1 /* $FreeBSD$ */
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 #include "opt_ipsec.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/mbuf.h>
46 #include <sys/socket.h>
47 #include <sys/syslog.h>
48 #include <sys/kernel.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/sysctl.h>
52
53 #include <net/if.h>
54 #include <net/vnet.h>
55
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/ip.h>
59 #include <netinet/ip_ecn.h>
60 #include <netinet/ip6.h>
61
62 #include <netipsec/ipsec.h>
63 #include <netipsec/ah.h>
64 #include <netipsec/ah_var.h>
65 #include <netipsec/xform.h>
66
67 #ifdef INET6
68 #include <netinet6/ip6_var.h>
69 #include <netipsec/ipsec6.h>
70 #include <netinet6/ip6_ecn.h>
71 #endif
72
73 #include <netipsec/key.h>
74 #include <netipsec/key_debug.h>
75
76 #include <opencrypto/cryptodev.h>
77
78 /*
79 * Return header size in bytes. The old protocol did not support
80 * the replay counter; the new protocol always includes the counter.
81 */
82 #define HDRSIZE(sav) \
83 (((sav)->flags & SADB_X_EXT_OLD) ? \
84 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
85 /*
86 * Return authenticator size in bytes, based on a field in the
87 * algorithm descriptor.
88 */
89 #define AUTHSIZE(sav) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \
90 xform_ah_authsize((sav)->tdb_authalgxform))
91
92 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */
93 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */
94 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat);
95 VNET_PCPUSTAT_SYSINIT(ahstat);
96
97 #ifdef VIMAGE
98 VNET_PCPUSTAT_SYSUNINIT(ahstat);
99 #endif /* VIMAGE */
100
101 #ifdef INET
102 SYSCTL_DECL(_net_inet_ah);
103 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable,
104 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, "");
105 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos,
106 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, "");
107 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat,
108 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)");
109 #endif
110
111 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
112 static struct timeval md5warn, ripewarn, kpdkmd5warn, kpdksha1warn;
113
114 static int ah_input_cb(struct cryptop*);
115 static int ah_output_cb(struct cryptop*);
116
117 int
118 xform_ah_authsize(const struct auth_hash *esph)
119 {
120 int alen;
121
122 if (esph == NULL)
123 return 0;
124
125 switch (esph->type) {
126 case CRYPTO_SHA2_256_HMAC:
127 case CRYPTO_SHA2_384_HMAC:
128 case CRYPTO_SHA2_512_HMAC:
129 alen = esph->hashsize / 2; /* RFC4868 2.3 */
130 break;
131
132 case CRYPTO_AES_128_NIST_GMAC:
133 case CRYPTO_AES_192_NIST_GMAC:
134 case CRYPTO_AES_256_NIST_GMAC:
135 alen = esph->hashsize;
136 break;
137
138 default:
139 alen = AH_HMAC_HASHLEN;
140 break;
141 }
142
143 return alen;
144 }
145
146 size_t
147 ah_hdrsiz(struct secasvar *sav)
148 {
149 size_t size;
150
151 if (sav != NULL) {
152 int authsize, rplen, align;
153
154 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
155 /*XXX not right for null algorithm--does it matter??*/
156
157 /* RFC4302: use the correct alignment. */
158 align = sizeof(uint32_t);
159 #ifdef INET6
160 if (sav->sah->saidx.dst.sa.sa_family == AF_INET6) {
161 align = sizeof(uint64_t);
162 }
163 #endif
164 rplen = HDRSIZE(sav);
165 authsize = AUTHSIZE(sav);
166 size = roundup(rplen + authsize, align);
167 } else {
168 /* default guess */
169 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
170 }
171 return size;
172 }
173
174 /*
175 * NB: public for use by esp_init.
176 */
177 int
178 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
179 {
180 const struct auth_hash *thash;
181 int keylen;
182
183 thash = auth_algorithm_lookup(sav->alg_auth);
184 if (thash == NULL) {
185 DPRINTF(("%s: unsupported authentication algorithm %u\n",
186 __func__, sav->alg_auth));
187 return EINVAL;
188 }
189
190 switch (sav->alg_auth) {
191 case SADB_AALG_MD5HMAC:
192 if (ratecheck(&md5warn, &ipsec_warn_interval))
193 gone_in(13, "MD5-HMAC authenticator for IPsec");
194 break;
195 case SADB_X_AALG_RIPEMD160HMAC:
196 if (ratecheck(&ripewarn, &ipsec_warn_interval))
197 gone_in(13, "RIPEMD160-HMAC authenticator for IPsec");
198 break;
199 case SADB_X_AALG_MD5:
200 if (ratecheck(&kpdkmd5warn, &ipsec_warn_interval))
201 gone_in(13, "Keyed-MD5 authenticator for IPsec");
202 break;
203 case SADB_X_AALG_SHA:
204 if (ratecheck(&kpdksha1warn, &ipsec_warn_interval))
205 gone_in(13, "Keyed-SHA1 authenticator for IPsec");
206 break;
207 }
208
209 /*
210 * Verify the replay state block allocation is consistent with
211 * the protocol type. We check here so we can make assumptions
212 * later during protocol processing.
213 */
214 /* NB: replay state is setup elsewhere (sigh) */
215 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
216 DPRINTF(("%s: replay state block inconsistency, "
217 "%s algorithm %s replay state\n", __func__,
218 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
219 sav->replay == NULL ? "without" : "with"));
220 return EINVAL;
221 }
222 if (sav->key_auth == NULL) {
223 DPRINTF(("%s: no authentication key for %s algorithm\n",
224 __func__, thash->name));
225 return EINVAL;
226 }
227 keylen = _KEYLEN(sav->key_auth);
228 if (keylen > thash->keysize && thash->keysize != 0) {
229 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
230 "keysize less than %d\n", __func__,
231 keylen, thash->name, thash->keysize));
232 return EINVAL;
233 }
234
235 sav->tdb_xform = xsp;
236 sav->tdb_authalgxform = thash;
237
238 /* Initialize crypto session. */
239 bzero(cria, sizeof (*cria));
240 cria->cri_alg = sav->tdb_authalgxform->type;
241 cria->cri_klen = _KEYBITS(sav->key_auth);
242 cria->cri_key = sav->key_auth->key_data;
243 cria->cri_mlen = AUTHSIZE(sav);
244
245 return 0;
246 }
247
248 /*
249 * ah_init() is called when an SPI is being set up.
250 */
251 static int
252 ah_init(struct secasvar *sav, struct xformsw *xsp)
253 {
254 struct cryptoini cria;
255 int error;
256
257 error = ah_init0(sav, xsp, &cria);
258 return error ? error :
259 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support);
260 }
261
262 /*
263 * Paranoia.
264 *
265 * NB: public for use by esp_zeroize (XXX).
266 */
267 int
268 ah_zeroize(struct secasvar *sav)
269 {
270
271 if (sav->key_auth)
272 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth));
273
274 crypto_freesession(sav->tdb_cryptoid);
275 sav->tdb_cryptoid = NULL;
276 sav->tdb_authalgxform = NULL;
277 sav->tdb_xform = NULL;
278 return 0;
279 }
280
281 /*
282 * Massage IPv4/IPv6 headers for AH processing.
283 */
284 static int
285 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
286 {
287 struct mbuf *m = *m0;
288 unsigned char *ptr;
289 int off, count;
290
291 #ifdef INET
292 struct ip *ip;
293 #endif /* INET */
294
295 #ifdef INET6
296 struct ip6_ext *ip6e;
297 struct ip6_hdr ip6;
298 int ad, alloc, nxt, noff;
299 #endif /* INET6 */
300
301 switch (proto) {
302 #ifdef INET
303 case AF_INET:
304 /*
305 * This is the least painful way of dealing with IPv4 header
306 * and option processing -- just make sure they're in
307 * contiguous memory.
308 */
309 *m0 = m = m_pullup(m, skip);
310 if (m == NULL) {
311 DPRINTF(("%s: m_pullup failed\n", __func__));
312 return ENOBUFS;
313 }
314
315 /* Fix the IP header */
316 ip = mtod(m, struct ip *);
317 if (V_ah_cleartos)
318 ip->ip_tos = 0;
319 ip->ip_ttl = 0;
320 ip->ip_sum = 0;
321
322 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
323 ip->ip_off &= htons(IP_DF);
324 else
325 ip->ip_off = htons(0);
326
327 ptr = mtod(m, unsigned char *);
328
329 /* IPv4 option processing */
330 for (off = sizeof(struct ip); off < skip;) {
331 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
332 off + 1 < skip)
333 ;
334 else {
335 DPRINTF(("%s: illegal IPv4 option length for "
336 "option %d\n", __func__, ptr[off]));
337
338 m_freem(m);
339 return EINVAL;
340 }
341
342 switch (ptr[off]) {
343 case IPOPT_EOL:
344 off = skip; /* End the loop. */
345 break;
346
347 case IPOPT_NOP:
348 off++;
349 break;
350
351 case IPOPT_SECURITY: /* 0x82 */
352 case 0x85: /* Extended security. */
353 case 0x86: /* Commercial security. */
354 case 0x94: /* Router alert */
355 case 0x95: /* RFC1770 */
356 /* Sanity check for option length. */
357 if (ptr[off + 1] < 2) {
358 DPRINTF(("%s: illegal IPv4 option "
359 "length for option %d\n",
360 __func__, ptr[off]));
361
362 m_freem(m);
363 return EINVAL;
364 }
365
366 off += ptr[off + 1];
367 break;
368
369 case IPOPT_LSRR:
370 case IPOPT_SSRR:
371 /* Sanity check for option length. */
372 if (ptr[off + 1] < 2) {
373 DPRINTF(("%s: illegal IPv4 option "
374 "length for option %d\n",
375 __func__, ptr[off]));
376
377 m_freem(m);
378 return EINVAL;
379 }
380
381 /*
382 * On output, if we have either of the
383 * source routing options, we should
384 * swap the destination address of the
385 * IP header with the last address
386 * specified in the option, as that is
387 * what the destination's IP header
388 * will look like.
389 */
390 if (out)
391 bcopy(ptr + off + ptr[off + 1] -
392 sizeof(struct in_addr),
393 &(ip->ip_dst), sizeof(struct in_addr));
394
395 /* Fall through */
396 default:
397 /* Sanity check for option length. */
398 if (ptr[off + 1] < 2) {
399 DPRINTF(("%s: illegal IPv4 option "
400 "length for option %d\n",
401 __func__, ptr[off]));
402 m_freem(m);
403 return EINVAL;
404 }
405
406 /* Zeroize all other options. */
407 count = ptr[off + 1];
408 bcopy(ipseczeroes, ptr + off, count);
409 off += count;
410 break;
411 }
412
413 /* Sanity check. */
414 if (off > skip) {
415 DPRINTF(("%s: malformed IPv4 options header\n",
416 __func__));
417
418 m_freem(m);
419 return EINVAL;
420 }
421 }
422
423 break;
424 #endif /* INET */
425
426 #ifdef INET6
427 case AF_INET6: /* Ugly... */
428 /* Copy and "cook" the IPv6 header. */
429 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
430
431 /* We don't do IPv6 Jumbograms. */
432 if (ip6.ip6_plen == 0) {
433 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
434 m_freem(m);
435 return EMSGSIZE;
436 }
437
438 ip6.ip6_flow = 0;
439 ip6.ip6_hlim = 0;
440 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
441 ip6.ip6_vfc |= IPV6_VERSION;
442
443 /* Scoped address handling. */
444 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
445 ip6.ip6_src.s6_addr16[1] = 0;
446 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
447 ip6.ip6_dst.s6_addr16[1] = 0;
448
449 /* Done with IPv6 header. */
450 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
451
452 /* Let's deal with the remaining headers (if any). */
453 if (skip - sizeof(struct ip6_hdr) > 0) {
454 if (m->m_len <= skip) {
455 ptr = (unsigned char *) malloc(
456 skip - sizeof(struct ip6_hdr),
457 M_XDATA, M_NOWAIT);
458 if (ptr == NULL) {
459 DPRINTF(("%s: failed to allocate memory"
460 "for IPv6 headers\n",__func__));
461 m_freem(m);
462 return ENOBUFS;
463 }
464
465 /*
466 * Copy all the protocol headers after
467 * the IPv6 header.
468 */
469 m_copydata(m, sizeof(struct ip6_hdr),
470 skip - sizeof(struct ip6_hdr), ptr);
471 alloc = 1;
472 } else {
473 /* No need to allocate memory. */
474 ptr = mtod(m, unsigned char *) +
475 sizeof(struct ip6_hdr);
476 alloc = 0;
477 }
478 } else
479 break;
480
481 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
482
483 for (off = 0; off < skip - sizeof(struct ip6_hdr);)
484 switch (nxt) {
485 case IPPROTO_HOPOPTS:
486 case IPPROTO_DSTOPTS:
487 ip6e = (struct ip6_ext *)(ptr + off);
488 noff = off + ((ip6e->ip6e_len + 1) << 3);
489
490 /* Sanity check. */
491 if (noff > skip - sizeof(struct ip6_hdr))
492 goto error6;
493
494 /*
495 * Zero out mutable options.
496 */
497 for (count = off + sizeof(struct ip6_ext);
498 count < noff;) {
499 if (ptr[count] == IP6OPT_PAD1) {
500 count++;
501 continue; /* Skip padding. */
502 }
503
504 ad = ptr[count + 1] + 2;
505 if (count + ad > noff)
506 goto error6;
507
508 if (ptr[count] & IP6OPT_MUTABLE)
509 memset(ptr + count, 0, ad);
510 count += ad;
511 }
512
513 if (count != noff)
514 goto error6;
515
516 /* Advance. */
517 off += ((ip6e->ip6e_len + 1) << 3);
518 nxt = ip6e->ip6e_nxt;
519 break;
520
521 case IPPROTO_ROUTING:
522 /*
523 * Always include routing headers in
524 * computation.
525 */
526 ip6e = (struct ip6_ext *) (ptr + off);
527 off += ((ip6e->ip6e_len + 1) << 3);
528 nxt = ip6e->ip6e_nxt;
529 break;
530
531 default:
532 DPRINTF(("%s: unexpected IPv6 header type %d",
533 __func__, off));
534 error6:
535 if (alloc)
536 free(ptr, M_XDATA);
537 m_freem(m);
538 return EINVAL;
539 }
540
541 /* Copyback and free, if we allocated. */
542 if (alloc) {
543 m_copyback(m, sizeof(struct ip6_hdr),
544 skip - sizeof(struct ip6_hdr), ptr);
545 free(ptr, M_XDATA);
546 }
547
548 break;
549 #endif /* INET6 */
550 }
551
552 return 0;
553 }
554
555 /*
556 * ah_input() gets called to verify that an input packet
557 * passes authentication.
558 */
559 static int
560 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
561 {
562 IPSEC_DEBUG_DECLARE(char buf[128]);
563 const struct auth_hash *ahx;
564 struct cryptodesc *crda;
565 struct cryptop *crp;
566 struct xform_data *xd;
567 struct newah *ah;
568 crypto_session_t cryptoid;
569 int hl, rplen, authsize, ahsize, error;
570
571 IPSEC_ASSERT(sav != NULL, ("null SA"));
572 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
573 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
574 ("null authentication xform"));
575
576 /* Figure out header size. */
577 rplen = HDRSIZE(sav);
578
579 if (m->m_len < skip + rplen) {
580 m = m_pullup(m, skip + rplen);
581 if (m == NULL) {
582 DPRINTF(("ah_input: cannot pullup header\n"));
583 AHSTAT_INC(ahs_hdrops); /*XXX*/
584 error = ENOBUFS;
585 goto bad;
586 }
587 }
588 ah = (struct newah *)(mtod(m, caddr_t) + skip);
589
590 /* Check replay window, if applicable. */
591 SECASVAR_LOCK(sav);
592 if (sav->replay != NULL && sav->replay->wsize != 0 &&
593 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) {
594 SECASVAR_UNLOCK(sav);
595 AHSTAT_INC(ahs_replay);
596 DPRINTF(("%s: packet replay failure: %s\n", __func__,
597 ipsec_sa2str(sav, buf, sizeof(buf))));
598 error = EACCES;
599 goto bad;
600 }
601 cryptoid = sav->tdb_cryptoid;
602 SECASVAR_UNLOCK(sav);
603
604 /* Verify AH header length. */
605 hl = sizeof(struct ah) + (ah->ah_len * sizeof (u_int32_t));
606 ahx = sav->tdb_authalgxform;
607 authsize = AUTHSIZE(sav);
608 ahsize = ah_hdrsiz(sav);
609 if (hl != ahsize) {
610 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
611 " for packet in SA %s/%08lx\n", __func__, hl,
612 (u_long)ahsize,
613 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
614 (u_long) ntohl(sav->spi)));
615 AHSTAT_INC(ahs_badauthl);
616 error = EACCES;
617 goto bad;
618 }
619 if (skip + ahsize > m->m_pkthdr.len) {
620 DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
621 " for packet in SA %s/%08lx\n", __func__,
622 m->m_pkthdr.len, (u_long)(skip + ahsize),
623 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
624 (u_long) ntohl(sav->spi)));
625 AHSTAT_INC(ahs_badauthl);
626 error = EACCES;
627 goto bad;
628 }
629 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
630
631 /* Get crypto descriptors. */
632 crp = crypto_getreq(1);
633 if (crp == NULL) {
634 DPRINTF(("%s: failed to acquire crypto descriptor\n",
635 __func__));
636 AHSTAT_INC(ahs_crypto);
637 error = ENOBUFS;
638 goto bad;
639 }
640
641 crda = crp->crp_desc;
642 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
643
644 crda->crd_skip = 0;
645 crda->crd_len = m->m_pkthdr.len;
646 crda->crd_inject = skip + rplen;
647
648 /* Authentication operation. */
649 crda->crd_alg = ahx->type;
650 crda->crd_klen = _KEYBITS(sav->key_auth);
651 crda->crd_key = sav->key_auth->key_data;
652
653 /* Allocate IPsec-specific opaque crypto info. */
654 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA,
655 M_NOWAIT | M_ZERO);
656 if (xd == NULL) {
657 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
658 AHSTAT_INC(ahs_crypto);
659 crypto_freereq(crp);
660 error = ENOBUFS;
661 goto bad;
662 }
663
664 /*
665 * Save the authenticator, the skipped portion of the packet,
666 * and the AH header.
667 */
668 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1));
669
670 /* Zeroize the authenticator on the packet. */
671 m_copyback(m, skip + rplen, authsize, ipseczeroes);
672
673 /* Save ah_nxt, since ah pointer can become invalid after "massage" */
674 hl = ah->ah_nxt;
675
676 /* "Massage" the packet headers for crypto processing. */
677 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
678 skip, ahx->type, 0);
679 if (error != 0) {
680 /* NB: mbuf is free'd by ah_massage_headers */
681 AHSTAT_INC(ahs_hdrops);
682 free(xd, M_XDATA);
683 crypto_freereq(crp);
684 key_freesav(&sav);
685 return (error);
686 }
687
688 /* Crypto operation descriptor. */
689 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
690 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
691 if (V_async_crypto)
692 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
693 crp->crp_buf = (caddr_t) m;
694 crp->crp_callback = ah_input_cb;
695 crp->crp_session = cryptoid;
696 crp->crp_opaque = (caddr_t) xd;
697
698 /* These are passed as-is to the callback. */
699 xd->sav = sav;
700 xd->nxt = hl;
701 xd->protoff = protoff;
702 xd->skip = skip;
703 xd->cryptoid = cryptoid;
704 xd->vnet = curvnet;
705 return (crypto_dispatch(crp));
706 bad:
707 m_freem(m);
708 key_freesav(&sav);
709 return (error);
710 }
711
712 /*
713 * AH input callback from the crypto driver.
714 */
715 static int
716 ah_input_cb(struct cryptop *crp)
717 {
718 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
719 unsigned char calc[AH_ALEN_MAX];
720 struct mbuf *m;
721 struct xform_data *xd;
722 struct secasvar *sav;
723 struct secasindex *saidx;
724 caddr_t ptr;
725 crypto_session_t cryptoid;
726 int authsize, rplen, ahsize, error, skip, protoff;
727 uint8_t nxt;
728
729 m = (struct mbuf *) crp->crp_buf;
730 xd = (struct xform_data *) crp->crp_opaque;
731 CURVNET_SET(xd->vnet);
732 sav = xd->sav;
733 skip = xd->skip;
734 nxt = xd->nxt;
735 protoff = xd->protoff;
736 cryptoid = xd->cryptoid;
737 saidx = &sav->sah->saidx;
738 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
739 saidx->dst.sa.sa_family == AF_INET6,
740 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
741
742 /* Check for crypto errors. */
743 if (crp->crp_etype) {
744 if (crp->crp_etype == EAGAIN) {
745 /* Reset the session ID */
746 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
747 crypto_freesession(cryptoid);
748 xd->cryptoid = crp->crp_session;
749 CURVNET_RESTORE();
750 return (crypto_dispatch(crp));
751 }
752 AHSTAT_INC(ahs_noxform);
753 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
754 error = crp->crp_etype;
755 goto bad;
756 } else {
757 AHSTAT_INC(ahs_hist[sav->alg_auth]);
758 crypto_freereq(crp); /* No longer needed. */
759 crp = NULL;
760 }
761
762 /* Shouldn't happen... */
763 if (m == NULL) {
764 AHSTAT_INC(ahs_crypto);
765 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
766 error = EINVAL;
767 goto bad;
768 }
769
770 /* Figure out header size. */
771 rplen = HDRSIZE(sav);
772 authsize = AUTHSIZE(sav);
773 ahsize = ah_hdrsiz(sav);
774
775 /* Copy authenticator off the packet. */
776 m_copydata(m, skip + rplen, authsize, calc);
777
778 /* Verify authenticator. */
779 ptr = (caddr_t) (xd + 1);
780 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) {
781 DPRINTF(("%s: authentication hash mismatch for packet "
782 "in SA %s/%08lx\n", __func__,
783 ipsec_address(&saidx->dst, buf, sizeof(buf)),
784 (u_long) ntohl(sav->spi)));
785 AHSTAT_INC(ahs_badauth);
786 error = EACCES;
787 goto bad;
788 }
789 /* Fix the Next Protocol field. */
790 ((uint8_t *) ptr)[protoff] = nxt;
791
792 /* Copyback the saved (uncooked) network headers. */
793 m_copyback(m, 0, skip, ptr);
794 free(xd, M_XDATA), xd = NULL; /* No longer needed */
795
796 /*
797 * Header is now authenticated.
798 */
799 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
800
801 /*
802 * Update replay sequence number, if appropriate.
803 */
804 if (sav->replay) {
805 u_int32_t seq;
806
807 m_copydata(m, skip + offsetof(struct newah, ah_seq),
808 sizeof (seq), (caddr_t) &seq);
809 SECASVAR_LOCK(sav);
810 if (ipsec_updatereplay(ntohl(seq), sav)) {
811 SECASVAR_UNLOCK(sav);
812 AHSTAT_INC(ahs_replay);
813 error = EACCES;
814 goto bad;
815 }
816 SECASVAR_UNLOCK(sav);
817 }
818
819 /*
820 * Remove the AH header and authenticator from the mbuf.
821 */
822 error = m_striphdr(m, skip, ahsize);
823 if (error) {
824 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
825 ipsec_address(&saidx->dst, buf, sizeof(buf)),
826 (u_long) ntohl(sav->spi)));
827 AHSTAT_INC(ahs_hdrops);
828 goto bad;
829 }
830
831 switch (saidx->dst.sa.sa_family) {
832 #ifdef INET6
833 case AF_INET6:
834 error = ipsec6_common_input_cb(m, sav, skip, protoff);
835 break;
836 #endif
837 #ifdef INET
838 case AF_INET:
839 error = ipsec4_common_input_cb(m, sav, skip, protoff);
840 break;
841 #endif
842 default:
843 panic("%s: Unexpected address family: %d saidx=%p", __func__,
844 saidx->dst.sa.sa_family, saidx);
845 }
846 CURVNET_RESTORE();
847 return error;
848 bad:
849 CURVNET_RESTORE();
850 if (sav)
851 key_freesav(&sav);
852 if (m != NULL)
853 m_freem(m);
854 if (xd != NULL)
855 free(xd, M_XDATA);
856 if (crp != NULL)
857 crypto_freereq(crp);
858 return error;
859 }
860
861 /*
862 * AH output routine, called by ipsec[46]_perform_request().
863 */
864 static int
865 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav,
866 u_int idx, int skip, int protoff)
867 {
868 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
869 const struct auth_hash *ahx;
870 struct cryptodesc *crda;
871 struct xform_data *xd;
872 struct mbuf *mi;
873 struct cryptop *crp;
874 struct newah *ah;
875 crypto_session_t cryptoid;
876 uint16_t iplen;
877 int error, rplen, authsize, ahsize, maxpacketsize, roff;
878 uint8_t prot;
879
880 IPSEC_ASSERT(sav != NULL, ("null SA"));
881 ahx = sav->tdb_authalgxform;
882 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
883
884 AHSTAT_INC(ahs_output);
885
886 /* Figure out header size. */
887 rplen = HDRSIZE(sav);
888 authsize = AUTHSIZE(sav);
889 ahsize = ah_hdrsiz(sav);
890
891 /* Check for maximum packet size violations. */
892 switch (sav->sah->saidx.dst.sa.sa_family) {
893 #ifdef INET
894 case AF_INET:
895 maxpacketsize = IP_MAXPACKET;
896 break;
897 #endif /* INET */
898 #ifdef INET6
899 case AF_INET6:
900 maxpacketsize = IPV6_MAXPACKET;
901 break;
902 #endif /* INET6 */
903 default:
904 DPRINTF(("%s: unknown/unsupported protocol family %u, "
905 "SA %s/%08lx\n", __func__,
906 sav->sah->saidx.dst.sa.sa_family,
907 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
908 (u_long) ntohl(sav->spi)));
909 AHSTAT_INC(ahs_nopf);
910 error = EPFNOSUPPORT;
911 goto bad;
912 }
913 if (ahsize + m->m_pkthdr.len > maxpacketsize) {
914 DPRINTF(("%s: packet in SA %s/%08lx got too big "
915 "(len %u, max len %u)\n", __func__,
916 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
917 (u_long) ntohl(sav->spi),
918 ahsize + m->m_pkthdr.len, maxpacketsize));
919 AHSTAT_INC(ahs_toobig);
920 error = EMSGSIZE;
921 goto bad;
922 }
923
924 /* Update the counters. */
925 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip);
926
927 m = m_unshare(m, M_NOWAIT);
928 if (m == NULL) {
929 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
930 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
931 (u_long) ntohl(sav->spi)));
932 AHSTAT_INC(ahs_hdrops);
933 error = ENOBUFS;
934 goto bad;
935 }
936
937 /* Inject AH header. */
938 mi = m_makespace(m, skip, ahsize, &roff);
939 if (mi == NULL) {
940 DPRINTF(("%s: failed to inject %u byte AH header for SA "
941 "%s/%08lx\n", __func__, ahsize,
942 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
943 (u_long) ntohl(sav->spi)));
944 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */
945 error = ENOBUFS;
946 goto bad;
947 }
948
949 /*
950 * The AH header is guaranteed by m_makespace() to be in
951 * contiguous memory, at roff bytes offset into the returned mbuf.
952 */
953 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
954
955 /* Initialize the AH header. */
956 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
957 ah->ah_len = (ahsize - sizeof(struct ah)) / sizeof(u_int32_t);
958 ah->ah_reserve = 0;
959 ah->ah_spi = sav->spi;
960
961 /* Zeroize authenticator. */
962 m_copyback(m, skip + rplen, authsize, ipseczeroes);
963
964 /* Zeroize padding */
965 m_copyback(m, skip + rplen + authsize, ahsize - (rplen + authsize),
966 ipseczeroes);
967
968 /* Insert packet replay counter, as requested. */
969 SECASVAR_LOCK(sav);
970 if (sav->replay) {
971 if (sav->replay->count == ~0 &&
972 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
973 SECASVAR_UNLOCK(sav);
974 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
975 __func__, ipsec_address(&sav->sah->saidx.dst, buf,
976 sizeof(buf)), (u_long) ntohl(sav->spi)));
977 AHSTAT_INC(ahs_wrap);
978 error = EACCES;
979 goto bad;
980 }
981 #ifdef REGRESSION
982 /* Emulate replay attack when ipsec_replay is TRUE. */
983 if (!V_ipsec_replay)
984 #endif
985 sav->replay->count++;
986 ah->ah_seq = htonl(sav->replay->count);
987 }
988 cryptoid = sav->tdb_cryptoid;
989 SECASVAR_UNLOCK(sav);
990
991 /* Get crypto descriptors. */
992 crp = crypto_getreq(1);
993 if (crp == NULL) {
994 DPRINTF(("%s: failed to acquire crypto descriptors\n",
995 __func__));
996 AHSTAT_INC(ahs_crypto);
997 error = ENOBUFS;
998 goto bad;
999 }
1000
1001 crda = crp->crp_desc;
1002 crda->crd_skip = 0;
1003 crda->crd_inject = skip + rplen;
1004 crda->crd_len = m->m_pkthdr.len;
1005
1006 /* Authentication operation. */
1007 crda->crd_alg = ahx->type;
1008 crda->crd_key = sav->key_auth->key_data;
1009 crda->crd_klen = _KEYBITS(sav->key_auth);
1010
1011 /* Allocate IPsec-specific opaque crypto info. */
1012 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA,
1013 M_NOWAIT | M_ZERO);
1014 if (xd == NULL) {
1015 crypto_freereq(crp);
1016 DPRINTF(("%s: failed to allocate xform_data\n", __func__));
1017 AHSTAT_INC(ahs_crypto);
1018 error = ENOBUFS;
1019 goto bad;
1020 }
1021
1022 /* Save the skipped portion of the packet. */
1023 m_copydata(m, 0, skip, (caddr_t) (xd + 1));
1024
1025 /*
1026 * Fix IP header length on the header used for
1027 * authentication. We don't need to fix the original
1028 * header length as it will be fixed by our caller.
1029 */
1030 switch (sav->sah->saidx.dst.sa.sa_family) {
1031 #ifdef INET
1032 case AF_INET:
1033 bcopy(((caddr_t)(xd + 1)) +
1034 offsetof(struct ip, ip_len),
1035 (caddr_t) &iplen, sizeof(u_int16_t));
1036 iplen = htons(ntohs(iplen) + ahsize);
1037 m_copyback(m, offsetof(struct ip, ip_len),
1038 sizeof(u_int16_t), (caddr_t) &iplen);
1039 break;
1040 #endif /* INET */
1041
1042 #ifdef INET6
1043 case AF_INET6:
1044 bcopy(((caddr_t)(xd + 1)) +
1045 offsetof(struct ip6_hdr, ip6_plen),
1046 (caddr_t) &iplen, sizeof(uint16_t));
1047 iplen = htons(ntohs(iplen) + ahsize);
1048 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1049 sizeof(uint16_t), (caddr_t) &iplen);
1050 break;
1051 #endif /* INET6 */
1052 }
1053
1054 /* Fix the Next Header field in saved header. */
1055 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH;
1056
1057 /* Update the Next Protocol field in the IP header. */
1058 prot = IPPROTO_AH;
1059 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot);
1060
1061 /* "Massage" the packet headers for crypto processing. */
1062 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1063 skip, ahx->type, 1);
1064 if (error != 0) {
1065 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1066 free(xd, M_XDATA);
1067 crypto_freereq(crp);
1068 goto bad;
1069 }
1070
1071 /* Crypto operation descriptor. */
1072 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1073 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1074 if (V_async_crypto)
1075 crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER;
1076 crp->crp_buf = (caddr_t) m;
1077 crp->crp_callback = ah_output_cb;
1078 crp->crp_session = cryptoid;
1079 crp->crp_opaque = (caddr_t) xd;
1080
1081 /* These are passed as-is to the callback. */
1082 xd->sp = sp;
1083 xd->sav = sav;
1084 xd->skip = skip;
1085 xd->idx = idx;
1086 xd->cryptoid = cryptoid;
1087 xd->vnet = curvnet;
1088
1089 return crypto_dispatch(crp);
1090 bad:
1091 if (m)
1092 m_freem(m);
1093 key_freesav(&sav);
1094 key_freesp(&sp);
1095 return (error);
1096 }
1097
1098 /*
1099 * AH output callback from the crypto driver.
1100 */
1101 static int
1102 ah_output_cb(struct cryptop *crp)
1103 {
1104 struct xform_data *xd;
1105 struct secpolicy *sp;
1106 struct secasvar *sav;
1107 struct mbuf *m;
1108 crypto_session_t cryptoid;
1109 caddr_t ptr;
1110 u_int idx;
1111 int skip, error;
1112
1113 m = (struct mbuf *) crp->crp_buf;
1114 xd = (struct xform_data *) crp->crp_opaque;
1115 CURVNET_SET(xd->vnet);
1116 sp = xd->sp;
1117 sav = xd->sav;
1118 skip = xd->skip;
1119 idx = xd->idx;
1120 cryptoid = xd->cryptoid;
1121 ptr = (caddr_t) (xd + 1);
1122
1123 /* Check for crypto errors. */
1124 if (crp->crp_etype) {
1125 if (crp->crp_etype == EAGAIN) {
1126 /* Reset the session ID */
1127 if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
1128 crypto_freesession(cryptoid);
1129 xd->cryptoid = crp->crp_session;
1130 CURVNET_RESTORE();
1131 return (crypto_dispatch(crp));
1132 }
1133 AHSTAT_INC(ahs_noxform);
1134 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1135 error = crp->crp_etype;
1136 m_freem(m);
1137 goto bad;
1138 }
1139
1140 /* Shouldn't happen... */
1141 if (m == NULL) {
1142 AHSTAT_INC(ahs_crypto);
1143 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1144 error = EINVAL;
1145 goto bad;
1146 }
1147 /*
1148 * Copy original headers (with the new protocol number) back
1149 * in place.
1150 */
1151 m_copyback(m, 0, skip, ptr);
1152
1153 free(xd, M_XDATA);
1154 crypto_freereq(crp);
1155 AHSTAT_INC(ahs_hist[sav->alg_auth]);
1156 #ifdef REGRESSION
1157 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1158 if (V_ipsec_integrity) {
1159 int alen;
1160
1161 /*
1162 * Corrupt HMAC if we want to test integrity verification of
1163 * the other side.
1164 */
1165 alen = AUTHSIZE(sav);
1166 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1167 }
1168 #endif
1169
1170 /* NB: m is reclaimed by ipsec_process_done. */
1171 error = ipsec_process_done(m, sp, sav, idx);
1172 CURVNET_RESTORE();
1173 return (error);
1174 bad:
1175 CURVNET_RESTORE();
1176 free(xd, M_XDATA);
1177 crypto_freereq(crp);
1178 key_freesav(&sav);
1179 key_freesp(&sp);
1180 return (error);
1181 }
1182
1183 static struct xformsw ah_xformsw = {
1184 .xf_type = XF_AH,
1185 .xf_name = "IPsec AH",
1186 .xf_init = ah_init,
1187 .xf_zeroize = ah_zeroize,
1188 .xf_input = ah_input,
1189 .xf_output = ah_output,
1190 };
1191
1192 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1193 xform_attach, &ah_xformsw);
1194 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1195 xform_detach, &ah_xformsw);
Cache object: dbbea24145c9b59ae79db1c27f2da435
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