1 /* $FreeBSD: releng/6.4/sys/netipsec/xform_ah.c 161999 2006-09-04 15:17:50Z pjd $ */
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
50 #include <net/if.h>
51
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip_ecn.h>
56 #include <netinet/ip6.h>
57
58 #include <net/route.h>
59 #include <netipsec/ipsec.h>
60 #include <netipsec/ah.h>
61 #include <netipsec/ah_var.h>
62 #include <netipsec/xform.h>
63
64 #ifdef INET6
65 #include <netinet6/ip6_var.h>
66 #include <netipsec/ipsec6.h>
67 #include <netinet6/ip6_ecn.h>
68 #endif
69
70 #include <netipsec/key.h>
71 #include <netipsec/key_debug.h>
72
73 #include <opencrypto/cryptodev.h>
74
75 /*
76 * Return header size in bytes. The old protocol did not support
77 * the replay counter; the new protocol always includes the counter.
78 */
79 #define HDRSIZE(sav) \
80 (((sav)->flags & SADB_X_EXT_OLD) ? \
81 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
82 /*
83 * Return authenticator size in bytes. The old protocol is known
84 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte
85 * authenticator.
86 */
87 #define AUTHSIZE(sav) \
88 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN)
89
90 int ah_enable = 1; /* control flow of packets with AH */
91 int ah_cleartos = 1; /* clear ip_tos when doing AH calc */
92 struct ahstat ahstat;
93
94 SYSCTL_DECL(_net_inet_ah);
95 SYSCTL_INT(_net_inet_ah, OID_AUTO,
96 ah_enable, CTLFLAG_RW, &ah_enable, 0, "");
97 SYSCTL_INT(_net_inet_ah, OID_AUTO,
98 ah_cleartos, CTLFLAG_RW, &ah_cleartos, 0, "");
99 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
100 stats, CTLFLAG_RD, &ahstat, ahstat, "");
101
102 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */
103
104 static int ah_input_cb(struct cryptop*);
105 static int ah_output_cb(struct cryptop*);
106
107 /*
108 * NB: this is public for use by the PF_KEY support.
109 */
110 struct auth_hash *
111 ah_algorithm_lookup(int alg)
112 {
113 if (alg >= AH_ALG_MAX)
114 return NULL;
115 switch (alg) {
116 case SADB_X_AALG_NULL:
117 return &auth_hash_null;
118 case SADB_AALG_MD5HMAC:
119 return &auth_hash_hmac_md5;
120 case SADB_AALG_SHA1HMAC:
121 return &auth_hash_hmac_sha1;
122 case SADB_X_AALG_RIPEMD160HMAC:
123 return &auth_hash_hmac_ripemd_160;
124 case SADB_X_AALG_MD5:
125 return &auth_hash_key_md5;
126 case SADB_X_AALG_SHA:
127 return &auth_hash_key_sha1;
128 case SADB_X_AALG_SHA2_256:
129 return &auth_hash_hmac_sha2_256;
130 case SADB_X_AALG_SHA2_384:
131 return &auth_hash_hmac_sha2_384;
132 case SADB_X_AALG_SHA2_512:
133 return &auth_hash_hmac_sha2_512;
134 }
135 return NULL;
136 }
137
138 size_t
139 ah_hdrsiz(struct secasvar *sav)
140 {
141 size_t size;
142
143 if (sav != NULL) {
144 int authsize;
145 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform"));
146 /*XXX not right for null algorithm--does it matter??*/
147 authsize = AUTHSIZE(sav);
148 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
149 } else {
150 /* default guess */
151 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
152 }
153 return size;
154 }
155
156 /*
157 * NB: public for use by esp_init.
158 */
159 int
160 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
161 {
162 struct auth_hash *thash;
163 int keylen;
164
165 thash = ah_algorithm_lookup(sav->alg_auth);
166 if (thash == NULL) {
167 DPRINTF(("%s: unsupported authentication algorithm %u\n",
168 __func__, sav->alg_auth));
169 return EINVAL;
170 }
171 /*
172 * Verify the replay state block allocation is consistent with
173 * the protocol type. We check here so we can make assumptions
174 * later during protocol processing.
175 */
176 /* NB: replay state is setup elsewhere (sigh) */
177 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
178 DPRINTF(("%s: replay state block inconsistency, "
179 "%s algorithm %s replay state\n", __func__,
180 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
181 sav->replay == NULL ? "without" : "with"));
182 return EINVAL;
183 }
184 if (sav->key_auth == NULL) {
185 DPRINTF(("%s: no authentication key for %s algorithm\n",
186 __func__, thash->name));
187 return EINVAL;
188 }
189 keylen = _KEYLEN(sav->key_auth);
190 if (keylen != thash->keysize && thash->keysize != 0) {
191 DPRINTF(("%s: invalid keylength %d, algorithm %s requires "
192 "keysize %d\n", __func__,
193 keylen, thash->name, thash->keysize));
194 return EINVAL;
195 }
196
197 sav->tdb_xform = xsp;
198 sav->tdb_authalgxform = thash;
199
200 /* Initialize crypto session. */
201 bzero(cria, sizeof (*cria));
202 cria->cri_alg = sav->tdb_authalgxform->type;
203 cria->cri_klen = _KEYBITS(sav->key_auth);
204 cria->cri_key = _KEYBUF(sav->key_auth);
205 cria->cri_mlen = AUTHSIZE(sav);
206
207 return 0;
208 }
209
210 /*
211 * ah_init() is called when an SPI is being set up.
212 */
213 static int
214 ah_init(struct secasvar *sav, struct xformsw *xsp)
215 {
216 struct cryptoini cria;
217 int error;
218
219 error = ah_init0(sav, xsp, &cria);
220 return error ? error :
221 crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support);
222 }
223
224 /*
225 * Paranoia.
226 *
227 * NB: public for use by esp_zeroize (XXX).
228 */
229 int
230 ah_zeroize(struct secasvar *sav)
231 {
232 int err;
233
234 if (sav->key_auth)
235 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
236
237 err = crypto_freesession(sav->tdb_cryptoid);
238 sav->tdb_cryptoid = 0;
239 sav->tdb_authalgxform = NULL;
240 sav->tdb_xform = NULL;
241 return err;
242 }
243
244 /*
245 * Massage IPv4/IPv6 headers for AH processing.
246 */
247 static int
248 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
249 {
250 struct mbuf *m = *m0;
251 unsigned char *ptr;
252 int off, count;
253
254 #ifdef INET
255 struct ip *ip;
256 #endif /* INET */
257
258 #ifdef INET6
259 struct ip6_ext *ip6e;
260 struct ip6_hdr ip6;
261 int alloc, len, ad;
262 #endif /* INET6 */
263
264 switch (proto) {
265 #ifdef INET
266 case AF_INET:
267 /*
268 * This is the least painful way of dealing with IPv4 header
269 * and option processing -- just make sure they're in
270 * contiguous memory.
271 */
272 *m0 = m = m_pullup(m, skip);
273 if (m == NULL) {
274 DPRINTF(("%s: m_pullup failed\n", __func__));
275 return ENOBUFS;
276 }
277
278 /* Fix the IP header */
279 ip = mtod(m, struct ip *);
280 if (ah_cleartos)
281 ip->ip_tos = 0;
282 ip->ip_ttl = 0;
283 ip->ip_sum = 0;
284
285 /*
286 * On input, fix ip_len which has been byte-swapped
287 * at ip_input().
288 */
289 if (!out) {
290 ip->ip_len = htons(ip->ip_len + skip);
291
292 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
293 ip->ip_off = htons(ip->ip_off & IP_DF);
294 else
295 ip->ip_off = 0;
296 } else {
297 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
298 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
299 else
300 ip->ip_off = 0;
301 }
302
303 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
304
305 /* IPv4 option processing */
306 for (off = sizeof(struct ip); off < skip;) {
307 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
308 off + 1 < skip)
309 ;
310 else {
311 DPRINTF(("%s: illegal IPv4 option length for "
312 "option %d\n", __func__, ptr[off]));
313
314 m_freem(m);
315 return EINVAL;
316 }
317
318 switch (ptr[off]) {
319 case IPOPT_EOL:
320 off = skip; /* End the loop. */
321 break;
322
323 case IPOPT_NOP:
324 off++;
325 break;
326
327 case IPOPT_SECURITY: /* 0x82 */
328 case 0x85: /* Extended security. */
329 case 0x86: /* Commercial security. */
330 case 0x94: /* Router alert */
331 case 0x95: /* RFC1770 */
332 /* Sanity check for option length. */
333 if (ptr[off + 1] < 2) {
334 DPRINTF(("%s: illegal IPv4 option "
335 "length for option %d\n",
336 __func__, ptr[off]));
337
338 m_freem(m);
339 return EINVAL;
340 }
341
342 off += ptr[off + 1];
343 break;
344
345 case IPOPT_LSRR:
346 case IPOPT_SSRR:
347 /* Sanity check for option length. */
348 if (ptr[off + 1] < 2) {
349 DPRINTF(("%s: illegal IPv4 option "
350 "length for option %d\n",
351 __func__, ptr[off]));
352
353 m_freem(m);
354 return EINVAL;
355 }
356
357 /*
358 * On output, if we have either of the
359 * source routing options, we should
360 * swap the destination address of the
361 * IP header with the last address
362 * specified in the option, as that is
363 * what the destination's IP header
364 * will look like.
365 */
366 if (out)
367 bcopy(ptr + off + ptr[off + 1] -
368 sizeof(struct in_addr),
369 &(ip->ip_dst), sizeof(struct in_addr));
370
371 /* Fall through */
372 default:
373 /* Sanity check for option length. */
374 if (ptr[off + 1] < 2) {
375 DPRINTF(("%s: illegal IPv4 option "
376 "length for option %d\n",
377 __func__, ptr[off]));
378 m_freem(m);
379 return EINVAL;
380 }
381
382 /* Zeroize all other options. */
383 count = ptr[off + 1];
384 bcopy(ipseczeroes, ptr, count);
385 off += count;
386 break;
387 }
388
389 /* Sanity check. */
390 if (off > skip) {
391 DPRINTF(("%s: malformed IPv4 options header\n",
392 __func__));
393
394 m_freem(m);
395 return EINVAL;
396 }
397 }
398
399 break;
400 #endif /* INET */
401
402 #ifdef INET6
403 case AF_INET6: /* Ugly... */
404 /* Copy and "cook" the IPv6 header. */
405 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
406
407 /* We don't do IPv6 Jumbograms. */
408 if (ip6.ip6_plen == 0) {
409 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
410 m_freem(m);
411 return EMSGSIZE;
412 }
413
414 ip6.ip6_flow = 0;
415 ip6.ip6_hlim = 0;
416 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
417 ip6.ip6_vfc |= IPV6_VERSION;
418
419 /* Scoped address handling. */
420 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
421 ip6.ip6_src.s6_addr16[1] = 0;
422 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
423 ip6.ip6_dst.s6_addr16[1] = 0;
424
425 /* Done with IPv6 header. */
426 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
427
428 /* Let's deal with the remaining headers (if any). */
429 if (skip - sizeof(struct ip6_hdr) > 0) {
430 if (m->m_len <= skip) {
431 ptr = (unsigned char *) malloc(
432 skip - sizeof(struct ip6_hdr),
433 M_XDATA, M_NOWAIT);
434 if (ptr == NULL) {
435 DPRINTF(("%s: failed to allocate memory"
436 "for IPv6 headers\n",__func__));
437 m_freem(m);
438 return ENOBUFS;
439 }
440
441 /*
442 * Copy all the protocol headers after
443 * the IPv6 header.
444 */
445 m_copydata(m, sizeof(struct ip6_hdr),
446 skip - sizeof(struct ip6_hdr), ptr);
447 alloc = 1;
448 } else {
449 /* No need to allocate memory. */
450 ptr = mtod(m, unsigned char *) +
451 sizeof(struct ip6_hdr);
452 alloc = 0;
453 }
454 } else
455 break;
456
457 off = ip6.ip6_nxt & 0xff; /* Next header type. */
458
459 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
460 switch (off) {
461 case IPPROTO_HOPOPTS:
462 case IPPROTO_DSTOPTS:
463 ip6e = (struct ip6_ext *) (ptr + len);
464
465 /*
466 * Process the mutable/immutable
467 * options -- borrows heavily from the
468 * KAME code.
469 */
470 for (count = len + sizeof(struct ip6_ext);
471 count < len + ((ip6e->ip6e_len + 1) << 3);) {
472 if (ptr[count] == IP6OPT_PAD1) {
473 count++;
474 continue; /* Skip padding. */
475 }
476
477 /* Sanity check. */
478 if (count > len +
479 ((ip6e->ip6e_len + 1) << 3)) {
480 m_freem(m);
481
482 /* Free, if we allocated. */
483 if (alloc)
484 FREE(ptr, M_XDATA);
485 return EINVAL;
486 }
487
488 ad = ptr[count + 1];
489
490 /* If mutable option, zeroize. */
491 if (ptr[count] & IP6OPT_MUTABLE)
492 bcopy(ipseczeroes, ptr + count,
493 ptr[count + 1]);
494
495 count += ad;
496
497 /* Sanity check. */
498 if (count >
499 skip - sizeof(struct ip6_hdr)) {
500 m_freem(m);
501
502 /* Free, if we allocated. */
503 if (alloc)
504 FREE(ptr, M_XDATA);
505 return EINVAL;
506 }
507 }
508
509 /* Advance. */
510 len += ((ip6e->ip6e_len + 1) << 3);
511 off = ip6e->ip6e_nxt;
512 break;
513
514 case IPPROTO_ROUTING:
515 /*
516 * Always include routing headers in
517 * computation.
518 */
519 ip6e = (struct ip6_ext *) (ptr + len);
520 len += ((ip6e->ip6e_len + 1) << 3);
521 off = ip6e->ip6e_nxt;
522 break;
523
524 default:
525 DPRINTF(("%s: unexpected IPv6 header type %d",
526 __func__, off));
527 if (alloc)
528 FREE(ptr, M_XDATA);
529 m_freem(m);
530 return EINVAL;
531 }
532
533 /* Copyback and free, if we allocated. */
534 if (alloc) {
535 m_copyback(m, sizeof(struct ip6_hdr),
536 skip - sizeof(struct ip6_hdr), ptr);
537 free(ptr, M_XDATA);
538 }
539
540 break;
541 #endif /* INET6 */
542 }
543
544 return 0;
545 }
546
547 /*
548 * ah_input() gets called to verify that an input packet
549 * passes authentication.
550 */
551 static int
552 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
553 {
554 struct auth_hash *ahx;
555 struct tdb_ident *tdbi;
556 struct tdb_crypto *tc;
557 struct m_tag *mtag;
558 struct newah *ah;
559 int hl, rplen, authsize;
560
561 struct cryptodesc *crda;
562 struct cryptop *crp;
563
564 IPSEC_SPLASSERT_SOFTNET(__func__);
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 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 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 ahstat.ahs_badauthl++;
603 m_freem(m);
604 return EACCES;
605 }
606 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 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_key = _KEYBUF(sav->key_auth);
627 crda->crd_klen = _KEYBITS(sav->key_auth);
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 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 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 */
722 static int
723 ah_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 NET_LOCK_GIANT();
739
740 crd = crp->crp_desc;
741
742 tc = (struct tdb_crypto *) crp->crp_opaque;
743 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
744 skip = tc->tc_skip;
745 nxt = tc->tc_nxt;
746 protoff = tc->tc_protoff;
747 mtag = (struct m_tag *) tc->tc_ptr;
748 m = (struct mbuf *) crp->crp_buf;
749
750 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
751 if (sav == NULL) {
752 ahstat.ahs_notdb++;
753 DPRINTF(("%s: SA expired while in crypto\n", __func__));
754 error = ENOBUFS; /*XXX*/
755 goto bad;
756 }
757
758 saidx = &sav->sah->saidx;
759 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
760 saidx->dst.sa.sa_family == AF_INET6,
761 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
762
763 ahx = (struct auth_hash *) sav->tdb_authalgxform;
764
765 /* Check for crypto errors. */
766 if (crp->crp_etype) {
767 if (sav->tdb_cryptoid != 0)
768 sav->tdb_cryptoid = crp->crp_sid;
769
770 if (crp->crp_etype == EAGAIN) {
771 error = crypto_dispatch(crp);
772 NET_UNLOCK_GIANT();
773 return error;
774 }
775
776 ahstat.ahs_noxform++;
777 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
778 error = crp->crp_etype;
779 goto bad;
780 } else {
781 ahstat.ahs_hist[sav->alg_auth]++;
782 crypto_freereq(crp); /* No longer needed. */
783 crp = NULL;
784 }
785
786 /* Shouldn't happen... */
787 if (m == NULL) {
788 ahstat.ahs_crypto++;
789 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
790 error = EINVAL;
791 goto bad;
792 }
793
794 /* Figure out header size. */
795 rplen = HDRSIZE(sav);
796 authsize = AUTHSIZE(sav);
797
798 /* Copy authenticator off the packet. */
799 m_copydata(m, skip + rplen, authsize, calc);
800
801 /*
802 * If we have an mtag, we don't need to verify the authenticator --
803 * it has been verified by an IPsec-aware NIC.
804 */
805 if (mtag == NULL) {
806 ptr = (caddr_t) (tc + 1);
807
808 /* Verify authenticator. */
809 if (bcmp(ptr + skip + rplen, calc, authsize)) {
810 DPRINTF(("%s: authentication hash mismatch for packet "
811 "in SA %s/%08lx\n", __func__,
812 ipsec_address(&saidx->dst),
813 (u_long) ntohl(sav->spi)));
814 ahstat.ahs_badauth++;
815 error = EACCES;
816 goto bad;
817 }
818
819 /* Fix the Next Protocol field. */
820 ((u_int8_t *) ptr)[protoff] = nxt;
821
822 /* Copyback the saved (uncooked) network headers. */
823 m_copyback(m, 0, skip, ptr);
824 } else {
825 /* Fix the Next Protocol field. */
826 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
827 }
828
829 free(tc, M_XDATA), tc = NULL; /* No longer needed */
830
831 /*
832 * Header is now authenticated.
833 */
834 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
835
836 /*
837 * Update replay sequence number, if appropriate.
838 */
839 if (sav->replay) {
840 u_int32_t seq;
841
842 m_copydata(m, skip + offsetof(struct newah, ah_seq),
843 sizeof (seq), (caddr_t) &seq);
844 if (ipsec_updatereplay(ntohl(seq), sav)) {
845 ahstat.ahs_replay++;
846 error = ENOBUFS; /*XXX as above*/
847 goto bad;
848 }
849 }
850
851 /*
852 * Remove the AH header and authenticator from the mbuf.
853 */
854 error = m_striphdr(m, skip, rplen + authsize);
855 if (error) {
856 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
857 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
858
859 ahstat.ahs_hdrops++;
860 goto bad;
861 }
862
863 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
864
865 KEY_FREESAV(&sav);
866 NET_UNLOCK_GIANT();
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 NET_UNLOCK_GIANT();
878 return error;
879 }
880
881 /*
882 * AH output routine, called by ipsec[46]_process_packet().
883 */
884 static int
885 ah_output(
886 struct mbuf *m,
887 struct ipsecrequest *isr,
888 struct mbuf **mp,
889 int skip,
890 int protoff)
891 {
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 IPSEC_SPLASSERT_SOFTNET(__func__);
904
905 sav = isr->sav;
906 IPSEC_ASSERT(sav != NULL, ("null SA"));
907 ahx = sav->tdb_authalgxform;
908 IPSEC_ASSERT(ahx != NULL, ("null authentication xform"));
909
910 ahstat.ahs_output++;
911
912 /* Figure out header size. */
913 rplen = HDRSIZE(sav);
914
915 /* Check for maximum packet size violations. */
916 switch (sav->sah->saidx.dst.sa.sa_family) {
917 #ifdef INET
918 case AF_INET:
919 maxpacketsize = IP_MAXPACKET;
920 break;
921 #endif /* INET */
922 #ifdef INET6
923 case AF_INET6:
924 maxpacketsize = IPV6_MAXPACKET;
925 break;
926 #endif /* INET6 */
927 default:
928 DPRINTF(("%s: unknown/unsupported protocol family %u, "
929 "SA %s/%08lx\n", __func__,
930 sav->sah->saidx.dst.sa.sa_family,
931 ipsec_address(&sav->sah->saidx.dst),
932 (u_long) ntohl(sav->spi)));
933 ahstat.ahs_nopf++;
934 error = EPFNOSUPPORT;
935 goto bad;
936 }
937 authsize = AUTHSIZE(sav);
938 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
939 DPRINTF(("%s: packet in SA %s/%08lx got too big "
940 "(len %u, max len %u)\n", __func__,
941 ipsec_address(&sav->sah->saidx.dst),
942 (u_long) ntohl(sav->spi),
943 rplen + authsize + m->m_pkthdr.len, maxpacketsize));
944 ahstat.ahs_toobig++;
945 error = EMSGSIZE;
946 goto bad;
947 }
948
949 /* Update the counters. */
950 ahstat.ahs_obytes += m->m_pkthdr.len - skip;
951
952 m = m_unshare(m, M_NOWAIT);
953 if (m == NULL) {
954 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
955 ipsec_address(&sav->sah->saidx.dst),
956 (u_long) ntohl(sav->spi)));
957 ahstat.ahs_hdrops++;
958 error = ENOBUFS;
959 goto bad;
960 }
961
962 /* Inject AH header. */
963 mi = m_makespace(m, skip, rplen + authsize, &roff);
964 if (mi == NULL) {
965 DPRINTF(("%s: failed to inject %u byte AH header for SA "
966 "%s/%08lx\n", __func__,
967 rplen + authsize,
968 ipsec_address(&sav->sah->saidx.dst),
969 (u_long) ntohl(sav->spi)));
970 ahstat.ahs_hdrops++; /*XXX differs from openbsd */
971 error = ENOBUFS;
972 goto bad;
973 }
974
975 /*
976 * The AH header is guaranteed by m_makespace() to be in
977 * contiguous memory, at roff bytes offset into the returned mbuf.
978 */
979 ah = (struct newah *)(mtod(mi, caddr_t) + roff);
980
981 /* Initialize the AH header. */
982 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
983 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
984 ah->ah_reserve = 0;
985 ah->ah_spi = sav->spi;
986
987 /* Zeroize authenticator. */
988 m_copyback(m, skip + rplen, authsize, ipseczeroes);
989
990 /* Insert packet replay counter, as requested. */
991 if (sav->replay) {
992 if (sav->replay->count == ~0 &&
993 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
994 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n",
995 __func__,
996 ipsec_address(&sav->sah->saidx.dst),
997 (u_long) ntohl(sav->spi)));
998 ahstat.ahs_wrap++;
999 error = EINVAL;
1000 goto bad;
1001 }
1002 sav->replay->count++;
1003 ah->ah_seq = htonl(sav->replay->count);
1004 }
1005
1006 /* Get crypto descriptors. */
1007 crp = crypto_getreq(1);
1008 if (crp == NULL) {
1009 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1010 __func__));
1011 ahstat.ahs_crypto++;
1012 error = ENOBUFS;
1013 goto bad;
1014 }
1015
1016 crda = crp->crp_desc;
1017
1018 crda->crd_skip = 0;
1019 crda->crd_inject = skip + rplen;
1020 crda->crd_len = m->m_pkthdr.len;
1021
1022 /* Authentication operation. */
1023 crda->crd_alg = ahx->type;
1024 crda->crd_key = _KEYBUF(sav->key_auth);
1025 crda->crd_klen = _KEYBITS(sav->key_auth);
1026
1027 /* Allocate IPsec-specific opaque crypto info. */
1028 tc = (struct tdb_crypto *) malloc(
1029 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1030 if (tc == NULL) {
1031 crypto_freereq(crp);
1032 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1033 ahstat.ahs_crypto++;
1034 error = ENOBUFS;
1035 goto bad;
1036 }
1037
1038 /* Save the skipped portion of the packet. */
1039 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1040
1041 /*
1042 * Fix IP header length on the header used for
1043 * authentication. We don't need to fix the original
1044 * header length as it will be fixed by our caller.
1045 */
1046 switch (sav->sah->saidx.dst.sa.sa_family) {
1047 #ifdef INET
1048 case AF_INET:
1049 bcopy(((caddr_t)(tc + 1)) +
1050 offsetof(struct ip, ip_len),
1051 (caddr_t) &iplen, sizeof(u_int16_t));
1052 iplen = htons(ntohs(iplen) + rplen + authsize);
1053 m_copyback(m, offsetof(struct ip, ip_len),
1054 sizeof(u_int16_t), (caddr_t) &iplen);
1055 break;
1056 #endif /* INET */
1057
1058 #ifdef INET6
1059 case AF_INET6:
1060 bcopy(((caddr_t)(tc + 1)) +
1061 offsetof(struct ip6_hdr, ip6_plen),
1062 (caddr_t) &iplen, sizeof(u_int16_t));
1063 iplen = htons(ntohs(iplen) + rplen + authsize);
1064 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1065 sizeof(u_int16_t), (caddr_t) &iplen);
1066 break;
1067 #endif /* INET6 */
1068 }
1069
1070 /* Fix the Next Header field in saved header. */
1071 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1072
1073 /* Update the Next Protocol field in the IP header. */
1074 prot = IPPROTO_AH;
1075 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1076
1077 /* "Massage" the packet headers for crypto processing. */
1078 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1079 skip, ahx->type, 1);
1080 if (error != 0) {
1081 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1082 free(tc, M_XDATA);
1083 crypto_freereq(crp);
1084 goto bad;
1085 }
1086
1087 /* Crypto operation descriptor. */
1088 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1089 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1090 crp->crp_buf = (caddr_t) m;
1091 crp->crp_callback = ah_output_cb;
1092 crp->crp_sid = sav->tdb_cryptoid;
1093 crp->crp_opaque = (caddr_t) tc;
1094
1095 /* These are passed as-is to the callback. */
1096 tc->tc_isr = isr;
1097 tc->tc_spi = sav->spi;
1098 tc->tc_dst = sav->sah->saidx.dst;
1099 tc->tc_proto = sav->sah->saidx.proto;
1100 tc->tc_skip = skip;
1101 tc->tc_protoff = protoff;
1102
1103 return crypto_dispatch(crp);
1104 bad:
1105 if (m)
1106 m_freem(m);
1107 return (error);
1108 }
1109
1110 /*
1111 * AH output callback from the crypto driver.
1112 */
1113 static int
1114 ah_output_cb(struct cryptop *crp)
1115 {
1116 int skip, protoff, error;
1117 struct tdb_crypto *tc;
1118 struct ipsecrequest *isr;
1119 struct secasvar *sav;
1120 struct mbuf *m;
1121 caddr_t ptr;
1122 int err;
1123
1124 NET_LOCK_GIANT();
1125
1126 tc = (struct tdb_crypto *) crp->crp_opaque;
1127 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1128 skip = tc->tc_skip;
1129 protoff = tc->tc_protoff;
1130 ptr = (caddr_t) (tc + 1);
1131 m = (struct mbuf *) crp->crp_buf;
1132
1133 isr = tc->tc_isr;
1134 IPSECREQUEST_LOCK(isr);
1135 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1136 if (sav == NULL) {
1137 ahstat.ahs_notdb++;
1138 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1139 error = ENOBUFS; /*XXX*/
1140 goto bad;
1141 }
1142 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1143
1144 /* Check for crypto errors. */
1145 if (crp->crp_etype) {
1146 if (sav->tdb_cryptoid != 0)
1147 sav->tdb_cryptoid = crp->crp_sid;
1148
1149 if (crp->crp_etype == EAGAIN) {
1150 KEY_FREESAV(&sav);
1151 IPSECREQUEST_UNLOCK(isr);
1152 error = crypto_dispatch(crp);
1153 NET_UNLOCK_GIANT();
1154 return error;
1155 }
1156
1157 ahstat.ahs_noxform++;
1158 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1159 error = crp->crp_etype;
1160 goto bad;
1161 }
1162
1163 /* Shouldn't happen... */
1164 if (m == NULL) {
1165 ahstat.ahs_crypto++;
1166 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1167 error = EINVAL;
1168 goto bad;
1169 }
1170 ahstat.ahs_hist[sav->alg_auth]++;
1171
1172 /*
1173 * Copy original headers (with the new protocol number) back
1174 * in place.
1175 */
1176 m_copyback(m, 0, skip, ptr);
1177
1178 /* No longer needed. */
1179 free(tc, M_XDATA);
1180 crypto_freereq(crp);
1181
1182 /* NB: m is reclaimed by ipsec_process_done. */
1183 err = ipsec_process_done(m, isr);
1184 KEY_FREESAV(&sav);
1185 IPSECREQUEST_UNLOCK(isr);
1186 NET_UNLOCK_GIANT();
1187 return err;
1188 bad:
1189 if (sav)
1190 KEY_FREESAV(&sav);
1191 IPSECREQUEST_UNLOCK(isr);
1192 if (m)
1193 m_freem(m);
1194 free(tc, M_XDATA);
1195 crypto_freereq(crp);
1196 NET_UNLOCK_GIANT();
1197 return error;
1198 }
1199
1200 static struct xformsw ah_xformsw = {
1201 XF_AH, XFT_AUTH, "IPsec AH",
1202 ah_init, ah_zeroize, ah_input, ah_output,
1203 };
1204
1205 static void
1206 ah_attach(void)
1207 {
1208 xform_register(&ah_xformsw);
1209 }
1210 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
Cache object: 45647830294010e634cb97a4b353b7c7
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