From ba221bbabadd5fc2c80677b52178138fd694cc26 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 27 Sep 2012 17:26:17 +0300 Subject: [PATCH] Bluetooth: Add function to derive AMP key using hmac hmac(sha256) will be used for AMP key generation. Signed-off-by: Dmitry Kasatkin Signed-off-by: Andrei Emeltchenko Signed-off-by: Gustavo Padovan --- net/bluetooth/amp.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/net/bluetooth/amp.c b/net/bluetooth/amp.c index 8ef912c..ea4d5ff 100644 --- a/net/bluetooth/amp.c +++ b/net/bluetooth/amp.c @@ -16,6 +16,7 @@ #include #include #include +#include /* Remote AMP Controllers interface */ static void amp_ctrl_get(struct amp_ctrl *ctrl) @@ -125,6 +126,41 @@ struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr, return hcon; } +/* AMP crypto key generation interface */ +static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output) +{ + int ret = 0; + struct crypto_shash *tfm; + + if (!ksize) + return -EINVAL; + + tfm = crypto_alloc_shash("hmac(sha256)", 0, 0); + if (IS_ERR(tfm)) { + BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm)); + return PTR_ERR(tfm); + } + + ret = crypto_shash_setkey(tfm, key, ksize); + if (ret) { + BT_DBG("crypto_ahash_setkey failed: err %d", ret); + } else { + struct { + struct shash_desc shash; + char ctx[crypto_shash_descsize(tfm)]; + } desc; + + desc.shash.tfm = tfm; + desc.shash.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + ret = crypto_shash_digest(&desc.shash, plaintext, psize, + output); + } + + crypto_free_shash(tfm); + return ret; +} + void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle) { struct hci_cp_read_local_amp_assoc cp; -- 2.7.4