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 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11i TKIP crypto support. 31 * 32 * Part of this module is derived from similar code in the Host 33 * AP driver. The code is used with the consent of the author and 34 * it's license is included below. 35 */ 36 #include "opt_wlan.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/mbuf.h> 41 #include <sys/malloc.h> 42 #include <sys/kernel.h> 43 #include <sys/module.h> 44 #include <sys/endian.h> 45 46 #include <sys/socket.h> 47 48 #include <net/if.h> 49 #include <net/if_media.h> 50 #include <net/ethernet.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, M_NOWAIT); 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 (k->wk_flags & IEEE80211_KEY_NOREPLAY) == 0) { 286 /* 287 * Replay violation; notify upper layer. 288 */ 289 ieee80211_notify_replay_failure(vap, wh, k, ctx->rx_rsc, tid); 290 vap->iv_stats.is_rx_tkipreplay++; 291 return 0; 292 } 293 /* 294 * NB: We can't update the rsc in the key until MIC is verified. 295 * 296 * We assume we are not preempted between doing the check above 297 * and updating wk_keyrsc when stripping the MIC in tkip_demic. 298 * Otherwise we might process another packet and discard it as 299 * a replay. 300 */ 301 302 /* 303 * Check if the device handled the decrypt in hardware. 304 * If so we just strip the header; otherwise we need to 305 * handle the decrypt in software. 306 */ 307 if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) && 308 !tkip_decrypt(ctx, k, m, hdrlen)) 309 return 0; 310 311 /* 312 * Copy up 802.11 header and strip crypto bits. 313 */ 314 memmove(mtod(m, uint8_t *) + tkip.ic_header, mtod(m, void *), hdrlen); 315 m_adj(m, tkip.ic_header); 316 m_adj(m, -tkip.ic_trailer); 317 318 return 1; 319 } 320 321 /* 322 * Verify and strip MIC from the frame. 323 */ 324 static int 325 tkip_demic(struct ieee80211_key *k, struct mbuf *m, int force) 326 { 327 struct tkip_ctx *ctx = k->wk_private; 328 struct ieee80211_frame *wh; 329 uint8_t tid; 330 331 wh = mtod(m, struct ieee80211_frame *); 332 if ((k->wk_flags & IEEE80211_KEY_SWDEMIC) || force) { 333 struct ieee80211vap *vap = ctx->tc_vap; 334 int hdrlen = ieee80211_hdrspace(vap->iv_ic, wh); 335 u8 mic[IEEE80211_WEP_MICLEN]; 336 u8 mic0[IEEE80211_WEP_MICLEN]; 337 338 vap->iv_stats.is_crypto_tkipdemic++; 339 340 michael_mic(ctx, k->wk_rxmic, 341 m, hdrlen, m->m_pkthdr.len - (hdrlen + tkip.ic_miclen), 342 mic); 343 m_copydata(m, m->m_pkthdr.len - tkip.ic_miclen, 344 tkip.ic_miclen, mic0); 345 if (memcmp(mic, mic0, tkip.ic_miclen)) { 346 /* NB: 802.11 layer handles statistic and debug msg */ 347 ieee80211_notify_michael_failure(vap, wh, 348 k->wk_rxkeyix != IEEE80211_KEYIX_NONE ? 349 k->wk_rxkeyix : k->wk_keyix); 350 return 0; 351 } 352 } 353 /* 354 * Strip MIC from the tail. 355 */ 356 m_adj(m, -tkip.ic_miclen); 357 358 /* 359 * Ok to update rsc now that MIC has been verified. 360 */ 361 tid = ieee80211_gettid(wh); 362 k->wk_keyrsc[tid] = ctx->rx_rsc; 363 364 return 1; 365 } 366 367 /* 368 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver 369 * 370 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 371 * 372 * This program is free software; you can redistribute it and/or modify 373 * it under the terms of the GNU General Public License version 2 as 374 * published by the Free Software Foundation. See README and COPYING for 375 * more details. 376 * 377 * Alternatively, this software may be distributed under the terms of BSD 378 * license. 379 */ 380 381 static const __u32 crc32_table[256] = { 382 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 383 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 384 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 385 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 386 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 387 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 388 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 389 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 390 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 391 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 392 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 393 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 394 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 395 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 396 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 397 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 398 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 399 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 400 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 401 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 402 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 403 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 404 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 405 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 406 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 407 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 408 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 409 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 410 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 411 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 412 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 413 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 414 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 415 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 416 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 417 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 418 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 419 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 420 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 421 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 422 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 423 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 424 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 425 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 426 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 427 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 428 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 429 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 430 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 431 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 432 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 433 0x2d02ef8dL 434 }; 435 436 static __inline u16 RotR1(u16 val) 437 { 438 return (val >> 1) | (val << 15); 439 } 440 441 static __inline u8 Lo8(u16 val) 442 { 443 return val & 0xff; 444 } 445 446 static __inline u8 Hi8(u16 val) 447 { 448 return val >> 8; 449 } 450 451 static __inline u16 Lo16(u32 val) 452 { 453 return val & 0xffff; 454 } 455 456 static __inline u16 Hi16(u32 val) 457 { 458 return val >> 16; 459 } 460 461 static __inline u16 Mk16(u8 hi, u8 lo) 462 { 463 return lo | (((u16) hi) << 8); 464 } 465 466 static __inline u16 Mk16_le(const u16 *v) 467 { 468 return le16toh(*v); 469 } 470 471 static const u16 Sbox[256] = { 472 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 473 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 474 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 475 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 476 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 477 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 478 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 479 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 480 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 481 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 482 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 483 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 484 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 485 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 486 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 487 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 488 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 489 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 490 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 491 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 492 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 493 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 494 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 495 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 496 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 497 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 498 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 499 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 500 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 501 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 502 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 503 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, 504 }; 505 506 static __inline u16 _S_(u16 v) 507 { 508 u16 t = Sbox[Hi8(v)]; 509 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); 510 } 511 512 #define PHASE1_LOOP_COUNT 8 513 514 static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32) 515 { 516 int i, j; 517 518 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ 519 TTAK[0] = Lo16(IV32); 520 TTAK[1] = Hi16(IV32); 521 TTAK[2] = Mk16(TA[1], TA[0]); 522 TTAK[3] = Mk16(TA[3], TA[2]); 523 TTAK[4] = Mk16(TA[5], TA[4]); 524 525 for (i = 0; i < PHASE1_LOOP_COUNT; i++) { 526 j = 2 * (i & 1); 527 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); 528 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); 529 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); 530 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); 531 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; 532 } 533 } 534 535 #ifndef _BYTE_ORDER 536 #error "Don't know native byte order" 537 #endif 538 539 static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, 540 u16 IV16) 541 { 542 /* Make temporary area overlap WEP seed so that the final copy can be 543 * avoided on little endian hosts. */ 544 u16 *PPK = (u16 *) &WEPSeed[4]; 545 546 /* Step 1 - make copy of TTAK and bring in TSC */ 547 PPK[0] = TTAK[0]; 548 PPK[1] = TTAK[1]; 549 PPK[2] = TTAK[2]; 550 PPK[3] = TTAK[3]; 551 PPK[4] = TTAK[4]; 552 PPK[5] = TTAK[4] + IV16; 553 554 /* Step 2 - 96-bit bijective mixing using S-box */ 555 PPK[0] += _S_(PPK[5] ^ Mk16_le((const u16 *) &TK[0])); 556 PPK[1] += _S_(PPK[0] ^ Mk16_le((const u16 *) &TK[2])); 557 PPK[2] += _S_(PPK[1] ^ Mk16_le((const u16 *) &TK[4])); 558 PPK[3] += _S_(PPK[2] ^ Mk16_le((const u16 *) &TK[6])); 559 PPK[4] += _S_(PPK[3] ^ Mk16_le((const u16 *) &TK[8])); 560 PPK[5] += _S_(PPK[4] ^ Mk16_le((const u16 *) &TK[10])); 561 562 PPK[0] += RotR1(PPK[5] ^ Mk16_le((const u16 *) &TK[12])); 563 PPK[1] += RotR1(PPK[0] ^ Mk16_le((const u16 *) &TK[14])); 564 PPK[2] += RotR1(PPK[1]); 565 PPK[3] += RotR1(PPK[2]); 566 PPK[4] += RotR1(PPK[3]); 567 PPK[5] += RotR1(PPK[4]); 568 569 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value 570 * WEPSeed[0..2] is transmitted as WEP IV */ 571 WEPSeed[0] = Hi8(IV16); 572 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; 573 WEPSeed[2] = Lo8(IV16); 574 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((const u16 *) &TK[0])) >> 1); 575 576 #if _BYTE_ORDER == _BIG_ENDIAN 577 { 578 int i; 579 for (i = 0; i < 6; i++) 580 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); 581 } 582 #endif 583 } 584 585 static void 586 wep_encrypt(u8 *key, struct mbuf *m0, u_int off, size_t data_len, 587 uint8_t icv[IEEE80211_WEP_CRCLEN]) 588 { 589 u32 i, j, k, crc; 590 size_t buflen; 591 u8 S[256]; 592 u8 *pos; 593 struct mbuf *m; 594 #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0) 595 596 /* Setup RC4 state */ 597 for (i = 0; i < 256; i++) 598 S[i] = i; 599 j = 0; 600 for (i = 0; i < 256; i++) { 601 j = (j + S[i] + key[i & 0x0f]) & 0xff; 602 S_SWAP(i, j); 603 } 604 605 /* Compute CRC32 over unencrypted data and apply RC4 to data */ 606 crc = ~0; 607 i = j = 0; 608 m = m0; 609 pos = mtod(m, uint8_t *) + off; 610 buflen = m->m_len - off; 611 for (;;) { 612 if (buflen > data_len) 613 buflen = data_len; 614 data_len -= buflen; 615 for (k = 0; k < buflen; k++) { 616 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 617 i = (i + 1) & 0xff; 618 j = (j + S[i]) & 0xff; 619 S_SWAP(i, j); 620 *pos++ ^= S[(S[i] + S[j]) & 0xff]; 621 } 622 m = m->m_next; 623 if (m == NULL) { 624 KASSERT(data_len == 0, 625 ("out of buffers with data_len %zu\n", data_len)); 626 break; 627 } 628 pos = mtod(m, uint8_t *); 629 buflen = m->m_len; 630 } 631 crc = ~crc; 632 633 /* Append little-endian CRC32 and encrypt it to produce ICV */ 634 icv[0] = crc; 635 icv[1] = crc >> 8; 636 icv[2] = crc >> 16; 637 icv[3] = crc >> 24; 638 for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) { 639 i = (i + 1) & 0xff; 640 j = (j + S[i]) & 0xff; 641 S_SWAP(i, j); 642 icv[k] ^= S[(S[i] + S[j]) & 0xff]; 643 } 644 } 645 646 static int 647 wep_decrypt(u8 *key, struct mbuf *m, u_int off, size_t data_len) 648 { 649 u32 i, j, k, crc; 650 u8 S[256]; 651 u8 *pos, icv[4]; 652 size_t buflen; 653 654 /* Setup RC4 state */ 655 for (i = 0; i < 256; i++) 656 S[i] = i; 657 j = 0; 658 for (i = 0; i < 256; i++) { 659 j = (j + S[i] + key[i & 0x0f]) & 0xff; 660 S_SWAP(i, j); 661 } 662 663 /* Apply RC4 to data and compute CRC32 over decrypted data */ 664 crc = ~0; 665 i = j = 0; 666 pos = mtod(m, uint8_t *) + off; 667 buflen = m->m_len - off; 668 for (;;) { 669 if (buflen > data_len) 670 buflen = data_len; 671 data_len -= buflen; 672 for (k = 0; k < buflen; k++) { 673 i = (i + 1) & 0xff; 674 j = (j + S[i]) & 0xff; 675 S_SWAP(i, j); 676 *pos ^= S[(S[i] + S[j]) & 0xff]; 677 crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8); 678 pos++; 679 } 680 m = m->m_next; 681 if (m == NULL) { 682 KASSERT(data_len == 0, 683 ("out of buffers with data_len %zu\n", data_len)); 684 break; 685 } 686 pos = mtod(m, uint8_t *); 687 buflen = m->m_len; 688 } 689 crc = ~crc; 690 691 /* Encrypt little-endian CRC32 and verify that it matches with the 692 * received ICV */ 693 icv[0] = crc; 694 icv[1] = crc >> 8; 695 icv[2] = crc >> 16; 696 icv[3] = crc >> 24; 697 for (k = 0; k < 4; k++) { 698 i = (i + 1) & 0xff; 699 j = (j + S[i]) & 0xff; 700 S_SWAP(i, j); 701 if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) { 702 /* ICV mismatch - drop frame */ 703 return -1; 704 } 705 } 706 707 return 0; 708 } 709 710 711 static __inline u32 rotl(u32 val, int bits) 712 { 713 return (val << bits) | (val >> (32 - bits)); 714 } 715 716 717 static __inline u32 rotr(u32 val, int bits) 718 { 719 return (val >> bits) | (val << (32 - bits)); 720 } 721 722 723 static __inline u32 xswap(u32 val) 724 { 725 return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8); 726 } 727 728 729 #define michael_block(l, r) \ 730 do { \ 731 r ^= rotl(l, 17); \ 732 l += r; \ 733 r ^= xswap(l); \ 734 l += r; \ 735 r ^= rotl(l, 3); \ 736 l += r; \ 737 r ^= rotr(l, 2); \ 738 l += r; \ 739 } while (0) 740 741 742 static __inline u32 get_le32_split(u8 b0, u8 b1, u8 b2, u8 b3) 743 { 744 return b0 | (b1 << 8) | (b2 << 16) | (b3 << 24); 745 } 746 747 static __inline u32 get_le32(const u8 *p) 748 { 749 return get_le32_split(p[0], p[1], p[2], p[3]); 750 } 751 752 753 static __inline void put_le32(u8 *p, u32 v) 754 { 755 p[0] = v; 756 p[1] = v >> 8; 757 p[2] = v >> 16; 758 p[3] = v >> 24; 759 } 760 761 /* 762 * Craft pseudo header used to calculate the MIC. 763 */ 764 static void 765 michael_mic_hdr(const struct ieee80211_frame *wh0, uint8_t hdr[16]) 766 { 767 const struct ieee80211_frame_addr4 *wh = 768 (const struct ieee80211_frame_addr4 *) wh0; 769 770 switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { 771 case IEEE80211_FC1_DIR_NODS: 772 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 773 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 774 break; 775 case IEEE80211_FC1_DIR_TODS: 776 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 777 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2); 778 break; 779 case IEEE80211_FC1_DIR_FROMDS: 780 IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */ 781 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr3); 782 break; 783 case IEEE80211_FC1_DIR_DSTODS: 784 IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */ 785 IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr4); 786 break; 787 } 788 789 if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS) { 790 const struct ieee80211_qosframe *qwh = 791 (const struct ieee80211_qosframe *) wh; 792 hdr[12] = qwh->i_qos[0] & IEEE80211_QOS_TID; 793 } else 794 hdr[12] = 0; 795 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ 796 } 797 798 static void 799 michael_mic(struct tkip_ctx *ctx, const u8 *key, 800 struct mbuf *m, u_int off, size_t data_len, 801 u8 mic[IEEE80211_WEP_MICLEN]) 802 { 803 uint8_t hdr[16]; 804 u32 l, r; 805 const uint8_t *data; 806 u_int space; 807 808 michael_mic_hdr(mtod(m, struct ieee80211_frame *), hdr); 809 810 l = get_le32(key); 811 r = get_le32(key + 4); 812 813 /* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */ 814 l ^= get_le32(hdr); 815 michael_block(l, r); 816 l ^= get_le32(&hdr[4]); 817 michael_block(l, r); 818 l ^= get_le32(&hdr[8]); 819 michael_block(l, r); 820 l ^= get_le32(&hdr[12]); 821 michael_block(l, r); 822 823 /* first buffer has special handling */ 824 data = mtod(m, const uint8_t *) + off; 825 space = m->m_len - off; 826 for (;;) { 827 if (space > data_len) 828 space = data_len; 829 /* collect 32-bit blocks from current buffer */ 830 while (space >= sizeof(uint32_t)) { 831 l ^= get_le32(data); 832 michael_block(l, r); 833 data += sizeof(uint32_t), space -= sizeof(uint32_t); 834 data_len -= sizeof(uint32_t); 835 } 836 /* 837 * NB: when space is zero we make one more trip around 838 * the loop to advance to the next mbuf where there is 839 * data. This handles the case where there are 4*n 840 * bytes in an mbuf followed by <4 bytes in a later mbuf. 841 * By making an extra trip we'll drop out of the loop 842 * with m pointing at the mbuf with 3 bytes and space 843 * set as required by the remainder handling below. 844 */ 845 if (data_len == 0 || 846 (data_len < sizeof(uint32_t) && space != 0)) 847 break; 848 m = m->m_next; 849 if (m == NULL) { 850 KASSERT(0, ("out of data, data_len %zu\n", data_len)); 851 break; 852 } 853 if (space != 0) { 854 const uint8_t *data_next; 855 /* 856 * Block straddles buffers, split references. 857 */ 858 data_next = mtod(m, const uint8_t *); 859 KASSERT(m->m_len >= sizeof(uint32_t) - space, 860 ("not enough data in following buffer, " 861 "m_len %u need %zu\n", m->m_len, 862 sizeof(uint32_t) - space)); 863 switch (space) { 864 case 1: 865 l ^= get_le32_split(data[0], data_next[0], 866 data_next[1], data_next[2]); 867 data = data_next + 3; 868 space = m->m_len - 3; 869 break; 870 case 2: 871 l ^= get_le32_split(data[0], data[1], 872 data_next[0], data_next[1]); 873 data = data_next + 2; 874 space = m->m_len - 2; 875 break; 876 case 3: 877 l ^= get_le32_split(data[0], data[1], 878 data[2], data_next[0]); 879 data = data_next + 1; 880 space = m->m_len - 1; 881 break; 882 } 883 michael_block(l, r); 884 data_len -= sizeof(uint32_t); 885 } else { 886 /* 887 * Setup for next buffer. 888 */ 889 data = mtod(m, const uint8_t *); 890 space = m->m_len; 891 } 892 } 893 /* 894 * Catch degenerate cases like mbuf[4*n+1 bytes] followed by 895 * mbuf[2 bytes]. I don't believe these should happen; if they 896 * do then we'll need more involved logic. 897 */ 898 KASSERT(data_len <= space, 899 ("not enough data, data_len %zu space %u\n", data_len, space)); 900 901 /* Last block and padding (0x5a, 4..7 x 0) */ 902 switch (data_len) { 903 case 0: 904 l ^= get_le32_split(0x5a, 0, 0, 0); 905 break; 906 case 1: 907 l ^= get_le32_split(data[0], 0x5a, 0, 0); 908 break; 909 case 2: 910 l ^= get_le32_split(data[0], data[1], 0x5a, 0); 911 break; 912 case 3: 913 l ^= get_le32_split(data[0], data[1], data[2], 0x5a); 914 break; 915 } 916 michael_block(l, r); 917 /* l ^= 0; */ 918 michael_block(l, r); 919 920 put_le32(mic, l); 921 put_le32(mic + 4, r); 922 } 923 924 static int 925 tkip_encrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 926 struct mbuf *m, int hdrlen) 927 { 928 struct ieee80211_frame *wh; 929 uint8_t icv[IEEE80211_WEP_CRCLEN]; 930 931 ctx->tc_vap->iv_stats.is_crypto_tkip++; 932 933 wh = mtod(m, struct ieee80211_frame *); 934 if (!ctx->tx_phase1_done) { 935 tkip_mixing_phase1(ctx->tx_ttak, key->wk_key, wh->i_addr2, 936 (u32)(key->wk_keytsc >> 16)); 937 ctx->tx_phase1_done = 1; 938 } 939 tkip_mixing_phase2(ctx->tx_rc4key, key->wk_key, ctx->tx_ttak, 940 (u16) key->wk_keytsc); 941 942 wep_encrypt(ctx->tx_rc4key, 943 m, hdrlen + tkip.ic_header, 944 m->m_pkthdr.len - (hdrlen + tkip.ic_header), 945 icv); 946 (void) m_append(m, IEEE80211_WEP_CRCLEN, icv); /* XXX check return */ 947 948 key->wk_keytsc++; 949 if ((u16)(key->wk_keytsc) == 0) 950 ctx->tx_phase1_done = 0; 951 return 1; 952 } 953 954 static int 955 tkip_decrypt(struct tkip_ctx *ctx, struct ieee80211_key *key, 956 struct mbuf *m, int hdrlen) 957 { 958 struct ieee80211_frame *wh; 959 struct ieee80211vap *vap = ctx->tc_vap; 960 u32 iv32; 961 u16 iv16; 962 u8 tid; 963 964 vap->iv_stats.is_crypto_tkip++; 965 966 wh = mtod(m, struct ieee80211_frame *); 967 /* NB: tkip_decap already verified header and left seq in rx_rsc */ 968 iv16 = (u16) ctx->rx_rsc; 969 iv32 = (u32) (ctx->rx_rsc >> 16); 970 971 tid = ieee80211_gettid(wh); 972 if (iv32 != (u32)(key->wk_keyrsc[tid] >> 16) || !ctx->rx_phase1_done) { 973 tkip_mixing_phase1(ctx->rx_ttak, key->wk_key, 974 wh->i_addr2, iv32); 975 ctx->rx_phase1_done = 1; 976 } 977 tkip_mixing_phase2(ctx->rx_rc4key, key->wk_key, ctx->rx_ttak, iv16); 978 979 /* NB: m is unstripped; deduct headers + ICV to get payload */ 980 if (wep_decrypt(ctx->rx_rc4key, 981 m, hdrlen + tkip.ic_header, 982 m->m_pkthdr.len - (hdrlen + tkip.ic_header + tkip.ic_trailer))) { 983 if (iv32 != (u32)(key->wk_keyrsc[tid] >> 16)) { 984 /* Previously cached Phase1 result was already lost, so 985 * it needs to be recalculated for the next packet. */ 986 ctx->rx_phase1_done = 0; 987 } 988 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 989 "%s", "TKIP ICV mismatch on decrypt"); 990 vap->iv_stats.is_rx_tkipicv++; 991 return 0; 992 } 993 return 1; 994 } 995 996 /* 997 * Module glue. 998 */ 999 IEEE80211_CRYPTO_MODULE(tkip, 1); 1000