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smp.c
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/*
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/algapi.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 !crypto_memneq(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 smp_chan *smp, 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])
{
struct hci_dev *hdev = smp->conn->hcon->hdev;
u8 p1[16], p2[16];
int err;
BT_DBG("%s", hdev->name);
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(smp->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(smp->tfm_aes, k, res);
if (err)
BT_ERR("Encrypt data error");
return err;
}
static int smp_s1(struct smp_chan *smp, u8 k[16], u8 r1[16], u8 r2[16],
u8 _r[16])
{
struct hci_dev *hdev = smp->conn->hcon->hdev;
int err;
BT_DBG("%s", hdev->name);
/* Just least significant octets from r1 and r2 are considered */
memcpy(_r, r2, 8);
memcpy(_r + 8, r1, 8);
err = smp_e(smp->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(&smp->ltk->list);
kfree(smp->ltk);
}
if (smp->slave_ltk) {
list_del(&smp->slave_ltk->list);
kfree(smp->slave_ltk);
}
if (smp->remote_irk) {
list_del(&smp->remote_irk->list);
kfree(smp->remote_irk);
}
}
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);
}
hci_dev_lock(hcon->hdev);
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);
hci_dev_unlock(hcon->hdev);
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, 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, 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 (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) {
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, 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, 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(&smp->remote_irk->list);
kfree(smp->remote_irk);
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 acheived */
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)