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sys/netipsec/xform_ah.c
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1 /* $FreeBSD: releng/8.0/sys/netipsec/xform_ah.c 196019 2009-08-01 19:26:27Z rwatson $ */ 2 /* $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */ 3 /*- 4 * The authors of this code are John Ioannidis (ji@tla.org), 5 * Angelos D. Keromytis (kermit@csd.uch.gr) and 6 * Niels Provos (provos@physnet.uni-hamburg.de). 7 * 8 * The original version of this code was written by John Ioannidis 9 * for BSD/OS in Athens, Greece, in November 1995. 10 * 11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12 * by Angelos D. Keromytis. 13 * 14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15 * and Niels Provos. 16 * 17 * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist. 18 * 19 * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 20 * Angelos D. Keromytis and Niels Provos. 21 * Copyright (c) 1999 Niklas Hallqvist. 22 * Copyright (c) 2001 Angelos D. Keromytis. 23 * 24 * Permission to use, copy, and modify this software with or without fee 25 * is hereby granted, provided that this entire notice is included in 26 * all copies of any software which is or includes a copy or 27 * modification of this software. 28 * You may use this code under the GNU public license if you so wish. Please 29 * contribute changes back to the authors under this freer than GPL license 30 * so that we may further the use of strong encryption without limitations to 31 * all. 32 * 33 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 34 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 35 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 36 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 37 * PURPOSE. 38 */ 39 #include "opt_inet.h" 40 #include "opt_inet6.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/mbuf.h> 45 #include <sys/socket.h> 46 #include <sys/syslog.h> 47 #include <sys/kernel.h> 48 #include <sys/sysctl.h> 49 50 #include <net/if.h> 51 #include <net/vnet.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_ecn.h> 57 #include <netinet/ip6.h> 58 59 #include <net/route.h> 60 #include <netipsec/ipsec.h> 61 #include <netipsec/ah.h> 62 #include <netipsec/ah_var.h> 63 #include <netipsec/xform.h> 64 65 #ifdef INET6 66 #include <netinet6/ip6_var.h> 67 #include <netipsec/ipsec6.h> 68 #include <netinet6/ip6_ecn.h> 69 #endif 70 71 #include <netipsec/key.h> 72 #include <netipsec/key_debug.h> 73 74 #include <opencrypto/cryptodev.h> 75 76 /* 77 * Return header size in bytes. The old protocol did not support 78 * the replay counter; the new protocol always includes the counter. 79 */ 80 #define HDRSIZE(sav) \ 81 (((sav)->flags & SADB_X_EXT_OLD) ? \ 82 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t)) 83 /* 84 * Return authenticator size in bytes. The old protocol is known 85 * to use a fixed 16-byte authenticator. The new algorithm use 12-byte 86 * authenticator. 87 */ 88 #define AUTHSIZE(sav) \ 89 ((sav->flags & SADB_X_EXT_OLD) ? 16 : AH_HMAC_HASHLEN) 90 91 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */ 92 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */ 93 VNET_DEFINE(struct ahstat, ahstat); 94 95 SYSCTL_DECL(_net_inet_ah); 96 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO, 97 ah_enable, CTLFLAG_RW, &VNET_NAME(ah_enable), 0, ""); 98 SYSCTL_VNET_INT(_net_inet_ah, OID_AUTO, 99 ah_cleartos, CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, ""); 100 SYSCTL_VNET_STRUCT(_net_inet_ah, IPSECCTL_STATS, 101 stats, CTLFLAG_RD, &VNET_NAME(ahstat), ahstat, ""); 102 103 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 104 105 static int ah_input_cb(struct cryptop*); 106 static int ah_output_cb(struct cryptop*); 107 108 /* 109 * NB: this is public for use by the PF_KEY support. 110 */ 111 struct auth_hash * 112 ah_algorithm_lookup(int alg) 113 { 114 if (alg > SADB_AALG_MAX) 115 return NULL; 116 switch (alg) { 117 case SADB_X_AALG_NULL: 118 return &auth_hash_null; 119 case SADB_AALG_MD5HMAC: 120 return &auth_hash_hmac_md5; 121 case SADB_AALG_SHA1HMAC: 122 return &auth_hash_hmac_sha1; 123 case SADB_X_AALG_RIPEMD160HMAC: 124 return &auth_hash_hmac_ripemd_160; 125 case SADB_X_AALG_MD5: 126 return &auth_hash_key_md5; 127 case SADB_X_AALG_SHA: 128 return &auth_hash_key_sha1; 129 case SADB_X_AALG_SHA2_256: 130 return &auth_hash_hmac_sha2_256; 131 case SADB_X_AALG_SHA2_384: 132 return &auth_hash_hmac_sha2_384; 133 case SADB_X_AALG_SHA2_512: 134 return &auth_hash_hmac_sha2_512; 135 } 136 return NULL; 137 } 138 139 size_t 140 ah_hdrsiz(struct secasvar *sav) 141 { 142 size_t size; 143 144 if (sav != NULL) { 145 int authsize; 146 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform")); 147 /*XXX not right for null algorithm--does it matter??*/ 148 authsize = AUTHSIZE(sav); 149 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav); 150 } else { 151 /* default guess */ 152 size = sizeof (struct ah) + sizeof (u_int32_t) + 16; 153 } 154 return size; 155 } 156 157 /* 158 * NB: public for use by esp_init. 159 */ 160 int 161 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria) 162 { 163 struct auth_hash *thash; 164 int keylen; 165 166 thash = ah_algorithm_lookup(sav->alg_auth); 167 if (thash == NULL) { 168 DPRINTF(("%s: unsupported authentication algorithm %u\n", 169 __func__, sav->alg_auth)); 170 return EINVAL; 171 } 172 /* 173 * Verify the replay state block allocation is consistent with 174 * the protocol type. We check here so we can make assumptions 175 * later during protocol processing. 176 */ 177 /* NB: replay state is setup elsewhere (sigh) */ 178 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) { 179 DPRINTF(("%s: replay state block inconsistency, " 180 "%s algorithm %s replay state\n", __func__, 181 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new", 182 sav->replay == NULL ? "without" : "with")); 183 return EINVAL; 184 } 185 if (sav->key_auth == NULL) { 186 DPRINTF(("%s: no authentication key for %s algorithm\n", 187 __func__, thash->name)); 188 return EINVAL; 189 } 190 keylen = _KEYLEN(sav->key_auth); 191 if (keylen != thash->keysize && thash->keysize != 0) { 192 DPRINTF(("%s: invalid keylength %d, algorithm %s requires " 193 "keysize %d\n", __func__, 194 keylen, thash->name, thash->keysize)); 195 return EINVAL; 196 } 197 198 sav->tdb_xform = xsp; 199 sav->tdb_authalgxform = thash; 200 201 /* Initialize crypto session. */ 202 bzero(cria, sizeof (*cria)); 203 cria->cri_alg = sav->tdb_authalgxform->type; 204 cria->cri_klen = _KEYBITS(sav->key_auth); 205 cria->cri_key = sav->key_auth->key_data; 206 cria->cri_mlen = AUTHSIZE(sav); 207 208 return 0; 209 } 210 211 /* 212 * ah_init() is called when an SPI is being set up. 213 */ 214 static int 215 ah_init(struct secasvar *sav, struct xformsw *xsp) 216 { 217 struct cryptoini cria; 218 int error; 219 220 error = ah_init0(sav, xsp, &cria); 221 return error ? error : 222 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support); 223 } 224 225 /* 226 * Paranoia. 227 * 228 * NB: public for use by esp_zeroize (XXX). 229 */ 230 int 231 ah_zeroize(struct secasvar *sav) 232 { 233 int err; 234 235 if (sav->key_auth) 236 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 237 238 err = crypto_freesession(sav->tdb_cryptoid); 239 sav->tdb_cryptoid = 0; 240 sav->tdb_authalgxform = NULL; 241 sav->tdb_xform = NULL; 242 return err; 243 } 244 245 /* 246 * Massage IPv4/IPv6 headers for AH processing. 247 */ 248 static int 249 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) 250 { 251 struct mbuf *m = *m0; 252 unsigned char *ptr; 253 int off, count; 254 255 #ifdef INET 256 struct ip *ip; 257 #endif /* INET */ 258 259 #ifdef INET6 260 struct ip6_ext *ip6e; 261 struct ip6_hdr ip6; 262 int alloc, len, ad; 263 #endif /* INET6 */ 264 265 switch (proto) { 266 #ifdef INET 267 case AF_INET: 268 /* 269 * This is the least painful way of dealing with IPv4 header 270 * and option processing -- just make sure they're in 271 * contiguous memory. 272 */ 273 *m0 = m = m_pullup(m, skip); 274 if (m == NULL) { 275 DPRINTF(("%s: m_pullup failed\n", __func__)); 276 return ENOBUFS; 277 } 278 279 /* Fix the IP header */ 280 ip = mtod(m, struct ip *); 281 if (V_ah_cleartos) 282 ip->ip_tos = 0; 283 ip->ip_ttl = 0; 284 ip->ip_sum = 0; 285 286 /* 287 * On input, fix ip_len which has been byte-swapped 288 * at ip_input(). 289 */ 290 if (!out) { 291 ip->ip_len = htons(ip->ip_len + skip); 292 293 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 294 ip->ip_off = htons(ip->ip_off & IP_DF); 295 else 296 ip->ip_off = 0; 297 } else { 298 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 299 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF); 300 else 301 ip->ip_off = 0; 302 } 303 304 ptr = mtod(m, unsigned char *) + sizeof(struct ip); 305 306 /* IPv4 option processing */ 307 for (off = sizeof(struct ip); off < skip;) { 308 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP || 309 off + 1 < skip) 310 ; 311 else { 312 DPRINTF(("%s: illegal IPv4 option length for " 313 "option %d\n", __func__, ptr[off])); 314 315 m_freem(m); 316 return EINVAL; 317 } 318 319 switch (ptr[off]) { 320 case IPOPT_EOL: 321 off = skip; /* End the loop. */ 322 break; 323 324 case IPOPT_NOP: 325 off++; 326 break; 327 328 case IPOPT_SECURITY: /* 0x82 */ 329 case 0x85: /* Extended security. */ 330 case 0x86: /* Commercial security. */ 331 case 0x94: /* Router alert */ 332 case 0x95: /* RFC1770 */ 333 /* Sanity check for option length. */ 334 if (ptr[off + 1] < 2) { 335 DPRINTF(("%s: illegal IPv4 option " 336 "length for option %d\n", 337 __func__, ptr[off])); 338 339 m_freem(m); 340 return EINVAL; 341 } 342 343 off += ptr[off + 1]; 344 break; 345 346 case IPOPT_LSRR: 347 case IPOPT_SSRR: 348 /* Sanity check for option length. */ 349 if (ptr[off + 1] < 2) { 350 DPRINTF(("%s: illegal IPv4 option " 351 "length for option %d\n", 352 __func__, ptr[off])); 353 354 m_freem(m); 355 return EINVAL; 356 } 357 358 /* 359 * On output, if we have either of the 360 * source routing options, we should 361 * swap the destination address of the 362 * IP header with the last address 363 * specified in the option, as that is 364 * what the destination's IP header 365 * will look like. 366 */ 367 if (out) 368 bcopy(ptr + off + ptr[off + 1] - 369 sizeof(struct in_addr), 370 &(ip->ip_dst), sizeof(struct in_addr)); 371 372 /* Fall through */ 373 default: 374 /* Sanity check for option length. */ 375 if (ptr[off + 1] < 2) { 376 DPRINTF(("%s: illegal IPv4 option " 377 "length for option %d\n", 378 __func__, ptr[off])); 379 m_freem(m); 380 return EINVAL; 381 } 382 383 /* Zeroize all other options. */ 384 count = ptr[off + 1]; 385 bcopy(ipseczeroes, ptr, count); 386 off += count; 387 break; 388 } 389 390 /* Sanity check. */ 391 if (off > skip) { 392 DPRINTF(("%s: malformed IPv4 options header\n", 393 __func__)); 394 395 m_freem(m); 396 return EINVAL; 397 } 398 } 399 400 break; 401 #endif /* INET */ 402 403 #ifdef INET6 404 case AF_INET6: /* Ugly... */ 405 /* Copy and "cook" the IPv6 header. */ 406 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6); 407 408 /* We don't do IPv6 Jumbograms. */ 409 if (ip6.ip6_plen == 0) { 410 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__)); 411 m_freem(m); 412 return EMSGSIZE; 413 } 414 415 ip6.ip6_flow = 0; 416 ip6.ip6_hlim = 0; 417 ip6.ip6_vfc &= ~IPV6_VERSION_MASK; 418 ip6.ip6_vfc |= IPV6_VERSION; 419 420 /* Scoped address handling. */ 421 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) 422 ip6.ip6_src.s6_addr16[1] = 0; 423 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) 424 ip6.ip6_dst.s6_addr16[1] = 0; 425 426 /* Done with IPv6 header. */ 427 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6); 428 429 /* Let's deal with the remaining headers (if any). */ 430 if (skip - sizeof(struct ip6_hdr) > 0) { 431 if (m->m_len <= skip) { 432 ptr = (unsigned char *) malloc( 433 skip - sizeof(struct ip6_hdr), 434 M_XDATA, M_NOWAIT); 435 if (ptr == NULL) { 436 DPRINTF(("%s: failed to allocate memory" 437 "for IPv6 headers\n",__func__)); 438 m_freem(m); 439 return ENOBUFS; 440 } 441 442 /* 443 * Copy all the protocol headers after 444 * the IPv6 header. 445 */ 446 m_copydata(m, sizeof(struct ip6_hdr), 447 skip - sizeof(struct ip6_hdr), ptr); 448 alloc = 1; 449 } else { 450 /* No need to allocate memory. */ 451 ptr = mtod(m, unsigned char *) + 452 sizeof(struct ip6_hdr); 453 alloc = 0; 454 } 455 } else 456 break; 457 458 off = ip6.ip6_nxt & 0xff; /* Next header type. */ 459 460 for (len = 0; len < skip - sizeof(struct ip6_hdr);) 461 switch (off) { 462 case IPPROTO_HOPOPTS: 463 case IPPROTO_DSTOPTS: 464 ip6e = (struct ip6_ext *) (ptr + len); 465 466 /* 467 * Process the mutable/immutable 468 * options -- borrows heavily from the 469 * KAME code. 470 */ 471 for (count = len + sizeof(struct ip6_ext); 472 count < len + ((ip6e->ip6e_len + 1) << 3);) { 473 if (ptr[count] == IP6OPT_PAD1) { 474 count++; 475 continue; /* Skip padding. */ 476 } 477 478 /* Sanity check. */ 479 if (count > len + 480 ((ip6e->ip6e_len + 1) << 3)) { 481 m_freem(m); 482 483 /* Free, if we allocated. */ 484 if (alloc) 485 free(ptr, M_XDATA); 486 return EINVAL; 487 } 488 489 ad = ptr[count + 1]; 490 491 /* If mutable option, zeroize. */ 492 if (ptr[count] & IP6OPT_MUTABLE) 493 bcopy(ipseczeroes, ptr + count, 494 ptr[count + 1]); 495 496 count += ad; 497 498 /* Sanity check. */ 499 if (count > 500 skip - sizeof(struct ip6_hdr)) { 501 m_freem(m); 502 503 /* Free, if we allocated. */ 504 if (alloc) 505 free(ptr, M_XDATA); 506 return EINVAL; 507 } 508 } 509 510 /* Advance. */ 511 len += ((ip6e->ip6e_len + 1) << 3); 512 off = ip6e->ip6e_nxt; 513 break; 514 515 case IPPROTO_ROUTING: 516 /* 517 * Always include routing headers in 518 * computation. 519 */ 520 ip6e = (struct ip6_ext *) (ptr + len); 521 len += ((ip6e->ip6e_len + 1) << 3); 522 off = ip6e->ip6e_nxt; 523 break; 524 525 default: 526 DPRINTF(("%s: unexpected IPv6 header type %d", 527 __func__, off)); 528 if (alloc) 529 free(ptr, M_XDATA); 530 m_freem(m); 531 return EINVAL; 532 } 533 534 /* Copyback and free, if we allocated. */ 535 if (alloc) { 536 m_copyback(m, sizeof(struct ip6_hdr), 537 skip - sizeof(struct ip6_hdr), ptr); 538 free(ptr, M_XDATA); 539 } 540 541 break; 542 #endif /* INET6 */ 543 } 544 545 return 0; 546 } 547 548 /* 549 * ah_input() gets called to verify that an input packet 550 * passes authentication. 551 */ 552 static int 553 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 554 { 555 struct auth_hash *ahx; 556 struct tdb_ident *tdbi; 557 struct tdb_crypto *tc; 558 struct m_tag *mtag; 559 struct newah *ah; 560 int hl, rplen, authsize; 561 562 struct cryptodesc *crda; 563 struct cryptop *crp; 564 565 IPSEC_ASSERT(sav != NULL, ("null SA")); 566 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key")); 567 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, 568 ("null authentication xform")); 569 570 /* Figure out header size. */ 571 rplen = HDRSIZE(sav); 572 573 /* XXX don't pullup, just copy header */ 574 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 575 if (ah == NULL) { 576 DPRINTF(("ah_input: cannot pullup header\n")); 577 V_ahstat.ahs_hdrops++; /*XXX*/ 578 m_freem(m); 579 return ENOBUFS; 580 } 581 582 /* Check replay window, if applicable. */ 583 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 584 V_ahstat.ahs_replay++; 585 DPRINTF(("%s: packet replay failure: %s\n", __func__, 586 ipsec_logsastr(sav))); 587 m_freem(m); 588 return ENOBUFS; 589 } 590 591 /* Verify AH header length. */ 592 hl = ah->ah_len * sizeof (u_int32_t); 593 ahx = sav->tdb_authalgxform; 594 authsize = AUTHSIZE(sav); 595 if (hl != authsize + rplen - sizeof (struct ah)) { 596 DPRINTF(("%s: bad authenticator length %u (expecting %lu)" 597 " for packet in SA %s/%08lx\n", __func__, 598 hl, (u_long) (authsize + rplen - sizeof (struct ah)), 599 ipsec_address(&sav->sah->saidx.dst), 600 (u_long) ntohl(sav->spi))); 601 V_ahstat.ahs_badauthl++; 602 m_freem(m); 603 return EACCES; 604 } 605 V_ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl; 606 607 /* Get crypto descriptors. */ 608 crp = crypto_getreq(1); 609 if (crp == NULL) { 610 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__)); 611 V_ahstat.ahs_crypto++; 612 m_freem(m); 613 return ENOBUFS; 614 } 615 616 crda = crp->crp_desc; 617 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor")); 618 619 crda->crd_skip = 0; 620 crda->crd_len = m->m_pkthdr.len; 621 crda->crd_inject = skip + rplen; 622 623 /* Authentication operation. */ 624 crda->crd_alg = ahx->type; 625 crda->crd_klen = _KEYBITS(sav->key_auth); 626 crda->crd_key = sav->key_auth->key_data; 627 628 /* Find out if we've already done crypto. */ 629 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 630 mtag != NULL; 631 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 632 tdbi = (struct tdb_ident *) (mtag + 1); 633 if (tdbi->proto == sav->sah->saidx.proto && 634 tdbi->spi == sav->spi && 635 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 636 sizeof (union sockaddr_union))) 637 break; 638 } 639 640 /* Allocate IPsec-specific opaque crypto info. */ 641 if (mtag == NULL) { 642 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) + 643 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO); 644 } else { 645 /* Hash verification has already been done successfully. */ 646 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto), 647 M_XDATA, M_NOWAIT|M_ZERO); 648 } 649 if (tc == NULL) { 650 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 651 V_ahstat.ahs_crypto++; 652 crypto_freereq(crp); 653 m_freem(m); 654 return ENOBUFS; 655 } 656 657 /* Only save information if crypto processing is needed. */ 658 if (mtag == NULL) { 659 int error; 660 661 /* 662 * Save the authenticator, the skipped portion of the packet, 663 * and the AH header. 664 */ 665 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1)); 666 667 /* Zeroize the authenticator on the packet. */ 668 m_copyback(m, skip + rplen, authsize, ipseczeroes); 669 670 /* "Massage" the packet headers for crypto processing. */ 671 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 672 skip, ahx->type, 0); 673 if (error != 0) { 674 /* NB: mbuf is free'd by ah_massage_headers */ 675 V_ahstat.ahs_hdrops++; 676 free(tc, M_XDATA); 677 crypto_freereq(crp); 678 return error; 679 } 680 } 681 682 /* Crypto operation descriptor. */ 683 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 684 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 685 crp->crp_buf = (caddr_t) m; 686 crp->crp_callback = ah_input_cb; 687 crp->crp_sid = sav->tdb_cryptoid; 688 crp->crp_opaque = (caddr_t) tc; 689 690 /* These are passed as-is to the callback. */ 691 tc->tc_spi = sav->spi; 692 tc->tc_dst = sav->sah->saidx.dst; 693 tc->tc_proto = sav->sah->saidx.proto; 694 tc->tc_nxt = ah->ah_nxt; 695 tc->tc_protoff = protoff; 696 tc->tc_skip = skip; 697 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */ 698 699 if (mtag == NULL) 700 return crypto_dispatch(crp); 701 else 702 return ah_input_cb(crp); 703 } 704 705 #ifdef INET6 706 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 707 if (saidx->dst.sa.sa_family == AF_INET6) { \ 708 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 709 } else { \ 710 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 711 } \ 712 } while (0) 713 #else 714 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 715 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 716 #endif 717 718 /* 719 * AH input callback from the crypto driver. 720 */ 721 static int 722 ah_input_cb(struct cryptop *crp) 723 { 724 int rplen, error, skip, protoff; 725 unsigned char calc[AH_ALEN_MAX]; 726 struct mbuf *m; 727 struct cryptodesc *crd; 728 struct auth_hash *ahx; 729 struct tdb_crypto *tc; 730 struct m_tag *mtag; 731 struct secasvar *sav; 732 struct secasindex *saidx; 733 u_int8_t nxt; 734 caddr_t ptr; 735 int authsize; 736 737 crd = crp->crp_desc; 738 739 tc = (struct tdb_crypto *) crp->crp_opaque; 740 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 741 skip = tc->tc_skip; 742 nxt = tc->tc_nxt; 743 protoff = tc->tc_protoff; 744 mtag = (struct m_tag *) tc->tc_ptr; 745 m = (struct mbuf *) crp->crp_buf; 746 747 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 748 if (sav == NULL) { 749 V_ahstat.ahs_notdb++; 750 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 751 error = ENOBUFS; /*XXX*/ 752 goto bad; 753 } 754 755 saidx = &sav->sah->saidx; 756 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 757 saidx->dst.sa.sa_family == AF_INET6, 758 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 759 760 ahx = (struct auth_hash *) sav->tdb_authalgxform; 761 762 /* Check for crypto errors. */ 763 if (crp->crp_etype) { 764 if (sav->tdb_cryptoid != 0) 765 sav->tdb_cryptoid = crp->crp_sid; 766 767 if (crp->crp_etype == EAGAIN) { 768 error = crypto_dispatch(crp); 769 return error; 770 } 771 772 V_ahstat.ahs_noxform++; 773 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 774 error = crp->crp_etype; 775 goto bad; 776 } else { 777 V_ahstat.ahs_hist[sav->alg_auth]++; 778 crypto_freereq(crp); /* No longer needed. */ 779 crp = NULL; 780 } 781 782 /* Shouldn't happen... */ 783 if (m == NULL) { 784 V_ahstat.ahs_crypto++; 785 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 786 error = EINVAL; 787 goto bad; 788 } 789 790 /* Figure out header size. */ 791 rplen = HDRSIZE(sav); 792 authsize = AUTHSIZE(sav); 793 794 /* Copy authenticator off the packet. */ 795 m_copydata(m, skip + rplen, authsize, calc); 796 797 /* 798 * If we have an mtag, we don't need to verify the authenticator -- 799 * it has been verified by an IPsec-aware NIC. 800 */ 801 if (mtag == NULL) { 802 ptr = (caddr_t) (tc + 1); 803 804 /* Verify authenticator. */ 805 if (bcmp(ptr + skip + rplen, calc, authsize)) { 806 DPRINTF(("%s: authentication hash mismatch for packet " 807 "in SA %s/%08lx\n", __func__, 808 ipsec_address(&saidx->dst), 809 (u_long) ntohl(sav->spi))); 810 V_ahstat.ahs_badauth++; 811 error = EACCES; 812 goto bad; 813 } 814 815 /* Fix the Next Protocol field. */ 816 ((u_int8_t *) ptr)[protoff] = nxt; 817 818 /* Copyback the saved (uncooked) network headers. */ 819 m_copyback(m, 0, skip, ptr); 820 } else { 821 /* Fix the Next Protocol field. */ 822 m_copyback(m, protoff, sizeof(u_int8_t), &nxt); 823 } 824 825 free(tc, M_XDATA), tc = NULL; /* No longer needed */ 826 827 /* 828 * Header is now authenticated. 829 */ 830 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM; 831 832 /* 833 * Update replay sequence number, if appropriate. 834 */ 835 if (sav->replay) { 836 u_int32_t seq; 837 838 m_copydata(m, skip + offsetof(struct newah, ah_seq), 839 sizeof (seq), (caddr_t) &seq); 840 if (ipsec_updatereplay(ntohl(seq), sav)) { 841 V_ahstat.ahs_replay++; 842 error = ENOBUFS; /*XXX as above*/ 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), (u_long) ntohl(sav->spi))); 854 855 V_ahstat.ahs_hdrops++; 856 goto bad; 857 } 858 859 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 860 861 KEY_FREESAV(&sav); 862 return error; 863 bad: 864 if (sav) 865 KEY_FREESAV(&sav); 866 if (m != NULL) 867 m_freem(m); 868 if (tc != NULL) 869 free(tc, M_XDATA); 870 if (crp != NULL) 871 crypto_freereq(crp); 872 return error; 873 } 874 875 /* 876 * AH output routine, called by ipsec[46]_process_packet(). 877 */ 878 static int 879 ah_output( 880 struct mbuf *m, 881 struct ipsecrequest *isr, 882 struct mbuf **mp, 883 int skip, 884 int protoff) 885 { 886 struct secasvar *sav; 887 struct auth_hash *ahx; 888 struct cryptodesc *crda; 889 struct tdb_crypto *tc; 890 struct mbuf *mi; 891 struct cryptop *crp; 892 u_int16_t iplen; 893 int error, rplen, authsize, maxpacketsize, roff; 894 u_int8_t prot; 895 struct newah *ah; 896 897 sav = isr->sav; 898 IPSEC_ASSERT(sav != NULL, ("null SA")); 899 ahx = sav->tdb_authalgxform; 900 IPSEC_ASSERT(ahx != NULL, ("null authentication xform")); 901 902 V_ahstat.ahs_output++; 903 904 /* Figure out header size. */ 905 rplen = HDRSIZE(sav); 906 907 /* Check for maximum packet size violations. */ 908 switch (sav->sah->saidx.dst.sa.sa_family) { 909 #ifdef INET 910 case AF_INET: 911 maxpacketsize = IP_MAXPACKET; 912 break; 913 #endif /* INET */ 914 #ifdef INET6 915 case AF_INET6: 916 maxpacketsize = IPV6_MAXPACKET; 917 break; 918 #endif /* INET6 */ 919 default: 920 DPRINTF(("%s: unknown/unsupported protocol family %u, " 921 "SA %s/%08lx\n", __func__, 922 sav->sah->saidx.dst.sa.sa_family, 923 ipsec_address(&sav->sah->saidx.dst), 924 (u_long) ntohl(sav->spi))); 925 V_ahstat.ahs_nopf++; 926 error = EPFNOSUPPORT; 927 goto bad; 928 } 929 authsize = AUTHSIZE(sav); 930 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 931 DPRINTF(("%s: packet in SA %s/%08lx got too big " 932 "(len %u, max len %u)\n", __func__, 933 ipsec_address(&sav->sah->saidx.dst), 934 (u_long) ntohl(sav->spi), 935 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 936 V_ahstat.ahs_toobig++; 937 error = EMSGSIZE; 938 goto bad; 939 } 940 941 /* Update the counters. */ 942 V_ahstat.ahs_obytes += m->m_pkthdr.len - skip; 943 944 m = m_unshare(m, M_NOWAIT); 945 if (m == NULL) { 946 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 947 ipsec_address(&sav->sah->saidx.dst), 948 (u_long) ntohl(sav->spi))); 949 V_ahstat.ahs_hdrops++; 950 error = ENOBUFS; 951 goto bad; 952 } 953 954 /* Inject AH header. */ 955 mi = m_makespace(m, skip, rplen + authsize, &roff); 956 if (mi == NULL) { 957 DPRINTF(("%s: failed to inject %u byte AH header for SA " 958 "%s/%08lx\n", __func__, 959 rplen + authsize, 960 ipsec_address(&sav->sah->saidx.dst), 961 (u_long) ntohl(sav->spi))); 962 V_ahstat.ahs_hdrops++; /*XXX differs from openbsd */ 963 error = ENOBUFS; 964 goto bad; 965 } 966 967 /* 968 * The AH header is guaranteed by m_makespace() to be in 969 * contiguous memory, at roff bytes offset into the returned mbuf. 970 */ 971 ah = (struct newah *)(mtod(mi, caddr_t) + roff); 972 973 /* Initialize the AH header. */ 974 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt); 975 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t); 976 ah->ah_reserve = 0; 977 ah->ah_spi = sav->spi; 978 979 /* Zeroize authenticator. */ 980 m_copyback(m, skip + rplen, authsize, ipseczeroes); 981 982 /* Insert packet replay counter, as requested. */ 983 if (sav->replay) { 984 if (sav->replay->count == ~0 && 985 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 986 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n", 987 __func__, 988 ipsec_address(&sav->sah->saidx.dst), 989 (u_long) ntohl(sav->spi))); 990 V_ahstat.ahs_wrap++; 991 error = EINVAL; 992 goto bad; 993 } 994 #ifdef REGRESSION 995 /* Emulate replay attack when ipsec_replay is TRUE. */ 996 if (!V_ipsec_replay) 997 #endif 998 sav->replay->count++; 999 ah->ah_seq = htonl(sav->replay->count); 1000 } 1001 1002 /* Get crypto descriptors. */ 1003 crp = crypto_getreq(1); 1004 if (crp == NULL) { 1005 DPRINTF(("%s: failed to acquire crypto descriptors\n", 1006 __func__)); 1007 V_ahstat.ahs_crypto++; 1008 error = ENOBUFS; 1009 goto bad; 1010 } 1011 1012 crda = crp->crp_desc; 1013 1014 crda->crd_skip = 0; 1015 crda->crd_inject = skip + rplen; 1016 crda->crd_len = m->m_pkthdr.len; 1017 1018 /* Authentication operation. */ 1019 crda->crd_alg = ahx->type; 1020 crda->crd_key = sav->key_auth->key_data; 1021 crda->crd_klen = _KEYBITS(sav->key_auth); 1022 1023 /* Allocate IPsec-specific opaque crypto info. */ 1024 tc = (struct tdb_crypto *) malloc( 1025 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO); 1026 if (tc == NULL) { 1027 crypto_freereq(crp); 1028 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 1029 V_ahstat.ahs_crypto++; 1030 error = ENOBUFS; 1031 goto bad; 1032 } 1033 1034 /* Save the skipped portion of the packet. */ 1035 m_copydata(m, 0, skip, (caddr_t) (tc + 1)); 1036 1037 /* 1038 * Fix IP header length on the header used for 1039 * authentication. We don't need to fix the original 1040 * header length as it will be fixed by our caller. 1041 */ 1042 switch (sav->sah->saidx.dst.sa.sa_family) { 1043 #ifdef INET 1044 case AF_INET: 1045 bcopy(((caddr_t)(tc + 1)) + 1046 offsetof(struct ip, ip_len), 1047 (caddr_t) &iplen, sizeof(u_int16_t)); 1048 iplen = htons(ntohs(iplen) + rplen + authsize); 1049 m_copyback(m, offsetof(struct ip, ip_len), 1050 sizeof(u_int16_t), (caddr_t) &iplen); 1051 break; 1052 #endif /* INET */ 1053 1054 #ifdef INET6 1055 case AF_INET6: 1056 bcopy(((caddr_t)(tc + 1)) + 1057 offsetof(struct ip6_hdr, ip6_plen), 1058 (caddr_t) &iplen, sizeof(u_int16_t)); 1059 iplen = htons(ntohs(iplen) + rplen + authsize); 1060 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), 1061 sizeof(u_int16_t), (caddr_t) &iplen); 1062 break; 1063 #endif /* INET6 */ 1064 } 1065 1066 /* Fix the Next Header field in saved header. */ 1067 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH; 1068 1069 /* Update the Next Protocol field in the IP header. */ 1070 prot = IPPROTO_AH; 1071 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot); 1072 1073 /* "Massage" the packet headers for crypto processing. */ 1074 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1075 skip, ahx->type, 1); 1076 if (error != 0) { 1077 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1078 free(tc, M_XDATA); 1079 crypto_freereq(crp); 1080 goto bad; 1081 } 1082 1083 /* Crypto operation descriptor. */ 1084 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1085 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 1086 crp->crp_buf = (caddr_t) m; 1087 crp->crp_callback = ah_output_cb; 1088 crp->crp_sid = sav->tdb_cryptoid; 1089 crp->crp_opaque = (caddr_t) tc; 1090 1091 /* These are passed as-is to the callback. */ 1092 tc->tc_isr = isr; 1093 tc->tc_spi = sav->spi; 1094 tc->tc_dst = sav->sah->saidx.dst; 1095 tc->tc_proto = sav->sah->saidx.proto; 1096 tc->tc_skip = skip; 1097 tc->tc_protoff = protoff; 1098 1099 return crypto_dispatch(crp); 1100 bad: 1101 if (m) 1102 m_freem(m); 1103 return (error); 1104 } 1105 1106 /* 1107 * AH output callback from the crypto driver. 1108 */ 1109 static int 1110 ah_output_cb(struct cryptop *crp) 1111 { 1112 int skip, protoff, error; 1113 struct tdb_crypto *tc; 1114 struct ipsecrequest *isr; 1115 struct secasvar *sav; 1116 struct mbuf *m; 1117 caddr_t ptr; 1118 int err; 1119 1120 tc = (struct tdb_crypto *) crp->crp_opaque; 1121 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 1122 skip = tc->tc_skip; 1123 protoff = tc->tc_protoff; 1124 ptr = (caddr_t) (tc + 1); 1125 m = (struct mbuf *) crp->crp_buf; 1126 1127 isr = tc->tc_isr; 1128 IPSECREQUEST_LOCK(isr); 1129 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 1130 if (sav == NULL) { 1131 V_ahstat.ahs_notdb++; 1132 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 1133 error = ENOBUFS; /*XXX*/ 1134 goto bad; 1135 } 1136 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n")); 1137 1138 /* Check for crypto errors. */ 1139 if (crp->crp_etype) { 1140 if (sav->tdb_cryptoid != 0) 1141 sav->tdb_cryptoid = crp->crp_sid; 1142 1143 if (crp->crp_etype == EAGAIN) { 1144 KEY_FREESAV(&sav); 1145 IPSECREQUEST_UNLOCK(isr); 1146 error = crypto_dispatch(crp); 1147 return error; 1148 } 1149 1150 V_ahstat.ahs_noxform++; 1151 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 1152 error = crp->crp_etype; 1153 goto bad; 1154 } 1155 1156 /* Shouldn't happen... */ 1157 if (m == NULL) { 1158 V_ahstat.ahs_crypto++; 1159 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 1160 error = EINVAL; 1161 goto bad; 1162 } 1163 V_ahstat.ahs_hist[sav->alg_auth]++; 1164 1165 /* 1166 * Copy original headers (with the new protocol number) back 1167 * in place. 1168 */ 1169 m_copyback(m, 0, skip, ptr); 1170 1171 /* No longer needed. */ 1172 free(tc, M_XDATA); 1173 crypto_freereq(crp); 1174 1175 #ifdef REGRESSION 1176 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 1177 if (V_ipsec_integrity) { 1178 int alen; 1179 1180 /* 1181 * Corrupt HMAC if we want to test integrity verification of 1182 * the other side. 1183 */ 1184 alen = AUTHSIZE(sav); 1185 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); 1186 } 1187 #endif 1188 1189 /* NB: m is reclaimed by ipsec_process_done. */ 1190 err = ipsec_process_done(m, isr); 1191 KEY_FREESAV(&sav); 1192 IPSECREQUEST_UNLOCK(isr); 1193 return err; 1194 bad: 1195 if (sav) 1196 KEY_FREESAV(&sav); 1197 IPSECREQUEST_UNLOCK(isr); 1198 if (m) 1199 m_freem(m); 1200 free(tc, M_XDATA); 1201 crypto_freereq(crp); 1202 return error; 1203 } 1204 1205 static struct xformsw ah_xformsw = { 1206 XF_AH, XFT_AUTH, "IPsec AH", 1207 ah_init, ah_zeroize, ah_input, ah_output, 1208 }; 1209 1210 static void 1211 ah_attach(void) 1212 { 1213 1214 xform_register(&ah_xformsw); 1215 } 1216 1217 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
Cache object: e6cf791d7af0afeab031d3e0bdf486e4
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