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>
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip_ecn.h>
57 #include <netinet/ip6.h>
59 #include <net/route.h>
60 #include <netipsec/ipsec.h>
61 #include <netipsec/ah.h>
62 #include <netipsec/ah_var.h>
63 #include <netipsec/xform.h>
66 #include <netinet6/ip6_var.h>
67 #include <netipsec/ipsec6.h>
68 #include <netinet6/ip6_ecn.h>
71 #include <netipsec/key.h>
72 #include <netipsec/key_debug.h>
74 #include <opencrypto/cryptodev.h>
77 * Return header size in bytes. The old protocol did not support
78 * the replay counter; the new protocol always includes the counter.
80 #define HDRSIZE(sav) \
81 (((sav)->flags & SADB_X_EXT_OLD) ? \
82 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
84 * Return authenticator size in bytes. The old protocol is known
85 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
88 #define AUTHSIZE(sav) ah_authsize(sav)
90 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
91 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
92 VNET_DEFINE(struct ahstat, ahstat);
94 SYSCTL_DECL(_net_inet_ah);
95 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
96 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
97 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
98 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
99 SYSCTL_VNET_STRUCT(_net_inet_ah, IPSECCTL_STATS,
100 stats, CTLFLAG_RD, &VNET_NAME(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 ah_authsize(struct secasvar *sav)
111 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
113 if (sav->flags & SADB_X_EXT_OLD)
116 switch (sav->alg_auth) {
117 case SADB_X_AALG_SHA2_256:
119 case SADB_X_AALG_SHA2_384:
121 case SADB_X_AALG_SHA2_512:
124 return AH_HMAC_HASHLEN;
129 * NB: this is public for use by the PF_KEY support.
132 ah_algorithm_lookup(int alg)
134 if (alg > SADB_AALG_MAX)
137 case SADB_X_AALG_NULL:
138 return &auth_hash_null;
139 case SADB_AALG_MD5HMAC:
140 return &auth_hash_hmac_md5;
141 case SADB_AALG_SHA1HMAC:
142 return &auth_hash_hmac_sha1;
143 case SADB_X_AALG_RIPEMD160HMAC:
144 return &auth_hash_hmac_ripemd_160;
145 case SADB_X_AALG_MD5:
146 return &auth_hash_key_md5;
147 case SADB_X_AALG_SHA:
148 return &auth_hash_key_sha1;
149 case SADB_X_AALG_SHA2_256:
150 return &auth_hash_hmac_sha2_256;
151 case SADB_X_AALG_SHA2_384:
152 return &auth_hash_hmac_sha2_384;
153 case SADB_X_AALG_SHA2_512:
154 return &auth_hash_hmac_sha2_512;
160 ah_hdrsiz(struct secasvar *sav)
166 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
167 /*XXX not right for null algorithm--does it matter??*/
168 authsize = AUTHSIZE(sav);
169 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
172 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
178 * NB: public for use by esp_init.
181 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
183 struct auth_hash *thash;
186 thash = ah_algorithm_lookup(sav->alg_auth);
188 DPRINTF(("%s: unsupported authentication algorithm %u\n",
189 __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 %d\n", __func__,
214 keylen, thash->name, thash->keysize));
218 sav->tdb_xform = xsp;
219 sav->tdb_authalgxform = thash;
221 /* Initialize crypto session. */
222 bzero(cria, sizeof (*cria));
223 cria->cri_alg = sav->tdb_authalgxform->type;
224 cria->cri_klen = _KEYBITS(sav->key_auth);
225 cria->cri_key = sav->key_auth->key_data;
226 cria->cri_mlen = AUTHSIZE(sav);
232 * ah_init() is called when an SPI is being set up.
235 ah_init(struct secasvar *sav, struct xformsw *xsp)
237 struct cryptoini cria;
240 error = ah_init0(sav, xsp, &cria);
241 return error ? error :
242 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
248 * NB: public for use by esp_zeroize (XXX).
251 ah_zeroize(struct secasvar *sav)
256 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
258 err = crypto_freesession(sav->tdb_cryptoid);
259 sav->tdb_cryptoid = 0;
260 sav->tdb_authalgxform = NULL;
261 sav->tdb_xform = NULL;
266 * Massage IPv4/IPv6 headers for AH processing.
269 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
271 struct mbuf *m = *m0;
280 struct ip6_ext *ip6e;
289 * This is the least painful way of dealing with IPv4 header
290 * and option processing -- just make sure they're in
293 *m0 = m = m_pullup(m, skip);
295 DPRINTF(("%s: m_pullup failed\n", __func__));
299 /* Fix the IP header */
300 ip = mtod(m, struct ip *);
307 * On input, fix ip_len which has been byte-swapped
311 ip->ip_len = htons(ip->ip_len + skip);
313 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
314 ip->ip_off = htons(ip->ip_off & IP_DF);
318 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
319 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
324 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
326 /* IPv4 option processing */
327 for (off = sizeof(struct ip); off < skip;) {
328 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
332 DPRINTF(("%s: illegal IPv4 option length for "
333 "option %d\n", __func__, ptr[off]));
341 off = skip; /* End the loop. */
348 case IPOPT_SECURITY: /* 0x82 */
349 case 0x85: /* Extended security. */
350 case 0x86: /* Commercial security. */
351 case 0x94: /* Router alert */
352 case 0x95: /* RFC1770 */
353 /* Sanity check for option length. */
354 if (ptr[off + 1] < 2) {
355 DPRINTF(("%s: illegal IPv4 option "
356 "length for option %d\n",
357 __func__, ptr[off]));
368 /* Sanity check for option length. */
369 if (ptr[off + 1] < 2) {
370 DPRINTF(("%s: illegal IPv4 option "
371 "length for option %d\n",
372 __func__, ptr[off]));
379 * On output, if we have either of the
380 * source routing options, we should
381 * swap the destination address of the
382 * IP header with the last address
383 * specified in the option, as that is
384 * what the destination's IP header
388 bcopy(ptr + off + ptr[off + 1] -
389 sizeof(struct in_addr),
390 &(ip->ip_dst), sizeof(struct in_addr));
394 /* Sanity check for option length. */
395 if (ptr[off + 1] < 2) {
396 DPRINTF(("%s: illegal IPv4 option "
397 "length for option %d\n",
398 __func__, ptr[off]));
403 /* Zeroize all other options. */
404 count = ptr[off + 1];
405 bcopy(ipseczeroes, ptr, count);
412 DPRINTF(("%s: malformed IPv4 options header\n",
424 case AF_INET6: /* Ugly... */
425 /* Copy and "cook" the IPv6 header. */
426 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
428 /* We don't do IPv6 Jumbograms. */
429 if (ip6.ip6_plen == 0) {
430 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
437 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
438 ip6.ip6_vfc |= IPV6_VERSION;
440 /* Scoped address handling. */
441 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
442 ip6.ip6_src.s6_addr16[1] = 0;
443 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
444 ip6.ip6_dst.s6_addr16[1] = 0;
446 /* Done with IPv6 header. */
447 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
449 /* Let's deal with the remaining headers (if any). */
450 if (skip - sizeof(struct ip6_hdr) > 0) {
451 if (m->m_len <= skip) {
452 ptr = (unsigned char *) malloc(
453 skip - sizeof(struct ip6_hdr),
456 DPRINTF(("%s: failed to allocate memory"
457 "for IPv6 headers\n",__func__));
463 * Copy all the protocol headers after
466 m_copydata(m, sizeof(struct ip6_hdr),
467 skip - sizeof(struct ip6_hdr), ptr);
470 /* No need to allocate memory. */
471 ptr = mtod(m, unsigned char *) +
472 sizeof(struct ip6_hdr);
478 off = ip6.ip6_nxt & 0xff; /* Next header type. */
480 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
482 case IPPROTO_HOPOPTS:
483 case IPPROTO_DSTOPTS:
484 ip6e = (struct ip6_ext *) (ptr + len);
487 * Process the mutable/immutable
488 * options -- borrows heavily from the
491 for (count = len + sizeof(struct ip6_ext);
492 count < len + ((ip6e->ip6e_len + 1) << 3);) {
493 if (ptr[count] == IP6OPT_PAD1) {
495 continue; /* Skip padding. */
500 ((ip6e->ip6e_len + 1) << 3)) {
503 /* Free, if we allocated. */
511 /* If mutable option, zeroize. */
512 if (ptr[count] & IP6OPT_MUTABLE)
513 bcopy(ipseczeroes, ptr + count,
520 skip - sizeof(struct ip6_hdr)) {
523 /* Free, if we allocated. */
531 len += ((ip6e->ip6e_len + 1) << 3);
532 off = ip6e->ip6e_nxt;
535 case IPPROTO_ROUTING:
537 * Always include routing headers in
540 ip6e = (struct ip6_ext *) (ptr + len);
541 len += ((ip6e->ip6e_len + 1) << 3);
542 off = ip6e->ip6e_nxt;
546 DPRINTF(("%s: unexpected IPv6 header type %d",
554 /* Copyback and free, if we allocated. */
556 m_copyback(m, sizeof(struct ip6_hdr),
557 skip - sizeof(struct ip6_hdr), ptr);
569 * ah_input() gets called to verify that an input packet
570 * passes authentication.
573 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
575 struct auth_hash *ahx;
576 struct tdb_ident *tdbi;
577 struct tdb_crypto *tc;
580 int hl, rplen, authsize;
582 struct cryptodesc *crda;
585 IPSEC_ASSERT(sav != NULL, ("null SA"));
586 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
587 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
588 ("null authentication xform"));
590 /* Figure out header size. */
591 rplen = HDRSIZE(sav);
593 /* XXX don't pullup, just copy header */
594 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
596 DPRINTF(("ah_input: cannot pullup header\n"));
597 V_ahstat.ahs_hdrops++; /*XXX*/
602 /* Check replay window, if applicable. */
603 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
604 V_ahstat.ahs_replay++;
605 DPRINTF(("%s: packet replay failure: %s\n", __func__,
606 ipsec_logsastr(sav)));
611 /* Verify AH header length. */
612 hl = ah->ah_len * sizeof (u_int32_t);
613 ahx = sav->tdb_authalgxform;
614 authsize = AUTHSIZE(sav);
615 if (hl != authsize + rplen - sizeof (struct ah)) {
616 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
617 " for packet in SA %s/%08lx\n", __func__,
618 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
619 ipsec_address(&sav->sah->saidx.dst),
620 (u_long) ntohl(sav->spi)));
621 V_ahstat.ahs_badauthl++;
625 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
627 /* Get crypto descriptors. */
628 crp = crypto_getreq(1);
630 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
631 V_ahstat.ahs_crypto++;
636 crda = crp->crp_desc;
637 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
640 crda->crd_len = m->m_pkthdr.len;
641 crda->crd_inject = skip + rplen;
643 /* Authentication operation. */
644 crda->crd_alg = ahx->type;
645 crda->crd_klen = _KEYBITS(sav->key_auth);
646 crda->crd_key = sav->key_auth->key_data;
648 /* Find out if we've already done crypto. */
649 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
651 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
652 tdbi = (struct tdb_ident *) (mtag + 1);
653 if (tdbi->proto == sav->sah->saidx.proto &&
654 tdbi->spi == sav->spi &&
655 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
656 sizeof (union sockaddr_union)))
660 /* Allocate IPsec-specific opaque crypto info. */
662 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
663 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
665 /* Hash verification has already been done successfully. */
666 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
667 M_XDATA, M_NOWAIT|M_ZERO);
670 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
671 V_ahstat.ahs_crypto++;
677 /* Only save information if crypto processing is needed. */
682 * Save the authenticator, the skipped portion of the packet,
685 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
687 /* Zeroize the authenticator on the packet. */
688 m_copyback(m, skip + rplen, authsize, ipseczeroes);
690 /* "Massage" the packet headers for crypto processing. */
691 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
694 /* NB: mbuf is free'd by ah_massage_headers */
695 V_ahstat.ahs_hdrops++;
702 /* Crypto operation descriptor. */
703 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
704 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
705 crp->crp_buf = (caddr_t) m;
706 crp->crp_callback = ah_input_cb;
707 crp->crp_sid = sav->tdb_cryptoid;
708 crp->crp_opaque = (caddr_t) tc;
710 /* These are passed as-is to the callback. */
711 tc->tc_spi = sav->spi;
712 tc->tc_dst = sav->sah->saidx.dst;
713 tc->tc_proto = sav->sah->saidx.proto;
714 tc->tc_nxt = ah->ah_nxt;
715 tc->tc_protoff = protoff;
717 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
720 return crypto_dispatch(crp);
722 return ah_input_cb(crp);
726 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
727 if (saidx->dst.sa.sa_family == AF_INET6) { \
728 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
730 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
734 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
735 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
739 * AH input callback from the crypto driver.
742 ah_input_cb(struct cryptop *crp)
744 int rplen, error, skip, protoff;
745 unsigned char calc[AH_ALEN_MAX];
747 struct cryptodesc *crd;
748 struct auth_hash *ahx;
749 struct tdb_crypto *tc;
751 struct secasvar *sav;
752 struct secasindex *saidx;
759 tc = (struct tdb_crypto *) crp->crp_opaque;
760 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
763 protoff = tc->tc_protoff;
764 mtag = (struct m_tag *) tc->tc_ptr;
765 m = (struct mbuf *) crp->crp_buf;
767 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
769 V_ahstat.ahs_notdb++;
770 DPRINTF(("%s: SA expired while in crypto\n", __func__));
771 error = ENOBUFS; /*XXX*/
775 saidx = &sav->sah->saidx;
776 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
777 saidx->dst.sa.sa_family == AF_INET6,
778 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
780 ahx = (struct auth_hash *) sav->tdb_authalgxform;
782 /* Check for crypto errors. */
783 if (crp->crp_etype) {
784 if (sav->tdb_cryptoid != 0)
785 sav->tdb_cryptoid = crp->crp_sid;
787 if (crp->crp_etype == EAGAIN) {
788 error = crypto_dispatch(crp);
792 V_ahstat.ahs_noxform++;
793 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
794 error = crp->crp_etype;
797 V_ahstat.ahs_hist[sav->alg_auth]++;
798 crypto_freereq(crp); /* No longer needed. */
802 /* Shouldn't happen... */
804 V_ahstat.ahs_crypto++;
805 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
810 /* Figure out header size. */
811 rplen = HDRSIZE(sav);
812 authsize = AUTHSIZE(sav);
814 /* Copy authenticator off the packet. */
815 m_copydata(m, skip + rplen, authsize, calc);
818 * If we have an mtag, we don't need to verify the authenticator --
819 * it has been verified by an IPsec-aware NIC.
822 ptr = (caddr_t) (tc + 1);
824 /* Verify authenticator. */
825 if (bcmp(ptr + skip + rplen, calc, authsize)) {
826 DPRINTF(("%s: authentication hash mismatch for packet "
827 "in SA %s/%08lx\n", __func__,
828 ipsec_address(&saidx->dst),
829 (u_long) ntohl(sav->spi)));
830 V_ahstat.ahs_badauth++;
835 /* Fix the Next Protocol field. */
836 ((u_int8_t *) ptr)[protoff] = nxt;
838 /* Copyback the saved (uncooked) network headers. */
839 m_copyback(m, 0, skip, ptr);
841 /* Fix the Next Protocol field. */
842 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
845 free(tc, M_XDATA), tc = NULL; /* No longer needed */
848 * Header is now authenticated.
850 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
853 * Update replay sequence number, if appropriate.
858 m_copydata(m, skip + offsetof(struct newah, ah_seq),
859 sizeof (seq), (caddr_t) &seq);
860 if (ipsec_updatereplay(ntohl(seq), sav)) {
861 V_ahstat.ahs_replay++;
862 error = ENOBUFS; /*XXX as above*/
868 * Remove the AH header and authenticator from the mbuf.
870 error = m_striphdr(m, skip, rplen + authsize);
872 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
873 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
875 V_ahstat.ahs_hdrops++;
879 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
896 * AH output routine, called by ipsec[46]_process_packet().
901 struct ipsecrequest *isr,
906 struct secasvar *sav;
907 struct auth_hash *ahx;
908 struct cryptodesc *crda;
909 struct tdb_crypto *tc;
913 int error, rplen, authsize, maxpacketsize, roff;
918 IPSEC_ASSERT(sav != NULL, ("null SA"));
919 ahx = sav->tdb_authalgxform;
920 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
922 V_ahstat.ahs_output++;
924 /* Figure out header size. */
925 rplen = HDRSIZE(sav);
927 /* Check for maximum packet size violations. */
928 switch (sav->sah->saidx.dst.sa.sa_family) {
931 maxpacketsize = IP_MAXPACKET;
936 maxpacketsize = IPV6_MAXPACKET;
940 DPRINTF(("%s: unknown/unsupported protocol family %u, "
941 "SA %s/%08lx\n", __func__,
942 sav->sah->saidx.dst.sa.sa_family,
943 ipsec_address(&sav->sah->saidx.dst),
944 (u_long) ntohl(sav->spi)));
946 error = EPFNOSUPPORT;
949 authsize = AUTHSIZE(sav);
950 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
951 DPRINTF(("%s: packet in SA %s/%08lx got too big "
952 "(len %u, max len %u)\n", __func__,
953 ipsec_address(&sav->sah->saidx.dst),
954 (u_long) ntohl(sav->spi),
955 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
956 V_ahstat.ahs_toobig++;
961 /* Update the counters. */
962 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
964 m = m_unshare(m, M_NOWAIT);
966 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
967 ipsec_address(&sav->sah->saidx.dst),
968 (u_long) ntohl(sav->spi)));
969 V_ahstat.ahs_hdrops++;
974 /* Inject AH header. */
975 mi = m_makespace(m, skip, rplen + authsize, &roff);
977 DPRINTF(("%s: failed to inject %u byte AH header for SA "
978 "%s/%08lx\n", __func__,
980 ipsec_address(&sav->sah->saidx.dst),
981 (u_long) ntohl(sav->spi)));
982 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */
988 * The AH header is guaranteed by m_makespace() to be in
989 * contiguous memory, at roff bytes offset into the returned mbuf.
991 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
993 /* Initialize the AH header. */
994 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
995 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
997 ah->ah_spi = sav->spi;
999 /* Zeroize authenticator. */
1000 m_copyback(m, skip + rplen, authsize, ipseczeroes);
1002 /* Insert packet replay counter, as requested. */
1004 if (sav->replay->count == ~0 &&
1005 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1006 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
1008 ipsec_address(&sav->sah->saidx.dst),
1009 (u_long) ntohl(sav->spi)));
1010 V_ahstat.ahs_wrap++;
1015 /* Emulate replay attack when ipsec_replay is TRUE. */
1016 if (!V_ipsec_replay)
1018 sav->replay->count++;
1019 ah->ah_seq = htonl(sav->replay->count);
1022 /* Get crypto descriptors. */
1023 crp = crypto_getreq(1);
1025 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1027 V_ahstat.ahs_crypto++;
1032 crda = crp->crp_desc;
1035 crda->crd_inject = skip + rplen;
1036 crda->crd_len = m->m_pkthdr.len;
1038 /* Authentication operation. */
1039 crda->crd_alg = ahx->type;
1040 crda->crd_key = sav->key_auth->key_data;
1041 crda->crd_klen = _KEYBITS(sav->key_auth);
1043 /* Allocate IPsec-specific opaque crypto info. */
1044 tc = (struct tdb_crypto *) malloc(
1045 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1047 crypto_freereq(crp);
1048 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1049 V_ahstat.ahs_crypto++;
1054 /* Save the skipped portion of the packet. */
1055 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1058 * Fix IP header length on the header used for
1059 * authentication. We don't need to fix the original
1060 * header length as it will be fixed by our caller.
1062 switch (sav->sah->saidx.dst.sa.sa_family) {
1065 bcopy(((caddr_t)(tc + 1)) +
1066 offsetof(struct ip, ip_len),
1067 (caddr_t) &iplen, sizeof(u_int16_t));
1068 iplen = htons(ntohs(iplen) + rplen + authsize);
1069 m_copyback(m, offsetof(struct ip, ip_len),
1070 sizeof(u_int16_t), (caddr_t) &iplen);
1076 bcopy(((caddr_t)(tc + 1)) +
1077 offsetof(struct ip6_hdr, ip6_plen),
1078 (caddr_t) &iplen, sizeof(u_int16_t));
1079 iplen = htons(ntohs(iplen) + rplen + authsize);
1080 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1081 sizeof(u_int16_t), (caddr_t) &iplen);
1086 /* Fix the Next Header field in saved header. */
1087 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1089 /* Update the Next Protocol field in the IP header. */
1091 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1093 /* "Massage" the packet headers for crypto processing. */
1094 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1095 skip, ahx->type, 1);
1097 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1099 crypto_freereq(crp);
1103 /* Crypto operation descriptor. */
1104 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1105 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1106 crp->crp_buf = (caddr_t) m;
1107 crp->crp_callback = ah_output_cb;
1108 crp->crp_sid = sav->tdb_cryptoid;
1109 crp->crp_opaque = (caddr_t) tc;
1111 /* These are passed as-is to the callback. */
1113 tc->tc_spi = sav->spi;
1114 tc->tc_dst = sav->sah->saidx.dst;
1115 tc->tc_proto = sav->sah->saidx.proto;
1117 tc->tc_protoff = protoff;
1119 return crypto_dispatch(crp);
1127 * AH output callback from the crypto driver.
1130 ah_output_cb(struct cryptop *crp)
1132 int skip, protoff, error;
1133 struct tdb_crypto *tc;
1134 struct ipsecrequest *isr;
1135 struct secasvar *sav;
1140 tc = (struct tdb_crypto *) crp->crp_opaque;
1141 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1143 protoff = tc->tc_protoff;
1144 ptr = (caddr_t) (tc + 1);
1145 m = (struct mbuf *) crp->crp_buf;
1148 IPSECREQUEST_LOCK(isr);
1149 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1151 V_ahstat.ahs_notdb++;
1152 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1153 error = ENOBUFS; /*XXX*/
1156 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1158 /* Check for crypto errors. */
1159 if (crp->crp_etype) {
1160 if (sav->tdb_cryptoid != 0)
1161 sav->tdb_cryptoid = crp->crp_sid;
1163 if (crp->crp_etype == EAGAIN) {
1165 IPSECREQUEST_UNLOCK(isr);
1166 error = crypto_dispatch(crp);
1170 V_ahstat.ahs_noxform++;
1171 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1172 error = crp->crp_etype;
1176 /* Shouldn't happen... */
1178 V_ahstat.ahs_crypto++;
1179 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1183 V_ahstat.ahs_hist[sav->alg_auth]++;
1186 * Copy original headers (with the new protocol number) back
1189 m_copyback(m, 0, skip, ptr);
1191 /* No longer needed. */
1193 crypto_freereq(crp);
1196 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1197 if (V_ipsec_integrity) {
1201 * Corrupt HMAC if we want to test integrity verification of
1204 alen = AUTHSIZE(sav);
1205 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1209 /* NB: m is reclaimed by ipsec_process_done. */
1210 err = ipsec_process_done(m, isr);
1212 IPSECREQUEST_UNLOCK(isr);
1217 IPSECREQUEST_UNLOCK(isr);
1221 crypto_freereq(crp);
1225 static struct xformsw ah_xformsw = {
1226 XF_AH, XFT_AUTH, "IPsec AH",
1227 ah_init, ah_zeroize, ah_input, ah_output,
1234 xform_register(&ah_xformsw);
1237 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);