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 * $FreeBSD: src/sys/net80211/ieee80211_crypto_ccmp.c,v 1.7.2.1 2005/12/22 19:02:08 sam Exp $ 32 * $DragonFly: src/sys/netproto/802_11/wlan_ccmp/ieee80211_crypto_ccmp.c,v 1.1 2006/05/18 13:51:46 sephe Exp $ 33 */ 34 35 /* 36 * IEEE 802.11i AES-CCMP crypto support. 37 * 38 * Part of this module is derived from similar code in the Host 39 * AP driver. The code is used with the consent of the author and 40 * it's license is included below. 41 */ 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/mbuf.h> 45 #include <sys/malloc.h> 46 #include <sys/kernel.h> 47 #include <sys/module.h> 48 49 #include <sys/socket.h> 50 51 #include <net/if.h> 52 #include <net/if_arp.h> 53 #include <net/if_media.h> 54 #include <net/ethernet.h> 55 56 #include <netproto/802_11/ieee80211_var.h> 57 58 #include <opencrypto/rijndael.h> 59 60 #define AES_BLOCK_LEN 16 61 62 struct ccmp_ctx { 63 struct ieee80211com *cc_ic; /* for diagnostics */ 64 rijndael_ctx cc_aes; 65 }; 66 67 static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 68 static void ccmp_detach(struct ieee80211_key *); 69 static int ccmp_setkey(struct ieee80211_key *); 70 static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, uint8_t keyid); 71 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int); 72 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int); 73 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int); 74 75 static const struct ieee80211_cipher ccmp = { 76 .ic_name = "AES-CCM", 77 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 78 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 79 IEEE80211_WEP_EXTIVLEN, 80 .ic_trailer = IEEE80211_WEP_MICLEN, 81 .ic_miclen = 0, 82 .ic_attach = ccmp_attach, 83 .ic_detach = ccmp_detach, 84 .ic_setkey = ccmp_setkey, 85 .ic_encap = ccmp_encap, 86 .ic_decap = ccmp_decap, 87 .ic_enmic = ccmp_enmic, 88 .ic_demic = ccmp_demic, 89 }; 90 91 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 92 static int ccmp_decrypt(struct ieee80211_key *, uint64_t pn, 93 struct mbuf *, int hdrlen); 94 95 /* number of references from net80211 layer */ 96 static int nrefs = 0; 97 98 static void * 99 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 100 { 101 struct ccmp_ctx *ctx; 102 103 ctx = malloc(sizeof(struct ccmp_ctx), M_DEVBUF, M_NOWAIT | M_ZERO); 104 if (ctx == NULL) { 105 ic->ic_stats.is_crypto_nomem++; 106 return NULL; 107 } 108 ctx->cc_ic = ic; 109 nrefs++; /* NB: we assume caller locking */ 110 return ctx; 111 } 112 113 static void 114 ccmp_detach(struct ieee80211_key *k) 115 { 116 struct ccmp_ctx *ctx = k->wk_private; 117 118 free(ctx, M_DEVBUF); 119 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 120 nrefs--; /* NB: we assume caller locking */ 121 } 122 123 static int 124 ccmp_setkey(struct ieee80211_key *k) 125 { 126 struct ccmp_ctx *ctx = k->wk_private; 127 128 if (k->wk_keylen != (128/NBBY)) { 129 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 130 "%s: Invalid key length %u, expecting %u\n", 131 __func__, k->wk_keylen, 128/NBBY); 132 return 0; 133 } 134 if (k->wk_flags & IEEE80211_KEY_SWCRYPT) { 135 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen * NBBY, 136 1); 137 } 138 return 1; 139 } 140 141 /* 142 * Add privacy headers appropriate for the specified key. 143 */ 144 static int 145 ccmp_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid) 146 { 147 struct ccmp_ctx *ctx = k->wk_private; 148 struct ieee80211com *ic = ctx->cc_ic; 149 uint8_t *ivp; 150 int hdrlen; 151 152 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *)); 153 154 /* 155 * Copy down 802.11 header and add the IV, KeyID, and ExtIV. 156 */ 157 M_PREPEND(m, ccmp.ic_header, M_NOWAIT); 158 if (m == NULL) 159 return 0; 160 ivp = mtod(m, uint8_t *); 161 ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen); 162 ivp += hdrlen; 163 164 k->wk_keytsc++; /* XXX wrap at 48 bits */ 165 ivp[0] = k->wk_keytsc >> 0; /* PN0 */ 166 ivp[1] = k->wk_keytsc >> 8; /* PN1 */ 167 ivp[2] = 0; /* Reserved */ 168 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */ 169 ivp[4] = k->wk_keytsc >> 16; /* PN2 */ 170 ivp[5] = k->wk_keytsc >> 24; /* PN3 */ 171 ivp[6] = k->wk_keytsc >> 32; /* PN4 */ 172 ivp[7] = k->wk_keytsc >> 40; /* PN5 */ 173 174 /* 175 * Finally, do software encrypt if neeed. 176 */ 177 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 178 !ccmp_encrypt(k, m, hdrlen)) 179 return 0; 180 181 return 1; 182 } 183 184 /* 185 * Add MIC to the frame as needed. 186 */ 187 static int 188 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force) 189 { 190 return 1; 191 } 192 193 static __inline uint64_t 194 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) 195 { 196 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24); 197 uint16_t iv16 = (b4 << 0) | (b5 << 8); 198 return (((uint64_t)iv16) << 32) | iv32; 199 } 200 201 /* 202 * Validate and strip privacy headers (and trailer) for a 203 * received frame. The specified key should be correct but 204 * is also verified. 205 */ 206 static int 207 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen) 208 { 209 struct ccmp_ctx *ctx = k->wk_private; 210 struct ieee80211_frame *wh; 211 uint8_t *ivp; 212 uint64_t pn; 213 214 /* 215 * Header should have extended IV and sequence number; 216 * verify the former and validate the latter. 217 */ 218 wh = mtod(m, struct ieee80211_frame *); 219 ivp = mtod(m, uint8_t *) + hdrlen; 220 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 221 /* 222 * No extended IV; discard frame. 223 */ 224 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 225 "[%6D] Missing ExtIV for AES-CCM cipher\n", 226 wh->i_addr2, ":"); 227 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 228 return 0; 229 } 230 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 231 if (pn <= k->wk_keyrsc) { 232 /* 233 * Replay violation. 234 */ 235 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 236 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 237 return 0; 238 } 239 240 /* 241 * Check if the device handled the decrypt in hardware. 242 * If so we just strip the header; otherwise we need to 243 * handle the decrypt in software. Note that for the 244 * latter we leave the header in place for use in the 245 * decryption work. 246 */ 247 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 248 !ccmp_decrypt(k, pn, m, hdrlen)) 249 return 0; 250 251 /* 252 * Copy up 802.11 header and strip crypto bits. 253 */ 254 ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp.ic_header, hdrlen); 255 m_adj(m, ccmp.ic_header); 256 m_adj(m, -ccmp.ic_trailer); 257 258 /* 259 * Ok to update rsc now. 260 */ 261 k->wk_keyrsc = pn; 262 263 return 1; 264 } 265 266 /* 267 * Verify and strip MIC from the frame. 268 */ 269 static int 270 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force) 271 { 272 return 1; 273 } 274 275 static __inline void 276 xor_block(uint8_t *b, const uint8_t *a, size_t len) 277 { 278 int i; 279 for (i = 0; i < len; i++) 280 b[i] ^= a[i]; 281 } 282 283 /* 284 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 285 * 286 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 287 * 288 * This program is free software; you can redistribute it and/or modify 289 * it under the terms of the GNU General Public License version 2 as 290 * published by the Free Software Foundation. See README and COPYING for 291 * more details. 292 * 293 * Alternatively, this software may be distributed under the terms of BSD 294 * license. 295 */ 296 297 static void 298 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 299 uint64_t pn, size_t dlen, 300 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 301 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 302 { 303 #define IS_4ADDRESS(wh) \ 304 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 305 #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 306 307 /* CCM Initial Block: 308 * Flag (Include authentication header, M=3 (8-octet MIC), 309 * L=1 (2-octet Dlen)) 310 * Nonce: 0x00 | A2 | PN 311 * Dlen */ 312 b0[0] = 0x59; 313 /* NB: b0[1] set below */ 314 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 315 b0[8] = pn >> 40; 316 b0[9] = pn >> 32; 317 b0[10] = pn >> 24; 318 b0[11] = pn >> 16; 319 b0[12] = pn >> 8; 320 b0[13] = pn >> 0; 321 b0[14] = (dlen >> 8) & 0xff; 322 b0[15] = dlen & 0xff; 323 324 /* AAD: 325 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 326 * A1 | A2 | A3 327 * SC with bits 4..15 (seq#) masked to zero 328 * A4 (if present) 329 * QC (if present) 330 */ 331 aad[0] = 0; /* AAD length >> 8 */ 332 /* NB: aad[1] set below */ 333 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 334 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 335 /* NB: we know 3 addresses are contiguous */ 336 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 337 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 338 aad[23] = 0; /* all bits masked */ 339 /* 340 * Construct variable-length portion of AAD based 341 * on whether this is a 4-address frame/QOS frame. 342 * We always zero-pad to 32 bytes before running it 343 * through the cipher. 344 * 345 * We also fill in the priority bits of the CCM 346 * initial block as we know whether or not we have 347 * a QOS frame. 348 */ 349 if (IS_4ADDRESS(wh)) { 350 IEEE80211_ADDR_COPY(aad + 24, 351 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 352 if (IS_QOS_DATA(wh)) { 353 struct ieee80211_qosframe_addr4 *qwh4 = 354 (struct ieee80211_qosframe_addr4 *) wh; 355 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 356 aad[31] = 0; 357 b0[1] = aad[30]; 358 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 359 } else { 360 *(uint16_t *)&aad[30] = 0; 361 b0[1] = 0; 362 aad[1] = 22 + IEEE80211_ADDR_LEN; 363 } 364 } else { 365 if (IS_QOS_DATA(wh)) { 366 struct ieee80211_qosframe *qwh = 367 (struct ieee80211_qosframe*) wh; 368 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 369 aad[25] = 0; 370 b0[1] = aad[24]; 371 aad[1] = 22 + 2; 372 } else { 373 *(uint16_t *)&aad[24] = 0; 374 b0[1] = 0; 375 aad[1] = 22; 376 } 377 *(uint16_t *)&aad[26] = 0; 378 *(uint32_t *)&aad[28] = 0; 379 } 380 381 /* Start with the first block and AAD */ 382 rijndael_encrypt(ctx, b0, auth); 383 xor_block(auth, aad, AES_BLOCK_LEN); 384 rijndael_encrypt(ctx, auth, auth); 385 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 386 rijndael_encrypt(ctx, auth, auth); 387 b0[0] &= 0x07; 388 b0[14] = b0[15] = 0; 389 rijndael_encrypt(ctx, b0, s0); 390 #undef IS_QOS_DATA 391 #undef IS_4ADDRESS 392 } 393 394 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 395 /* Authentication */ \ 396 xor_block(_b, _pos, _len); \ 397 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 398 /* Encryption, with counter */ \ 399 _b0[14] = (_i >> 8) & 0xff; \ 400 _b0[15] = _i & 0xff; \ 401 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 402 xor_block(_pos, _e, _len); \ 403 } while (0) 404 405 static int 406 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 407 { 408 struct ccmp_ctx *ctx = key->wk_private; 409 struct ieee80211_frame *wh; 410 struct mbuf *m = m0; 411 int data_len, i, space; 412 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 413 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 414 uint8_t *pos; 415 416 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 417 418 wh = mtod(m, struct ieee80211_frame *); 419 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header); 420 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc, 421 data_len, b0, aad, b, s0); 422 423 i = 1; 424 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 425 /* NB: assumes header is entirely in first mbuf */ 426 space = m->m_len - (hdrlen + ccmp.ic_header); 427 for (;;) { 428 if (space > data_len) 429 space = data_len; 430 /* 431 * Do full blocks. 432 */ 433 while (space >= AES_BLOCK_LEN) { 434 CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN); 435 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 436 data_len -= AES_BLOCK_LEN; 437 i++; 438 } 439 if (data_len <= 0) /* no more data */ 440 break; 441 m = m->m_next; 442 if (m == NULL) { /* last buffer */ 443 if (space != 0) { 444 /* 445 * Short last block. 446 */ 447 CCMP_ENCRYPT(i, b, b0, pos, e, space); 448 } 449 break; 450 } 451 if (space != 0) { 452 uint8_t *pos_next; 453 int space_next; 454 int len, dl, sp; 455 struct mbuf *n; 456 457 /* 458 * Block straddles one or more mbufs, gather data 459 * into the block buffer b, apply the cipher, then 460 * scatter the results back into the mbuf chain. 461 * The buffer will automatically get space bytes 462 * of data at offset 0 copied in+out by the 463 * CCMP_ENCRYPT request so we must take care of 464 * the remaining data. 465 */ 466 n = m; 467 dl = data_len; 468 sp = space; 469 for (;;) { 470 pos_next = mtod(n, uint8_t *); 471 len = min(dl, AES_BLOCK_LEN); 472 space_next = len > sp ? len - sp : 0; 473 if (n->m_len >= space_next) { 474 /* 475 * This mbuf has enough data; just grab 476 * what we need and stop. 477 */ 478 xor_block(b+sp, pos_next, space_next); 479 break; 480 } 481 /* 482 * This mbuf's contents are insufficient, 483 * take 'em all and prepare to advance to 484 * the next mbuf. 485 */ 486 xor_block(b+sp, pos_next, n->m_len); 487 sp += n->m_len, dl -= n->m_len; 488 n = n->m_next; 489 if (n == NULL) 490 break; 491 } 492 493 CCMP_ENCRYPT(i, b, b0, pos, e, space); 494 495 /* NB: just like above, but scatter data to mbufs */ 496 dl = data_len; 497 sp = space; 498 for (;;) { 499 pos_next = mtod(m, uint8_t *); 500 len = min(dl, AES_BLOCK_LEN); 501 space_next = len > sp ? len - sp : 0; 502 if (m->m_len >= space_next) { 503 xor_block(pos_next, e+sp, space_next); 504 break; 505 } 506 xor_block(pos_next, e+sp, m->m_len); 507 sp += m->m_len, dl -= m->m_len; 508 m = m->m_next; 509 if (m == NULL) 510 goto done; 511 } 512 /* 513 * Do bookkeeping. m now points to the last mbuf 514 * we grabbed data from. We know we consumed a 515 * full block of data as otherwise we'd have hit 516 * the end of the mbuf chain, so deduct from data_len. 517 * Otherwise advance the block number (i) and setup 518 * pos+space to reflect contents of the new mbuf. 519 */ 520 data_len -= AES_BLOCK_LEN; 521 i++; 522 pos = pos_next + space_next; 523 space = m->m_len - space_next; 524 } else { 525 /* 526 * Setup for next buffer. 527 */ 528 pos = mtod(m, uint8_t *); 529 space = m->m_len; 530 } 531 } 532 done: 533 /* tack on MIC */ 534 xor_block(b, s0, ccmp.ic_trailer); 535 return ieee80211_mbuf_append(m0, ccmp.ic_trailer, b); 536 } 537 #undef CCMP_ENCRYPT 538 539 #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 540 /* Decrypt, with counter */ \ 541 _b0[14] = (_i >> 8) & 0xff; \ 542 _b0[15] = _i & 0xff; \ 543 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 544 xor_block(_pos, _b, _len); \ 545 /* Authentication */ \ 546 xor_block(_a, _pos, _len); \ 547 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 548 } while (0) 549 550 static int 551 ccmp_decrypt(struct ieee80211_key *key, uint64_t pn, struct mbuf *m, int hdrlen) 552 { 553 struct ccmp_ctx *ctx = key->wk_private; 554 struct ieee80211_frame *wh; 555 uint8_t aad[2 * AES_BLOCK_LEN]; 556 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 557 uint8_t mic[AES_BLOCK_LEN]; 558 size_t data_len; 559 int i; 560 uint8_t *pos; 561 u_int space; 562 563 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 564 565 wh = mtod(m, struct ieee80211_frame *); 566 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 567 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 568 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 569 xor_block(mic, b, ccmp.ic_trailer); 570 571 i = 1; 572 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 573 space = m->m_len - (hdrlen + ccmp.ic_header); 574 for (;;) { 575 if (space > data_len) 576 space = data_len; 577 while (space >= AES_BLOCK_LEN) { 578 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 579 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 580 data_len -= AES_BLOCK_LEN; 581 i++; 582 } 583 if (data_len <= 0) /* no more data */ 584 break; 585 m = m->m_next; 586 if (m == NULL) { /* last buffer */ 587 if (space != 0) /* short last block */ 588 CCMP_DECRYPT(i, b, b0, pos, a, space); 589 break; 590 } 591 if (space != 0) { 592 uint8_t *pos_next; 593 u_int space_next; 594 u_int len; 595 596 /* 597 * Block straddles buffers, split references. We 598 * do not handle splits that require >2 buffers 599 * since rx'd frames are never badly fragmented 600 * because drivers typically recv in clusters. 601 */ 602 pos_next = mtod(m, uint8_t *); 603 len = min(data_len, AES_BLOCK_LEN); 604 space_next = len > space ? len - space : 0; 605 KASSERT(m->m_len >= space_next, 606 ("not enough data in following buffer, " 607 "m_len %u need %u\n", m->m_len, space_next)); 608 609 xor_block(b+space, pos_next, space_next); 610 CCMP_DECRYPT(i, b, b0, pos, a, space); 611 xor_block(pos_next, b+space, space_next); 612 data_len -= len; 613 i++; 614 615 pos = pos_next + space_next; 616 space = m->m_len - space_next; 617 } else { 618 /* 619 * Setup for next buffer. 620 */ 621 pos = mtod(m, uint8_t *); 622 space = m->m_len; 623 } 624 } 625 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 626 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 627 "[%6D] AES-CCM decrypt failed; MIC mismatch\n", 628 wh->i_addr2, ":"); 629 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 630 return 0; 631 } 632 return 1; 633 } 634 #undef CCMP_DECRYPT 635 636 /* 637 * Module glue. 638 */ 639 static int 640 ccmp_modevent(module_t mod, int type, void *unused) 641 { 642 switch (type) { 643 case MOD_LOAD: 644 ieee80211_crypto_register(&ccmp); 645 return 0; 646 case MOD_UNLOAD: 647 if (nrefs) { 648 printf("wlan_ccmp: still in use (%u dynamic refs)\n", 649 nrefs); 650 return EBUSY; 651 } 652 ieee80211_crypto_unregister(&ccmp); 653 return 0; 654 } 655 return EINVAL; 656 } 657 658 static moduledata_t ccmp_mod = { 659 "wlan_ccmp", 660 ccmp_modevent, 661 0 662 }; 663 DECLARE_MODULE(wlan_ccmp, ccmp_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 664 MODULE_VERSION(wlan_ccmp, 1); 665 MODULE_DEPEND(wlan_ccmp, wlan, 1, 1, 1); 666