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: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c
index 3abe194..5c36b2d 100644
--- a/net/mac80211/tkip.c
+++ b/net/mac80211/tkip.c
@@ -214,6 +214,59 @@
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
