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>
48 #include <sys/sysctl.h>
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip_ecn.h>
56 #include <netinet/ip6.h>
58 #include <net/route.h>
59 #include <netipsec/ipsec.h>
60 #include <netipsec/ah.h>
61 #include <netipsec/ah_var.h>
62 #include <netipsec/xform.h>
65 #include <netinet6/ip6_var.h>
66 #include <netipsec/ipsec6.h>
67 #include <netinet6/ip6_ecn.h>
70 #include <netipsec/key.h>
71 #include <netipsec/key_debug.h>
73 #include <opencrypto/cryptodev.h>
76 * Return header size in bytes. The old protocol did not support
77 * the replay counter; the new protocol always includes the counter.
79 #define HDRSIZE(sav) \
80 (((sav)->flags & SADB_X_EXT_OLD) ? \
81 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
83 * Return authenticator size in bytes. The old protocol is known
84 * to use a fixed 16-byte authenticator. The new algorithm gets
85 * this size from the xform but is (currently) always 12.
87 #define AUTHSIZE(sav) \
88 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
90 int ah_enable = 1; /* control flow of packets with AH */
91 int ah_cleartos = 1; /* clear ip_tos when doing AH calc */
94 SYSCTL_DECL(_net_inet_ah);
95 SYSCTL_INT(_net_inet_ah, OID_AUTO,
96 ah_enable, CTLFLAG_RW, &ah_enable, 0, "");
97 SYSCTL_INT(_net_inet_ah, OID_AUTO,
98 ah_cleartos, CTLFLAG_RW, &ah_cleartos, 0, "");
99 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
100 stats, CTLFLAG_RD, &ahstat, ahstat, "");
102 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
104 static int ah_input_cb(struct cryptop*);
105 static int ah_output_cb(struct cryptop*);
108 * NB: this is public for use by the PF_KEY support.
111 ah_algorithm_lookup(int alg)
113 if (alg >= AH_ALG_MAX)
116 case SADB_X_AALG_NULL:
117 return &auth_hash_null;
118 case SADB_AALG_MD5HMAC:
119 return &auth_hash_hmac_md5_96;
120 case SADB_AALG_SHA1HMAC:
121 return &auth_hash_hmac_sha1_96;
122 case SADB_X_AALG_RIPEMD160HMAC:
123 return &auth_hash_hmac_ripemd_160_96;
124 case SADB_X_AALG_MD5:
125 return &auth_hash_key_md5;
126 case SADB_X_AALG_SHA:
127 return &auth_hash_key_sha1;
128 case SADB_X_AALG_SHA2_256:
129 return &auth_hash_hmac_sha2_256;
130 case SADB_X_AALG_SHA2_384:
131 return &auth_hash_hmac_sha2_384;
132 case SADB_X_AALG_SHA2_512:
133 return &auth_hash_hmac_sha2_512;
139 ah_hdrsiz(struct secasvar *sav)
145 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
146 /*XXX not right for null algorithm--does it matter??*/
147 authsize = AUTHSIZE(sav);
148 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
151 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
157 * NB: public for use by esp_init.
160 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
162 struct auth_hash *thash;
165 thash = ah_algorithm_lookup(sav->alg_auth);
167 DPRINTF(("%s: unsupported authentication algorithm %u\n",
168 __func__, sav->alg_auth));
172 * Verify the replay state block allocation is consistent with
173 * the protocol type. We check here so we can make assumptions
174 * later during protocol processing.
176 /* NB: replay state is setup elsewhere (sigh) */
177 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
178 DPRINTF(("%s: replay state block inconsistency, "
179 "%s algorithm %s replay state\n", __func__,
180 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
181 sav->replay == NULL ? "without" : "with"));
184 if (sav->key_auth == NULL) {
185 DPRINTF(("%s: no authentication key for %s algorithm\n",
186 __func__, thash->name));
189 keylen = _KEYLEN(sav->key_auth);
190 if (keylen != thash->keysize && thash->keysize != 0) {
191 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
192 "keysize %d\n", __func__,
193 keylen, thash->name, thash->keysize));
197 sav->tdb_xform = xsp;
198 sav->tdb_authalgxform = thash;
200 /* Initialize crypto session. */
201 bzero(cria, sizeof (*cria));
202 cria->cri_alg = sav->tdb_authalgxform->type;
203 cria->cri_klen = _KEYBITS(sav->key_auth);
204 cria->cri_key = _KEYBUF(sav->key_auth);
210 * ah_init() is called when an SPI is being set up.
213 ah_init(struct secasvar *sav, struct xformsw *xsp)
215 struct cryptoini cria;
218 error = ah_init0(sav, xsp, &cria);
219 return error ? error :
220 crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support);
226 * NB: public for use by esp_zeroize (XXX).
229 ah_zeroize(struct secasvar *sav)
234 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
236 err = crypto_freesession(sav->tdb_cryptoid);
237 sav->tdb_cryptoid = 0;
238 sav->tdb_authalgxform = NULL;
239 sav->tdb_xform = NULL;
244 * Massage IPv4/IPv6 headers for AH processing.
247 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
249 struct mbuf *m = *m0;
258 struct ip6_ext *ip6e;
267 * This is the least painful way of dealing with IPv4 header
268 * and option processing -- just make sure they're in
271 *m0 = m = m_pullup(m, skip);
273 DPRINTF(("%s: m_pullup failed\n", __func__));
277 /* Fix the IP header */
278 ip = mtod(m, struct ip *);
285 * On input, fix ip_len which has been byte-swapped
289 ip->ip_len = htons(ip->ip_len + skip);
291 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
292 ip->ip_off = htons(ip->ip_off & IP_DF);
296 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
297 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
302 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
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, 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 off = ip6.ip6_nxt & 0xff; /* Next header type. */
458 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
460 case IPPROTO_HOPOPTS:
461 case IPPROTO_DSTOPTS:
462 ip6e = (struct ip6_ext *) (ptr + len);
465 * Process the mutable/immutable
466 * options -- borrows heavily from the
469 for (count = len + sizeof(struct ip6_ext);
470 count < len + ((ip6e->ip6e_len + 1) << 3);) {
471 if (ptr[count] == IP6OPT_PAD1) {
473 continue; /* Skip padding. */
478 ((ip6e->ip6e_len + 1) << 3)) {
481 /* Free, if we allocated. */
489 /* If mutable option, zeroize. */
490 if (ptr[count] & IP6OPT_MUTABLE)
491 bcopy(ipseczeroes, ptr + count,
498 skip - sizeof(struct ip6_hdr)) {
501 /* Free, if we allocated. */
509 len += ((ip6e->ip6e_len + 1) << 3);
510 off = ip6e->ip6e_nxt;
513 case IPPROTO_ROUTING:
515 * Always include routing headers in
518 ip6e = (struct ip6_ext *) (ptr + len);
519 len += ((ip6e->ip6e_len + 1) << 3);
520 off = ip6e->ip6e_nxt;
524 DPRINTF(("%s: unexpected IPv6 header type %d",
532 /* Copyback and free, if we allocated. */
534 m_copyback(m, sizeof(struct ip6_hdr),
535 skip - sizeof(struct ip6_hdr), ptr);
547 * ah_input() gets called to verify that an input packet
548 * passes authentication.
551 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
553 struct auth_hash *ahx;
554 struct tdb_ident *tdbi;
555 struct tdb_crypto *tc;
558 int hl, rplen, authsize;
560 struct cryptodesc *crda;
563 IPSEC_SPLASSERT_SOFTNET(__func__);
565 IPSEC_ASSERT(sav != NULL, ("null SA"));
566 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
567 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
568 ("null authentication xform"));
570 /* Figure out header size. */
571 rplen = HDRSIZE(sav);
573 /* XXX don't pullup, just copy header */
574 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
576 DPRINTF(("ah_input: cannot pullup header\n"));
577 ahstat.ahs_hdrops++; /*XXX*/
582 /* Check replay window, if applicable. */
583 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
585 DPRINTF(("%s: packet replay failure: %s\n", __func__,
586 ipsec_logsastr(sav)));
591 /* Verify AH header length. */
592 hl = ah->ah_len * sizeof (u_int32_t);
593 ahx = sav->tdb_authalgxform;
594 authsize = AUTHSIZE(sav);
595 if (hl != authsize + rplen - sizeof (struct ah)) {
596 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
597 " for packet in SA %s/%08lx\n", __func__,
598 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
599 ipsec_address(&sav->sah->saidx.dst),
600 (u_long) ntohl(sav->spi)));
601 ahstat.ahs_badauthl++;
605 ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
607 /* Get crypto descriptors. */
608 crp = crypto_getreq(1);
610 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
616 crda = crp->crp_desc;
617 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
620 crda->crd_len = m->m_pkthdr.len;
621 crda->crd_inject = skip + rplen;
623 /* Authentication operation. */
624 crda->crd_alg = ahx->type;
625 crda->crd_key = _KEYBUF(sav->key_auth);
626 crda->crd_klen = _KEYBITS(sav->key_auth);
628 /* Find out if we've already done crypto. */
629 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
631 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
632 tdbi = (struct tdb_ident *) (mtag + 1);
633 if (tdbi->proto == sav->sah->saidx.proto &&
634 tdbi->spi == sav->spi &&
635 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
636 sizeof (union sockaddr_union)))
640 /* Allocate IPsec-specific opaque crypto info. */
642 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
643 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
645 /* Hash verification has already been done successfully. */
646 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
647 M_XDATA, M_NOWAIT|M_ZERO);
650 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
657 /* Only save information if crypto processing is needed. */
662 * Save the authenticator, the skipped portion of the packet,
665 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
667 /* Zeroize the authenticator on the packet. */
668 m_copyback(m, skip + rplen, authsize, ipseczeroes);
670 /* "Massage" the packet headers for crypto processing. */
671 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
674 /* NB: mbuf is free'd by ah_massage_headers */
682 /* Crypto operation descriptor. */
683 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
684 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
685 crp->crp_buf = (caddr_t) m;
686 crp->crp_callback = ah_input_cb;
687 crp->crp_sid = sav->tdb_cryptoid;
688 crp->crp_opaque = (caddr_t) tc;
690 /* These are passed as-is to the callback. */
691 tc->tc_spi = sav->spi;
692 tc->tc_dst = sav->sah->saidx.dst;
693 tc->tc_proto = sav->sah->saidx.proto;
694 tc->tc_nxt = ah->ah_nxt;
695 tc->tc_protoff = protoff;
697 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
700 return crypto_dispatch(crp);
702 return ah_input_cb(crp);
706 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
707 if (saidx->dst.sa.sa_family == AF_INET6) { \
708 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
710 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
714 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
715 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
719 * AH input callback from the crypto driver.
722 ah_input_cb(struct cryptop *crp)
724 int rplen, error, skip, protoff;
725 unsigned char calc[AH_ALEN_MAX];
727 struct cryptodesc *crd;
728 struct auth_hash *ahx;
729 struct tdb_crypto *tc;
731 struct secasvar *sav;
732 struct secasindex *saidx;
739 tc = (struct tdb_crypto *) crp->crp_opaque;
740 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
743 protoff = tc->tc_protoff;
744 mtag = (struct m_tag *) tc->tc_ptr;
745 m = (struct mbuf *) crp->crp_buf;
747 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
750 DPRINTF(("%s: SA expired while in crypto\n", __func__));
751 error = ENOBUFS; /*XXX*/
755 saidx = &sav->sah->saidx;
756 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
757 saidx->dst.sa.sa_family == AF_INET6,
758 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
760 ahx = (struct auth_hash *) sav->tdb_authalgxform;
762 /* Check for crypto errors. */
763 if (crp->crp_etype) {
764 if (sav->tdb_cryptoid != 0)
765 sav->tdb_cryptoid = crp->crp_sid;
767 if (crp->crp_etype == EAGAIN)
768 return crypto_dispatch(crp);
770 ahstat.ahs_noxform++;
771 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
772 error = crp->crp_etype;
775 ahstat.ahs_hist[sav->alg_auth]++;
776 crypto_freereq(crp); /* No longer needed. */
780 /* Shouldn't happen... */
783 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
788 /* Figure out header size. */
789 rplen = HDRSIZE(sav);
790 authsize = AUTHSIZE(sav);
792 /* Copy authenticator off the packet. */
793 m_copydata(m, skip + rplen, authsize, calc);
796 * If we have an mtag, we don't need to verify the authenticator --
797 * it has been verified by an IPsec-aware NIC.
800 ptr = (caddr_t) (tc + 1);
802 /* Verify authenticator. */
803 if (bcmp(ptr + skip + rplen, calc, authsize)) {
804 DPRINTF(("%s: authentication hash mismatch for packet "
805 "in SA %s/%08lx\n", __func__,
806 ipsec_address(&saidx->dst),
807 (u_long) ntohl(sav->spi)));
808 ahstat.ahs_badauth++;
813 /* Fix the Next Protocol field. */
814 ((u_int8_t *) ptr)[protoff] = nxt;
816 /* Copyback the saved (uncooked) network headers. */
817 m_copyback(m, 0, skip, ptr);
819 /* Fix the Next Protocol field. */
820 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
823 free(tc, M_XDATA), tc = NULL; /* No longer needed */
826 * Header is now authenticated.
828 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
831 * Update replay sequence number, if appropriate.
836 m_copydata(m, skip + offsetof(struct newah, ah_seq),
837 sizeof (seq), (caddr_t) &seq);
838 if (ipsec_updatereplay(ntohl(seq), sav)) {
840 error = ENOBUFS; /*XXX as above*/
846 * Remove the AH header and authenticator from the mbuf.
848 error = m_striphdr(m, skip, rplen + authsize);
850 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
851 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
857 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
875 * AH output routine, called by ipsec[46]_process_packet().
880 struct ipsecrequest *isr,
885 struct secasvar *sav;
886 struct auth_hash *ahx;
887 struct cryptodesc *crda;
888 struct tdb_crypto *tc;
892 int error, rplen, authsize, maxpacketsize, roff;
896 IPSEC_SPLASSERT_SOFTNET(__func__);
899 IPSEC_ASSERT(sav != NULL, ("null SA"));
900 ahx = sav->tdb_authalgxform;
901 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
905 /* Figure out header size. */
906 rplen = HDRSIZE(sav);
908 /* Check for maximum packet size violations. */
909 switch (sav->sah->saidx.dst.sa.sa_family) {
912 maxpacketsize = IP_MAXPACKET;
917 maxpacketsize = IPV6_MAXPACKET;
921 DPRINTF(("%s: unknown/unsupported protocol family %u, "
922 "SA %s/%08lx\n", __func__,
923 sav->sah->saidx.dst.sa.sa_family,
924 ipsec_address(&sav->sah->saidx.dst),
925 (u_long) ntohl(sav->spi)));
927 error = EPFNOSUPPORT;
930 authsize = AUTHSIZE(sav);
931 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
932 DPRINTF(("%s: packet in SA %s/%08lx got too big "
933 "(len %u, max len %u)\n", __func__,
934 ipsec_address(&sav->sah->saidx.dst),
935 (u_long) ntohl(sav->spi),
936 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
942 /* Update the counters. */
943 ahstat.ahs_obytes += m->m_pkthdr.len - skip;
947 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
948 ipsec_address(&sav->sah->saidx.dst),
949 (u_long) ntohl(sav->spi)));
955 /* Inject AH header. */
956 mi = m_makespace(m, skip, rplen + authsize, &roff);
958 DPRINTF(("%s: failed to inject %u byte AH header for SA "
959 "%s/%08lx\n", __func__,
961 ipsec_address(&sav->sah->saidx.dst),
962 (u_long) ntohl(sav->spi)));
963 ahstat.ahs_hdrops++; /*XXX differs from openbsd */
969 * The AH header is guaranteed by m_makespace() to be in
970 * contiguous memory, at roff bytes offset into the returned mbuf.
972 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
974 /* Initialize the AH header. */
975 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
976 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
978 ah->ah_spi = sav->spi;
980 /* Zeroize authenticator. */
981 m_copyback(m, skip + rplen, authsize, ipseczeroes);
983 /* Insert packet replay counter, as requested. */
985 if (sav->replay->count == ~0 &&
986 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
987 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
989 ipsec_address(&sav->sah->saidx.dst),
990 (u_long) ntohl(sav->spi)));
995 sav->replay->count++;
996 ah->ah_seq = htonl(sav->replay->count);
999 /* Get crypto descriptors. */
1000 crp = crypto_getreq(1);
1002 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1004 ahstat.ahs_crypto++;
1009 crda = crp->crp_desc;
1012 crda->crd_inject = skip + rplen;
1013 crda->crd_len = m->m_pkthdr.len;
1015 /* Authentication operation. */
1016 crda->crd_alg = ahx->type;
1017 crda->crd_key = _KEYBUF(sav->key_auth);
1018 crda->crd_klen = _KEYBITS(sav->key_auth);
1020 /* Allocate IPsec-specific opaque crypto info. */
1021 tc = (struct tdb_crypto *) malloc(
1022 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1024 crypto_freereq(crp);
1025 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1026 ahstat.ahs_crypto++;
1031 /* Save the skipped portion of the packet. */
1032 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1035 * Fix IP header length on the header used for
1036 * authentication. We don't need to fix the original
1037 * header length as it will be fixed by our caller.
1039 switch (sav->sah->saidx.dst.sa.sa_family) {
1042 bcopy(((caddr_t)(tc + 1)) +
1043 offsetof(struct ip, ip_len),
1044 (caddr_t) &iplen, sizeof(u_int16_t));
1045 iplen = htons(ntohs(iplen) + rplen + authsize);
1046 m_copyback(m, offsetof(struct ip, ip_len),
1047 sizeof(u_int16_t), (caddr_t) &iplen);
1053 bcopy(((caddr_t)(tc + 1)) +
1054 offsetof(struct ip6_hdr, ip6_plen),
1055 (caddr_t) &iplen, sizeof(u_int16_t));
1056 iplen = htons(ntohs(iplen) + rplen + authsize);
1057 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1058 sizeof(u_int16_t), (caddr_t) &iplen);
1063 /* Fix the Next Header field in saved header. */
1064 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1066 /* Update the Next Protocol field in the IP header. */
1068 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1070 /* "Massage" the packet headers for crypto processing. */
1071 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1072 skip, ahx->type, 1);
1074 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1076 crypto_freereq(crp);
1080 /* Crypto operation descriptor. */
1081 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1082 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1083 crp->crp_buf = (caddr_t) m;
1084 crp->crp_callback = ah_output_cb;
1085 crp->crp_sid = sav->tdb_cryptoid;
1086 crp->crp_opaque = (caddr_t) tc;
1088 /* These are passed as-is to the callback. */
1090 tc->tc_spi = sav->spi;
1091 tc->tc_dst = sav->sah->saidx.dst;
1092 tc->tc_proto = sav->sah->saidx.proto;
1094 tc->tc_protoff = protoff;
1096 return crypto_dispatch(crp);
1104 * AH output callback from the crypto driver.
1107 ah_output_cb(struct cryptop *crp)
1109 int skip, protoff, error;
1110 struct tdb_crypto *tc;
1111 struct ipsecrequest *isr;
1112 struct secasvar *sav;
1117 tc = (struct tdb_crypto *) crp->crp_opaque;
1118 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1120 protoff = tc->tc_protoff;
1121 ptr = (caddr_t) (tc + 1);
1122 m = (struct mbuf *) crp->crp_buf;
1125 IPSECREQUEST_LOCK(isr);
1126 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1129 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1130 error = ENOBUFS; /*XXX*/
1133 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1135 /* Check for crypto errors. */
1136 if (crp->crp_etype) {
1137 if (sav->tdb_cryptoid != 0)
1138 sav->tdb_cryptoid = crp->crp_sid;
1140 if (crp->crp_etype == EAGAIN) {
1142 IPSECREQUEST_UNLOCK(isr);
1143 return crypto_dispatch(crp);
1146 ahstat.ahs_noxform++;
1147 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1148 error = crp->crp_etype;
1152 /* Shouldn't happen... */
1154 ahstat.ahs_crypto++;
1155 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1159 ahstat.ahs_hist[sav->alg_auth]++;
1162 * Copy original headers (with the new protocol number) back
1165 m_copyback(m, 0, skip, ptr);
1167 /* No longer needed. */
1169 crypto_freereq(crp);
1171 /* NB: m is reclaimed by ipsec_process_done. */
1172 err = ipsec_process_done(m, isr);
1174 IPSECREQUEST_UNLOCK(isr);
1180 IPSECREQUEST_UNLOCK(isr);
1184 crypto_freereq(crp);
1188 static struct xformsw ah_xformsw = {
1189 XF_AH, XFT_AUTH, "IPsec AH",
1190 ah_init, ah_zeroize, ah_input, ah_output,
1196 xform_register(&ah_xformsw);
1198 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);