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)
251 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
253 err = crypto_freesession(sav->tdb_cryptoid);
254 sav->tdb_cryptoid = 0;
255 sav->tdb_authalgxform = NULL;
256 sav->tdb_xform = NULL;
261 * Massage IPv4/IPv6 headers for AH processing.
264 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
266 struct mbuf *m = *m0;
275 struct ip6_ext *ip6e;
277 int ad, alloc, nxt, noff;
284 * This is the least painful way of dealing with IPv4 header
285 * and option processing -- just make sure they're in
288 *m0 = m = m_pullup(m, skip);
290 DPRINTF(("%s: m_pullup failed\n", __func__));
294 /* Fix the IP header */
295 ip = mtod(m, struct ip *);
301 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
302 ip->ip_off &= htons(IP_DF);
304 ip->ip_off = htons(0);
306 ptr = mtod(m, unsigned char *);
308 /* IPv4 option processing */
309 for (off = sizeof(struct ip); off < skip;) {
310 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
314 DPRINTF(("%s: illegal IPv4 option length for "
315 "option %d\n", __func__, ptr[off]));
323 off = skip; /* End the loop. */
330 case IPOPT_SECURITY: /* 0x82 */
331 case 0x85: /* Extended security. */
332 case 0x86: /* Commercial security. */
333 case 0x94: /* Router alert */
334 case 0x95: /* RFC1770 */
335 /* Sanity check for option length. */
336 if (ptr[off + 1] < 2) {
337 DPRINTF(("%s: illegal IPv4 option "
338 "length for option %d\n",
339 __func__, ptr[off]));
350 /* Sanity check for option length. */
351 if (ptr[off + 1] < 2) {
352 DPRINTF(("%s: illegal IPv4 option "
353 "length for option %d\n",
354 __func__, ptr[off]));
361 * On output, if we have either of the
362 * source routing options, we should
363 * swap the destination address of the
364 * IP header with the last address
365 * specified in the option, as that is
366 * what the destination's IP header
370 bcopy(ptr + off + ptr[off + 1] -
371 sizeof(struct in_addr),
372 &(ip->ip_dst), sizeof(struct in_addr));
376 /* Sanity check for option length. */
377 if (ptr[off + 1] < 2) {
378 DPRINTF(("%s: illegal IPv4 option "
379 "length for option %d\n",
380 __func__, ptr[off]));
385 /* Zeroize all other options. */
386 count = ptr[off + 1];
387 bcopy(ipseczeroes, ptr + off, count);
394 DPRINTF(("%s: malformed IPv4 options header\n",
406 case AF_INET6: /* Ugly... */
407 /* Copy and "cook" the IPv6 header. */
408 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
410 /* We don't do IPv6 Jumbograms. */
411 if (ip6.ip6_plen == 0) {
412 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
419 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
420 ip6.ip6_vfc |= IPV6_VERSION;
422 /* Scoped address handling. */
423 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
424 ip6.ip6_src.s6_addr16[1] = 0;
425 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
426 ip6.ip6_dst.s6_addr16[1] = 0;
428 /* Done with IPv6 header. */
429 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
431 /* Let's deal with the remaining headers (if any). */
432 if (skip - sizeof(struct ip6_hdr) > 0) {
433 if (m->m_len <= skip) {
434 ptr = (unsigned char *) malloc(
435 skip - sizeof(struct ip6_hdr),
438 DPRINTF(("%s: failed to allocate memory"
439 "for IPv6 headers\n",__func__));
445 * Copy all the protocol headers after
448 m_copydata(m, sizeof(struct ip6_hdr),
449 skip - sizeof(struct ip6_hdr), ptr);
452 /* No need to allocate memory. */
453 ptr = mtod(m, unsigned char *) +
454 sizeof(struct ip6_hdr);
460 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
462 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
464 case IPPROTO_HOPOPTS:
465 case IPPROTO_DSTOPTS:
466 ip6e = (struct ip6_ext *)(ptr + off);
467 noff = off + ((ip6e->ip6e_len + 1) << 3);
470 if (noff > skip - sizeof(struct ip6_hdr))
474 * Zero out mutable options.
476 for (count = off + sizeof(struct ip6_ext);
478 if (ptr[count] == IP6OPT_PAD1) {
480 continue; /* Skip padding. */
483 ad = ptr[count + 1] + 2;
484 if (count + ad > noff)
487 if (ptr[count] & IP6OPT_MUTABLE)
488 memset(ptr + count, 0, ad);
496 off += ((ip6e->ip6e_len + 1) << 3);
497 nxt = ip6e->ip6e_nxt;
500 case IPPROTO_ROUTING:
502 * Always include routing headers in
505 ip6e = (struct ip6_ext *) (ptr + off);
506 off += ((ip6e->ip6e_len + 1) << 3);
507 nxt = ip6e->ip6e_nxt;
511 DPRINTF(("%s: unexpected IPv6 header type %d",
520 /* Copyback and free, if we allocated. */
522 m_copyback(m, sizeof(struct ip6_hdr),
523 skip - sizeof(struct ip6_hdr), ptr);
535 * ah_input() gets called to verify that an input packet
536 * passes authentication.
539 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
541 IPSEC_DEBUG_DECLARE(char buf[128]);
542 const struct auth_hash *ahx;
543 struct cryptodesc *crda;
545 struct xform_data *xd;
548 int hl, rplen, authsize, ahsize, error;
550 IPSEC_ASSERT(sav != NULL, ("null SA"));
551 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
552 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
553 ("null authentication xform"));
555 /* Figure out header size. */
556 rplen = HDRSIZE(sav);
558 /* XXX don't pullup, just copy header */
559 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
561 DPRINTF(("ah_input: cannot pullup header\n"));
562 AHSTAT_INC(ahs_hdrops); /*XXX*/
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(1);
611 DPRINTF(("%s: failed to acquire crypto descriptor\n",
613 AHSTAT_INC(ahs_crypto);
618 crda = crp->crp_desc;
619 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
622 crda->crd_len = m->m_pkthdr.len;
623 crda->crd_inject = skip + rplen;
625 /* Authentication operation. */
626 crda->crd_alg = ahx->type;
627 crda->crd_klen = _KEYBITS(sav->key_auth);
628 crda->crd_key = sav->key_auth->key_data;
630 /* Allocate IPsec-specific opaque crypto info. */
631 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
634 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
635 AHSTAT_INC(ahs_crypto);
642 * Save the authenticator, the skipped portion of the packet,
645 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
647 /* Zeroize the authenticator on the packet. */
648 m_copyback(m, skip + rplen, authsize, ipseczeroes);
650 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
653 /* "Massage" the packet headers for crypto processing. */
654 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
657 /* NB: mbuf is free'd by ah_massage_headers */
658 AHSTAT_INC(ahs_hdrops);
665 /* Crypto operation descriptor. */
666 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
667 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
669 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
670 crp->crp_buf = (caddr_t) m;
671 crp->crp_callback = ah_input_cb;
672 crp->crp_sid = cryptoid;
673 crp->crp_opaque = (caddr_t) xd;
675 /* These are passed as-is to the callback. */
678 xd->protoff = protoff;
680 xd->cryptoid = cryptoid;
682 return (crypto_dispatch(crp));
690 * AH input callback from the crypto driver.
693 ah_input_cb(struct cryptop *crp)
695 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
696 unsigned char calc[AH_ALEN_MAX];
698 struct xform_data *xd;
699 struct secasvar *sav;
700 struct secasindex *saidx;
703 int authsize, rplen, ahsize, error, skip, protoff;
706 m = (struct mbuf *) crp->crp_buf;
707 xd = (struct xform_data *) crp->crp_opaque;
708 CURVNET_SET(xd->vnet);
712 protoff = xd->protoff;
713 cryptoid = xd->cryptoid;
714 saidx = &sav->sah->saidx;
715 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
716 saidx->dst.sa.sa_family == AF_INET6,
717 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
719 /* Check for crypto errors. */
720 if (crp->crp_etype) {
721 if (crp->crp_etype == EAGAIN) {
722 /* Reset the session ID */
723 if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0)
724 crypto_freesession(cryptoid);
725 xd->cryptoid = crp->crp_sid;
727 return (crypto_dispatch(crp));
729 AHSTAT_INC(ahs_noxform);
730 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
731 error = crp->crp_etype;
734 AHSTAT_INC(ahs_hist[sav->alg_auth]);
735 crypto_freereq(crp); /* No longer needed. */
739 /* Shouldn't happen... */
741 AHSTAT_INC(ahs_crypto);
742 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
747 /* Figure out header size. */
748 rplen = HDRSIZE(sav);
749 authsize = AUTHSIZE(sav);
750 ahsize = ah_hdrsiz(sav);
752 /* Copy authenticator off the packet. */
753 m_copydata(m, skip + rplen, authsize, calc);
755 /* Verify authenticator. */
756 ptr = (caddr_t) (xd + 1);
757 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
758 DPRINTF(("%s: authentication hash mismatch for packet "
759 "in SA %s/%08lx\n", __func__,
760 ipsec_address(&saidx->dst, buf, sizeof(buf)),
761 (u_long) ntohl(sav->spi)));
762 AHSTAT_INC(ahs_badauth);
766 /* Fix the Next Protocol field. */
767 ((uint8_t *) ptr)[protoff] = nxt;
769 /* Copyback the saved (uncooked) network headers. */
770 m_copyback(m, 0, skip, ptr);
771 free(xd, M_XDATA), xd = NULL; /* No longer needed */
774 * Header is now authenticated.
776 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
779 * Update replay sequence number, if appropriate.
784 m_copydata(m, skip + offsetof(struct newah, ah_seq),
785 sizeof (seq), (caddr_t) &seq);
787 if (ipsec_updatereplay(ntohl(seq), sav)) {
788 SECASVAR_UNLOCK(sav);
789 AHSTAT_INC(ahs_replay);
793 SECASVAR_UNLOCK(sav);
797 * Remove the AH header and authenticator from the mbuf.
799 error = m_striphdr(m, skip, ahsize);
801 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
802 ipsec_address(&saidx->dst, buf, sizeof(buf)),
803 (u_long) ntohl(sav->spi)));
804 AHSTAT_INC(ahs_hdrops);
808 switch (saidx->dst.sa.sa_family) {
811 error = ipsec6_common_input_cb(m, sav, skip, protoff);
816 error = ipsec4_common_input_cb(m, sav, skip, protoff);
820 panic("%s: Unexpected address family: %d saidx=%p", __func__,
821 saidx->dst.sa.sa_family, saidx);
839 * AH output routine, called by ipsec[46]_perform_request().
842 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
843 u_int idx, int skip, int protoff)
845 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
846 const struct auth_hash *ahx;
847 struct cryptodesc *crda;
848 struct xform_data *xd;
854 int error, rplen, authsize, ahsize, maxpacketsize, roff;
857 IPSEC_ASSERT(sav != NULL, ("null SA"));
858 ahx = sav->tdb_authalgxform;
859 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
861 AHSTAT_INC(ahs_output);
863 /* Figure out header size. */
864 rplen = HDRSIZE(sav);
865 authsize = AUTHSIZE(sav);
866 ahsize = ah_hdrsiz(sav);
868 /* Check for maximum packet size violations. */
869 switch (sav->sah->saidx.dst.sa.sa_family) {
872 maxpacketsize = IP_MAXPACKET;
877 maxpacketsize = IPV6_MAXPACKET;
881 DPRINTF(("%s: unknown/unsupported protocol family %u, "
882 "SA %s/%08lx\n", __func__,
883 sav->sah->saidx.dst.sa.sa_family,
884 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
885 (u_long) ntohl(sav->spi)));
886 AHSTAT_INC(ahs_nopf);
887 error = EPFNOSUPPORT;
890 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
891 DPRINTF(("%s: packet in SA %s/%08lx got too big "
892 "(len %u, max len %u)\n", __func__,
893 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
894 (u_long) ntohl(sav->spi),
895 ahsize + m->m_pkthdr.len, maxpacketsize));
896 AHSTAT_INC(ahs_toobig);
901 /* Update the counters. */
902 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
904 m = m_unshare(m, M_NOWAIT);
906 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
907 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
908 (u_long) ntohl(sav->spi)));
909 AHSTAT_INC(ahs_hdrops);
914 /* Inject AH header. */
915 mi = m_makespace(m, skip, ahsize, &roff);
917 DPRINTF(("%s: failed to inject %u byte AH header for SA "
918 "%s/%08lx\n", __func__, ahsize,
919 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
920 (u_long) ntohl(sav->spi)));
921 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
927 * The AH header is guaranteed by m_makespace() to be in
928 * contiguous memory, at roff bytes offset into the returned mbuf.
930 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
932 /* Initialize the AH header. */
933 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
934 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
936 ah->ah_spi = sav->spi;
938 /* Zeroize authenticator. */
939 m_copyback(m, skip + rplen, authsize, ipseczeroes);
941 /* Zeroize padding */
942 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
945 /* Insert packet replay counter, as requested. */
948 if (sav->replay->count == ~0 &&
949 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
950 SECASVAR_UNLOCK(sav);
951 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
952 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
953 sizeof(buf)), (u_long) ntohl(sav->spi)));
954 AHSTAT_INC(ahs_wrap);
959 /* Emulate replay attack when ipsec_replay is TRUE. */
962 sav->replay->count++;
963 ah->ah_seq = htonl(sav->replay->count);
965 cryptoid = sav->tdb_cryptoid;
966 SECASVAR_UNLOCK(sav);
968 /* Get crypto descriptors. */
969 crp = crypto_getreq(1);
971 DPRINTF(("%s: failed to acquire crypto descriptors\n",
973 AHSTAT_INC(ahs_crypto);
978 crda = crp->crp_desc;
980 crda->crd_inject = skip + rplen;
981 crda->crd_len = m->m_pkthdr.len;
983 /* Authentication operation. */
984 crda->crd_alg = ahx->type;
985 crda->crd_key = sav->key_auth->key_data;
986 crda->crd_klen = _KEYBITS(sav->key_auth);
988 /* Allocate IPsec-specific opaque crypto info. */
989 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
993 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
994 AHSTAT_INC(ahs_crypto);
999 /* Save the skipped portion of the packet. */
1000 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
1003 * Fix IP header length on the header used for
1004 * authentication. We don't need to fix the original
1005 * header length as it will be fixed by our caller.
1007 switch (sav->sah->saidx.dst.sa.sa_family) {
1010 bcopy(((caddr_t)(xd + 1)) +
1011 offsetof(struct ip, ip_len),
1012 (caddr_t) &iplen, sizeof(u_int16_t));
1013 iplen = htons(ntohs(iplen) + ahsize);
1014 m_copyback(m, offsetof(struct ip, ip_len),
1015 sizeof(u_int16_t), (caddr_t) &iplen);
1021 bcopy(((caddr_t)(xd + 1)) +
1022 offsetof(struct ip6_hdr, ip6_plen),
1023 (caddr_t) &iplen, sizeof(uint16_t));
1024 iplen = htons(ntohs(iplen) + ahsize);
1025 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1026 sizeof(uint16_t), (caddr_t) &iplen);
1031 /* Fix the Next Header field in saved header. */
1032 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1034 /* Update the Next Protocol field in the IP header. */
1036 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1038 /* "Massage" the packet headers for crypto processing. */
1039 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1040 skip, ahx->type, 1);
1042 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1044 crypto_freereq(crp);
1048 /* Crypto operation descriptor. */
1049 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1050 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1052 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1053 crp->crp_buf = (caddr_t) m;
1054 crp->crp_callback = ah_output_cb;
1055 crp->crp_sid = cryptoid;
1056 crp->crp_opaque = (caddr_t) xd;
1058 /* These are passed as-is to the callback. */
1063 xd->cryptoid = cryptoid;
1066 return crypto_dispatch(crp);
1076 * AH output callback from the crypto driver.
1079 ah_output_cb(struct cryptop *crp)
1081 struct xform_data *xd;
1082 struct secpolicy *sp;
1083 struct secasvar *sav;
1090 m = (struct mbuf *) crp->crp_buf;
1091 xd = (struct xform_data *) crp->crp_opaque;
1092 CURVNET_SET(xd->vnet);
1097 cryptoid = xd->cryptoid;
1098 ptr = (caddr_t) (xd + 1);
1100 /* Check for crypto errors. */
1101 if (crp->crp_etype) {
1102 if (crp->crp_etype == EAGAIN) {
1103 /* Reset the session ID */
1104 if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0)
1105 crypto_freesession(cryptoid);
1106 xd->cryptoid = crp->crp_sid;
1108 return (crypto_dispatch(crp));
1110 AHSTAT_INC(ahs_noxform);
1111 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1112 error = crp->crp_etype;
1117 /* Shouldn't happen... */
1119 AHSTAT_INC(ahs_crypto);
1120 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1125 * Copy original headers (with the new protocol number) back
1128 m_copyback(m, 0, skip, ptr);
1131 crypto_freereq(crp);
1132 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1134 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1135 if (V_ipsec_integrity) {
1139 * Corrupt HMAC if we want to test integrity verification of
1142 alen = AUTHSIZE(sav);
1143 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1147 /* NB: m is reclaimed by ipsec_process_done. */
1148 error = ipsec_process_done(m, sp, sav, idx);
1154 crypto_freereq(crp);
1160 static struct xformsw ah_xformsw = {
1162 .xf_name = "IPsec AH",
1164 .xf_zeroize = ah_zeroize,
1165 .xf_input = ah_input,
1166 .xf_output = ah_output,
1169 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1170 xform_attach, &ah_xformsw);
1171 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1172 xform_detach, &ah_xformsw);