Bluetooth: Add support for storing the key size

In some cases it will be useful having the key size used for
encrypting the link. For example, some profiles may restrict
some operations depending on the key length.

The key size is stored in the key that is passed to userspace
using the pin_length field in the key structure.

For now this field is only valid for LE controllers. 3.0+HS
controllers define the Read Encryption Key Size command, this
field is intended for storing the value returned by that
command.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 4ff530e3892bec1b9708a0514bc2ea7ea507e0fb..c41e275917c789334670f205cee6eca66cd65cf5 100644 (file)
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -261,6 +261,7 @@ struct hci_conn {
        __u8            sec_level;
        __u8            pending_sec_level;
        __u8            pin_length;
+       __u8            enc_key_size;
        __u8            io_capability;
        __u8            power_save;
        __u16           disc_timeout;
@@ -556,7 +557,7 @@ 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);
 int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
-                                       __le16 ediv, u8 rand[8], u8 ltk[16]);
+                       u8 key_size, __le16 ediv, u8 rand[8], u8 ltk[16]);
 int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr);
 
 int hci_remote_oob_data_clear(struct hci_dev *hdev);

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 4885914449f66f644843a1d8a4ab44805868c56a..908fcd384ab4a6b0872af95d9d7b476e3aea51a1 100644 (file)
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1149,7 +1149,7 @@ int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
 }
 
 int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
-                                       __le16 ediv, u8 rand[8], u8 ltk[16])
+                       u8 key_size, __le16 ediv, u8 rand[8], u8 ltk[16])
 {
        struct link_key *key, *old_key;
        struct key_master_id *id;
@@ -1174,6 +1174,7 @@ int hci_add_ltk(struct hci_dev *hdev, int new_key, bdaddr_t *bdaddr,
        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;

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index ca5ff6eedf02685c04ca5867668899037d5fca21..a40170e022e84e5e88f4ccbe4eb8724d5411c49d 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2876,6 +2876,7 @@ 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;
 
        hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp);
 

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index f424d6ab4c1e9b943dc90a278cefe1366d95c93e..53e109eb043e073a22479b479082bdee0a321d6d 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -956,8 +956,8 @@ static int load_keys(struct sock *sk, u16 index, unsigned char *data, u16 len)
                        if (key->dlen != sizeof(struct key_master_id))
                                continue;
 
-                       hci_add_ltk(hdev, 0, &key->bdaddr, id->ediv,
-                                                       id->rand, key->val);
+                       hci_add_ltk(hdev, 0, &key->bdaddr, key->pin_len,
+                                               id->ediv, id->rand, key->val);
 
                        continue;
                }

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index a8b971b75a67a7f4c2a5675e5ebebb888cfe5245..391888b88a929bdcb93166b0d3ed2c1ae1e3d7f3 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -401,6 +401,7 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
                                SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
 
                hci_le_start_enc(hcon, ediv, rand, stk);
+               hcon->enc_key_size = conn->smp_key_size;
        } else {
                u8 stk[16], r[16], rand[8];
                __le16 ediv;
@@ -417,7 +418,8 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
                memset(stk + conn->smp_key_size, 0,
                                SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
 
-               hci_add_ltk(conn->hcon->hdev, 0, conn->dst, ediv, rand, stk);
+               hci_add_ltk(conn->hcon->hdev, 0, conn->dst, conn->smp_key_size,
+                                                       ediv, rand, stk);
        }
 
        return 0;
@@ -487,6 +489,8 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
 
                        hci_le_start_enc(hcon, master->ediv, master->rand,
                                                                key->val);
+                       hcon->enc_key_size = key->pin_len;
+
                        goto done;
                }
 
@@ -528,8 +532,8 @@ static int smp_cmd_master_ident(struct l2cap_conn *conn, struct sk_buff *skb)
 
        skb_pull(skb, sizeof(*rp));
 
-       hci_add_ltk(conn->hcon->hdev, 1, conn->src, rp->ediv,
-                                               rp->rand, conn->tk);
+       hci_add_ltk(conn->hcon->hdev, 1, conn->src, conn->smp_key_size,
+                                               rp->ediv, rp->rand, conn->tk);
 
        smp_distribute_keys(conn, 1);
 
@@ -654,8 +658,8 @@ 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, ediv,
-                                                       ident.rand, enc.ltk);
+               hci_add_ltk(conn->hcon->hdev, 1, conn->dst, conn->smp_key_size,
+                                               ediv, ident.rand, enc.ltk);
 
                ident.ediv = cpu_to_le16(ediv);