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);
245 ah_cleanup(struct secasvar *sav)
248 crypto_freesession(sav->tdb_cryptoid);
249 sav->tdb_cryptoid = NULL;
250 sav->tdb_authalgxform = NULL;
254 * Massage IPv4/IPv6 headers for AH processing.
257 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
259 struct mbuf *m = *m0;
268 struct ip6_ext *ip6e;
270 int ad, alloc, nxt, noff;
277 * This is the least painful way of dealing with IPv4 header
278 * and option processing -- just make sure they're in
281 *m0 = m = m_pullup(m, skip);
283 DPRINTF(("%s: m_pullup failed\n", __func__));
287 /* Fix the IP header */
288 ip = mtod(m, struct ip *);
293 ip->ip_off = htons(0);
295 ptr = mtod(m, unsigned char *);
297 /* IPv4 option processing */
298 for (off = sizeof(struct ip); off < skip;) {
299 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
303 DPRINTF(("%s: illegal IPv4 option length for "
304 "option %d\n", __func__, ptr[off]));
312 off = skip; /* End the loop. */
319 case IPOPT_SECURITY: /* 0x82 */
320 case 0x85: /* Extended security. */
321 case 0x86: /* Commercial security. */
322 case 0x94: /* Router alert */
323 case 0x95: /* RFC1770 */
324 /* Sanity check for option length. */
325 if (ptr[off + 1] < 2) {
326 DPRINTF(("%s: illegal IPv4 option "
327 "length for option %d\n",
328 __func__, ptr[off]));
339 /* Sanity check for option length. */
340 if (ptr[off + 1] < 2) {
341 DPRINTF(("%s: illegal IPv4 option "
342 "length for option %d\n",
343 __func__, ptr[off]));
350 * On output, if we have either of the
351 * source routing options, we should
352 * swap the destination address of the
353 * IP header with the last address
354 * specified in the option, as that is
355 * what the destination's IP header
359 bcopy(ptr + off + ptr[off + 1] -
360 sizeof(struct in_addr),
361 &(ip->ip_dst), sizeof(struct in_addr));
365 /* Sanity check for option length. */
366 if (ptr[off + 1] < 2) {
367 DPRINTF(("%s: illegal IPv4 option "
368 "length for option %d\n",
369 __func__, ptr[off]));
374 /* Zeroize all other options. */
375 count = ptr[off + 1];
376 bcopy(ipseczeroes, ptr + off, count);
383 DPRINTF(("%s: malformed IPv4 options header\n",
395 case AF_INET6: /* Ugly... */
396 /* Copy and "cook" the IPv6 header. */
397 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
399 /* We don't do IPv6 Jumbograms. */
400 if (ip6.ip6_plen == 0) {
401 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
408 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
409 ip6.ip6_vfc |= IPV6_VERSION;
411 /* Scoped address handling. */
412 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
413 ip6.ip6_src.s6_addr16[1] = 0;
414 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
415 ip6.ip6_dst.s6_addr16[1] = 0;
417 /* Done with IPv6 header. */
418 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
420 /* Let's deal with the remaining headers (if any). */
421 if (skip - sizeof(struct ip6_hdr) > 0) {
422 if (m->m_len <= skip) {
423 ptr = (unsigned char *) malloc(
424 skip - sizeof(struct ip6_hdr),
427 DPRINTF(("%s: failed to allocate memory"
428 "for IPv6 headers\n",__func__));
434 * Copy all the protocol headers after
437 m_copydata(m, sizeof(struct ip6_hdr),
438 skip - sizeof(struct ip6_hdr), ptr);
441 /* No need to allocate memory. */
442 ptr = mtod(m, unsigned char *) +
443 sizeof(struct ip6_hdr);
449 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
451 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
453 case IPPROTO_HOPOPTS:
454 case IPPROTO_DSTOPTS:
455 ip6e = (struct ip6_ext *)(ptr + off);
456 noff = off + ((ip6e->ip6e_len + 1) << 3);
459 if (noff > skip - sizeof(struct ip6_hdr))
463 * Zero out mutable options.
465 for (count = off + sizeof(struct ip6_ext);
467 if (ptr[count] == IP6OPT_PAD1) {
469 continue; /* Skip padding. */
472 ad = ptr[count + 1] + 2;
473 if (count + ad > noff)
476 if (ptr[count] & IP6OPT_MUTABLE)
477 memset(ptr + count, 0, ad);
485 off += ((ip6e->ip6e_len + 1) << 3);
486 nxt = ip6e->ip6e_nxt;
489 case IPPROTO_ROUTING:
491 * Always include routing headers in
494 ip6e = (struct ip6_ext *) (ptr + off);
495 off += ((ip6e->ip6e_len + 1) << 3);
496 nxt = ip6e->ip6e_nxt;
500 DPRINTF(("%s: unexpected IPv6 header type %d",
509 /* Copyback and free, if we allocated. */
511 m_copyback(m, sizeof(struct ip6_hdr),
512 skip - sizeof(struct ip6_hdr), ptr);
524 * ah_input() gets called to verify that an input packet
525 * passes authentication.
528 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
530 IPSEC_DEBUG_DECLARE(char buf[128]);
531 const struct auth_hash *ahx;
533 struct xform_data *xd;
535 crypto_session_t cryptoid;
536 int hl, rplen, authsize, ahsize, error;
538 IPSEC_ASSERT(sav != NULL, ("null SA"));
539 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
540 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
541 ("null authentication xform"));
543 /* Figure out header size. */
544 rplen = HDRSIZE(sav);
546 if (m->m_len < skip + rplen) {
547 m = m_pullup(m, skip + rplen);
549 DPRINTF(("ah_input: cannot pullup header\n"));
550 AHSTAT_INC(ahs_hdrops); /*XXX*/
555 ah = (struct newah *)(mtod(m, caddr_t) + skip);
557 /* Check replay window, if applicable. */
559 if (sav->replay != NULL && sav->replay->wsize != 0 &&
560 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) {
561 SECASVAR_UNLOCK(sav);
562 AHSTAT_INC(ahs_replay);
563 DPRINTF(("%s: packet replay failure: %s\n", __func__,
564 ipsec_sa2str(sav, buf, sizeof(buf))));
568 cryptoid = sav->tdb_cryptoid;
569 SECASVAR_UNLOCK(sav);
571 /* Verify AH header length. */
572 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
573 ahx = sav->tdb_authalgxform;
574 authsize = AUTHSIZE(sav);
575 ahsize = ah_hdrsiz(sav);
577 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
578 " for packet in SA %s/%08lx\n", __func__, hl,
580 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
581 (u_long) ntohl(sav->spi)));
582 AHSTAT_INC(ahs_badauthl);
586 if (skip + ahsize > m->m_pkthdr.len) {
587 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
588 " for packet in SA %s/%08lx\n", __func__,
589 m->m_pkthdr.len, (u_long)(skip + ahsize),
590 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
591 (u_long) ntohl(sav->spi)));
592 AHSTAT_INC(ahs_badauthl);
596 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
598 /* Get crypto descriptors. */
599 crp = crypto_getreq(cryptoid, M_NOWAIT);
601 DPRINTF(("%s: failed to acquire crypto descriptor\n",
603 AHSTAT_INC(ahs_crypto);
608 crp->crp_payload_start = 0;
609 crp->crp_payload_length = m->m_pkthdr.len;
610 crp->crp_digest_start = skip + rplen;
612 /* Allocate IPsec-specific opaque crypto info. */
613 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
616 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
617 AHSTAT_INC(ahs_crypto);
624 * Save the authenticator, the skipped portion of the packet,
627 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
629 /* Zeroize the authenticator on the packet. */
630 m_copyback(m, skip + rplen, authsize, ipseczeroes);
632 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
635 /* "Massage" the packet headers for crypto processing. */
636 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
639 /* NB: mbuf is free'd by ah_massage_headers */
640 AHSTAT_INC(ahs_hdrops);
647 /* Crypto operation descriptor. */
648 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
649 crp->crp_flags = CRYPTO_F_CBIFSYNC;
651 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
652 crypto_use_mbuf(crp, m);
653 crp->crp_callback = ah_input_cb;
654 crp->crp_opaque = xd;
656 /* These are passed as-is to the callback. */
659 xd->protoff = protoff;
661 xd->cryptoid = cryptoid;
663 return (crypto_dispatch(crp));
671 * AH input callback from the crypto driver.
674 ah_input_cb(struct cryptop *crp)
676 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
677 unsigned char calc[AH_ALEN_MAX];
679 struct xform_data *xd;
680 struct secasvar *sav;
681 struct secasindex *saidx;
683 crypto_session_t cryptoid;
684 int authsize, rplen, ahsize, error, skip, protoff;
687 m = crp->crp_buf.cb_mbuf;
688 xd = crp->crp_opaque;
689 CURVNET_SET(xd->vnet);
693 protoff = xd->protoff;
694 cryptoid = xd->cryptoid;
695 saidx = &sav->sah->saidx;
696 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
697 saidx->dst.sa.sa_family == AF_INET6,
698 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
700 /* Check for crypto errors. */
701 if (crp->crp_etype) {
702 if (crp->crp_etype == EAGAIN) {
703 /* Reset the session ID */
704 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
705 crypto_freesession(cryptoid);
706 xd->cryptoid = crp->crp_session;
708 return (crypto_dispatch(crp));
710 AHSTAT_INC(ahs_noxform);
711 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
712 error = crp->crp_etype;
715 AHSTAT_INC(ahs_hist[sav->alg_auth]);
716 crypto_freereq(crp); /* No longer needed. */
720 /* Shouldn't happen... */
722 AHSTAT_INC(ahs_crypto);
723 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
728 /* Figure out header size. */
729 rplen = HDRSIZE(sav);
730 authsize = AUTHSIZE(sav);
731 ahsize = ah_hdrsiz(sav);
733 /* Copy authenticator off the packet. */
734 m_copydata(m, skip + rplen, authsize, calc);
736 /* Verify authenticator. */
737 ptr = (caddr_t) (xd + 1);
738 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
739 DPRINTF(("%s: authentication hash mismatch for packet "
740 "in SA %s/%08lx\n", __func__,
741 ipsec_address(&saidx->dst, buf, sizeof(buf)),
742 (u_long) ntohl(sav->spi)));
743 AHSTAT_INC(ahs_badauth);
747 /* Fix the Next Protocol field. */
748 ((uint8_t *) ptr)[protoff] = nxt;
750 /* Copyback the saved (uncooked) network headers. */
751 m_copyback(m, 0, skip, ptr);
752 free(xd, M_XDATA), xd = NULL; /* No longer needed */
755 * Header is now authenticated.
757 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
760 * Update replay sequence number, if appropriate.
765 m_copydata(m, skip + offsetof(struct newah, ah_seq),
766 sizeof (seq), (caddr_t) &seq);
768 if (ipsec_updatereplay(ntohl(seq), sav)) {
769 SECASVAR_UNLOCK(sav);
770 AHSTAT_INC(ahs_replay);
774 SECASVAR_UNLOCK(sav);
778 * Remove the AH header and authenticator from the mbuf.
780 error = m_striphdr(m, skip, ahsize);
782 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
783 ipsec_address(&saidx->dst, buf, sizeof(buf)),
784 (u_long) ntohl(sav->spi)));
785 AHSTAT_INC(ahs_hdrops);
789 switch (saidx->dst.sa.sa_family) {
792 error = ipsec6_common_input_cb(m, sav, skip, protoff);
797 error = ipsec4_common_input_cb(m, sav, skip, protoff);
801 panic("%s: Unexpected address family: %d saidx=%p", __func__,
802 saidx->dst.sa.sa_family, saidx);
820 * AH output routine, called by ipsec[46]_perform_request().
823 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
824 u_int idx, int skip, int protoff)
826 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
827 const struct auth_hash *ahx;
828 struct xform_data *xd;
832 crypto_session_t cryptoid;
834 int error, rplen, authsize, ahsize, maxpacketsize, roff;
837 IPSEC_ASSERT(sav != NULL, ("null SA"));
838 ahx = sav->tdb_authalgxform;
839 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
841 AHSTAT_INC(ahs_output);
843 /* Figure out header size. */
844 rplen = HDRSIZE(sav);
845 authsize = AUTHSIZE(sav);
846 ahsize = ah_hdrsiz(sav);
848 /* Check for maximum packet size violations. */
849 switch (sav->sah->saidx.dst.sa.sa_family) {
852 maxpacketsize = IP_MAXPACKET;
857 maxpacketsize = IPV6_MAXPACKET;
861 DPRINTF(("%s: unknown/unsupported protocol family %u, "
862 "SA %s/%08lx\n", __func__,
863 sav->sah->saidx.dst.sa.sa_family,
864 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
865 (u_long) ntohl(sav->spi)));
866 AHSTAT_INC(ahs_nopf);
867 error = EPFNOSUPPORT;
870 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
871 DPRINTF(("%s: packet in SA %s/%08lx got too big "
872 "(len %u, max len %u)\n", __func__,
873 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
874 (u_long) ntohl(sav->spi),
875 ahsize + m->m_pkthdr.len, maxpacketsize));
876 AHSTAT_INC(ahs_toobig);
881 /* Update the counters. */
882 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
884 m = m_unshare(m, M_NOWAIT);
886 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
887 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
888 (u_long) ntohl(sav->spi)));
889 AHSTAT_INC(ahs_hdrops);
894 /* Inject AH header. */
895 mi = m_makespace(m, skip, ahsize, &roff);
897 DPRINTF(("%s: failed to inject %u byte AH header for SA "
898 "%s/%08lx\n", __func__, ahsize,
899 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
900 (u_long) ntohl(sav->spi)));
901 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
907 * The AH header is guaranteed by m_makespace() to be in
908 * contiguous memory, at roff bytes offset into the returned mbuf.
910 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
912 /* Initialize the AH header. */
913 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
914 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
916 ah->ah_spi = sav->spi;
918 /* Zeroize authenticator. */
919 m_copyback(m, skip + rplen, authsize, ipseczeroes);
921 /* Zeroize padding */
922 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
925 /* Insert packet replay counter, as requested. */
928 if (sav->replay->count == ~0 &&
929 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
930 SECASVAR_UNLOCK(sav);
931 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
932 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
933 sizeof(buf)), (u_long) ntohl(sav->spi)));
934 AHSTAT_INC(ahs_wrap);
939 /* Emulate replay attack when ipsec_replay is TRUE. */
942 sav->replay->count++;
943 ah->ah_seq = htonl(sav->replay->count);
945 cryptoid = sav->tdb_cryptoid;
946 SECASVAR_UNLOCK(sav);
948 /* Get crypto descriptors. */
949 crp = crypto_getreq(cryptoid, M_NOWAIT);
951 DPRINTF(("%s: failed to acquire crypto descriptors\n",
953 AHSTAT_INC(ahs_crypto);
958 crp->crp_payload_start = 0;
959 crp->crp_payload_length = m->m_pkthdr.len;
960 crp->crp_digest_start = skip + rplen;
962 /* Allocate IPsec-specific opaque crypto info. */
963 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
967 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
968 AHSTAT_INC(ahs_crypto);
973 /* Save the skipped portion of the packet. */
974 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
977 * Fix IP header length on the header used for
978 * authentication. We don't need to fix the original
979 * header length as it will be fixed by our caller.
981 switch (sav->sah->saidx.dst.sa.sa_family) {
984 bcopy(((caddr_t)(xd + 1)) +
985 offsetof(struct ip, ip_len),
986 (caddr_t) &iplen, sizeof(u_int16_t));
987 iplen = htons(ntohs(iplen) + ahsize);
988 m_copyback(m, offsetof(struct ip, ip_len),
989 sizeof(u_int16_t), (caddr_t) &iplen);
995 bcopy(((caddr_t)(xd + 1)) +
996 offsetof(struct ip6_hdr, ip6_plen),
997 (caddr_t) &iplen, sizeof(uint16_t));
998 iplen = htons(ntohs(iplen) + ahsize);
999 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1000 sizeof(uint16_t), (caddr_t) &iplen);
1005 /* Fix the Next Header field in saved header. */
1006 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1008 /* Update the Next Protocol field in the IP header. */
1010 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1012 /* "Massage" the packet headers for crypto processing. */
1013 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1014 skip, ahx->type, 1);
1016 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1018 crypto_freereq(crp);
1022 /* Crypto operation descriptor. */
1023 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
1024 crp->crp_flags = CRYPTO_F_CBIFSYNC;
1026 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1027 crypto_use_mbuf(crp, m);
1028 crp->crp_callback = ah_output_cb;
1029 crp->crp_opaque = xd;
1031 /* These are passed as-is to the callback. */
1036 xd->cryptoid = cryptoid;
1039 return crypto_dispatch(crp);
1049 * AH output callback from the crypto driver.
1052 ah_output_cb(struct cryptop *crp)
1054 struct xform_data *xd;
1055 struct secpolicy *sp;
1056 struct secasvar *sav;
1058 crypto_session_t cryptoid;
1063 m = crp->crp_buf.cb_mbuf;
1064 xd = (struct xform_data *) crp->crp_opaque;
1065 CURVNET_SET(xd->vnet);
1070 cryptoid = xd->cryptoid;
1071 ptr = (caddr_t) (xd + 1);
1073 /* Check for crypto errors. */
1074 if (crp->crp_etype) {
1075 if (crp->crp_etype == EAGAIN) {
1076 /* Reset the session ID */
1077 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1078 crypto_freesession(cryptoid);
1079 xd->cryptoid = crp->crp_session;
1081 return (crypto_dispatch(crp));
1083 AHSTAT_INC(ahs_noxform);
1084 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1085 error = crp->crp_etype;
1090 /* Shouldn't happen... */
1092 AHSTAT_INC(ahs_crypto);
1093 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1098 * Copy original headers (with the new protocol number) back
1101 m_copyback(m, 0, skip, ptr);
1104 crypto_freereq(crp);
1105 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1107 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1108 if (V_ipsec_integrity) {
1112 * Corrupt HMAC if we want to test integrity verification of
1115 alen = AUTHSIZE(sav);
1116 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1120 /* NB: m is reclaimed by ipsec_process_done. */
1121 error = ipsec_process_done(m, sp, sav, idx);
1127 crypto_freereq(crp);
1133 static struct xformsw ah_xformsw = {
1135 .xf_name = "IPsec AH",
1137 .xf_cleanup = ah_cleanup,
1138 .xf_input = ah_input,
1139 .xf_output = ah_output,
1142 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1143 xform_attach, &ah_xformsw);
1144 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1145 xform_detach, &ah_xformsw);