ieee80211_crypto_ccmp.c revision 1.1.1.2 1 1.1 dyoung /*-
2 1.1 dyoung * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
3 1.1 dyoung * All rights reserved.
4 1.1 dyoung *
5 1.1 dyoung * Redistribution and use in source and binary forms, with or without
6 1.1 dyoung * modification, are permitted provided that the following conditions
7 1.1 dyoung * are met:
8 1.1 dyoung * 1. Redistributions of source code must retain the above copyright
9 1.1 dyoung * notice, this list of conditions and the following disclaimer.
10 1.1 dyoung * 2. Redistributions in binary form must reproduce the above copyright
11 1.1 dyoung * notice, this list of conditions and the following disclaimer in the
12 1.1 dyoung * documentation and/or other materials provided with the distribution.
13 1.1 dyoung * 3. The name of the author may not be used to endorse or promote products
14 1.1 dyoung * derived from this software without specific prior written permission.
15 1.1 dyoung *
16 1.1 dyoung * Alternatively, this software may be distributed under the terms of the
17 1.1 dyoung * GNU General Public License ("GPL") version 2 as published by the Free
18 1.1 dyoung * Software Foundation.
19 1.1 dyoung *
20 1.1 dyoung * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 1.1 dyoung * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 1.1 dyoung * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 1.1 dyoung * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 1.1 dyoung * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 1.1 dyoung * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 1.1 dyoung * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 1.1 dyoung * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 1.1 dyoung * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 1.1 dyoung * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 1.1 dyoung */
31 1.1 dyoung
32 1.1 dyoung #include <sys/cdefs.h>
33 1.1.1.2 dyoung __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_ccmp.c,v 1.7 2005/07/11 03:06:23 sam Exp $");
34 1.1 dyoung
35 1.1 dyoung /*
36 1.1 dyoung * IEEE 802.11i AES-CCMP crypto support.
37 1.1 dyoung *
38 1.1 dyoung * Part of this module is derived from similar code in the Host
39 1.1 dyoung * AP driver. The code is used with the consent of the author and
40 1.1 dyoung * it's license is included below.
41 1.1 dyoung */
42 1.1 dyoung #include <sys/param.h>
43 1.1 dyoung #include <sys/systm.h>
44 1.1 dyoung #include <sys/mbuf.h>
45 1.1 dyoung #include <sys/malloc.h>
46 1.1 dyoung #include <sys/kernel.h>
47 1.1 dyoung #include <sys/module.h>
48 1.1 dyoung
49 1.1 dyoung #include <sys/socket.h>
50 1.1 dyoung
51 1.1 dyoung #include <net/if.h>
52 1.1 dyoung #include <net/if_media.h>
53 1.1 dyoung #include <net/ethernet.h>
54 1.1 dyoung
55 1.1 dyoung #include <net80211/ieee80211_var.h>
56 1.1 dyoung
57 1.1 dyoung #include <crypto/rijndael/rijndael.h>
58 1.1 dyoung
59 1.1 dyoung #define AES_BLOCK_LEN 16
60 1.1 dyoung
61 1.1 dyoung struct ccmp_ctx {
62 1.1 dyoung struct ieee80211com *cc_ic; /* for diagnostics */
63 1.1 dyoung rijndael_ctx cc_aes;
64 1.1 dyoung };
65 1.1 dyoung
66 1.1 dyoung static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *);
67 1.1 dyoung static void ccmp_detach(struct ieee80211_key *);
68 1.1 dyoung static int ccmp_setkey(struct ieee80211_key *);
69 1.1 dyoung static int ccmp_encap(struct ieee80211_key *k, struct mbuf *, u_int8_t keyid);
70 1.1.1.2 dyoung static int ccmp_decap(struct ieee80211_key *, struct mbuf *, int);
71 1.1.1.2 dyoung static int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int);
72 1.1.1.2 dyoung static int ccmp_demic(struct ieee80211_key *, struct mbuf *, int);
73 1.1 dyoung
74 1.1 dyoung static const struct ieee80211_cipher ccmp = {
75 1.1 dyoung .ic_name = "AES-CCM",
76 1.1 dyoung .ic_cipher = IEEE80211_CIPHER_AES_CCM,
77 1.1 dyoung .ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN +
78 1.1 dyoung IEEE80211_WEP_EXTIVLEN,
79 1.1 dyoung .ic_trailer = IEEE80211_WEP_MICLEN,
80 1.1 dyoung .ic_miclen = 0,
81 1.1 dyoung .ic_attach = ccmp_attach,
82 1.1 dyoung .ic_detach = ccmp_detach,
83 1.1 dyoung .ic_setkey = ccmp_setkey,
84 1.1 dyoung .ic_encap = ccmp_encap,
85 1.1 dyoung .ic_decap = ccmp_decap,
86 1.1 dyoung .ic_enmic = ccmp_enmic,
87 1.1 dyoung .ic_demic = ccmp_demic,
88 1.1 dyoung };
89 1.1 dyoung
90 1.1 dyoung static int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
91 1.1 dyoung static int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn,
92 1.1 dyoung struct mbuf *, int hdrlen);
93 1.1 dyoung
94 1.1 dyoung static void *
95 1.1 dyoung ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k)
96 1.1 dyoung {
97 1.1 dyoung struct ccmp_ctx *ctx;
98 1.1 dyoung
99 1.1 dyoung MALLOC(ctx, struct ccmp_ctx *, sizeof(struct ccmp_ctx),
100 1.1 dyoung M_DEVBUF, M_NOWAIT | M_ZERO);
101 1.1 dyoung if (ctx == NULL) {
102 1.1 dyoung ic->ic_stats.is_crypto_nomem++;
103 1.1 dyoung return NULL;
104 1.1 dyoung }
105 1.1 dyoung ctx->cc_ic = ic;
106 1.1 dyoung return ctx;
107 1.1 dyoung }
108 1.1 dyoung
109 1.1 dyoung static void
110 1.1 dyoung ccmp_detach(struct ieee80211_key *k)
111 1.1 dyoung {
112 1.1 dyoung struct ccmp_ctx *ctx = k->wk_private;
113 1.1 dyoung
114 1.1 dyoung FREE(ctx, M_DEVBUF);
115 1.1 dyoung }
116 1.1 dyoung
117 1.1 dyoung static int
118 1.1 dyoung ccmp_setkey(struct ieee80211_key *k)
119 1.1 dyoung {
120 1.1 dyoung struct ccmp_ctx *ctx = k->wk_private;
121 1.1 dyoung
122 1.1 dyoung if (k->wk_keylen != (128/NBBY)) {
123 1.1 dyoung IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO,
124 1.1 dyoung "%s: Invalid key length %u, expecting %u\n",
125 1.1 dyoung __func__, k->wk_keylen, 128/NBBY);
126 1.1 dyoung return 0;
127 1.1 dyoung }
128 1.1 dyoung if (k->wk_flags & IEEE80211_KEY_SWCRYPT)
129 1.1 dyoung rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY);
130 1.1 dyoung return 1;
131 1.1 dyoung }
132 1.1 dyoung
133 1.1 dyoung /*
134 1.1 dyoung * Add privacy headers appropriate for the specified key.
135 1.1 dyoung */
136 1.1 dyoung static int
137 1.1 dyoung ccmp_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid)
138 1.1 dyoung {
139 1.1 dyoung struct ccmp_ctx *ctx = k->wk_private;
140 1.1 dyoung struct ieee80211com *ic = ctx->cc_ic;
141 1.1 dyoung u_int8_t *ivp;
142 1.1 dyoung int hdrlen;
143 1.1 dyoung
144 1.1 dyoung hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
145 1.1 dyoung
146 1.1 dyoung /*
147 1.1 dyoung * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
148 1.1 dyoung */
149 1.1 dyoung M_PREPEND(m, ccmp.ic_header, M_NOWAIT);
150 1.1 dyoung if (m == NULL)
151 1.1 dyoung return 0;
152 1.1 dyoung ivp = mtod(m, u_int8_t *);
153 1.1 dyoung ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen);
154 1.1 dyoung ivp += hdrlen;
155 1.1 dyoung
156 1.1 dyoung k->wk_keytsc++; /* XXX wrap at 48 bits */
157 1.1 dyoung ivp[0] = k->wk_keytsc >> 0; /* PN0 */
158 1.1 dyoung ivp[1] = k->wk_keytsc >> 8; /* PN1 */
159 1.1 dyoung ivp[2] = 0; /* Reserved */
160 1.1 dyoung ivp[3] = keyid | IEEE80211_WEP_EXTIV; /* KeyID | ExtID */
161 1.1 dyoung ivp[4] = k->wk_keytsc >> 16; /* PN2 */
162 1.1 dyoung ivp[5] = k->wk_keytsc >> 24; /* PN3 */
163 1.1 dyoung ivp[6] = k->wk_keytsc >> 32; /* PN4 */
164 1.1 dyoung ivp[7] = k->wk_keytsc >> 40; /* PN5 */
165 1.1 dyoung
166 1.1 dyoung /*
167 1.1 dyoung * Finally, do software encrypt if neeed.
168 1.1 dyoung */
169 1.1 dyoung if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
170 1.1 dyoung !ccmp_encrypt(k, m, hdrlen))
171 1.1 dyoung return 0;
172 1.1 dyoung
173 1.1 dyoung return 1;
174 1.1 dyoung }
175 1.1 dyoung
176 1.1 dyoung /*
177 1.1 dyoung * Add MIC to the frame as needed.
178 1.1 dyoung */
179 1.1 dyoung static int
180 1.1.1.2 dyoung ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
181 1.1 dyoung {
182 1.1 dyoung
183 1.1 dyoung return 1;
184 1.1 dyoung }
185 1.1 dyoung
186 1.1 dyoung static __inline uint64_t
187 1.1 dyoung READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5)
188 1.1 dyoung {
189 1.1 dyoung uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24);
190 1.1 dyoung uint16_t iv16 = (b4 << 0) | (b5 << 8);
191 1.1 dyoung return (((uint64_t)iv16) << 32) | iv32;
192 1.1 dyoung }
193 1.1 dyoung
194 1.1 dyoung /*
195 1.1 dyoung * Validate and strip privacy headers (and trailer) for a
196 1.1 dyoung * received frame. The specified key should be correct but
197 1.1 dyoung * is also verified.
198 1.1 dyoung */
199 1.1 dyoung static int
200 1.1.1.2 dyoung ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
201 1.1 dyoung {
202 1.1 dyoung struct ccmp_ctx *ctx = k->wk_private;
203 1.1 dyoung struct ieee80211_frame *wh;
204 1.1 dyoung uint8_t *ivp;
205 1.1 dyoung uint64_t pn;
206 1.1 dyoung
207 1.1 dyoung /*
208 1.1 dyoung * Header should have extended IV and sequence number;
209 1.1 dyoung * verify the former and validate the latter.
210 1.1 dyoung */
211 1.1 dyoung wh = mtod(m, struct ieee80211_frame *);
212 1.1 dyoung ivp = mtod(m, uint8_t *) + hdrlen;
213 1.1 dyoung if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
214 1.1 dyoung /*
215 1.1 dyoung * No extended IV; discard frame.
216 1.1 dyoung */
217 1.1 dyoung IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO,
218 1.1 dyoung "[%s] Missing ExtIV for AES-CCM cipher\n",
219 1.1 dyoung ether_sprintf(wh->i_addr2));
220 1.1 dyoung ctx->cc_ic->ic_stats.is_rx_ccmpformat++;
221 1.1 dyoung return 0;
222 1.1 dyoung }
223 1.1 dyoung pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]);
224 1.1 dyoung if (pn <= k->wk_keyrsc) {
225 1.1 dyoung /*
226 1.1 dyoung * Replay violation.
227 1.1 dyoung */
228 1.1 dyoung ieee80211_notify_replay_failure(ctx->cc_ic, wh, k, pn);
229 1.1 dyoung ctx->cc_ic->ic_stats.is_rx_ccmpreplay++;
230 1.1 dyoung return 0;
231 1.1 dyoung }
232 1.1 dyoung
233 1.1 dyoung /*
234 1.1 dyoung * Check if the device handled the decrypt in hardware.
235 1.1 dyoung * If so we just strip the header; otherwise we need to
236 1.1 dyoung * handle the decrypt in software. Note that for the
237 1.1 dyoung * latter we leave the header in place for use in the
238 1.1 dyoung * decryption work.
239 1.1 dyoung */
240 1.1 dyoung if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
241 1.1 dyoung !ccmp_decrypt(k, pn, m, hdrlen))
242 1.1 dyoung return 0;
243 1.1 dyoung
244 1.1 dyoung /*
245 1.1 dyoung * Copy up 802.11 header and strip crypto bits.
246 1.1 dyoung */
247 1.1 dyoung ovbcopy(mtod(m, void *), mtod(m, u_int8_t *) + ccmp.ic_header, hdrlen);
248 1.1 dyoung m_adj(m, ccmp.ic_header);
249 1.1 dyoung m_adj(m, -ccmp.ic_trailer);
250 1.1 dyoung
251 1.1 dyoung /*
252 1.1 dyoung * Ok to update rsc now.
253 1.1 dyoung */
254 1.1 dyoung k->wk_keyrsc = pn;
255 1.1 dyoung
256 1.1 dyoung return 1;
257 1.1 dyoung }
258 1.1 dyoung
259 1.1 dyoung /*
260 1.1 dyoung * Verify and strip MIC from the frame.
261 1.1 dyoung */
262 1.1 dyoung static int
263 1.1.1.2 dyoung ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force)
264 1.1 dyoung {
265 1.1 dyoung return 1;
266 1.1 dyoung }
267 1.1 dyoung
268 1.1 dyoung static __inline void
269 1.1 dyoung xor_block(uint8_t *b, const uint8_t *a, size_t len)
270 1.1 dyoung {
271 1.1 dyoung int i;
272 1.1 dyoung for (i = 0; i < len; i++)
273 1.1 dyoung b[i] ^= a[i];
274 1.1 dyoung }
275 1.1 dyoung
276 1.1 dyoung /*
277 1.1 dyoung * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
278 1.1 dyoung *
279 1.1 dyoung * Copyright (c) 2003-2004, Jouni Malinen <jkmaline (at) cc.hut.fi>
280 1.1 dyoung *
281 1.1 dyoung * This program is free software; you can redistribute it and/or modify
282 1.1 dyoung * it under the terms of the GNU General Public License version 2 as
283 1.1 dyoung * published by the Free Software Foundation. See README and COPYING for
284 1.1 dyoung * more details.
285 1.1 dyoung *
286 1.1 dyoung * Alternatively, this software may be distributed under the terms of BSD
287 1.1 dyoung * license.
288 1.1 dyoung */
289 1.1 dyoung
290 1.1 dyoung static void
291 1.1 dyoung ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh,
292 1.1 dyoung u_int64_t pn, size_t dlen,
293 1.1 dyoung uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN],
294 1.1 dyoung uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN])
295 1.1 dyoung {
296 1.1 dyoung #define IS_4ADDRESS(wh) \
297 1.1 dyoung ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS)
298 1.1 dyoung #define IS_QOS_DATA(wh) IEEE80211_QOS_HAS_SEQ(wh)
299 1.1 dyoung
300 1.1 dyoung /* CCM Initial Block:
301 1.1 dyoung * Flag (Include authentication header, M=3 (8-octet MIC),
302 1.1 dyoung * L=1 (2-octet Dlen))
303 1.1 dyoung * Nonce: 0x00 | A2 | PN
304 1.1 dyoung * Dlen */
305 1.1 dyoung b0[0] = 0x59;
306 1.1 dyoung /* NB: b0[1] set below */
307 1.1 dyoung IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2);
308 1.1 dyoung b0[8] = pn >> 40;
309 1.1 dyoung b0[9] = pn >> 32;
310 1.1 dyoung b0[10] = pn >> 24;
311 1.1 dyoung b0[11] = pn >> 16;
312 1.1 dyoung b0[12] = pn >> 8;
313 1.1 dyoung b0[13] = pn >> 0;
314 1.1 dyoung b0[14] = (dlen >> 8) & 0xff;
315 1.1 dyoung b0[15] = dlen & 0xff;
316 1.1 dyoung
317 1.1 dyoung /* AAD:
318 1.1 dyoung * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
319 1.1 dyoung * A1 | A2 | A3
320 1.1 dyoung * SC with bits 4..15 (seq#) masked to zero
321 1.1 dyoung * A4 (if present)
322 1.1 dyoung * QC (if present)
323 1.1 dyoung */
324 1.1 dyoung aad[0] = 0; /* AAD length >> 8 */
325 1.1 dyoung /* NB: aad[1] set below */
326 1.1 dyoung aad[2] = wh->i_fc[0] & 0x8f; /* XXX magic #s */
327 1.1 dyoung aad[3] = wh->i_fc[1] & 0xc7; /* XXX magic #s */
328 1.1 dyoung /* NB: we know 3 addresses are contiguous */
329 1.1 dyoung memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN);
330 1.1 dyoung aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK;
331 1.1 dyoung aad[23] = 0; /* all bits masked */
332 1.1 dyoung /*
333 1.1 dyoung * Construct variable-length portion of AAD based
334 1.1 dyoung * on whether this is a 4-address frame/QOS frame.
335 1.1 dyoung * We always zero-pad to 32 bytes before running it
336 1.1 dyoung * through the cipher.
337 1.1 dyoung *
338 1.1 dyoung * We also fill in the priority bits of the CCM
339 1.1 dyoung * initial block as we know whether or not we have
340 1.1 dyoung * a QOS frame.
341 1.1 dyoung */
342 1.1 dyoung if (IS_4ADDRESS(wh)) {
343 1.1 dyoung IEEE80211_ADDR_COPY(aad + 24,
344 1.1 dyoung ((struct ieee80211_frame_addr4 *)wh)->i_addr4);
345 1.1 dyoung if (IS_QOS_DATA(wh)) {
346 1.1 dyoung struct ieee80211_qosframe_addr4 *qwh4 =
347 1.1 dyoung (struct ieee80211_qosframe_addr4 *) wh;
348 1.1 dyoung aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */
349 1.1 dyoung aad[31] = 0;
350 1.1 dyoung b0[1] = aad[30];
351 1.1 dyoung aad[1] = 22 + IEEE80211_ADDR_LEN + 2;
352 1.1 dyoung } else {
353 1.1 dyoung *(u_int16_t *)&aad[30] = 0;
354 1.1 dyoung b0[1] = 0;
355 1.1 dyoung aad[1] = 22 + IEEE80211_ADDR_LEN;
356 1.1 dyoung }
357 1.1 dyoung } else {
358 1.1 dyoung if (IS_QOS_DATA(wh)) {
359 1.1 dyoung struct ieee80211_qosframe *qwh =
360 1.1 dyoung (struct ieee80211_qosframe*) wh;
361 1.1 dyoung aad[24] = qwh->i_qos[0] & 0x0f; /* just priority bits */
362 1.1 dyoung aad[25] = 0;
363 1.1 dyoung b0[1] = aad[24];
364 1.1 dyoung aad[1] = 22 + 2;
365 1.1 dyoung } else {
366 1.1 dyoung *(u_int16_t *)&aad[24] = 0;
367 1.1 dyoung b0[1] = 0;
368 1.1 dyoung aad[1] = 22;
369 1.1 dyoung }
370 1.1 dyoung *(u_int16_t *)&aad[26] = 0;
371 1.1 dyoung *(u_int32_t *)&aad[28] = 0;
372 1.1 dyoung }
373 1.1 dyoung
374 1.1 dyoung /* Start with the first block and AAD */
375 1.1 dyoung rijndael_encrypt(ctx, b0, auth);
376 1.1 dyoung xor_block(auth, aad, AES_BLOCK_LEN);
377 1.1 dyoung rijndael_encrypt(ctx, auth, auth);
378 1.1 dyoung xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
379 1.1 dyoung rijndael_encrypt(ctx, auth, auth);
380 1.1 dyoung b0[0] &= 0x07;
381 1.1 dyoung b0[14] = b0[15] = 0;
382 1.1 dyoung rijndael_encrypt(ctx, b0, s0);
383 1.1 dyoung #undef IS_QOS_DATA
384 1.1 dyoung #undef IS_4ADDRESS
385 1.1 dyoung }
386 1.1 dyoung
387 1.1 dyoung #define CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do { \
388 1.1 dyoung /* Authentication */ \
389 1.1 dyoung xor_block(_b, _pos, _len); \
390 1.1 dyoung rijndael_encrypt(&ctx->cc_aes, _b, _b); \
391 1.1 dyoung /* Encryption, with counter */ \
392 1.1 dyoung _b0[14] = (_i >> 8) & 0xff; \
393 1.1 dyoung _b0[15] = _i & 0xff; \
394 1.1 dyoung rijndael_encrypt(&ctx->cc_aes, _b0, _e); \
395 1.1 dyoung xor_block(_pos, _e, _len); \
396 1.1 dyoung } while (0)
397 1.1 dyoung
398 1.1 dyoung static int
399 1.1 dyoung ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
400 1.1 dyoung {
401 1.1 dyoung struct ccmp_ctx *ctx = key->wk_private;
402 1.1 dyoung struct ieee80211_frame *wh;
403 1.1 dyoung struct mbuf *m = m0;
404 1.1.1.2 dyoung int data_len, i, space;
405 1.1 dyoung uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN],
406 1.1 dyoung e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN];
407 1.1 dyoung uint8_t *pos;
408 1.1 dyoung
409 1.1 dyoung ctx->cc_ic->ic_stats.is_crypto_ccmp++;
410 1.1 dyoung
411 1.1 dyoung wh = mtod(m, struct ieee80211_frame *);
412 1.1 dyoung data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header);
413 1.1 dyoung ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc,
414 1.1 dyoung data_len, b0, aad, b, s0);
415 1.1 dyoung
416 1.1 dyoung i = 1;
417 1.1 dyoung pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
418 1.1 dyoung /* NB: assumes header is entirely in first mbuf */
419 1.1 dyoung space = m->m_len - (hdrlen + ccmp.ic_header);
420 1.1 dyoung for (;;) {
421 1.1 dyoung if (space > data_len)
422 1.1 dyoung space = data_len;
423 1.1 dyoung /*
424 1.1 dyoung * Do full blocks.
425 1.1 dyoung */
426 1.1 dyoung while (space >= AES_BLOCK_LEN) {
427 1.1 dyoung CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN);
428 1.1 dyoung pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
429 1.1 dyoung data_len -= AES_BLOCK_LEN;
430 1.1 dyoung i++;
431 1.1 dyoung }
432 1.1 dyoung if (data_len <= 0) /* no more data */
433 1.1 dyoung break;
434 1.1 dyoung m = m->m_next;
435 1.1 dyoung if (m == NULL) { /* last buffer */
436 1.1 dyoung if (space != 0) {
437 1.1 dyoung /*
438 1.1 dyoung * Short last block.
439 1.1 dyoung */
440 1.1 dyoung CCMP_ENCRYPT(i, b, b0, pos, e, space);
441 1.1 dyoung }
442 1.1 dyoung break;
443 1.1 dyoung }
444 1.1 dyoung if (space != 0) {
445 1.1 dyoung uint8_t *pos_next;
446 1.1.1.2 dyoung int space_next;
447 1.1.1.2 dyoung int len, dl, sp;
448 1.1.1.2 dyoung struct mbuf *n;
449 1.1 dyoung
450 1.1 dyoung /*
451 1.1.1.2 dyoung * Block straddles one or more mbufs, gather data
452 1.1.1.2 dyoung * into the block buffer b, apply the cipher, then
453 1.1.1.2 dyoung * scatter the results back into the mbuf chain.
454 1.1.1.2 dyoung * The buffer will automatically get space bytes
455 1.1.1.2 dyoung * of data at offset 0 copied in+out by the
456 1.1.1.2 dyoung * CCMP_ENCRYPT request so we must take care of
457 1.1.1.2 dyoung * the remaining data.
458 1.1 dyoung */
459 1.1.1.2 dyoung n = m;
460 1.1.1.2 dyoung dl = data_len;
461 1.1.1.2 dyoung sp = space;
462 1.1.1.2 dyoung for (;;) {
463 1.1.1.2 dyoung pos_next = mtod(n, uint8_t *);
464 1.1.1.2 dyoung len = min(dl, AES_BLOCK_LEN);
465 1.1.1.2 dyoung space_next = len > sp ? len - sp : 0;
466 1.1.1.2 dyoung if (n->m_len >= space_next) {
467 1.1.1.2 dyoung /*
468 1.1.1.2 dyoung * This mbuf has enough data; just grab
469 1.1.1.2 dyoung * what we need and stop.
470 1.1.1.2 dyoung */
471 1.1.1.2 dyoung xor_block(b+sp, pos_next, space_next);
472 1.1.1.2 dyoung break;
473 1.1.1.2 dyoung }
474 1.1.1.2 dyoung /*
475 1.1.1.2 dyoung * This mbuf's contents are insufficient,
476 1.1.1.2 dyoung * take 'em all and prepare to advance to
477 1.1.1.2 dyoung * the next mbuf.
478 1.1.1.2 dyoung */
479 1.1.1.2 dyoung xor_block(b+sp, pos_next, n->m_len);
480 1.1.1.2 dyoung sp += n->m_len, dl -= n->m_len;
481 1.1.1.2 dyoung n = n->m_next;
482 1.1.1.2 dyoung if (n == NULL)
483 1.1.1.2 dyoung break;
484 1.1.1.2 dyoung }
485 1.1 dyoung
486 1.1 dyoung CCMP_ENCRYPT(i, b, b0, pos, e, space);
487 1.1 dyoung
488 1.1.1.2 dyoung /* NB: just like above, but scatter data to mbufs */
489 1.1.1.2 dyoung dl = data_len;
490 1.1.1.2 dyoung sp = space;
491 1.1.1.2 dyoung for (;;) {
492 1.1.1.2 dyoung pos_next = mtod(m, uint8_t *);
493 1.1.1.2 dyoung len = min(dl, AES_BLOCK_LEN);
494 1.1.1.2 dyoung space_next = len > sp ? len - sp : 0;
495 1.1.1.2 dyoung if (m->m_len >= space_next) {
496 1.1.1.2 dyoung xor_block(pos_next, e+sp, space_next);
497 1.1.1.2 dyoung break;
498 1.1.1.2 dyoung }
499 1.1.1.2 dyoung xor_block(pos_next, e+sp, m->m_len);
500 1.1.1.2 dyoung sp += m->m_len, dl -= m->m_len;
501 1.1.1.2 dyoung m = m->m_next;
502 1.1.1.2 dyoung if (m == NULL)
503 1.1.1.2 dyoung goto done;
504 1.1.1.2 dyoung }
505 1.1.1.2 dyoung /*
506 1.1.1.2 dyoung * Do bookkeeping. m now points to the last mbuf
507 1.1.1.2 dyoung * we grabbed data from. We know we consumed a
508 1.1.1.2 dyoung * full block of data as otherwise we'd have hit
509 1.1.1.2 dyoung * the end of the mbuf chain, so deduct from data_len.
510 1.1.1.2 dyoung * Otherwise advance the block number (i) and setup
511 1.1.1.2 dyoung * pos+space to reflect contents of the new mbuf.
512 1.1.1.2 dyoung */
513 1.1.1.2 dyoung data_len -= AES_BLOCK_LEN;
514 1.1.1.2 dyoung i++;
515 1.1 dyoung pos = pos_next + space_next;
516 1.1 dyoung space = m->m_len - space_next;
517 1.1 dyoung } else {
518 1.1 dyoung /*
519 1.1 dyoung * Setup for next buffer.
520 1.1 dyoung */
521 1.1 dyoung pos = mtod(m, uint8_t *);
522 1.1 dyoung space = m->m_len;
523 1.1 dyoung }
524 1.1 dyoung }
525 1.1.1.2 dyoung done:
526 1.1 dyoung /* tack on MIC */
527 1.1 dyoung xor_block(b, s0, ccmp.ic_trailer);
528 1.1 dyoung return m_append(m0, ccmp.ic_trailer, b);
529 1.1 dyoung }
530 1.1 dyoung #undef CCMP_ENCRYPT
531 1.1 dyoung
532 1.1 dyoung #define CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do { \
533 1.1 dyoung /* Decrypt, with counter */ \
534 1.1 dyoung _b0[14] = (_i >> 8) & 0xff; \
535 1.1 dyoung _b0[15] = _i & 0xff; \
536 1.1 dyoung rijndael_encrypt(&ctx->cc_aes, _b0, _b); \
537 1.1 dyoung xor_block(_pos, _b, _len); \
538 1.1 dyoung /* Authentication */ \
539 1.1 dyoung xor_block(_a, _pos, _len); \
540 1.1 dyoung rijndael_encrypt(&ctx->cc_aes, _a, _a); \
541 1.1 dyoung } while (0)
542 1.1 dyoung
543 1.1 dyoung static int
544 1.1 dyoung ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen)
545 1.1 dyoung {
546 1.1 dyoung struct ccmp_ctx *ctx = key->wk_private;
547 1.1 dyoung struct ieee80211_frame *wh;
548 1.1 dyoung uint8_t aad[2 * AES_BLOCK_LEN];
549 1.1 dyoung uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN];
550 1.1 dyoung uint8_t mic[AES_BLOCK_LEN];
551 1.1 dyoung size_t data_len;
552 1.1 dyoung int i;
553 1.1 dyoung uint8_t *pos;
554 1.1 dyoung u_int space;
555 1.1 dyoung
556 1.1 dyoung ctx->cc_ic->ic_stats.is_crypto_ccmp++;
557 1.1 dyoung
558 1.1 dyoung wh = mtod(m, struct ieee80211_frame *);
559 1.1 dyoung data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer);
560 1.1 dyoung ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b);
561 1.1 dyoung m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic);
562 1.1 dyoung xor_block(mic, b, ccmp.ic_trailer);
563 1.1 dyoung
564 1.1 dyoung i = 1;
565 1.1 dyoung pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
566 1.1 dyoung space = m->m_len - (hdrlen + ccmp.ic_header);
567 1.1 dyoung for (;;) {
568 1.1 dyoung if (space > data_len)
569 1.1 dyoung space = data_len;
570 1.1 dyoung while (space >= AES_BLOCK_LEN) {
571 1.1 dyoung CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN);
572 1.1 dyoung pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
573 1.1 dyoung data_len -= AES_BLOCK_LEN;
574 1.1 dyoung i++;
575 1.1 dyoung }
576 1.1 dyoung if (data_len <= 0) /* no more data */
577 1.1 dyoung break;
578 1.1 dyoung m = m->m_next;
579 1.1 dyoung if (m == NULL) { /* last buffer */
580 1.1 dyoung if (space != 0) /* short last block */
581 1.1 dyoung CCMP_DECRYPT(i, b, b0, pos, a, space);
582 1.1 dyoung break;
583 1.1 dyoung }
584 1.1 dyoung if (space != 0) {
585 1.1 dyoung uint8_t *pos_next;
586 1.1 dyoung u_int space_next;
587 1.1 dyoung u_int len;
588 1.1 dyoung
589 1.1 dyoung /*
590 1.1 dyoung * Block straddles buffers, split references. We
591 1.1.1.2 dyoung * do not handle splits that require >2 buffers
592 1.1.1.2 dyoung * since rx'd frames are never badly fragmented
593 1.1.1.2 dyoung * because drivers typically recv in clusters.
594 1.1 dyoung */
595 1.1 dyoung pos_next = mtod(m, uint8_t *);
596 1.1 dyoung len = min(data_len, AES_BLOCK_LEN);
597 1.1 dyoung space_next = len > space ? len - space : 0;
598 1.1 dyoung KASSERT(m->m_len >= space_next,
599 1.1 dyoung ("not enough data in following buffer, "
600 1.1 dyoung "m_len %u need %u\n", m->m_len, space_next));
601 1.1 dyoung
602 1.1 dyoung xor_block(b+space, pos_next, space_next);
603 1.1 dyoung CCMP_DECRYPT(i, b, b0, pos, a, space);
604 1.1 dyoung xor_block(pos_next, b+space, space_next);
605 1.1 dyoung data_len -= len;
606 1.1 dyoung i++;
607 1.1 dyoung
608 1.1 dyoung pos = pos_next + space_next;
609 1.1 dyoung space = m->m_len - space_next;
610 1.1 dyoung } else {
611 1.1 dyoung /*
612 1.1 dyoung * Setup for next buffer.
613 1.1 dyoung */
614 1.1 dyoung pos = mtod(m, uint8_t *);
615 1.1 dyoung space = m->m_len;
616 1.1 dyoung }
617 1.1 dyoung }
618 1.1 dyoung if (memcmp(mic, a, ccmp.ic_trailer) != 0) {
619 1.1 dyoung IEEE80211_DPRINTF(ctx->cc_ic, IEEE80211_MSG_CRYPTO,
620 1.1 dyoung "[%s] AES-CCM decrypt failed; MIC mismatch\n",
621 1.1 dyoung ether_sprintf(wh->i_addr2));
622 1.1 dyoung ctx->cc_ic->ic_stats.is_rx_ccmpmic++;
623 1.1 dyoung return 0;
624 1.1 dyoung }
625 1.1 dyoung return 1;
626 1.1 dyoung }
627 1.1 dyoung #undef CCMP_DECRYPT
628 1.1 dyoung
629 1.1 dyoung /*
630 1.1 dyoung * Module glue.
631 1.1 dyoung */
632 1.1 dyoung static int
633 1.1 dyoung ccmp_modevent(module_t mod, int type, void *unused)
634 1.1 dyoung {
635 1.1 dyoung switch (type) {
636 1.1 dyoung case MOD_LOAD:
637 1.1 dyoung ieee80211_crypto_register(&ccmp);
638 1.1 dyoung return 0;
639 1.1 dyoung case MOD_UNLOAD:
640 1.1 dyoung ieee80211_crypto_unregister(&ccmp);
641 1.1 dyoung return 0;
642 1.1 dyoung }
643 1.1 dyoung return EINVAL;
644 1.1 dyoung }
645 1.1 dyoung
646 1.1 dyoung static moduledata_t ccmp_mod = {
647 1.1 dyoung "wlan_ccmp",
648 1.1 dyoung ccmp_modevent,
649 1.1 dyoung 0
650 1.1 dyoung };
651 1.1 dyoung DECLARE_MODULE(wlan_ccmp, ccmp_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
652 1.1 dyoung MODULE_VERSION(wlan_ccmp, 1);
653 1.1 dyoung MODULE_DEPEND(wlan_ccmp, wlan, 1, 1, 1);
654