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 <netipsec/ipsec.h>
62 #include <netipsec/ah.h>
63 #include <netipsec/ah_var.h>
64 #include <netipsec/xform.h>
67 #include <netinet6/ip6_var.h>
68 #include <netipsec/ipsec6.h>
69 #include <netinet6/ip6_ecn.h>
72 #include <netipsec/key.h>
73 #include <netipsec/key_debug.h>
75 #include <opencrypto/cryptodev.h>
78 * Return header size in bytes. The old protocol did not support
79 * the replay counter; the new protocol always includes the counter.
81 #define HDRSIZE(sav) \
82 (((sav)->flags & SADB_X_EXT_OLD) ? \
83 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
85 * Return authenticator size in bytes, based on a field in the
86 * algorithm descriptor.
88 #define AUTHSIZE(sav) \
89 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->hashsize)
91 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
92 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
93 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
94 VNET_PCPUSTAT_SYSINIT(ahstat);
97 VNET_PCPUSTAT_SYSUNINIT(ahstat);
101 SYSCTL_DECL(_net_inet_ah);
102 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable,
103 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
104 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos,
105 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
106 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
107 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
110 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
112 static int ah_input_cb(struct cryptop*);
113 static int ah_output_cb(struct cryptop*);
116 * NB: this is public for use by the PF_KEY support.
119 ah_algorithm_lookup(int alg)
121 if (alg > SADB_AALG_MAX)
124 case SADB_X_AALG_NULL:
125 return &auth_hash_null;
126 case SADB_AALG_MD5HMAC:
127 return &auth_hash_hmac_md5;
128 case SADB_AALG_SHA1HMAC:
129 return &auth_hash_hmac_sha1;
130 case SADB_X_AALG_RIPEMD160HMAC:
131 return &auth_hash_hmac_ripemd_160;
132 case SADB_X_AALG_MD5:
133 return &auth_hash_key_md5;
134 case SADB_X_AALG_SHA:
135 return &auth_hash_key_sha1;
136 case SADB_X_AALG_SHA2_256:
137 return &auth_hash_hmac_sha2_256;
138 case SADB_X_AALG_SHA2_384:
139 return &auth_hash_hmac_sha2_384;
140 case SADB_X_AALG_SHA2_512:
141 return &auth_hash_hmac_sha2_512;
142 case SADB_X_AALG_AES128GMAC:
143 return &auth_hash_nist_gmac_aes_128;
144 case SADB_X_AALG_AES192GMAC:
145 return &auth_hash_nist_gmac_aes_192;
146 case SADB_X_AALG_AES256GMAC:
147 return &auth_hash_nist_gmac_aes_256;
153 ah_hdrsiz(struct secasvar *sav)
159 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
160 /*XXX not right for null algorithm--does it matter??*/
161 authsize = AUTHSIZE(sav);
162 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
165 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
171 * NB: public for use by esp_init.
174 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
176 struct auth_hash *thash;
179 thash = ah_algorithm_lookup(sav->alg_auth);
181 DPRINTF(("%s: unsupported authentication algorithm %u\n",
182 __func__, sav->alg_auth));
186 * Verify the replay state block allocation is consistent with
187 * the protocol type. We check here so we can make assumptions
188 * later during protocol processing.
190 /* NB: replay state is setup elsewhere (sigh) */
191 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
192 DPRINTF(("%s: replay state block inconsistency, "
193 "%s algorithm %s replay state\n", __func__,
194 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
195 sav->replay == NULL ? "without" : "with"));
198 if (sav->key_auth == NULL) {
199 DPRINTF(("%s: no authentication key for %s algorithm\n",
200 __func__, thash->name));
203 keylen = _KEYLEN(sav->key_auth);
204 if (keylen != thash->keysize && thash->keysize != 0) {
205 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
206 "keysize %d\n", __func__,
207 keylen, thash->name, thash->keysize));
211 sav->tdb_xform = xsp;
212 sav->tdb_authalgxform = thash;
214 /* Initialize crypto session. */
215 bzero(cria, sizeof (*cria));
216 cria->cri_alg = sav->tdb_authalgxform->type;
217 cria->cri_klen = _KEYBITS(sav->key_auth);
218 cria->cri_key = sav->key_auth->key_data;
219 cria->cri_mlen = AUTHSIZE(sav);
225 * ah_init() is called when an SPI is being set up.
228 ah_init(struct secasvar *sav, struct xformsw *xsp)
230 struct cryptoini cria;
233 error = ah_init0(sav, xsp, &cria);
234 return error ? error :
235 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
241 * NB: public for use by esp_zeroize (XXX).
244 ah_zeroize(struct secasvar *sav)
249 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
251 err = crypto_freesession(sav->tdb_cryptoid);
252 sav->tdb_cryptoid = 0;
253 sav->tdb_authalgxform = NULL;
254 sav->tdb_xform = NULL;
259 * Massage IPv4/IPv6 headers for AH processing.
262 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
264 struct mbuf *m = *m0;
273 struct ip6_ext *ip6e;
282 * This is the least painful way of dealing with IPv4 header
283 * and option processing -- just make sure they're in
286 *m0 = m = m_pullup(m, skip);
288 DPRINTF(("%s: m_pullup failed\n", __func__));
292 /* Fix the IP header */
293 ip = mtod(m, struct ip *);
299 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
300 ip->ip_off &= htons(IP_DF);
302 ip->ip_off = htons(0);
304 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
306 /* IPv4 option processing */
307 for (off = sizeof(struct ip); off < skip;) {
308 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
312 DPRINTF(("%s: illegal IPv4 option length for "
313 "option %d\n", __func__, ptr[off]));
321 off = skip; /* End the loop. */
328 case IPOPT_SECURITY: /* 0x82 */
329 case 0x85: /* Extended security. */
330 case 0x86: /* Commercial security. */
331 case 0x94: /* Router alert */
332 case 0x95: /* RFC1770 */
333 /* Sanity check for option length. */
334 if (ptr[off + 1] < 2) {
335 DPRINTF(("%s: illegal IPv4 option "
336 "length for option %d\n",
337 __func__, ptr[off]));
348 /* Sanity check for option length. */
349 if (ptr[off + 1] < 2) {
350 DPRINTF(("%s: illegal IPv4 option "
351 "length for option %d\n",
352 __func__, ptr[off]));
359 * On output, if we have either of the
360 * source routing options, we should
361 * swap the destination address of the
362 * IP header with the last address
363 * specified in the option, as that is
364 * what the destination's IP header
368 bcopy(ptr + off + ptr[off + 1] -
369 sizeof(struct in_addr),
370 &(ip->ip_dst), sizeof(struct in_addr));
374 /* Sanity check for option length. */
375 if (ptr[off + 1] < 2) {
376 DPRINTF(("%s: illegal IPv4 option "
377 "length for option %d\n",
378 __func__, ptr[off]));
383 /* Zeroize all other options. */
384 count = ptr[off + 1];
385 bcopy(ipseczeroes, ptr, count);
392 DPRINTF(("%s: malformed IPv4 options header\n",
404 case AF_INET6: /* Ugly... */
405 /* Copy and "cook" the IPv6 header. */
406 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
408 /* We don't do IPv6 Jumbograms. */
409 if (ip6.ip6_plen == 0) {
410 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
417 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
418 ip6.ip6_vfc |= IPV6_VERSION;
420 /* Scoped address handling. */
421 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
422 ip6.ip6_src.s6_addr16[1] = 0;
423 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
424 ip6.ip6_dst.s6_addr16[1] = 0;
426 /* Done with IPv6 header. */
427 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
429 /* Let's deal with the remaining headers (if any). */
430 if (skip - sizeof(struct ip6_hdr) > 0) {
431 if (m->m_len <= skip) {
432 ptr = (unsigned char *) malloc(
433 skip - sizeof(struct ip6_hdr),
436 DPRINTF(("%s: failed to allocate memory"
437 "for IPv6 headers\n",__func__));
443 * Copy all the protocol headers after
446 m_copydata(m, sizeof(struct ip6_hdr),
447 skip - sizeof(struct ip6_hdr), ptr);
450 /* No need to allocate memory. */
451 ptr = mtod(m, unsigned char *) +
452 sizeof(struct ip6_hdr);
458 off = ip6.ip6_nxt & 0xff; /* Next header type. */
460 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
462 case IPPROTO_HOPOPTS:
463 case IPPROTO_DSTOPTS:
464 ip6e = (struct ip6_ext *) (ptr + len);
467 * Process the mutable/immutable
468 * options -- borrows heavily from the
471 for (count = len + sizeof(struct ip6_ext);
472 count < len + ((ip6e->ip6e_len + 1) << 3);) {
473 if (ptr[count] == IP6OPT_PAD1) {
475 continue; /* Skip padding. */
480 ((ip6e->ip6e_len + 1) << 3)) {
483 /* Free, if we allocated. */
491 /* If mutable option, zeroize. */
492 if (ptr[count] & IP6OPT_MUTABLE)
493 bcopy(ipseczeroes, ptr + count,
500 skip - sizeof(struct ip6_hdr)) {
503 /* Free, if we allocated. */
511 len += ((ip6e->ip6e_len + 1) << 3);
512 off = ip6e->ip6e_nxt;
515 case IPPROTO_ROUTING:
517 * Always include routing headers in
520 ip6e = (struct ip6_ext *) (ptr + len);
521 len += ((ip6e->ip6e_len + 1) << 3);
522 off = ip6e->ip6e_nxt;
526 DPRINTF(("%s: unexpected IPv6 header type %d",
534 /* Copyback and free, if we allocated. */
536 m_copyback(m, sizeof(struct ip6_hdr),
537 skip - sizeof(struct ip6_hdr), ptr);
549 * ah_input() gets called to verify that an input packet
550 * passes authentication.
553 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
556 struct auth_hash *ahx;
557 struct tdb_crypto *tc;
559 int hl, rplen, authsize, error;
561 struct cryptodesc *crda;
564 IPSEC_ASSERT(sav != NULL, ("null SA"));
565 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
566 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
567 ("null authentication xform"));
569 /* Figure out header size. */
570 rplen = HDRSIZE(sav);
572 /* XXX don't pullup, just copy header */
573 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
575 DPRINTF(("ah_input: cannot pullup header\n"));
576 AHSTAT_INC(ahs_hdrops); /*XXX*/
581 /* Check replay window, if applicable. */
582 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
583 AHSTAT_INC(ahs_replay);
584 DPRINTF(("%s: packet replay failure: %s\n", __func__,
585 ipsec_logsastr(sav, buf, sizeof(buf))));
590 /* Verify AH header length. */
591 hl = ah->ah_len * sizeof (u_int32_t);
592 ahx = sav->tdb_authalgxform;
593 authsize = AUTHSIZE(sav);
594 if (hl != authsize + rplen - sizeof (struct ah)) {
595 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
596 " for packet in SA %s/%08lx\n", __func__, hl,
597 (u_long) (authsize + rplen - sizeof (struct ah)),
598 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
599 (u_long) ntohl(sav->spi)));
600 AHSTAT_INC(ahs_badauthl);
604 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
606 /* Get crypto descriptors. */
607 crp = crypto_getreq(1);
609 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
610 AHSTAT_INC(ahs_crypto);
615 crda = crp->crp_desc;
616 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
619 crda->crd_len = m->m_pkthdr.len;
620 crda->crd_inject = skip + rplen;
622 /* Authentication operation. */
623 crda->crd_alg = ahx->type;
624 crda->crd_klen = _KEYBITS(sav->key_auth);
625 crda->crd_key = sav->key_auth->key_data;
627 /* Allocate IPsec-specific opaque crypto info. */
628 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
629 skip + rplen + authsize, M_XDATA, M_NOWAIT | M_ZERO);
631 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
632 AHSTAT_INC(ahs_crypto);
639 * Save the authenticator, the skipped portion of the packet,
642 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
644 /* Zeroize the authenticator on the packet. */
645 m_copyback(m, skip + rplen, authsize, ipseczeroes);
647 /* "Massage" the packet headers for crypto processing. */
648 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
651 /* NB: mbuf is free'd by ah_massage_headers */
652 AHSTAT_INC(ahs_hdrops);
658 /* Crypto operation descriptor. */
659 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
660 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
661 crp->crp_buf = (caddr_t) m;
662 crp->crp_callback = ah_input_cb;
663 crp->crp_sid = sav->tdb_cryptoid;
664 crp->crp_opaque = (caddr_t) tc;
666 /* These are passed as-is to the callback. */
667 tc->tc_spi = sav->spi;
668 tc->tc_dst = sav->sah->saidx.dst;
669 tc->tc_proto = sav->sah->saidx.proto;
670 tc->tc_nxt = ah->ah_nxt;
671 tc->tc_protoff = protoff;
675 return (crypto_dispatch(crp));
679 * AH input callback from the crypto driver.
682 ah_input_cb(struct cryptop *crp)
684 char buf[INET6_ADDRSTRLEN];
685 int rplen, error, skip, protoff;
686 unsigned char calc[AH_ALEN_MAX];
688 struct cryptodesc *crd;
689 struct auth_hash *ahx;
690 struct tdb_crypto *tc;
691 struct secasvar *sav;
692 struct secasindex *saidx;
699 tc = (struct tdb_crypto *) crp->crp_opaque;
700 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
703 protoff = tc->tc_protoff;
704 m = (struct mbuf *) crp->crp_buf;
707 IPSEC_ASSERT(sav != NULL, ("null SA!"));
709 saidx = &sav->sah->saidx;
710 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
711 saidx->dst.sa.sa_family == AF_INET6,
712 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
714 ahx = (struct auth_hash *) sav->tdb_authalgxform;
716 /* Check for crypto errors. */
717 if (crp->crp_etype) {
718 if (sav->tdb_cryptoid != 0)
719 sav->tdb_cryptoid = crp->crp_sid;
721 if (crp->crp_etype == EAGAIN)
722 return (crypto_dispatch(crp));
724 AHSTAT_INC(ahs_noxform);
725 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
726 error = crp->crp_etype;
729 AHSTAT_INC(ahs_hist[sav->alg_auth]);
730 crypto_freereq(crp); /* No longer needed. */
734 /* Shouldn't happen... */
736 AHSTAT_INC(ahs_crypto);
737 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
742 /* Figure out header size. */
743 rplen = HDRSIZE(sav);
744 authsize = AUTHSIZE(sav);
746 /* Copy authenticator off the packet. */
747 m_copydata(m, skip + rplen, authsize, calc);
749 /* Verify authenticator. */
750 ptr = (caddr_t) (tc + 1);
751 if (bcmp(ptr + skip + rplen, calc, authsize)) {
752 DPRINTF(("%s: authentication hash mismatch for packet "
753 "in SA %s/%08lx\n", __func__,
754 ipsec_address(&saidx->dst, buf, sizeof(buf)),
755 (u_long) ntohl(sav->spi)));
756 AHSTAT_INC(ahs_badauth);
760 /* Fix the Next Protocol field. */
761 ((u_int8_t *) ptr)[protoff] = nxt;
763 /* Copyback the saved (uncooked) network headers. */
764 m_copyback(m, 0, skip, ptr);
765 free(tc, M_XDATA), tc = NULL; /* No longer needed */
768 * Header is now authenticated.
770 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
773 * Update replay sequence number, if appropriate.
778 m_copydata(m, skip + offsetof(struct newah, ah_seq),
779 sizeof (seq), (caddr_t) &seq);
780 if (ipsec_updatereplay(ntohl(seq), sav)) {
781 AHSTAT_INC(ahs_replay);
782 error = ENOBUFS; /*XXX as above*/
788 * Remove the AH header and authenticator from the mbuf.
790 error = m_striphdr(m, skip, rplen + authsize);
792 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
793 ipsec_address(&saidx->dst, buf, sizeof(buf)),
794 (u_long) ntohl(sav->spi)));
795 AHSTAT_INC(ahs_hdrops);
799 switch (saidx->dst.sa.sa_family) {
802 error = ipsec6_common_input_cb(m, sav, skip, protoff);
807 error = ipsec4_common_input_cb(m, sav, skip, protoff);
811 panic("%s: Unexpected address family: %d saidx=%p", __func__,
812 saidx->dst.sa.sa_family, saidx);
830 * AH output routine, called by ipsec[46]_process_packet().
833 ah_output(struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp,
834 int skip, int protoff)
836 char buf[INET6_ADDRSTRLEN];
837 struct secasvar *sav;
838 struct auth_hash *ahx;
839 struct cryptodesc *crda;
840 struct tdb_crypto *tc;
844 int error, rplen, authsize, maxpacketsize, roff;
849 IPSEC_ASSERT(sav != NULL, ("null SA"));
850 ahx = sav->tdb_authalgxform;
851 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
853 AHSTAT_INC(ahs_output);
855 /* Figure out header size. */
856 rplen = HDRSIZE(sav);
858 /* Check for maximum packet size violations. */
859 switch (sav->sah->saidx.dst.sa.sa_family) {
862 maxpacketsize = IP_MAXPACKET;
867 maxpacketsize = IPV6_MAXPACKET;
871 DPRINTF(("%s: unknown/unsupported protocol family %u, "
872 "SA %s/%08lx\n", __func__,
873 sav->sah->saidx.dst.sa.sa_family,
874 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
875 (u_long) ntohl(sav->spi)));
876 AHSTAT_INC(ahs_nopf);
877 error = EPFNOSUPPORT;
880 authsize = AUTHSIZE(sav);
881 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
882 DPRINTF(("%s: packet in SA %s/%08lx got too big "
883 "(len %u, max len %u)\n", __func__,
884 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
885 (u_long) ntohl(sav->spi),
886 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
887 AHSTAT_INC(ahs_toobig);
892 /* Update the counters. */
893 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
895 m = m_unshare(m, M_NOWAIT);
897 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
898 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
899 (u_long) ntohl(sav->spi)));
900 AHSTAT_INC(ahs_hdrops);
905 /* Inject AH header. */
906 mi = m_makespace(m, skip, rplen + authsize, &roff);
908 DPRINTF(("%s: failed to inject %u byte AH header for SA "
909 "%s/%08lx\n", __func__,
911 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
912 (u_long) ntohl(sav->spi)));
913 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
919 * The AH header is guaranteed by m_makespace() to be in
920 * contiguous memory, at roff bytes offset into the returned mbuf.
922 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
924 /* Initialize the AH header. */
925 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
926 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
928 ah->ah_spi = sav->spi;
930 /* Zeroize authenticator. */
931 m_copyback(m, skip + rplen, authsize, ipseczeroes);
933 /* Insert packet replay counter, as requested. */
935 if (sav->replay->count == ~0 &&
936 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
937 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
938 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
939 sizeof(buf)), (u_long) ntohl(sav->spi)));
940 AHSTAT_INC(ahs_wrap);
945 /* Emulate replay attack when ipsec_replay is TRUE. */
948 sav->replay->count++;
949 ah->ah_seq = htonl(sav->replay->count);
952 /* Get crypto descriptors. */
953 crp = crypto_getreq(1);
955 DPRINTF(("%s: failed to acquire crypto descriptors\n",
957 AHSTAT_INC(ahs_crypto);
962 crda = crp->crp_desc;
965 crda->crd_inject = skip + rplen;
966 crda->crd_len = m->m_pkthdr.len;
968 /* Authentication operation. */
969 crda->crd_alg = ahx->type;
970 crda->crd_key = sav->key_auth->key_data;
971 crda->crd_klen = _KEYBITS(sav->key_auth);
973 /* Allocate IPsec-specific opaque crypto info. */
974 tc = (struct tdb_crypto *) malloc(
975 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
978 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
979 AHSTAT_INC(ahs_crypto);
984 /* Save the skipped portion of the packet. */
985 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
988 * Fix IP header length on the header used for
989 * authentication. We don't need to fix the original
990 * header length as it will be fixed by our caller.
992 switch (sav->sah->saidx.dst.sa.sa_family) {
995 bcopy(((caddr_t)(tc + 1)) +
996 offsetof(struct ip, ip_len),
997 (caddr_t) &iplen, sizeof(u_int16_t));
998 iplen = htons(ntohs(iplen) + rplen + authsize);
999 m_copyback(m, offsetof(struct ip, ip_len),
1000 sizeof(u_int16_t), (caddr_t) &iplen);
1006 bcopy(((caddr_t)(tc + 1)) +
1007 offsetof(struct ip6_hdr, ip6_plen),
1008 (caddr_t) &iplen, sizeof(u_int16_t));
1009 iplen = htons(ntohs(iplen) + rplen + authsize);
1010 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1011 sizeof(u_int16_t), (caddr_t) &iplen);
1016 /* Fix the Next Header field in saved header. */
1017 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1019 /* Update the Next Protocol field in the IP header. */
1021 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1023 /* "Massage" the packet headers for crypto processing. */
1024 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1025 skip, ahx->type, 1);
1027 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1029 crypto_freereq(crp);
1033 /* Crypto operation descriptor. */
1034 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1035 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1036 crp->crp_buf = (caddr_t) m;
1037 crp->crp_callback = ah_output_cb;
1038 crp->crp_sid = sav->tdb_cryptoid;
1039 crp->crp_opaque = (caddr_t) tc;
1041 /* These are passed as-is to the callback. */
1045 tc->tc_spi = sav->spi;
1046 tc->tc_dst = sav->sah->saidx.dst;
1047 tc->tc_proto = sav->sah->saidx.proto;
1049 tc->tc_protoff = protoff;
1051 return crypto_dispatch(crp);
1059 * AH output callback from the crypto driver.
1062 ah_output_cb(struct cryptop *crp)
1064 int skip, protoff, error;
1065 struct tdb_crypto *tc;
1066 struct ipsecrequest *isr;
1067 struct secasvar *sav;
1071 tc = (struct tdb_crypto *) crp->crp_opaque;
1072 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1074 protoff = tc->tc_protoff;
1075 ptr = (caddr_t) (tc + 1);
1076 m = (struct mbuf *) crp->crp_buf;
1079 IPSEC_ASSERT(isr->sp != NULL, ("NULL isr->sp"));
1080 IPSECREQUEST_LOCK(isr);
1082 /* With the isr lock released SA pointer can be updated. */
1083 if (sav != isr->sav) {
1084 AHSTAT_INC(ahs_notdb);
1085 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1086 error = ENOBUFS; /*XXX*/
1090 /* Check for crypto errors. */
1091 if (crp->crp_etype) {
1092 if (sav->tdb_cryptoid != 0)
1093 sav->tdb_cryptoid = crp->crp_sid;
1095 if (crp->crp_etype == EAGAIN) {
1096 IPSECREQUEST_UNLOCK(isr);
1097 return (crypto_dispatch(crp));
1100 AHSTAT_INC(ahs_noxform);
1101 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1102 error = crp->crp_etype;
1106 /* Shouldn't happen... */
1108 AHSTAT_INC(ahs_crypto);
1109 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1113 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1116 * Copy original headers (with the new protocol number) back
1119 m_copyback(m, 0, skip, ptr);
1121 /* No longer needed. */
1123 crypto_freereq(crp);
1126 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1127 if (V_ipsec_integrity) {
1131 * Corrupt HMAC if we want to test integrity verification of
1134 alen = AUTHSIZE(sav);
1135 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1139 /* NB: m is reclaimed by ipsec_process_done. */
1140 error = ipsec_process_done(m, isr);
1142 IPSECREQUEST_UNLOCK(isr);
1143 KEY_FREESP(&isr->sp);
1148 IPSECREQUEST_UNLOCK(isr);
1149 KEY_FREESP(&isr->sp);
1153 crypto_freereq(crp);
1157 static struct xformsw ah_xformsw = {
1158 XF_AH, XFT_AUTH, "IPsec AH",
1159 ah_init, ah_zeroize, ah_input, ah_output,
1166 xform_register(&ah_xformsw);
1169 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);