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_media.h> 53#include <net/ethernet.h> 54 55#include <net80211/ieee80211_var.h> 56 57#include <crypto/rijndael/rijndael.h> 58 59#define AES_BLOCK_LEN 16 60 61struct ccmp_ctx { 62 struct ieee80211com *cc_ic; /* for diagnostics */ 63 rijndael_ctx cc_aes; 64}; 65 66static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 67static void ccmp_detach(struct ieee80211_key *); 68static int ccmp_setkey(struct ieee80211_key *); 69static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, u_int8_t keyid); 70static int ccmp_decap(struct ieee80211_key *, struct mbuf *); 71static int ccmp_enmic(struct ieee80211_key *, struct mbuf *); 72static int ccmp_demic(struct ieee80211_key *, struct mbuf *); 73 74static const struct ieee80211_cipher ccmp = { 75 .ic_name = "AES-CCM", 76 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 77 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 78 IEEE80211_WEP_EXTIVLEN, 79 .ic_trailer = IEEE80211_WEP_MICLEN, 80 .ic_miclen = 0, 81 .ic_attach = ccmp_attach, 82 .ic_detach = ccmp_detach, 83 .ic_setkey = ccmp_setkey, 84 .ic_encap = ccmp_encap, 85 .ic_decap = ccmp_decap, 86 .ic_enmic = ccmp_enmic, 87 .ic_demic = ccmp_demic, 88}; 89 90static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 91static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 92 struct mbuf *, int hdrlen); 93 94static void * 95ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 96{ 97 struct ccmp_ctx *ctx; 98 99 MALLOC(ctx, struct ccmp_ctx *, sizeof(struct ccmp_ctx), 100 M_DEVBUF, M_NOWAIT | M_ZERO); 101 if (ctx == NULL) { 102 ic->ic_stats.is_crypto_nomem++; 103 return NULL; 104 } 105 ctx->cc_ic = ic; 106 return ctx; 107} 108 109static void 110ccmp_detach(struct ieee80211_key *k) 111{ 112 struct ccmp_ctx *ctx = k->wk_private; 113 114 FREE(ctx, M_DEVBUF); 115} 116 117static int 118ccmp_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 */ 136static int 137ccmp_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) 138{ 139 struct ccmp_ctx *ctx = k->wk_private; 140 struct ieee80211com *ic = ctx->cc_ic; 141 u_int8_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, u_int8_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 */ 179static int 180ccmp_enmic(struct ieee80211_key *k, struct mbuf *m) 181{ 182 183 return 1; 184} 185 186static __inline uint64_t 187READ_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 */ 199static int 200ccmp_decap(struct ieee80211_key *k, struct mbuf *m) 201{ 202 struct ccmp_ctx *ctx = k->wk_private; 203 struct ieee80211_frame *wh; 204 uint8_t *ivp; 205 uint64_t pn; 206 int hdrlen; 207 208 /* 209 * Header should have extended IV and sequence number; 210 * verify the former and validate the latter. 211 */ 212 wh = mtod(m, struct ieee80211_frame *); 213 hdrlen = ieee80211_hdrsize(wh); 214 ivp = mtod(m, uint8_t *) + hdrlen; 215 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 216 /* 217 * No extended IV; discard frame. 218 */ 219 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 220 "[%s] Missing ExtIV for AES-CCM cipher\n", 221 ether_sprintf(wh->i_addr2)); 222 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 223 return 0; 224 } 225 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 226 if (pn <= k->wk_keyrsc) { 227 /* 228 * Replay violation. 229 */ 230 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 231 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 232 return 0; 233 } 234 235 /* 236 * Check if the device handled the decrypt in hardware. 237 * If so we just strip the header; otherwise we need to 238 * handle the decrypt in software. Note that for the 239 * latter we leave the header in place for use in the 240 * decryption work. 241 */ 242 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 243 !ccmp_decrypt(k, pn, m, hdrlen)) 244 return 0; 245 246 /* 247 * Copy up 802.11 header and strip crypto bits. 248 */ 249 ovbcopy(mtod(m, void *), mtod(m, u_int8_t *) + ccmp.ic_header, hdrlen); 250 m_adj(m, ccmp.ic_header); 251 m_adj(m, -ccmp.ic_trailer); 252 253 /* 254 * Ok to update rsc now. 255 */ 256 k->wk_keyrsc = pn; 257 258 return 1; 259} 260 261/* 262 * Verify and strip MIC from the frame. 263 */ 264static int 265ccmp_demic(struct ieee80211_key *k, struct mbuf *m) 266{ 267 return 1; 268} 269 270static __inline void 271xor_block(uint8_t *b, const uint8_t *a, size_t len) 272{ 273 int i; 274 for (i = 0; i < len; i++) 275 b[i] ^= a[i]; 276} 277 278/* 279 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 280 * 281 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 282 * 283 * This program is free software; you can redistribute it and/or modify 284 * it under the terms of the GNU General Public License version 2 as 285 * published by the Free Software Foundation. See README and COPYING for 286 * more details. 287 * 288 * Alternatively, this software may be distributed under the terms of BSD 289 * license. 290 */ 291 292static void 293ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 294 u_int64_t pn, size_t dlen, 295 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 296 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 297{ 298#define IS_4ADDRESS(wh) \ 299 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 300#define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 301 302 /* CCM Initial Block: 303 * Flag (Include authentication header, M=3 (8-octet MIC), 304 * L=1 (2-octet Dlen)) 305 * Nonce: 0x00 | A2 | PN 306 * Dlen */ 307 b0[0] = 0x59; 308 /* NB: b0[1] set below */ 309 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 310 b0[8] = pn >> 40; 311 b0[9] = pn >> 32; 312 b0[10] = pn >> 24; 313 b0[11] = pn >> 16; 314 b0[12] = pn >> 8; 315 b0[13] = pn >> 0; 316 b0[14] = (dlen >> 8) & 0xff; 317 b0[15] = dlen & 0xff; 318 319 /* AAD: 320 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 321 * A1 | A2 | A3 322 * SC with bits 4..15 (seq#) masked to zero 323 * A4 (if present) 324 * QC (if present) 325 */ 326 aad[0] = 0; /* AAD length >> 8 */ 327 /* NB: aad[1] set below */ 328 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 329 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 330 /* NB: we know 3 addresses are contiguous */ 331 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 332 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 333 aad[23] = 0; /* all bits masked */ 334 /* 335 * Construct variable-length portion of AAD based 336 * on whether this is a 4-address frame/QOS frame. 337 * We always zero-pad to 32 bytes before running it 338 * through the cipher. 339 * 340 * We also fill in the priority bits of the CCM 341 * initial block as we know whether or not we have 342 * a QOS frame. 343 */ 344 if (IS_4ADDRESS(wh)) { 345 IEEE80211_ADDR_COPY(aad + 24, 346 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 347 if (IS_QOS_DATA(wh)) { 348 struct ieee80211_qosframe_addr4 *qwh4 = 349 (struct ieee80211_qosframe_addr4 *) wh; 350 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 351 aad[31] = 0; 352 b0[1] = aad[30]; 353 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 354 } else { 355 *(u_int16_t *)&aad[30] = 0; 356 b0[1] = 0; 357 aad[1] = 22 + IEEE80211_ADDR_LEN; 358 } 359 } else { 360 if (IS_QOS_DATA(wh)) { 361 struct ieee80211_qosframe *qwh = 362 (struct ieee80211_qosframe*) wh; 363 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 364 aad[25] = 0; 365 b0[1] = aad[24]; 366 aad[1] = 22 + 2; 367 } else { 368 *(u_int16_t *)&aad[24] = 0; 369 b0[1] = 0; 370 aad[1] = 22; 371 } 372 *(u_int16_t *)&aad[26] = 0; 373 *(u_int32_t *)&aad[28] = 0; 374 } 375 376 /* Start with the first block and AAD */ 377 rijndael_encrypt(ctx, b0, auth); 378 xor_block(auth, aad, AES_BLOCK_LEN); 379 rijndael_encrypt(ctx, auth, auth); 380 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 381 rijndael_encrypt(ctx, auth, auth); 382 b0[0] &= 0x07; 383 b0[14] = b0[15] = 0; 384 rijndael_encrypt(ctx, b0, s0); 385#undef IS_QOS_DATA 386#undef IS_4ADDRESS 387} 388 389#define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 390 /* Authentication */ \ 391 xor_block(_b, _pos, _len); \ 392 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 393 /* Encryption, with counter */ \ 394 _b0[14] = (_i >> 8) & 0xff; \ 395 _b0[15] = _i & 0xff; \ 396 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 397 xor_block(_pos, _e, _len); \ 398} while (0) 399 400static int 401ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 402{ 403 struct ccmp_ctx *ctx = key->wk_private; 404 struct ieee80211_frame *wh; 405 struct mbuf *m = m0; 406 int data_len, i; 407 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 408 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 409 uint8_t *pos; 410 u_int space; 411 412 ctx->cc_ic->ic_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 u_int space_next; 450 u_int len; 451 452 /* 453 * Block straddles buffers, split references. We 454 * do not handle splits that require >2 buffers. 455 */ 456 pos_next = mtod(m, uint8_t *); 457 len = min(data_len, AES_BLOCK_LEN); 458 space_next = len > space ? len - space : 0; 459 KASSERT(m->m_len >= space_next, 460 ("not enough data in following buffer, " 461 "m_len %u need %u\n", m->m_len, space_next)); 462 463 xor_block(b+space, pos_next, space_next); 464 CCMP_ENCRYPT(i, b, b0, pos, e, space); 465 xor_block(pos_next, e+space, space_next); 466 data_len -= len; 467 /* XXX could check for data_len <= 0 */ 468 i++; 469 470 pos = pos_next + space_next; 471 space = m->m_len - space_next; 472 } else { 473 /* 474 * Setup for next buffer. 475 */ 476 pos = mtod(m, uint8_t *); 477 space = m->m_len; 478 } 479 } 480 /* tack on MIC */ 481 xor_block(b, s0, ccmp.ic_trailer); 482 return m_append(m0, ccmp.ic_trailer, b); 483} 484#undef CCMP_ENCRYPT 485 486#define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 487 /* Decrypt, with counter */ \ 488 _b0[14] = (_i >> 8) & 0xff; \ 489 _b0[15] = _i & 0xff; \ 490 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 491 xor_block(_pos, _b, _len); \ 492 /* Authentication */ \ 493 xor_block(_a, _pos, _len); \ 494 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 495} while (0) 496 497static int 498ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) 499{ 500 struct ccmp_ctx *ctx = key->wk_private; 501 struct ieee80211_frame *wh; 502 uint8_t aad[2 * AES_BLOCK_LEN]; 503 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 504 uint8_t mic[AES_BLOCK_LEN]; 505 size_t data_len; 506 int i; 507 uint8_t *pos; 508 u_int space; 509 510 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 511 512 wh = mtod(m, struct ieee80211_frame *); 513 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 514 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 515 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 516 xor_block(mic, b, ccmp.ic_trailer); 517 518 i = 1; 519 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 520 space = m->m_len - (hdrlen + ccmp.ic_header); 521 for (;;) { 522 if (space > data_len) 523 space = data_len; 524 while (space >= AES_BLOCK_LEN) { 525 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 526 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 527 data_len -= AES_BLOCK_LEN; 528 i++; 529 } 530 if (data_len <= 0) /* no more data */ 531 break; 532 m = m->m_next; 533 if (m == NULL) { /* last buffer */ 534 if (space != 0) /* short last block */ 535 CCMP_DECRYPT(i, b, b0, pos, a, space); 536 break; 537 } 538 if (space != 0) { 539 uint8_t *pos_next; 540 u_int space_next; 541 u_int len; 542 543 /* 544 * Block straddles buffers, split references. We 545 * do not handle splits that require >2 buffers. 546 */ 547 pos_next = mtod(m, uint8_t *); 548 len = min(data_len, AES_BLOCK_LEN); 549 space_next = len > space ? len - space : 0; 550 KASSERT(m->m_len >= space_next, 551 ("not enough data in following buffer, " 552 "m_len %u need %u\n", m->m_len, space_next)); 553 554 xor_block(b+space, pos_next, space_next); 555 CCMP_DECRYPT(i, b, b0, pos, a, space); 556 xor_block(pos_next, b+space, space_next); 557 data_len -= len; 558 i++; 559 560 pos = pos_next + space_next; 561 space = m->m_len - space_next; 562 } else { 563 /* 564 * Setup for next buffer. 565 */ 566 pos = mtod(m, uint8_t *); 567 space = m->m_len; 568 } 569 } 570 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 571 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 572 "[%s] AES-CCM decrypt failed; MIC mismatch\n", 573 ether_sprintf(wh->i_addr2)); 574 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 575 return 0; 576 } 577 return 1; 578} 579#undef CCMP_DECRYPT 580 581/* 582 * Module glue. 583 */ 584static int 585ccmp_modevent(module_t mod, int type, void *unused) 586{ 587 switch (type) { 588 case MOD_LOAD: 589 ieee80211_crypto_register(&ccmp); 590 return 0; 591 case MOD_UNLOAD: 592 ieee80211_crypto_unregister(&ccmp); 593 return 0; 594 } 595 return EINVAL; 596} 597 598static moduledata_t ccmp_mod = { 599 "wlan_ccmp", 600 ccmp_modevent, 601 0 602}; 603DECLARE_MODULE(wlan_ccmp, ccmp_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 604MODULE_VERSION(wlan_ccmp, 1); 605MODULE_DEPEND(wlan_ccmp, wlan, 1, 1, 1);
| 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_media.h> 53#include <net/ethernet.h> 54 55#include <net80211/ieee80211_var.h> 56 57#include <crypto/rijndael/rijndael.h> 58 59#define AES_BLOCK_LEN 16 60 61struct ccmp_ctx { 62 struct ieee80211com *cc_ic; /* for diagnostics */ 63 rijndael_ctx cc_aes; 64}; 65 66static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *); 67static void ccmp_detach(struct ieee80211_key *); 68static int ccmp_setkey(struct ieee80211_key *); 69static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, u_int8_t keyid); 70static int ccmp_decap(struct ieee80211_key *, struct mbuf *); 71static int ccmp_enmic(struct ieee80211_key *, struct mbuf *); 72static int ccmp_demic(struct ieee80211_key *, struct mbuf *); 73 74static const struct ieee80211_cipher ccmp = { 75 .ic_name = "AES-CCM", 76 .ic_cipher = IEEE80211_CIPHER_AES_CCM, 77 .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + 78 IEEE80211_WEP_EXTIVLEN, 79 .ic_trailer = IEEE80211_WEP_MICLEN, 80 .ic_miclen = 0, 81 .ic_attach = ccmp_attach, 82 .ic_detach = ccmp_detach, 83 .ic_setkey = ccmp_setkey, 84 .ic_encap = ccmp_encap, 85 .ic_decap = ccmp_decap, 86 .ic_enmic = ccmp_enmic, 87 .ic_demic = ccmp_demic, 88}; 89 90static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen); 91static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn, 92 struct mbuf *, int hdrlen); 93 94static void * 95ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k) 96{ 97 struct ccmp_ctx *ctx; 98 99 MALLOC(ctx, struct ccmp_ctx *, sizeof(struct ccmp_ctx), 100 M_DEVBUF, M_NOWAIT | M_ZERO); 101 if (ctx == NULL) { 102 ic->ic_stats.is_crypto_nomem++; 103 return NULL; 104 } 105 ctx->cc_ic = ic; 106 return ctx; 107} 108 109static void 110ccmp_detach(struct ieee80211_key *k) 111{ 112 struct ccmp_ctx *ctx = k->wk_private; 113 114 FREE(ctx, M_DEVBUF); 115} 116 117static int 118ccmp_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 */ 136static int 137ccmp_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid) 138{ 139 struct ccmp_ctx *ctx = k->wk_private; 140 struct ieee80211com *ic = ctx->cc_ic; 141 u_int8_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, u_int8_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 */ 179static int 180ccmp_enmic(struct ieee80211_key *k, struct mbuf *m) 181{ 182 183 return 1; 184} 185 186static __inline uint64_t 187READ_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 */ 199static int 200ccmp_decap(struct ieee80211_key *k, struct mbuf *m) 201{ 202 struct ccmp_ctx *ctx = k->wk_private; 203 struct ieee80211_frame *wh; 204 uint8_t *ivp; 205 uint64_t pn; 206 int hdrlen; 207 208 /* 209 * Header should have extended IV and sequence number; 210 * verify the former and validate the latter. 211 */ 212 wh = mtod(m, struct ieee80211_frame *); 213 hdrlen = ieee80211_hdrsize(wh); 214 ivp = mtod(m, uint8_t *) + hdrlen; 215 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) { 216 /* 217 * No extended IV; discard frame. 218 */ 219 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 220 "[%s] Missing ExtIV for AES-CCM cipher\n", 221 ether_sprintf(wh->i_addr2)); 222 ctx->cc_ic->ic_stats.is_rx_ccmpformat++; 223 return 0; 224 } 225 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]); 226 if (pn <= k->wk_keyrsc) { 227 /* 228 * Replay violation. 229 */ 230 ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn); 231 ctx->cc_ic->ic_stats.is_rx_ccmpreplay++; 232 return 0; 233 } 234 235 /* 236 * Check if the device handled the decrypt in hardware. 237 * If so we just strip the header; otherwise we need to 238 * handle the decrypt in software. Note that for the 239 * latter we leave the header in place for use in the 240 * decryption work. 241 */ 242 if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) && 243 !ccmp_decrypt(k, pn, m, hdrlen)) 244 return 0; 245 246 /* 247 * Copy up 802.11 header and strip crypto bits. 248 */ 249 ovbcopy(mtod(m, void *), mtod(m, u_int8_t *) + ccmp.ic_header, hdrlen); 250 m_adj(m, ccmp.ic_header); 251 m_adj(m, -ccmp.ic_trailer); 252 253 /* 254 * Ok to update rsc now. 255 */ 256 k->wk_keyrsc = pn; 257 258 return 1; 259} 260 261/* 262 * Verify and strip MIC from the frame. 263 */ 264static int 265ccmp_demic(struct ieee80211_key *k, struct mbuf *m) 266{ 267 return 1; 268} 269 270static __inline void 271xor_block(uint8_t *b, const uint8_t *a, size_t len) 272{ 273 int i; 274 for (i = 0; i < len; i++) 275 b[i] ^= a[i]; 276} 277 278/* 279 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver 280 * 281 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi> 282 * 283 * This program is free software; you can redistribute it and/or modify 284 * it under the terms of the GNU General Public License version 2 as 285 * published by the Free Software Foundation. See README and COPYING for 286 * more details. 287 * 288 * Alternatively, this software may be distributed under the terms of BSD 289 * license. 290 */ 291 292static void 293ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh, 294 u_int64_t pn, size_t dlen, 295 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN], 296 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN]) 297{ 298#define IS_4ADDRESS(wh) \ 299 ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS) 300#define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh) 301 302 /* CCM Initial Block: 303 * Flag (Include authentication header, M=3 (8-octet MIC), 304 * L=1 (2-octet Dlen)) 305 * Nonce: 0x00 | A2 | PN 306 * Dlen */ 307 b0[0] = 0x59; 308 /* NB: b0[1] set below */ 309 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2); 310 b0[8] = pn >> 40; 311 b0[9] = pn >> 32; 312 b0[10] = pn >> 24; 313 b0[11] = pn >> 16; 314 b0[12] = pn >> 8; 315 b0[13] = pn >> 0; 316 b0[14] = (dlen >> 8) & 0xff; 317 b0[15] = dlen & 0xff; 318 319 /* AAD: 320 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one 321 * A1 | A2 | A3 322 * SC with bits 4..15 (seq#) masked to zero 323 * A4 (if present) 324 * QC (if present) 325 */ 326 aad[0] = 0; /* AAD length >> 8 */ 327 /* NB: aad[1] set below */ 328 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */ 329 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */ 330 /* NB: we know 3 addresses are contiguous */ 331 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN); 332 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK; 333 aad[23] = 0; /* all bits masked */ 334 /* 335 * Construct variable-length portion of AAD based 336 * on whether this is a 4-address frame/QOS frame. 337 * We always zero-pad to 32 bytes before running it 338 * through the cipher. 339 * 340 * We also fill in the priority bits of the CCM 341 * initial block as we know whether or not we have 342 * a QOS frame. 343 */ 344 if (IS_4ADDRESS(wh)) { 345 IEEE80211_ADDR_COPY(aad + 24, 346 ((struct ieee80211_frame_addr4 *)wh)->i_addr4); 347 if (IS_QOS_DATA(wh)) { 348 struct ieee80211_qosframe_addr4 *qwh4 = 349 (struct ieee80211_qosframe_addr4 *) wh; 350 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */ 351 aad[31] = 0; 352 b0[1] = aad[30]; 353 aad[1] = 22 + IEEE80211_ADDR_LEN + 2; 354 } else { 355 *(u_int16_t *)&aad[30] = 0; 356 b0[1] = 0; 357 aad[1] = 22 + IEEE80211_ADDR_LEN; 358 } 359 } else { 360 if (IS_QOS_DATA(wh)) { 361 struct ieee80211_qosframe *qwh = 362 (struct ieee80211_qosframe*) wh; 363 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */ 364 aad[25] = 0; 365 b0[1] = aad[24]; 366 aad[1] = 22 + 2; 367 } else { 368 *(u_int16_t *)&aad[24] = 0; 369 b0[1] = 0; 370 aad[1] = 22; 371 } 372 *(u_int16_t *)&aad[26] = 0; 373 *(u_int32_t *)&aad[28] = 0; 374 } 375 376 /* Start with the first block and AAD */ 377 rijndael_encrypt(ctx, b0, auth); 378 xor_block(auth, aad, AES_BLOCK_LEN); 379 rijndael_encrypt(ctx, auth, auth); 380 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN); 381 rijndael_encrypt(ctx, auth, auth); 382 b0[0] &= 0x07; 383 b0[14] = b0[15] = 0; 384 rijndael_encrypt(ctx, b0, s0); 385#undef IS_QOS_DATA 386#undef IS_4ADDRESS 387} 388 389#define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \ 390 /* Authentication */ \ 391 xor_block(_b, _pos, _len); \ 392 rijndael_encrypt(&ctx->cc_aes, _b, _b); \ 393 /* Encryption, with counter */ \ 394 _b0[14] = (_i >> 8) & 0xff; \ 395 _b0[15] = _i & 0xff; \ 396 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \ 397 xor_block(_pos, _e, _len); \ 398} while (0) 399 400static int 401ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen) 402{ 403 struct ccmp_ctx *ctx = key->wk_private; 404 struct ieee80211_frame *wh; 405 struct mbuf *m = m0; 406 int data_len, i; 407 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], 408 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN]; 409 uint8_t *pos; 410 u_int space; 411 412 ctx->cc_ic->ic_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 u_int space_next; 450 u_int len; 451 452 /* 453 * Block straddles buffers, split references. We 454 * do not handle splits that require >2 buffers. 455 */ 456 pos_next = mtod(m, uint8_t *); 457 len = min(data_len, AES_BLOCK_LEN); 458 space_next = len > space ? len - space : 0; 459 KASSERT(m->m_len >= space_next, 460 ("not enough data in following buffer, " 461 "m_len %u need %u\n", m->m_len, space_next)); 462 463 xor_block(b+space, pos_next, space_next); 464 CCMP_ENCRYPT(i, b, b0, pos, e, space); 465 xor_block(pos_next, e+space, space_next); 466 data_len -= len; 467 /* XXX could check for data_len <= 0 */ 468 i++; 469 470 pos = pos_next + space_next; 471 space = m->m_len - space_next; 472 } else { 473 /* 474 * Setup for next buffer. 475 */ 476 pos = mtod(m, uint8_t *); 477 space = m->m_len; 478 } 479 } 480 /* tack on MIC */ 481 xor_block(b, s0, ccmp.ic_trailer); 482 return m_append(m0, ccmp.ic_trailer, b); 483} 484#undef CCMP_ENCRYPT 485 486#define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \ 487 /* Decrypt, with counter */ \ 488 _b0[14] = (_i >> 8) & 0xff; \ 489 _b0[15] = _i & 0xff; \ 490 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \ 491 xor_block(_pos, _b, _len); \ 492 /* Authentication */ \ 493 xor_block(_a, _pos, _len); \ 494 rijndael_encrypt(&ctx->cc_aes, _a, _a); \ 495} while (0) 496 497static int 498ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen) 499{ 500 struct ccmp_ctx *ctx = key->wk_private; 501 struct ieee80211_frame *wh; 502 uint8_t aad[2 * AES_BLOCK_LEN]; 503 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN]; 504 uint8_t mic[AES_BLOCK_LEN]; 505 size_t data_len; 506 int i; 507 uint8_t *pos; 508 u_int space; 509 510 ctx->cc_ic->ic_stats.is_crypto_ccmp++; 511 512 wh = mtod(m, struct ieee80211_frame *); 513 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer); 514 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b); 515 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic); 516 xor_block(mic, b, ccmp.ic_trailer); 517 518 i = 1; 519 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header; 520 space = m->m_len - (hdrlen + ccmp.ic_header); 521 for (;;) { 522 if (space > data_len) 523 space = data_len; 524 while (space >= AES_BLOCK_LEN) { 525 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN); 526 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN; 527 data_len -= AES_BLOCK_LEN; 528 i++; 529 } 530 if (data_len <= 0) /* no more data */ 531 break; 532 m = m->m_next; 533 if (m == NULL) { /* last buffer */ 534 if (space != 0) /* short last block */ 535 CCMP_DECRYPT(i, b, b0, pos, a, space); 536 break; 537 } 538 if (space != 0) { 539 uint8_t *pos_next; 540 u_int space_next; 541 u_int len; 542 543 /* 544 * Block straddles buffers, split references. We 545 * do not handle splits that require >2 buffers. 546 */ 547 pos_next = mtod(m, uint8_t *); 548 len = min(data_len, AES_BLOCK_LEN); 549 space_next = len > space ? len - space : 0; 550 KASSERT(m->m_len >= space_next, 551 ("not enough data in following buffer, " 552 "m_len %u need %u\n", m->m_len, space_next)); 553 554 xor_block(b+space, pos_next, space_next); 555 CCMP_DECRYPT(i, b, b0, pos, a, space); 556 xor_block(pos_next, b+space, space_next); 557 data_len -= len; 558 i++; 559 560 pos = pos_next + space_next; 561 space = m->m_len - space_next; 562 } else { 563 /* 564 * Setup for next buffer. 565 */ 566 pos = mtod(m, uint8_t *); 567 space = m->m_len; 568 } 569 } 570 if (memcmp(mic, a, ccmp.ic_trailer) != 0) { 571 IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO, 572 "[%s] AES-CCM decrypt failed; MIC mismatch\n", 573 ether_sprintf(wh->i_addr2)); 574 ctx->cc_ic->ic_stats.is_rx_ccmpmic++; 575 return 0; 576 } 577 return 1; 578} 579#undef CCMP_DECRYPT 580 581/* 582 * Module glue. 583 */ 584static int 585ccmp_modevent(module_t mod, int type, void *unused) 586{ 587 switch (type) { 588 case MOD_LOAD: 589 ieee80211_crypto_register(&ccmp); 590 return 0; 591 case MOD_UNLOAD: 592 ieee80211_crypto_unregister(&ccmp); 593 return 0; 594 } 595 return EINVAL; 596} 597 598static moduledata_t ccmp_mod = { 599 "wlan_ccmp", 600 ccmp_modevent, 601 0 602}; 603DECLARE_MODULE(wlan_ccmp, ccmp_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST); 604MODULE_VERSION(wlan_ccmp, 1); 605MODULE_DEPEND(wlan_ccmp, wlan, 1, 1, 1);
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