1 /* $NetBSD: ieee80211_crypto_ccmp.c,v 1.15 2018/09/03 16:29:36 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * Alternatively, this software may be distributed under the terms of the 19 * GNU General Public License ("GPL") version 2 as published by the Free 20 * Software Foundation. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #ifdef __FreeBSD__ 36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_ccmp.c,v 1.7 2005/07/11 03:06:23 sam Exp $"); 37 #endif 38 #ifdef __NetBSD__ 39 __KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_ccmp.c,v 1.15 2018/09/03 16:29:36 riastradh Exp $"); 40 #endif 41 42 /* 43 * IEEE 802.11i AES-CCMP crypto support. 44 * 45 * Part of this module is derived from similar code in the Host 46 * AP driver. The code is used with the consent of the author and 47 * its license is included below. 48 */ 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/mbuf.h> 52 #include <sys/malloc.h> 53 #include <sys/kernel.h> 54 55 #include <sys/socket.h> 56 57 #include <net/if.h> 58 #include <net/if_ether.h> 59 #include <net/if_media.h> 60 61 #include <net80211/ieee80211_var.h> 62 63 #include <crypto/rijndael/rijndael.h> 64 65 #define AES_BLOCK_LEN 16 66 67 struct ccmp_ctx { 68 struct ieee80211com *cc_ic; /* for diagnostics */ 69 rijndael_ctx cc_aes; 70 }; 71 72 static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 73 static void ccmp_detach(struct ieee80211_key *); 74 static int ccmp_setkey(struct ieee80211_key *); 75 static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, u_int8_t keyid); 76 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); 77 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); 78 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); 79 80 const struct ieee80211_cipher ieee80211_cipher_ccmp = { 81 .ic_name = "AES-CCM", 82 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 83 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 84 IEEE80211_WEP_EXTIVLEN, 85 .ic_trailer = IEEE80211_WEP_MICLEN, 86 .ic_miclen = 0, 87 .ic_attach = ccmp_attach, 88 .ic_detach = ccmp_detach, 89 .ic_setkey = ccmp_setkey, 90 .ic_encap = ccmp_encap, 91 .ic_decap = ccmp_decap, 92 .ic_enmic = ccmp_enmic, 93 .ic_demic = ccmp_demic, 94 }; 95 96 #define ccmp ieee80211_cipher_ccmp 97 98 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 99 static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 100 struct mbuf *, int hdrlen); 101 102 static void * 103 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 104 { 105 struct ccmp_ctx *ctx; 106 107 ctx = malloc(sizeof(struct ccmp_ctx), M_DEVBUF, M_NOWAIT | M_ZERO); 108 if (ctx == NULL) { 109 ic->ic_stats.is_crypto_nomem++; 110 return NULL; 111 } 112 ctx->cc_ic = ic; 113 return ctx; 114 } 115 116 static void 117 ccmp_detach(struct ieee80211_key *k) 118 { 119 struct ccmp_ctx *ctx = k->wk_private; 120 121 free(ctx, M_DEVBUF); 122 } 123 124 static int 125 ccmp_setkey(struct ieee80211_key *k) 126 { 127 struct ccmp_ctx *ctx = k->wk_private; 128 129 if (k->wk_keylen != (128/NBBY)) { 130 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 131 "%s: Invalid key length %u, expecting %u\n", 132 __func__, k->wk_keylen, 128/NBBY); 133 return 0; 134 } 135 if (k->wk_flags & IEEE80211_KEY_SWCRYPT) 136 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY); 137 return 1; 138 } 139 140 /* 141 * Add privacy headers appropriate for the specified key. 142 */ 143 static int 144 ccmp_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) 145 { 146 struct ccmp_ctx *ctx = k->wk_private; 147 struct ieee80211com *ic = ctx->cc_ic; 148 u_int8_t *ivp; 149 int hdrlen; 150 151 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 152 ivp = mtod(m, u_int8_t *) + hdrlen; 153 154 k->wk_keytsc++; /* XXX wrap at 48 bits */ 155 ivp[0] = k->wk_keytsc >> 0; /* PN0 */ 156 ivp[1] = k->wk_keytsc >> 8; /* PN1 */ 157 ivp[2] = 0; /* Reserved */ 158 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 159 ivp[4] = k->wk_keytsc >> 16; /* PN2 */ 160 ivp[5] = k->wk_keytsc >> 24; /* PN3 */ 161 ivp[6] = k->wk_keytsc >> 32; /* PN4 */ 162 ivp[7] = k->wk_keytsc >> 40; /* PN5 */ 163 164 /* 165 * Finally, do software encrypt if neeed. 166 */ 167 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 168 !ccmp_encrypt(k, m, hdrlen)) 169 return 0; 170 171 return 1; 172 } 173 174 /* 175 * Add MIC to the frame as needed. 176 */ 177 static int 178 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, 179 int force) 180 { 181 182 return 1; 183 } 184 185 static __inline uint64_t 186 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 187 { 188 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 189 uint16_t iv16 = (b4 << 0) | (b5 << 8); 190 return (((uint64_t)iv16) << 32) | iv32; 191 } 192 193 /* 194 * Validate and strip privacy headers (and trailer) for a 195 * received frame. The specified key should be correct but 196 * is also verified. 197 */ 198 static int 199 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 200 { 201 struct ccmp_ctx *ctx = k->wk_private; 202 struct ieee80211_frame *wh; 203 uint8_t *ivp; 204 uint64_t pn; 205 206 /* 207 * Header should have extended IV and sequence number; 208 * verify the former and validate the latter. 209 */ 210 wh = mtod(m, struct ieee80211_frame *); 211 ivp = mtod(m, uint8_t *) + hdrlen; 212 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 213 /* 214 * No extended IV; discard frame. 215 */ 216 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 217 "[%s] Missing ExtIV for AES-CCM cipher\n", 218 ether_sprintf(wh->i_addr2)); 219 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 220 return 0; 221 } 222 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 223 if (pn <= k->wk_keyrsc) { 224 /* 225 * Replay violation. 226 */ 227 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 228 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 229 return 0; 230 } 231 232 /* 233 * Check if the device handled the decrypt in hardware. 234 * If so we just strip the header; otherwise we need to 235 * handle the decrypt in software. Note that for the 236 * latter we leave the header in place for use in the 237 * decryption work. 238 */ 239 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 240 !ccmp_decrypt(k, pn, m, hdrlen)) 241 return 0; 242 243 /* 244 * Copy up 802.11 header and strip crypto bits. 245 */ 246 memmove(mtod(m, u_int8_t *) + ccmp.ic_header, mtod(m, void *), hdrlen); 247 m_adj(m, ccmp.ic_header); 248 m_adj(m, -ccmp.ic_trailer); 249 250 /* 251 * Ok to update rsc now. 252 */ 253 k->wk_keyrsc = pn; 254 255 return 1; 256 } 257 258 /* 259 * Verify and strip MIC from the frame. 260 */ 261 static int 262 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) 263 { 264 return 1; 265 } 266 267 static __inline void 268 xor_block(uint8_t *b, const uint8_t *a, size_t len) 269 { 270 int i; 271 for (i = 0; i < len; i++) 272 b[i] ^= a[i]; 273 } 274 275 /* 276 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 277 * 278 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 279 * 280 * This program is free software; you can redistribute it and/or modify 281 * it under the terms of the GNU General Public License version 2 as 282 * published by the Free Software Foundation. See README and COPYING for 283 * more details. 284 * 285 * Alternatively, this software may be distributed under the terms of BSD 286 * license. 287 */ 288 289 static void 290 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 291 u_int64_t pn, size_t dlen, 292 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 293 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 294 { 295 #define IS_4ADDRESS(wh) \ 296 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 297 #define IS_QOS_DATA(wh) ieee80211_has_qos(wh) 298 299 /* CCM Initial Block: 300 * Flag (Include authentication header, M=3 (8-octet MIC), 301 * L=1 (2-octet Dlen)) 302 * Nonce: 0x00 | A2 | PN 303 * Dlen */ 304 b0[0] = 0x59; 305 /* NB: b0[1] set below */ 306 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 307 b0[8] = pn >> 40; 308 b0[9] = pn >> 32; 309 b0[10] = pn >> 24; 310 b0[11] = pn >> 16; 311 b0[12] = pn >> 8; 312 b0[13] = pn >> 0; 313 b0[14] = (dlen >> 8) & 0xff; 314 b0[15] = dlen & 0xff; 315 316 /* AAD: 317 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 318 * A1 | A2 | A3 319 * SC with bits 4..15 (seq#) masked to zero 320 * A4 (if present) 321 * QC (if present) 322 */ 323 aad[0] = 0; /* AAD length >> 8 */ 324 /* NB: aad[1] set below */ 325 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 326 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 327 /* NB: we know 3 addresses are contiguous */ 328 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 329 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 330 aad[23] = 0; /* all bits masked */ 331 /* 332 * Construct variable-length portion of AAD based 333 * on whether this is a 4-address frame/QOS frame. 334 * We always zero-pad to 32 bytes before running it 335 * through the cipher. 336 * 337 * We also fill in the priority bits of the CCM 338 * initial block as we know whether or not we have 339 * a QOS frame. 340 */ 341 if (IS_4ADDRESS(wh)) { 342 IEEE80211_ADDR_COPY(aad + 24, 343 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 344 if (IS_QOS_DATA(wh)) { 345 struct ieee80211_qosframe_addr4 *qwh4 = 346 (struct ieee80211_qosframe_addr4 *) wh; 347 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 348 aad[31] = 0; 349 b0[1] = aad[30]; 350 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 351 } else { 352 *(u_int16_t *)&aad[30] = 0; 353 b0[1] = 0; 354 aad[1] = 22 + IEEE80211_ADDR_LEN; 355 } 356 } else { 357 if (IS_QOS_DATA(wh)) { 358 struct ieee80211_qosframe *qwh = 359 (struct ieee80211_qosframe*) wh; 360 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 361 aad[25] = 0; 362 b0[1] = aad[24]; 363 aad[1] = 22 + 2; 364 } else { 365 *(u_int16_t *)&aad[24] = 0; 366 b0[1] = 0; 367 aad[1] = 22; 368 } 369 *(u_int16_t *)&aad[26] = 0; 370 *(u_int32_t *)&aad[28] = 0; 371 } 372 373 /* Start with the first block and AAD */ 374 rijndael_encrypt(ctx, b0, auth); 375 xor_block(auth, aad, AES_BLOCK_LEN); 376 rijndael_encrypt(ctx, auth, auth); 377 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 378 rijndael_encrypt(ctx, auth, auth); 379 b0[0] &= 0x07; 380 b0[14] = b0[15] = 0; 381 rijndael_encrypt(ctx, b0, s0); 382 #undef IS_QOS_DATA 383 #undef IS_4ADDRESS 384 } 385 386 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 387 /* Authentication */ \ 388 xor_block(_b, _pos, _len); \ 389 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 390 /* Encryption, with counter */ \ 391 _b0[14] = (_i >> 8) & 0xff; \ 392 _b0[15] = _i & 0xff; \ 393 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 394 xor_block(_pos, _e, _len); \ 395 } while (0) 396 397 static int 398 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 399 { 400 struct ccmp_ctx *ctx = key->wk_private; 401 struct ieee80211_frame *wh; 402 struct mbuf *m = m0; 403 int data_len, i, space; 404 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 405 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 406 uint8_t *pos; 407 408 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 409 410 wh = mtod(m, struct ieee80211_frame *); 411 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header); 412 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc, 413 data_len, b0, aad, b, s0); 414 415 i = 1; 416 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 417 /* NB: assumes header is entirely in first mbuf */ 418 space = m->m_len - (hdrlen + ccmp.ic_header); 419 for (;;) { 420 if (space > data_len) 421 space = data_len; 422 423 /* 424 * Do full blocks. 425 */ 426 while (space >= AES_BLOCK_LEN) { 427 CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN); 428 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 429 data_len -= AES_BLOCK_LEN; 430 i++; 431 } 432 if (data_len <= 0) /* no more data */ 433 break; 434 435 m = m->m_next; 436 if (m == NULL) { /* last buffer */ 437 if (space != 0) { 438 /* 439 * Short last block. 440 */ 441 CCMP_ENCRYPT(i, b, b0, pos, e, space); 442 } 443 break; 444 } 445 if (space != 0) { 446 uint8_t *pos_next; 447 int space_next; 448 int len, dl, sp; 449 struct mbuf *n; 450 451 /* 452 * Block straddles one or more mbufs, gather data 453 * into the block buffer b, apply the cipher, then 454 * scatter the results back into the mbuf chain. 455 * The buffer will automatically get space bytes 456 * of data at offset 0 copied in+out by the 457 * CCMP_ENCRYPT request so we must take care of 458 * the remaining data. 459 */ 460 n = m; 461 dl = data_len; 462 sp = space; 463 for (;;) { 464 pos_next = mtod(n, uint8_t *); 465 len = uimin(dl, AES_BLOCK_LEN); 466 space_next = len > sp ? len - sp : 0; 467 if (n->m_len >= space_next) { 468 /* 469 * This mbuf has enough data; just grab 470 * what we need and stop. 471 */ 472 xor_block(b+sp, pos_next, space_next); 473 break; 474 } 475 /* 476 * This mbuf's contents are insufficient, 477 * take them all and prepare to advance to 478 * the next mbuf. 479 */ 480 xor_block(b+sp, pos_next, n->m_len); 481 sp += n->m_len, dl -= n->m_len; 482 n = n->m_next; 483 if (n == NULL) 484 break; 485 } 486 487 CCMP_ENCRYPT(i, b, b0, pos, e, space); 488 489 /* NB: just like above, but scatter data to mbufs */ 490 dl = data_len; 491 sp = space; 492 for (;;) { 493 pos_next = mtod(m, uint8_t *); 494 len = uimin(dl, AES_BLOCK_LEN); 495 space_next = len > sp ? len - sp : 0; 496 if (m->m_len >= space_next) { 497 xor_block(pos_next, e+sp, space_next); 498 break; 499 } 500 xor_block(pos_next, e+sp, m->m_len); 501 sp += m->m_len, dl -= m->m_len; 502 m = m->m_next; 503 if (m == NULL) 504 goto done; 505 } 506 507 /* 508 * Do bookkeeping. m now points to the last mbuf 509 * we grabbed data from. We know we consumed a 510 * full block of data as otherwise we'd have hit 511 * the end of the mbuf chain, so deduct from data_len. 512 * Otherwise advance the block number (i) and setup 513 * pos+space to reflect contents of the new mbuf. 514 */ 515 data_len -= AES_BLOCK_LEN; 516 i++; 517 pos = pos_next + space_next; 518 space = m->m_len - space_next; 519 } else { 520 /* 521 * Setup for next buffer. 522 */ 523 pos = mtod(m, uint8_t *); 524 space = m->m_len; 525 } 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, 548 int hdrlen) 549 { 550 struct ccmp_ctx *ctx = key->wk_private; 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_ic->ic_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; 582 583 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 } 589 590 if (space != 0) { 591 uint8_t *pos_next; 592 u_int space_next; 593 u_int len; 594 595 /* 596 * Block straddles buffers, split references. We 597 * do not handle splits that require >2 buffers 598 * since rx'd frames are never badly fragmented 599 * because drivers typically recv in clusters. 600 */ 601 pos_next = mtod(m, uint8_t *); 602 len = uimin(data_len, AES_BLOCK_LEN); 603 space_next = len > space ? len - space : 0; 604 IASSERT(m->m_len >= space_next, 605 ("not enough data in following buffer, " 606 "m_len %u need %u\n", m->m_len, space_next)); 607 608 xor_block(b+space, pos_next, space_next); 609 CCMP_DECRYPT(i, b, b0, pos, a, space); 610 xor_block(pos_next, b+space, space_next); 611 data_len -= len; 612 i++; 613 614 pos = pos_next + space_next; 615 space = m->m_len - space_next; 616 } else { 617 /* 618 * Setup for next buffer. 619 */ 620 pos = mtod(m, uint8_t *); 621 space = m->m_len; 622 } 623 } 624 625 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 626 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 627 "[%s] AES-CCM decrypt failed; MIC mismatch\n", 628 ether_sprintf(wh->i_addr2)); 629 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 630 return 0; 631 } 632 633 return 1; 634 } 635 #undef CCMP_DECRYPT 636 637 IEEE80211_CRYPTO_SETUP(ccmp_register) 638 { 639 ieee80211_crypto_register(&ccmp); 640 } 641