summaryrefslogtreecommitdiffstats
path: root/net/bluetooth/smp.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/bluetooth/smp.c')
-rw-r--r--net/bluetooth/smp.c418
1 files changed, 352 insertions, 66 deletions
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 45007362683b..f886bcae1b7e 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -78,6 +78,70 @@ static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
return err;
}
+static int smp_ah(struct crypto_blkcipher *tfm, u8 irk[16], u8 r[3], u8 res[3])
+{
+ u8 _res[16], k[16];
+ int err;
+
+ /* r' = padding || r */
+ memset(_res, 0, 13);
+ _res[13] = r[2];
+ _res[14] = r[1];
+ _res[15] = r[0];
+
+ swap128(irk, k);
+ err = smp_e(tfm, k, _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.
+ */
+ res[0] = _res[15];
+ res[1] = _res[14];
+ res[2] = _res[13];
+
+ return 0;
+}
+
+bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],
+ bdaddr_t *bdaddr)
+{
+ u8 hash[3];
+ int err;
+
+ 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 crypto_blkcipher *tfm, u8 irk[16], bdaddr_t *rpa)
+{
+ int err;
+
+ 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, 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])
@@ -203,31 +267,45 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
struct smp_cmd_pairing *req,
struct smp_cmd_pairing *rsp, __u8 authreq)
{
- u8 dist_keys = 0;
+ struct smp_chan *smp = conn->smp_chan;
+ struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
+ u8 local_dist = 0, remote_dist = 0;
if (test_bit(HCI_PAIRABLE, &conn->hcon->hdev->dev_flags)) {
- dist_keys = SMP_DIST_ENC_KEY;
+ local_dist = SMP_DIST_ENC_KEY;
+ remote_dist = SMP_DIST_ENC_KEY;
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 = 0;
- req->resp_key_dist = dist_keys;
+ 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 = 0;
- rsp->resp_key_dist = req->resp_key_dist & dist_keys;
+ 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)
@@ -356,29 +434,23 @@ static void confirm_work(struct work_struct *work)
{
struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
struct l2cap_conn *conn = smp->conn;
- struct crypto_blkcipher *tfm;
+ struct hci_dev *hdev = conn->hcon->hdev;
+ struct crypto_blkcipher *tfm = hdev->tfm_aes;
struct smp_cmd_pairing_confirm cp;
int ret;
u8 res[16], reason;
BT_DBG("conn %p", conn);
- tfm = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(tfm)) {
- reason = SMP_UNSPECIFIED;
- goto error;
- }
+ /* Prevent mutual access to hdev->tfm_aes */
+ hci_dev_lock(hdev);
- smp->tfm = tfm;
+ ret = smp_c1(tfm, 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, res);
+
+ hci_dev_unlock(hdev);
- if (conn->hcon->out)
- ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
- conn->hcon->src_type, &conn->hcon->src,
- conn->hcon->dst_type, &conn->hcon->dst, res);
- else
- ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
- conn->hcon->dst_type, &conn->hcon->dst,
- conn->hcon->src_type, &conn->hcon->src, res);
if (ret) {
reason = SMP_UNSPECIFIED;
goto error;
@@ -400,7 +472,8 @@ static void random_work(struct work_struct *work)
struct smp_chan *smp = container_of(work, struct smp_chan, random);
struct l2cap_conn *conn = smp->conn;
struct hci_conn *hcon = conn->hcon;
- struct crypto_blkcipher *tfm = smp->tfm;
+ struct hci_dev *hdev = hcon->hdev;
+ struct crypto_blkcipher *tfm = hdev->tfm_aes;
u8 reason, confirm[16], res[16], key[16];
int ret;
@@ -411,14 +484,15 @@ static void random_work(struct work_struct *work)
BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
- if (hcon->out)
- ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
- hcon->src_type, &hcon->src,
- hcon->dst_type, &hcon->dst, res);
- else
- ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
- hcon->dst_type, &hcon->dst,
- hcon->src_type, &hcon->src, res);
+ /* Prevent mutual access to hdev->tfm_aes */
+ hci_dev_lock(hdev);
+
+ ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
+ hcon->init_addr_type, &hcon->init_addr,
+ hcon->resp_addr_type, &hcon->resp_addr, res);
+
+ hci_dev_unlock(hdev);
+
if (ret) {
reason = SMP_UNSPECIFIED;
goto error;
@@ -433,11 +507,9 @@ static void random_work(struct work_struct *work)
}
if (hcon->out) {
- u8 stk[16], rand[8];
- __le16 ediv;
-
- memset(rand, 0, sizeof(rand));
- ediv = 0;
+ u8 stk[16];
+ __le64 rand = 0;
+ __le16 ediv = 0;
smp_s1(tfm, smp->tk, smp->rrnd, smp->prnd, key);
swap128(key, stk);
@@ -453,11 +525,9 @@ static void random_work(struct work_struct *work)
hci_le_start_enc(hcon, ediv, rand, stk);
hcon->enc_key_size = smp->enc_key_size;
} else {
- u8 stk[16], r[16], rand[8];
- __le16 ediv;
-
- memset(rand, 0, sizeof(rand));
- ediv = 0;
+ u8 stk[16], r[16];
+ __le64 rand = 0;
+ __le16 ediv = 0;
swap128(smp->prnd, r);
smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
@@ -469,7 +539,7 @@ static void random_work(struct work_struct *work)
SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);
hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
- HCI_SMP_STK_SLAVE, 0, 0, stk, smp->enc_key_size,
+ HCI_SMP_STK_SLAVE, 0, stk, smp->enc_key_size,
ediv, rand);
}
@@ -479,6 +549,20 @@ error:
smp_failure(conn, reason);
}
+static void smp_reencrypt(struct work_struct *work)
+{
+ struct smp_chan *smp = container_of(work, struct smp_chan,
+ reencrypt.work);
+ struct l2cap_conn *conn = smp->conn;
+ struct hci_conn *hcon = conn->hcon;
+ struct smp_ltk *ltk = smp->ltk;
+
+ BT_DBG("");
+
+ hci_le_start_enc(hcon, ltk->ediv, ltk->rand, ltk->val);
+ hcon->enc_key_size = ltk->enc_size;
+}
+
static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
{
struct smp_chan *smp;
@@ -489,6 +573,7 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
INIT_WORK(&smp->confirm, confirm_work);
INIT_WORK(&smp->random, random_work);
+ INIT_DELAYED_WORK(&smp->reencrypt, smp_reencrypt);
smp->conn = conn;
conn->smp_chan = smp;
@@ -502,11 +587,32 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
void smp_chan_destroy(struct l2cap_conn *conn)
{
struct smp_chan *smp = conn->smp_chan;
+ bool complete;
BUG_ON(!smp);
- if (smp->tfm)
- crypto_free_blkcipher(smp->tfm);
+ cancel_delayed_work_sync(&smp->reencrypt);
+
+ complete = test_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
+ mgmt_smp_complete(conn->hcon, complete);
+
+ /* 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);
+ }
+ }
kfree(smp);
conn->smp_chan = NULL;
@@ -565,6 +671,9 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p", conn);
+ if (skb->len < sizeof(*req))
+ return SMP_UNSPECIFIED;
+
if (conn->hcon->link_mode & HCI_LM_MASTER)
return SMP_CMD_NOTSUPP;
@@ -617,6 +726,9 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p", conn);
+ if (skb->len < sizeof(*rsp))
+ return SMP_UNSPECIFIED;
+
if (!(conn->hcon->link_mode & HCI_LM_MASTER))
return SMP_CMD_NOTSUPP;
@@ -661,6 +773,9 @@ static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
+ if (skb->len < sizeof(smp->pcnf))
+ return SMP_UNSPECIFIED;
+
memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
skb_pull(skb, sizeof(smp->pcnf));
@@ -686,6 +801,9 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p", conn);
+ if (skb->len < sizeof(smp->rrnd))
+ return SMP_UNSPECIFIED;
+
swap128(skb->data, smp->rrnd);
skb_pull(skb, sizeof(smp->rrnd));
@@ -699,7 +817,8 @@ static u8 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);
+ key = hci_find_ltk_by_addr(hcon->hdev, &hcon->dst, hcon->dst_type,
+ hcon->out);
if (!key)
return 0;
@@ -724,6 +843,9 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
BT_DBG("conn %p", conn);
+ if (skb->len < sizeof(*rp))
+ return SMP_UNSPECIFIED;
+
if (!(conn->hcon->link_mode & HCI_LM_MASTER))
return SMP_CMD_NOTSUPP;
@@ -813,6 +935,15 @@ static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb)
struct smp_cmd_encrypt_info *rp = (void *) skb->data;
struct smp_chan *smp = conn->smp_chan;
+ BT_DBG("conn %p", conn);
+
+ if (skb->len < sizeof(*rp))
+ return SMP_UNSPECIFIED;
+
+ /* Ignore this PDU if it wasn't requested */
+ if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
+ return 0;
+
skb_pull(skb, sizeof(*rp));
memcpy(smp->tk, rp->ltk, sizeof(smp->tk));
@@ -826,21 +957,114 @@ static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
struct smp_chan *smp = conn->smp_chan;
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_UNSPECIFIED;
+
+ /* Ignore this PDU if it wasn't requested */
+ if (!(smp->remote_key_dist & SMP_DIST_ENC_KEY))
+ return 0;
+
+ /* Mark the information as received */
+ smp->remote_key_dist &= ~SMP_DIST_ENC_KEY;
+
skb_pull(skb, sizeof(*rp));
hci_dev_lock(hdev);
authenticated = (hcon->sec_level == BT_SECURITY_HIGH);
- hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, HCI_SMP_LTK, 1,
- authenticated, smp->tk, smp->enc_key_size,
- rp->ediv, rp->rand);
- smp_distribute_keys(conn, 1);
+ ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, HCI_SMP_LTK,
+ authenticated, smp->tk, smp->enc_key_size,
+ rp->ediv, rp->rand);
+ smp->ltk = ltk;
+ if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
+ smp_distribute_keys(conn);
hci_dev_unlock(hdev);
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 smp_chan *smp = conn->smp_chan;
+
+ BT_DBG("");
+
+ if (skb->len < sizeof(*info))
+ return SMP_UNSPECIFIED;
+
+ /* Ignore this PDU if it wasn't requested */
+ if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
+ return 0;
+
+ 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 smp_chan *smp = conn->smp_chan;
+ struct hci_conn *hcon = conn->hcon;
+ bdaddr_t rpa;
+
+ BT_DBG("");
+
+ if (skb->len < sizeof(*info))
+ return SMP_UNSPECIFIED;
+
+ /* Ignore this PDU if it wasn't requested */
+ if (!(smp->remote_key_dist & SMP_DIST_ID_KEY))
+ return 0;
+
+ /* Mark the information as received */
+ smp->remote_key_dist &= ~SMP_DIST_ID_KEY;
+
+ 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");
+ smp_distribute_keys(conn);
+ return 0;
+ }
+
+ 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);
+
+ /* Track the connection based on the Identity Address from now on */
+ bacpy(&hcon->dst, &smp->id_addr);
+ hcon->dst_type = smp->id_addr_type;
+
+ l2cap_conn_update_id_addr(hcon);
+
+ smp_distribute_keys(conn);
+
+ return 0;
+}
+
int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
{
struct hci_conn *hcon = conn->hcon;
@@ -915,7 +1139,13 @@ int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *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:
/* Just ignored */
reason = 0;
@@ -937,26 +1167,51 @@ done:
return err;
}
-int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
+static void smp_notify_keys(struct l2cap_conn *conn)
+{
+ struct smp_chan *smp = conn->smp_chan;
+ struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
+
+ if (smp->remote_irk)
+ mgmt_new_irk(hdev, smp->remote_irk);
+
+ if (smp->ltk) {
+ smp->ltk->bdaddr_type = hcon->dst_type;
+ bacpy(&smp->ltk->bdaddr, &hcon->dst);
+ mgmt_new_ltk(hdev, smp->ltk);
+ }
+
+ 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);
+ }
+}
+
+int smp_distribute_keys(struct l2cap_conn *conn)
{
struct smp_cmd_pairing *req, *rsp;
struct smp_chan *smp = conn->smp_chan;
+ struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
+ bool ltk_encrypt;
__u8 *keydist;
- BT_DBG("conn %p force %d", conn, force);
+ BT_DBG("conn %p", conn);
- if (!test_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags))
+ if (!test_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags))
return 0;
rsp = (void *) &smp->prsp[1];
/* The responder sends its keys first */
- if (!force && conn->hcon->out && (rsp->resp_key_dist & 0x07))
+ if (hcon->out && (smp->remote_key_dist & 0x07))
return 0;
req = (void *) &smp->preq[1];
- if (conn->hcon->out) {
+ if (hcon->out) {
keydist = &rsp->init_key_dist;
*keydist &= req->init_key_dist;
} else {
@@ -964,28 +1219,30 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
*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 hci_conn *hcon = conn->hcon;
+ 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(ident.rand, sizeof(ident.rand));
+ get_random_bytes(&rand, sizeof(rand));
smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);
authenticated = hcon->sec_level == BT_SECURITY_HIGH;
- hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
- HCI_SMP_LTK_SLAVE, 1, authenticated,
- enc.ltk, smp->enc_key_size, ediv, ident.rand);
+ ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type,
+ HCI_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);
@@ -996,14 +1253,18 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
struct smp_cmd_ident_addr_info addrinfo;
struct smp_cmd_ident_info idinfo;
- /* Send a dummy key */
- get_random_bytes(idinfo.irk, sizeof(idinfo.irk));
+ memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk));
smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo);
- /* Just public address */
- memset(&addrinfo, 0, sizeof(addrinfo));
- bacpy(&addrinfo.bdaddr, &conn->hcon->src);
+ /* 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);
@@ -1022,9 +1283,34 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
*keydist &= ~SMP_DIST_SIGN;
}
- if (conn->hcon->out || force) {
- clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags);
+ /* If there are still keys to be received wait for them */
+ if ((smp->remote_key_dist & 0x07))
+ return 0;
+
+ /* Check if we should try to re-encrypt the link with the LTK.
+ * SMP_FLAG_LTK_ENCRYPT flag is used to track whether we've
+ * already tried this (in which case we shouldn't try again).
+ *
+ * The request will trigger an encryption key refresh event
+ * which will cause a call to auth_cfm and eventually lead to
+ * l2cap_core.c calling this smp_distribute_keys function again
+ * and thereby completing the process.
+ */
+ if (smp->ltk)
+ ltk_encrypt = !test_and_set_bit(SMP_FLAG_LTK_ENCRYPT,
+ &smp->smp_flags);
+ else
+ ltk_encrypt = false;
+
+ /* Re-encrypt the link with LTK if possible */
+ if (ltk_encrypt && hcon->out) {
+ queue_delayed_work(hdev->req_workqueue, &smp->reencrypt,
+ SMP_REENCRYPT_TIMEOUT);
+ } else {
+ clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->flags);
cancel_delayed_work_sync(&conn->security_timer);
+ set_bit(SMP_FLAG_COMPLETE, &smp->smp_flags);
+ smp_notify_keys(conn);
smp_chan_destroy(conn);
}