Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_crypto_ccmp.c
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1 /*- 2 * Copyright (c) 2002-2007 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 <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/mbuf.h> 39 #include <sys/malloc.h> 40 #include <sys/kernel.h> 41 #include <sys/module.h> 42 43 #include <sys/socket.h> 44 45 #include <net/if.h> 46 #include <net/if_media.h> 47 #include <net/ethernet.h> 48 49 #include <net80211/ieee80211_var.h> 50 51 #include <crypto/rijndael/rijndael.h> 52 53 #define AES_BLOCK_LEN 16 54 55 struct ccmp_ctx { 56 struct ieee80211com *cc_ic; /* for diagnostics */ 57 rijndael_ctx cc_aes; 58 }; 59 60 static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 61 static void ccmp_detach(struct ieee80211_key *); 62 static int ccmp_setkey(struct ieee80211_key *); 63 static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, uint8_t keyid); 64 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); 65 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); 66 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); 67 68 static const struct ieee80211_cipher ccmp = { 69 .ic_name = "AES-CCM", 70 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 71 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 72 IEEE80211_WEP_EXTIVLEN, 73 .ic_trailer = IEEE80211_WEP_MICLEN, 74 .ic_miclen = 0, 75 .ic_attach = ccmp_attach, 76 .ic_detach = ccmp_detach, 77 .ic_setkey = ccmp_setkey, 78 .ic_encap = ccmp_encap, 79 .ic_decap = ccmp_decap, 80 .ic_enmic = ccmp_enmic, 81 .ic_demic = ccmp_demic, 82 }; 83 84 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 85 static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 86 struct mbuf *, int hdrlen); 87 88 /* number of references from net80211 layer */ 89 static int nrefs = 0; 90 91 static void * 92 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 93 { 94 struct ccmp_ctx *ctx; 95 96 MALLOC(ctx, struct ccmp_ctx *, sizeof(struct ccmp_ctx), 97 M_DEVBUF, M_NOWAIT | M_ZERO); 98 if (ctx == NULL) { 99 ic->ic_stats.is_crypto_nomem++; 100 return NULL; 101 } 102 ctx->cc_ic = ic; 103 nrefs++; /* NB: we assume caller locking */ 104 return ctx; 105 } 106 107 static void 108 ccmp_detach(struct ieee80211_key *k) 109 { 110 struct ccmp_ctx *ctx = k->wk_private; 111 112 FREE(ctx, M_DEVBUF); 113 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 114 nrefs--; /* NB: we assume caller locking */ 115 } 116 117 static int 118 ccmp_setkey(struct ieee80211_key *k) 119 { 120 struct ccmp_ctx *ctx = k->wk_private; 121 122 if (k->wk_keylen != (128/NBBY)) { 123 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 124 "%s: Invalid key length %u, expecting %u\n", 125 __func__, k->wk_keylen, 128/NBBY); 126 return 0; 127 } 128 if (k->wk_flags & IEEE80211_KEY_SWCRYPT) 129 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY); 130 return 1; 131 } 132 133 /* 134 * Add privacy headers appropriate for the specified key. 135 */ 136 static int 137 ccmp_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid) 138 { 139 struct ccmp_ctx *ctx = k->wk_private; 140 struct ieee80211com *ic = ctx->cc_ic; 141 uint8_t *ivp; 142 int hdrlen; 143 144 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 145 146 /* 147 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 148 */ 149 M_PREPEND(m, ccmp.ic_header, M_NOWAIT); 150 if (m == NULL) 151 return 0; 152 ivp = mtod(m, uint8_t *); 153 ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen); 154 ivp += hdrlen; 155 156 k->wk_keytsc++; /* XXX wrap at 48 bits */ 157 ivp[0] = k->wk_keytsc >> 0; /* PN0 */ 158 ivp[1] = k->wk_keytsc >> 8; /* PN1 */ 159 ivp[2] = 0; /* Reserved */ 160 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 161 ivp[4] = k->wk_keytsc >> 16; /* PN2 */ 162 ivp[5] = k->wk_keytsc >> 24; /* PN3 */ 163 ivp[6] = k->wk_keytsc >> 32; /* PN4 */ 164 ivp[7] = k->wk_keytsc >> 40; /* PN5 */ 165 166 /* 167 * Finally, do software encrypt if neeed. 168 */ 169 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 170 !ccmp_encrypt(k, m, hdrlen)) 171 return 0; 172 173 return 1; 174 } 175 176 /* 177 * Add MIC to the frame as needed. 178 */ 179 static int 180 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 181 { 182 183 return 1; 184 } 185 186 static __inline uint64_t 187 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 188 { 189 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 190 uint16_t iv16 = (b4 << 0) | (b5 << 8); 191 return (((uint64_t)iv16) << 32) | iv32; 192 } 193 194 /* 195 * Validate and strip privacy headers (and trailer) for a 196 * received frame. The specified key should be correct but 197 * is also verified. 198 */ 199 static int 200 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 201 { 202 struct ccmp_ctx *ctx = k->wk_private; 203 struct ieee80211_frame *wh; 204 uint8_t *ivp; 205 uint64_t pn; 206 207 /* 208 * Header should have extended IV and sequence number; 209 * verify the former and validate the latter. 210 */ 211 wh = mtod(m, struct ieee80211_frame *); 212 ivp = mtod(m, uint8_t *) + hdrlen; 213 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 214 /* 215 * No extended IV; discard frame. 216 */ 217 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 218 "[%s] Missing ExtIV for AES-CCM cipher\n", 219 ether_sprintf(wh->i_addr2)); 220 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 221 return 0; 222 } 223 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 224 if (pn <= k->wk_keyrsc) { 225 /* 226 * Replay violation. 227 */ 228 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 229 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 230 return 0; 231 } 232 233 /* 234 * Check if the device handled the decrypt in hardware. 235 * If so we just strip the header; otherwise we need to 236 * handle the decrypt in software. Note that for the 237 * latter we leave the header in place for use in the 238 * decryption work. 239 */ 240 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 241 !ccmp_decrypt(k, pn, m, hdrlen)) 242 return 0; 243 244 /* 245 * Copy up 802.11 header and strip crypto bits. 246 */ 247 ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp.ic_header, hdrlen); 248 m_adj(m, ccmp.ic_header); 249 m_adj(m, -ccmp.ic_trailer); 250 251 /* 252 * Ok to update rsc now. 253 */ 254 k->wk_keyrsc = pn; 255 256 return 1; 257 } 258 259 /* 260 * Verify and strip MIC from the frame. 261 */ 262 static int 263 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) 264 { 265 return 1; 266 } 267 268 static __inline void 269 xor_block(uint8_t *b, const uint8_t *a, size_t len) 270 { 271 int i; 272 for (i = 0; i < len; i++) 273 b[i] ^= a[i]; 274 } 275 276 /* 277 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 278 * 279 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 280 * 281 * This program is free software; you can redistribute it and/or modify 282 * it under the terms of the GNU General Public License version 2 as 283 * published by the Free Software Foundation. See README and COPYING for 284 * more details. 285 * 286 * Alternatively, this software may be distributed under the terms of BSD 287 * license. 288 */ 289 290 static void 291 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 292 u_int64_t pn, size_t dlen, 293 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 294 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 295 { 296 #define IS_4ADDRESS(wh) \ 297 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 298 #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 299 300 /* CCM Initial Block: 301 * Flag (Include authentication header, M=3 (8-octet MIC), 302 * L=1 (2-octet Dlen)) 303 * Nonce: 0x00 | A2 | PN 304 * Dlen */ 305 b0[0] = 0x59; 306 /* NB: b0[1] set below */ 307 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 308 b0[8] = pn >> 40; 309 b0[9] = pn >> 32; 310 b0[10] = pn >> 24; 311 b0[11] = pn >> 16; 312 b0[12] = pn >> 8; 313 b0[13] = pn >> 0; 314 b0[14] = (dlen >> 8) & 0xff; 315 b0[15] = dlen & 0xff; 316 317 /* AAD: 318 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 319 * A1 | A2 | A3 320 * SC with bits 4..15 (seq#) masked to zero 321 * A4 (if present) 322 * QC (if present) 323 */ 324 aad[0] = 0; /* AAD length >> 8 */ 325 /* NB: aad[1] set below */ 326 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 327 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 328 /* NB: we know 3 addresses are contiguous */ 329 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 330 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 331 aad[23] = 0; /* all bits masked */ 332 /* 333 * Construct variable-length portion of AAD based 334 * on whether this is a 4-address frame/QOS frame. 335 * We always zero-pad to 32 bytes before running it 336 * through the cipher. 337 * 338 * We also fill in the priority bits of the CCM 339 * initial block as we know whether or not we have 340 * a QOS frame. 341 */ 342 if (IS_4ADDRESS(wh)) { 343 IEEE80211_ADDR_COPY(aad + 24, 344 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 345 if (IS_QOS_DATA(wh)) { 346 struct ieee80211_qosframe_addr4 *qwh4 = 347 (struct ieee80211_qosframe_addr4 *) wh; 348 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 349 aad[31] = 0; 350 b0[1] = aad[30]; 351 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 352 } else { 353 *(uint16_t *)&aad[30] = 0; 354 b0[1] = 0; 355 aad[1] = 22 + IEEE80211_ADDR_LEN; 356 } 357 } else { 358 if (IS_QOS_DATA(wh)) { 359 struct ieee80211_qosframe *qwh = 360 (struct ieee80211_qosframe*) wh; 361 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 362 aad[25] = 0; 363 b0[1] = aad[24]; 364 aad[1] = 22 + 2; 365 } else { 366 *(uint16_t *)&aad[24] = 0; 367 b0[1] = 0; 368 aad[1] = 22; 369 } 370 *(uint16_t *)&aad[26] = 0; 371 *(uint32_t *)&aad[28] = 0; 372 } 373 374 /* Start with the first block and AAD */ 375 rijndael_encrypt(ctx, b0, auth); 376 xor_block(auth, aad, AES_BLOCK_LEN); 377 rijndael_encrypt(ctx, auth, auth); 378 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 379 rijndael_encrypt(ctx, auth, auth); 380 b0[0] &= 0x07; 381 b0[14] = b0[15] = 0; 382 rijndael_encrypt(ctx, b0, s0); 383 #undef IS_QOS_DATA 384 #undef IS_4ADDRESS 385 } 386 387 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 388 /* Authentication */ \ 389 xor_block(_b, _pos, _len); \ 390 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 391 /* Encryption, with counter */ \ 392 _b0[14] = (_i >> 8) & 0xff; \ 393 _b0[15] = _i & 0xff; \ 394 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 395 xor_block(_pos, _e, _len); \ 396 } while (0) 397 398 static int 399 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 400 { 401 struct ccmp_ctx *ctx = key->wk_private; 402 struct ieee80211_frame *wh; 403 struct mbuf *m = m0; 404 int data_len, i, space; 405 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 406 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 407 uint8_t *pos; 408 409 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 410 411 wh = mtod(m, struct ieee80211_frame *); 412 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header); 413 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc, 414 data_len, b0, aad, b, s0); 415 416 i = 1; 417 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 418 /* NB: assumes header is entirely in first mbuf */ 419 space = m->m_len - (hdrlen + ccmp.ic_header); 420 for (;;) { 421 if (space > data_len) 422 space = data_len; 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 m = m->m_next; 435 if (m == NULL) { /* last buffer */ 436 if (space != 0) { 437 /* 438 * Short last block. 439 */ 440 CCMP_ENCRYPT(i, b, b0, pos, e, space); 441 } 442 break; 443 } 444 if (space != 0) { 445 uint8_t *pos_next; 446 int space_next; 447 int len, dl, sp; 448 struct mbuf *n; 449 450 /* 451 * Block straddles one or more mbufs, gather data 452 * into the block buffer b, apply the cipher, then 453 * scatter the results back into the mbuf chain. 454 * The buffer will automatically get space bytes 455 * of data at offset 0 copied in+out by the 456 * CCMP_ENCRYPT request so we must take care of 457 * the remaining data. 458 */ 459 n = m; 460 dl = data_len; 461 sp = space; 462 for (;;) { 463 pos_next = mtod(n, uint8_t *); 464 len = min(dl, AES_BLOCK_LEN); 465 space_next = len > sp ? len - sp : 0; 466 if (n->m_len >= space_next) { 467 /* 468 * This mbuf has enough data; just grab 469 * what we need and stop. 470 */ 471 xor_block(b+sp, pos_next, space_next); 472 break; 473 } 474 /* 475 * This mbuf's contents are insufficient, 476 * take 'em all and prepare to advance to 477 * the next mbuf. 478 */ 479 xor_block(b+sp, pos_next, n->m_len); 480 sp += n->m_len, dl -= n->m_len; 481 n = n->m_next; 482 if (n == NULL) 483 break; 484 } 485 486 CCMP_ENCRYPT(i, b, b0, pos, e, space); 487 488 /* NB: just like above, but scatter data to mbufs */ 489 dl = data_len; 490 sp = space; 491 for (;;) { 492 pos_next = mtod(m, uint8_t *); 493 len = min(dl, AES_BLOCK_LEN); 494 space_next = len > sp ? len - sp : 0; 495 if (m->m_len >= space_next) { 496 xor_block(pos_next, e+sp, space_next); 497 break; 498 } 499 xor_block(pos_next, e+sp, m->m_len); 500 sp += m->m_len, dl -= m->m_len; 501 m = m->m_next; 502 if (m == NULL) 503 goto done; 504 } 505 /* 506 * Do bookkeeping. m now points to the last mbuf 507 * we grabbed data from. We know we consumed a 508 * full block of data as otherwise we'd have hit 509 * the end of the mbuf chain, so deduct from data_len. 510 * Otherwise advance the block number (i) and setup 511 * pos+space to reflect contents of the new mbuf. 512 */ 513 data_len -= AES_BLOCK_LEN; 514 i++; 515 pos = pos_next + space_next; 516 space = m->m_len - space_next; 517 } else { 518 /* 519 * Setup for next buffer. 520 */ 521 pos = mtod(m, uint8_t *); 522 space = m->m_len; 523 } 524 } 525 done: 526 /* tack on MIC */ 527 xor_block(b, s0, ccmp.ic_trailer); 528 return m_append(m0, ccmp.ic_trailer, b); 529 } 530 #undef CCMP_ENCRYPT 531 532 #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 533 /* Decrypt, with counter */ \ 534 _b0[14] = (_i >> 8) & 0xff; \ 535 _b0[15] = _i & 0xff; \ 536 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 537 xor_block(_pos, _b, _len); \ 538 /* Authentication */ \ 539 xor_block(_a, _pos, _len); \ 540 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 541 } while (0) 542 543 static int 544 ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) 545 { 546 struct ccmp_ctx *ctx = key->wk_private; 547 struct ieee80211_frame *wh; 548 uint8_t aad[2 * AES_BLOCK_LEN]; 549 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 550 uint8_t mic[AES_BLOCK_LEN]; 551 size_t data_len; 552 int i; 553 uint8_t *pos; 554 u_int space; 555 556 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 557 558 wh = mtod(m, struct ieee80211_frame *); 559 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 560 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 561 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 562 xor_block(mic, b, ccmp.ic_trailer); 563 564 i = 1; 565 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 566 space = m->m_len - (hdrlen + ccmp.ic_header); 567 for (;;) { 568 if (space > data_len) 569 space = data_len; 570 while (space >= AES_BLOCK_LEN) { 571 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 572 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 573 data_len -= AES_BLOCK_LEN; 574 i++; 575 } 576 if (data_len <= 0) /* no more data */ 577 break; 578 m = m->m_next; 579 if (m == NULL) { /* last buffer */ 580 if (space != 0) /* short last block */ 581 CCMP_DECRYPT(i, b, b0, pos, a, space); 582 break; 583 } 584 if (space != 0) { 585 uint8_t *pos_next; 586 u_int space_next; 587 u_int len; 588 589 /* 590 * Block straddles buffers, split references. We 591 * do not handle splits that require >2 buffers 592 * since rx'd frames are never badly fragmented 593 * because drivers typically recv in clusters. 594 */ 595 pos_next = mtod(m, uint8_t *); 596 len = min(data_len, AES_BLOCK_LEN); 597 space_next = len > space ? len - space : 0; 598 KASSERT(m->m_len >= space_next, 599 ("not enough data in following buffer, " 600 "m_len %u need %u\n", m->m_len, space_next)); 601 602 xor_block(b+space, pos_next, space_next); 603 CCMP_DECRYPT(i, b, b0, pos, a, space); 604 xor_block(pos_next, b+space, space_next); 605 data_len -= len; 606 i++; 607 608 pos = pos_next + space_next; 609 space = m->m_len - space_next; 610 } else { 611 /* 612 * Setup for next buffer. 613 */ 614 pos = mtod(m, uint8_t *); 615 space = m->m_len; 616 } 617 } 618 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 619 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 620 "[%s] AES-CCM decrypt failed; MIC mismatch\n", 621 ether_sprintf(wh->i_addr2)); 622 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 623 return 0; 624 } 625 return 1; 626 } 627 #undef CCMP_DECRYPT 628 629 /* 630 * Module glue. 631 */ 632 IEEE80211_CRYPTO_MODULE(ccmp, 1);
Cache object: 178335b90775508ef1a75cabec51777e
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