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_ccmp.c,v 1.7 2005/07/11 03:06:23 sam Exp $"); 35 #endif 36 #ifdef __NetBSD__ 37 __KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_ccmp.c,v 1.4 2005/11/18 16:57:22 skrll Exp $"); 38 #endif 39 40 /* 41 * IEEE 802.11i AES-CCMP 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 53 #include <sys/socket.h> 54 55 #include <net/if.h> 56 #include <net/if_media.h> 57 58 #include <net80211/ieee80211_var.h> 59 60 #include <crypto/rijndael/rijndael.h> 61 62 #define AES_BLOCK_LEN 16 63 64 struct ccmp_ctx { 65 struct ieee80211com *cc_ic; /* for diagnostics */ 66 rijndael_ctx cc_aes; 67 }; 68 69 static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 70 static void ccmp_detach(struct ieee80211_key *); 71 static int ccmp_setkey(struct ieee80211_key *); 72 static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, u_int8_t keyid); 73 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); 74 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); 75 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); 76 77 const struct ieee80211_cipher ieee80211_cipher_ccmp = { 78 .ic_name = "AES-CCM", 79 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 80 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 81 IEEE80211_WEP_EXTIVLEN, 82 .ic_trailer = IEEE80211_WEP_MICLEN, 83 .ic_miclen = 0, 84 .ic_attach = ccmp_attach, 85 .ic_detach = ccmp_detach, 86 .ic_setkey = ccmp_setkey, 87 .ic_encap = ccmp_encap, 88 .ic_decap = ccmp_decap, 89 .ic_enmic = ccmp_enmic, 90 .ic_demic = ccmp_demic, 91 }; 92 93 #define ccmp ieee80211_cipher_ccmp 94 95 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 96 static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 97 struct mbuf *, int hdrlen); 98 99 static void * 100 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 101 { 102 struct ccmp_ctx *ctx; 103 104 MALLOC(ctx, struct ccmp_ctx *, sizeof(struct ccmp_ctx), 105 M_DEVBUF, M_NOWAIT | M_ZERO); 106 if (ctx == NULL) { 107 ic->ic_stats.is_crypto_nomem++; 108 return NULL; 109 } 110 ctx->cc_ic = ic; 111 return ctx; 112 } 113 114 static void 115 ccmp_detach(struct ieee80211_key *k) 116 { 117 struct ccmp_ctx *ctx = k->wk_private; 118 119 FREE(ctx, M_DEVBUF); 120 } 121 122 static int 123 ccmp_setkey(struct ieee80211_key *k) 124 { 125 struct ccmp_ctx *ctx = k->wk_private; 126 127 if (k->wk_keylen != (128/NBBY)) { 128 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 129 "%s: Invalid key length %u, expecting %u\n", 130 __func__, k->wk_keylen, 128/NBBY); 131 return 0; 132 } 133 if (k->wk_flags & IEEE80211_KEY_SWCRYPT) 134 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY); 135 return 1; 136 } 137 138 /* 139 * Add privacy headers appropriate for the specified key. 140 */ 141 static int 142 ccmp_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) 143 { 144 struct ccmp_ctx *ctx = k->wk_private; 145 struct ieee80211com *ic = ctx->cc_ic; 146 u_int8_t *ivp; 147 int hdrlen; 148 149 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 150 151 /* 152 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 153 */ 154 M_PREPEND(m, ccmp.ic_header, M_NOWAIT); 155 if (m == NULL) 156 return 0; 157 ivp = mtod(m, u_int8_t *); 158 ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen); 159 ivp += hdrlen; 160 161 k->wk_keytsc++; /* XXX wrap at 48 bits */ 162 ivp[0] = k->wk_keytsc >> 0; /* PN0 */ 163 ivp[1] = k->wk_keytsc >> 8; /* PN1 */ 164 ivp[2] = 0; /* Reserved */ 165 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 166 ivp[4] = k->wk_keytsc >> 16; /* PN2 */ 167 ivp[5] = k->wk_keytsc >> 24; /* PN3 */ 168 ivp[6] = k->wk_keytsc >> 32; /* PN4 */ 169 ivp[7] = k->wk_keytsc >> 40; /* PN5 */ 170 171 /* 172 * Finally, do software encrypt if neeed. 173 */ 174 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 175 !ccmp_encrypt(k, m, hdrlen)) 176 return 0; 177 178 return 1; 179 } 180 181 /* 182 * Add MIC to the frame as needed. 183 */ 184 static int 185 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 186 { 187 188 return 1; 189 } 190 191 static __inline uint64_t 192 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 193 { 194 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 195 uint16_t iv16 = (b4 << 0) | (b5 << 8); 196 return (((uint64_t)iv16) << 32) | iv32; 197 } 198 199 /* 200 * Validate and strip privacy headers (and trailer) for a 201 * received frame. The specified key should be correct but 202 * is also verified. 203 */ 204 static int 205 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 206 { 207 struct ccmp_ctx *ctx = k->wk_private; 208 struct ieee80211_frame *wh; 209 uint8_t *ivp; 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_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 223 "[%s] Missing ExtIV for AES-CCM cipher\n", 224 ether_sprintf(wh->i_addr2)); 225 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 226 return 0; 227 } 228 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 229 if (pn <= k->wk_keyrsc) { 230 /* 231 * Replay violation. 232 */ 233 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 234 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 235 return 0; 236 } 237 238 /* 239 * Check if the device handled the decrypt in hardware. 240 * If so we just strip the header; otherwise we need to 241 * handle the decrypt in software. Note that for the 242 * latter we leave the header in place for use in the 243 * decryption work. 244 */ 245 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 246 !ccmp_decrypt(k, pn, m, hdrlen)) 247 return 0; 248 249 /* 250 * Copy up 802.11 header and strip crypto bits. 251 */ 252 ovbcopy(mtod(m, void *), mtod(m, u_int8_t *) + ccmp.ic_header, hdrlen); 253 m_adj(m, ccmp.ic_header); 254 m_adj(m, -ccmp.ic_trailer); 255 256 /* 257 * Ok to update rsc now. 258 */ 259 k->wk_keyrsc = pn; 260 261 return 1; 262 } 263 264 /* 265 * Verify and strip MIC from the frame. 266 */ 267 static int 268 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) 269 { 270 return 1; 271 } 272 273 static __inline void 274 xor_block(uint8_t *b, const uint8_t *a, size_t len) 275 { 276 int i; 277 for (i = 0; i < len; i++) 278 b[i] ^= a[i]; 279 } 280 281 /* 282 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 283 * 284 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 285 * 286 * This program is free software; you can redistribute it and/or modify 287 * it under the terms of the GNU General Public License version 2 as 288 * published by the Free Software Foundation. See README and COPYING for 289 * more details. 290 * 291 * Alternatively, this software may be distributed under the terms of BSD 292 * license. 293 */ 294 295 static void 296 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 297 u_int64_t pn, size_t dlen, 298 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 299 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 300 { 301 #define IS_4ADDRESS(wh) \ 302 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 303 #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 304 305 /* CCM Initial Block: 306 * Flag (Include authentication header, M=3 (8-octet MIC), 307 * L=1 (2-octet Dlen)) 308 * Nonce: 0x00 | A2 | PN 309 * Dlen */ 310 b0[0] = 0x59; 311 /* NB: b0[1] set below */ 312 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 313 b0[8] = pn >> 40; 314 b0[9] = pn >> 32; 315 b0[10] = pn >> 24; 316 b0[11] = pn >> 16; 317 b0[12] = pn >> 8; 318 b0[13] = pn >> 0; 319 b0[14] = (dlen >> 8) & 0xff; 320 b0[15] = dlen & 0xff; 321 322 /* AAD: 323 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 324 * A1 | A2 | A3 325 * SC with bits 4..15 (seq#) masked to zero 326 * A4 (if present) 327 * QC (if present) 328 */ 329 aad[0] = 0; /* AAD length >> 8 */ 330 /* NB: aad[1] set below */ 331 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 332 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 333 /* NB: we know 3 addresses are contiguous */ 334 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 335 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 336 aad[23] = 0; /* all bits masked */ 337 /* 338 * Construct variable-length portion of AAD based 339 * on whether this is a 4-address frame/QOS frame. 340 * We always zero-pad to 32 bytes before running it 341 * through the cipher. 342 * 343 * We also fill in the priority bits of the CCM 344 * initial block as we know whether or not we have 345 * a QOS frame. 346 */ 347 if (IS_4ADDRESS(wh)) { 348 IEEE80211_ADDR_COPY(aad + 24, 349 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 350 if (IS_QOS_DATA(wh)) { 351 struct ieee80211_qosframe_addr4 *qwh4 = 352 (struct ieee80211_qosframe_addr4 *) wh; 353 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 354 aad[31] = 0; 355 b0[1] = aad[30]; 356 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 357 } else { 358 *(u_int16_t *)&aad[30] = 0; 359 b0[1] = 0; 360 aad[1] = 22 + IEEE80211_ADDR_LEN; 361 } 362 } else { 363 if (IS_QOS_DATA(wh)) { 364 struct ieee80211_qosframe *qwh = 365 (struct ieee80211_qosframe*) wh; 366 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 367 aad[25] = 0; 368 b0[1] = aad[24]; 369 aad[1] = 22 + 2; 370 } else { 371 *(u_int16_t *)&aad[24] = 0; 372 b0[1] = 0; 373 aad[1] = 22; 374 } 375 *(u_int16_t *)&aad[26] = 0; 376 *(u_int32_t *)&aad[28] = 0; 377 } 378 379 /* Start with the first block and AAD */ 380 rijndael_encrypt(ctx, b0, auth); 381 xor_block(auth, aad, AES_BLOCK_LEN); 382 rijndael_encrypt(ctx, auth, auth); 383 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 384 rijndael_encrypt(ctx, auth, auth); 385 b0[0] &= 0x07; 386 b0[14] = b0[15] = 0; 387 rijndael_encrypt(ctx, b0, s0); 388 #undef IS_QOS_DATA 389 #undef IS_4ADDRESS 390 } 391 392 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 393 /* Authentication */ \ 394 xor_block(_b, _pos, _len); \ 395 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 396 /* Encryption, with counter */ \ 397 _b0[14] = (_i >> 8) & 0xff; \ 398 _b0[15] = _i & 0xff; \ 399 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 400 xor_block(_pos, _e, _len); \ 401 } while (0) 402 403 static int 404 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 405 { 406 struct ccmp_ctx *ctx = key->wk_private; 407 struct ieee80211_frame *wh; 408 struct mbuf *m = m0; 409 int data_len, i, space; 410 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 411 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 412 uint8_t *pos; 413 414 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 415 416 wh = mtod(m, struct ieee80211_frame *); 417 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header); 418 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc, 419 data_len, b0, aad, b, s0); 420 421 i = 1; 422 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 423 /* NB: assumes header is entirely in first mbuf */ 424 space = m->m_len - (hdrlen + ccmp.ic_header); 425 for (;;) { 426 if (space > data_len) 427 space = data_len; 428 /* 429 * Do full blocks. 430 */ 431 while (space >= AES_BLOCK_LEN) { 432 CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN); 433 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 434 data_len -= AES_BLOCK_LEN; 435 i++; 436 } 437 if (data_len <= 0) /* no more data */ 438 break; 439 m = m->m_next; 440 if (m == NULL) { /* last buffer */ 441 if (space != 0) { 442 /* 443 * Short last block. 444 */ 445 CCMP_ENCRYPT(i, b, b0, pos, e, space); 446 } 447 break; 448 } 449 if (space != 0) { 450 uint8_t *pos_next; 451 int space_next; 452 int len, dl, sp; 453 struct mbuf *n; 454 455 /* 456 * Block straddles one or more mbufs, gather data 457 * into the block buffer b, apply the cipher, then 458 * scatter the results back into the mbuf chain. 459 * The buffer will automatically get space bytes 460 * of data at offset 0 copied in+out by the 461 * CCMP_ENCRYPT request so we must take care of 462 * the remaining data. 463 */ 464 n = m; 465 dl = data_len; 466 sp = space; 467 for (;;) { 468 pos_next = mtod(n, uint8_t *); 469 len = min(dl, AES_BLOCK_LEN); 470 space_next = len > sp ? len - sp : 0; 471 if (n->m_len >= space_next) { 472 /* 473 * This mbuf has enough data; just grab 474 * what we need and stop. 475 */ 476 xor_block(b+sp, pos_next, space_next); 477 break; 478 } 479 /* 480 * This mbuf's contents are insufficient, 481 * take 'em all and prepare to advance to 482 * the next mbuf. 483 */ 484 xor_block(b+sp, pos_next, n->m_len); 485 sp += n->m_len, dl -= n->m_len; 486 n = n->m_next; 487 if (n == NULL) 488 break; 489 } 490 491 CCMP_ENCRYPT(i, b, b0, pos, e, space); 492 493 /* NB: just like above, but scatter data to mbufs */ 494 dl = data_len; 495 sp = space; 496 for (;;) { 497 pos_next = mtod(m, uint8_t *); 498 len = min(dl, AES_BLOCK_LEN); 499 space_next = len > sp ? len - sp : 0; 500 if (m->m_len >= space_next) { 501 xor_block(pos_next, e+sp, space_next); 502 break; 503 } 504 xor_block(pos_next, e+sp, m->m_len); 505 sp += m->m_len, dl -= m->m_len; 506 m = m->m_next; 507 if (m == NULL) 508 goto done; 509 } 510 /* 511 * Do bookkeeping. m now points to the last mbuf 512 * we grabbed data from. We know we consumed a 513 * full block of data as otherwise we'd have hit 514 * the end of the mbuf chain, so deduct from data_len. 515 * Otherwise advance the block number (i) and setup 516 * pos+space to reflect contents of the new mbuf. 517 */ 518 data_len -= AES_BLOCK_LEN; 519 i++; 520 pos = pos_next + space_next; 521 space = m->m_len - space_next; 522 } else { 523 /* 524 * Setup for next buffer. 525 */ 526 pos = mtod(m, uint8_t *); 527 space = m->m_len; 528 } 529 } 530 done: 531 /* tack on MIC */ 532 xor_block(b, s0, ccmp.ic_trailer); 533 return m_append(m0, ccmp.ic_trailer, b); 534 } 535 #undef CCMP_ENCRYPT 536 537 #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 538 /* Decrypt, with counter */ \ 539 _b0[14] = (_i >> 8) & 0xff; \ 540 _b0[15] = _i & 0xff; \ 541 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 542 xor_block(_pos, _b, _len); \ 543 /* Authentication */ \ 544 xor_block(_a, _pos, _len); \ 545 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 546 } while (0) 547 548 static int 549 ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) 550 { 551 struct ccmp_ctx *ctx = key->wk_private; 552 struct ieee80211_frame *wh; 553 uint8_t aad[2 * AES_BLOCK_LEN]; 554 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 555 uint8_t mic[AES_BLOCK_LEN]; 556 size_t data_len; 557 int i; 558 uint8_t *pos; 559 u_int space; 560 561 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 562 563 wh = mtod(m, struct ieee80211_frame *); 564 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 565 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 566 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 567 xor_block(mic, b, ccmp.ic_trailer); 568 569 i = 1; 570 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 571 space = m->m_len - (hdrlen + ccmp.ic_header); 572 for (;;) { 573 if (space > data_len) 574 space = data_len; 575 while (space >= AES_BLOCK_LEN) { 576 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 577 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 578 data_len -= AES_BLOCK_LEN; 579 i++; 580 } 581 if (data_len <= 0) /* no more data */ 582 break; 583 m = m->m_next; 584 if (m == NULL) { /* last buffer */ 585 if (space != 0) /* short last block */ 586 CCMP_DECRYPT(i, b, b0, pos, a, space); 587 break; 588 } 589 if (space != 0) { 590 uint8_t *pos_next; 591 u_int space_next; 592 u_int len; 593 594 /* 595 * Block straddles buffers, split references. We 596 * do not handle splits that require >2 buffers 597 * since rx'd frames are never badly fragmented 598 * because drivers typically recv in clusters. 599 */ 600 pos_next = mtod(m, uint8_t *); 601 len = min(data_len, AES_BLOCK_LEN); 602 space_next = len > space ? len - space : 0; 603 IASSERT(m->m_len >= space_next, 604 ("not enough data in following buffer, " 605 "m_len %u need %u\n", m->m_len, space_next)); 606 607 xor_block(b+space, pos_next, space_next); 608 CCMP_DECRYPT(i, b, b0, pos, a, space); 609 xor_block(pos_next, b+space, space_next); 610 data_len -= len; 611 i++; 612 613 pos = pos_next + space_next; 614 space = m->m_len - space_next; 615 } else { 616 /* 617 * Setup for next buffer. 618 */ 619 pos = mtod(m, uint8_t *); 620 space = m->m_len; 621 } 622 } 623 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 624 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 625 "[%s] AES-CCM decrypt failed; MIC mismatch\n", 626 ether_sprintf(wh->i_addr2)); 627 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 628 return 0; 629 } 630 return 1; 631 } 632 #undef CCMP_DECRYPT 633 634 IEEE80211_CRYPTO_SETUP(ccmp_register) 635 { 636 ieee80211_crypto_register(&ccmp); 637 } 638