1 /* $NetBSD: xform_ah.c,v 1.97 2018/05/01 08:27:13 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 1.97 2018/05/01 08:27:13 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) 101 102 percpu_t *ahstat_percpu; 103 104 int ah_enable = 1; /* control flow of packets with AH */ 105 int ip4_ah_cleartos = 1; /* clear ip_tos when doing AH calc */ 106 107 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 108 109 int ah_max_authsize; /* max authsize over all algorithms */ 110 111 static int ah_input_cb(struct cryptop *); 112 static int ah_output_cb(struct cryptop *); 113 114 const uint8_t ah_stats[256] = { SADB_AALG_STATS_INIT }; 115 116 static pool_cache_t ah_tdb_crypto_pool_cache; 117 static size_t ah_pool_item_size; 118 119 /* 120 * NB: this is public for use by the PF_KEY support. 121 */ 122 const struct auth_hash * 123 ah_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 } 150 151 size_t 152 ah_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 */ 172 int 173 ah_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 */ 226 static int 227 ah_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 */ 244 int 245 ah_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 */ 264 static int 265 ah_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)); 487 error6: 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 */ 513 static int 514 ah_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 /* m already freed */ 536 return ENOBUFS; 537 } 538 539 nxt = ah->ah_nxt; 540 541 /* Check replay window, if applicable. */ 542 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 543 char buf[IPSEC_LOGSASTRLEN]; 544 DPRINTF(("%s: packet replay failure: %s\n", __func__, 545 ipsec_logsastr(sav, buf, sizeof(buf)))); 546 stat = AH_STAT_REPLAY; 547 error = EACCES; 548 goto bad; 549 } 550 551 /* Verify AH header length. */ 552 hl = ah->ah_len * sizeof(uint32_t); 553 ahx = sav->tdb_authalgxform; 554 authsize = AUTHSIZE(sav); 555 if (hl != authsize + rplen - sizeof(struct ah)) { 556 char buf[IPSEC_ADDRSTRLEN]; 557 DPRINTF(("%s: bad authenticator length %u (expecting %lu)" 558 " for packet in SA %s/%08lx\n", __func__, 559 hl, (u_long) (authsize + rplen - sizeof(struct ah)), 560 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 561 (u_long) ntohl(sav->spi))); 562 stat = AH_STAT_BADAUTHL; 563 error = EACCES; 564 goto bad; 565 } 566 if (skip + authsize + rplen > m->m_pkthdr.len) { 567 char buf[IPSEC_ADDRSTRLEN]; 568 DPRINTF(("%s: bad mbuf length %u (expecting >= %lu)" 569 " for packet in SA %s/%08lx\n", __func__, 570 m->m_pkthdr.len, (u_long)(skip + authsize + rplen), 571 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 572 (u_long) ntohl(sav->spi))); 573 stat = AH_STAT_BADAUTHL; 574 error = EACCES; 575 goto bad; 576 } 577 578 AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl); 579 580 /* Get crypto descriptors. */ 581 crp = crypto_getreq(1); 582 if (crp == NULL) { 583 DPRINTF(("%s: failed to acquire crypto descriptor\n", __func__)); 584 stat = AH_STAT_CRYPTO; 585 error = ENOBUFS; 586 goto bad; 587 } 588 589 crda = crp->crp_desc; 590 KASSERT(crda != NULL); 591 592 crda->crd_skip = 0; 593 crda->crd_len = m->m_pkthdr.len; 594 crda->crd_inject = skip + rplen; 595 596 /* Authentication operation. */ 597 crda->crd_alg = ahx->type; 598 crda->crd_key = _KEYBUF(sav->key_auth); 599 crda->crd_klen = _KEYBITS(sav->key_auth); 600 601 /* Allocate IPsec-specific opaque crypto info. */ 602 size_t size = sizeof(*tc); 603 size_t extra = skip + rplen + authsize; 604 size += extra; 605 606 if (__predict_true(size <= ah_pool_item_size)) { 607 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 608 pool_used = true; 609 } else { 610 /* size can exceed on IPv6 packets with large options. */ 611 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 612 pool_used = false; 613 } 614 if (tc == NULL) { 615 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 616 stat = AH_STAT_CRYPTO; 617 error = ENOBUFS; 618 goto bad; 619 } 620 621 error = m_makewritable(&m, 0, extra, M_NOWAIT); 622 if (error) { 623 DPRINTF(("%s: failed to m_makewritable\n", __func__)); 624 goto bad; 625 } 626 627 /* 628 * Save the authenticator, the skipped portion of the packet, 629 * and the AH header. 630 */ 631 m_copydata(m, 0, extra, (tc + 1)); 632 /* Zeroize the authenticator on the packet. */ 633 m_copyback(m, skip + rplen, authsize, ipseczeroes); 634 635 /* "Massage" the packet headers for crypto processing. */ 636 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 637 skip, ahx->type, 0); 638 if (error != 0) { 639 /* NB: mbuf is free'd by ah_massage_headers */ 640 m = NULL; 641 goto bad; 642 } 643 644 { 645 int s = pserialize_read_enter(); 646 647 /* 648 * Take another reference to the SA for opencrypto callback. 649 */ 650 if (__predict_false(sav->state == SADB_SASTATE_DEAD)) { 651 pserialize_read_exit(s); 652 stat = AH_STAT_NOTDB; 653 error = ENOENT; 654 goto bad; 655 } 656 KEY_SA_REF(sav); 657 pserialize_read_exit(s); 658 } 659 660 /* Crypto operation descriptor. */ 661 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 662 crp->crp_flags = CRYPTO_F_IMBUF; 663 crp->crp_buf = m; 664 crp->crp_callback = ah_input_cb; 665 crp->crp_sid = sav->tdb_cryptoid; 666 crp->crp_opaque = tc; 667 668 /* These are passed as-is to the callback. */ 669 tc->tc_spi = sav->spi; 670 tc->tc_dst = sav->sah->saidx.dst; 671 tc->tc_proto = sav->sah->saidx.proto; 672 tc->tc_nxt = nxt; 673 tc->tc_protoff = protoff; 674 tc->tc_skip = skip; 675 tc->tc_sav = sav; 676 677 DPRINTF(("%s: hash over %d bytes, skip %d: " 678 "crda len %d skip %d inject %d\n", __func__, 679 crp->crp_ilen, tc->tc_skip, 680 crda->crd_len, crda->crd_skip, crda->crd_inject)); 681 682 return crypto_dispatch(crp); 683 684 bad: 685 if (tc != NULL) { 686 if (__predict_true(pool_used)) 687 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 688 else 689 kmem_intr_free(tc, size); 690 } 691 if (crp != NULL) 692 crypto_freereq(crp); 693 if (m != NULL) 694 m_freem(m); 695 AH_STATINC(stat); 696 return error; 697 } 698 699 #ifdef INET6 700 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) do { \ 701 if (saidx->dst.sa.sa_family == AF_INET6) { \ 702 error = ipsec6_common_input_cb(m, sav, skip, protoff); \ 703 } else { \ 704 error = ipsec4_common_input_cb(m, sav, skip, protoff); \ 705 } \ 706 } while (0) 707 #else 708 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) \ 709 (error = ipsec4_common_input_cb(m, sav, skip, protoff)) 710 #endif 711 712 /* 713 * AH input callback from the crypto driver. 714 */ 715 static int 716 ah_input_cb(struct cryptop *crp) 717 { 718 char buf[IPSEC_ADDRSTRLEN]; 719 int rplen, error, skip, protoff; 720 unsigned char calc[AH_ALEN_MAX]; 721 struct mbuf *m; 722 struct tdb_crypto *tc; 723 struct secasvar *sav; 724 struct secasindex *saidx; 725 uint8_t nxt; 726 char *ptr; 727 int authsize; 728 uint16_t dport; 729 uint16_t sport; 730 bool pool_used; 731 size_t size; 732 IPSEC_DECLARE_LOCK_VARIABLE; 733 734 KASSERT(crp->crp_opaque != NULL); 735 tc = crp->crp_opaque; 736 skip = tc->tc_skip; 737 nxt = tc->tc_nxt; 738 protoff = tc->tc_protoff; 739 m = crp->crp_buf; 740 741 /* find the source port for NAT-T */ 742 nat_t_ports_get(m, &dport, &sport); 743 744 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 745 746 sav = tc->tc_sav; 747 saidx = &sav->sah->saidx; 748 KASSERTMSG(saidx->dst.sa.sa_family == AF_INET || 749 saidx->dst.sa.sa_family == AF_INET6, 750 "unexpected protocol family %u", saidx->dst.sa.sa_family); 751 752 /* Figure out header size. */ 753 rplen = HDRSIZE(sav); 754 authsize = AUTHSIZE(sav); 755 756 size = sizeof(*tc) + skip + rplen + authsize; 757 if (__predict_true(size <= ah_pool_item_size)) 758 pool_used = true; 759 else 760 pool_used = false; 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 IPSEC_RELEASE_GLOBAL_LOCKS(); 769 return crypto_dispatch(crp); 770 } 771 772 AH_STATINC(AH_STAT_NOXFORM); 773 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 774 error = crp->crp_etype; 775 goto bad; 776 } else { 777 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 778 crypto_freereq(crp); /* No longer needed. */ 779 crp = NULL; 780 } 781 782 if (ipsec_debug) 783 memset(calc, 0, sizeof(calc)); 784 785 /* Copy authenticator off the packet. */ 786 m_copydata(m, skip + rplen, authsize, calc); 787 788 ptr = (char *)(tc + 1); 789 const uint8_t *pppp = ptr + skip + rplen; 790 791 /* Verify authenticator. */ 792 if (!consttime_memequal(pppp, calc, authsize)) { 793 DPRINTF(("%s: authentication hash mismatch " \ 794 "over %d bytes " \ 795 "for packet in SA %s/%08lx:\n" \ 796 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \ 797 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", 798 __func__, authsize, 799 ipsec_address(&saidx->dst, buf, sizeof(buf)), 800 (u_long) ntohl(sav->spi), 801 calc[0], calc[1], calc[2], calc[3], 802 calc[4], calc[5], calc[6], calc[7], 803 calc[8], calc[9], calc[10], calc[11], 804 pppp[0], pppp[1], pppp[2], pppp[3], 805 pppp[4], pppp[5], pppp[6], pppp[7], 806 pppp[8], pppp[9], pppp[10], pppp[11] 807 )); 808 AH_STATINC(AH_STAT_BADAUTH); 809 error = EACCES; 810 goto bad; 811 } 812 813 /* Fix the Next Protocol field. */ 814 ptr[protoff] = nxt; 815 816 /* Copyback the saved (uncooked) network headers. */ 817 m_copyback(m, 0, skip, ptr); 818 819 if (__predict_true(pool_used)) 820 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 821 else 822 kmem_intr_free(tc, size); 823 tc = NULL; 824 825 /* 826 * Header is now authenticated. 827 */ 828 m->m_flags |= M_AUTHIPHDR; 829 830 /* 831 * Update replay sequence number, if appropriate. 832 */ 833 if (sav->replay) { 834 uint32_t seq; 835 836 m_copydata(m, skip + offsetof(struct newah, ah_seq), 837 sizeof(seq), &seq); 838 if (ipsec_updatereplay(ntohl(seq), sav)) { 839 AH_STATINC(AH_STAT_REPLAY); 840 error = ENOBUFS; /* XXX */ 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, buf, sizeof(buf)), 852 (u_long) ntohl(sav->spi))); 853 854 AH_STATINC(AH_STAT_HDROPS); 855 goto bad; 856 } 857 858 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff); 859 860 KEY_SA_UNREF(&sav); 861 IPSEC_RELEASE_GLOBAL_LOCKS(); 862 return error; 863 864 bad: 865 if (sav) 866 KEY_SA_UNREF(&sav); 867 IPSEC_RELEASE_GLOBAL_LOCKS(); 868 if (m != NULL) 869 m_freem(m); 870 if (tc != NULL) { 871 if (pool_used) 872 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 873 else 874 kmem_intr_free(tc, size); 875 } 876 if (crp != NULL) 877 crypto_freereq(crp); 878 return error; 879 } 880 881 /* 882 * AH output routine, called by ipsec[46]_process_packet(). 883 */ 884 static int 885 ah_output(struct mbuf *m, const struct ipsecrequest *isr, struct secasvar *sav, 886 struct mbuf **mp, int skip, int protoff) 887 { 888 char buf[IPSEC_ADDRSTRLEN]; 889 const struct auth_hash *ahx; 890 struct cryptodesc *crda; 891 struct tdb_crypto *tc; 892 struct mbuf *mi; 893 struct cryptop *crp; 894 uint16_t iplen; 895 int error, rplen, authsize, maxpacketsize, roff; 896 uint8_t prot; 897 struct newah *ah; 898 size_t ipoffs; 899 bool pool_used; 900 901 KASSERT(sav != NULL); 902 KASSERT(sav->tdb_authalgxform != NULL); 903 ahx = sav->tdb_authalgxform; 904 905 AH_STATINC(AH_STAT_OUTPUT); 906 907 /* Figure out header size. */ 908 rplen = HDRSIZE(sav); 909 910 /* Check for maximum packet size violations. */ 911 switch (sav->sah->saidx.dst.sa.sa_family) { 912 #ifdef INET 913 case AF_INET: 914 maxpacketsize = IP_MAXPACKET; 915 ipoffs = offsetof(struct ip, ip_len); 916 break; 917 #endif 918 #ifdef INET6 919 case AF_INET6: 920 maxpacketsize = IPV6_MAXPACKET; 921 ipoffs = offsetof(struct ip6_hdr, ip6_plen); 922 break; 923 #endif 924 default: 925 DPRINTF(("%s: unknown/unsupported protocol " 926 "family %u, SA %s/%08lx\n", __func__, 927 sav->sah->saidx.dst.sa.sa_family, 928 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 929 (u_long) ntohl(sav->spi))); 930 AH_STATINC(AH_STAT_NOPF); 931 error = EPFNOSUPPORT; 932 goto bad; 933 } 934 authsize = AUTHSIZE(sav); 935 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 936 DPRINTF(("%s: packet in SA %s/%08lx got too big " 937 "(len %u, max len %u)\n", __func__, 938 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 939 (u_long) ntohl(sav->spi), 940 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 941 AH_STATINC(AH_STAT_TOOBIG); 942 error = EMSGSIZE; 943 goto bad; 944 } 945 946 /* Update the counters. */ 947 AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip); 948 949 m = m_clone(m); 950 if (m == NULL) { 951 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 952 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 953 (u_long) ntohl(sav->spi))); 954 AH_STATINC(AH_STAT_HDROPS); 955 error = ENOBUFS; 956 goto bad; 957 } 958 959 /* Inject AH header. */ 960 mi = m_makespace(m, skip, rplen + authsize, &roff); 961 if (mi == NULL) { 962 DPRINTF(("%s: failed to inject %u byte AH header for SA " 963 "%s/%08lx\n", __func__, 964 rplen + authsize, 965 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 966 (u_long) ntohl(sav->spi))); 967 AH_STATINC(AH_STAT_HDROPS); 968 error = ENOBUFS; 969 goto bad; 970 } 971 972 /* 973 * The AH header is guaranteed by m_makespace() to be in 974 * contiguous memory, at roff bytes offset into the returned mbuf. 975 */ 976 ah = (struct newah *)(mtod(mi, char *) + roff); 977 978 /* Initialize the AH header. */ 979 m_copydata(m, protoff, sizeof(uint8_t), &ah->ah_nxt); 980 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(uint32_t); 981 ah->ah_reserve = 0; 982 ah->ah_spi = sav->spi; 983 984 /* Zeroize authenticator. */ 985 m_copyback(m, skip + rplen, authsize, ipseczeroes); 986 987 /* Insert packet replay counter, as requested. */ 988 if (sav->replay) { 989 if (sav->replay->count == ~0 && 990 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 991 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n", 992 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 993 sizeof(buf)), (u_long) ntohl(sav->spi))); 994 AH_STATINC(AH_STAT_WRAP); 995 error = EINVAL; 996 goto bad; 997 } 998 #ifdef IPSEC_DEBUG 999 /* Emulate replay attack when ipsec_replay is TRUE. */ 1000 if (!ipsec_replay) 1001 #endif 1002 sav->replay->count++; 1003 ah->ah_seq = htonl(sav->replay->count); 1004 } 1005 1006 /* Get crypto descriptors. */ 1007 crp = crypto_getreq(1); 1008 if (crp == NULL) { 1009 DPRINTF(("%s: failed to acquire crypto descriptors\n", 1010 __func__)); 1011 AH_STATINC(AH_STAT_CRYPTO); 1012 error = ENOBUFS; 1013 goto bad; 1014 } 1015 1016 crda = crp->crp_desc; 1017 1018 crda->crd_skip = 0; 1019 crda->crd_inject = skip + rplen; 1020 crda->crd_len = m->m_pkthdr.len; 1021 1022 /* Authentication operation. */ 1023 crda->crd_alg = ahx->type; 1024 crda->crd_key = _KEYBUF(sav->key_auth); 1025 crda->crd_klen = _KEYBITS(sav->key_auth); 1026 1027 /* Allocate IPsec-specific opaque crypto info. */ 1028 size_t size = sizeof(*tc) + skip; 1029 1030 if (__predict_true(size <= ah_pool_item_size)) { 1031 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 1032 pool_used = true; 1033 } else { 1034 /* size can exceed on IPv6 packets with large options. */ 1035 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 1036 pool_used = false; 1037 } 1038 if (tc == NULL) { 1039 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 1040 AH_STATINC(AH_STAT_CRYPTO); 1041 error = ENOBUFS; 1042 goto bad_crp; 1043 } 1044 1045 uint8_t *pext = (char *)(tc + 1); 1046 /* Save the skipped portion of the packet. */ 1047 m_copydata(m, 0, skip, pext); 1048 1049 /* 1050 * Fix IP header length on the header used for 1051 * authentication. We don't need to fix the original 1052 * header length as it will be fixed by our caller. 1053 */ 1054 memcpy(&iplen, pext + ipoffs, sizeof(iplen)); 1055 iplen = htons(ntohs(iplen) + rplen + authsize); 1056 m_copyback(m, ipoffs, sizeof(iplen), &iplen); 1057 1058 /* Fix the Next Header field in saved header. */ 1059 pext[protoff] = IPPROTO_AH; 1060 1061 /* Update the Next Protocol field in the IP header. */ 1062 prot = IPPROTO_AH; 1063 m_copyback(m, protoff, sizeof(prot), &prot); 1064 1065 /* "Massage" the packet headers for crypto processing. */ 1066 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1067 skip, ahx->type, 1); 1068 if (error != 0) { 1069 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1070 goto bad_tc; 1071 } 1072 1073 { 1074 int s = pserialize_read_enter(); 1075 1076 /* 1077 * Take another reference to the SP and the SA for opencrypto callback. 1078 */ 1079 if (__predict_false(isr->sp->state == IPSEC_SPSTATE_DEAD || 1080 sav->state == SADB_SASTATE_DEAD)) { 1081 pserialize_read_exit(s); 1082 AH_STATINC(AH_STAT_NOTDB); 1083 error = ENOENT; 1084 goto bad_tc; 1085 } 1086 KEY_SP_REF(isr->sp); 1087 KEY_SA_REF(sav); 1088 pserialize_read_exit(s); 1089 } 1090 1091 /* Crypto operation descriptor. */ 1092 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1093 crp->crp_flags = CRYPTO_F_IMBUF; 1094 crp->crp_buf = m; 1095 crp->crp_callback = ah_output_cb; 1096 crp->crp_sid = sav->tdb_cryptoid; 1097 crp->crp_opaque = tc; 1098 1099 /* These are passed as-is to the callback. */ 1100 tc->tc_isr = isr; 1101 tc->tc_spi = sav->spi; 1102 tc->tc_dst = sav->sah->saidx.dst; 1103 tc->tc_proto = sav->sah->saidx.proto; 1104 tc->tc_skip = skip; 1105 tc->tc_protoff = protoff; 1106 tc->tc_sav = sav; 1107 1108 return crypto_dispatch(crp); 1109 1110 bad_tc: 1111 if (__predict_true(pool_used)) 1112 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1113 else 1114 kmem_intr_free(tc, size); 1115 bad_crp: 1116 crypto_freereq(crp); 1117 bad: 1118 if (m) 1119 m_freem(m); 1120 return error; 1121 } 1122 1123 /* 1124 * AH output callback from the crypto driver. 1125 */ 1126 static int 1127 ah_output_cb(struct cryptop *crp) 1128 { 1129 int skip, error; 1130 struct tdb_crypto *tc; 1131 const struct ipsecrequest *isr; 1132 struct secasvar *sav; 1133 struct mbuf *m; 1134 void *ptr; 1135 int err; 1136 size_t size; 1137 bool pool_used; 1138 IPSEC_DECLARE_LOCK_VARIABLE; 1139 1140 KASSERT(crp->crp_opaque != NULL); 1141 tc = crp->crp_opaque; 1142 skip = tc->tc_skip; 1143 ptr = (tc + 1); 1144 m = crp->crp_buf; 1145 size = sizeof(*tc) + skip; 1146 pool_used = size <= ah_pool_item_size; 1147 1148 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 1149 1150 isr = tc->tc_isr; 1151 sav = tc->tc_sav; 1152 1153 /* Check for crypto errors. */ 1154 if (crp->crp_etype) { 1155 if (sav->tdb_cryptoid != 0) 1156 sav->tdb_cryptoid = crp->crp_sid; 1157 1158 if (crp->crp_etype == EAGAIN) { 1159 IPSEC_RELEASE_GLOBAL_LOCKS(); 1160 return crypto_dispatch(crp); 1161 } 1162 1163 AH_STATINC(AH_STAT_NOXFORM); 1164 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 1165 error = crp->crp_etype; 1166 goto bad; 1167 } 1168 1169 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 1170 1171 /* 1172 * Copy original headers (with the new protocol number) back 1173 * in place. 1174 */ 1175 m_copyback(m, 0, skip, ptr); 1176 1177 /* No longer needed. */ 1178 if (__predict_true(pool_used)) 1179 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1180 else 1181 kmem_intr_free(tc, size); 1182 crypto_freereq(crp); 1183 1184 #ifdef IPSEC_DEBUG 1185 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 1186 if (ipsec_integrity) { 1187 int alen; 1188 1189 /* 1190 * Corrupt HMAC if we want to test integrity verification of 1191 * the other side. 1192 */ 1193 alen = AUTHSIZE(sav); 1194 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); 1195 } 1196 #endif 1197 1198 /* NB: m is reclaimed by ipsec_process_done. */ 1199 err = ipsec_process_done(m, isr, sav); 1200 KEY_SA_UNREF(&sav); 1201 KEY_SP_UNREF(&isr->sp); 1202 IPSEC_RELEASE_GLOBAL_LOCKS(); 1203 return err; 1204 bad: 1205 if (sav) 1206 KEY_SA_UNREF(&sav); 1207 KEY_SP_UNREF(&isr->sp); 1208 IPSEC_RELEASE_GLOBAL_LOCKS(); 1209 if (m) 1210 m_freem(m); 1211 if (__predict_true(pool_used)) 1212 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1213 else 1214 kmem_intr_free(tc, size); 1215 crypto_freereq(crp); 1216 return error; 1217 } 1218 1219 static struct xformsw ah_xformsw = { 1220 .xf_type = XF_AH, 1221 .xf_flags = XFT_AUTH, 1222 .xf_name = "IPsec AH", 1223 .xf_init = ah_init, 1224 .xf_zeroize = ah_zeroize, 1225 .xf_input = ah_input, 1226 .xf_output = ah_output, 1227 .xf_next = NULL, 1228 }; 1229 1230 void 1231 ah_attach(void) 1232 { 1233 ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS); 1234 1235 #define MAXAUTHSIZE(name) \ 1236 if ((auth_hash_ ## name).authsize > ah_max_authsize) \ 1237 ah_max_authsize = (auth_hash_ ## name).authsize 1238 1239 ah_max_authsize = 0; 1240 MAXAUTHSIZE(null); 1241 MAXAUTHSIZE(md5); 1242 MAXAUTHSIZE(sha1); 1243 MAXAUTHSIZE(key_md5); 1244 MAXAUTHSIZE(key_sha1); 1245 MAXAUTHSIZE(hmac_md5); 1246 MAXAUTHSIZE(hmac_sha1); 1247 MAXAUTHSIZE(hmac_ripemd_160); 1248 MAXAUTHSIZE(hmac_md5_96); 1249 MAXAUTHSIZE(hmac_sha1_96); 1250 MAXAUTHSIZE(hmac_ripemd_160_96); 1251 MAXAUTHSIZE(hmac_sha2_256); 1252 MAXAUTHSIZE(hmac_sha2_384); 1253 MAXAUTHSIZE(hmac_sha2_512); 1254 MAXAUTHSIZE(aes_xcbc_mac_96); 1255 MAXAUTHSIZE(gmac_aes_128); 1256 MAXAUTHSIZE(gmac_aes_192); 1257 MAXAUTHSIZE(gmac_aes_256); 1258 IPSECLOG(LOG_DEBUG, "ah_max_authsize=%d\n", ah_max_authsize); 1259 1260 #undef MAXAUTHSIZE 1261 1262 ah_pool_item_size = sizeof(struct tdb_crypto) + 1263 sizeof(struct ip) + MAX_IPOPTLEN + 1264 sizeof(struct ah) + sizeof(uint32_t) + ah_max_authsize; 1265 ah_tdb_crypto_pool_cache = pool_cache_init(ah_pool_item_size, 1266 coherency_unit, 0, 0, "ah_tdb_crypto", NULL, IPL_SOFTNET, 1267 NULL, NULL, NULL); 1268 1269 xform_register(&ah_xformsw); 1270 } 1271