1 /* $FreeBSD: releng/8.1/sys/netipsec/xform_esp.c 207695 2010-05-06 06:44:19Z bz $ */
2 /* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
3 /*-
4 * The authors of this code are John Ioannidis (ji@tla.org),
5 * Angelos D. Keromytis (kermit@csd.uch.gr) and
6 * Niels Provos (provos@physnet.uni-hamburg.de).
7 *
8 * The original version of this code was written by John Ioannidis
9 * for BSD/OS in Athens, Greece, in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis.
18 *
19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
20 * Angelos D. Keromytis and Niels Provos.
21 * Copyright (c) 2001 Angelos D. Keromytis.
22 *
23 * Permission to use, copy, and modify this software with or without fee
24 * is hereby granted, provided that this entire notice is included in
25 * all copies of any software which is or includes a copy or
26 * modification of this software.
27 * You may use this code under the GNU public license if you so wish. Please
28 * contribute changes back to the authors under this freer than GPL license
29 * so that we may further the use of strong encryption without limitations to
30 * all.
31 *
32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
36 * PURPOSE.
37 */
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/syslog.h>
46 #include <sys/kernel.h>
47 #include <sys/random.h>
48 #include <sys/sysctl.h>
49
50 #include <net/if.h>
51 #include <net/vnet.h>
52
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip_ecn.h>
57 #include <netinet/ip6.h>
58
59 #include <net/route.h>
60 #include <netipsec/ipsec.h>
61 #include <netipsec/ah.h>
62 #include <netipsec/ah_var.h>
63 #include <netipsec/esp.h>
64 #include <netipsec/esp_var.h>
65 #include <netipsec/xform.h>
66
67 #ifdef INET6
68 #include <netinet6/ip6_var.h>
69 #include <netipsec/ipsec6.h>
70 #include <netinet6/ip6_ecn.h>
71 #endif
72
73 #include <netipsec/key.h>
74 #include <netipsec/key_debug.h>
75
76 #include <opencrypto/cryptodev.h>
77 #include <opencrypto/xform.h>
78
79 VNET_DEFINE(int, esp_enable) = 1;
80 VNET_DEFINE(struct espstat, espstat);
81
82 SYSCTL_DECL(_net_inet_esp);
83 SYSCTL_VNET_INT(_net_inet_esp, OID_AUTO,
84 esp_enable, CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
85 SYSCTL_VNET_STRUCT(_net_inet_esp, IPSECCTL_STATS,
86 stats, CTLFLAG_RD, &VNET_NAME(espstat), espstat, "");
87
88 static VNET_DEFINE(int, esp_max_ivlen); /* max iv length over all algorithms */
89 #define V_esp_max_ivlen VNET(esp_max_ivlen)
90
91 static int esp_input_cb(struct cryptop *op);
92 static int esp_output_cb(struct cryptop *crp);
93
94 /*
95 * NB: this is public for use by the PF_KEY support.
96 * NB: if you add support here; be sure to add code to esp_attach below!
97 */
98 struct enc_xform *
99 esp_algorithm_lookup(int alg)
100 {
101 if (alg >= ESP_ALG_MAX)
102 return NULL;
103 switch (alg) {
104 case SADB_EALG_DESCBC:
105 return &enc_xform_des;
106 case SADB_EALG_3DESCBC:
107 return &enc_xform_3des;
108 case SADB_X_EALG_AES:
109 return &enc_xform_rijndael128;
110 case SADB_X_EALG_BLOWFISHCBC:
111 return &enc_xform_blf;
112 case SADB_X_EALG_CAST128CBC:
113 return &enc_xform_cast5;
114 case SADB_X_EALG_SKIPJACK:
115 return &enc_xform_skipjack;
116 case SADB_EALG_NULL:
117 return &enc_xform_null;
118 case SADB_X_EALG_CAMELLIACBC:
119 return &enc_xform_camellia;
120 }
121 return NULL;
122 }
123
124 size_t
125 esp_hdrsiz(struct secasvar *sav)
126 {
127 size_t size;
128
129 if (sav != NULL) {
130 /*XXX not right for null algorithm--does it matter??*/
131 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
132 ("SA with null xform"));
133 if (sav->flags & SADB_X_EXT_OLD)
134 size = sizeof (struct esp);
135 else
136 size = sizeof (struct newesp);
137 size += sav->tdb_encalgxform->blocksize + 9;
138 /*XXX need alg check???*/
139 if (sav->tdb_authalgxform != NULL && sav->replay)
140 size += ah_hdrsiz(sav);
141 } else {
142 /*
143 * base header size
144 * + max iv length for CBC mode
145 * + max pad length
146 * + sizeof (pad length field)
147 * + sizeof (next header field)
148 * + max icv supported.
149 */
150 size = sizeof (struct newesp) + V_esp_max_ivlen + 9 + 16;
151 }
152 return size;
153 }
154
155 /*
156 * esp_init() is called when an SPI is being set up.
157 */
158 static int
159 esp_init(struct secasvar *sav, struct xformsw *xsp)
160 {
161 struct enc_xform *txform;
162 struct cryptoini cria, crie;
163 int keylen;
164 int error;
165
166 txform = esp_algorithm_lookup(sav->alg_enc);
167 if (txform == NULL) {
168 DPRINTF(("%s: unsupported encryption algorithm %d\n",
169 __func__, sav->alg_enc));
170 return EINVAL;
171 }
172 if (sav->key_enc == NULL) {
173 DPRINTF(("%s: no encoding key for %s algorithm\n",
174 __func__, txform->name));
175 return EINVAL;
176 }
177 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) {
178 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
179 __func__));
180 return EINVAL;
181 }
182 keylen = _KEYLEN(sav->key_enc);
183 if (txform->minkey > keylen || keylen > txform->maxkey) {
184 DPRINTF(("%s: invalid key length %u, must be in the range "
185 "[%u..%u] for algorithm %s\n", __func__,
186 keylen, txform->minkey, txform->maxkey,
187 txform->name));
188 return EINVAL;
189 }
190
191 /*
192 * NB: The null xform needs a non-zero blocksize to keep the
193 * crypto code happy but if we use it to set ivlen then
194 * the ESP header will be processed incorrectly. The
195 * compromise is to force it to zero here.
196 */
197 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize);
198 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK);
199 if (sav->iv == NULL) {
200 DPRINTF(("%s: no memory for IV\n", __func__));
201 return EINVAL;
202 }
203 key_randomfill(sav->iv, sav->ivlen); /*XXX*/
204
205 /*
206 * Setup AH-related state.
207 */
208 if (sav->alg_auth != 0) {
209 error = ah_init0(sav, xsp, &cria);
210 if (error)
211 return error;
212 }
213
214 /* NB: override anything set in ah_init0 */
215 sav->tdb_xform = xsp;
216 sav->tdb_encalgxform = txform;
217
218 /* Initialize crypto session. */
219 bzero(&crie, sizeof (crie));
220 crie.cri_alg = sav->tdb_encalgxform->type;
221 crie.cri_klen = _KEYBITS(sav->key_enc);
222 crie.cri_key = sav->key_enc->key_data;
223 /* XXX Rounds ? */
224
225 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
226 /* init both auth & enc */
227 crie.cri_next = &cria;
228 error = crypto_newsession(&sav->tdb_cryptoid,
229 &crie, V_crypto_support);
230 } else if (sav->tdb_encalgxform) {
231 error = crypto_newsession(&sav->tdb_cryptoid,
232 &crie, V_crypto_support);
233 } else if (sav->tdb_authalgxform) {
234 error = crypto_newsession(&sav->tdb_cryptoid,
235 &cria, V_crypto_support);
236 } else {
237 /* XXX cannot happen? */
238 DPRINTF(("%s: no encoding OR authentication xform!\n",
239 __func__));
240 error = EINVAL;
241 }
242 return error;
243 }
244
245 /*
246 * Paranoia.
247 */
248 static int
249 esp_zeroize(struct secasvar *sav)
250 {
251 /* NB: ah_zerorize free's the crypto session state */
252 int error = ah_zeroize(sav);
253
254 if (sav->key_enc)
255 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
256 if (sav->iv) {
257 free(sav->iv, M_XDATA);
258 sav->iv = NULL;
259 }
260 sav->tdb_encalgxform = NULL;
261 sav->tdb_xform = NULL;
262 return error;
263 }
264
265 /*
266 * ESP input processing, called (eventually) through the protocol switch.
267 */
268 static int
269 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
270 {
271 struct auth_hash *esph;
272 struct enc_xform *espx;
273 struct tdb_ident *tdbi;
274 struct tdb_crypto *tc;
275 int plen, alen, hlen;
276 struct m_tag *mtag;
277 struct newesp *esp;
278
279 struct cryptodesc *crde;
280 struct cryptop *crp;
281
282 IPSEC_ASSERT(sav != NULL, ("null SA"));
283 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
284 IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0,
285 ("misaligned packet, skip %u pkt len %u",
286 skip, m->m_pkthdr.len));
287
288 /* XXX don't pullup, just copy header */
289 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
290
291 esph = sav->tdb_authalgxform;
292 espx = sav->tdb_encalgxform;
293
294 /* Determine the ESP header length */
295 if (sav->flags & SADB_X_EXT_OLD)
296 hlen = sizeof (struct esp) + sav->ivlen;
297 else
298 hlen = sizeof (struct newesp) + sav->ivlen;
299 /* Authenticator hash size */
300 alen = esph ? AH_HMAC_HASHLEN : 0;
301
302 /*
303 * Verify payload length is multiple of encryption algorithm
304 * block size.
305 *
306 * NB: This works for the null algorithm because the blocksize
307 * is 4 and all packets must be 4-byte aligned regardless
308 * of the algorithm.
309 */
310 plen = m->m_pkthdr.len - (skip + hlen + alen);
311 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
312 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
313 " SA %s/%08lx\n", __func__,
314 plen, espx->blocksize,
315 ipsec_address(&sav->sah->saidx.dst),
316 (u_long) ntohl(sav->spi)));
317 V_espstat.esps_badilen++;
318 m_freem(m);
319 return EINVAL;
320 }
321
322 /*
323 * Check sequence number.
324 */
325 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
326 DPRINTF(("%s: packet replay check for %s\n", __func__,
327 ipsec_logsastr(sav))); /*XXX*/
328 V_espstat.esps_replay++;
329 m_freem(m);
330 return ENOBUFS; /*XXX*/
331 }
332
333 /* Update the counters */
334 V_espstat.esps_ibytes += m->m_pkthdr.len - (skip + hlen + alen);
335
336 /* Find out if we've already done crypto */
337 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
338 mtag != NULL;
339 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
340 tdbi = (struct tdb_ident *) (mtag + 1);
341 if (tdbi->proto == sav->sah->saidx.proto &&
342 tdbi->spi == sav->spi &&
343 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
344 sizeof(union sockaddr_union)))
345 break;
346 }
347
348 /* Get crypto descriptors */
349 crp = crypto_getreq(esph && espx ? 2 : 1);
350 if (crp == NULL) {
351 DPRINTF(("%s: failed to acquire crypto descriptors\n",
352 __func__));
353 V_espstat.esps_crypto++;
354 m_freem(m);
355 return ENOBUFS;
356 }
357
358 /* Get IPsec-specific opaque pointer */
359 if (esph == NULL || mtag != NULL)
360 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
361 M_XDATA, M_NOWAIT|M_ZERO);
362 else
363 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
364 M_XDATA, M_NOWAIT|M_ZERO);
365 if (tc == NULL) {
366 crypto_freereq(crp);
367 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
368 V_espstat.esps_crypto++;
369 m_freem(m);
370 return ENOBUFS;
371 }
372
373 tc->tc_ptr = (caddr_t) mtag;
374
375 if (esph) {
376 struct cryptodesc *crda = crp->crp_desc;
377
378 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
379
380 /* Authentication descriptor */
381 crda->crd_skip = skip;
382 crda->crd_len = m->m_pkthdr.len - (skip + alen);
383 crda->crd_inject = m->m_pkthdr.len - alen;
384
385 crda->crd_alg = esph->type;
386 crda->crd_key = sav->key_auth->key_data;
387 crda->crd_klen = _KEYBITS(sav->key_auth);
388
389 /* Copy the authenticator */
390 if (mtag == NULL)
391 m_copydata(m, m->m_pkthdr.len - alen, alen,
392 (caddr_t) (tc + 1));
393
394 /* Chain authentication request */
395 crde = crda->crd_next;
396 } else {
397 crde = crp->crp_desc;
398 }
399
400 /* Crypto operation descriptor */
401 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
402 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
403 crp->crp_buf = (caddr_t) m;
404 crp->crp_callback = esp_input_cb;
405 crp->crp_sid = sav->tdb_cryptoid;
406 crp->crp_opaque = (caddr_t) tc;
407
408 /* These are passed as-is to the callback */
409 tc->tc_spi = sav->spi;
410 tc->tc_dst = sav->sah->saidx.dst;
411 tc->tc_proto = sav->sah->saidx.proto;
412 tc->tc_protoff = protoff;
413 tc->tc_skip = skip;
414
415 /* Decryption descriptor */
416 if (espx) {
417 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
418 crde->crd_skip = skip + hlen;
419 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
420 crde->crd_inject = skip + hlen - sav->ivlen;
421
422 crde->crd_alg = espx->type;
423 crde->crd_key = sav->key_enc->key_data;
424 crde->crd_klen = _KEYBITS(sav->key_enc);
425 /* XXX Rounds ? */
426 }
427
428 if (mtag == NULL)
429 return crypto_dispatch(crp);
430 else
431 return esp_input_cb(crp);
432 }
433
434 #ifdef INET6
435 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
436 if (saidx->dst.sa.sa_family == AF_INET6) { \
437 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
438 } else { \
439 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
440 } \
441 } while (0)
442 #else
443 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
444 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
445 #endif
446
447 /*
448 * ESP input callback from the crypto driver.
449 */
450 static int
451 esp_input_cb(struct cryptop *crp)
452 {
453 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
454 int hlen, skip, protoff, error;
455 struct mbuf *m;
456 struct cryptodesc *crd;
457 struct auth_hash *esph;
458 struct enc_xform *espx;
459 struct tdb_crypto *tc;
460 struct m_tag *mtag;
461 struct secasvar *sav;
462 struct secasindex *saidx;
463 caddr_t ptr;
464
465 crd = crp->crp_desc;
466 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
467
468 tc = (struct tdb_crypto *) crp->crp_opaque;
469 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
470 skip = tc->tc_skip;
471 protoff = tc->tc_protoff;
472 mtag = (struct m_tag *) tc->tc_ptr;
473 m = (struct mbuf *) crp->crp_buf;
474
475 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
476 if (sav == NULL) {
477 V_espstat.esps_notdb++;
478 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
479 __func__, ipsec_address(&tc->tc_dst),
480 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
481 error = ENOBUFS; /*XXX*/
482 goto bad;
483 }
484
485 saidx = &sav->sah->saidx;
486 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
487 saidx->dst.sa.sa_family == AF_INET6,
488 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
489
490 esph = sav->tdb_authalgxform;
491 espx = sav->tdb_encalgxform;
492
493 /* Check for crypto errors */
494 if (crp->crp_etype) {
495 /* Reset the session ID */
496 if (sav->tdb_cryptoid != 0)
497 sav->tdb_cryptoid = crp->crp_sid;
498
499 if (crp->crp_etype == EAGAIN) {
500 KEY_FREESAV(&sav);
501 error = crypto_dispatch(crp);
502 return error;
503 }
504
505 V_espstat.esps_noxform++;
506 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
507 error = crp->crp_etype;
508 goto bad;
509 }
510
511 /* Shouldn't happen... */
512 if (m == NULL) {
513 V_espstat.esps_crypto++;
514 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
515 error = EINVAL;
516 goto bad;
517 }
518 V_espstat.esps_hist[sav->alg_enc]++;
519
520 /* If authentication was performed, check now. */
521 if (esph != NULL) {
522 /*
523 * If we have a tag, it means an IPsec-aware NIC did
524 * the verification for us. Otherwise we need to
525 * check the authentication calculation.
526 */
527 V_ahstat.ahs_hist[sav->alg_auth]++;
528 if (mtag == NULL) {
529 /* Copy the authenticator from the packet */
530 m_copydata(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
531 AH_HMAC_HASHLEN, aalg);
532
533 ptr = (caddr_t) (tc + 1);
534
535 /* Verify authenticator */
536 if (bcmp(ptr, aalg, AH_HMAC_HASHLEN) != 0) {
537 DPRINTF(("%s: "
538 "authentication hash mismatch for packet in SA %s/%08lx\n",
539 __func__,
540 ipsec_address(&saidx->dst),
541 (u_long) ntohl(sav->spi)));
542 V_espstat.esps_badauth++;
543 error = EACCES;
544 goto bad;
545 }
546 }
547
548 /* Remove trailing authenticator */
549 m_adj(m, -AH_HMAC_HASHLEN);
550 }
551
552 /* Release the crypto descriptors */
553 free(tc, M_XDATA), tc = NULL;
554 crypto_freereq(crp), crp = NULL;
555
556 /*
557 * Packet is now decrypted.
558 */
559 m->m_flags |= M_DECRYPTED;
560
561 /*
562 * Update replay sequence number, if appropriate.
563 */
564 if (sav->replay) {
565 u_int32_t seq;
566
567 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
568 sizeof (seq), (caddr_t) &seq);
569 if (ipsec_updatereplay(ntohl(seq), sav)) {
570 DPRINTF(("%s: packet replay check for %s\n", __func__,
571 ipsec_logsastr(sav)));
572 V_espstat.esps_replay++;
573 error = ENOBUFS;
574 goto bad;
575 }
576 }
577
578 /* Determine the ESP header length */
579 if (sav->flags & SADB_X_EXT_OLD)
580 hlen = sizeof (struct esp) + sav->ivlen;
581 else
582 hlen = sizeof (struct newesp) + sav->ivlen;
583
584 /* Remove the ESP header and IV from the mbuf. */
585 error = m_striphdr(m, skip, hlen);
586 if (error) {
587 V_espstat.esps_hdrops++;
588 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
589 ipsec_address(&sav->sah->saidx.dst),
590 (u_long) ntohl(sav->spi)));
591 goto bad;
592 }
593
594 /* Save the last three bytes of decrypted data */
595 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
596
597 /* Verify pad length */
598 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
599 V_espstat.esps_badilen++;
600 DPRINTF(("%s: invalid padding length %d for %u byte packet "
601 "in SA %s/%08lx\n", __func__,
602 lastthree[1], m->m_pkthdr.len - skip,
603 ipsec_address(&sav->sah->saidx.dst),
604 (u_long) ntohl(sav->spi)));
605 error = EINVAL;
606 goto bad;
607 }
608
609 /* Verify correct decryption by checking the last padding bytes */
610 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
611 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
612 V_espstat.esps_badenc++;
613 DPRINTF(("%s: decryption failed for packet in "
614 "SA %s/%08lx\n", __func__,
615 ipsec_address(&sav->sah->saidx.dst),
616 (u_long) ntohl(sav->spi)));
617 error = EINVAL;
618 goto bad;
619 }
620 }
621
622 /* Trim the mbuf chain to remove trailing authenticator and padding */
623 m_adj(m, -(lastthree[1] + 2));
624
625 /* Restore the Next Protocol field */
626 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
627
628 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
629
630 KEY_FREESAV(&sav);
631 return error;
632 bad:
633 if (sav)
634 KEY_FREESAV(&sav);
635 if (m != NULL)
636 m_freem(m);
637 if (tc != NULL)
638 free(tc, M_XDATA);
639 if (crp != NULL)
640 crypto_freereq(crp);
641 return error;
642 }
643
644 /*
645 * ESP output routine, called by ipsec[46]_process_packet().
646 */
647 static int
648 esp_output(
649 struct mbuf *m,
650 struct ipsecrequest *isr,
651 struct mbuf **mp,
652 int skip,
653 int protoff
654 )
655 {
656 struct enc_xform *espx;
657 struct auth_hash *esph;
658 int hlen, rlen, plen, padding, blks, alen, i, roff;
659 struct mbuf *mo = (struct mbuf *) NULL;
660 struct tdb_crypto *tc;
661 struct secasvar *sav;
662 struct secasindex *saidx;
663 unsigned char *pad;
664 u_int8_t prot;
665 int error, maxpacketsize;
666
667 struct cryptodesc *crde = NULL, *crda = NULL;
668 struct cryptop *crp;
669
670 sav = isr->sav;
671 IPSEC_ASSERT(sav != NULL, ("null SA"));
672 esph = sav->tdb_authalgxform;
673 espx = sav->tdb_encalgxform;
674 IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
675
676 if (sav->flags & SADB_X_EXT_OLD)
677 hlen = sizeof (struct esp) + sav->ivlen;
678 else
679 hlen = sizeof (struct newesp) + sav->ivlen;
680
681 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
682 /*
683 * NB: The null encoding transform has a blocksize of 4
684 * so that headers are properly aligned.
685 */
686 blks = espx->blocksize; /* IV blocksize */
687
688 /* XXX clamp padding length a la KAME??? */
689 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
690 plen = rlen + padding; /* Padded payload length. */
691
692 if (esph)
693 alen = AH_HMAC_HASHLEN;
694 else
695 alen = 0;
696
697 V_espstat.esps_output++;
698
699 saidx = &sav->sah->saidx;
700 /* Check for maximum packet size violations. */
701 switch (saidx->dst.sa.sa_family) {
702 #ifdef INET
703 case AF_INET:
704 maxpacketsize = IP_MAXPACKET;
705 break;
706 #endif /* INET */
707 #ifdef INET6
708 case AF_INET6:
709 maxpacketsize = IPV6_MAXPACKET;
710 break;
711 #endif /* INET6 */
712 default:
713 DPRINTF(("%s: unknown/unsupported protocol "
714 "family %d, SA %s/%08lx\n", __func__,
715 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst),
716 (u_long) ntohl(sav->spi)));
717 V_espstat.esps_nopf++;
718 error = EPFNOSUPPORT;
719 goto bad;
720 }
721 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
722 DPRINTF(("%s: packet in SA %s/%08lx got too big "
723 "(len %u, max len %u)\n", __func__,
724 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi),
725 skip + hlen + rlen + padding + alen, maxpacketsize));
726 V_espstat.esps_toobig++;
727 error = EMSGSIZE;
728 goto bad;
729 }
730
731 /* Update the counters. */
732 V_espstat.esps_obytes += m->m_pkthdr.len - skip;
733
734 m = m_unshare(m, M_NOWAIT);
735 if (m == NULL) {
736 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
737 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
738 V_espstat.esps_hdrops++;
739 error = ENOBUFS;
740 goto bad;
741 }
742
743 /* Inject ESP header. */
744 mo = m_makespace(m, skip, hlen, &roff);
745 if (mo == NULL) {
746 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
747 __func__, hlen, ipsec_address(&saidx->dst),
748 (u_long) ntohl(sav->spi)));
749 V_espstat.esps_hdrops++; /* XXX diffs from openbsd */
750 error = ENOBUFS;
751 goto bad;
752 }
753
754 /* Initialize ESP header. */
755 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
756 if (sav->replay) {
757 u_int32_t replay;
758
759 #ifdef REGRESSION
760 /* Emulate replay attack when ipsec_replay is TRUE. */
761 if (!V_ipsec_replay)
762 #endif
763 sav->replay->count++;
764 replay = htonl(sav->replay->count);
765 bcopy((caddr_t) &replay,
766 mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
767 sizeof(u_int32_t));
768 }
769
770 /*
771 * Add padding -- better to do it ourselves than use the crypto engine,
772 * although if/when we support compression, we'd have to do that.
773 */
774 pad = (u_char *) m_pad(m, padding + alen);
775 if (pad == NULL) {
776 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
777 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
778 m = NULL; /* NB: free'd by m_pad */
779 error = ENOBUFS;
780 goto bad;
781 }
782
783 /*
784 * Add padding: random, zero, or self-describing.
785 * XXX catch unexpected setting
786 */
787 switch (sav->flags & SADB_X_EXT_PMASK) {
788 case SADB_X_EXT_PRAND:
789 (void) read_random(pad, padding - 2);
790 break;
791 case SADB_X_EXT_PZERO:
792 bzero(pad, padding - 2);
793 break;
794 case SADB_X_EXT_PSEQ:
795 for (i = 0; i < padding - 2; i++)
796 pad[i] = i+1;
797 break;
798 }
799
800 /* Fix padding length and Next Protocol in padding itself. */
801 pad[padding - 2] = padding - 2;
802 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
803
804 /* Fix Next Protocol in IPv4/IPv6 header. */
805 prot = IPPROTO_ESP;
806 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
807
808 /* Get crypto descriptors. */
809 crp = crypto_getreq(esph && espx ? 2 : 1);
810 if (crp == NULL) {
811 DPRINTF(("%s: failed to acquire crypto descriptors\n",
812 __func__));
813 V_espstat.esps_crypto++;
814 error = ENOBUFS;
815 goto bad;
816 }
817
818 if (espx) {
819 crde = crp->crp_desc;
820 crda = crde->crd_next;
821
822 /* Encryption descriptor. */
823 crde->crd_skip = skip + hlen;
824 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
825 crde->crd_flags = CRD_F_ENCRYPT;
826 crde->crd_inject = skip + hlen - sav->ivlen;
827
828 /* Encryption operation. */
829 crde->crd_alg = espx->type;
830 crde->crd_key = sav->key_enc->key_data;
831 crde->crd_klen = _KEYBITS(sav->key_enc);
832 /* XXX Rounds ? */
833 } else
834 crda = crp->crp_desc;
835
836 /* IPsec-specific opaque crypto info. */
837 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
838 M_XDATA, M_NOWAIT|M_ZERO);
839 if (tc == NULL) {
840 crypto_freereq(crp);
841 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
842 V_espstat.esps_crypto++;
843 error = ENOBUFS;
844 goto bad;
845 }
846
847 /* Callback parameters */
848 tc->tc_isr = isr;
849 tc->tc_spi = sav->spi;
850 tc->tc_dst = saidx->dst;
851 tc->tc_proto = saidx->proto;
852
853 /* Crypto operation descriptor. */
854 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
855 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
856 crp->crp_buf = (caddr_t) m;
857 crp->crp_callback = esp_output_cb;
858 crp->crp_opaque = (caddr_t) tc;
859 crp->crp_sid = sav->tdb_cryptoid;
860
861 if (esph) {
862 /* Authentication descriptor. */
863 crda->crd_skip = skip;
864 crda->crd_len = m->m_pkthdr.len - (skip + alen);
865 crda->crd_inject = m->m_pkthdr.len - alen;
866
867 /* Authentication operation. */
868 crda->crd_alg = esph->type;
869 crda->crd_key = sav->key_auth->key_data;
870 crda->crd_klen = _KEYBITS(sav->key_auth);
871 }
872
873 return crypto_dispatch(crp);
874 bad:
875 if (m)
876 m_freem(m);
877 return (error);
878 }
879
880 /*
881 * ESP output callback from the crypto driver.
882 */
883 static int
884 esp_output_cb(struct cryptop *crp)
885 {
886 struct tdb_crypto *tc;
887 struct ipsecrequest *isr;
888 struct secasvar *sav;
889 struct mbuf *m;
890 int err, error;
891
892 tc = (struct tdb_crypto *) crp->crp_opaque;
893 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
894 m = (struct mbuf *) crp->crp_buf;
895
896 isr = tc->tc_isr;
897 IPSECREQUEST_LOCK(isr);
898 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
899 if (sav == NULL) {
900 V_espstat.esps_notdb++;
901 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
902 __func__, ipsec_address(&tc->tc_dst),
903 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
904 error = ENOBUFS; /*XXX*/
905 goto bad;
906 }
907 IPSEC_ASSERT(isr->sav == sav,
908 ("SA changed was %p now %p\n", isr->sav, sav));
909
910 /* Check for crypto errors. */
911 if (crp->crp_etype) {
912 /* Reset session ID. */
913 if (sav->tdb_cryptoid != 0)
914 sav->tdb_cryptoid = crp->crp_sid;
915
916 if (crp->crp_etype == EAGAIN) {
917 KEY_FREESAV(&sav);
918 IPSECREQUEST_UNLOCK(isr);
919 error = crypto_dispatch(crp);
920 return error;
921 }
922
923 V_espstat.esps_noxform++;
924 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
925 error = crp->crp_etype;
926 goto bad;
927 }
928
929 /* Shouldn't happen... */
930 if (m == NULL) {
931 V_espstat.esps_crypto++;
932 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
933 error = EINVAL;
934 goto bad;
935 }
936 V_espstat.esps_hist[sav->alg_enc]++;
937 if (sav->tdb_authalgxform != NULL)
938 V_ahstat.ahs_hist[sav->alg_auth]++;
939
940 /* Release crypto descriptors. */
941 free(tc, M_XDATA);
942 crypto_freereq(crp);
943
944 #ifdef REGRESSION
945 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
946 if (V_ipsec_integrity) {
947 static unsigned char ipseczeroes[AH_HMAC_HASHLEN];
948 struct auth_hash *esph;
949
950 /*
951 * Corrupt HMAC if we want to test integrity verification of
952 * the other side.
953 */
954 esph = sav->tdb_authalgxform;
955 if (esph != NULL) {
956 m_copyback(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
957 AH_HMAC_HASHLEN, ipseczeroes);
958 }
959 }
960 #endif
961
962 /* NB: m is reclaimed by ipsec_process_done. */
963 err = ipsec_process_done(m, isr);
964 KEY_FREESAV(&sav);
965 IPSECREQUEST_UNLOCK(isr);
966 return err;
967 bad:
968 if (sav)
969 KEY_FREESAV(&sav);
970 IPSECREQUEST_UNLOCK(isr);
971 if (m)
972 m_freem(m);
973 free(tc, M_XDATA);
974 crypto_freereq(crp);
975 return error;
976 }
977
978 static struct xformsw esp_xformsw = {
979 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
980 esp_init, esp_zeroize, esp_input,
981 esp_output
982 };
983
984 static void
985 esp_attach(void)
986 {
987 #define MAXIV(xform) \
988 if (xform.blocksize > V_esp_max_ivlen) \
989 V_esp_max_ivlen = xform.blocksize \
990
991 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */
992 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */
993 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */
994 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */
995 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */
996 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */
997 MAXIV(enc_xform_null); /* SADB_EALG_NULL */
998 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */
999
1000 xform_register(&esp_xformsw);
1001 #undef MAXIV
1002 }
1003 SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
Cache object: e0e208c5423cff6df1da18aecf58aba7
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