1/* $FreeBSD: head/sys/netipsec/xform_ah.c 195699 2009-07-14 22:48:30Z rwatson $ */
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#include <net/vnet.h>
53
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#include <netinet/ip.h>
57#include <netinet/ip_ecn.h>
58#include <netinet/ip6.h>
59
60#include <net/route.h>
61#include <netipsec/ipsec.h>
62#include <netipsec/ah.h>
63#include <netipsec/ah_var.h>
64#include <netipsec/xform.h>
65
66#ifdef INET6
67#include <netinet6/ip6_var.h>
68#include <netipsec/ipsec6.h>
69#include <netinet6/ip6_ecn.h>
70#endif
71
72#include <netipsec/key.h>
73#include <netipsec/key_debug.h>
74
75#include <opencrypto/cryptodev.h>
76
77/*
78 * Return header size in bytes. The old protocol did not support
79 * the replay counter; the new protocol always includes the counter.
80 */
81#define HDRSIZE(sav) \
82 (((sav)->flags & SADB_X_EXT_OLD) ? \
83 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
84/*
85 * Return authenticator size in bytes. The old protocol is known
86 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
87 * authenticator.
88 */
89#define AUTHSIZE(sav) \
90 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
91
92VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
93VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
94VNET_DEFINE(struct ahstat, ahstat);
95
96SYSCTL_DECL(_net_inet_ah);
97SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
98 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
99SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
100 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
101SYSCTL_VNET_STRUCT(_net_inet_ah, IPSECCTL_STATS,
102 stats, CTLFLAG_RD, &VNET_NAME(ahstat), ahstat, "");
103
104static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
105
106static int ah_input_cb(struct cryptop*);
107static int ah_output_cb(struct cryptop*);
108
109/*
110 * NB: this is public for use by the PF_KEY support.
111 */
112struct auth_hash *
113ah_algorithm_lookup(int alg)
114{
115 if (alg > SADB_AALG_MAX)
116 return NULL;
117 switch (alg) {
118 case SADB_X_AALG_NULL:
119 return &auth_hash_null;
120 case SADB_AALG_MD5HMAC:
121 return &auth_hash_hmac_md5;
122 case SADB_AALG_SHA1HMAC:
123 return &auth_hash_hmac_sha1;
124 case SADB_X_AALG_RIPEMD160HMAC:
125 return &auth_hash_hmac_ripemd_160;
126 case SADB_X_AALG_MD5:
127 return &auth_hash_key_md5;
128 case SADB_X_AALG_SHA:
129 return &auth_hash_key_sha1;
130 case SADB_X_AALG_SHA2_256:
131 return &auth_hash_hmac_sha2_256;
132 case SADB_X_AALG_SHA2_384:
133 return &auth_hash_hmac_sha2_384;
134 case SADB_X_AALG_SHA2_512:
135 return &auth_hash_hmac_sha2_512;
136 }
137 return NULL;
138}
139
140size_t
141ah_hdrsiz(struct secasvar *sav)
142{
143 size_t size;
144
145 if (sav != NULL) {
146 int authsize;
147 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
148 /*XXX not right for null algorithm--does it matter??*/
149 authsize = AUTHSIZE(sav);
150 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
151 } else {
152 /* default guess */
153 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
154 }
155 return size;
156}
157
158/*
159 * NB: public for use by esp_init.
160 */
161int
162ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
163{
164 struct auth_hash *thash;
165 int keylen;
166
167 thash = ah_algorithm_lookup(sav->alg_auth);
168 if (thash == NULL) {
169 DPRINTF(("%s: unsupported authentication algorithm %u\n",
170 __func__, sav->alg_auth));
171 return EINVAL;
172 }
173 /*
174 * Verify the replay state block allocation is consistent with
175 * the protocol type. We check here so we can make assumptions
176 * later during protocol processing.
177 */
178 /* NB: replay state is setup elsewhere (sigh) */
179 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
180 DPRINTF(("%s: replay state block inconsistency, "
181 "%s algorithm %s replay state\n", __func__,
182 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
183 sav->replay == NULL ? "without" : "with"));
184 return EINVAL;
185 }
186 if (sav->key_auth == NULL) {
187 DPRINTF(("%s: no authentication key for %s algorithm\n",
188 __func__, thash->name));
189 return EINVAL;
190 }
191 keylen = _KEYLEN(sav->key_auth);
192 if (keylen != thash->keysize && thash->keysize != 0) {
193 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
194 "keysize %d\n", __func__,
195 keylen, thash->name, thash->keysize));
196 return EINVAL;
197 }
198
199 sav->tdb_xform = xsp;
200 sav->tdb_authalgxform = thash;
201
202 /* Initialize crypto session. */
203 bzero(cria, sizeof (*cria));
204 cria->cri_alg = sav->tdb_authalgxform->type;
205 cria->cri_klen = _KEYBITS(sav->key_auth);
206 cria->cri_key = sav->key_auth->key_data;
207 cria->cri_mlen = AUTHSIZE(sav);
208
209 return 0;
210}
211
212/*
213 * ah_init() is called when an SPI is being set up.
214 */
215static int
216ah_init(struct secasvar *sav, struct xformsw *xsp)
217{
218 struct cryptoini cria;
219 int error;
220
221 error = ah_init0(sav, xsp, &cria);
222 return error ? error :
223 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
224}
225
226/*
227 * Paranoia.
228 *
229 * NB: public for use by esp_zeroize (XXX).
230 */
231int
232ah_zeroize(struct secasvar *sav)
233{
234 int err;
235
236 if (sav->key_auth)
237 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
238
239 err = crypto_freesession(sav->tdb_cryptoid);
240 sav->tdb_cryptoid = 0;
241 sav->tdb_authalgxform = NULL;
242 sav->tdb_xform = NULL;
243 return err;
244}
245
246/*
247 * Massage IPv4/IPv6 headers for AH processing.
248 */
249static int
250ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
251{
252 struct mbuf *m = *m0;
253 unsigned char *ptr;
254 int off, count;
255
256#ifdef INET
257 struct ip *ip;
258#endif /* INET */
259
260#ifdef INET6
261 struct ip6_ext *ip6e;
262 struct ip6_hdr ip6;
263 int alloc, len, ad;
264#endif /* INET6 */
265
266 switch (proto) {
267#ifdef INET
268 case AF_INET:
269 /*
270 * This is the least painful way of dealing with IPv4 header
271 * and option processing -- just make sure they're in
272 * contiguous memory.
273 */
274 *m0 = m = m_pullup(m, skip);
275 if (m == NULL) {
276 DPRINTF(("%s: m_pullup failed\n", __func__));
277 return ENOBUFS;
278 }
279
280 /* Fix the IP header */
281 ip = mtod(m, struct ip *);
282 if (V_ah_cleartos)
283 ip->ip_tos = 0;
284 ip->ip_ttl = 0;
285 ip->ip_sum = 0;
286
287 /*
288 * On input, fix ip_len which has been byte-swapped
289 * at ip_input().
290 */
291 if (!out) {
292 ip->ip_len = htons(ip->ip_len + skip);
293
294 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
295 ip->ip_off = htons(ip->ip_off & IP_DF);
296 else
297 ip->ip_off = 0;
298 } else {
299 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
300 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
301 else
302 ip->ip_off = 0;
303 }
304
305 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
306
307 /* IPv4 option processing */
308 for (off = sizeof(struct ip); off < skip;) {
309 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
310 off + 1 < skip)
311 ;
312 else {
313 DPRINTF(("%s: illegal IPv4 option length for "
314 "option %d\n", __func__, ptr[off]));
315
316 m_freem(m);
317 return EINVAL;
318 }
319
320 switch (ptr[off]) {
321 case IPOPT_EOL:
322 off = skip; /* End the loop. */
323 break;
324
325 case IPOPT_NOP:
326 off++;
327 break;
328
329 case IPOPT_SECURITY: /* 0x82 */
330 case 0x85: /* Extended security. */
331 case 0x86: /* Commercial security. */
332 case 0x94: /* Router alert */
333 case 0x95: /* RFC1770 */
334 /* Sanity check for option length. */
335 if (ptr[off + 1] < 2) {
336 DPRINTF(("%s: illegal IPv4 option "
337 "length for option %d\n",
338 __func__, ptr[off]));
339
340 m_freem(m);
341 return EINVAL;
342 }
343
344 off += ptr[off + 1];
345 break;
346
347 case IPOPT_LSRR:
348 case IPOPT_SSRR:
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 /*
360 * On output, if we have either of the
361 * source routing options, we should
362 * swap the destination address of the
363 * IP header with the last address
364 * specified in the option, as that is
365 * what the destination's IP header
366 * will look like.
367 */
368 if (out)
369 bcopy(ptr + off + ptr[off + 1] -
370 sizeof(struct in_addr),
371 &(ip->ip_dst), sizeof(struct in_addr));
372
373 /* Fall through */
374 default:
375 /* Sanity check for option length. */
376 if (ptr[off + 1] < 2) {
377 DPRINTF(("%s: illegal IPv4 option "
378 "length for option %d\n",
379 __func__, ptr[off]));
380 m_freem(m);
381 return EINVAL;
382 }
383
384 /* Zeroize all other options. */
385 count = ptr[off + 1];
386 bcopy(ipseczeroes, ptr, count);
387 off += count;
388 break;
389 }
390
391 /* Sanity check. */
392 if (off > skip) {
393 DPRINTF(("%s: malformed IPv4 options header\n",
394 __func__));
395
396 m_freem(m);
397 return EINVAL;
398 }
399 }
400
401 break;
402#endif /* INET */
403
404#ifdef INET6
405 case AF_INET6: /* Ugly... */
406 /* Copy and "cook" the IPv6 header. */
407 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
408
409 /* We don't do IPv6 Jumbograms. */
410 if (ip6.ip6_plen == 0) {
411 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
412 m_freem(m);
413 return EMSGSIZE;
414 }
415
416 ip6.ip6_flow = 0;
417 ip6.ip6_hlim = 0;
418 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
419 ip6.ip6_vfc |= IPV6_VERSION;
420
421 /* Scoped address handling. */
422 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
423 ip6.ip6_src.s6_addr16[1] = 0;
424 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
425 ip6.ip6_dst.s6_addr16[1] = 0;
426
427 /* Done with IPv6 header. */
428 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
429
430 /* Let's deal with the remaining headers (if any). */
431 if (skip - sizeof(struct ip6_hdr) > 0) {
432 if (m->m_len <= skip) {
433 ptr = (unsigned char *) malloc(
434 skip - sizeof(struct ip6_hdr),
435 M_XDATA, M_NOWAIT);
436 if (ptr == NULL) {
437 DPRINTF(("%s: failed to allocate memory"
438 "for IPv6 headers\n",__func__));
439 m_freem(m);
440 return ENOBUFS;
441 }
442
443 /*
444 * Copy all the protocol headers after
445 * the IPv6 header.
446 */
447 m_copydata(m, sizeof(struct ip6_hdr),
448 skip - sizeof(struct ip6_hdr), ptr);
449 alloc = 1;
450 } else {
451 /* No need to allocate memory. */
452 ptr = mtod(m, unsigned char *) +
453 sizeof(struct ip6_hdr);
454 alloc = 0;
455 }
456 } else
457 break;
458
459 off = ip6.ip6_nxt & 0xff; /* Next header type. */
460
461 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
462 switch (off) {
463 case IPPROTO_HOPOPTS:
464 case IPPROTO_DSTOPTS:
465 ip6e = (struct ip6_ext *) (ptr + len);
466
467 /*
468 * Process the mutable/immutable
469 * options -- borrows heavily from the
470 * KAME code.
471 */
472 for (count = len + sizeof(struct ip6_ext);
473 count < len + ((ip6e->ip6e_len + 1) << 3);) {
474 if (ptr[count] == IP6OPT_PAD1) {
475 count++;
476 continue; /* Skip padding. */
477 }
478
479 /* Sanity check. */
480 if (count > len +
481 ((ip6e->ip6e_len + 1) << 3)) {
482 m_freem(m);
483
484 /* Free, if we allocated. */
485 if (alloc)
486 free(ptr, M_XDATA);
487 return EINVAL;
488 }
489
490 ad = ptr[count + 1];
491
492 /* If mutable option, zeroize. */
493 if (ptr[count] & IP6OPT_MUTABLE)
494 bcopy(ipseczeroes, ptr + count,
495 ptr[count + 1]);
496
497 count += ad;
498
499 /* Sanity check. */
500 if (count >
501 skip - sizeof(struct ip6_hdr)) {
502 m_freem(m);
503
504 /* Free, if we allocated. */
505 if (alloc)
506 free(ptr, M_XDATA);
507 return EINVAL;
508 }
509 }
510
511 /* Advance. */
512 len += ((ip6e->ip6e_len + 1) << 3);
513 off = ip6e->ip6e_nxt;
514 break;
515
516 case IPPROTO_ROUTING:
517 /*
518 * Always include routing headers in
519 * computation.
520 */
521 ip6e = (struct ip6_ext *) (ptr + len);
522 len += ((ip6e->ip6e_len + 1) << 3);
523 off = ip6e->ip6e_nxt;
524 break;
525
526 default:
527 DPRINTF(("%s: unexpected IPv6 header type %d",
528 __func__, off));
529 if (alloc)
530 free(ptr, M_XDATA);
531 m_freem(m);
532 return EINVAL;
533 }
534
535 /* Copyback and free, if we allocated. */
536 if (alloc) {
537 m_copyback(m, sizeof(struct ip6_hdr),
538 skip - sizeof(struct ip6_hdr), ptr);
539 free(ptr, M_XDATA);
540 }
541
542 break;
543#endif /* INET6 */
544 }
545
546 return 0;
547}
548
549/*
550 * ah_input() gets called to verify that an input packet
551 * passes authentication.
552 */
553static int
554ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
555{
556 struct auth_hash *ahx;
557 struct tdb_ident *tdbi;
558 struct tdb_crypto *tc;
559 struct m_tag *mtag;
560 struct newah *ah;
561 int hl, rplen, authsize;
562
563 struct cryptodesc *crda;
564 struct cryptop *crp;
565
566 IPSEC_ASSERT(sav != NULL, ("null SA"));
567 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
568 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
569 ("null authentication xform"));
570
571 /* Figure out header size. */
572 rplen = HDRSIZE(sav);
573
574 /* XXX don't pullup, just copy header */
575 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
576 if (ah == NULL) {
577 DPRINTF(("ah_input: cannot pullup header\n"));
578 V_ahstat.ahs_hdrops++; /*XXX*/
579 m_freem(m);
580 return ENOBUFS;
581 }
582
583 /* Check replay window, if applicable. */
584 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
585 V_ahstat.ahs_replay++;
586 DPRINTF(("%s: packet replay failure: %s\n", __func__,
587 ipsec_logsastr(sav)));
588 m_freem(m);
589 return ENOBUFS;
590 }
591
592 /* Verify AH header length. */
593 hl = ah->ah_len * sizeof (u_int32_t);
594 ahx = sav->tdb_authalgxform;
595 authsize = AUTHSIZE(sav);
596 if (hl != authsize + rplen - sizeof (struct ah)) {
597 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
598 " for packet in SA %s/%08lx\n", __func__,
599 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
600 ipsec_address(&sav->sah->saidx.dst),
601 (u_long) ntohl(sav->spi)));
602 V_ahstat.ahs_badauthl++;
603 m_freem(m);
604 return EACCES;
605 }
606 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
607
608 /* Get crypto descriptors. */
609 crp = crypto_getreq(1);
610 if (crp == NULL) {
611 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
612 V_ahstat.ahs_crypto++;
613 m_freem(m);
614 return ENOBUFS;
615 }
616
617 crda = crp->crp_desc;
618 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
619
620 crda->crd_skip = 0;
621 crda->crd_len = m->m_pkthdr.len;
622 crda->crd_inject = skip + rplen;
623
624 /* Authentication operation. */
625 crda->crd_alg = ahx->type;
626 crda->crd_klen = _KEYBITS(sav->key_auth);
627 crda->crd_key = sav->key_auth->key_data;
628
629 /* Find out if we've already done crypto. */
630 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
631 mtag != NULL;
632 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
633 tdbi = (struct tdb_ident *) (mtag + 1);
634 if (tdbi->proto == sav->sah->saidx.proto &&
635 tdbi->spi == sav->spi &&
636 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
637 sizeof (union sockaddr_union)))
638 break;
639 }
640
641 /* Allocate IPsec-specific opaque crypto info. */
642 if (mtag == NULL) {
643 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
644 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
645 } else {
646 /* Hash verification has already been done successfully. */
647 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
648 M_XDATA, M_NOWAIT|M_ZERO);
649 }
650 if (tc == NULL) {
651 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
652 V_ahstat.ahs_crypto++;
653 crypto_freereq(crp);
654 m_freem(m);
655 return ENOBUFS;
656 }
657
658 /* Only save information if crypto processing is needed. */
659 if (mtag == NULL) {
660 int error;
661
662 /*
663 * Save the authenticator, the skipped portion of the packet,
664 * and the AH header.
665 */
666 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
667
668 /* Zeroize the authenticator on the packet. */
669 m_copyback(m, skip + rplen, authsize, ipseczeroes);
670
671 /* "Massage" the packet headers for crypto processing. */
672 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
673 skip, ahx->type, 0);
674 if (error != 0) {
675 /* NB: mbuf is free'd by ah_massage_headers */
676 V_ahstat.ahs_hdrops++;
677 free(tc, M_XDATA);
678 crypto_freereq(crp);
679 return error;
680 }
681 }
682
683 /* Crypto operation descriptor. */
684 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
685 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
686 crp->crp_buf = (caddr_t) m;
687 crp->crp_callback = ah_input_cb;
688 crp->crp_sid = sav->tdb_cryptoid;
689 crp->crp_opaque = (caddr_t) tc;
690
691 /* These are passed as-is to the callback. */
692 tc->tc_spi = sav->spi;
693 tc->tc_dst = sav->sah->saidx.dst;
694 tc->tc_proto = sav->sah->saidx.proto;
695 tc->tc_nxt = ah->ah_nxt;
696 tc->tc_protoff = protoff;
697 tc->tc_skip = skip;
698 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
699
700 if (mtag == NULL)
701 return crypto_dispatch(crp);
702 else
703 return ah_input_cb(crp);
704}
705
706#ifdef INET6
707#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
708 if (saidx->dst.sa.sa_family == AF_INET6) { \
709 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
710 } else { \
711 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
712 } \
713} while (0)
714#else
715#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
716 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
717#endif
718
719/*
720 * AH input callback from the crypto driver.
721 */
722static int
723ah_input_cb(struct cryptop *crp)
724{
725 int rplen, error, skip, protoff;
726 unsigned char calc[AH_ALEN_MAX];
727 struct mbuf *m;
728 struct cryptodesc *crd;
729 struct auth_hash *ahx;
730 struct tdb_crypto *tc;
731 struct m_tag *mtag;
732 struct secasvar *sav;
733 struct secasindex *saidx;
734 u_int8_t nxt;
735 caddr_t ptr;
736 int authsize;
737
738 crd = crp->crp_desc;
739
740 tc = (struct tdb_crypto *) crp->crp_opaque;
741 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
742 skip = tc->tc_skip;
743 nxt = tc->tc_nxt;
744 protoff = tc->tc_protoff;
745 mtag = (struct m_tag *) tc->tc_ptr;
746 m = (struct mbuf *) crp->crp_buf;
747
748 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
749 if (sav == NULL) {
750 V_ahstat.ahs_notdb++;
751 DPRINTF(("%s: SA expired while in crypto\n", __func__));
752 error = ENOBUFS; /*XXX*/
753 goto bad;
754 }
755
756 saidx = &sav->sah->saidx;
757 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
758 saidx->dst.sa.sa_family == AF_INET6,
759 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
760
761 ahx = (struct auth_hash *) sav->tdb_authalgxform;
762
763 /* Check for crypto errors. */
764 if (crp->crp_etype) {
765 if (sav->tdb_cryptoid != 0)
766 sav->tdb_cryptoid = crp->crp_sid;
767
768 if (crp->crp_etype == EAGAIN) {
769 error = crypto_dispatch(crp);
770 return error;
771 }
772
773 V_ahstat.ahs_noxform++;
774 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
775 error = crp->crp_etype;
776 goto bad;
777 } else {
778 V_ahstat.ahs_hist[sav->alg_auth]++;
779 crypto_freereq(crp); /* No longer needed. */
780 crp = NULL;
781 }
782
783 /* Shouldn't happen... */
784 if (m == NULL) {
785 V_ahstat.ahs_crypto++;
786 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
787 error = EINVAL;
788 goto bad;
789 }
790
791 /* Figure out header size. */
792 rplen = HDRSIZE(sav);
793 authsize = AUTHSIZE(sav);
794
795 /* Copy authenticator off the packet. */
796 m_copydata(m, skip + rplen, authsize, calc);
797
798 /*
799 * If we have an mtag, we don't need to verify the authenticator --
800 * it has been verified by an IPsec-aware NIC.
801 */
802 if (mtag == NULL) {
803 ptr = (caddr_t) (tc + 1);
804
805 /* Verify authenticator. */
806 if (bcmp(ptr + skip + rplen, calc, authsize)) {
807 DPRINTF(("%s: authentication hash mismatch for packet "
808 "in SA %s/%08lx\n", __func__,
809 ipsec_address(&saidx->dst),
810 (u_long) ntohl(sav->spi)));
811 V_ahstat.ahs_badauth++;
812 error = EACCES;
813 goto bad;
814 }
815
816 /* Fix the Next Protocol field. */
817 ((u_int8_t *) ptr)[protoff] = nxt;
818
819 /* Copyback the saved (uncooked) network headers. */
820 m_copyback(m, 0, skip, ptr);
821 } else {
822 /* Fix the Next Protocol field. */
823 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
824 }
825
826 free(tc, M_XDATA), tc = NULL; /* No longer needed */
827
828 /*
829 * Header is now authenticated.
830 */
831 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
832
833 /*
834 * Update replay sequence number, if appropriate.
835 */
836 if (sav->replay) {
837 u_int32_t seq;
838
839 m_copydata(m, skip + offsetof(struct newah, ah_seq),
840 sizeof (seq), (caddr_t) &seq);
841 if (ipsec_updatereplay(ntohl(seq), sav)) {
842 V_ahstat.ahs_replay++;
843 error = ENOBUFS; /*XXX as above*/
844 goto bad;
845 }
846 }
847
848 /*
849 * Remove the AH header and authenticator from the mbuf.
850 */
851 error = m_striphdr(m, skip, rplen + authsize);
852 if (error) {
853 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
854 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
855
856 V_ahstat.ahs_hdrops++;
857 goto bad;
858 }
859
860 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
861
862 KEY_FREESAV(&sav);
863 return error;
864bad:
865 if (sav)
866 KEY_FREESAV(&sav);
867 if (m != NULL)
868 m_freem(m);
869 if (tc != NULL)
870 free(tc, M_XDATA);
871 if (crp != NULL)
872 crypto_freereq(crp);
873 return error;
874}
875
876/*
877 * AH output routine, called by ipsec[46]_process_packet().
878 */
879static int
880ah_output(
881 struct mbuf *m,
882 struct ipsecrequest *isr,
883 struct mbuf **mp,
884 int skip,
885 int protoff)
886{
887 struct secasvar *sav;
888 struct auth_hash *ahx;
889 struct cryptodesc *crda;
890 struct tdb_crypto *tc;
891 struct mbuf *mi;
892 struct cryptop *crp;
893 u_int16_t iplen;
894 int error, rplen, authsize, maxpacketsize, roff;
895 u_int8_t prot;
896 struct newah *ah;
897
898 sav = isr->sav;
899 IPSEC_ASSERT(sav != NULL, ("null SA"));
900 ahx = sav->tdb_authalgxform;
901 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
902
903 V_ahstat.ahs_output++;
904
905 /* Figure out header size. */
906 rplen = HDRSIZE(sav);
907
908 /* Check for maximum packet size violations. */
909 switch (sav->sah->saidx.dst.sa.sa_family) {
910#ifdef INET
911 case AF_INET:
912 maxpacketsize = IP_MAXPACKET;
913 break;
914#endif /* INET */
915#ifdef INET6
916 case AF_INET6:
917 maxpacketsize = IPV6_MAXPACKET;
918 break;
919#endif /* INET6 */
920 default:
921 DPRINTF(("%s: unknown/unsupported protocol family %u, "
922 "SA %s/%08lx\n", __func__,
923 sav->sah->saidx.dst.sa.sa_family,
924 ipsec_address(&sav->sah->saidx.dst),
925 (u_long) ntohl(sav->spi)));
926 V_ahstat.ahs_nopf++;
927 error = EPFNOSUPPORT;
928 goto bad;
929 }
930 authsize = AUTHSIZE(sav);
931 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
932 DPRINTF(("%s: packet in SA %s/%08lx got too big "
933 "(len %u, max len %u)\n", __func__,
934 ipsec_address(&sav->sah->saidx.dst),
935 (u_long) ntohl(sav->spi),
936 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
937 V_ahstat.ahs_toobig++;
938 error = EMSGSIZE;
939 goto bad;
940 }
941
942 /* Update the counters. */
943 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
944
945 m = m_unshare(m, M_NOWAIT);
946 if (m == NULL) {
947 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
948 ipsec_address(&sav->sah->saidx.dst),
949 (u_long) ntohl(sav->spi)));
950 V_ahstat.ahs_hdrops++;
951 error = ENOBUFS;
952 goto bad;
953 }
954
955 /* Inject AH header. */
956 mi = m_makespace(m, skip, rplen + authsize, &roff);
957 if (mi == NULL) {
958 DPRINTF(("%s: failed to inject %u byte AH header for SA "
959 "%s/%08lx\n", __func__,
960 rplen + authsize,
961 ipsec_address(&sav->sah->saidx.dst),
962 (u_long) ntohl(sav->spi)));
963 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */
964 error = ENOBUFS;
965 goto bad;
966 }
967
968 /*
969 * The AH header is guaranteed by m_makespace() to be in
970 * contiguous memory, at roff bytes offset into the returned mbuf.
971 */
972 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
973
974 /* Initialize the AH header. */
975 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
976 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
977 ah->ah_reserve = 0;
978 ah->ah_spi = sav->spi;
979
980 /* Zeroize authenticator. */
981 m_copyback(m, skip + rplen, authsize, ipseczeroes);
982
983 /* Insert packet replay counter, as requested. */
984 if (sav->replay) {
985 if (sav->replay->count == ~0 &&
986 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
987 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
988 __func__,
989 ipsec_address(&sav->sah->saidx.dst),
990 (u_long) ntohl(sav->spi)));
991 V_ahstat.ahs_wrap++;
992 error = EINVAL;
993 goto bad;
994 }
995#ifdef REGRESSION
996 /* Emulate replay attack when ipsec_replay is TRUE. */
997 if (!V_ipsec_replay)
998#endif
999 sav->replay->count++;
1000 ah->ah_seq = htonl(sav->replay->count);
1001 }
1002
1003 /* Get crypto descriptors. */
1004 crp = crypto_getreq(1);
1005 if (crp == NULL) {
1006 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1007 __func__));
1008 V_ahstat.ahs_crypto++;
1009 error = ENOBUFS;
1010 goto bad;
1011 }
1012
1013 crda = crp->crp_desc;
1014
1015 crda->crd_skip = 0;
1016 crda->crd_inject = skip + rplen;
1017 crda->crd_len = m->m_pkthdr.len;
1018
1019 /* Authentication operation. */
1020 crda->crd_alg = ahx->type;
1021 crda->crd_key = sav->key_auth->key_data;
1022 crda->crd_klen = _KEYBITS(sav->key_auth);
1023
1024 /* Allocate IPsec-specific opaque crypto info. */
1025 tc = (struct tdb_crypto *) malloc(
1026 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1027 if (tc == NULL) {
1028 crypto_freereq(crp);
1029 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1030 V_ahstat.ahs_crypto++;
1031 error = ENOBUFS;
1032 goto bad;
1033 }
1034
1035 /* Save the skipped portion of the packet. */
1036 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1037
1038 /*
1039 * Fix IP header length on the header used for
1040 * authentication. We don't need to fix the original
1041 * header length as it will be fixed by our caller.
1042 */
1043 switch (sav->sah->saidx.dst.sa.sa_family) {
1044#ifdef INET
1045 case AF_INET:
1046 bcopy(((caddr_t)(tc + 1)) +
1047 offsetof(struct ip, ip_len),
1048 (caddr_t) &iplen, sizeof(u_int16_t));
1049 iplen = htons(ntohs(iplen) + rplen + authsize);
1050 m_copyback(m, offsetof(struct ip, ip_len),
1051 sizeof(u_int16_t), (caddr_t) &iplen);
1052 break;
1053#endif /* INET */
1054
1055#ifdef INET6
1056 case AF_INET6:
1057 bcopy(((caddr_t)(tc + 1)) +
1058 offsetof(struct ip6_hdr, ip6_plen),
1059 (caddr_t) &iplen, sizeof(u_int16_t));
1060 iplen = htons(ntohs(iplen) + rplen + authsize);
1061 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1062 sizeof(u_int16_t), (caddr_t) &iplen);
1063 break;
1064#endif /* INET6 */
1065 }
1066
1067 /* Fix the Next Header field in saved header. */
1068 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1069
1070 /* Update the Next Protocol field in the IP header. */
1071 prot = IPPROTO_AH;
1072 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1073
1074 /* "Massage" the packet headers for crypto processing. */
1075 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1076 skip, ahx->type, 1);
1077 if (error != 0) {
1078 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1079 free(tc, M_XDATA);
1080 crypto_freereq(crp);
1081 goto bad;
1082 }
1083
1084 /* Crypto operation descriptor. */
1085 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1086 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1087 crp->crp_buf = (caddr_t) m;
1088 crp->crp_callback = ah_output_cb;
1089 crp->crp_sid = sav->tdb_cryptoid;
1090 crp->crp_opaque = (caddr_t) tc;
1091
1092 /* These are passed as-is to the callback. */
1093 tc->tc_isr = isr;
1094 tc->tc_spi = sav->spi;
1095 tc->tc_dst = sav->sah->saidx.dst;
1096 tc->tc_proto = sav->sah->saidx.proto;
1097 tc->tc_skip = skip;
1098 tc->tc_protoff = protoff;
1099
1100 return crypto_dispatch(crp);
1101bad:
1102 if (m)
1103 m_freem(m);
1104 return (error);
1105}
1106
1107/*
1108 * AH output callback from the crypto driver.
1109 */
1110static int
1111ah_output_cb(struct cryptop *crp)
1112{
1113 int skip, protoff, error;
1114 struct tdb_crypto *tc;
1115 struct ipsecrequest *isr;
1116 struct secasvar *sav;
1117 struct mbuf *m;
1118 caddr_t ptr;
1119 int err;
1120
1121 tc = (struct tdb_crypto *) crp->crp_opaque;
1122 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1123 skip = tc->tc_skip;
1124 protoff = tc->tc_protoff;
1125 ptr = (caddr_t) (tc + 1);
1126 m = (struct mbuf *) crp->crp_buf;
1127
1128 isr = tc->tc_isr;
1129 IPSECREQUEST_LOCK(isr);
1130 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1131 if (sav == NULL) {
1132 V_ahstat.ahs_notdb++;
1133 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1134 error = ENOBUFS; /*XXX*/
1135 goto bad;
1136 }
1137 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1138
1139 /* Check for crypto errors. */
1140 if (crp->crp_etype) {
1141 if (sav->tdb_cryptoid != 0)
1142 sav->tdb_cryptoid = crp->crp_sid;
1143
1144 if (crp->crp_etype == EAGAIN) {
1145 KEY_FREESAV(&sav);
1146 IPSECREQUEST_UNLOCK(isr);
1147 error = crypto_dispatch(crp);
1148 return error;
1149 }
1150
1151 V_ahstat.ahs_noxform++;
1152 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1153 error = crp->crp_etype;
1154 goto bad;
1155 }
1156
1157 /* Shouldn't happen... */
1158 if (m == NULL) {
1159 V_ahstat.ahs_crypto++;
1160 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1161 error = EINVAL;
1162 goto bad;
1163 }
1164 V_ahstat.ahs_hist[sav->alg_auth]++;
1165
1166 /*
1167 * Copy original headers (with the new protocol number) back
1168 * in place.
1169 */
1170 m_copyback(m, 0, skip, ptr);
1171
1172 /* No longer needed. */
1173 free(tc, M_XDATA);
1174 crypto_freereq(crp);
1175
1176#ifdef REGRESSION
1177 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1178 if (V_ipsec_integrity) {
1179 int alen;
1180
1181 /*
1182 * Corrupt HMAC if we want to test integrity verification of
1183 * the other side.
1184 */
1185 alen = AUTHSIZE(sav);
1186 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1187 }
1188#endif
1189
1190 /* NB: m is reclaimed by ipsec_process_done. */
1191 err = ipsec_process_done(m, isr);
1192 KEY_FREESAV(&sav);
1193 IPSECREQUEST_UNLOCK(isr);
1194 return err;
1195bad:
1196 if (sav)
1197 KEY_FREESAV(&sav);
1198 IPSECREQUEST_UNLOCK(isr);
1199 if (m)
1200 m_freem(m);
1201 free(tc, M_XDATA);
1202 crypto_freereq(crp);
1203 return error;
1204}
1205
1206static struct xformsw ah_xformsw = {
1207 XF_AH, XFT_AUTH, "IPsec AH",
1208 ah_init, ah_zeroize, ah_input, ah_output,
1209};
1210
1211static void
1212ah_attach(void)
1213{
1214
1215 xform_register(&ah_xformsw);
1216}
1217
1218SYSINIT(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#include <net/vnet.h>
53
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#include <netinet/ip.h>
57#include <netinet/ip_ecn.h>
58#include <netinet/ip6.h>
59
60#include <net/route.h>
61#include <netipsec/ipsec.h>
62#include <netipsec/ah.h>
63#include <netipsec/ah_var.h>
64#include <netipsec/xform.h>
65
66#ifdef INET6
67#include <netinet6/ip6_var.h>
68#include <netipsec/ipsec6.h>
69#include <netinet6/ip6_ecn.h>
70#endif
71
72#include <netipsec/key.h>
73#include <netipsec/key_debug.h>
74
75#include <opencrypto/cryptodev.h>
76
77/*
78 * Return header size in bytes. The old protocol did not support
79 * the replay counter; the new protocol always includes the counter.
80 */
81#define HDRSIZE(sav) \
82 (((sav)->flags & SADB_X_EXT_OLD) ? \
83 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
84/*
85 * Return authenticator size in bytes. The old protocol is known
86 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
87 * authenticator.
88 */
89#define AUTHSIZE(sav) \
90 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
91
92VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
93VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
94VNET_DEFINE(struct ahstat, ahstat);
95
96SYSCTL_DECL(_net_inet_ah);
97SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
98 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
99SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO,
100 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
101SYSCTL_VNET_STRUCT(_net_inet_ah, IPSECCTL_STATS,
102 stats, CTLFLAG_RD, &VNET_NAME(ahstat), ahstat, "");
103
104static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
105
106static int ah_input_cb(struct cryptop*);
107static int ah_output_cb(struct cryptop*);
108
109/*
110 * NB: this is public for use by the PF_KEY support.
111 */
112struct auth_hash *
113ah_algorithm_lookup(int alg)
114{
115 if (alg > SADB_AALG_MAX)
116 return NULL;
117 switch (alg) {
118 case SADB_X_AALG_NULL:
119 return &auth_hash_null;
120 case SADB_AALG_MD5HMAC:
121 return &auth_hash_hmac_md5;
122 case SADB_AALG_SHA1HMAC:
123 return &auth_hash_hmac_sha1;
124 case SADB_X_AALG_RIPEMD160HMAC:
125 return &auth_hash_hmac_ripemd_160;
126 case SADB_X_AALG_MD5:
127 return &auth_hash_key_md5;
128 case SADB_X_AALG_SHA:
129 return &auth_hash_key_sha1;
130 case SADB_X_AALG_SHA2_256:
131 return &auth_hash_hmac_sha2_256;
132 case SADB_X_AALG_SHA2_384:
133 return &auth_hash_hmac_sha2_384;
134 case SADB_X_AALG_SHA2_512:
135 return &auth_hash_hmac_sha2_512;
136 }
137 return NULL;
138}
139
140size_t
141ah_hdrsiz(struct secasvar *sav)
142{
143 size_t size;
144
145 if (sav != NULL) {
146 int authsize;
147 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
148 /*XXX not right for null algorithm--does it matter??*/
149 authsize = AUTHSIZE(sav);
150 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
151 } else {
152 /* default guess */
153 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
154 }
155 return size;
156}
157
158/*
159 * NB: public for use by esp_init.
160 */
161int
162ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
163{
164 struct auth_hash *thash;
165 int keylen;
166
167 thash = ah_algorithm_lookup(sav->alg_auth);
168 if (thash == NULL) {
169 DPRINTF(("%s: unsupported authentication algorithm %u\n",
170 __func__, sav->alg_auth));
171 return EINVAL;
172 }
173 /*
174 * Verify the replay state block allocation is consistent with
175 * the protocol type. We check here so we can make assumptions
176 * later during protocol processing.
177 */
178 /* NB: replay state is setup elsewhere (sigh) */
179 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
180 DPRINTF(("%s: replay state block inconsistency, "
181 "%s algorithm %s replay state\n", __func__,
182 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
183 sav->replay == NULL ? "without" : "with"));
184 return EINVAL;
185 }
186 if (sav->key_auth == NULL) {
187 DPRINTF(("%s: no authentication key for %s algorithm\n",
188 __func__, thash->name));
189 return EINVAL;
190 }
191 keylen = _KEYLEN(sav->key_auth);
192 if (keylen != thash->keysize && thash->keysize != 0) {
193 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
194 "keysize %d\n", __func__,
195 keylen, thash->name, thash->keysize));
196 return EINVAL;
197 }
198
199 sav->tdb_xform = xsp;
200 sav->tdb_authalgxform = thash;
201
202 /* Initialize crypto session. */
203 bzero(cria, sizeof (*cria));
204 cria->cri_alg = sav->tdb_authalgxform->type;
205 cria->cri_klen = _KEYBITS(sav->key_auth);
206 cria->cri_key = sav->key_auth->key_data;
207 cria->cri_mlen = AUTHSIZE(sav);
208
209 return 0;
210}
211
212/*
213 * ah_init() is called when an SPI is being set up.
214 */
215static int
216ah_init(struct secasvar *sav, struct xformsw *xsp)
217{
218 struct cryptoini cria;
219 int error;
220
221 error = ah_init0(sav, xsp, &cria);
222 return error ? error :
223 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
224}
225
226/*
227 * Paranoia.
228 *
229 * NB: public for use by esp_zeroize (XXX).
230 */
231int
232ah_zeroize(struct secasvar *sav)
233{
234 int err;
235
236 if (sav->key_auth)
237 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
238
239 err = crypto_freesession(sav->tdb_cryptoid);
240 sav->tdb_cryptoid = 0;
241 sav->tdb_authalgxform = NULL;
242 sav->tdb_xform = NULL;
243 return err;
244}
245
246/*
247 * Massage IPv4/IPv6 headers for AH processing.
248 */
249static int
250ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
251{
252 struct mbuf *m = *m0;
253 unsigned char *ptr;
254 int off, count;
255
256#ifdef INET
257 struct ip *ip;
258#endif /* INET */
259
260#ifdef INET6
261 struct ip6_ext *ip6e;
262 struct ip6_hdr ip6;
263 int alloc, len, ad;
264#endif /* INET6 */
265
266 switch (proto) {
267#ifdef INET
268 case AF_INET:
269 /*
270 * This is the least painful way of dealing with IPv4 header
271 * and option processing -- just make sure they're in
272 * contiguous memory.
273 */
274 *m0 = m = m_pullup(m, skip);
275 if (m == NULL) {
276 DPRINTF(("%s: m_pullup failed\n", __func__));
277 return ENOBUFS;
278 }
279
280 /* Fix the IP header */
281 ip = mtod(m, struct ip *);
282 if (V_ah_cleartos)
283 ip->ip_tos = 0;
284 ip->ip_ttl = 0;
285 ip->ip_sum = 0;
286
287 /*
288 * On input, fix ip_len which has been byte-swapped
289 * at ip_input().
290 */
291 if (!out) {
292 ip->ip_len = htons(ip->ip_len + skip);
293
294 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
295 ip->ip_off = htons(ip->ip_off & IP_DF);
296 else
297 ip->ip_off = 0;
298 } else {
299 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
300 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
301 else
302 ip->ip_off = 0;
303 }
304
305 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
306
307 /* IPv4 option processing */
308 for (off = sizeof(struct ip); off < skip;) {
309 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
310 off + 1 < skip)
311 ;
312 else {
313 DPRINTF(("%s: illegal IPv4 option length for "
314 "option %d\n", __func__, ptr[off]));
315
316 m_freem(m);
317 return EINVAL;
318 }
319
320 switch (ptr[off]) {
321 case IPOPT_EOL:
322 off = skip; /* End the loop. */
323 break;
324
325 case IPOPT_NOP:
326 off++;
327 break;
328
329 case IPOPT_SECURITY: /* 0x82 */
330 case 0x85: /* Extended security. */
331 case 0x86: /* Commercial security. */
332 case 0x94: /* Router alert */
333 case 0x95: /* RFC1770 */
334 /* Sanity check for option length. */
335 if (ptr[off + 1] < 2) {
336 DPRINTF(("%s: illegal IPv4 option "
337 "length for option %d\n",
338 __func__, ptr[off]));
339
340 m_freem(m);
341 return EINVAL;
342 }
343
344 off += ptr[off + 1];
345 break;
346
347 case IPOPT_LSRR:
348 case IPOPT_SSRR:
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 /*
360 * On output, if we have either of the
361 * source routing options, we should
362 * swap the destination address of the
363 * IP header with the last address
364 * specified in the option, as that is
365 * what the destination's IP header
366 * will look like.
367 */
368 if (out)
369 bcopy(ptr + off + ptr[off + 1] -
370 sizeof(struct in_addr),
371 &(ip->ip_dst), sizeof(struct in_addr));
372
373 /* Fall through */
374 default:
375 /* Sanity check for option length. */
376 if (ptr[off + 1] < 2) {
377 DPRINTF(("%s: illegal IPv4 option "
378 "length for option %d\n",
379 __func__, ptr[off]));
380 m_freem(m);
381 return EINVAL;
382 }
383
384 /* Zeroize all other options. */
385 count = ptr[off + 1];
386 bcopy(ipseczeroes, ptr, count);
387 off += count;
388 break;
389 }
390
391 /* Sanity check. */
392 if (off > skip) {
393 DPRINTF(("%s: malformed IPv4 options header\n",
394 __func__));
395
396 m_freem(m);
397 return EINVAL;
398 }
399 }
400
401 break;
402#endif /* INET */
403
404#ifdef INET6
405 case AF_INET6: /* Ugly... */
406 /* Copy and "cook" the IPv6 header. */
407 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
408
409 /* We don't do IPv6 Jumbograms. */
410 if (ip6.ip6_plen == 0) {
411 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
412 m_freem(m);
413 return EMSGSIZE;
414 }
415
416 ip6.ip6_flow = 0;
417 ip6.ip6_hlim = 0;
418 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
419 ip6.ip6_vfc |= IPV6_VERSION;
420
421 /* Scoped address handling. */
422 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
423 ip6.ip6_src.s6_addr16[1] = 0;
424 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
425 ip6.ip6_dst.s6_addr16[1] = 0;
426
427 /* Done with IPv6 header. */
428 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
429
430 /* Let's deal with the remaining headers (if any). */
431 if (skip - sizeof(struct ip6_hdr) > 0) {
432 if (m->m_len <= skip) {
433 ptr = (unsigned char *) malloc(
434 skip - sizeof(struct ip6_hdr),
435 M_XDATA, M_NOWAIT);
436 if (ptr == NULL) {
437 DPRINTF(("%s: failed to allocate memory"
438 "for IPv6 headers\n",__func__));
439 m_freem(m);
440 return ENOBUFS;
441 }
442
443 /*
444 * Copy all the protocol headers after
445 * the IPv6 header.
446 */
447 m_copydata(m, sizeof(struct ip6_hdr),
448 skip - sizeof(struct ip6_hdr), ptr);
449 alloc = 1;
450 } else {
451 /* No need to allocate memory. */
452 ptr = mtod(m, unsigned char *) +
453 sizeof(struct ip6_hdr);
454 alloc = 0;
455 }
456 } else
457 break;
458
459 off = ip6.ip6_nxt & 0xff; /* Next header type. */
460
461 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
462 switch (off) {
463 case IPPROTO_HOPOPTS:
464 case IPPROTO_DSTOPTS:
465 ip6e = (struct ip6_ext *) (ptr + len);
466
467 /*
468 * Process the mutable/immutable
469 * options -- borrows heavily from the
470 * KAME code.
471 */
472 for (count = len + sizeof(struct ip6_ext);
473 count < len + ((ip6e->ip6e_len + 1) << 3);) {
474 if (ptr[count] == IP6OPT_PAD1) {
475 count++;
476 continue; /* Skip padding. */
477 }
478
479 /* Sanity check. */
480 if (count > len +
481 ((ip6e->ip6e_len + 1) << 3)) {
482 m_freem(m);
483
484 /* Free, if we allocated. */
485 if (alloc)
486 free(ptr, M_XDATA);
487 return EINVAL;
488 }
489
490 ad = ptr[count + 1];
491
492 /* If mutable option, zeroize. */
493 if (ptr[count] & IP6OPT_MUTABLE)
494 bcopy(ipseczeroes, ptr + count,
495 ptr[count + 1]);
496
497 count += ad;
498
499 /* Sanity check. */
500 if (count >
501 skip - sizeof(struct ip6_hdr)) {
502 m_freem(m);
503
504 /* Free, if we allocated. */
505 if (alloc)
506 free(ptr, M_XDATA);
507 return EINVAL;
508 }
509 }
510
511 /* Advance. */
512 len += ((ip6e->ip6e_len + 1) << 3);
513 off = ip6e->ip6e_nxt;
514 break;
515
516 case IPPROTO_ROUTING:
517 /*
518 * Always include routing headers in
519 * computation.
520 */
521 ip6e = (struct ip6_ext *) (ptr + len);
522 len += ((ip6e->ip6e_len + 1) << 3);
523 off = ip6e->ip6e_nxt;
524 break;
525
526 default:
527 DPRINTF(("%s: unexpected IPv6 header type %d",
528 __func__, off));
529 if (alloc)
530 free(ptr, M_XDATA);
531 m_freem(m);
532 return EINVAL;
533 }
534
535 /* Copyback and free, if we allocated. */
536 if (alloc) {
537 m_copyback(m, sizeof(struct ip6_hdr),
538 skip - sizeof(struct ip6_hdr), ptr);
539 free(ptr, M_XDATA);
540 }
541
542 break;
543#endif /* INET6 */
544 }
545
546 return 0;
547}
548
549/*
550 * ah_input() gets called to verify that an input packet
551 * passes authentication.
552 */
553static int
554ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
555{
556 struct auth_hash *ahx;
557 struct tdb_ident *tdbi;
558 struct tdb_crypto *tc;
559 struct m_tag *mtag;
560 struct newah *ah;
561 int hl, rplen, authsize;
562
563 struct cryptodesc *crda;
564 struct cryptop *crp;
565
566 IPSEC_ASSERT(sav != NULL, ("null SA"));
567 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
568 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
569 ("null authentication xform"));
570
571 /* Figure out header size. */
572 rplen = HDRSIZE(sav);
573
574 /* XXX don't pullup, just copy header */
575 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
576 if (ah == NULL) {
577 DPRINTF(("ah_input: cannot pullup header\n"));
578 V_ahstat.ahs_hdrops++; /*XXX*/
579 m_freem(m);
580 return ENOBUFS;
581 }
582
583 /* Check replay window, if applicable. */
584 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
585 V_ahstat.ahs_replay++;
586 DPRINTF(("%s: packet replay failure: %s\n", __func__,
587 ipsec_logsastr(sav)));
588 m_freem(m);
589 return ENOBUFS;
590 }
591
592 /* Verify AH header length. */
593 hl = ah->ah_len * sizeof (u_int32_t);
594 ahx = sav->tdb_authalgxform;
595 authsize = AUTHSIZE(sav);
596 if (hl != authsize + rplen - sizeof (struct ah)) {
597 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
598 " for packet in SA %s/%08lx\n", __func__,
599 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
600 ipsec_address(&sav->sah->saidx.dst),
601 (u_long) ntohl(sav->spi)));
602 V_ahstat.ahs_badauthl++;
603 m_freem(m);
604 return EACCES;
605 }
606 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
607
608 /* Get crypto descriptors. */
609 crp = crypto_getreq(1);
610 if (crp == NULL) {
611 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
612 V_ahstat.ahs_crypto++;
613 m_freem(m);
614 return ENOBUFS;
615 }
616
617 crda = crp->crp_desc;
618 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
619
620 crda->crd_skip = 0;
621 crda->crd_len = m->m_pkthdr.len;
622 crda->crd_inject = skip + rplen;
623
624 /* Authentication operation. */
625 crda->crd_alg = ahx->type;
626 crda->crd_klen = _KEYBITS(sav->key_auth);
627 crda->crd_key = sav->key_auth->key_data;
628
629 /* Find out if we've already done crypto. */
630 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
631 mtag != NULL;
632 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
633 tdbi = (struct tdb_ident *) (mtag + 1);
634 if (tdbi->proto == sav->sah->saidx.proto &&
635 tdbi->spi == sav->spi &&
636 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
637 sizeof (union sockaddr_union)))
638 break;
639 }
640
641 /* Allocate IPsec-specific opaque crypto info. */
642 if (mtag == NULL) {
643 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
644 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
645 } else {
646 /* Hash verification has already been done successfully. */
647 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
648 M_XDATA, M_NOWAIT|M_ZERO);
649 }
650 if (tc == NULL) {
651 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
652 V_ahstat.ahs_crypto++;
653 crypto_freereq(crp);
654 m_freem(m);
655 return ENOBUFS;
656 }
657
658 /* Only save information if crypto processing is needed. */
659 if (mtag == NULL) {
660 int error;
661
662 /*
663 * Save the authenticator, the skipped portion of the packet,
664 * and the AH header.
665 */
666 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
667
668 /* Zeroize the authenticator on the packet. */
669 m_copyback(m, skip + rplen, authsize, ipseczeroes);
670
671 /* "Massage" the packet headers for crypto processing. */
672 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
673 skip, ahx->type, 0);
674 if (error != 0) {
675 /* NB: mbuf is free'd by ah_massage_headers */
676 V_ahstat.ahs_hdrops++;
677 free(tc, M_XDATA);
678 crypto_freereq(crp);
679 return error;
680 }
681 }
682
683 /* Crypto operation descriptor. */
684 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
685 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
686 crp->crp_buf = (caddr_t) m;
687 crp->crp_callback = ah_input_cb;
688 crp->crp_sid = sav->tdb_cryptoid;
689 crp->crp_opaque = (caddr_t) tc;
690
691 /* These are passed as-is to the callback. */
692 tc->tc_spi = sav->spi;
693 tc->tc_dst = sav->sah->saidx.dst;
694 tc->tc_proto = sav->sah->saidx.proto;
695 tc->tc_nxt = ah->ah_nxt;
696 tc->tc_protoff = protoff;
697 tc->tc_skip = skip;
698 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
699
700 if (mtag == NULL)
701 return crypto_dispatch(crp);
702 else
703 return ah_input_cb(crp);
704}
705
706#ifdef INET6
707#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
708 if (saidx->dst.sa.sa_family == AF_INET6) { \
709 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
710 } else { \
711 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
712 } \
713} while (0)
714#else
715#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
716 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
717#endif
718
719/*
720 * AH input callback from the crypto driver.
721 */
722static int
723ah_input_cb(struct cryptop *crp)
724{
725 int rplen, error, skip, protoff;
726 unsigned char calc[AH_ALEN_MAX];
727 struct mbuf *m;
728 struct cryptodesc *crd;
729 struct auth_hash *ahx;
730 struct tdb_crypto *tc;
731 struct m_tag *mtag;
732 struct secasvar *sav;
733 struct secasindex *saidx;
734 u_int8_t nxt;
735 caddr_t ptr;
736 int authsize;
737
738 crd = crp->crp_desc;
739
740 tc = (struct tdb_crypto *) crp->crp_opaque;
741 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
742 skip = tc->tc_skip;
743 nxt = tc->tc_nxt;
744 protoff = tc->tc_protoff;
745 mtag = (struct m_tag *) tc->tc_ptr;
746 m = (struct mbuf *) crp->crp_buf;
747
748 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
749 if (sav == NULL) {
750 V_ahstat.ahs_notdb++;
751 DPRINTF(("%s: SA expired while in crypto\n", __func__));
752 error = ENOBUFS; /*XXX*/
753 goto bad;
754 }
755
756 saidx = &sav->sah->saidx;
757 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
758 saidx->dst.sa.sa_family == AF_INET6,
759 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
760
761 ahx = (struct auth_hash *) sav->tdb_authalgxform;
762
763 /* Check for crypto errors. */
764 if (crp->crp_etype) {
765 if (sav->tdb_cryptoid != 0)
766 sav->tdb_cryptoid = crp->crp_sid;
767
768 if (crp->crp_etype == EAGAIN) {
769 error = crypto_dispatch(crp);
770 return error;
771 }
772
773 V_ahstat.ahs_noxform++;
774 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
775 error = crp->crp_etype;
776 goto bad;
777 } else {
778 V_ahstat.ahs_hist[sav->alg_auth]++;
779 crypto_freereq(crp); /* No longer needed. */
780 crp = NULL;
781 }
782
783 /* Shouldn't happen... */
784 if (m == NULL) {
785 V_ahstat.ahs_crypto++;
786 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
787 error = EINVAL;
788 goto bad;
789 }
790
791 /* Figure out header size. */
792 rplen = HDRSIZE(sav);
793 authsize = AUTHSIZE(sav);
794
795 /* Copy authenticator off the packet. */
796 m_copydata(m, skip + rplen, authsize, calc);
797
798 /*
799 * If we have an mtag, we don't need to verify the authenticator --
800 * it has been verified by an IPsec-aware NIC.
801 */
802 if (mtag == NULL) {
803 ptr = (caddr_t) (tc + 1);
804
805 /* Verify authenticator. */
806 if (bcmp(ptr + skip + rplen, calc, authsize)) {
807 DPRINTF(("%s: authentication hash mismatch for packet "
808 "in SA %s/%08lx\n", __func__,
809 ipsec_address(&saidx->dst),
810 (u_long) ntohl(sav->spi)));
811 V_ahstat.ahs_badauth++;
812 error = EACCES;
813 goto bad;
814 }
815
816 /* Fix the Next Protocol field. */
817 ((u_int8_t *) ptr)[protoff] = nxt;
818
819 /* Copyback the saved (uncooked) network headers. */
820 m_copyback(m, 0, skip, ptr);
821 } else {
822 /* Fix the Next Protocol field. */
823 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
824 }
825
826 free(tc, M_XDATA), tc = NULL; /* No longer needed */
827
828 /*
829 * Header is now authenticated.
830 */
831 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
832
833 /*
834 * Update replay sequence number, if appropriate.
835 */
836 if (sav->replay) {
837 u_int32_t seq;
838
839 m_copydata(m, skip + offsetof(struct newah, ah_seq),
840 sizeof (seq), (caddr_t) &seq);
841 if (ipsec_updatereplay(ntohl(seq), sav)) {
842 V_ahstat.ahs_replay++;
843 error = ENOBUFS; /*XXX as above*/
844 goto bad;
845 }
846 }
847
848 /*
849 * Remove the AH header and authenticator from the mbuf.
850 */
851 error = m_striphdr(m, skip, rplen + authsize);
852 if (error) {
853 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
854 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
855
856 V_ahstat.ahs_hdrops++;
857 goto bad;
858 }
859
860 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
861
862 KEY_FREESAV(&sav);
863 return error;
864bad:
865 if (sav)
866 KEY_FREESAV(&sav);
867 if (m != NULL)
868 m_freem(m);
869 if (tc != NULL)
870 free(tc, M_XDATA);
871 if (crp != NULL)
872 crypto_freereq(crp);
873 return error;
874}
875
876/*
877 * AH output routine, called by ipsec[46]_process_packet().
878 */
879static int
880ah_output(
881 struct mbuf *m,
882 struct ipsecrequest *isr,
883 struct mbuf **mp,
884 int skip,
885 int protoff)
886{
887 struct secasvar *sav;
888 struct auth_hash *ahx;
889 struct cryptodesc *crda;
890 struct tdb_crypto *tc;
891 struct mbuf *mi;
892 struct cryptop *crp;
893 u_int16_t iplen;
894 int error, rplen, authsize, maxpacketsize, roff;
895 u_int8_t prot;
896 struct newah *ah;
897
898 sav = isr->sav;
899 IPSEC_ASSERT(sav != NULL, ("null SA"));
900 ahx = sav->tdb_authalgxform;
901 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
902
903 V_ahstat.ahs_output++;
904
905 /* Figure out header size. */
906 rplen = HDRSIZE(sav);
907
908 /* Check for maximum packet size violations. */
909 switch (sav->sah->saidx.dst.sa.sa_family) {
910#ifdef INET
911 case AF_INET:
912 maxpacketsize = IP_MAXPACKET;
913 break;
914#endif /* INET */
915#ifdef INET6
916 case AF_INET6:
917 maxpacketsize = IPV6_MAXPACKET;
918 break;
919#endif /* INET6 */
920 default:
921 DPRINTF(("%s: unknown/unsupported protocol family %u, "
922 "SA %s/%08lx\n", __func__,
923 sav->sah->saidx.dst.sa.sa_family,
924 ipsec_address(&sav->sah->saidx.dst),
925 (u_long) ntohl(sav->spi)));
926 V_ahstat.ahs_nopf++;
927 error = EPFNOSUPPORT;
928 goto bad;
929 }
930 authsize = AUTHSIZE(sav);
931 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
932 DPRINTF(("%s: packet in SA %s/%08lx got too big "
933 "(len %u, max len %u)\n", __func__,
934 ipsec_address(&sav->sah->saidx.dst),
935 (u_long) ntohl(sav->spi),
936 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
937 V_ahstat.ahs_toobig++;
938 error = EMSGSIZE;
939 goto bad;
940 }
941
942 /* Update the counters. */
943 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
944
945 m = m_unshare(m, M_NOWAIT);
946 if (m == NULL) {
947 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
948 ipsec_address(&sav->sah->saidx.dst),
949 (u_long) ntohl(sav->spi)));
950 V_ahstat.ahs_hdrops++;
951 error = ENOBUFS;
952 goto bad;
953 }
954
955 /* Inject AH header. */
956 mi = m_makespace(m, skip, rplen + authsize, &roff);
957 if (mi == NULL) {
958 DPRINTF(("%s: failed to inject %u byte AH header for SA "
959 "%s/%08lx\n", __func__,
960 rplen + authsize,
961 ipsec_address(&sav->sah->saidx.dst),
962 (u_long) ntohl(sav->spi)));
963 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */
964 error = ENOBUFS;
965 goto bad;
966 }
967
968 /*
969 * The AH header is guaranteed by m_makespace() to be in
970 * contiguous memory, at roff bytes offset into the returned mbuf.
971 */
972 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
973
974 /* Initialize the AH header. */
975 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
976 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
977 ah->ah_reserve = 0;
978 ah->ah_spi = sav->spi;
979
980 /* Zeroize authenticator. */
981 m_copyback(m, skip + rplen, authsize, ipseczeroes);
982
983 /* Insert packet replay counter, as requested. */
984 if (sav->replay) {
985 if (sav->replay->count == ~0 &&
986 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
987 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
988 __func__,
989 ipsec_address(&sav->sah->saidx.dst),
990 (u_long) ntohl(sav->spi)));
991 V_ahstat.ahs_wrap++;
992 error = EINVAL;
993 goto bad;
994 }
995#ifdef REGRESSION
996 /* Emulate replay attack when ipsec_replay is TRUE. */
997 if (!V_ipsec_replay)
998#endif
999 sav->replay->count++;
1000 ah->ah_seq = htonl(sav->replay->count);
1001 }
1002
1003 /* Get crypto descriptors. */
1004 crp = crypto_getreq(1);
1005 if (crp == NULL) {
1006 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1007 __func__));
1008 V_ahstat.ahs_crypto++;
1009 error = ENOBUFS;
1010 goto bad;
1011 }
1012
1013 crda = crp->crp_desc;
1014
1015 crda->crd_skip = 0;
1016 crda->crd_inject = skip + rplen;
1017 crda->crd_len = m->m_pkthdr.len;
1018
1019 /* Authentication operation. */
1020 crda->crd_alg = ahx->type;
1021 crda->crd_key = sav->key_auth->key_data;
1022 crda->crd_klen = _KEYBITS(sav->key_auth);
1023
1024 /* Allocate IPsec-specific opaque crypto info. */
1025 tc = (struct tdb_crypto *) malloc(
1026 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1027 if (tc == NULL) {
1028 crypto_freereq(crp);
1029 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1030 V_ahstat.ahs_crypto++;
1031 error = ENOBUFS;
1032 goto bad;
1033 }
1034
1035 /* Save the skipped portion of the packet. */
1036 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1037
1038 /*
1039 * Fix IP header length on the header used for
1040 * authentication. We don't need to fix the original
1041 * header length as it will be fixed by our caller.
1042 */
1043 switch (sav->sah->saidx.dst.sa.sa_family) {
1044#ifdef INET
1045 case AF_INET:
1046 bcopy(((caddr_t)(tc + 1)) +
1047 offsetof(struct ip, ip_len),
1048 (caddr_t) &iplen, sizeof(u_int16_t));
1049 iplen = htons(ntohs(iplen) + rplen + authsize);
1050 m_copyback(m, offsetof(struct ip, ip_len),
1051 sizeof(u_int16_t), (caddr_t) &iplen);
1052 break;
1053#endif /* INET */
1054
1055#ifdef INET6
1056 case AF_INET6:
1057 bcopy(((caddr_t)(tc + 1)) +
1058 offsetof(struct ip6_hdr, ip6_plen),
1059 (caddr_t) &iplen, sizeof(u_int16_t));
1060 iplen = htons(ntohs(iplen) + rplen + authsize);
1061 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1062 sizeof(u_int16_t), (caddr_t) &iplen);
1063 break;
1064#endif /* INET6 */
1065 }
1066
1067 /* Fix the Next Header field in saved header. */
1068 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1069
1070 /* Update the Next Protocol field in the IP header. */
1071 prot = IPPROTO_AH;
1072 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1073
1074 /* "Massage" the packet headers for crypto processing. */
1075 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1076 skip, ahx->type, 1);
1077 if (error != 0) {
1078 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1079 free(tc, M_XDATA);
1080 crypto_freereq(crp);
1081 goto bad;
1082 }
1083
1084 /* Crypto operation descriptor. */
1085 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1086 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1087 crp->crp_buf = (caddr_t) m;
1088 crp->crp_callback = ah_output_cb;
1089 crp->crp_sid = sav->tdb_cryptoid;
1090 crp->crp_opaque = (caddr_t) tc;
1091
1092 /* These are passed as-is to the callback. */
1093 tc->tc_isr = isr;
1094 tc->tc_spi = sav->spi;
1095 tc->tc_dst = sav->sah->saidx.dst;
1096 tc->tc_proto = sav->sah->saidx.proto;
1097 tc->tc_skip = skip;
1098 tc->tc_protoff = protoff;
1099
1100 return crypto_dispatch(crp);
1101bad:
1102 if (m)
1103 m_freem(m);
1104 return (error);
1105}
1106
1107/*
1108 * AH output callback from the crypto driver.
1109 */
1110static int
1111ah_output_cb(struct cryptop *crp)
1112{
1113 int skip, protoff, error;
1114 struct tdb_crypto *tc;
1115 struct ipsecrequest *isr;
1116 struct secasvar *sav;
1117 struct mbuf *m;
1118 caddr_t ptr;
1119 int err;
1120
1121 tc = (struct tdb_crypto *) crp->crp_opaque;
1122 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1123 skip = tc->tc_skip;
1124 protoff = tc->tc_protoff;
1125 ptr = (caddr_t) (tc + 1);
1126 m = (struct mbuf *) crp->crp_buf;
1127
1128 isr = tc->tc_isr;
1129 IPSECREQUEST_LOCK(isr);
1130 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1131 if (sav == NULL) {
1132 V_ahstat.ahs_notdb++;
1133 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1134 error = ENOBUFS; /*XXX*/
1135 goto bad;
1136 }
1137 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1138
1139 /* Check for crypto errors. */
1140 if (crp->crp_etype) {
1141 if (sav->tdb_cryptoid != 0)
1142 sav->tdb_cryptoid = crp->crp_sid;
1143
1144 if (crp->crp_etype == EAGAIN) {
1145 KEY_FREESAV(&sav);
1146 IPSECREQUEST_UNLOCK(isr);
1147 error = crypto_dispatch(crp);
1148 return error;
1149 }
1150
1151 V_ahstat.ahs_noxform++;
1152 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1153 error = crp->crp_etype;
1154 goto bad;
1155 }
1156
1157 /* Shouldn't happen... */
1158 if (m == NULL) {
1159 V_ahstat.ahs_crypto++;
1160 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1161 error = EINVAL;
1162 goto bad;
1163 }
1164 V_ahstat.ahs_hist[sav->alg_auth]++;
1165
1166 /*
1167 * Copy original headers (with the new protocol number) back
1168 * in place.
1169 */
1170 m_copyback(m, 0, skip, ptr);
1171
1172 /* No longer needed. */
1173 free(tc, M_XDATA);
1174 crypto_freereq(crp);
1175
1176#ifdef REGRESSION
1177 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1178 if (V_ipsec_integrity) {
1179 int alen;
1180
1181 /*
1182 * Corrupt HMAC if we want to test integrity verification of
1183 * the other side.
1184 */
1185 alen = AUTHSIZE(sav);
1186 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1187 }
1188#endif
1189
1190 /* NB: m is reclaimed by ipsec_process_done. */
1191 err = ipsec_process_done(m, isr);
1192 KEY_FREESAV(&sav);
1193 IPSECREQUEST_UNLOCK(isr);
1194 return err;
1195bad:
1196 if (sav)
1197 KEY_FREESAV(&sav);
1198 IPSECREQUEST_UNLOCK(isr);
1199 if (m)
1200 m_freem(m);
1201 free(tc, M_XDATA);
1202 crypto_freereq(crp);
1203 return error;
1204}
1205
1206static struct xformsw ah_xformsw = {
1207 XF_AH, XFT_AUTH, "IPsec AH",
1208 ah_init, ah_zeroize, ah_input, ah_output,
1209};
1210
1211static void
1212ah_attach(void)
1213{
1214
1215 xform_register(&ah_xformsw);
1216}
1217
1218SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);