net/wireless/lib80211_crypt_tkip.c

   1 /*
   2  * lib80211 crypt: host-based TKIP encryption implementation for lib80211
   3  *
   4  * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
   5  * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation. See README and COPYING for
  10  * more details.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/err.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <linux/random.h>
  20 #include <linux/scatterlist.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/mm.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/if_arp.h>
  26 #include <asm/string.h>
  27
  28 #include <linux/wireless.h>
  29 #include <linux/ieee80211.h>
  30 #include <net/iw_handler.h>
  31
  32 #include <crypto/hash.h>
  33 #include <linux/crypto.h>
  34 #include <linux/crc32.h>
  35
  36 #include <net/lib80211.h>
  37
  38 MODULE_AUTHOR("Jouni Malinen");
  39 MODULE_DESCRIPTION("lib80211 crypt: TKIP");
  40 MODULE_LICENSE("GPL");
  41
  42 #define TKIP_HDR_LEN 8
  43
  44 struct lib80211_tkip_data {
  45 #define TKIP_KEY_LEN 32
  46         u8 key[TKIP_KEY_LEN];
  47         int key_set;
  48
  49         u32 tx_iv32;
  50         u16 tx_iv16;
  51         u16 tx_ttak[5];
  52         int tx_phase1_done;
  53
  54         u32 rx_iv32;
  55         u16 rx_iv16;
  56         u16 rx_ttak[5];
  57         int rx_phase1_done;
  58         u32 rx_iv32_new;
  59         u16 rx_iv16_new;
  60
  61         u32 dot11RSNAStatsTKIPReplays;
  62         u32 dot11RSNAStatsTKIPICVErrors;
  63         u32 dot11RSNAStatsTKIPLocalMICFailures;
  64
  65         int key_idx;
  66
  67         struct crypto_cipher *rx_tfm_arc4;
  68         struct crypto_shash *rx_tfm_michael;
  69         struct crypto_cipher *tx_tfm_arc4;
  70         struct crypto_shash *tx_tfm_michael;
  71
  72         /* scratch buffers for virt_to_page() (crypto API) */
  73         u8 rx_hdr[16], tx_hdr[16];
  74
  75         unsigned long flags;
  76 };
  77
  78 static unsigned long lib80211_tkip_set_flags(unsigned long flags, void *priv)
  79 {
  80         struct lib80211_tkip_data *_priv = priv;
  81         unsigned long old_flags = _priv->flags;
  82         _priv->flags = flags;
  83         return old_flags;
  84 }
  85
  86 static unsigned long lib80211_tkip_get_flags(void *priv)
  87 {
  88         struct lib80211_tkip_data *_priv = priv;
  89         return _priv->flags;
  90 }
  91
  92 static void *lib80211_tkip_init(int key_idx)
  93 {
  94         struct lib80211_tkip_data *priv;
  95
  96         priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
  97         if (priv == NULL)
  98                 goto fail;
  99
 100         priv->key_idx = key_idx;
 101
 102         priv->tx_tfm_arc4 = crypto_alloc_cipher("arc4", 0, 0);
 103         if (IS_ERR(priv->tx_tfm_arc4)) {
 104                 priv->tx_tfm_arc4 = NULL;
 105                 goto fail;
 106         }
 107
 108         priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
 109         if (IS_ERR(priv->tx_tfm_michael)) {
 110                 priv->tx_tfm_michael = NULL;
 111                 goto fail;
 112         }
 113
 114         priv->rx_tfm_arc4 = crypto_alloc_cipher("arc4", 0, 0);
 115         if (IS_ERR(priv->rx_tfm_arc4)) {
 116                 priv->rx_tfm_arc4 = NULL;
 117                 goto fail;
 118         }
 119
 120         priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
 121         if (IS_ERR(priv->rx_tfm_michael)) {
 122                 priv->rx_tfm_michael = NULL;
 123                 goto fail;
 124         }
 125
 126         return priv;
 127
 128       fail:
 129         if (priv) {
 130                 crypto_free_shash(priv->tx_tfm_michael);
 131                 crypto_free_cipher(priv->tx_tfm_arc4);
 132                 crypto_free_shash(priv->rx_tfm_michael);
 133                 crypto_free_cipher(priv->rx_tfm_arc4);
 134                 kfree(priv);
 135         }
 136
 137         return NULL;
 138 }
 139
 140 static void lib80211_tkip_deinit(void *priv)
 141 {
 142         struct lib80211_tkip_data *_priv = priv;
 143         if (_priv) {
 144                 crypto_free_shash(_priv->tx_tfm_michael);
 145                 crypto_free_cipher(_priv->tx_tfm_arc4);
 146                 crypto_free_shash(_priv->rx_tfm_michael);
 147                 crypto_free_cipher(_priv->rx_tfm_arc4);
 148         }
 149         kfree(priv);
 150 }
 151
 152 static inline u16 RotR1(u16 val)
 153 {
 154         return (val >> 1) | (val << 15);
 155 }
 156
 157 static inline u8 Lo8(u16 val)
 158 {
 159         return val & 0xff;
 160 }
 161
 162 static inline u8 Hi8(u16 val)
 163 {
 164         return val >> 8;
 165 }
 166
 167 static inline u16 Lo16(u32 val)
 168 {
 169         return val & 0xffff;
 170 }
 171
 172 static inline u16 Hi16(u32 val)
 173 {
 174         return val >> 16;
 175 }
 176
 177 static inline u16 Mk16(u8 hi, u8 lo)
 178 {
 179         return lo | (((u16) hi) << 8);
 180 }
 181
 182 static inline u16 Mk16_le(__le16 * v)
 183 {
 184         return le16_to_cpu(*v);
 185 }
 186
 187 static const u16 Sbox[256] = {
 188         0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
 189         0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
 190         0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
 191         0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
 192         0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
 193         0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
 194         0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
 195         0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
 196         0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
 197         0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
 198         0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
 199         0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
 200         0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
 201         0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
 202         0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
 203         0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
 204         0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
 205         0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
 206         0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
 207         0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
 208         0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
 209         0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
 210         0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
 211         0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
 212         0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
 213         0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
 214         0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
 215         0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
 216         0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
 217         0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
 218         0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
 219         0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
 220 };
 221
 222 static inline u16 _S_(u16 v)
 223 {
 224         u16 t = Sbox[Hi8(v)];
 225         return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
 226 }
 227
 228 #define PHASE1_LOOP_COUNT 8
 229
 230 static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
 231                                u32 IV32)
 232 {
 233         int i, j;
 234
 235         /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
 236         TTAK[0] = Lo16(IV32);
 237         TTAK[1] = Hi16(IV32);
 238         TTAK[2] = Mk16(TA[1], TA[0]);
 239         TTAK[3] = Mk16(TA[3], TA[2]);
 240         TTAK[4] = Mk16(TA[5], TA[4]);
 241
 242         for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
 243                 j = 2 * (i & 1);
 244                 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
 245                 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
 246                 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
 247                 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
 248                 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
 249         }
 250 }
 251
 252 static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
 253                                u16 IV16)
 254 {
 255         /* Make temporary area overlap WEP seed so that the final copy can be
 256          * avoided on little endian hosts. */
 257         u16 *PPK = (u16 *) & WEPSeed[4];
 258
 259         /* Step 1 - make copy of TTAK and bring in TSC */
 260         PPK[0] = TTAK[0];
 261         PPK[1] = TTAK[1];
 262         PPK[2] = TTAK[2];
 263         PPK[3] = TTAK[3];
 264         PPK[4] = TTAK[4];
 265         PPK[5] = TTAK[4] + IV16;
 266
 267         /* Step 2 - 96-bit bijective mixing using S-box */
 268         PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0]));
 269         PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
 270         PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
 271         PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
 272         PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
 273         PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
 274
 275         PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
 276         PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14]));
 277         PPK[2] += RotR1(PPK[1]);
 278         PPK[3] += RotR1(PPK[2]);
 279         PPK[4] += RotR1(PPK[3]);
 280         PPK[5] += RotR1(PPK[4]);
 281
 282         /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
 283          * WEPSeed[0..2] is transmitted as WEP IV */
 284         WEPSeed[0] = Hi8(IV16);
 285         WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
 286         WEPSeed[2] = Lo8(IV16);
 287         WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1);
 288
 289 #ifdef __BIG_ENDIAN
 290         {
 291                 int i;
 292                 for (i = 0; i < 6; i++)
 293                         PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
 294         }
 295 #endif
 296 }
 297
 298 static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
 299                               u8 * rc4key, int keylen, void *priv)
 300 {
 301         struct lib80211_tkip_data *tkey = priv;
 302         u8 *pos;
 303         struct ieee80211_hdr *hdr;
 304
 305         hdr = (struct ieee80211_hdr *)skb->data;
 306
 307         if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
 308                 return -1;
 309
 310         if (rc4key == NULL || keylen < 16)
 311                 return -1;
 312
 313         if (!tkey->tx_phase1_done) {
 314                 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
 315                                    tkey->tx_iv32);
 316                 tkey->tx_phase1_done = 1;
 317         }
 318         tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
 319
 320         pos = skb_push(skb, TKIP_HDR_LEN);
 321         memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
 322         pos += hdr_len;
 323
 324         *pos++ = *rc4key;
 325         *pos++ = *(rc4key + 1);
 326         *pos++ = *(rc4key + 2);
 327         *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
 328         *pos++ = tkey->tx_iv32 & 0xff;
 329         *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
 330         *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
 331         *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
 332
 333         tkey->tx_iv16++;
 334         if (tkey->tx_iv16 == 0) {
 335                 tkey->tx_phase1_done = 0;
 336                 tkey->tx_iv32++;
 337         }
 338
 339         return TKIP_HDR_LEN;
 340 }
 341
 342 static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 343 {
 344         struct lib80211_tkip_data *tkey = priv;
 345         int len;
 346         u8 rc4key[16], *pos, *icv;
 347         u32 crc;
 348         int i;
 349
 350         if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
 351                 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 352                 net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
 353                                     hdr->addr1);
 354                 return -1;
 355         }
 356
 357         if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
 358                 return -1;
 359
 360         len = skb->len - hdr_len;
 361         pos = skb->data + hdr_len;
 362
 363         if ((lib80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
 364                 return -1;
 365
 366         crc = ~crc32_le(~0, pos, len);
 367         icv = skb_put(skb, 4);
 368         icv[0] = crc;
 369         icv[1] = crc >> 8;
 370         icv[2] = crc >> 16;
 371         icv[3] = crc >> 24;
 372
 373         crypto_cipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
 374         for (i = 0; i < len + 4; i++)
 375                 crypto_cipher_encrypt_one(tkey->tx_tfm_arc4, pos + i, pos + i);
 376         return 0;
 377 }
 378
 379 /*
 380  * deal with seq counter wrapping correctly.
 381  * refer to timer_after() for jiffies wrapping handling
 382  */
 383 static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
 384                                     u32 iv32_o, u16 iv16_o)
 385 {
 386         if ((s32)iv32_n - (s32)iv32_o < 0 ||
 387             (iv32_n == iv32_o && iv16_n <= iv16_o))
 388                 return 1;
 389         return 0;
 390 }
 391
 392 static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 393 {
 394         struct lib80211_tkip_data *tkey = priv;
 395         u8 rc4key[16];
 396         u8 keyidx, *pos;
 397         u32 iv32;
 398         u16 iv16;
 399         struct ieee80211_hdr *hdr;
 400         u8 icv[4];
 401         u32 crc;
 402         int plen;
 403         int i;
 404
 405         hdr = (struct ieee80211_hdr *)skb->data;
 406
 407         if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
 408                 net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
 409                                     hdr->addr2);
 410                 return -1;
 411         }
 412
 413         if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
 414                 return -1;
 415
 416         pos = skb->data + hdr_len;
 417         keyidx = pos[3];
 418         if (!(keyidx & (1 << 5))) {
 419                 net_dbg_ratelimited("TKIP: received packet without ExtIV flag from %pM\n",
 420                                     hdr->addr2);
 421                 return -2;
 422         }
 423         keyidx >>= 6;
 424         if (tkey->key_idx != keyidx) {
 425                 net_dbg_ratelimited("TKIP: RX tkey->key_idx=%d frame keyidx=%d\n",
 426                                     tkey->key_idx, keyidx);
 427                 return -6;
 428         }
 429         if (!tkey->key_set) {
 430                 net_dbg_ratelimited("TKIP: received packet from %pM with keyid=%d that does not have a configured key\n",
 431                                     hdr->addr2, keyidx);
 432                 return -3;
 433         }
 434         iv16 = (pos[0] << 8) | pos[2];
 435         iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
 436         pos += TKIP_HDR_LEN;
 437
 438         if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
 439 #ifdef CONFIG_LIB80211_DEBUG
 440                 net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
 441                                     hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
 442                                     iv32, iv16);
 443 #endif
 444                 tkey->dot11RSNAStatsTKIPReplays++;
 445                 return -4;
 446         }
 447
 448         if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
 449                 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
 450                 tkey->rx_phase1_done = 1;
 451         }
 452         tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
 453
 454         plen = skb->len - hdr_len - 12;
 455
 456         crypto_cipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
 457         for (i = 0; i < plen + 4; i++)
 458                 crypto_cipher_decrypt_one(tkey->rx_tfm_arc4, pos + i, pos + i);
 459
 460         crc = ~crc32_le(~0, pos, plen);
 461         icv[0] = crc;
 462         icv[1] = crc >> 8;
 463         icv[2] = crc >> 16;
 464         icv[3] = crc >> 24;
 465         if (memcmp(icv, pos + plen, 4) != 0) {
 466                 if (iv32 != tkey->rx_iv32) {
 467                         /* Previously cached Phase1 result was already lost, so
 468                          * it needs to be recalculated for the next packet. */
 469                         tkey->rx_phase1_done = 0;
 470                 }
 471 #ifdef CONFIG_LIB80211_DEBUG
 472                 net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
 473                                     hdr->addr2);
 474 #endif
 475                 tkey->dot11RSNAStatsTKIPICVErrors++;
 476                 return -5;
 477         }
 478
 479         /* Update real counters only after Michael MIC verification has
 480          * completed */
 481         tkey->rx_iv32_new = iv32;
 482         tkey->rx_iv16_new = iv16;
 483
 484         /* Remove IV and ICV */
 485         memmove(skb->data + TKIP_HDR_LEN, skb->data, hdr_len);
 486         skb_pull(skb, TKIP_HDR_LEN);
 487         skb_trim(skb, skb->len - 4);
 488
 489         return keyidx;
 490 }
 491
 492 static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
 493                        u8 *data, size_t data_len, u8 *mic)
 494 {
 495         SHASH_DESC_ON_STACK(desc, tfm_michael);
 496         int err;
 497
 498         if (tfm_michael == NULL) {
 499                 pr_warn("%s(): tfm_michael == NULL\n", __func__);
 500                 return -1;
 501         }
 502
 503         desc->tfm = tfm_michael;
 504
 505         if (crypto_shash_setkey(tfm_michael, key, 8))
 506                 return -1;
 507
 508         err = crypto_shash_init(desc);
 509         if (err)
 510                 goto out;
 511         err = crypto_shash_update(desc, hdr, 16);
 512         if (err)
 513                 goto out;
 514         err = crypto_shash_update(desc, data, data_len);
 515         if (err)
 516                 goto out;
 517         err = crypto_shash_final(desc, mic);
 518
 519 out:
 520         shash_desc_zero(desc);
 521         return err;
 522 }
 523
 524 static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
 525 {
 526         struct ieee80211_hdr *hdr11;
 527
 528         hdr11 = (struct ieee80211_hdr *)skb->data;
 529
 530         switch (le16_to_cpu(hdr11->frame_control) &
 531                 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
 532         case IEEE80211_FCTL_TODS:
 533                 memcpy(hdr, hdr11->addr3, ETH_ALEN);    /* DA */
 534                 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
 535                 break;
 536         case IEEE80211_FCTL_FROMDS:
 537                 memcpy(hdr, hdr11->addr1, ETH_ALEN);    /* DA */
 538                 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
 539                 break;
 540         case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
 541                 memcpy(hdr, hdr11->addr3, ETH_ALEN);    /* DA */
 542                 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
 543                 break;
 544         default:
 545                 memcpy(hdr, hdr11->addr1, ETH_ALEN);    /* DA */
 546                 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
 547                 break;
 548         }
 549
 550         if (ieee80211_is_data_qos(hdr11->frame_control)) {
 551                 hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
 552                         & IEEE80211_QOS_CTL_TID_MASK;
 553         } else
 554                 hdr[12] = 0;            /* priority */
 555
 556         hdr[13] = hdr[14] = hdr[15] = 0;        /* reserved */
 557 }
 558
 559 static int lib80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
 560                                      void *priv)
 561 {
 562         struct lib80211_tkip_data *tkey = priv;
 563         u8 *pos;
 564
 565         if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
 566                 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
 567                        "(tailroom=%d hdr_len=%d skb->len=%d)\n",
 568                        skb_tailroom(skb), hdr_len, skb->len);
 569                 return -1;
 570         }
 571
 572         michael_mic_hdr(skb, tkey->tx_hdr);
 573         pos = skb_put(skb, 8);
 574         if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
 575                         skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
 576                 return -1;
 577
 578         return 0;
 579 }
 580
 581 static void lib80211_michael_mic_failure(struct net_device *dev,
 582                                           struct ieee80211_hdr *hdr,
 583                                           int keyidx)
 584 {
 585         union iwreq_data wrqu;
 586         struct iw_michaelmicfailure ev;
 587
 588         /* TODO: needed parameters: count, keyid, key type, TSC */
 589         memset(&ev, 0, sizeof(ev));
 590         ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
 591         if (hdr->addr1[0] & 0x01)
 592                 ev.flags |= IW_MICFAILURE_GROUP;
 593         else
 594                 ev.flags |= IW_MICFAILURE_PAIRWISE;
 595         ev.src_addr.sa_family = ARPHRD_ETHER;
 596         memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
 597         memset(&wrqu, 0, sizeof(wrqu));
 598         wrqu.data.length = sizeof(ev);
 599         wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
 600 }
 601
 602 static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
 603                                         int hdr_len, void *priv)
 604 {
 605         struct lib80211_tkip_data *tkey = priv;
 606         u8 mic[8];
 607
 608         if (!tkey->key_set)
 609                 return -1;
 610
 611         michael_mic_hdr(skb, tkey->rx_hdr);
 612         if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
 613                         skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
 614                 return -1;
 615         if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
 616                 struct ieee80211_hdr *hdr;
 617                 hdr = (struct ieee80211_hdr *)skb->data;
 618                 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
 619                        "MSDU from %pM keyidx=%d\n",
 620                        skb->dev ? skb->dev->name : "N/A", hdr->addr2,
 621                        keyidx);
 622                 if (skb->dev)
 623                         lib80211_michael_mic_failure(skb->dev, hdr, keyidx);
 624                 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
 625                 return -1;
 626         }
 627
 628         /* Update TSC counters for RX now that the packet verification has
 629          * completed. */
 630         tkey->rx_iv32 = tkey->rx_iv32_new;
 631         tkey->rx_iv16 = tkey->rx_iv16_new;
 632
 633         skb_trim(skb, skb->len - 8);
 634
 635         return 0;
 636 }
 637
 638 static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
 639 {
 640         struct lib80211_tkip_data *tkey = priv;
 641         int keyidx;
 642         struct crypto_shash *tfm = tkey->tx_tfm_michael;
 643         struct crypto_cipher *tfm2 = tkey->tx_tfm_arc4;
 644         struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
 645         struct crypto_cipher *tfm4 = tkey->rx_tfm_arc4;
 646
 647         keyidx = tkey->key_idx;
 648         memset(tkey, 0, sizeof(*tkey));
 649         tkey->key_idx = keyidx;
 650         tkey->tx_tfm_michael = tfm;
 651         tkey->tx_tfm_arc4 = tfm2;
 652         tkey->rx_tfm_michael = tfm3;
 653         tkey->rx_tfm_arc4 = tfm4;
 654         if (len == TKIP_KEY_LEN) {
 655                 memcpy(tkey->key, key, TKIP_KEY_LEN);
 656                 tkey->key_set = 1;
 657                 tkey->tx_iv16 = 1;      /* TSC is initialized to 1 */
 658                 if (seq) {
 659                         tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
 660                             (seq[3] << 8) | seq[2];
 661                         tkey->rx_iv16 = (seq[1] << 8) | seq[0];
 662                 }
 663         } else if (len == 0)
 664                 tkey->key_set = 0;
 665         else
 666                 return -1;
 667
 668         return 0;
 669 }
 670
 671 static int lib80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
 672 {
 673         struct lib80211_tkip_data *tkey = priv;
 674
 675         if (len < TKIP_KEY_LEN)
 676                 return -1;
 677
 678         if (!tkey->key_set)
 679                 return 0;
 680         memcpy(key, tkey->key, TKIP_KEY_LEN);
 681
 682         if (seq) {
 683                 /* Return the sequence number of the last transmitted frame. */
 684                 u16 iv16 = tkey->tx_iv16;
 685                 u32 iv32 = tkey->tx_iv32;
 686                 if (iv16 == 0)
 687                         iv32--;
 688                 iv16--;
 689                 seq[0] = tkey->tx_iv16;
 690                 seq[1] = tkey->tx_iv16 >> 8;
 691                 seq[2] = tkey->tx_iv32;
 692                 seq[3] = tkey->tx_iv32 >> 8;
 693                 seq[4] = tkey->tx_iv32 >> 16;
 694                 seq[5] = tkey->tx_iv32 >> 24;
 695         }
 696
 697         return TKIP_KEY_LEN;
 698 }
 699
 700 static void lib80211_tkip_print_stats(struct seq_file *m, void *priv)
 701 {
 702         struct lib80211_tkip_data *tkip = priv;
 703         seq_printf(m,
 704                    "key[%d] alg=TKIP key_set=%d "
 705                    "tx_pn=%02x%02x%02x%02x%02x%02x "
 706                    "rx_pn=%02x%02x%02x%02x%02x%02x "
 707                    "replays=%d icv_errors=%d local_mic_failures=%d\n",
 708                    tkip->key_idx, tkip->key_set,
 709                    (tkip->tx_iv32 >> 24) & 0xff,
 710                    (tkip->tx_iv32 >> 16) & 0xff,
 711                    (tkip->tx_iv32 >> 8) & 0xff,
 712                    tkip->tx_iv32 & 0xff,
 713                    (tkip->tx_iv16 >> 8) & 0xff,
 714                    tkip->tx_iv16 & 0xff,
 715                    (tkip->rx_iv32 >> 24) & 0xff,
 716                    (tkip->rx_iv32 >> 16) & 0xff,
 717                    (tkip->rx_iv32 >> 8) & 0xff,
 718                    tkip->rx_iv32 & 0xff,
 719                    (tkip->rx_iv16 >> 8) & 0xff,
 720                    tkip->rx_iv16 & 0xff,
 721                    tkip->dot11RSNAStatsTKIPReplays,
 722                    tkip->dot11RSNAStatsTKIPICVErrors,
 723                    tkip->dot11RSNAStatsTKIPLocalMICFailures);
 724 }
 725
 726 static struct lib80211_crypto_ops lib80211_crypt_tkip = {
 727         .name = "TKIP",
 728         .init = lib80211_tkip_init,
 729         .deinit = lib80211_tkip_deinit,
 730         .encrypt_mpdu = lib80211_tkip_encrypt,
 731         .decrypt_mpdu = lib80211_tkip_decrypt,
 732         .encrypt_msdu = lib80211_michael_mic_add,
 733         .decrypt_msdu = lib80211_michael_mic_verify,
 734         .set_key = lib80211_tkip_set_key,
 735         .get_key = lib80211_tkip_get_key,
 736         .print_stats = lib80211_tkip_print_stats,
 737         .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
 738         .extra_mpdu_postfix_len = 4,    /* ICV */
 739         .extra_msdu_postfix_len = 8,    /* MIC */
 740         .get_flags = lib80211_tkip_get_flags,
 741         .set_flags = lib80211_tkip_set_flags,
 742         .owner = THIS_MODULE,
 743 };
 744
 745 static int __init lib80211_crypto_tkip_init(void)
 746 {
 747         return lib80211_register_crypto_ops(&lib80211_crypt_tkip);
 748 }
 749
 750 static void __exit lib80211_crypto_tkip_exit(void)
 751 {
 752         lib80211_unregister_crypto_ops(&lib80211_crypt_tkip);
 753 }
 754
 755 module_init(lib80211_crypto_tkip_init);
 756 module_exit(lib80211_crypto_tkip_exit);