xref: /illumos-gate/usr/src/uts/common/io/net80211/net80211_crypto_ccmp.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 2001 Atsushi Onoe
8  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * Alternatively, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") version 2 as published by the Free
24  * Software Foundation.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #pragma ident	"%Z%%M%	%I%	%E% SMI"
39 
40 /*
41  * IEEE 802.11i CCMP crypto support.
42  */
43 #include <sys/byteorder.h>
44 #include <sys/crypto/common.h>
45 #include <sys/crypto/api.h>
46 #include <sys/crc32.h>
47 #include <sys/random.h>
48 #include <sys/strsun.h>
49 #include "net80211_impl.h"
50 
51 struct ccmp_ctx {
52 	struct ieee80211com *cc_ic;	/* for diagnostics */
53 };
54 
55 #define	AES_BLOCK_LEN	16
56 #define	AES_NONCE_LEN	13
57 
58 static void *ccmp_attach(struct ieee80211com *, struct ieee80211_key *);
59 static void ccmp_detach(struct ieee80211_key *);
60 static int ccmp_setkey(struct ieee80211_key *);
61 static int ccmp_encap(struct ieee80211_key *k, mblk_t *, uint8_t);
62 static int ccmp_decap(struct ieee80211_key *, mblk_t *, int);
63 static int ccmp_enmic(struct ieee80211_key *, mblk_t *, int);
64 static int ccmp_demic(struct ieee80211_key *, mblk_t *, int);
65 
66 static int ccmp_encrypt(struct ieee80211_key *, mblk_t *, int);
67 static int ccmp_decrypt(struct ieee80211_key *, uint64_t pn, mblk_t *, int);
68 
69 const struct ieee80211_cipher ccmp = {
70 	"AES-CCM",
71 	IEEE80211_CIPHER_AES_CCM,
72 	IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN +
73 	    IEEE80211_WEP_EXTIVLEN,
74 	IEEE80211_WEP_MICLEN,
75 	0,
76 	ccmp_attach,
77 	ccmp_detach,
78 	ccmp_setkey,
79 	ccmp_encap,
80 	ccmp_decap,
81 	ccmp_enmic,
82 	ccmp_demic,
83 };
84 
85 /* ARGSUSED */
86 static void *
87 ccmp_attach(struct ieee80211com *ic, struct ieee80211_key *k)
88 {
89 	struct ccmp_ctx *ctx;
90 
91 	ctx = kmem_zalloc(sizeof (struct ccmp_ctx), KM_SLEEP);
92 	if (ctx == NULL)
93 		return (NULL);
94 
95 	ctx->cc_ic = ic;
96 	return (ctx);
97 }
98 
99 static void
100 ccmp_detach(struct ieee80211_key *k)
101 {
102 	struct ccmp_ctx *ctx = k->wk_private;
103 
104 	if (ctx != NULL)
105 		kmem_free(ctx, sizeof (struct ccmp_ctx));
106 }
107 
108 static int
109 ccmp_setkey(struct ieee80211_key *k)
110 {
111 	if (k->wk_keylen != (128/NBBY))
112 		return (0);
113 
114 	return (1);
115 }
116 
117 /*
118  * Add privacy headers appropriate for the specified key.
119  */
120 static int
121 ccmp_encap(struct ieee80211_key *k, mblk_t *mp, uint8_t keyid)
122 {
123 	uint8_t *ivp;
124 	int hdrlen;
125 
126 	hdrlen = ieee80211_hdrspace(mp->b_rptr);
127 	/*
128 	 * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
129 	 */
130 	ivp = mp->b_rptr;
131 	ivp += hdrlen;
132 
133 	k->wk_keytsc++;				/* wrap at 48 bits */
134 	ivp[0] = k->wk_keytsc >> 0;		/* PN0 */
135 	ivp[1] = k->wk_keytsc >> 8;		/* PN1 */
136 	ivp[2] = 0;				/* Reserved */
137 	ivp[3] = keyid | IEEE80211_WEP_EXTIV;	/* KeyID | ExtID */
138 	ivp[4] = k->wk_keytsc >> 16;		/* PN2 */
139 	ivp[5] = k->wk_keytsc >> 24;		/* PN3 */
140 	ivp[6] = k->wk_keytsc >> 32;		/* PN4 */
141 	ivp[7] = k->wk_keytsc >> 40;		/* PN5 */
142 
143 	/*
144 	 * Finally, do software encrypt if neeed.
145 	 */
146 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
147 	    !ccmp_encrypt(k, mp, hdrlen))
148 		return (0);
149 
150 	return (1);
151 }
152 
153 /*
154  * Validate and strip privacy headers (and trailer) for a
155  * received frame. The specified key should be correct but
156  * is also verified.
157  */
158 static int
159 ccmp_decap(struct ieee80211_key *k, mblk_t *mp, int hdrlen)
160 {
161 	struct ieee80211_frame tmp;
162 	uint8_t *ivp;
163 	uint64_t pn;
164 
165 	/*
166 	 * Header should have extended IV and sequence number;
167 	 * verify the former and validate the latter.
168 	 */
169 	ivp = mp->b_rptr + hdrlen;
170 	if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
171 		/*
172 		 * No extended IV; discard frame.
173 		 */
174 		return (0);
175 	}
176 
177 	pn = ieee80211_read_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]);
178 	if (pn <= k->wk_keyrsc) {
179 		/*
180 		 * Replay violation.
181 		 */
182 		return (0);
183 	}
184 
185 	/*
186 	 * Check if the device handled the decrypt in hardware.
187 	 * If so we just strip the header; otherwise we need to
188 	 * handle the decrypt in software.  Note that for the
189 	 * latter we leave the header in place for use in the
190 	 * decryption work.
191 	 */
192 	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
193 	    !ccmp_decrypt(k, pn, mp, hdrlen))
194 		return (0);
195 
196 	/*
197 	 * Copy up 802.11 header and strip crypto bits.
198 	 */
199 	bcopy(mp->b_rptr, &tmp, hdrlen);
200 	bcopy(&tmp, mp->b_rptr + ccmp.ic_header, hdrlen);
201 	mp->b_rptr += ccmp.ic_header;
202 	mp->b_wptr -= ccmp.ic_trailer;
203 
204 	/*
205 	 * Ok to update rsc now.
206 	 */
207 	k->wk_keyrsc = pn;
208 
209 	return (1);
210 }
211 
212 /*
213  * Add MIC to the frame as needed.
214  */
215 /* ARGSUSED */
216 static int
217 ccmp_enmic(struct ieee80211_key *k, mblk_t *mp, int force)
218 {
219 	return (1);
220 }
221 
222 /*
223  * Verify and strip MIC from the frame.
224  */
225 /* ARGSUSED */
226 static int
227 ccmp_demic(struct ieee80211_key *k, mblk_t *mp, int force)
228 {
229 	return (1);
230 }
231 
232 static int
233 aes_ccm_encrypt(CK_AES_CCM_PARAMS *cmparam, const uint8_t *key, int keylen,
234     const uint8_t *plaintext, int plain_len,
235     uint8_t *ciphertext, int cipher_len)
236 {
237 	crypto_mechanism_t mech;
238 	crypto_key_t crkey;
239 	crypto_data_t d1, d2;
240 
241 	int rv;
242 
243 	ieee80211_dbg(IEEE80211_MSG_CRYPTO,
244 	    "aes_ccm_encrypt(len=%d, keylen=%d)", plain_len, keylen);
245 
246 	bzero(&crkey, sizeof (crkey));
247 
248 	crkey.ck_format = CRYPTO_KEY_RAW;
249 	crkey.ck_data   = (char *)key;
250 	/* keys are measured in bits, not bytes, so multiply by 8 */
251 	crkey.ck_length = keylen * 8;
252 
253 	mech.cm_type	  = crypto_mech2id(SUN_CKM_AES_CCM);
254 	mech.cm_param	  = (caddr_t)cmparam;
255 	mech.cm_param_len = sizeof (CK_AES_CCM_PARAMS);
256 
257 #if defined(__amd64) || defined(__sparc)
258 	ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%lx", mech.cm_type);
259 #else
260 	ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%llx", mech.cm_type);
261 #endif
262 
263 	bzero(&d1, sizeof (d1));
264 	bzero(&d2, sizeof (d2));
265 
266 	d1.cd_format = CRYPTO_DATA_RAW;
267 	d1.cd_offset = 0;
268 	d1.cd_length = plain_len;
269 	d1.cd_raw.iov_base = (char *)plaintext;
270 	d1.cd_raw.iov_len  = plain_len;
271 
272 	d2.cd_format = CRYPTO_DATA_RAW;
273 	d2.cd_offset = 0;
274 	d2.cd_length = cipher_len;
275 	d2.cd_raw.iov_base = (char *)ciphertext;
276 	d2.cd_raw.iov_len  = cipher_len;
277 
278 
279 	rv = crypto_encrypt(&mech, &d1, &crkey, NULL, &d2, NULL);
280 	if (rv != CRYPTO_SUCCESS)
281 		ieee80211_err("aes_ccm_encrypt failed (%x)", rv);
282 	return (rv);
283 }
284 
285 static int
286 aes_ccm_decrypt(CK_AES_CCM_PARAMS *cmparam, const uint8_t *key, int keylen,
287     const uint8_t *ciphertext, int cipher_len,
288     uint8_t *plaintext, int plain_len)
289 {
290 	crypto_mechanism_t mech;
291 	crypto_key_t crkey;
292 	crypto_data_t d1, d2;
293 
294 	int rv;
295 
296 	ieee80211_dbg(IEEE80211_MSG_CRYPTO,
297 	    "aes_ccm_decrypt(len=%d, keylen=%d)", cipher_len, keylen);
298 
299 	bzero(&crkey, sizeof (crkey));
300 
301 	crkey.ck_format = CRYPTO_KEY_RAW;
302 	crkey.ck_data   = (char *)key;
303 	/* keys are measured in bits, not bytes, so multiply by 8 */
304 	crkey.ck_length = keylen * 8;
305 
306 	mech.cm_type	  = crypto_mech2id(SUN_CKM_AES_CCM);
307 	mech.cm_param	  = (caddr_t)cmparam;
308 	mech.cm_param_len = sizeof (CK_AES_CCM_PARAMS);
309 
310 #if defined(__amd64) || defined(__sparc)
311 	ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%lx", mech.cm_type);
312 #else
313 	ieee80211_dbg(IEEE80211_MSG_CRYPTO, "cm_type=%llx", mech.cm_type);
314 #endif
315 
316 	bzero(&d1, sizeof (d1));
317 	bzero(&d2, sizeof (d2));
318 
319 	d1.cd_format = CRYPTO_DATA_RAW;
320 	d1.cd_offset = 0;
321 	d1.cd_length = cipher_len;
322 	d1.cd_raw.iov_base = (char *)ciphertext;
323 	d1.cd_raw.iov_len  = cipher_len;
324 
325 	d2.cd_format = CRYPTO_DATA_RAW;
326 	d2.cd_offset = 0;
327 	d2.cd_length = plain_len;
328 	d2.cd_raw.iov_base = (char *)plaintext;
329 	d2.cd_raw.iov_len  = plain_len;
330 
331 
332 	rv = crypto_decrypt(&mech, &d1, &crkey, NULL, &d2, NULL);
333 	if (rv != CRYPTO_SUCCESS)
334 		ieee80211_err("aes_ccm_decrypt failed (%x)", rv);
335 	return (rv);
336 }
337 
338 /*
339  * For the avoidance of doubt, except that if any license choice other
340  * than GPL or LGPL is available it will apply instead, Sun elects to
341  * use only the General Public License version 2 (GPLv2) at this time
342  * for any software where a choice of GPL license versions is made
343  * available with the language indicating that GPLv2 or any later
344  * version may be used, or where a choice of which version of the GPL
345  * is applied is otherwise unspecified.
346  */
347 
348 /*
349  * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
350  *
351  * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
352  *
353  * This program is free software; you can redistribute it and/or modify
354  * it under the terms of the GNU General Public License version 2 as
355  * published by the Free Software Foundation. See README and COPYING for
356  * more details.
357  *
358  * Alternatively, this software may be distributed under the terms of BSD
359  * license.
360  */
361 
362 static void
363 ccmp_init(struct ieee80211_frame *wh, uint64_t pn, size_t dlen,
364     uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN])
365 {
366 	/*
367 	 * CCM Initial Block:
368 	 * Flag (Include authentication header, M=3 (8-octet MIC),
369 	 * L=1 (2-octet Dlen))
370 	 * Nonce: 0x00 | A2 | PN
371 	 * Dlen
372 	 */
373 	b0[0] = 0x59;
374 	/* b0[1] set below */
375 	IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2);
376 	b0[8] = pn >> 40;
377 	b0[9] = pn >> 32;
378 	b0[10] = pn >> 24;
379 	b0[11] = pn >> 16;
380 	b0[12] = pn >> 8;
381 	b0[13] = (uint8_t)(pn >> 0);
382 	b0[14] = (dlen >> 8) & 0xff;
383 	b0[15] = dlen & 0xff;
384 
385 	/*
386 	 * AAD:
387 	 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
388 	 * A1 | A2 | A3
389 	 * SC with bits 4..15 (seq#) masked to zero
390 	 * A4 (if present)
391 	 * QC (if present)
392 	 */
393 	aad[0] = 0;	/* AAD length >> 8 */
394 	/* aad[1] set below */
395 	aad[2] = wh->i_fc[0] & 0x8f;	/* magic #s */
396 	aad[3] = wh->i_fc[1] & 0xc7;	/* magic #s */
397 	/* we know 3 addresses are contiguous */
398 	(void) memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN);
399 	aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK;
400 	aad[23] = 0; /* all bits masked */
401 	/*
402 	 * Construct variable-length portion of AAD based
403 	 * on whether this is a 4-address frame/QOS frame.
404 	 * We always zero-pad to 32 bytes before running it
405 	 * through the cipher.
406 	 *
407 	 * We also fill in the priority bits of the CCM
408 	 * initial block as we know whether or not we have
409 	 * a QOS frame.
410 	 */
411 	*(uint16_t *)&aad[24] = 0;
412 	b0[1] = 0;
413 	aad[1] = 22;
414 	*(uint16_t *)&aad[26] = 0;
415 	*(uint32_t *)&aad[28] = 0;
416 }
417 
418 static int
419 ccmp_encrypt(struct ieee80211_key *key, mblk_t *mp, int hdrlen)
420 {
421 	struct ieee80211_frame *wh;
422 	int rv, data_len;
423 	uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN];
424 	uint8_t *pos;
425 	CK_AES_CCM_PARAMS cmparam;
426 	uint8_t buf[IEEE80211_MAX_LEN];
427 
428 	wh = (struct ieee80211_frame *)mp->b_rptr;
429 	data_len = MBLKL(mp) - (hdrlen + ccmp.ic_header);
430 	pos = mp->b_rptr + hdrlen + ccmp.ic_header;
431 
432 	ccmp_init(wh, key->wk_keytsc, data_len, b0, aad);
433 
434 	cmparam.ulMACSize = IEEE80211_WEP_MICLEN;
435 	cmparam.ulNonceSize = AES_NONCE_LEN; /* N size */
436 	cmparam.ulAuthDataSize = aad[1]; /* A size */
437 	cmparam.ulDataSize = data_len;	/* data length; */
438 	cmparam.nonce = &b0[1]; /* N */
439 	cmparam.authData = &aad[2]; /* A */
440 
441 	rv = aes_ccm_encrypt(&cmparam,
442 	    key->wk_key, key->wk_keylen,
443 	    pos, data_len, buf, data_len + IEEE80211_WEP_MICLEN);
444 
445 	bcopy(buf, pos, data_len + IEEE80211_WEP_MICLEN);
446 	mp->b_wptr += ccmp.ic_trailer;
447 
448 	return ((rv == CRYPTO_SUCCESS)? 1 : 0);
449 }
450 
451 static int
452 ccmp_decrypt(struct ieee80211_key *key, uint64_t pn, mblk_t *mp, int hdrlen)
453 {
454 	struct ieee80211_frame *wh;
455 	int rv, data_len;
456 	uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN];
457 	uint8_t *pos;
458 	CK_AES_CCM_PARAMS cmparam;
459 	uint8_t buf[IEEE80211_MAX_LEN];
460 
461 	wh = (struct ieee80211_frame *)mp->b_rptr;
462 	data_len = MBLKL(mp) - (hdrlen + ccmp.ic_header);
463 	pos = mp->b_rptr + hdrlen + ccmp.ic_header;
464 
465 	ccmp_init(wh, pn, data_len, b0, aad);
466 
467 	cmparam.ulMACSize = IEEE80211_WEP_MICLEN; /* MIC = 8 */
468 	cmparam.ulNonceSize = AES_NONCE_LEN; /* N size */
469 	cmparam.ulAuthDataSize = aad[1]; /* A size */
470 	cmparam.ulDataSize = data_len;
471 	cmparam.nonce = &b0[1]; /* N */
472 	cmparam.authData = &aad[2]; /* A */
473 
474 	rv = aes_ccm_decrypt(&cmparam,
475 	    key->wk_key, key->wk_keylen, pos, data_len, buf, data_len);
476 	bcopy(buf, pos, data_len);
477 
478 	return ((rv == CRYPTO_SUCCESS)? 1 : 0);
479 }
480