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_POLY1305:
135 case CRYPTO_AES_NIST_GMAC:
136 alen = esph->hashsize;
140 alen = AH_HMAC_HASHLEN;
148 ah_hdrsiz(struct secasvar *sav)
153 int authsize, rplen, align;
155 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
156 /*XXX not right for null algorithm--does it matter??*/
158 /* RFC4302: use the correct alignment. */
159 align = sizeof(uint32_t);
161 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
162 align = sizeof(uint64_t);
165 rplen = HDRSIZE(sav);
166 authsize = AUTHSIZE(sav);
167 size = roundup(rplen + authsize, align);
170 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
176 * NB: public for use by esp_init.
179 ah_init0(struct secasvar *sav, struct xformsw *xsp,
180 struct crypto_session_params *csp)
182 const struct auth_hash *thash;
185 thash = auth_algorithm_lookup(sav->alg_auth);
187 DPRINTF(("%s: unsupported authentication algorithm %u\n",
188 __func__, sav->alg_auth));
193 * Verify the replay state block allocation is consistent with
194 * the protocol type. We check here so we can make assumptions
195 * later during protocol processing.
197 /* NB: replay state is setup elsewhere (sigh) */
198 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
199 DPRINTF(("%s: replay state block inconsistency, "
200 "%s algorithm %s replay state\n", __func__,
201 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
202 sav->replay == NULL ? "without" : "with"));
205 if (sav->key_auth == NULL) {
206 DPRINTF(("%s: no authentication key for %s algorithm\n",
207 __func__, thash->name));
210 keylen = _KEYLEN(sav->key_auth);
211 if (keylen > thash->keysize && thash->keysize != 0) {
212 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
213 "keysize less than %d\n", __func__,
214 keylen, thash->name, thash->keysize));
218 sav->tdb_xform = xsp;
219 sav->tdb_authalgxform = thash;
221 /* Initialize crypto session. */
222 csp->csp_auth_alg = sav->tdb_authalgxform->type;
223 if (csp->csp_auth_alg != CRYPTO_NULL_HMAC) {
224 csp->csp_auth_klen = _KEYBITS(sav->key_auth) / 8;
225 csp->csp_auth_key = sav->key_auth->key_data;
227 csp->csp_auth_mlen = AUTHSIZE(sav);
233 * ah_init() is called when an SPI is being set up.
236 ah_init(struct secasvar *sav, struct xformsw *xsp)
238 struct crypto_session_params csp;
241 memset(&csp, 0, sizeof(csp));
242 csp.csp_mode = CSP_MODE_DIGEST;
244 if (sav->flags & SADB_X_SAFLAGS_ESN)
245 csp.csp_flags |= CSP_F_ESN;
247 error = ah_init0(sav, xsp, &csp);
248 return error ? error :
249 crypto_newsession(&sav->tdb_cryptoid, &csp, V_crypto_support);
253 ah_cleanup(struct secasvar *sav)
256 crypto_freesession(sav->tdb_cryptoid);
257 sav->tdb_cryptoid = NULL;
258 sav->tdb_authalgxform = NULL;
262 * Massage IPv4/IPv6 headers for AH processing.
265 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
267 struct mbuf *m = *m0;
276 struct ip6_ext *ip6e;
278 int ad, alloc, nxt, noff;
285 * This is the least painful way of dealing with IPv4 header
286 * and option processing -- just make sure they're in
289 *m0 = m = m_pullup(m, skip);
291 DPRINTF(("%s: m_pullup failed\n", __func__));
295 /* Fix the IP header */
296 ip = mtod(m, struct ip *);
301 ip->ip_off = htons(0);
303 ptr = mtod(m, unsigned char *);
305 /* IPv4 option processing */
306 for (off = sizeof(struct ip); off < skip;) {
307 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
311 DPRINTF(("%s: illegal IPv4 option length for "
312 "option %d\n", __func__, ptr[off]));
320 off = skip; /* End the loop. */
327 case IPOPT_SECURITY: /* 0x82 */
328 case 0x85: /* Extended security. */
329 case 0x86: /* Commercial security. */
330 case 0x94: /* Router alert */
331 case 0x95: /* RFC1770 */
332 /* Sanity check for option length. */
333 if (ptr[off + 1] < 2) {
334 DPRINTF(("%s: illegal IPv4 option "
335 "length for option %d\n",
336 __func__, ptr[off]));
347 /* Sanity check for option length. */
348 if (ptr[off + 1] < 2) {
349 DPRINTF(("%s: illegal IPv4 option "
350 "length for option %d\n",
351 __func__, ptr[off]));
358 * On output, if we have either of the
359 * source routing options, we should
360 * swap the destination address of the
361 * IP header with the last address
362 * specified in the option, as that is
363 * what the destination's IP header
367 bcopy(ptr + off + ptr[off + 1] -
368 sizeof(struct in_addr),
369 &(ip->ip_dst), sizeof(struct in_addr));
373 /* Sanity check for option length. */
374 if (ptr[off + 1] < 2) {
375 DPRINTF(("%s: illegal IPv4 option "
376 "length for option %d\n",
377 __func__, ptr[off]));
382 /* Zeroize all other options. */
383 count = ptr[off + 1];
384 bcopy(ipseczeroes, ptr + off, count);
391 DPRINTF(("%s: malformed IPv4 options header\n",
403 case AF_INET6: /* Ugly... */
404 /* Copy and "cook" the IPv6 header. */
405 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
407 /* We don't do IPv6 Jumbograms. */
408 if (ip6.ip6_plen == 0) {
409 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
416 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
417 ip6.ip6_vfc |= IPV6_VERSION;
419 /* Scoped address handling. */
420 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
421 ip6.ip6_src.s6_addr16[1] = 0;
422 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
423 ip6.ip6_dst.s6_addr16[1] = 0;
425 /* Done with IPv6 header. */
426 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
428 /* Let's deal with the remaining headers (if any). */
429 if (skip - sizeof(struct ip6_hdr) > 0) {
430 if (m->m_len <= skip) {
431 ptr = (unsigned char *) malloc(
432 skip - sizeof(struct ip6_hdr),
435 DPRINTF(("%s: failed to allocate memory"
436 "for IPv6 headers\n",__func__));
442 * Copy all the protocol headers after
445 m_copydata(m, sizeof(struct ip6_hdr),
446 skip - sizeof(struct ip6_hdr), ptr);
449 /* No need to allocate memory. */
450 ptr = mtod(m, unsigned char *) +
451 sizeof(struct ip6_hdr);
457 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
459 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
461 case IPPROTO_HOPOPTS:
462 case IPPROTO_DSTOPTS:
463 ip6e = (struct ip6_ext *)(ptr + off);
464 noff = off + ((ip6e->ip6e_len + 1) << 3);
467 if (noff > skip - sizeof(struct ip6_hdr))
471 * Zero out mutable options.
473 for (count = off + sizeof(struct ip6_ext);
475 if (ptr[count] == IP6OPT_PAD1) {
477 continue; /* Skip padding. */
480 ad = ptr[count + 1] + 2;
481 if (count + ad > noff)
484 if (ptr[count] & IP6OPT_MUTABLE)
485 memset(ptr + count, 0, ad);
493 off += ((ip6e->ip6e_len + 1) << 3);
494 nxt = ip6e->ip6e_nxt;
497 case IPPROTO_ROUTING:
499 * Always include routing headers in
502 ip6e = (struct ip6_ext *) (ptr + off);
503 off += ((ip6e->ip6e_len + 1) << 3);
504 nxt = ip6e->ip6e_nxt;
508 DPRINTF(("%s: unexpected IPv6 header type %d",
517 /* Copyback and free, if we allocated. */
519 m_copyback(m, sizeof(struct ip6_hdr),
520 skip - sizeof(struct ip6_hdr), ptr);
532 * ah_input() gets called to verify that an input packet
533 * passes authentication.
536 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
538 IPSEC_DEBUG_DECLARE(char buf[128]);
539 const struct auth_hash *ahx;
541 struct xform_data *xd;
543 crypto_session_t cryptoid;
544 int hl, rplen, authsize, ahsize, error;
547 SECASVAR_RLOCK_TRACKER;
549 IPSEC_ASSERT(sav != NULL, ("null SA"));
550 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
551 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
552 ("null authentication xform"));
554 /* Figure out header size. */
555 rplen = HDRSIZE(sav);
557 if (m->m_len < skip + rplen) {
558 m = m_pullup(m, skip + rplen);
560 DPRINTF(("ah_input: cannot pullup header\n"));
561 AHSTAT_INC(ahs_hdrops); /*XXX*/
566 ah = (struct newah *)(mtod(m, caddr_t) + skip);
568 /* Check replay window, if applicable. */
570 if (sav->replay != NULL && sav->replay->wsize != 0 &&
571 ipsec_chkreplay(ntohl(ah->ah_seq), &seqh, sav) == 0) {
572 SECASVAR_RUNLOCK(sav);
573 AHSTAT_INC(ahs_replay);
574 DPRINTF(("%s: packet replay failure: %s\n", __func__,
575 ipsec_sa2str(sav, buf, sizeof(buf))));
579 cryptoid = sav->tdb_cryptoid;
580 SECASVAR_RUNLOCK(sav);
582 /* Verify AH header length. */
583 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
584 ahx = sav->tdb_authalgxform;
585 authsize = AUTHSIZE(sav);
586 ahsize = ah_hdrsiz(sav);
588 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
589 " for packet in SA %s/%08lx\n", __func__, hl,
591 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
592 (u_long) ntohl(sav->spi)));
593 AHSTAT_INC(ahs_badauthl);
597 if (skip + ahsize > m->m_pkthdr.len) {
598 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
599 " for packet in SA %s/%08lx\n", __func__,
600 m->m_pkthdr.len, (u_long)(skip + ahsize),
601 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
602 (u_long) ntohl(sav->spi)));
603 AHSTAT_INC(ahs_badauthl);
607 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
609 /* Get crypto descriptors. */
610 crp = crypto_getreq(cryptoid, M_NOWAIT);
612 DPRINTF(("%s: failed to acquire crypto descriptor\n",
614 AHSTAT_INC(ahs_crypto);
619 crp->crp_payload_start = 0;
620 crp->crp_payload_length = m->m_pkthdr.len;
621 crp->crp_digest_start = skip + rplen;
623 /* Allocate IPsec-specific opaque crypto info. */
624 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_AH,
627 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
628 AHSTAT_INC(ahs_crypto);
635 * Save the authenticator, the skipped portion of the packet,
638 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
640 /* Zeroize the authenticator on the packet. */
641 m_copyback(m, skip + rplen, authsize, ipseczeroes);
643 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
646 /* "Massage" the packet headers for crypto processing. */
647 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
650 /* NB: mbuf is free'd by ah_massage_headers */
651 AHSTAT_INC(ahs_hdrops);
658 /* Crypto operation descriptor. */
659 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
660 crp->crp_flags = CRYPTO_F_CBIFSYNC;
661 crypto_use_mbuf(crp, m);
662 crp->crp_callback = ah_input_cb;
663 crp->crp_opaque = xd;
665 if (sav->flags & SADB_X_SAFLAGS_ESN &&
666 sav->replay != NULL && sav->replay->wsize != 0) {
668 memcpy(crp->crp_esn, &seqh, sizeof(seqh));
671 /* These are passed as-is to the callback. */
674 xd->protoff = protoff;
676 xd->cryptoid = cryptoid;
679 return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
681 return (crypto_dispatch(crp));
689 * AH input callback from the crypto driver.
692 ah_input_cb(struct cryptop *crp)
694 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
695 unsigned char calc[AH_ALEN_MAX];
697 struct xform_data *xd;
698 struct secasvar *sav;
699 struct secasindex *saidx;
701 crypto_session_t cryptoid;
702 int authsize, rplen, ahsize, error, skip, protoff;
705 SECASVAR_RLOCK_TRACKER;
707 m = crp->crp_buf.cb_mbuf;
708 xd = crp->crp_opaque;
709 CURVNET_SET(xd->vnet);
713 protoff = xd->protoff;
714 cryptoid = xd->cryptoid;
715 saidx = &sav->sah->saidx;
716 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
717 saidx->dst.sa.sa_family == AF_INET6,
718 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
720 /* Check for crypto errors. */
721 if (crp->crp_etype) {
722 if (crp->crp_etype == EAGAIN) {
723 /* Reset the session ID */
724 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
725 crypto_freesession(cryptoid);
726 xd->cryptoid = crp->crp_session;
728 return (crypto_dispatch(crp));
730 AHSTAT_INC(ahs_noxform);
731 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
732 error = crp->crp_etype;
735 AHSTAT_INC(ahs_hist[sav->alg_auth]);
736 crypto_freereq(crp); /* No longer needed. */
740 /* Shouldn't happen... */
742 AHSTAT_INC(ahs_crypto);
743 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
748 /* Figure out header size. */
749 rplen = HDRSIZE(sav);
750 authsize = AUTHSIZE(sav);
751 ahsize = ah_hdrsiz(sav);
753 /* Copy authenticator off the packet. */
754 m_copydata(m, skip + rplen, authsize, calc);
756 /* Verify authenticator. */
757 ptr = (caddr_t) (xd + 1);
758 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
759 DPRINTF(("%s: authentication hash mismatch for packet "
760 "in SA %s/%08lx\n", __func__,
761 ipsec_address(&saidx->dst, buf, sizeof(buf)),
762 (u_long) ntohl(sav->spi)));
763 AHSTAT_INC(ahs_badauth);
767 /* Fix the Next Protocol field. */
768 ((uint8_t *) ptr)[protoff] = nxt;
770 /* Copyback the saved (uncooked) network headers. */
771 m_copyback(m, 0, skip, ptr);
772 free(xd, M_AH), xd = NULL; /* No longer needed */
775 * Header is now authenticated.
777 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
780 * Update replay sequence number, if appropriate.
785 m_copydata(m, skip + offsetof(struct newah, ah_seq),
786 sizeof (seq), (caddr_t) &seq);
788 if (ipsec_updatereplay(ntohl(seq), sav)) {
789 SECASVAR_RUNLOCK(sav);
790 AHSTAT_INC(ahs_replay);
794 SECASVAR_RUNLOCK(sav);
798 * Remove the AH header and authenticator from the mbuf.
800 error = m_striphdr(m, skip, ahsize);
802 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
803 ipsec_address(&saidx->dst, buf, sizeof(buf)),
804 (u_long) ntohl(sav->spi)));
805 AHSTAT_INC(ahs_hdrops);
809 switch (saidx->dst.sa.sa_family) {
812 error = ipsec6_common_input_cb(m, sav, skip, protoff);
817 error = ipsec4_common_input_cb(m, sav, skip, protoff);
821 panic("%s: Unexpected address family: %d saidx=%p", __func__,
822 saidx->dst.sa.sa_family, saidx);
840 * AH output routine, called by ipsec[46]_perform_request().
843 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
844 u_int idx, int skip, int protoff)
846 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
847 const struct auth_hash *ahx;
848 struct xform_data *xd;
852 crypto_session_t cryptoid;
854 int error, rplen, authsize, ahsize, maxpacketsize, roff;
858 SECASVAR_RLOCK_TRACKER;
860 IPSEC_ASSERT(sav != NULL, ("null SA"));
861 ahx = sav->tdb_authalgxform;
862 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
864 AHSTAT_INC(ahs_output);
866 /* Figure out header size. */
867 rplen = HDRSIZE(sav);
868 authsize = AUTHSIZE(sav);
869 ahsize = ah_hdrsiz(sav);
871 /* Check for maximum packet size violations. */
872 switch (sav->sah->saidx.dst.sa.sa_family) {
875 maxpacketsize = IP_MAXPACKET;
880 maxpacketsize = IPV6_MAXPACKET;
884 DPRINTF(("%s: unknown/unsupported protocol family %u, "
885 "SA %s/%08lx\n", __func__,
886 sav->sah->saidx.dst.sa.sa_family,
887 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
888 (u_long) ntohl(sav->spi)));
889 AHSTAT_INC(ahs_nopf);
890 error = EPFNOSUPPORT;
893 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
894 DPRINTF(("%s: packet in SA %s/%08lx got too big "
895 "(len %u, max len %u)\n", __func__,
896 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
897 (u_long) ntohl(sav->spi),
898 ahsize + m->m_pkthdr.len, maxpacketsize));
899 AHSTAT_INC(ahs_toobig);
904 /* Update the counters. */
905 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
907 m = m_unshare(m, M_NOWAIT);
909 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
910 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
911 (u_long) ntohl(sav->spi)));
912 AHSTAT_INC(ahs_hdrops);
917 /* Inject AH header. */
918 mi = m_makespace(m, skip, ahsize, &roff);
920 DPRINTF(("%s: failed to inject %u byte AH header for SA "
921 "%s/%08lx\n", __func__, ahsize,
922 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
923 (u_long) ntohl(sav->spi)));
924 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
930 * The AH header is guaranteed by m_makespace() to be in
931 * contiguous memory, at roff bytes offset into the returned mbuf.
933 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
935 /* Initialize the AH header. */
936 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
937 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
939 ah->ah_spi = sav->spi;
941 /* Zeroize authenticator. */
942 m_copyback(m, skip + rplen, authsize, ipseczeroes);
944 /* Zeroize padding */
945 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
948 /* Insert packet replay counter, as requested. */
951 SECREPLAY_LOCK(sav->replay);
952 if ((sav->replay->count == ~0 ||
953 (!(sav->flags & SADB_X_SAFLAGS_ESN) &&
954 ((uint32_t)sav->replay->count) == ~0)) &&
955 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
956 SECREPLAY_UNLOCK(sav->replay);
957 SECASVAR_RUNLOCK(sav);
958 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
959 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
960 sizeof(buf)), (u_long) ntohl(sav->spi)));
961 AHSTAT_INC(ahs_wrap);
966 /* Emulate replay attack when ipsec_replay is TRUE. */
969 sav->replay->count++;
970 ah->ah_seq = htonl((uint32_t)sav->replay->count);
971 SECREPLAY_UNLOCK(sav->replay);
973 cryptoid = sav->tdb_cryptoid;
974 SECASVAR_RUNLOCK(sav);
976 /* Get crypto descriptors. */
977 crp = crypto_getreq(cryptoid, M_NOWAIT);
979 DPRINTF(("%s: failed to acquire crypto descriptors\n",
981 AHSTAT_INC(ahs_crypto);
986 crp->crp_payload_start = 0;
987 crp->crp_payload_length = m->m_pkthdr.len;
988 crp->crp_digest_start = skip + rplen;
990 /* Allocate IPsec-specific opaque crypto info. */
991 xd = malloc(sizeof(struct xform_data) + skip, M_AH,
995 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
996 AHSTAT_INC(ahs_crypto);
1001 /* Save the skipped portion of the packet. */
1002 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
1005 * Fix IP header length on the header used for
1006 * authentication. We don't need to fix the original
1007 * header length as it will be fixed by our caller.
1009 switch (sav->sah->saidx.dst.sa.sa_family) {
1012 bcopy(((caddr_t)(xd + 1)) +
1013 offsetof(struct ip, ip_len),
1014 (caddr_t) &iplen, sizeof(u_int16_t));
1015 iplen = htons(ntohs(iplen) + ahsize);
1016 m_copyback(m, offsetof(struct ip, ip_len),
1017 sizeof(u_int16_t), (caddr_t) &iplen);
1023 bcopy(((caddr_t)(xd + 1)) +
1024 offsetof(struct ip6_hdr, ip6_plen),
1025 (caddr_t) &iplen, sizeof(uint16_t));
1026 iplen = htons(ntohs(iplen) + ahsize);
1027 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1028 sizeof(uint16_t), (caddr_t) &iplen);
1033 /* Fix the Next Header field in saved header. */
1034 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1036 /* Update the Next Protocol field in the IP header. */
1038 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1040 /* "Massage" the packet headers for crypto processing. */
1041 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1042 skip, ahx->type, 1);
1044 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1046 crypto_freereq(crp);
1050 /* Crypto operation descriptor. */
1051 crp->crp_op = CRYPTO_OP_COMPUTE_DIGEST;
1052 crp->crp_flags = CRYPTO_F_CBIFSYNC;
1053 crypto_use_mbuf(crp, m);
1054 crp->crp_callback = ah_output_cb;
1055 crp->crp_opaque = xd;
1057 if (sav->flags & SADB_X_SAFLAGS_ESN && sav->replay != NULL) {
1058 SECREPLAY_LOCK(sav->replay);
1059 seqh = htonl((uint32_t)(sav->replay->count >> IPSEC_SEQH_SHIFT));
1060 memcpy(crp->crp_esn, &seqh, sizeof(seqh));
1061 SECREPLAY_UNLOCK(sav->replay);
1064 /* These are passed as-is to the callback. */
1069 xd->cryptoid = cryptoid;
1073 return (crypto_dispatch_async(crp, CRYPTO_ASYNC_ORDERED));
1075 return (crypto_dispatch(crp));
1085 * AH output callback from the crypto driver.
1088 ah_output_cb(struct cryptop *crp)
1090 struct xform_data *xd;
1091 struct secpolicy *sp;
1092 struct secasvar *sav;
1094 crypto_session_t cryptoid;
1099 m = crp->crp_buf.cb_mbuf;
1100 xd = (struct xform_data *) crp->crp_opaque;
1101 CURVNET_SET(xd->vnet);
1106 cryptoid = xd->cryptoid;
1107 ptr = (caddr_t) (xd + 1);
1109 /* Check for crypto errors. */
1110 if (crp->crp_etype) {
1111 if (crp->crp_etype == EAGAIN) {
1112 /* Reset the session ID */
1113 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1114 crypto_freesession(cryptoid);
1115 xd->cryptoid = crp->crp_session;
1117 return (crypto_dispatch(crp));
1119 AHSTAT_INC(ahs_noxform);
1120 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1121 error = crp->crp_etype;
1126 /* Shouldn't happen... */
1128 AHSTAT_INC(ahs_crypto);
1129 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1134 * Copy original headers (with the new protocol number) back
1137 m_copyback(m, 0, skip, ptr);
1140 crypto_freereq(crp);
1141 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1143 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1144 if (V_ipsec_integrity) {
1148 * Corrupt HMAC if we want to test integrity verification of
1151 alen = AUTHSIZE(sav);
1152 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1156 /* NB: m is reclaimed by ipsec_process_done. */
1157 error = ipsec_process_done(m, sp, sav, idx);
1163 crypto_freereq(crp);
1169 static struct xformsw ah_xformsw = {
1171 .xf_name = "IPsec AH",
1173 .xf_cleanup = ah_cleanup,
1174 .xf_input = ah_input,
1175 .xf_output = ah_output,
1178 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1179 xform_attach, &ah_xformsw);
1180 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1181 xform_detach, &ah_xformsw);