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 AES-CCMP 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 45 #include <sys/socket.h> 46 47 #include <net/if.h> 48 #include <net/if_media.h> 49 #include <net/ethernet.h> 50 51 #include <net80211/ieee80211_var.h> 52 53 #include <crypto/rijndael/rijndael.h> 54 55 #define AES_BLOCK_LEN 16 56 57 struct ccmp_ctx { 58 struct ieee80211vap *cc_vap; /* for diagnostics+statistics */ 59 struct ieee80211com *cc_ic; 60 rijndael_ctx cc_aes; 61 }; 62 63 static void *ccmp_attach(struct ieee80211vap *, struct ieee80211_key *); 64 static void ccmp_detach(struct ieee80211_key *); 65 static int ccmp_setkey(struct ieee80211_key *); 66 static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, uint8_t keyid); 67 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); 68 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); 69 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); 70 71 static const struct ieee80211_cipher ccmp = { 72 .ic_name = "AES-CCM", 73 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 74 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 75 IEEE80211_WEP_EXTIVLEN, 76 .ic_trailer = IEEE80211_WEP_MICLEN, 77 .ic_miclen = 0, 78 .ic_attach = ccmp_attach, 79 .ic_detach = ccmp_detach, 80 .ic_setkey = ccmp_setkey, 81 .ic_encap = ccmp_encap, 82 .ic_decap = ccmp_decap, 83 .ic_enmic = ccmp_enmic, 84 .ic_demic = ccmp_demic, 85 }; 86 87 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 88 static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 89 struct mbuf *, int hdrlen); 90 91 /* number of references from net80211 layer */ 92 static int nrefs = 0; 93 94 static void * 95 ccmp_attach(struct ieee80211vap *vap, struct ieee80211_key *k) 96 { 97 struct ccmp_ctx *ctx; 98 99 ctx = (struct ccmp_ctx *) IEEE80211_MALLOC(sizeof(struct ccmp_ctx), 100 M_80211_CRYPTO, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 101 if (ctx == NULL) { 102 vap->iv_stats.is_crypto_nomem++; 103 return NULL; 104 } 105 ctx->cc_vap = vap; 106 ctx->cc_ic = vap->iv_ic; 107 nrefs++; /* NB: we assume caller locking */ 108 return ctx; 109 } 110 111 static void 112 ccmp_detach(struct ieee80211_key *k) 113 { 114 struct ccmp_ctx *ctx = k->wk_private; 115 116 IEEE80211_FREE(ctx, M_80211_CRYPTO); 117 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 118 nrefs--; /* NB: we assume caller locking */ 119 } 120 121 static int 122 ccmp_setkey(struct ieee80211_key *k) 123 { 124 struct ccmp_ctx *ctx = k->wk_private; 125 126 if (k->wk_keylen != (128/NBBY)) { 127 IEEE80211_DPRINTF(ctx->cc_vap, IEEE80211_MSG_CRYPTO, 128 "%s: Invalid key length %u, expecting %u\n", 129 __func__, k->wk_keylen, 128/NBBY); 130 return 0; 131 } 132 if (k->wk_flags & IEEE80211_KEY_SWENCRYPT) 133 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY); 134 return 1; 135 } 136 137 /* 138 * Add privacy headers appropriate for the specified key. 139 */ 140 static int 141 ccmp_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid) 142 { 143 struct ccmp_ctx *ctx = k->wk_private; 144 struct ieee80211com *ic = ctx->cc_ic; 145 uint8_t *ivp; 146 int hdrlen; 147 148 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 149 150 /* 151 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 152 */ 153 M_PREPEND(m, ccmp.ic_header, M_NOWAIT); 154 if (m == NULL) 155 return 0; 156 ivp = mtod(m, uint8_t *); 157 ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen); 158 ivp += hdrlen; 159 160 k->wk_keytsc++; /* XXX wrap at 48 bits */ 161 ivp[0] = k->wk_keytsc >> 0; /* PN0 */ 162 ivp[1] = k->wk_keytsc >> 8; /* PN1 */ 163 ivp[2] = 0; /* Reserved */ 164 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 165 ivp[4] = k->wk_keytsc >> 16; /* PN2 */ 166 ivp[5] = k->wk_keytsc >> 24; /* PN3 */ 167 ivp[6] = k->wk_keytsc >> 32; /* PN4 */ 168 ivp[7] = k->wk_keytsc >> 40; /* PN5 */ 169 170 /* 171 * Finally, do software encrypt if neeed. 172 */ 173 if ((k->wk_flags & IEEE80211_KEY_SWENCRYPT) && 174 !ccmp_encrypt(k, m, hdrlen)) 175 return 0; 176 177 return 1; 178 } 179 180 /* 181 * Add MIC to the frame as needed. 182 */ 183 static int 184 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 185 { 186 187 return 1; 188 } 189 190 static __inline uint64_t 191 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 192 { 193 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 194 uint16_t iv16 = (b4 << 0) | (b5 << 8); 195 return (((uint64_t)iv16) << 32) | iv32; 196 } 197 198 /* 199 * Validate and strip privacy headers (and trailer) for a 200 * received frame. The specified key should be correct but 201 * is also verified. 202 */ 203 static int 204 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 205 { 206 struct ccmp_ctx *ctx = k->wk_private; 207 struct ieee80211vap *vap = ctx->cc_vap; 208 struct ieee80211_frame *wh; 209 uint8_t *ivp, tid; 210 uint64_t pn; 211 212 /* 213 * Header should have extended IV and sequence number; 214 * verify the former and validate the latter. 215 */ 216 wh = mtod(m, struct ieee80211_frame *); 217 ivp = mtod(m, uint8_t *) + hdrlen; 218 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 219 /* 220 * No extended IV; discard frame. 221 */ 222 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 223 "%s", "missing ExtIV for AES-CCM cipher"); 224 vap->iv_stats.is_rx_ccmpformat++; 225 return 0; 226 } 227 tid = ieee80211_gettid(wh); 228 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 229 if (pn <= k->wk_keyrsc[tid] && 230 (k->wk_flags & IEEE80211_KEY_NOREPLAY) == 0) { 231 /* 232 * Replay violation. 233 */ 234 ieee80211_notify_replay_failure(vap, wh, k, pn, tid); 235 vap->iv_stats.is_rx_ccmpreplay++; 236 return 0; 237 } 238 239 /* 240 * Check if the device handled the decrypt in hardware. 241 * If so we just strip the header; otherwise we need to 242 * handle the decrypt in software. Note that for the 243 * latter we leave the header in place for use in the 244 * decryption work. 245 */ 246 if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) && 247 !ccmp_decrypt(k, pn, m, hdrlen)) 248 return 0; 249 250 /* 251 * Copy up 802.11 header and strip crypto bits. 252 */ 253 ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp.ic_header, hdrlen); 254 m_adj(m, ccmp.ic_header); 255 m_adj(m, -ccmp.ic_trailer); 256 257 /* 258 * Ok to update rsc now. 259 */ 260 k->wk_keyrsc[tid] = pn; 261 262 return 1; 263 } 264 265 /* 266 * Verify and strip MIC from the frame. 267 */ 268 static int 269 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) 270 { 271 return 1; 272 } 273 274 static __inline void 275 xor_block(uint8_t *b, const uint8_t *a, size_t len) 276 { 277 int i; 278 for (i = 0; i < len; i++) 279 b[i] ^= a[i]; 280 } 281 282 /* 283 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 284 * 285 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 286 * 287 * This program is free software; you can redistribute it and/or modify 288 * it under the terms of the GNU General Public License version 2 as 289 * published by the Free Software Foundation. See README and COPYING for 290 * more details. 291 * 292 * Alternatively, this software may be distributed under the terms of BSD 293 * license. 294 */ 295 296 static void 297 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 298 u_int64_t pn, size_t dlen, 299 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 300 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 301 { 302 #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 303 304 /* CCM Initial Block: 305 * Flag (Include authentication header, M=3 (8-octet MIC), 306 * L=1 (2-octet Dlen)) 307 * Nonce: 0x00 | A2 | PN 308 * Dlen */ 309 b0[0] = 0x59; 310 /* NB: b0[1] set below */ 311 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 312 b0[8] = pn >> 40; 313 b0[9] = pn >> 32; 314 b0[10] = pn >> 24; 315 b0[11] = pn >> 16; 316 b0[12] = pn >> 8; 317 b0[13] = pn >> 0; 318 b0[14] = (dlen >> 8) & 0xff; 319 b0[15] = dlen & 0xff; 320 321 /* AAD: 322 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 323 * A1 | A2 | A3 324 * SC with bits 4..15 (seq#) masked to zero 325 * A4 (if present) 326 * QC (if present) 327 */ 328 aad[0] = 0; /* AAD length >> 8 */ 329 /* NB: aad[1] set below */ 330 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 331 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 332 /* NB: we know 3 addresses are contiguous */ 333 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 334 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 335 aad[23] = 0; /* all bits masked */ 336 /* 337 * Construct variable-length portion of AAD based 338 * on whether this is a 4-address frame/QOS frame. 339 * We always zero-pad to 32 bytes before running it 340 * through the cipher. 341 * 342 * We also fill in the priority bits of the CCM 343 * initial block as we know whether or not we have 344 * a QOS frame. 345 */ 346 if (IEEE80211_IS_DSTODS(wh)) { 347 IEEE80211_ADDR_COPY(aad + 24, 348 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 349 if (IS_QOS_DATA(wh)) { 350 struct ieee80211_qosframe_addr4 *qwh4 = 351 (struct ieee80211_qosframe_addr4 *) wh; 352 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 353 aad[31] = 0; 354 b0[1] = aad[30]; 355 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 356 } else { 357 *(uint16_t *)&aad[30] = 0; 358 b0[1] = 0; 359 aad[1] = 22 + IEEE80211_ADDR_LEN; 360 } 361 } else { 362 if (IS_QOS_DATA(wh)) { 363 struct ieee80211_qosframe *qwh = 364 (struct ieee80211_qosframe*) wh; 365 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 366 aad[25] = 0; 367 b0[1] = aad[24]; 368 aad[1] = 22 + 2; 369 } else { 370 *(uint16_t *)&aad[24] = 0; 371 b0[1] = 0; 372 aad[1] = 22; 373 } 374 *(uint16_t *)&aad[26] = 0; 375 *(uint32_t *)&aad[28] = 0; 376 } 377 378 /* Start with the first block and AAD */ 379 rijndael_encrypt(ctx, b0, auth); 380 xor_block(auth, aad, AES_BLOCK_LEN); 381 rijndael_encrypt(ctx, auth, auth); 382 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 383 rijndael_encrypt(ctx, auth, auth); 384 b0[0] &= 0x07; 385 b0[14] = b0[15] = 0; 386 rijndael_encrypt(ctx, b0, s0); 387 #undef IS_QOS_DATA 388 } 389 390 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 391 /* Authentication */ \ 392 xor_block(_b, _pos, _len); \ 393 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 394 /* Encryption, with counter */ \ 395 _b0[14] = (_i >> 8) & 0xff; \ 396 _b0[15] = _i & 0xff; \ 397 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 398 xor_block(_pos, _e, _len); \ 399 } while (0) 400 401 static int 402 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 403 { 404 struct ccmp_ctx *ctx = key->wk_private; 405 struct ieee80211_frame *wh; 406 struct mbuf *m = m0; 407 int data_len, i, space; 408 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 409 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 410 uint8_t *pos; 411 412 ctx->cc_vap->iv_stats.is_crypto_ccmp++; 413 414 wh = mtod(m, struct ieee80211_frame *); 415 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header); 416 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc, 417 data_len, b0, aad, b, s0); 418 419 i = 1; 420 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 421 /* NB: assumes header is entirely in first mbuf */ 422 space = m->m_len - (hdrlen + ccmp.ic_header); 423 for (;;) { 424 if (space > data_len) 425 space = data_len; 426 /* 427 * Do full blocks. 428 */ 429 while (space >= AES_BLOCK_LEN) { 430 CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN); 431 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 432 data_len -= AES_BLOCK_LEN; 433 i++; 434 } 435 if (data_len <= 0) /* no more data */ 436 break; 437 m = m->m_next; 438 if (m == NULL) { /* last buffer */ 439 if (space != 0) { 440 /* 441 * Short last block. 442 */ 443 CCMP_ENCRYPT(i, b, b0, pos, e, space); 444 } 445 break; 446 } 447 if (space != 0) { 448 uint8_t *pos_next; 449 int space_next; 450 int len, dl, sp; 451 struct mbuf *n; 452 453 /* 454 * Block straddles one or more mbufs, gather data 455 * into the block buffer b, apply the cipher, then 456 * scatter the results back into the mbuf chain. 457 * The buffer will automatically get space bytes 458 * of data at offset 0 copied in+out by the 459 * CCMP_ENCRYPT request so we must take care of 460 * the remaining data. 461 */ 462 n = m; 463 dl = data_len; 464 sp = space; 465 for (;;) { 466 pos_next = mtod(n, uint8_t *); 467 len = min(dl, AES_BLOCK_LEN); 468 space_next = len > sp ? len - sp : 0; 469 if (n->m_len >= space_next) { 470 /* 471 * This mbuf has enough data; just grab 472 * what we need and stop. 473 */ 474 xor_block(b+sp, pos_next, space_next); 475 break; 476 } 477 /* 478 * This mbuf's contents are insufficient, 479 * take 'em all and prepare to advance to 480 * the next mbuf. 481 */ 482 xor_block(b+sp, pos_next, n->m_len); 483 sp += n->m_len, dl -= n->m_len; 484 n = n->m_next; 485 if (n == NULL) 486 break; 487 } 488 489 CCMP_ENCRYPT(i, b, b0, pos, e, space); 490 491 /* NB: just like above, but scatter data to mbufs */ 492 dl = data_len; 493 sp = space; 494 for (;;) { 495 pos_next = mtod(m, uint8_t *); 496 len = min(dl, AES_BLOCK_LEN); 497 space_next = len > sp ? len - sp : 0; 498 if (m->m_len >= space_next) { 499 xor_block(pos_next, e+sp, space_next); 500 break; 501 } 502 xor_block(pos_next, e+sp, m->m_len); 503 sp += m->m_len, dl -= m->m_len; 504 m = m->m_next; 505 if (m == NULL) 506 goto done; 507 } 508 /* 509 * Do bookkeeping. m now points to the last mbuf 510 * we grabbed data from. We know we consumed a 511 * full block of data as otherwise we'd have hit 512 * the end of the mbuf chain, so deduct from data_len. 513 * Otherwise advance the block number (i) and setup 514 * pos+space to reflect contents of the new mbuf. 515 */ 516 data_len -= AES_BLOCK_LEN; 517 i++; 518 pos = pos_next + space_next; 519 space = m->m_len - space_next; 520 } else { 521 /* 522 * Setup for next buffer. 523 */ 524 pos = mtod(m, uint8_t *); 525 space = m->m_len; 526 } 527 } 528 done: 529 /* tack on MIC */ 530 xor_block(b, s0, ccmp.ic_trailer); 531 return m_append(m0, ccmp.ic_trailer, b); 532 } 533 #undef CCMP_ENCRYPT 534 535 #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 536 /* Decrypt, with counter */ \ 537 _b0[14] = (_i >> 8) & 0xff; \ 538 _b0[15] = _i & 0xff; \ 539 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 540 xor_block(_pos, _b, _len); \ 541 /* Authentication */ \ 542 xor_block(_a, _pos, _len); \ 543 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 544 } while (0) 545 546 static int 547 ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) 548 { 549 struct ccmp_ctx *ctx = key->wk_private; 550 struct ieee80211vap *vap = ctx->cc_vap; 551 struct ieee80211_frame *wh; 552 uint8_t aad[2 * AES_BLOCK_LEN]; 553 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 554 uint8_t mic[AES_BLOCK_LEN]; 555 size_t data_len; 556 int i; 557 uint8_t *pos; 558 u_int space; 559 560 ctx->cc_vap->iv_stats.is_crypto_ccmp++; 561 562 wh = mtod(m, struct ieee80211_frame *); 563 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 564 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 565 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 566 xor_block(mic, b, ccmp.ic_trailer); 567 568 i = 1; 569 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 570 space = m->m_len - (hdrlen + ccmp.ic_header); 571 for (;;) { 572 if (space > data_len) 573 space = data_len; 574 while (space >= AES_BLOCK_LEN) { 575 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 576 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 577 data_len -= AES_BLOCK_LEN; 578 i++; 579 } 580 if (data_len <= 0) /* no more data */ 581 break; 582 m = m->m_next; 583 if (m == NULL) { /* last buffer */ 584 if (space != 0) /* short last block */ 585 CCMP_DECRYPT(i, b, b0, pos, a, space); 586 break; 587 } 588 if (space != 0) { 589 uint8_t *pos_next; 590 u_int space_next; 591 u_int len; 592 593 /* 594 * Block straddles buffers, split references. We 595 * do not handle splits that require >2 buffers 596 * since rx'd frames are never badly fragmented 597 * because drivers typically recv in clusters. 598 */ 599 pos_next = mtod(m, uint8_t *); 600 len = min(data_len, AES_BLOCK_LEN); 601 space_next = len > space ? len - space : 0; 602 KASSERT(m->m_len >= space_next, 603 ("not enough data in following buffer, " 604 "m_len %u need %u\n", m->m_len, space_next)); 605 606 xor_block(b+space, pos_next, space_next); 607 CCMP_DECRYPT(i, b, b0, pos, a, space); 608 xor_block(pos_next, b+space, space_next); 609 data_len -= len; 610 i++; 611 612 pos = pos_next + space_next; 613 space = m->m_len - space_next; 614 } else { 615 /* 616 * Setup for next buffer. 617 */ 618 pos = mtod(m, uint8_t *); 619 space = m->m_len; 620 } 621 } 622 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 623 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2, 624 "%s", "AES-CCM decrypt failed; MIC mismatch"); 625 vap->iv_stats.is_rx_ccmpmic++; 626 return 0; 627 } 628 return 1; 629 } 630 #undef CCMP_DECRYPT 631 632 /* 633 * Module glue. 634 */ 635 IEEE80211_CRYPTO_MODULE(ccmp, 1); 636