[PATCH] mac80211: Remove obsolete TKIP flexibility

[Jouni Malinen <jouni.malinen@atheros.com>]

The TKIP implementation was originally prepared to be a bit more
flexible in the way Michael MIC TX/RX keys are configured. However, we
are now taking care of the TX/RX MIC key swapping in user space, so
this code will not be needed. Similarly, there were some remaining WPA
testing code that won't be used in their current form. Remove the
unneeded extra complexity.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

---
 net/mac80211/wpa.c |   32 +++++++-------------------------
 1 file changed, 7 insertions(+), 25 deletions(-)

--- wireless-testing.orig/net/mac80211/wpa.c	2011-02-03 13:54:05.000000000 +0200
+++ wireless-testing/net/mac80211/wpa.c	2011-02-03 17:55:31.000000000 +0200
@@ -26,13 +26,12 @@
 ieee80211_tx_result
 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
 {
-	u8 *data, *key, *mic, key_offset;
+	u8 *data, *key, *mic;
 	size_t data_len;
 	unsigned int hdrlen;
 	struct ieee80211_hdr *hdr;
 	struct sk_buff *skb = tx->skb;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	int authenticator;
 	int tail;
 
 	hdr = (struct ieee80211_hdr *)skb->data;
@@ -62,15 +61,7 @@ ieee80211_tx_h_michael_mic_add(struct ie
 		    skb_headroom(skb) < TKIP_IV_LEN))
 		return TX_DROP;
 
-#if 0
-	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
-#else
-	authenticator = 1;
-#endif
-	key_offset = authenticator ?
-		NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
-		NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
-	key = &tx->key->conf.key[key_offset];
+	key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
 	mic = skb_put(skb, MICHAEL_MIC_LEN);
 	michael_mic(key, hdr, data, data_len, mic);
 
@@ -81,14 +72,13 @@ ieee80211_tx_h_michael_mic_add(struct ie
 ieee80211_rx_result
 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
 {
-	u8 *data, *key = NULL, key_offset;
+	u8 *data, *key = NULL;
 	size_t data_len;
 	unsigned int hdrlen;
 	u8 mic[MICHAEL_MIC_LEN];
 	struct sk_buff *skb = rx->skb;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-	int authenticator = 1, wpa_test = 0;
 
 	/* No way to verify the MIC if the hardware stripped it */
 	if (status->flag & RX_FLAG_MMIC_STRIPPED)
@@ -106,17 +96,9 @@ ieee80211_rx_h_michael_mic_verify(struct
 	data = skb->data + hdrlen;
 	data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
 
-#if 0
-	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
-#else
-	authenticator = 1;
-#endif
-	key_offset = authenticator ?
-		NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
-		NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
-	key = &rx->key->conf.key[key_offset];
+	key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
 	michael_mic(key, hdr, data, data_len, mic);
-	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
+	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0) {
 		if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
 			return RX_DROP_UNUSABLE;
 
@@ -208,7 +190,7 @@ ieee80211_rx_result
 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
-	int hdrlen, res, hwaccel = 0, wpa_test = 0;
+	int hdrlen, res, hwaccel = 0;
 	struct ieee80211_key *key = rx->key;
 	struct sk_buff *skb = rx->skb;
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
@@ -235,7 +217,7 @@ ieee80211_crypto_tkip_decrypt(struct iee
 					  hdr->addr1, hwaccel, rx->queue,
 					  &rx->tkip_iv32,
 					  &rx->tkip_iv16);
-	if (res != TKIP_DECRYPT_OK || wpa_test)
+	if (res != TKIP_DECRYPT_OK)
 		return RX_DROP_UNUSABLE;
 
 	/* Trim ICV */

-- 
Jouni Malinen                                            PGP id EFC895FA