2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
32 * IEEE 802.11i AES-CCMP crypto support.
34 * Part of this module is derived from similar code in the Host
35 * AP driver. The code is used with the consent of the author and
36 * it's license is included below.
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/malloc.h>
44 #include <sys/kernel.h>
45 #include <sys/module.h>
47 #include <sys/socket.h>
50 #include <net/if_media.h>
51 #include <net/ethernet.h>
53 #include <net80211/ieee80211_var.h>
55 #include <crypto/rijndael/rijndael.h>
57 #define AES_BLOCK_LEN 16
60 struct ieee80211vap *cc_vap; /* for diagnostics+statistics */
61 struct ieee80211com *cc_ic;
65 static void *ccmp_attach(struct ieee80211vap *, struct ieee80211_key *);
66 static void ccmp_detach(struct ieee80211_key *);
67 static int ccmp_setkey(struct ieee80211_key *);
68 static void ccmp_setiv(struct ieee80211_key *, uint8_t *);
69 static int ccmp_encap(struct ieee80211_key *, struct mbuf *);
70 static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int);
71 static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int);
72 static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int);
74 static const struct ieee80211_cipher ccmp = {
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,
81 .ic_attach = ccmp_attach,
82 .ic_detach = ccmp_detach,
83 .ic_setkey = ccmp_setkey,
84 .ic_setiv = ccmp_setiv,
85 .ic_encap = ccmp_encap,
86 .ic_decap = ccmp_decap,
87 .ic_enmic = ccmp_enmic,
88 .ic_demic = ccmp_demic,
91 static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
92 static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn,
93 struct mbuf *, int hdrlen);
95 /* number of references from net80211 layer */
99 ccmp_attach(struct ieee80211vap *vap, struct ieee80211_key *k)
101 struct ccmp_ctx *ctx;
103 ctx = (struct ccmp_ctx *) IEEE80211_MALLOC(sizeof(struct ccmp_ctx),
104 M_80211_CRYPTO, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
106 vap->iv_stats.is_crypto_nomem++;
110 ctx->cc_ic = vap->iv_ic;
111 nrefs++; /* NB: we assume caller locking */
116 ccmp_detach(struct ieee80211_key *k)
118 struct ccmp_ctx *ctx = k->wk_private;
120 IEEE80211_FREE(ctx, M_80211_CRYPTO);
121 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
122 nrefs--; /* NB: we assume caller locking */
126 ccmp_setkey(struct ieee80211_key *k)
128 struct ccmp_ctx *ctx = k->wk_private;
130 if (k->wk_keylen != (128/NBBY)) {
131 IEEE80211_DPRINTF(ctx->cc_vap, IEEE80211_MSG_CRYPTO,
132 "%s: Invalid key length %u, expecting %u\n",
133 __func__, k->wk_keylen, 128/NBBY);
136 if (k->wk_flags & IEEE80211_KEY_SWENCRYPT)
137 rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY);
142 ccmp_setiv(struct ieee80211_key *k, uint8_t *ivp)
144 struct ccmp_ctx *ctx = k->wk_private;
145 struct ieee80211vap *vap = ctx->cc_vap;
148 keyid = ieee80211_crypto_get_keyid(vap, k) << 6;
151 ivp[0] = k->wk_keytsc >> 0; /* PN0 */
152 ivp[1] = k->wk_keytsc >> 8; /* PN1 */
153 ivp[2] = 0; /* Reserved */
154 ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */
155 ivp[4] = k->wk_keytsc >> 16; /* PN2 */
156 ivp[5] = k->wk_keytsc >> 24; /* PN3 */
157 ivp[6] = k->wk_keytsc >> 32; /* PN4 */
158 ivp[7] = k->wk_keytsc >> 40; /* PN5 */
162 * Add privacy headers appropriate for the specified key.
165 ccmp_encap(struct ieee80211_key *k, struct mbuf *m)
167 const struct ieee80211_frame *wh;
168 struct ccmp_ctx *ctx = k->wk_private;
169 struct ieee80211com *ic = ctx->cc_ic;
174 hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
175 wh = mtod(m, const struct ieee80211_frame *);
176 is_mgmt = IEEE80211_IS_MGMT(wh);
179 * Check to see if we need to insert IV/MIC.
181 * Some offload devices don't require the IV to be inserted
182 * as part of the hardware encryption.
184 if (is_mgmt && (k->wk_flags & IEEE80211_KEY_NOIVMGT))
186 if ((! is_mgmt) && (k->wk_flags & IEEE80211_KEY_NOIV))
190 * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
192 M_PREPEND(m, ccmp.ic_header, M_NOWAIT);
195 ivp = mtod(m, uint8_t *);
196 ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen);
202 * Finally, do software encrypt if needed.
204 if ((k->wk_flags & IEEE80211_KEY_SWENCRYPT) &&
205 !ccmp_encrypt(k, m, hdrlen))
212 * Add MIC to the frame as needed.
215 ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
221 static __inline uint64_t
222 READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5)
224 uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24);
225 uint16_t iv16 = (b4 << 0) | (b5 << 8);
226 return (((uint64_t)iv16) << 32) | iv32;
230 * Validate and strip privacy headers (and trailer) for a
231 * received frame. The specified key should be correct but
235 ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
237 const struct ieee80211_rx_stats *rxs;
238 struct ccmp_ctx *ctx = k->wk_private;
239 struct ieee80211vap *vap = ctx->cc_vap;
240 struct ieee80211_frame *wh;
244 rxs = ieee80211_get_rx_params_ptr(m);
246 if ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP))
250 * Header should have extended IV and sequence number;
251 * verify the former and validate the latter.
253 wh = mtod(m, struct ieee80211_frame *);
254 ivp = mtod(m, uint8_t *) + hdrlen;
255 if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
257 * No extended IV; discard frame.
259 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
260 "%s", "missing ExtIV for AES-CCM cipher");
261 vap->iv_stats.is_rx_ccmpformat++;
264 tid = ieee80211_gettid(wh);
265 pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]);
266 if (pn <= k->wk_keyrsc[tid] &&
267 (k->wk_flags & IEEE80211_KEY_NOREPLAY) == 0) {
271 ieee80211_notify_replay_failure(vap, wh, k, pn, tid);
272 vap->iv_stats.is_rx_ccmpreplay++;
277 * Check if the device handled the decrypt in hardware.
278 * If so we just strip the header; otherwise we need to
279 * handle the decrypt in software. Note that for the
280 * latter we leave the header in place for use in the
283 if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) &&
284 !ccmp_decrypt(k, pn, m, hdrlen))
289 * Copy up 802.11 header and strip crypto bits.
291 if (! ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP))) {
292 ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp.ic_header,
294 m_adj(m, ccmp.ic_header);
298 * XXX TODO: see if MMIC_STRIP also covers CCMP MIC trailer.
300 if (! ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_MMIC_STRIP)))
301 m_adj(m, -ccmp.ic_trailer);
304 * Ok to update rsc now.
306 if (! ((rxs != NULL) && (rxs->c_pktflags & IEEE80211_RX_F_IV_STRIP))) {
307 k->wk_keyrsc[tid] = pn;
314 * Verify and strip MIC from the frame.
317 ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force)
323 xor_block(uint8_t *b, const uint8_t *a, size_t len)
326 for (i = 0; i < len; i++)
331 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
333 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
335 * This program is free software; you can redistribute it and/or modify
336 * it under the terms of the GNU General Public License version 2 as
337 * published by the Free Software Foundation. See README and COPYING for
340 * Alternatively, this software may be distributed under the terms of BSD
345 ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh,
346 u_int64_t pn, size_t dlen,
347 uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN],
348 uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN])
350 #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh)
352 /* CCM Initial Block:
353 * Flag (Include authentication header, M=3 (8-octet MIC),
354 * L=1 (2-octet Dlen))
355 * Nonce: 0x00 | A2 | PN
358 /* NB: b0[1] set below */
359 IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2);
366 b0[14] = (dlen >> 8) & 0xff;
367 b0[15] = dlen & 0xff;
370 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
372 * SC with bits 4..15 (seq#) masked to zero
376 aad[0] = 0; /* AAD length >> 8 */
377 /* NB: aad[1] set below */
378 aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */
379 aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */
380 /* NB: we know 3 addresses are contiguous */
381 memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN);
382 aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK;
383 aad[23] = 0; /* all bits masked */
385 * Construct variable-length portion of AAD based
386 * on whether this is a 4-address frame/QOS frame.
387 * We always zero-pad to 32 bytes before running it
388 * through the cipher.
390 * We also fill in the priority bits of the CCM
391 * initial block as we know whether or not we have
394 if (IEEE80211_IS_DSTODS(wh)) {
395 IEEE80211_ADDR_COPY(aad + 24,
396 ((struct ieee80211_frame_addr4 *)wh)->i_addr4);
397 if (IS_QOS_DATA(wh)) {
398 struct ieee80211_qosframe_addr4 *qwh4 =
399 (struct ieee80211_qosframe_addr4 *) wh;
400 aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */
403 aad[1] = 22 + IEEE80211_ADDR_LEN + 2;
405 *(uint16_t *)&aad[30] = 0;
407 aad[1] = 22 + IEEE80211_ADDR_LEN;
410 if (IS_QOS_DATA(wh)) {
411 struct ieee80211_qosframe *qwh =
412 (struct ieee80211_qosframe*) wh;
413 aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */
418 *(uint16_t *)&aad[24] = 0;
422 *(uint16_t *)&aad[26] = 0;
423 *(uint32_t *)&aad[28] = 0;
426 /* Start with the first block and AAD */
427 rijndael_encrypt(ctx, b0, auth);
428 xor_block(auth, aad, AES_BLOCK_LEN);
429 rijndael_encrypt(ctx, auth, auth);
430 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
431 rijndael_encrypt(ctx, auth, auth);
434 rijndael_encrypt(ctx, b0, s0);
438 #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \
439 /* Authentication */ \
440 xor_block(_b, _pos, _len); \
441 rijndael_encrypt(&ctx->cc_aes, _b, _b); \
442 /* Encryption, with counter */ \
443 _b0[14] = (_i >> 8) & 0xff; \
444 _b0[15] = _i & 0xff; \
445 rijndael_encrypt(&ctx->cc_aes, _b0, _e); \
446 xor_block(_pos, _e, _len); \
450 ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
452 struct ccmp_ctx *ctx = key->wk_private;
453 struct ieee80211_frame *wh;
455 int data_len, i, space;
456 uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN],
457 e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN];
460 ctx->cc_vap->iv_stats.is_crypto_ccmp++;
462 wh = mtod(m, struct ieee80211_frame *);
463 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header);
464 ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc,
465 data_len, b0, aad, b, s0);
468 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
469 /* NB: assumes header is entirely in first mbuf */
470 space = m->m_len - (hdrlen + ccmp.ic_header);
472 if (space > data_len)
477 while (space >= AES_BLOCK_LEN) {
478 CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN);
479 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
480 data_len -= AES_BLOCK_LEN;
483 if (data_len <= 0) /* no more data */
486 if (m == NULL) { /* last buffer */
491 CCMP_ENCRYPT(i, b, b0, pos, e, space);
502 * Block straddles one or more mbufs, gather data
503 * into the block buffer b, apply the cipher, then
504 * scatter the results back into the mbuf chain.
505 * The buffer will automatically get space bytes
506 * of data at offset 0 copied in+out by the
507 * CCMP_ENCRYPT request so we must take care of
508 * the remaining data.
514 pos_next = mtod(n, uint8_t *);
515 len = min(dl, AES_BLOCK_LEN);
516 space_next = len > sp ? len - sp : 0;
517 if (n->m_len >= space_next) {
519 * This mbuf has enough data; just grab
520 * what we need and stop.
522 xor_block(b+sp, pos_next, space_next);
526 * This mbuf's contents are insufficient,
527 * take 'em all and prepare to advance to
530 xor_block(b+sp, pos_next, n->m_len);
531 sp += n->m_len, dl -= n->m_len;
537 CCMP_ENCRYPT(i, b, b0, pos, e, space);
539 /* NB: just like above, but scatter data to mbufs */
543 pos_next = mtod(m, uint8_t *);
544 len = min(dl, AES_BLOCK_LEN);
545 space_next = len > sp ? len - sp : 0;
546 if (m->m_len >= space_next) {
547 xor_block(pos_next, e+sp, space_next);
550 xor_block(pos_next, e+sp, m->m_len);
551 sp += m->m_len, dl -= m->m_len;
557 * Do bookkeeping. m now points to the last mbuf
558 * we grabbed data from. We know we consumed a
559 * full block of data as otherwise we'd have hit
560 * the end of the mbuf chain, so deduct from data_len.
561 * Otherwise advance the block number (i) and setup
562 * pos+space to reflect contents of the new mbuf.
564 data_len -= AES_BLOCK_LEN;
566 pos = pos_next + space_next;
567 space = m->m_len - space_next;
570 * Setup for next buffer.
572 pos = mtod(m, uint8_t *);
578 xor_block(b, s0, ccmp.ic_trailer);
579 return m_append(m0, ccmp.ic_trailer, b);
583 #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \
584 /* Decrypt, with counter */ \
585 _b0[14] = (_i >> 8) & 0xff; \
586 _b0[15] = _i & 0xff; \
587 rijndael_encrypt(&ctx->cc_aes, _b0, _b); \
588 xor_block(_pos, _b, _len); \
589 /* Authentication */ \
590 xor_block(_a, _pos, _len); \
591 rijndael_encrypt(&ctx->cc_aes, _a, _a); \
595 ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen)
597 struct ccmp_ctx *ctx = key->wk_private;
598 struct ieee80211vap *vap = ctx->cc_vap;
599 struct ieee80211_frame *wh;
600 uint8_t aad[2 * AES_BLOCK_LEN];
601 uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN];
602 uint8_t mic[AES_BLOCK_LEN];
608 ctx->cc_vap->iv_stats.is_crypto_ccmp++;
610 wh = mtod(m, struct ieee80211_frame *);
611 data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer);
612 ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b);
613 m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic);
614 xor_block(mic, b, ccmp.ic_trailer);
617 pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
618 space = m->m_len - (hdrlen + ccmp.ic_header);
620 if (space > data_len)
622 while (space >= AES_BLOCK_LEN) {
623 CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN);
624 pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
625 data_len -= AES_BLOCK_LEN;
628 if (data_len <= 0) /* no more data */
631 if (m == NULL) { /* last buffer */
632 if (space != 0) /* short last block */
633 CCMP_DECRYPT(i, b, b0, pos, a, space);
642 * Block straddles buffers, split references. We
643 * do not handle splits that require >2 buffers
644 * since rx'd frames are never badly fragmented
645 * because drivers typically recv in clusters.
647 pos_next = mtod(m, uint8_t *);
648 len = min(data_len, AES_BLOCK_LEN);
649 space_next = len > space ? len - space : 0;
650 KASSERT(m->m_len >= space_next,
651 ("not enough data in following buffer, "
652 "m_len %u need %u\n", m->m_len, space_next));
654 xor_block(b+space, pos_next, space_next);
655 CCMP_DECRYPT(i, b, b0, pos, a, space);
656 xor_block(pos_next, b+space, space_next);
660 pos = pos_next + space_next;
661 space = m->m_len - space_next;
664 * Setup for next buffer.
666 pos = mtod(m, uint8_t *);
670 if (memcmp(mic, a, ccmp.ic_trailer) != 0) {
671 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
672 "%s", "AES-CCM decrypt failed; MIC mismatch");
673 vap->iv_stats.is_rx_ccmpmic++;
683 IEEE80211_CRYPTO_MODULE(ccmp, 1);