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Commit 5a349186 authored by Andrei Emeltchenko's avatar Andrei Emeltchenko Committed by Gustavo Padovan
Browse files

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: default avatarAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
parent ba221bba

include/net/bluetooth/amp.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ void amp_ctrl_list_flush(struct amp_mgr *mgr); 
struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,

			     u8 remote_id);



int phylink_gen_key(struct hci_conn *hcon, u8 *data, u8 *len, u8 *type);



void amp_read_loc_info(struct hci_dev *hdev, struct amp_mgr *mgr);

void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle);

void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr);

net/bluetooth/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ menuconfig BT 
	select CRYPTO_BLKCIPHER

	select CRYPTO_AES

	select CRYPTO_ECB

	select CRYPTO_SHA256

	help

	  Bluetooth is low-cost, low-power, short-range wireless technology.

	  It was designed as a replacement for cables and other short-range

net/bluetooth/amp.c

+45 −0
Original line number Diff line number Diff line
@@ -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;