1/* $FreeBSD: head/sys/netipsec/xform_ah.c 190909 2009-04-11 05:58:58Z zec $ */
2/* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
3/*-
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).
7 *
8 * The original version of this code was written by John Ioannidis
9 * for BSD/OS in Athens, Greece, in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
18 *
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.
23 *
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
31 * all.
32 *
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
37 * PURPOSE.
38 */
39#include "opt_inet.h"
40#include "opt_inet6.h"
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/mbuf.h>
45#include <sys/socket.h>
46#include <sys/syslog.h>
47#include <sys/kernel.h>
48#include <sys/sysctl.h>
49#include <sys/vimage.h>
50
51#include <net/if.h>
52
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>
58
59#include <net/route.h>
60#include <netipsec/ipsec.h>
61#include <netipsec/ah.h>
62#include <netipsec/ah_var.h>
63#include <netipsec/xform.h>
64
65#ifdef INET6
66#include <netinet6/ip6_var.h>
67#include <netipsec/ipsec6.h>
68#include <netinet6/ip6_ecn.h>
69#endif
70
71#include <netipsec/key.h>
72#include <netipsec/key_debug.h>
73
74#include <opencrypto/cryptodev.h>
75
76static int ah_iattach(const void *);
77
78#ifndef VIMAGE_GLOBALS
79static const vnet_modinfo_t vnet_ah_modinfo = {
80 .vmi_id = VNET_MOD_AH,
81 .vmi_name = "ipsec_ah",
82 .vmi_dependson = VNET_MOD_IPSEC,
83 .vmi_iattach = ah_iattach
84};
85#endif /* !VIMAGE_GLOBALS */
86
87/*
88 * Return header size in bytes. The old protocol did not support
89 * the replay counter; the new protocol always includes the counter.
90 */
91#define HDRSIZE(sav) \
92 (((sav)->flags & SADB_X_EXT_OLD) ? \
93 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
94/*
95 * Return authenticator size in bytes. The old protocol is known
96 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
97 * authenticator.
98 */
99#define AUTHSIZE(sav) \
100 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
101
102#ifdef VIMAGE_GLOBALS
103int ah_enable;
104int ah_cleartos;
105struct ahstat ahstat;
106#endif
107
108SYSCTL_DECL(_net_inet_ah);
109SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
110 ah_enable, CTLFLAG_RW, ah_enable, 0, "");
111SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
112 ah_cleartos, CTLFLAG_RW, ah_cleartos, 0, "");
113SYSCTL_V_STRUCT(V_NET, vnet_ipsec, _net_inet_ah, IPSECCTL_STATS,
114 stats, CTLFLAG_RD, ahstat, ahstat, "");
115
116static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
117
118static int ah_input_cb(struct cryptop*);
119static int ah_output_cb(struct cryptop*);
120
121/*
122 * NB: this is public for use by the PF_KEY support.
123 */
124struct auth_hash *
125ah_algorithm_lookup(int alg)
126{
127 if (alg > SADB_AALG_MAX)
128 return NULL;
129 switch (alg) {
130 case SADB_X_AALG_NULL:
131 return &auth_hash_null;
132 case SADB_AALG_MD5HMAC:
133 return &auth_hash_hmac_md5;
134 case SADB_AALG_SHA1HMAC:
135 return &auth_hash_hmac_sha1;
136 case SADB_X_AALG_RIPEMD160HMAC:
137 return &auth_hash_hmac_ripemd_160;
138 case SADB_X_AALG_MD5:
139 return &auth_hash_key_md5;
140 case SADB_X_AALG_SHA:
141 return &auth_hash_key_sha1;
142 case SADB_X_AALG_SHA2_256:
143 return &auth_hash_hmac_sha2_256;
144 case SADB_X_AALG_SHA2_384:
145 return &auth_hash_hmac_sha2_384;
146 case SADB_X_AALG_SHA2_512:
147 return &auth_hash_hmac_sha2_512;
148 }
149 return NULL;
150}
151
152size_t
153ah_hdrsiz(struct secasvar *sav)
154{
155 size_t size;
156
157 if (sav != NULL) {
158 int authsize;
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);
163 } else {
164 /* default guess */
165 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
166 }
167 return size;
168}
169
170/*
171 * NB: public for use by esp_init.
172 */
173int
174ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
175{
176 INIT_VNET_IPSEC(curvnet);
177 struct auth_hash *thash;
178 int keylen;
179
180 thash = ah_algorithm_lookup(sav->alg_auth);
181 if (thash == NULL) {
182 DPRINTF(("%s: unsupported authentication algorithm %u\n",
183 __func__, sav->alg_auth));
184 return EINVAL;
185 }
186 /*
187 * Verify the replay state block allocation is consistent with
188 * the protocol type. We check here so we can make assumptions
189 * later during protocol processing.
190 */
191 /* NB: replay state is setup elsewhere (sigh) */
192 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
193 DPRINTF(("%s: replay state block inconsistency, "
194 "%s algorithm %s replay state\n", __func__,
195 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
196 sav->replay == NULL ? "without" : "with"));
197 return EINVAL;
198 }
199 if (sav->key_auth == NULL) {
200 DPRINTF(("%s: no authentication key for %s algorithm\n",
201 __func__, thash->name));
202 return EINVAL;
203 }
204 keylen = _KEYLEN(sav->key_auth);
205 if (keylen != thash->keysize && thash->keysize != 0) {
206 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
207 "keysize %d\n", __func__,
208 keylen, thash->name, thash->keysize));
209 return EINVAL;
210 }
211
212 sav->tdb_xform = xsp;
213 sav->tdb_authalgxform = thash;
214
215 /* Initialize crypto session. */
216 bzero(cria, sizeof (*cria));
217 cria->cri_alg = sav->tdb_authalgxform->type;
218 cria->cri_klen = _KEYBITS(sav->key_auth);
219 cria->cri_key = sav->key_auth->key_data;
220 cria->cri_mlen = AUTHSIZE(sav);
221
222 return 0;
223}
224
225/*
226 * ah_init() is called when an SPI is being set up.
227 */
228static int
229ah_init(struct secasvar *sav, struct xformsw *xsp)
230{
231 INIT_VNET_IPSEC(curvnet);
232 struct cryptoini cria;
233 int error;
234
235 error = ah_init0(sav, xsp, &cria);
236 return error ? error :
237 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
238}
239
240/*
241 * Paranoia.
242 *
243 * NB: public for use by esp_zeroize (XXX).
244 */
245int
246ah_zeroize(struct secasvar *sav)
247{
248 int err;
249
250 if (sav->key_auth)
251 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
252
253 err = crypto_freesession(sav->tdb_cryptoid);
254 sav->tdb_cryptoid = 0;
255 sav->tdb_authalgxform = NULL;
256 sav->tdb_xform = NULL;
257 return err;
258}
259
260/*
261 * Massage IPv4/IPv6 headers for AH processing.
262 */
263static int
264ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
265{
266 INIT_VNET_IPSEC(curvnet);
267 struct mbuf *m = *m0;
268 unsigned char *ptr;
269 int off, count;
270
271#ifdef INET
272 struct ip *ip;
273#endif /* INET */
274
275#ifdef INET6
276 struct ip6_ext *ip6e;
277 struct ip6_hdr ip6;
278 int alloc, len, ad;
279#endif /* INET6 */
280
281 switch (proto) {
282#ifdef INET
283 case AF_INET:
284 /*
285 * This is the least painful way of dealing with IPv4 header
286 * and option processing -- just make sure they're in
287 * contiguous memory.
288 */
289 *m0 = m = m_pullup(m, skip);
290 if (m == NULL) {
291 DPRINTF(("%s: m_pullup failed\n", __func__));
292 return ENOBUFS;
293 }
294
295 /* Fix the IP header */
296 ip = mtod(m, struct ip *);
297 if (V_ah_cleartos)
298 ip->ip_tos = 0;
299 ip->ip_ttl = 0;
300 ip->ip_sum = 0;
301
302 /*
303 * On input, fix ip_len which has been byte-swapped
304 * at ip_input().
305 */
306 if (!out) {
307 ip->ip_len = htons(ip->ip_len + skip);
308
309 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
310 ip->ip_off = htons(ip->ip_off & IP_DF);
311 else
312 ip->ip_off = 0;
313 } else {
314 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
315 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
316 else
317 ip->ip_off = 0;
318 }
319
320 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
321
322 /* IPv4 option processing */
323 for (off = sizeof(struct ip); off < skip;) {
324 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
325 off + 1 < skip)
326 ;
327 else {
328 DPRINTF(("%s: illegal IPv4 option length for "
329 "option %d\n", __func__, ptr[off]));
330
331 m_freem(m);
332 return EINVAL;
333 }
334
335 switch (ptr[off]) {
336 case IPOPT_EOL:
337 off = skip; /* End the loop. */
338 break;
339
340 case IPOPT_NOP:
341 off++;
342 break;
343
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]));
354
355 m_freem(m);
356 return EINVAL;
357 }
358
359 off += ptr[off + 1];
360 break;
361
362 case IPOPT_LSRR:
363 case IPOPT_SSRR:
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]));
369
370 m_freem(m);
371 return EINVAL;
372 }
373
374 /*
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
381 * will look like.
382 */
383 if (out)
384 bcopy(ptr + off + ptr[off + 1] -
385 sizeof(struct in_addr),
386 &(ip->ip_dst), sizeof(struct in_addr));
387
388 /* Fall through */
389 default:
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]));
395 m_freem(m);
396 return EINVAL;
397 }
398
399 /* Zeroize all other options. */
400 count = ptr[off + 1];
401 bcopy(ipseczeroes, ptr, count);
402 off += count;
403 break;
404 }
405
406 /* Sanity check. */
407 if (off > skip) {
408 DPRINTF(("%s: malformed IPv4 options header\n",
409 __func__));
410
411 m_freem(m);
412 return EINVAL;
413 }
414 }
415
416 break;
417#endif /* INET */
418
419#ifdef INET6
420 case AF_INET6: /* Ugly... */
421 /* Copy and "cook" the IPv6 header. */
422 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
423
424 /* We don't do IPv6 Jumbograms. */
425 if (ip6.ip6_plen == 0) {
426 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
427 m_freem(m);
428 return EMSGSIZE;
429 }
430
431 ip6.ip6_flow = 0;
432 ip6.ip6_hlim = 0;
433 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
434 ip6.ip6_vfc |= IPV6_VERSION;
435
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;
441
442 /* Done with IPv6 header. */
443 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
444
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),
450 M_XDATA, M_NOWAIT);
451 if (ptr == NULL) {
452 DPRINTF(("%s: failed to allocate memory"
453 "for IPv6 headers\n",__func__));
454 m_freem(m);
455 return ENOBUFS;
456 }
457
458 /*
459 * Copy all the protocol headers after
460 * the IPv6 header.
461 */
462 m_copydata(m, sizeof(struct ip6_hdr),
463 skip - sizeof(struct ip6_hdr), ptr);
464 alloc = 1;
465 } else {
466 /* No need to allocate memory. */
467 ptr = mtod(m, unsigned char *) +
468 sizeof(struct ip6_hdr);
469 alloc = 0;
470 }
471 } else
472 break;
473
474 off = ip6.ip6_nxt & 0xff; /* Next header type. */
475
476 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
477 switch (off) {
478 case IPPROTO_HOPOPTS:
479 case IPPROTO_DSTOPTS:
480 ip6e = (struct ip6_ext *) (ptr + len);
481
482 /*
483 * Process the mutable/immutable
484 * options -- borrows heavily from the
485 * KAME code.
486 */
487 for (count = len + sizeof(struct ip6_ext);
488 count < len + ((ip6e->ip6e_len + 1) << 3);) {
489 if (ptr[count] == IP6OPT_PAD1) {
490 count++;
491 continue; /* Skip padding. */
492 }
493
494 /* Sanity check. */
495 if (count > len +
496 ((ip6e->ip6e_len + 1) << 3)) {
497 m_freem(m);
498
499 /* Free, if we allocated. */
500 if (alloc)
501 free(ptr, M_XDATA);
502 return EINVAL;
503 }
504
505 ad = ptr[count + 1];
506
507 /* If mutable option, zeroize. */
508 if (ptr[count] & IP6OPT_MUTABLE)
509 bcopy(ipseczeroes, ptr + count,
510 ptr[count + 1]);
511
512 count += ad;
513
514 /* Sanity check. */
515 if (count >
516 skip - sizeof(struct ip6_hdr)) {
517 m_freem(m);
518
519 /* Free, if we allocated. */
520 if (alloc)
521 free(ptr, M_XDATA);
522 return EINVAL;
523 }
524 }
525
526 /* Advance. */
527 len += ((ip6e->ip6e_len + 1) << 3);
528 off = ip6e->ip6e_nxt;
529 break;
530
531 case IPPROTO_ROUTING:
532 /*
533 * Always include routing headers in
534 * computation.
535 */
536 ip6e = (struct ip6_ext *) (ptr + len);
537 len += ((ip6e->ip6e_len + 1) << 3);
538 off = ip6e->ip6e_nxt;
539 break;
540
541 default:
542 DPRINTF(("%s: unexpected IPv6 header type %d",
543 __func__, off));
544 if (alloc)
545 free(ptr, M_XDATA);
546 m_freem(m);
547 return EINVAL;
548 }
549
550 /* Copyback and free, if we allocated. */
551 if (alloc) {
552 m_copyback(m, sizeof(struct ip6_hdr),
553 skip - sizeof(struct ip6_hdr), ptr);
554 free(ptr, M_XDATA);
555 }
556
557 break;
558#endif /* INET6 */
559 }
560
561 return 0;
562}
563
564/*
565 * ah_input() gets called to verify that an input packet
566 * passes authentication.
567 */
568static int
569ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
570{
571 INIT_VNET_IPSEC(curvnet);
572 struct auth_hash *ahx;
573 struct tdb_ident *tdbi;
574 struct tdb_crypto *tc;
575 struct m_tag *mtag;
576 struct newah *ah;
577 int hl, rplen, authsize;
578
579 struct cryptodesc *crda;
580 struct cryptop *crp;
581
582 IPSEC_ASSERT(sav != NULL, ("null SA"));
583 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
584 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
585 ("null authentication xform"));
586
587 /* Figure out header size. */
588 rplen = HDRSIZE(sav);
589
590 /* XXX don't pullup, just copy header */
591 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
592 if (ah == NULL) {
593 DPRINTF(("ah_input: cannot pullup header\n"));
594 V_ahstat.ahs_hdrops++; /*XXX*/
595 m_freem(m);
596 return ENOBUFS;
597 }
598
599 /* Check replay window, if applicable. */
600 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
601 V_ahstat.ahs_replay++;
602 DPRINTF(("%s: packet replay failure: %s\n", __func__,
603 ipsec_logsastr(sav)));
604 m_freem(m);
605 return ENOBUFS;
606 }
607
608 /* Verify AH header length. */
609 hl = ah->ah_len * sizeof (u_int32_t);
610 ahx = sav->tdb_authalgxform;
611 authsize = AUTHSIZE(sav);
612 if (hl != authsize + rplen - sizeof (struct ah)) {
613 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
614 " for packet in SA %s/%08lx\n", __func__,
615 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
616 ipsec_address(&sav->sah->saidx.dst),
617 (u_long) ntohl(sav->spi)));
618 V_ahstat.ahs_badauthl++;
619 m_freem(m);
620 return EACCES;
621 }
622 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
623
624 /* Get crypto descriptors. */
625 crp = crypto_getreq(1);
626 if (crp == NULL) {
627 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
628 V_ahstat.ahs_crypto++;
629 m_freem(m);
630 return ENOBUFS;
631 }
632
633 crda = crp->crp_desc;
634 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
635
636 crda->crd_skip = 0;
637 crda->crd_len = m->m_pkthdr.len;
638 crda->crd_inject = skip + rplen;
639
640 /* Authentication operation. */
641 crda->crd_alg = ahx->type;
642 crda->crd_klen = _KEYBITS(sav->key_auth);
643 crda->crd_key = sav->key_auth->key_data;
644
645 /* Find out if we've already done crypto. */
646 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
647 mtag != NULL;
648 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
649 tdbi = (struct tdb_ident *) (mtag + 1);
650 if (tdbi->proto == sav->sah->saidx.proto &&
651 tdbi->spi == sav->spi &&
652 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
653 sizeof (union sockaddr_union)))
654 break;
655 }
656
657 /* Allocate IPsec-specific opaque crypto info. */
658 if (mtag == NULL) {
659 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
660 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
661 } else {
662 /* Hash verification has already been done successfully. */
663 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
664 M_XDATA, M_NOWAIT|M_ZERO);
665 }
666 if (tc == NULL) {
667 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
668 V_ahstat.ahs_crypto++;
669 crypto_freereq(crp);
670 m_freem(m);
671 return ENOBUFS;
672 }
673
674 /* Only save information if crypto processing is needed. */
675 if (mtag == NULL) {
676 int error;
677
678 /*
679 * Save the authenticator, the skipped portion of the packet,
680 * and the AH header.
681 */
682 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
683
684 /* Zeroize the authenticator on the packet. */
685 m_copyback(m, skip + rplen, authsize, ipseczeroes);
686
687 /* "Massage" the packet headers for crypto processing. */
688 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
689 skip, ahx->type, 0);
690 if (error != 0) {
691 /* NB: mbuf is free'd by ah_massage_headers */
692 V_ahstat.ahs_hdrops++;
693 free(tc, M_XDATA);
694 crypto_freereq(crp);
695 return error;
696 }
697 }
698
699 /* Crypto operation descriptor. */
700 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
701 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
702 crp->crp_buf = (caddr_t) m;
703 crp->crp_callback = ah_input_cb;
704 crp->crp_sid = sav->tdb_cryptoid;
705 crp->crp_opaque = (caddr_t) tc;
706
707 /* These are passed as-is to the callback. */
708 tc->tc_spi = sav->spi;
709 tc->tc_dst = sav->sah->saidx.dst;
710 tc->tc_proto = sav->sah->saidx.proto;
711 tc->tc_nxt = ah->ah_nxt;
712 tc->tc_protoff = protoff;
713 tc->tc_skip = skip;
714 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
715
716 if (mtag == NULL)
717 return crypto_dispatch(crp);
718 else
719 return ah_input_cb(crp);
720}
721
722#ifdef INET6
723#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
724 if (saidx->dst.sa.sa_family == AF_INET6) { \
725 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
726 } else { \
727 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
728 } \
729} while (0)
730#else
731#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
732 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
733#endif
734
735/*
736 * AH input callback from the crypto driver.
737 */
738static int
739ah_input_cb(struct cryptop *crp)
740{
741 INIT_VNET_IPSEC(curvnet);
742 int rplen, error, skip, protoff;
743 unsigned char calc[AH_ALEN_MAX];
744 struct mbuf *m;
745 struct cryptodesc *crd;
746 struct auth_hash *ahx;
747 struct tdb_crypto *tc;
748 struct m_tag *mtag;
749 struct secasvar *sav;
750 struct secasindex *saidx;
751 u_int8_t nxt;
752 caddr_t ptr;
753 int authsize;
754
755 crd = crp->crp_desc;
756
757 tc = (struct tdb_crypto *) crp->crp_opaque;
758 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
759 skip = tc->tc_skip;
760 nxt = tc->tc_nxt;
761 protoff = tc->tc_protoff;
762 mtag = (struct m_tag *) tc->tc_ptr;
763 m = (struct mbuf *) crp->crp_buf;
764
765 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
766 if (sav == NULL) {
767 V_ahstat.ahs_notdb++;
768 DPRINTF(("%s: SA expired while in crypto\n", __func__));
769 error = ENOBUFS; /*XXX*/
770 goto bad;
771 }
772
773 saidx = &sav->sah->saidx;
774 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
775 saidx->dst.sa.sa_family == AF_INET6,
776 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
777
778 ahx = (struct auth_hash *) sav->tdb_authalgxform;
779
780 /* Check for crypto errors. */
781 if (crp->crp_etype) {
782 if (sav->tdb_cryptoid != 0)
783 sav->tdb_cryptoid = crp->crp_sid;
784
785 if (crp->crp_etype == EAGAIN) {
786 error = crypto_dispatch(crp);
787 return error;
788 }
789
790 V_ahstat.ahs_noxform++;
791 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
792 error = crp->crp_etype;
793 goto bad;
794 } else {
795 V_ahstat.ahs_hist[sav->alg_auth]++;
796 crypto_freereq(crp); /* No longer needed. */
797 crp = NULL;
798 }
799
800 /* Shouldn't happen... */
801 if (m == NULL) {
802 V_ahstat.ahs_crypto++;
803 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
804 error = EINVAL;
805 goto bad;
806 }
807
808 /* Figure out header size. */
809 rplen = HDRSIZE(sav);
810 authsize = AUTHSIZE(sav);
811
812 /* Copy authenticator off the packet. */
813 m_copydata(m, skip + rplen, authsize, calc);
814
815 /*
816 * If we have an mtag, we don't need to verify the authenticator --
817 * it has been verified by an IPsec-aware NIC.
818 */
819 if (mtag == NULL) {
820 ptr = (caddr_t) (tc + 1);
821
822 /* Verify authenticator. */
823 if (bcmp(ptr + skip + rplen, calc, authsize)) {
824 DPRINTF(("%s: authentication hash mismatch for packet "
825 "in SA %s/%08lx\n", __func__,
826 ipsec_address(&saidx->dst),
827 (u_long) ntohl(sav->spi)));
828 V_ahstat.ahs_badauth++;
829 error = EACCES;
830 goto bad;
831 }
832
833 /* Fix the Next Protocol field. */
834 ((u_int8_t *) ptr)[protoff] = nxt;
835
836 /* Copyback the saved (uncooked) network headers. */
837 m_copyback(m, 0, skip, ptr);
838 } else {
839 /* Fix the Next Protocol field. */
840 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
841 }
842
843 free(tc, M_XDATA), tc = NULL; /* No longer needed */
844
845 /*
846 * Header is now authenticated.
847 */
848 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
849
850 /*
851 * Update replay sequence number, if appropriate.
852 */
853 if (sav->replay) {
854 u_int32_t seq;
855
856 m_copydata(m, skip + offsetof(struct newah, ah_seq),
857 sizeof (seq), (caddr_t) &seq);
858 if (ipsec_updatereplay(ntohl(seq), sav)) {
859 V_ahstat.ahs_replay++;
860 error = ENOBUFS; /*XXX as above*/
861 goto bad;
862 }
863 }
864
865 /*
866 * Remove the AH header and authenticator from the mbuf.
867 */
868 error = m_striphdr(m, skip, rplen + authsize);
869 if (error) {
870 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
871 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
872
873 V_ahstat.ahs_hdrops++;
874 goto bad;
875 }
876
877 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
878
879 KEY_FREESAV(&sav);
880 return error;
881bad:
882 if (sav)
883 KEY_FREESAV(&sav);
884 if (m != NULL)
885 m_freem(m);
886 if (tc != NULL)
887 free(tc, M_XDATA);
888 if (crp != NULL)
889 crypto_freereq(crp);
890 return error;
891}
892
893/*
894 * AH output routine, called by ipsec[46]_process_packet().
895 */
896static int
897ah_output(
898 struct mbuf *m,
899 struct ipsecrequest *isr,
900 struct mbuf **mp,
901 int skip,
902 int protoff)
903{
904 INIT_VNET_IPSEC(curvnet);
905 struct secasvar *sav;
906 struct auth_hash *ahx;
907 struct cryptodesc *crda;
908 struct tdb_crypto *tc;
909 struct mbuf *mi;
910 struct cryptop *crp;
911 u_int16_t iplen;
912 int error, rplen, authsize, maxpacketsize, roff;
913 u_int8_t prot;
914 struct newah *ah;
915
916 sav = isr->sav;
917 IPSEC_ASSERT(sav != NULL, ("null SA"));
918 ahx = sav->tdb_authalgxform;
919 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
920
921 V_ahstat.ahs_output++;
922
923 /* Figure out header size. */
924 rplen = HDRSIZE(sav);
925
926 /* Check for maximum packet size violations. */
927 switch (sav->sah->saidx.dst.sa.sa_family) {
928#ifdef INET
929 case AF_INET:
930 maxpacketsize = IP_MAXPACKET;
931 break;
932#endif /* INET */
933#ifdef INET6
934 case AF_INET6:
935 maxpacketsize = IPV6_MAXPACKET;
936 break;
937#endif /* INET6 */
938 default:
939 DPRINTF(("%s: unknown/unsupported protocol family %u, "
940 "SA %s/%08lx\n", __func__,
941 sav->sah->saidx.dst.sa.sa_family,
942 ipsec_address(&sav->sah->saidx.dst),
943 (u_long) ntohl(sav->spi)));
944 V_ahstat.ahs_nopf++;
945 error = EPFNOSUPPORT;
946 goto bad;
947 }
948 authsize = AUTHSIZE(sav);
949 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
950 DPRINTF(("%s: packet in SA %s/%08lx got too big "
951 "(len %u, max len %u)\n", __func__,
952 ipsec_address(&sav->sah->saidx.dst),
953 (u_long) ntohl(sav->spi),
954 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
955 V_ahstat.ahs_toobig++;
956 error = EMSGSIZE;
957 goto bad;
958 }
959
960 /* Update the counters. */
961 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
962
963 m = m_unshare(m, M_NOWAIT);
964 if (m == NULL) {
965 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
966 ipsec_address(&sav->sah->saidx.dst),
967 (u_long) ntohl(sav->spi)));
968 V_ahstat.ahs_hdrops++;
969 error = ENOBUFS;
970 goto bad;
971 }
972
973 /* Inject AH header. */
974 mi = m_makespace(m, skip, rplen + authsize, &roff);
975 if (mi == NULL) {
976 DPRINTF(("%s: failed to inject %u byte AH header for SA "
977 "%s/%08lx\n", __func__,
978 rplen + authsize,
979 ipsec_address(&sav->sah->saidx.dst),
980 (u_long) ntohl(sav->spi)));
981 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */
982 error = ENOBUFS;
983 goto bad;
984 }
985
986 /*
987 * The AH header is guaranteed by m_makespace() to be in
988 * contiguous memory, at roff bytes offset into the returned mbuf.
989 */
990 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
991
992 /* Initialize the AH header. */
993 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
994 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
995 ah->ah_reserve = 0;
996 ah->ah_spi = sav->spi;
997
998 /* Zeroize authenticator. */
999 m_copyback(m, skip + rplen, authsize, ipseczeroes);
1000
1001 /* Insert packet replay counter, as requested. */
1002 if (sav->replay) {
1003 if (sav->replay->count == ~0 &&
1004 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1005 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
1006 __func__,
1007 ipsec_address(&sav->sah->saidx.dst),
1008 (u_long) ntohl(sav->spi)));
1009 V_ahstat.ahs_wrap++;
1010 error = EINVAL;
1011 goto bad;
1012 }
1013#ifdef REGRESSION
1014 /* Emulate replay attack when ipsec_replay is TRUE. */
1015 if (!V_ipsec_replay)
1016#endif
1017 sav->replay->count++;
1018 ah->ah_seq = htonl(sav->replay->count);
1019 }
1020
1021 /* Get crypto descriptors. */
1022 crp = crypto_getreq(1);
1023 if (crp == NULL) {
1024 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1025 __func__));
1026 V_ahstat.ahs_crypto++;
1027 error = ENOBUFS;
1028 goto bad;
1029 }
1030
1031 crda = crp->crp_desc;
1032
1033 crda->crd_skip = 0;
1034 crda->crd_inject = skip + rplen;
1035 crda->crd_len = m->m_pkthdr.len;
1036
1037 /* Authentication operation. */
1038 crda->crd_alg = ahx->type;
1039 crda->crd_key = sav->key_auth->key_data;
1040 crda->crd_klen = _KEYBITS(sav->key_auth);
1041
1042 /* Allocate IPsec-specific opaque crypto info. */
1043 tc = (struct tdb_crypto *) malloc(
1044 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1045 if (tc == NULL) {
1046 crypto_freereq(crp);
1047 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1048 V_ahstat.ahs_crypto++;
1049 error = ENOBUFS;
1050 goto bad;
1051 }
1052
1053 /* Save the skipped portion of the packet. */
1054 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1055
1056 /*
1057 * Fix IP header length on the header used for
1058 * authentication. We don't need to fix the original
1059 * header length as it will be fixed by our caller.
1060 */
1061 switch (sav->sah->saidx.dst.sa.sa_family) {
1062#ifdef INET
1063 case AF_INET:
1064 bcopy(((caddr_t)(tc + 1)) +
1065 offsetof(struct ip, ip_len),
1066 (caddr_t) &iplen, sizeof(u_int16_t));
1067 iplen = htons(ntohs(iplen) + rplen + authsize);
1068 m_copyback(m, offsetof(struct ip, ip_len),
1069 sizeof(u_int16_t), (caddr_t) &iplen);
1070 break;
1071#endif /* INET */
1072
1073#ifdef INET6
1074 case AF_INET6:
1075 bcopy(((caddr_t)(tc + 1)) +
1076 offsetof(struct ip6_hdr, ip6_plen),
1077 (caddr_t) &iplen, sizeof(u_int16_t));
1078 iplen = htons(ntohs(iplen) + rplen + authsize);
1079 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1080 sizeof(u_int16_t), (caddr_t) &iplen);
1081 break;
1082#endif /* INET6 */
1083 }
1084
1085 /* Fix the Next Header field in saved header. */
1086 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1087
1088 /* Update the Next Protocol field in the IP header. */
1089 prot = IPPROTO_AH;
1090 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1091
1092 /* "Massage" the packet headers for crypto processing. */
1093 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1094 skip, ahx->type, 1);
1095 if (error != 0) {
1096 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1097 free(tc, M_XDATA);
1098 crypto_freereq(crp);
1099 goto bad;
1100 }
1101
1102 /* Crypto operation descriptor. */
1103 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1104 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1105 crp->crp_buf = (caddr_t) m;
1106 crp->crp_callback = ah_output_cb;
1107 crp->crp_sid = sav->tdb_cryptoid;
1108 crp->crp_opaque = (caddr_t) tc;
1109
1110 /* These are passed as-is to the callback. */
1111 tc->tc_isr = isr;
1112 tc->tc_spi = sav->spi;
1113 tc->tc_dst = sav->sah->saidx.dst;
1114 tc->tc_proto = sav->sah->saidx.proto;
1115 tc->tc_skip = skip;
1116 tc->tc_protoff = protoff;
1117
1118 return crypto_dispatch(crp);
1119bad:
1120 if (m)
1121 m_freem(m);
1122 return (error);
1123}
1124
1125/*
1126 * AH output callback from the crypto driver.
1127 */
1128static int
1129ah_output_cb(struct cryptop *crp)
1130{
1131 INIT_VNET_IPSEC(curvnet);
1132 int skip, protoff, error;
1133 struct tdb_crypto *tc;
1134 struct ipsecrequest *isr;
1135 struct secasvar *sav;
1136 struct mbuf *m;
1137 caddr_t ptr;
1138 int err;
1139
1140 tc = (struct tdb_crypto *) crp->crp_opaque;
1141 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1142 skip = tc->tc_skip;
1143 protoff = tc->tc_protoff;
1144 ptr = (caddr_t) (tc + 1);
1145 m = (struct mbuf *) crp->crp_buf;
1146
1147 isr = tc->tc_isr;
1148 IPSECREQUEST_LOCK(isr);
1149 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1150 if (sav == NULL) {
1151 V_ahstat.ahs_notdb++;
1152 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1153 error = ENOBUFS; /*XXX*/
1154 goto bad;
1155 }
1156 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1157
1158 /* Check for crypto errors. */
1159 if (crp->crp_etype) {
1160 if (sav->tdb_cryptoid != 0)
1161 sav->tdb_cryptoid = crp->crp_sid;
1162
1163 if (crp->crp_etype == EAGAIN) {
1164 KEY_FREESAV(&sav);
1165 IPSECREQUEST_UNLOCK(isr);
1166 error = crypto_dispatch(crp);
1167 return error;
1168 }
1169
1170 V_ahstat.ahs_noxform++;
1171 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1172 error = crp->crp_etype;
1173 goto bad;
1174 }
1175
1176 /* Shouldn't happen... */
1177 if (m == NULL) {
1178 V_ahstat.ahs_crypto++;
1179 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1180 error = EINVAL;
1181 goto bad;
1182 }
1183 V_ahstat.ahs_hist[sav->alg_auth]++;
1184
1185 /*
1186 * Copy original headers (with the new protocol number) back
1187 * in place.
1188 */
1189 m_copyback(m, 0, skip, ptr);
1190
1191 /* No longer needed. */
1192 free(tc, M_XDATA);
1193 crypto_freereq(crp);
1194
1195#ifdef REGRESSION
1196 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1197 if (V_ipsec_integrity) {
1198 int alen;
1199
1200 /*
1201 * Corrupt HMAC if we want to test integrity verification of
1202 * the other side.
1203 */
1204 alen = AUTHSIZE(sav);
1205 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1206 }
1207#endif
1208
1209 /* NB: m is reclaimed by ipsec_process_done. */
1210 err = ipsec_process_done(m, isr);
1211 KEY_FREESAV(&sav);
1212 IPSECREQUEST_UNLOCK(isr);
1213 return err;
1214bad:
1215 if (sav)
1216 KEY_FREESAV(&sav);
1217 IPSECREQUEST_UNLOCK(isr);
1218 if (m)
1219 m_freem(m);
1220 free(tc, M_XDATA);
1221 crypto_freereq(crp);
1222 return error;
1223}
1224
1225static struct xformsw ah_xformsw = {
1226 XF_AH, XFT_AUTH, "IPsec AH",
1227 ah_init, ah_zeroize, ah_input, ah_output,
1228};
1229
1230static void
1231ah_attach(void)
1232{
1233
1234 xform_register(&ah_xformsw);
1235#ifndef VIMAGE_GLOBALS
1236 vnet_mod_register(&vnet_ah_modinfo);
1237#else
1238 ah_iattach(NULL);
1239#endif
1240}
1241
1242static int
1243ah_iattach(const void *unused __unused)
1244{
1245 INIT_VNET_IPSEC(curvnet);
1246
1247 V_ah_enable = 1; /* control flow of packets with AH */
1248 V_ah_cleartos = 1; /* clear ip_tos when doing AH calc */
1249
1250 return (0);
1251}
1252SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
2/* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
3/*-
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).
7 *
8 * The original version of this code was written by John Ioannidis
9 * for BSD/OS in Athens, Greece, in November 1995.
10 *
11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
12 * by Angelos D. Keromytis.
13 *
14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
15 * and Niels Provos.
16 *
17 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
18 *
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.
23 *
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
31 * all.
32 *
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
37 * PURPOSE.
38 */
39#include "opt_inet.h"
40#include "opt_inet6.h"
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/mbuf.h>
45#include <sys/socket.h>
46#include <sys/syslog.h>
47#include <sys/kernel.h>
48#include <sys/sysctl.h>
49#include <sys/vimage.h>
50
51#include <net/if.h>
52
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>
58
59#include <net/route.h>
60#include <netipsec/ipsec.h>
61#include <netipsec/ah.h>
62#include <netipsec/ah_var.h>
63#include <netipsec/xform.h>
64
65#ifdef INET6
66#include <netinet6/ip6_var.h>
67#include <netipsec/ipsec6.h>
68#include <netinet6/ip6_ecn.h>
69#endif
70
71#include <netipsec/key.h>
72#include <netipsec/key_debug.h>
73
74#include <opencrypto/cryptodev.h>
75
76static int ah_iattach(const void *);
77
78#ifndef VIMAGE_GLOBALS
79static const vnet_modinfo_t vnet_ah_modinfo = {
80 .vmi_id = VNET_MOD_AH,
81 .vmi_name = "ipsec_ah",
82 .vmi_dependson = VNET_MOD_IPSEC,
83 .vmi_iattach = ah_iattach
84};
85#endif /* !VIMAGE_GLOBALS */
86
87/*
88 * Return header size in bytes. The old protocol did not support
89 * the replay counter; the new protocol always includes the counter.
90 */
91#define HDRSIZE(sav) \
92 (((sav)->flags & SADB_X_EXT_OLD) ? \
93 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
94/*
95 * Return authenticator size in bytes. The old protocol is known
96 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
97 * authenticator.
98 */
99#define AUTHSIZE(sav) \
100 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
101
102#ifdef VIMAGE_GLOBALS
103int ah_enable;
104int ah_cleartos;
105struct ahstat ahstat;
106#endif
107
108SYSCTL_DECL(_net_inet_ah);
109SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
110 ah_enable, CTLFLAG_RW, ah_enable, 0, "");
111SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
112 ah_cleartos, CTLFLAG_RW, ah_cleartos, 0, "");
113SYSCTL_V_STRUCT(V_NET, vnet_ipsec, _net_inet_ah, IPSECCTL_STATS,
114 stats, CTLFLAG_RD, ahstat, ahstat, "");
115
116static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
117
118static int ah_input_cb(struct cryptop*);
119static int ah_output_cb(struct cryptop*);
120
121/*
122 * NB: this is public for use by the PF_KEY support.
123 */
124struct auth_hash *
125ah_algorithm_lookup(int alg)
126{
127 if (alg > SADB_AALG_MAX)
128 return NULL;
129 switch (alg) {
130 case SADB_X_AALG_NULL:
131 return &auth_hash_null;
132 case SADB_AALG_MD5HMAC:
133 return &auth_hash_hmac_md5;
134 case SADB_AALG_SHA1HMAC:
135 return &auth_hash_hmac_sha1;
136 case SADB_X_AALG_RIPEMD160HMAC:
137 return &auth_hash_hmac_ripemd_160;
138 case SADB_X_AALG_MD5:
139 return &auth_hash_key_md5;
140 case SADB_X_AALG_SHA:
141 return &auth_hash_key_sha1;
142 case SADB_X_AALG_SHA2_256:
143 return &auth_hash_hmac_sha2_256;
144 case SADB_X_AALG_SHA2_384:
145 return &auth_hash_hmac_sha2_384;
146 case SADB_X_AALG_SHA2_512:
147 return &auth_hash_hmac_sha2_512;
148 }
149 return NULL;
150}
151
152size_t
153ah_hdrsiz(struct secasvar *sav)
154{
155 size_t size;
156
157 if (sav != NULL) {
158 int authsize;
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);
163 } else {
164 /* default guess */
165 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
166 }
167 return size;
168}
169
170/*
171 * NB: public for use by esp_init.
172 */
173int
174ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
175{
176 INIT_VNET_IPSEC(curvnet);
177 struct auth_hash *thash;
178 int keylen;
179
180 thash = ah_algorithm_lookup(sav->alg_auth);
181 if (thash == NULL) {
182 DPRINTF(("%s: unsupported authentication algorithm %u\n",
183 __func__, sav->alg_auth));
184 return EINVAL;
185 }
186 /*
187 * Verify the replay state block allocation is consistent with
188 * the protocol type. We check here so we can make assumptions
189 * later during protocol processing.
190 */
191 /* NB: replay state is setup elsewhere (sigh) */
192 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
193 DPRINTF(("%s: replay state block inconsistency, "
194 "%s algorithm %s replay state\n", __func__,
195 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
196 sav->replay == NULL ? "without" : "with"));
197 return EINVAL;
198 }
199 if (sav->key_auth == NULL) {
200 DPRINTF(("%s: no authentication key for %s algorithm\n",
201 __func__, thash->name));
202 return EINVAL;
203 }
204 keylen = _KEYLEN(sav->key_auth);
205 if (keylen != thash->keysize && thash->keysize != 0) {
206 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
207 "keysize %d\n", __func__,
208 keylen, thash->name, thash->keysize));
209 return EINVAL;
210 }
211
212 sav->tdb_xform = xsp;
213 sav->tdb_authalgxform = thash;
214
215 /* Initialize crypto session. */
216 bzero(cria, sizeof (*cria));
217 cria->cri_alg = sav->tdb_authalgxform->type;
218 cria->cri_klen = _KEYBITS(sav->key_auth);
219 cria->cri_key = sav->key_auth->key_data;
220 cria->cri_mlen = AUTHSIZE(sav);
221
222 return 0;
223}
224
225/*
226 * ah_init() is called when an SPI is being set up.
227 */
228static int
229ah_init(struct secasvar *sav, struct xformsw *xsp)
230{
231 INIT_VNET_IPSEC(curvnet);
232 struct cryptoini cria;
233 int error;
234
235 error = ah_init0(sav, xsp, &cria);
236 return error ? error :
237 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
238}
239
240/*
241 * Paranoia.
242 *
243 * NB: public for use by esp_zeroize (XXX).
244 */
245int
246ah_zeroize(struct secasvar *sav)
247{
248 int err;
249
250 if (sav->key_auth)
251 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
252
253 err = crypto_freesession(sav->tdb_cryptoid);
254 sav->tdb_cryptoid = 0;
255 sav->tdb_authalgxform = NULL;
256 sav->tdb_xform = NULL;
257 return err;
258}
259
260/*
261 * Massage IPv4/IPv6 headers for AH processing.
262 */
263static int
264ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
265{
266 INIT_VNET_IPSEC(curvnet);
267 struct mbuf *m = *m0;
268 unsigned char *ptr;
269 int off, count;
270
271#ifdef INET
272 struct ip *ip;
273#endif /* INET */
274
275#ifdef INET6
276 struct ip6_ext *ip6e;
277 struct ip6_hdr ip6;
278 int alloc, len, ad;
279#endif /* INET6 */
280
281 switch (proto) {
282#ifdef INET
283 case AF_INET:
284 /*
285 * This is the least painful way of dealing with IPv4 header
286 * and option processing -- just make sure they're in
287 * contiguous memory.
288 */
289 *m0 = m = m_pullup(m, skip);
290 if (m == NULL) {
291 DPRINTF(("%s: m_pullup failed\n", __func__));
292 return ENOBUFS;
293 }
294
295 /* Fix the IP header */
296 ip = mtod(m, struct ip *);
297 if (V_ah_cleartos)
298 ip->ip_tos = 0;
299 ip->ip_ttl = 0;
300 ip->ip_sum = 0;
301
302 /*
303 * On input, fix ip_len which has been byte-swapped
304 * at ip_input().
305 */
306 if (!out) {
307 ip->ip_len = htons(ip->ip_len + skip);
308
309 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
310 ip->ip_off = htons(ip->ip_off & IP_DF);
311 else
312 ip->ip_off = 0;
313 } else {
314 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
315 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
316 else
317 ip->ip_off = 0;
318 }
319
320 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
321
322 /* IPv4 option processing */
323 for (off = sizeof(struct ip); off < skip;) {
324 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
325 off + 1 < skip)
326 ;
327 else {
328 DPRINTF(("%s: illegal IPv4 option length for "
329 "option %d\n", __func__, ptr[off]));
330
331 m_freem(m);
332 return EINVAL;
333 }
334
335 switch (ptr[off]) {
336 case IPOPT_EOL:
337 off = skip; /* End the loop. */
338 break;
339
340 case IPOPT_NOP:
341 off++;
342 break;
343
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]));
354
355 m_freem(m);
356 return EINVAL;
357 }
358
359 off += ptr[off + 1];
360 break;
361
362 case IPOPT_LSRR:
363 case IPOPT_SSRR:
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]));
369
370 m_freem(m);
371 return EINVAL;
372 }
373
374 /*
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
381 * will look like.
382 */
383 if (out)
384 bcopy(ptr + off + ptr[off + 1] -
385 sizeof(struct in_addr),
386 &(ip->ip_dst), sizeof(struct in_addr));
387
388 /* Fall through */
389 default:
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]));
395 m_freem(m);
396 return EINVAL;
397 }
398
399 /* Zeroize all other options. */
400 count = ptr[off + 1];
401 bcopy(ipseczeroes, ptr, count);
402 off += count;
403 break;
404 }
405
406 /* Sanity check. */
407 if (off > skip) {
408 DPRINTF(("%s: malformed IPv4 options header\n",
409 __func__));
410
411 m_freem(m);
412 return EINVAL;
413 }
414 }
415
416 break;
417#endif /* INET */
418
419#ifdef INET6
420 case AF_INET6: /* Ugly... */
421 /* Copy and "cook" the IPv6 header. */
422 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
423
424 /* We don't do IPv6 Jumbograms. */
425 if (ip6.ip6_plen == 0) {
426 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
427 m_freem(m);
428 return EMSGSIZE;
429 }
430
431 ip6.ip6_flow = 0;
432 ip6.ip6_hlim = 0;
433 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
434 ip6.ip6_vfc |= IPV6_VERSION;
435
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;
441
442 /* Done with IPv6 header. */
443 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
444
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),
450 M_XDATA, M_NOWAIT);
451 if (ptr == NULL) {
452 DPRINTF(("%s: failed to allocate memory"
453 "for IPv6 headers\n",__func__));
454 m_freem(m);
455 return ENOBUFS;
456 }
457
458 /*
459 * Copy all the protocol headers after
460 * the IPv6 header.
461 */
462 m_copydata(m, sizeof(struct ip6_hdr),
463 skip - sizeof(struct ip6_hdr), ptr);
464 alloc = 1;
465 } else {
466 /* No need to allocate memory. */
467 ptr = mtod(m, unsigned char *) +
468 sizeof(struct ip6_hdr);
469 alloc = 0;
470 }
471 } else
472 break;
473
474 off = ip6.ip6_nxt & 0xff; /* Next header type. */
475
476 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
477 switch (off) {
478 case IPPROTO_HOPOPTS:
479 case IPPROTO_DSTOPTS:
480 ip6e = (struct ip6_ext *) (ptr + len);
481
482 /*
483 * Process the mutable/immutable
484 * options -- borrows heavily from the
485 * KAME code.
486 */
487 for (count = len + sizeof(struct ip6_ext);
488 count < len + ((ip6e->ip6e_len + 1) << 3);) {
489 if (ptr[count] == IP6OPT_PAD1) {
490 count++;
491 continue; /* Skip padding. */
492 }
493
494 /* Sanity check. */
495 if (count > len +
496 ((ip6e->ip6e_len + 1) << 3)) {
497 m_freem(m);
498
499 /* Free, if we allocated. */
500 if (alloc)
501 free(ptr, M_XDATA);
502 return EINVAL;
503 }
504
505 ad = ptr[count + 1];
506
507 /* If mutable option, zeroize. */
508 if (ptr[count] & IP6OPT_MUTABLE)
509 bcopy(ipseczeroes, ptr + count,
510 ptr[count + 1]);
511
512 count += ad;
513
514 /* Sanity check. */
515 if (count >
516 skip - sizeof(struct ip6_hdr)) {
517 m_freem(m);
518
519 /* Free, if we allocated. */
520 if (alloc)
521 free(ptr, M_XDATA);
522 return EINVAL;
523 }
524 }
525
526 /* Advance. */
527 len += ((ip6e->ip6e_len + 1) << 3);
528 off = ip6e->ip6e_nxt;
529 break;
530
531 case IPPROTO_ROUTING:
532 /*
533 * Always include routing headers in
534 * computation.
535 */
536 ip6e = (struct ip6_ext *) (ptr + len);
537 len += ((ip6e->ip6e_len + 1) << 3);
538 off = ip6e->ip6e_nxt;
539 break;
540
541 default:
542 DPRINTF(("%s: unexpected IPv6 header type %d",
543 __func__, off));
544 if (alloc)
545 free(ptr, M_XDATA);
546 m_freem(m);
547 return EINVAL;
548 }
549
550 /* Copyback and free, if we allocated. */
551 if (alloc) {
552 m_copyback(m, sizeof(struct ip6_hdr),
553 skip - sizeof(struct ip6_hdr), ptr);
554 free(ptr, M_XDATA);
555 }
556
557 break;
558#endif /* INET6 */
559 }
560
561 return 0;
562}
563
564/*
565 * ah_input() gets called to verify that an input packet
566 * passes authentication.
567 */
568static int
569ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
570{
571 INIT_VNET_IPSEC(curvnet);
572 struct auth_hash *ahx;
573 struct tdb_ident *tdbi;
574 struct tdb_crypto *tc;
575 struct m_tag *mtag;
576 struct newah *ah;
577 int hl, rplen, authsize;
578
579 struct cryptodesc *crda;
580 struct cryptop *crp;
581
582 IPSEC_ASSERT(sav != NULL, ("null SA"));
583 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
584 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
585 ("null authentication xform"));
586
587 /* Figure out header size. */
588 rplen = HDRSIZE(sav);
589
590 /* XXX don't pullup, just copy header */
591 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
592 if (ah == NULL) {
593 DPRINTF(("ah_input: cannot pullup header\n"));
594 V_ahstat.ahs_hdrops++; /*XXX*/
595 m_freem(m);
596 return ENOBUFS;
597 }
598
599 /* Check replay window, if applicable. */
600 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
601 V_ahstat.ahs_replay++;
602 DPRINTF(("%s: packet replay failure: %s\n", __func__,
603 ipsec_logsastr(sav)));
604 m_freem(m);
605 return ENOBUFS;
606 }
607
608 /* Verify AH header length. */
609 hl = ah->ah_len * sizeof (u_int32_t);
610 ahx = sav->tdb_authalgxform;
611 authsize = AUTHSIZE(sav);
612 if (hl != authsize + rplen - sizeof (struct ah)) {
613 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
614 " for packet in SA %s/%08lx\n", __func__,
615 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
616 ipsec_address(&sav->sah->saidx.dst),
617 (u_long) ntohl(sav->spi)));
618 V_ahstat.ahs_badauthl++;
619 m_freem(m);
620 return EACCES;
621 }
622 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
623
624 /* Get crypto descriptors. */
625 crp = crypto_getreq(1);
626 if (crp == NULL) {
627 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
628 V_ahstat.ahs_crypto++;
629 m_freem(m);
630 return ENOBUFS;
631 }
632
633 crda = crp->crp_desc;
634 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
635
636 crda->crd_skip = 0;
637 crda->crd_len = m->m_pkthdr.len;
638 crda->crd_inject = skip + rplen;
639
640 /* Authentication operation. */
641 crda->crd_alg = ahx->type;
642 crda->crd_klen = _KEYBITS(sav->key_auth);
643 crda->crd_key = sav->key_auth->key_data;
644
645 /* Find out if we've already done crypto. */
646 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
647 mtag != NULL;
648 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
649 tdbi = (struct tdb_ident *) (mtag + 1);
650 if (tdbi->proto == sav->sah->saidx.proto &&
651 tdbi->spi == sav->spi &&
652 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
653 sizeof (union sockaddr_union)))
654 break;
655 }
656
657 /* Allocate IPsec-specific opaque crypto info. */
658 if (mtag == NULL) {
659 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
660 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
661 } else {
662 /* Hash verification has already been done successfully. */
663 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
664 M_XDATA, M_NOWAIT|M_ZERO);
665 }
666 if (tc == NULL) {
667 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
668 V_ahstat.ahs_crypto++;
669 crypto_freereq(crp);
670 m_freem(m);
671 return ENOBUFS;
672 }
673
674 /* Only save information if crypto processing is needed. */
675 if (mtag == NULL) {
676 int error;
677
678 /*
679 * Save the authenticator, the skipped portion of the packet,
680 * and the AH header.
681 */
682 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
683
684 /* Zeroize the authenticator on the packet. */
685 m_copyback(m, skip + rplen, authsize, ipseczeroes);
686
687 /* "Massage" the packet headers for crypto processing. */
688 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
689 skip, ahx->type, 0);
690 if (error != 0) {
691 /* NB: mbuf is free'd by ah_massage_headers */
692 V_ahstat.ahs_hdrops++;
693 free(tc, M_XDATA);
694 crypto_freereq(crp);
695 return error;
696 }
697 }
698
699 /* Crypto operation descriptor. */
700 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
701 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
702 crp->crp_buf = (caddr_t) m;
703 crp->crp_callback = ah_input_cb;
704 crp->crp_sid = sav->tdb_cryptoid;
705 crp->crp_opaque = (caddr_t) tc;
706
707 /* These are passed as-is to the callback. */
708 tc->tc_spi = sav->spi;
709 tc->tc_dst = sav->sah->saidx.dst;
710 tc->tc_proto = sav->sah->saidx.proto;
711 tc->tc_nxt = ah->ah_nxt;
712 tc->tc_protoff = protoff;
713 tc->tc_skip = skip;
714 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
715
716 if (mtag == NULL)
717 return crypto_dispatch(crp);
718 else
719 return ah_input_cb(crp);
720}
721
722#ifdef INET6
723#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
724 if (saidx->dst.sa.sa_family == AF_INET6) { \
725 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
726 } else { \
727 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
728 } \
729} while (0)
730#else
731#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
732 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
733#endif
734
735/*
736 * AH input callback from the crypto driver.
737 */
738static int
739ah_input_cb(struct cryptop *crp)
740{
741 INIT_VNET_IPSEC(curvnet);
742 int rplen, error, skip, protoff;
743 unsigned char calc[AH_ALEN_MAX];
744 struct mbuf *m;
745 struct cryptodesc *crd;
746 struct auth_hash *ahx;
747 struct tdb_crypto *tc;
748 struct m_tag *mtag;
749 struct secasvar *sav;
750 struct secasindex *saidx;
751 u_int8_t nxt;
752 caddr_t ptr;
753 int authsize;
754
755 crd = crp->crp_desc;
756
757 tc = (struct tdb_crypto *) crp->crp_opaque;
758 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
759 skip = tc->tc_skip;
760 nxt = tc->tc_nxt;
761 protoff = tc->tc_protoff;
762 mtag = (struct m_tag *) tc->tc_ptr;
763 m = (struct mbuf *) crp->crp_buf;
764
765 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
766 if (sav == NULL) {
767 V_ahstat.ahs_notdb++;
768 DPRINTF(("%s: SA expired while in crypto\n", __func__));
769 error = ENOBUFS; /*XXX*/
770 goto bad;
771 }
772
773 saidx = &sav->sah->saidx;
774 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
775 saidx->dst.sa.sa_family == AF_INET6,
776 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
777
778 ahx = (struct auth_hash *) sav->tdb_authalgxform;
779
780 /* Check for crypto errors. */
781 if (crp->crp_etype) {
782 if (sav->tdb_cryptoid != 0)
783 sav->tdb_cryptoid = crp->crp_sid;
784
785 if (crp->crp_etype == EAGAIN) {
786 error = crypto_dispatch(crp);
787 return error;
788 }
789
790 V_ahstat.ahs_noxform++;
791 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
792 error = crp->crp_etype;
793 goto bad;
794 } else {
795 V_ahstat.ahs_hist[sav->alg_auth]++;
796 crypto_freereq(crp); /* No longer needed. */
797 crp = NULL;
798 }
799
800 /* Shouldn't happen... */
801 if (m == NULL) {
802 V_ahstat.ahs_crypto++;
803 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
804 error = EINVAL;
805 goto bad;
806 }
807
808 /* Figure out header size. */
809 rplen = HDRSIZE(sav);
810 authsize = AUTHSIZE(sav);
811
812 /* Copy authenticator off the packet. */
813 m_copydata(m, skip + rplen, authsize, calc);
814
815 /*
816 * If we have an mtag, we don't need to verify the authenticator --
817 * it has been verified by an IPsec-aware NIC.
818 */
819 if (mtag == NULL) {
820 ptr = (caddr_t) (tc + 1);
821
822 /* Verify authenticator. */
823 if (bcmp(ptr + skip + rplen, calc, authsize)) {
824 DPRINTF(("%s: authentication hash mismatch for packet "
825 "in SA %s/%08lx\n", __func__,
826 ipsec_address(&saidx->dst),
827 (u_long) ntohl(sav->spi)));
828 V_ahstat.ahs_badauth++;
829 error = EACCES;
830 goto bad;
831 }
832
833 /* Fix the Next Protocol field. */
834 ((u_int8_t *) ptr)[protoff] = nxt;
835
836 /* Copyback the saved (uncooked) network headers. */
837 m_copyback(m, 0, skip, ptr);
838 } else {
839 /* Fix the Next Protocol field. */
840 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
841 }
842
843 free(tc, M_XDATA), tc = NULL; /* No longer needed */
844
845 /*
846 * Header is now authenticated.
847 */
848 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
849
850 /*
851 * Update replay sequence number, if appropriate.
852 */
853 if (sav->replay) {
854 u_int32_t seq;
855
856 m_copydata(m, skip + offsetof(struct newah, ah_seq),
857 sizeof (seq), (caddr_t) &seq);
858 if (ipsec_updatereplay(ntohl(seq), sav)) {
859 V_ahstat.ahs_replay++;
860 error = ENOBUFS; /*XXX as above*/
861 goto bad;
862 }
863 }
864
865 /*
866 * Remove the AH header and authenticator from the mbuf.
867 */
868 error = m_striphdr(m, skip, rplen + authsize);
869 if (error) {
870 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
871 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
872
873 V_ahstat.ahs_hdrops++;
874 goto bad;
875 }
876
877 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
878
879 KEY_FREESAV(&sav);
880 return error;
881bad:
882 if (sav)
883 KEY_FREESAV(&sav);
884 if (m != NULL)
885 m_freem(m);
886 if (tc != NULL)
887 free(tc, M_XDATA);
888 if (crp != NULL)
889 crypto_freereq(crp);
890 return error;
891}
892
893/*
894 * AH output routine, called by ipsec[46]_process_packet().
895 */
896static int
897ah_output(
898 struct mbuf *m,
899 struct ipsecrequest *isr,
900 struct mbuf **mp,
901 int skip,
902 int protoff)
903{
904 INIT_VNET_IPSEC(curvnet);
905 struct secasvar *sav;
906 struct auth_hash *ahx;
907 struct cryptodesc *crda;
908 struct tdb_crypto *tc;
909 struct mbuf *mi;
910 struct cryptop *crp;
911 u_int16_t iplen;
912 int error, rplen, authsize, maxpacketsize, roff;
913 u_int8_t prot;
914 struct newah *ah;
915
916 sav = isr->sav;
917 IPSEC_ASSERT(sav != NULL, ("null SA"));
918 ahx = sav->tdb_authalgxform;
919 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
920
921 V_ahstat.ahs_output++;
922
923 /* Figure out header size. */
924 rplen = HDRSIZE(sav);
925
926 /* Check for maximum packet size violations. */
927 switch (sav->sah->saidx.dst.sa.sa_family) {
928#ifdef INET
929 case AF_INET:
930 maxpacketsize = IP_MAXPACKET;
931 break;
932#endif /* INET */
933#ifdef INET6
934 case AF_INET6:
935 maxpacketsize = IPV6_MAXPACKET;
936 break;
937#endif /* INET6 */
938 default:
939 DPRINTF(("%s: unknown/unsupported protocol family %u, "
940 "SA %s/%08lx\n", __func__,
941 sav->sah->saidx.dst.sa.sa_family,
942 ipsec_address(&sav->sah->saidx.dst),
943 (u_long) ntohl(sav->spi)));
944 V_ahstat.ahs_nopf++;
945 error = EPFNOSUPPORT;
946 goto bad;
947 }
948 authsize = AUTHSIZE(sav);
949 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
950 DPRINTF(("%s: packet in SA %s/%08lx got too big "
951 "(len %u, max len %u)\n", __func__,
952 ipsec_address(&sav->sah->saidx.dst),
953 (u_long) ntohl(sav->spi),
954 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
955 V_ahstat.ahs_toobig++;
956 error = EMSGSIZE;
957 goto bad;
958 }
959
960 /* Update the counters. */
961 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
962
963 m = m_unshare(m, M_NOWAIT);
964 if (m == NULL) {
965 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
966 ipsec_address(&sav->sah->saidx.dst),
967 (u_long) ntohl(sav->spi)));
968 V_ahstat.ahs_hdrops++;
969 error = ENOBUFS;
970 goto bad;
971 }
972
973 /* Inject AH header. */
974 mi = m_makespace(m, skip, rplen + authsize, &roff);
975 if (mi == NULL) {
976 DPRINTF(("%s: failed to inject %u byte AH header for SA "
977 "%s/%08lx\n", __func__,
978 rplen + authsize,
979 ipsec_address(&sav->sah->saidx.dst),
980 (u_long) ntohl(sav->spi)));
981 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */
982 error = ENOBUFS;
983 goto bad;
984 }
985
986 /*
987 * The AH header is guaranteed by m_makespace() to be in
988 * contiguous memory, at roff bytes offset into the returned mbuf.
989 */
990 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
991
992 /* Initialize the AH header. */
993 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
994 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
995 ah->ah_reserve = 0;
996 ah->ah_spi = sav->spi;
997
998 /* Zeroize authenticator. */
999 m_copyback(m, skip + rplen, authsize, ipseczeroes);
1000
1001 /* Insert packet replay counter, as requested. */
1002 if (sav->replay) {
1003 if (sav->replay->count == ~0 &&
1004 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1005 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
1006 __func__,
1007 ipsec_address(&sav->sah->saidx.dst),
1008 (u_long) ntohl(sav->spi)));
1009 V_ahstat.ahs_wrap++;
1010 error = EINVAL;
1011 goto bad;
1012 }
1013#ifdef REGRESSION
1014 /* Emulate replay attack when ipsec_replay is TRUE. */
1015 if (!V_ipsec_replay)
1016#endif
1017 sav->replay->count++;
1018 ah->ah_seq = htonl(sav->replay->count);
1019 }
1020
1021 /* Get crypto descriptors. */
1022 crp = crypto_getreq(1);
1023 if (crp == NULL) {
1024 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1025 __func__));
1026 V_ahstat.ahs_crypto++;
1027 error = ENOBUFS;
1028 goto bad;
1029 }
1030
1031 crda = crp->crp_desc;
1032
1033 crda->crd_skip = 0;
1034 crda->crd_inject = skip + rplen;
1035 crda->crd_len = m->m_pkthdr.len;
1036
1037 /* Authentication operation. */
1038 crda->crd_alg = ahx->type;
1039 crda->crd_key = sav->key_auth->key_data;
1040 crda->crd_klen = _KEYBITS(sav->key_auth);
1041
1042 /* Allocate IPsec-specific opaque crypto info. */
1043 tc = (struct tdb_crypto *) malloc(
1044 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1045 if (tc == NULL) {
1046 crypto_freereq(crp);
1047 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1048 V_ahstat.ahs_crypto++;
1049 error = ENOBUFS;
1050 goto bad;
1051 }
1052
1053 /* Save the skipped portion of the packet. */
1054 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1055
1056 /*
1057 * Fix IP header length on the header used for
1058 * authentication. We don't need to fix the original
1059 * header length as it will be fixed by our caller.
1060 */
1061 switch (sav->sah->saidx.dst.sa.sa_family) {
1062#ifdef INET
1063 case AF_INET:
1064 bcopy(((caddr_t)(tc + 1)) +
1065 offsetof(struct ip, ip_len),
1066 (caddr_t) &iplen, sizeof(u_int16_t));
1067 iplen = htons(ntohs(iplen) + rplen + authsize);
1068 m_copyback(m, offsetof(struct ip, ip_len),
1069 sizeof(u_int16_t), (caddr_t) &iplen);
1070 break;
1071#endif /* INET */
1072
1073#ifdef INET6
1074 case AF_INET6:
1075 bcopy(((caddr_t)(tc + 1)) +
1076 offsetof(struct ip6_hdr, ip6_plen),
1077 (caddr_t) &iplen, sizeof(u_int16_t));
1078 iplen = htons(ntohs(iplen) + rplen + authsize);
1079 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1080 sizeof(u_int16_t), (caddr_t) &iplen);
1081 break;
1082#endif /* INET6 */
1083 }
1084
1085 /* Fix the Next Header field in saved header. */
1086 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1087
1088 /* Update the Next Protocol field in the IP header. */
1089 prot = IPPROTO_AH;
1090 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1091
1092 /* "Massage" the packet headers for crypto processing. */
1093 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1094 skip, ahx->type, 1);
1095 if (error != 0) {
1096 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1097 free(tc, M_XDATA);
1098 crypto_freereq(crp);
1099 goto bad;
1100 }
1101
1102 /* Crypto operation descriptor. */
1103 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1104 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1105 crp->crp_buf = (caddr_t) m;
1106 crp->crp_callback = ah_output_cb;
1107 crp->crp_sid = sav->tdb_cryptoid;
1108 crp->crp_opaque = (caddr_t) tc;
1109
1110 /* These are passed as-is to the callback. */
1111 tc->tc_isr = isr;
1112 tc->tc_spi = sav->spi;
1113 tc->tc_dst = sav->sah->saidx.dst;
1114 tc->tc_proto = sav->sah->saidx.proto;
1115 tc->tc_skip = skip;
1116 tc->tc_protoff = protoff;
1117
1118 return crypto_dispatch(crp);
1119bad:
1120 if (m)
1121 m_freem(m);
1122 return (error);
1123}
1124
1125/*
1126 * AH output callback from the crypto driver.
1127 */
1128static int
1129ah_output_cb(struct cryptop *crp)
1130{
1131 INIT_VNET_IPSEC(curvnet);
1132 int skip, protoff, error;
1133 struct tdb_crypto *tc;
1134 struct ipsecrequest *isr;
1135 struct secasvar *sav;
1136 struct mbuf *m;
1137 caddr_t ptr;
1138 int err;
1139
1140 tc = (struct tdb_crypto *) crp->crp_opaque;
1141 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1142 skip = tc->tc_skip;
1143 protoff = tc->tc_protoff;
1144 ptr = (caddr_t) (tc + 1);
1145 m = (struct mbuf *) crp->crp_buf;
1146
1147 isr = tc->tc_isr;
1148 IPSECREQUEST_LOCK(isr);
1149 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1150 if (sav == NULL) {
1151 V_ahstat.ahs_notdb++;
1152 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1153 error = ENOBUFS; /*XXX*/
1154 goto bad;
1155 }
1156 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1157
1158 /* Check for crypto errors. */
1159 if (crp->crp_etype) {
1160 if (sav->tdb_cryptoid != 0)
1161 sav->tdb_cryptoid = crp->crp_sid;
1162
1163 if (crp->crp_etype == EAGAIN) {
1164 KEY_FREESAV(&sav);
1165 IPSECREQUEST_UNLOCK(isr);
1166 error = crypto_dispatch(crp);
1167 return error;
1168 }
1169
1170 V_ahstat.ahs_noxform++;
1171 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1172 error = crp->crp_etype;
1173 goto bad;
1174 }
1175
1176 /* Shouldn't happen... */
1177 if (m == NULL) {
1178 V_ahstat.ahs_crypto++;
1179 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1180 error = EINVAL;
1181 goto bad;
1182 }
1183 V_ahstat.ahs_hist[sav->alg_auth]++;
1184
1185 /*
1186 * Copy original headers (with the new protocol number) back
1187 * in place.
1188 */
1189 m_copyback(m, 0, skip, ptr);
1190
1191 /* No longer needed. */
1192 free(tc, M_XDATA);
1193 crypto_freereq(crp);
1194
1195#ifdef REGRESSION
1196 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1197 if (V_ipsec_integrity) {
1198 int alen;
1199
1200 /*
1201 * Corrupt HMAC if we want to test integrity verification of
1202 * the other side.
1203 */
1204 alen = AUTHSIZE(sav);
1205 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1206 }
1207#endif
1208
1209 /* NB: m is reclaimed by ipsec_process_done. */
1210 err = ipsec_process_done(m, isr);
1211 KEY_FREESAV(&sav);
1212 IPSECREQUEST_UNLOCK(isr);
1213 return err;
1214bad:
1215 if (sav)
1216 KEY_FREESAV(&sav);
1217 IPSECREQUEST_UNLOCK(isr);
1218 if (m)
1219 m_freem(m);
1220 free(tc, M_XDATA);
1221 crypto_freereq(crp);
1222 return error;
1223}
1224
1225static struct xformsw ah_xformsw = {
1226 XF_AH, XFT_AUTH, "IPsec AH",
1227 ah_init, ah_zeroize, ah_input, ah_output,
1228};
1229
1230static void
1231ah_attach(void)
1232{
1233
1234 xform_register(&ah_xformsw);
1235#ifndef VIMAGE_GLOBALS
1236 vnet_mod_register(&vnet_ah_modinfo);
1237#else
1238 ah_iattach(NULL);
1239#endif
1240}
1241
1242static int
1243ah_iattach(const void *unused __unused)
1244{
1245 INIT_VNET_IPSEC(curvnet);
1246
1247 V_ah_enable = 1; /* control flow of packets with AH */
1248 V_ah_cleartos = 1; /* clear ip_tos when doing AH calc */
1249
1250 return (0);
1251}
1252SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);