diff options
| author | Andrei Emeltchenko <andrei.emeltchenko@intel.com> | 2012-09-27 16:26:18 +0200 |
|---|---|---|
| committer | Gustavo Padovan <gustavo.padovan@collabora.co.uk> | 2012-09-27 22:30:22 +0200 |
| commit | 5a349186692950b13896abc3fb2f491d023f95a1 (patch) | |
| tree | 90cd3162c3f7d3277e6a8816c384c7ab0d76e1d8 /net/bluetooth/amp.c | |
| parent | Bluetooth: Add function to derive AMP key using hmac (diff) | |
| download | linux-5a349186692950b13896abc3fb2f491d023f95a1.tar.xz linux-5a349186692950b13896abc3fb2f491d023f95a1.zip | |
Bluetooth: AMP: Add AMP key calculation
Function calculates AMP keys using hmac_sha256 helper. Calculated keys
are Generic AMP Link Key (gamp) and Dedicated AMP Link Key with
keyID "802b" for 802.11 PAL.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Diffstat (limited to 'net/bluetooth/amp.c')
| -rw-r--r-- | net/bluetooth/amp.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c index ea4d5ffc1151..67bc2c2f8783 100644 --- a/net/bluetooth/amp.c +++ b/net/bluetooth/amp.c @@ -161,6 +161,51 @@ static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output) return ret; } +int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type) +{ + struct hci_dev *hdev = conn->hdev; + struct link_key *key; + u8 keybuf[HCI_AMP_LINK_KEY_SIZE]; + u8 gamp_key[HCI_AMP_LINK_KEY_SIZE]; + int err; + + if (!hci_conn_check_link_mode(conn)) + return -EACCES; + + BT_DBG("conn %p key_type %d", conn, conn->key_type); + + /* Legacy key */ + if (conn->key_type < 3) { + BT_ERR("Legacy key type %d", conn->key_type); + return -EACCES; + } + + *type = conn->key_type; + *len = HCI_AMP_LINK_KEY_SIZE; + + key = hci_find_link_key(hdev, &conn->dst); + + /* BR/EDR Link Key concatenated together with itself */ + memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE); + memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE); + + /* Derive Generic AMP Link Key (gamp) */ + err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key); + if (err) { + BT_ERR("Could not derive Generic AMP Key: err %d", err); + return err; + } + + if (conn->key_type == HCI_LK_DEBUG_COMBINATION) { + BT_DBG("Use Generic AMP Key (gamp)"); + memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE); + return err; + } + + /* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */ + return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data); +} + void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle) { struct hci_cp_read_local_amp_assoc cp; |