2 /* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
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).
8 * The original version of this code was written by John Ioannidis
9 * for BSD/OS in Athens, Greece, in November 1995.
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
17 * Additional features in 1999 by Angelos D. Keromytis.
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.
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
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
39 #include "opt_inet6.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/socket.h>
45 #include <sys/syslog.h>
46 #include <sys/kernel.h>
48 #include <sys/random.h>
49 #include <sys/mutex.h>
50 #include <sys/sysctl.h>
51 #include <sys/mutex.h>
52 #include <machine/atomic.h>
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>
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>
71 #include <netinet6/ip6_var.h>
72 #include <netipsec/ipsec6.h>
73 #include <netinet6/ip6_ecn.h>
76 #include <netipsec/key.h>
77 #include <netipsec/key_debug.h>
79 #include <opencrypto/cryptodev.h>
80 #include <opencrypto/xform.h>
82 VNET_DEFINE(int, esp_enable) = 1;
83 VNET_PCPUSTAT_DEFINE(struct espstat, espstat);
84 VNET_PCPUSTAT_SYSINIT(espstat);
87 VNET_PCPUSTAT_SYSUNINIT(espstat);
90 SYSCTL_DECL(_net_inet_esp);
91 SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable,
92 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
93 SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats,
94 struct espstat, espstat,
95 "ESP statistics (struct espstat, netipsec/esp_var.h");
97 static struct timeval deswarn, blfwarn, castwarn, camelliawarn;
99 static int esp_input_cb(struct cryptop *op);
100 static int esp_output_cb(struct cryptop *crp);
103 esp_hdrsiz(struct secasvar *sav)
108 /*XXX not right for null algorithm--does it matter??*/
109 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
110 ("SA with null xform"));
111 if (sav->flags & SADB_X_EXT_OLD)
112 size = sizeof (struct esp);
114 size = sizeof (struct newesp);
115 size += sav->tdb_encalgxform->blocksize + 9;
116 /*XXX need alg check???*/
117 if (sav->tdb_authalgxform != NULL && sav->replay)
118 size += ah_hdrsiz(sav);
122 * + max iv length for CBC mode
124 * + sizeof (pad length field)
125 * + sizeof (next header field)
126 * + max icv supported.
128 size = sizeof (struct newesp) + EALG_MAX_BLOCK_LEN + 9 + 16;
134 * esp_init() is called when an SPI is being set up.
137 esp_init(struct secasvar *sav, struct xformsw *xsp)
139 const struct enc_xform *txform;
140 struct cryptoini cria, crie;
144 txform = enc_algorithm_lookup(sav->alg_enc);
145 if (txform == NULL) {
146 DPRINTF(("%s: unsupported encryption algorithm %d\n",
147 __func__, sav->alg_enc));
150 if (sav->key_enc == NULL) {
151 DPRINTF(("%s: no encoding key for %s algorithm\n",
152 __func__, txform->name));
155 if ((sav->flags & (SADB_X_EXT_OLD | SADB_X_EXT_IV4B)) ==
157 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
162 switch (sav->alg_enc) {
163 case SADB_EALG_DESCBC:
164 if (ratecheck(&deswarn, &ipsec_warn_interval))
165 gone_in(13, "DES cipher for IPsec");
167 case SADB_X_EALG_BLOWFISHCBC:
168 if (ratecheck(&blfwarn, &ipsec_warn_interval))
169 gone_in(13, "Blowfish cipher for IPsec");
171 case SADB_X_EALG_CAST128CBC:
172 if (ratecheck(&castwarn, &ipsec_warn_interval))
173 gone_in(13, "CAST cipher for IPsec");
175 case SADB_X_EALG_CAMELLIACBC:
176 if (ratecheck(&camelliawarn, &ipsec_warn_interval))
177 gone_in(13, "Camellia cipher for IPsec");
181 /* subtract off the salt, RFC4106, 8.1 and RFC3686, 5.1 */
182 keylen = _KEYLEN(sav->key_enc) - SAV_ISCTRORGCM(sav) * 4;
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,
191 if (SAV_ISCTRORGCM(sav))
192 sav->ivlen = 8; /* RFC4106 3.1 and RFC3686 3.1 */
194 sav->ivlen = txform->ivsize;
197 * Setup AH-related state.
199 if (sav->alg_auth != 0) {
200 error = ah_init0(sav, xsp, &cria);
205 /* NB: override anything set in ah_init0 */
206 sav->tdb_xform = xsp;
207 sav->tdb_encalgxform = txform;
210 * Whenever AES-GCM is used for encryption, one
211 * of the AES authentication algorithms is chosen
212 * as well, based on the key size.
214 if (sav->alg_enc == SADB_X_EALG_AESGCM16) {
216 case AES_128_GMAC_KEY_LEN:
217 sav->alg_auth = SADB_X_AALG_AES128GMAC;
218 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_128;
220 case AES_192_GMAC_KEY_LEN:
221 sav->alg_auth = SADB_X_AALG_AES192GMAC;
222 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_192;
224 case AES_256_GMAC_KEY_LEN:
225 sav->alg_auth = SADB_X_AALG_AES256GMAC;
226 sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_256;
229 DPRINTF(("%s: invalid key length %u"
230 "for algorithm %s\n", __func__,
231 keylen, txform->name));
234 bzero(&cria, sizeof(cria));
235 cria.cri_alg = sav->tdb_authalgxform->type;
236 cria.cri_key = sav->key_enc->key_data;
237 cria.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISGCM(sav) * 32;
240 /* Initialize crypto session. */
241 bzero(&crie, sizeof(crie));
242 crie.cri_alg = sav->tdb_encalgxform->type;
243 crie.cri_key = sav->key_enc->key_data;
244 crie.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISCTRORGCM(sav) * 32;
246 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
247 /* init both auth & enc */
248 crie.cri_next = &cria;
249 error = crypto_newsession(&sav->tdb_cryptoid,
250 &crie, V_crypto_support);
251 } else if (sav->tdb_encalgxform) {
252 error = crypto_newsession(&sav->tdb_cryptoid,
253 &crie, V_crypto_support);
254 } else if (sav->tdb_authalgxform) {
255 error = crypto_newsession(&sav->tdb_cryptoid,
256 &cria, V_crypto_support);
258 /* XXX cannot happen? */
259 DPRINTF(("%s: no encoding OR authentication xform!\n",
270 esp_zeroize(struct secasvar *sav)
272 /* NB: ah_zerorize free's the crypto session state */
273 int error = ah_zeroize(sav);
276 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
277 sav->tdb_encalgxform = NULL;
278 sav->tdb_xform = NULL;
283 * ESP input processing, called (eventually) through the protocol switch.
286 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
288 IPSEC_DEBUG_DECLARE(char buf[128]);
289 const struct auth_hash *esph;
290 const struct enc_xform *espx;
291 struct xform_data *xd;
292 struct cryptodesc *crde;
296 crypto_session_t cryptoid;
297 int alen, error, hlen, plen;
299 IPSEC_ASSERT(sav != NULL, ("null SA"));
300 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
303 /* Valid IP Packet length ? */
304 if ( (skip&3) || (m->m_pkthdr.len&3) ){
305 DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
306 __func__, skip, m->m_pkthdr.len));
307 ESPSTAT_INC(esps_badilen);
311 if (m->m_len < skip + sizeof(*esp)) {
312 m = m_pullup(m, skip + sizeof(*esp));
314 DPRINTF(("%s: cannot pullup header\n", __func__));
315 ESPSTAT_INC(esps_hdrops); /*XXX*/
320 esp = (struct newesp *)(mtod(m, caddr_t) + skip);
322 esph = sav->tdb_authalgxform;
323 espx = sav->tdb_encalgxform;
325 /* Determine the ESP header and auth length */
326 if (sav->flags & SADB_X_EXT_OLD)
327 hlen = sizeof (struct esp) + sav->ivlen;
329 hlen = sizeof (struct newesp) + sav->ivlen;
331 alen = xform_ah_authsize(esph);
334 * Verify payload length is multiple of encryption algorithm
337 * NB: This works for the null algorithm because the blocksize
338 * is 4 and all packets must be 4-byte aligned regardless
341 plen = m->m_pkthdr.len - (skip + hlen + alen);
342 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
343 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
344 " SA %s/%08lx\n", __func__, plen, espx->blocksize,
345 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
346 (u_long)ntohl(sav->spi)));
347 ESPSTAT_INC(esps_badilen);
352 * Check sequence number.
355 if (esph != NULL && sav->replay != NULL && sav->replay->wsize != 0) {
356 if (ipsec_chkreplay(ntohl(esp->esp_seq), sav) == 0) {
357 SECASVAR_UNLOCK(sav);
358 DPRINTF(("%s: packet replay check for %s\n", __func__,
359 ipsec_sa2str(sav, buf, sizeof(buf))));
360 ESPSTAT_INC(esps_replay);
365 cryptoid = sav->tdb_cryptoid;
366 SECASVAR_UNLOCK(sav);
368 /* Update the counters */
369 ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen));
371 /* Get crypto descriptors */
372 crp = crypto_getreq(esph && espx ? 2 : 1);
374 DPRINTF(("%s: failed to acquire crypto descriptors\n",
376 ESPSTAT_INC(esps_crypto);
381 /* Get IPsec-specific opaque pointer */
382 xd = malloc(sizeof(*xd) + alen, M_XDATA, M_NOWAIT | M_ZERO);
384 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
385 ESPSTAT_INC(esps_crypto);
392 struct cryptodesc *crda = crp->crp_desc;
394 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
396 /* Authentication descriptor */
397 crda->crd_skip = skip;
399 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
401 crda->crd_len = m->m_pkthdr.len - (skip + alen);
402 crda->crd_inject = m->m_pkthdr.len - alen;
404 crda->crd_alg = esph->type;
406 /* Copy the authenticator */
407 m_copydata(m, m->m_pkthdr.len - alen, alen,
410 /* Chain authentication request */
411 crde = crda->crd_next;
413 crde = crp->crp_desc;
416 /* Crypto operation descriptor */
417 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
418 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
420 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
421 crp->crp_buf = (caddr_t) m;
422 crp->crp_callback = esp_input_cb;
423 crp->crp_session = cryptoid;
424 crp->crp_opaque = (caddr_t) xd;
426 /* These are passed as-is to the callback */
428 xd->protoff = protoff;
430 xd->cryptoid = cryptoid;
433 /* Decryption descriptor */
434 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
435 crde->crd_skip = skip + hlen;
436 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
437 crde->crd_inject = skip + hlen - sav->ivlen;
439 if (SAV_ISCTRORGCM(sav)) {
440 ivp = &crde->crd_iv[0];
442 /* GCM IV Format: RFC4106 4 */
443 /* CTR IV Format: RFC3686 4 */
444 /* Salt is last four bytes of key, RFC4106 8.1 */
445 /* Nonce is last four bytes of key, RFC3686 5.1 */
446 memcpy(ivp, sav->key_enc->key_data +
447 _KEYLEN(sav->key_enc) - 4, 4);
449 if (SAV_ISCTR(sav)) {
450 /* Initial block counter is 1, RFC3686 4 */
451 be32enc(&ivp[sav->ivlen + 4], 1);
454 m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
455 crde->crd_flags |= CRD_F_IV_EXPLICIT;
458 crde->crd_alg = espx->type;
460 return (crypto_dispatch(crp));
468 * ESP input callback from the crypto driver.
471 esp_input_cb(struct cryptop *crp)
473 IPSEC_DEBUG_DECLARE(char buf[128]);
474 u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN];
475 const struct auth_hash *esph;
477 struct cryptodesc *crd;
478 struct xform_data *xd;
479 struct secasvar *sav;
480 struct secasindex *saidx;
482 crypto_session_t cryptoid;
483 int hlen, skip, protoff, error, alen;
486 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
488 m = (struct mbuf *) crp->crp_buf;
489 xd = (struct xform_data *) crp->crp_opaque;
490 CURVNET_SET(xd->vnet);
493 protoff = xd->protoff;
494 cryptoid = xd->cryptoid;
495 saidx = &sav->sah->saidx;
496 esph = sav->tdb_authalgxform;
498 /* Check for crypto errors */
499 if (crp->crp_etype) {
500 if (crp->crp_etype == EAGAIN) {
501 /* Reset the session ID */
502 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
503 crypto_freesession(cryptoid);
504 xd->cryptoid = crp->crp_session;
506 return (crypto_dispatch(crp));
508 ESPSTAT_INC(esps_noxform);
509 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
510 error = crp->crp_etype;
514 /* Shouldn't happen... */
516 ESPSTAT_INC(esps_crypto);
517 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
521 ESPSTAT_INC(esps_hist[sav->alg_enc]);
523 /* If authentication was performed, check now. */
525 alen = xform_ah_authsize(esph);
526 AHSTAT_INC(ahs_hist[sav->alg_auth]);
527 /* Copy the authenticator from the packet */
528 m_copydata(m, m->m_pkthdr.len - alen, alen, aalg);
529 ptr = (caddr_t) (xd + 1);
531 /* Verify authenticator */
532 if (timingsafe_bcmp(ptr, aalg, alen) != 0) {
533 DPRINTF(("%s: authentication hash mismatch for "
534 "packet in SA %s/%08lx\n", __func__,
535 ipsec_address(&saidx->dst, buf, sizeof(buf)),
536 (u_long) ntohl(sav->spi)));
537 ESPSTAT_INC(esps_badauth);
541 m->m_flags |= M_AUTHIPDGM;
542 /* Remove trailing authenticator */
546 /* Release the crypto descriptors */
547 free(xd, M_XDATA), xd = NULL;
548 crypto_freereq(crp), crp = NULL;
551 * Packet is now decrypted.
553 m->m_flags |= M_DECRYPTED;
556 * Update replay sequence number, if appropriate.
561 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
562 sizeof (seq), (caddr_t) &seq);
564 if (ipsec_updatereplay(ntohl(seq), sav)) {
565 SECASVAR_UNLOCK(sav);
566 DPRINTF(("%s: packet replay check for %s\n", __func__,
567 ipsec_sa2str(sav, buf, sizeof(buf))));
568 ESPSTAT_INC(esps_replay);
572 SECASVAR_UNLOCK(sav);
575 /* Determine the ESP header length */
576 if (sav->flags & SADB_X_EXT_OLD)
577 hlen = sizeof (struct esp) + sav->ivlen;
579 hlen = sizeof (struct newesp) + sav->ivlen;
581 /* Remove the ESP header and IV from the mbuf. */
582 error = m_striphdr(m, skip, hlen);
584 ESPSTAT_INC(esps_hdrops);
585 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
586 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
587 (u_long) ntohl(sav->spi)));
591 /* Save the last three bytes of decrypted data */
592 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
594 /* Verify pad length */
595 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
596 ESPSTAT_INC(esps_badilen);
597 DPRINTF(("%s: invalid padding length %d for %u byte packet "
598 "in SA %s/%08lx\n", __func__, lastthree[1],
599 m->m_pkthdr.len - skip,
600 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
601 (u_long) ntohl(sav->spi)));
606 /* Verify correct decryption by checking the last padding bytes */
607 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
608 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
609 ESPSTAT_INC(esps_badenc);
610 DPRINTF(("%s: decryption failed for packet in "
611 "SA %s/%08lx\n", __func__, ipsec_address(
612 &sav->sah->saidx.dst, buf, sizeof(buf)),
613 (u_long) ntohl(sav->spi)));
621 * Silently drop packet if next header field is IPPROTO_NONE.
623 if (lastthree[2] == IPPROTO_NONE)
626 /* Trim the mbuf chain to remove trailing authenticator and padding */
627 m_adj(m, -(lastthree[1] + 2));
629 /* Restore the Next Protocol field */
630 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
632 switch (saidx->dst.sa.sa_family) {
635 error = ipsec6_common_input_cb(m, sav, skip, protoff);
640 error = ipsec4_common_input_cb(m, sav, skip, protoff);
644 panic("%s: Unexpected address family: %d saidx=%p", __func__,
645 saidx->dst.sa.sa_family, saidx);
662 * ESP output routine, called by ipsec[46]_perform_request().
665 esp_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
666 u_int idx, int skip, int protoff)
668 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
669 struct cryptodesc *crde = NULL, *crda = NULL;
671 const struct auth_hash *esph;
672 const struct enc_xform *espx;
673 struct mbuf *mo = NULL;
674 struct xform_data *xd;
675 struct secasindex *saidx;
679 crypto_session_t cryptoid;
680 int hlen, rlen, padding, blks, alen, i, roff;
681 int error, maxpacketsize;
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"));
689 if (sav->flags & SADB_X_EXT_OLD)
690 hlen = sizeof (struct esp) + sav->ivlen;
692 hlen = sizeof (struct newesp) + sav->ivlen;
694 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
696 * RFC4303 2.4 Requires 4 byte alignment.
698 blks = MAX(4, espx->blocksize); /* Cipher blocksize */
700 /* XXX clamp padding length a la KAME??? */
701 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
703 alen = xform_ah_authsize(esph);
705 ESPSTAT_INC(esps_output);
707 saidx = &sav->sah->saidx;
708 /* Check for maximum packet size violations. */
709 switch (saidx->dst.sa.sa_family) {
712 maxpacketsize = IP_MAXPACKET;
717 maxpacketsize = IPV6_MAXPACKET;
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;
730 DPRINTF(("%s: skip %d hlen %d rlen %d padding %d alen %d blksd %d\n",
731 __func__, skip, hlen, rlen, padding, alen, blks)); */
732 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
733 DPRINTF(("%s: packet in SA %s/%08lx got too big "
734 "(len %u, max len %u)\n", __func__,
735 ipsec_address(&saidx->dst, buf, sizeof(buf)),
736 (u_long) ntohl(sav->spi),
737 skip + hlen + rlen + padding + alen, maxpacketsize));
738 ESPSTAT_INC(esps_toobig);
743 /* Update the counters. */
744 ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip);
746 m = m_unshare(m, M_NOWAIT);
748 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
749 ipsec_address(&saidx->dst, buf, sizeof(buf)),
750 (u_long) ntohl(sav->spi)));
751 ESPSTAT_INC(esps_hdrops);
756 /* Inject ESP header. */
757 mo = m_makespace(m, skip, hlen, &roff);
759 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
760 __func__, hlen, ipsec_address(&saidx->dst, buf,
761 sizeof(buf)), (u_long) ntohl(sav->spi)));
762 ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */
767 /* Initialize ESP header. */
768 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff,
775 /* Emulate replay attack when ipsec_replay is TRUE. */
778 sav->replay->count++;
779 replay = htonl(sav->replay->count);
781 bcopy((caddr_t) &replay, mtod(mo, caddr_t) + roff +
782 sizeof(uint32_t), sizeof(uint32_t));
784 cryptoid = sav->tdb_cryptoid;
785 if (SAV_ISCTRORGCM(sav))
787 SECASVAR_UNLOCK(sav);
790 * Add padding -- better to do it ourselves than use the crypto engine,
791 * although if/when we support compression, we'd have to do that.
793 pad = (u_char *) m_pad(m, padding + alen);
795 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
796 ipsec_address(&saidx->dst, buf, sizeof(buf)),
797 (u_long) ntohl(sav->spi)));
798 m = NULL; /* NB: free'd by m_pad */
804 * Add padding: random, zero, or self-describing.
805 * XXX catch unexpected setting
807 switch (sav->flags & SADB_X_EXT_PMASK) {
808 case SADB_X_EXT_PRAND:
809 arc4random_buf(pad, padding - 2);
811 case SADB_X_EXT_PZERO:
812 bzero(pad, padding - 2);
814 case SADB_X_EXT_PSEQ:
815 for (i = 0; i < padding - 2; i++)
820 /* Fix padding length and Next Protocol in padding itself. */
821 pad[padding - 2] = padding - 2;
822 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
824 /* Fix Next Protocol in IPv4/IPv6 header. */
826 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
828 /* Get crypto descriptors. */
829 crp = crypto_getreq(esph != NULL ? 2 : 1);
831 DPRINTF(("%s: failed to acquire crypto descriptors\n",
833 ESPSTAT_INC(esps_crypto);
838 /* IPsec-specific opaque crypto info. */
839 xd = malloc(sizeof(struct xform_data), M_XDATA, M_NOWAIT | M_ZERO);
842 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
843 ESPSTAT_INC(esps_crypto);
848 crde = crp->crp_desc;
849 crda = crde->crd_next;
851 /* Encryption descriptor. */
852 crde->crd_skip = skip + hlen;
853 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
854 crde->crd_flags = CRD_F_ENCRYPT;
855 crde->crd_inject = skip + hlen - sav->ivlen;
857 /* Encryption operation. */
858 crde->crd_alg = espx->type;
859 if (SAV_ISCTRORGCM(sav)) {
860 ivp = &crde->crd_iv[0];
862 /* GCM IV Format: RFC4106 4 */
863 /* CTR IV Format: RFC3686 4 */
864 /* Salt is last four bytes of key, RFC4106 8.1 */
865 /* Nonce is last four bytes of key, RFC3686 5.1 */
866 memcpy(ivp, sav->key_enc->key_data +
867 _KEYLEN(sav->key_enc) - 4, 4);
868 be64enc(&ivp[4], cntr);
869 if (SAV_ISCTR(sav)) {
870 /* Initial block counter is 1, RFC3686 4 */
871 /* XXXAE: should we use this only for first packet? */
872 be32enc(&ivp[sav->ivlen + 4], 1);
875 m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]);
876 crde->crd_flags |= CRD_F_IV_EXPLICIT|CRD_F_IV_PRESENT;
879 /* Callback parameters */
883 xd->cryptoid = cryptoid;
886 /* Crypto operation descriptor. */
887 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
888 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
890 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
891 crp->crp_buf = (caddr_t) m;
892 crp->crp_callback = esp_output_cb;
893 crp->crp_opaque = (caddr_t) xd;
894 crp->crp_session = cryptoid;
897 /* Authentication descriptor. */
898 crda->crd_alg = esph->type;
899 crda->crd_skip = skip;
901 crda->crd_len = 8; /* RFC4106 5, SPI + SN */
903 crda->crd_len = m->m_pkthdr.len - (skip + alen);
904 crda->crd_inject = m->m_pkthdr.len - alen;
907 return crypto_dispatch(crp);
916 * ESP output callback from the crypto driver.
919 esp_output_cb(struct cryptop *crp)
921 struct xform_data *xd;
922 struct secpolicy *sp;
923 struct secasvar *sav;
925 crypto_session_t cryptoid;
929 xd = (struct xform_data *) crp->crp_opaque;
930 CURVNET_SET(xd->vnet);
931 m = (struct mbuf *) crp->crp_buf;
935 cryptoid = xd->cryptoid;
937 /* Check for crypto errors. */
938 if (crp->crp_etype) {
939 if (crp->crp_etype == EAGAIN) {
940 /* Reset the session ID */
941 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
942 crypto_freesession(cryptoid);
943 xd->cryptoid = crp->crp_session;
945 return (crypto_dispatch(crp));
947 ESPSTAT_INC(esps_noxform);
948 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
949 error = crp->crp_etype;
954 /* Shouldn't happen... */
956 ESPSTAT_INC(esps_crypto);
957 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
963 ESPSTAT_INC(esps_hist[sav->alg_enc]);
964 if (sav->tdb_authalgxform != NULL)
965 AHSTAT_INC(ahs_hist[sav->alg_auth]);
968 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
969 if (V_ipsec_integrity) {
970 static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN];
971 const struct auth_hash *esph;
974 * Corrupt HMAC if we want to test integrity verification of
977 esph = sav->tdb_authalgxform;
981 alen = xform_ah_authsize(esph);
982 m_copyback(m, m->m_pkthdr.len - alen,
988 /* NB: m is reclaimed by ipsec_process_done. */
989 error = ipsec_process_done(m, sp, sav, idx);
1001 static struct xformsw esp_xformsw = {
1003 .xf_name = "IPsec ESP",
1004 .xf_init = esp_init,
1005 .xf_zeroize = esp_zeroize,
1006 .xf_input = esp_input,
1007 .xf_output = esp_output,
1010 SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1011 xform_attach, &esp_xformsw);
1012 SYSUNINIT(esp_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1013 xform_detach, &esp_xformsw);