From 5d2cdcd4e85c5187db30a6b29f79fbbe59f39f78 Mon Sep 17 00:00:00 2001 From: Emmanuel Grumbach Date: Thu, 20 Mar 2008 15:06:41 +0200 Subject: 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 Signed-off-by: Tomas Winkler Signed-off-by: John W. Linville --- net/mac80211/tkip.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'net/mac80211/tkip.c') diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c index 3abe194e4d5..5c36b2df3fa 100644 --- a/net/mac80211/tkip.c +++ b/net/mac80211/tkip.c @@ -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 -- cgit v1.2.3