89#define V_esp_max_ivlen VNET(esp_max_ivlen)
90
91static int esp_input_cb(struct cryptop *op);
92static int esp_output_cb(struct cryptop *crp);
93
94/*
95 * NB: this is public for use by the PF_KEY support.
96 * NB: if you add support here; be sure to add code to esp_attach below!
97 */
98struct enc_xform *
99esp_algorithm_lookup(int alg)
100{
101 if (alg >= ESP_ALG_MAX)
102 return NULL;
103 switch (alg) {
104 case SADB_EALG_DESCBC:
105 return &enc_xform_des;
106 case SADB_EALG_3DESCBC:
107 return &enc_xform_3des;
108 case SADB_X_EALG_AES:
109 return &enc_xform_rijndael128;
110 case SADB_X_EALG_BLOWFISHCBC:
111 return &enc_xform_blf;
112 case SADB_X_EALG_CAST128CBC:
113 return &enc_xform_cast5;
114 case SADB_X_EALG_SKIPJACK:
115 return &enc_xform_skipjack;
116 case SADB_EALG_NULL:
117 return &enc_xform_null;
118 case SADB_X_EALG_CAMELLIACBC:
119 return &enc_xform_camellia;
120 }
121 return NULL;
122}
123
124size_t
125esp_hdrsiz(struct secasvar *sav)
126{
127 size_t size;
128
129 if (sav != NULL) {
130 /*XXX not right for null algorithm--does it matter??*/
131 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
132 ("SA with null xform"));
133 if (sav->flags & SADB_X_EXT_OLD)
134 size = sizeof (struct esp);
135 else
136 size = sizeof (struct newesp);
137 size += sav->tdb_encalgxform->blocksize + 9;
138 /*XXX need alg check???*/
139 if (sav->tdb_authalgxform != NULL && sav->replay)
140 size += ah_hdrsiz(sav);
141 } else {
142 /*
143 * base header size
144 * + max iv length for CBC mode
145 * + max pad length
146 * + sizeof (pad length field)
147 * + sizeof (next header field)
148 * + max icv supported.
149 */
150 size = sizeof (struct newesp) + V_esp_max_ivlen + 9 + 16;
151 }
152 return size;
153}
154
155/*
156 * esp_init() is called when an SPI is being set up.
157 */
158static int
159esp_init(struct secasvar *sav, struct xformsw *xsp)
160{
161 struct enc_xform *txform;
162 struct cryptoini cria, crie;
163 int keylen;
164 int error;
165
166 txform = esp_algorithm_lookup(sav->alg_enc);
167 if (txform == NULL) {
168 DPRINTF(("%s: unsupported encryption algorithm %d\n",
169 __func__, sav->alg_enc));
170 return EINVAL;
171 }
172 if (sav->key_enc == NULL) {
173 DPRINTF(("%s: no encoding key for %s algorithm\n",
174 __func__, txform->name));
175 return EINVAL;
176 }
177 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) {
178 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
179 __func__));
180 return EINVAL;
181 }
182 keylen = _KEYLEN(sav->key_enc);
183 if (txform->minkey > keylen || keylen > txform->maxkey) {
184 DPRINTF(("%s: invalid key length %u, must be in the range "
185 "[%u..%u] for algorithm %s\n", __func__,
186 keylen, txform->minkey, txform->maxkey,
187 txform->name));
188 return EINVAL;
189 }
190
191 /*
192 * NB: The null xform needs a non-zero blocksize to keep the
193 * crypto code happy but if we use it to set ivlen then
194 * the ESP header will be processed incorrectly. The
195 * compromise is to force it to zero here.
196 */
197 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize);
198 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK);
199 if (sav->iv == NULL) {
200 DPRINTF(("%s: no memory for IV\n", __func__));
201 return EINVAL;
202 }
203 key_randomfill(sav->iv, sav->ivlen); /*XXX*/
204
205 /*
206 * Setup AH-related state.
207 */
208 if (sav->alg_auth != 0) {
209 error = ah_init0(sav, xsp, &cria);
210 if (error)
211 return error;
212 }
213
214 /* NB: override anything set in ah_init0 */
215 sav->tdb_xform = xsp;
216 sav->tdb_encalgxform = txform;
217
218 /* Initialize crypto session. */
219 bzero(&crie, sizeof (crie));
220 crie.cri_alg = sav->tdb_encalgxform->type;
221 crie.cri_klen = _KEYBITS(sav->key_enc);
222 crie.cri_key = sav->key_enc->key_data;
223 /* XXX Rounds ? */
224
225 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
226 /* init both auth & enc */
227 crie.cri_next = &cria;
228 error = crypto_newsession(&sav->tdb_cryptoid,
229 &crie, V_crypto_support);
230 } else if (sav->tdb_encalgxform) {
231 error = crypto_newsession(&sav->tdb_cryptoid,
232 &crie, V_crypto_support);
233 } else if (sav->tdb_authalgxform) {
234 error = crypto_newsession(&sav->tdb_cryptoid,
235 &cria, V_crypto_support);
236 } else {
237 /* XXX cannot happen? */
238 DPRINTF(("%s: no encoding OR authentication xform!\n",
239 __func__));
240 error = EINVAL;
241 }
242 return error;
243}
244
245/*
246 * Paranoia.
247 */
248static int
249esp_zeroize(struct secasvar *sav)
250{
251 /* NB: ah_zerorize free's the crypto session state */
252 int error = ah_zeroize(sav);
253
254 if (sav->key_enc)
255 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
256 if (sav->iv) {
257 free(sav->iv, M_XDATA);
258 sav->iv = NULL;
259 }
260 sav->tdb_encalgxform = NULL;
261 sav->tdb_xform = NULL;
262 return error;
263}
264
265/*
266 * ESP input processing, called (eventually) through the protocol switch.
267 */
268static int
269esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
270{
271 struct auth_hash *esph;
272 struct enc_xform *espx;
273 struct tdb_ident *tdbi;
274 struct tdb_crypto *tc;
275 int plen, alen, hlen;
276 struct m_tag *mtag;
277 struct newesp *esp;
278
279 struct cryptodesc *crde;
280 struct cryptop *crp;
281
282 IPSEC_ASSERT(sav != NULL, ("null SA"));
283 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
284
285 /* Valid IP Packet length ? */
286 if ( (skip&3) || (m->m_pkthdr.len&3) ){
287 DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
288 __func__, skip, m->m_pkthdr.len));
289 V_espstat.esps_badilen++;
290 m_freem(m);
291 return EINVAL;
292 }
293
294 /* XXX don't pullup, just copy header */
295 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
296
297 esph = sav->tdb_authalgxform;
298 espx = sav->tdb_encalgxform;
299
300 /* Determine the ESP header length */
301 if (sav->flags & SADB_X_EXT_OLD)
302 hlen = sizeof (struct esp) + sav->ivlen;
303 else
304 hlen = sizeof (struct newesp) + sav->ivlen;
305 /* Authenticator hash size */
306 alen = esph ? AH_HMAC_HASHLEN : 0;
307
308 /*
309 * Verify payload length is multiple of encryption algorithm
310 * block size.
311 *
312 * NB: This works for the null algorithm because the blocksize
313 * is 4 and all packets must be 4-byte aligned regardless
314 * of the algorithm.
315 */
316 plen = m->m_pkthdr.len - (skip + hlen + alen);
317 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
318 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
319 " SA %s/%08lx\n", __func__,
320 plen, espx->blocksize,
321 ipsec_address(&sav->sah->saidx.dst),
322 (u_long) ntohl(sav->spi)));
323 V_espstat.esps_badilen++;
324 m_freem(m);
325 return EINVAL;
326 }
327
328 /*
329 * Check sequence number.
330 */
331 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
332 DPRINTF(("%s: packet replay check for %s\n", __func__,
333 ipsec_logsastr(sav))); /*XXX*/
334 V_espstat.esps_replay++;
335 m_freem(m);
336 return ENOBUFS; /*XXX*/
337 }
338
339 /* Update the counters */
340 V_espstat.esps_ibytes += m->m_pkthdr.len - (skip + hlen + alen);
341
342 /* Find out if we've already done crypto */
343 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
344 mtag != NULL;
345 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
346 tdbi = (struct tdb_ident *) (mtag + 1);
347 if (tdbi->proto == sav->sah->saidx.proto &&
348 tdbi->spi == sav->spi &&
349 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
350 sizeof(union sockaddr_union)))
351 break;
352 }
353
354 /* Get crypto descriptors */
355 crp = crypto_getreq(esph && espx ? 2 : 1);
356 if (crp == NULL) {
357 DPRINTF(("%s: failed to acquire crypto descriptors\n",
358 __func__));
359 V_espstat.esps_crypto++;
360 m_freem(m);
361 return ENOBUFS;
362 }
363
364 /* Get IPsec-specific opaque pointer */
365 if (esph == NULL || mtag != NULL)
366 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
367 M_XDATA, M_NOWAIT|M_ZERO);
368 else
369 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
370 M_XDATA, M_NOWAIT|M_ZERO);
371 if (tc == NULL) {
372 crypto_freereq(crp);
373 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
374 V_espstat.esps_crypto++;
375 m_freem(m);
376 return ENOBUFS;
377 }
378
379 tc->tc_ptr = (caddr_t) mtag;
380
381 if (esph) {
382 struct cryptodesc *crda = crp->crp_desc;
383
384 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
385
386 /* Authentication descriptor */
387 crda->crd_skip = skip;
388 crda->crd_len = m->m_pkthdr.len - (skip + alen);
389 crda->crd_inject = m->m_pkthdr.len - alen;
390
391 crda->crd_alg = esph->type;
392 crda->crd_key = sav->key_auth->key_data;
393 crda->crd_klen = _KEYBITS(sav->key_auth);
394
395 /* Copy the authenticator */
396 if (mtag == NULL)
397 m_copydata(m, m->m_pkthdr.len - alen, alen,
398 (caddr_t) (tc + 1));
399
400 /* Chain authentication request */
401 crde = crda->crd_next;
402 } else {
403 crde = crp->crp_desc;
404 }
405
406 /* Crypto operation descriptor */
407 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
408 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
409 crp->crp_buf = (caddr_t) m;
410 crp->crp_callback = esp_input_cb;
411 crp->crp_sid = sav->tdb_cryptoid;
412 crp->crp_opaque = (caddr_t) tc;
413
414 /* These are passed as-is to the callback */
415 tc->tc_spi = sav->spi;
416 tc->tc_dst = sav->sah->saidx.dst;
417 tc->tc_proto = sav->sah->saidx.proto;
418 tc->tc_protoff = protoff;
419 tc->tc_skip = skip;
420
421 /* Decryption descriptor */
422 if (espx) {
423 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
424 crde->crd_skip = skip + hlen;
425 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
426 crde->crd_inject = skip + hlen - sav->ivlen;
427
428 crde->crd_alg = espx->type;
429 crde->crd_key = sav->key_enc->key_data;
430 crde->crd_klen = _KEYBITS(sav->key_enc);
431 /* XXX Rounds ? */
432 }
433
434 if (mtag == NULL)
435 return crypto_dispatch(crp);
436 else
437 return esp_input_cb(crp);
438}
439
440#ifdef INET6
441#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
442 if (saidx->dst.sa.sa_family == AF_INET6) { \
443 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
444 } else { \
445 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
446 } \
447} while (0)
448#else
449#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
450 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
451#endif
452
453/*
454 * ESP input callback from the crypto driver.
455 */
456static int
457esp_input_cb(struct cryptop *crp)
458{
459 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
460 int hlen, skip, protoff, error;
461 struct mbuf *m;
462 struct cryptodesc *crd;
463 struct auth_hash *esph;
464 struct enc_xform *espx;
465 struct tdb_crypto *tc;
466 struct m_tag *mtag;
467 struct secasvar *sav;
468 struct secasindex *saidx;
469 caddr_t ptr;
470
471 crd = crp->crp_desc;
472 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
473
474 tc = (struct tdb_crypto *) crp->crp_opaque;
475 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
476 skip = tc->tc_skip;
477 protoff = tc->tc_protoff;
478 mtag = (struct m_tag *) tc->tc_ptr;
479 m = (struct mbuf *) crp->crp_buf;
480
481 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
482 if (sav == NULL) {
483 V_espstat.esps_notdb++;
484 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
485 __func__, ipsec_address(&tc->tc_dst),
486 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
487 error = ENOBUFS; /*XXX*/
488 goto bad;
489 }
490
491 saidx = &sav->sah->saidx;
492 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
493 saidx->dst.sa.sa_family == AF_INET6,
494 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
495
496 esph = sav->tdb_authalgxform;
497 espx = sav->tdb_encalgxform;
498
499 /* Check for crypto errors */
500 if (crp->crp_etype) {
501 /* Reset the session ID */
502 if (sav->tdb_cryptoid != 0)
503 sav->tdb_cryptoid = crp->crp_sid;
504
505 if (crp->crp_etype == EAGAIN) {
506 KEY_FREESAV(&sav);
507 error = crypto_dispatch(crp);
508 return error;
509 }
510
511 V_espstat.esps_noxform++;
512 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
513 error = crp->crp_etype;
514 goto bad;
515 }
516
517 /* Shouldn't happen... */
518 if (m == NULL) {
519 V_espstat.esps_crypto++;
520 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
521 error = EINVAL;
522 goto bad;
523 }
524 V_espstat.esps_hist[sav->alg_enc]++;
525
526 /* If authentication was performed, check now. */
527 if (esph != NULL) {
528 /*
529 * If we have a tag, it means an IPsec-aware NIC did
530 * the verification for us. Otherwise we need to
531 * check the authentication calculation.
532 */
533 V_ahstat.ahs_hist[sav->alg_auth]++;
534 if (mtag == NULL) {
535 /* Copy the authenticator from the packet */
536 m_copydata(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
537 AH_HMAC_HASHLEN, aalg);
538
539 ptr = (caddr_t) (tc + 1);
540
541 /* Verify authenticator */
542 if (bcmp(ptr, aalg, AH_HMAC_HASHLEN) != 0) {
543 DPRINTF(("%s: "
544 "authentication hash mismatch for packet in SA %s/%08lx\n",
545 __func__,
546 ipsec_address(&saidx->dst),
547 (u_long) ntohl(sav->spi)));
548 V_espstat.esps_badauth++;
549 error = EACCES;
550 goto bad;
551 }
552 }
553
554 /* Remove trailing authenticator */
555 m_adj(m, -AH_HMAC_HASHLEN);
556 }
557
558 /* Release the crypto descriptors */
559 free(tc, M_XDATA), tc = NULL;
560 crypto_freereq(crp), crp = NULL;
561
562 /*
563 * Packet is now decrypted.
564 */
565 m->m_flags |= M_DECRYPTED;
566
567 /*
568 * Update replay sequence number, if appropriate.
569 */
570 if (sav->replay) {
571 u_int32_t seq;
572
573 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
574 sizeof (seq), (caddr_t) &seq);
575 if (ipsec_updatereplay(ntohl(seq), sav)) {
576 DPRINTF(("%s: packet replay check for %s\n", __func__,
577 ipsec_logsastr(sav)));
578 V_espstat.esps_replay++;
579 error = ENOBUFS;
580 goto bad;
581 }
582 }
583
584 /* Determine the ESP header length */
585 if (sav->flags & SADB_X_EXT_OLD)
586 hlen = sizeof (struct esp) + sav->ivlen;
587 else
588 hlen = sizeof (struct newesp) + sav->ivlen;
589
590 /* Remove the ESP header and IV from the mbuf. */
591 error = m_striphdr(m, skip, hlen);
592 if (error) {
593 V_espstat.esps_hdrops++;
594 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
595 ipsec_address(&sav->sah->saidx.dst),
596 (u_long) ntohl(sav->spi)));
597 goto bad;
598 }
599
600 /* Save the last three bytes of decrypted data */
601 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
602
603 /* Verify pad length */
604 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
605 V_espstat.esps_badilen++;
606 DPRINTF(("%s: invalid padding length %d for %u byte packet "
607 "in SA %s/%08lx\n", __func__,
608 lastthree[1], m->m_pkthdr.len - skip,
609 ipsec_address(&sav->sah->saidx.dst),
610 (u_long) ntohl(sav->spi)));
611 error = EINVAL;
612 goto bad;
613 }
614
615 /* Verify correct decryption by checking the last padding bytes */
616 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
617 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
618 V_espstat.esps_badenc++;
619 DPRINTF(("%s: decryption failed for packet in "
620 "SA %s/%08lx\n", __func__,
621 ipsec_address(&sav->sah->saidx.dst),
622 (u_long) ntohl(sav->spi)));
623 error = EINVAL;
624 goto bad;
625 }
626 }
627
628 /* Trim the mbuf chain to remove trailing authenticator and padding */
629 m_adj(m, -(lastthree[1] + 2));
630
631 /* Restore the Next Protocol field */
632 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
633
634 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
635
636 KEY_FREESAV(&sav);
637 return error;
638bad:
639 if (sav)
640 KEY_FREESAV(&sav);
641 if (m != NULL)
642 m_freem(m);
643 if (tc != NULL)
644 free(tc, M_XDATA);
645 if (crp != NULL)
646 crypto_freereq(crp);
647 return error;
648}
649
650/*
651 * ESP output routine, called by ipsec[46]_process_packet().
652 */
653static int
654esp_output(
655 struct mbuf *m,
656 struct ipsecrequest *isr,
657 struct mbuf **mp,
658 int skip,
659 int protoff
660)
661{
662 struct enc_xform *espx;
663 struct auth_hash *esph;
664 int hlen, rlen, plen, padding, blks, alen, i, roff;
665 struct mbuf *mo = (struct mbuf *) NULL;
666 struct tdb_crypto *tc;
667 struct secasvar *sav;
668 struct secasindex *saidx;
669 unsigned char *pad;
670 u_int8_t prot;
671 int error, maxpacketsize;
672
673 struct cryptodesc *crde = NULL, *crda = NULL;
674 struct cryptop *crp;
675
676 sav = isr->sav;
677 IPSEC_ASSERT(sav != NULL, ("null SA"));
678 esph = sav->tdb_authalgxform;
679 espx = sav->tdb_encalgxform;
680 IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
681
682 if (sav->flags & SADB_X_EXT_OLD)
683 hlen = sizeof (struct esp) + sav->ivlen;
684 else
685 hlen = sizeof (struct newesp) + sav->ivlen;
686
687 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
688 /*
689 * NB: The null encoding transform has a blocksize of 4
690 * so that headers are properly aligned.
691 */
692 blks = espx->blocksize; /* IV blocksize */
693
694 /* XXX clamp padding length a la KAME??? */
695 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
696 plen = rlen + padding; /* Padded payload length. */
697
698 if (esph)
699 alen = AH_HMAC_HASHLEN;
700 else
701 alen = 0;
702
703 V_espstat.esps_output++;
704
705 saidx = &sav->sah->saidx;
706 /* Check for maximum packet size violations. */
707 switch (saidx->dst.sa.sa_family) {
708#ifdef INET
709 case AF_INET:
710 maxpacketsize = IP_MAXPACKET;
711 break;
712#endif /* INET */
713#ifdef INET6
714 case AF_INET6:
715 maxpacketsize = IPV6_MAXPACKET;
716 break;
717#endif /* INET6 */
718 default:
719 DPRINTF(("%s: unknown/unsupported protocol "
720 "family %d, SA %s/%08lx\n", __func__,
721 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst),
722 (u_long) ntohl(sav->spi)));
723 V_espstat.esps_nopf++;
724 error = EPFNOSUPPORT;
725 goto bad;
726 }
727 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
728 DPRINTF(("%s: packet in SA %s/%08lx got too big "
729 "(len %u, max len %u)\n", __func__,
730 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi),
731 skip + hlen + rlen + padding + alen, maxpacketsize));
732 V_espstat.esps_toobig++;
733 error = EMSGSIZE;
734 goto bad;
735 }
736
737 /* Update the counters. */
738 V_espstat.esps_obytes += m->m_pkthdr.len - skip;
739
740 m = m_unshare(m, M_NOWAIT);
741 if (m == NULL) {
742 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
743 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
744 V_espstat.esps_hdrops++;
745 error = ENOBUFS;
746 goto bad;
747 }
748
749 /* Inject ESP header. */
750 mo = m_makespace(m, skip, hlen, &roff);
751 if (mo == NULL) {
752 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
753 __func__, hlen, ipsec_address(&saidx->dst),
754 (u_long) ntohl(sav->spi)));
755 V_espstat.esps_hdrops++; /* XXX diffs from openbsd */
756 error = ENOBUFS;
757 goto bad;
758 }
759
760 /* Initialize ESP header. */
761 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
762 if (sav->replay) {
763 u_int32_t replay;
764
765#ifdef REGRESSION
766 /* Emulate replay attack when ipsec_replay is TRUE. */
767 if (!V_ipsec_replay)
768#endif
769 sav->replay->count++;
770 replay = htonl(sav->replay->count);
771 bcopy((caddr_t) &replay,
772 mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
773 sizeof(u_int32_t));
774 }
775
776 /*
777 * Add padding -- better to do it ourselves than use the crypto engine,
778 * although if/when we support compression, we'd have to do that.
779 */
780 pad = (u_char *) m_pad(m, padding + alen);
781 if (pad == NULL) {
782 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
783 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
784 m = NULL; /* NB: free'd by m_pad */
785 error = ENOBUFS;
786 goto bad;
787 }
788
789 /*
790 * Add padding: random, zero, or self-describing.
791 * XXX catch unexpected setting
792 */
793 switch (sav->flags & SADB_X_EXT_PMASK) {
794 case SADB_X_EXT_PRAND:
795 (void) read_random(pad, padding - 2);
796 break;
797 case SADB_X_EXT_PZERO:
798 bzero(pad, padding - 2);
799 break;
800 case SADB_X_EXT_PSEQ:
801 for (i = 0; i < padding - 2; i++)
802 pad[i] = i+1;
803 break;
804 }
805
806 /* Fix padding length and Next Protocol in padding itself. */
807 pad[padding - 2] = padding - 2;
808 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
809
810 /* Fix Next Protocol in IPv4/IPv6 header. */
811 prot = IPPROTO_ESP;
812 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
813
814 /* Get crypto descriptors. */
815 crp = crypto_getreq(esph && espx ? 2 : 1);
816 if (crp == NULL) {
817 DPRINTF(("%s: failed to acquire crypto descriptors\n",
818 __func__));
819 V_espstat.esps_crypto++;
820 error = ENOBUFS;
821 goto bad;
822 }
823
824 if (espx) {
825 crde = crp->crp_desc;
826 crda = crde->crd_next;
827
828 /* Encryption descriptor. */
829 crde->crd_skip = skip + hlen;
830 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
831 crde->crd_flags = CRD_F_ENCRYPT;
832 crde->crd_inject = skip + hlen - sav->ivlen;
833
834 /* Encryption operation. */
835 crde->crd_alg = espx->type;
836 crde->crd_key = sav->key_enc->key_data;
837 crde->crd_klen = _KEYBITS(sav->key_enc);
838 /* XXX Rounds ? */
839 } else
840 crda = crp->crp_desc;
841
842 /* IPsec-specific opaque crypto info. */
843 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
844 M_XDATA, M_NOWAIT|M_ZERO);
845 if (tc == NULL) {
846 crypto_freereq(crp);
847 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
848 V_espstat.esps_crypto++;
849 error = ENOBUFS;
850 goto bad;
851 }
852
853 /* Callback parameters */
854 tc->tc_isr = isr;
855 tc->tc_spi = sav->spi;
856 tc->tc_dst = saidx->dst;
857 tc->tc_proto = saidx->proto;
858
859 /* Crypto operation descriptor. */
860 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
861 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
862 crp->crp_buf = (caddr_t) m;
863 crp->crp_callback = esp_output_cb;
864 crp->crp_opaque = (caddr_t) tc;
865 crp->crp_sid = sav->tdb_cryptoid;
866
867 if (esph) {
868 /* Authentication descriptor. */
869 crda->crd_skip = skip;
870 crda->crd_len = m->m_pkthdr.len - (skip + alen);
871 crda->crd_inject = m->m_pkthdr.len - alen;
872
873 /* Authentication operation. */
874 crda->crd_alg = esph->type;
875 crda->crd_key = sav->key_auth->key_data;
876 crda->crd_klen = _KEYBITS(sav->key_auth);
877 }
878
879 return crypto_dispatch(crp);
880bad:
881 if (m)
882 m_freem(m);
883 return (error);
884}
885
886/*
887 * ESP output callback from the crypto driver.
888 */
889static int
890esp_output_cb(struct cryptop *crp)
891{
892 struct tdb_crypto *tc;
893 struct ipsecrequest *isr;
894 struct secasvar *sav;
895 struct mbuf *m;
896 int err, error;
897
898 tc = (struct tdb_crypto *) crp->crp_opaque;
899 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
900 m = (struct mbuf *) crp->crp_buf;
901
902 isr = tc->tc_isr;
903 IPSECREQUEST_LOCK(isr);
904 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
905 if (sav == NULL) {
906 V_espstat.esps_notdb++;
907 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
908 __func__, ipsec_address(&tc->tc_dst),
909 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
910 error = ENOBUFS; /*XXX*/
911 goto bad;
912 }
913 IPSEC_ASSERT(isr->sav == sav,
914 ("SA changed was %p now %p\n", isr->sav, sav));
915
916 /* Check for crypto errors. */
917 if (crp->crp_etype) {
918 /* Reset session ID. */
919 if (sav->tdb_cryptoid != 0)
920 sav->tdb_cryptoid = crp->crp_sid;
921
922 if (crp->crp_etype == EAGAIN) {
923 KEY_FREESAV(&sav);
924 IPSECREQUEST_UNLOCK(isr);
925 error = crypto_dispatch(crp);
926 return error;
927 }
928
929 V_espstat.esps_noxform++;
930 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
931 error = crp->crp_etype;
932 goto bad;
933 }
934
935 /* Shouldn't happen... */
936 if (m == NULL) {
937 V_espstat.esps_crypto++;
938 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
939 error = EINVAL;
940 goto bad;
941 }
942 V_espstat.esps_hist[sav->alg_enc]++;
943 if (sav->tdb_authalgxform != NULL)
944 V_ahstat.ahs_hist[sav->alg_auth]++;
945
946 /* Release crypto descriptors. */
947 free(tc, M_XDATA);
948 crypto_freereq(crp);
949
950#ifdef REGRESSION
951 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
952 if (V_ipsec_integrity) {
953 static unsigned char ipseczeroes[AH_HMAC_HASHLEN];
954 struct auth_hash *esph;
955
956 /*
957 * Corrupt HMAC if we want to test integrity verification of
958 * the other side.
959 */
960 esph = sav->tdb_authalgxform;
961 if (esph != NULL) {
962 m_copyback(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
963 AH_HMAC_HASHLEN, ipseczeroes);
964 }
965 }
966#endif
967
968 /* NB: m is reclaimed by ipsec_process_done. */
969 err = ipsec_process_done(m, isr);
970 KEY_FREESAV(&sav);
971 IPSECREQUEST_UNLOCK(isr);
972 return err;
973bad:
974 if (sav)
975 KEY_FREESAV(&sav);
976 IPSECREQUEST_UNLOCK(isr);
977 if (m)
978 m_freem(m);
979 free(tc, M_XDATA);
980 crypto_freereq(crp);
981 return error;
982}
983
984static struct xformsw esp_xformsw = {
985 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
986 esp_init, esp_zeroize, esp_input,
987 esp_output
988};
989
990static void
991esp_attach(void)
992{
993#define MAXIV(xform) \
994 if (xform.blocksize > V_esp_max_ivlen) \
995 V_esp_max_ivlen = xform.blocksize \
996
997 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */
998 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */
999 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */
1000 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */
1001 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */
1002 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */
1003 MAXIV(enc_xform_null); /* SADB_EALG_NULL */
1004 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */
1005
1006 xform_register(&esp_xformsw);
1007#undef MAXIV
1008}
1009SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
| 89#define V_esp_max_ivlen VNET(esp_max_ivlen)
90
91static int esp_input_cb(struct cryptop *op);
92static int esp_output_cb(struct cryptop *crp);
93
94/*
95 * NB: this is public for use by the PF_KEY support.
96 * NB: if you add support here; be sure to add code to esp_attach below!
97 */
98struct enc_xform *
99esp_algorithm_lookup(int alg)
100{
101 if (alg >= ESP_ALG_MAX)
102 return NULL;
103 switch (alg) {
104 case SADB_EALG_DESCBC:
105 return &enc_xform_des;
106 case SADB_EALG_3DESCBC:
107 return &enc_xform_3des;
108 case SADB_X_EALG_AES:
109 return &enc_xform_rijndael128;
110 case SADB_X_EALG_BLOWFISHCBC:
111 return &enc_xform_blf;
112 case SADB_X_EALG_CAST128CBC:
113 return &enc_xform_cast5;
114 case SADB_X_EALG_SKIPJACK:
115 return &enc_xform_skipjack;
116 case SADB_EALG_NULL:
117 return &enc_xform_null;
118 case SADB_X_EALG_CAMELLIACBC:
119 return &enc_xform_camellia;
120 }
121 return NULL;
122}
123
124size_t
125esp_hdrsiz(struct secasvar *sav)
126{
127 size_t size;
128
129 if (sav != NULL) {
130 /*XXX not right for null algorithm--does it matter??*/
131 IPSEC_ASSERT(sav->tdb_encalgxform != NULL,
132 ("SA with null xform"));
133 if (sav->flags & SADB_X_EXT_OLD)
134 size = sizeof (struct esp);
135 else
136 size = sizeof (struct newesp);
137 size += sav->tdb_encalgxform->blocksize + 9;
138 /*XXX need alg check???*/
139 if (sav->tdb_authalgxform != NULL && sav->replay)
140 size += ah_hdrsiz(sav);
141 } else {
142 /*
143 * base header size
144 * + max iv length for CBC mode
145 * + max pad length
146 * + sizeof (pad length field)
147 * + sizeof (next header field)
148 * + max icv supported.
149 */
150 size = sizeof (struct newesp) + V_esp_max_ivlen + 9 + 16;
151 }
152 return size;
153}
154
155/*
156 * esp_init() is called when an SPI is being set up.
157 */
158static int
159esp_init(struct secasvar *sav, struct xformsw *xsp)
160{
161 struct enc_xform *txform;
162 struct cryptoini cria, crie;
163 int keylen;
164 int error;
165
166 txform = esp_algorithm_lookup(sav->alg_enc);
167 if (txform == NULL) {
168 DPRINTF(("%s: unsupported encryption algorithm %d\n",
169 __func__, sav->alg_enc));
170 return EINVAL;
171 }
172 if (sav->key_enc == NULL) {
173 DPRINTF(("%s: no encoding key for %s algorithm\n",
174 __func__, txform->name));
175 return EINVAL;
176 }
177 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) {
178 DPRINTF(("%s: 4-byte IV not supported with protocol\n",
179 __func__));
180 return EINVAL;
181 }
182 keylen = _KEYLEN(sav->key_enc);
183 if (txform->minkey > keylen || keylen > txform->maxkey) {
184 DPRINTF(("%s: invalid key length %u, must be in the range "
185 "[%u..%u] for algorithm %s\n", __func__,
186 keylen, txform->minkey, txform->maxkey,
187 txform->name));
188 return EINVAL;
189 }
190
191 /*
192 * NB: The null xform needs a non-zero blocksize to keep the
193 * crypto code happy but if we use it to set ivlen then
194 * the ESP header will be processed incorrectly. The
195 * compromise is to force it to zero here.
196 */
197 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize);
198 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK);
199 if (sav->iv == NULL) {
200 DPRINTF(("%s: no memory for IV\n", __func__));
201 return EINVAL;
202 }
203 key_randomfill(sav->iv, sav->ivlen); /*XXX*/
204
205 /*
206 * Setup AH-related state.
207 */
208 if (sav->alg_auth != 0) {
209 error = ah_init0(sav, xsp, &cria);
210 if (error)
211 return error;
212 }
213
214 /* NB: override anything set in ah_init0 */
215 sav->tdb_xform = xsp;
216 sav->tdb_encalgxform = txform;
217
218 /* Initialize crypto session. */
219 bzero(&crie, sizeof (crie));
220 crie.cri_alg = sav->tdb_encalgxform->type;
221 crie.cri_klen = _KEYBITS(sav->key_enc);
222 crie.cri_key = sav->key_enc->key_data;
223 /* XXX Rounds ? */
224
225 if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
226 /* init both auth & enc */
227 crie.cri_next = &cria;
228 error = crypto_newsession(&sav->tdb_cryptoid,
229 &crie, V_crypto_support);
230 } else if (sav->tdb_encalgxform) {
231 error = crypto_newsession(&sav->tdb_cryptoid,
232 &crie, V_crypto_support);
233 } else if (sav->tdb_authalgxform) {
234 error = crypto_newsession(&sav->tdb_cryptoid,
235 &cria, V_crypto_support);
236 } else {
237 /* XXX cannot happen? */
238 DPRINTF(("%s: no encoding OR authentication xform!\n",
239 __func__));
240 error = EINVAL;
241 }
242 return error;
243}
244
245/*
246 * Paranoia.
247 */
248static int
249esp_zeroize(struct secasvar *sav)
250{
251 /* NB: ah_zerorize free's the crypto session state */
252 int error = ah_zeroize(sav);
253
254 if (sav->key_enc)
255 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc));
256 if (sav->iv) {
257 free(sav->iv, M_XDATA);
258 sav->iv = NULL;
259 }
260 sav->tdb_encalgxform = NULL;
261 sav->tdb_xform = NULL;
262 return error;
263}
264
265/*
266 * ESP input processing, called (eventually) through the protocol switch.
267 */
268static int
269esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
270{
271 struct auth_hash *esph;
272 struct enc_xform *espx;
273 struct tdb_ident *tdbi;
274 struct tdb_crypto *tc;
275 int plen, alen, hlen;
276 struct m_tag *mtag;
277 struct newesp *esp;
278
279 struct cryptodesc *crde;
280 struct cryptop *crp;
281
282 IPSEC_ASSERT(sav != NULL, ("null SA"));
283 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform"));
284
285 /* Valid IP Packet length ? */
286 if ( (skip&3) || (m->m_pkthdr.len&3) ){
287 DPRINTF(("%s: misaligned packet, skip %u pkt len %u",
288 __func__, skip, m->m_pkthdr.len));
289 V_espstat.esps_badilen++;
290 m_freem(m);
291 return EINVAL;
292 }
293
294 /* XXX don't pullup, just copy header */
295 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp));
296
297 esph = sav->tdb_authalgxform;
298 espx = sav->tdb_encalgxform;
299
300 /* Determine the ESP header length */
301 if (sav->flags & SADB_X_EXT_OLD)
302 hlen = sizeof (struct esp) + sav->ivlen;
303 else
304 hlen = sizeof (struct newesp) + sav->ivlen;
305 /* Authenticator hash size */
306 alen = esph ? AH_HMAC_HASHLEN : 0;
307
308 /*
309 * Verify payload length is multiple of encryption algorithm
310 * block size.
311 *
312 * NB: This works for the null algorithm because the blocksize
313 * is 4 and all packets must be 4-byte aligned regardless
314 * of the algorithm.
315 */
316 plen = m->m_pkthdr.len - (skip + hlen + alen);
317 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
318 DPRINTF(("%s: payload of %d octets not a multiple of %d octets,"
319 " SA %s/%08lx\n", __func__,
320 plen, espx->blocksize,
321 ipsec_address(&sav->sah->saidx.dst),
322 (u_long) ntohl(sav->spi)));
323 V_espstat.esps_badilen++;
324 m_freem(m);
325 return EINVAL;
326 }
327
328 /*
329 * Check sequence number.
330 */
331 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
332 DPRINTF(("%s: packet replay check for %s\n", __func__,
333 ipsec_logsastr(sav))); /*XXX*/
334 V_espstat.esps_replay++;
335 m_freem(m);
336 return ENOBUFS; /*XXX*/
337 }
338
339 /* Update the counters */
340 V_espstat.esps_ibytes += m->m_pkthdr.len - (skip + hlen + alen);
341
342 /* Find out if we've already done crypto */
343 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
344 mtag != NULL;
345 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
346 tdbi = (struct tdb_ident *) (mtag + 1);
347 if (tdbi->proto == sav->sah->saidx.proto &&
348 tdbi->spi == sav->spi &&
349 !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
350 sizeof(union sockaddr_union)))
351 break;
352 }
353
354 /* Get crypto descriptors */
355 crp = crypto_getreq(esph && espx ? 2 : 1);
356 if (crp == NULL) {
357 DPRINTF(("%s: failed to acquire crypto descriptors\n",
358 __func__));
359 V_espstat.esps_crypto++;
360 m_freem(m);
361 return ENOBUFS;
362 }
363
364 /* Get IPsec-specific opaque pointer */
365 if (esph == NULL || mtag != NULL)
366 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
367 M_XDATA, M_NOWAIT|M_ZERO);
368 else
369 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen,
370 M_XDATA, M_NOWAIT|M_ZERO);
371 if (tc == NULL) {
372 crypto_freereq(crp);
373 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
374 V_espstat.esps_crypto++;
375 m_freem(m);
376 return ENOBUFS;
377 }
378
379 tc->tc_ptr = (caddr_t) mtag;
380
381 if (esph) {
382 struct cryptodesc *crda = crp->crp_desc;
383
384 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor"));
385
386 /* Authentication descriptor */
387 crda->crd_skip = skip;
388 crda->crd_len = m->m_pkthdr.len - (skip + alen);
389 crda->crd_inject = m->m_pkthdr.len - alen;
390
391 crda->crd_alg = esph->type;
392 crda->crd_key = sav->key_auth->key_data;
393 crda->crd_klen = _KEYBITS(sav->key_auth);
394
395 /* Copy the authenticator */
396 if (mtag == NULL)
397 m_copydata(m, m->m_pkthdr.len - alen, alen,
398 (caddr_t) (tc + 1));
399
400 /* Chain authentication request */
401 crde = crda->crd_next;
402 } else {
403 crde = crp->crp_desc;
404 }
405
406 /* Crypto operation descriptor */
407 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
408 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
409 crp->crp_buf = (caddr_t) m;
410 crp->crp_callback = esp_input_cb;
411 crp->crp_sid = sav->tdb_cryptoid;
412 crp->crp_opaque = (caddr_t) tc;
413
414 /* These are passed as-is to the callback */
415 tc->tc_spi = sav->spi;
416 tc->tc_dst = sav->sah->saidx.dst;
417 tc->tc_proto = sav->sah->saidx.proto;
418 tc->tc_protoff = protoff;
419 tc->tc_skip = skip;
420
421 /* Decryption descriptor */
422 if (espx) {
423 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor"));
424 crde->crd_skip = skip + hlen;
425 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
426 crde->crd_inject = skip + hlen - sav->ivlen;
427
428 crde->crd_alg = espx->type;
429 crde->crd_key = sav->key_enc->key_data;
430 crde->crd_klen = _KEYBITS(sav->key_enc);
431 /* XXX Rounds ? */
432 }
433
434 if (mtag == NULL)
435 return crypto_dispatch(crp);
436 else
437 return esp_input_cb(crp);
438}
439
440#ifdef INET6
441#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \
442 if (saidx->dst.sa.sa_family == AF_INET6) { \
443 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
444 } else { \
445 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
446 } \
447} while (0)
448#else
449#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \
450 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
451#endif
452
453/*
454 * ESP input callback from the crypto driver.
455 */
456static int
457esp_input_cb(struct cryptop *crp)
458{
459 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN];
460 int hlen, skip, protoff, error;
461 struct mbuf *m;
462 struct cryptodesc *crd;
463 struct auth_hash *esph;
464 struct enc_xform *espx;
465 struct tdb_crypto *tc;
466 struct m_tag *mtag;
467 struct secasvar *sav;
468 struct secasindex *saidx;
469 caddr_t ptr;
470
471 crd = crp->crp_desc;
472 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!"));
473
474 tc = (struct tdb_crypto *) crp->crp_opaque;
475 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!"));
476 skip = tc->tc_skip;
477 protoff = tc->tc_protoff;
478 mtag = (struct m_tag *) tc->tc_ptr;
479 m = (struct mbuf *) crp->crp_buf;
480
481 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
482 if (sav == NULL) {
483 V_espstat.esps_notdb++;
484 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
485 __func__, ipsec_address(&tc->tc_dst),
486 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
487 error = ENOBUFS; /*XXX*/
488 goto bad;
489 }
490
491 saidx = &sav->sah->saidx;
492 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
493 saidx->dst.sa.sa_family == AF_INET6,
494 ("unexpected protocol family %u", saidx->dst.sa.sa_family));
495
496 esph = sav->tdb_authalgxform;
497 espx = sav->tdb_encalgxform;
498
499 /* Check for crypto errors */
500 if (crp->crp_etype) {
501 /* Reset the session ID */
502 if (sav->tdb_cryptoid != 0)
503 sav->tdb_cryptoid = crp->crp_sid;
504
505 if (crp->crp_etype == EAGAIN) {
506 KEY_FREESAV(&sav);
507 error = crypto_dispatch(crp);
508 return error;
509 }
510
511 V_espstat.esps_noxform++;
512 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
513 error = crp->crp_etype;
514 goto bad;
515 }
516
517 /* Shouldn't happen... */
518 if (m == NULL) {
519 V_espstat.esps_crypto++;
520 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
521 error = EINVAL;
522 goto bad;
523 }
524 V_espstat.esps_hist[sav->alg_enc]++;
525
526 /* If authentication was performed, check now. */
527 if (esph != NULL) {
528 /*
529 * If we have a tag, it means an IPsec-aware NIC did
530 * the verification for us. Otherwise we need to
531 * check the authentication calculation.
532 */
533 V_ahstat.ahs_hist[sav->alg_auth]++;
534 if (mtag == NULL) {
535 /* Copy the authenticator from the packet */
536 m_copydata(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
537 AH_HMAC_HASHLEN, aalg);
538
539 ptr = (caddr_t) (tc + 1);
540
541 /* Verify authenticator */
542 if (bcmp(ptr, aalg, AH_HMAC_HASHLEN) != 0) {
543 DPRINTF(("%s: "
544 "authentication hash mismatch for packet in SA %s/%08lx\n",
545 __func__,
546 ipsec_address(&saidx->dst),
547 (u_long) ntohl(sav->spi)));
548 V_espstat.esps_badauth++;
549 error = EACCES;
550 goto bad;
551 }
552 }
553
554 /* Remove trailing authenticator */
555 m_adj(m, -AH_HMAC_HASHLEN);
556 }
557
558 /* Release the crypto descriptors */
559 free(tc, M_XDATA), tc = NULL;
560 crypto_freereq(crp), crp = NULL;
561
562 /*
563 * Packet is now decrypted.
564 */
565 m->m_flags |= M_DECRYPTED;
566
567 /*
568 * Update replay sequence number, if appropriate.
569 */
570 if (sav->replay) {
571 u_int32_t seq;
572
573 m_copydata(m, skip + offsetof(struct newesp, esp_seq),
574 sizeof (seq), (caddr_t) &seq);
575 if (ipsec_updatereplay(ntohl(seq), sav)) {
576 DPRINTF(("%s: packet replay check for %s\n", __func__,
577 ipsec_logsastr(sav)));
578 V_espstat.esps_replay++;
579 error = ENOBUFS;
580 goto bad;
581 }
582 }
583
584 /* Determine the ESP header length */
585 if (sav->flags & SADB_X_EXT_OLD)
586 hlen = sizeof (struct esp) + sav->ivlen;
587 else
588 hlen = sizeof (struct newesp) + sav->ivlen;
589
590 /* Remove the ESP header and IV from the mbuf. */
591 error = m_striphdr(m, skip, hlen);
592 if (error) {
593 V_espstat.esps_hdrops++;
594 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__,
595 ipsec_address(&sav->sah->saidx.dst),
596 (u_long) ntohl(sav->spi)));
597 goto bad;
598 }
599
600 /* Save the last three bytes of decrypted data */
601 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree);
602
603 /* Verify pad length */
604 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) {
605 V_espstat.esps_badilen++;
606 DPRINTF(("%s: invalid padding length %d for %u byte packet "
607 "in SA %s/%08lx\n", __func__,
608 lastthree[1], m->m_pkthdr.len - skip,
609 ipsec_address(&sav->sah->saidx.dst),
610 (u_long) ntohl(sav->spi)));
611 error = EINVAL;
612 goto bad;
613 }
614
615 /* Verify correct decryption by checking the last padding bytes */
616 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) {
617 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) {
618 V_espstat.esps_badenc++;
619 DPRINTF(("%s: decryption failed for packet in "
620 "SA %s/%08lx\n", __func__,
621 ipsec_address(&sav->sah->saidx.dst),
622 (u_long) ntohl(sav->spi)));
623 error = EINVAL;
624 goto bad;
625 }
626 }
627
628 /* Trim the mbuf chain to remove trailing authenticator and padding */
629 m_adj(m, -(lastthree[1] + 2));
630
631 /* Restore the Next Protocol field */
632 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2);
633
634 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
635
636 KEY_FREESAV(&sav);
637 return error;
638bad:
639 if (sav)
640 KEY_FREESAV(&sav);
641 if (m != NULL)
642 m_freem(m);
643 if (tc != NULL)
644 free(tc, M_XDATA);
645 if (crp != NULL)
646 crypto_freereq(crp);
647 return error;
648}
649
650/*
651 * ESP output routine, called by ipsec[46]_process_packet().
652 */
653static int
654esp_output(
655 struct mbuf *m,
656 struct ipsecrequest *isr,
657 struct mbuf **mp,
658 int skip,
659 int protoff
660)
661{
662 struct enc_xform *espx;
663 struct auth_hash *esph;
664 int hlen, rlen, plen, padding, blks, alen, i, roff;
665 struct mbuf *mo = (struct mbuf *) NULL;
666 struct tdb_crypto *tc;
667 struct secasvar *sav;
668 struct secasindex *saidx;
669 unsigned char *pad;
670 u_int8_t prot;
671 int error, maxpacketsize;
672
673 struct cryptodesc *crde = NULL, *crda = NULL;
674 struct cryptop *crp;
675
676 sav = isr->sav;
677 IPSEC_ASSERT(sav != NULL, ("null SA"));
678 esph = sav->tdb_authalgxform;
679 espx = sav->tdb_encalgxform;
680 IPSEC_ASSERT(espx != NULL, ("null encoding xform"));
681
682 if (sav->flags & SADB_X_EXT_OLD)
683 hlen = sizeof (struct esp) + sav->ivlen;
684 else
685 hlen = sizeof (struct newesp) + sav->ivlen;
686
687 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */
688 /*
689 * NB: The null encoding transform has a blocksize of 4
690 * so that headers are properly aligned.
691 */
692 blks = espx->blocksize; /* IV blocksize */
693
694 /* XXX clamp padding length a la KAME??? */
695 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2;
696 plen = rlen + padding; /* Padded payload length. */
697
698 if (esph)
699 alen = AH_HMAC_HASHLEN;
700 else
701 alen = 0;
702
703 V_espstat.esps_output++;
704
705 saidx = &sav->sah->saidx;
706 /* Check for maximum packet size violations. */
707 switch (saidx->dst.sa.sa_family) {
708#ifdef INET
709 case AF_INET:
710 maxpacketsize = IP_MAXPACKET;
711 break;
712#endif /* INET */
713#ifdef INET6
714 case AF_INET6:
715 maxpacketsize = IPV6_MAXPACKET;
716 break;
717#endif /* INET6 */
718 default:
719 DPRINTF(("%s: unknown/unsupported protocol "
720 "family %d, SA %s/%08lx\n", __func__,
721 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst),
722 (u_long) ntohl(sav->spi)));
723 V_espstat.esps_nopf++;
724 error = EPFNOSUPPORT;
725 goto bad;
726 }
727 if (skip + hlen + rlen + padding + alen > maxpacketsize) {
728 DPRINTF(("%s: packet in SA %s/%08lx got too big "
729 "(len %u, max len %u)\n", __func__,
730 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi),
731 skip + hlen + rlen + padding + alen, maxpacketsize));
732 V_espstat.esps_toobig++;
733 error = EMSGSIZE;
734 goto bad;
735 }
736
737 /* Update the counters. */
738 V_espstat.esps_obytes += m->m_pkthdr.len - skip;
739
740 m = m_unshare(m, M_NOWAIT);
741 if (m == NULL) {
742 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__,
743 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
744 V_espstat.esps_hdrops++;
745 error = ENOBUFS;
746 goto bad;
747 }
748
749 /* Inject ESP header. */
750 mo = m_makespace(m, skip, hlen, &roff);
751 if (mo == NULL) {
752 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n",
753 __func__, hlen, ipsec_address(&saidx->dst),
754 (u_long) ntohl(sav->spi)));
755 V_espstat.esps_hdrops++; /* XXX diffs from openbsd */
756 error = ENOBUFS;
757 goto bad;
758 }
759
760 /* Initialize ESP header. */
761 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t));
762 if (sav->replay) {
763 u_int32_t replay;
764
765#ifdef REGRESSION
766 /* Emulate replay attack when ipsec_replay is TRUE. */
767 if (!V_ipsec_replay)
768#endif
769 sav->replay->count++;
770 replay = htonl(sav->replay->count);
771 bcopy((caddr_t) &replay,
772 mtod(mo, caddr_t) + roff + sizeof(u_int32_t),
773 sizeof(u_int32_t));
774 }
775
776 /*
777 * Add padding -- better to do it ourselves than use the crypto engine,
778 * although if/when we support compression, we'd have to do that.
779 */
780 pad = (u_char *) m_pad(m, padding + alen);
781 if (pad == NULL) {
782 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__,
783 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
784 m = NULL; /* NB: free'd by m_pad */
785 error = ENOBUFS;
786 goto bad;
787 }
788
789 /*
790 * Add padding: random, zero, or self-describing.
791 * XXX catch unexpected setting
792 */
793 switch (sav->flags & SADB_X_EXT_PMASK) {
794 case SADB_X_EXT_PRAND:
795 (void) read_random(pad, padding - 2);
796 break;
797 case SADB_X_EXT_PZERO:
798 bzero(pad, padding - 2);
799 break;
800 case SADB_X_EXT_PSEQ:
801 for (i = 0; i < padding - 2; i++)
802 pad[i] = i+1;
803 break;
804 }
805
806 /* Fix padding length and Next Protocol in padding itself. */
807 pad[padding - 2] = padding - 2;
808 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1);
809
810 /* Fix Next Protocol in IPv4/IPv6 header. */
811 prot = IPPROTO_ESP;
812 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot);
813
814 /* Get crypto descriptors. */
815 crp = crypto_getreq(esph && espx ? 2 : 1);
816 if (crp == NULL) {
817 DPRINTF(("%s: failed to acquire crypto descriptors\n",
818 __func__));
819 V_espstat.esps_crypto++;
820 error = ENOBUFS;
821 goto bad;
822 }
823
824 if (espx) {
825 crde = crp->crp_desc;
826 crda = crde->crd_next;
827
828 /* Encryption descriptor. */
829 crde->crd_skip = skip + hlen;
830 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
831 crde->crd_flags = CRD_F_ENCRYPT;
832 crde->crd_inject = skip + hlen - sav->ivlen;
833
834 /* Encryption operation. */
835 crde->crd_alg = espx->type;
836 crde->crd_key = sav->key_enc->key_data;
837 crde->crd_klen = _KEYBITS(sav->key_enc);
838 /* XXX Rounds ? */
839 } else
840 crda = crp->crp_desc;
841
842 /* IPsec-specific opaque crypto info. */
843 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto),
844 M_XDATA, M_NOWAIT|M_ZERO);
845 if (tc == NULL) {
846 crypto_freereq(crp);
847 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
848 V_espstat.esps_crypto++;
849 error = ENOBUFS;
850 goto bad;
851 }
852
853 /* Callback parameters */
854 tc->tc_isr = isr;
855 tc->tc_spi = sav->spi;
856 tc->tc_dst = saidx->dst;
857 tc->tc_proto = saidx->proto;
858
859 /* Crypto operation descriptor. */
860 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
861 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC;
862 crp->crp_buf = (caddr_t) m;
863 crp->crp_callback = esp_output_cb;
864 crp->crp_opaque = (caddr_t) tc;
865 crp->crp_sid = sav->tdb_cryptoid;
866
867 if (esph) {
868 /* Authentication descriptor. */
869 crda->crd_skip = skip;
870 crda->crd_len = m->m_pkthdr.len - (skip + alen);
871 crda->crd_inject = m->m_pkthdr.len - alen;
872
873 /* Authentication operation. */
874 crda->crd_alg = esph->type;
875 crda->crd_key = sav->key_auth->key_data;
876 crda->crd_klen = _KEYBITS(sav->key_auth);
877 }
878
879 return crypto_dispatch(crp);
880bad:
881 if (m)
882 m_freem(m);
883 return (error);
884}
885
886/*
887 * ESP output callback from the crypto driver.
888 */
889static int
890esp_output_cb(struct cryptop *crp)
891{
892 struct tdb_crypto *tc;
893 struct ipsecrequest *isr;
894 struct secasvar *sav;
895 struct mbuf *m;
896 int err, error;
897
898 tc = (struct tdb_crypto *) crp->crp_opaque;
899 IPSEC_ASSERT(tc != NULL, ("null opaque data area!"));
900 m = (struct mbuf *) crp->crp_buf;
901
902 isr = tc->tc_isr;
903 IPSECREQUEST_LOCK(isr);
904 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
905 if (sav == NULL) {
906 V_espstat.esps_notdb++;
907 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n",
908 __func__, ipsec_address(&tc->tc_dst),
909 (u_long) ntohl(tc->tc_spi), tc->tc_proto));
910 error = ENOBUFS; /*XXX*/
911 goto bad;
912 }
913 IPSEC_ASSERT(isr->sav == sav,
914 ("SA changed was %p now %p\n", isr->sav, sav));
915
916 /* Check for crypto errors. */
917 if (crp->crp_etype) {
918 /* Reset session ID. */
919 if (sav->tdb_cryptoid != 0)
920 sav->tdb_cryptoid = crp->crp_sid;
921
922 if (crp->crp_etype == EAGAIN) {
923 KEY_FREESAV(&sav);
924 IPSECREQUEST_UNLOCK(isr);
925 error = crypto_dispatch(crp);
926 return error;
927 }
928
929 V_espstat.esps_noxform++;
930 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
931 error = crp->crp_etype;
932 goto bad;
933 }
934
935 /* Shouldn't happen... */
936 if (m == NULL) {
937 V_espstat.esps_crypto++;
938 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
939 error = EINVAL;
940 goto bad;
941 }
942 V_espstat.esps_hist[sav->alg_enc]++;
943 if (sav->tdb_authalgxform != NULL)
944 V_ahstat.ahs_hist[sav->alg_auth]++;
945
946 /* Release crypto descriptors. */
947 free(tc, M_XDATA);
948 crypto_freereq(crp);
949
950#ifdef REGRESSION
951 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
952 if (V_ipsec_integrity) {
953 static unsigned char ipseczeroes[AH_HMAC_HASHLEN];
954 struct auth_hash *esph;
955
956 /*
957 * Corrupt HMAC if we want to test integrity verification of
958 * the other side.
959 */
960 esph = sav->tdb_authalgxform;
961 if (esph != NULL) {
962 m_copyback(m, m->m_pkthdr.len - AH_HMAC_HASHLEN,
963 AH_HMAC_HASHLEN, ipseczeroes);
964 }
965 }
966#endif
967
968 /* NB: m is reclaimed by ipsec_process_done. */
969 err = ipsec_process_done(m, isr);
970 KEY_FREESAV(&sav);
971 IPSECREQUEST_UNLOCK(isr);
972 return err;
973bad:
974 if (sav)
975 KEY_FREESAV(&sav);
976 IPSECREQUEST_UNLOCK(isr);
977 if (m)
978 m_freem(m);
979 free(tc, M_XDATA);
980 crypto_freereq(crp);
981 return error;
982}
983
984static struct xformsw esp_xformsw = {
985 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP",
986 esp_init, esp_zeroize, esp_input,
987 esp_output
988};
989
990static void
991esp_attach(void)
992{
993#define MAXIV(xform) \
994 if (xform.blocksize > V_esp_max_ivlen) \
995 V_esp_max_ivlen = xform.blocksize \
996
997 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */
998 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */
999 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */
1000 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */
1001 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */
1002 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */
1003 MAXIV(enc_xform_null); /* SADB_EALG_NULL */
1004 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */
1005
1006 xform_register(&esp_xformsw);
1007#undef MAXIV
1008}
1009SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
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