xform_ah.c revision 1.91
1/* $NetBSD: xform_ah.c,v 1.91 2018/04/19 07:22:29 maxv Exp $ */ 2/* $FreeBSD: src/sys/netipsec/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 1.91 2018/04/19 07:22:29 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 struct ip6_rthdr *rh; 277 int alloc, nxt; 278#endif 279 280 switch (proto) { 281#ifdef INET 282 case AF_INET: 283 /* 284 * This is the least painful way of dealing with IPv4 header 285 * and option processing -- just make sure they're in 286 * contiguous memory. 287 */ 288 *m0 = m = m_pullup(m, skip); 289 if (m == NULL) { 290 DPRINTF(("%s: m_pullup failed\n", __func__)); 291 return ENOBUFS; 292 } 293 294 /* Fix the IP header */ 295 ip = mtod(m, struct ip *); 296 if (ip4_ah_cleartos) 297 ip->ip_tos = 0; 298 ip->ip_ttl = 0; 299 ip->ip_sum = 0; 300 ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask); 301 302 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 303 ip->ip_off &= htons(IP_DF); 304 else 305 ip->ip_off = 0; 306 307 ptr = mtod(m, unsigned char *); 308 309 /* IPv4 option processing */ 310 for (off = sizeof(struct ip); off < skip;) { 311 if (ptr[off] == IPOPT_EOL) { 312 break; 313 } else if (ptr[off] == IPOPT_NOP) { 314 optlen = 1; 315 } else if (off + 1 < skip) { 316 optlen = ptr[off + 1]; 317 if (optlen < 2 || off + optlen > skip) { 318 m_freem(m); 319 return EINVAL; 320 } 321 } else { 322 m_freem(m); 323 return EINVAL; 324 } 325 326 switch (ptr[off]) { 327 case IPOPT_NOP: 328 case IPOPT_SECURITY: 329 case 0x85: /* Extended security. */ 330 case 0x86: /* Commercial security. */ 331 case 0x94: /* Router alert */ 332 case 0x95: /* RFC1770 */ 333 break; 334 335 case IPOPT_LSRR: 336 case IPOPT_SSRR: 337 /* 338 * On output, if we have either of the 339 * source routing options, we should 340 * swap the destination address of the 341 * IP header with the last address 342 * specified in the option, as that is 343 * what the destination's IP header 344 * will look like. 345 */ 346 if (out) 347 memcpy(&ip->ip_dst, 348 ptr + off + optlen - 349 sizeof(struct in_addr), 350 sizeof(struct in_addr)); 351 /* FALLTHROUGH */ 352 353 default: 354 /* Zeroize all other options. */ 355 memcpy(ptr + off, ipseczeroes, optlen); 356 break; 357 } 358 359 off += optlen; 360 361 /* Sanity check. */ 362 if (off > skip) { 363 m_freem(m); 364 return EINVAL; 365 } 366 } 367 368 break; 369#endif /* INET */ 370 371#ifdef INET6 372 case AF_INET6: /* Ugly... */ 373 /* Copy and "cook" the IPv6 header. */ 374 m_copydata(m, 0, sizeof(ip6), &ip6); 375 376 /* We don't do IPv6 Jumbograms. */ 377 if (ip6.ip6_plen == 0) { 378 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__)); 379 m_freem(m); 380 return EMSGSIZE; 381 } 382 383 ip6.ip6_flow = 0; 384 ip6.ip6_hlim = 0; 385 ip6.ip6_vfc &= ~IPV6_VERSION_MASK; 386 ip6.ip6_vfc |= IPV6_VERSION; 387 388 /* Scoped address handling. */ 389 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) 390 ip6.ip6_src.s6_addr16[1] = 0; 391 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) 392 ip6.ip6_dst.s6_addr16[1] = 0; 393 394 /* Done with IPv6 header. */ 395 m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6); 396 397 /* Let's deal with the remaining headers (if any). */ 398 if (skip - sizeof(struct ip6_hdr) > 0) { 399 if (m->m_len <= skip) { 400 ptr = malloc(skip - sizeof(struct ip6_hdr), 401 M_XDATA, M_NOWAIT); 402 if (ptr == NULL) { 403 DPRINTF(("%s: failed to allocate " 404 "memory for IPv6 headers\n", 405 __func__)); 406 m_freem(m); 407 return ENOBUFS; 408 } 409 410 /* 411 * Copy all the protocol headers after 412 * the IPv6 header. 413 */ 414 m_copydata(m, sizeof(struct ip6_hdr), 415 skip - sizeof(struct ip6_hdr), ptr); 416 alloc = 1; 417 } else { 418 /* No need to allocate memory. */ 419 ptr = mtod(m, unsigned char *) + 420 sizeof(struct ip6_hdr); 421 alloc = 0; 422 } 423 } else 424 break; 425 426 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */ 427 428 for (off = 0; off < skip - sizeof(struct ip6_hdr);) { 429 int noff; 430 431 switch (nxt) { 432 case IPPROTO_HOPOPTS: 433 case IPPROTO_DSTOPTS: 434 ip6e = (struct ip6_ext *)(ptr + off); 435 noff = off + ((ip6e->ip6e_len + 1) << 3); 436 437 /* Sanity check. */ 438 if (noff > skip - sizeof(struct ip6_hdr)) { 439 goto error6; 440 } 441 442 /* 443 * Zero out mutable options. 444 */ 445 for (count = off + sizeof(struct ip6_ext); 446 count < noff;) { 447 if (ptr[count] == IP6OPT_PAD1) { 448 count++; 449 continue; 450 } 451 452 if (count + 1 >= noff) { 453 goto error6; 454 } 455 optlen = ptr[count + 1] + 2; 456 457 if (count + optlen > noff) { 458 goto error6; 459 } 460 461 if (ptr[count] & IP6OPT_MUTABLE) { 462 memset(ptr + count, 0, optlen); 463 } 464 465 count += optlen; 466 } 467 468 if (count != noff) { 469 goto error6; 470 } 471 472 /* Advance. */ 473 off += ((ip6e->ip6e_len + 1) << 3); 474 nxt = ip6e->ip6e_nxt; 475 break; 476 477 case IPPROTO_ROUTING: 478 /* 479 * Always include routing headers in 480 * computation. 481 */ 482 ip6e = (struct ip6_ext *)(ptr + off); 483 rh = (struct ip6_rthdr *)(ptr + off); 484 /* 485 * must adjust content to make it look like 486 * its final form (as seen at the final 487 * destination). 488 * we only know how to massage type 0 routing 489 * header. 490 */ 491 if (out && rh->ip6r_type == IPV6_RTHDR_TYPE_0) { 492 struct ip6_rthdr0 *rh0; 493 struct in6_addr *addr, finaldst; 494 int i; 495 496 rh0 = (struct ip6_rthdr0 *)rh; 497 addr = (struct in6_addr *)(rh0 + 1); 498 499 for (i = 0; i < rh0->ip6r0_segleft; i++) 500 in6_clearscope(&addr[i]); 501 502 finaldst = addr[rh0->ip6r0_segleft - 1]; 503 memmove(&addr[1], &addr[0], 504 sizeof(struct in6_addr) * 505 (rh0->ip6r0_segleft - 1)); 506 507 m_copydata(m, 0, sizeof(ip6), &ip6); 508 addr[0] = ip6.ip6_dst; 509 ip6.ip6_dst = finaldst; 510 m_copyback(m, 0, sizeof(ip6), &ip6); 511 512 rh0->ip6r0_segleft = 0; 513 } 514 515 /* advance */ 516 off += ((ip6e->ip6e_len + 1) << 3); 517 nxt = ip6e->ip6e_nxt; 518 break; 519 520 default: 521 DPRINTF(("%s: unexpected IPv6 header type %d\n", 522 __func__, off)); 523error6: 524 if (alloc) 525 free(ptr, M_XDATA); 526 m_freem(m); 527 return EINVAL; 528 } 529 } 530 531 /* Copyback and free, if we allocated. */ 532 if (alloc) { 533 m_copyback(m, sizeof(struct ip6_hdr), 534 skip - sizeof(struct ip6_hdr), ptr); 535 free(ptr, M_XDATA); 536 } 537 538 break; 539#endif /* INET6 */ 540 } 541 542 return 0; 543} 544 545/* 546 * ah_input() gets called to verify that an input packet 547 * passes authentication. 548 */ 549static int 550ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 551{ 552 const struct auth_hash *ahx; 553 struct tdb_crypto *tc = NULL; 554 struct newah *ah; 555 int hl, rplen, authsize, error, stat = AH_STAT_HDROPS; 556 struct cryptodesc *crda; 557 struct cryptop *crp = NULL; 558 bool pool_used; 559 uint8_t nxt; 560 561 IPSEC_SPLASSERT_SOFTNET(__func__); 562 563 KASSERT(sav != NULL); 564 KASSERT(sav->key_auth != NULL); 565 KASSERT(sav->tdb_authalgxform != NULL); 566 567 /* Figure out header size. */ 568 rplen = HDRSIZE(sav); 569 570 /* XXX don't pullup, just copy header */ 571 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 572 if (ah == NULL) { 573 DPRINTF(("%s: cannot pullup header\n", __func__)); 574 error = ENOBUFS; 575 stat = AH_STAT_HDROPS; /*XXX*/ 576 goto bad; 577 } 578 579 nxt = ah->ah_nxt; 580 581 /* Check replay window, if applicable. */ 582 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 583 char buf[IPSEC_LOGSASTRLEN]; 584 DPRINTF(("%s: packet replay failure: %s\n", __func__, 585 ipsec_logsastr(sav, buf, sizeof(buf)))); 586 stat = AH_STAT_REPLAY; 587 error = ENOBUFS; 588 goto bad; 589 } 590 591 /* Verify AH header length. */ 592 hl = ah->ah_len * sizeof(uint32_t); 593 ahx = sav->tdb_authalgxform; 594 authsize = AUTHSIZE(sav); 595 if (hl != authsize + rplen - sizeof(struct ah)) { 596 char buf[IPSEC_ADDRSTRLEN]; 597 DPRINTF(("%s: bad authenticator length %u (expecting %lu)" 598 " for packet in SA %s/%08lx\n", __func__, 599 hl, (u_long) (authsize + rplen - sizeof(struct ah)), 600 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 601 (u_long) ntohl(sav->spi))); 602 stat = AH_STAT_BADAUTHL; 603 error = EACCES; 604 goto bad; 605 } 606 if (skip + authsize + rplen > m->m_pkthdr.len) { 607 char buf[IPSEC_ADDRSTRLEN]; 608 DPRINTF(("%s: bad mbuf length %u (expecting >= %lu)" 609 " for packet in SA %s/%08lx\n", __func__, 610 m->m_pkthdr.len, (u_long)(skip + authsize + rplen), 611 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 612 (u_long) ntohl(sav->spi))); 613 stat = AH_STAT_BADAUTHL; 614 error = EACCES; 615 goto bad; 616 } 617 618 AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl); 619 620 /* Get crypto descriptors. */ 621 crp = crypto_getreq(1); 622 if (crp == NULL) { 623 DPRINTF(("%s: failed to acquire crypto descriptor\n", __func__)); 624 stat = AH_STAT_CRYPTO; 625 error = ENOBUFS; 626 goto bad; 627 } 628 629 crda = crp->crp_desc; 630 KASSERT(crda != NULL); 631 632 crda->crd_skip = 0; 633 crda->crd_len = m->m_pkthdr.len; 634 crda->crd_inject = skip + rplen; 635 636 /* Authentication operation. */ 637 crda->crd_alg = ahx->type; 638 crda->crd_key = _KEYBUF(sav->key_auth); 639 crda->crd_klen = _KEYBITS(sav->key_auth); 640 641 /* Allocate IPsec-specific opaque crypto info. */ 642 size_t size = sizeof(*tc); 643 size_t extra = skip + rplen + authsize; 644 size += extra; 645 646 if (__predict_true(size <= ah_pool_item_size)) { 647 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 648 pool_used = true; 649 } else { 650 /* size can exceed on IPv6 packets with large options. */ 651 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 652 pool_used = false; 653 } 654 if (tc == NULL) { 655 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 656 stat = AH_STAT_CRYPTO; 657 error = ENOBUFS; 658 goto bad; 659 } 660 661 error = m_makewritable(&m, 0, extra, M_NOWAIT); 662 if (error) { 663 DPRINTF(("%s: failed to m_makewritable\n", __func__)); 664 goto bad; 665 } 666 667 /* 668 * Save the authenticator, the skipped portion of the packet, 669 * and the AH header. 670 */ 671 m_copydata(m, 0, extra, (tc + 1)); 672 /* Zeroize the authenticator on the packet. */ 673 m_copyback(m, skip + rplen, authsize, ipseczeroes); 674 675 /* "Massage" the packet headers for crypto processing. */ 676 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 677 skip, ahx->type, 0); 678 if (error != 0) { 679 /* NB: mbuf is free'd by ah_massage_headers */ 680 m = NULL; 681 goto bad; 682 } 683 684 { 685 int s = pserialize_read_enter(); 686 687 /* 688 * Take another reference to the SA for opencrypto callback. 689 */ 690 if (__predict_false(sav->state == SADB_SASTATE_DEAD)) { 691 pserialize_read_exit(s); 692 stat = AH_STAT_NOTDB; 693 error = ENOENT; 694 goto bad; 695 } 696 KEY_SA_REF(sav); 697 pserialize_read_exit(s); 698 } 699 700 /* Crypto operation descriptor. */ 701 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 702 crp->crp_flags = CRYPTO_F_IMBUF; 703 crp->crp_buf = m; 704 crp->crp_callback = ah_input_cb; 705 crp->crp_sid = sav->tdb_cryptoid; 706 crp->crp_opaque = tc; 707 708 /* These are passed as-is to the callback. */ 709 tc->tc_spi = sav->spi; 710 tc->tc_dst = sav->sah->saidx.dst; 711 tc->tc_proto = sav->sah->saidx.proto; 712 tc->tc_nxt = nxt; 713 tc->tc_protoff = protoff; 714 tc->tc_skip = skip; 715 tc->tc_sav = sav; 716 717 DPRINTF(("%s: hash over %d bytes, skip %d: " 718 "crda len %d skip %d inject %d\n", __func__, 719 crp->crp_ilen, tc->tc_skip, 720 crda->crd_len, crda->crd_skip, crda->crd_inject)); 721 722 return crypto_dispatch(crp); 723 724bad: 725 if (tc != NULL) { 726 if (__predict_true(pool_used)) 727 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 728 else 729 kmem_intr_free(tc, size); 730 } 731 if (crp != NULL) 732 crypto_freereq(crp); 733 if (m != NULL) 734 m_freem(m); 735 AH_STATINC(stat); 736 return error; 737} 738 739#ifdef INET6 740#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) do { \ 741 if (saidx->dst.sa.sa_family == AF_INET6) { \ 742 error = ipsec6_common_input_cb(m, sav, skip, protoff); \ 743 } else { \ 744 error = ipsec4_common_input_cb(m, sav, skip, protoff); \ 745 } \ 746} while (0) 747#else 748#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) \ 749 (error = ipsec4_common_input_cb(m, sav, skip, protoff)) 750#endif 751 752/* 753 * AH input callback from the crypto driver. 754 */ 755static int 756ah_input_cb(struct cryptop *crp) 757{ 758 char buf[IPSEC_ADDRSTRLEN]; 759 int rplen, error, skip, protoff; 760 unsigned char calc[AH_ALEN_MAX]; 761 struct mbuf *m; 762 struct tdb_crypto *tc; 763 struct secasvar *sav; 764 struct secasindex *saidx; 765 uint8_t nxt; 766 char *ptr; 767 int authsize; 768 uint16_t dport; 769 uint16_t sport; 770 bool pool_used; 771 size_t size; 772 IPSEC_DECLARE_LOCK_VARIABLE; 773 774 KASSERT(crp->crp_opaque != NULL); 775 tc = crp->crp_opaque; 776 skip = tc->tc_skip; 777 nxt = tc->tc_nxt; 778 protoff = tc->tc_protoff; 779 m = crp->crp_buf; 780 781 /* find the source port for NAT-T */ 782 nat_t_ports_get(m, &dport, &sport); 783 784 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 785 786 sav = tc->tc_sav; 787 saidx = &sav->sah->saidx; 788 KASSERTMSG(saidx->dst.sa.sa_family == AF_INET || 789 saidx->dst.sa.sa_family == AF_INET6, 790 "unexpected protocol family %u", saidx->dst.sa.sa_family); 791 792 /* Figure out header size. */ 793 rplen = HDRSIZE(sav); 794 authsize = AUTHSIZE(sav); 795 796 size = sizeof(*tc) + skip + rplen + authsize; 797 if (__predict_true(size <= ah_pool_item_size)) 798 pool_used = true; 799 else 800 pool_used = false; 801 802 /* Check for crypto errors. */ 803 if (crp->crp_etype) { 804 if (sav->tdb_cryptoid != 0) 805 sav->tdb_cryptoid = crp->crp_sid; 806 807 if (crp->crp_etype == EAGAIN) { 808 IPSEC_RELEASE_GLOBAL_LOCKS(); 809 return crypto_dispatch(crp); 810 } 811 812 AH_STATINC(AH_STAT_NOXFORM); 813 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 814 error = crp->crp_etype; 815 goto bad; 816 } else { 817 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 818 crypto_freereq(crp); /* No longer needed. */ 819 crp = NULL; 820 } 821 822 if (ipsec_debug) 823 memset(calc, 0, sizeof(calc)); 824 825 /* Copy authenticator off the packet. */ 826 m_copydata(m, skip + rplen, authsize, calc); 827 828 ptr = (char *)(tc + 1); 829 const uint8_t *pppp = ptr + skip + rplen; 830 831 /* Verify authenticator. */ 832 if (!consttime_memequal(pppp, calc, authsize)) { 833 DPRINTF(("%s: authentication hash mismatch " \ 834 "over %d bytes " \ 835 "for packet in SA %s/%08lx:\n" \ 836 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \ 837 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", 838 __func__, authsize, 839 ipsec_address(&saidx->dst, buf, sizeof(buf)), 840 (u_long) ntohl(sav->spi), 841 calc[0], calc[1], calc[2], calc[3], 842 calc[4], calc[5], calc[6], calc[7], 843 calc[8], calc[9], calc[10], calc[11], 844 pppp[0], pppp[1], pppp[2], pppp[3], 845 pppp[4], pppp[5], pppp[6], pppp[7], 846 pppp[8], pppp[9], pppp[10], pppp[11] 847 )); 848 AH_STATINC(AH_STAT_BADAUTH); 849 error = EACCES; 850 goto bad; 851 } 852 853 /* Fix the Next Protocol field. */ 854 ptr[protoff] = nxt; 855 856 /* Copyback the saved (uncooked) network headers. */ 857 m_copyback(m, 0, skip, ptr); 858 859 if (__predict_true(pool_used)) 860 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 861 else 862 kmem_intr_free(tc, size); 863 tc = NULL; 864 865 /* 866 * Header is now authenticated. 867 */ 868 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM; 869 870 /* 871 * Update replay sequence number, if appropriate. 872 */ 873 if (sav->replay) { 874 uint32_t seq; 875 876 m_copydata(m, skip + offsetof(struct newah, ah_seq), 877 sizeof(seq), &seq); 878 if (ipsec_updatereplay(ntohl(seq), sav)) { 879 AH_STATINC(AH_STAT_REPLAY); 880 error = ENOBUFS; /* XXX */ 881 goto bad; 882 } 883 } 884 885 /* 886 * Remove the AH header and authenticator from the mbuf. 887 */ 888 error = m_striphdr(m, skip, rplen + authsize); 889 if (error) { 890 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__, 891 ipsec_address(&saidx->dst, buf, sizeof(buf)), 892 (u_long) ntohl(sav->spi))); 893 894 AH_STATINC(AH_STAT_HDROPS); 895 goto bad; 896 } 897 898 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff); 899 900 KEY_SA_UNREF(&sav); 901 IPSEC_RELEASE_GLOBAL_LOCKS(); 902 return error; 903 904bad: 905 if (sav) 906 KEY_SA_UNREF(&sav); 907 IPSEC_RELEASE_GLOBAL_LOCKS(); 908 if (m != NULL) 909 m_freem(m); 910 if (tc != NULL) { 911 if (pool_used) 912 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 913 else 914 kmem_intr_free(tc, size); 915 } 916 if (crp != NULL) 917 crypto_freereq(crp); 918 return error; 919} 920 921/* 922 * AH output routine, called by ipsec[46]_process_packet(). 923 */ 924static int 925ah_output(struct mbuf *m, const struct ipsecrequest *isr, struct secasvar *sav, 926 struct mbuf **mp, int skip, int protoff) 927{ 928 char buf[IPSEC_ADDRSTRLEN]; 929 const struct auth_hash *ahx; 930 struct cryptodesc *crda; 931 struct tdb_crypto *tc; 932 struct mbuf *mi; 933 struct cryptop *crp; 934 uint16_t iplen; 935 int error, rplen, authsize, maxpacketsize, roff; 936 uint8_t prot; 937 struct newah *ah; 938 size_t ipoffs; 939 bool pool_used; 940 941 IPSEC_SPLASSERT_SOFTNET(__func__); 942 943 KASSERT(sav != NULL); 944 KASSERT(sav->tdb_authalgxform != NULL); 945 ahx = sav->tdb_authalgxform; 946 947 AH_STATINC(AH_STAT_OUTPUT); 948 949 /* Figure out header size. */ 950 rplen = HDRSIZE(sav); 951 952 /* Check for maximum packet size violations. */ 953 switch (sav->sah->saidx.dst.sa.sa_family) { 954#ifdef INET 955 case AF_INET: 956 maxpacketsize = IP_MAXPACKET; 957 ipoffs = offsetof(struct ip, ip_len); 958 break; 959#endif 960#ifdef INET6 961 case AF_INET6: 962 maxpacketsize = IPV6_MAXPACKET; 963 ipoffs = offsetof(struct ip6_hdr, ip6_plen); 964 break; 965#endif 966 default: 967 DPRINTF(("%s: unknown/unsupported protocol " 968 "family %u, SA %s/%08lx\n", __func__, 969 sav->sah->saidx.dst.sa.sa_family, 970 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 971 (u_long) ntohl(sav->spi))); 972 AH_STATINC(AH_STAT_NOPF); 973 error = EPFNOSUPPORT; 974 goto bad; 975 } 976 authsize = AUTHSIZE(sav); 977 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 978 DPRINTF(("%s: packet in SA %s/%08lx got too big " 979 "(len %u, max len %u)\n", __func__, 980 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 981 (u_long) ntohl(sav->spi), 982 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 983 AH_STATINC(AH_STAT_TOOBIG); 984 error = EMSGSIZE; 985 goto bad; 986 } 987 988 /* Update the counters. */ 989 AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip); 990 991 m = m_clone(m); 992 if (m == NULL) { 993 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 994 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 995 (u_long) ntohl(sav->spi))); 996 AH_STATINC(AH_STAT_HDROPS); 997 error = ENOBUFS; 998 goto bad; 999 } 1000 1001 /* Inject AH header. */ 1002 mi = m_makespace(m, skip, rplen + authsize, &roff); 1003 if (mi == NULL) { 1004 DPRINTF(("%s: failed to inject %u byte AH header for SA " 1005 "%s/%08lx\n", __func__, 1006 rplen + authsize, 1007 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 1008 (u_long) ntohl(sav->spi))); 1009 AH_STATINC(AH_STAT_HDROPS); 1010 error = ENOBUFS; 1011 goto bad; 1012 } 1013 1014 /* 1015 * The AH header is guaranteed by m_makespace() to be in 1016 * contiguous memory, at roff bytes offset into the returned mbuf. 1017 */ 1018 ah = (struct newah *)(mtod(mi, char *) + roff); 1019 1020 /* Initialize the AH header. */ 1021 m_copydata(m, protoff, sizeof(uint8_t), &ah->ah_nxt); 1022 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(uint32_t); 1023 ah->ah_reserve = 0; 1024 ah->ah_spi = sav->spi; 1025 1026 /* Zeroize authenticator. */ 1027 m_copyback(m, skip + rplen, authsize, ipseczeroes); 1028 1029 /* Insert packet replay counter, as requested. */ 1030 if (sav->replay) { 1031 if (sav->replay->count == ~0 && 1032 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1033 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n", 1034 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 1035 sizeof(buf)), (u_long) ntohl(sav->spi))); 1036 AH_STATINC(AH_STAT_WRAP); 1037 error = EINVAL; 1038 goto bad; 1039 } 1040#ifdef IPSEC_DEBUG 1041 /* Emulate replay attack when ipsec_replay is TRUE. */ 1042 if (!ipsec_replay) 1043#endif 1044 sav->replay->count++; 1045 ah->ah_seq = htonl(sav->replay->count); 1046 } 1047 1048 /* Get crypto descriptors. */ 1049 crp = crypto_getreq(1); 1050 if (crp == NULL) { 1051 DPRINTF(("%s: failed to acquire crypto descriptors\n", 1052 __func__)); 1053 AH_STATINC(AH_STAT_CRYPTO); 1054 error = ENOBUFS; 1055 goto bad; 1056 } 1057 1058 crda = crp->crp_desc; 1059 1060 crda->crd_skip = 0; 1061 crda->crd_inject = skip + rplen; 1062 crda->crd_len = m->m_pkthdr.len; 1063 1064 /* Authentication operation. */ 1065 crda->crd_alg = ahx->type; 1066 crda->crd_key = _KEYBUF(sav->key_auth); 1067 crda->crd_klen = _KEYBITS(sav->key_auth); 1068 1069 /* Allocate IPsec-specific opaque crypto info. */ 1070 size_t size = sizeof(*tc) + skip; 1071 1072 if (__predict_true(size <= ah_pool_item_size)) { 1073 tc = pool_cache_get(ah_tdb_crypto_pool_cache, PR_NOWAIT); 1074 pool_used = true; 1075 } else { 1076 /* size can exceed on IPv6 packets with large options. */ 1077 tc = kmem_intr_zalloc(size, KM_NOSLEEP); 1078 pool_used = false; 1079 } 1080 if (tc == NULL) { 1081 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 1082 AH_STATINC(AH_STAT_CRYPTO); 1083 error = ENOBUFS; 1084 goto bad_crp; 1085 } 1086 1087 uint8_t *pext = (char *)(tc + 1); 1088 /* Save the skipped portion of the packet. */ 1089 m_copydata(m, 0, skip, pext); 1090 1091 /* 1092 * Fix IP header length on the header used for 1093 * authentication. We don't need to fix the original 1094 * header length as it will be fixed by our caller. 1095 */ 1096 memcpy(&iplen, pext + ipoffs, sizeof(iplen)); 1097 iplen = htons(ntohs(iplen) + rplen + authsize); 1098 m_copyback(m, ipoffs, sizeof(iplen), &iplen); 1099 1100 /* Fix the Next Header field in saved header. */ 1101 pext[protoff] = IPPROTO_AH; 1102 1103 /* Update the Next Protocol field in the IP header. */ 1104 prot = IPPROTO_AH; 1105 m_copyback(m, protoff, sizeof(prot), &prot); 1106 1107 /* "Massage" the packet headers for crypto processing. */ 1108 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1109 skip, ahx->type, 1); 1110 if (error != 0) { 1111 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1112 goto bad_tc; 1113 } 1114 1115 { 1116 int s = pserialize_read_enter(); 1117 1118 /* 1119 * Take another reference to the SP and the SA for opencrypto callback. 1120 */ 1121 if (__predict_false(isr->sp->state == IPSEC_SPSTATE_DEAD || 1122 sav->state == SADB_SASTATE_DEAD)) { 1123 pserialize_read_exit(s); 1124 AH_STATINC(AH_STAT_NOTDB); 1125 error = ENOENT; 1126 goto bad_tc; 1127 } 1128 KEY_SP_REF(isr->sp); 1129 KEY_SA_REF(sav); 1130 pserialize_read_exit(s); 1131 } 1132 1133 /* Crypto operation descriptor. */ 1134 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1135 crp->crp_flags = CRYPTO_F_IMBUF; 1136 crp->crp_buf = m; 1137 crp->crp_callback = ah_output_cb; 1138 crp->crp_sid = sav->tdb_cryptoid; 1139 crp->crp_opaque = tc; 1140 1141 /* These are passed as-is to the callback. */ 1142 tc->tc_isr = isr; 1143 tc->tc_spi = sav->spi; 1144 tc->tc_dst = sav->sah->saidx.dst; 1145 tc->tc_proto = sav->sah->saidx.proto; 1146 tc->tc_skip = skip; 1147 tc->tc_protoff = protoff; 1148 tc->tc_sav = sav; 1149 1150 return crypto_dispatch(crp); 1151 1152bad_tc: 1153 if (__predict_true(pool_used)) 1154 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1155 else 1156 kmem_intr_free(tc, size); 1157bad_crp: 1158 crypto_freereq(crp); 1159bad: 1160 if (m) 1161 m_freem(m); 1162 return error; 1163} 1164 1165/* 1166 * AH output callback from the crypto driver. 1167 */ 1168static int 1169ah_output_cb(struct cryptop *crp) 1170{ 1171 int skip, error; 1172 struct tdb_crypto *tc; 1173 const struct ipsecrequest *isr; 1174 struct secasvar *sav; 1175 struct mbuf *m; 1176 void *ptr; 1177 int err; 1178 size_t size; 1179 bool pool_used; 1180 IPSEC_DECLARE_LOCK_VARIABLE; 1181 1182 KASSERT(crp->crp_opaque != NULL); 1183 tc = crp->crp_opaque; 1184 skip = tc->tc_skip; 1185 ptr = (tc + 1); 1186 m = crp->crp_buf; 1187 size = sizeof(*tc) + skip; 1188 pool_used = size <= ah_pool_item_size; 1189 1190 IPSEC_ACQUIRE_GLOBAL_LOCKS(); 1191 1192 isr = tc->tc_isr; 1193 sav = tc->tc_sav; 1194 1195 /* Check for crypto errors. */ 1196 if (crp->crp_etype) { 1197 if (sav->tdb_cryptoid != 0) 1198 sav->tdb_cryptoid = crp->crp_sid; 1199 1200 if (crp->crp_etype == EAGAIN) { 1201 IPSEC_RELEASE_GLOBAL_LOCKS(); 1202 return crypto_dispatch(crp); 1203 } 1204 1205 AH_STATINC(AH_STAT_NOXFORM); 1206 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 1207 error = crp->crp_etype; 1208 goto bad; 1209 } 1210 1211 AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]); 1212 1213 /* 1214 * Copy original headers (with the new protocol number) back 1215 * in place. 1216 */ 1217 m_copyback(m, 0, skip, ptr); 1218 1219 /* No longer needed. */ 1220 if (__predict_true(pool_used)) 1221 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1222 else 1223 kmem_intr_free(tc, size); 1224 crypto_freereq(crp); 1225 1226#ifdef IPSEC_DEBUG 1227 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 1228 if (ipsec_integrity) { 1229 int alen; 1230 1231 /* 1232 * Corrupt HMAC if we want to test integrity verification of 1233 * the other side. 1234 */ 1235 alen = AUTHSIZE(sav); 1236 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); 1237 } 1238#endif 1239 1240 /* NB: m is reclaimed by ipsec_process_done. */ 1241 err = ipsec_process_done(m, isr, sav); 1242 KEY_SA_UNREF(&sav); 1243 KEY_SP_UNREF(&isr->sp); 1244 IPSEC_RELEASE_GLOBAL_LOCKS(); 1245 return err; 1246bad: 1247 if (sav) 1248 KEY_SA_UNREF(&sav); 1249 KEY_SP_UNREF(&isr->sp); 1250 IPSEC_RELEASE_GLOBAL_LOCKS(); 1251 if (m) 1252 m_freem(m); 1253 if (__predict_true(pool_used)) 1254 pool_cache_put(ah_tdb_crypto_pool_cache, tc); 1255 else 1256 kmem_intr_free(tc, size); 1257 crypto_freereq(crp); 1258 return error; 1259} 1260 1261static struct xformsw ah_xformsw = { 1262 .xf_type = XF_AH, 1263 .xf_flags = XFT_AUTH, 1264 .xf_name = "IPsec AH", 1265 .xf_init = ah_init, 1266 .xf_zeroize = ah_zeroize, 1267 .xf_input = ah_input, 1268 .xf_output = ah_output, 1269 .xf_next = NULL, 1270}; 1271 1272void 1273ah_attach(void) 1274{ 1275 ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS); 1276 1277#define MAXAUTHSIZE(name) \ 1278 if ((auth_hash_ ## name).authsize > ah_max_authsize) \ 1279 ah_max_authsize = (auth_hash_ ## name).authsize 1280 1281 ah_max_authsize = 0; 1282 MAXAUTHSIZE(null); 1283 MAXAUTHSIZE(md5); 1284 MAXAUTHSIZE(sha1); 1285 MAXAUTHSIZE(key_md5); 1286 MAXAUTHSIZE(key_sha1); 1287 MAXAUTHSIZE(hmac_md5); 1288 MAXAUTHSIZE(hmac_sha1); 1289 MAXAUTHSIZE(hmac_ripemd_160); 1290 MAXAUTHSIZE(hmac_md5_96); 1291 MAXAUTHSIZE(hmac_sha1_96); 1292 MAXAUTHSIZE(hmac_ripemd_160_96); 1293 MAXAUTHSIZE(hmac_sha2_256); 1294 MAXAUTHSIZE(hmac_sha2_384); 1295 MAXAUTHSIZE(hmac_sha2_512); 1296 MAXAUTHSIZE(aes_xcbc_mac_96); 1297 MAXAUTHSIZE(gmac_aes_128); 1298 MAXAUTHSIZE(gmac_aes_192); 1299 MAXAUTHSIZE(gmac_aes_256); 1300 IPSECLOG(LOG_DEBUG, "ah_max_authsize=%d\n", ah_max_authsize); 1301 1302#undef MAXAUTHSIZE 1303 1304 ah_pool_item_size = sizeof(struct tdb_crypto) + 1305 sizeof(struct ip) + MAX_IPOPTLEN + 1306 sizeof(struct ah) + sizeof(uint32_t) + ah_max_authsize; 1307 ah_tdb_crypto_pool_cache = pool_cache_init(ah_pool_item_size, 1308 coherency_unit, 0, 0, "ah_tdb_crypto", NULL, IPL_SOFTNET, 1309 NULL, NULL, NULL); 1310 1311 xform_register(&ah_xformsw); 1312} 1313