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 <netipsec/ipsec.h>
60 #include <netipsec/ah.h>
61 #include <netipsec/ah_var.h>
62 #include <netipsec/xform.h>
65 #include <netinet6/ip6_var.h>
66 #include <netipsec/ipsec6.h>
67 #include <netinet6/ip6_ecn.h>
70 #include <netipsec/key.h>
71 #include <netipsec/key_debug.h>
73 #include <opencrypto/cryptodev.h>
76 * Return header size in bytes. The old protocol did not support
77 * the replay counter; the new protocol always includes the counter.
79 #define HDRSIZE(sav) \
80 (((sav)->flags & SADB_X_EXT_OLD) ? \
81 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
83 * Return authenticator size in bytes. The old protocol is known
84 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
87 #define AUTHSIZE(sav) ah_authsize(sav)
89 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
90 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
91 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
92 VNET_PCPUSTAT_SYSINIT(ahstat);
95 VNET_PCPUSTAT_SYSUNINIT(ahstat);
99 SYSCTL_DECL(_net_inet_ah);
100 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
101 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
102 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
103 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
104 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
105 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
108 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
110 static int ah_input_cb(struct cryptop*);
111 static int ah_output_cb(struct cryptop*);
114 ah_authsize(struct secasvar *sav)
117 IPSEC_ASSERT(sav != NULL, ("%s: sav == NULL", __func__));
119 if (sav->flags & SADB_X_EXT_OLD)
122 switch (sav->alg_auth) {
123 case SADB_X_AALG_SHA2_256:
125 case SADB_X_AALG_SHA2_384:
127 case SADB_X_AALG_SHA2_512:
130 return AH_HMAC_HASHLEN;
135 * NB: this is public for use by the PF_KEY support.
138 ah_algorithm_lookup(int alg)
140 if (alg > SADB_AALG_MAX)
143 case SADB_X_AALG_NULL:
144 return &auth_hash_null;
145 case SADB_AALG_MD5HMAC:
146 return &auth_hash_hmac_md5;
147 case SADB_AALG_SHA1HMAC:
148 return &auth_hash_hmac_sha1;
149 case SADB_X_AALG_RIPEMD160HMAC:
150 return &auth_hash_hmac_ripemd_160;
151 case SADB_X_AALG_MD5:
152 return &auth_hash_key_md5;
153 case SADB_X_AALG_SHA:
154 return &auth_hash_key_sha1;
155 case SADB_X_AALG_SHA2_256:
156 return &auth_hash_hmac_sha2_256;
157 case SADB_X_AALG_SHA2_384:
158 return &auth_hash_hmac_sha2_384;
159 case SADB_X_AALG_SHA2_512:
160 return &auth_hash_hmac_sha2_512;
166 ah_hdrsiz(struct secasvar *sav)
172 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
173 /*XXX not right for null algorithm--does it matter??*/
174 authsize = AUTHSIZE(sav);
175 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
178 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
184 * NB: public for use by esp_init.
187 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
189 struct auth_hash *thash;
192 thash = ah_algorithm_lookup(sav->alg_auth);
194 DPRINTF(("%s: unsupported authentication algorithm %u\n",
195 __func__, sav->alg_auth));
199 * Verify the replay state block allocation is consistent with
200 * the protocol type. We check here so we can make assumptions
201 * later during protocol processing.
203 /* NB: replay state is setup elsewhere (sigh) */
204 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
205 DPRINTF(("%s: replay state block inconsistency, "
206 "%s algorithm %s replay state\n", __func__,
207 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
208 sav->replay == NULL ? "without" : "with"));
211 if (sav->key_auth == NULL) {
212 DPRINTF(("%s: no authentication key for %s algorithm\n",
213 __func__, thash->name));
216 keylen = _KEYLEN(sav->key_auth);
217 if (keylen != thash->keysize && thash->keysize != 0) {
218 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
219 "keysize %d\n", __func__,
220 keylen, thash->name, thash->keysize));
224 sav->tdb_xform = xsp;
225 sav->tdb_authalgxform = thash;
227 /* Initialize crypto session. */
228 bzero(cria, sizeof (*cria));
229 cria->cri_alg = sav->tdb_authalgxform->type;
230 cria->cri_klen = _KEYBITS(sav->key_auth);
231 cria->cri_key = sav->key_auth->key_data;
232 cria->cri_mlen = AUTHSIZE(sav);
238 * ah_init() is called when an SPI is being set up.
241 ah_init(struct secasvar *sav, struct xformsw *xsp)
243 struct cryptoini cria;
246 error = ah_init0(sav, xsp, &cria);
247 return error ? error :
248 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
254 * NB: public for use by esp_zeroize (XXX).
257 ah_zeroize(struct secasvar *sav)
262 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
264 err = crypto_freesession(sav->tdb_cryptoid);
265 sav->tdb_cryptoid = 0;
266 sav->tdb_authalgxform = NULL;
267 sav->tdb_xform = NULL;
272 * Massage IPv4/IPv6 headers for AH processing.
275 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
277 struct mbuf *m = *m0;
286 struct ip6_ext *ip6e;
295 * This is the least painful way of dealing with IPv4 header
296 * and option processing -- just make sure they're in
299 *m0 = m = m_pullup(m, skip);
301 DPRINTF(("%s: m_pullup failed\n", __func__));
305 /* Fix the IP header */
306 ip = mtod(m, struct ip *);
312 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
313 ip->ip_off &= htons(IP_DF);
315 ip->ip_off = htons(0);
317 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
319 /* IPv4 option processing */
320 for (off = sizeof(struct ip); off < skip;) {
321 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
325 DPRINTF(("%s: illegal IPv4 option length for "
326 "option %d\n", __func__, ptr[off]));
334 off = skip; /* End the loop. */
341 case IPOPT_SECURITY: /* 0x82 */
342 case 0x85: /* Extended security. */
343 case 0x86: /* Commercial security. */
344 case 0x94: /* Router alert */
345 case 0x95: /* RFC1770 */
346 /* Sanity check for option length. */
347 if (ptr[off + 1] < 2) {
348 DPRINTF(("%s: illegal IPv4 option "
349 "length for option %d\n",
350 __func__, ptr[off]));
361 /* Sanity check for option length. */
362 if (ptr[off + 1] < 2) {
363 DPRINTF(("%s: illegal IPv4 option "
364 "length for option %d\n",
365 __func__, ptr[off]));
372 * On output, if we have either of the
373 * source routing options, we should
374 * swap the destination address of the
375 * IP header with the last address
376 * specified in the option, as that is
377 * what the destination's IP header
381 bcopy(ptr + off + ptr[off + 1] -
382 sizeof(struct in_addr),
383 &(ip->ip_dst), sizeof(struct in_addr));
387 /* Sanity check for option length. */
388 if (ptr[off + 1] < 2) {
389 DPRINTF(("%s: illegal IPv4 option "
390 "length for option %d\n",
391 __func__, ptr[off]));
396 /* Zeroize all other options. */
397 count = ptr[off + 1];
398 bcopy(ipseczeroes, ptr, count);
405 DPRINTF(("%s: malformed IPv4 options header\n",
417 case AF_INET6: /* Ugly... */
418 /* Copy and "cook" the IPv6 header. */
419 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
421 /* We don't do IPv6 Jumbograms. */
422 if (ip6.ip6_plen == 0) {
423 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
430 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
431 ip6.ip6_vfc |= IPV6_VERSION;
433 /* Scoped address handling. */
434 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
435 ip6.ip6_src.s6_addr16[1] = 0;
436 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
437 ip6.ip6_dst.s6_addr16[1] = 0;
439 /* Done with IPv6 header. */
440 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
442 /* Let's deal with the remaining headers (if any). */
443 if (skip - sizeof(struct ip6_hdr) > 0) {
444 if (m->m_len <= skip) {
445 ptr = (unsigned char *) malloc(
446 skip - sizeof(struct ip6_hdr),
449 DPRINTF(("%s: failed to allocate memory"
450 "for IPv6 headers\n",__func__));
456 * Copy all the protocol headers after
459 m_copydata(m, sizeof(struct ip6_hdr),
460 skip - sizeof(struct ip6_hdr), ptr);
463 /* No need to allocate memory. */
464 ptr = mtod(m, unsigned char *) +
465 sizeof(struct ip6_hdr);
471 off = ip6.ip6_nxt & 0xff; /* Next header type. */
473 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
475 case IPPROTO_HOPOPTS:
476 case IPPROTO_DSTOPTS:
477 ip6e = (struct ip6_ext *) (ptr + len);
480 * Process the mutable/immutable
481 * options -- borrows heavily from the
484 for (count = len + sizeof(struct ip6_ext);
485 count < len + ((ip6e->ip6e_len + 1) << 3);) {
486 if (ptr[count] == IP6OPT_PAD1) {
488 continue; /* Skip padding. */
493 ((ip6e->ip6e_len + 1) << 3)) {
496 /* Free, if we allocated. */
504 /* If mutable option, zeroize. */
505 if (ptr[count] & IP6OPT_MUTABLE)
506 bcopy(ipseczeroes, ptr + count,
513 skip - sizeof(struct ip6_hdr)) {
516 /* Free, if we allocated. */
524 len += ((ip6e->ip6e_len + 1) << 3);
525 off = ip6e->ip6e_nxt;
528 case IPPROTO_ROUTING:
530 * Always include routing headers in
533 ip6e = (struct ip6_ext *) (ptr + len);
534 len += ((ip6e->ip6e_len + 1) << 3);
535 off = ip6e->ip6e_nxt;
539 DPRINTF(("%s: unexpected IPv6 header type %d",
547 /* Copyback and free, if we allocated. */
549 m_copyback(m, sizeof(struct ip6_hdr),
550 skip - sizeof(struct ip6_hdr), ptr);
562 * ah_input() gets called to verify that an input packet
563 * passes authentication.
566 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
568 struct auth_hash *ahx;
569 struct tdb_ident *tdbi;
570 struct tdb_crypto *tc;
573 int hl, rplen, authsize;
575 struct cryptodesc *crda;
578 IPSEC_ASSERT(sav != NULL, ("null SA"));
579 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
580 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
581 ("null authentication xform"));
583 /* Figure out header size. */
584 rplen = HDRSIZE(sav);
586 /* XXX don't pullup, just copy header */
587 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
589 DPRINTF(("ah_input: cannot pullup header\n"));
590 AHSTAT_INC(ahs_hdrops); /*XXX*/
595 /* Check replay window, if applicable. */
596 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
597 AHSTAT_INC(ahs_replay);
598 DPRINTF(("%s: packet replay failure: %s\n", __func__,
599 ipsec_logsastr(sav)));
604 /* Verify AH header length. */
605 hl = ah->ah_len * sizeof (u_int32_t);
606 ahx = sav->tdb_authalgxform;
607 authsize = AUTHSIZE(sav);
608 if (hl != authsize + rplen - sizeof (struct ah)) {
609 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
610 " for packet in SA %s/%08lx\n", __func__,
611 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
612 ipsec_address(&sav->sah->saidx.dst),
613 (u_long) ntohl(sav->spi)));
614 AHSTAT_INC(ahs_badauthl);
618 if (skip + authsize + rplen > m->m_pkthdr.len) {
619 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
620 " for packet in SA %s/%08lx\n", __func__,
621 m->m_pkthdr.len, (u_long) (skip + authsize + rplen),
622 ipsec_address(&sav->sah->saidx.dst),
623 (u_long) ntohl(sav->spi)));
624 AHSTAT_INC(ahs_badauthl);
628 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
630 /* Get crypto descriptors. */
631 crp = crypto_getreq(1);
633 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
634 AHSTAT_INC(ahs_crypto);
639 crda = crp->crp_desc;
640 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
643 crda->crd_len = m->m_pkthdr.len;
644 crda->crd_inject = skip + rplen;
646 /* Authentication operation. */
647 crda->crd_alg = ahx->type;
648 crda->crd_klen = _KEYBITS(sav->key_auth);
649 crda->crd_key = sav->key_auth->key_data;
651 /* Find out if we've already done crypto. */
652 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
654 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
655 tdbi = (struct tdb_ident *) (mtag + 1);
656 if (tdbi->proto == sav->sah->saidx.proto &&
657 tdbi->spi == sav->spi &&
658 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
659 sizeof (union sockaddr_union)))
663 /* Allocate IPsec-specific opaque crypto info. */
665 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
666 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
668 /* Hash verification has already been done successfully. */
669 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
670 M_XDATA, M_NOWAIT|M_ZERO);
673 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
674 AHSTAT_INC(ahs_crypto);
680 /* Only save information if crypto processing is needed. */
685 * Save the authenticator, the skipped portion of the packet,
688 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
690 /* Zeroize the authenticator on the packet. */
691 m_copyback(m, skip + rplen, authsize, ipseczeroes);
693 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
696 /* "Massage" the packet headers for crypto processing. */
697 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
700 /* NB: mbuf is free'd by ah_massage_headers */
701 AHSTAT_INC(ahs_hdrops);
708 /* Crypto operation descriptor. */
709 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
710 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
711 crp->crp_buf = (caddr_t) m;
712 crp->crp_callback = ah_input_cb;
713 crp->crp_sid = sav->tdb_cryptoid;
714 crp->crp_opaque = (caddr_t) tc;
716 /* These are passed as-is to the callback. */
717 tc->tc_spi = sav->spi;
718 tc->tc_dst = sav->sah->saidx.dst;
719 tc->tc_proto = sav->sah->saidx.proto;
721 tc->tc_protoff = protoff;
723 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
728 return crypto_dispatch(crp);
730 return ah_input_cb(crp);
734 * AH input callback from the crypto driver.
737 ah_input_cb(struct cryptop *crp)
739 int rplen, error, skip, protoff;
740 unsigned char calc[AH_ALEN_MAX];
742 struct cryptodesc *crd;
743 struct auth_hash *ahx;
744 struct tdb_crypto *tc;
746 struct secasvar *sav;
747 struct secasindex *saidx;
754 tc = (struct tdb_crypto *) crp->crp_opaque;
755 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
758 protoff = tc->tc_protoff;
759 mtag = (struct m_tag *) tc->tc_ptr;
760 m = (struct mbuf *) crp->crp_buf;
763 IPSEC_ASSERT(sav != NULL, ("null SA!"));
765 saidx = &sav->sah->saidx;
766 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
767 saidx->dst.sa.sa_family == AF_INET6,
768 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
770 ahx = (struct auth_hash *) sav->tdb_authalgxform;
772 /* Check for crypto errors. */
773 if (crp->crp_etype) {
774 if (sav->tdb_cryptoid != 0)
775 sav->tdb_cryptoid = crp->crp_sid;
777 if (crp->crp_etype == EAGAIN)
778 return (crypto_dispatch(crp));
780 AHSTAT_INC(ahs_noxform);
781 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
782 error = crp->crp_etype;
785 AHSTAT_INC(ahs_hist[sav->alg_auth]);
786 crypto_freereq(crp); /* No longer needed. */
790 /* Shouldn't happen... */
792 AHSTAT_INC(ahs_crypto);
793 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
798 /* Figure out header size. */
799 rplen = HDRSIZE(sav);
800 authsize = AUTHSIZE(sav);
802 /* Copy authenticator off the packet. */
803 m_copydata(m, skip + rplen, authsize, calc);
806 * If we have an mtag, we don't need to verify the authenticator --
807 * it has been verified by an IPsec-aware NIC.
810 ptr = (caddr_t) (tc + 1);
812 /* Verify authenticator. */
813 if (bcmp(ptr + skip + rplen, calc, authsize)) {
814 DPRINTF(("%s: authentication hash mismatch for packet "
815 "in SA %s/%08lx\n", __func__,
816 ipsec_address(&saidx->dst),
817 (u_long) ntohl(sav->spi)));
818 AHSTAT_INC(ahs_badauth);
823 /* Fix the Next Protocol field. */
824 ((u_int8_t *) ptr)[protoff] = nxt;
826 /* Copyback the saved (uncooked) network headers. */
827 m_copyback(m, 0, skip, ptr);
829 /* Fix the Next Protocol field. */
830 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
833 free(tc, M_XDATA), tc = NULL; /* No longer needed */
836 * Header is now authenticated.
838 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
841 * Update replay sequence number, if appropriate.
846 m_copydata(m, skip + offsetof(struct newah, ah_seq),
847 sizeof (seq), (caddr_t) &seq);
848 if (ipsec_updatereplay(ntohl(seq), sav)) {
849 AHSTAT_INC(ahs_replay);
850 error = ENOBUFS; /*XXX as above*/
856 * Remove the AH header and authenticator from the mbuf.
858 error = m_striphdr(m, skip, rplen + authsize);
860 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
861 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
863 AHSTAT_INC(ahs_hdrops);
867 switch (saidx->dst.sa.sa_family) {
870 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag);
875 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag);
879 panic("%s: Unexpected address family: %d saidx=%p", __func__,
880 saidx->dst.sa.sa_family, saidx);
898 * AH output routine, called by ipsec[46]_process_packet().
903 struct ipsecrequest *isr,
908 struct secasvar *sav;
909 struct auth_hash *ahx;
910 struct cryptodesc *crda;
911 struct tdb_crypto *tc;
915 int error, rplen, authsize, maxpacketsize, roff;
920 IPSEC_ASSERT(sav != NULL, ("null SA"));
921 ahx = sav->tdb_authalgxform;
922 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
924 AHSTAT_INC(ahs_output);
926 /* Figure out header size. */
927 rplen = HDRSIZE(sav);
929 /* Check for maximum packet size violations. */
930 switch (sav->sah->saidx.dst.sa.sa_family) {
933 maxpacketsize = IP_MAXPACKET;
938 maxpacketsize = IPV6_MAXPACKET;
942 DPRINTF(("%s: unknown/unsupported protocol family %u, "
943 "SA %s/%08lx\n", __func__,
944 sav->sah->saidx.dst.sa.sa_family,
945 ipsec_address(&sav->sah->saidx.dst),
946 (u_long) ntohl(sav->spi)));
947 AHSTAT_INC(ahs_nopf);
948 error = EPFNOSUPPORT;
951 authsize = AUTHSIZE(sav);
952 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
953 DPRINTF(("%s: packet in SA %s/%08lx got too big "
954 "(len %u, max len %u)\n", __func__,
955 ipsec_address(&sav->sah->saidx.dst),
956 (u_long) ntohl(sav->spi),
957 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
958 AHSTAT_INC(ahs_toobig);
963 /* Update the counters. */
964 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
966 m = m_unshare(m, M_NOWAIT);
968 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
969 ipsec_address(&sav->sah->saidx.dst),
970 (u_long) ntohl(sav->spi)));
971 AHSTAT_INC(ahs_hdrops);
976 /* Inject AH header. */
977 mi = m_makespace(m, skip, rplen + authsize, &roff);
979 DPRINTF(("%s: failed to inject %u byte AH header for SA "
980 "%s/%08lx\n", __func__,
982 ipsec_address(&sav->sah->saidx.dst),
983 (u_long) ntohl(sav->spi)));
984 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
990 * The AH header is guaranteed by m_makespace() to be in
991 * contiguous memory, at roff bytes offset into the returned mbuf.
993 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
995 /* Initialize the AH header. */
996 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
997 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
999 ah->ah_spi = sav->spi;
1001 /* Zeroize authenticator. */
1002 m_copyback(m, skip + rplen, authsize, ipseczeroes);
1004 /* Insert packet replay counter, as requested. */
1006 if (sav->replay->count == ~0 &&
1007 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1008 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
1010 ipsec_address(&sav->sah->saidx.dst),
1011 (u_long) ntohl(sav->spi)));
1012 AHSTAT_INC(ahs_wrap);
1017 /* Emulate replay attack when ipsec_replay is TRUE. */
1018 if (!V_ipsec_replay)
1020 sav->replay->count++;
1021 ah->ah_seq = htonl(sav->replay->count);
1024 /* Get crypto descriptors. */
1025 crp = crypto_getreq(1);
1027 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1029 AHSTAT_INC(ahs_crypto);
1034 crda = crp->crp_desc;
1037 crda->crd_inject = skip + rplen;
1038 crda->crd_len = m->m_pkthdr.len;
1040 /* Authentication operation. */
1041 crda->crd_alg = ahx->type;
1042 crda->crd_key = sav->key_auth->key_data;
1043 crda->crd_klen = _KEYBITS(sav->key_auth);
1045 /* Allocate IPsec-specific opaque crypto info. */
1046 tc = (struct tdb_crypto *) malloc(
1047 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1049 crypto_freereq(crp);
1050 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1051 AHSTAT_INC(ahs_crypto);
1056 /* Save the skipped portion of the packet. */
1057 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1060 * Fix IP header length on the header used for
1061 * authentication. We don't need to fix the original
1062 * header length as it will be fixed by our caller.
1064 switch (sav->sah->saidx.dst.sa.sa_family) {
1067 bcopy(((caddr_t)(tc + 1)) +
1068 offsetof(struct ip, ip_len),
1069 (caddr_t) &iplen, sizeof(u_int16_t));
1070 iplen = htons(ntohs(iplen) + rplen + authsize);
1071 m_copyback(m, offsetof(struct ip, ip_len),
1072 sizeof(u_int16_t), (caddr_t) &iplen);
1078 bcopy(((caddr_t)(tc + 1)) +
1079 offsetof(struct ip6_hdr, ip6_plen),
1080 (caddr_t) &iplen, sizeof(u_int16_t));
1081 iplen = htons(ntohs(iplen) + rplen + authsize);
1082 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1083 sizeof(u_int16_t), (caddr_t) &iplen);
1088 /* Fix the Next Header field in saved header. */
1089 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1091 /* Update the Next Protocol field in the IP header. */
1093 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1095 /* "Massage" the packet headers for crypto processing. */
1096 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1097 skip, ahx->type, 1);
1099 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1101 crypto_freereq(crp);
1105 /* Crypto operation descriptor. */
1106 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1107 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1108 crp->crp_buf = (caddr_t) m;
1109 crp->crp_callback = ah_output_cb;
1110 crp->crp_sid = sav->tdb_cryptoid;
1111 crp->crp_opaque = (caddr_t) tc;
1113 /* These are passed as-is to the callback. */
1117 tc->tc_spi = sav->spi;
1118 tc->tc_dst = sav->sah->saidx.dst;
1119 tc->tc_proto = sav->sah->saidx.proto;
1121 tc->tc_protoff = protoff;
1123 return crypto_dispatch(crp);
1131 * AH output callback from the crypto driver.
1134 ah_output_cb(struct cryptop *crp)
1136 int skip, protoff, error;
1137 struct tdb_crypto *tc;
1138 struct ipsecrequest *isr;
1139 struct secasvar *sav;
1143 tc = (struct tdb_crypto *) crp->crp_opaque;
1144 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1146 protoff = tc->tc_protoff;
1147 ptr = (caddr_t) (tc + 1);
1148 m = (struct mbuf *) crp->crp_buf;
1151 IPSECREQUEST_LOCK(isr);
1153 /* With the isr lock released SA pointer can be updated. */
1154 if (sav != isr->sav) {
1155 AHSTAT_INC(ahs_notdb);
1156 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1157 error = ENOBUFS; /*XXX*/
1161 /* Check for crypto errors. */
1162 if (crp->crp_etype) {
1163 if (sav->tdb_cryptoid != 0)
1164 sav->tdb_cryptoid = crp->crp_sid;
1166 if (crp->crp_etype == EAGAIN) {
1167 IPSECREQUEST_UNLOCK(isr);
1168 return (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 error = 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);