[NET] ieee80211 subsystem

Contributors:
Host AP contributors
James Ketrenos <jketreno@linux.intel.com>
Francois Romieu <romieu@fr.zoreil.com>
Adrian Bunk <bunk@stusta.de>
Matthew Galgoci <mgalgoci@parcelfarce.linux.th
eplanet.co.uk>

1 files changed, 708 insertions, 0 deletions

diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c
new file mode 100644
index 00000000000..f91d92c6df2
--- /dev/null
+++ b/net/ieee80211/ieee80211_crypt_tkip.c
@@ -0,0 +1,708 @@
+/*
+ * Host AP crypt: host-based TKIP encryption implementation for Host AP driver
+ *
+ * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation. See README and COPYING for
+ * more details.
+ */
+
+#include <linux/config.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <asm/string.h>
+
+#include <net/ieee80211.h>
+
+
+#include <linux/crypto.h>
+#include <asm/scatterlist.h>
+#include <linux/crc32.h>
+
+MODULE_AUTHOR("Jouni Malinen");
+MODULE_DESCRIPTION("Host AP crypt: TKIP");
+MODULE_LICENSE("GPL");
+
+struct ieee80211_tkip_data {
+#define TKIP_KEY_LEN 32
+	u8 key[TKIP_KEY_LEN];
+	int key_set;
+
+	u32 tx_iv32;
+	u16 tx_iv16;
+	u16 tx_ttak[5];
+	int tx_phase1_done;
+
+	u32 rx_iv32;
+	u16 rx_iv16;
+	u16 rx_ttak[5];
+	int rx_phase1_done;
+	u32 rx_iv32_new;
+	u16 rx_iv16_new;
+
+	u32 dot11RSNAStatsTKIPReplays;
+	u32 dot11RSNAStatsTKIPICVErrors;
+	u32 dot11RSNAStatsTKIPLocalMICFailures;
+
+	int key_idx;
+
+	struct crypto_tfm *tfm_arc4;
+	struct crypto_tfm *tfm_michael;
+
+	/* scratch buffers for virt_to_page() (crypto API) */
+	u8 rx_hdr[16], tx_hdr[16];
+};
+
+static void * ieee80211_tkip_init(int key_idx)
+{
+	struct ieee80211_tkip_data *priv;
+
+	priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
+	if (priv == NULL)
+		goto fail;
+	memset(priv, 0, sizeof(*priv));
+	priv->key_idx = key_idx;
+
+	priv->tfm_arc4 = crypto_alloc_tfm("arc4", 0);
+	if (priv->tfm_arc4 == NULL) {
+		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
+		       "crypto API arc4\n");
+		goto fail;
+	}
+
+	priv->tfm_michael = crypto_alloc_tfm("michael_mic", 0);
+	if (priv->tfm_michael == NULL) {
+		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
+		       "crypto API michael_mic\n");
+		goto fail;
+	}
+
+	return priv;
+
+fail:
+	if (priv) {
+		if (priv->tfm_michael)
+			crypto_free_tfm(priv->tfm_michael);
+		if (priv->tfm_arc4)
+			crypto_free_tfm(priv->tfm_arc4);
+		kfree(priv);
+	}
+
+	return NULL;
+}
+
+
+static void ieee80211_tkip_deinit(void *priv)
+{
+	struct ieee80211_tkip_data *_priv = priv;
+	if (_priv && _priv->tfm_michael)
+		crypto_free_tfm(_priv->tfm_michael);
+	if (_priv && _priv->tfm_arc4)
+		crypto_free_tfm(_priv->tfm_arc4);
+	kfree(priv);
+}
+
+
+static inline u16 RotR1(u16 val)
+{
+	return (val >> 1) | (val << 15);
+}
+
+
+static inline u8 Lo8(u16 val)
+{
+	return val & 0xff;
+}
+
+
+static inline u8 Hi8(u16 val)
+{
+	return val >> 8;
+}
+
+
+static inline u16 Lo16(u32 val)
+{
+	return val & 0xffff;
+}
+
+
+static inline u16 Hi16(u32 val)
+{
+	return val >> 16;
+}
+
+
+static inline u16 Mk16(u8 hi, u8 lo)
+{
+	return lo | (((u16) hi) << 8);
+}
+
+
+static inline u16 Mk16_le(u16 *v)
+{
+	return le16_to_cpu(*v);
+}
+
+
+static const u16 Sbox[256] =
+{
+	0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
+	0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
+	0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
+	0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
+	0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
+	0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
+	0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
+	0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
+	0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
+	0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
+	0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
+	0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
+	0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
+	0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
+	0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
+	0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
+	0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
+	0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
+	0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
+	0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
+	0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
+	0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
+	0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
+	0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
+	0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
+	0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
+	0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
+	0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
+	0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
+	0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
+	0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
+	0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
+};
+
+
+static inline u16 _S_(u16 v)
+{
+	u16 t = Sbox[Hi8(v)];
+	return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
+}
+
+
+#define PHASE1_LOOP_COUNT 8
+
+static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
+{
+	int i, j;
+
+	/* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
+	TTAK[0] = Lo16(IV32);
+	TTAK[1] = Hi16(IV32);
+	TTAK[2] = Mk16(TA[1], TA[0]);
+	TTAK[3] = Mk16(TA[3], TA[2]);
+	TTAK[4] = Mk16(TA[5], TA[4]);
+
+	for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
+		j = 2 * (i & 1);
+		TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
+		TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
+		TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
+		TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
+		TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
+	}
+}
+
+
+static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
+			       u16 IV16)
+{
+	/* Make temporary area overlap WEP seed so that the final copy can be
+	 * avoided on little endian hosts. */
+	u16 *PPK = (u16 *) &WEPSeed[4];
+
+	/* Step 1 - make copy of TTAK and bring in TSC */
+	PPK[0] = TTAK[0];
+	PPK[1] = TTAK[1];
+	PPK[2] = TTAK[2];
+	PPK[3] = TTAK[3];
+	PPK[4] = TTAK[4];
+	PPK[5] = TTAK[4] + IV16;
+
+	/* Step 2 - 96-bit bijective mixing using S-box */
+	PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0]));
+	PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2]));
+	PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4]));
+	PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6]));
+	PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8]));
+	PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10]));
+
+	PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12]));
+	PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14]));
+	PPK[2] += RotR1(PPK[1]);
+	PPK[3] += RotR1(PPK[2]);
+	PPK[4] += RotR1(PPK[3]);
+	PPK[5] += RotR1(PPK[4]);
+
+	/* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
+	 * WEPSeed[0..2] is transmitted as WEP IV */
+	WEPSeed[0] = Hi8(IV16);
+	WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
+	WEPSeed[2] = Lo8(IV16);
+	WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1);
+
+#ifdef __BIG_ENDIAN
+	{
+		int i;
+		for (i = 0; i < 6; i++)
+			PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
+	}
+#endif
+}
+
+static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+	int len;
+	u8 rc4key[16], *pos, *icv;
+	struct ieee80211_hdr *hdr;
+	u32 crc;
+	struct scatterlist sg;
+
+	if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 ||
+	    skb->len < hdr_len)
+		return -1;
+
+	hdr = (struct ieee80211_hdr *) skb->data;
+	if (!tkey->tx_phase1_done) {
+		tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
+				   tkey->tx_iv32);
+		tkey->tx_phase1_done = 1;
+	}
+	tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
+
+	len = skb->len - hdr_len;
+	pos = skb_push(skb, 8);
+	memmove(pos, pos + 8, hdr_len);
+	pos += hdr_len;
+	icv = skb_put(skb, 4);
+
+	*pos++ = rc4key[0];
+	*pos++ = rc4key[1];
+	*pos++ = rc4key[2];
+	*pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */;
+	*pos++ = tkey->tx_iv32 & 0xff;
+	*pos++ = (tkey->tx_iv32 >> 8) & 0xff;
+	*pos++ = (tkey->tx_iv32 >> 16) & 0xff;
+	*pos++ = (tkey->tx_iv32 >> 24) & 0xff;
+
+	crc = ~crc32_le(~0, pos, len);
+	icv[0] = crc;
+	icv[1] = crc >> 8;
+	icv[2] = crc >> 16;
+	icv[3] = crc >> 24;
+
+	crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
+	sg.page = virt_to_page(pos);
+	sg.offset = offset_in_page(pos);
+	sg.length = len + 4;
+	crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4);
+
+	tkey->tx_iv16++;
+	if (tkey->tx_iv16 == 0) {
+		tkey->tx_phase1_done = 0;
+		tkey->tx_iv32++;
+	}
+
+	return 0;
+}
+
+static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+	u8 rc4key[16];
+	u8 keyidx, *pos;
+	u32 iv32;
+	u16 iv16;
+	struct ieee80211_hdr *hdr;
+	u8 icv[4];
+	u32 crc;
+	struct scatterlist sg;
+	int plen;
+
+	if (skb->len < hdr_len + 8 + 4)
+		return -1;
+
+	hdr = (struct ieee80211_hdr *) skb->data;
+	pos = skb->data + hdr_len;
+	keyidx = pos[3];
+	if (!(keyidx & (1 << 5))) {
+		if (net_ratelimit()) {
+			printk(KERN_DEBUG "TKIP: received packet without ExtIV"
+			       " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
+		}
+		return -2;
+	}
+	keyidx >>= 6;
+	if (tkey->key_idx != keyidx) {
+		printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame "
+		       "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
+		return -6;
+	}
+	if (!tkey->key_set) {
+		if (net_ratelimit()) {
+			printk(KERN_DEBUG "TKIP: received packet from " MAC_FMT
+			       " with keyid=%d that does not have a configured"
+			       " key\n", MAC_ARG(hdr->addr2), keyidx);
+		}
+		return -3;
+	}
+	iv16 = (pos[0] << 8) | pos[2];
+	iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
+	pos += 8;
+
+	if (iv32 < tkey->rx_iv32 ||
+	    (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) {
+		if (net_ratelimit()) {
+			printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT
+			       " previous TSC %08x%04x received TSC "
+			       "%08x%04x\n", MAC_ARG(hdr->addr2),
+			       tkey->rx_iv32, tkey->rx_iv16, iv32, iv16);
+		}
+		tkey->dot11RSNAStatsTKIPReplays++;
+		return -4;
+	}
+
+	if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
+		tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
+		tkey->rx_phase1_done = 1;
+	}
+	tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
+
+	plen = skb->len - hdr_len - 12;
+
+	crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
+	sg.page = virt_to_page(pos);
+	sg.offset = offset_in_page(pos);
+	sg.length = plen + 4;
+	crypto_cipher_decrypt(tkey->tfm_arc4, &sg, &sg, plen + 4);
+
+	crc = ~crc32_le(~0, pos, plen);
+	icv[0] = crc;
+	icv[1] = crc >> 8;
+	icv[2] = crc >> 16;
+	icv[3] = crc >> 24;
+	if (memcmp(icv, pos + plen, 4) != 0) {
+		if (iv32 != tkey->rx_iv32) {
+			/* Previously cached Phase1 result was already lost, so
+			 * it needs to be recalculated for the next packet. */
+			tkey->rx_phase1_done = 0;
+		}
+		if (net_ratelimit()) {
+			printk(KERN_DEBUG "TKIP: ICV error detected: STA="
+			       MAC_FMT "\n", MAC_ARG(hdr->addr2));
+		}
+		tkey->dot11RSNAStatsTKIPICVErrors++;
+		return -5;
+	}
+
+	/* Update real counters only after Michael MIC verification has
+	 * completed */
+	tkey->rx_iv32_new = iv32;
+	tkey->rx_iv16_new = iv16;
+
+	/* Remove IV and ICV */
+	memmove(skb->data + 8, skb->data, hdr_len);
+	skb_pull(skb, 8);
+	skb_trim(skb, skb->len - 4);
+
+	return keyidx;
+}
+
+
+static int michael_mic(struct ieee80211_tkip_data *tkey, u8 *key, u8 *hdr,
+		       u8 *data, size_t data_len, u8 *mic)
+{
+	struct scatterlist sg[2];
+
+	if (tkey->tfm_michael == NULL) {
+		printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
+		return -1;
+	}
+	sg[0].page = virt_to_page(hdr);
+	sg[0].offset = offset_in_page(hdr);
+	sg[0].length = 16;
+
+	sg[1].page = virt_to_page(data);
+	sg[1].offset = offset_in_page(data);
+	sg[1].length = data_len;
+
+	crypto_digest_init(tkey->tfm_michael);
+	crypto_digest_setkey(tkey->tfm_michael, key, 8);
+	crypto_digest_update(tkey->tfm_michael, sg, 2);
+	crypto_digest_final(tkey->tfm_michael, mic);
+
+	return 0;
+}
+
+static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr)
+{
+	struct ieee80211_hdr *hdr11;
+
+	hdr11 = (struct ieee80211_hdr *) skb->data;
+	switch (le16_to_cpu(hdr11->frame_ctl) &
+		(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
+	case IEEE80211_FCTL_TODS:
+		memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
+		memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
+		break;
+	case IEEE80211_FCTL_FROMDS:
+		memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
+		memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
+		break;
+	case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
+		memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
+		memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
+		break;
+	case 0:
+		memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
+		memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
+		break;
+	}
+
+	hdr[12] = 0; /* priority */
+	hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
+}
+
+
+static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+	u8 *pos;
+
+	if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
+		printk(KERN_DEBUG "Invalid packet for Michael MIC add "
+		       "(tailroom=%d hdr_len=%d skb->len=%d)\n",
+		       skb_tailroom(skb), hdr_len, skb->len);
+		return -1;
+	}
+
+	michael_mic_hdr(skb, tkey->tx_hdr);
+	pos = skb_put(skb, 8);
+	if (michael_mic(tkey, &tkey->key[16], tkey->tx_hdr,
+			skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
+		return -1;
+
+	return 0;
+}
+
+
+#if WIRELESS_EXT >= 18
+static void ieee80211_michael_mic_failure(struct net_device *dev,
+				       struct ieee80211_hdr *hdr,
+				       int keyidx)
+{
+	union iwreq_data wrqu;
+	struct iw_michaelmicfailure ev;
+
+	/* TODO: needed parameters: count, keyid, key type, TSC */
+	memset(&ev, 0, sizeof(ev));
+	ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
+	if (hdr->addr1[0] & 0x01)
+		ev.flags |= IW_MICFAILURE_GROUP;
+	else
+		ev.flags |= IW_MICFAILURE_PAIRWISE;
+	ev.src_addr.sa_family = ARPHRD_ETHER;
+	memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
+	memset(&wrqu, 0, sizeof(wrqu));
+	wrqu.data.length = sizeof(ev);
+	wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *) &ev);
+}
+#elif WIRELESS_EXT >= 15
+static void ieee80211_michael_mic_failure(struct net_device *dev,
+				       struct ieee80211_hdr *hdr,
+				       int keyidx)
+{
+	union iwreq_data wrqu;
+	char buf[128];
+
+	/* TODO: needed parameters: count, keyid, key type, TSC */
+	sprintf(buf, "MLME-MICHAELMICFAILURE.indication(keyid=%d %scast addr="
+		MAC_FMT ")", keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni",
+		MAC_ARG(hdr->addr2));
+	memset(&wrqu, 0, sizeof(wrqu));
+	wrqu.data.length = strlen(buf);
+	wireless_send_event(dev, IWEVCUSTOM, &wrqu, buf);
+}
+#else /* WIRELESS_EXT >= 15 */
+static inline void ieee80211_michael_mic_failure(struct net_device *dev,
+					      struct ieee80211_hdr *hdr,
+					      int keyidx)
+{
+}
+#endif /* WIRELESS_EXT >= 15 */
+
+
+static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
+				     int hdr_len, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+	u8 mic[8];
+
+	if (!tkey->key_set)
+		return -1;
+
+	michael_mic_hdr(skb, tkey->rx_hdr);
+	if (michael_mic(tkey, &tkey->key[24], tkey->rx_hdr,
+			skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
+		return -1;
+	if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
+		struct ieee80211_hdr *hdr;
+		hdr = (struct ieee80211_hdr *) skb->data;
+		printk(KERN_DEBUG "%s: Michael MIC verification failed for "
+		       "MSDU from " MAC_FMT " keyidx=%d\n",
+		       skb->dev ? skb->dev->name : "N/A", MAC_ARG(hdr->addr2),
+		       keyidx);
+		if (skb->dev)
+			ieee80211_michael_mic_failure(skb->dev, hdr, keyidx);
+		tkey->dot11RSNAStatsTKIPLocalMICFailures++;
+		return -1;
+	}
+
+	/* Update TSC counters for RX now that the packet verification has
+	 * completed. */
+	tkey->rx_iv32 = tkey->rx_iv32_new;
+	tkey->rx_iv16 = tkey->rx_iv16_new;
+
+	skb_trim(skb, skb->len - 8);
+
+	return 0;
+}
+
+
+static int ieee80211_tkip_set_key(void *key, int len, u8 *seq, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+	int keyidx;
+	struct crypto_tfm *tfm = tkey->tfm_michael;
+	struct crypto_tfm *tfm2 = tkey->tfm_arc4;
+
+	keyidx = tkey->key_idx;
+	memset(tkey, 0, sizeof(*tkey));
+	tkey->key_idx = keyidx;
+	tkey->tfm_michael = tfm;
+	tkey->tfm_arc4 = tfm2;
+	if (len == TKIP_KEY_LEN) {
+		memcpy(tkey->key, key, TKIP_KEY_LEN);
+		tkey->key_set = 1;
+		tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
+		if (seq) {
+			tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
+				(seq[3] << 8) | seq[2];
+			tkey->rx_iv16 = (seq[1] << 8) | seq[0];
+		}
+	} else if (len == 0)
+		tkey->key_set = 0;
+	else
+		return -1;
+
+	return 0;
+}
+
+
+static int ieee80211_tkip_get_key(void *key, int len, u8 *seq, void *priv)
+{
+	struct ieee80211_tkip_data *tkey = priv;
+
+	if (len < TKIP_KEY_LEN)
+		return -1;
+
+	if (!tkey->key_set)
+		return 0;
+	memcpy(key, tkey->key, TKIP_KEY_LEN);
+
+	if (seq) {
+		/* Return the sequence number of the last transmitted frame. */
+		u16 iv16 = tkey->tx_iv16;
+		u32 iv32 = tkey->tx_iv32;
+		if (iv16 == 0)
+			iv32--;
+		iv16--;
+		seq[0] = tkey->tx_iv16;
+		seq[1] = tkey->tx_iv16 >> 8;
+		seq[2] = tkey->tx_iv32;
+		seq[3] = tkey->tx_iv32 >> 8;
+		seq[4] = tkey->tx_iv32 >> 16;
+		seq[5] = tkey->tx_iv32 >> 24;
+	}
+
+	return TKIP_KEY_LEN;
+}
+
+
+static char * ieee80211_tkip_print_stats(char *p, void *priv)
+{
+	struct ieee80211_tkip_data *tkip = priv;
+	p += sprintf(p, "key[%d] alg=TKIP key_set=%d "
+		     "tx_pn=%02x%02x%02x%02x%02x%02x "
+		     "rx_pn=%02x%02x%02x%02x%02x%02x "
+		     "replays=%d icv_errors=%d local_mic_failures=%d\n",
+		     tkip->key_idx, tkip->key_set,
+		     (tkip->tx_iv32 >> 24) & 0xff,
+		     (tkip->tx_iv32 >> 16) & 0xff,
+		     (tkip->tx_iv32 >> 8) & 0xff,
+		     tkip->tx_iv32 & 0xff,
+		     (tkip->tx_iv16 >> 8) & 0xff,
+		     tkip->tx_iv16 & 0xff,
+		     (tkip->rx_iv32 >> 24) & 0xff,
+		     (tkip->rx_iv32 >> 16) & 0xff,
+		     (tkip->rx_iv32 >> 8) & 0xff,
+		     tkip->rx_iv32 & 0xff,
+		     (tkip->rx_iv16 >> 8) & 0xff,
+		     tkip->rx_iv16 & 0xff,
+		     tkip->dot11RSNAStatsTKIPReplays,
+		     tkip->dot11RSNAStatsTKIPICVErrors,
+		     tkip->dot11RSNAStatsTKIPLocalMICFailures);
+	return p;
+}
+
+
+static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
+	.name			= "TKIP",
+	.init			= ieee80211_tkip_init,
+	.deinit			= ieee80211_tkip_deinit,
+	.encrypt_mpdu		= ieee80211_tkip_encrypt,
+	.decrypt_mpdu		= ieee80211_tkip_decrypt,
+	.encrypt_msdu		= ieee80211_michael_mic_add,
+	.decrypt_msdu		= ieee80211_michael_mic_verify,
+	.set_key		= ieee80211_tkip_set_key,
+	.get_key		= ieee80211_tkip_get_key,
+	.print_stats		= ieee80211_tkip_print_stats,
+	.extra_prefix_len	= 4 + 4, /* IV + ExtIV */
+	.extra_postfix_len	= 8 + 4, /* MIC + ICV */
+	.owner		        = THIS_MODULE,
+};
+
+
+static int __init ieee80211_crypto_tkip_init(void)
+{
+	return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip);
+}
+
+
+static void __exit ieee80211_crypto_tkip_exit(void)
+{
+	ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip);
+}
+
+
+module_init(ieee80211_crypto_tkip_init);
+module_exit(ieee80211_crypto_tkip_exit);