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Bluetooth: Use the updated key structures for handling LTKs
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This updates all the users of the older way, that was using the
link_keys list to store the SMP keys, to use the new way.

This includes defining new types for the keys, we have a type for each
combination of STK/LTK and Master/Slave.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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Vinicius Costa Gomes authored and Johan Hedberg committed Feb 13, 2012
1 parent b899efa commit c9839a1
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Showing 4 changed files with 71 additions and 65 deletions.
11 changes: 6 additions & 5 deletions include/net/bluetooth/hci_core.h
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Original file line number Diff line number Diff line change
Expand Up @@ -658,12 +658,13 @@ int hci_link_keys_clear(struct hci_dev *hdev);
struct link_key *hci_find_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
bdaddr_t *bdaddr, u8 *val, u8 type, u8 pin_len);
struct link_key *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8]);
struct link_key *hci_find_link_key_type(struct hci_dev *hdev,
bdaddr_t *bdaddr, u8 type);
struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8]);
int hci_add_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 addr_type, u8 type,
int new_key, u8 authenticated, u8 tk[16],
u8 enc_size, u16 ediv, u8 rand[8]);
struct smp_ltk *hci_find_ltk_by_addr(struct hci_dev *hdev, bdaddr_t *bdaddr,
u8 addr_type);
int hci_remove_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr);
int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
u8 key_size, __le16 ediv, u8 rand[8], u8 ltk[16]);
int hci_smp_ltks_clear(struct hci_dev *hdev);
int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);

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76 changes: 33 additions & 43 deletions net/bluetooth/hci_core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1222,41 +1222,35 @@ static int hci_persistent_key(struct hci_dev *hdev, struct hci_conn *conn,
return 0;
}

struct link_key *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8])
struct smp_ltk *hci_find_ltk(struct hci_dev *hdev, __le16 ediv, u8 rand[8])
{
struct link_key *k;

list_for_each_entry(k, &hdev->link_keys, list) {
struct key_master_id *id;
struct smp_ltk *k;

if (k->type != HCI_LK_SMP_LTK)
list_for_each_entry(k, &hdev->long_term_keys, list) {
if (k->ediv != ediv ||
memcmp(rand, k->rand, sizeof(k->rand)))
continue;

if (k->dlen != sizeof(*id))
continue;

id = (void *) &k->data;
if (id->ediv == ediv &&
(memcmp(rand, id->rand, sizeof(id->rand)) == 0))
return k;
return k;
}

return NULL;
}
EXPORT_SYMBOL(hci_find_ltk);

struct link_key *hci_find_link_key_type(struct hci_dev *hdev,
bdaddr_t *bdaddr, u8 type)
struct smp_ltk *hci_find_ltk_by_addr(struct hci_dev *hdev, bdaddr_t *bdaddr,
u8 addr_type)
{
struct link_key *k;
struct smp_ltk *k;

list_for_each_entry(k, &hdev->link_keys, list)
if (k->type == type && bacmp(bdaddr, &k->bdaddr) == 0)
list_for_each_entry(k, &hdev->long_term_keys, list)
if (addr_type == k->bdaddr_type &&
bacmp(bdaddr, &k->bdaddr) == 0)
return k;

return NULL;
}
EXPORT_SYMBOL(hci_find_link_key_type);
EXPORT_SYMBOL(hci_find_ltk_by_addr);

int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
bdaddr_t *bdaddr, u8 *val, u8 type, u8 pin_len)
Expand Down Expand Up @@ -1313,40 +1307,36 @@ int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
return 0;
}

int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
u8 key_size, __le16 ediv, u8 rand[8], u8 ltk[16])
int hci_add_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 addr_type, u8 type,
int new_key, u8 authenticated, u8 tk[16],
u8 enc_size, u16 ediv, u8 rand[8])
{
struct link_key *key, *old_key;
struct key_master_id *id;
u8 old_key_type;
struct smp_ltk *key, *old_key;

BT_DBG("%s addr %s", hdev->name, batostr(bdaddr));
if (!(type & HCI_SMP_STK) && !(type & HCI_SMP_LTK))
return 0;

old_key = hci_find_link_key_type(hdev, bdaddr, HCI_LK_SMP_LTK);
if (old_key) {
old_key = hci_find_ltk_by_addr(hdev, bdaddr, addr_type);
if (old_key)
key = old_key;
old_key_type = old_key->type;
} else {
key = kzalloc(sizeof(*key) + sizeof(*id), GFP_ATOMIC);
else {
key = kzalloc(sizeof(*key), GFP_ATOMIC);
if (!key)
return -ENOMEM;
list_add(&key->list, &hdev->link_keys);
old_key_type = 0xff;
list_add(&key->list, &hdev->long_term_keys);
}

key->dlen = sizeof(*id);

bacpy(&key->bdaddr, bdaddr);
memcpy(key->val, ltk, sizeof(key->val));
key->type = HCI_LK_SMP_LTK;
key->pin_len = key_size;

id = (void *) &key->data;
id->ediv = ediv;
memcpy(id->rand, rand, sizeof(id->rand));
key->bdaddr_type = addr_type;
memcpy(key->val, tk, sizeof(key->val));
key->authenticated = authenticated;
key->ediv = ediv;
key->enc_size = enc_size;
key->type = type;
memcpy(key->rand, rand, sizeof(key->rand));

if (new_key)
mgmt_new_link_key(hdev, key, old_key_type);
if (!new_key)
return 0;

return 0;
}
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11 changes: 9 additions & 2 deletions net/bluetooth/hci_event.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3256,7 +3256,7 @@ static inline void hci_le_ltk_request_evt(struct hci_dev *hdev,
struct hci_cp_le_ltk_reply cp;
struct hci_cp_le_ltk_neg_reply neg;
struct hci_conn *conn;
struct link_key *ltk;
struct smp_ltk *ltk;

BT_DBG("%s handle %d", hdev->name, cpu_to_le16(ev->handle));

Expand All @@ -3272,10 +3272,17 @@ static inline void hci_le_ltk_request_evt(struct hci_dev *hdev,

memcpy(cp.ltk, ltk->val, sizeof(ltk->val));
cp.handle = cpu_to_le16(conn->handle);
conn->pin_length = ltk->pin_len;

if (ltk->authenticated)
conn->sec_level = BT_SECURITY_HIGH;

hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp);

if (ltk->type & HCI_SMP_STK) {
list_del(&ltk->list);
kfree(ltk);
}

hci_dev_unlock(hdev);

return;
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38 changes: 23 additions & 15 deletions net/bluetooth/smp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -475,8 +475,9 @@ static void random_work(struct work_struct *work)
memset(stk + smp->enc_key_size, 0,
SMP_MAX_ENC_KEY_SIZE - smp->enc_key_size);

hci_add_ltk(hcon->hdev, 0, conn->dst, smp->enc_key_size,
ediv, rand, stk);
hci_add_ltk(hcon->hdev, conn->dst, hcon->dst_type,
HCI_SMP_STK_SLAVE, 0, 0, stk,
smp->enc_key_size, ediv, rand);
}

return;
Expand Down Expand Up @@ -701,22 +702,18 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)

static u8 smp_ltk_encrypt(struct l2cap_conn *conn)
{
struct link_key *key;
struct key_master_id *master;
struct smp_ltk *key;
struct hci_conn *hcon = conn->hcon;

key = hci_find_link_key_type(hcon->hdev, conn->dst,
HCI_LK_SMP_LTK);
key = hci_find_ltk_by_addr(hcon->hdev, conn->dst, hcon->dst_type);
if (!key)
return 0;

if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags))
return 1;

master = (void *) key->data;
hci_le_start_enc(hcon, master->ediv, master->rand,
key->val);
hcon->enc_key_size = key->pin_len;
hci_le_start_enc(hcon, key->ediv, key->rand, key->val);
hcon->enc_key_size = key->enc_size;

return 1;

Expand Down Expand Up @@ -819,13 +816,19 @@ static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
{
struct smp_cmd_master_ident *rp = (void *) skb->data;
struct smp_chan *smp = conn->smp_chan;
struct hci_dev *hdev = conn->hcon->hdev;
struct hci_conn *hcon = conn->hcon;
u8 authenticated;

skb_pull(skb, sizeof(*rp));

hci_add_ltk(conn->hcon->hdev, 1, conn->dst, smp->enc_key_size,
rp->ediv, rp->rand, smp->tk);

hci_dev_lock(hdev);
authenticated = (conn->hcon->sec_level == BT_SECURITY_HIGH);
hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
HCI_SMP_LTK, 1, authenticated, smp->tk,
smp->enc_key_size, rp->ediv, rp->rand);
smp_distribute_keys(conn, 1);
hci_dev_unlock(hdev);

return 0;
}
Expand Down Expand Up @@ -935,6 +938,8 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
if (*keydist & SMP_DIST_ENC_KEY) {
struct smp_cmd_encrypt_info enc;
struct smp_cmd_master_ident ident;
struct hci_conn *hcon = conn->hcon;
u8 authenticated;
__le16 ediv;

get_random_bytes(enc.ltk, sizeof(enc.ltk));
Expand All @@ -943,8 +948,11 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)

smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc);

hci_add_ltk(conn->hcon->hdev, 1, conn->dst, smp->enc_key_size,
ediv, ident.rand, enc.ltk);
authenticated = hcon->sec_level == BT_SECURITY_HIGH;
hci_add_ltk(conn->hcon->hdev, conn->dst, hcon->dst_type,
HCI_SMP_LTK_SLAVE, 1, authenticated,
enc.ltk, smp->enc_key_size,
ediv, ident.rand);

ident.ediv = cpu_to_le16(ediv);

Expand Down

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