1 /*- 2 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * Alternatively, this software may be distributed under the terms of the 17 * GNU General Public License ("GPL") version 2 as published by the Free 18 * Software Foundation. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifdef __FreeBSD__ 34 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_tkip.c,v 1.10 2005/08/08 18:46:35 sam Exp $"); 35 #endif 36 #ifdef __NetBSD__ 37 __KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_tkip.c,v 1.10 2008/12/17 20:51:37 cegger Exp $"); 38 #endif 39 40 /* 41 * IEEE 802.11i TKIP crypto support. 42 * 43 * Part of this module is derived from similar code in the Host 44 * AP driver. The code is used with the consent of the author and 45 * it's license is included below. 46 */ 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/mbuf.h> 50 #include <sys/malloc.h> 51 #include <sys/kernel.h> 52 #include <sys/endian.h> 53 54 #include <sys/socket.h> 55 56 #include <net/if.h> 57 #include <net/if_ether.h> 58 #include <net/if_media.h> 59 60 #include <net80211/ieee80211_var.h> 61 62 static void *tkip_attach(struct ieee80211com *, struct ieee80211_key *); 63 static void tkip_detach(struct ieee80211_key *); 64 static int tkip_setkey(struct ieee80211_key *); 65 static int tkip_encap(struct ieee80211_key *, struct mbuf *m, u_int8_t keyid); 66 static int tkip_enmic(struct ieee80211_key *, struct mbuf *, int); 67 static int tkip_decap(struct ieee80211_key *, struct mbuf *, int); 68 static int tkip_demic(struct ieee80211_key *, struct mbuf *, int); 69 70 const struct ieee80211_cipher ieee80211_cipher_tkip = { 71 .ic_name = "TKIP", 72 .ic_cipher = IEEE80211_CIPHER_TKIP, 73 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 74 IEEE80211_WEP_EXTIVLEN, 75 .ic_trailer = IEEE80211_WEP_CRCLEN, 76 .ic_miclen = IEEE80211_WEP_MICLEN, 77 .ic_attach = tkip_attach, 78 .ic_detach = tkip_detach, 79 .ic_setkey = tkip_setkey, 80 .ic_encap = tkip_encap, 81 .ic_decap = tkip_decap, 82 .ic_enmic = tkip_enmic, 83 .ic_demic = tkip_demic, 84 }; 85 86 #define tkip ieee80211_cipher_tkip 87 88 typedef uint8_t u8; 89 typedef uint16_t u16; 90 typedef uint32_t __u32; 91 typedef uint32_t u32; 92 93 struct tkip_ctx { 94 struct ieee80211com *tc_ic; /* for diagnostics */ 95 96 u16 tx_ttak[5]; 97 int tx_phase1_done; 98 u8 tx_rc4key[16]; /* XXX for test module; make locals? */ 99 100 u16 rx_ttak[5]; 101 int rx_phase1_done; 102 u8 rx_rc4key[16]; /* XXX for test module; make locals? */ 103 uint64_t rx_rsc; /* held until MIC verified */ 104 }; 105 106 static void michael_mic(struct tkip_ctx *, const u8 *key, 107 struct mbuf *m, u_int off, size_t data_len, 108 u8 mic[IEEE80211_WEP_MICLEN]); 109 static int tkip_encrypt(struct tkip_ctx *, struct ieee80211_key *, 110 struct mbuf *, int hdr_len); 111 static int tkip_decrypt(struct tkip_ctx *, struct ieee80211_key *, 112 struct mbuf *, int hdr_len); 113 114 static void * 115 tkip_attach(struct ieee80211com *ic, struct ieee80211_key *k) 116 { 117 struct tkip_ctx *ctx; 118 119 ctx = malloc(sizeof(struct tkip_ctx), M_DEVBUF, M_NOWAIT | M_ZERO); 120 if (ctx == NULL) { 121 ic->ic_stats.is_crypto_nomem++; 122 return NULL; 123 } 124 125 ctx->tc_ic = ic; 126 return ctx; 127 } 128 129 static void 130 tkip_detach(struct ieee80211_key *k) 131 { 132 struct tkip_ctx *ctx = k->wk_private; 133 134 free(ctx, M_DEVBUF); 135 } 136 137 static int 138 tkip_setkey(struct ieee80211_key *k) 139 { 140 struct tkip_ctx *ctx = k->wk_private; 141 142 if (k->wk_keylen != (128/NBBY)) { 143 (void) ctx; /* XXX */ 144 IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, 145 "%s: Invalid key length %u, expecting %u\n", 146 __func__, k->wk_keylen, 128/NBBY); 147 return 0; 148 } 149 k->wk_keytsc = 1; /* TSC starts at 1 */ 150 return 1; 151 } 152 153 /* 154 * Add privacy headers and do any s/w encryption required. 155 */ 156 static int 157 tkip_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) 158 { 159 struct tkip_ctx *ctx = k->wk_private; 160 struct ieee80211com *ic = ctx->tc_ic; 161 u_int8_t *ivp; 162 int hdrlen; 163 164 /* 165 * Handle TKIP counter measures requirement. 166 */ 167 if (ic->ic_flags & IEEE80211_F_COUNTERM) { 168 #ifdef IEEE80211_DEBUG 169 struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); 170 #endif 171 172 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 173 "[%s] Discard frame due to countermeasures (%s)\n", 174 ether_sprintf(wh->i_addr2), __func__); 175 ic->ic_stats.is_crypto_tkipcm++; 176 return 0; 177 } 178 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 179 180 /* 181 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 182 */ 183 M_PREPEND(m, tkip.ic_header, M_NOWAIT); 184 if (m == NULL) 185 return 0; 186 ivp = mtod(m, u_int8_t *); 187 memmove(ivp, ivp + tkip.ic_header, hdrlen); 188 ivp += hdrlen; 189 190 ivp[0] = k->wk_keytsc >> 8; /* TSC1 */ 191 ivp[1] = (ivp[0] | 0x20) & 0x7f; /* WEP seed */ 192 ivp[2] = k->wk_keytsc >> 0; /* TSC0 */ 193 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 194 ivp[4] = k->wk_keytsc >> 16; /* TSC2 */ 195 ivp[5] = k->wk_keytsc >> 24; /* TSC3 */ 196 ivp[6] = k->wk_keytsc >> 32; /* TSC4 */ 197 ivp[7] = k->wk_keytsc >> 40; /* TSC5 */ 198 199 /* 200 * Finally, do software encrypt if neeed. 201 */ 202 if (k->wk_flags & IEEE80211_KEY_SWCRYPT) { 203 if (!tkip_encrypt(ctx, k, m, hdrlen)) 204 return 0; 205 /* NB: tkip_encrypt handles wk_keytsc */ 206 } else 207 k->wk_keytsc++; 208 209 return 1; 210 } 211 212 /* 213 * Add MIC to the frame as needed. 214 */ 215 static int 216 tkip_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 217 { 218 struct tkip_ctx *ctx = k->wk_private; 219 220 if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) { 221 struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); 222 struct ieee80211com *ic = ctx->tc_ic; 223 int hdrlen; 224 uint8_t mic[IEEE80211_WEP_MICLEN]; 225 226 ic->ic_stats.is_crypto_tkipenmic++; 227 228 hdrlen = ieee80211_hdrspace(ic, wh); 229 230 michael_mic(ctx, k->wk_txmic, 231 m, hdrlen, m->m_pkthdr.len - hdrlen, mic); 232 return m_append(m, tkip.ic_miclen, mic); 233 } 234 return 1; 235 } 236 237 static __inline uint64_t 238 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 239 { 240 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 241 uint16_t iv16 = (b4 << 0) | (b5 << 8); 242 return (((uint64_t)iv16) << 32) | iv32; 243 } 244 245 /* 246 * Validate and strip privacy headers (and trailer) for a 247 * received frame. If necessary, decrypt the frame using 248 * the specified key. 249 */ 250 static int 251 tkip_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 252 { 253 struct tkip_ctx *ctx = k->wk_private; 254 struct ieee80211com *ic = ctx->tc_ic; 255 struct ieee80211_frame *wh; 256 uint8_t *ivp; 257 258 /* 259 * Header should have extended IV and sequence number; 260 * verify the former and validate the latter. 261 */ 262 wh = mtod(m, struct ieee80211_frame *); 263 ivp = mtod(m, uint8_t *) + hdrlen; 264 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 265 /* 266 * No extended IV; discard frame. 267 */ 268 IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, 269 "[%s] missing ExtIV for TKIP cipher\n", 270 ether_sprintf(wh->i_addr2)); 271 ctx->tc_ic->ic_stats.is_rx_tkipformat++; 272 return 0; 273 } 274 /* 275 * Handle TKIP counter measures requirement. 276 */ 277 if (ic->ic_flags & IEEE80211_F_COUNTERM) { 278 IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO, 279 "[%s] discard frame due to countermeasures (%s)\n", 280 ether_sprintf(wh->i_addr2), __func__); 281 ic->ic_stats.is_crypto_tkipcm++; 282 return 0; 283 } 284 285 ctx->rx_rsc = READ_6(ivp[2], ivp[0], ivp[4], ivp[5], ivp[6], ivp[7]); 286 if (ctx->rx_rsc <= k->wk_keyrsc) { 287 /* 288 * Replay violation; notify upper layer. 289 */ 290 ieee80211_notify_replay_failure(ctx->tc_ic, wh, k, ctx->rx_rsc); 291 ctx->tc_ic->ic_stats.is_rx_tkipreplay++; 292 return 0; 293 } 294 /* 295 * NB: We can't update the rsc in the key until MIC is verified. 296 * 297 * We assume we are not preempted between doing the check above 298 * and updating wk_keyrsc when stripping the MIC in tkip_demic. 299 * Otherwise we might process another packet and discard it as 300 * a replay. 301 */ 302 303 /* 304 * Check if the device handled the decrypt in hardware. 305 * If so we just strip the header; otherwise we need to 306 * handle the decrypt in software. 307 */ 308 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 309 !tkip_decrypt(ctx, k, m, hdrlen)) 310 return 0; 311 312 /* 313 * Copy up 802.11 header and strip crypto bits. 314 */ 315 memmove(mtod(m, uint8_t *) + tkip.ic_header, mtod(m, void *), hdrlen); 316 m_adj(m, tkip.ic_header); 317 m_adj(m, -tkip.ic_trailer); 318 319 return 1; 320 } 321 322 /* 323 * Verify and strip MIC from the frame. 324 */ 325 static int 326 tkip_demic(struct ieee80211_key *k, struct mbuf *m, int force) 327 { 328 struct tkip_ctx *ctx = k->wk_private; 329 330 if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) { 331 struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); 332 struct ieee80211com *ic = ctx->tc_ic; 333 int hdrlen = ieee80211_hdrspace(ic, wh); 334 u8 mic[IEEE80211_WEP_MICLEN]; 335 u8 mic0[IEEE80211_WEP_MICLEN]; 336 337 ic->ic_stats.is_crypto_tkipdemic++; 338 339 michael_mic(ctx, k->wk_rxmic, 340 m, hdrlen, m->m_pkthdr.len - (hdrlen + tkip.ic_miclen), 341 mic); 342 m_copydata(m, m->m_pkthdr.len - tkip.ic_miclen, 343 tkip.ic_miclen, mic0); 344 if (memcmp(mic, mic0, tkip.ic_miclen)) { 345 /* NB: 802.11 layer handles statistic and debug msg */ 346 ieee80211_notify_michael_failure(ic, wh, 347 k->wk_rxkeyix != IEEE80211_KEYIX_NONE ? 348 k->wk_rxkeyix : k->wk_keyix); 349 return 0; 350 } 351 } 352 /* 353 * Strip MIC from the tail. 354 */ 355 m_adj(m, -tkip.ic_miclen); 356 357 /* 358 * Ok to update rsc now that MIC has been verified. 359 */ 360 k->wk_keyrsc = ctx->rx_rsc; 361 362 return 1; 363 } 364 365 /* 366 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver 367 * 368 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 369 * 370 * This program is free software; you can redistribute it and/or modify 371 * it under the terms of the GNU General Public License version 2 as 372 * published by the Free Software Foundation. See README and COPYING for 373 * more details. 374 * 375 * Alternatively, this software may be distributed under the terms of BSD 376 * license. 377 */ 378 379 static const __u32 crc32_table[256] = { 380 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 381 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 382 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 383 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 384 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 385 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 386 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 387 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 388 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 389 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 390 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 391 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 392 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 393 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 394 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 395 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 396 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 397 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 398 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 399 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 400 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 401 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 402 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 403 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 404 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 405 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 406 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 407 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 408 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 409 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 410 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 411 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 412 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 413 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 414 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 415 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 416 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 417 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 418 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 419 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 420 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 421 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 422 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 423 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 424 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 425 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 426 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 427 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 428 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 429 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 430 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 431 0x2d02ef8dL 432 }; 433 434 static __inline u16 RotR1(u16 val) 435 { 436 return (val >> 1) | (val << 15); 437 } 438 439 static __inline u8 Lo8(u16 val) 440 { 441 return val & 0xff; 442 } 443 444 static __inline u8 Hi8(u16 val) 445 { 446 return val >> 8; 447 } 448 449 static __inline u16 Lo16(u32 val) 450 { 451 return val & 0xffff; 452 } 453 454 static __inline u16 Hi16(u32 val) 455 { 456 return val >> 16; 457 } 458 459 static __inline u16 Mk16(u8 hi, u8 lo) 460 { 461 return lo | (((u16) hi) << 8); 462 } 463 464 static __inline u16 Mk16_le(const u16 *v) 465 { 466 return le16toh(*v); 467 } 468 469 static const u16 Sbox[256] = { 470 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 471 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 472 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 473 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 474 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 475 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 476 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 477 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 478 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 479 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 480 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 481 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 482 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 483 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 484 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 485 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 486 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 487 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 488 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 489 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 490 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 491 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 492 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 493 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 494 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 495 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 496 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 497 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 498 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 499 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 500 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 501 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, 502 }; 503 504 static __inline u16 _S_(u16 v) 505 { 506 u16 t = Sbox[Hi8(v)]; 507 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); 508 } 509 510 #define PHASE1_LOOP_COUNT 8 511 512 static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32) 513 { 514 int i, j; 515 516 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ 517 TTAK[0] = Lo16(IV32); 518 TTAK[1] = Hi16(IV32); 519 TTAK[2] = Mk16(TA[1], TA[0]); 520 TTAK[3] = Mk16(TA[3], TA[2]); 521 TTAK[4] = Mk16(TA[5], TA[4]); 522 523 for (i = 0; i < PHASE1_LOOP_COUNT; i++) { 524 j = 2 * (i & 1); 525 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); 526 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); 527 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); 528 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); 529 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; 530 } 531 } 532 533 #ifndef _BYTE_ORDER 534 #error "Don't know native byte order" 535 #endif 536 537 static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, 538 u16 IV16) 539 { 540 /* Make temporary area overlap WEP seed so that the final copy can be 541 * avoided on little endian hosts. */ 542 u16 *PPK = (u16 *) &WEPSeed[4]; 543 544 /* Step 1 - make copy of TTAK and bring in TSC */ 545 PPK[0] = TTAK[0]; 546 PPK[1] = TTAK[1]; 547 PPK[2] = TTAK[2]; 548 PPK[3] = TTAK[3]; 549 PPK[4] = TTAK[4]; 550 PPK[5] = TTAK[4] + IV16; 551 552 /* Step 2 - 96-bit bijective mixing using S-box */ 553 PPK[0] += _S_(PPK[5] ^ Mk16_le((const u16 *) &TK[0])); 554 PPK[1] += _S_(PPK[0] ^ Mk16_le((const u16 *) &TK[2])); 555 PPK[2] += _S_(PPK[1] ^ Mk16_le((const u16 *) &TK[4])); 556 PPK[3] += _S_(PPK[2] ^ Mk16_le((const u16 *) &TK[6])); 557 PPK[4] += _S_(PPK[3] ^ Mk16_le((const u16 *) &TK[8])); 558 PPK[5] += _S_(PPK[4] ^ Mk16_le((const u16 *) &TK[10])); 559 560 PPK[0] += RotR1(PPK[5] ^ Mk16_le((const u16 *) &TK[12])); 561 PPK[1] += RotR1(PPK[0] ^ Mk16_le((const u16 *) &TK[14])); 562 PPK[2] += RotR1(PPK[1]); 563 PPK[3] += RotR1(PPK[2]); 564 PPK[4] += RotR1(PPK[3]); 565 PPK[5] += RotR1(PPK[4]); 566 567 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value 568 * WEPSeed[0..2] is transmitted as WEP IV */ 569 WEPSeed[0] = Hi8(IV16); 570 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; 571 WEPSeed[2] = Lo8(IV16); 572 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((const u16 *) &TK[0])) >> 1); 573 574 #if _BYTE_ORDER == _BIG_ENDIAN 575 { 576 int i; 577 for (i = 0; i < 6; i++) 578 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); 579 } 580 #endif 581 } 582 583 static void 584 wep_encrypt(u8 *key, struct mbuf *m0, u_int off, size_t data_len, 585 uint8_t icv[IEEE80211_WEP_CRCLEN]) 586 { 587 u32 i, j, k, crc; 588 size_t buflen; 589 u8 S[256]; 590 u8 *pos; 591 struct mbuf *m; 592 #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0) 593 594 /* Setup RC4 state */ 595 for (i = 0; i < 256; i++) 596 S[i] = i; 597 j = 0; 598 for (i = 0; i < 256; i++) { 599 j = (j + S[i] + key[i & 0x0f]) & 0xff; 600 S_SWAP(i, j); 601 } 602 603 /* Compute CRC32 over unencrypted data and apply RC4 to data */ 604 crc = ~0; 605 i = j = 0; 606 m = m0; 607 pos = mtod(m, uint8_t *) + off; 608 buflen = m->m_len - off; 609 for (;;) { 610 if (buflen > data_len) 611 buflen = data_len; 612 data_len -= buflen; 613 for (k = 0; k < buflen; k++) { 614 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 615 i = (i + 1) & 0xff; 616 j = (j + S[i]) & 0xff; 617 S_SWAP(i, j); 618 *pos++ ^= S[(S[i] + S[j]) & 0xff]; 619 } 620 m = m->m_next; 621 if (m == NULL) { 622 IASSERT(data_len == 0, 623 ("out of buffers with data_len %zu\n", data_len)); 624 break; 625 } 626 pos = mtod(m, uint8_t *); 627 buflen = m->m_len; 628 } 629 crc = ~crc; 630 631 /* Append little-endian CRC32 and encrypt it to produce ICV */ 632 icv[0] = crc; 633 icv[1] = crc >> 8; 634 icv[2] = crc >> 16; 635 icv[3] = crc >> 24; 636 for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) { 637 i = (i + 1) & 0xff; 638 j = (j + S[i]) & 0xff; 639 S_SWAP(i, j); 640 icv[k] ^= S[(S[i] + S[j]) & 0xff]; 641 } 642 } 643 644 static int 645 wep_decrypt(u8 *key, struct mbuf *m, u_int off, size_t data_len) 646 { 647 u32 i, j, k, crc; 648 u8 S[256]; 649 u8 *pos, icv[4]; 650 size_t buflen; 651 652 /* Setup RC4 state */ 653 for (i = 0; i < 256; i++) 654 S[i] = i; 655 j = 0; 656 for (i = 0; i < 256; i++) { 657 j = (j + S[i] + key[i & 0x0f]) & 0xff; 658 S_SWAP(i, j); 659 } 660 661 /* Apply RC4 to data and compute CRC32 over decrypted data */ 662 crc = ~0; 663 i = j = 0; 664 pos = mtod(m, uint8_t *) + off; 665 buflen = m->m_len - off; 666 for (;;) { 667 if (buflen > data_len) 668 buflen = data_len; 669 data_len -= buflen; 670 for (k = 0; k < buflen; k++) { 671 i = (i + 1) & 0xff; 672 j = (j + S[i]) & 0xff; 673 S_SWAP(i, j); 674 *pos ^= S[(S[i] + S[j]) & 0xff]; 675 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 676 pos++; 677 } 678 m = m->m_next; 679 if (m == NULL) { 680 IASSERT(data_len == 0, 681 ("out of buffers with data_len %zu\n", data_len)); 682 break; 683 } 684 pos = mtod(m, uint8_t *); 685 buflen = m->m_len; 686 } 687 crc = ~crc; 688 689 /* Encrypt little-endian CRC32 and verify that it matches with the 690 * received ICV */ 691 icv[0] = crc; 692 icv[1] = crc >> 8; 693 icv[2] = crc >> 16; 694 icv[3] = crc >> 24; 695 for (k = 0; k < 4; k++) { 696 i = (i + 1) & 0xff; 697 j = (j + S[i]) & 0xff; 698 S_SWAP(i, j); 699 if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) { 700 /* ICV mismatch - drop frame */ 701 return -1; 702 } 703 } 704 705 return 0; 706 } 707 708 709 static __inline u32 rotl(u32 val, int bits) 710 { 711 return (val << bits) | (val >> (32 - bits)); 712 } 713 714 715 static __inline u32 rotr(u32 val, int bits) 716 { 717 return (val >> bits) | (val << (32 - bits)); 718 } 719 720 721 static __inline u32 xswap(u32 val) 722 { 723 return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8); 724 } 725 726 727 #define michael_block(l, r) \ 728 do { \ 729 r ^= rotl(l, 17); \ 730 l += r; \ 731 r ^= xswap(l); \ 732 l += r; \ 733 r ^= rotl(l, 3); \ 734 l += r; \ 735 r ^= rotr(l, 2); \ 736 l += r; \ 737 } while (0) 738 739 740 static __inline u32 get_le32_split(u8 b0, u8 b1, u8 b2, u8 b3) 741 { 742 return b0 | (b1 << 8) | (b2 << 16) | (b3 << 24); 743 } 744 745 static __inline u32 get_le32(const u8 *p) 746 { 747 return get_le32_split(p[0], p[1], p[2], p[3]); 748 } 749 750 751 static __inline void put_le32(u8 *p, u32 v) 752 { 753 p[0] = v; 754 p[1] = v >> 8; 755 p[2] = v >> 16; 756 p[3] = v >> 24; 757 } 758 759 /* 760 * Craft pseudo header used to calculate the MIC. 761 */ 762 static void 763 michael_mic_hdr(const struct ieee80211_frame *wh0, uint8_t hdr[16]) 764 { 765 const struct ieee80211_frame_addr4 *wh = 766 (const struct ieee80211_frame_addr4 *) wh0; 767 768 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 769 case IEEE80211_FC1_DIR_NODS: 770 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 771 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 772 break; 773 case IEEE80211_FC1_DIR_TODS: 774 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 775 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 776 break; 777 case IEEE80211_FC1_DIR_FROMDS: 778 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 779 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr3); 780 break; 781 case IEEE80211_FC1_DIR_DSTODS: 782 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 783 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr4); 784 break; 785 } 786 787 if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS) { 788 const struct ieee80211_qosframe *qwh = 789 (const struct ieee80211_qosframe *) wh; 790 hdr[12] = qwh->i_qos[0] & IEEE80211_QOS_TID; 791 } else 792 hdr[12] = 0; 793 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ 794 } 795 796 static void 797 michael_mic(struct tkip_ctx *ctx, const u8 *key, 798 struct mbuf *m, u_int off, size_t data_len, 799 u8 mic[IEEE80211_WEP_MICLEN]) 800 { 801 uint8_t hdr[16]; 802 u32 l, r; 803 const uint8_t *data; 804 u_int space; 805 806 michael_mic_hdr(mtod(m, struct ieee80211_frame *), hdr); 807 808 l = get_le32(key); 809 r = get_le32(key + 4); 810 811 /* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */ 812 l ^= get_le32(hdr); 813 michael_block(l, r); 814 l ^= get_le32(&hdr[4]); 815 michael_block(l, r); 816 l ^= get_le32(&hdr[8]); 817 michael_block(l, r); 818 l ^= get_le32(&hdr[12]); 819 michael_block(l, r); 820 821 /* first buffer has special handling */ 822 data = mtod(m, const uint8_t *) + off; 823 space = m->m_len - off; 824 for (;;) { 825 if (space > data_len) 826 space = data_len; 827 /* collect 32-bit blocks from current buffer */ 828 while (space >= sizeof(uint32_t)) { 829 l ^= get_le32(data); 830 michael_block(l, r); 831 data += sizeof(uint32_t); 832 space -= sizeof(uint32_t); 833 data_len -= sizeof(uint32_t); 834 } 835 /* 836 * NB: when space is zero we make one more trip around 837 * the loop to advance to the next mbuf where there is 838 * data. This handles the case where there are 4*n 839 * bytes in an mbuf followed by <4 bytes in a later mbuf. 840 * By making an extra trip we'll drop out of the loop 841 * with m pointing at the mbuf with 3 bytes and space 842 * set as required by the remainder handling below. 843 */ 844 if (!data_len || (data_len < sizeof(uint32_t) && space != 0)) 845 break; 846 m = m->m_next; 847 if (m == NULL) { 848 IASSERT(0, ("out of data, data_len %zu\n", data_len)); 849 break; 850 } 851 if (space != 0) { 852 const uint8_t *data_next; 853 /* 854 * Block straddles buffers, split references. 855 */ 856 data_next = mtod(m, const uint8_t *); 857 IASSERT(m->m_len >= sizeof(uint32_t) - space, 858 ("not enough data in following buffer, " 859 "m_len %u need %zu\n", m->m_len, 860 sizeof(uint32_t) - space)); 861 switch (space) { 862 case 1: 863 l ^= get_le32_split(data[0], data_next[0], 864 data_next[1], data_next[2]); 865 data = data_next + 3; 866 space = m->m_len - 3; 867 break; 868 case 2: 869 l ^= get_le32_split(data[0], data[1], 870 data_next[0], data_next[1]); 871 data = data_next + 2; 872 space = m->m_len - 2; 873 break; 874 case 3: 875 l ^= get_le32_split(data[0], data[1], 876 data[2], data_next[0]); 877 data = data_next + 1; 878 space = m->m_len - 1; 879 break; 880 } 881 michael_block(l, r); 882 data_len -= sizeof(uint32_t); 883 } else { 884 /* 885 * Setup for next buffer. 886 */ 887 data = mtod(m, const uint8_t *); 888 space = m->m_len; 889 } 890 } 891 /* 892 * Catch degenerate cases like mbuf[4*n+1 bytes] followed by 893 * mbuf[2 bytes]. I don't believe these should happen; if they 894 * do then we'll need more involved logic. 895 */ 896 KASSERT(data_len <= space); 897 898 /* Last block and padding (0x5a, 4..7 x 0) */ 899 switch (data_len) { 900 case 0: 901 l ^= get_le32_split(0x5a, 0, 0, 0); 902 break; 903 case 1: 904 l ^= get_le32_split(data[0], 0x5a, 0, 0); 905 break; 906 case 2: 907 l ^= get_le32_split(data[0], data[1], 0x5a, 0); 908 break; 909 case 3: 910 l ^= get_le32_split(data[0], data[1], data[2], 0x5a); 911 break; 912 } 913 michael_block(l, r); 914 /* l ^= 0; */ 915 michael_block(l, r); 916 917 put_le32(mic, l); 918 put_le32(mic + 4, r); 919 } 920 921 static int 922 tkip_encrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 923 struct mbuf *m, int hdrlen) 924 { 925 struct ieee80211_frame *wh; 926 uint8_t icv[IEEE80211_WEP_CRCLEN]; 927 928 ctx->tc_ic->ic_stats.is_crypto_tkip++; 929 930 wh = mtod(m, struct ieee80211_frame *); 931 if (!ctx->tx_phase1_done) { 932 tkip_mixing_phase1(ctx->tx_ttak, key->wk_key, wh->i_addr2, 933 (u32)(key->wk_keytsc >> 16)); 934 ctx->tx_phase1_done = 1; 935 } 936 tkip_mixing_phase2(ctx->tx_rc4key, key->wk_key, ctx->tx_ttak, 937 (u16) key->wk_keytsc); 938 939 wep_encrypt(ctx->tx_rc4key, 940 m, hdrlen + tkip.ic_header, 941 m->m_pkthdr.len - (hdrlen + tkip.ic_header), 942 icv); 943 (void) m_append(m, IEEE80211_WEP_CRCLEN, icv); /* XXX check return */ 944 945 key->wk_keytsc++; 946 if ((u16)(key->wk_keytsc) == 0) 947 ctx->tx_phase1_done = 0; 948 return 1; 949 } 950 951 static int 952 tkip_decrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 953 struct mbuf *m, int hdrlen) 954 { 955 struct ieee80211_frame *wh; 956 u32 iv32; 957 u16 iv16; 958 959 ctx->tc_ic->ic_stats.is_crypto_tkip++; 960 961 wh = mtod(m, struct ieee80211_frame *); 962 /* NB: tkip_decap already verified header and left seq in rx_rsc */ 963 iv16 = (u16) ctx->rx_rsc; 964 iv32 = (u32) (ctx->rx_rsc >> 16); 965 966 if (iv32 != (u32)(key->wk_keyrsc >> 16) || !ctx->rx_phase1_done) { 967 tkip_mixing_phase1(ctx->rx_ttak, key->wk_key, 968 wh->i_addr2, iv32); 969 ctx->rx_phase1_done = 1; 970 } 971 tkip_mixing_phase2(ctx->rx_rc4key, key->wk_key, ctx->rx_ttak, iv16); 972 973 /* NB: m is unstripped; deduct headers + ICV to get payload */ 974 if (wep_decrypt(ctx->rx_rc4key, 975 m, hdrlen + tkip.ic_header, 976 m->m_pkthdr.len - (hdrlen + tkip.ic_header + tkip.ic_trailer))) { 977 if (iv32 != (u32)(key->wk_keyrsc >> 16)) { 978 /* Previously cached Phase1 result was already lost, so 979 * it needs to be recalculated for the next packet. */ 980 ctx->rx_phase1_done = 0; 981 } 982 IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO, 983 "[%s] TKIP ICV mismatch on decrypt\n", 984 ether_sprintf(wh->i_addr2)); 985 ctx->tc_ic->ic_stats.is_rx_tkipicv++; 986 return 0; 987 } 988 return 1; 989 } 990 991 IEEE80211_CRYPTO_SETUP(tkip_register) 992 { 993 ieee80211_crypto_register(&tkip); 994 } 995