Commit 5d2cdcd4 authored by Emmanuel Grumbach's avatar Emmanuel Grumbach Committed by John W. Linville

mac80211: get a TKIP phase key from skb

This patch makes mac80211 able to compute a TKIP key from an skb.
The requested key can be a phase 1 or a phase 2 key.
This is useful for drivers who need to provide tkip key to their
HW to enable HW encryption.
Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 17e476b8
......@@ -643,6 +643,21 @@ enum sta_notify_cmd {
STA_NOTIFY_ADD, STA_NOTIFY_REMOVE
};
/**
* enum ieee80211_tkip_key_type - get tkip key
*
* Used by drivers which need to get a tkip key for skb. Some drivers need a
* phase 1 key, others need a phase 2 key. A single function allows the driver
* to get the key, this enum indicates what type of key is required.
*
* @IEEE80211_TKIP_P1_KEY: the driver needs a phase 1 key
* @IEEE80211_TKIP_P2_KEY: the driver needs a phase 2 key
*/
enum ieee80211_tkip_key_type {
IEEE80211_TKIP_P1_KEY,
IEEE80211_TKIP_P2_KEY,
};
/**
* enum ieee80211_hw_flags - hardware flags
*
......@@ -1471,6 +1486,21 @@ int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb);
*/
int ieee80211_get_hdrlen(u16 fc);
/**
* ieee80211_get_tkip_key - get a TKIP rc4 for skb
*
* This function computes a TKIP rc4 key for an skb. It computes
* a phase 1 key if needed (iv16 wraps around). This function is to
* be used by drivers which can do HW encryption but need to compute
* to phase 1/2 key in SW.
*
* @keyconf: the parameter passed with the set key
* @skb: the skb for which the key is needed
* @rc4key: a buffer to which the key will be written
*/
void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
struct sk_buff *skb,
enum ieee80211_tkip_key_type type, u8 *key);
/**
* ieee80211_wake_queue - wake specific queue
* @hw: pointer as obtained from ieee80211_alloc_hw().
......
......@@ -214,6 +214,59 @@ void ieee80211_tkip_gen_rc4key(struct ieee80211_key *key, u8 *ta,
key->u.tkip.iv16, rc4key);
}
void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
struct sk_buff *skb, enum ieee80211_tkip_key_type type,
u8 *outkey)
{
struct ieee80211_key *key = (struct ieee80211_key *)
container_of(keyconf, struct ieee80211_key, conf);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u8 *data = (u8 *) hdr;
u16 fc = le16_to_cpu(hdr->frame_control);
int hdr_len = ieee80211_get_hdrlen(fc);
u8 *ta = hdr->addr2;
u16 iv16;
u32 iv32;
iv16 = data[hdr_len] << 8;
iv16 += data[hdr_len + 2];
iv32 = data[hdr_len + 4] +
(data[hdr_len + 5] >> 8) +
(data[hdr_len + 6] >> 16) +
(data[hdr_len + 7] >> 24);
#ifdef CONFIG_TKIP_DEBUG
printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n",
iv16, iv32);
if (iv32 != key->u.tkip.iv32) {
printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n",
iv32, key->u.tkip.iv32);
printk(KERN_DEBUG "Wrap around of iv16 in the middle of a "
"fragmented packet\n");
}
#endif /* CONFIG_TKIP_DEBUG */
/* Update the p1k only when the iv16 in the packet wraps around, this
* might occur after the wrap around of iv16 in the key in case of
* fragmented packets. */
if (iv16 == 0 || !key->u.tkip.tx_initialized) {
/* IV16 wrapped around - perform TKIP phase 1 */
tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
iv32, key->u.tkip.p1k);
key->u.tkip.tx_initialized = 1;
}
if (type == IEEE80211_TKIP_P1_KEY) {
memcpy(outkey, key->u.tkip.p1k, sizeof(u16) * 5);
return;
}
tkip_mixing_phase2(key->u.tkip.p1k,
&key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], iv16, outkey);
}
EXPORT_SYMBOL(ieee80211_get_tkip_key);
/* Encrypt packet payload with TKIP using @key. @pos is a pointer to the
* beginning of the buffer containing payload. This payload must include
* headroom of eight octets for IV and Ext. IV and taildroom of four octets
......
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