1/* $FreeBSD: head/sys/netipsec/xform_esp.c 286292 2015-08-04 17:47:11Z jmg $ */
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/lock.h>
48#include <sys/random.h>
49#include <sys/rwlock.h>
50#include <sys/sysctl.h>
51#include <sys/mutex.h>
52#include <machine/atomic.h>
53
54#include <net/if.h>
55#include <net/vnet.h>
56
57#include <netinet/in.h>
58#include <netinet/in_systm.h>
59#include <netinet/ip.h>
60#include <netinet/ip_ecn.h>
61#include <netinet/ip6.h>
62
63#include <netipsec/ipsec.h>
64#include <netipsec/ah.h>
65#include <netipsec/ah_var.h>
66#include <netipsec/esp.h>
67#include <netipsec/esp_var.h>
68#include <netipsec/xform.h>
69
70#ifdef INET6
71#include <netinet6/ip6_var.h>
72#include <netipsec/ipsec6.h>
73#include <netinet6/ip6_ecn.h>
74#endif
75
76#include <netipsec/key.h>
77#include <netipsec/key_debug.h>
78
79#include <opencrypto/cryptodev.h>
80#include <opencrypto/xform.h>
81
82VNET_DEFINE(int, esp_enable) = 1;
83VNET_PCPUSTAT_DEFINE(struct espstat, espstat);
84VNET_PCPUSTAT_SYSINIT(espstat);
85
86#ifdef VIMAGE
87VNET_PCPUSTAT_SYSUNINIT(espstat);
88#endif /* VIMAGE */
89
90SYSCTL_DECL(_net_inet_esp);
91SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable,
92 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
93SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats,
94 struct espstat, espstat,
95 "ESP statistics (struct espstat, netipsec/esp_var.h");
96
97static int esp_input_cb(struct cryptop *op);
98static int esp_output_cb(struct cryptop *crp);
99
100/*
101 * NB: this is public for use by the PF_KEY support.
102 * NB: if you add support here; be sure to add code to esp_attach below!
103 */
104struct enc_xform *
105esp_algorithm_lookup(int alg)
106{
107 if (alg >= ESP_ALG_MAX)
108 return NULL;
109 switch (alg) {
110 case SADB_EALG_DESCBC:
111 return &enc_xform_des;
112 case SADB_EALG_3DESCBC:
113 return &enc_xform_3des;
114 case SADB_X_EALG_AES:
115 return &enc_xform_rijndael128;
116 case SADB_X_EALG_BLOWFISHCBC:
117 return &enc_xform_blf;
118 case SADB_X_EALG_CAST128CBC:
119 return &enc_xform_cast5;
120 case SADB_EALG_NULL:
121 return &enc_xform_null;
122 case SADB_X_EALG_CAMELLIACBC:
123 return &enc_xform_camellia;
124 case SADB_X_EALG_AESCTR:
125 return &enc_xform_aes_icm;
126 case SADB_X_EALG_AESGCM16:
127 return &enc_xform_aes_nist_gcm;
128 case SADB_X_EALG_AESGMAC:
129 return &enc_xform_aes_nist_gmac;
130 }
131 return NULL;
132}
133
134size_t
135esp_hdrsiz(struct secasvar *sav)
136{
137 size_t size;
138
139 if (sav != NULL) {
140 /*XXX not right for null algorithm--does it matter??*/
141 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
142 ("SA with null xform"));
143 if (sav->flags & SADB_X_EXT_OLD)
144 size = sizeof (struct esp);
145 else
146 size = sizeof (struct newesp);
147 size += sav->tdb_encalgxform->blocksize + 9;
148 /*XXX need alg check???*/
149 if (sav->tdb_authalgxform != NULL && sav->replay)
150 size += ah_hdrsiz(sav);
151 } else {
152 /*
153 * base header size
154 * + max iv length for CBC mode
155 * + max pad length
156 * + sizeof (pad length field)
157 * + sizeof (next header field)
158 * + max icv supported.
159 */
160 size = sizeof (struct newesp) + EALG_MAX_BLOCK_LEN + 9 + 16;
161 }
162 return size;
163}
164
165/*
166 * esp_init() is called when an SPI is being set up.
167 */
168static int
169esp_init(struct secasvar *sav, struct xformsw *xsp)
170{
171 struct enc_xform *txform;
172 struct cryptoini cria, crie;
173 int keylen;
174 int error;
175
176 txform = esp_algorithm_lookup(sav->alg_enc);
177 if (txform == NULL) {
178 DPRINTF(("%s: unsupported encryption algorithm %d\n",
179 __func__, sav->alg_enc));
180 return EINVAL;
181 }
182 if (sav->key_enc == NULL) {
183 DPRINTF(("%s: no encoding key for %s algorithm\n",
184 __func__, txform->name));
185 return EINVAL;
186 }
187 if ((sav->flags & (SADB_X_EXT_OLD | SADB_X_EXT_IV4B)) ==
188 SADB_X_EXT_IV4B) {
189 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
190 __func__));
191 return EINVAL;
192 }
193 /* subtract off the salt, RFC4106, 8.1 and RFC3686, 5.1 */
194 keylen = _KEYLEN(sav->key_enc) - SAV_ISCTRORGCM(sav) * 4;
195 if (txform->minkey > keylen || keylen > txform->maxkey) {
196 DPRINTF(("%s: invalid key length %u, must be in the range "
197 "[%u..%u] for algorithm %s\n", __func__,
198 keylen, txform->minkey, txform->maxkey,
199 txform->name));
200 return EINVAL;
201 }
202
203 /*
204 * NB: The null xform needs a non-zero blocksize to keep the
205 * crypto code happy but if we use it to set ivlen then
206 * the ESP header will be processed incorrectly. The
207 * compromise is to force it to zero here.
208 */
209 if (SAV_ISCTRORGCM(sav))
210 sav->ivlen = 8; /* RFC4106 3.1 and RFC3686 3.1 */
211 else
212 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->ivsize);
213
214 /*
215 * Setup AH-related state.
216 */
217 if (sav->alg_auth != 0) {
218 error = ah_init0(sav, xsp, &cria);
219 if (error)
220 return error;
221 }
222
223 /* NB: override anything set in ah_init0 */
224 sav->tdb_xform = xsp;
225 sav->tdb_encalgxform = txform;
226
227 /*
228 * Whenever AES-GCM is used for encryption, one
229 * of the AES authentication algorithms is chosen
230 * as well, based on the key size.
231 */
232 if (sav->alg_enc == SADB_X_EALG_AESGCM16) {
233 switch (keylen) {
234 case AES_128_GMAC_KEY_LEN:
235 sav->alg_auth = SADB_X_AALG_AES128GMAC;
236 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_128;
237 break;
238 case AES_192_GMAC_KEY_LEN:
239 sav->alg_auth = SADB_X_AALG_AES192GMAC;
240 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_192;
241 break;
242 case AES_256_GMAC_KEY_LEN:
243 sav->alg_auth = SADB_X_AALG_AES256GMAC;
244 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_256;
245 break;
246 default:
247 DPRINTF(("%s: invalid key length %u"
248 "for algorithm %s\n", __func__,
249 keylen, txform->name));
250 return EINVAL;
251 }
252 bzero(&cria, sizeof(cria));
253 cria.cri_alg = sav->tdb_authalgxform->type;
254 cria.cri_key = sav->key_enc->key_data;
255 cria.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISGCM(sav) * 32;
256 }
257
258 /* Initialize crypto session. */
259 bzero(&crie, sizeof(crie));
260 crie.cri_alg = sav->tdb_encalgxform->type;
261 crie.cri_key = sav->key_enc->key_data;
262 crie.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISCTRORGCM(sav) * 32;
263
264 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
265 /* init both auth & enc */
266 crie.cri_next = &cria;
267 error = crypto_newsession(&sav->tdb_cryptoid,
268 &crie, V_crypto_support);
269 } else if (sav->tdb_encalgxform) {
270 error = crypto_newsession(&sav->tdb_cryptoid,
271 &crie, V_crypto_support);
272 } else if (sav->tdb_authalgxform) {
273 error = crypto_newsession(&sav->tdb_cryptoid,
274 &cria, V_crypto_support);
275 } else {
276 /* XXX cannot happen? */
277 DPRINTF(("%s: no encoding OR authentication xform!\n",
278 __func__));
279 error = EINVAL;
280 }
281 return error;
282}
283
284/*
285 * Paranoia.
286 */
287static int
288esp_zeroize(struct secasvar *sav)
289{
290 /* NB: ah_zerorize free's the crypto session state */
291 int error = ah_zeroize(sav);
292
293 if (sav->key_enc)
294 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
295 sav->tdb_encalgxform = NULL;
296 sav->tdb_xform = NULL;
297 return error;
298}
299
300/*
301 * ESP input processing, called (eventually) through the protocol switch.
302 */
303static int
304esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
305{
306 char buf[128];
307 struct auth_hash *esph;
308 struct enc_xform *espx;
309 struct tdb_crypto *tc;
310 uint8_t *ivp;
311 int plen, alen, hlen;
312 struct newesp *esp;
313 struct cryptodesc *crde;
314 struct cryptop *crp;
315
316 IPSEC_ASSERT(sav != NULL, ("null SA"));
317 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
318
319 /* Valid IP Packet length ? */
320 if ( (skip&3) || (m->m_pkthdr.len&3) ){
321 DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
322 __func__, skip, m->m_pkthdr.len));
323 ESPSTAT_INC(esps_badilen);
324 m_freem(m);
325 return EINVAL;
326 }
327 /* XXX don't pullup, just copy header */
328 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
329
330 esph = sav->tdb_authalgxform;
331 espx = sav->tdb_encalgxform;
332
333 /* Determine the ESP header and auth length */
334 if (sav->flags & SADB_X_EXT_OLD)
335 hlen = sizeof (struct esp) + sav->ivlen;
336 else
337 hlen = sizeof (struct newesp) + sav->ivlen;
338
339 alen = xform_ah_authsize(esph);
340
341 /*
342 * Verify payload length is multiple of encryption algorithm
343 * block size.
344 *
345 * NB: This works for the null algorithm because the blocksize
346 * is 4 and all packets must be 4-byte aligned regardless
347 * of the algorithm.
348 */
349 plen = m->m_pkthdr.len - (skip + hlen + alen);
350 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
351 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
352 " SA %s/%08lx\n", __func__, plen, espx->blocksize,
353 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
354 (u_long)ntohl(sav->spi)));
355 ESPSTAT_INC(esps_badilen);
356 m_freem(m);
357 return EINVAL;
358 }
359
360 /*
361 * Check sequence number.
362 */
363 if (esph != NULL && sav->replay != NULL &&
364 !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
365 DPRINTF(("%s: packet replay check for %s\n", __func__,
366 ipsec_logsastr(sav, buf, sizeof(buf)))); /*XXX*/
367 ESPSTAT_INC(esps_replay);
368 m_freem(m);
369 return ENOBUFS; /*XXX*/
370 }
371
372 /* Update the counters */
373 ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
374
375 /* Get crypto descriptors */
376 crp = crypto_getreq(esph && espx ? 2 : 1);
377 if (crp == NULL) {
378 DPRINTF(("%s: failed to acquire crypto descriptors\n",
379 __func__));
380 ESPSTAT_INC(esps_crypto);
381 m_freem(m);
382 return ENOBUFS;
383 }
384
385 /* Get IPsec-specific opaque pointer */
386 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
387 M_XDATA, M_NOWAIT | M_ZERO);
388 if (tc == NULL) {
389 crypto_freereq(crp);
390 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
391 ESPSTAT_INC(esps_crypto);
392 m_freem(m);
393 return ENOBUFS;
394 }
395
396 if (esph != NULL) {
397 struct cryptodesc *crda = crp->crp_desc;
398
399 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
400
401 /* Authentication descriptor */
402 crda->crd_skip = skip;
403 if (SAV_ISGCM(sav))
404 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
405 else
406 crda->crd_len = m->m_pkthdr.len - (skip + alen);
407 crda->crd_inject = m->m_pkthdr.len - alen;
408
409 crda->crd_alg = esph->type;
410
411 /* Copy the authenticator */
412 m_copydata(m, m->m_pkthdr.len - alen, alen,
413 (caddr_t) (tc + 1));
414
415 /* Chain authentication request */
416 crde = crda->crd_next;
417 } else {
418 crde = crp->crp_desc;
419 }
420
421 /* Crypto operation descriptor */
422 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
423 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
424 crp->crp_buf = (caddr_t) m;
425 crp->crp_callback = esp_input_cb;
426 crp->crp_sid = sav->tdb_cryptoid;
427 crp->crp_opaque = (caddr_t) tc;
428
429 /* These are passed as-is to the callback */
430 tc->tc_spi = sav->spi;
431 tc->tc_dst = sav->sah->saidx.dst;
432 tc->tc_proto = sav->sah->saidx.proto;
433 tc->tc_protoff = protoff;
434 tc->tc_skip = skip;
435 KEY_ADDREFSA(sav);
436 tc->tc_sav = sav;
437
438 /* Decryption descriptor */
439 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
440 crde->crd_skip = skip + hlen;
441 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
442 crde->crd_inject = skip + hlen - sav->ivlen;
443
444 if (SAV_ISCTRORGCM(sav)) {
445 ivp = &crde->crd_iv[0];
446
447 /* GCM IV Format: RFC4106 4 */
448 /* CTR IV Format: RFC3686 4 */
449 /* Salt is last four bytes of key, RFC4106 8.1 */
450 /* Nonce is last four bytes of key, RFC3686 5.1 */
451 memcpy(ivp, sav->key_enc->key_data +
452 _KEYLEN(sav->key_enc) - 4, 4);
453
454 if (SAV_ISCTR(sav)) {
455 /* Initial block counter is 1, RFC3686 4 */
456 be32enc(&ivp[sav->ivlen + 4], 1);
457 }
458
459 m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
460 crde->crd_flags |= CRD_F_IV_EXPLICIT;
461 }
462
463 crde->crd_alg = espx->type;
464
465 return (crypto_dispatch(crp));
466}
467
468/*
469 * ESP input callback from the crypto driver.
470 */
471static int
472esp_input_cb(struct cryptop *crp)
473{
474 char buf[128];
475 u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN];
476 int hlen, skip, protoff, error, alen;
477 struct mbuf *m;
478 struct cryptodesc *crd;
479 struct auth_hash *esph;
480 struct enc_xform *espx;
481 struct tdb_crypto *tc;
482 struct secasvar *sav;
483 struct secasindex *saidx;
484 caddr_t ptr;
485
486 crd = crp->crp_desc;
487 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
488
489 tc = (struct tdb_crypto *) crp->crp_opaque;
490 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
491 skip = tc->tc_skip;
492 protoff = tc->tc_protoff;
493 m = (struct mbuf *) crp->crp_buf;
494
495 sav = tc->tc_sav;
496 IPSEC_ASSERT(sav != NULL, ("null SA!"));
497
498 saidx = &sav->sah->saidx;
499 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
500 saidx->dst.sa.sa_family == AF_INET6,
501 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
502
503 esph = sav->tdb_authalgxform;
504 espx = sav->tdb_encalgxform;
505
506 /* Check for crypto errors */
507 if (crp->crp_etype) {
508 /* Reset the session ID */
509 if (sav->tdb_cryptoid != 0)
510 sav->tdb_cryptoid = crp->crp_sid;
511
512 if (crp->crp_etype == EAGAIN)
513 return (crypto_dispatch(crp));
514
515 ESPSTAT_INC(esps_noxform);
516 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
517 error = crp->crp_etype;
518 goto bad;
519 }
520
521 /* Shouldn't happen... */
522 if (m == NULL) {
523 ESPSTAT_INC(esps_crypto);
524 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
525 error = EINVAL;
526 goto bad;
527 }
528 ESPSTAT_INC(esps_hist[sav->alg_enc]);
529
530 /* If authentication was performed, check now. */
531 if (esph != NULL) {
532 alen = xform_ah_authsize(esph);
533 AHSTAT_INC(ahs_hist[sav->alg_auth]);
534 /* Copy the authenticator from the packet */
535 m_copydata(m, m->m_pkthdr.len - alen, alen, aalg);
536 ptr = (caddr_t) (tc + 1);
537
538 /* Verify authenticator */
539 if (timingsafe_bcmp(ptr, aalg, alen) != 0) {
540 DPRINTF(("%s: authentication hash mismatch for "
541 "packet in SA %s/%08lx\n", __func__,
542 ipsec_address(&saidx->dst, buf, sizeof(buf)),
543 (u_long) ntohl(sav->spi)));
544 ESPSTAT_INC(esps_badauth);
545 error = EACCES;
546 goto bad;
547 }
548
549 /* Remove trailing authenticator */
550 m_adj(m, -alen);
551 }
552
553 /* Release the crypto descriptors */
554 free(tc, M_XDATA), tc = NULL;
555 crypto_freereq(crp), crp = NULL;
556
557 /*
558 * Packet is now decrypted.
559 */
560 m->m_flags |= M_DECRYPTED;
561
562 /*
563 * Update replay sequence number, if appropriate.
564 */
565 if (sav->replay) {
566 u_int32_t seq;
567
568 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
569 sizeof (seq), (caddr_t) &seq);
570 if (ipsec_updatereplay(ntohl(seq), sav)) {
571 DPRINTF(("%s: packet replay check for %s\n", __func__,
572 ipsec_logsastr(sav, buf, sizeof(buf))));
573 ESPSTAT_INC(esps_replay);
574 error = ENOBUFS;
575 goto bad;
576 }
577 }
578
579 /* Determine the ESP header length */
580 if (sav->flags & SADB_X_EXT_OLD)
581 hlen = sizeof (struct esp) + sav->ivlen;
582 else
583 hlen = sizeof (struct newesp) + sav->ivlen;
584
585 /* Remove the ESP header and IV from the mbuf. */
586 error = m_striphdr(m, skip, hlen);
587 if (error) {
588 ESPSTAT_INC(esps_hdrops);
589 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
590 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
591 (u_long) ntohl(sav->spi)));
592 goto bad;
593 }
594
595 /* Save the last three bytes of decrypted data */
596 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
597
598 /* Verify pad length */
599 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
600 ESPSTAT_INC(esps_badilen);
601 DPRINTF(("%s: invalid padding length %d for %u byte packet "
602 "in SA %s/%08lx\n", __func__, lastthree[1],
603 m->m_pkthdr.len - skip,
604 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
605 (u_long) ntohl(sav->spi)));
606 error = EINVAL;
607 goto bad;
608 }
609
610 /* Verify correct decryption by checking the last padding bytes */
611 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
612 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
613 ESPSTAT_INC(esps_badenc);
614 DPRINTF(("%s: decryption failed for packet in "
615 "SA %s/%08lx\n", __func__, ipsec_address(
616 &sav->sah->saidx.dst, buf, sizeof(buf)),
617 (u_long) ntohl(sav->spi)));
618 error = EINVAL;
619 goto bad;
620 }
621 }
622
623 /* Trim the mbuf chain to remove trailing authenticator and padding */
624 m_adj(m, -(lastthree[1] + 2));
625
626 /* Restore the Next Protocol field */
627 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
628
629 switch (saidx->dst.sa.sa_family) {
630#ifdef INET6
631 case AF_INET6:
632 error = ipsec6_common_input_cb(m, sav, skip, protoff);
633 break;
634#endif
635#ifdef INET
636 case AF_INET:
637 error = ipsec4_common_input_cb(m, sav, skip, protoff);
638 break;
639#endif
640 default:
641 panic("%s: Unexpected address family: %d saidx=%p", __func__,
642 saidx->dst.sa.sa_family, saidx);
643 }
644
645 KEY_FREESAV(&sav);
646 return error;
647bad:
648 if (sav)
649 KEY_FREESAV(&sav);
650 if (m != NULL)
651 m_freem(m);
652 if (tc != NULL)
653 free(tc, M_XDATA);
654 if (crp != NULL)
655 crypto_freereq(crp);
656 return error;
657}
658
659/*
660 * ESP output routine, called by ipsec[46]_process_packet().
661 */
662static int
663esp_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
664 int skip, int protoff)
665{
666 char buf[INET6_ADDRSTRLEN];
667 struct enc_xform *espx;
668 struct auth_hash *esph;
669 uint8_t *ivp;
670 uint64_t cntr;
671 int hlen, rlen, padding, blks, alen, i, roff;
672 struct mbuf *mo = (struct mbuf *) NULL;
673 struct tdb_crypto *tc;
674 struct secasvar *sav;
675 struct secasindex *saidx;
676 unsigned char *pad;
677 u_int8_t prot;
678 int error, maxpacketsize;
679
680 struct cryptodesc *crde = NULL, *crda = NULL;
681 struct cryptop *crp;
682
683 sav = isr->sav;
684 IPSEC_ASSERT(sav != NULL, ("null SA"));
685 esph = sav->tdb_authalgxform;
686 espx = sav->tdb_encalgxform;
687 IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
688
689 if (sav->flags & SADB_X_EXT_OLD)
690 hlen = sizeof (struct esp) + sav->ivlen;
691 else
692 hlen = sizeof (struct newesp) + sav->ivlen;
693
694 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
695 /*
696 * RFC4303 2.4 Requires 4 byte alignment.
697 */
698 blks = MAX(4, espx->blocksize); /* Cipher blocksize */
699
700 /* XXX clamp padding length a la KAME??? */
701 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
702
703 alen = xform_ah_authsize(esph);
704
705 ESPSTAT_INC(esps_output);
706
707 saidx = &sav->sah->saidx;
708 /* Check for maximum packet size violations. */
709 switch (saidx->dst.sa.sa_family) {
710#ifdef INET
711 case AF_INET:
712 maxpacketsize = IP_MAXPACKET;
713 break;
714#endif /* INET */
715#ifdef INET6
716 case AF_INET6:
717 maxpacketsize = IPV6_MAXPACKET;
718 break;
719#endif /* INET6 */
720 default:
721 DPRINTF(("%s: unknown/unsupported protocol "
722 "family %d, SA %s/%08lx\n", __func__,
723 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst,
724 buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
725 ESPSTAT_INC(esps_nopf);
726 error = EPFNOSUPPORT;
727 goto bad;
728 }
729 DPRINTF(("%s: skip %d hlen %d rlen %d padding %d alen %d blksd %d\n",
730 __func__, skip, hlen, rlen, padding, alen, blks));
731 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
732 DPRINTF(("%s: packet in SA %s/%08lx got too big "
733 "(len %u, max len %u)\n", __func__,
734 ipsec_address(&saidx->dst, buf, sizeof(buf)),
735 (u_long) ntohl(sav->spi),
736 skip + hlen + rlen + padding + alen, maxpacketsize));
737 ESPSTAT_INC(esps_toobig);
738 error = EMSGSIZE;
739 goto bad;
740 }
741
742 /* Update the counters. */
743 ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip);
744
745 m = m_unshare(m, M_NOWAIT);
746 if (m == NULL) {
747 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
748 ipsec_address(&saidx->dst, buf, sizeof(buf)),
749 (u_long) ntohl(sav->spi)));
750 ESPSTAT_INC(esps_hdrops);
751 error = ENOBUFS;
752 goto bad;
753 }
754
755 /* Inject ESP header. */
756 mo = m_makespace(m, skip, hlen, &roff);
757 if (mo == NULL) {
758 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
759 __func__, hlen, ipsec_address(&saidx->dst, buf,
760 sizeof(buf)), (u_long) ntohl(sav->spi)));
761 ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */
762 error = ENOBUFS;
763 goto bad;
764 }
765
766 /* Initialize ESP header. */
767 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
768 if (sav->replay) {
769 u_int32_t replay;
770
771#ifdef REGRESSION
772 /* Emulate replay attack when ipsec_replay is TRUE. */
773 if (!V_ipsec_replay)
774#endif
775 sav->replay->count++;
776 replay = htonl(sav->replay->count);
777 bcopy((caddr_t) &replay,
778 mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
779 sizeof(u_int32_t));
780 }
781
782 /*
783 * Add padding -- better to do it ourselves than use the crypto engine,
784 * although if/when we support compression, we'd have to do that.
785 */
786 pad = (u_char *) m_pad(m, padding + alen);
787 if (pad == NULL) {
788 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
789 ipsec_address(&saidx->dst, buf, sizeof(buf)),
790 (u_long) ntohl(sav->spi)));
791 m = NULL; /* NB: free'd by m_pad */
792 error = ENOBUFS;
793 goto bad;
794 }
795
796 /*
797 * Add padding: random, zero, or self-describing.
798 * XXX catch unexpected setting
799 */
800 switch (sav->flags & SADB_X_EXT_PMASK) {
801 case SADB_X_EXT_PRAND:
802 (void) read_random(pad, padding - 2);
803 break;
804 case SADB_X_EXT_PZERO:
805 bzero(pad, padding - 2);
806 break;
807 case SADB_X_EXT_PSEQ:
808 for (i = 0; i < padding - 2; i++)
809 pad[i] = i+1;
810 break;
811 }
812
813 /* Fix padding length and Next Protocol in padding itself. */
814 pad[padding - 2] = padding - 2;
815 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
816
817 /* Fix Next Protocol in IPv4/IPv6 header. */
818 prot = IPPROTO_ESP;
819 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
820
821 /* Get crypto descriptors. */
822 crp = crypto_getreq(esph != NULL ? 2 : 1);
823 if (crp == NULL) {
824 DPRINTF(("%s: failed to acquire crypto descriptors\n",
825 __func__));
826 ESPSTAT_INC(esps_crypto);
827 error = ENOBUFS;
828 goto bad;
829 }
830
831 /* IPsec-specific opaque crypto info. */
832 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
833 M_XDATA, M_NOWAIT|M_ZERO);
834 if (tc == NULL) {
835 crypto_freereq(crp);
836 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
837 ESPSTAT_INC(esps_crypto);
838 error = ENOBUFS;
839 goto bad;
840 }
841
842 crde = crp->crp_desc;
843 crda = crde->crd_next;
844
845 /* Encryption descriptor. */
846 crde->crd_skip = skip + hlen;
847 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
848 crde->crd_flags = CRD_F_ENCRYPT;
849 crde->crd_inject = skip + hlen - sav->ivlen;
850
851 /* Encryption operation. */
852 crde->crd_alg = espx->type;
853 if (SAV_ISCTRORGCM(sav)) {
854 ivp = &crde->crd_iv[0];
855
856 /* GCM IV Format: RFC4106 4 */
857 /* CTR IV Format: RFC3686 4 */
858 /* Salt is last four bytes of key, RFC4106 8.1 */
859 /* Nonce is last four bytes of key, RFC3686 5.1 */
860 memcpy(ivp, sav->key_enc->key_data +
861 _KEYLEN(sav->key_enc) - 4, 4);
862 SECASVAR_LOCK(sav);
863 cntr = sav->cntr++;
864 SECASVAR_UNLOCK(sav);
865 be64enc(&ivp[4], cntr);
866
867 if (SAV_ISCTR(sav)) {
868 /* Initial block counter is 1, RFC3686 4 */
869 be32enc(&ivp[sav->ivlen + 4], 1);
870 }
871
872 m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
873 crde->crd_flags |= CRD_F_IV_EXPLICIT|CRD_F_IV_PRESENT;
874 }
875
876 /* Callback parameters */
877 tc->tc_isr = isr;
878 KEY_ADDREFSA(sav);
879 tc->tc_sav = sav;
880 tc->tc_spi = sav->spi;
881 tc->tc_dst = saidx->dst;
882 tc->tc_proto = saidx->proto;
883
884 /* Crypto operation descriptor. */
885 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
886 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
887 crp->crp_buf = (caddr_t) m;
888 crp->crp_callback = esp_output_cb;
889 crp->crp_opaque = (caddr_t) tc;
890 crp->crp_sid = sav->tdb_cryptoid;
891
892 if (esph) {
893 /* Authentication descriptor. */
894 crda->crd_alg = esph->type;
895 crda->crd_skip = skip;
896 if (SAV_ISGCM(sav))
897 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
898 else
899 crda->crd_len = m->m_pkthdr.len - (skip + alen);
900 crda->crd_inject = m->m_pkthdr.len - alen;
901 }
902
903 return crypto_dispatch(crp);
904bad:
905 if (m)
906 m_freem(m);
907 return (error);
908}
909
910/*
911 * ESP output callback from the crypto driver.
912 */
913static int
914esp_output_cb(struct cryptop *crp)
915{
916 char buf[INET6_ADDRSTRLEN];
917 struct tdb_crypto *tc;
918 struct ipsecrequest *isr;
919 struct secasvar *sav;
920 struct mbuf *m;
921 int error;
922
923 tc = (struct tdb_crypto *) crp->crp_opaque;
924 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
925 m = (struct mbuf *) crp->crp_buf;
926
927 isr = tc->tc_isr;
928 IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
929 IPSECREQUEST_LOCK(isr);
930 sav = tc->tc_sav;
931
932 /* With the isr lock released, SA pointer may have changed. */
933 if (sav != isr->sav) {
934 ESPSTAT_INC(esps_notdb);
935 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
936 __func__, ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
937 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
938 error = ENOBUFS; /*XXX*/
939 goto bad;
940 }
941
942 /* Check for crypto errors. */
943 if (crp->crp_etype) {
944 /* Reset session ID. */
945 if (sav->tdb_cryptoid != 0)
946 sav->tdb_cryptoid = crp->crp_sid;
947
948 if (crp->crp_etype == EAGAIN) {
949 IPSECREQUEST_UNLOCK(isr);
950 return (crypto_dispatch(crp));
951 }
952
953 ESPSTAT_INC(esps_noxform);
954 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
955 error = crp->crp_etype;
956 goto bad;
957 }
958
959 /* Shouldn't happen... */
960 if (m == NULL) {
961 ESPSTAT_INC(esps_crypto);
962 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
963 error = EINVAL;
964 goto bad;
965 }
966 ESPSTAT_INC(esps_hist[sav->alg_enc]);
967 if (sav->tdb_authalgxform != NULL)
968 AHSTAT_INC(ahs_hist[sav->alg_auth]);
969
970 /* Release crypto descriptors. */
971 free(tc, M_XDATA);
972 crypto_freereq(crp);
973
974#ifdef REGRESSION
975 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
976 if (V_ipsec_integrity) {
977 static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
978 struct auth_hash *esph;
979
980 /*
981 * Corrupt HMAC if we want to test integrity verification of
982 * the other side.
983 */
984 esph = sav->tdb_authalgxform;
985 if (esph != NULL) {
986 int alen;
987
988 alen = xform_ah_authsize(esph);
989 m_copyback(m, m->m_pkthdr.len - alen,
990 alen, ipseczeroes);
991 }
992 }
993#endif
994
995 /* NB: m is reclaimed by ipsec_process_done. */
996 error = ipsec_process_done(m, isr);
997 KEY_FREESAV(&sav);
998 IPSECREQUEST_UNLOCK(isr);
999 KEY_FREESP(&isr->sp);
1000 return (error);
1001bad:
1002 if (sav)
1003 KEY_FREESAV(&sav);
1004 IPSECREQUEST_UNLOCK(isr);
1005 KEY_FREESP(&isr->sp);
1006 if (m)
1007 m_freem(m);
1008 free(tc, M_XDATA);
1009 crypto_freereq(crp);
1010 return (error);
1011}
1012
1013static struct xformsw esp_xformsw = {
1014 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
1015 esp_init, esp_zeroize, esp_input,
1016 esp_output
1017};
1018
1019static void
1020esp_attach(void)
1021{
1022
1023 xform_register(&esp_xformsw);
1024}
1025SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
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/lock.h>
48#include <sys/random.h>
49#include <sys/rwlock.h>
50#include <sys/sysctl.h>
51#include <sys/mutex.h>
52#include <machine/atomic.h>
53
54#include <net/if.h>
55#include <net/vnet.h>
56
57#include <netinet/in.h>
58#include <netinet/in_systm.h>
59#include <netinet/ip.h>
60#include <netinet/ip_ecn.h>
61#include <netinet/ip6.h>
62
63#include <netipsec/ipsec.h>
64#include <netipsec/ah.h>
65#include <netipsec/ah_var.h>
66#include <netipsec/esp.h>
67#include <netipsec/esp_var.h>
68#include <netipsec/xform.h>
69
70#ifdef INET6
71#include <netinet6/ip6_var.h>
72#include <netipsec/ipsec6.h>
73#include <netinet6/ip6_ecn.h>
74#endif
75
76#include <netipsec/key.h>
77#include <netipsec/key_debug.h>
78
79#include <opencrypto/cryptodev.h>
80#include <opencrypto/xform.h>
81
82VNET_DEFINE(int, esp_enable) = 1;
83VNET_PCPUSTAT_DEFINE(struct espstat, espstat);
84VNET_PCPUSTAT_SYSINIT(espstat);
85
86#ifdef VIMAGE
87VNET_PCPUSTAT_SYSUNINIT(espstat);
88#endif /* VIMAGE */
89
90SYSCTL_DECL(_net_inet_esp);
91SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable,
92 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
93SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats,
94 struct espstat, espstat,
95 "ESP statistics (struct espstat, netipsec/esp_var.h");
96
97static int esp_input_cb(struct cryptop *op);
98static int esp_output_cb(struct cryptop *crp);
99
100/*
101 * NB: this is public for use by the PF_KEY support.
102 * NB: if you add support here; be sure to add code to esp_attach below!
103 */
104struct enc_xform *
105esp_algorithm_lookup(int alg)
106{
107 if (alg >= ESP_ALG_MAX)
108 return NULL;
109 switch (alg) {
110 case SADB_EALG_DESCBC:
111 return &enc_xform_des;
112 case SADB_EALG_3DESCBC:
113 return &enc_xform_3des;
114 case SADB_X_EALG_AES:
115 return &enc_xform_rijndael128;
116 case SADB_X_EALG_BLOWFISHCBC:
117 return &enc_xform_blf;
118 case SADB_X_EALG_CAST128CBC:
119 return &enc_xform_cast5;
120 case SADB_EALG_NULL:
121 return &enc_xform_null;
122 case SADB_X_EALG_CAMELLIACBC:
123 return &enc_xform_camellia;
124 case SADB_X_EALG_AESCTR:
125 return &enc_xform_aes_icm;
126 case SADB_X_EALG_AESGCM16:
127 return &enc_xform_aes_nist_gcm;
128 case SADB_X_EALG_AESGMAC:
129 return &enc_xform_aes_nist_gmac;
130 }
131 return NULL;
132}
133
134size_t
135esp_hdrsiz(struct secasvar *sav)
136{
137 size_t size;
138
139 if (sav != NULL) {
140 /*XXX not right for null algorithm--does it matter??*/
141 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
142 ("SA with null xform"));
143 if (sav->flags & SADB_X_EXT_OLD)
144 size = sizeof (struct esp);
145 else
146 size = sizeof (struct newesp);
147 size += sav->tdb_encalgxform->blocksize + 9;
148 /*XXX need alg check???*/
149 if (sav->tdb_authalgxform != NULL && sav->replay)
150 size += ah_hdrsiz(sav);
151 } else {
152 /*
153 * base header size
154 * + max iv length for CBC mode
155 * + max pad length
156 * + sizeof (pad length field)
157 * + sizeof (next header field)
158 * + max icv supported.
159 */
160 size = sizeof (struct newesp) + EALG_MAX_BLOCK_LEN + 9 + 16;
161 }
162 return size;
163}
164
165/*
166 * esp_init() is called when an SPI is being set up.
167 */
168static int
169esp_init(struct secasvar *sav, struct xformsw *xsp)
170{
171 struct enc_xform *txform;
172 struct cryptoini cria, crie;
173 int keylen;
174 int error;
175
176 txform = esp_algorithm_lookup(sav->alg_enc);
177 if (txform == NULL) {
178 DPRINTF(("%s: unsupported encryption algorithm %d\n",
179 __func__, sav->alg_enc));
180 return EINVAL;
181 }
182 if (sav->key_enc == NULL) {
183 DPRINTF(("%s: no encoding key for %s algorithm\n",
184 __func__, txform->name));
185 return EINVAL;
186 }
187 if ((sav->flags & (SADB_X_EXT_OLD | SADB_X_EXT_IV4B)) ==
188 SADB_X_EXT_IV4B) {
189 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
190 __func__));
191 return EINVAL;
192 }
193 /* subtract off the salt, RFC4106, 8.1 and RFC3686, 5.1 */
194 keylen = _KEYLEN(sav->key_enc) - SAV_ISCTRORGCM(sav) * 4;
195 if (txform->minkey > keylen || keylen > txform->maxkey) {
196 DPRINTF(("%s: invalid key length %u, must be in the range "
197 "[%u..%u] for algorithm %s\n", __func__,
198 keylen, txform->minkey, txform->maxkey,
199 txform->name));
200 return EINVAL;
201 }
202
203 /*
204 * NB: The null xform needs a non-zero blocksize to keep the
205 * crypto code happy but if we use it to set ivlen then
206 * the ESP header will be processed incorrectly. The
207 * compromise is to force it to zero here.
208 */
209 if (SAV_ISCTRORGCM(sav))
210 sav->ivlen = 8; /* RFC4106 3.1 and RFC3686 3.1 */
211 else
212 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->ivsize);
213
214 /*
215 * Setup AH-related state.
216 */
217 if (sav->alg_auth != 0) {
218 error = ah_init0(sav, xsp, &cria);
219 if (error)
220 return error;
221 }
222
223 /* NB: override anything set in ah_init0 */
224 sav->tdb_xform = xsp;
225 sav->tdb_encalgxform = txform;
226
227 /*
228 * Whenever AES-GCM is used for encryption, one
229 * of the AES authentication algorithms is chosen
230 * as well, based on the key size.
231 */
232 if (sav->alg_enc == SADB_X_EALG_AESGCM16) {
233 switch (keylen) {
234 case AES_128_GMAC_KEY_LEN:
235 sav->alg_auth = SADB_X_AALG_AES128GMAC;
236 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_128;
237 break;
238 case AES_192_GMAC_KEY_LEN:
239 sav->alg_auth = SADB_X_AALG_AES192GMAC;
240 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_192;
241 break;
242 case AES_256_GMAC_KEY_LEN:
243 sav->alg_auth = SADB_X_AALG_AES256GMAC;
244 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_256;
245 break;
246 default:
247 DPRINTF(("%s: invalid key length %u"
248 "for algorithm %s\n", __func__,
249 keylen, txform->name));
250 return EINVAL;
251 }
252 bzero(&cria, sizeof(cria));
253 cria.cri_alg = sav->tdb_authalgxform->type;
254 cria.cri_key = sav->key_enc->key_data;
255 cria.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISGCM(sav) * 32;
256 }
257
258 /* Initialize crypto session. */
259 bzero(&crie, sizeof(crie));
260 crie.cri_alg = sav->tdb_encalgxform->type;
261 crie.cri_key = sav->key_enc->key_data;
262 crie.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISCTRORGCM(sav) * 32;
263
264 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
265 /* init both auth & enc */
266 crie.cri_next = &cria;
267 error = crypto_newsession(&sav->tdb_cryptoid,
268 &crie, V_crypto_support);
269 } else if (sav->tdb_encalgxform) {
270 error = crypto_newsession(&sav->tdb_cryptoid,
271 &crie, V_crypto_support);
272 } else if (sav->tdb_authalgxform) {
273 error = crypto_newsession(&sav->tdb_cryptoid,
274 &cria, V_crypto_support);
275 } else {
276 /* XXX cannot happen? */
277 DPRINTF(("%s: no encoding OR authentication xform!\n",
278 __func__));
279 error = EINVAL;
280 }
281 return error;
282}
283
284/*
285 * Paranoia.
286 */
287static int
288esp_zeroize(struct secasvar *sav)
289{
290 /* NB: ah_zerorize free's the crypto session state */
291 int error = ah_zeroize(sav);
292
293 if (sav->key_enc)
294 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
295 sav->tdb_encalgxform = NULL;
296 sav->tdb_xform = NULL;
297 return error;
298}
299
300/*
301 * ESP input processing, called (eventually) through the protocol switch.
302 */
303static int
304esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
305{
306 char buf[128];
307 struct auth_hash *esph;
308 struct enc_xform *espx;
309 struct tdb_crypto *tc;
310 uint8_t *ivp;
311 int plen, alen, hlen;
312 struct newesp *esp;
313 struct cryptodesc *crde;
314 struct cryptop *crp;
315
316 IPSEC_ASSERT(sav != NULL, ("null SA"));
317 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
318
319 /* Valid IP Packet length ? */
320 if ( (skip&3) || (m->m_pkthdr.len&3) ){
321 DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
322 __func__, skip, m->m_pkthdr.len));
323 ESPSTAT_INC(esps_badilen);
324 m_freem(m);
325 return EINVAL;
326 }
327 /* XXX don't pullup, just copy header */
328 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
329
330 esph = sav->tdb_authalgxform;
331 espx = sav->tdb_encalgxform;
332
333 /* Determine the ESP header and auth length */
334 if (sav->flags & SADB_X_EXT_OLD)
335 hlen = sizeof (struct esp) + sav->ivlen;
336 else
337 hlen = sizeof (struct newesp) + sav->ivlen;
338
339 alen = xform_ah_authsize(esph);
340
341 /*
342 * Verify payload length is multiple of encryption algorithm
343 * block size.
344 *
345 * NB: This works for the null algorithm because the blocksize
346 * is 4 and all packets must be 4-byte aligned regardless
347 * of the algorithm.
348 */
349 plen = m->m_pkthdr.len - (skip + hlen + alen);
350 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
351 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
352 " SA %s/%08lx\n", __func__, plen, espx->blocksize,
353 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
354 (u_long)ntohl(sav->spi)));
355 ESPSTAT_INC(esps_badilen);
356 m_freem(m);
357 return EINVAL;
358 }
359
360 /*
361 * Check sequence number.
362 */
363 if (esph != NULL && sav->replay != NULL &&
364 !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
365 DPRINTF(("%s: packet replay check for %s\n", __func__,
366 ipsec_logsastr(sav, buf, sizeof(buf)))); /*XXX*/
367 ESPSTAT_INC(esps_replay);
368 m_freem(m);
369 return ENOBUFS; /*XXX*/
370 }
371
372 /* Update the counters */
373 ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
374
375 /* Get crypto descriptors */
376 crp = crypto_getreq(esph && espx ? 2 : 1);
377 if (crp == NULL) {
378 DPRINTF(("%s: failed to acquire crypto descriptors\n",
379 __func__));
380 ESPSTAT_INC(esps_crypto);
381 m_freem(m);
382 return ENOBUFS;
383 }
384
385 /* Get IPsec-specific opaque pointer */
386 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
387 M_XDATA, M_NOWAIT | M_ZERO);
388 if (tc == NULL) {
389 crypto_freereq(crp);
390 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
391 ESPSTAT_INC(esps_crypto);
392 m_freem(m);
393 return ENOBUFS;
394 }
395
396 if (esph != NULL) {
397 struct cryptodesc *crda = crp->crp_desc;
398
399 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
400
401 /* Authentication descriptor */
402 crda->crd_skip = skip;
403 if (SAV_ISGCM(sav))
404 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
405 else
406 crda->crd_len = m->m_pkthdr.len - (skip + alen);
407 crda->crd_inject = m->m_pkthdr.len - alen;
408
409 crda->crd_alg = esph->type;
410
411 /* Copy the authenticator */
412 m_copydata(m, m->m_pkthdr.len - alen, alen,
413 (caddr_t) (tc + 1));
414
415 /* Chain authentication request */
416 crde = crda->crd_next;
417 } else {
418 crde = crp->crp_desc;
419 }
420
421 /* Crypto operation descriptor */
422 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
423 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
424 crp->crp_buf = (caddr_t) m;
425 crp->crp_callback = esp_input_cb;
426 crp->crp_sid = sav->tdb_cryptoid;
427 crp->crp_opaque = (caddr_t) tc;
428
429 /* These are passed as-is to the callback */
430 tc->tc_spi = sav->spi;
431 tc->tc_dst = sav->sah->saidx.dst;
432 tc->tc_proto = sav->sah->saidx.proto;
433 tc->tc_protoff = protoff;
434 tc->tc_skip = skip;
435 KEY_ADDREFSA(sav);
436 tc->tc_sav = sav;
437
438 /* Decryption descriptor */
439 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
440 crde->crd_skip = skip + hlen;
441 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
442 crde->crd_inject = skip + hlen - sav->ivlen;
443
444 if (SAV_ISCTRORGCM(sav)) {
445 ivp = &crde->crd_iv[0];
446
447 /* GCM IV Format: RFC4106 4 */
448 /* CTR IV Format: RFC3686 4 */
449 /* Salt is last four bytes of key, RFC4106 8.1 */
450 /* Nonce is last four bytes of key, RFC3686 5.1 */
451 memcpy(ivp, sav->key_enc->key_data +
452 _KEYLEN(sav->key_enc) - 4, 4);
453
454 if (SAV_ISCTR(sav)) {
455 /* Initial block counter is 1, RFC3686 4 */
456 be32enc(&ivp[sav->ivlen + 4], 1);
457 }
458
459 m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
460 crde->crd_flags |= CRD_F_IV_EXPLICIT;
461 }
462
463 crde->crd_alg = espx->type;
464
465 return (crypto_dispatch(crp));
466}
467
468/*
469 * ESP input callback from the crypto driver.
470 */
471static int
472esp_input_cb(struct cryptop *crp)
473{
474 char buf[128];
475 u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN];
476 int hlen, skip, protoff, error, alen;
477 struct mbuf *m;
478 struct cryptodesc *crd;
479 struct auth_hash *esph;
480 struct enc_xform *espx;
481 struct tdb_crypto *tc;
482 struct secasvar *sav;
483 struct secasindex *saidx;
484 caddr_t ptr;
485
486 crd = crp->crp_desc;
487 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
488
489 tc = (struct tdb_crypto *) crp->crp_opaque;
490 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
491 skip = tc->tc_skip;
492 protoff = tc->tc_protoff;
493 m = (struct mbuf *) crp->crp_buf;
494
495 sav = tc->tc_sav;
496 IPSEC_ASSERT(sav != NULL, ("null SA!"));
497
498 saidx = &sav->sah->saidx;
499 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
500 saidx->dst.sa.sa_family == AF_INET6,
501 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
502
503 esph = sav->tdb_authalgxform;
504 espx = sav->tdb_encalgxform;
505
506 /* Check for crypto errors */
507 if (crp->crp_etype) {
508 /* Reset the session ID */
509 if (sav->tdb_cryptoid != 0)
510 sav->tdb_cryptoid = crp->crp_sid;
511
512 if (crp->crp_etype == EAGAIN)
513 return (crypto_dispatch(crp));
514
515 ESPSTAT_INC(esps_noxform);
516 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
517 error = crp->crp_etype;
518 goto bad;
519 }
520
521 /* Shouldn't happen... */
522 if (m == NULL) {
523 ESPSTAT_INC(esps_crypto);
524 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
525 error = EINVAL;
526 goto bad;
527 }
528 ESPSTAT_INC(esps_hist[sav->alg_enc]);
529
530 /* If authentication was performed, check now. */
531 if (esph != NULL) {
532 alen = xform_ah_authsize(esph);
533 AHSTAT_INC(ahs_hist[sav->alg_auth]);
534 /* Copy the authenticator from the packet */
535 m_copydata(m, m->m_pkthdr.len - alen, alen, aalg);
536 ptr = (caddr_t) (tc + 1);
537
538 /* Verify authenticator */
539 if (timingsafe_bcmp(ptr, aalg, alen) != 0) {
540 DPRINTF(("%s: authentication hash mismatch for "
541 "packet in SA %s/%08lx\n", __func__,
542 ipsec_address(&saidx->dst, buf, sizeof(buf)),
543 (u_long) ntohl(sav->spi)));
544 ESPSTAT_INC(esps_badauth);
545 error = EACCES;
546 goto bad;
547 }
548
549 /* Remove trailing authenticator */
550 m_adj(m, -alen);
551 }
552
553 /* Release the crypto descriptors */
554 free(tc, M_XDATA), tc = NULL;
555 crypto_freereq(crp), crp = NULL;
556
557 /*
558 * Packet is now decrypted.
559 */
560 m->m_flags |= M_DECRYPTED;
561
562 /*
563 * Update replay sequence number, if appropriate.
564 */
565 if (sav->replay) {
566 u_int32_t seq;
567
568 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
569 sizeof (seq), (caddr_t) &seq);
570 if (ipsec_updatereplay(ntohl(seq), sav)) {
571 DPRINTF(("%s: packet replay check for %s\n", __func__,
572 ipsec_logsastr(sav, buf, sizeof(buf))));
573 ESPSTAT_INC(esps_replay);
574 error = ENOBUFS;
575 goto bad;
576 }
577 }
578
579 /* Determine the ESP header length */
580 if (sav->flags & SADB_X_EXT_OLD)
581 hlen = sizeof (struct esp) + sav->ivlen;
582 else
583 hlen = sizeof (struct newesp) + sav->ivlen;
584
585 /* Remove the ESP header and IV from the mbuf. */
586 error = m_striphdr(m, skip, hlen);
587 if (error) {
588 ESPSTAT_INC(esps_hdrops);
589 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
590 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
591 (u_long) ntohl(sav->spi)));
592 goto bad;
593 }
594
595 /* Save the last three bytes of decrypted data */
596 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
597
598 /* Verify pad length */
599 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
600 ESPSTAT_INC(esps_badilen);
601 DPRINTF(("%s: invalid padding length %d for %u byte packet "
602 "in SA %s/%08lx\n", __func__, lastthree[1],
603 m->m_pkthdr.len - skip,
604 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
605 (u_long) ntohl(sav->spi)));
606 error = EINVAL;
607 goto bad;
608 }
609
610 /* Verify correct decryption by checking the last padding bytes */
611 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
612 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
613 ESPSTAT_INC(esps_badenc);
614 DPRINTF(("%s: decryption failed for packet in "
615 "SA %s/%08lx\n", __func__, ipsec_address(
616 &sav->sah->saidx.dst, buf, sizeof(buf)),
617 (u_long) ntohl(sav->spi)));
618 error = EINVAL;
619 goto bad;
620 }
621 }
622
623 /* Trim the mbuf chain to remove trailing authenticator and padding */
624 m_adj(m, -(lastthree[1] + 2));
625
626 /* Restore the Next Protocol field */
627 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
628
629 switch (saidx->dst.sa.sa_family) {
630#ifdef INET6
631 case AF_INET6:
632 error = ipsec6_common_input_cb(m, sav, skip, protoff);
633 break;
634#endif
635#ifdef INET
636 case AF_INET:
637 error = ipsec4_common_input_cb(m, sav, skip, protoff);
638 break;
639#endif
640 default:
641 panic("%s: Unexpected address family: %d saidx=%p", __func__,
642 saidx->dst.sa.sa_family, saidx);
643 }
644
645 KEY_FREESAV(&sav);
646 return error;
647bad:
648 if (sav)
649 KEY_FREESAV(&sav);
650 if (m != NULL)
651 m_freem(m);
652 if (tc != NULL)
653 free(tc, M_XDATA);
654 if (crp != NULL)
655 crypto_freereq(crp);
656 return error;
657}
658
659/*
660 * ESP output routine, called by ipsec[46]_process_packet().
661 */
662static int
663esp_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
664 int skip, int protoff)
665{
666 char buf[INET6_ADDRSTRLEN];
667 struct enc_xform *espx;
668 struct auth_hash *esph;
669 uint8_t *ivp;
670 uint64_t cntr;
671 int hlen, rlen, padding, blks, alen, i, roff;
672 struct mbuf *mo = (struct mbuf *) NULL;
673 struct tdb_crypto *tc;
674 struct secasvar *sav;
675 struct secasindex *saidx;
676 unsigned char *pad;
677 u_int8_t prot;
678 int error, maxpacketsize;
679
680 struct cryptodesc *crde = NULL, *crda = NULL;
681 struct cryptop *crp;
682
683 sav = isr->sav;
684 IPSEC_ASSERT(sav != NULL, ("null SA"));
685 esph = sav->tdb_authalgxform;
686 espx = sav->tdb_encalgxform;
687 IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
688
689 if (sav->flags & SADB_X_EXT_OLD)
690 hlen = sizeof (struct esp) + sav->ivlen;
691 else
692 hlen = sizeof (struct newesp) + sav->ivlen;
693
694 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
695 /*
696 * RFC4303 2.4 Requires 4 byte alignment.
697 */
698 blks = MAX(4, espx->blocksize); /* Cipher blocksize */
699
700 /* XXX clamp padding length a la KAME??? */
701 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
702
703 alen = xform_ah_authsize(esph);
704
705 ESPSTAT_INC(esps_output);
706
707 saidx = &sav->sah->saidx;
708 /* Check for maximum packet size violations. */
709 switch (saidx->dst.sa.sa_family) {
710#ifdef INET
711 case AF_INET:
712 maxpacketsize = IP_MAXPACKET;
713 break;
714#endif /* INET */
715#ifdef INET6
716 case AF_INET6:
717 maxpacketsize = IPV6_MAXPACKET;
718 break;
719#endif /* INET6 */
720 default:
721 DPRINTF(("%s: unknown/unsupported protocol "
722 "family %d, SA %s/%08lx\n", __func__,
723 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst,
724 buf, sizeof(buf)), (u_long) ntohl(sav->spi)));
725 ESPSTAT_INC(esps_nopf);
726 error = EPFNOSUPPORT;
727 goto bad;
728 }
729 DPRINTF(("%s: skip %d hlen %d rlen %d padding %d alen %d blksd %d\n",
730 __func__, skip, hlen, rlen, padding, alen, blks));
731 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
732 DPRINTF(("%s: packet in SA %s/%08lx got too big "
733 "(len %u, max len %u)\n", __func__,
734 ipsec_address(&saidx->dst, buf, sizeof(buf)),
735 (u_long) ntohl(sav->spi),
736 skip + hlen + rlen + padding + alen, maxpacketsize));
737 ESPSTAT_INC(esps_toobig);
738 error = EMSGSIZE;
739 goto bad;
740 }
741
742 /* Update the counters. */
743 ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip);
744
745 m = m_unshare(m, M_NOWAIT);
746 if (m == NULL) {
747 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
748 ipsec_address(&saidx->dst, buf, sizeof(buf)),
749 (u_long) ntohl(sav->spi)));
750 ESPSTAT_INC(esps_hdrops);
751 error = ENOBUFS;
752 goto bad;
753 }
754
755 /* Inject ESP header. */
756 mo = m_makespace(m, skip, hlen, &roff);
757 if (mo == NULL) {
758 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
759 __func__, hlen, ipsec_address(&saidx->dst, buf,
760 sizeof(buf)), (u_long) ntohl(sav->spi)));
761 ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */
762 error = ENOBUFS;
763 goto bad;
764 }
765
766 /* Initialize ESP header. */
767 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
768 if (sav->replay) {
769 u_int32_t replay;
770
771#ifdef REGRESSION
772 /* Emulate replay attack when ipsec_replay is TRUE. */
773 if (!V_ipsec_replay)
774#endif
775 sav->replay->count++;
776 replay = htonl(sav->replay->count);
777 bcopy((caddr_t) &replay,
778 mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
779 sizeof(u_int32_t));
780 }
781
782 /*
783 * Add padding -- better to do it ourselves than use the crypto engine,
784 * although if/when we support compression, we'd have to do that.
785 */
786 pad = (u_char *) m_pad(m, padding + alen);
787 if (pad == NULL) {
788 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
789 ipsec_address(&saidx->dst, buf, sizeof(buf)),
790 (u_long) ntohl(sav->spi)));
791 m = NULL; /* NB: free'd by m_pad */
792 error = ENOBUFS;
793 goto bad;
794 }
795
796 /*
797 * Add padding: random, zero, or self-describing.
798 * XXX catch unexpected setting
799 */
800 switch (sav->flags & SADB_X_EXT_PMASK) {
801 case SADB_X_EXT_PRAND:
802 (void) read_random(pad, padding - 2);
803 break;
804 case SADB_X_EXT_PZERO:
805 bzero(pad, padding - 2);
806 break;
807 case SADB_X_EXT_PSEQ:
808 for (i = 0; i < padding - 2; i++)
809 pad[i] = i+1;
810 break;
811 }
812
813 /* Fix padding length and Next Protocol in padding itself. */
814 pad[padding - 2] = padding - 2;
815 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
816
817 /* Fix Next Protocol in IPv4/IPv6 header. */
818 prot = IPPROTO_ESP;
819 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
820
821 /* Get crypto descriptors. */
822 crp = crypto_getreq(esph != NULL ? 2 : 1);
823 if (crp == NULL) {
824 DPRINTF(("%s: failed to acquire crypto descriptors\n",
825 __func__));
826 ESPSTAT_INC(esps_crypto);
827 error = ENOBUFS;
828 goto bad;
829 }
830
831 /* IPsec-specific opaque crypto info. */
832 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
833 M_XDATA, M_NOWAIT|M_ZERO);
834 if (tc == NULL) {
835 crypto_freereq(crp);
836 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
837 ESPSTAT_INC(esps_crypto);
838 error = ENOBUFS;
839 goto bad;
840 }
841
842 crde = crp->crp_desc;
843 crda = crde->crd_next;
844
845 /* Encryption descriptor. */
846 crde->crd_skip = skip + hlen;
847 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
848 crde->crd_flags = CRD_F_ENCRYPT;
849 crde->crd_inject = skip + hlen - sav->ivlen;
850
851 /* Encryption operation. */
852 crde->crd_alg = espx->type;
853 if (SAV_ISCTRORGCM(sav)) {
854 ivp = &crde->crd_iv[0];
855
856 /* GCM IV Format: RFC4106 4 */
857 /* CTR IV Format: RFC3686 4 */
858 /* Salt is last four bytes of key, RFC4106 8.1 */
859 /* Nonce is last four bytes of key, RFC3686 5.1 */
860 memcpy(ivp, sav->key_enc->key_data +
861 _KEYLEN(sav->key_enc) - 4, 4);
862 SECASVAR_LOCK(sav);
863 cntr = sav->cntr++;
864 SECASVAR_UNLOCK(sav);
865 be64enc(&ivp[4], cntr);
866
867 if (SAV_ISCTR(sav)) {
868 /* Initial block counter is 1, RFC3686 4 */
869 be32enc(&ivp[sav->ivlen + 4], 1);
870 }
871
872 m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
873 crde->crd_flags |= CRD_F_IV_EXPLICIT|CRD_F_IV_PRESENT;
874 }
875
876 /* Callback parameters */
877 tc->tc_isr = isr;
878 KEY_ADDREFSA(sav);
879 tc->tc_sav = sav;
880 tc->tc_spi = sav->spi;
881 tc->tc_dst = saidx->dst;
882 tc->tc_proto = saidx->proto;
883
884 /* Crypto operation descriptor. */
885 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
886 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
887 crp->crp_buf = (caddr_t) m;
888 crp->crp_callback = esp_output_cb;
889 crp->crp_opaque = (caddr_t) tc;
890 crp->crp_sid = sav->tdb_cryptoid;
891
892 if (esph) {
893 /* Authentication descriptor. */
894 crda->crd_alg = esph->type;
895 crda->crd_skip = skip;
896 if (SAV_ISGCM(sav))
897 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
898 else
899 crda->crd_len = m->m_pkthdr.len - (skip + alen);
900 crda->crd_inject = m->m_pkthdr.len - alen;
901 }
902
903 return crypto_dispatch(crp);
904bad:
905 if (m)
906 m_freem(m);
907 return (error);
908}
909
910/*
911 * ESP output callback from the crypto driver.
912 */
913static int
914esp_output_cb(struct cryptop *crp)
915{
916 char buf[INET6_ADDRSTRLEN];
917 struct tdb_crypto *tc;
918 struct ipsecrequest *isr;
919 struct secasvar *sav;
920 struct mbuf *m;
921 int error;
922
923 tc = (struct tdb_crypto *) crp->crp_opaque;
924 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
925 m = (struct mbuf *) crp->crp_buf;
926
927 isr = tc->tc_isr;
928 IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
929 IPSECREQUEST_LOCK(isr);
930 sav = tc->tc_sav;
931
932 /* With the isr lock released, SA pointer may have changed. */
933 if (sav != isr->sav) {
934 ESPSTAT_INC(esps_notdb);
935 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
936 __func__, ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
937 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
938 error = ENOBUFS; /*XXX*/
939 goto bad;
940 }
941
942 /* Check for crypto errors. */
943 if (crp->crp_etype) {
944 /* Reset session ID. */
945 if (sav->tdb_cryptoid != 0)
946 sav->tdb_cryptoid = crp->crp_sid;
947
948 if (crp->crp_etype == EAGAIN) {
949 IPSECREQUEST_UNLOCK(isr);
950 return (crypto_dispatch(crp));
951 }
952
953 ESPSTAT_INC(esps_noxform);
954 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
955 error = crp->crp_etype;
956 goto bad;
957 }
958
959 /* Shouldn't happen... */
960 if (m == NULL) {
961 ESPSTAT_INC(esps_crypto);
962 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
963 error = EINVAL;
964 goto bad;
965 }
966 ESPSTAT_INC(esps_hist[sav->alg_enc]);
967 if (sav->tdb_authalgxform != NULL)
968 AHSTAT_INC(ahs_hist[sav->alg_auth]);
969
970 /* Release crypto descriptors. */
971 free(tc, M_XDATA);
972 crypto_freereq(crp);
973
974#ifdef REGRESSION
975 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
976 if (V_ipsec_integrity) {
977 static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
978 struct auth_hash *esph;
979
980 /*
981 * Corrupt HMAC if we want to test integrity verification of
982 * the other side.
983 */
984 esph = sav->tdb_authalgxform;
985 if (esph != NULL) {
986 int alen;
987
988 alen = xform_ah_authsize(esph);
989 m_copyback(m, m->m_pkthdr.len - alen,
990 alen, ipseczeroes);
991 }
992 }
993#endif
994
995 /* NB: m is reclaimed by ipsec_process_done. */
996 error = ipsec_process_done(m, isr);
997 KEY_FREESAV(&sav);
998 IPSECREQUEST_UNLOCK(isr);
999 KEY_FREESP(&isr->sp);
1000 return (error);
1001bad:
1002 if (sav)
1003 KEY_FREESAV(&sav);
1004 IPSECREQUEST_UNLOCK(isr);
1005 KEY_FREESP(&isr->sp);
1006 if (m)
1007 m_freem(m);
1008 free(tc, M_XDATA);
1009 crypto_freereq(crp);
1010 return (error);
1011}
1012
1013static struct xformsw esp_xformsw = {
1014 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
1015 esp_init, esp_zeroize, esp_input,
1016 esp_output
1017};
1018
1019static void
1020esp_attach(void)
1021{
1022
1023 xform_register(&esp_xformsw);
1024}
1025SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);