
| |
| rsp = (void *) &smp->prsp[1]; |
| |
| /* The responder sends its keys first */ |
| if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { |
| smp_allow_key_dist(smp); |
| return; |
| } |
| |
| req = (void *) &smp->preq[1]; |
| |
| if (hcon->out) { |
| keydist = &rsp->init_key_dist; |
| *keydist &= req->init_key_dist; |
| } else { |
| keydist = &rsp->resp_key_dist; |
| *keydist &= req->resp_key_dist; |
| } |
| |
| BT_DBG("keydist 0x%x", *keydist); |
| |
| if (*keydist & SMP_DIST_ENC_KEY) { |
| struct smp_cmd_encrypt_info enc; |
| struct smp_cmd_master_ident ident; |
| struct smp_ltk *ltk; |
| u8 authenticated; |
| __le16 ediv; |
| __le64 rand; |
| |
| get_random_bytes(enc.ltk, sizeof(enc.ltk)); |
| get_random_bytes(&ediv, sizeof(ediv)); |
| get_random_bytes(&rand, sizeof(rand)); |
| |
| smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); |
| |
| authenticated = hcon->sec_level == BT_SECURITY_HIGH; |
| ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, |
| SMP_LTK_SLAVE, authenticated, enc.ltk, |
| smp->enc_key_size, ediv, rand); |
| smp->slave_ltk = ltk; |
| |
| ident.ediv = ediv; |
| ident.rand = rand; |
| |
| smp_send_cmd(conn, SMP_CMD_MASTER_IDENT, sizeof(ident), &ident); |
| |
| *keydist &= ~SMP_DIST_ENC_KEY; |
| } |
| |
| if (*keydist & SMP_DIST_ID_KEY) { |
| struct smp_cmd_ident_addr_info addrinfo; |
| struct smp_cmd_ident_info idinfo; |
| |
| memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); |
| |
| smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); |
| |
| /* The hci_conn contains the local identity address |
| * after the connection has been established. |
| * |
| * This is true even when the connection has been |
| * established using a resolvable random address. |
| */ |
| bacpy(&addrinfo.bdaddr, &hcon->src); |
| addrinfo.addr_type = hcon->src_type; |
| |
| smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), |
| &addrinfo); |
| |
| *keydist &= ~SMP_DIST_ID_KEY; |
| } |
| |
| if (*keydist & SMP_DIST_SIGN) { |
| struct smp_cmd_sign_info sign; |
| struct smp_csrk *csrk; |
| |
| /* Generate a new random key */ |
| get_random_bytes(sign.csrk, sizeof(sign.csrk)); |
| |
| csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); |
| if (csrk) { |
| csrk->master = 0x00; |
| memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); |
| } |
| smp->slave_csrk = csrk; |
| |
| smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); |
| |
| *keydist &= ~SMP_DIST_SIGN; |
| } |
| |
| /* If there are still keys to be received wait for them */ |
| if (smp->remote_key_dist & KEY_DIST_MASK) { |
| smp_allow_key_dist(smp); |
| return; |
| } |
| |
| set_bit(SMP_FLAG_COMPLETE, &smp->flags); |
| smp_notify_keys(conn); |
| |
| smp_chan_destroy(conn); |
| } |
| |
| static void smp_timeout(struct work_struct *work) |
| { |
| struct smp_chan *smp = container_of(work, struct smp_chan, |
| security_timer.work); |
| struct l2cap_conn *conn = smp->conn; |
| |
| BT_DBG("conn %p", conn); |
| |
| hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); |
| } |
| |
| static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp; |
| |
| smp = kzalloc(sizeof(*smp), GFP_ATOMIC); |
| if (!smp) |
| return NULL; |
| |
| smp->tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC); |
| if (IS_ERR(smp->tfm_aes)) { |
| BT_ERR("Unable to create ECB crypto context"); |
| kfree(smp); |
| return NULL; |
| } |
| |
| smp->conn = conn; |
| chan->data = smp; |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); |
| |
| INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); |
| |
| hci_conn_hold(conn->hcon); |
| |
| return smp; |
| } |
| |
| int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) |
| { |
| struct l2cap_conn *conn = hcon->l2cap_data; |
| struct l2cap_chan *chan; |
| struct smp_chan *smp; |
| u32 value; |
| int err; |
| |
| BT_DBG(""); |
| |
| if (!conn) |
| return -ENOTCONN; |
| |
| chan = conn->smp; |
| if (!chan) |
| return -ENOTCONN; |
| |
| l2cap_chan_lock(chan); |
| if (!chan->data) { |
| err = -ENOTCONN; |
| goto unlock; |
| } |
| |
| smp = chan->data; |
| |
| switch (mgmt_op) { |
| case MGMT_OP_USER_PASSKEY_REPLY: |
| value = le32_to_cpu(passkey); |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| BT_DBG("PassKey: %d", value); |
| put_unaligned_le32(value, smp->tk); |
| /* Fall Through */ |
| case MGMT_OP_USER_CONFIRM_REPLY: |
| set_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| break; |
| case MGMT_OP_USER_PASSKEY_NEG_REPLY: |
| case MGMT_OP_USER_CONFIRM_NEG_REPLY: |
| smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); |
| err = 0; |
| goto unlock; |
| default: |
| smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); |
| err = -EOPNOTSUPP; |
| goto unlock; |
| } |
| |
| err = 0; |
| |
| /* If it is our turn to send Pairing Confirm, do so now */ |
| if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { |
| u8 rsp = smp_confirm(smp); |
| if (rsp) |
| smp_failure(conn, rsp); |
| } |
| |
| unlock: |
| l2cap_chan_unlock(chan); |
| return err; |
| } |
| |
| static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_pairing rsp, *req = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| struct smp_chan *smp; |
| u8 key_size, auth, sec_level; |
| int ret; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*req)) |
| return SMP_INVALID_PARAMS; |
| |
| if (conn->hcon->role != HCI_ROLE_SLAVE) |
| return SMP_CMD_NOTSUPP; |
| |
| if (!chan->data) |
| smp = smp_chan_create(conn); |
| else |
| smp = chan->data; |
| |
| if (!smp) |
| return SMP_UNSPECIFIED; |
| |
| /* We didn't start the pairing, so match remote */ |
| auth = req->auth_req & AUTH_REQ_MASK; |
| |
| if (!test_bit(HCI_BONDABLE, &hdev->dev_flags) && |
| (auth & SMP_AUTH_BONDING)) |
| return SMP_PAIRING_NOTSUPP; |
| |
| smp->preq[0] = SMP_CMD_PAIRING_REQ; |
| memcpy(&smp->preq[1], req, sizeof(*req)); |
| skb_pull(skb, sizeof(*req)); |
| |
| if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| sec_level = BT_SECURITY_MEDIUM; |
| else |
| sec_level = authreq_to_seclevel(auth); |
| |
| if (sec_level > conn->hcon->pending_sec_level) |
| conn->hcon->pending_sec_level = sec_level; |
| |
| /* If we need MITM check that it can be achieved */ |
| if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { |
| u8 method; |
| |
| method = get_auth_method(smp, conn->hcon->io_capability, |
| req->io_capability); |
| if (method == JUST_WORKS || method == JUST_CFM) |
| return SMP_AUTH_REQUIREMENTS; |
| } |
| |
| 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; |
| |
| get_random_bytes(smp->prnd, sizeof(smp->prnd)); |
| |
| smp->prsp[0] = SMP_CMD_PAIRING_RSP; |
| memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| |
| /* Request setup of TK */ |
| ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| return 0; |
| } |
| |
| static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_pairing *req, *rsp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| u8 key_size, auth; |
| int ret; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*rsp)) |
| return SMP_INVALID_PARAMS; |
| |
| if (conn->hcon->role != HCI_ROLE_MASTER) |
| return SMP_CMD_NOTSUPP; |
| |
| skb_pull(skb, sizeof(*rsp)); |
| |
| req = (void *) &smp->preq[1]; |
| |
| key_size = min(req->max_key_size, rsp->max_key_size); |
| if (check_enc_key_size(conn, key_size)) |
| return SMP_ENC_KEY_SIZE; |
| |
| auth = rsp->auth_req & AUTH_REQ_MASK; |
| |
| /* If we need MITM check that it can be achieved */ |
| if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { |
| u8 method; |
| |
| method = get_auth_method(smp, req->io_capability, |
| rsp->io_capability); |
| if (method == JUST_WORKS || method == JUST_CFM) |
| return SMP_AUTH_REQUIREMENTS; |
| } |
| |
| get_random_bytes(smp->prnd, sizeof(smp->prnd)); |
| |
| smp->prsp[0] = SMP_CMD_PAIRING_RSP; |
| memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); |
| |
| /* Update remote key distribution in case the remote cleared |
| * some bits that we had enabled in our request. |
| */ |
| smp->remote_key_dist &= rsp->resp_key_dist; |
| |
| auth |= req->auth_req; |
| |
| ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| /* Can't compose response until we have been confirmed */ |
| if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) |
| return smp_confirm(smp); |
| |
| return 0; |
| } |
| |
| static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave"); |
| |
| if (skb->len < sizeof(smp->pcnf)) |
| return SMP_INVALID_PARAMS; |
| |
| memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); |
| skb_pull(skb, sizeof(smp->pcnf)); |
| |
| if (conn->hcon->out) { |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), |
| smp->prnd); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| return 0; |
| } |
| |
| if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) |
| return smp_confirm(smp); |
| else |
| set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| return 0; |
| } |
| |
| static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(smp->rrnd)) |
| return SMP_INVALID_PARAMS; |
| |
| memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); |
| skb_pull(skb, sizeof(smp->rrnd)); |
| |
| return smp_random(smp); |
| } |
| |
| static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) |
| { |
| struct smp_ltk *key; |
| struct hci_conn *hcon = conn->hcon; |
| |
| key = hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type, |
| hcon->role); |
| if (!key) |
| return false; |
| |
| if (smp_ltk_sec_level(key) < sec_level) |
| return false; |
| |
| if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) |
| return true; |
| |
| hci_le_start_enc(hcon, key->ediv, key->rand, key->val); |
| hcon->enc_key_size = key->enc_size; |
| |
| /* We never store STKs for master role, so clear this flag */ |
| clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); |
| |
| return true; |
| } |
| |
| bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, |
| enum smp_key_pref key_pref) |
| { |
| if (sec_level == BT_SECURITY_LOW) |
| return true; |
| |
| /* If we're encrypted with an STK but the caller prefers using |
| * LTK claim insufficient security. This way we allow the |
| * connection to be re-encrypted with an LTK, even if the LTK |
| * provides the same level of security. Only exception is if we |
| * don't have an LTK (e.g. because of key distribution bits). |
| */ |
| if (key_pref == SMP_USE_LTK && |
| test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && |
| hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type, |
| hcon->role)) |
| return false; |
| |
| if (hcon->sec_level >= sec_level) |
| return true; |
| |
| return false; |
| } |
| |
| 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; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_chan *smp; |
| u8 sec_level, auth; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| if (hcon->role != HCI_ROLE_MASTER) |
| return SMP_CMD_NOTSUPP; |
| |
| auth = rp->auth_req & AUTH_REQ_MASK; |
| |
| if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| sec_level = BT_SECURITY_MEDIUM; |
| else |
| sec_level = authreq_to_seclevel(auth); |
| |
| if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) |
| return 0; |
| |
| if (sec_level > hcon->pending_sec_level) |
| hcon->pending_sec_level = sec_level; |
| |
| if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) |
| return 0; |
| |
| smp = smp_chan_create(conn); |
| if (!smp) |
| return SMP_UNSPECIFIED; |
| |
| if (!test_bit(HCI_BONDABLE, &hcon->hdev->dev_flags) && |
| (auth & SMP_AUTH_BONDING)) |
| return SMP_PAIRING_NOTSUPP; |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| memset(&cp, 0, sizeof(cp)); |
| build_pairing_cmd(conn, &cp, NULL, auth); |
| |
| 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); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); |
| |
| return 0; |
| } |
| |
| int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) |
| { |
| struct l2cap_conn *conn = hcon->l2cap_data; |
| struct l2cap_chan *chan; |
| struct smp_chan *smp; |
| __u8 authreq; |
| int ret; |
| |
| BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level); |
| |
| /* This may be NULL if there's an unexpected disconnection */ |
| if (!conn) |
| return 1; |
| |
| chan = conn->smp; |
| |
| if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) |
| return 1; |
| |
| if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) |
| return 1; |
| |
| if (sec_level > hcon->pending_sec_level) |
| hcon->pending_sec_level = sec_level; |
| |
| if (hcon->role == HCI_ROLE_MASTER) |
| if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) |
| return 0; |
| |
| l2cap_chan_lock(chan); |
| |
| /* If SMP is already in progress ignore this request */ |
| if (chan->data) { |
| ret = 0; |
| goto unlock; |
| } |
| |
| smp = smp_chan_create(conn); |
| if (!smp) { |
| ret = 1; |
| goto unlock; |
| } |
| |
| authreq = seclevel_to_authreq(sec_level); |
| |
| /* Require MITM if IO Capability allows or the security level |
| * requires it. |
| */ |
| if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || |
| hcon->pending_sec_level > BT_SECURITY_MEDIUM) |
| authreq |= SMP_AUTH_MITM; |
| |
| if (hcon->role == HCI_ROLE_MASTER) { |
| struct smp_cmd_pairing cp; |
| |
| 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); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); |
| } else { |
| struct smp_cmd_security_req cp; |
| cp.auth_req = authreq; |
| smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); |
| } |
| |
| set_bit(SMP_FLAG_INITIATOR, &smp->flags); |
| ret = 0; |
| |
| unlock: |
| l2cap_chan_unlock(chan); |
| return ret; |
| } |
| |
| static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_encrypt_info *rp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_MASTER_IDENT); |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_master_ident *rp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_ltk *ltk; |
| u8 authenticated; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; |
| |
| if (smp->remote_key_dist & SMP_DIST_ID_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| authenticated = (hcon->sec_level == BT_SECURITY_HIGH); |
| ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, |
| authenticated, smp->tk, smp->enc_key_size, |
| rp->ediv, rp->rand); |
| smp->ltk = ltk; |
| if (!(smp->remote_key_dist & KEY_DIST_MASK)) |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_ident_info *info = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| BT_DBG(""); |
| |
| if (skb->len < sizeof(*info)) |
| return SMP_INVALID_PARAMS; |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); |
| |
| skb_pull(skb, sizeof(*info)); |
| |
| memcpy(smp->irk, info->irk, 16); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, |
| struct sk_buff *skb) |
| { |
| struct smp_cmd_ident_addr_info *info = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| bdaddr_t rpa; |
| |
| BT_DBG(""); |
| |
| if (skb->len < sizeof(*info)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_ID_KEY; |
| |
| if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| |
| skb_pull(skb, sizeof(*info)); |
| |
| /* Strictly speaking the Core Specification (4.1) allows sending |
| * an empty address which would force us to rely on just the IRK |
| * as "identity information". However, since such |
| * implementations are not known of and in order to not over |
| * complicate our implementation, simply pretend that we never |
| * received an IRK for such a device. |
| */ |
| if (!bacmp(&info->bdaddr, BDADDR_ANY)) { |
| BT_ERR("Ignoring IRK with no identity address"); |
| goto distribute; |
| } |
| |
| bacpy(&smp->id_addr, &info->bdaddr); |
| smp->id_addr_type = info->addr_type; |
| |
| if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) |
| bacpy(&rpa, &hcon->dst); |
| else |
| bacpy(&rpa, BDADDR_ANY); |
| |
| smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, |
| smp->id_addr_type, smp->irk, &rpa); |
| |
| distribute: |
| if (!(smp->remote_key_dist & KEY_DIST_MASK)) |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_sign_info *rp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct smp_csrk *csrk; |
| |
| BT_DBG("conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_SIGN; |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); |
| if (csrk) { |
| csrk->master = 0x01; |
| memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); |
| } |
| smp->csrk = csrk; |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) |
| { |
| struct l2cap_conn *conn = chan->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_chan *smp; |
| __u8 code, reason; |
| int err = 0; |
| |
| if (hcon->type != LE_LINK) { |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| if (skb->len < 1) |
| return -EILSEQ; |
| |
| if (!test_bit(HCI_LE_ENABLED, &hcon->hdev->dev_flags)) { |
| reason = SMP_PAIRING_NOTSUPP; |
| goto done; |
| } |
| |
| code = skb->data[0]; |
| skb_pull(skb, sizeof(code)); |
| |
| smp = chan->data; |
| |
| if (code > SMP_CMD_MAX) |
| goto drop; |
| |
| if (smp && !test_and_clear_bit(code, &smp->allow_cmd)) |
| goto drop; |
| |
| /* If we don't have a context the only allowed commands are |
| * pairing request and security request. |
| */ |
| if (!smp && code != SMP_CMD_PAIRING_REQ && code != SMP_CMD_SECURITY_REQ) |
| goto drop; |
| |
| switch (code) { |
| case SMP_CMD_PAIRING_REQ: |
| reason = smp_cmd_pairing_req(conn, skb); |
| break; |
| |
| case SMP_CMD_PAIRING_FAIL: |
| smp_failure(conn, 0); |
| err = -EPERM; |
| break; |
| |
| case SMP_CMD_PAIRING_RSP: |
| reason = smp_cmd_pairing_rsp(conn, skb); |
| break; |
| |
| case SMP_CMD_SECURITY_REQ: |
| reason = smp_cmd_security_req(conn, skb); |
| break; |
| |
| case SMP_CMD_PAIRING_CONFIRM: |
| reason = smp_cmd_pairing_confirm(conn, skb); |
| break; |
| |
| case SMP_CMD_PAIRING_RANDOM: |
| reason = smp_cmd_pairing_random(conn, skb); |
| break; |
| |
| case SMP_CMD_ENCRYPT_INFO: |
| reason = smp_cmd_encrypt_info(conn, skb); |
| break; |
| |
| case SMP_CMD_MASTER_IDENT: |
| reason = smp_cmd_master_ident(conn, skb); |
| break; |
| |
| case SMP_CMD_IDENT_INFO: |
| reason = smp_cmd_ident_info(conn, skb); |
| break; |
| |
| case SMP_CMD_IDENT_ADDR_INFO: |
| reason = smp_cmd_ident_addr_info(conn, skb); |
| break; |
| |
| case SMP_CMD_SIGN_INFO: |
| reason = smp_cmd_sign_info(conn, skb); |
| break; |
| |
| default: |
| BT_DBG("Unknown command code 0x%2.2x", code); |
| reason = SMP_CMD_NOTSUPP; |
| goto done; |
| } |
| |
| done: |
| if (!err) { |
| if (reason) |
| smp_failure(conn, reason); |
| kfree_skb(skb); |
| } |
| |
| return err; |
| |
| drop: |
| BT_ERR("%s unexpected SMP command 0x%02x from %pMR", hcon->hdev->name, |
| code, &hcon->dst); |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| static void smp_teardown_cb(struct l2cap_chan *chan, int err) |
| { |
| struct l2cap_conn *conn = chan->conn; |
| |
| BT_DBG("chan %p", chan); |
| |
| if (chan->data) |
| smp_chan_destroy(conn); |
| |
| conn->smp = NULL; |
| l2cap_chan_put(chan); |
| } |
| |
| static void smp_resume_cb(struct l2cap_chan *chan) |
| { |
| struct smp_chan *smp = chan->data; |
| struct l2cap_conn *conn = chan->conn; |
| struct hci_conn *hcon = conn->hcon; |
| |
| BT_DBG("chan %p", chan); |
| |
| if (!smp) |
| return; |
| |
| if (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags)) |
| return; |
| |
| cancel_delayed_work(&smp->security_timer); |
| |
| smp_distribute_keys(smp); |
| } |
| |
| static void smp_ready_cb(struct l2cap_chan *chan) |
| { |
| struct l2cap_conn *conn = chan->conn; |
| |
| BT_DBG("chan %p", chan); |
| |
| conn->smp = chan; |
| l2cap_chan_hold(chan); |
| } |
| |
| static int smp_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) |
| { |
| int err; |
| |
| BT_DBG("chan %p", chan); |
| |
| err = smp_sig_channel(chan, skb); |
| if (err) { |
| struct smp_chan *smp = chan->data; |
| |
| if (smp) |
| cancel_delayed_work_sync(&smp->security_timer); |
| |
| hci_disconnect(chan->conn->hcon, HCI_ERROR_AUTH_FAILURE); |
| } |
| |
| return err; |
| } |
| |
| static struct sk_buff *smp_alloc_skb_cb(struct l2cap_chan *chan, |
| unsigned long hdr_len, |
| unsigned long len, int nb) |
| { |
| struct sk_buff *skb; |
| |
| skb = bt_skb_alloc(hdr_len + len, GFP_KERNEL); |
| if (!skb) |
| return ERR_PTR(-ENOMEM); |
| |
| skb->priority = HCI_PRIO_MAX; |
| bt_cb(skb)->chan = chan; |
| |
| return skb; |
| } |
| |
| static const struct l2cap_ops smp_chan_ops = { |
| .name = "Security Manager", |
| .ready = smp_ready_cb, |
| .recv = smp_recv_cb, |
| .alloc_skb = smp_alloc_skb_cb, |
| .teardown = smp_teardown_cb, |
| .resume = smp_resume_cb, |
| |
| .new_connection = l2cap_chan_no_new_connection, |
| .state_change = l2cap_chan_no_state_change, |
| .close = l2cap_chan_no_close, |
| .defer = l2cap_chan_no_defer, |
| .suspend = l2cap_chan_no_suspend, |
| .set_shutdown = l2cap_chan_no_set_shutdown, |
| .get_sndtimeo = l2cap_chan_no_get_sndtimeo, |
| .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec, |
| }; |
| |
| static inline struct l2cap_chan *smp_new_conn_cb(struct l2cap_chan *pchan) |
| { |
| struct l2cap_chan *chan; |
| |
| BT_DBG("pchan %p", pchan); |
| |
| chan = l2cap_chan_create(); |
| if (!chan) |
| return NULL; |
| |
| chan->chan_type = pchan->chan_type; |
| chan->ops = &smp_chan_ops; |
| chan->scid = pchan->scid; |
| chan->dcid = chan->scid; |
| chan->imtu = pchan->imtu; |
| chan->omtu = pchan->omtu; |
| chan->mode = pchan->mode; |
| |
| /* Other L2CAP channels may request SMP routines in order to |
| * change the security level. This means that the SMP channel |
| * lock must be considered in its own category to avoid lockdep |
| * warnings. |
| */ |
| atomic_set(&chan->nesting, L2CAP_NESTING_SMP); |
| |
| BT_DBG("created chan %p", chan); |
| |
| return chan; |
| } |
| |
| static const struct l2cap_ops smp_root_chan_ops = { |
| .name = "Security Manager Root", |
| .new_connection = smp_new_conn_cb, |
| |
| /* None of these are implemented for the root channel */ |
| .close = l2cap_chan_no_close, |
| .alloc_skb = l2cap_chan_no_alloc_skb, |
| .recv = l2cap_chan_no_recv, |
| .state_change = l2cap_chan_no_state_change, |
| .teardown = l2cap_chan_no_teardown, |
| .ready = l2cap_chan_no_ready, |
| .defer = l2cap_chan_no_defer, |
| .suspend = l2cap_chan_no_suspend, |
| .resume = l2cap_chan_no_resume, |
| .set_shutdown = l2cap_chan_no_set_shutdown, |
| .get_sndtimeo = l2cap_chan_no_get_sndtimeo, |
| .memcpy_fromiovec = l2cap_chan_no_memcpy_fromiovec, |
| }; |
| |
| int smp_register(struct hci_dev *hdev) |
| { |
| struct l2cap_chan *chan; |
| struct crypto_blkcipher *tfm_aes; |
| |
| BT_DBG("%s", hdev->name); |
| |
| tfm_aes = crypto_alloc_blkcipher("ecb(aes)", 0, 0); |
| if (IS_ERR(tfm_aes)) { |
| int err = PTR_ERR(tfm_aes); |
| BT_ERR("Unable to create crypto context"); |
| return err; |
| } |
| |
| chan = l2cap_chan_create(); |
| if (!chan) { |
| crypto_free_blkcipher(tfm_aes); |
| return -ENOMEM; |
| } |
| |
| chan->data = tfm_aes; |
| |
| l2cap_add_scid(chan, L2CAP_CID_SMP); |
| |
| l2cap_chan_set_defaults(chan); |
| |
| bacpy(&chan->src, &hdev->bdaddr); |
| chan->src_type = BDADDR_LE_PUBLIC; |
| chan->state = BT_LISTEN; |
| chan->mode = L2CAP_MODE_BASIC; |
| chan->imtu = L2CAP_DEFAULT_MTU; |
| chan->ops = &smp_root_chan_ops; |
| |
| /* Set correct nesting level for a parent/listening channel */ |
| atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); |
| |
| hdev->smp_data = chan; |
| |
| return 0; |
| } |
| |
| void smp_unregister(struct hci_dev *hdev) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| struct crypto_blkcipher *tfm_aes; |
| |
| if (!chan) |
| return; |
| |
| BT_DBG("%s chan %p", hdev->name, chan); |
| |
| tfm_aes = chan->data; |
| if (tfm_aes) { |
| chan->data = NULL; |
| crypto_free_blkcipher(tfm_aes); |
| } |
| |
| hdev->smp_data = NULL; |
| l2cap_chan_put(chan); |
| } |