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"
41 #include "opt_ipsec.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
46 #include <sys/socket.h>
47 #include <sys/syslog.h>
48 #include <sys/kernel.h>
50 #include <sys/mutex.h>
51 #include <sys/sysctl.h>
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/ip.h>
59 #include <netinet/ip_ecn.h>
60 #include <netinet/ip6.h>
62 #include <netipsec/ipsec.h>
63 #include <netipsec/ah.h>
64 #include <netipsec/ah_var.h>
65 #include <netipsec/xform.h>
68 #include <netinet6/ip6_var.h>
69 #include <netipsec/ipsec6.h>
70 #include <netinet6/ip6_ecn.h>
73 #include <netipsec/key.h>
74 #include <netipsec/key_debug.h>
76 #include <opencrypto/cryptodev.h>
79 * Return header size in bytes. The old protocol did not support
80 * the replay counter; the new protocol always includes the counter.
82 #define HDRSIZE(sav) \
83 (((sav)->flags & SADB_X_EXT_OLD) ? \
84 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
86 * Return authenticator size in bytes, based on a field in the
87 * algorithm descriptor.
89 #define AUTHSIZE(sav) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \
90 xform_ah_authsize((sav)->tdb_authalgxform))
92 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
93 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
94 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
95 VNET_PCPUSTAT_SYSINIT(ahstat);
98 VNET_PCPUSTAT_SYSUNINIT(ahstat);
102 SYSCTL_DECL(_net_inet_ah);
103 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable,
104 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
105 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos,
106 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
107 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
108 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
111 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
113 static int ah_input_cb(struct cryptop*);
114 static int ah_output_cb(struct cryptop*);
117 xform_ah_authsize(const struct auth_hash *esph)
124 switch (esph->type) {
125 case CRYPTO_SHA2_256_HMAC:
126 case CRYPTO_SHA2_384_HMAC:
127 case CRYPTO_SHA2_512_HMAC:
128 alen = esph->hashsize / 2; /* RFC4868 2.3 */
131 case CRYPTO_AES_NIST_GMAC:
132 alen = esph->hashsize;
136 alen = AH_HMAC_HASHLEN;
144 ah_hdrsiz(struct secasvar *sav)
149 int authsize, rplen, align;
151 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
152 /*XXX not right for null algorithm--does it matter??*/
154 /* RFC4302: use the correct alignment. */
155 align = sizeof(uint32_t);
157 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
158 align = sizeof(uint64_t);
161 rplen = HDRSIZE(sav);
162 authsize = AUTHSIZE(sav);
163 size = roundup(rplen + authsize, align);
166 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
172 * NB: public for use by esp_init.
175 ah_init0(struct secasvar *sav, struct xformsw *xsp,
176 struct crypto_session_params *csp)
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));
189 * Verify the replay state block allocation is consistent with
190 * the protocol type. We check here so we can make assumptions
191 * later during protocol processing.
193 /* NB: replay state is setup elsewhere (sigh) */
194 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
195 DPRINTF(("%s: replay state block inconsistency, "
196 "%s algorithm %s replay state\n", __func__,
197 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
198 sav->replay == NULL ? "without" : "with"));
201 if (sav->key_auth == NULL) {
202 DPRINTF(("%s: no authentication key for %s algorithm\n",
203 __func__, thash->name));
206 keylen = _KEYLEN(sav->key_auth);
207 if (keylen > thash->keysize && thash->keysize != 0) {
208 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
209 "keysize less than %d\n", __func__,
210 keylen, thash->name, thash->keysize));
214 sav->tdb_xform = xsp;
215 sav->tdb_authalgxform = thash;
217 /* Initialize crypto session. */
218 csp->csp_auth_alg = sav->tdb_authalgxform->type;
219 if (csp->csp_auth_alg != CRYPTO_NULL_HMAC) {
220 csp->csp_auth_klen = _KEYBITS(sav->key_auth) / 8;
221 csp->csp_auth_key = sav->key_auth->key_data;
223 csp->csp_auth_mlen = AUTHSIZE(sav);
229 * ah_init() is called when an SPI is being set up.
232 ah_init(struct secasvar *sav, struct xformsw *xsp)
234 struct crypto_session_params csp;
237 memset(&csp, 0, sizeof(csp));
238 csp.csp_mode = CSP_MODE_DIGEST;
239 error = ah_init0(sav, xsp, &csp);
240 return error ? error :
241 crypto_newsession(&sav->tdb_cryptoid, &csp, V_crypto_support);
247 * NB: public for use by esp_zeroize (XXX).
250 ah_zeroize(struct secasvar *sav)
254 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
256 crypto_freesession(sav->tdb_cryptoid);
257 sav->tdb_cryptoid = NULL;
258 sav->tdb_authalgxform = NULL;
259 sav->tdb_xform = NULL;
264 * Massage IPv4/IPv6 headers for AH processing.
267 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
269 struct mbuf *m = *m0;
278 struct ip6_ext *ip6e;
280 int ad, alloc, nxt, noff;
287 * This is the least painful way of dealing with IPv4 header
288 * and option processing -- just make sure they're in
291 *m0 = m = m_pullup(m, skip);
293 DPRINTF(("%s: m_pullup failed\n", __func__));
297 /* Fix the IP header */
298 ip = mtod(m, struct ip *);
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;
543 struct xform_data *xd;
545 crypto_session_t cryptoid;
546 int hl, rplen, authsize, ahsize, error;
548 IPSEC_ASSERT(sav != NULL, ("null SA"));
549 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
550 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
551 ("null authentication xform"));
553 /* Figure out header size. */
554 rplen = HDRSIZE(sav);
556 if (m->m_len < skip + rplen) {
557 m = m_pullup(m, skip + rplen);
559 DPRINTF(("ah_input: cannot pullup header\n"));
560 AHSTAT_INC(ahs_hdrops); /*XXX*/
565 ah = (struct newah *)(mtod(m, caddr_t) + skip);
567 /* Check replay window, if applicable. */
569 if (sav->replay != NULL && sav->replay->wsize != 0 &&
570 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) {
571 SECASVAR_UNLOCK(sav);
572 AHSTAT_INC(ahs_replay);
573 DPRINTF(("%s: packet replay failure: %s\n", __func__,
574 ipsec_sa2str(sav, buf, sizeof(buf))));
578 cryptoid = sav->tdb_cryptoid;
579 SECASVAR_UNLOCK(sav);
581 /* Verify AH header length. */
582 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
583 ahx = sav->tdb_authalgxform;
584 authsize = AUTHSIZE(sav);
585 ahsize = ah_hdrsiz(sav);
587 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
588 " for packet in SA %s/%08lx\n", __func__, hl,
590 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
591 (u_long) ntohl(sav->spi)));
592 AHSTAT_INC(ahs_badauthl);
596 if (skip + ahsize > m->m_pkthdr.len) {
597 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
598 " for packet in SA %s/%08lx\n", __func__,
599 m->m_pkthdr.len, (u_long)(skip + ahsize),
600 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
601 (u_long) ntohl(sav->spi)));
602 AHSTAT_INC(ahs_badauthl);
606 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
608 /* Get crypto descriptors. */
609 crp = crypto_getreq(cryptoid, M_NOWAIT);
611 DPRINTF(("%s: failed to acquire crypto descriptor\n",
613 AHSTAT_INC(ahs_crypto);
618 crp->crp_payload_start = 0;
619 crp->crp_payload_length = m->m_pkthdr.len;
620 crp->crp_digest_start = skip + rplen;
622 /* Allocate IPsec-specific opaque crypto info. */
623 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
626 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
627 AHSTAT_INC(ahs_crypto);
634 * Save the authenticator, the skipped portion of the packet,
637 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
639 /* Zeroize the authenticator on the packet. */
640 m_copyback(m, skip + rplen, authsize, ipseczeroes);
642 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
645 /* "Massage" the packet headers for crypto processing. */
646 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
649 /* NB: mbuf is free'd by ah_massage_headers */
650 AHSTAT_INC(ahs_hdrops);
657 /* Crypto operation descriptor. */
658 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
659 crp->crp_flags = CRYPTO_F_CBIFSYNC;
661 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
662 crypto_use_mbuf(crp, m);
663 crp->crp_callback = ah_input_cb;
664 crp->crp_opaque = xd;
666 /* These are passed as-is to the callback. */
669 xd->protoff = protoff;
671 xd->cryptoid = cryptoid;
673 return (crypto_dispatch(crp));
681 * AH input callback from the crypto driver.
684 ah_input_cb(struct cryptop *crp)
686 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
687 unsigned char calc[AH_ALEN_MAX];
689 struct xform_data *xd;
690 struct secasvar *sav;
691 struct secasindex *saidx;
693 crypto_session_t cryptoid;
694 int authsize, rplen, ahsize, error, skip, protoff;
697 m = crp->crp_buf.cb_mbuf;
698 xd = crp->crp_opaque;
699 CURVNET_SET(xd->vnet);
703 protoff = xd->protoff;
704 cryptoid = xd->cryptoid;
705 saidx = &sav->sah->saidx;
706 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
707 saidx->dst.sa.sa_family == AF_INET6,
708 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
710 /* Check for crypto errors. */
711 if (crp->crp_etype) {
712 if (crp->crp_etype == EAGAIN) {
713 /* Reset the session ID */
714 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
715 crypto_freesession(cryptoid);
716 xd->cryptoid = crp->crp_session;
718 return (crypto_dispatch(crp));
720 AHSTAT_INC(ahs_noxform);
721 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
722 error = crp->crp_etype;
725 AHSTAT_INC(ahs_hist[sav->alg_auth]);
726 crypto_freereq(crp); /* No longer needed. */
730 /* Shouldn't happen... */
732 AHSTAT_INC(ahs_crypto);
733 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
738 /* Figure out header size. */
739 rplen = HDRSIZE(sav);
740 authsize = AUTHSIZE(sav);
741 ahsize = ah_hdrsiz(sav);
743 /* Copy authenticator off the packet. */
744 m_copydata(m, skip + rplen, authsize, calc);
746 /* Verify authenticator. */
747 ptr = (caddr_t) (xd + 1);
748 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
749 DPRINTF(("%s: authentication hash mismatch for packet "
750 "in SA %s/%08lx\n", __func__,
751 ipsec_address(&saidx->dst, buf, sizeof(buf)),
752 (u_long) ntohl(sav->spi)));
753 AHSTAT_INC(ahs_badauth);
757 /* Fix the Next Protocol field. */
758 ((uint8_t *) ptr)[protoff] = nxt;
760 /* Copyback the saved (uncooked) network headers. */
761 m_copyback(m, 0, skip, ptr);
762 free(xd, M_XDATA), xd = NULL; /* No longer needed */
765 * Header is now authenticated.
767 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
770 * Update replay sequence number, if appropriate.
775 m_copydata(m, skip + offsetof(struct newah, ah_seq),
776 sizeof (seq), (caddr_t) &seq);
778 if (ipsec_updatereplay(ntohl(seq), sav)) {
779 SECASVAR_UNLOCK(sav);
780 AHSTAT_INC(ahs_replay);
784 SECASVAR_UNLOCK(sav);
788 * Remove the AH header and authenticator from the mbuf.
790 error = m_striphdr(m, skip, ahsize);
792 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
793 ipsec_address(&saidx->dst, buf, sizeof(buf)),
794 (u_long) ntohl(sav->spi)));
795 AHSTAT_INC(ahs_hdrops);
799 switch (saidx->dst.sa.sa_family) {
802 error = ipsec6_common_input_cb(m, sav, skip, protoff);
807 error = ipsec4_common_input_cb(m, sav, skip, protoff);
811 panic("%s: Unexpected address family: %d saidx=%p", __func__,
812 saidx->dst.sa.sa_family, saidx);
830 * AH output routine, called by ipsec[46]_perform_request().
833 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
834 u_int idx, int skip, int protoff)
836 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
837 const struct auth_hash *ahx;
838 struct xform_data *xd;
842 crypto_session_t cryptoid;
844 int error, rplen, authsize, ahsize, maxpacketsize, roff;
847 IPSEC_ASSERT(sav != NULL, ("null SA"));
848 ahx = sav->tdb_authalgxform;
849 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
851 AHSTAT_INC(ahs_output);
853 /* Figure out header size. */
854 rplen = HDRSIZE(sav);
855 authsize = AUTHSIZE(sav);
856 ahsize = ah_hdrsiz(sav);
858 /* Check for maximum packet size violations. */
859 switch (sav->sah->saidx.dst.sa.sa_family) {
862 maxpacketsize = IP_MAXPACKET;
867 maxpacketsize = IPV6_MAXPACKET;
871 DPRINTF(("%s: unknown/unsupported protocol family %u, "
872 "SA %s/%08lx\n", __func__,
873 sav->sah->saidx.dst.sa.sa_family,
874 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
875 (u_long) ntohl(sav->spi)));
876 AHSTAT_INC(ahs_nopf);
877 error = EPFNOSUPPORT;
880 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
881 DPRINTF(("%s: packet in SA %s/%08lx got too big "
882 "(len %u, max len %u)\n", __func__,
883 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
884 (u_long) ntohl(sav->spi),
885 ahsize + m->m_pkthdr.len, maxpacketsize));
886 AHSTAT_INC(ahs_toobig);
891 /* Update the counters. */
892 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
894 m = m_unshare(m, M_NOWAIT);
896 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
897 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
898 (u_long) ntohl(sav->spi)));
899 AHSTAT_INC(ahs_hdrops);
904 /* Inject AH header. */
905 mi = m_makespace(m, skip, ahsize, &roff);
907 DPRINTF(("%s: failed to inject %u byte AH header for SA "
908 "%s/%08lx\n", __func__, ahsize,
909 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
910 (u_long) ntohl(sav->spi)));
911 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
917 * The AH header is guaranteed by m_makespace() to be in
918 * contiguous memory, at roff bytes offset into the returned mbuf.
920 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
922 /* Initialize the AH header. */
923 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
924 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
926 ah->ah_spi = sav->spi;
928 /* Zeroize authenticator. */
929 m_copyback(m, skip + rplen, authsize, ipseczeroes);
931 /* Zeroize padding */
932 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
935 /* Insert packet replay counter, as requested. */
938 if (sav->replay->count == ~0 &&
939 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
940 SECASVAR_UNLOCK(sav);
941 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
942 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
943 sizeof(buf)), (u_long) ntohl(sav->spi)));
944 AHSTAT_INC(ahs_wrap);
949 /* Emulate replay attack when ipsec_replay is TRUE. */
952 sav->replay->count++;
953 ah->ah_seq = htonl(sav->replay->count);
955 cryptoid = sav->tdb_cryptoid;
956 SECASVAR_UNLOCK(sav);
958 /* Get crypto descriptors. */
959 crp = crypto_getreq(cryptoid, M_NOWAIT);
961 DPRINTF(("%s: failed to acquire crypto descriptors\n",
963 AHSTAT_INC(ahs_crypto);
968 crp->crp_payload_start = 0;
969 crp->crp_payload_length = m->m_pkthdr.len;
970 crp->crp_digest_start = skip + rplen;
972 /* Allocate IPsec-specific opaque crypto info. */
973 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
977 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
978 AHSTAT_INC(ahs_crypto);
983 /* Save the skipped portion of the packet. */
984 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
987 * Fix IP header length on the header used for
988 * authentication. We don't need to fix the original
989 * header length as it will be fixed by our caller.
991 switch (sav->sah->saidx.dst.sa.sa_family) {
994 bcopy(((caddr_t)(xd + 1)) +
995 offsetof(struct ip, ip_len),
996 (caddr_t) &iplen, sizeof(u_int16_t));
997 iplen = htons(ntohs(iplen) + ahsize);
998 m_copyback(m, offsetof(struct ip, ip_len),
999 sizeof(u_int16_t), (caddr_t) &iplen);
1005 bcopy(((caddr_t)(xd + 1)) +
1006 offsetof(struct ip6_hdr, ip6_plen),
1007 (caddr_t) &iplen, sizeof(uint16_t));
1008 iplen = htons(ntohs(iplen) + ahsize);
1009 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1010 sizeof(uint16_t), (caddr_t) &iplen);
1015 /* Fix the Next Header field in saved header. */
1016 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1018 /* Update the Next Protocol field in the IP header. */
1020 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1022 /* "Massage" the packet headers for crypto processing. */
1023 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1024 skip, ahx->type, 1);
1026 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1028 crypto_freereq(crp);
1032 /* Crypto operation descriptor. */
1033 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
1034 crp->crp_flags = CRYPTO_F_CBIFSYNC;
1036 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1037 crypto_use_mbuf(crp, m);
1038 crp->crp_callback = ah_output_cb;
1039 crp->crp_opaque = xd;
1041 /* These are passed as-is to the callback. */
1046 xd->cryptoid = cryptoid;
1049 return crypto_dispatch(crp);
1059 * AH output callback from the crypto driver.
1062 ah_output_cb(struct cryptop *crp)
1064 struct xform_data *xd;
1065 struct secpolicy *sp;
1066 struct secasvar *sav;
1068 crypto_session_t cryptoid;
1073 m = crp->crp_buf.cb_mbuf;
1074 xd = (struct xform_data *) crp->crp_opaque;
1075 CURVNET_SET(xd->vnet);
1080 cryptoid = xd->cryptoid;
1081 ptr = (caddr_t) (xd + 1);
1083 /* Check for crypto errors. */
1084 if (crp->crp_etype) {
1085 if (crp->crp_etype == EAGAIN) {
1086 /* Reset the session ID */
1087 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1088 crypto_freesession(cryptoid);
1089 xd->cryptoid = crp->crp_session;
1091 return (crypto_dispatch(crp));
1093 AHSTAT_INC(ahs_noxform);
1094 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1095 error = crp->crp_etype;
1100 /* Shouldn't happen... */
1102 AHSTAT_INC(ahs_crypto);
1103 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1108 * Copy original headers (with the new protocol number) back
1111 m_copyback(m, 0, skip, ptr);
1114 crypto_freereq(crp);
1115 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1117 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1118 if (V_ipsec_integrity) {
1122 * Corrupt HMAC if we want to test integrity verification of
1125 alen = AUTHSIZE(sav);
1126 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1130 /* NB: m is reclaimed by ipsec_process_done. */
1131 error = ipsec_process_done(m, sp, sav, idx);
1137 crypto_freereq(crp);
1143 static struct xformsw ah_xformsw = {
1145 .xf_name = "IPsec AH",
1147 .xf_zeroize = ah_zeroize,
1148 .xf_input = ah_input,
1149 .xf_output = ah_output,
1152 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1153 xform_attach, &ah_xformsw);
1154 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1155 xform_detach, &ah_xformsw);