ieee80211_crypt_tkip.c revision f61fb9356d20977258bb59a8d9f1857d2c58ac98
1/* 2 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver 3 * 4 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. See README and COPYING for 9 * more details. 10 */ 11 12//#include <linux/config.h> 13#include <linux/version.h> 14#include <linux/module.h> 15#include <linux/init.h> 16#include <linux/slab.h> 17#include <linux/random.h> 18#include <linux/skbuff.h> 19#include <linux/netdevice.h> 20#include <linux/if_ether.h> 21#include <linux/if_arp.h> 22#include <asm/string.h> 23 24#include "ieee80211.h" 25 26#include <linux/crypto.h> 27 #include <linux/scatterlist.h> 28#include <linux/crc32.h> 29 30MODULE_AUTHOR("Jouni Malinen"); 31MODULE_DESCRIPTION("Host AP crypt: TKIP"); 32MODULE_LICENSE("GPL"); 33 34struct ieee80211_tkip_data { 35#define TKIP_KEY_LEN 32 36 u8 key[TKIP_KEY_LEN]; 37 int key_set; 38 39 u32 tx_iv32; 40 u16 tx_iv16; 41 u16 tx_ttak[5]; 42 int tx_phase1_done; 43 44 u32 rx_iv32; 45 u16 rx_iv16; 46 u16 rx_ttak[5]; 47 int rx_phase1_done; 48 u32 rx_iv32_new; 49 u16 rx_iv16_new; 50 51 u32 dot11RSNAStatsTKIPReplays; 52 u32 dot11RSNAStatsTKIPICVErrors; 53 u32 dot11RSNAStatsTKIPLocalMICFailures; 54 55 int key_idx; 56 57 struct crypto_blkcipher *rx_tfm_arc4; 58 struct crypto_hash *rx_tfm_michael; 59 struct crypto_blkcipher *tx_tfm_arc4; 60 struct crypto_hash *tx_tfm_michael; 61 62 /* scratch buffers for virt_to_page() (crypto API) */ 63 u8 rx_hdr[16], tx_hdr[16]; 64}; 65 66static void * ieee80211_tkip_init(int key_idx) 67{ 68 struct ieee80211_tkip_data *priv; 69 70 priv = kmalloc(sizeof(*priv), GFP_ATOMIC); 71 if (priv == NULL) 72 goto fail; 73 memset(priv, 0, sizeof(*priv)); 74 priv->key_idx = key_idx; 75 76 priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, 77 CRYPTO_ALG_ASYNC); 78 if (IS_ERR(priv->tx_tfm_arc4)) { 79 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " 80 "crypto API arc4\n"); 81 priv->tx_tfm_arc4 = NULL; 82 goto fail; 83 } 84 85 priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0, 86 CRYPTO_ALG_ASYNC); 87 if (IS_ERR(priv->tx_tfm_michael)) { 88 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " 89 "crypto API michael_mic\n"); 90 priv->tx_tfm_michael = NULL; 91 goto fail; 92 } 93 94 priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, 95 CRYPTO_ALG_ASYNC); 96 if (IS_ERR(priv->rx_tfm_arc4)) { 97 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " 98 "crypto API arc4\n"); 99 priv->rx_tfm_arc4 = NULL; 100 goto fail; 101 } 102 103 priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0, 104 CRYPTO_ALG_ASYNC); 105 if (IS_ERR(priv->rx_tfm_michael)) { 106 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " 107 "crypto API michael_mic\n"); 108 priv->rx_tfm_michael = NULL; 109 goto fail; 110 } 111 112 return priv; 113 114fail: 115 if (priv) { 116 if (priv->tx_tfm_michael) 117 crypto_free_hash(priv->tx_tfm_michael); 118 if (priv->tx_tfm_arc4) 119 crypto_free_blkcipher(priv->tx_tfm_arc4); 120 if (priv->rx_tfm_michael) 121 crypto_free_hash(priv->rx_tfm_michael); 122 if (priv->rx_tfm_arc4) 123 crypto_free_blkcipher(priv->rx_tfm_arc4); 124 kfree(priv); 125 } 126 127 return NULL; 128} 129 130 131static void ieee80211_tkip_deinit(void *priv) 132{ 133 struct ieee80211_tkip_data *_priv = priv; 134 135 if (_priv) { 136 if (_priv->tx_tfm_michael) 137 crypto_free_hash(_priv->tx_tfm_michael); 138 if (_priv->tx_tfm_arc4) 139 crypto_free_blkcipher(_priv->tx_tfm_arc4); 140 if (_priv->rx_tfm_michael) 141 crypto_free_hash(_priv->rx_tfm_michael); 142 if (_priv->rx_tfm_arc4) 143 crypto_free_blkcipher(_priv->rx_tfm_arc4); 144 } 145 kfree(priv); 146} 147 148 149static inline u16 RotR1(u16 val) 150{ 151 return (val >> 1) | (val << 15); 152} 153 154 155static inline u8 Lo8(u16 val) 156{ 157 return val & 0xff; 158} 159 160 161static inline u8 Hi8(u16 val) 162{ 163 return val >> 8; 164} 165 166 167static inline u16 Lo16(u32 val) 168{ 169 return val & 0xffff; 170} 171 172 173static inline u16 Hi16(u32 val) 174{ 175 return val >> 16; 176} 177 178 179static inline u16 Mk16(u8 hi, u8 lo) 180{ 181 return lo | (((u16) hi) << 8); 182} 183 184 185static inline u16 Mk16_le(u16 *v) 186{ 187 return le16_to_cpu(*v); 188} 189 190 191static const u16 Sbox[256] = 192{ 193 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 194 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 195 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 196 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 197 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 198 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 199 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 200 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 201 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 202 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 203 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 204 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 205 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 206 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 207 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 208 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 209 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 210 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 211 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 212 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 213 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 214 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 215 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 216 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 217 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 218 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 219 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 220 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 221 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 222 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 223 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 224 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, 225}; 226 227 228static inline u16 _S_(u16 v) 229{ 230 u16 t = Sbox[Hi8(v)]; 231 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); 232} 233 234 235#define PHASE1_LOOP_COUNT 8 236 237 238static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32) 239{ 240 int i, j; 241 242 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ 243 TTAK[0] = Lo16(IV32); 244 TTAK[1] = Hi16(IV32); 245 TTAK[2] = Mk16(TA[1], TA[0]); 246 TTAK[3] = Mk16(TA[3], TA[2]); 247 TTAK[4] = Mk16(TA[5], TA[4]); 248 249 for (i = 0; i < PHASE1_LOOP_COUNT; i++) { 250 j = 2 * (i & 1); 251 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); 252 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); 253 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); 254 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); 255 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; 256 } 257} 258 259 260static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, 261 u16 IV16) 262{ 263 /* Make temporary area overlap WEP seed so that the final copy can be 264 * avoided on little endian hosts. */ 265 u16 *PPK = (u16 *) &WEPSeed[4]; 266 267 /* Step 1 - make copy of TTAK and bring in TSC */ 268 PPK[0] = TTAK[0]; 269 PPK[1] = TTAK[1]; 270 PPK[2] = TTAK[2]; 271 PPK[3] = TTAK[3]; 272 PPK[4] = TTAK[4]; 273 PPK[5] = TTAK[4] + IV16; 274 275 /* Step 2 - 96-bit bijective mixing using S-box */ 276 PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0])); 277 PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2])); 278 PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4])); 279 PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6])); 280 PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8])); 281 PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10])); 282 283 PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12])); 284 PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14])); 285 PPK[2] += RotR1(PPK[1]); 286 PPK[3] += RotR1(PPK[2]); 287 PPK[4] += RotR1(PPK[3]); 288 PPK[5] += RotR1(PPK[4]); 289 290 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value 291 * WEPSeed[0..2] is transmitted as WEP IV */ 292 WEPSeed[0] = Hi8(IV16); 293 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; 294 WEPSeed[2] = Lo8(IV16); 295 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1); 296 297#ifdef __BIG_ENDIAN 298 { 299 int i; 300 for (i = 0; i < 6; i++) 301 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); 302 } 303#endif 304} 305 306 307static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) 308{ 309 struct ieee80211_tkip_data *tkey = priv; 310 int len; 311 u8 *pos; 312 struct ieee80211_hdr_4addr *hdr; 313 cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE); 314 struct blkcipher_desc desc = {.tfm = tkey->tx_tfm_arc4}; 315 int ret = 0; 316 u8 rc4key[16], *icv; 317 u32 crc; 318 struct scatterlist sg; 319 320 if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 || 321 skb->len < hdr_len) 322 return -1; 323 324 hdr = (struct ieee80211_hdr_4addr *) skb->data; 325 326 if (!tcb_desc->bHwSec) 327 { 328 if (!tkey->tx_phase1_done) { 329 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2, 330 tkey->tx_iv32); 331 tkey->tx_phase1_done = 1; 332 } 333 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16); 334 } 335 else 336 tkey->tx_phase1_done = 1; 337 338 339 len = skb->len - hdr_len; 340 pos = skb_push(skb, 8); 341 memmove(pos, pos + 8, hdr_len); 342 pos += hdr_len; 343 344 if (tcb_desc->bHwSec) 345 { 346 *pos++ = Hi8(tkey->tx_iv16); 347 *pos++ = (Hi8(tkey->tx_iv16) | 0x20) & 0x7F; 348 *pos++ = Lo8(tkey->tx_iv16); 349 } 350 else 351 { 352 *pos++ = rc4key[0]; 353 *pos++ = rc4key[1]; 354 *pos++ = rc4key[2]; 355 } 356 357 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */; 358 *pos++ = tkey->tx_iv32 & 0xff; 359 *pos++ = (tkey->tx_iv32 >> 8) & 0xff; 360 *pos++ = (tkey->tx_iv32 >> 16) & 0xff; 361 *pos++ = (tkey->tx_iv32 >> 24) & 0xff; 362 363 if (!tcb_desc->bHwSec) 364 { 365 icv = skb_put(skb, 4); 366 crc = ~crc32_le(~0, pos, len); 367 icv[0] = crc; 368 icv[1] = crc >> 8; 369 icv[2] = crc >> 16; 370 icv[3] = crc >> 24; 371 crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16); 372 sg_init_one(&sg, pos, len+4); 373 ret= crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4); 374 } 375 376 tkey->tx_iv16++; 377 if (tkey->tx_iv16 == 0) { 378 tkey->tx_phase1_done = 0; 379 tkey->tx_iv32++; 380 } 381 382 if (!tcb_desc->bHwSec) 383 return ret; 384 else 385 return 0; 386 387 388} 389 390static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) 391{ 392 struct ieee80211_tkip_data *tkey = priv; 393 u8 keyidx, *pos; 394 u32 iv32; 395 u16 iv16; 396 struct ieee80211_hdr_4addr *hdr; 397 cb_desc *tcb_desc = (cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE); 398 struct blkcipher_desc desc = {.tfm = tkey->rx_tfm_arc4}; 399 u8 rc4key[16]; 400 u8 icv[4]; 401 u32 crc; 402 struct scatterlist sg; 403 int plen; 404 if (skb->len < hdr_len + 8 + 4) 405 return -1; 406 407 hdr = (struct ieee80211_hdr_4addr *) skb->data; 408 pos = skb->data + hdr_len; 409 keyidx = pos[3]; 410 if (!(keyidx & (1 << 5))) { 411 if (net_ratelimit()) { 412 printk(KERN_DEBUG "TKIP: received packet without ExtIV" 413 " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2)); 414 } 415 return -2; 416 } 417 keyidx >>= 6; 418 if (tkey->key_idx != keyidx) { 419 printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame " 420 "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv); 421 return -6; 422 } 423 if (!tkey->key_set) { 424 if (net_ratelimit()) { 425 printk(KERN_DEBUG "TKIP: received packet from " MAC_FMT 426 " with keyid=%d that does not have a configured" 427 " key\n", MAC_ARG(hdr->addr2), keyidx); 428 } 429 return -3; 430 } 431 iv16 = (pos[0] << 8) | pos[2]; 432 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); 433 pos += 8; 434 435 if (!tcb_desc->bHwSec) 436 { 437 if (iv32 < tkey->rx_iv32 || 438 (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) { 439 if (net_ratelimit()) { 440 printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT 441 " previous TSC %08x%04x received TSC " 442 "%08x%04x\n", MAC_ARG(hdr->addr2), 443 tkey->rx_iv32, tkey->rx_iv16, iv32, iv16); 444 } 445 tkey->dot11RSNAStatsTKIPReplays++; 446 return -4; 447 } 448 449 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) { 450 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32); 451 tkey->rx_phase1_done = 1; 452 } 453 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16); 454 455 plen = skb->len - hdr_len - 12; 456 457 crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16); 458 sg_init_one(&sg, pos, plen+4); 459 460 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) { 461 if (net_ratelimit()) { 462 printk(KERN_DEBUG ": TKIP: failed to decrypt " 463 "received packet from " MAC_FMT "\n", 464 MAC_ARG(hdr->addr2)); 465 } 466 return -7; 467 } 468 469 crc = ~crc32_le(~0, pos, plen); 470 icv[0] = crc; 471 icv[1] = crc >> 8; 472 icv[2] = crc >> 16; 473 icv[3] = crc >> 24; 474 475 if (memcmp(icv, pos + plen, 4) != 0) { 476 if (iv32 != tkey->rx_iv32) { 477 /* Previously cached Phase1 result was already lost, so 478 * it needs to be recalculated for the next packet. */ 479 tkey->rx_phase1_done = 0; 480 } 481 if (net_ratelimit()) { 482 printk(KERN_DEBUG "TKIP: ICV error detected: STA=" 483 MAC_FMT "\n", MAC_ARG(hdr->addr2)); 484 } 485 tkey->dot11RSNAStatsTKIPICVErrors++; 486 return -5; 487 } 488 489 } 490 491 /* Update real counters only after Michael MIC verification has 492 * completed */ 493 tkey->rx_iv32_new = iv32; 494 tkey->rx_iv16_new = iv16; 495 496 /* Remove IV and ICV */ 497 memmove(skb->data + 8, skb->data, hdr_len); 498 skb_pull(skb, 8); 499 skb_trim(skb, skb->len - 4); 500 501 return keyidx; 502} 503 504static int michael_mic(struct crypto_hash *tfm_michael, u8 * key, u8 * hdr, 505 u8 * data, size_t data_len, u8 * mic) 506{ 507 struct hash_desc desc; 508 struct scatterlist sg[2]; 509 510 if (tfm_michael == NULL) { 511 printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); 512 return -1; 513 } 514 515 sg_init_table(sg, 2); 516 sg_set_buf(&sg[0], hdr, 16); 517 sg_set_buf(&sg[1], data, data_len); 518 519 if (crypto_hash_setkey(tfm_michael, key, 8)) 520 return -1; 521 522 desc.tfm = tfm_michael; 523 desc.flags = 0; 524 return crypto_hash_digest(&desc, sg, data_len + 16, mic); 525} 526 527static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr) 528{ 529 struct ieee80211_hdr_4addr *hdr11; 530 531 hdr11 = (struct ieee80211_hdr_4addr *) skb->data; 532 switch (le16_to_cpu(hdr11->frame_ctl) & 533 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) { 534 case IEEE80211_FCTL_TODS: 535 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ 536 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ 537 break; 538 case IEEE80211_FCTL_FROMDS: 539 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ 540 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */ 541 break; 542 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS: 543 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ 544 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */ 545 break; 546 case 0: 547 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ 548 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ 549 break; 550 } 551 552 hdr[12] = 0; /* priority */ 553 554 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ 555} 556 557 558static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv) 559{ 560 struct ieee80211_tkip_data *tkey = priv; 561 u8 *pos; 562 struct ieee80211_hdr_4addr *hdr; 563 564 hdr = (struct ieee80211_hdr_4addr *) skb->data; 565 566 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) { 567 printk(KERN_DEBUG "Invalid packet for Michael MIC add " 568 "(tailroom=%d hdr_len=%d skb->len=%d)\n", 569 skb_tailroom(skb), hdr_len, skb->len); 570 return -1; 571 } 572 573 michael_mic_hdr(skb, tkey->tx_hdr); 574 575 // { david, 2006.9.1 576 // fix the wpa process with wmm enabled. 577 if(IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) { 578 tkey->tx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07; 579 } 580 // } 581 pos = skb_put(skb, 8); 582 583 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr, 584 skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) 585 return -1; 586 587 return 0; 588} 589 590static void ieee80211_michael_mic_failure(struct net_device *dev, 591 struct ieee80211_hdr_4addr *hdr, 592 int keyidx) 593{ 594 union iwreq_data wrqu; 595 struct iw_michaelmicfailure ev; 596 597 /* TODO: needed parameters: count, keyid, key type, TSC */ 598 memset(&ev, 0, sizeof(ev)); 599 ev.flags = keyidx & IW_MICFAILURE_KEY_ID; 600 if (hdr->addr1[0] & 0x01) 601 ev.flags |= IW_MICFAILURE_GROUP; 602 else 603 ev.flags |= IW_MICFAILURE_PAIRWISE; 604 ev.src_addr.sa_family = ARPHRD_ETHER; 605 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN); 606 memset(&wrqu, 0, sizeof(wrqu)); 607 wrqu.data.length = sizeof(ev); 608 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *) &ev); 609} 610 611static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx, 612 int hdr_len, void *priv) 613{ 614 struct ieee80211_tkip_data *tkey = priv; 615 u8 mic[8]; 616 struct ieee80211_hdr_4addr *hdr; 617 618 hdr = (struct ieee80211_hdr_4addr *) skb->data; 619 620 if (!tkey->key_set) 621 return -1; 622 623 michael_mic_hdr(skb, tkey->rx_hdr); 624 // { david, 2006.9.1 625 // fix the wpa process with wmm enabled. 626 if(IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) { 627 tkey->rx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07; 628 } 629 // } 630 631 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr, 632 skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) 633 return -1; 634 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { 635 struct ieee80211_hdr_4addr *hdr; 636 hdr = (struct ieee80211_hdr_4addr *) skb->data; 637 printk(KERN_DEBUG "%s: Michael MIC verification failed for " 638 "MSDU from " MAC_FMT " keyidx=%d\n", 639 skb->dev ? skb->dev->name : "N/A", MAC_ARG(hdr->addr2), 640 keyidx); 641 if (skb->dev) 642 ieee80211_michael_mic_failure(skb->dev, hdr, keyidx); 643 tkey->dot11RSNAStatsTKIPLocalMICFailures++; 644 return -1; 645 } 646 647 /* Update TSC counters for RX now that the packet verification has 648 * completed. */ 649 tkey->rx_iv32 = tkey->rx_iv32_new; 650 tkey->rx_iv16 = tkey->rx_iv16_new; 651 652 skb_trim(skb, skb->len - 8); 653 654 return 0; 655} 656 657 658static int ieee80211_tkip_set_key(void *key, int len, u8 *seq, void *priv) 659{ 660 struct ieee80211_tkip_data *tkey = priv; 661 int keyidx; 662 struct crypto_hash *tfm = tkey->tx_tfm_michael; 663 struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4; 664 struct crypto_hash *tfm3 = tkey->rx_tfm_michael; 665 struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4; 666 667 keyidx = tkey->key_idx; 668 memset(tkey, 0, sizeof(*tkey)); 669 tkey->key_idx = keyidx; 670 tkey->tx_tfm_michael = tfm; 671 tkey->tx_tfm_arc4 = tfm2; 672 tkey->rx_tfm_michael = tfm3; 673 tkey->rx_tfm_arc4 = tfm4; 674 675 if (len == TKIP_KEY_LEN) { 676 memcpy(tkey->key, key, TKIP_KEY_LEN); 677 tkey->key_set = 1; 678 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */ 679 if (seq) { 680 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) | 681 (seq[3] << 8) | seq[2]; 682 tkey->rx_iv16 = (seq[1] << 8) | seq[0]; 683 } 684 } else if (len == 0) 685 tkey->key_set = 0; 686 else 687 return -1; 688 689 return 0; 690} 691 692 693static int ieee80211_tkip_get_key(void *key, int len, u8 *seq, void *priv) 694{ 695 struct ieee80211_tkip_data *tkey = priv; 696 697 if (len < TKIP_KEY_LEN) 698 return -1; 699 700 if (!tkey->key_set) 701 return 0; 702 memcpy(key, tkey->key, TKIP_KEY_LEN); 703 704 if (seq) { 705 /* Return the sequence number of the last transmitted frame. */ 706 u16 iv16 = tkey->tx_iv16; 707 u32 iv32 = tkey->tx_iv32; 708 if (iv16 == 0) 709 iv32--; 710 iv16--; 711 seq[0] = tkey->tx_iv16; 712 seq[1] = tkey->tx_iv16 >> 8; 713 seq[2] = tkey->tx_iv32; 714 seq[3] = tkey->tx_iv32 >> 8; 715 seq[4] = tkey->tx_iv32 >> 16; 716 seq[5] = tkey->tx_iv32 >> 24; 717 } 718 719 return TKIP_KEY_LEN; 720} 721 722 723static char * ieee80211_tkip_print_stats(char *p, void *priv) 724{ 725 struct ieee80211_tkip_data *tkip = priv; 726 p += sprintf(p, "key[%d] alg=TKIP key_set=%d " 727 "tx_pn=%02x%02x%02x%02x%02x%02x " 728 "rx_pn=%02x%02x%02x%02x%02x%02x " 729 "replays=%d icv_errors=%d local_mic_failures=%d\n", 730 tkip->key_idx, tkip->key_set, 731 (tkip->tx_iv32 >> 24) & 0xff, 732 (tkip->tx_iv32 >> 16) & 0xff, 733 (tkip->tx_iv32 >> 8) & 0xff, 734 tkip->tx_iv32 & 0xff, 735 (tkip->tx_iv16 >> 8) & 0xff, 736 tkip->tx_iv16 & 0xff, 737 (tkip->rx_iv32 >> 24) & 0xff, 738 (tkip->rx_iv32 >> 16) & 0xff, 739 (tkip->rx_iv32 >> 8) & 0xff, 740 tkip->rx_iv32 & 0xff, 741 (tkip->rx_iv16 >> 8) & 0xff, 742 tkip->rx_iv16 & 0xff, 743 tkip->dot11RSNAStatsTKIPReplays, 744 tkip->dot11RSNAStatsTKIPICVErrors, 745 tkip->dot11RSNAStatsTKIPLocalMICFailures); 746 return p; 747} 748 749 750static struct ieee80211_crypto_ops ieee80211_crypt_tkip = { 751 .name = "TKIP", 752 .init = ieee80211_tkip_init, 753 .deinit = ieee80211_tkip_deinit, 754 .encrypt_mpdu = ieee80211_tkip_encrypt, 755 .decrypt_mpdu = ieee80211_tkip_decrypt, 756 .encrypt_msdu = ieee80211_michael_mic_add, 757 .decrypt_msdu = ieee80211_michael_mic_verify, 758 .set_key = ieee80211_tkip_set_key, 759 .get_key = ieee80211_tkip_get_key, 760 .print_stats = ieee80211_tkip_print_stats, 761 .extra_prefix_len = 4 + 4, /* IV + ExtIV */ 762 .extra_postfix_len = 8 + 4, /* MIC + ICV */ 763 .owner = THIS_MODULE, 764}; 765 766int __init ieee80211_crypto_tkip_init(void) 767{ 768 return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip); 769} 770 771void __exit ieee80211_crypto_tkip_exit(void) 772{ 773 ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip); 774} 775 776void ieee80211_tkip_null(void) 777{ 778// printk("============>%s()\n", __FUNCTION__); 779 return; 780} 781