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);
95 SYSCTL_DECL(_net_inet_ah);
96 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
97 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
98 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
99 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
100 SYSCTL_VNET_STRUCT(_net_inet_ah, IPSECCTL_STATS,
101 stats, CTLFLAG_RD, &VNET_NAME(ahstat), ahstat, "");
104 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
106 static int ah_input_cb(struct cryptop*);
107 static int ah_output_cb(struct cryptop*);
110 ah_authsize(struct secasvar *sav)
113 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
115 if (sav->flags & SADB_X_EXT_OLD)
118 switch (sav->alg_auth) {
119 case SADB_X_AALG_SHA2_256:
121 case SADB_X_AALG_SHA2_384:
123 case SADB_X_AALG_SHA2_512:
126 return AH_HMAC_HASHLEN;
131 * NB: this is public for use by the PF_KEY support.
134 ah_algorithm_lookup(int alg)
136 if (alg > SADB_AALG_MAX)
139 case SADB_X_AALG_NULL:
140 return &auth_hash_null;
141 case SADB_AALG_MD5HMAC:
142 return &auth_hash_hmac_md5;
143 case SADB_AALG_SHA1HMAC:
144 return &auth_hash_hmac_sha1;
145 case SADB_X_AALG_RIPEMD160HMAC:
146 return &auth_hash_hmac_ripemd_160;
147 case SADB_X_AALG_MD5:
148 return &auth_hash_key_md5;
149 case SADB_X_AALG_SHA:
150 return &auth_hash_key_sha1;
151 case SADB_X_AALG_SHA2_256:
152 return &auth_hash_hmac_sha2_256;
153 case SADB_X_AALG_SHA2_384:
154 return &auth_hash_hmac_sha2_384;
155 case SADB_X_AALG_SHA2_512:
156 return &auth_hash_hmac_sha2_512;
162 ah_hdrsiz(struct secasvar *sav)
168 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
169 /*XXX not right for null algorithm--does it matter??*/
170 authsize = AUTHSIZE(sav);
171 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
174 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
180 * NB: public for use by esp_init.
183 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
185 struct auth_hash *thash;
188 thash = ah_algorithm_lookup(sav->alg_auth);
190 DPRINTF(("%s: unsupported authentication algorithm %u\n",
191 __func__, sav->alg_auth));
195 * Verify the replay state block allocation is consistent with
196 * the protocol type. We check here so we can make assumptions
197 * later during protocol processing.
199 /* NB: replay state is setup elsewhere (sigh) */
200 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
201 DPRINTF(("%s: replay state block inconsistency, "
202 "%s algorithm %s replay state\n", __func__,
203 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
204 sav->replay == NULL ? "without" : "with"));
207 if (sav->key_auth == NULL) {
208 DPRINTF(("%s: no authentication key for %s algorithm\n",
209 __func__, thash->name));
212 keylen = _KEYLEN(sav->key_auth);
213 if (keylen != thash->keysize && thash->keysize != 0) {
214 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
215 "keysize %d\n", __func__,
216 keylen, thash->name, thash->keysize));
220 sav->tdb_xform = xsp;
221 sav->tdb_authalgxform = thash;
223 /* Initialize crypto session. */
224 bzero(cria, sizeof (*cria));
225 cria->cri_alg = sav->tdb_authalgxform->type;
226 cria->cri_klen = _KEYBITS(sav->key_auth);
227 cria->cri_key = sav->key_auth->key_data;
228 cria->cri_mlen = AUTHSIZE(sav);
234 * ah_init() is called when an SPI is being set up.
237 ah_init(struct secasvar *sav, struct xformsw *xsp)
239 struct cryptoini cria;
242 error = ah_init0(sav, xsp, &cria);
243 return error ? error :
244 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
250 * NB: public for use by esp_zeroize (XXX).
253 ah_zeroize(struct secasvar *sav)
258 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
260 err = crypto_freesession(sav->tdb_cryptoid);
261 sav->tdb_cryptoid = 0;
262 sav->tdb_authalgxform = NULL;
263 sav->tdb_xform = NULL;
268 * Massage IPv4/IPv6 headers for AH processing.
271 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
273 struct mbuf *m = *m0;
282 struct ip6_ext *ip6e;
291 * This is the least painful way of dealing with IPv4 header
292 * and option processing -- just make sure they're in
295 *m0 = m = m_pullup(m, skip);
297 DPRINTF(("%s: m_pullup failed\n", __func__));
301 /* Fix the IP header */
302 ip = mtod(m, struct ip *);
309 * On input, fix ip_len which has been byte-swapped
313 ip->ip_len = htons(ip->ip_len + skip);
315 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
316 ip->ip_off = htons(ip->ip_off & IP_DF);
320 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
321 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
326 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
328 /* IPv4 option processing */
329 for (off = sizeof(struct ip); off < skip;) {
330 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
334 DPRINTF(("%s: illegal IPv4 option length for "
335 "option %d\n", __func__, ptr[off]));
343 off = skip; /* End the loop. */
350 case IPOPT_SECURITY: /* 0x82 */
351 case 0x85: /* Extended security. */
352 case 0x86: /* Commercial security. */
353 case 0x94: /* Router alert */
354 case 0x95: /* RFC1770 */
355 /* Sanity check for option length. */
356 if (ptr[off + 1] < 2) {
357 DPRINTF(("%s: illegal IPv4 option "
358 "length for option %d\n",
359 __func__, ptr[off]));
370 /* Sanity check for option length. */
371 if (ptr[off + 1] < 2) {
372 DPRINTF(("%s: illegal IPv4 option "
373 "length for option %d\n",
374 __func__, ptr[off]));
381 * On output, if we have either of the
382 * source routing options, we should
383 * swap the destination address of the
384 * IP header with the last address
385 * specified in the option, as that is
386 * what the destination's IP header
390 bcopy(ptr + off + ptr[off + 1] -
391 sizeof(struct in_addr),
392 &(ip->ip_dst), sizeof(struct in_addr));
396 /* Sanity check for option length. */
397 if (ptr[off + 1] < 2) {
398 DPRINTF(("%s: illegal IPv4 option "
399 "length for option %d\n",
400 __func__, ptr[off]));
405 /* Zeroize all other options. */
406 count = ptr[off + 1];
407 bcopy(ipseczeroes, ptr, count);
414 DPRINTF(("%s: malformed IPv4 options header\n",
426 case AF_INET6: /* Ugly... */
427 /* Copy and "cook" the IPv6 header. */
428 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
430 /* We don't do IPv6 Jumbograms. */
431 if (ip6.ip6_plen == 0) {
432 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
439 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
440 ip6.ip6_vfc |= IPV6_VERSION;
442 /* Scoped address handling. */
443 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
444 ip6.ip6_src.s6_addr16[1] = 0;
445 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
446 ip6.ip6_dst.s6_addr16[1] = 0;
448 /* Done with IPv6 header. */
449 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
451 /* Let's deal with the remaining headers (if any). */
452 if (skip - sizeof(struct ip6_hdr) > 0) {
453 if (m->m_len <= skip) {
454 ptr = (unsigned char *) malloc(
455 skip - sizeof(struct ip6_hdr),
458 DPRINTF(("%s: failed to allocate memory"
459 "for IPv6 headers\n",__func__));
465 * Copy all the protocol headers after
468 m_copydata(m, sizeof(struct ip6_hdr),
469 skip - sizeof(struct ip6_hdr), ptr);
472 /* No need to allocate memory. */
473 ptr = mtod(m, unsigned char *) +
474 sizeof(struct ip6_hdr);
480 off = ip6.ip6_nxt & 0xff; /* Next header type. */
482 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
484 case IPPROTO_HOPOPTS:
485 case IPPROTO_DSTOPTS:
486 ip6e = (struct ip6_ext *) (ptr + len);
489 * Process the mutable/immutable
490 * options -- borrows heavily from the
493 for (count = len + sizeof(struct ip6_ext);
494 count < len + ((ip6e->ip6e_len + 1) << 3);) {
495 if (ptr[count] == IP6OPT_PAD1) {
497 continue; /* Skip padding. */
502 ((ip6e->ip6e_len + 1) << 3)) {
505 /* Free, if we allocated. */
513 /* If mutable option, zeroize. */
514 if (ptr[count] & IP6OPT_MUTABLE)
515 bcopy(ipseczeroes, ptr + count,
522 skip - sizeof(struct ip6_hdr)) {
525 /* Free, if we allocated. */
533 len += ((ip6e->ip6e_len + 1) << 3);
534 off = ip6e->ip6e_nxt;
537 case IPPROTO_ROUTING:
539 * Always include routing headers in
542 ip6e = (struct ip6_ext *) (ptr + len);
543 len += ((ip6e->ip6e_len + 1) << 3);
544 off = ip6e->ip6e_nxt;
548 DPRINTF(("%s: unexpected IPv6 header type %d",
556 /* Copyback and free, if we allocated. */
558 m_copyback(m, sizeof(struct ip6_hdr),
559 skip - sizeof(struct ip6_hdr), ptr);
571 * ah_input() gets called to verify that an input packet
572 * passes authentication.
575 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
577 struct auth_hash *ahx;
578 struct tdb_ident *tdbi;
579 struct tdb_crypto *tc;
582 int hl, rplen, authsize;
584 struct cryptodesc *crda;
587 IPSEC_ASSERT(sav != NULL, ("null SA"));
588 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
589 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
590 ("null authentication xform"));
592 /* Figure out header size. */
593 rplen = HDRSIZE(sav);
595 /* XXX don't pullup, just copy header */
596 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
598 DPRINTF(("ah_input: cannot pullup header\n"));
599 AHSTAT_INC(ahs_hdrops); /*XXX*/
604 /* Check replay window, if applicable. */
605 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
606 AHSTAT_INC(ahs_replay);
607 DPRINTF(("%s: packet replay failure: %s\n", __func__,
608 ipsec_logsastr(sav)));
613 /* Verify AH header length. */
614 hl = ah->ah_len * sizeof (u_int32_t);
615 ahx = sav->tdb_authalgxform;
616 authsize = AUTHSIZE(sav);
617 if (hl != authsize + rplen - sizeof (struct ah)) {
618 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
619 " for packet in SA %s/%08lx\n", __func__,
620 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
621 ipsec_address(&sav->sah->saidx.dst),
622 (u_long) ntohl(sav->spi)));
623 AHSTAT_INC(ahs_badauthl);
627 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
629 /* Get crypto descriptors. */
630 crp = crypto_getreq(1);
632 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
633 AHSTAT_INC(ahs_crypto);
638 crda = crp->crp_desc;
639 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
642 crda->crd_len = m->m_pkthdr.len;
643 crda->crd_inject = skip + rplen;
645 /* Authentication operation. */
646 crda->crd_alg = ahx->type;
647 crda->crd_klen = _KEYBITS(sav->key_auth);
648 crda->crd_key = sav->key_auth->key_data;
650 /* Find out if we've already done crypto. */
651 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
653 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
654 tdbi = (struct tdb_ident *) (mtag + 1);
655 if (tdbi->proto == sav->sah->saidx.proto &&
656 tdbi->spi == sav->spi &&
657 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
658 sizeof (union sockaddr_union)))
662 /* Allocate IPsec-specific opaque crypto info. */
664 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
665 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
667 /* Hash verification has already been done successfully. */
668 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
669 M_XDATA, M_NOWAIT|M_ZERO);
672 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
673 AHSTAT_INC(ahs_crypto);
679 /* Only save information if crypto processing is needed. */
684 * Save the authenticator, the skipped portion of the packet,
687 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
689 /* Zeroize the authenticator on the packet. */
690 m_copyback(m, skip + rplen, authsize, ipseczeroes);
692 /* "Massage" the packet headers for crypto processing. */
693 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
696 /* NB: mbuf is free'd by ah_massage_headers */
697 AHSTAT_INC(ahs_hdrops);
704 /* Crypto operation descriptor. */
705 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
706 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
707 crp->crp_buf = (caddr_t) m;
708 crp->crp_callback = ah_input_cb;
709 crp->crp_sid = sav->tdb_cryptoid;
710 crp->crp_opaque = (caddr_t) tc;
712 /* These are passed as-is to the callback. */
713 tc->tc_spi = sav->spi;
714 tc->tc_dst = sav->sah->saidx.dst;
715 tc->tc_proto = sav->sah->saidx.proto;
716 tc->tc_nxt = ah->ah_nxt;
717 tc->tc_protoff = protoff;
719 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
724 return crypto_dispatch(crp);
726 return ah_input_cb(crp);
730 * AH input callback from the crypto driver.
733 ah_input_cb(struct cryptop *crp)
735 int rplen, error, skip, protoff;
736 unsigned char calc[AH_ALEN_MAX];
738 struct cryptodesc *crd;
739 struct auth_hash *ahx;
740 struct tdb_crypto *tc;
742 struct secasvar *sav;
743 struct secasindex *saidx;
750 tc = (struct tdb_crypto *) crp->crp_opaque;
751 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
754 protoff = tc->tc_protoff;
755 mtag = (struct m_tag *) tc->tc_ptr;
756 m = (struct mbuf *) crp->crp_buf;
759 IPSEC_ASSERT(sav != NULL, ("null SA!"));
761 saidx = &sav->sah->saidx;
762 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
763 saidx->dst.sa.sa_family == AF_INET6,
764 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
766 ahx = (struct auth_hash *) sav->tdb_authalgxform;
768 /* Check for crypto errors. */
769 if (crp->crp_etype) {
770 if (sav->tdb_cryptoid != 0)
771 sav->tdb_cryptoid = crp->crp_sid;
773 if (crp->crp_etype == EAGAIN) {
774 error = crypto_dispatch(crp);
778 AHSTAT_INC(ahs_noxform);
779 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
780 error = crp->crp_etype;
783 AHSTAT_INC(ahs_hist[sav->alg_auth]);
784 crypto_freereq(crp); /* No longer needed. */
788 /* Shouldn't happen... */
790 AHSTAT_INC(ahs_crypto);
791 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
796 /* Figure out header size. */
797 rplen = HDRSIZE(sav);
798 authsize = AUTHSIZE(sav);
800 /* Copy authenticator off the packet. */
801 m_copydata(m, skip + rplen, authsize, calc);
804 * If we have an mtag, we don't need to verify the authenticator --
805 * it has been verified by an IPsec-aware NIC.
808 ptr = (caddr_t) (tc + 1);
810 /* Verify authenticator. */
811 if (bcmp(ptr + skip + rplen, calc, authsize)) {
812 DPRINTF(("%s: authentication hash mismatch for packet "
813 "in SA %s/%08lx\n", __func__,
814 ipsec_address(&saidx->dst),
815 (u_long) ntohl(sav->spi)));
816 AHSTAT_INC(ahs_badauth);
821 /* Fix the Next Protocol field. */
822 ((u_int8_t *) ptr)[protoff] = nxt;
824 /* Copyback the saved (uncooked) network headers. */
825 m_copyback(m, 0, skip, ptr);
827 /* Fix the Next Protocol field. */
828 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
831 free(tc, M_XDATA), tc = NULL; /* No longer needed */
834 * Header is now authenticated.
836 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
839 * Update replay sequence number, if appropriate.
844 m_copydata(m, skip + offsetof(struct newah, ah_seq),
845 sizeof (seq), (caddr_t) &seq);
846 if (ipsec_updatereplay(ntohl(seq), sav)) {
847 AHSTAT_INC(ahs_replay);
848 error = ENOBUFS; /*XXX as above*/
854 * Remove the AH header and authenticator from the mbuf.
856 error = m_striphdr(m, skip, rplen + authsize);
858 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
859 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
861 AHSTAT_INC(ahs_hdrops);
865 switch (saidx->dst.sa.sa_family) {
868 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag);
873 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag);
877 panic("%s: Unexpected address family: %d saidx=%p", __func__,
878 saidx->dst.sa.sa_family, saidx);
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 AHSTAT_INC(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)));
945 AHSTAT_INC(ahs_nopf);
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 AHSTAT_INC(ahs_toobig);
961 /* Update the counters. */
962 AHSTAT_ADD(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 AHSTAT_INC(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 AHSTAT_INC(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 AHSTAT_INC(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 AHSTAT_INC(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 AHSTAT_INC(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. */
1115 tc->tc_spi = sav->spi;
1116 tc->tc_dst = sav->sah->saidx.dst;
1117 tc->tc_proto = sav->sah->saidx.proto;
1119 tc->tc_protoff = protoff;
1121 return crypto_dispatch(crp);
1129 * AH output callback from the crypto driver.
1132 ah_output_cb(struct cryptop *crp)
1134 int skip, protoff, error;
1135 struct tdb_crypto *tc;
1136 struct ipsecrequest *isr;
1137 struct secasvar *sav;
1142 tc = (struct tdb_crypto *) crp->crp_opaque;
1143 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1145 protoff = tc->tc_protoff;
1146 ptr = (caddr_t) (tc + 1);
1147 m = (struct mbuf *) crp->crp_buf;
1150 IPSECREQUEST_LOCK(isr);
1152 /* With the isr lock released SA pointer can be updated. */
1153 if (sav != isr->sav) {
1154 AHSTAT_INC(ahs_notdb);
1155 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1156 error = ENOBUFS; /*XXX*/
1160 /* Check for crypto errors. */
1161 if (crp->crp_etype) {
1162 if (sav->tdb_cryptoid != 0)
1163 sav->tdb_cryptoid = crp->crp_sid;
1165 if (crp->crp_etype == EAGAIN) {
1166 IPSECREQUEST_UNLOCK(isr);
1167 error = crypto_dispatch(crp);
1171 AHSTAT_INC(ahs_noxform);
1172 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1173 error = crp->crp_etype;
1177 /* Shouldn't happen... */
1179 AHSTAT_INC(ahs_crypto);
1180 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1184 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1187 * Copy original headers (with the new protocol number) back
1190 m_copyback(m, 0, skip, ptr);
1192 /* No longer needed. */
1194 crypto_freereq(crp);
1197 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1198 if (V_ipsec_integrity) {
1202 * Corrupt HMAC if we want to test integrity verification of
1205 alen = AUTHSIZE(sav);
1206 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1210 /* NB: m is reclaimed by ipsec_process_done. */
1211 err = ipsec_process_done(m, isr);
1213 IPSECREQUEST_UNLOCK(isr);
1218 IPSECREQUEST_UNLOCK(isr);
1222 crypto_freereq(crp);
1226 static struct xformsw ah_xformsw = {
1227 XF_AH, XFT_AUTH, "IPsec AH",
1228 ah_init, ah_zeroize, ah_input, ah_output,
1235 xform_register(&ah_xformsw);
1238 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);