2 /* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 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 and Niklas Hallqvist.
19 * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
20 * Angelos D. Keromytis and Niels Provos.
21 * Copyright (c) 1999 Niklas Hallqvist.
22 * Copyright (c) 2001 Angelos D. Keromytis.
24 * Permission to use, copy, and modify this software with or without fee
25 * is hereby granted, provided that this entire notice is included in
26 * all copies of any software which is or includes a copy or
27 * modification of this software.
28 * You may use this code under the GNU public license if you so wish. Please
29 * contribute changes back to the authors under this freer than GPL license
30 * so that we may further the use of strong encryption without limitations to
33 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
34 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
35 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
36 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
40 #include "opt_inet6.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
45 #include <sys/socket.h>
46 #include <sys/syslog.h>
47 #include <sys/kernel.h>
49 #include <sys/mutex.h>
50 #include <sys/sysctl.h>
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_ecn.h>
59 #include <netinet/ip6.h>
61 #include <netipsec/ipsec.h>
62 #include <netipsec/ah.h>
63 #include <netipsec/ah_var.h>
64 #include <netipsec/xform.h>
67 #include <netinet6/ip6_var.h>
68 #include <netipsec/ipsec6.h>
69 #include <netinet6/ip6_ecn.h>
72 #include <netipsec/key.h>
73 #include <netipsec/key_debug.h>
75 #include <opencrypto/cryptodev.h>
78 * Return header size in bytes. The old protocol did not support
79 * the replay counter; the new protocol always includes the counter.
81 #define HDRSIZE(sav) \
82 (((sav)->flags & SADB_X_EXT_OLD) ? \
83 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
85 * Return authenticator size in bytes, based on a field in the
86 * algorithm descriptor.
88 #define AUTHSIZE(sav) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \
89 xform_ah_authsize((sav)->tdb_authalgxform))
91 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
92 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
93 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
94 VNET_PCPUSTAT_SYSINIT(ahstat);
97 VNET_PCPUSTAT_SYSUNINIT(ahstat);
101 SYSCTL_DECL(_net_inet_ah);
102 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable,
103 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
104 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos,
105 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
106 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
107 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
110 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
112 static int ah_input_cb(struct cryptop*);
113 static int ah_output_cb(struct cryptop*);
116 xform_ah_authsize(const struct auth_hash *esph)
123 switch (esph->type) {
124 case CRYPTO_SHA2_256_HMAC:
125 case CRYPTO_SHA2_384_HMAC:
126 case CRYPTO_SHA2_512_HMAC:
127 alen = esph->hashsize / 2; /* RFC4868 2.3 */
130 case CRYPTO_AES_128_NIST_GMAC:
131 case CRYPTO_AES_192_NIST_GMAC:
132 case CRYPTO_AES_256_NIST_GMAC:
133 alen = esph->hashsize;
137 alen = AH_HMAC_HASHLEN;
145 ah_hdrsiz(struct secasvar *sav)
150 int authsize, rplen, align;
152 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
153 /*XXX not right for null algorithm--does it matter??*/
155 /* RFC4302: use the correct alignment. */
156 align = sizeof(uint32_t);
158 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
159 align = sizeof(uint64_t);
162 rplen = HDRSIZE(sav);
163 authsize = AUTHSIZE(sav);
164 size = roundup(rplen + authsize, align);
167 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
173 * NB: public for use by esp_init.
176 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
178 const struct auth_hash *thash;
181 thash = auth_algorithm_lookup(sav->alg_auth);
183 DPRINTF(("%s: unsupported authentication algorithm %u\n",
184 __func__, sav->alg_auth));
188 * Verify the replay state block allocation is consistent with
189 * the protocol type. We check here so we can make assumptions
190 * later during protocol processing.
192 /* NB: replay state is setup elsewhere (sigh) */
193 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
194 DPRINTF(("%s: replay state block inconsistency, "
195 "%s algorithm %s replay state\n", __func__,
196 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
197 sav->replay == NULL ? "without" : "with"));
200 if (sav->key_auth == NULL) {
201 DPRINTF(("%s: no authentication key for %s algorithm\n",
202 __func__, thash->name));
205 keylen = _KEYLEN(sav->key_auth);
206 if (keylen > thash->keysize && thash->keysize != 0) {
207 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
208 "keysize less than %d\n", __func__,
209 keylen, thash->name, thash->keysize));
213 sav->tdb_xform = xsp;
214 sav->tdb_authalgxform = thash;
216 /* Initialize crypto session. */
217 bzero(cria, sizeof (*cria));
218 cria->cri_alg = sav->tdb_authalgxform->type;
219 cria->cri_klen = _KEYBITS(sav->key_auth);
220 cria->cri_key = sav->key_auth->key_data;
221 cria->cri_mlen = AUTHSIZE(sav);
227 * ah_init() is called when an SPI is being set up.
230 ah_init(struct secasvar *sav, struct xformsw *xsp)
232 struct cryptoini cria;
235 error = ah_init0(sav, xsp, &cria);
236 return error ? error :
237 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
243 * NB: public for use by esp_zeroize (XXX).
246 ah_zeroize(struct secasvar *sav)
250 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
252 crypto_freesession(sav->tdb_cryptoid);
253 sav->tdb_cryptoid = NULL;
254 sav->tdb_authalgxform = NULL;
255 sav->tdb_xform = NULL;
260 * Massage IPv4/IPv6 headers for AH processing.
263 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
265 struct mbuf *m = *m0;
274 struct ip6_ext *ip6e;
276 int ad, alloc, nxt, noff;
283 * This is the least painful way of dealing with IPv4 header
284 * and option processing -- just make sure they're in
287 *m0 = m = m_pullup(m, skip);
289 DPRINTF(("%s: m_pullup failed\n", __func__));
293 /* Fix the IP header */
294 ip = mtod(m, struct ip *);
300 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
301 ip->ip_off &= htons(IP_DF);
303 ip->ip_off = htons(0);
305 ptr = mtod(m, unsigned char *);
307 /* IPv4 option processing */
308 for (off = sizeof(struct ip); off < skip;) {
309 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
313 DPRINTF(("%s: illegal IPv4 option length for "
314 "option %d\n", __func__, ptr[off]));
322 off = skip; /* End the loop. */
329 case IPOPT_SECURITY: /* 0x82 */
330 case 0x85: /* Extended security. */
331 case 0x86: /* Commercial security. */
332 case 0x94: /* Router alert */
333 case 0x95: /* RFC1770 */
334 /* Sanity check for option length. */
335 if (ptr[off + 1] < 2) {
336 DPRINTF(("%s: illegal IPv4 option "
337 "length for option %d\n",
338 __func__, ptr[off]));
349 /* Sanity check for option length. */
350 if (ptr[off + 1] < 2) {
351 DPRINTF(("%s: illegal IPv4 option "
352 "length for option %d\n",
353 __func__, ptr[off]));
360 * On output, if we have either of the
361 * source routing options, we should
362 * swap the destination address of the
363 * IP header with the last address
364 * specified in the option, as that is
365 * what the destination's IP header
369 bcopy(ptr + off + ptr[off + 1] -
370 sizeof(struct in_addr),
371 &(ip->ip_dst), sizeof(struct in_addr));
375 /* Sanity check for option length. */
376 if (ptr[off + 1] < 2) {
377 DPRINTF(("%s: illegal IPv4 option "
378 "length for option %d\n",
379 __func__, ptr[off]));
384 /* Zeroize all other options. */
385 count = ptr[off + 1];
386 bcopy(ipseczeroes, ptr + off, count);
393 DPRINTF(("%s: malformed IPv4 options header\n",
405 case AF_INET6: /* Ugly... */
406 /* Copy and "cook" the IPv6 header. */
407 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
409 /* We don't do IPv6 Jumbograms. */
410 if (ip6.ip6_plen == 0) {
411 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
418 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
419 ip6.ip6_vfc |= IPV6_VERSION;
421 /* Scoped address handling. */
422 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
423 ip6.ip6_src.s6_addr16[1] = 0;
424 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
425 ip6.ip6_dst.s6_addr16[1] = 0;
427 /* Done with IPv6 header. */
428 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
430 /* Let's deal with the remaining headers (if any). */
431 if (skip - sizeof(struct ip6_hdr) > 0) {
432 if (m->m_len <= skip) {
433 ptr = (unsigned char *) malloc(
434 skip - sizeof(struct ip6_hdr),
437 DPRINTF(("%s: failed to allocate memory"
438 "for IPv6 headers\n",__func__));
444 * Copy all the protocol headers after
447 m_copydata(m, sizeof(struct ip6_hdr),
448 skip - sizeof(struct ip6_hdr), ptr);
451 /* No need to allocate memory. */
452 ptr = mtod(m, unsigned char *) +
453 sizeof(struct ip6_hdr);
459 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
461 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
463 case IPPROTO_HOPOPTS:
464 case IPPROTO_DSTOPTS:
465 ip6e = (struct ip6_ext *)(ptr + off);
466 noff = off + ((ip6e->ip6e_len + 1) << 3);
469 if (noff > skip - sizeof(struct ip6_hdr))
473 * Zero out mutable options.
475 for (count = off + sizeof(struct ip6_ext);
477 if (ptr[count] == IP6OPT_PAD1) {
479 continue; /* Skip padding. */
482 ad = ptr[count + 1] + 2;
483 if (count + ad > noff)
486 if (ptr[count] & IP6OPT_MUTABLE)
487 memset(ptr + count, 0, ad);
495 off += ((ip6e->ip6e_len + 1) << 3);
496 nxt = ip6e->ip6e_nxt;
499 case IPPROTO_ROUTING:
501 * Always include routing headers in
504 ip6e = (struct ip6_ext *) (ptr + off);
505 off += ((ip6e->ip6e_len + 1) << 3);
506 nxt = ip6e->ip6e_nxt;
510 DPRINTF(("%s: unexpected IPv6 header type %d",
519 /* Copyback and free, if we allocated. */
521 m_copyback(m, sizeof(struct ip6_hdr),
522 skip - sizeof(struct ip6_hdr), ptr);
534 * ah_input() gets called to verify that an input packet
535 * passes authentication.
538 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
540 IPSEC_DEBUG_DECLARE(char buf[128]);
541 const struct auth_hash *ahx;
542 struct cryptodesc *crda;
544 struct xform_data *xd;
546 crypto_session_t cryptoid;
547 int hl, rplen, authsize, ahsize, error;
549 IPSEC_ASSERT(sav != NULL, ("null SA"));
550 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
551 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
552 ("null authentication xform"));
554 /* Figure out header size. */
555 rplen = HDRSIZE(sav);
557 /* XXX don't pullup, just copy header */
558 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
560 DPRINTF(("ah_input: cannot pullup header\n"));
561 AHSTAT_INC(ahs_hdrops); /*XXX*/
566 /* Check replay window, if applicable. */
568 if (sav->replay != NULL && sav->replay->wsize != 0 &&
569 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) {
570 SECASVAR_UNLOCK(sav);
571 AHSTAT_INC(ahs_replay);
572 DPRINTF(("%s: packet replay failure: %s\n", __func__,
573 ipsec_sa2str(sav, buf, sizeof(buf))));
577 cryptoid = sav->tdb_cryptoid;
578 SECASVAR_UNLOCK(sav);
580 /* Verify AH header length. */
581 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
582 ahx = sav->tdb_authalgxform;
583 authsize = AUTHSIZE(sav);
584 ahsize = ah_hdrsiz(sav);
586 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
587 " for packet in SA %s/%08lx\n", __func__, hl,
589 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
590 (u_long) ntohl(sav->spi)));
591 AHSTAT_INC(ahs_badauthl);
595 if (skip + ahsize > m->m_pkthdr.len) {
596 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
597 " for packet in SA %s/%08lx\n", __func__,
598 m->m_pkthdr.len, (u_long)(skip + ahsize),
599 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
600 (u_long) ntohl(sav->spi)));
601 AHSTAT_INC(ahs_badauthl);
605 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
607 /* Get crypto descriptors. */
608 crp = crypto_getreq(1);
610 DPRINTF(("%s: failed to acquire crypto descriptor\n",
612 AHSTAT_INC(ahs_crypto);
617 crda = crp->crp_desc;
618 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
621 crda->crd_len = m->m_pkthdr.len;
622 crda->crd_inject = skip + rplen;
624 /* Authentication operation. */
625 crda->crd_alg = ahx->type;
626 crda->crd_klen = _KEYBITS(sav->key_auth);
627 crda->crd_key = sav->key_auth->key_data;
629 /* Allocate IPsec-specific opaque crypto info. */
630 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
633 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
634 AHSTAT_INC(ahs_crypto);
641 * Save the authenticator, the skipped portion of the packet,
644 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
646 /* Zeroize the authenticator on the packet. */
647 m_copyback(m, skip + rplen, authsize, ipseczeroes);
649 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
652 /* "Massage" the packet headers for crypto processing. */
653 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
656 /* NB: mbuf is free'd by ah_massage_headers */
657 AHSTAT_INC(ahs_hdrops);
664 /* Crypto operation descriptor. */
665 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
666 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
668 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
669 crp->crp_buf = (caddr_t) m;
670 crp->crp_callback = ah_input_cb;
671 crp->crp_session = cryptoid;
672 crp->crp_opaque = (caddr_t) xd;
674 /* These are passed as-is to the callback. */
677 xd->protoff = protoff;
679 xd->cryptoid = cryptoid;
681 return (crypto_dispatch(crp));
689 * AH input callback from the crypto driver.
692 ah_input_cb(struct cryptop *crp)
694 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
695 unsigned char calc[AH_ALEN_MAX];
697 struct xform_data *xd;
698 struct secasvar *sav;
699 struct secasindex *saidx;
701 crypto_session_t cryptoid;
702 int authsize, rplen, ahsize, error, skip, protoff;
705 m = (struct mbuf *) crp->crp_buf;
706 xd = (struct xform_data *) crp->crp_opaque;
707 CURVNET_SET(xd->vnet);
711 protoff = xd->protoff;
712 cryptoid = xd->cryptoid;
713 saidx = &sav->sah->saidx;
714 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
715 saidx->dst.sa.sa_family == AF_INET6,
716 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
718 /* Check for crypto errors. */
719 if (crp->crp_etype) {
720 if (crp->crp_etype == EAGAIN) {
721 /* Reset the session ID */
722 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
723 crypto_freesession(cryptoid);
724 xd->cryptoid = crp->crp_session;
726 return (crypto_dispatch(crp));
728 AHSTAT_INC(ahs_noxform);
729 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
730 error = crp->crp_etype;
733 AHSTAT_INC(ahs_hist[sav->alg_auth]);
734 crypto_freereq(crp); /* No longer needed. */
738 /* Shouldn't happen... */
740 AHSTAT_INC(ahs_crypto);
741 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
746 /* Figure out header size. */
747 rplen = HDRSIZE(sav);
748 authsize = AUTHSIZE(sav);
749 ahsize = ah_hdrsiz(sav);
751 /* Copy authenticator off the packet. */
752 m_copydata(m, skip + rplen, authsize, calc);
754 /* Verify authenticator. */
755 ptr = (caddr_t) (xd + 1);
756 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
757 DPRINTF(("%s: authentication hash mismatch for packet "
758 "in SA %s/%08lx\n", __func__,
759 ipsec_address(&saidx->dst, buf, sizeof(buf)),
760 (u_long) ntohl(sav->spi)));
761 AHSTAT_INC(ahs_badauth);
765 /* Fix the Next Protocol field. */
766 ((uint8_t *) ptr)[protoff] = nxt;
768 /* Copyback the saved (uncooked) network headers. */
769 m_copyback(m, 0, skip, ptr);
770 free(xd, M_XDATA), xd = NULL; /* No longer needed */
773 * Header is now authenticated.
775 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
778 * Update replay sequence number, if appropriate.
783 m_copydata(m, skip + offsetof(struct newah, ah_seq),
784 sizeof (seq), (caddr_t) &seq);
786 if (ipsec_updatereplay(ntohl(seq), sav)) {
787 SECASVAR_UNLOCK(sav);
788 AHSTAT_INC(ahs_replay);
792 SECASVAR_UNLOCK(sav);
796 * Remove the AH header and authenticator from the mbuf.
798 error = m_striphdr(m, skip, ahsize);
800 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
801 ipsec_address(&saidx->dst, buf, sizeof(buf)),
802 (u_long) ntohl(sav->spi)));
803 AHSTAT_INC(ahs_hdrops);
807 switch (saidx->dst.sa.sa_family) {
810 error = ipsec6_common_input_cb(m, sav, skip, protoff);
815 error = ipsec4_common_input_cb(m, sav, skip, protoff);
819 panic("%s: Unexpected address family: %d saidx=%p", __func__,
820 saidx->dst.sa.sa_family, saidx);
838 * AH output routine, called by ipsec[46]_perform_request().
841 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
842 u_int idx, int skip, int protoff)
844 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
845 const struct auth_hash *ahx;
846 struct cryptodesc *crda;
847 struct xform_data *xd;
851 crypto_session_t cryptoid;
853 int error, rplen, authsize, ahsize, maxpacketsize, roff;
856 IPSEC_ASSERT(sav != NULL, ("null SA"));
857 ahx = sav->tdb_authalgxform;
858 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
860 AHSTAT_INC(ahs_output);
862 /* Figure out header size. */
863 rplen = HDRSIZE(sav);
864 authsize = AUTHSIZE(sav);
865 ahsize = ah_hdrsiz(sav);
867 /* Check for maximum packet size violations. */
868 switch (sav->sah->saidx.dst.sa.sa_family) {
871 maxpacketsize = IP_MAXPACKET;
876 maxpacketsize = IPV6_MAXPACKET;
880 DPRINTF(("%s: unknown/unsupported protocol family %u, "
881 "SA %s/%08lx\n", __func__,
882 sav->sah->saidx.dst.sa.sa_family,
883 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
884 (u_long) ntohl(sav->spi)));
885 AHSTAT_INC(ahs_nopf);
886 error = EPFNOSUPPORT;
889 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
890 DPRINTF(("%s: packet in SA %s/%08lx got too big "
891 "(len %u, max len %u)\n", __func__,
892 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
893 (u_long) ntohl(sav->spi),
894 ahsize + m->m_pkthdr.len, maxpacketsize));
895 AHSTAT_INC(ahs_toobig);
900 /* Update the counters. */
901 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
903 m = m_unshare(m, M_NOWAIT);
905 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
906 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
907 (u_long) ntohl(sav->spi)));
908 AHSTAT_INC(ahs_hdrops);
913 /* Inject AH header. */
914 mi = m_makespace(m, skip, ahsize, &roff);
916 DPRINTF(("%s: failed to inject %u byte AH header for SA "
917 "%s/%08lx\n", __func__, ahsize,
918 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
919 (u_long) ntohl(sav->spi)));
920 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
926 * The AH header is guaranteed by m_makespace() to be in
927 * contiguous memory, at roff bytes offset into the returned mbuf.
929 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
931 /* Initialize the AH header. */
932 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
933 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
935 ah->ah_spi = sav->spi;
937 /* Zeroize authenticator. */
938 m_copyback(m, skip + rplen, authsize, ipseczeroes);
940 /* Zeroize padding */
941 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
944 /* Insert packet replay counter, as requested. */
947 if (sav->replay->count == ~0 &&
948 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
949 SECASVAR_UNLOCK(sav);
950 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
951 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
952 sizeof(buf)), (u_long) ntohl(sav->spi)));
953 AHSTAT_INC(ahs_wrap);
958 /* Emulate replay attack when ipsec_replay is TRUE. */
961 sav->replay->count++;
962 ah->ah_seq = htonl(sav->replay->count);
964 cryptoid = sav->tdb_cryptoid;
965 SECASVAR_UNLOCK(sav);
967 /* Get crypto descriptors. */
968 crp = crypto_getreq(1);
970 DPRINTF(("%s: failed to acquire crypto descriptors\n",
972 AHSTAT_INC(ahs_crypto);
977 crda = crp->crp_desc;
979 crda->crd_inject = skip + rplen;
980 crda->crd_len = m->m_pkthdr.len;
982 /* Authentication operation. */
983 crda->crd_alg = ahx->type;
984 crda->crd_key = sav->key_auth->key_data;
985 crda->crd_klen = _KEYBITS(sav->key_auth);
987 /* Allocate IPsec-specific opaque crypto info. */
988 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
992 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
993 AHSTAT_INC(ahs_crypto);
998 /* Save the skipped portion of the packet. */
999 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
1002 * Fix IP header length on the header used for
1003 * authentication. We don't need to fix the original
1004 * header length as it will be fixed by our caller.
1006 switch (sav->sah->saidx.dst.sa.sa_family) {
1009 bcopy(((caddr_t)(xd + 1)) +
1010 offsetof(struct ip, ip_len),
1011 (caddr_t) &iplen, sizeof(u_int16_t));
1012 iplen = htons(ntohs(iplen) + ahsize);
1013 m_copyback(m, offsetof(struct ip, ip_len),
1014 sizeof(u_int16_t), (caddr_t) &iplen);
1020 bcopy(((caddr_t)(xd + 1)) +
1021 offsetof(struct ip6_hdr, ip6_plen),
1022 (caddr_t) &iplen, sizeof(uint16_t));
1023 iplen = htons(ntohs(iplen) + ahsize);
1024 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1025 sizeof(uint16_t), (caddr_t) &iplen);
1030 /* Fix the Next Header field in saved header. */
1031 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1033 /* Update the Next Protocol field in the IP header. */
1035 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1037 /* "Massage" the packet headers for crypto processing. */
1038 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1039 skip, ahx->type, 1);
1041 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1043 crypto_freereq(crp);
1047 /* Crypto operation descriptor. */
1048 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1049 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1051 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1052 crp->crp_buf = (caddr_t) m;
1053 crp->crp_callback = ah_output_cb;
1054 crp->crp_session = cryptoid;
1055 crp->crp_opaque = (caddr_t) xd;
1057 /* These are passed as-is to the callback. */
1062 xd->cryptoid = cryptoid;
1065 return crypto_dispatch(crp);
1075 * AH output callback from the crypto driver.
1078 ah_output_cb(struct cryptop *crp)
1080 struct xform_data *xd;
1081 struct secpolicy *sp;
1082 struct secasvar *sav;
1084 crypto_session_t cryptoid;
1089 m = (struct mbuf *) crp->crp_buf;
1090 xd = (struct xform_data *) crp->crp_opaque;
1091 CURVNET_SET(xd->vnet);
1096 cryptoid = xd->cryptoid;
1097 ptr = (caddr_t) (xd + 1);
1099 /* Check for crypto errors. */
1100 if (crp->crp_etype) {
1101 if (crp->crp_etype == EAGAIN) {
1102 /* Reset the session ID */
1103 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1104 crypto_freesession(cryptoid);
1105 xd->cryptoid = crp->crp_session;
1107 return (crypto_dispatch(crp));
1109 AHSTAT_INC(ahs_noxform);
1110 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1111 error = crp->crp_etype;
1116 /* Shouldn't happen... */
1118 AHSTAT_INC(ahs_crypto);
1119 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1124 * Copy original headers (with the new protocol number) back
1127 m_copyback(m, 0, skip, ptr);
1130 crypto_freereq(crp);
1131 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1133 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1134 if (V_ipsec_integrity) {
1138 * Corrupt HMAC if we want to test integrity verification of
1141 alen = AUTHSIZE(sav);
1142 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1146 /* NB: m is reclaimed by ipsec_process_done. */
1147 error = ipsec_process_done(m, sp, sav, idx);
1153 crypto_freereq(crp);
1159 static struct xformsw ah_xformsw = {
1161 .xf_name = "IPsec AH",
1163 .xf_zeroize = ah_zeroize,
1164 .xf_input = ah_input,
1165 .xf_output = ah_output,
1168 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1169 xform_attach, &ah_xformsw);
1170 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1171 xform_detach, &ah_xformsw);