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DEFINITIONS
This source file includes following definitions.
- ieee80211_tkip_set_flags
- ieee80211_tkip_get_flags
- ieee80211_tkip_init
- ieee80211_tkip_deinit
- RotR1
- Lo8
- Hi8
- Lo16
- Hi16
- Mk16
- Mk16_le
- _S_
- tkip_mixing_phase1
- tkip_mixing_phase2
- ieee80211_tkip_hdr
- ieee80211_tkip_encrypt
- tkip_replay_check
- ieee80211_tkip_decrypt
- michael_mic
- michael_mic_hdr
- ieee80211_michael_mic_add
- ieee80211_michael_mic_failure
- ieee80211_michael_mic_verify
- ieee80211_tkip_set_key
- ieee80211_tkip_get_key
- ieee80211_tkip_print_stats
- ieee80211_crypto_tkip_init
- ieee80211_crypto_tkip_exit
/*
* Host AP crypt: host-based TKIP encryption implementation for Host AP driver
*
* Copyright (c) 2003-2004, Jouni Malinen <j@w1.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/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/mm.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>
#include <asm/string.h>
#include <net/ieee80211.h>
#include <linux/crypto.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_blkcipher *rx_tfm_arc4;
struct crypto_hash *rx_tfm_michael;
struct crypto_blkcipher *tx_tfm_arc4;
struct crypto_hash *tx_tfm_michael;
/* scratch buffers for virt_to_page() (crypto API) */
u8 rx_hdr[16], tx_hdr[16];
unsigned long flags;
};
static unsigned long ieee80211_tkip_set_flags(unsigned long flags, void *priv)
{
struct ieee80211_tkip_data *_priv = priv;
unsigned long old_flags = _priv->flags;
_priv->flags = flags;
return old_flags;
}
static unsigned long ieee80211_tkip_get_flags(void *priv)
{
struct ieee80211_tkip_data *_priv = priv;
return _priv->flags;
}
static void *ieee80211_tkip_init(int key_idx)
{
struct ieee80211_tkip_data *priv;
priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
if (priv == NULL)
goto fail;
priv->key_idx = key_idx;
priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(priv->tx_tfm_arc4)) {
printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
"crypto API arc4\n");
priv->tx_tfm_arc4 = NULL;
goto fail;
}
priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(priv->tx_tfm_michael)) {
printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
"crypto API michael_mic\n");
priv->tx_tfm_michael = NULL;
goto fail;
}
priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(priv->rx_tfm_arc4)) {
printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
"crypto API arc4\n");
priv->rx_tfm_arc4 = NULL;
goto fail;
}
priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(priv->rx_tfm_michael)) {
printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
"crypto API michael_mic\n");
priv->rx_tfm_michael = NULL;
goto fail;
}
return priv;
fail:
if (priv) {
if (priv->tx_tfm_michael)
crypto_free_hash(priv->tx_tfm_michael);
if (priv->tx_tfm_arc4)
crypto_free_blkcipher(priv->tx_tfm_arc4);
if (priv->rx_tfm_michael)
crypto_free_hash(priv->rx_tfm_michael);
if (priv->rx_tfm_arc4)
crypto_free_blkcipher(priv->rx_tfm_arc4);
kfree(priv);
}
return NULL;
}
static void ieee80211_tkip_deinit(void *priv)
{
struct ieee80211_tkip_data *_priv = priv;
if (_priv) {
if (_priv->tx_tfm_michael)
crypto_free_hash(_priv->tx_tfm_michael);
if (_priv->tx_tfm_arc4)
crypto_free_blkcipher(_priv->tx_tfm_arc4);
if (_priv->rx_tfm_michael)
crypto_free_hash(_priv->rx_tfm_michael);
if (_priv->rx_tfm_arc4)
crypto_free_blkcipher(_priv->rx_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(__le16 * 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((__le16 *) & TK[0]));
PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & 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((__le16 *) & 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_hdr(struct sk_buff *skb, int hdr_len,
u8 * rc4key, int keylen, void *priv)
{
struct ieee80211_tkip_data *tkey = priv;
int len;
u8 *pos;
struct ieee80211_hdr_4addr *hdr;
hdr = (struct ieee80211_hdr_4addr *)skb->data;
if (skb_headroom(skb) < 8 || skb->len < hdr_len)
return -1;
if (rc4key == NULL || keylen < 16)
return -1;
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;
*pos++ = *rc4key;
*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;
tkey->tx_iv16++;
if (tkey->tx_iv16 == 0) {
tkey->tx_phase1_done = 0;
tkey->tx_iv32++;
}
return 8;
}
static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
struct ieee80211_tkip_data *tkey = priv;
struct blkcipher_desc desc = { .tfm = tkey->tx_tfm_arc4 };
int len;
u8 rc4key[16], *pos, *icv;
u32 crc;
struct scatterlist sg;
DECLARE_MAC_BUF(mac);
if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
if (net_ratelimit()) {
struct ieee80211_hdr_4addr *hdr =
(struct ieee80211_hdr_4addr *)skb->data;
printk(KERN_DEBUG ": TKIP countermeasures: dropped "
"TX packet to %s\n",
print_mac(mac, hdr->addr1));
}
return -1;
}
if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
return -1;
len = skb->len - hdr_len;
pos = skb->data + hdr_len;
if ((ieee80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
return -1;
icv = skb_put(skb, 4);
crc = ~crc32_le(~0, pos, len);
icv[0] = crc;
icv[1] = crc >> 8;
icv[2] = crc >> 16;
icv[3] = crc >> 24;
crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
sg_init_one(&sg, pos, len + 4);
return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
}
/*
* deal with seq counter wrapping correctly.
* refer to timer_after() for jiffies wrapping handling
*/
static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
u32 iv32_o, u16 iv16_o)
{
if ((s32)iv32_n - (s32)iv32_o < 0 ||
(iv32_n == iv32_o && iv16_n <= iv16_o))
return 1;
return 0;
}
static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
struct ieee80211_tkip_data *tkey = priv;
struct blkcipher_desc desc = { .tfm = tkey->rx_tfm_arc4 };
u8 rc4key[16];
u8 keyidx, *pos;
u32 iv32;
u16 iv16;
struct ieee80211_hdr_4addr *hdr;
u8 icv[4];
u32 crc;
struct scatterlist sg;
int plen;
DECLARE_MAC_BUF(mac);
hdr = (struct ieee80211_hdr_4addr *)skb->data;
if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
if (net_ratelimit()) {
printk(KERN_DEBUG ": TKIP countermeasures: dropped "
"received packet from %s\n",
print_mac(mac, hdr->addr2));
}
return -1;
}
if (skb->len < hdr_len + 8 + 4)
return -1;
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 %s\n", print_mac(mac, 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 %s"
" with keyid=%d that does not have a configured"
" key\n", print_mac(mac, 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 (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
if (ieee80211_ratelimit_debug(IEEE80211_DL_DROP)) {
IEEE80211_DEBUG_DROP("TKIP: replay detected: STA=%s"
" previous TSC %08x%04x received TSC "
"%08x%04x\n", print_mac(mac, 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_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
sg_init_one(&sg, pos, plen + 4);
if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) {
if (net_ratelimit()) {
printk(KERN_DEBUG ": TKIP: failed to decrypt "
"received packet from %s\n",
print_mac(mac, hdr->addr2));
}
return -7;
}
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 (ieee80211_ratelimit_debug(IEEE80211_DL_DROP)) {
IEEE80211_DEBUG_DROP("TKIP: ICV error detected: STA="
"%s\n", print_mac(mac, 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 crypto_hash *tfm_michael, u8 * key, u8 * hdr,
u8 * data, size_t data_len, u8 * mic)
{
struct hash_desc desc;
struct scatterlist sg[2];
if (tfm_michael == NULL) {
printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
return -1;
}
sg_init_table(sg, 2);
sg_set_buf(&sg[0], hdr, 16);
sg_set_buf(&sg[1], data, data_len);
if (crypto_hash_setkey(tfm_michael, key, 8))
return -1;
desc.tfm = tfm_michael;
desc.flags = 0;
return crypto_hash_digest(&desc, sg, data_len + 16, mic);
}
static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
{
struct ieee80211_hdr_4addr *hdr11;
u16 stype;
hdr11 = (struct ieee80211_hdr_4addr *)skb->data;
stype = WLAN_FC_GET_STYPE(le16_to_cpu(hdr11->frame_ctl));
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;
}
if (stype & IEEE80211_STYPE_QOS_DATA) {
const struct ieee80211_hdr_3addrqos *qoshdr =
(struct ieee80211_hdr_3addrqos *)skb->data;
hdr[12] = le16_to_cpu(qoshdr->qos_ctl) & IEEE80211_QCTL_TID;
} else
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->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
return -1;
return 0;
}
static void ieee80211_michael_mic_failure(struct net_device *dev,
struct ieee80211_hdr_4addr *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);
}
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];
DECLARE_MAC_BUF(mac);
if (!tkey->key_set)
return -1;
michael_mic_hdr(skb, tkey->rx_hdr);
if (michael_mic(tkey->rx_tfm_michael, &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_4addr *hdr;
hdr = (struct ieee80211_hdr_4addr *)skb->data;
printk(KERN_DEBUG "%s: Michael MIC verification failed for "
"MSDU from %s keyidx=%d\n",
skb->dev ? skb->dev->name : "N/A", print_mac(mac, 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_hash *tfm = tkey->tx_tfm_michael;
struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4;
struct crypto_hash *tfm3 = tkey->rx_tfm_michael;
struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4;
keyidx = tkey->key_idx;
memset(tkey, 0, sizeof(*tkey));
tkey->key_idx = keyidx;
tkey->tx_tfm_michael = tfm;
tkey->tx_tfm_arc4 = tfm2;
tkey->rx_tfm_michael = tfm3;
tkey->rx_tfm_arc4 = tfm4;
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,
.build_iv = ieee80211_tkip_hdr,
.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_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
.extra_mpdu_postfix_len = 4, /* ICV */
.extra_msdu_postfix_len = 8, /* MIC */
.get_flags = ieee80211_tkip_get_flags,
.set_flags = ieee80211_tkip_set_flags,
.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);