1 /* $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.19 2008/10/23 15:53:51 des Exp $ */
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
76 /*
77 * Return header size in bytes. The old protocol did not support
78 * the replay counter; the new protocol always includes the counter.
79 */
80 #define HDRSIZE(sav) \
81 (((sav)->flags & SADB_X_EXT_OLD) ? \
82 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
83 /*
84 * Return authenticator size in bytes. The old protocol is known
85 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
86 * authenticator.
87 */
88 #define AUTHSIZE(sav) \
89 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
90
91 int ah_enable = 1; /* control flow of packets with AH */
92 int ah_cleartos = 1; /* clear ip_tos when doing AH calc */
93 struct ahstat ahstat;
94
95 SYSCTL_DECL(_net_inet_ah);
96 SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
97 ah_enable, CTLFLAG_RW, ah_enable, 0, "");
98 SYSCTL_V_INT(V_NET, vnet_ipsec, _net_inet_ah, OID_AUTO,
99 ah_cleartos, CTLFLAG_RW, ah_cleartos, 0, "");
100 SYSCTL_V_STRUCT(V_NET, vnet_ipsec, _net_inet_ah, IPSECCTL_STATS,
101 stats, CTLFLAG_RD, ahstat, ahstat, "");
102
103 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
104
105 static int ah_input_cb(struct cryptop*);
106 static int ah_output_cb(struct cryptop*);
107
108 /*
109 * NB: this is public for use by the PF_KEY support.
110 */
111 struct auth_hash *
112 ah_algorithm_lookup(int alg)
113 {
114 if (alg > SADB_AALG_MAX)
115 return NULL;
116 switch (alg) {
117 case SADB_X_AALG_NULL:
118 return &auth_hash_null;
119 case SADB_AALG_MD5HMAC:
120 return &auth_hash_hmac_md5;
121 case SADB_AALG_SHA1HMAC:
122 return &auth_hash_hmac_sha1;
123 case SADB_X_AALG_RIPEMD160HMAC:
124 return &auth_hash_hmac_ripemd_160;
125 case SADB_X_AALG_MD5:
126 return &auth_hash_key_md5;
127 case SADB_X_AALG_SHA:
128 return &auth_hash_key_sha1;
129 case SADB_X_AALG_SHA2_256:
130 return &auth_hash_hmac_sha2_256;
131 case SADB_X_AALG_SHA2_384:
132 return &auth_hash_hmac_sha2_384;
133 case SADB_X_AALG_SHA2_512:
134 return &auth_hash_hmac_sha2_512;
135 }
136 return NULL;
137 }
138
139 size_t
140 ah_hdrsiz(struct secasvar *sav)
141 {
142 size_t size;
143
144 if (sav != NULL) {
145 int authsize;
146 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
147 /*XXX not right for null algorithm--does it matter??*/
148 authsize = AUTHSIZE(sav);
149 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
150 } else {
151 /* default guess */
152 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
153 }
154 return size;
155 }
156
157 /*
158 * NB: public for use by esp_init.
159 */
160 int
161 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
162 {
163 INIT_VNET_IPSEC(curvnet);
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 */
215 static int
216 ah_init(struct secasvar *sav, struct xformsw *xsp)
217 {
218 INIT_VNET_IPSEC(curvnet);
219 struct cryptoini cria;
220 int error;
221
222 error = ah_init0(sav, xsp, &cria);
223 return error ? error :
224 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
225 }
226
227 /*
228 * Paranoia.
229 *
230 * NB: public for use by esp_zeroize (XXX).
231 */
232 int
233 ah_zeroize(struct secasvar *sav)
234 {
235 int err;
236
237 if (sav->key_auth)
238 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
239
240 err = crypto_freesession(sav->tdb_cryptoid);
241 sav->tdb_cryptoid = 0;
242 sav->tdb_authalgxform = NULL;
243 sav->tdb_xform = NULL;
244 return err;
245 }
246
247 /*
248 * Massage IPv4/IPv6 headers for AH processing.
249 */
250 static int
251 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
252 {
253 INIT_VNET_IPSEC(curvnet);
254 struct mbuf *m = *m0;
255 unsigned char *ptr;
256 int off, count;
257
258 #ifdef INET
259 struct ip *ip;
260 #endif /* INET */
261
262 #ifdef INET6
263 struct ip6_ext *ip6e;
264 struct ip6_hdr ip6;
265 int alloc, len, ad;
266 #endif /* INET6 */
267
268 switch (proto) {
269 #ifdef INET
270 case AF_INET:
271 /*
272 * This is the least painful way of dealing with IPv4 header
273 * and option processing -- just make sure they're in
274 * contiguous memory.
275 */
276 *m0 = m = m_pullup(m, skip);
277 if (m == NULL) {
278 DPRINTF(("%s: m_pullup failed\n", __func__));
279 return ENOBUFS;
280 }
281
282 /* Fix the IP header */
283 ip = mtod(m, struct ip *);
284 if (V_ah_cleartos)
285 ip->ip_tos = 0;
286 ip->ip_ttl = 0;
287 ip->ip_sum = 0;
288
289 /*
290 * On input, fix ip_len which has been byte-swapped
291 * at ip_input().
292 */
293 if (!out) {
294 ip->ip_len = htons(ip->ip_len + skip);
295
296 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
297 ip->ip_off = htons(ip->ip_off & IP_DF);
298 else
299 ip->ip_off = 0;
300 } else {
301 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
302 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
303 else
304 ip->ip_off = 0;
305 }
306
307 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
308
309 /* IPv4 option processing */
310 for (off = sizeof(struct ip); off < skip;) {
311 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
312 off + 1 < skip)
313 ;
314 else {
315 DPRINTF(("%s: illegal IPv4 option length for "
316 "option %d\n", __func__, ptr[off]));
317
318 m_freem(m);
319 return EINVAL;
320 }
321
322 switch (ptr[off]) {
323 case IPOPT_EOL:
324 off = skip; /* End the loop. */
325 break;
326
327 case IPOPT_NOP:
328 off++;
329 break;
330
331 case IPOPT_SECURITY: /* 0x82 */
332 case 0x85: /* Extended security. */
333 case 0x86: /* Commercial security. */
334 case 0x94: /* Router alert */
335 case 0x95: /* RFC1770 */
336 /* Sanity check for option length. */
337 if (ptr[off + 1] < 2) {
338 DPRINTF(("%s: illegal IPv4 option "
339 "length for option %d\n",
340 __func__, ptr[off]));
341
342 m_freem(m);
343 return EINVAL;
344 }
345
346 off += ptr[off + 1];
347 break;
348
349 case IPOPT_LSRR:
350 case IPOPT_SSRR:
351 /* Sanity check for option length. */
352 if (ptr[off + 1] < 2) {
353 DPRINTF(("%s: illegal IPv4 option "
354 "length for option %d\n",
355 __func__, ptr[off]));
356
357 m_freem(m);
358 return EINVAL;
359 }
360
361 /*
362 * On output, if we have either of the
363 * source routing options, we should
364 * swap the destination address of the
365 * IP header with the last address
366 * specified in the option, as that is
367 * what the destination's IP header
368 * will look like.
369 */
370 if (out)
371 bcopy(ptr + off + ptr[off + 1] -
372 sizeof(struct in_addr),
373 &(ip->ip_dst), sizeof(struct in_addr));
374
375 /* Fall through */
376 default:
377 /* Sanity check for option length. */
378 if (ptr[off + 1] < 2) {
379 DPRINTF(("%s: illegal IPv4 option "
380 "length for option %d\n",
381 __func__, ptr[off]));
382 m_freem(m);
383 return EINVAL;
384 }
385
386 /* Zeroize all other options. */
387 count = ptr[off + 1];
388 bcopy(ipseczeroes, ptr, count);
389 off += count;
390 break;
391 }
392
393 /* Sanity check. */
394 if (off > skip) {
395 DPRINTF(("%s: malformed IPv4 options header\n",
396 __func__));
397
398 m_freem(m);
399 return EINVAL;
400 }
401 }
402
403 break;
404 #endif /* INET */
405
406 #ifdef INET6
407 case AF_INET6: /* Ugly... */
408 /* Copy and "cook" the IPv6 header. */
409 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
410
411 /* We don't do IPv6 Jumbograms. */
412 if (ip6.ip6_plen == 0) {
413 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
414 m_freem(m);
415 return EMSGSIZE;
416 }
417
418 ip6.ip6_flow = 0;
419 ip6.ip6_hlim = 0;
420 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
421 ip6.ip6_vfc |= IPV6_VERSION;
422
423 /* Scoped address handling. */
424 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
425 ip6.ip6_src.s6_addr16[1] = 0;
426 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
427 ip6.ip6_dst.s6_addr16[1] = 0;
428
429 /* Done with IPv6 header. */
430 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
431
432 /* Let's deal with the remaining headers (if any). */
433 if (skip - sizeof(struct ip6_hdr) > 0) {
434 if (m->m_len <= skip) {
435 ptr = (unsigned char *) malloc(
436 skip - sizeof(struct ip6_hdr),
437 M_XDATA, M_NOWAIT);
438 if (ptr == NULL) {
439 DPRINTF(("%s: failed to allocate memory"
440 "for IPv6 headers\n",__func__));
441 m_freem(m);
442 return ENOBUFS;
443 }
444
445 /*
446 * Copy all the protocol headers after
447 * the IPv6 header.
448 */
449 m_copydata(m, sizeof(struct ip6_hdr),
450 skip - sizeof(struct ip6_hdr), ptr);
451 alloc = 1;
452 } else {
453 /* No need to allocate memory. */
454 ptr = mtod(m, unsigned char *) +
455 sizeof(struct ip6_hdr);
456 alloc = 0;
457 }
458 } else
459 break;
460
461 off = ip6.ip6_nxt & 0xff; /* Next header type. */
462
463 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
464 switch (off) {
465 case IPPROTO_HOPOPTS:
466 case IPPROTO_DSTOPTS:
467 ip6e = (struct ip6_ext *) (ptr + len);
468
469 /*
470 * Process the mutable/immutable
471 * options -- borrows heavily from the
472 * KAME code.
473 */
474 for (count = len + sizeof(struct ip6_ext);
475 count < len + ((ip6e->ip6e_len + 1) << 3);) {
476 if (ptr[count] == IP6OPT_PAD1) {
477 count++;
478 continue; /* Skip padding. */
479 }
480
481 /* Sanity check. */
482 if (count > len +
483 ((ip6e->ip6e_len + 1) << 3)) {
484 m_freem(m);
485
486 /* Free, if we allocated. */
487 if (alloc)
488 free(ptr, M_XDATA);
489 return EINVAL;
490 }
491
492 ad = ptr[count + 1];
493
494 /* If mutable option, zeroize. */
495 if (ptr[count] & IP6OPT_MUTABLE)
496 bcopy(ipseczeroes, ptr + count,
497 ptr[count + 1]);
498
499 count += ad;
500
501 /* Sanity check. */
502 if (count >
503 skip - sizeof(struct ip6_hdr)) {
504 m_freem(m);
505
506 /* Free, if we allocated. */
507 if (alloc)
508 free(ptr, M_XDATA);
509 return EINVAL;
510 }
511 }
512
513 /* Advance. */
514 len += ((ip6e->ip6e_len + 1) << 3);
515 off = ip6e->ip6e_nxt;
516 break;
517
518 case IPPROTO_ROUTING:
519 /*
520 * Always include routing headers in
521 * computation.
522 */
523 ip6e = (struct ip6_ext *) (ptr + len);
524 len += ((ip6e->ip6e_len + 1) << 3);
525 off = ip6e->ip6e_nxt;
526 break;
527
528 default:
529 DPRINTF(("%s: unexpected IPv6 header type %d",
530 __func__, off));
531 if (alloc)
532 free(ptr, M_XDATA);
533 m_freem(m);
534 return EINVAL;
535 }
536
537 /* Copyback and free, if we allocated. */
538 if (alloc) {
539 m_copyback(m, sizeof(struct ip6_hdr),
540 skip - sizeof(struct ip6_hdr), ptr);
541 free(ptr, M_XDATA);
542 }
543
544 break;
545 #endif /* INET6 */
546 }
547
548 return 0;
549 }
550
551 /*
552 * ah_input() gets called to verify that an input packet
553 * passes authentication.
554 */
555 static int
556 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
557 {
558 INIT_VNET_IPSEC(curvnet);
559 struct auth_hash *ahx;
560 struct tdb_ident *tdbi;
561 struct tdb_crypto *tc;
562 struct m_tag *mtag;
563 struct newah *ah;
564 int hl, rplen, authsize;
565
566 struct cryptodesc *crda;
567 struct cryptop *crp;
568
569 IPSEC_ASSERT(sav != NULL, ("null SA"));
570 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
571 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
572 ("null authentication xform"));
573
574 /* Figure out header size. */
575 rplen = HDRSIZE(sav);
576
577 /* XXX don't pullup, just copy header */
578 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
579 if (ah == NULL) {
580 DPRINTF(("ah_input: cannot pullup header\n"));
581 V_ahstat.ahs_hdrops++; /*XXX*/
582 m_freem(m);
583 return ENOBUFS;
584 }
585
586 /* Check replay window, if applicable. */
587 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
588 V_ahstat.ahs_replay++;
589 DPRINTF(("%s: packet replay failure: %s\n", __func__,
590 ipsec_logsastr(sav)));
591 m_freem(m);
592 return ENOBUFS;
593 }
594
595 /* Verify AH header length. */
596 hl = ah->ah_len * sizeof (u_int32_t);
597 ahx = sav->tdb_authalgxform;
598 authsize = AUTHSIZE(sav);
599 if (hl != authsize + rplen - sizeof (struct ah)) {
600 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
601 " for packet in SA %s/%08lx\n", __func__,
602 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
603 ipsec_address(&sav->sah->saidx.dst),
604 (u_long) ntohl(sav->spi)));
605 V_ahstat.ahs_badauthl++;
606 m_freem(m);
607 return EACCES;
608 }
609 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
610
611 /* Get crypto descriptors. */
612 crp = crypto_getreq(1);
613 if (crp == NULL) {
614 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
615 V_ahstat.ahs_crypto++;
616 m_freem(m);
617 return ENOBUFS;
618 }
619
620 crda = crp->crp_desc;
621 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
622
623 crda->crd_skip = 0;
624 crda->crd_len = m->m_pkthdr.len;
625 crda->crd_inject = skip + rplen;
626
627 /* Authentication operation. */
628 crda->crd_alg = ahx->type;
629 crda->crd_klen = _KEYBITS(sav->key_auth);
630 crda->crd_key = sav->key_auth->key_data;
631
632 /* Find out if we've already done crypto. */
633 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
634 mtag != NULL;
635 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
636 tdbi = (struct tdb_ident *) (mtag + 1);
637 if (tdbi->proto == sav->sah->saidx.proto &&
638 tdbi->spi == sav->spi &&
639 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
640 sizeof (union sockaddr_union)))
641 break;
642 }
643
644 /* Allocate IPsec-specific opaque crypto info. */
645 if (mtag == NULL) {
646 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
647 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
648 } else {
649 /* Hash verification has already been done successfully. */
650 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
651 M_XDATA, M_NOWAIT|M_ZERO);
652 }
653 if (tc == NULL) {
654 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
655 V_ahstat.ahs_crypto++;
656 crypto_freereq(crp);
657 m_freem(m);
658 return ENOBUFS;
659 }
660
661 /* Only save information if crypto processing is needed. */
662 if (mtag == NULL) {
663 int error;
664
665 /*
666 * Save the authenticator, the skipped portion of the packet,
667 * and the AH header.
668 */
669 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
670
671 /* Zeroize the authenticator on the packet. */
672 m_copyback(m, skip + rplen, authsize, ipseczeroes);
673
674 /* "Massage" the packet headers for crypto processing. */
675 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
676 skip, ahx->type, 0);
677 if (error != 0) {
678 /* NB: mbuf is free'd by ah_massage_headers */
679 V_ahstat.ahs_hdrops++;
680 free(tc, M_XDATA);
681 crypto_freereq(crp);
682 return error;
683 }
684 }
685
686 /* Crypto operation descriptor. */
687 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
688 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
689 crp->crp_buf = (caddr_t) m;
690 crp->crp_callback = ah_input_cb;
691 crp->crp_sid = sav->tdb_cryptoid;
692 crp->crp_opaque = (caddr_t) tc;
693
694 /* These are passed as-is to the callback. */
695 tc->tc_spi = sav->spi;
696 tc->tc_dst = sav->sah->saidx.dst;
697 tc->tc_proto = sav->sah->saidx.proto;
698 tc->tc_nxt = ah->ah_nxt;
699 tc->tc_protoff = protoff;
700 tc->tc_skip = skip;
701 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
702
703 if (mtag == NULL)
704 return crypto_dispatch(crp);
705 else
706 return ah_input_cb(crp);
707 }
708
709 #ifdef INET6
710 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
711 if (saidx->dst.sa.sa_family == AF_INET6) { \
712 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
713 } else { \
714 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
715 } \
716 } while (0)
717 #else
718 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
719 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
720 #endif
721
722 /*
723 * AH input callback from the crypto driver.
724 */
725 static int
726 ah_input_cb(struct cryptop *crp)
727 {
728 INIT_VNET_IPSEC(curvnet);
729 int rplen, error, skip, protoff;
730 unsigned char calc[AH_ALEN_MAX];
731 struct mbuf *m;
732 struct cryptodesc *crd;
733 struct auth_hash *ahx;
734 struct tdb_crypto *tc;
735 struct m_tag *mtag;
736 struct secasvar *sav;
737 struct secasindex *saidx;
738 u_int8_t nxt;
739 caddr_t ptr;
740 int authsize;
741
742 crd = crp->crp_desc;
743
744 tc = (struct tdb_crypto *) crp->crp_opaque;
745 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
746 skip = tc->tc_skip;
747 nxt = tc->tc_nxt;
748 protoff = tc->tc_protoff;
749 mtag = (struct m_tag *) tc->tc_ptr;
750 m = (struct mbuf *) crp->crp_buf;
751
752 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
753 if (sav == NULL) {
754 V_ahstat.ahs_notdb++;
755 DPRINTF(("%s: SA expired while in crypto\n", __func__));
756 error = ENOBUFS; /*XXX*/
757 goto bad;
758 }
759
760 saidx = &sav->sah->saidx;
761 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
762 saidx->dst.sa.sa_family == AF_INET6,
763 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
764
765 ahx = (struct auth_hash *) sav->tdb_authalgxform;
766
767 /* Check for crypto errors. */
768 if (crp->crp_etype) {
769 if (sav->tdb_cryptoid != 0)
770 sav->tdb_cryptoid = crp->crp_sid;
771
772 if (crp->crp_etype == EAGAIN) {
773 error = crypto_dispatch(crp);
774 return error;
775 }
776
777 V_ahstat.ahs_noxform++;
778 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
779 error = crp->crp_etype;
780 goto bad;
781 } else {
782 V_ahstat.ahs_hist[sav->alg_auth]++;
783 crypto_freereq(crp); /* No longer needed. */
784 crp = NULL;
785 }
786
787 /* Shouldn't happen... */
788 if (m == NULL) {
789 V_ahstat.ahs_crypto++;
790 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
791 error = EINVAL;
792 goto bad;
793 }
794
795 /* Figure out header size. */
796 rplen = HDRSIZE(sav);
797 authsize = AUTHSIZE(sav);
798
799 /* Copy authenticator off the packet. */
800 m_copydata(m, skip + rplen, authsize, calc);
801
802 /*
803 * If we have an mtag, we don't need to verify the authenticator --
804 * it has been verified by an IPsec-aware NIC.
805 */
806 if (mtag == NULL) {
807 ptr = (caddr_t) (tc + 1);
808
809 /* Verify authenticator. */
810 if (bcmp(ptr + skip + rplen, calc, authsize)) {
811 DPRINTF(("%s: authentication hash mismatch for packet "
812 "in SA %s/%08lx\n", __func__,
813 ipsec_address(&saidx->dst),
814 (u_long) ntohl(sav->spi)));
815 V_ahstat.ahs_badauth++;
816 error = EACCES;
817 goto bad;
818 }
819
820 /* Fix the Next Protocol field. */
821 ((u_int8_t *) ptr)[protoff] = nxt;
822
823 /* Copyback the saved (uncooked) network headers. */
824 m_copyback(m, 0, skip, ptr);
825 } else {
826 /* Fix the Next Protocol field. */
827 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
828 }
829
830 free(tc, M_XDATA), tc = NULL; /* No longer needed */
831
832 /*
833 * Header is now authenticated.
834 */
835 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
836
837 /*
838 * Update replay sequence number, if appropriate.
839 */
840 if (sav->replay) {
841 u_int32_t seq;
842
843 m_copydata(m, skip + offsetof(struct newah, ah_seq),
844 sizeof (seq), (caddr_t) &seq);
845 if (ipsec_updatereplay(ntohl(seq), sav)) {
846 V_ahstat.ahs_replay++;
847 error = ENOBUFS; /*XXX as above*/
848 goto bad;
849 }
850 }
851
852 /*
853 * Remove the AH header and authenticator from the mbuf.
854 */
855 error = m_striphdr(m, skip, rplen + authsize);
856 if (error) {
857 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
858 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
859
860 V_ahstat.ahs_hdrops++;
861 goto bad;
862 }
863
864 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
865
866 KEY_FREESAV(&sav);
867 return error;
868 bad:
869 if (sav)
870 KEY_FREESAV(&sav);
871 if (m != NULL)
872 m_freem(m);
873 if (tc != NULL)
874 free(tc, M_XDATA);
875 if (crp != NULL)
876 crypto_freereq(crp);
877 return error;
878 }
879
880 /*
881 * AH output routine, called by ipsec[46]_process_packet().
882 */
883 static int
884 ah_output(
885 struct mbuf *m,
886 struct ipsecrequest *isr,
887 struct mbuf **mp,
888 int skip,
889 int protoff)
890 {
891 INIT_VNET_IPSEC(curvnet);
892 struct secasvar *sav;
893 struct auth_hash *ahx;
894 struct cryptodesc *crda;
895 struct tdb_crypto *tc;
896 struct mbuf *mi;
897 struct cryptop *crp;
898 u_int16_t iplen;
899 int error, rplen, authsize, maxpacketsize, roff;
900 u_int8_t prot;
901 struct newah *ah;
902
903 sav = isr->sav;
904 IPSEC_ASSERT(sav != NULL, ("null SA"));
905 ahx = sav->tdb_authalgxform;
906 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
907
908 V_ahstat.ahs_output++;
909
910 /* Figure out header size. */
911 rplen = HDRSIZE(sav);
912
913 /* Check for maximum packet size violations. */
914 switch (sav->sah->saidx.dst.sa.sa_family) {
915 #ifdef INET
916 case AF_INET:
917 maxpacketsize = IP_MAXPACKET;
918 break;
919 #endif /* INET */
920 #ifdef INET6
921 case AF_INET6:
922 maxpacketsize = IPV6_MAXPACKET;
923 break;
924 #endif /* INET6 */
925 default:
926 DPRINTF(("%s: unknown/unsupported protocol family %u, "
927 "SA %s/%08lx\n", __func__,
928 sav->sah->saidx.dst.sa.sa_family,
929 ipsec_address(&sav->sah->saidx.dst),
930 (u_long) ntohl(sav->spi)));
931 V_ahstat.ahs_nopf++;
932 error = EPFNOSUPPORT;
933 goto bad;
934 }
935 authsize = AUTHSIZE(sav);
936 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
937 DPRINTF(("%s: packet in SA %s/%08lx got too big "
938 "(len %u, max len %u)\n", __func__,
939 ipsec_address(&sav->sah->saidx.dst),
940 (u_long) ntohl(sav->spi),
941 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
942 V_ahstat.ahs_toobig++;
943 error = EMSGSIZE;
944 goto bad;
945 }
946
947 /* Update the counters. */
948 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip;
949
950 m = m_unshare(m, M_NOWAIT);
951 if (m == NULL) {
952 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
953 ipsec_address(&sav->sah->saidx.dst),
954 (u_long) ntohl(sav->spi)));
955 V_ahstat.ahs_hdrops++;
956 error = ENOBUFS;
957 goto bad;
958 }
959
960 /* Inject AH header. */
961 mi = m_makespace(m, skip, rplen + authsize, &roff);
962 if (mi == NULL) {
963 DPRINTF(("%s: failed to inject %u byte AH header for SA "
964 "%s/%08lx\n", __func__,
965 rplen + authsize,
966 ipsec_address(&sav->sah->saidx. |