rtllib_crypt_tkip.c revision 316de3cabb5472225195a86f2dc150cf90698682
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/module.h> 13#include <linux/init.h> 14#include <linux/slab.h> 15#include <linux/random.h> 16#include <linux/skbuff.h> 17#include <linux/netdevice.h> 18#include <linux/if_ether.h> 19#include <linux/if_arp.h> 20#include <linux/string.h> 21#include <linux/crypto.h> 22#include <linux/scatterlist.h> 23#include <linux/crc32.h> 24 25#include "rtllib.h" 26 27struct rtllib_tkip_data { 28#define TKIP_KEY_LEN 32 29 u8 key[TKIP_KEY_LEN]; 30 int key_set; 31 32 u32 tx_iv32; 33 u16 tx_iv16; 34 u16 tx_ttak[5]; 35 int tx_phase1_done; 36 37 u32 rx_iv32; 38 u16 rx_iv16; 39 bool initialized; 40 u16 rx_ttak[5]; 41 int rx_phase1_done; 42 u32 rx_iv32_new; 43 u16 rx_iv16_new; 44 45 u32 dot11RSNAStatsTKIPReplays; 46 u32 dot11RSNAStatsTKIPICVErrors; 47 u32 dot11RSNAStatsTKIPLocalMICFailures; 48 49 int key_idx; 50 struct crypto_blkcipher *rx_tfm_arc4; 51 struct crypto_hash *rx_tfm_michael; 52 struct crypto_blkcipher *tx_tfm_arc4; 53 struct crypto_hash *tx_tfm_michael; 54 /* scratch buffers for virt_to_page() (crypto API) */ 55 u8 rx_hdr[16], tx_hdr[16]; 56}; 57 58static void *rtllib_tkip_init(int key_idx) 59{ 60 struct rtllib_tkip_data *priv; 61 62 priv = kzalloc(sizeof(*priv), GFP_ATOMIC); 63 if (priv == NULL) 64 goto fail; 65 priv->key_idx = key_idx; 66 priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, 67 CRYPTO_ALG_ASYNC); 68 if (IS_ERR(priv->tx_tfm_arc4)) { 69 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate " 70 "crypto API arc4\n"); 71 priv->tx_tfm_arc4 = NULL; 72 goto fail; 73 } 74 75 priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0, 76 CRYPTO_ALG_ASYNC); 77 if (IS_ERR(priv->tx_tfm_michael)) { 78 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate " 79 "crypto API michael_mic\n"); 80 priv->tx_tfm_michael = NULL; 81 goto fail; 82 } 83 84 priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, 85 CRYPTO_ALG_ASYNC); 86 if (IS_ERR(priv->rx_tfm_arc4)) { 87 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate " 88 "crypto API arc4\n"); 89 priv->rx_tfm_arc4 = NULL; 90 goto fail; 91 } 92 93 priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0, 94 CRYPTO_ALG_ASYNC); 95 if (IS_ERR(priv->rx_tfm_michael)) { 96 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate " 97 "crypto API michael_mic\n"); 98 priv->rx_tfm_michael = NULL; 99 goto fail; 100 } 101 return priv; 102 103fail: 104 if (priv) { 105 if (priv->tx_tfm_michael) 106 crypto_free_hash(priv->tx_tfm_michael); 107 if (priv->tx_tfm_arc4) 108 crypto_free_blkcipher(priv->tx_tfm_arc4); 109 if (priv->rx_tfm_michael) 110 crypto_free_hash(priv->rx_tfm_michael); 111 if (priv->rx_tfm_arc4) 112 crypto_free_blkcipher(priv->rx_tfm_arc4); 113 kfree(priv); 114 } 115 116 return NULL; 117} 118 119 120static void rtllib_tkip_deinit(void *priv) 121{ 122 struct rtllib_tkip_data *_priv = priv; 123 124 if (_priv) { 125 if (_priv->tx_tfm_michael) 126 crypto_free_hash(_priv->tx_tfm_michael); 127 if (_priv->tx_tfm_arc4) 128 crypto_free_blkcipher(_priv->tx_tfm_arc4); 129 if (_priv->rx_tfm_michael) 130 crypto_free_hash(_priv->rx_tfm_michael); 131 if (_priv->rx_tfm_arc4) 132 crypto_free_blkcipher(_priv->rx_tfm_arc4); 133 } 134 kfree(priv); 135} 136 137 138static inline u16 RotR1(u16 val) 139{ 140 return (val >> 1) | (val << 15); 141} 142 143 144static inline u8 Lo8(u16 val) 145{ 146 return val & 0xff; 147} 148 149 150static inline u8 Hi8(u16 val) 151{ 152 return val >> 8; 153} 154 155 156static inline u16 Lo16(u32 val) 157{ 158 return val & 0xffff; 159} 160 161 162static inline u16 Hi16(u32 val) 163{ 164 return val >> 16; 165} 166 167 168static inline u16 Mk16(u8 hi, u8 lo) 169{ 170 return lo | (((u16) hi) << 8); 171} 172 173 174static inline u16 Mk16_le(u16 *v) 175{ 176 return *v; 177} 178 179 180static const u16 Sbox[256] = { 181 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 182 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 183 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 184 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 185 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 186 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 187 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 188 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 189 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 190 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 191 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 192 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 193 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 194 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 195 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 196 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 197 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 198 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 199 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 200 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 201 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 202 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 203 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 204 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 205 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 206 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 207 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 208 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 209 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 210 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 211 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 212 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, 213}; 214 215 216static inline u16 _S_(u16 v) 217{ 218 u16 t = Sbox[Hi8(v)]; 219 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); 220} 221 222 223#define PHASE1_LOOP_COUNT 8 224 225 226static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32) 227{ 228 int i, j; 229 230 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ 231 TTAK[0] = Lo16(IV32); 232 TTAK[1] = Hi16(IV32); 233 TTAK[2] = Mk16(TA[1], TA[0]); 234 TTAK[3] = Mk16(TA[3], TA[2]); 235 TTAK[4] = Mk16(TA[5], TA[4]); 236 237 for (i = 0; i < PHASE1_LOOP_COUNT; i++) { 238 j = 2 * (i & 1); 239 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); 240 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); 241 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); 242 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); 243 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; 244 } 245} 246 247 248static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, 249 u16 IV16) 250{ 251 /* Make temporary area overlap WEP seed so that the final copy can be 252 * avoided on little endian hosts. */ 253 u16 *PPK = (u16 *) &WEPSeed[4]; 254 255 /* Step 1 - make copy of TTAK and bring in TSC */ 256 PPK[0] = TTAK[0]; 257 PPK[1] = TTAK[1]; 258 PPK[2] = TTAK[2]; 259 PPK[3] = TTAK[3]; 260 PPK[4] = TTAK[4]; 261 PPK[5] = TTAK[4] + IV16; 262 263 /* Step 2 - 96-bit bijective mixing using S-box */ 264 PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0])); 265 PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2])); 266 PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4])); 267 PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6])); 268 PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8])); 269 PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10])); 270 271 PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12])); 272 PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14])); 273 PPK[2] += RotR1(PPK[1]); 274 PPK[3] += RotR1(PPK[2]); 275 PPK[4] += RotR1(PPK[3]); 276 PPK[5] += RotR1(PPK[4]); 277 278 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value 279 * WEPSeed[0..2] is transmitted as WEP IV */ 280 WEPSeed[0] = Hi8(IV16); 281 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; 282 WEPSeed[2] = Lo8(IV16); 283 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1); 284 285#ifdef __BIG_ENDIAN 286 { 287 int i; 288 for (i = 0; i < 6; i++) 289 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); 290 } 291#endif 292} 293 294 295static int rtllib_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) 296{ 297 struct rtllib_tkip_data *tkey = priv; 298 int len; 299 u8 *pos; 300 struct rtllib_hdr_4addr *hdr; 301 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb + 302 MAX_DEV_ADDR_SIZE); 303 struct blkcipher_desc desc = {.tfm = tkey->tx_tfm_arc4}; 304 int ret = 0; 305 u8 rc4key[16], *icv; 306 u32 crc; 307 struct scatterlist sg; 308 309 if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 || 310 skb->len < hdr_len) 311 return -1; 312 313 hdr = (struct rtllib_hdr_4addr *) skb->data; 314 315 if (!tcb_desc->bHwSec) { 316 if (!tkey->tx_phase1_done) { 317 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2, 318 tkey->tx_iv32); 319 tkey->tx_phase1_done = 1; 320 } 321 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, 322 tkey->tx_iv16); 323 } else 324 tkey->tx_phase1_done = 1; 325 326 327 len = skb->len - hdr_len; 328 pos = skb_push(skb, 8); 329 memmove(pos, pos + 8, hdr_len); 330 pos += hdr_len; 331 332 if (tcb_desc->bHwSec) { 333 *pos++ = Hi8(tkey->tx_iv16); 334 *pos++ = (Hi8(tkey->tx_iv16) | 0x20) & 0x7F; 335 *pos++ = Lo8(tkey->tx_iv16); 336 } else { 337 *pos++ = rc4key[0]; 338 *pos++ = rc4key[1]; 339 *pos++ = rc4key[2]; 340 } 341 342 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */; 343 *pos++ = tkey->tx_iv32 & 0xff; 344 *pos++ = (tkey->tx_iv32 >> 8) & 0xff; 345 *pos++ = (tkey->tx_iv32 >> 16) & 0xff; 346 *pos++ = (tkey->tx_iv32 >> 24) & 0xff; 347 348 if (!tcb_desc->bHwSec) { 349 icv = skb_put(skb, 4); 350 crc = ~crc32_le(~0, pos, len); 351 icv[0] = crc; 352 icv[1] = crc >> 8; 353 icv[2] = crc >> 16; 354 icv[3] = crc >> 24; 355 356 sg_init_one(&sg, pos, len+4); 357 358 359 crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16); 360 ret = crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4); 361 } 362 363 tkey->tx_iv16++; 364 if (tkey->tx_iv16 == 0) { 365 tkey->tx_phase1_done = 0; 366 tkey->tx_iv32++; 367 } 368 369 if (!tcb_desc->bHwSec) 370 return ret; 371 else 372 return 0; 373 374 375} 376 377static int rtllib_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) 378{ 379 struct rtllib_tkip_data *tkey = priv; 380 u8 keyidx, *pos; 381 u32 iv32; 382 u16 iv16; 383 struct rtllib_hdr_4addr *hdr; 384 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb + 385 MAX_DEV_ADDR_SIZE); 386 struct blkcipher_desc desc = {.tfm = tkey->rx_tfm_arc4}; 387 u8 rc4key[16]; 388 u8 icv[4]; 389 u32 crc; 390 struct scatterlist sg; 391 int plen; 392 if (skb->len < hdr_len + 8 + 4) 393 return -1; 394 395 hdr = (struct rtllib_hdr_4addr *) skb->data; 396 pos = skb->data + hdr_len; 397 keyidx = pos[3]; 398 if (!(keyidx & (1 << 5))) { 399 if (net_ratelimit()) { 400 printk(KERN_DEBUG "TKIP: received packet without ExtIV" 401 " flag from %pM\n", hdr->addr2); 402 } 403 return -2; 404 } 405 keyidx >>= 6; 406 if (tkey->key_idx != keyidx) { 407 printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame " 408 "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv); 409 return -6; 410 } 411 if (!tkey->key_set) { 412 if (net_ratelimit()) { 413 printk(KERN_DEBUG "TKIP: received packet from %pM" 414 " with keyid=%d that does not have a configured" 415 " key\n", hdr->addr2, keyidx); 416 } 417 return -3; 418 } 419 iv16 = (pos[0] << 8) | pos[2]; 420 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); 421 pos += 8; 422 423 if (!tcb_desc->bHwSec || (skb->cb[0] == 1)) { 424 if ((iv32 < tkey->rx_iv32 || 425 (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) && 426 tkey->initialized) { 427 if (net_ratelimit()) { 428 printk(KERN_DEBUG "TKIP: replay detected: STA=" 429 " %pM previous TSC %08x%04x received " 430 "TSC %08x%04x\n",hdr->addr2, 431 tkey->rx_iv32, tkey->rx_iv16, iv32, iv16); 432 } 433 tkey->dot11RSNAStatsTKIPReplays++; 434 return -4; 435 } 436 tkey->initialized = true; 437 438 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) { 439 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, 440 hdr->addr2, iv32); 441 tkey->rx_phase1_done = 1; 442 } 443 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16); 444 445 plen = skb->len - hdr_len - 12; 446 447 sg_init_one(&sg, pos, plen+4); 448 449 crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16); 450 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) { 451 if (net_ratelimit()) { 452 printk(KERN_DEBUG ": TKIP: failed to decrypt " 453 "received packet from %pM\n", 454 hdr->addr2); 455 } 456 return -7; 457 } 458 459 crc = ~crc32_le(~0, pos, plen); 460 icv[0] = crc; 461 icv[1] = crc >> 8; 462 icv[2] = crc >> 16; 463 icv[3] = crc >> 24; 464 465 if (memcmp(icv, pos + plen, 4) != 0) { 466 if (iv32 != tkey->rx_iv32) { 467 /* Previously cached Phase1 result was already 468 * lost, so it needs to be recalculated for the 469 * next packet. */ 470 tkey->rx_phase1_done = 0; 471 } 472 if (net_ratelimit()) { 473 printk(KERN_DEBUG "TKIP: ICV error detected: STA=" 474 " %pM\n", hdr->addr2); 475 } 476 tkey->dot11RSNAStatsTKIPICVErrors++; 477 return -5; 478 } 479 480 } 481 482 /* Update real counters only after Michael MIC verification has 483 * completed */ 484 tkey->rx_iv32_new = iv32; 485 tkey->rx_iv16_new = iv16; 486 487 /* Remove IV and ICV */ 488 memmove(skb->data + 8, skb->data, hdr_len); 489 skb_pull(skb, 8); 490 skb_trim(skb, skb->len - 4); 491 492 return keyidx; 493} 494 495 496static int michael_mic(struct crypto_hash *tfm_michael, u8 *key, u8 *hdr, 497 u8 *data, size_t data_len, u8 *mic) 498{ 499 struct hash_desc desc; 500 struct scatterlist sg[2]; 501 502 if (tfm_michael == NULL) { 503 printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); 504 return -1; 505 } 506 sg_init_table(sg, 2); 507 sg_set_buf(&sg[0], hdr, 16); 508 sg_set_buf(&sg[1], data, data_len); 509 510 if (crypto_hash_setkey(tfm_michael, key, 8)) 511 return -1; 512 513 desc.tfm = tfm_michael; 514 desc.flags = 0; 515 return crypto_hash_digest(&desc, sg, data_len + 16, mic); 516} 517 518static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr) 519{ 520 struct rtllib_hdr_4addr *hdr11; 521 522 hdr11 = (struct rtllib_hdr_4addr *) skb->data; 523 switch (le16_to_cpu(hdr11->frame_ctl) & 524 (RTLLIB_FCTL_FROMDS | RTLLIB_FCTL_TODS)) { 525 case RTLLIB_FCTL_TODS: 526 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ 527 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ 528 break; 529 case RTLLIB_FCTL_FROMDS: 530 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ 531 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */ 532 break; 533 case RTLLIB_FCTL_FROMDS | RTLLIB_FCTL_TODS: 534 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ 535 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */ 536 break; 537 case 0: 538 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ 539 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ 540 break; 541 } 542 543 hdr[12] = 0; /* priority */ 544 545 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ 546} 547 548 549static int rtllib_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv) 550{ 551 struct rtllib_tkip_data *tkey = priv; 552 u8 *pos; 553 struct rtllib_hdr_4addr *hdr; 554 555 hdr = (struct rtllib_hdr_4addr *) skb->data; 556 557 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) { 558 printk(KERN_DEBUG "Invalid packet for Michael MIC add " 559 "(tailroom=%d hdr_len=%d skb->len=%d)\n", 560 skb_tailroom(skb), hdr_len, skb->len); 561 return -1; 562 } 563 564 michael_mic_hdr(skb, tkey->tx_hdr); 565 566 if (RTLLIB_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) 567 tkey->tx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07; 568 pos = skb_put(skb, 8); 569 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr, 570 skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) 571 return -1; 572 573 return 0; 574} 575 576 577static void rtllib_michael_mic_failure(struct net_device *dev, 578 struct rtllib_hdr_4addr *hdr, 579 int keyidx) 580{ 581 union iwreq_data wrqu; 582 struct iw_michaelmicfailure ev; 583 584 /* TODO: needed parameters: count, keyid, key type, TSC */ 585 memset(&ev, 0, sizeof(ev)); 586 ev.flags = keyidx & IW_MICFAILURE_KEY_ID; 587 if (hdr->addr1[0] & 0x01) 588 ev.flags |= IW_MICFAILURE_GROUP; 589 else 590 ev.flags |= IW_MICFAILURE_PAIRWISE; 591 ev.src_addr.sa_family = ARPHRD_ETHER; 592 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN); 593 memset(&wrqu, 0, sizeof(wrqu)); 594 wrqu.data.length = sizeof(ev); 595 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *) &ev); 596} 597 598static int rtllib_michael_mic_verify(struct sk_buff *skb, int keyidx, 599 int hdr_len, void *priv) 600{ 601 struct rtllib_tkip_data *tkey = priv; 602 u8 mic[8]; 603 struct rtllib_hdr_4addr *hdr; 604 605 hdr = (struct rtllib_hdr_4addr *) skb->data; 606 607 if (!tkey->key_set) 608 return -1; 609 610 michael_mic_hdr(skb, tkey->rx_hdr); 611 if (RTLLIB_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl))) 612 tkey->rx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07; 613 614 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr, 615 skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) 616 return -1; 617 618 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { 619 struct rtllib_hdr_4addr *hdr; 620 hdr = (struct rtllib_hdr_4addr *) skb->data; 621 printk(KERN_DEBUG "%s: Michael MIC verification failed for " 622 "MSDU from %pM keyidx=%d\n", 623 skb->dev ? skb->dev->name : "N/A", hdr->addr2, 624 keyidx); 625 printk(KERN_DEBUG "%d\n", 626 memcmp(mic, skb->data + skb->len - 8, 8) != 0); 627 if (skb->dev) { 628 printk(KERN_INFO "skb->dev != NULL\n"); 629 rtllib_michael_mic_failure(skb->dev, hdr, keyidx); 630 } 631 tkey->dot11RSNAStatsTKIPLocalMICFailures++; 632 return -1; 633 } 634 635 /* Update TSC counters for RX now that the packet verification has 636 * completed. */ 637 tkey->rx_iv32 = tkey->rx_iv32_new; 638 tkey->rx_iv16 = tkey->rx_iv16_new; 639 640 skb_trim(skb, skb->len - 8); 641 642 return 0; 643} 644 645 646static int rtllib_tkip_set_key(void *key, int len, u8 *seq, void *priv) 647{ 648 struct rtllib_tkip_data *tkey = priv; 649 int keyidx; 650 struct crypto_hash *tfm = tkey->tx_tfm_michael; 651 struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4; 652 struct crypto_hash *tfm3 = tkey->rx_tfm_michael; 653 struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4; 654 655 keyidx = tkey->key_idx; 656 memset(tkey, 0, sizeof(*tkey)); 657 tkey->key_idx = keyidx; 658 tkey->tx_tfm_michael = tfm; 659 tkey->tx_tfm_arc4 = tfm2; 660 tkey->rx_tfm_michael = tfm3; 661 tkey->rx_tfm_arc4 = tfm4; 662 663 if (len == TKIP_KEY_LEN) { 664 memcpy(tkey->key, key, TKIP_KEY_LEN); 665 tkey->key_set = 1; 666 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */ 667 if (seq) { 668 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) | 669 (seq[3] << 8) | seq[2]; 670 tkey->rx_iv16 = (seq[1] << 8) | seq[0]; 671 } 672 } else if (len == 0) 673 tkey->key_set = 0; 674 else 675 return -1; 676 677 return 0; 678} 679 680 681static int rtllib_tkip_get_key(void *key, int len, u8 *seq, void *priv) 682{ 683 struct rtllib_tkip_data *tkey = priv; 684 685 if (len < TKIP_KEY_LEN) 686 return -1; 687 688 if (!tkey->key_set) 689 return 0; 690 memcpy(key, tkey->key, TKIP_KEY_LEN); 691 692 if (seq) { 693 /* Return the sequence number of the last transmitted frame. */ 694 u16 iv16 = tkey->tx_iv16; 695 u32 iv32 = tkey->tx_iv32; 696 if (iv16 == 0) 697 iv32--; 698 iv16--; 699 seq[0] = tkey->tx_iv16; 700 seq[1] = tkey->tx_iv16 >> 8; 701 seq[2] = tkey->tx_iv32; 702 seq[3] = tkey->tx_iv32 >> 8; 703 seq[4] = tkey->tx_iv32 >> 16; 704 seq[5] = tkey->tx_iv32 >> 24; 705 } 706 707 return TKIP_KEY_LEN; 708} 709 710 711static void rtllib_tkip_print_stats(struct seq_file *m, void *priv) 712{ 713 struct rtllib_tkip_data *tkip = priv; 714 seq_printf(m, 715 "key[%d] alg=TKIP key_set=%d " 716 "tx_pn=%02x%02x%02x%02x%02x%02x " 717 "rx_pn=%02x%02x%02x%02x%02x%02x " 718 "replays=%d icv_errors=%d local_mic_failures=%d\n", 719 tkip->key_idx, tkip->key_set, 720 (tkip->tx_iv32 >> 24) & 0xff, 721 (tkip->tx_iv32 >> 16) & 0xff, 722 (tkip->tx_iv32 >> 8) & 0xff, 723 tkip->tx_iv32 & 0xff, 724 (tkip->tx_iv16 >> 8) & 0xff, 725 tkip->tx_iv16 & 0xff, 726 (tkip->rx_iv32 >> 24) & 0xff, 727 (tkip->rx_iv32 >> 16) & 0xff, 728 (tkip->rx_iv32 >> 8) & 0xff, 729 tkip->rx_iv32 & 0xff, 730 (tkip->rx_iv16 >> 8) & 0xff, 731 tkip->rx_iv16 & 0xff, 732 tkip->dot11RSNAStatsTKIPReplays, 733 tkip->dot11RSNAStatsTKIPICVErrors, 734 tkip->dot11RSNAStatsTKIPLocalMICFailures); 735} 736 737static struct lib80211_crypto_ops rtllib_crypt_tkip = { 738 .name = "R-TKIP", 739 .init = rtllib_tkip_init, 740 .deinit = rtllib_tkip_deinit, 741 .encrypt_mpdu = rtllib_tkip_encrypt, 742 .decrypt_mpdu = rtllib_tkip_decrypt, 743 .encrypt_msdu = rtllib_michael_mic_add, 744 .decrypt_msdu = rtllib_michael_mic_verify, 745 .set_key = rtllib_tkip_set_key, 746 .get_key = rtllib_tkip_get_key, 747 .print_stats = rtllib_tkip_print_stats, 748 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */ 749 .extra_mpdu_postfix_len = 4, /* ICV */ 750 .extra_msdu_postfix_len = 8, /* MIC */ 751 .owner = THIS_MODULE, 752}; 753 754 755static int __init rtllib_crypto_tkip_init(void) 756{ 757 return lib80211_register_crypto_ops(&rtllib_crypt_tkip); 758} 759 760 761static void __exit rtllib_crypto_tkip_exit(void) 762{ 763 lib80211_unregister_crypto_ops(&rtllib_crypt_tkip); 764} 765 766module_init(rtllib_crypto_tkip_init); 767module_exit(rtllib_crypto_tkip_exit); 768 769MODULE_LICENSE("GPL"); 770