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_PCPUSTAT_DEFINE(struct ahstat, ahstat);
93 VNET_PCPUSTAT_SYSINIT(ahstat);
96 VNET_PCPUSTAT_SYSUNINIT(ahstat);
100 SYSCTL_DECL(_net_inet_ah);
101 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
102 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
103 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
104 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
105 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
106 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
109 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
111 static int ah_input_cb(struct cryptop*);
112 static int ah_output_cb(struct cryptop*);
115 ah_authsize(struct secasvar *sav)
118 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
120 if (sav->flags & SADB_X_EXT_OLD)
123 switch (sav->alg_auth) {
124 case SADB_X_AALG_SHA2_256:
126 case SADB_X_AALG_SHA2_384:
128 case SADB_X_AALG_SHA2_512:
131 return AH_HMAC_HASHLEN;
136 * NB: this is public for use by the PF_KEY support.
139 ah_algorithm_lookup(int alg)
141 if (alg > SADB_AALG_MAX)
144 case SADB_X_AALG_NULL:
145 return &auth_hash_null;
146 case SADB_AALG_MD5HMAC:
147 return &auth_hash_hmac_md5;
148 case SADB_AALG_SHA1HMAC:
149 return &auth_hash_hmac_sha1;
150 case SADB_X_AALG_RIPEMD160HMAC:
151 return &auth_hash_hmac_ripemd_160;
152 case SADB_X_AALG_MD5:
153 return &auth_hash_key_md5;
154 case SADB_X_AALG_SHA:
155 return &auth_hash_key_sha1;
156 case SADB_X_AALG_SHA2_256:
157 return &auth_hash_hmac_sha2_256;
158 case SADB_X_AALG_SHA2_384:
159 return &auth_hash_hmac_sha2_384;
160 case SADB_X_AALG_SHA2_512:
161 return &auth_hash_hmac_sha2_512;
167 ah_hdrsiz(struct secasvar *sav)
173 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
174 /*XXX not right for null algorithm--does it matter??*/
175 authsize = AUTHSIZE(sav);
176 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
179 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
185 * NB: public for use by esp_init.
188 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
190 struct auth_hash *thash;
193 thash = ah_algorithm_lookup(sav->alg_auth);
195 DPRINTF(("%s: unsupported authentication algorithm %u\n",
196 __func__, sav->alg_auth));
200 * Verify the replay state block allocation is consistent with
201 * the protocol type. We check here so we can make assumptions
202 * later during protocol processing.
204 /* NB: replay state is setup elsewhere (sigh) */
205 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
206 DPRINTF(("%s: replay state block inconsistency, "
207 "%s algorithm %s replay state\n", __func__,
208 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
209 sav->replay == NULL ? "without" : "with"));
212 if (sav->key_auth == NULL) {
213 DPRINTF(("%s: no authentication key for %s algorithm\n",
214 __func__, thash->name));
217 keylen = _KEYLEN(sav->key_auth);
218 if (keylen != thash->keysize && thash->keysize != 0) {
219 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
220 "keysize %d\n", __func__,
221 keylen, thash->name, thash->keysize));
225 sav->tdb_xform = xsp;
226 sav->tdb_authalgxform = thash;
228 /* Initialize crypto session. */
229 bzero(cria, sizeof (*cria));
230 cria->cri_alg = sav->tdb_authalgxform->type;
231 cria->cri_klen = _KEYBITS(sav->key_auth);
232 cria->cri_key = sav->key_auth->key_data;
233 cria->cri_mlen = AUTHSIZE(sav);
239 * ah_init() is called when an SPI is being set up.
242 ah_init(struct secasvar *sav, struct xformsw *xsp)
244 struct cryptoini cria;
247 error = ah_init0(sav, xsp, &cria);
248 return error ? error :
249 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
255 * NB: public for use by esp_zeroize (XXX).
258 ah_zeroize(struct secasvar *sav)
263 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
265 err = crypto_freesession(sav->tdb_cryptoid);
266 sav->tdb_cryptoid = 0;
267 sav->tdb_authalgxform = NULL;
268 sav->tdb_xform = NULL;
273 * Massage IPv4/IPv6 headers for AH processing.
276 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
278 struct mbuf *m = *m0;
287 struct ip6_ext *ip6e;
296 * This is the least painful way of dealing with IPv4 header
297 * and option processing -- just make sure they're in
300 *m0 = m = m_pullup(m, skip);
302 DPRINTF(("%s: m_pullup failed\n", __func__));
306 /* Fix the IP header */
307 ip = mtod(m, struct ip *);
313 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
314 ip->ip_off &= htons(IP_DF);
316 ip->ip_off = htons(0);
318 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
320 /* IPv4 option processing */
321 for (off = sizeof(struct ip); off < skip;) {
322 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
326 DPRINTF(("%s: illegal IPv4 option length for "
327 "option %d\n", __func__, ptr[off]));
335 off = skip; /* End the loop. */
342 case IPOPT_SECURITY: /* 0x82 */
343 case 0x85: /* Extended security. */
344 case 0x86: /* Commercial security. */
345 case 0x94: /* Router alert */
346 case 0x95: /* RFC1770 */
347 /* Sanity check for option length. */
348 if (ptr[off + 1] < 2) {
349 DPRINTF(("%s: illegal IPv4 option "
350 "length for option %d\n",
351 __func__, ptr[off]));
362 /* Sanity check for option length. */
363 if (ptr[off + 1] < 2) {
364 DPRINTF(("%s: illegal IPv4 option "
365 "length for option %d\n",
366 __func__, ptr[off]));
373 * On output, if we have either of the
374 * source routing options, we should
375 * swap the destination address of the
376 * IP header with the last address
377 * specified in the option, as that is
378 * what the destination's IP header
382 bcopy(ptr + off + ptr[off + 1] -
383 sizeof(struct in_addr),
384 &(ip->ip_dst), sizeof(struct in_addr));
388 /* Sanity check for option length. */
389 if (ptr[off + 1] < 2) {
390 DPRINTF(("%s: illegal IPv4 option "
391 "length for option %d\n",
392 __func__, ptr[off]));
397 /* Zeroize all other options. */
398 count = ptr[off + 1];
399 bcopy(ipseczeroes, ptr, count);
406 DPRINTF(("%s: malformed IPv4 options header\n",
418 case AF_INET6: /* Ugly... */
419 /* Copy and "cook" the IPv6 header. */
420 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
422 /* We don't do IPv6 Jumbograms. */
423 if (ip6.ip6_plen == 0) {
424 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
431 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
432 ip6.ip6_vfc |= IPV6_VERSION;
434 /* Scoped address handling. */
435 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
436 ip6.ip6_src.s6_addr16[1] = 0;
437 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
438 ip6.ip6_dst.s6_addr16[1] = 0;
440 /* Done with IPv6 header. */
441 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
443 /* Let's deal with the remaining headers (if any). */
444 if (skip - sizeof(struct ip6_hdr) > 0) {
445 if (m->m_len <= skip) {
446 ptr = (unsigned char *) malloc(
447 skip - sizeof(struct ip6_hdr),
450 DPRINTF(("%s: failed to allocate memory"
451 "for IPv6 headers\n",__func__));
457 * Copy all the protocol headers after
460 m_copydata(m, sizeof(struct ip6_hdr),
461 skip - sizeof(struct ip6_hdr), ptr);
464 /* No need to allocate memory. */
465 ptr = mtod(m, unsigned char *) +
466 sizeof(struct ip6_hdr);
472 off = ip6.ip6_nxt & 0xff; /* Next header type. */
474 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
476 case IPPROTO_HOPOPTS:
477 case IPPROTO_DSTOPTS:
478 ip6e = (struct ip6_ext *) (ptr + len);
481 * Process the mutable/immutable
482 * options -- borrows heavily from the
485 for (count = len + sizeof(struct ip6_ext);
486 count < len + ((ip6e->ip6e_len + 1) << 3);) {
487 if (ptr[count] == IP6OPT_PAD1) {
489 continue; /* Skip padding. */
494 ((ip6e->ip6e_len + 1) << 3)) {
497 /* Free, if we allocated. */
505 /* If mutable option, zeroize. */
506 if (ptr[count] & IP6OPT_MUTABLE)
507 bcopy(ipseczeroes, ptr + count,
514 skip - sizeof(struct ip6_hdr)) {
517 /* Free, if we allocated. */
525 len += ((ip6e->ip6e_len + 1) << 3);
526 off = ip6e->ip6e_nxt;
529 case IPPROTO_ROUTING:
531 * Always include routing headers in
534 ip6e = (struct ip6_ext *) (ptr + len);
535 len += ((ip6e->ip6e_len + 1) << 3);
536 off = ip6e->ip6e_nxt;
540 DPRINTF(("%s: unexpected IPv6 header type %d",
548 /* Copyback and free, if we allocated. */
550 m_copyback(m, sizeof(struct ip6_hdr),
551 skip - sizeof(struct ip6_hdr), ptr);
563 * ah_input() gets called to verify that an input packet
564 * passes authentication.
567 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
569 struct auth_hash *ahx;
570 struct tdb_ident *tdbi;
571 struct tdb_crypto *tc;
574 int hl, rplen, authsize;
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)));
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__,
612 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
613 ipsec_address(&sav->sah->saidx.dst),
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 /* Find out if we've already done crypto. */
643 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
645 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
646 tdbi = (struct tdb_ident *) (mtag + 1);
647 if (tdbi->proto == sav->sah->saidx.proto &&
648 tdbi->spi == sav->spi &&
649 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
650 sizeof (union sockaddr_union)))
654 /* Allocate IPsec-specific opaque crypto info. */
656 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
657 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
659 /* Hash verification has already been done successfully. */
660 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
661 M_XDATA, M_NOWAIT|M_ZERO);
664 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
665 AHSTAT_INC(ahs_crypto);
671 /* Only save information if crypto processing is needed. */
676 * Save the authenticator, the skipped portion of the packet,
679 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
681 /* Zeroize the authenticator on the packet. */
682 m_copyback(m, skip + rplen, authsize, ipseczeroes);
684 /* "Massage" the packet headers for crypto processing. */
685 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
688 /* NB: mbuf is free'd by ah_massage_headers */
689 AHSTAT_INC(ahs_hdrops);
696 /* Crypto operation descriptor. */
697 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
698 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
699 crp->crp_buf = (caddr_t) m;
700 crp->crp_callback = ah_input_cb;
701 crp->crp_sid = sav->tdb_cryptoid;
702 crp->crp_opaque = (caddr_t) tc;
704 /* These are passed as-is to the callback. */
705 tc->tc_spi = sav->spi;
706 tc->tc_dst = sav->sah->saidx.dst;
707 tc->tc_proto = sav->sah->saidx.proto;
708 tc->tc_nxt = ah->ah_nxt;
709 tc->tc_protoff = protoff;
711 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
716 return crypto_dispatch(crp);
718 return ah_input_cb(crp);
722 * AH input callback from the crypto driver.
725 ah_input_cb(struct cryptop *crp)
727 int rplen, error, skip, protoff;
728 unsigned char calc[AH_ALEN_MAX];
730 struct cryptodesc *crd;
731 struct auth_hash *ahx;
732 struct tdb_crypto *tc;
734 struct secasvar *sav;
735 struct secasindex *saidx;
742 tc = (struct tdb_crypto *) crp->crp_opaque;
743 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
746 protoff = tc->tc_protoff;
747 mtag = (struct m_tag *) tc->tc_ptr;
748 m = (struct mbuf *) crp->crp_buf;
751 IPSEC_ASSERT(sav != NULL, ("null SA!"));
753 saidx = &sav->sah->saidx;
754 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
755 saidx->dst.sa.sa_family == AF_INET6,
756 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
758 ahx = (struct auth_hash *) sav->tdb_authalgxform;
760 /* Check for crypto errors. */
761 if (crp->crp_etype) {
762 if (sav->tdb_cryptoid != 0)
763 sav->tdb_cryptoid = crp->crp_sid;
765 if (crp->crp_etype == EAGAIN)
766 return (crypto_dispatch(crp));
768 AHSTAT_INC(ahs_noxform);
769 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
770 error = crp->crp_etype;
773 AHSTAT_INC(ahs_hist[sav->alg_auth]);
774 crypto_freereq(crp); /* No longer needed. */
778 /* Shouldn't happen... */
780 AHSTAT_INC(ahs_crypto);
781 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
786 /* Figure out header size. */
787 rplen = HDRSIZE(sav);
788 authsize = AUTHSIZE(sav);
790 /* Copy authenticator off the packet. */
791 m_copydata(m, skip + rplen, authsize, calc);
794 * If we have an mtag, we don't need to verify the authenticator --
795 * it has been verified by an IPsec-aware NIC.
798 ptr = (caddr_t) (tc + 1);
800 /* Verify authenticator. */
801 if (bcmp(ptr + skip + rplen, calc, authsize)) {
802 DPRINTF(("%s: authentication hash mismatch for packet "
803 "in SA %s/%08lx\n", __func__,
804 ipsec_address(&saidx->dst),
805 (u_long) ntohl(sav->spi)));
806 AHSTAT_INC(ahs_badauth);
811 /* Fix the Next Protocol field. */
812 ((u_int8_t *) ptr)[protoff] = nxt;
814 /* Copyback the saved (uncooked) network headers. */
815 m_copyback(m, 0, skip, ptr);
817 /* Fix the Next Protocol field. */
818 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
821 free(tc, M_XDATA), tc = NULL; /* No longer needed */
824 * Header is now authenticated.
826 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
829 * Update replay sequence number, if appropriate.
834 m_copydata(m, skip + offsetof(struct newah, ah_seq),
835 sizeof (seq), (caddr_t) &seq);
836 if (ipsec_updatereplay(ntohl(seq), sav)) {
837 AHSTAT_INC(ahs_replay);
838 error = ENOBUFS; /*XXX as above*/
844 * Remove the AH header and authenticator from the mbuf.
846 error = m_striphdr(m, skip, rplen + authsize);
848 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
849 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
851 AHSTAT_INC(ahs_hdrops);
855 switch (saidx->dst.sa.sa_family) {
858 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag);
863 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag);
867 panic("%s: Unexpected address family: %d saidx=%p", __func__,
868 saidx->dst.sa.sa_family, saidx);
886 * AH output routine, called by ipsec[46]_process_packet().
891 struct ipsecrequest *isr,
896 struct secasvar *sav;
897 struct auth_hash *ahx;
898 struct cryptodesc *crda;
899 struct tdb_crypto *tc;
903 int error, rplen, authsize, maxpacketsize, roff;
908 IPSEC_ASSERT(sav != NULL, ("null SA"));
909 ahx = sav->tdb_authalgxform;
910 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
912 AHSTAT_INC(ahs_output);
914 /* Figure out header size. */
915 rplen = HDRSIZE(sav);
917 /* Check for maximum packet size violations. */
918 switch (sav->sah->saidx.dst.sa.sa_family) {
921 maxpacketsize = IP_MAXPACKET;
926 maxpacketsize = IPV6_MAXPACKET;
930 DPRINTF(("%s: unknown/unsupported protocol family %u, "
931 "SA %s/%08lx\n", __func__,
932 sav->sah->saidx.dst.sa.sa_family,
933 ipsec_address(&sav->sah->saidx.dst),
934 (u_long) ntohl(sav->spi)));
935 AHSTAT_INC(ahs_nopf);
936 error = EPFNOSUPPORT;
939 authsize = AUTHSIZE(sav);
940 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
941 DPRINTF(("%s: packet in SA %s/%08lx got too big "
942 "(len %u, max len %u)\n", __func__,
943 ipsec_address(&sav->sah->saidx.dst),
944 (u_long) ntohl(sav->spi),
945 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
946 AHSTAT_INC(ahs_toobig);
951 /* Update the counters. */
952 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
954 m = m_unshare(m, M_NOWAIT);
956 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
957 ipsec_address(&sav->sah->saidx.dst),
958 (u_long) ntohl(sav->spi)));
959 AHSTAT_INC(ahs_hdrops);
964 /* Inject AH header. */
965 mi = m_makespace(m, skip, rplen + authsize, &roff);
967 DPRINTF(("%s: failed to inject %u byte AH header for SA "
968 "%s/%08lx\n", __func__,
970 ipsec_address(&sav->sah->saidx.dst),
971 (u_long) ntohl(sav->spi)));
972 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
978 * The AH header is guaranteed by m_makespace() to be in
979 * contiguous memory, at roff bytes offset into the returned mbuf.
981 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
983 /* Initialize the AH header. */
984 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
985 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
987 ah->ah_spi = sav->spi;
989 /* Zeroize authenticator. */
990 m_copyback(m, skip + rplen, authsize, ipseczeroes);
992 /* Insert packet replay counter, as requested. */
994 if (sav->replay->count == ~0 &&
995 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
996 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
998 ipsec_address(&sav->sah->saidx.dst),
999 (u_long) ntohl(sav->spi)));
1000 AHSTAT_INC(ahs_wrap);
1005 /* Emulate replay attack when ipsec_replay is TRUE. */
1006 if (!V_ipsec_replay)
1008 sav->replay->count++;
1009 ah->ah_seq = htonl(sav->replay->count);
1012 /* Get crypto descriptors. */
1013 crp = crypto_getreq(1);
1015 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1017 AHSTAT_INC(ahs_crypto);
1022 crda = crp->crp_desc;
1025 crda->crd_inject = skip + rplen;
1026 crda->crd_len = m->m_pkthdr.len;
1028 /* Authentication operation. */
1029 crda->crd_alg = ahx->type;
1030 crda->crd_key = sav->key_auth->key_data;
1031 crda->crd_klen = _KEYBITS(sav->key_auth);
1033 /* Allocate IPsec-specific opaque crypto info. */
1034 tc = (struct tdb_crypto *) malloc(
1035 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1037 crypto_freereq(crp);
1038 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1039 AHSTAT_INC(ahs_crypto);
1044 /* Save the skipped portion of the packet. */
1045 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1048 * Fix IP header length on the header used for
1049 * authentication. We don't need to fix the original
1050 * header length as it will be fixed by our caller.
1052 switch (sav->sah->saidx.dst.sa.sa_family) {
1055 bcopy(((caddr_t)(tc + 1)) +
1056 offsetof(struct ip, ip_len),
1057 (caddr_t) &iplen, sizeof(u_int16_t));
1058 iplen = htons(ntohs(iplen) + rplen + authsize);
1059 m_copyback(m, offsetof(struct ip, ip_len),
1060 sizeof(u_int16_t), (caddr_t) &iplen);
1066 bcopy(((caddr_t)(tc + 1)) +
1067 offsetof(struct ip6_hdr, ip6_plen),
1068 (caddr_t) &iplen, sizeof(u_int16_t));
1069 iplen = htons(ntohs(iplen) + rplen + authsize);
1070 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1071 sizeof(u_int16_t), (caddr_t) &iplen);
1076 /* Fix the Next Header field in saved header. */
1077 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1079 /* Update the Next Protocol field in the IP header. */
1081 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1083 /* "Massage" the packet headers for crypto processing. */
1084 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1085 skip, ahx->type, 1);
1087 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1089 crypto_freereq(crp);
1093 /* Crypto operation descriptor. */
1094 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1095 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1096 crp->crp_buf = (caddr_t) m;
1097 crp->crp_callback = ah_output_cb;
1098 crp->crp_sid = sav->tdb_cryptoid;
1099 crp->crp_opaque = (caddr_t) tc;
1101 /* These are passed as-is to the callback. */
1105 tc->tc_spi = sav->spi;
1106 tc->tc_dst = sav->sah->saidx.dst;
1107 tc->tc_proto = sav->sah->saidx.proto;
1109 tc->tc_protoff = protoff;
1111 return crypto_dispatch(crp);
1119 * AH output callback from the crypto driver.
1122 ah_output_cb(struct cryptop *crp)
1124 int skip, protoff, error;
1125 struct tdb_crypto *tc;
1126 struct ipsecrequest *isr;
1127 struct secasvar *sav;
1131 tc = (struct tdb_crypto *) crp->crp_opaque;
1132 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1134 protoff = tc->tc_protoff;
1135 ptr = (caddr_t) (tc + 1);
1136 m = (struct mbuf *) crp->crp_buf;
1139 IPSECREQUEST_LOCK(isr);
1141 /* With the isr lock released SA pointer can be updated. */
1142 if (sav != isr->sav) {
1143 AHSTAT_INC(ahs_notdb);
1144 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1145 error = ENOBUFS; /*XXX*/
1149 /* Check for crypto errors. */
1150 if (crp->crp_etype) {
1151 if (sav->tdb_cryptoid != 0)
1152 sav->tdb_cryptoid = crp->crp_sid;
1154 if (crp->crp_etype == EAGAIN) {
1155 IPSECREQUEST_UNLOCK(isr);
1156 return (crypto_dispatch(crp));
1159 AHSTAT_INC(ahs_noxform);
1160 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1161 error = crp->crp_etype;
1165 /* Shouldn't happen... */
1167 AHSTAT_INC(ahs_crypto);
1168 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1172 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1175 * Copy original headers (with the new protocol number) back
1178 m_copyback(m, 0, skip, ptr);
1180 /* No longer needed. */
1182 crypto_freereq(crp);
1185 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1186 if (V_ipsec_integrity) {
1190 * Corrupt HMAC if we want to test integrity verification of
1193 alen = AUTHSIZE(sav);
1194 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1198 /* NB: m is reclaimed by ipsec_process_done. */
1199 error = ipsec_process_done(m, isr);
1201 IPSECREQUEST_UNLOCK(isr);
1206 IPSECREQUEST_UNLOCK(isr);
1210 crypto_freereq(crp);
1214 static struct xformsw ah_xformsw = {
1215 XF_AH, XFT_AUTH, "IPsec AH",
1216 ah_init, ah_zeroize, ah_input, ah_output,
1223 xform_register(&ah_xformsw);
1226 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);