2 /* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
4 * The authors of this code are John Ioannidis (ji@tla.org),
5 * Angelos D. Keromytis (kermit@csd.uch.gr) and
6 * Niels Provos (provos@physnet.uni-hamburg.de).
8 * The original version of this code was written by John Ioannidis
9 * for BSD/OS in Athens, Greece, in November 1995.
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
17 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
19 * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
20 * Angelos D. Keromytis and Niels Provos.
21 * Copyright (c) 1999 Niklas Hallqvist.
22 * Copyright (c) 2001 Angelos D. Keromytis.
24 * Permission to use, copy, and modify this software with or without fee
25 * is hereby granted, provided that this entire notice is included in
26 * all copies of any software which is or includes a copy or
27 * modification of this software.
28 * You may use this code under the GNU public license if you so wish. Please
29 * contribute changes back to the authors under this freer than GPL license
30 * so that we may further the use of strong encryption without limitations to
33 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
34 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
35 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
36 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
40 #include "opt_inet6.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
45 #include <sys/socket.h>
46 #include <sys/syslog.h>
47 #include <sys/kernel.h>
49 #include <sys/rwlock.h>
50 #include <sys/sysctl.h>
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_ecn.h>
59 #include <netinet/ip6.h>
61 #include <net/route.h>
62 #include <netipsec/ipsec.h>
63 #include <netipsec/ah.h>
64 #include <netipsec/ah_var.h>
65 #include <netipsec/xform.h>
68 #include <netinet6/ip6_var.h>
69 #include <netipsec/ipsec6.h>
70 #include <netinet6/ip6_ecn.h>
73 #include <netipsec/key.h>
74 #include <netipsec/key_debug.h>
76 #include <opencrypto/cryptodev.h>
79 * Return header size in bytes. The old protocol did not support
80 * the replay counter; the new protocol always includes the counter.
82 #define HDRSIZE(sav) \
83 (((sav)->flags & SADB_X_EXT_OLD) ? \
84 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
86 * Return authenticator size in bytes. The old protocol is known
87 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
90 #define AUTHSIZE(sav) ah_authsize(sav)
92 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
93 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
94 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
95 VNET_PCPUSTAT_SYSINIT(ahstat);
98 VNET_PCPUSTAT_SYSUNINIT(ahstat);
102 SYSCTL_DECL(_net_inet_ah);
103 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
104 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
105 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
106 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
107 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
108 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
111 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
113 static int ah_input_cb(struct cryptop*);
114 static int ah_output_cb(struct cryptop*);
117 ah_authsize(struct secasvar *sav)
120 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
122 if (sav->flags & SADB_X_EXT_OLD)
125 switch (sav->alg_auth) {
126 case SADB_X_AALG_SHA2_256:
128 case SADB_X_AALG_SHA2_384:
130 case SADB_X_AALG_SHA2_512:
133 return AH_HMAC_HASHLEN;
138 * NB: this is public for use by the PF_KEY support.
141 ah_algorithm_lookup(int alg)
143 if (alg > SADB_AALG_MAX)
146 case SADB_X_AALG_NULL:
147 return &auth_hash_null;
148 case SADB_AALG_MD5HMAC:
149 return &auth_hash_hmac_md5;
150 case SADB_AALG_SHA1HMAC:
151 return &auth_hash_hmac_sha1;
152 case SADB_X_AALG_RIPEMD160HMAC:
153 return &auth_hash_hmac_ripemd_160;
154 case SADB_X_AALG_MD5:
155 return &auth_hash_key_md5;
156 case SADB_X_AALG_SHA:
157 return &auth_hash_key_sha1;
158 case SADB_X_AALG_SHA2_256:
159 return &auth_hash_hmac_sha2_256;
160 case SADB_X_AALG_SHA2_384:
161 return &auth_hash_hmac_sha2_384;
162 case SADB_X_AALG_SHA2_512:
163 return &auth_hash_hmac_sha2_512;
169 ah_hdrsiz(struct secasvar *sav)
175 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
176 /*XXX not right for null algorithm--does it matter??*/
177 authsize = AUTHSIZE(sav);
178 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
181 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
187 * NB: public for use by esp_init.
190 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
192 struct auth_hash *thash;
195 thash = ah_algorithm_lookup(sav->alg_auth);
197 DPRINTF(("%s: unsupported authentication algorithm %u\n",
198 __func__, sav->alg_auth));
202 * Verify the replay state block allocation is consistent with
203 * the protocol type. We check here so we can make assumptions
204 * later during protocol processing.
206 /* NB: replay state is setup elsewhere (sigh) */
207 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
208 DPRINTF(("%s: replay state block inconsistency, "
209 "%s algorithm %s replay state\n", __func__,
210 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
211 sav->replay == NULL ? "without" : "with"));
214 if (sav->key_auth == NULL) {
215 DPRINTF(("%s: no authentication key for %s algorithm\n",
216 __func__, thash->name));
219 keylen = _KEYLEN(sav->key_auth);
220 if (keylen != thash->keysize && thash->keysize != 0) {
221 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
222 "keysize %d\n", __func__,
223 keylen, thash->name, thash->keysize));
227 sav->tdb_xform = xsp;
228 sav->tdb_authalgxform = thash;
230 /* Initialize crypto session. */
231 bzero(cria, sizeof (*cria));
232 cria->cri_alg = sav->tdb_authalgxform->type;
233 cria->cri_klen = _KEYBITS(sav->key_auth);
234 cria->cri_key = sav->key_auth->key_data;
235 cria->cri_mlen = AUTHSIZE(sav);
241 * ah_init() is called when an SPI is being set up.
244 ah_init(struct secasvar *sav, struct xformsw *xsp)
246 struct cryptoini cria;
249 error = ah_init0(sav, xsp, &cria);
250 return error ? error :
251 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
257 * NB: public for use by esp_zeroize (XXX).
260 ah_zeroize(struct secasvar *sav)
265 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
267 err = crypto_freesession(sav->tdb_cryptoid);
268 sav->tdb_cryptoid = 0;
269 sav->tdb_authalgxform = NULL;
270 sav->tdb_xform = NULL;
275 * Massage IPv4/IPv6 headers for AH processing.
278 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
280 struct mbuf *m = *m0;
289 struct ip6_ext *ip6e;
298 * This is the least painful way of dealing with IPv4 header
299 * and option processing -- just make sure they're in
302 *m0 = m = m_pullup(m, skip);
304 DPRINTF(("%s: m_pullup failed\n", __func__));
308 /* Fix the IP header */
309 ip = mtod(m, struct ip *);
315 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
316 ip->ip_off &= htons(IP_DF);
318 ip->ip_off = htons(0);
320 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
322 /* IPv4 option processing */
323 for (off = sizeof(struct ip); off < skip;) {
324 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
328 DPRINTF(("%s: illegal IPv4 option length for "
329 "option %d\n", __func__, ptr[off]));
337 off = skip; /* End the loop. */
344 case IPOPT_SECURITY: /* 0x82 */
345 case 0x85: /* Extended security. */
346 case 0x86: /* Commercial security. */
347 case 0x94: /* Router alert */
348 case 0x95: /* RFC1770 */
349 /* Sanity check for option length. */
350 if (ptr[off + 1] < 2) {
351 DPRINTF(("%s: illegal IPv4 option "
352 "length for option %d\n",
353 __func__, ptr[off]));
364 /* Sanity check for option length. */
365 if (ptr[off + 1] < 2) {
366 DPRINTF(("%s: illegal IPv4 option "
367 "length for option %d\n",
368 __func__, ptr[off]));
375 * On output, if we have either of the
376 * source routing options, we should
377 * swap the destination address of the
378 * IP header with the last address
379 * specified in the option, as that is
380 * what the destination's IP header
384 bcopy(ptr + off + ptr[off + 1] -
385 sizeof(struct in_addr),
386 &(ip->ip_dst), sizeof(struct in_addr));
390 /* Sanity check for option length. */
391 if (ptr[off + 1] < 2) {
392 DPRINTF(("%s: illegal IPv4 option "
393 "length for option %d\n",
394 __func__, ptr[off]));
399 /* Zeroize all other options. */
400 count = ptr[off + 1];
401 bcopy(ipseczeroes, ptr, count);
408 DPRINTF(("%s: malformed IPv4 options header\n",
420 case AF_INET6: /* Ugly... */
421 /* Copy and "cook" the IPv6 header. */
422 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
424 /* We don't do IPv6 Jumbograms. */
425 if (ip6.ip6_plen == 0) {
426 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
433 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
434 ip6.ip6_vfc |= IPV6_VERSION;
436 /* Scoped address handling. */
437 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
438 ip6.ip6_src.s6_addr16[1] = 0;
439 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
440 ip6.ip6_dst.s6_addr16[1] = 0;
442 /* Done with IPv6 header. */
443 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
445 /* Let's deal with the remaining headers (if any). */
446 if (skip - sizeof(struct ip6_hdr) > 0) {
447 if (m->m_len <= skip) {
448 ptr = (unsigned char *) malloc(
449 skip - sizeof(struct ip6_hdr),
452 DPRINTF(("%s: failed to allocate memory"
453 "for IPv6 headers\n",__func__));
459 * Copy all the protocol headers after
462 m_copydata(m, sizeof(struct ip6_hdr),
463 skip - sizeof(struct ip6_hdr), ptr);
466 /* No need to allocate memory. */
467 ptr = mtod(m, unsigned char *) +
468 sizeof(struct ip6_hdr);
474 off = ip6.ip6_nxt & 0xff; /* Next header type. */
476 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
478 case IPPROTO_HOPOPTS:
479 case IPPROTO_DSTOPTS:
480 ip6e = (struct ip6_ext *) (ptr + len);
483 * Process the mutable/immutable
484 * options -- borrows heavily from the
487 for (count = len + sizeof(struct ip6_ext);
488 count < len + ((ip6e->ip6e_len + 1) << 3);) {
489 if (ptr[count] == IP6OPT_PAD1) {
491 continue; /* Skip padding. */
496 ((ip6e->ip6e_len + 1) << 3)) {
499 /* Free, if we allocated. */
507 /* If mutable option, zeroize. */
508 if (ptr[count] & IP6OPT_MUTABLE)
509 bcopy(ipseczeroes, ptr + count,
516 skip - sizeof(struct ip6_hdr)) {
519 /* Free, if we allocated. */
527 len += ((ip6e->ip6e_len + 1) << 3);
528 off = ip6e->ip6e_nxt;
531 case IPPROTO_ROUTING:
533 * Always include routing headers in
536 ip6e = (struct ip6_ext *) (ptr + len);
537 len += ((ip6e->ip6e_len + 1) << 3);
538 off = ip6e->ip6e_nxt;
542 DPRINTF(("%s: unexpected IPv6 header type %d",
550 /* Copyback and free, if we allocated. */
552 m_copyback(m, sizeof(struct ip6_hdr),
553 skip - sizeof(struct ip6_hdr), ptr);
565 * ah_input() gets called to verify that an input packet
566 * passes authentication.
569 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
571 struct auth_hash *ahx;
572 struct tdb_ident *tdbi;
573 struct tdb_crypto *tc;
576 int hl, rplen, authsize;
578 struct cryptodesc *crda;
581 IPSEC_ASSERT(sav != NULL, ("null SA"));
582 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
583 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
584 ("null authentication xform"));
586 /* Figure out header size. */
587 rplen = HDRSIZE(sav);
589 /* XXX don't pullup, just copy header */
590 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
592 DPRINTF(("ah_input: cannot pullup header\n"));
593 AHSTAT_INC(ahs_hdrops); /*XXX*/
598 /* Check replay window, if applicable. */
599 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
600 AHSTAT_INC(ahs_replay);
601 DPRINTF(("%s: packet replay failure: %s\n", __func__,
602 ipsec_logsastr(sav)));
607 /* Verify AH header length. */
608 hl = ah->ah_len * sizeof (u_int32_t);
609 ahx = sav->tdb_authalgxform;
610 authsize = AUTHSIZE(sav);
611 if (hl != authsize + rplen - sizeof (struct ah)) {
612 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
613 " for packet in SA %s/%08lx\n", __func__,
614 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
615 ipsec_address(&sav->sah->saidx.dst),
616 (u_long) ntohl(sav->spi)));
617 AHSTAT_INC(ahs_badauthl);
621 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
623 /* Get crypto descriptors. */
624 crp = crypto_getreq(1);
626 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
627 AHSTAT_INC(ahs_crypto);
632 crda = crp->crp_desc;
633 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
636 crda->crd_len = m->m_pkthdr.len;
637 crda->crd_inject = skip + rplen;
639 /* Authentication operation. */
640 crda->crd_alg = ahx->type;
641 crda->crd_klen = _KEYBITS(sav->key_auth);
642 crda->crd_key = sav->key_auth->key_data;
644 /* Find out if we've already done crypto. */
645 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
647 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
648 tdbi = (struct tdb_ident *) (mtag + 1);
649 if (tdbi->proto == sav->sah->saidx.proto &&
650 tdbi->spi == sav->spi &&
651 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
652 sizeof (union sockaddr_union)))
656 /* Allocate IPsec-specific opaque crypto info. */
658 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
659 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
661 /* Hash verification has already been done successfully. */
662 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
663 M_XDATA, M_NOWAIT|M_ZERO);
666 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
667 AHSTAT_INC(ahs_crypto);
673 /* Only save information if crypto processing is needed. */
678 * Save the authenticator, the skipped portion of the packet,
681 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
683 /* Zeroize the authenticator on the packet. */
684 m_copyback(m, skip + rplen, authsize, ipseczeroes);
686 /* "Massage" the packet headers for crypto processing. */
687 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
690 /* NB: mbuf is free'd by ah_massage_headers */
691 AHSTAT_INC(ahs_hdrops);
698 /* Crypto operation descriptor. */
699 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
700 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
701 crp->crp_buf = (caddr_t) m;
702 crp->crp_callback = ah_input_cb;
703 crp->crp_sid = sav->tdb_cryptoid;
704 crp->crp_opaque = (caddr_t) tc;
706 /* These are passed as-is to the callback. */
707 tc->tc_spi = sav->spi;
708 tc->tc_dst = sav->sah->saidx.dst;
709 tc->tc_proto = sav->sah->saidx.proto;
710 tc->tc_nxt = ah->ah_nxt;
711 tc->tc_protoff = protoff;
713 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
718 return crypto_dispatch(crp);
720 return ah_input_cb(crp);
724 * AH input callback from the crypto driver.
727 ah_input_cb(struct cryptop *crp)
729 int rplen, error, skip, protoff;
730 unsigned char calc[AH_ALEN_MAX];
732 struct cryptodesc *crd;
733 struct auth_hash *ahx;
734 struct tdb_crypto *tc;
736 struct secasvar *sav;
737 struct secasindex *saidx;
744 tc = (struct tdb_crypto *) crp->crp_opaque;
745 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
748 protoff = tc->tc_protoff;
749 mtag = (struct m_tag *) tc->tc_ptr;
750 m = (struct mbuf *) crp->crp_buf;
753 IPSEC_ASSERT(sav != NULL, ("null SA!"));
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_INC(ahs_noxform);
771 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
772 error = crp->crp_etype;
775 AHSTAT_INC(ahs_hist[sav->alg_auth]);
776 crypto_freereq(crp); /* No longer needed. */
780 /* Shouldn't happen... */
782 AHSTAT_INC(ahs_crypto);
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_INC(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)) {
839 AHSTAT_INC(ahs_replay);
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)));
853 AHSTAT_INC(ahs_hdrops);
857 switch (saidx->dst.sa.sa_family) {
860 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag);
865 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag);
869 panic("%s: Unexpected address family: %d saidx=%p", __func__,
870 saidx->dst.sa.sa_family, saidx);
888 * AH output routine, called by ipsec[46]_process_packet().
893 struct ipsecrequest *isr,
898 struct secasvar *sav;
899 struct auth_hash *ahx;
900 struct cryptodesc *crda;
901 struct tdb_crypto *tc;
905 int error, rplen, authsize, maxpacketsize, roff;
910 IPSEC_ASSERT(sav != NULL, ("null SA"));
911 ahx = sav->tdb_authalgxform;
912 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
914 AHSTAT_INC(ahs_output);
916 /* Figure out header size. */
917 rplen = HDRSIZE(sav);
919 /* Check for maximum packet size violations. */
920 switch (sav->sah->saidx.dst.sa.sa_family) {
923 maxpacketsize = IP_MAXPACKET;
928 maxpacketsize = IPV6_MAXPACKET;
932 DPRINTF(("%s: unknown/unsupported protocol family %u, "
933 "SA %s/%08lx\n", __func__,
934 sav->sah->saidx.dst.sa.sa_family,
935 ipsec_address(&sav->sah->saidx.dst),
936 (u_long) ntohl(sav->spi)));
937 AHSTAT_INC(ahs_nopf);
938 error = EPFNOSUPPORT;
941 authsize = AUTHSIZE(sav);
942 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
943 DPRINTF(("%s: packet in SA %s/%08lx got too big "
944 "(len %u, max len %u)\n", __func__,
945 ipsec_address(&sav->sah->saidx.dst),
946 (u_long) ntohl(sav->spi),
947 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
948 AHSTAT_INC(ahs_toobig);
953 /* Update the counters. */
954 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
956 m = m_unshare(m, M_NOWAIT);
958 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
959 ipsec_address(&sav->sah->saidx.dst),
960 (u_long) ntohl(sav->spi)));
961 AHSTAT_INC(ahs_hdrops);
966 /* Inject AH header. */
967 mi = m_makespace(m, skip, rplen + authsize, &roff);
969 DPRINTF(("%s: failed to inject %u byte AH header for SA "
970 "%s/%08lx\n", __func__,
972 ipsec_address(&sav->sah->saidx.dst),
973 (u_long) ntohl(sav->spi)));
974 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
980 * The AH header is guaranteed by m_makespace() to be in
981 * contiguous memory, at roff bytes offset into the returned mbuf.
983 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
985 /* Initialize the AH header. */
986 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
987 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
989 ah->ah_spi = sav->spi;
991 /* Zeroize authenticator. */
992 m_copyback(m, skip + rplen, authsize, ipseczeroes);
994 /* Insert packet replay counter, as requested. */
996 if (sav->replay->count == ~0 &&
997 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
998 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
1000 ipsec_address(&sav->sah->saidx.dst),
1001 (u_long) ntohl(sav->spi)));
1002 AHSTAT_INC(ahs_wrap);
1007 /* Emulate replay attack when ipsec_replay is TRUE. */
1008 if (!V_ipsec_replay)
1010 sav->replay->count++;
1011 ah->ah_seq = htonl(sav->replay->count);
1014 /* Get crypto descriptors. */
1015 crp = crypto_getreq(1);
1017 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1019 AHSTAT_INC(ahs_crypto);
1024 crda = crp->crp_desc;
1027 crda->crd_inject = skip + rplen;
1028 crda->crd_len = m->m_pkthdr.len;
1030 /* Authentication operation. */
1031 crda->crd_alg = ahx->type;
1032 crda->crd_key = sav->key_auth->key_data;
1033 crda->crd_klen = _KEYBITS(sav->key_auth);
1035 /* Allocate IPsec-specific opaque crypto info. */
1036 tc = (struct tdb_crypto *) malloc(
1037 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1039 crypto_freereq(crp);
1040 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1041 AHSTAT_INC(ahs_crypto);
1046 /* Save the skipped portion of the packet. */
1047 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1050 * Fix IP header length on the header used for
1051 * authentication. We don't need to fix the original
1052 * header length as it will be fixed by our caller.
1054 switch (sav->sah->saidx.dst.sa.sa_family) {
1057 bcopy(((caddr_t)(tc + 1)) +
1058 offsetof(struct ip, ip_len),
1059 (caddr_t) &iplen, sizeof(u_int16_t));
1060 iplen = htons(ntohs(iplen) + rplen + authsize);
1061 m_copyback(m, offsetof(struct ip, ip_len),
1062 sizeof(u_int16_t), (caddr_t) &iplen);
1068 bcopy(((caddr_t)(tc + 1)) +
1069 offsetof(struct ip6_hdr, ip6_plen),
1070 (caddr_t) &iplen, sizeof(u_int16_t));
1071 iplen = htons(ntohs(iplen) + rplen + authsize);
1072 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1073 sizeof(u_int16_t), (caddr_t) &iplen);
1078 /* Fix the Next Header field in saved header. */
1079 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1081 /* Update the Next Protocol field in the IP header. */
1083 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1085 /* "Massage" the packet headers for crypto processing. */
1086 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1087 skip, ahx->type, 1);
1089 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1091 crypto_freereq(crp);
1095 /* Crypto operation descriptor. */
1096 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1097 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1098 crp->crp_buf = (caddr_t) m;
1099 crp->crp_callback = ah_output_cb;
1100 crp->crp_sid = sav->tdb_cryptoid;
1101 crp->crp_opaque = (caddr_t) tc;
1103 /* These are passed as-is to the callback. */
1107 tc->tc_spi = sav->spi;
1108 tc->tc_dst = sav->sah->saidx.dst;
1109 tc->tc_proto = sav->sah->saidx.proto;
1111 tc->tc_protoff = protoff;
1113 return crypto_dispatch(crp);
1121 * AH output callback from the crypto driver.
1124 ah_output_cb(struct cryptop *crp)
1126 int skip, protoff, error;
1127 struct tdb_crypto *tc;
1128 struct ipsecrequest *isr;
1129 struct secasvar *sav;
1133 tc = (struct tdb_crypto *) crp->crp_opaque;
1134 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1136 protoff = tc->tc_protoff;
1137 ptr = (caddr_t) (tc + 1);
1138 m = (struct mbuf *) crp->crp_buf;
1141 IPSECREQUEST_LOCK(isr);
1143 /* With the isr lock released SA pointer can be updated. */
1144 if (sav != isr->sav) {
1145 AHSTAT_INC(ahs_notdb);
1146 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1147 error = ENOBUFS; /*XXX*/
1151 /* Check for crypto errors. */
1152 if (crp->crp_etype) {
1153 if (sav->tdb_cryptoid != 0)
1154 sav->tdb_cryptoid = crp->crp_sid;
1156 if (crp->crp_etype == EAGAIN) {
1157 IPSECREQUEST_UNLOCK(isr);
1158 return (crypto_dispatch(crp));
1161 AHSTAT_INC(ahs_noxform);
1162 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1163 error = crp->crp_etype;
1167 /* Shouldn't happen... */
1169 AHSTAT_INC(ahs_crypto);
1170 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1174 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1177 * Copy original headers (with the new protocol number) back
1180 m_copyback(m, 0, skip, ptr);
1182 /* No longer needed. */
1184 crypto_freereq(crp);
1187 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1188 if (V_ipsec_integrity) {
1192 * Corrupt HMAC if we want to test integrity verification of
1195 alen = AUTHSIZE(sav);
1196 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1200 /* NB: m is reclaimed by ipsec_process_done. */
1201 error = ipsec_process_done(m, isr);
1203 IPSECREQUEST_UNLOCK(isr);
1208 IPSECREQUEST_UNLOCK(isr);
1212 crypto_freereq(crp);
1216 static struct xformsw ah_xformsw = {
1217 XF_AH, XFT_AUTH, "IPsec AH",
1218 ah_init, ah_zeroize, ah_input, ah_output,
1225 xform_register(&ah_xformsw);
1228 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);