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/mutex.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) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \
89 xform_ah_authsize((sav)->tdb_authalgxform))
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 */
111 static struct timeval md5warn, ripewarn, kpdkmd5warn, kpdksha1warn;
113 static int ah_input_cb(struct cryptop*);
114 static int ah_output_cb(struct cryptop*);
117 xform_ah_authsize(const struct auth_hash *esph)
124 switch (esph->type) {
125 case CRYPTO_SHA2_256_HMAC:
126 case CRYPTO_SHA2_384_HMAC:
127 case CRYPTO_SHA2_512_HMAC:
128 alen = esph->hashsize / 2; /* RFC4868 2.3 */
131 case CRYPTO_AES_128_NIST_GMAC:
132 case CRYPTO_AES_192_NIST_GMAC:
133 case CRYPTO_AES_256_NIST_GMAC:
134 alen = esph->hashsize;
138 alen = AH_HMAC_HASHLEN;
146 ah_hdrsiz(struct secasvar *sav)
151 int authsize, rplen, align;
153 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
154 /*XXX not right for null algorithm--does it matter??*/
156 /* RFC4302: use the correct alignment. */
157 align = sizeof(uint32_t);
159 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
160 align = sizeof(uint64_t);
163 rplen = HDRSIZE(sav);
164 authsize = AUTHSIZE(sav);
165 size = roundup(rplen + authsize, align);
168 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
174 * NB: public for use by esp_init.
177 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
179 const struct auth_hash *thash;
182 thash = auth_algorithm_lookup(sav->alg_auth);
184 DPRINTF(("%s: unsupported authentication algorithm %u\n",
185 __func__, sav->alg_auth));
189 switch (sav->alg_auth) {
190 case SADB_AALG_MD5HMAC:
191 if (ratecheck(&md5warn, &ipsec_warn_interval))
192 gone_in(13, "MD5-HMAC authenticator for IPsec");
194 case SADB_X_AALG_RIPEMD160HMAC:
195 if (ratecheck(&ripewarn, &ipsec_warn_interval))
196 gone_in(13, "RIPEMD160-HMAC authenticator for IPsec");
198 case SADB_X_AALG_MD5:
199 if (ratecheck(&kpdkmd5warn, &ipsec_warn_interval))
200 gone_in(13, "Keyed-MD5 authenticator for IPsec");
202 case SADB_X_AALG_SHA:
203 if (ratecheck(&kpdksha1warn, &ipsec_warn_interval))
204 gone_in(13, "Keyed-SHA1 authenticator for IPsec");
209 * Verify the replay state block allocation is consistent with
210 * the protocol type. We check here so we can make assumptions
211 * later during protocol processing.
213 /* NB: replay state is setup elsewhere (sigh) */
214 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
215 DPRINTF(("%s: replay state block inconsistency, "
216 "%s algorithm %s replay state\n", __func__,
217 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
218 sav->replay == NULL ? "without" : "with"));
221 if (sav->key_auth == NULL) {
222 DPRINTF(("%s: no authentication key for %s algorithm\n",
223 __func__, thash->name));
226 keylen = _KEYLEN(sav->key_auth);
227 if (keylen > thash->keysize && thash->keysize != 0) {
228 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
229 "keysize less than %d\n", __func__,
230 keylen, thash->name, thash->keysize));
234 sav->tdb_xform = xsp;
235 sav->tdb_authalgxform = thash;
237 /* Initialize crypto session. */
238 bzero(cria, sizeof (*cria));
239 cria->cri_alg = sav->tdb_authalgxform->type;
240 cria->cri_klen = _KEYBITS(sav->key_auth);
241 cria->cri_key = sav->key_auth->key_data;
242 cria->cri_mlen = AUTHSIZE(sav);
248 * ah_init() is called when an SPI is being set up.
251 ah_init(struct secasvar *sav, struct xformsw *xsp)
253 struct cryptoini cria;
256 error = ah_init0(sav, xsp, &cria);
257 return error ? error :
258 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
264 * NB: public for use by esp_zeroize (XXX).
267 ah_zeroize(struct secasvar *sav)
271 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
273 crypto_freesession(sav->tdb_cryptoid);
274 sav->tdb_cryptoid = NULL;
275 sav->tdb_authalgxform = NULL;
276 sav->tdb_xform = NULL;
281 * Massage IPv4/IPv6 headers for AH processing.
284 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
286 struct mbuf *m = *m0;
295 struct ip6_ext *ip6e;
297 int ad, alloc, nxt, noff;
304 * This is the least painful way of dealing with IPv4 header
305 * and option processing -- just make sure they're in
308 *m0 = m = m_pullup(m, skip);
310 DPRINTF(("%s: m_pullup failed\n", __func__));
314 /* Fix the IP header */
315 ip = mtod(m, struct ip *);
321 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
322 ip->ip_off &= htons(IP_DF);
324 ip->ip_off = htons(0);
326 ptr = mtod(m, unsigned char *);
328 /* IPv4 option processing */
329 for (off = sizeof(struct ip); off < skip;) {
330 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
334 DPRINTF(("%s: illegal IPv4 option length for "
335 "option %d\n", __func__, ptr[off]));
343 off = skip; /* End the loop. */
350 case IPOPT_SECURITY: /* 0x82 */
351 case 0x85: /* Extended security. */
352 case 0x86: /* Commercial security. */
353 case 0x94: /* Router alert */
354 case 0x95: /* RFC1770 */
355 /* Sanity check for option length. */
356 if (ptr[off + 1] < 2) {
357 DPRINTF(("%s: illegal IPv4 option "
358 "length for option %d\n",
359 __func__, ptr[off]));
370 /* Sanity check for option length. */
371 if (ptr[off + 1] < 2) {
372 DPRINTF(("%s: illegal IPv4 option "
373 "length for option %d\n",
374 __func__, ptr[off]));
381 * On output, if we have either of the
382 * source routing options, we should
383 * swap the destination address of the
384 * IP header with the last address
385 * specified in the option, as that is
386 * what the destination's IP header
390 bcopy(ptr + off + ptr[off + 1] -
391 sizeof(struct in_addr),
392 &(ip->ip_dst), sizeof(struct in_addr));
396 /* Sanity check for option length. */
397 if (ptr[off + 1] < 2) {
398 DPRINTF(("%s: illegal IPv4 option "
399 "length for option %d\n",
400 __func__, ptr[off]));
405 /* Zeroize all other options. */
406 count = ptr[off + 1];
407 bcopy(ipseczeroes, ptr + off, count);
414 DPRINTF(("%s: malformed IPv4 options header\n",
426 case AF_INET6: /* Ugly... */
427 /* Copy and "cook" the IPv6 header. */
428 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
430 /* We don't do IPv6 Jumbograms. */
431 if (ip6.ip6_plen == 0) {
432 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
439 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
440 ip6.ip6_vfc |= IPV6_VERSION;
442 /* Scoped address handling. */
443 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
444 ip6.ip6_src.s6_addr16[1] = 0;
445 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
446 ip6.ip6_dst.s6_addr16[1] = 0;
448 /* Done with IPv6 header. */
449 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
451 /* Let's deal with the remaining headers (if any). */
452 if (skip - sizeof(struct ip6_hdr) > 0) {
453 if (m->m_len <= skip) {
454 ptr = (unsigned char *) malloc(
455 skip - sizeof(struct ip6_hdr),
458 DPRINTF(("%s: failed to allocate memory"
459 "for IPv6 headers\n",__func__));
465 * Copy all the protocol headers after
468 m_copydata(m, sizeof(struct ip6_hdr),
469 skip - sizeof(struct ip6_hdr), ptr);
472 /* No need to allocate memory. */
473 ptr = mtod(m, unsigned char *) +
474 sizeof(struct ip6_hdr);
480 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
482 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
484 case IPPROTO_HOPOPTS:
485 case IPPROTO_DSTOPTS:
486 ip6e = (struct ip6_ext *)(ptr + off);
487 noff = off + ((ip6e->ip6e_len + 1) << 3);
490 if (noff > skip - sizeof(struct ip6_hdr))
494 * Zero out mutable options.
496 for (count = off + sizeof(struct ip6_ext);
498 if (ptr[count] == IP6OPT_PAD1) {
500 continue; /* Skip padding. */
503 ad = ptr[count + 1] + 2;
504 if (count + ad > noff)
507 if (ptr[count] & IP6OPT_MUTABLE)
508 memset(ptr + count, 0, ad);
516 off += ((ip6e->ip6e_len + 1) << 3);
517 nxt = ip6e->ip6e_nxt;
520 case IPPROTO_ROUTING:
522 * Always include routing headers in
525 ip6e = (struct ip6_ext *) (ptr + off);
526 off += ((ip6e->ip6e_len + 1) << 3);
527 nxt = ip6e->ip6e_nxt;
531 DPRINTF(("%s: unexpected IPv6 header type %d",
540 /* Copyback and free, if we allocated. */
542 m_copyback(m, sizeof(struct ip6_hdr),
543 skip - sizeof(struct ip6_hdr), ptr);
555 * ah_input() gets called to verify that an input packet
556 * passes authentication.
559 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
561 IPSEC_DEBUG_DECLARE(char buf[128]);
562 const struct auth_hash *ahx;
563 struct cryptodesc *crda;
565 struct xform_data *xd;
567 crypto_session_t cryptoid;
568 int hl, rplen, authsize, ahsize, error;
570 IPSEC_ASSERT(sav != NULL, ("null SA"));
571 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
572 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
573 ("null authentication xform"));
575 /* Figure out header size. */
576 rplen = HDRSIZE(sav);
578 /* XXX don't pullup, just copy header */
579 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
581 DPRINTF(("ah_input: cannot pullup header\n"));
582 AHSTAT_INC(ahs_hdrops); /*XXX*/
587 /* Check replay window, if applicable. */
589 if (sav->replay != NULL && sav->replay->wsize != 0 &&
590 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) {
591 SECASVAR_UNLOCK(sav);
592 AHSTAT_INC(ahs_replay);
593 DPRINTF(("%s: packet replay failure: %s\n", __func__,
594 ipsec_sa2str(sav, buf, sizeof(buf))));
598 cryptoid = sav->tdb_cryptoid;
599 SECASVAR_UNLOCK(sav);
601 /* Verify AH header length. */
602 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
603 ahx = sav->tdb_authalgxform;
604 authsize = AUTHSIZE(sav);
605 ahsize = ah_hdrsiz(sav);
607 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
608 " for packet in SA %s/%08lx\n", __func__, hl,
610 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
611 (u_long) ntohl(sav->spi)));
612 AHSTAT_INC(ahs_badauthl);
616 if (skip + ahsize > m->m_pkthdr.len) {
617 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
618 " for packet in SA %s/%08lx\n", __func__,
619 m->m_pkthdr.len, (u_long)(skip + ahsize),
620 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
621 (u_long) ntohl(sav->spi)));
622 AHSTAT_INC(ahs_badauthl);
626 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
628 /* Get crypto descriptors. */
629 crp = crypto_getreq(1);
631 DPRINTF(("%s: failed to acquire crypto descriptor\n",
633 AHSTAT_INC(ahs_crypto);
638 crda = crp->crp_desc;
639 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
642 crda->crd_len = m->m_pkthdr.len;
643 crda->crd_inject = skip + rplen;
645 /* Authentication operation. */
646 crda->crd_alg = ahx->type;
647 crda->crd_klen = _KEYBITS(sav->key_auth);
648 crda->crd_key = sav->key_auth->key_data;
650 /* Allocate IPsec-specific opaque crypto info. */
651 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
654 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
655 AHSTAT_INC(ahs_crypto);
662 * Save the authenticator, the skipped portion of the packet,
665 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
667 /* Zeroize the authenticator on the packet. */
668 m_copyback(m, skip + rplen, authsize, ipseczeroes);
670 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
673 /* "Massage" the packet headers for crypto processing. */
674 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
677 /* NB: mbuf is free'd by ah_massage_headers */
678 AHSTAT_INC(ahs_hdrops);
685 /* Crypto operation descriptor. */
686 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
687 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
689 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
690 crp->crp_buf = (caddr_t) m;
691 crp->crp_callback = ah_input_cb;
692 crp->crp_session = cryptoid;
693 crp->crp_opaque = (caddr_t) xd;
695 /* These are passed as-is to the callback. */
698 xd->protoff = protoff;
700 xd->cryptoid = cryptoid;
702 return (crypto_dispatch(crp));
710 * AH input callback from the crypto driver.
713 ah_input_cb(struct cryptop *crp)
715 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
716 unsigned char calc[AH_ALEN_MAX];
718 struct xform_data *xd;
719 struct secasvar *sav;
720 struct secasindex *saidx;
722 crypto_session_t cryptoid;
723 int authsize, rplen, ahsize, error, skip, protoff;
726 m = (struct mbuf *) crp->crp_buf;
727 xd = (struct xform_data *) crp->crp_opaque;
728 CURVNET_SET(xd->vnet);
732 protoff = xd->protoff;
733 cryptoid = xd->cryptoid;
734 saidx = &sav->sah->saidx;
735 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
736 saidx->dst.sa.sa_family == AF_INET6,
737 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
739 /* Check for crypto errors. */
740 if (crp->crp_etype) {
741 if (crp->crp_etype == EAGAIN) {
742 /* Reset the session ID */
743 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
744 crypto_freesession(cryptoid);
745 xd->cryptoid = crp->crp_session;
747 return (crypto_dispatch(crp));
749 AHSTAT_INC(ahs_noxform);
750 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
751 error = crp->crp_etype;
754 AHSTAT_INC(ahs_hist[sav->alg_auth]);
755 crypto_freereq(crp); /* No longer needed. */
759 /* Shouldn't happen... */
761 AHSTAT_INC(ahs_crypto);
762 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
767 /* Figure out header size. */
768 rplen = HDRSIZE(sav);
769 authsize = AUTHSIZE(sav);
770 ahsize = ah_hdrsiz(sav);
772 /* Copy authenticator off the packet. */
773 m_copydata(m, skip + rplen, authsize, calc);
775 /* Verify authenticator. */
776 ptr = (caddr_t) (xd + 1);
777 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
778 DPRINTF(("%s: authentication hash mismatch for packet "
779 "in SA %s/%08lx\n", __func__,
780 ipsec_address(&saidx->dst, buf, sizeof(buf)),
781 (u_long) ntohl(sav->spi)));
782 AHSTAT_INC(ahs_badauth);
786 /* Fix the Next Protocol field. */
787 ((uint8_t *) ptr)[protoff] = nxt;
789 /* Copyback the saved (uncooked) network headers. */
790 m_copyback(m, 0, skip, ptr);
791 free(xd, M_XDATA), xd = NULL; /* No longer needed */
794 * Header is now authenticated.
796 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
799 * Update replay sequence number, if appropriate.
804 m_copydata(m, skip + offsetof(struct newah, ah_seq),
805 sizeof (seq), (caddr_t) &seq);
807 if (ipsec_updatereplay(ntohl(seq), sav)) {
808 SECASVAR_UNLOCK(sav);
809 AHSTAT_INC(ahs_replay);
813 SECASVAR_UNLOCK(sav);
817 * Remove the AH header and authenticator from the mbuf.
819 error = m_striphdr(m, skip, ahsize);
821 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
822 ipsec_address(&saidx->dst, buf, sizeof(buf)),
823 (u_long) ntohl(sav->spi)));
824 AHSTAT_INC(ahs_hdrops);
828 switch (saidx->dst.sa.sa_family) {
831 error = ipsec6_common_input_cb(m, sav, skip, protoff);
836 error = ipsec4_common_input_cb(m, sav, skip, protoff);
840 panic("%s: Unexpected address family: %d saidx=%p", __func__,
841 saidx->dst.sa.sa_family, saidx);
859 * AH output routine, called by ipsec[46]_perform_request().
862 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
863 u_int idx, int skip, int protoff)
865 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
866 const struct auth_hash *ahx;
867 struct cryptodesc *crda;
868 struct xform_data *xd;
872 crypto_session_t cryptoid;
874 int error, rplen, authsize, ahsize, maxpacketsize, roff;
877 IPSEC_ASSERT(sav != NULL, ("null SA"));
878 ahx = sav->tdb_authalgxform;
879 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
881 AHSTAT_INC(ahs_output);
883 /* Figure out header size. */
884 rplen = HDRSIZE(sav);
885 authsize = AUTHSIZE(sav);
886 ahsize = ah_hdrsiz(sav);
888 /* Check for maximum packet size violations. */
889 switch (sav->sah->saidx.dst.sa.sa_family) {
892 maxpacketsize = IP_MAXPACKET;
897 maxpacketsize = IPV6_MAXPACKET;
901 DPRINTF(("%s: unknown/unsupported protocol family %u, "
902 "SA %s/%08lx\n", __func__,
903 sav->sah->saidx.dst.sa.sa_family,
904 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
905 (u_long) ntohl(sav->spi)));
906 AHSTAT_INC(ahs_nopf);
907 error = EPFNOSUPPORT;
910 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
911 DPRINTF(("%s: packet in SA %s/%08lx got too big "
912 "(len %u, max len %u)\n", __func__,
913 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
914 (u_long) ntohl(sav->spi),
915 ahsize + m->m_pkthdr.len, maxpacketsize));
916 AHSTAT_INC(ahs_toobig);
921 /* Update the counters. */
922 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
924 m = m_unshare(m, M_NOWAIT);
926 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
927 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
928 (u_long) ntohl(sav->spi)));
929 AHSTAT_INC(ahs_hdrops);
934 /* Inject AH header. */
935 mi = m_makespace(m, skip, ahsize, &roff);
937 DPRINTF(("%s: failed to inject %u byte AH header for SA "
938 "%s/%08lx\n", __func__, ahsize,
939 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
940 (u_long) ntohl(sav->spi)));
941 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
947 * The AH header is guaranteed by m_makespace() to be in
948 * contiguous memory, at roff bytes offset into the returned mbuf.
950 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
952 /* Initialize the AH header. */
953 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
954 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
956 ah->ah_spi = sav->spi;
958 /* Zeroize authenticator. */
959 m_copyback(m, skip + rplen, authsize, ipseczeroes);
961 /* Zeroize padding */
962 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
965 /* Insert packet replay counter, as requested. */
968 if (sav->replay->count == ~0 &&
969 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
970 SECASVAR_UNLOCK(sav);
971 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
972 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
973 sizeof(buf)), (u_long) ntohl(sav->spi)));
974 AHSTAT_INC(ahs_wrap);
979 /* Emulate replay attack when ipsec_replay is TRUE. */
982 sav->replay->count++;
983 ah->ah_seq = htonl(sav->replay->count);
985 cryptoid = sav->tdb_cryptoid;
986 SECASVAR_UNLOCK(sav);
988 /* Get crypto descriptors. */
989 crp = crypto_getreq(1);
991 DPRINTF(("%s: failed to acquire crypto descriptors\n",
993 AHSTAT_INC(ahs_crypto);
998 crda = crp->crp_desc;
1000 crda->crd_inject = skip + rplen;
1001 crda->crd_len = m->m_pkthdr.len;
1003 /* Authentication operation. */
1004 crda->crd_alg = ahx->type;
1005 crda->crd_key = sav->key_auth->key_data;
1006 crda->crd_klen = _KEYBITS(sav->key_auth);
1008 /* Allocate IPsec-specific opaque crypto info. */
1009 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
1012 crypto_freereq(crp);
1013 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
1014 AHSTAT_INC(ahs_crypto);
1019 /* Save the skipped portion of the packet. */
1020 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
1023 * Fix IP header length on the header used for
1024 * authentication. We don't need to fix the original
1025 * header length as it will be fixed by our caller.
1027 switch (sav->sah->saidx.dst.sa.sa_family) {
1030 bcopy(((caddr_t)(xd + 1)) +
1031 offsetof(struct ip, ip_len),
1032 (caddr_t) &iplen, sizeof(u_int16_t));
1033 iplen = htons(ntohs(iplen) + ahsize);
1034 m_copyback(m, offsetof(struct ip, ip_len),
1035 sizeof(u_int16_t), (caddr_t) &iplen);
1041 bcopy(((caddr_t)(xd + 1)) +
1042 offsetof(struct ip6_hdr, ip6_plen),
1043 (caddr_t) &iplen, sizeof(uint16_t));
1044 iplen = htons(ntohs(iplen) + ahsize);
1045 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1046 sizeof(uint16_t), (caddr_t) &iplen);
1051 /* Fix the Next Header field in saved header. */
1052 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1054 /* Update the Next Protocol field in the IP header. */
1056 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1058 /* "Massage" the packet headers for crypto processing. */
1059 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1060 skip, ahx->type, 1);
1062 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1064 crypto_freereq(crp);
1068 /* Crypto operation descriptor. */
1069 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1070 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1072 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1073 crp->crp_buf = (caddr_t) m;
1074 crp->crp_callback = ah_output_cb;
1075 crp->crp_session = cryptoid;
1076 crp->crp_opaque = (caddr_t) xd;
1078 /* These are passed as-is to the callback. */
1083 xd->cryptoid = cryptoid;
1086 return crypto_dispatch(crp);
1096 * AH output callback from the crypto driver.
1099 ah_output_cb(struct cryptop *crp)
1101 struct xform_data *xd;
1102 struct secpolicy *sp;
1103 struct secasvar *sav;
1105 crypto_session_t cryptoid;
1110 m = (struct mbuf *) crp->crp_buf;
1111 xd = (struct xform_data *) crp->crp_opaque;
1112 CURVNET_SET(xd->vnet);
1117 cryptoid = xd->cryptoid;
1118 ptr = (caddr_t) (xd + 1);
1120 /* Check for crypto errors. */
1121 if (crp->crp_etype) {
1122 if (crp->crp_etype == EAGAIN) {
1123 /* Reset the session ID */
1124 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1125 crypto_freesession(cryptoid);
1126 xd->cryptoid = crp->crp_session;
1128 return (crypto_dispatch(crp));
1130 AHSTAT_INC(ahs_noxform);
1131 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1132 error = crp->crp_etype;
1137 /* Shouldn't happen... */
1139 AHSTAT_INC(ahs_crypto);
1140 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1145 * Copy original headers (with the new protocol number) back
1148 m_copyback(m, 0, skip, ptr);
1151 crypto_freereq(crp);
1152 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1154 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1155 if (V_ipsec_integrity) {
1159 * Corrupt HMAC if we want to test integrity verification of
1162 alen = AUTHSIZE(sav);
1163 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1167 /* NB: m is reclaimed by ipsec_process_done. */
1168 error = ipsec_process_done(m, sp, sav, idx);
1174 crypto_freereq(crp);
1180 static struct xformsw ah_xformsw = {
1182 .xf_name = "IPsec AH",
1184 .xf_zeroize = ah_zeroize,
1185 .xf_input = ah_input,
1186 .xf_output = ah_output,
1189 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1190 xform_attach, &ah_xformsw);
1191 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1192 xform_detach, &ah_xformsw);