1 /* $FreeBSD: releng/5.4/sys/netipsec/xform_ah.c 141090 2005-01-31 23:27:04Z imp $ */
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 gets
85 * this size from the xform but is (currently) always 12.
86 */
87 #define AUTHSIZE(sav) \
88 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
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_96;
120 case SADB_AALG_SHA1HMAC:
121 return &auth_hash_hmac_sha1_96;
122 case SADB_X_AALG_RIPEMD160HMAC:
123 return &auth_hash_hmac_ripemd_160_96;
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
206 return 0;
207 }
208
209 /*
210 * ah_init() is called when an SPI is being set up.
211 */
212 static int
213 ah_init(struct secasvar *sav, struct xformsw *xsp)
214 {
215 struct cryptoini cria;
216 int error;
217
218 error = ah_init0(sav, xsp, &cria);
219 return error ? error :
220 crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support);
221 }
222
223 /*
224 * Paranoia.
225 *
226 * NB: public for use by esp_zeroize (XXX).
227 */
228 int
229 ah_zeroize(struct secasvar *sav)
230 {
231 int err;
232
233 if (sav->key_auth)
234 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
235
236 err = crypto_freesession(sav->tdb_cryptoid);
237 sav->tdb_cryptoid = 0;
238 sav->tdb_authalgxform = NULL;
239 sav->tdb_xform = NULL;
240 return err;
241 }
242
243 /*
244 * Massage IPv4/IPv6 headers for AH processing.
245 */
246 static int
247 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
248 {
249 struct mbuf *m = *m0;
250 unsigned char *ptr;
251 int off, count;
252
253 #ifdef INET
254 struct ip *ip;
255 #endif /* INET */
256
257 #ifdef INET6
258 struct ip6_ext *ip6e;
259 struct ip6_hdr ip6;
260 int alloc, len, ad;
261 #endif /* INET6 */
262
263 switch (proto) {
264 #ifdef INET
265 case AF_INET:
266 /*
267 * This is the least painful way of dealing with IPv4 header
268 * and option processing -- just make sure they're in
269 * contiguous memory.
270 */
271 *m0 = m = m_pullup(m, skip);
272 if (m == NULL) {
273 DPRINTF(("%s: m_pullup failed\n", __func__));
274 return ENOBUFS;
275 }
276
277 /* Fix the IP header */
278 ip = mtod(m, struct ip *);
279 if (ah_cleartos)
280 ip->ip_tos = 0;
281 ip->ip_ttl = 0;
282 ip->ip_sum = 0;
283
284 /*
285 * On input, fix ip_len which has been byte-swapped
286 * at ip_input().
287 */
288 if (!out) {
289 ip->ip_len = htons(ip->ip_len + skip);
290
291 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
292 ip->ip_off = htons(ip->ip_off & IP_DF);
293 else
294 ip->ip_off = 0;
295 } else {
296 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
297 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF);
298 else
299 ip->ip_off = 0;
300 }
301
302 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
303
304 /* IPv4 option processing */
305 for (off = sizeof(struct ip); off < skip;) {
306 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
307 off + 1 < skip)
308 ;
309 else {
310 DPRINTF(("%s: illegal IPv4 option length for "
311 "option %d\n", __func__, ptr[off]));
312
313 m_freem(m);
314 return EINVAL;
315 }
316
317 switch (ptr[off]) {
318 case IPOPT_EOL:
319 off = skip; /* End the loop. */
320 break;
321
322 case IPOPT_NOP:
323 off++;
324 break;
325
326 case IPOPT_SECURITY: /* 0x82 */
327 case 0x85: /* Extended security. */
328 case 0x86: /* Commercial security. */
329 case 0x94: /* Router alert */
330 case 0x95: /* RFC1770 */
331 /* Sanity check for option length. */
332 if (ptr[off + 1] < 2) {
333 DPRINTF(("%s: illegal IPv4 option "
334 "length for option %d\n",
335 __func__, ptr[off]));
336
337 m_freem(m);
338 return EINVAL;
339 }
340
341 off += ptr[off + 1];
342 break;
343
344 case IPOPT_LSRR:
345 case IPOPT_SSRR:
346 /* Sanity check for option length. */
347 if (ptr[off + 1] < 2) {
348 DPRINTF(("%s: illegal IPv4 option "
349 "length for option %d\n",
350 __func__, ptr[off]));
351
352 m_freem(m);
353 return EINVAL;
354 }
355
356 /*
357 * On output, if we have either of the
358 * source routing options, we should
359 * swap the destination address of the
360 * IP header with the last address
361 * specified in the option, as that is
362 * what the destination's IP header
363 * will look like.
364 */
365 if (out)
366 bcopy(ptr + off + ptr[off + 1] -
367 sizeof(struct in_addr),
368 &(ip->ip_dst), sizeof(struct in_addr));
369
370 /* Fall through */
371 default:
372 /* Sanity check for option length. */
373 if (ptr[off + 1] < 2) {
374 DPRINTF(("%s: illegal IPv4 option "
375 "length for option %d\n",
376 __func__, ptr[off]));
377 m_freem(m);
378 return EINVAL;
379 }
380
381 /* Zeroize all other options. */
382 count = ptr[off + 1];
383 bcopy(ipseczeroes, ptr, count);
384 off += count;
385 break;
386 }
387
388 /* Sanity check. */
389 if (off > skip) {
390 DPRINTF(("%s: malformed IPv4 options header\n",
391 __func__));
392
393 m_freem(m);
394 return EINVAL;
395 }
396 }
397
398 break;
399 #endif /* INET */
400
401 #ifdef INET6
402 case AF_INET6: /* Ugly... */
403 /* Copy and "cook" the IPv6 header. */
404 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6);
405
406 /* We don't do IPv6 Jumbograms. */
407 if (ip6.ip6_plen == 0) {
408 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__));
409 m_freem(m);
410 return EMSGSIZE;
411 }
412
413 ip6.ip6_flow = 0;
414 ip6.ip6_hlim = 0;
415 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
416 ip6.ip6_vfc |= IPV6_VERSION;
417
418 /* Scoped address handling. */
419 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
420 ip6.ip6_src.s6_addr16[1] = 0;
421 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
422 ip6.ip6_dst.s6_addr16[1] = 0;
423
424 /* Done with IPv6 header. */
425 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6);
426
427 /* Let's deal with the remaining headers (if any). */
428 if (skip - sizeof(struct ip6_hdr) > 0) {
429 if (m->m_len <= skip) {
430 ptr = (unsigned char *) malloc(
431 skip - sizeof(struct ip6_hdr),
432 M_XDATA, M_NOWAIT);
433 if (ptr == NULL) {
434 DPRINTF(("%s: failed to allocate memory"
435 "for IPv6 headers\n",__func__));
436 m_freem(m);
437 return ENOBUFS;
438 }
439
440 /*
441 * Copy all the protocol headers after
442 * the IPv6 header.
443 */
444 m_copydata(m, sizeof(struct ip6_hdr),
445 skip - sizeof(struct ip6_hdr), ptr);
446 alloc = 1;
447 } else {
448 /* No need to allocate memory. */
449 ptr = mtod(m, unsigned char *) +
450 sizeof(struct ip6_hdr);
451 alloc = 0;
452 }
453 } else
454 break;
455
456 off = ip6.ip6_nxt & 0xff; /* Next header type. */
457
458 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
459 switch (off) {
460 case IPPROTO_HOPOPTS:
461 case IPPROTO_DSTOPTS:
462 ip6e = (struct ip6_ext *) (ptr + len);
463
464 /*
465 * Process the mutable/immutable
466 * options -- borrows heavily from the
467 * KAME code.
468 */
469 for (count = len + sizeof(struct ip6_ext);
470 count < len + ((ip6e->ip6e_len + 1) << 3);) {
471 if (ptr[count] == IP6OPT_PAD1) {
472 count++;
473 continue; /* Skip padding. */
474 }
475
476 /* Sanity check. */
477 if (count > len +
478 ((ip6e->ip6e_len + 1) << 3)) {
479 m_freem(m);
480
481 /* Free, if we allocated. */
482 if (alloc)
483 FREE(ptr, M_XDATA);
484 return EINVAL;
485 }
486
487 ad = ptr[count + 1];
488
489 /* If mutable option, zeroize. */
490 if (ptr[count] & IP6OPT_MUTABLE)
491 bcopy(ipseczeroes, ptr + count,
492 ptr[count + 1]);
493
494 count += ad;
495
496 /* Sanity check. */
497 if (count >
498 skip - sizeof(struct ip6_hdr)) {
499 m_freem(m);
500
501 /* Free, if we allocated. */
502 if (alloc)
503 FREE(ptr, M_XDATA);
504 return EINVAL;
505 }
506 }
507
508 /* Advance. */
509 len += ((ip6e->ip6e_len + 1) << 3);
510 off = ip6e->ip6e_nxt;
511 break;
512
513 case IPPROTO_ROUTING:
514 /*
515 * Always include routing headers in
516 * computation.
517 */
518 ip6e = (struct ip6_ext *) (ptr + len);
519 len += ((ip6e->ip6e_len + 1) << 3);
520 off = ip6e->ip6e_nxt;
521 break;
522
523 default:
524 DPRINTF(("%s: unexpected IPv6 header type %d",
525 __func__, off));
526 if (alloc)
527 FREE(ptr, M_XDATA);
528 m_freem(m);
529 return EINVAL;
530 }
531
532 /* Copyback and free, if we allocated. */
533 if (alloc) {
534 m_copyback(m, sizeof(struct ip6_hdr),
535 skip - sizeof(struct ip6_hdr), ptr);
536 free(ptr, M_XDATA);
537 }
538
539 break;
540 #endif /* INET6 */
541 }
542
543 return 0;
544 }
545
546 /*
547 * ah_input() gets called to verify that an input packet
548 * passes authentication.
549 */
550 static int
551 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
552 {
553 struct auth_hash *ahx;
554 struct tdb_ident *tdbi;
555 struct tdb_crypto *tc;
556 struct m_tag *mtag;
557 struct newah *ah;
558 int hl, rplen, authsize;
559
560 struct cryptodesc *crda;
561 struct cryptop *crp;
562
563 IPSEC_SPLASSERT_SOFTNET(__func__);
564
565 IPSEC_ASSERT(sav != NULL, ("null SA"));
566 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key"));
567 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
568 ("null authentication xform"));
569
570 /* Figure out header size. */
571 rplen = HDRSIZE(sav);
572
573 /* XXX don't pullup, just copy header */
574 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
575 if (ah == NULL) {
576 DPRINTF(("ah_input: cannot pullup header\n"));
577 ahstat.ahs_hdrops++; /*XXX*/
578 m_freem(m);
579 return ENOBUFS;
580 }
581
582 /* Check replay window, if applicable. */
583 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
584 ahstat.ahs_replay++;
585 DPRINTF(("%s: packet replay failure: %s\n", __func__,
586 ipsec_logsastr(sav)));
587 m_freem(m);
588 return ENOBUFS;
589 }
590
591 /* Verify AH header length. */
592 hl = ah->ah_len * sizeof (u_int32_t);
593 ahx = sav->tdb_authalgxform;
594 authsize = AUTHSIZE(sav);
595 if (hl != authsize + rplen - sizeof (struct ah)) {
596 DPRINTF(("%s: bad authenticator length %u (expecting %lu)"
597 " for packet in SA %s/%08lx\n", __func__,
598 hl, (u_long) (authsize + rplen - sizeof (struct ah)),
599 ipsec_address(&sav->sah->saidx.dst),
600 (u_long) ntohl(sav->spi)));
601 ahstat.ahs_badauthl++;
602 m_freem(m);
603 return EACCES;
604 }
605 ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
606
607 /* Get crypto descriptors. */
608 crp = crypto_getreq(1);
609 if (crp == NULL) {
610 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__));
611 ahstat.ahs_crypto++;
612 m_freem(m);
613 return ENOBUFS;
614 }
615
616 crda = crp->crp_desc;
617 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor"));
618
619 crda->crd_skip = 0;
620 crda->crd_len = m->m_pkthdr.len;
621 crda->crd_inject = skip + rplen;
622
623 /* Authentication operation. */
624 crda->crd_alg = ahx->type;
625 crda->crd_key = _KEYBUF(sav->key_auth);
626 crda->crd_klen = _KEYBITS(sav->key_auth);
627
628 /* Find out if we've already done crypto. */
629 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
630 mtag != NULL;
631 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
632 tdbi = (struct tdb_ident *) (mtag + 1);
633 if (tdbi->proto == sav->sah->saidx.proto &&
634 tdbi->spi == sav->spi &&
635 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
636 sizeof (union sockaddr_union)))
637 break;
638 }
639
640 /* Allocate IPsec-specific opaque crypto info. */
641 if (mtag == NULL) {
642 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
643 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
644 } else {
645 /* Hash verification has already been done successfully. */
646 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
647 M_XDATA, M_NOWAIT|M_ZERO);
648 }
649 if (tc == NULL) {
650 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
651 ahstat.ahs_crypto++;
652 crypto_freereq(crp);
653 m_freem(m);
654 return ENOBUFS;
655 }
656
657 /* Only save information if crypto processing is needed. */
658 if (mtag == NULL) {
659 int error;
660
661 /*
662 * Save the authenticator, the skipped portion of the packet,
663 * and the AH header.
664 */
665 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
666
667 /* Zeroize the authenticator on the packet. */
668 m_copyback(m, skip + rplen, authsize, ipseczeroes);
669
670 /* "Massage" the packet headers for crypto processing. */
671 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
672 skip, ahx->type, 0);
673 if (error != 0) {
674 /* NB: mbuf is free'd by ah_massage_headers */
675 ahstat.ahs_hdrops++;
676 free(tc, M_XDATA);
677 crypto_freereq(crp);
678 return error;
679 }
680 }
681
682 /* Crypto operation descriptor. */
683 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
684 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
685 crp->crp_buf = (caddr_t) m;
686 crp->crp_callback = ah_input_cb;
687 crp->crp_sid = sav->tdb_cryptoid;
688 crp->crp_opaque = (caddr_t) tc;
689
690 /* These are passed as-is to the callback. */
691 tc->tc_spi = sav->spi;
692 tc->tc_dst = sav->sah->saidx.dst;
693 tc->tc_proto = sav->sah->saidx.proto;
694 tc->tc_nxt = ah->ah_nxt;
695 tc->tc_protoff = protoff;
696 tc->tc_skip = skip;
697 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
698
699 if (mtag == NULL)
700 return crypto_dispatch(crp);
701 else
702 return ah_input_cb(crp);
703 }
704
705 #ifdef INET6
706 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
707 if (saidx->dst.sa.sa_family == AF_INET6) { \
708 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
709 } else { \
710 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
711 } \
712 } while (0)
713 #else
714 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
715 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
716 #endif
717
718 /*
719 * AH input callback from the crypto driver.
720 */
721 static int
722 ah_input_cb(struct cryptop *crp)
723 {
724 int rplen, error, skip, protoff;
725 unsigned char calc[AH_ALEN_MAX];
726 struct mbuf *m;
727 struct cryptodesc *crd;
728 struct auth_hash *ahx;
729 struct tdb_crypto *tc;
730 struct m_tag *mtag;
731 struct secasvar *sav;
732 struct secasindex *saidx;
733 u_int8_t nxt;
734 caddr_t ptr;
735 int authsize;
736
737 crd = crp->crp_desc;
738
739 tc = (struct tdb_crypto *) crp->crp_opaque;
740 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
741 skip = tc->tc_skip;
742 nxt = tc->tc_nxt;
743 protoff = tc->tc_protoff;
744 mtag = (struct m_tag *) tc->tc_ptr;
745 m = (struct mbuf *) crp->crp_buf;
746
747 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
748 if (sav == NULL) {
749 ahstat.ahs_notdb++;
750 DPRINTF(("%s: SA expired while in crypto\n", __func__));
751 error = ENOBUFS; /*XXX*/
752 goto bad;
753 }
754
755 saidx = &sav->sah->saidx;
756 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
757 saidx->dst.sa.sa_family == AF_INET6,
758 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
759
760 ahx = (struct auth_hash *) sav->tdb_authalgxform;
761
762 /* Check for crypto errors. */
763 if (crp->crp_etype) {
764 if (sav->tdb_cryptoid != 0)
765 sav->tdb_cryptoid = crp->crp_sid;
766
767 if (crp->crp_etype == EAGAIN)
768 return crypto_dispatch(crp);
769
770 ahstat.ahs_noxform++;
771 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
772 error = crp->crp_etype;
773 goto bad;
774 } else {
775 ahstat.ahs_hist[sav->alg_auth]++;
776 crypto_freereq(crp); /* No longer needed. */
777 crp = NULL;
778 }
779
780 /* Shouldn't happen... */
781 if (m == NULL) {
782 ahstat.ahs_crypto++;
783 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
784 error = EINVAL;
785 goto bad;
786 }
787
788 /* Figure out header size. */
789 rplen = HDRSIZE(sav);
790 authsize = AUTHSIZE(sav);
791
792 /* Copy authenticator off the packet. */
793 m_copydata(m, skip + rplen, authsize, calc);
794
795 /*
796 * If we have an mtag, we don't need to verify the authenticator --
797 * it has been verified by an IPsec-aware NIC.
798 */
799 if (mtag == NULL) {
800 ptr = (caddr_t) (tc + 1);
801
802 /* Verify authenticator. */
803 if (bcmp(ptr + skip + rplen, calc, authsize)) {
804 DPRINTF(("%s: authentication hash mismatch for packet "
805 "in SA %s/%08lx\n", __func__,
806 ipsec_address(&saidx->dst),
807 (u_long) ntohl(sav->spi)));
808 ahstat.ahs_badauth++;
809 error = EACCES;
810 goto bad;
811 }
812
813 /* Fix the Next Protocol field. */
814 ((u_int8_t *) ptr)[protoff] = nxt;
815
816 /* Copyback the saved (uncooked) network headers. */
817 m_copyback(m, 0, skip, ptr);
818 } else {
819 /* Fix the Next Protocol field. */
820 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
821 }
822
823 free(tc, M_XDATA), tc = NULL; /* No longer needed */
824
825 /*
826 * Header is now authenticated.
827 */
828 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
829
830 /*
831 * Update replay sequence number, if appropriate.
832 */
833 if (sav->replay) {
834 u_int32_t seq;
835
836 m_copydata(m, skip + offsetof(struct newah, ah_seq),
837 sizeof (seq), (caddr_t) &seq);
838 if (ipsec_updatereplay(ntohl(seq), sav)) {
839 ahstat.ahs_replay++;
840 error = ENOBUFS; /*XXX as above*/
841 goto bad;
842 }
843 }
844
845 /*
846 * Remove the AH header and authenticator from the mbuf.
847 */
848 error = m_striphdr(m, skip, rplen + authsize);
849 if (error) {
850 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__,
851 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
852
853 ahstat.ahs_hdrops++;
854 goto bad;
855 }
856
857 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
858
859 KEY_FREESAV(&sav);
860
861 return error;
862 bad:
863 if (sav)
864 KEY_FREESAV(&sav);
865 if (m != NULL)
866 m_freem(m);
867 if (tc != NULL)
868 free(tc, M_XDATA);
869 if (crp != NULL)
870 crypto_freereq(crp);
871 return error;
872 }
873
874 /*
875 * AH output routine, called by ipsec[46]_process_packet().
876 */
877 static int
878 ah_output(
879 struct mbuf *m,
880 struct ipsecrequest *isr,
881 struct mbuf **mp,
882 int skip,
883 int protoff)
884 {
885 struct secasvar *sav;
886 struct auth_hash *ahx;
887 struct cryptodesc *crda;
888 struct tdb_crypto *tc;
889 struct mbuf *mi;
890 struct cryptop *crp;
891 u_int16_t iplen;
892 int error, rplen, authsize, maxpacketsize, roff;
893 u_int8_t prot;
894 struct newah *ah;
895
896 IPSEC_SPLASSERT_SOFTNET(__func__);
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 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 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 ahstat.ahs_toobig++;
938 error = EMSGSIZE;
939 goto bad;
940 }
941
942 /* Update the counters. */
943 ahstat.ahs_obytes += m->m_pkthdr.len - skip;
944
945 m = m_clone(m);
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 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 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 ahstat.ahs_wrap++;
992 error = EINVAL;
993 goto bad;
994 }
995 sav->replay->count++;
996 ah->ah_seq = htonl(sav->replay->count);
997 }
998
999 /* Get crypto descriptors. */
1000 crp = crypto_getreq(1);
1001 if (crp == NULL) {
1002 DPRINTF(("%s: failed to acquire crypto descriptors\n",
1003 __func__));
1004 ahstat.ahs_crypto++;
1005 error = ENOBUFS;
1006 goto bad;
1007 }
1008
1009 crda = crp->crp_desc;
1010
1011 crda->crd_skip = 0;
1012 crda->crd_inject = skip + rplen;
1013 crda->crd_len = m->m_pkthdr.len;
1014
1015 /* Authentication operation. */
1016 crda->crd_alg = ahx->type;
1017 crda->crd_key = _KEYBUF(sav->key_auth);
1018 crda->crd_klen = _KEYBITS(sav->key_auth);
1019
1020 /* Allocate IPsec-specific opaque crypto info. */
1021 tc = (struct tdb_crypto *) malloc(
1022 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1023 if (tc == NULL) {
1024 crypto_freereq(crp);
1025 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
1026 ahstat.ahs_crypto++;
1027 error = ENOBUFS;
1028 goto bad;
1029 }
1030
1031 /* Save the skipped portion of the packet. */
1032 m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1033
1034 /*
1035 * Fix IP header length on the header used for
1036 * authentication. We don't need to fix the original
1037 * header length as it will be fixed by our caller.
1038 */
1039 switch (sav->sah->saidx.dst.sa.sa_family) {
1040 #ifdef INET
1041 case AF_INET:
1042 bcopy(((caddr_t)(tc + 1)) +
1043 offsetof(struct ip, ip_len),
1044 (caddr_t) &iplen, sizeof(u_int16_t));
1045 iplen = htons(ntohs(iplen) + rplen + authsize);
1046 m_copyback(m, offsetof(struct ip, ip_len),
1047 sizeof(u_int16_t), (caddr_t) &iplen);
1048 break;
1049 #endif /* INET */
1050
1051 #ifdef INET6
1052 case AF_INET6:
1053 bcopy(((caddr_t)(tc + 1)) +
1054 offsetof(struct ip6_hdr, ip6_plen),
1055 (caddr_t) &iplen, sizeof(u_int16_t));
1056 iplen = htons(ntohs(iplen) + rplen + authsize);
1057 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1058 sizeof(u_int16_t), (caddr_t) &iplen);
1059 break;
1060 #endif /* INET6 */
1061 }
1062
1063 /* Fix the Next Header field in saved header. */
1064 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1065
1066 /* Update the Next Protocol field in the IP header. */
1067 prot = IPPROTO_AH;
1068 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1069
1070 /* "Massage" the packet headers for crypto processing. */
1071 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1072 skip, ahx->type, 1);
1073 if (error != 0) {
1074 m = NULL; /* mbuf was free'd by ah_massage_headers. */
1075 free(tc, M_XDATA);
1076 crypto_freereq(crp);
1077 goto bad;
1078 }
1079
1080 /* Crypto operation descriptor. */
1081 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1082 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
1083 crp->crp_buf = (caddr_t) m;
1084 crp->crp_callback = ah_output_cb;
1085 crp->crp_sid = sav->tdb_cryptoid;
1086 crp->crp_opaque = (caddr_t) tc;
1087
1088 /* These are passed as-is to the callback. */
1089 tc->tc_isr = isr;
1090 tc->tc_spi = sav->spi;
1091 tc->tc_dst = sav->sah->saidx.dst;
1092 tc->tc_proto = sav->sah->saidx.proto;
1093 tc->tc_skip = skip;
1094 tc->tc_protoff = protoff;
1095
1096 return crypto_dispatch(crp);
1097 bad:
1098 if (m)
1099 m_freem(m);
1100 return (error);
1101 }
1102
1103 /*
1104 * AH output callback from the crypto driver.
1105 */
1106 static int
1107 ah_output_cb(struct cryptop *crp)
1108 {
1109 int skip, protoff, error;
1110 struct tdb_crypto *tc;
1111 struct ipsecrequest *isr;
1112 struct secasvar *sav;
1113 struct mbuf *m;
1114 caddr_t ptr;
1115 int err;
1116
1117 tc = (struct tdb_crypto *) crp->crp_opaque;
1118 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
1119 skip = tc->tc_skip;
1120 protoff = tc->tc_protoff;
1121 ptr = (caddr_t) (tc + 1);
1122 m = (struct mbuf *) crp->crp_buf;
1123
1124 isr = tc->tc_isr;
1125 IPSECREQUEST_LOCK(isr);
1126 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1127 if (sav == NULL) {
1128 ahstat.ahs_notdb++;
1129 DPRINTF(("%s: SA expired while in crypto\n", __func__));
1130 error = ENOBUFS; /*XXX*/
1131 goto bad;
1132 }
1133 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n"));
1134
1135 /* Check for crypto errors. */
1136 if (crp->crp_etype) {
1137 if (sav->tdb_cryptoid != 0)
1138 sav->tdb_cryptoid = crp->crp_sid;
1139
1140 if (crp->crp_etype == EAGAIN) {
1141 KEY_FREESAV(&sav);
1142 IPSECREQUEST_UNLOCK(isr);
1143 return crypto_dispatch(crp);
1144 }
1145
1146 ahstat.ahs_noxform++;
1147 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
1148 error = crp->crp_etype;
1149 goto bad;
1150 }
1151
1152 /* Shouldn't happen... */
1153 if (m == NULL) {
1154 ahstat.ahs_crypto++;
1155 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
1156 error = EINVAL;
1157 goto bad;
1158 }
1159 ahstat.ahs_hist[sav->alg_auth]++;
1160
1161 /*
1162 * Copy original headers (with the new protocol number) back
1163 * in place.
1164 */
1165 m_copyback(m, 0, skip, ptr);
1166
1167 /* No longer needed. */
1168 free(tc, M_XDATA);
1169 crypto_freereq(crp);
1170
1171 /* NB: m is reclaimed by ipsec_process_done. */
1172 err = ipsec_process_done(m, isr);
1173 KEY_FREESAV(&sav);
1174 IPSECREQUEST_UNLOCK(isr);
1175
1176 return err;
1177 bad:
1178 if (sav)
1179 KEY_FREESAV(&sav);
1180 IPSECREQUEST_UNLOCK(isr);
1181 if (m)
1182 m_freem(m);
1183 free(tc, M_XDATA);
1184 crypto_freereq(crp);
1185 return error;
1186 }
1187
1188 static struct xformsw ah_xformsw = {
1189 XF_AH, XFT_AUTH, "IPsec AH",
1190 ah_init, ah_zeroize, ah_input, ah_output,
1191 };
1192
1193 static void
1194 ah_attach(void)
1195 {
1196 xform_register(&ah_xformsw);
1197 }
1198 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
Cache object: dc2657a24393e42fb2ea274db529a7a4
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