1 /*- 2 * Copyright (c) 2002-2008 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * $FreeBSD: head/sys/net80211/ieee80211_crypto_tkip.c 203673 2010-02-08 18:16:59Z bschmidt $ 26 */ 27 28 /* 29 * IEEE 802.11i TKIP crypto support. 30 * 31 * Part of this module is derived from similar code in the Host 32 * AP driver. The code is used with the consent of the author and 33 * it's license is included below. 34 */ 35 #include "opt_wlan.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/mbuf.h> 40 #include <sys/malloc.h> 41 #include <sys/kernel.h> 42 #include <sys/module.h> 43 #include <sys/endian.h> 44 45 #include <sys/socket.h> 46 47 #include <net/if.h> 48 #include <net/if_media.h> 49 #include <net/ethernet.h> 50 #include <net/route.h> 51 52 #include <netproto/802_11/ieee80211_var.h> 53 54 static void *tkip_attach(struct ieee80211vap *, struct ieee80211_key *); 55 static void tkip_detach(struct ieee80211_key *); 56 static int tkip_setkey(struct ieee80211_key *); 57 static int tkip_encap(struct ieee80211_key *, struct mbuf *m, uint8_t keyid); 58 static int tkip_enmic(struct ieee80211_key *, struct mbuf *, int); 59 static int tkip_decap(struct ieee80211_key *, struct mbuf *, int); 60 static int tkip_demic(struct ieee80211_key *, struct mbuf *, int); 61 62 static const struct ieee80211_cipher tkip = { 63 .ic_name = "TKIP", 64 .ic_cipher = IEEE80211_CIPHER_TKIP, 65 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 66 IEEE80211_WEP_EXTIVLEN, 67 .ic_trailer = IEEE80211_WEP_CRCLEN, 68 .ic_miclen = IEEE80211_WEP_MICLEN, 69 .ic_attach = tkip_attach, 70 .ic_detach = tkip_detach, 71 .ic_setkey = tkip_setkey, 72 .ic_encap = tkip_encap, 73 .ic_decap = tkip_decap, 74 .ic_enmic = tkip_enmic, 75 .ic_demic = tkip_demic, 76 }; 77 78 typedef uint8_t u8; 79 typedef uint16_t u16; 80 typedef uint32_t __u32; 81 typedef uint32_t u32; 82 83 struct tkip_ctx { 84 struct ieee80211vap *tc_vap; /* for diagnostics+statistics */ 85 86 u16 tx_ttak[5]; 87 int tx_phase1_done; 88 u8 tx_rc4key[16]; /* XXX for test module; make locals? */ 89 90 u16 rx_ttak[5]; 91 int rx_phase1_done; 92 u8 rx_rc4key[16]; /* XXX for test module; make locals? */ 93 uint64_t rx_rsc; /* held until MIC verified */ 94 }; 95 96 static void michael_mic(struct tkip_ctx *, const u8 *key, 97 struct mbuf *m, u_int off, size_t data_len, 98 u8 mic[IEEE80211_WEP_MICLEN]); 99 static int tkip_encrypt(struct tkip_ctx *, struct ieee80211_key *, 100 struct mbuf *, int hdr_len); 101 static int tkip_decrypt(struct tkip_ctx *, struct ieee80211_key *, 102 struct mbuf *, int hdr_len); 103 104 /* number of references from net80211 layer */ 105 static int nrefs = 0; 106 107 static void * 108 tkip_attach(struct ieee80211vap *vap, struct ieee80211_key *k) 109 { 110 struct tkip_ctx *ctx; 111 112 ctx = (struct tkip_ctx *) kmalloc(sizeof(struct tkip_ctx), 113 M_80211_CRYPTO, M_INTWAIT | M_ZERO); 114 if (ctx == NULL) { 115 vap->iv_stats.is_crypto_nomem++; 116 return NULL; 117 } 118 119 ctx->tc_vap = vap; 120 nrefs++; /* NB: we assume caller locking */ 121 return ctx; 122 } 123 124 static void 125 tkip_detach(struct ieee80211_key *k) 126 { 127 struct tkip_ctx *ctx = k->wk_private; 128 129 kfree(ctx, M_80211_CRYPTO); 130 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 131 nrefs--; /* NB: we assume caller locking */ 132 } 133 134 static int 135 tkip_setkey(struct ieee80211_key *k) 136 { 137 struct tkip_ctx *ctx = k->wk_private; 138 139 if (k->wk_keylen != (128/NBBY)) { 140 (void) ctx; /* XXX */ 141 IEEE80211_DPRINTF(ctx->tc_vap, IEEE80211_MSG_CRYPTO, 142 "%s: Invalid key length %u, expecting %u\n", 143 __func__, k->wk_keylen, 128/NBBY); 144 return 0; 145 } 146 k->wk_keytsc = 1; /* TSC starts at 1 */ 147 ctx->rx_phase1_done = 0; 148 return 1; 149 } 150 151 /* 152 * Add privacy headers and do any s/w encryption required. 153 */ 154 static int 155 tkip_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid) 156 { 157 struct tkip_ctx *ctx = k->wk_private; 158 struct ieee80211vap *vap = ctx->tc_vap; 159 struct ieee80211com *ic = vap->iv_ic; 160 uint8_t *ivp; 161 int hdrlen; 162 163 /* 164 * Handle TKIP counter measures requirement. 165 */ 166 if (vap->iv_flags & IEEE80211_F_COUNTERM) { 167 #ifdef IEEE80211_DEBUG 168 struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); 169 #endif 170 171 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 172 "discard frame due to countermeasures (%s)", __func__); 173 vap->iv_stats.is_crypto_tkipcm++; 174 return 0; 175 } 176 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 177 178 /* 179 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 180 */ 181 M_PREPEND(m, tkip.ic_header, MB_DONTWAIT); 182 if (m == NULL) 183 return 0; 184 ivp = mtod(m, uint8_t *); 185 memmove(ivp, ivp + tkip.ic_header, hdrlen); 186 ivp += hdrlen; 187 188 ivp[0] = k->wk_keytsc >> 8; /* TSC1 */ 189 ivp[1] = (ivp[0] | 0x20) & 0x7f; /* WEP seed */ 190 ivp[2] = k->wk_keytsc >> 0; /* TSC0 */ 191 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 192 ivp[4] = k->wk_keytsc >> 16; /* TSC2 */ 193 ivp[5] = k->wk_keytsc >> 24; /* TSC3 */ 194 ivp[6] = k->wk_keytsc >> 32; /* TSC4 */ 195 ivp[7] = k->wk_keytsc >> 40; /* TSC5 */ 196 197 /* 198 * Finally, do software encrypt if neeed. 199 */ 200 if (k->wk_flags & IEEE80211_KEY_SWENCRYPT) { 201 if (!tkip_encrypt(ctx, k, m, hdrlen)) 202 return 0; 203 /* NB: tkip_encrypt handles wk_keytsc */ 204 } else 205 k->wk_keytsc++; 206 207 return 1; 208 } 209 210 /* 211 * Add MIC to the frame as needed. 212 */ 213 static int 214 tkip_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 215 { 216 struct tkip_ctx *ctx = k->wk_private; 217 218 if (force || (k->wk_flags & IEEE80211_KEY_SWENMIC)) { 219 struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *); 220 struct ieee80211vap *vap = ctx->tc_vap; 221 struct ieee80211com *ic = vap->iv_ic; 222 int hdrlen; 223 uint8_t mic[IEEE80211_WEP_MICLEN]; 224 225 vap->iv_stats.is_crypto_tkipenmic++; 226 227 hdrlen = ieee80211_hdrspace(ic, wh); 228 229 michael_mic(ctx, k->wk_txmic, 230 m, hdrlen, m->m_pkthdr.len - hdrlen, mic); 231 return m_append(m, tkip.ic_miclen, mic); 232 } 233 return 1; 234 } 235 236 static __inline uint64_t 237 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 238 { 239 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 240 uint16_t iv16 = (b4 << 0) | (b5 << 8); 241 return (((uint64_t)iv16) << 32) | iv32; 242 } 243 244 /* 245 * Validate and strip privacy headers (and trailer) for a 246 * received frame. If necessary, decrypt the frame using 247 * the specified key. 248 */ 249 static int 250 tkip_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 251 { 252 struct tkip_ctx *ctx = k->wk_private; 253 struct ieee80211vap *vap = ctx->tc_vap; 254 struct ieee80211_frame *wh; 255 uint8_t *ivp, tid; 256 257 /* 258 * Header should have extended IV and sequence number; 259 * verify the former and validate the latter. 260 */ 261 wh = mtod(m, struct ieee80211_frame *); 262 ivp = mtod(m, uint8_t *) + hdrlen; 263 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 264 /* 265 * No extended IV; discard frame. 266 */ 267 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 268 "%s", "missing ExtIV for TKIP cipher"); 269 vap->iv_stats.is_rx_tkipformat++; 270 return 0; 271 } 272 /* 273 * Handle TKIP counter measures requirement. 274 */ 275 if (vap->iv_flags & IEEE80211_F_COUNTERM) { 276 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 277 "discard frame due to countermeasures (%s)", __func__); 278 vap->iv_stats.is_crypto_tkipcm++; 279 return 0; 280 } 281 282 tid = ieee80211_gettid(wh); 283 ctx->rx_rsc = READ_6(ivp[2], ivp[0], ivp[4], ivp[5], ivp[6], ivp[7]); 284 if (ctx->rx_rsc <= k->wk_keyrsc[tid]) { 285 /* 286 * Replay violation; notify upper layer. 287 */ 288 ieee80211_notify_replay_failure(vap, wh, k, ctx->rx_rsc, tid); 289 vap->iv_stats.is_rx_tkipreplay++; 290 return 0; 291 } 292 /* 293 * NB: We can't update the rsc in the key until MIC is verified. 294 * 295 * We assume we are not preempted between doing the check above 296 * and updating wk_keyrsc when stripping the MIC in tkip_demic. 297 * Otherwise we might process another packet and discard it as 298 * a replay. 299 */ 300 301 /* 302 * Check if the device handled the decrypt in hardware. 303 * If so we just strip the header; otherwise we need to 304 * handle the decrypt in software. 305 */ 306 if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) && 307 !tkip_decrypt(ctx, k, m, hdrlen)) 308 return 0; 309 310 /* 311 * Copy up 802.11 header and strip crypto bits. 312 */ 313 memmove(mtod(m, uint8_t *) + tkip.ic_header, mtod(m, void *), hdrlen); 314 m_adj(m, tkip.ic_header); 315 m_adj(m, -tkip.ic_trailer); 316 317 return 1; 318 } 319 320 /* 321 * Verify and strip MIC from the frame. 322 */ 323 static int 324 tkip_demic(struct ieee80211_key *k, struct mbuf *m, int force) 325 { 326 struct tkip_ctx *ctx = k->wk_private; 327 struct ieee80211_frame *wh; 328 uint8_t tid; 329 330 wh = mtod(m, struct ieee80211_frame *); 331 if ((k->wk_flags & IEEE80211_KEY_SWDEMIC) || force) { 332 struct ieee80211vap *vap = ctx->tc_vap; 333 int hdrlen = ieee80211_hdrspace(vap->iv_ic, wh); 334 u8 mic[IEEE80211_WEP_MICLEN]; 335 u8 mic0[IEEE80211_WEP_MICLEN]; 336 337 vap->iv_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(vap, 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 tid = ieee80211_gettid(wh); 361 k->wk_keyrsc[tid] = ctx->rx_rsc; 362 363 return 1; 364 } 365 366 /* 367 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver 368 * 369 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 370 * 371 * This program is free software; you can redistribute it and/or modify 372 * it under the terms of the GNU General Public License version 2 as 373 * published by the Free Software Foundation. See README and COPYING for 374 * more details. 375 * 376 * Alternatively, this software may be distributed under the terms of BSD 377 * license. 378 */ 379 380 static const __u32 crc32_table[256] = { 381 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 382 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 383 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 384 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 385 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 386 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 387 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 388 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 389 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 390 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 391 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 392 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 393 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 394 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 395 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 396 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 397 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 398 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 399 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 400 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 401 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 402 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 403 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 404 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 405 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 406 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 407 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 408 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 409 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 410 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 411 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 412 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 413 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 414 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 415 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 416 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 417 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 418 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 419 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 420 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 421 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 422 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 423 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 424 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 425 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 426 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 427 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 428 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 429 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 430 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 431 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 432 0x2d02ef8dL 433 }; 434 435 static __inline u16 RotR1(u16 val) 436 { 437 return (val >> 1) | (val << 15); 438 } 439 440 static __inline u8 Lo8(u16 val) 441 { 442 return val & 0xff; 443 } 444 445 static __inline u8 Hi8(u16 val) 446 { 447 return val >> 8; 448 } 449 450 static __inline u16 Lo16(u32 val) 451 { 452 return val & 0xffff; 453 } 454 455 static __inline u16 Hi16(u32 val) 456 { 457 return val >> 16; 458 } 459 460 static __inline u16 Mk16(u8 hi, u8 lo) 461 { 462 return lo | (((u16) hi) << 8); 463 } 464 465 static __inline u16 Mk16_le(const u16 *v) 466 { 467 return le16toh(*v); 468 } 469 470 static const u16 Sbox[256] = { 471 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 472 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 473 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 474 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 475 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 476 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 477 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 478 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 479 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 480 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 481 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 482 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 483 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 484 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 485 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 486 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 487 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 488 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 489 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 490 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 491 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 492 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 493 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 494 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 495 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 496 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 497 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 498 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 499 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 500 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 501 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 502 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, 503 }; 504 505 static __inline u16 _S_(u16 v) 506 { 507 u16 t = Sbox[Hi8(v)]; 508 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); 509 } 510 511 #define PHASE1_LOOP_COUNT 8 512 513 static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32) 514 { 515 int i, j; 516 517 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ 518 TTAK[0] = Lo16(IV32); 519 TTAK[1] = Hi16(IV32); 520 TTAK[2] = Mk16(TA[1], TA[0]); 521 TTAK[3] = Mk16(TA[3], TA[2]); 522 TTAK[4] = Mk16(TA[5], TA[4]); 523 524 for (i = 0; i < PHASE1_LOOP_COUNT; i++) { 525 j = 2 * (i & 1); 526 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); 527 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); 528 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); 529 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); 530 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; 531 } 532 } 533 534 #ifndef _BYTE_ORDER 535 #error "Don't know native byte order" 536 #endif 537 538 static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, 539 u16 IV16) 540 { 541 /* Make temporary area overlap WEP seed so that the final copy can be 542 * avoided on little endian hosts. */ 543 u16 *PPK = (u16 *) &WEPSeed[4]; 544 545 /* Step 1 - make copy of TTAK and bring in TSC */ 546 PPK[0] = TTAK[0]; 547 PPK[1] = TTAK[1]; 548 PPK[2] = TTAK[2]; 549 PPK[3] = TTAK[3]; 550 PPK[4] = TTAK[4]; 551 PPK[5] = TTAK[4] + IV16; 552 553 /* Step 2 - 96-bit bijective mixing using S-box */ 554 PPK[0] += _S_(PPK[5] ^ Mk16_le((const u16 *) &TK[0])); 555 PPK[1] += _S_(PPK[0] ^ Mk16_le((const u16 *) &TK[2])); 556 PPK[2] += _S_(PPK[1] ^ Mk16_le((const u16 *) &TK[4])); 557 PPK[3] += _S_(PPK[2] ^ Mk16_le((const u16 *) &TK[6])); 558 PPK[4] += _S_(PPK[3] ^ Mk16_le((const u16 *) &TK[8])); 559 PPK[5] += _S_(PPK[4] ^ Mk16_le((const u16 *) &TK[10])); 560 561 PPK[0] += RotR1(PPK[5] ^ Mk16_le((const u16 *) &TK[12])); 562 PPK[1] += RotR1(PPK[0] ^ Mk16_le((const u16 *) &TK[14])); 563 PPK[2] += RotR1(PPK[1]); 564 PPK[3] += RotR1(PPK[2]); 565 PPK[4] += RotR1(PPK[3]); 566 PPK[5] += RotR1(PPK[4]); 567 568 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value 569 * WEPSeed[0..2] is transmitted as WEP IV */ 570 WEPSeed[0] = Hi8(IV16); 571 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; 572 WEPSeed[2] = Lo8(IV16); 573 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((const u16 *) &TK[0])) >> 1); 574 575 #if _BYTE_ORDER == _BIG_ENDIAN 576 { 577 int i; 578 for (i = 0; i < 6; i++) 579 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); 580 } 581 #endif 582 } 583 584 static void 585 wep_encrypt(u8 *key, struct mbuf *m0, u_int off, size_t data_len, 586 uint8_t icv[IEEE80211_WEP_CRCLEN]) 587 { 588 u32 i, j, k, crc; 589 size_t buflen; 590 u8 S[256]; 591 u8 *pos; 592 struct mbuf *m; 593 #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0) 594 595 /* Setup RC4 state */ 596 for (i = 0; i < 256; i++) 597 S[i] = i; 598 j = 0; 599 for (i = 0; i < 256; i++) { 600 j = (j + S[i] + key[i & 0x0f]) & 0xff; 601 S_SWAP(i, j); 602 } 603 604 /* Compute CRC32 over unencrypted data and apply RC4 to data */ 605 crc = ~0; 606 i = j = 0; 607 m = m0; 608 pos = mtod(m, uint8_t *) + off; 609 buflen = m->m_len - off; 610 for (;;) { 611 if (buflen > data_len) 612 buflen = data_len; 613 data_len -= buflen; 614 for (k = 0; k < buflen; k++) { 615 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 616 i = (i + 1) & 0xff; 617 j = (j + S[i]) & 0xff; 618 S_SWAP(i, j); 619 *pos++ ^= S[(S[i] + S[j]) & 0xff]; 620 } 621 m = m->m_next; 622 if (m == NULL) { 623 KASSERT(data_len == 0, 624 ("out of buffers with data_len %zu", data_len)); 625 break; 626 } 627 pos = mtod(m, uint8_t *); 628 buflen = m->m_len; 629 } 630 crc = ~crc; 631 632 /* Append little-endian CRC32 and encrypt it to produce ICV */ 633 icv[0] = crc; 634 icv[1] = crc >> 8; 635 icv[2] = crc >> 16; 636 icv[3] = crc >> 24; 637 for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) { 638 i = (i + 1) & 0xff; 639 j = (j + S[i]) & 0xff; 640 S_SWAP(i, j); 641 icv[k] ^= S[(S[i] + S[j]) & 0xff]; 642 } 643 } 644 645 static int 646 wep_decrypt(u8 *key, struct mbuf *m, u_int off, size_t data_len) 647 { 648 u32 i, j, k, crc; 649 u8 S[256]; 650 u8 *pos, icv[4]; 651 size_t buflen; 652 653 /* Setup RC4 state */ 654 for (i = 0; i < 256; i++) 655 S[i] = i; 656 j = 0; 657 for (i = 0; i < 256; i++) { 658 j = (j + S[i] + key[i & 0x0f]) & 0xff; 659 S_SWAP(i, j); 660 } 661 662 /* Apply RC4 to data and compute CRC32 over decrypted data */ 663 crc = ~0; 664 i = j = 0; 665 pos = mtod(m, uint8_t *) + off; 666 buflen = m->m_len - off; 667 for (;;) { 668 if (buflen > data_len) 669 buflen = data_len; 670 data_len -= buflen; 671 for (k = 0; k < buflen; k++) { 672 i = (i + 1) & 0xff; 673 j = (j + S[i]) & 0xff; 674 S_SWAP(i, j); 675 *pos ^= S[(S[i] + S[j]) & 0xff]; 676 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 677 pos++; 678 } 679 m = m->m_next; 680 if (m == NULL) { 681 KASSERT(data_len == 0, 682 ("out of buffers with data_len %zu", data_len)); 683 break; 684 } 685 pos = mtod(m, uint8_t *); 686 buflen = m->m_len; 687 } 688 crc = ~crc; 689 690 /* Encrypt little-endian CRC32 and verify that it matches with the 691 * received ICV */ 692 icv[0] = crc; 693 icv[1] = crc >> 8; 694 icv[2] = crc >> 16; 695 icv[3] = crc >> 24; 696 for (k = 0; k < 4; k++) { 697 i = (i + 1) & 0xff; 698 j = (j + S[i]) & 0xff; 699 S_SWAP(i, j); 700 if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) { 701 /* ICV mismatch - drop frame */ 702 return -1; 703 } 704 } 705 706 return 0; 707 } 708 709 710 static __inline u32 rotl(u32 val, int bits) 711 { 712 return (val << bits) | (val >> (32 - bits)); 713 } 714 715 716 static __inline u32 rotr(u32 val, int bits) 717 { 718 return (val >> bits) | (val << (32 - bits)); 719 } 720 721 722 static __inline u32 xswap(u32 val) 723 { 724 return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8); 725 } 726 727 728 #define michael_block(l, r) \ 729 do { \ 730 r ^= rotl(l, 17); \ 731 l += r; \ 732 r ^= xswap(l); \ 733 l += r; \ 734 r ^= rotl(l, 3); \ 735 l += r; \ 736 r ^= rotr(l, 2); \ 737 l += r; \ 738 } while (0) 739 740 741 static __inline u32 get_le32_split(u8 b0, u8 b1, u8 b2, u8 b3) 742 { 743 return b0 | (b1 << 8) | (b2 << 16) | (b3 << 24); 744 } 745 746 static __inline u32 get_le32(const u8 *p) 747 { 748 return get_le32_split(p[0], p[1], p[2], p[3]); 749 } 750 751 752 static __inline void put_le32(u8 *p, u32 v) 753 { 754 p[0] = v; 755 p[1] = v >> 8; 756 p[2] = v >> 16; 757 p[3] = v >> 24; 758 } 759 760 /* 761 * Craft pseudo header used to calculate the MIC. 762 */ 763 static void 764 michael_mic_hdr(const struct ieee80211_frame *wh0, uint8_t hdr[16]) 765 { 766 const struct ieee80211_frame_addr4 *wh = 767 (const struct ieee80211_frame_addr4 *) wh0; 768 769 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 770 case IEEE80211_FC1_DIR_NODS: 771 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 772 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 773 break; 774 case IEEE80211_FC1_DIR_TODS: 775 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 776 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 777 break; 778 case IEEE80211_FC1_DIR_FROMDS: 779 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 780 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr3); 781 break; 782 case IEEE80211_FC1_DIR_DSTODS: 783 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 784 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr4); 785 break; 786 } 787 788 if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS) { 789 const struct ieee80211_qosframe *qwh = 790 (const struct ieee80211_qosframe *) wh; 791 hdr[12] = qwh->i_qos[0] & IEEE80211_QOS_TID; 792 } else 793 hdr[12] = 0; 794 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ 795 } 796 797 static void 798 michael_mic(struct tkip_ctx *ctx, const u8 *key, 799 struct mbuf *m, u_int off, size_t data_len, 800 u8 mic[IEEE80211_WEP_MICLEN]) 801 { 802 uint8_t hdr[16]; 803 u32 l, r; 804 const uint8_t *data; 805 u_int space; 806 807 michael_mic_hdr(mtod(m, struct ieee80211_frame *), hdr); 808 809 l = get_le32(key); 810 r = get_le32(key + 4); 811 812 /* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */ 813 l ^= get_le32(hdr); 814 michael_block(l, r); 815 l ^= get_le32(&hdr[4]); 816 michael_block(l, r); 817 l ^= get_le32(&hdr[8]); 818 michael_block(l, r); 819 l ^= get_le32(&hdr[12]); 820 michael_block(l, r); 821 822 /* first buffer has special handling */ 823 data = mtod(m, const uint8_t *) + off; 824 space = m->m_len - off; 825 for (;;) { 826 if (space > data_len) 827 space = data_len; 828 /* collect 32-bit blocks from current buffer */ 829 while (space >= sizeof(uint32_t)) { 830 l ^= get_le32(data); 831 michael_block(l, r); 832 data += sizeof(uint32_t), 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 == 0 || 845 (data_len < sizeof(uint32_t) && space != 0)) 846 break; 847 m = m->m_next; 848 if (m == NULL) { 849 KASSERT(0, ("out of data, data_len %zu", data_len)); 850 break; 851 } 852 if (space != 0) { 853 const uint8_t *data_next; 854 /* 855 * Block straddles buffers, split references. 856 */ 857 data_next = mtod(m, const uint8_t *); 858 KASSERT(m->m_len >= sizeof(uint32_t) - space, 859 ("not enough data in following buffer, " 860 "m_len %u need %zu", m->m_len, 861 sizeof(uint32_t) - space)); 862 switch (space) { 863 case 1: 864 l ^= get_le32_split(data[0], data_next[0], 865 data_next[1], data_next[2]); 866 data = data_next + 3; 867 space = m->m_len - 3; 868 break; 869 case 2: 870 l ^= get_le32_split(data[0], data[1], 871 data_next[0], data_next[1]); 872 data = data_next + 2; 873 space = m->m_len - 2; 874 break; 875 case 3: 876 l ^= get_le32_split(data[0], data[1], 877 data[2], data_next[0]); 878 data = data_next + 1; 879 space = m->m_len - 1; 880 break; 881 } 882 michael_block(l, r); 883 data_len -= sizeof(uint32_t); 884 } else { 885 /* 886 * Setup for next buffer. 887 */ 888 data = mtod(m, const uint8_t *); 889 space = m->m_len; 890 } 891 } 892 /* 893 * Catch degenerate cases like mbuf[4*n+1 bytes] followed by 894 * mbuf[2 bytes]. I don't believe these should happen; if they 895 * do then we'll need more involved logic. 896 */ 897 KASSERT(data_len <= space, 898 ("not enough data, data_len %zu space %u", data_len, space)); 899 900 /* Last block and padding (0x5a, 4..7 x 0) */ 901 switch (data_len) { 902 case 0: 903 l ^= get_le32_split(0x5a, 0, 0, 0); 904 break; 905 case 1: 906 l ^= get_le32_split(data[0], 0x5a, 0, 0); 907 break; 908 case 2: 909 l ^= get_le32_split(data[0], data[1], 0x5a, 0); 910 break; 911 case 3: 912 l ^= get_le32_split(data[0], data[1], data[2], 0x5a); 913 break; 914 } 915 michael_block(l, r); 916 /* l ^= 0; */ 917 michael_block(l, r); 918 919 put_le32(mic, l); 920 put_le32(mic + 4, r); 921 } 922 923 static int 924 tkip_encrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 925 struct mbuf *m, int hdrlen) 926 { 927 struct ieee80211_frame *wh; 928 uint8_t icv[IEEE80211_WEP_CRCLEN]; 929 930 ctx->tc_vap->iv_stats.is_crypto_tkip++; 931 932 wh = mtod(m, struct ieee80211_frame *); 933 if (!ctx->tx_phase1_done) { 934 tkip_mixing_phase1(ctx->tx_ttak, key->wk_key, wh->i_addr2, 935 (u32)(key->wk_keytsc >> 16)); 936 ctx->tx_phase1_done = 1; 937 } 938 tkip_mixing_phase2(ctx->tx_rc4key, key->wk_key, ctx->tx_ttak, 939 (u16) key->wk_keytsc); 940 941 wep_encrypt(ctx->tx_rc4key, 942 m, hdrlen + tkip.ic_header, 943 m->m_pkthdr.len - (hdrlen + tkip.ic_header), 944 icv); 945 (void) m_append(m, IEEE80211_WEP_CRCLEN, icv); /* XXX check return */ 946 947 key->wk_keytsc++; 948 if ((u16)(key->wk_keytsc) == 0) 949 ctx->tx_phase1_done = 0; 950 return 1; 951 } 952 953 static int 954 tkip_decrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 955 struct mbuf *m, int hdrlen) 956 { 957 struct ieee80211_frame *wh; 958 struct ieee80211vap *vap = ctx->tc_vap; 959 u32 iv32; 960 u16 iv16; 961 u8 tid; 962 963 vap->iv_stats.is_crypto_tkip++; 964 965 wh = mtod(m, struct ieee80211_frame *); 966 /* NB: tkip_decap already verified header and left seq in rx_rsc */ 967 iv16 = (u16) ctx->rx_rsc; 968 iv32 = (u32) (ctx->rx_rsc >> 16); 969 970 tid = ieee80211_gettid(wh); 971 if (iv32 != (u32)(key->wk_keyrsc[tid] >> 16) || !ctx->rx_phase1_done) { 972 tkip_mixing_phase1(ctx->rx_ttak, key->wk_key, 973 wh->i_addr2, iv32); 974 ctx->rx_phase1_done = 1; 975 } 976 tkip_mixing_phase2(ctx->rx_rc4key, key->wk_key, ctx->rx_ttak, iv16); 977 978 /* NB: m is unstripped; deduct headers + ICV to get payload */ 979 if (wep_decrypt(ctx->rx_rc4key, 980 m, hdrlen + tkip.ic_header, 981 m->m_pkthdr.len - (hdrlen + tkip.ic_header + tkip.ic_trailer))) { 982 if (iv32 != (u32)(key->wk_keyrsc[tid] >> 16)) { 983 /* Previously cached Phase1 result was already lost, so 984 * it needs to be recalculated for the next packet. */ 985 ctx->rx_phase1_done = 0; 986 } 987 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 988 "%s", "TKIP ICV mismatch on decrypt"); 989 vap->iv_stats.is_rx_tkipicv++; 990 return 0; 991 } 992 return 1; 993 } 994 995 /* 996 * Module glue. 997 */ 998 IEEE80211_CRYPTO_MODULE(tkip, 1); 999