xform_ah.c revision 1.96
1/* $NetBSD: xform_ah.c,v 1.96 2018/05/01 08:16:34 maxv Exp $ */ 2/* $FreeBSD: xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $ */ 3/* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */ 4/* 5 * The authors of this code are John Ioannidis (ji@tla.org), 6 * Angelos D. Keromytis (kermit@csd.uch.gr) and 7 * Niels Provos (provos@physnet.uni-hamburg.de). 8 * 9 * The original version of this code was written by John Ioannidis 10 * for BSD/OS in Athens, Greece, in November 1995. 11 * 12 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 13 * by Angelos D. Keromytis. 14 * 15 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 16 * and Niels Provos. 17 * 18 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist. 19 * 20 * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 21 * Angelos D. Keromytis and Niels Provos. 22 * Copyright (c) 1999 Niklas Hallqvist. 23 * Copyright (c) 2001 Angelos D. Keromytis. 24 * 25 * Permission to use, copy, and modify this software with or without fee 26 * is hereby granted, provided that this entire notice is included in 27 * all copies of any software which is or includes a copy or 28 * modification of this software. 29 * You may use this code under the GNU public license if you so wish. Please 30 * contribute changes back to the authors under this freer than GPL license 31 * so that we may further the use of strong encryption without limitations to 32 * all. 33 * 34 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 35 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 36 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 37 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 38 * PURPOSE. 39 */ 40 41#include <sys/cdefs.h> 42__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.96 2018/05/01 08:16:34 maxv Exp $"); 43 44#if defined(_KERNEL_OPT) 45#include "opt_inet.h" 46#include "opt_ipsec.h" 47#endif 48 49#include <sys/param.h> 50#include <sys/systm.h> 51#include <sys/mbuf.h> 52#include <sys/socket.h> 53#include <sys/syslog.h> 54#include <sys/kernel.h> 55#include <sys/sysctl.h> 56#include <sys/pool.h> 57#include <sys/pserialize.h> 58#include <sys/kmem.h> 59 60#include <net/if.h> 61 62#include <netinet/in.h> 63#include <netinet/in_systm.h> 64#include <netinet/ip.h> 65#include <netinet/ip_ecn.h> 66#include <netinet/ip_var.h> 67#include <netinet/ip6.h> 68 69#include <net/route.h> 70#include <netipsec/ipsec.h> 71#include <netipsec/ipsec_private.h> 72#include <netipsec/ah.h> 73#include <netipsec/ah_var.h> 74#include <netipsec/xform.h> 75 76#ifdef INET6 77#include <netinet6/ip6_var.h> 78#include <netinet6/scope6_var.h> 79#include <netipsec/ipsec6.h> 80#endif 81 82#include <netipsec/key.h> 83#include <netipsec/key_debug.h> 84 85#include <opencrypto/cryptodev.h> 86 87/* 88 * Return header size in bytes. The old protocol did not support 89 * the replay counter; the new protocol always includes the counter. 90 */ 91#define HDRSIZE(sav) \ 92 (((sav)->flags & SADB_X_EXT_OLD) ? \ 93 sizeof(struct ah) : sizeof(struct ah) + sizeof(uint32_t)) 94/* 95 * Return authenticator size in bytes. The old protocol is known 96 * to use a fixed 16-byte authenticator. The new algorithm gets 97 * this size from the xform but is (currently) always 12. 98 */ 99#define AUTHSIZE(sav) \ 100 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize) 101 102percpu_t *ahstat_percpu; 103 104int ah_enable = 1; /* control flow of packets with AH */ 105int ip4_ah_cleartos = 1; /* clear ip_tos when doing AH calc */ 106 107static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 108 109int ah_max_authsize; /* max authsize over all algorithms */ 110 111static int ah_input_cb(struct cryptop *); 112static int ah_output_cb(struct cryptop *); 113 114const uint8_t ah_stats[256] = { SADB_AALG_STATS_INIT }; 115 116static pool_cache_t ah_tdb_crypto_pool_cache; 117static size_t ah_pool_item_size; 118 119/* 120 * NB: this is public for use by the PF_KEY support. 121 */ 122const struct auth_hash * 123ah_algorithm_lookup(int alg) 124{ 125 126 switch (alg) { 127 case SADB_X_AALG_NULL: 128 return &auth_hash_null; 129 case SADB_AALG_MD5HMAC: 130 return &auth_hash_hmac_md5_96; 131 case SADB_AALG_SHA1HMAC: 132 return &auth_hash_hmac_sha1_96; 133 case SADB_X_AALG_RIPEMD160HMAC: 134 return &auth_hash_hmac_ripemd_160_96; 135 case SADB_X_AALG_MD5: 136 return &auth_hash_key_md5; 137 case SADB_X_AALG_SHA: 138 return &auth_hash_key_sha1; 139 case SADB_X_AALG_SHA2_256: 140 return &auth_hash_hmac_sha2_256; 141 case SADB_X_AALG_SHA2_384: 142 return &auth_hash_hmac_sha2_384; 143 case SADB_X_AALG_SHA2_512: 144 return &auth_hash_hmac_sha2_512; 145 case SADB_X_AALG_AES_XCBC_MAC: 146 return &auth_hash_aes_xcbc_mac_96; 147 } 148 return NULL; 149} 150 151size_t 152ah_hdrsiz(const struct secasvar *sav) 153{ 154 size_t size; 155 156 if (sav != NULL) { 157 int authsize; 158 KASSERT(sav->tdb_authalgxform != NULL); 159 /*XXX not right for null algorithm--does it matter??*/ 160 authsize = AUTHSIZE(sav); 161 size = roundup(authsize, sizeof(uint32_t)) + HDRSIZE(sav); 162 } else { 163 /* default guess */ 164 size = sizeof(struct ah) + sizeof(uint32_t) + ah_max_authsize; 165 } 166 return size; 167} 168 169/* 170 * NB: public for use by esp_init. 171 */ 172int 173ah_init0(struct secasvar *sav, const struct xformsw *xsp, 174 struct cryptoini *cria) 175{ 176 const struct auth_hash *thash; 177 int keylen; 178 179 thash = ah_algorithm_lookup(sav->alg_auth); 180 if (thash == NULL) { 181 DPRINTF(("%s: unsupported authentication algorithm %u\n", 182 __func__, sav->alg_auth)); 183 return EINVAL; 184 } 185 /* 186 * Verify the replay state block allocation is consistent with 187 * the protocol type. We check here so we can make assumptions 188 * later during protocol processing. 189 */ 190 /* NB: replay state is setup elsewhere (sigh) */ 191 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) { 192 DPRINTF(("%s: replay state block inconsistency, " 193 "%s algorithm %s replay state\n", __func__, 194 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new", 195 sav->replay == NULL ? "without" : "with")); 196 return EINVAL; 197 } 198 if (sav->key_auth == NULL) { 199 DPRINTF(("%s: no authentication key for %s algorithm\n", 200 __func__, thash->name)); 201 return EINVAL; 202 } 203 keylen = _KEYLEN(sav->key_auth); 204 if (keylen != thash->keysize && thash->keysize != 0) { 205 DPRINTF(("%s: invalid keylength %d, algorithm %s requires " 206 "keysize %d\n", __func__, 207 keylen, thash->name, thash->keysize)); 208 return EINVAL; 209 } 210 211 sav->tdb_xform = xsp; 212 sav->tdb_authalgxform = thash; 213 214 /* Initialize crypto session. */ 215 memset(cria, 0, sizeof(*cria)); 216 cria->cri_alg = sav->tdb_authalgxform->type; 217 cria->cri_klen = _KEYBITS(sav->key_auth); 218 cria->cri_key = _KEYBUF(sav->key_auth); 219 220 return 0; 221} 222 223/* 224 * ah_init() is called when an SPI is being set up. 225 */ 226static int 227ah_init(struct secasvar *sav, const struct xformsw *xsp) 228{ 229 struct cryptoini cria; 230 int error; 231 232 error = ah_init0(sav, xsp, &cria); 233 if (!error) 234 error = crypto_newsession(&sav->tdb_cryptoid, 235 &cria, crypto_support); 236 return error; 237} 238 239/* 240 * Paranoia. 241 * 242 * NB: public for use by esp_zeroize (XXX). 243 */ 244int 245ah_zeroize(struct secasvar *sav) 246{ 247 int err; 248 249 if (sav->key_auth) { 250 explicit_memset(_KEYBUF(sav->key_auth), 0, 251 _KEYLEN(sav->key_auth)); 252 } 253 254 err = crypto_freesession(sav->tdb_cryptoid); 255 sav->tdb_cryptoid = 0; 256 sav->tdb_authalgxform = NULL; 257 sav->tdb_xform = NULL; 258 return err; 259} 260 261/* 262 * Massage IPv4/IPv6 headers for AH processing. 263 */ 264static int 265ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) 266{ 267 struct mbuf *m = *m0; 268 unsigned char *ptr; 269 int off, count, optlen; 270#ifdef INET 271 struct ip *ip; 272#endif 273#ifdef INET6 274 struct ip6_ext *ip6e; 275 struct ip6_hdr ip6; 276 int alloc, nxt; 277#endif 278 279 switch (proto) { 280#ifdef INET 281 case AF_INET: 282 /* 283 * This is the least painful way of dealing with IPv4 header 284 * and option processing -- just make sure they're in 285 * contiguous memory. 286 */ 287 *m0 = m = m_pullup(m, skip); 288 if (m == NULL) { 289 DPRINTF(("%s: m_pullup failed\n", __func__)); 290 return ENOBUFS; 291 } 292 293 /* Fix the IP header */ 294 ip = mtod(m, struct ip *); 295 if (ip4_ah_cleartos) 296 ip->ip_tos = 0; 297 ip->ip_ttl = 0; 298 ip->ip_sum = 0; 299 ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask); 300 301 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 302 ip->ip_off &= htons(IP_DF); 303 else 304 ip->ip_off = 0; 305 306 ptr = mtod(m, unsigned char *); 307 308 /* IPv4 option processing */ 309 for (off = sizeof(struct ip); off < skip;) { 310 if (ptr[off] == IPOPT_EOL) { 311 break; 312 } else if (ptr[off] == IPOPT_NOP) { 313 optlen = 1; 314 } else if (off + 1 < skip) { 315 optlen = ptr[off + 1]; 316 if (optlen < 2 || off + optlen > skip) { 317 m_freem(m); 318 return EINVAL; 319 } 320 } else { 321 m_freem(m); 322 return EINVAL; 323 } 324 325 switch (ptr[off]) { 326 case IPOPT_NOP: 327 case IPOPT_SECURITY: 328 case 0x85: /* Extended security. */ 329 case 0x86: /* Commercial security. */ 330 case 0x94: /* Router alert */ 331 case 0x95: /* RFC1770 */ 332 break; 333 334 case IPOPT_LSRR: 335 case IPOPT_SSRR: 336 /* 337 * On output, if we have either of the 338 * source routing options, we should 339 * swap the destination address of the 340 * IP header with the last address 341 * specified in the option, as that is 342 * what the destination's IP header 343 * will look like. 344 */ 345 if (out) 346 memcpy(&ip->ip_dst, 347 ptr + off + optlen - 348 sizeof(struct in_addr), 349 sizeof(struct in_addr)); 350 /* FALLTHROUGH */ 351 352 default: 353 /* Zeroize all other options. */ 354 memcpy(ptr + off, ipseczeroes, optlen); 355 break; 356 } 357 358 off += optlen; 359 360 /* Sanity check. */ 361 if (off > skip) { 362 m_freem(m); 363 return EINVAL; 364 } 365 } 366 367 break; 368#endif /* INET */ 369 370#ifdef INET6 371 case AF_INET6: /* Ugly... */ 372 /* Copy and "cook" the IPv6 header. */ 373 m_copydata(m, 0, sizeof(ip6), &ip6); 374 375 /* We don't do IPv6 Jumbograms. */ 376 if (ip6.ip6_plen == 0) { 377 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__)); 378 m_freem(m); 379 return EMSGSIZE; 380 } 381 382 ip6.ip6_flow = 0; 383 ip6.ip6_hlim = 0; 384 ip6.ip6_vfc &= ~IPV6_VERSION_MASK; 385 ip6.ip6_vfc |= IPV6_VERSION; 386 387 /* Scoped address handling. */ 388 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) 389 ip6.ip6_src.s6_addr16[1] = 0; 390 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) 391 ip6.ip6_dst.s6_addr16[1] = 0; 392 393 /* Done with IPv6 header. */ 394 m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6); 395 396 /* Let's deal with the remaining headers (if any). */ 397 if (skip - sizeof(struct ip6_hdr) > 0) { 398 if (m->m_len <= skip) { 399 ptr = malloc(skip - sizeof(struct ip6_hdr), 400 M_XDATA, M_NOWAIT); 401 if (ptr == NULL) { 402 DPRINTF(("%s: failed to allocate " 403 "memory for IPv6 headers\n", 404 __func__)); 405 m_freem(m); 406 return ENOBUFS; 407 } 408 409 /* 410 * Copy all the protocol headers after 411 * the IPv6 header. 412 */ 413 m_copydata(m, sizeof(struct ip6_hdr), 414 skip - sizeof(struct ip6_hdr), ptr); 415 alloc = 1; 416 } else { 417 /* No need to allocate memory. */ 418 ptr = mtod(m, unsigned char *) + 419 sizeof(struct ip6_hdr); 420 alloc = 0; 421 } 422 } else 423 break; 424 425 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */ 426 427 for (off = 0; off < skip - sizeof(struct ip6_hdr);) { 428 int noff; 429 430 switch (nxt) { 431 case IPPROTO_HOPOPTS: 432 case IPPROTO_DSTOPTS: 433 ip6e = (struct ip6_ext *)(ptr + off); 434 noff = off + ((ip6e->ip6e_len + 1) << 3); 435 436 /* Sanity check. */ 437 if (noff > skip - sizeof(struct ip6_hdr)) { 438 goto error6; 439 } 440 441 /* 442 * Zero out mutable options. 443 */ 444 for (count = off + sizeof(struct ip6_ext); 445 count < noff;) { 446 if (ptr[count] == IP6OPT_PAD1) { 447 count++; 448 continue; 449 } 450 451 if (count + 1 >= noff) { 452 goto error6; 453 } 454 optlen = ptr[count + 1] + 2; 455 456 if (count + optlen > noff) { 457 goto error6; 458 } 459 460 if (ptr[count] & IP6OPT_MUTABLE) { 461 memset(ptr + count, 0, optlen); 462 } 463 464 count += optlen; 465 } 466 467 if (count != noff) { 468 goto error6; 469 } 470 471 /* Advance. */ 472 off += ((ip6e->ip6e_len + 1) << 3); 473 nxt = ip6e->ip6e_nxt; 474 break; 475 476 case IPPROTO_ROUTING: 477 ip6e = (struct ip6_ext *)(ptr + off); 478 479 /* advance */ 480 off += ((ip6e->ip6e_len + 1) << 3); 481 nxt = ip6e->ip6e_nxt; 482 break; 483 484 default: 485 DPRINTF(("%s: unexpected IPv6 header type %d\n", 486 __func__, off)); 487error6: 488 if (alloc) 489 free(ptr, M_XDATA); 490 m_freem(m); 491 return EINVAL; 492 } 493 } 494 495 /* Copyback and free, if we allocated. */ 496 if (alloc) { 497 m_copyback(m, sizeof(struct ip6_hdr), 498 skip - sizeof(struct ip6_hdr), ptr); 499 free(ptr, M_XDATA); 500 } 501 502 break; 503#endif /* INET6 */ 504 } 505 506 return 0; 507} 508 509/* 510 * ah_input() gets called to verify that an input packet 511 * passes authentication. 512 */ 513static int 514ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 515{ 516 const struct auth_hash *ahx; 517 struct tdb_crypto *tc = NULL; 518 struct newah *ah; 519 int hl, rplen, authsize, error, stat = AH_STAT_HDROPS; 520 struct cryptodesc *crda; 521 struct cryptop *crp = NULL; 522 bool pool_used; 523 uint8_t nxt; 524 525 KASSERT(sav != NULL); 526 KASSERT(sav->key_auth != NULL); 527 KASSERT(sav->tdb_authalgxform != NULL); 528 529 /* Figure out header size. */ 530 rplen = HDRSIZE(sav); 531 532 /* XXX don't pullup, just copy header */ 533 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 534 if (ah == NULL) { 535 DPRINTF(("%s: cannot pullup header\n", __func__)); 536 error = ENOBUFS; 537 stat = AH_STAT_HDROPS; /*XXX*/ 538 goto bad; 539 } 540 541 nxt = ah->ah_nxt; 542 543 /* Check replay window, if applicable. */ 544 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 545 char buf[IPSEC_LOGSASTRLEN]; 546 DPRINTF(("%s: packet replay failure: %s\n", __func__, 547 ipsec_logsastr(sav, buf, sizeof(buf)))); 548 stat = AH_STAT_REPLAY; 549 error = EACCES; 550 goto bad; 551 } 552 553 /* Verify AH header length. */ 554 hl = ah->ah_len * sizeof(uint32_t); 555 ahx = sav->tdb_authalgxform; 556 authsize = AUTHSIZE(sav); 557 if (hl != authsize + rplen - sizeof(struct ah)) { 558 char buf[IPSEC_ADDRSTRLEN]; 559 DPRINTF(("%s: bad authenticator length %u (expecting %lu)" 560 " for packet in SA %s/%08lx\n", __func__, 561 hl, (u_long) (authsize + rplen - sizeof(struct ah)), 562 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 563 (u_long) ntohl(sav->spi))); 564 stat = AH_STAT_BADAUTHL; 565 error = EACCES; 566 goto bad; 567 } 568 if (skip + authsize + rplen > m->m_pkthdr.len) { 569 char buf[IPSEC_ADDRSTRLEN]; 570 DPRINTF(("%s: bad mbuf length %u (expecting >= %lu)" 571 " for packet in SA %s/%08lx\n", __func__, 572 m->m_pkthdr.len, (u_long)(skip + authsize + rplen), 573 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 574 (u_long) ntohl(sav->spi))); 575 stat = AH_STAT_BADAUTHL; 576 error = EACCES; 577 goto bad; 578 } 579 580 AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl); 581 582 /* Get crypto descriptors. */ 583 crp = crypto_getreq(1); 584 if (crp == NULL) { 585 DPRINTF(("%s: failed to acquire crypto descriptor\n", __func__)); 586 stat = AH_STAT_CRYPTO; 587 error = ENOBUFS; 588 goto bad; 589 } 590 591 crda = crp->crp_desc; 592 KASSERT(crda != NULL); 593 594 crda->crd_skip = 0; 595 crda->crd_len = m->m_pkthdr.len; 596 crda->crd_inject = skip + rplen; 597 598 /* Authentication operation. */ 599 crda->crd_alg = ahx->type; 600 crda->crd_key = _KEYBUF(sav->key_auth); 601 crda->crd_klen = _KEYBITS(sav->key_auth); 602 603 /* Allocate IPsec-specific opaque crypto info. */ 604 size_t size = sizeof(*tc); 605 size_t extra = skip + rplen + authsize; 606 size += extra; 607 608 if (__predict_true(size <= ah_pool_item_size)) { 609 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 610 pool_used = true; 611 } else { 612 /* size can exceed on IPv6 packets with large options. */ 613 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 614 pool_used = false; 615 } 616 if (tc == NULL) { 617 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 618 stat = AH_STAT_CRYPTO; 619 error = ENOBUFS; 620 goto bad; 621 } 622 623 error = m_makewritable(&m, 0, extra, M_NOWAIT); 624 if (error) { 625 DPRINTF(("%s: failed to m_makewritable\n", __func__)); 626 goto bad; 627 } 628 629 /* 630 * Save the authenticator, the skipped portion of the packet, 631 * and the AH header. 632 */ 633 m_copydata(m, 0, extra, (tc + 1)); 634 /* Zeroize the authenticator on the packet. */ 635 m_copyback(m, skip + rplen, authsize, ipseczeroes); 636 637 /* "Massage" the packet headers for crypto processing. */ 638 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 639 skip, ahx->type, 0); 640 if (error != 0) { 641 /* NB: mbuf is free'd by ah_massage_headers */ 642 m = NULL; 643 goto bad; 644 } 645 646 { 647 int s = pserialize_read_enter(); 648 649 /* 650 * Take another reference to the SA for opencrypto callback. 651 */ 652 if (__predict_false(sav->state == SADB_SASTATE_DEAD)) { 653 pserialize_read_exit(s); 654 stat = AH_STAT_NOTDB; 655 error = ENOENT; 656 goto bad; 657 } 658 KEY_SA_REF(sav); 659 pserialize_read_exit(s); 660 } 661 662 /* Crypto operation descriptor. */ 663 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 664 crp->crp_flags = CRYPTO_F_IMBUF; 665 crp->crp_buf = m; 666 crp->crp_callback = ah_input_cb; 667 crp->crp_sid = sav->tdb_cryptoid; 668 crp->crp_opaque = tc; 669 670 /* These are passed as-is to the callback. */ 671 tc->tc_spi = sav->spi; 672 tc->tc_dst = sav->sah->saidx.dst; 673 tc->tc_proto = sav->sah->saidx.proto; 674 tc->tc_nxt = nxt; 675 tc->tc_protoff = protoff; 676 tc->tc_skip = skip; 677 tc->tc_sav = sav; 678 679 DPRINTF(("%s: hash over %d bytes, skip %d: " 680 "crda len %d skip %d inject %d\n", __func__, 681 crp->crp_ilen, tc->tc_skip, 682 crda->crd_len, crda->crd_skip, crda->crd_inject)); 683 684 return crypto_dispatch(crp); 685 686bad: 687 if (tc != NULL) { 688 if (__predict_true(pool_used)) 689 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 690 else 691 kmem_intr_free(tc, size); 692 } 693 if (crp != NULL) 694 crypto_freereq(crp); 695 if (m != NULL) 696 m_freem(m); 697 AH_STATINC(stat); 698 return error; 699} 700 701#ifdef INET6 702#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) do { \ 703 if (saidx->dst.sa.sa_family == AF_INET6) { \ 704 error = ipsec6_common_input_cb(m, sav, skip, protoff); \ 705 } else { \ 706 error = ipsec4_common_input_cb(m, sav, skip, protoff); \ 707 } \ 708} while (0) 709#else 710#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) \ 711 (error = ipsec4_common_input_cb(m, sav, skip, protoff)) 712#endif 713 714/* 715 * AH input callback from the crypto driver. 716 */ 717static int 718ah_input_cb(struct cryptop *crp) 719{ 720 char buf[IPSEC_ADDRSTRLEN]; 721 int rplen, error, skip, protoff; 722 unsigned char calc[AH_ALEN_MAX]; 723 struct mbuf *m; 724 struct tdb_crypto *tc; 725 struct secasvar *sav; 726 struct secasindex *saidx; 727 uint8_t nxt; 728 char *ptr; 729 int authsize; 730 uint16_t dport; 731 uint16_t sport; 732 bool pool_used; 733 size_t size; 734 IPSEC_DECLARE_LOCK_VARIABLE; 735 736 KASSERT(crp->crp_opaque != NULL); 737 tc = crp->crp_opaque; 738 skip = tc->tc_skip; 739 nxt = tc->tc_nxt; 740 protoff = tc->tc_protoff; 741 m = crp->crp_buf; 742 743 /* find the source port for NAT-T */ 744 nat_t_ports_get(m, &dport, &sport); 745 746 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 747 748 sav = tc->tc_sav; 749 saidx = &sav->sah->saidx; 750 KASSERTMSG(saidx->dst.sa.sa_family == AF_INET || 751 saidx->dst.sa.sa_family == AF_INET6, 752 "unexpected protocol family %u", saidx->dst.sa.sa_family); 753 754 /* Figure out header size. */ 755 rplen = HDRSIZE(sav); 756 authsize = AUTHSIZE(sav); 757 758 size = sizeof(*tc) + skip + rplen + authsize; 759 if (__predict_true(size <= ah_pool_item_size)) 760 pool_used = true; 761 else 762 pool_used = false; 763 764 /* Check for crypto errors. */ 765 if (crp->crp_etype) { 766 if (sav->tdb_cryptoid != 0) 767 sav->tdb_cryptoid = crp->crp_sid; 768 769 if (crp->crp_etype == EAGAIN) { 770 IPSEC_RELEASE_GLOBAL_LOCKS(); 771 return crypto_dispatch(crp); 772 } 773 774 AH_STATINC(AH_STAT_NOXFORM); 775 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 776 error = crp->crp_etype; 777 goto bad; 778 } else { 779 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 780 crypto_freereq(crp); /* No longer needed. */ 781 crp = NULL; 782 } 783 784 if (ipsec_debug) 785 memset(calc, 0, sizeof(calc)); 786 787 /* Copy authenticator off the packet. */ 788 m_copydata(m, skip + rplen, authsize, calc); 789 790 ptr = (char *)(tc + 1); 791 const uint8_t *pppp = ptr + skip + rplen; 792 793 /* Verify authenticator. */ 794 if (!consttime_memequal(pppp, calc, authsize)) { 795 DPRINTF(("%s: authentication hash mismatch " \ 796 "over %d bytes " \ 797 "for packet in SA %s/%08lx:\n" \ 798 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \ 799 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", 800 __func__, authsize, 801 ipsec_address(&saidx->dst, buf, sizeof(buf)), 802 (u_long) ntohl(sav->spi), 803 calc[0], calc[1], calc[2], calc[3], 804 calc[4], calc[5], calc[6], calc[7], 805 calc[8], calc[9], calc[10], calc[11], 806 pppp[0], pppp[1], pppp[2], pppp[3], 807 pppp[4], pppp[5], pppp[6], pppp[7], 808 pppp[8], pppp[9], pppp[10], pppp[11] 809 )); 810 AH_STATINC(AH_STAT_BADAUTH); 811 error = EACCES; 812 goto bad; 813 } 814 815 /* Fix the Next Protocol field. */ 816 ptr[protoff] = nxt; 817 818 /* Copyback the saved (uncooked) network headers. */ 819 m_copyback(m, 0, skip, ptr); 820 821 if (__predict_true(pool_used)) 822 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 823 else 824 kmem_intr_free(tc, size); 825 tc = NULL; 826 827 /* 828 * Header is now authenticated. 829 */ 830 m->m_flags |= M_AUTHIPHDR; 831 832 /* 833 * Update replay sequence number, if appropriate. 834 */ 835 if (sav->replay) { 836 uint32_t seq; 837 838 m_copydata(m, skip + offsetof(struct newah, ah_seq), 839 sizeof(seq), &seq); 840 if (ipsec_updatereplay(ntohl(seq), sav)) { 841 AH_STATINC(AH_STAT_REPLAY); 842 error = ENOBUFS; /* XXX */ 843 goto bad; 844 } 845 } 846 847 /* 848 * Remove the AH header and authenticator from the mbuf. 849 */ 850 error = m_striphdr(m, skip, rplen + authsize); 851 if (error) { 852 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__, 853 ipsec_address(&saidx->dst, buf, sizeof(buf)), 854 (u_long) ntohl(sav->spi))); 855 856 AH_STATINC(AH_STAT_HDROPS); 857 goto bad; 858 } 859 860 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff); 861 862 KEY_SA_UNREF(&sav); 863 IPSEC_RELEASE_GLOBAL_LOCKS(); 864 return error; 865 866bad: 867 if (sav) 868 KEY_SA_UNREF(&sav); 869 IPSEC_RELEASE_GLOBAL_LOCKS(); 870 if (m != NULL) 871 m_freem(m); 872 if (tc != NULL) { 873 if (pool_used) 874 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 875 else 876 kmem_intr_free(tc, size); 877 } 878 if (crp != NULL) 879 crypto_freereq(crp); 880 return error; 881} 882 883/* 884 * AH output routine, called by ipsec[46]_process_packet(). 885 */ 886static int 887ah_output(struct mbuf *m, const struct ipsecrequest *isr, struct secasvar *sav, 888 struct mbuf **mp, int skip, int protoff) 889{ 890 char buf[IPSEC_ADDRSTRLEN]; 891 const struct auth_hash *ahx; 892 struct cryptodesc *crda; 893 struct tdb_crypto *tc; 894 struct mbuf *mi; 895 struct cryptop *crp; 896 uint16_t iplen; 897 int error, rplen, authsize, maxpacketsize, roff; 898 uint8_t prot; 899 struct newah *ah; 900 size_t ipoffs; 901 bool pool_used; 902 903 KASSERT(sav != NULL); 904 KASSERT(sav->tdb_authalgxform != NULL); 905 ahx = sav->tdb_authalgxform; 906 907 AH_STATINC(AH_STAT_OUTPUT); 908 909 /* Figure out header size. */ 910 rplen = HDRSIZE(sav); 911 912 /* Check for maximum packet size violations. */ 913 switch (sav->sah->saidx.dst.sa.sa_family) { 914#ifdef INET 915 case AF_INET: 916 maxpacketsize = IP_MAXPACKET; 917 ipoffs = offsetof(struct ip, ip_len); 918 break; 919#endif 920#ifdef INET6 921 case AF_INET6: 922 maxpacketsize = IPV6_MAXPACKET; 923 ipoffs = offsetof(struct ip6_hdr, ip6_plen); 924 break; 925#endif 926 default: 927 DPRINTF(("%s: unknown/unsupported protocol " 928 "family %u, SA %s/%08lx\n", __func__, 929 sav->sah->saidx.dst.sa.sa_family, 930 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 931 (u_long) ntohl(sav->spi))); 932 AH_STATINC(AH_STAT_NOPF); 933 error = EPFNOSUPPORT; 934 goto bad; 935 } 936 authsize = AUTHSIZE(sav); 937 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 938 DPRINTF(("%s: packet in SA %s/%08lx got too big " 939 "(len %u, max len %u)\n", __func__, 940 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 941 (u_long) ntohl(sav->spi), 942 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 943 AH_STATINC(AH_STAT_TOOBIG); 944 error = EMSGSIZE; 945 goto bad; 946 } 947 948 /* Update the counters. */ 949 AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip); 950 951 m = m_clone(m); 952 if (m == NULL) { 953 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 954 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 955 (u_long) ntohl(sav->spi))); 956 AH_STATINC(AH_STAT_HDROPS); 957 error = ENOBUFS; 958 goto bad; 959 } 960 961 /* Inject AH header. */ 962 mi = m_makespace(m, skip, rplen + authsize, &roff); 963 if (mi == NULL) { 964 DPRINTF(("%s: failed to inject %u byte AH header for SA " 965 "%s/%08lx\n", __func__, 966 rplen + authsize, 967 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 968 (u_long) ntohl(sav->spi))); 969 AH_STATINC(AH_STAT_HDROPS); 970 error = ENOBUFS; 971 goto bad; 972 } 973 974 /* 975 * The AH header is guaranteed by m_makespace() to be in 976 * contiguous memory, at roff bytes offset into the returned mbuf. 977 */ 978 ah = (struct newah *)(mtod(mi, char *) + roff); 979 980 /* Initialize the AH header. */ 981 m_copydata(m, protoff, sizeof(uint8_t), &ah->ah_nxt); 982 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(uint32_t); 983 ah->ah_reserve = 0; 984 ah->ah_spi = sav->spi; 985 986 /* Zeroize authenticator. */ 987 m_copyback(m, skip + rplen, authsize, ipseczeroes); 988 989 /* Insert packet replay counter, as requested. */ 990 if (sav->replay) { 991 if (sav->replay->count == ~0 && 992 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 993 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n", 994 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 995 sizeof(buf)), (u_long) ntohl(sav->spi))); 996 AH_STATINC(AH_STAT_WRAP); 997 error = EINVAL; 998 goto bad; 999 } 1000#ifdef IPSEC_DEBUG 1001 /* Emulate replay attack when ipsec_replay is TRUE. */ 1002 if (!ipsec_replay) 1003#endif 1004 sav->replay->count++; 1005 ah->ah_seq = htonl(sav->replay->count); 1006 } 1007 1008 /* Get crypto descriptors. */ 1009 crp = crypto_getreq(1); 1010 if (crp == NULL) { 1011 DPRINTF(("%s: failed to acquire crypto descriptors\n", 1012 __func__)); 1013 AH_STATINC(AH_STAT_CRYPTO); 1014 error = ENOBUFS; 1015 goto bad; 1016 } 1017 1018 crda = crp->crp_desc; 1019 1020 crda->crd_skip = 0; 1021 crda->crd_inject = skip + rplen; 1022 crda->crd_len = m->m_pkthdr.len; 1023 1024 /* Authentication operation. */ 1025 crda->crd_alg = ahx->type; 1026 crda->crd_key = _KEYBUF(sav->key_auth); 1027 crda->crd_klen = _KEYBITS(sav->key_auth); 1028 1029 /* Allocate IPsec-specific opaque crypto info. */ 1030 size_t size = sizeof(*tc) + skip; 1031 1032 if (__predict_true(size <= ah_pool_item_size)) { 1033 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 1034 pool_used = true; 1035 } else { 1036 /* size can exceed on IPv6 packets with large options. */ 1037 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 1038 pool_used = false; 1039 } 1040 if (tc == NULL) { 1041 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 1042 AH_STATINC(AH_STAT_CRYPTO); 1043 error = ENOBUFS; 1044 goto bad_crp; 1045 } 1046 1047 uint8_t *pext = (char *)(tc + 1); 1048 /* Save the skipped portion of the packet. */ 1049 m_copydata(m, 0, skip, pext); 1050 1051 /* 1052 * Fix IP header length on the header used for 1053 * authentication. We don't need to fix the original 1054 * header length as it will be fixed by our caller. 1055 */ 1056 memcpy(&iplen, pext + ipoffs, sizeof(iplen)); 1057 iplen = htons(ntohs(iplen) + rplen + authsize); 1058 m_copyback(m, ipoffs, sizeof(iplen), &iplen); 1059 1060 /* Fix the Next Header field in saved header. */ 1061 pext[protoff] = IPPROTO_AH; 1062 1063 /* Update the Next Protocol field in the IP header. */ 1064 prot = IPPROTO_AH; 1065 m_copyback(m, protoff, sizeof(prot), &prot); 1066 1067 /* "Massage" the packet headers for crypto processing. */ 1068 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1069 skip, ahx->type, 1); 1070 if (error != 0) { 1071 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1072 goto bad_tc; 1073 } 1074 1075 { 1076 int s = pserialize_read_enter(); 1077 1078 /* 1079 * Take another reference to the SP and the SA for opencrypto callback. 1080 */ 1081 if (__predict_false(isr->sp->state == IPSEC_SPSTATE_DEAD || 1082 sav->state == SADB_SASTATE_DEAD)) { 1083 pserialize_read_exit(s); 1084 AH_STATINC(AH_STAT_NOTDB); 1085 error = ENOENT; 1086 goto bad_tc; 1087 } 1088 KEY_SP_REF(isr->sp); 1089 KEY_SA_REF(sav); 1090 pserialize_read_exit(s); 1091 } 1092 1093 /* Crypto operation descriptor. */ 1094 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1095 crp->crp_flags = CRYPTO_F_IMBUF; 1096 crp->crp_buf = m; 1097 crp->crp_callback = ah_output_cb; 1098 crp->crp_sid = sav->tdb_cryptoid; 1099 crp->crp_opaque = tc; 1100 1101 /* These are passed as-is to the callback. */ 1102 tc->tc_isr = isr; 1103 tc->tc_spi = sav->spi; 1104 tc->tc_dst = sav->sah->saidx.dst; 1105 tc->tc_proto = sav->sah->saidx.proto; 1106 tc->tc_skip = skip; 1107 tc->tc_protoff = protoff; 1108 tc->tc_sav = sav; 1109 1110 return crypto_dispatch(crp); 1111 1112bad_tc: 1113 if (__predict_true(pool_used)) 1114 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1115 else 1116 kmem_intr_free(tc, size); 1117bad_crp: 1118 crypto_freereq(crp); 1119bad: 1120 if (m) 1121 m_freem(m); 1122 return error; 1123} 1124 1125/* 1126 * AH output callback from the crypto driver. 1127 */ 1128static int 1129ah_output_cb(struct cryptop *crp) 1130{ 1131 int skip, error; 1132 struct tdb_crypto *tc; 1133 const struct ipsecrequest *isr; 1134 struct secasvar *sav; 1135 struct mbuf *m; 1136 void *ptr; 1137 int err; 1138 size_t size; 1139 bool pool_used; 1140 IPSEC_DECLARE_LOCK_VARIABLE; 1141 1142 KASSERT(crp->crp_opaque != NULL); 1143 tc = crp->crp_opaque; 1144 skip = tc->tc_skip; 1145 ptr = (tc + 1); 1146 m = crp->crp_buf; 1147 size = sizeof(*tc) + skip; 1148 pool_used = size <= ah_pool_item_size; 1149 1150 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 1151 1152 isr = tc->tc_isr; 1153 sav = tc->tc_sav; 1154 1155 /* Check for crypto errors. */ 1156 if (crp->crp_etype) { 1157 if (sav->tdb_cryptoid != 0) 1158 sav->tdb_cryptoid = crp->crp_sid; 1159 1160 if (crp->crp_etype == EAGAIN) { 1161 IPSEC_RELEASE_GLOBAL_LOCKS(); 1162 return crypto_dispatch(crp); 1163 } 1164 1165 AH_STATINC(AH_STAT_NOXFORM); 1166 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 1167 error = crp->crp_etype; 1168 goto bad; 1169 } 1170 1171 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 1172 1173 /* 1174 * Copy original headers (with the new protocol number) back 1175 * in place. 1176 */ 1177 m_copyback(m, 0, skip, ptr); 1178 1179 /* No longer needed. */ 1180 if (__predict_true(pool_used)) 1181 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1182 else 1183 kmem_intr_free(tc, size); 1184 crypto_freereq(crp); 1185 1186#ifdef IPSEC_DEBUG 1187 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 1188 if (ipsec_integrity) { 1189 int alen; 1190 1191 /* 1192 * Corrupt HMAC if we want to test integrity verification of 1193 * the other side. 1194 */ 1195 alen = AUTHSIZE(sav); 1196 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); 1197 } 1198#endif 1199 1200 /* NB: m is reclaimed by ipsec_process_done. */ 1201 err = ipsec_process_done(m, isr, sav); 1202 KEY_SA_UNREF(&sav); 1203 KEY_SP_UNREF(&isr->sp); 1204 IPSEC_RELEASE_GLOBAL_LOCKS(); 1205 return err; 1206bad: 1207 if (sav) 1208 KEY_SA_UNREF(&sav); 1209 KEY_SP_UNREF(&isr->sp); 1210 IPSEC_RELEASE_GLOBAL_LOCKS(); 1211 if (m) 1212 m_freem(m); 1213 if (__predict_true(pool_used)) 1214 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1215 else 1216 kmem_intr_free(tc, size); 1217 crypto_freereq(crp); 1218 return error; 1219} 1220 1221static struct xformsw ah_xformsw = { 1222 .xf_type = XF_AH, 1223 .xf_flags = XFT_AUTH, 1224 .xf_name = "IPsec AH", 1225 .xf_init = ah_init, 1226 .xf_zeroize = ah_zeroize, 1227 .xf_input = ah_input, 1228 .xf_output = ah_output, 1229 .xf_next = NULL, 1230}; 1231 1232void 1233ah_attach(void) 1234{ 1235 ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS); 1236 1237#define MAXAUTHSIZE(name) \ 1238 if ((auth_hash_ ## name).authsize > ah_max_authsize) \ 1239 ah_max_authsize = (auth_hash_ ## name).authsize 1240 1241 ah_max_authsize = 0; 1242 MAXAUTHSIZE(null); 1243 MAXAUTHSIZE(md5); 1244 MAXAUTHSIZE(sha1); 1245 MAXAUTHSIZE(key_md5); 1246 MAXAUTHSIZE(key_sha1); 1247 MAXAUTHSIZE(hmac_md5); 1248 MAXAUTHSIZE(hmac_sha1); 1249 MAXAUTHSIZE(hmac_ripemd_160); 1250 MAXAUTHSIZE(hmac_md5_96); 1251 MAXAUTHSIZE(hmac_sha1_96); 1252 MAXAUTHSIZE(hmac_ripemd_160_96); 1253 MAXAUTHSIZE(hmac_sha2_256); 1254 MAXAUTHSIZE(hmac_sha2_384); 1255 MAXAUTHSIZE(hmac_sha2_512); 1256 MAXAUTHSIZE(aes_xcbc_mac_96); 1257 MAXAUTHSIZE(gmac_aes_128); 1258 MAXAUTHSIZE(gmac_aes_192); 1259 MAXAUTHSIZE(gmac_aes_256); 1260 IPSECLOG(LOG_DEBUG, "ah_max_authsize=%d\n", ah_max_authsize); 1261 1262#undef MAXAUTHSIZE 1263 1264 ah_pool_item_size = sizeof(struct tdb_crypto) + 1265 sizeof(struct ip) + MAX_IPOPTLEN + 1266 sizeof(struct ah) + sizeof(uint32_t) + ah_max_authsize; 1267 ah_tdb_crypto_pool_cache = pool_cache_init(ah_pool_item_size, 1268 coherency_unit, 0, 0, "ah_tdb_crypto", NULL, IPL_SOFTNET, 1269 NULL, NULL, NULL); 1270 1271 xform_register(&ah_xformsw); 1272} 1273