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/rwlock.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. The old protocol is known
86 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
89 #define AUTHSIZE(sav) ah_authsize(sav)
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 ah_authsize(struct secasvar *sav)
119 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
121 if (sav->flags & SADB_X_EXT_OLD)
124 switch (sav->alg_auth) {
125 case SADB_X_AALG_SHA2_256:
127 case SADB_X_AALG_SHA2_384:
129 case SADB_X_AALG_SHA2_512:
132 return AH_HMAC_HASHLEN;
137 * NB: this is public for use by the PF_KEY support.
140 ah_algorithm_lookup(int alg)
142 if (alg > SADB_AALG_MAX)
145 case SADB_X_AALG_NULL:
146 return &auth_hash_null;
147 case SADB_AALG_MD5HMAC:
148 return &auth_hash_hmac_md5;
149 case SADB_AALG_SHA1HMAC:
150 return &auth_hash_hmac_sha1;
151 case SADB_X_AALG_RIPEMD160HMAC:
152 return &auth_hash_hmac_ripemd_160;
153 case SADB_X_AALG_MD5:
154 return &auth_hash_key_md5;
155 case SADB_X_AALG_SHA:
156 return &auth_hash_key_sha1;
157 case SADB_X_AALG_SHA2_256:
158 return &auth_hash_hmac_sha2_256;
159 case SADB_X_AALG_SHA2_384:
160 return &auth_hash_hmac_sha2_384;
161 case SADB_X_AALG_SHA2_512:
162 return &auth_hash_hmac_sha2_512;
168 ah_hdrsiz(struct secasvar *sav)
174 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
175 /*XXX not right for null algorithm--does it matter??*/
176 authsize = AUTHSIZE(sav);
177 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
180 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
186 * NB: public for use by esp_init.
189 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
191 struct auth_hash *thash;
194 thash = ah_algorithm_lookup(sav->alg_auth);
196 DPRINTF(("%s: unsupported authentication algorithm %u\n",
197 __func__, sav->alg_auth));
201 * Verify the replay state block allocation is consistent with
202 * the protocol type. We check here so we can make assumptions
203 * later during protocol processing.
205 /* NB: replay state is setup elsewhere (sigh) */
206 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
207 DPRINTF(("%s: replay state block inconsistency, "
208 "%s algorithm %s replay state\n", __func__,
209 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
210 sav->replay == NULL ? "without" : "with"));
213 if (sav->key_auth == NULL) {
214 DPRINTF(("%s: no authentication key for %s algorithm\n",
215 __func__, thash->name));
218 keylen = _KEYLEN(sav->key_auth);
219 if (keylen != thash->keysize && thash->keysize != 0) {
220 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
221 "keysize %d\n", __func__,
222 keylen, thash->name, thash->keysize));
226 sav->tdb_xform = xsp;
227 sav->tdb_authalgxform = thash;
229 /* Initialize crypto session. */
230 bzero(cria, sizeof (*cria));
231 cria->cri_alg = sav->tdb_authalgxform->type;
232 cria->cri_klen = _KEYBITS(sav->key_auth);
233 cria->cri_key = sav->key_auth->key_data;
234 cria->cri_mlen = AUTHSIZE(sav);
240 * ah_init() is called when an SPI is being set up.
243 ah_init(struct secasvar *sav, struct xformsw *xsp)
245 struct cryptoini cria;
248 error = ah_init0(sav, xsp, &cria);
249 return error ? error :
250 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
256 * NB: public for use by esp_zeroize (XXX).
259 ah_zeroize(struct secasvar *sav)
264 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
266 err = crypto_freesession(sav->tdb_cryptoid);
267 sav->tdb_cryptoid = 0;
268 sav->tdb_authalgxform = NULL;
269 sav->tdb_xform = NULL;
274 * Massage IPv4/IPv6 headers for AH processing.
277 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
279 struct mbuf *m = *m0;
288 struct ip6_ext *ip6e;
297 * This is the least painful way of dealing with IPv4 header
298 * and option processing -- just make sure they're in
301 *m0 = m = m_pullup(m, skip);
303 DPRINTF(("%s: m_pullup failed\n", __func__));
307 /* Fix the IP header */
308 ip = mtod(m, struct ip *);
314 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
315 ip->ip_off &= htons(IP_DF);
317 ip->ip_off = htons(0);
319 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
321 /* IPv4 option processing */
322 for (off = sizeof(struct ip); off < skip;) {
323 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
327 DPRINTF(("%s: illegal IPv4 option length for "
328 "option %d\n", __func__, ptr[off]));
336 off = skip; /* End the loop. */
343 case IPOPT_SECURITY: /* 0x82 */
344 case 0x85: /* Extended security. */
345 case 0x86: /* Commercial security. */
346 case 0x94: /* Router alert */
347 case 0x95: /* RFC1770 */
348 /* Sanity check for option length. */
349 if (ptr[off + 1] < 2) {
350 DPRINTF(("%s: illegal IPv4 option "
351 "length for option %d\n",
352 __func__, ptr[off]));
363 /* Sanity check for option length. */
364 if (ptr[off + 1] < 2) {
365 DPRINTF(("%s: illegal IPv4 option "
366 "length for option %d\n",
367 __func__, ptr[off]));
374 * On output, if we have either of the
375 * source routing options, we should
376 * swap the destination address of the
377 * IP header with the last address
378 * specified in the option, as that is
379 * what the destination's IP header
383 bcopy(ptr + off + ptr[off + 1] -
384 sizeof(struct in_addr),
385 &(ip->ip_dst), sizeof(struct in_addr));
389 /* Sanity check for option length. */
390 if (ptr[off + 1] < 2) {
391 DPRINTF(("%s: illegal IPv4 option "
392 "length for option %d\n",
393 __func__, ptr[off]));
398 /* Zeroize all other options. */
399 count = ptr[off + 1];
400 bcopy(ipseczeroes, ptr, count);
407 DPRINTF(("%s: malformed IPv4 options header\n",
419 case AF_INET6: /* Ugly... */
420 /* Copy and "cook" the IPv6 header. */
421 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
423 /* We don't do IPv6 Jumbograms. */
424 if (ip6.ip6_plen == 0) {
425 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
432 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
433 ip6.ip6_vfc |= IPV6_VERSION;
435 /* Scoped address handling. */
436 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
437 ip6.ip6_src.s6_addr16[1] = 0;
438 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
439 ip6.ip6_dst.s6_addr16[1] = 0;
441 /* Done with IPv6 header. */
442 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
444 /* Let's deal with the remaining headers (if any). */
445 if (skip - sizeof(struct ip6_hdr) > 0) {
446 if (m->m_len <= skip) {
447 ptr = (unsigned char *) malloc(
448 skip - sizeof(struct ip6_hdr),
451 DPRINTF(("%s: failed to allocate memory"
452 "for IPv6 headers\n",__func__));
458 * Copy all the protocol headers after
461 m_copydata(m, sizeof(struct ip6_hdr),
462 skip - sizeof(struct ip6_hdr), ptr);
465 /* No need to allocate memory. */
466 ptr = mtod(m, unsigned char *) +
467 sizeof(struct ip6_hdr);
473 off = ip6.ip6_nxt & 0xff; /* Next header type. */
475 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
477 case IPPROTO_HOPOPTS:
478 case IPPROTO_DSTOPTS:
479 ip6e = (struct ip6_ext *) (ptr + len);
482 * Process the mutable/immutable
483 * options -- borrows heavily from the
486 for (count = len + sizeof(struct ip6_ext);
487 count < len + ((ip6e->ip6e_len + 1) << 3);) {
488 if (ptr[count] == IP6OPT_PAD1) {
490 continue; /* Skip padding. */
495 ((ip6e->ip6e_len + 1) << 3)) {
498 /* Free, if we allocated. */
506 /* If mutable option, zeroize. */
507 if (ptr[count] & IP6OPT_MUTABLE)
508 bcopy(ipseczeroes, ptr + count,
515 skip - sizeof(struct ip6_hdr)) {
518 /* Free, if we allocated. */
526 len += ((ip6e->ip6e_len + 1) << 3);
527 off = ip6e->ip6e_nxt;
530 case IPPROTO_ROUTING:
532 * Always include routing headers in
535 ip6e = (struct ip6_ext *) (ptr + len);
536 len += ((ip6e->ip6e_len + 1) << 3);
537 off = ip6e->ip6e_nxt;
541 DPRINTF(("%s: unexpected IPv6 header type %d",
549 /* Copyback and free, if we allocated. */
551 m_copyback(m, sizeof(struct ip6_hdr),
552 skip - sizeof(struct ip6_hdr), ptr);
564 * ah_input() gets called to verify that an input packet
565 * passes authentication.
568 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
571 struct auth_hash *ahx;
572 struct tdb_crypto *tc;
574 int hl, rplen, authsize, error;
576 struct cryptodesc *crda;
579 IPSEC_ASSERT(sav != NULL, ("null SA"));
580 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
581 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
582 ("null authentication xform"));
584 /* Figure out header size. */
585 rplen = HDRSIZE(sav);
587 /* XXX don't pullup, just copy header */
588 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
590 DPRINTF(("ah_input: cannot pullup header\n"));
591 AHSTAT_INC(ahs_hdrops); /*XXX*/
596 /* Check replay window, if applicable. */
597 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
598 AHSTAT_INC(ahs_replay);
599 DPRINTF(("%s: packet replay failure: %s\n", __func__,
600 ipsec_logsastr(sav, buf, sizeof(buf))));
605 /* Verify AH header length. */
606 hl = ah->ah_len * sizeof (u_int32_t);
607 ahx = sav->tdb_authalgxform;
608 authsize = AUTHSIZE(sav);
609 if (hl != authsize + rplen - sizeof (struct ah)) {
610 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
611 " for packet in SA %s/%08lx\n", __func__, hl,
612 (u_long) (authsize + rplen - sizeof (struct ah)),
613 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
614 (u_long) ntohl(sav->spi)));
615 AHSTAT_INC(ahs_badauthl);
619 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
621 /* Get crypto descriptors. */
622 crp = crypto_getreq(1);
624 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
625 AHSTAT_INC(ahs_crypto);
630 crda = crp->crp_desc;
631 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
634 crda->crd_len = m->m_pkthdr.len;
635 crda->crd_inject = skip + rplen;
637 /* Authentication operation. */
638 crda->crd_alg = ahx->type;
639 crda->crd_klen = _KEYBITS(sav->key_auth);
640 crda->crd_key = sav->key_auth->key_data;
642 /* Allocate IPsec-specific opaque crypto info. */
643 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
644 skip + rplen + authsize, M_XDATA, M_NOWAIT | M_ZERO);
646 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
647 AHSTAT_INC(ahs_crypto);
654 * Save the authenticator, the skipped portion of the packet,
657 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
659 /* Zeroize the authenticator on the packet. */
660 m_copyback(m, skip + rplen, authsize, ipseczeroes);
662 /* "Massage" the packet headers for crypto processing. */
663 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
666 /* NB: mbuf is free'd by ah_massage_headers */
667 AHSTAT_INC(ahs_hdrops);
673 /* Crypto operation descriptor. */
674 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
675 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
676 crp->crp_buf = (caddr_t) m;
677 crp->crp_callback = ah_input_cb;
678 crp->crp_sid = sav->tdb_cryptoid;
679 crp->crp_opaque = (caddr_t) tc;
681 /* These are passed as-is to the callback. */
682 tc->tc_spi = sav->spi;
683 tc->tc_dst = sav->sah->saidx.dst;
684 tc->tc_proto = sav->sah->saidx.proto;
685 tc->tc_nxt = ah->ah_nxt;
686 tc->tc_protoff = protoff;
690 return (crypto_dispatch(crp));
694 * AH input callback from the crypto driver.
697 ah_input_cb(struct cryptop *crp)
699 char buf[INET6_ADDRSTRLEN];
700 int rplen, error, skip, protoff;
701 unsigned char calc[AH_ALEN_MAX];
703 struct cryptodesc *crd;
704 struct auth_hash *ahx;
705 struct tdb_crypto *tc;
706 struct secasvar *sav;
707 struct secasindex *saidx;
714 tc = (struct tdb_crypto *) crp->crp_opaque;
715 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
718 protoff = tc->tc_protoff;
719 m = (struct mbuf *) crp->crp_buf;
722 IPSEC_ASSERT(sav != NULL, ("null SA!"));
724 saidx = &sav->sah->saidx;
725 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
726 saidx->dst.sa.sa_family == AF_INET6,
727 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
729 ahx = (struct auth_hash *) sav->tdb_authalgxform;
731 /* Check for crypto errors. */
732 if (crp->crp_etype) {
733 if (sav->tdb_cryptoid != 0)
734 sav->tdb_cryptoid = crp->crp_sid;
736 if (crp->crp_etype == EAGAIN)
737 return (crypto_dispatch(crp));
739 AHSTAT_INC(ahs_noxform);
740 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
741 error = crp->crp_etype;
744 AHSTAT_INC(ahs_hist[sav->alg_auth]);
745 crypto_freereq(crp); /* No longer needed. */
749 /* Shouldn't happen... */
751 AHSTAT_INC(ahs_crypto);
752 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
757 /* Figure out header size. */
758 rplen = HDRSIZE(sav);
759 authsize = AUTHSIZE(sav);
761 /* Copy authenticator off the packet. */
762 m_copydata(m, skip + rplen, authsize, calc);
764 /* Verify authenticator. */
765 ptr = (caddr_t) (tc + 1);
766 if (bcmp(ptr + skip + rplen, calc, authsize)) {
767 DPRINTF(("%s: authentication hash mismatch for packet "
768 "in SA %s/%08lx\n", __func__,
769 ipsec_address(&saidx->dst, buf, sizeof(buf)),
770 (u_long) ntohl(sav->spi)));
771 AHSTAT_INC(ahs_badauth);
775 /* Fix the Next Protocol field. */
776 ((u_int8_t *) ptr)[protoff] = nxt;
778 /* Copyback the saved (uncooked) network headers. */
779 m_copyback(m, 0, skip, ptr);
780 free(tc, M_XDATA), tc = NULL; /* No longer needed */
783 * Header is now authenticated.
785 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
788 * Update replay sequence number, if appropriate.
793 m_copydata(m, skip + offsetof(struct newah, ah_seq),
794 sizeof (seq), (caddr_t) &seq);
795 if (ipsec_updatereplay(ntohl(seq), sav)) {
796 AHSTAT_INC(ahs_replay);
797 error = ENOBUFS; /*XXX as above*/
803 * Remove the AH header and authenticator from the mbuf.
805 error = m_striphdr(m, skip, rplen + authsize);
807 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
808 ipsec_address(&saidx->dst, buf, sizeof(buf)),
809 (u_long) ntohl(sav->spi)));
810 AHSTAT_INC(ahs_hdrops);
814 switch (saidx->dst.sa.sa_family) {
817 error = ipsec6_common_input_cb(m, sav, skip, protoff);
822 error = ipsec4_common_input_cb(m, sav, skip, protoff);
826 panic("%s: Unexpected address family: %d saidx=%p", __func__,
827 saidx->dst.sa.sa_family, saidx);
845 * AH output routine, called by ipsec[46]_process_packet().
848 ah_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
849 int skip, int protoff)
851 char buf[INET6_ADDRSTRLEN];
852 struct secasvar *sav;
853 struct auth_hash *ahx;
854 struct cryptodesc *crda;
855 struct tdb_crypto *tc;
859 int error, rplen, authsize, maxpacketsize, roff;
864 IPSEC_ASSERT(sav != NULL, ("null SA"));
865 ahx = sav->tdb_authalgxform;
866 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
868 AHSTAT_INC(ahs_output);
870 /* Figure out header size. */
871 rplen = HDRSIZE(sav);
873 /* Check for maximum packet size violations. */
874 switch (sav->sah->saidx.dst.sa.sa_family) {
877 maxpacketsize = IP_MAXPACKET;
882 maxpacketsize = IPV6_MAXPACKET;
886 DPRINTF(("%s: unknown/unsupported protocol family %u, "
887 "SA %s/%08lx\n", __func__,
888 sav->sah->saidx.dst.sa.sa_family,
889 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
890 (u_long) ntohl(sav->spi)));
891 AHSTAT_INC(ahs_nopf);
892 error = EPFNOSUPPORT;
895 authsize = AUTHSIZE(sav);
896 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
897 DPRINTF(("%s: packet in SA %s/%08lx got too big "
898 "(len %u, max len %u)\n", __func__,
899 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
900 (u_long) ntohl(sav->spi),
901 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
902 AHSTAT_INC(ahs_toobig);
907 /* Update the counters. */
908 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
910 m = m_unshare(m, M_NOWAIT);
912 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
913 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
914 (u_long) ntohl(sav->spi)));
915 AHSTAT_INC(ahs_hdrops);
920 /* Inject AH header. */
921 mi = m_makespace(m, skip, rplen + authsize, &roff);
923 DPRINTF(("%s: failed to inject %u byte AH header for SA "
924 "%s/%08lx\n", __func__,
926 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
927 (u_long) ntohl(sav->spi)));
928 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
934 * The AH header is guaranteed by m_makespace() to be in
935 * contiguous memory, at roff bytes offset into the returned mbuf.
937 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
939 /* Initialize the AH header. */
940 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
941 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
943 ah->ah_spi = sav->spi;
945 /* Zeroize authenticator. */
946 m_copyback(m, skip + rplen, authsize, ipseczeroes);
948 /* Insert packet replay counter, as requested. */
950 if (sav->replay->count == ~0 &&
951 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
952 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
953 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
954 sizeof(buf)), (u_long) ntohl(sav->spi)));
955 AHSTAT_INC(ahs_wrap);
960 /* Emulate replay attack when ipsec_replay is TRUE. */
963 sav->replay->count++;
964 ah->ah_seq = htonl(sav->replay->count);
967 /* Get crypto descriptors. */
968 crp = crypto_getreq(1);
970 DPRINTF(("%s: failed to acquire crypto descriptors\n",
972 AHSTAT_INC(ahs_crypto);
977 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 tc = (struct tdb_crypto *) malloc(
990 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
993 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
994 AHSTAT_INC(ahs_crypto);
999 /* Save the skipped portion of the packet. */
1000 m_copydata(m, 0, skip, (caddr_t) (tc + 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)(tc + 1)) +
1011 offsetof(struct ip, ip_len),
1012 (caddr_t) &iplen, sizeof(u_int16_t));
1013 iplen = htons(ntohs(iplen) + rplen + authsize);
1014 m_copyback(m, offsetof(struct ip, ip_len),
1015 sizeof(u_int16_t), (caddr_t) &iplen);
1021 bcopy(((caddr_t)(tc + 1)) +
1022 offsetof(struct ip6_hdr, ip6_plen),
1023 (caddr_t) &iplen, sizeof(u_int16_t));
1024 iplen = htons(ntohs(iplen) + rplen + authsize);
1025 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1026 sizeof(u_int16_t), (caddr_t) &iplen);
1031 /* Fix the Next Header field in saved header. */
1032 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1034 /* Update the Next Protocol field in the IP header. */
1036 m_copyback(m, protoff, sizeof(u_int8_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;
1051 crp->crp_buf = (caddr_t) m;
1052 crp->crp_callback = ah_output_cb;
1053 crp->crp_sid = sav->tdb_cryptoid;
1054 crp->crp_opaque = (caddr_t) tc;
1056 /* These are passed as-is to the callback. */
1060 tc->tc_spi = sav->spi;
1061 tc->tc_dst = sav->sah->saidx.dst;
1062 tc->tc_proto = sav->sah->saidx.proto;
1064 tc->tc_protoff = protoff;
1066 return crypto_dispatch(crp);
1074 * AH output callback from the crypto driver.
1077 ah_output_cb(struct cryptop *crp)
1079 int skip, protoff, error;
1080 struct tdb_crypto *tc;
1081 struct ipsecrequest *isr;
1082 struct secasvar *sav;
1086 tc = (struct tdb_crypto *) crp->crp_opaque;
1087 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1089 protoff = tc->tc_protoff;
1090 ptr = (caddr_t) (tc + 1);
1091 m = (struct mbuf *) crp->crp_buf;
1094 IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
1095 IPSECREQUEST_LOCK(isr);
1097 /* With the isr lock released SA pointer can be updated. */
1098 if (sav != isr->sav) {
1099 AHSTAT_INC(ahs_notdb);
1100 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1101 error = ENOBUFS; /*XXX*/
1105 /* Check for crypto errors. */
1106 if (crp->crp_etype) {
1107 if (sav->tdb_cryptoid != 0)
1108 sav->tdb_cryptoid = crp->crp_sid;
1110 if (crp->crp_etype == EAGAIN) {
1111 IPSECREQUEST_UNLOCK(isr);
1112 return (crypto_dispatch(crp));
1115 AHSTAT_INC(ahs_noxform);
1116 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1117 error = crp->crp_etype;
1121 /* Shouldn't happen... */
1123 AHSTAT_INC(ahs_crypto);
1124 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1128 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1131 * Copy original headers (with the new protocol number) back
1134 m_copyback(m, 0, skip, ptr);
1136 /* No longer needed. */
1138 crypto_freereq(crp);
1141 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1142 if (V_ipsec_integrity) {
1146 * Corrupt HMAC if we want to test integrity verification of
1149 alen = AUTHSIZE(sav);
1150 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1154 /* NB: m is reclaimed by ipsec_process_done. */
1155 error = ipsec_process_done(m, isr);
1157 IPSECREQUEST_UNLOCK(isr);
1158 KEY_FREESP(&isr->sp);
1163 IPSECREQUEST_UNLOCK(isr);
1164 KEY_FREESP(&isr->sp);
1168 crypto_freereq(crp);
1172 static struct xformsw ah_xformsw = {
1173 XF_AH, XFT_AUTH, "IPsec AH",
1174 ah_init, ah_zeroize, ah_input, ah_output,
1181 xform_register(&ah_xformsw);
1184 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);