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>
45 #include <sys/malloc.h>
47 #include <sys/socket.h>
48 #include <sys/syslog.h>
49 #include <sys/kernel.h>
51 #include <sys/mutex.h>
52 #include <sys/sysctl.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/xform.h>
69 #include <netinet6/ip6_var.h>
70 #include <netipsec/ipsec6.h>
71 #include <netinet6/ip6_ecn.h>
74 #include <netipsec/key.h>
75 #include <netipsec/key_debug.h>
77 #include <opencrypto/cryptodev.h>
80 * Return header size in bytes. The old protocol did not support
81 * the replay counter; the new protocol always includes the counter.
83 #define HDRSIZE(sav) \
84 (((sav)->flags & SADB_X_EXT_OLD) ? \
85 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
87 * Return authenticator size in bytes, based on a field in the
88 * algorithm descriptor.
90 #define AUTHSIZE(sav) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \
91 xform_ah_authsize((sav)->tdb_authalgxform))
93 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
94 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
95 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
96 VNET_PCPUSTAT_SYSINIT(ahstat);
99 VNET_PCPUSTAT_SYSUNINIT(ahstat);
103 SYSCTL_DECL(_net_inet_ah);
104 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable,
105 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
106 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos,
107 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
108 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
109 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
112 static MALLOC_DEFINE(M_AH, "ah", "IPsec AH");
114 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
116 static int ah_input_cb(struct cryptop*);
117 static int ah_output_cb(struct cryptop*);
120 xform_ah_authsize(const struct auth_hash *esph)
127 switch (esph->type) {
128 case CRYPTO_SHA2_256_HMAC:
129 case CRYPTO_SHA2_384_HMAC:
130 case CRYPTO_SHA2_512_HMAC:
131 alen = esph->hashsize / 2; /* RFC4868 2.3 */
134 case CRYPTO_AES_NIST_GMAC:
135 alen = esph->hashsize;
139 alen = AH_HMAC_HASHLEN;
147 ah_hdrsiz(struct secasvar *sav)
152 int authsize, rplen, align;
154 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
155 /*XXX not right for null algorithm--does it matter??*/
157 /* RFC4302: use the correct alignment. */
158 align = sizeof(uint32_t);
160 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
161 align = sizeof(uint64_t);
164 rplen = HDRSIZE(sav);
165 authsize = AUTHSIZE(sav);
166 size = roundup(rplen + authsize, align);
169 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
175 * NB: public for use by esp_init.
178 ah_init0(struct secasvar *sav, struct xformsw *xsp,
179 struct crypto_session_params *csp)
181 const struct auth_hash *thash;
184 thash = auth_algorithm_lookup(sav->alg_auth);
186 DPRINTF(("%s: unsupported authentication algorithm %u\n",
187 __func__, sav->alg_auth));
192 * Verify the replay state block allocation is consistent with
193 * the protocol type. We check here so we can make assumptions
194 * later during protocol processing.
196 /* NB: replay state is setup elsewhere (sigh) */
197 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
198 DPRINTF(("%s: replay state block inconsistency, "
199 "%s algorithm %s replay state\n", __func__,
200 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
201 sav->replay == NULL ? "without" : "with"));
204 if (sav->key_auth == NULL) {
205 DPRINTF(("%s: no authentication key for %s algorithm\n",
206 __func__, thash->name));
209 keylen = _KEYLEN(sav->key_auth);
210 if (keylen > thash->keysize && thash->keysize != 0) {
211 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
212 "keysize less than %d\n", __func__,
213 keylen, thash->name, thash->keysize));
217 sav->tdb_xform = xsp;
218 sav->tdb_authalgxform = thash;
220 /* Initialize crypto session. */
221 csp->csp_auth_alg = sav->tdb_authalgxform->type;
222 if (csp->csp_auth_alg != CRYPTO_NULL_HMAC) {
223 csp->csp_auth_klen = _KEYBITS(sav->key_auth) / 8;
224 csp->csp_auth_key = sav->key_auth->key_data;
226 csp->csp_auth_mlen = AUTHSIZE(sav);
232 * ah_init() is called when an SPI is being set up.
235 ah_init(struct secasvar *sav, struct xformsw *xsp)
237 struct crypto_session_params csp;
240 memset(&csp, 0, sizeof(csp));
241 csp.csp_mode = CSP_MODE_DIGEST;
243 if (sav->flags & SADB_X_SAFLAGS_ESN)
244 csp.csp_flags |= CSP_F_ESN;
246 error = ah_init0(sav, xsp, &csp);
247 return error ? error :
248 crypto_newsession(&sav->tdb_cryptoid, &csp, V_crypto_support);
252 ah_cleanup(struct secasvar *sav)
255 crypto_freesession(sav->tdb_cryptoid);
256 sav->tdb_cryptoid = NULL;
257 sav->tdb_authalgxform = 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 *);
300 ip->ip_off = htons(0);
302 ptr = mtod(m, unsigned char *);
304 /* IPv4 option processing */
305 for (off = sizeof(struct ip); off < skip;) {
306 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
310 DPRINTF(("%s: illegal IPv4 option length for "
311 "option %d\n", __func__, ptr[off]));
319 off = skip; /* End the loop. */
326 case IPOPT_SECURITY: /* 0x82 */
327 case 0x85: /* Extended security. */
328 case 0x86: /* Commercial security. */
329 case 0x94: /* Router alert */
330 case 0x95: /* RFC1770 */
331 /* Sanity check for option length. */
332 if (ptr[off + 1] < 2) {
333 DPRINTF(("%s: illegal IPv4 option "
334 "length for option %d\n",
335 __func__, ptr[off]));
346 /* Sanity check for option length. */
347 if (ptr[off + 1] < 2) {
348 DPRINTF(("%s: illegal IPv4 option "
349 "length for option %d\n",
350 __func__, ptr[off]));
357 * On output, if we have either of the
358 * source routing options, we should
359 * swap the destination address of the
360 * IP header with the last address
361 * specified in the option, as that is
362 * what the destination's IP header
366 bcopy(ptr + off + ptr[off + 1] -
367 sizeof(struct in_addr),
368 &(ip->ip_dst), sizeof(struct in_addr));
372 /* Sanity check for option length. */
373 if (ptr[off + 1] < 2) {
374 DPRINTF(("%s: illegal IPv4 option "
375 "length for option %d\n",
376 __func__, ptr[off]));
381 /* Zeroize all other options. */
382 count = ptr[off + 1];
383 bcopy(ipseczeroes, ptr + off, count);
390 DPRINTF(("%s: malformed IPv4 options header\n",
402 case AF_INET6: /* Ugly... */
403 /* Copy and "cook" the IPv6 header. */
404 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
406 /* We don't do IPv6 Jumbograms. */
407 if (ip6.ip6_plen == 0) {
408 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
415 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
416 ip6.ip6_vfc |= IPV6_VERSION;
418 /* Scoped address handling. */
419 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
420 ip6.ip6_src.s6_addr16[1] = 0;
421 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
422 ip6.ip6_dst.s6_addr16[1] = 0;
424 /* Done with IPv6 header. */
425 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
427 /* Let's deal with the remaining headers (if any). */
428 if (skip - sizeof(struct ip6_hdr) > 0) {
429 if (m->m_len <= skip) {
430 ptr = (unsigned char *) malloc(
431 skip - sizeof(struct ip6_hdr),
434 DPRINTF(("%s: failed to allocate memory"
435 "for IPv6 headers\n",__func__));
441 * Copy all the protocol headers after
444 m_copydata(m, sizeof(struct ip6_hdr),
445 skip - sizeof(struct ip6_hdr), ptr);
448 /* No need to allocate memory. */
449 ptr = mtod(m, unsigned char *) +
450 sizeof(struct ip6_hdr);
456 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
458 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
460 case IPPROTO_HOPOPTS:
461 case IPPROTO_DSTOPTS:
462 ip6e = (struct ip6_ext *)(ptr + off);
463 noff = off + ((ip6e->ip6e_len + 1) << 3);
466 if (noff > skip - sizeof(struct ip6_hdr))
470 * Zero out mutable options.
472 for (count = off + sizeof(struct ip6_ext);
474 if (ptr[count] == IP6OPT_PAD1) {
476 continue; /* Skip padding. */
479 ad = ptr[count + 1] + 2;
480 if (count + ad > noff)
483 if (ptr[count] & IP6OPT_MUTABLE)
484 memset(ptr + count, 0, ad);
492 off += ((ip6e->ip6e_len + 1) << 3);
493 nxt = ip6e->ip6e_nxt;
496 case IPPROTO_ROUTING:
498 * Always include routing headers in
501 ip6e = (struct ip6_ext *) (ptr + off);
502 off += ((ip6e->ip6e_len + 1) << 3);
503 nxt = ip6e->ip6e_nxt;
507 DPRINTF(("%s: unexpected IPv6 header type %d",
516 /* Copyback and free, if we allocated. */
518 m_copyback(m, sizeof(struct ip6_hdr),
519 skip - sizeof(struct ip6_hdr), ptr);
531 * ah_input() gets called to verify that an input packet
532 * passes authentication.
535 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
537 IPSEC_DEBUG_DECLARE(char buf[128]);
538 const struct auth_hash *ahx;
540 struct xform_data *xd;
542 crypto_session_t cryptoid;
543 int hl, rplen, authsize, ahsize, error;
546 IPSEC_ASSERT(sav != NULL, ("null SA"));
547 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
548 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
549 ("null authentication xform"));
551 /* Figure out header size. */
552 rplen = HDRSIZE(sav);
554 if (m->m_len < skip + rplen) {
555 m = m_pullup(m, skip + rplen);
557 DPRINTF(("ah_input: cannot pullup header\n"));
558 AHSTAT_INC(ahs_hdrops); /*XXX*/
563 ah = (struct newah *)(mtod(m, caddr_t) + skip);
565 /* Check replay window, if applicable. */
567 if (sav->replay != NULL && sav->replay->wsize != 0 &&
568 ipsec_chkreplay(ntohl(ah->ah_seq), &seqh, sav) == 0) {
569 SECASVAR_UNLOCK(sav);
570 AHSTAT_INC(ahs_replay);
571 DPRINTF(("%s: packet replay failure: %s\n", __func__,
572 ipsec_sa2str(sav, buf, sizeof(buf))));
576 cryptoid = sav->tdb_cryptoid;
577 SECASVAR_UNLOCK(sav);
579 /* Verify AH header length. */
580 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
581 ahx = sav->tdb_authalgxform;
582 authsize = AUTHSIZE(sav);
583 ahsize = ah_hdrsiz(sav);
585 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
586 " for packet in SA %s/%08lx\n", __func__, hl,
588 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
589 (u_long) ntohl(sav->spi)));
590 AHSTAT_INC(ahs_badauthl);
594 if (skip + ahsize > m->m_pkthdr.len) {
595 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
596 " for packet in SA %s/%08lx\n", __func__,
597 m->m_pkthdr.len, (u_long)(skip + ahsize),
598 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
599 (u_long) ntohl(sav->spi)));
600 AHSTAT_INC(ahs_badauthl);
604 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
606 /* Get crypto descriptors. */
607 crp = crypto_getreq(cryptoid, M_NOWAIT);
609 DPRINTF(("%s: failed to acquire crypto descriptor\n",
611 AHSTAT_INC(ahs_crypto);
616 crp->crp_payload_start = 0;
617 crp->crp_payload_length = m->m_pkthdr.len;
618 crp->crp_digest_start = skip + rplen;
620 /* Allocate IPsec-specific opaque crypto info. */
621 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_AH,
624 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
625 AHSTAT_INC(ahs_crypto);
632 * Save the authenticator, the skipped portion of the packet,
635 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
637 /* Zeroize the authenticator on the packet. */
638 m_copyback(m, skip + rplen, authsize, ipseczeroes);
640 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
643 /* "Massage" the packet headers for crypto processing. */
644 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
647 /* NB: mbuf is free'd by ah_massage_headers */
648 AHSTAT_INC(ahs_hdrops);
655 /* Crypto operation descriptor. */
656 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
657 crp->crp_flags = CRYPTO_F_CBIFSYNC;
658 crypto_use_mbuf(crp, m);
659 crp->crp_callback = ah_input_cb;
660 crp->crp_opaque = xd;
662 if (sav->flags & SADB_X_SAFLAGS_ESN &&
663 sav->replay != NULL && sav->replay->wsize != 0) {
665 memcpy(crp->crp_esn, &seqh, sizeof(seqh));
668 /* These are passed as-is to the callback. */
671 xd->protoff = protoff;
673 xd->cryptoid = cryptoid;
676 return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
678 return (crypto_dispatch(crp));
686 * AH input callback from the crypto driver.
689 ah_input_cb(struct cryptop *crp)
691 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
692 unsigned char calc[AH_ALEN_MAX];
694 struct xform_data *xd;
695 struct secasvar *sav;
696 struct secasindex *saidx;
698 crypto_session_t cryptoid;
699 int authsize, rplen, ahsize, error, skip, protoff;
702 m = crp->crp_buf.cb_mbuf;
703 xd = crp->crp_opaque;
704 CURVNET_SET(xd->vnet);
708 protoff = xd->protoff;
709 cryptoid = xd->cryptoid;
710 saidx = &sav->sah->saidx;
711 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
712 saidx->dst.sa.sa_family == AF_INET6,
713 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
715 /* Check for crypto errors. */
716 if (crp->crp_etype) {
717 if (crp->crp_etype == EAGAIN) {
718 /* Reset the session ID */
719 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
720 crypto_freesession(cryptoid);
721 xd->cryptoid = crp->crp_session;
723 return (crypto_dispatch(crp));
725 AHSTAT_INC(ahs_noxform);
726 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
727 error = crp->crp_etype;
730 AHSTAT_INC(ahs_hist[sav->alg_auth]);
731 crypto_freereq(crp); /* No longer needed. */
735 /* Shouldn't happen... */
737 AHSTAT_INC(ahs_crypto);
738 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
743 /* Figure out header size. */
744 rplen = HDRSIZE(sav);
745 authsize = AUTHSIZE(sav);
746 ahsize = ah_hdrsiz(sav);
748 /* Copy authenticator off the packet. */
749 m_copydata(m, skip + rplen, authsize, calc);
751 /* Verify authenticator. */
752 ptr = (caddr_t) (xd + 1);
753 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
754 DPRINTF(("%s: authentication hash mismatch for packet "
755 "in SA %s/%08lx\n", __func__,
756 ipsec_address(&saidx->dst, buf, sizeof(buf)),
757 (u_long) ntohl(sav->spi)));
758 AHSTAT_INC(ahs_badauth);
762 /* Fix the Next Protocol field. */
763 ((uint8_t *) ptr)[protoff] = nxt;
765 /* Copyback the saved (uncooked) network headers. */
766 m_copyback(m, 0, skip, ptr);
767 free(xd, M_AH), xd = NULL; /* No longer needed */
770 * Header is now authenticated.
772 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
775 * Update replay sequence number, if appropriate.
780 m_copydata(m, skip + offsetof(struct newah, ah_seq),
781 sizeof (seq), (caddr_t) &seq);
783 if (ipsec_updatereplay(ntohl(seq), sav)) {
784 SECASVAR_UNLOCK(sav);
785 AHSTAT_INC(ahs_replay);
789 SECASVAR_UNLOCK(sav);
793 * Remove the AH header and authenticator from the mbuf.
795 error = m_striphdr(m, skip, ahsize);
797 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
798 ipsec_address(&saidx->dst, buf, sizeof(buf)),
799 (u_long) ntohl(sav->spi)));
800 AHSTAT_INC(ahs_hdrops);
804 switch (saidx->dst.sa.sa_family) {
807 error = ipsec6_common_input_cb(m, sav, skip, protoff);
812 error = ipsec4_common_input_cb(m, sav, skip, protoff);
816 panic("%s: Unexpected address family: %d saidx=%p", __func__,
817 saidx->dst.sa.sa_family, saidx);
835 * AH output routine, called by ipsec[46]_perform_request().
838 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
839 u_int idx, int skip, int protoff)
841 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
842 const struct auth_hash *ahx;
843 struct xform_data *xd;
847 crypto_session_t cryptoid;
849 int error, rplen, authsize, ahsize, maxpacketsize, roff;
853 IPSEC_ASSERT(sav != NULL, ("null SA"));
854 ahx = sav->tdb_authalgxform;
855 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
857 AHSTAT_INC(ahs_output);
859 /* Figure out header size. */
860 rplen = HDRSIZE(sav);
861 authsize = AUTHSIZE(sav);
862 ahsize = ah_hdrsiz(sav);
864 /* Check for maximum packet size violations. */
865 switch (sav->sah->saidx.dst.sa.sa_family) {
868 maxpacketsize = IP_MAXPACKET;
873 maxpacketsize = IPV6_MAXPACKET;
877 DPRINTF(("%s: unknown/unsupported protocol family %u, "
878 "SA %s/%08lx\n", __func__,
879 sav->sah->saidx.dst.sa.sa_family,
880 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
881 (u_long) ntohl(sav->spi)));
882 AHSTAT_INC(ahs_nopf);
883 error = EPFNOSUPPORT;
886 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
887 DPRINTF(("%s: packet in SA %s/%08lx got too big "
888 "(len %u, max len %u)\n", __func__,
889 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
890 (u_long) ntohl(sav->spi),
891 ahsize + m->m_pkthdr.len, maxpacketsize));
892 AHSTAT_INC(ahs_toobig);
897 /* Update the counters. */
898 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
900 m = m_unshare(m, M_NOWAIT);
902 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
903 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
904 (u_long) ntohl(sav->spi)));
905 AHSTAT_INC(ahs_hdrops);
910 /* Inject AH header. */
911 mi = m_makespace(m, skip, ahsize, &roff);
913 DPRINTF(("%s: failed to inject %u byte AH header for SA "
914 "%s/%08lx\n", __func__, ahsize,
915 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
916 (u_long) ntohl(sav->spi)));
917 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
923 * The AH header is guaranteed by m_makespace() to be in
924 * contiguous memory, at roff bytes offset into the returned mbuf.
926 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
928 /* Initialize the AH header. */
929 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
930 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
932 ah->ah_spi = sav->spi;
934 /* Zeroize authenticator. */
935 m_copyback(m, skip + rplen, authsize, ipseczeroes);
937 /* Zeroize padding */
938 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
941 /* Insert packet replay counter, as requested. */
944 if ((sav->replay->count == ~0 ||
945 (!(sav->flags & SADB_X_SAFLAGS_ESN) &&
946 ((uint32_t)sav->replay->count) == ~0)) &&
947 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
948 SECASVAR_UNLOCK(sav);
949 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
950 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
951 sizeof(buf)), (u_long) ntohl(sav->spi)));
952 AHSTAT_INC(ahs_wrap);
957 /* Emulate replay attack when ipsec_replay is TRUE. */
960 sav->replay->count++;
961 ah->ah_seq = htonl((uint32_t)sav->replay->count);
963 cryptoid = sav->tdb_cryptoid;
964 SECASVAR_UNLOCK(sav);
966 /* Get crypto descriptors. */
967 crp = crypto_getreq(cryptoid, M_NOWAIT);
969 DPRINTF(("%s: failed to acquire crypto descriptors\n",
971 AHSTAT_INC(ahs_crypto);
976 crp->crp_payload_start = 0;
977 crp->crp_payload_length = m->m_pkthdr.len;
978 crp->crp_digest_start = skip + rplen;
980 /* Allocate IPsec-specific opaque crypto info. */
981 xd = malloc(sizeof(struct xform_data) + skip, M_AH,
985 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
986 AHSTAT_INC(ahs_crypto);
991 /* Save the skipped portion of the packet. */
992 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
995 * Fix IP header length on the header used for
996 * authentication. We don't need to fix the original
997 * header length as it will be fixed by our caller.
999 switch (sav->sah->saidx.dst.sa.sa_family) {
1002 bcopy(((caddr_t)(xd + 1)) +
1003 offsetof(struct ip, ip_len),
1004 (caddr_t) &iplen, sizeof(u_int16_t));
1005 iplen = htons(ntohs(iplen) + ahsize);
1006 m_copyback(m, offsetof(struct ip, ip_len),
1007 sizeof(u_int16_t), (caddr_t) &iplen);
1013 bcopy(((caddr_t)(xd + 1)) +
1014 offsetof(struct ip6_hdr, ip6_plen),
1015 (caddr_t) &iplen, sizeof(uint16_t));
1016 iplen = htons(ntohs(iplen) + ahsize);
1017 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1018 sizeof(uint16_t), (caddr_t) &iplen);
1023 /* Fix the Next Header field in saved header. */
1024 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1026 /* Update the Next Protocol field in the IP header. */
1028 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1030 /* "Massage" the packet headers for crypto processing. */
1031 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1032 skip, ahx->type, 1);
1034 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1036 crypto_freereq(crp);
1040 /* Crypto operation descriptor. */
1041 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
1042 crp->crp_flags = CRYPTO_F_CBIFSYNC;
1043 crypto_use_mbuf(crp, m);
1044 crp->crp_callback = ah_output_cb;
1045 crp->crp_opaque = xd;
1047 if (sav->flags & SADB_X_SAFLAGS_ESN && sav->replay != NULL) {
1048 seqh = htonl((uint32_t)(sav->replay->count >> IPSEC_SEQH_SHIFT));
1049 memcpy(crp->crp_esn, &seqh, sizeof(seqh));
1052 /* These are passed as-is to the callback. */
1057 xd->cryptoid = cryptoid;
1061 return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
1063 return (crypto_dispatch(crp));
1073 * AH output callback from the crypto driver.
1076 ah_output_cb(struct cryptop *crp)
1078 struct xform_data *xd;
1079 struct secpolicy *sp;
1080 struct secasvar *sav;
1082 crypto_session_t cryptoid;
1087 m = crp->crp_buf.cb_mbuf;
1088 xd = (struct xform_data *) crp->crp_opaque;
1089 CURVNET_SET(xd->vnet);
1094 cryptoid = xd->cryptoid;
1095 ptr = (caddr_t) (xd + 1);
1097 /* Check for crypto errors. */
1098 if (crp->crp_etype) {
1099 if (crp->crp_etype == EAGAIN) {
1100 /* Reset the session ID */
1101 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1102 crypto_freesession(cryptoid);
1103 xd->cryptoid = crp->crp_session;
1105 return (crypto_dispatch(crp));
1107 AHSTAT_INC(ahs_noxform);
1108 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1109 error = crp->crp_etype;
1114 /* Shouldn't happen... */
1116 AHSTAT_INC(ahs_crypto);
1117 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1122 * Copy original headers (with the new protocol number) back
1125 m_copyback(m, 0, skip, ptr);
1128 crypto_freereq(crp);
1129 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1131 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1132 if (V_ipsec_integrity) {
1136 * Corrupt HMAC if we want to test integrity verification of
1139 alen = AUTHSIZE(sav);
1140 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1144 /* NB: m is reclaimed by ipsec_process_done. */
1145 error = ipsec_process_done(m, sp, sav, idx);
1151 crypto_freereq(crp);
1157 static struct xformsw ah_xformsw = {
1159 .xf_name = "IPsec AH",
1161 .xf_cleanup = ah_cleanup,
1162 .xf_input = ah_input,
1163 .xf_output = ah_output,
1166 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1167 xform_attach, &ah_xformsw);
1168 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1169 xform_detach, &ah_xformsw);