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sys/netipsec/xform_ah.c
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1 /* $FreeBSD: releng/5.0/sys/netipsec/xform_ah.c 105197 2002-10-16 02:10:08Z sam $ */ 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 52 #include <netinet/in.h> 53 #include <netinet/in_systm.h> 54 #include <netinet/ip.h> 55 #include <netinet/ip_ecn.h> 56 #include <netinet/ip6.h> 57 58 #include <net/route.h> 59 #include <netipsec/ipsec.h> 60 #include <netipsec/ah.h> 61 #include <netipsec/ah_var.h> 62 #include <netipsec/xform.h> 63 64 #ifdef INET6 65 #include <netinet6/ip6_var.h> 66 #include <netipsec/ipsec6.h> 67 #include <netinet6/ip6_ecn.h> 68 #endif 69 70 #include <netipsec/key.h> 71 #include <netipsec/key_debug.h> 72 73 #include <opencrypto/cryptodev.h> 74 75 /* 76 * Return header size in bytes. The old protocol did not support 77 * the replay counter; the new protocol always includes the counter. 78 */ 79 #define HDRSIZE(sav) \ 80 (((sav)->flags & SADB_X_EXT_OLD) ? \ 81 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t)) 82 /* 83 * Return authenticator size in bytes. The old protocol is known 84 * to use a fixed 16-byte authenticator. The new algorithm gets 85 * this size from the xform but is (currently) always 12. 86 */ 87 #define AUTHSIZE(sav) \ 88 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize) 89 90 int ah_enable = 1; /* control flow of packets with AH */ 91 int ah_cleartos = 1; /* clear ip_tos when doing AH calc */ 92 struct ahstat ahstat; 93 94 SYSCTL_DECL(_net_inet_ah); 95 SYSCTL_INT(_net_inet_ah, OID_AUTO, 96 ah_enable, CTLFLAG_RW, &ah_enable, 0, ""); 97 SYSCTL_INT(_net_inet_ah, OID_AUTO, 98 ah_cleartos, CTLFLAG_RW, &ah_cleartos, 0, ""); 99 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS, 100 stats, CTLFLAG_RD, &ahstat, ahstat, ""); 101 102 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 103 104 static int ah_input_cb(struct cryptop*); 105 static int ah_output_cb(struct cryptop*); 106 107 /* 108 * NB: this is public for use by the PF_KEY support. 109 */ 110 struct auth_hash * 111 ah_algorithm_lookup(int alg) 112 { 113 if (alg >= AH_ALG_MAX) 114 return NULL; 115 switch (alg) { 116 case SADB_X_AALG_NULL: 117 return &auth_hash_null; 118 case SADB_AALG_MD5HMAC: 119 return &auth_hash_hmac_md5_96; 120 case SADB_AALG_SHA1HMAC: 121 return &auth_hash_hmac_sha1_96; 122 case SADB_X_AALG_RIPEMD160HMAC: 123 return &auth_hash_hmac_ripemd_160_96; 124 case SADB_X_AALG_MD5: 125 return &auth_hash_key_md5; 126 case SADB_X_AALG_SHA: 127 return &auth_hash_key_sha1; 128 case SADB_X_AALG_SHA2_256: 129 return &auth_hash_hmac_sha2_256; 130 case SADB_X_AALG_SHA2_384: 131 return &auth_hash_hmac_sha2_384; 132 case SADB_X_AALG_SHA2_512: 133 return &auth_hash_hmac_sha2_512; 134 } 135 return NULL; 136 } 137 138 size_t 139 ah_hdrsiz(struct secasvar *sav) 140 { 141 size_t size; 142 143 if (sav != NULL) { 144 int authsize; 145 KASSERT(sav->tdb_authalgxform != NULL, 146 ("ah_hdrsiz: 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(("ah_init: unsupported authentication algorithm %u\n", 169 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(("ah_init: replay state block inconsistency, " 180 "%s algorithm %s replay state\n", 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(("ah_init: no authentication key for %s " 187 "algorithm\n", thash->name)); 188 return EINVAL; 189 } 190 keylen = _KEYLEN(sav->key_auth); 191 if (keylen != thash->keysize && thash->keysize != 0) { 192 DPRINTF(("ah_init: invalid keylength %d, algorithm " 193 "%s requires keysize %d\n", 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 = _KEYBUF(sav->key_auth); 206 207 return 0; 208 } 209 210 /* 211 * ah_init() is called when an SPI is being set up. 212 */ 213 static int 214 ah_init(struct secasvar *sav, struct xformsw *xsp) 215 { 216 struct cryptoini cria; 217 int error; 218 219 error = ah_init0(sav, xsp, &cria); 220 return error ? error : 221 crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support); 222 } 223 224 /* 225 * Paranoia. 226 * 227 * NB: public for use by esp_zeroize (XXX). 228 */ 229 int 230 ah_zeroize(struct secasvar *sav) 231 { 232 int err; 233 234 if (sav->key_auth) 235 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 236 237 err = crypto_freesession(sav->tdb_cryptoid); 238 sav->tdb_cryptoid = 0; 239 sav->tdb_authalgxform = NULL; 240 sav->tdb_xform = NULL; 241 return err; 242 } 243 244 /* 245 * Massage IPv4/IPv6 headers for AH processing. 246 */ 247 static int 248 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) 249 { 250 struct mbuf *m = *m0; 251 unsigned char *ptr; 252 int off, count; 253 254 #ifdef INET 255 struct ip *ip; 256 #endif /* INET */ 257 258 #ifdef INET6 259 struct ip6_ext *ip6e; 260 struct ip6_hdr ip6; 261 int alloc, len, ad; 262 #endif /* INET6 */ 263 264 switch (proto) { 265 #ifdef INET 266 case AF_INET: 267 /* 268 * This is the least painful way of dealing with IPv4 header 269 * and option processing -- just make sure they're in 270 * contiguous memory. 271 */ 272 *m0 = m = m_pullup(m, skip); 273 if (m == NULL) { 274 DPRINTF(("ah_massage_headers: m_pullup failed\n")); 275 return ENOBUFS; 276 } 277 278 /* Fix the IP header */ 279 ip = mtod(m, struct ip *); 280 if (ah_cleartos) 281 ip->ip_tos = 0; 282 ip->ip_ttl = 0; 283 ip->ip_sum = 0; 284 285 /* 286 * On input, fix ip_len which has been byte-swapped 287 * at ip_input(). 288 */ 289 if (!out) { 290 ip->ip_len = htons(ip->ip_len + skip); 291 292 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 293 ip->ip_off = htons(ip->ip_off & IP_DF); 294 else 295 ip->ip_off = 0; 296 } else { 297 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 298 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF); 299 else 300 ip->ip_off = 0; 301 } 302 303 ptr = mtod(m, unsigned char *) + sizeof(struct ip); 304 305 /* IPv4 option processing */ 306 for (off = sizeof(struct ip); off < skip;) { 307 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP || 308 off + 1 < skip) 309 ; 310 else { 311 DPRINTF(("ah_massage_headers: illegal IPv4 " 312 "option length for option %d\n", 313 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(("ah_massage_headers: " 336 "illegal IPv4 option length for " 337 "option %d\n", 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(("ah_massage_headers: " 351 "illegal IPv4 option length for " 352 "option %d\n", 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(("ah_massage_headers: " 377 "illegal IPv4 option length for " 378 "option %d\n", 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(("ah_massage_headers(): malformed " 393 "IPv4 options header\n")); 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(("ah_massage_headers: unsupported IPv6 jumbogram\n")); 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(("ah_massage_headers: failed " 437 "to allocate memory for IPv6 " 438 "headers\n")); 439 m_freem(m); 440 return ENOBUFS; 441 } 442 443 /* 444 * Copy all the protocol headers after 445 * the IPv6 header. 446 */ 447 m_copydata(m, sizeof(struct ip6_hdr), 448 skip - sizeof(struct ip6_hdr), ptr); 449 alloc = 1; 450 } else { 451 /* No need to allocate memory. */ 452 ptr = mtod(m, unsigned char *) + 453 sizeof(struct ip6_hdr); 454 alloc = 0; 455 } 456 } else 457 break; 458 459 off = ip6.ip6_nxt & 0xff; /* Next header type. */ 460 461 for (len = 0; len < skip - sizeof(struct ip6_hdr);) 462 switch (off) { 463 case IPPROTO_HOPOPTS: 464 case IPPROTO_DSTOPTS: 465 ip6e = (struct ip6_ext *) (ptr + len); 466 467 /* 468 * Process the mutable/immutable 469 * options -- borrows heavily from the 470 * KAME code. 471 */ 472 for (count = len + sizeof(struct ip6_ext); 473 count < len + ((ip6e->ip6e_len + 1) << 3);) { 474 if (ptr[count] == IP6OPT_PAD1) { 475 count++; 476 continue; /* Skip padding. */ 477 } 478 479 /* Sanity check. */ 480 if (count > len + 481 ((ip6e->ip6e_len + 1) << 3)) { 482 m_freem(m); 483 484 /* Free, if we allocated. */ 485 if (alloc) 486 FREE(ptr, M_XDATA); 487 return EINVAL; 488 } 489 490 ad = ptr[count + 1]; 491 492 /* If mutable option, zeroize. */ 493 if (ptr[count] & IP6OPT_MUTABLE) 494 bcopy(ipseczeroes, ptr + count, 495 ptr[count + 1]); 496 497 count += ad; 498 499 /* Sanity check. */ 500 if (count > 501 skip - sizeof(struct ip6_hdr)) { 502 m_freem(m); 503 504 /* Free, if we allocated. */ 505 if (alloc) 506 FREE(ptr, M_XDATA); 507 return EINVAL; 508 } 509 } 510 511 /* Advance. */ 512 len += ((ip6e->ip6e_len + 1) << 3); 513 off = ip6e->ip6e_nxt; 514 break; 515 516 case IPPROTO_ROUTING: 517 /* 518 * Always include routing headers in 519 * computation. 520 */ 521 ip6e = (struct ip6_ext *) (ptr + len); 522 len += ((ip6e->ip6e_len + 1) << 3); 523 off = ip6e->ip6e_nxt; 524 break; 525 526 default: 527 DPRINTF(("ah_massage_headers: unexpected " 528 "IPv6 header type %d", off)); 529 if (alloc) 530 FREE(ptr, M_XDATA); 531 m_freem(m); 532 return EINVAL; 533 } 534 535 /* Copyback and free, if we allocated. */ 536 if (alloc) { 537 m_copyback(m, sizeof(struct ip6_hdr), 538 skip - sizeof(struct ip6_hdr), ptr); 539 free(ptr, M_XDATA); 540 } 541 542 break; 543 #endif /* INET6 */ 544 } 545 546 return 0; 547 } 548 549 /* 550 * ah_input() gets called to verify that an input packet 551 * passes authentication. 552 */ 553 static int 554 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 555 { 556 struct auth_hash *ahx; 557 struct tdb_ident *tdbi; 558 struct tdb_crypto *tc; 559 struct m_tag *mtag; 560 struct newah *ah; 561 int hl, rplen, authsize; 562 563 struct cryptodesc *crda; 564 struct cryptop *crp; 565 566 #if 0 567 SPLASSERT(net, "ah_input"); 568 #endif 569 570 KASSERT(sav != NULL, ("ah_input: null SA")); 571 KASSERT(sav->key_auth != NULL, 572 ("ah_input: null authentication key")); 573 KASSERT(sav->tdb_authalgxform != NULL, 574 ("ah_input: null authentication xform")); 575 576 /* Figure out header size. */ 577 rplen = HDRSIZE(sav); 578 579 /* XXX don't pullup, just copy header */ 580 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 581 if (ah == NULL) { 582 DPRINTF(("ah_input: cannot pullup header\n")); 583 ahstat.ahs_hdrops++; /*XXX*/ 584 m_freem(m); 585 return ENOBUFS; 586 } 587 588 /* Check replay window, if applicable. */ 589 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 590 ahstat.ahs_replay++; 591 DPRINTF(("ah_input: packet replay failure: %s\n", 592 ipsec_logsastr(sav))); 593 m_freem(m); 594 return ENOBUFS; 595 } 596 597 /* Verify AH header length. */ 598 hl = ah->ah_len * sizeof (u_int32_t); 599 ahx = sav->tdb_authalgxform; 600 authsize = AUTHSIZE(sav); 601 if (hl != authsize + rplen - sizeof (struct ah)) { 602 DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)" 603 " for packet in SA %s/%08lx\n", 604 hl, (u_long) (authsize + rplen - sizeof (struct ah)), 605 ipsec_address(&sav->sah->saidx.dst), 606 (u_long) ntohl(sav->spi))); 607 ahstat.ahs_badauthl++; 608 m_freem(m); 609 return EACCES; 610 } 611 ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl; 612 613 /* Get crypto descriptors. */ 614 crp = crypto_getreq(1); 615 if (crp == NULL) { 616 DPRINTF(("ah_input: failed to acquire crypto descriptor\n")); 617 ahstat.ahs_crypto++; 618 m_freem(m); 619 return ENOBUFS; 620 } 621 622 crda = crp->crp_desc; 623 KASSERT(crda != NULL, ("ah_input: null crypto descriptor")); 624 625 crda->crd_skip = 0; 626 crda->crd_len = m->m_pkthdr.len; 627 crda->crd_inject = skip + rplen; 628 629 /* Authentication operation. */ 630 crda->crd_alg = ahx->type; 631 crda->crd_key = _KEYBUF(sav->key_auth); 632 crda->crd_klen = _KEYBITS(sav->key_auth); 633 634 /* Find out if we've already done crypto. */ 635 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 636 mtag != NULL; 637 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 638 tdbi = (struct tdb_ident *) (mtag + 1); 639 if (tdbi->proto == sav->sah->saidx.proto && 640 tdbi->spi == sav->spi && 641 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 642 sizeof (union sockaddr_union))) 643 break; 644 } 645 646 /* Allocate IPsec-specific opaque crypto info. */ 647 if (mtag == NULL) { 648 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) + 649 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO); 650 } else { 651 /* Hash verification has already been done successfully. */ 652 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto), 653 M_XDATA, M_NOWAIT|M_ZERO); 654 } 655 if (tc == NULL) { 656 DPRINTF(("ah_input: failed to allocate tdb_crypto\n")); 657 ahstat.ahs_crypto++; 658 crypto_freereq(crp); 659 m_freem(m); 660 return ENOBUFS; 661 } 662 663 /* Only save information if crypto processing is needed. */ 664 if (mtag == NULL) { 665 int error; 666 667 /* 668 * Save the authenticator, the skipped portion of the packet, 669 * and the AH header. 670 */ 671 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1)); 672 673 /* Zeroize the authenticator on the packet. */ 674 m_copyback(m, skip + rplen, authsize, ipseczeroes); 675 676 /* "Massage" the packet headers for crypto processing. */ 677 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 678 skip, ahx->type, 0); 679 if (error != 0) { 680 /* NB: mbuf is free'd by ah_massage_headers */ 681 ahstat.ahs_hdrops++; 682 free(tc, M_XDATA); 683 crypto_freereq(crp); 684 return error; 685 } 686 } 687 688 /* Crypto operation descriptor. */ 689 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 690 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_NODELAY; 691 crp->crp_buf = (caddr_t) m; 692 crp->crp_callback = ah_input_cb; 693 crp->crp_sid = sav->tdb_cryptoid; 694 crp->crp_opaque = (caddr_t) tc; 695 696 /* These are passed as-is to the callback. */ 697 tc->tc_spi = sav->spi; 698 tc->tc_dst = sav->sah->saidx.dst; 699 tc->tc_proto = sav->sah->saidx.proto; 700 tc->tc_nxt = ah->ah_nxt; 701 tc->tc_protoff = protoff; 702 tc->tc_skip = skip; 703 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */ 704 705 if (mtag == NULL) 706 return crypto_dispatch(crp); 707 else 708 return ah_input_cb(crp); 709 } 710 711 #ifdef INET6 712 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 713 if (saidx->dst.sa.sa_family == AF_INET6) { \ 714 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 715 } else { \ 716 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 717 } \ 718 } while (0) 719 #else 720 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 721 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 722 #endif 723 724 /* 725 * AH input callback from the crypto driver. 726 */ 727 static int 728 ah_input_cb(struct cryptop *crp) 729 { 730 int rplen, error, skip, protoff; 731 unsigned char calc[AH_ALEN_MAX]; 732 struct mbuf *m; 733 struct cryptodesc *crd; 734 struct auth_hash *ahx; 735 struct tdb_crypto *tc; 736 struct m_tag *mtag; 737 struct secasvar *sav; 738 struct secasindex *saidx; 739 u_int8_t nxt; 740 caddr_t ptr; 741 int s, authsize; 742 743 crd = crp->crp_desc; 744 745 tc = (struct tdb_crypto *) crp->crp_opaque; 746 KASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!")); 747 skip = tc->tc_skip; 748 nxt = tc->tc_nxt; 749 protoff = tc->tc_protoff; 750 mtag = (struct m_tag *) tc->tc_ptr; 751 m = (struct mbuf *) crp->crp_buf; 752 753 s = splnet(); 754 755 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 756 if (sav == NULL) { 757 ahstat.ahs_notdb++; 758 DPRINTF(("ah_input_cb: SA expired while in crypto\n")); 759 error = ENOBUFS; /*XXX*/ 760 goto bad; 761 } 762 763 saidx = &sav->sah->saidx; 764 KASSERT(saidx->dst.sa.sa_family == AF_INET || 765 saidx->dst.sa.sa_family == AF_INET6, 766 ("ah_input_cb: unexpected protocol family %u", 767 saidx->dst.sa.sa_family)); 768 769 ahx = (struct auth_hash *) sav->tdb_authalgxform; 770 771 /* Check for crypto errors. */ 772 if (crp->crp_etype) { 773 if (sav->tdb_cryptoid != 0) 774 sav->tdb_cryptoid = crp->crp_sid; 775 776 if (crp->crp_etype == EAGAIN) 777 return crypto_dispatch(crp); 778 779 ahstat.ahs_noxform++; 780 DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype)); 781 error = crp->crp_etype; 782 goto bad; 783 } else { 784 ahstat.ahs_hist[sav->alg_auth]++; 785 crypto_freereq(crp); /* No longer needed. */ 786 crp = NULL; 787 } 788 789 /* Shouldn't happen... */ 790 if (m == NULL) { 791 ahstat.ahs_crypto++; 792 DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n")); 793 error = EINVAL; 794 goto bad; 795 } 796 797 /* Figure out header size. */ 798 rplen = HDRSIZE(sav); 799 authsize = AUTHSIZE(sav); 800 801 /* Copy authenticator off the packet. */ 802 m_copydata(m, skip + rplen, authsize, calc); 803 804 /* 805 * If we have an mtag, we don't need to verify the authenticator -- 806 * it has been verified by an IPsec-aware NIC. 807 */ 808 if (mtag == NULL) { 809 ptr = (caddr_t) (tc + 1); 810 811 /* Verify authenticator. */ 812 if (bcmp(ptr + skip + rplen, calc, authsize)) { 813 DPRINTF(("ah_input: authentication hash mismatch " 814 "for packet in SA %s/%08lx\n", 815 ipsec_address(&saidx->dst), 816 (u_long) ntohl(sav->spi))); 817 ahstat.ahs_badauth++; 818 error = EACCES; 819 goto bad; 820 } 821 822 /* Fix the Next Protocol field. */ 823 ((u_int8_t *) ptr)[protoff] = nxt; 824 825 /* Copyback the saved (uncooked) network headers. */ 826 m_copyback(m, 0, skip, ptr); 827 } else { 828 /* Fix the Next Protocol field. */ 829 m_copyback(m, protoff, sizeof(u_int8_t), &nxt); 830 } 831 832 free(tc, M_XDATA), tc = NULL; /* No longer needed */ 833 834 /* 835 * Header is now authenticated. 836 */ 837 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM; 838 839 /* 840 * Update replay sequence number, if appropriate. 841 */ 842 if (sav->replay) { 843 u_int32_t seq; 844 845 m_copydata(m, skip + offsetof(struct newah, ah_seq), 846 sizeof (seq), (caddr_t) &seq); 847 if (ipsec_updatereplay(ntohl(seq), sav)) { 848 ahstat.ahs_replay++; 849 error = ENOBUFS; /*XXX as above*/ 850 goto bad; 851 } 852 } 853 854 /* 855 * Remove the AH header and authenticator from the mbuf. 856 */ 857 error = m_striphdr(m, skip, rplen + authsize); 858 if (error) { 859 DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n", 860 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 861 862 ahstat.ahs_hdrops++; 863 goto bad; 864 } 865 866 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 867 868 KEY_FREESAV(&sav); 869 splx(s); 870 return error; 871 bad: 872 if (sav) 873 KEY_FREESAV(&sav); 874 splx(s); 875 if (m != NULL) 876 m_freem(m); 877 if (tc != NULL) 878 free(tc, M_XDATA); 879 if (crp != NULL) 880 crypto_freereq(crp); 881 return error; 882 } 883 884 /* 885 * AH output routine, called by ipsec[46]_process_packet(). 886 */ 887 static int 888 ah_output( 889 struct mbuf *m, 890 struct ipsecrequest *isr, 891 struct mbuf **mp, 892 int skip, 893 int protoff) 894 { 895 struct secasvar *sav; 896 struct auth_hash *ahx; 897 struct cryptodesc *crda; 898 struct tdb_crypto *tc; 899 struct mbuf *mi; 900 struct cryptop *crp; 901 u_int16_t iplen; 902 int error, rplen, authsize, maxpacketsize, roff; 903 u_int8_t prot; 904 struct newah *ah; 905 906 #if 0 907 SPLASSERT(net, "ah_output"); 908 #endif 909 910 sav = isr->sav; 911 KASSERT(sav != NULL, ("ah_output: null SA")); 912 ahx = sav->tdb_authalgxform; 913 KASSERT(ahx != NULL, ("ah_output: null authentication xform")); 914 915 ahstat.ahs_output++; 916 917 /* Figure out header size. */ 918 rplen = HDRSIZE(sav); 919 920 /* Check for maximum packet size violations. */ 921 switch (sav->sah->saidx.dst.sa.sa_family) { 922 #ifdef INET 923 case AF_INET: 924 maxpacketsize = IP_MAXPACKET; 925 break; 926 #endif /* INET */ 927 #ifdef INET6 928 case AF_INET6: 929 maxpacketsize = IPV6_MAXPACKET; 930 break; 931 #endif /* INET6 */ 932 default: 933 DPRINTF(("ah_output: unknown/unsupported protocol " 934 "family %u, SA %s/%08lx\n", 935 sav->sah->saidx.dst.sa.sa_family, 936 ipsec_address(&sav->sah->saidx.dst), 937 (u_long) ntohl(sav->spi))); 938 ahstat.ahs_nopf++; 939 error = EPFNOSUPPORT; 940 goto bad; 941 } 942 authsize = AUTHSIZE(sav); 943 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 944 DPRINTF(("ah_output: packet in SA %s/%08lx got too big " 945 "(len %u, max len %u)\n", 946 ipsec_address(&sav->sah->saidx.dst), 947 (u_long) ntohl(sav->spi), 948 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 949 ahstat.ahs_toobig++; 950 error = EMSGSIZE; 951 goto bad; 952 } 953 954 /* Update the counters. */ 955 ahstat.ahs_obytes += m->m_pkthdr.len - skip; 956 957 m = m_clone(m); 958 if (m == NULL) { 959 DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n", 960 ipsec_address(&sav->sah->saidx.dst), 961 (u_long) ntohl(sav->spi))); 962 ahstat.ahs_hdrops++; 963 error = ENOBUFS; 964 goto bad; 965 } 966 967 /* Inject AH header. */ 968 mi = m_makespace(m, skip, rplen + authsize, &roff); 969 if (mi == NULL) { 970 DPRINTF(("ah_output: failed to inject %u byte AH header for SA " 971 "%s/%08lx\n", 972 rplen + authsize, 973 ipsec_address(&sav->sah->saidx.dst), 974 (u_long) ntohl(sav->spi))); 975 ahstat.ahs_hdrops++; /*XXX differs from openbsd */ 976 error = ENOBUFS; 977 goto bad; 978 } 979 980 /* 981 * The AH header is guaranteed by m_makespace() to be in 982 * contiguous memory, at roff bytes offset into the returned mbuf. 983 */ 984 ah = (struct newah *)(mtod(mi, caddr_t) + roff); 985 986 /* Initialize the AH header. */ 987 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt); 988 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t); 989 ah->ah_reserve = 0; 990 ah->ah_spi = sav->spi; 991 992 /* Zeroize authenticator. */ 993 m_copyback(m, skip + rplen, authsize, ipseczeroes); 994 995 /* Insert packet replay counter, as requested. */ 996 if (sav->replay) { 997 if (sav->replay->count == ~0 && 998 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 999 DPRINTF(("ah_output: replay counter wrapped for SA " 1000 "%s/%08lx\n", 1001 ipsec_address(&sav->sah->saidx.dst), 1002 (u_long) ntohl(sav->spi))); 1003 ahstat.ahs_wrap++; 1004 error = EINVAL; 1005 goto bad; 1006 } 1007 sav->replay->count++; 1008 ah->ah_seq = htonl(sav->replay->count); 1009 } 1010 1011 /* Get crypto descriptors. */ 1012 crp = crypto_getreq(1); 1013 if (crp == NULL) { 1014 DPRINTF(("ah_output: failed to acquire crypto descriptors\n")); 1015 ahstat.ahs_crypto++; 1016 error = ENOBUFS; 1017 goto bad; 1018 } 1019 1020 crda = crp->crp_desc; 1021 1022 crda->crd_skip = 0; 1023 crda->crd_inject = skip + rplen; 1024 crda->crd_len = m->m_pkthdr.len; 1025 1026 /* Authentication operation. */ 1027 crda->crd_alg = ahx->type; 1028 crda->crd_key = _KEYBUF(sav->key_auth); 1029 crda->crd_klen = _KEYBITS(sav->key_auth); 1030 1031 /* Allocate IPsec-specific opaque crypto info. */ 1032 tc = (struct tdb_crypto *) malloc( 1033 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO); 1034 if (tc == NULL) { 1035 crypto_freereq(crp); 1036 DPRINTF(("ah_output: failed to allocate tdb_crypto\n")); 1037 ahstat.ahs_crypto++; 1038 error = ENOBUFS; 1039 goto bad; 1040 } 1041 1042 /* Save the skipped portion of the packet. */ 1043 m_copydata(m, 0, skip, (caddr_t) (tc + 1)); 1044 1045 /* 1046 * Fix IP header length on the header used for 1047 * authentication. We don't need to fix the original 1048 * header length as it will be fixed by our caller. 1049 */ 1050 switch (sav->sah->saidx.dst.sa.sa_family) { 1051 #ifdef INET 1052 case AF_INET: 1053 bcopy(((caddr_t)(tc + 1)) + 1054 offsetof(struct ip, ip_len), 1055 (caddr_t) &iplen, sizeof(u_int16_t)); 1056 iplen = htons(ntohs(iplen) + rplen + authsize); 1057 m_copyback(m, offsetof(struct ip, ip_len), 1058 sizeof(u_int16_t), (caddr_t) &iplen); 1059 break; 1060 #endif /* INET */ 1061 1062 #ifdef INET6 1063 case AF_INET6: 1064 bcopy(((caddr_t)(tc + 1)) + 1065 offsetof(struct ip6_hdr, ip6_plen), 1066 (caddr_t) &iplen, sizeof(u_int16_t)); 1067 iplen = htons(ntohs(iplen) + rplen + authsize); 1068 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), 1069 sizeof(u_int16_t), (caddr_t) &iplen); 1070 break; 1071 #endif /* INET6 */ 1072 } 1073 1074 /* Fix the Next Header field in saved header. */ 1075 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH; 1076 1077 /* Update the Next Protocol field in the IP header. */ 1078 prot = IPPROTO_AH; 1079 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot); 1080 1081 /* "Massage" the packet headers for crypto processing. */ 1082 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1083 skip, ahx->type, 1); 1084 if (error != 0) { 1085 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1086 free(tc, M_XDATA); 1087 crypto_freereq(crp); 1088 goto bad; 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 = (caddr_t) m; 1095 crp->crp_callback = ah_output_cb; 1096 crp->crp_sid = sav->tdb_cryptoid; 1097 crp->crp_opaque = (caddr_t) 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 1107 return crypto_dispatch(crp); 1108 bad: 1109 if (m) 1110 m_freem(m); 1111 return (error); 1112 } 1113 1114 /* 1115 * AH output callback from the crypto driver. 1116 */ 1117 static int 1118 ah_output_cb(struct cryptop *crp) 1119 { 1120 int skip, protoff, error; 1121 struct tdb_crypto *tc; 1122 struct ipsecrequest *isr; 1123 struct secasvar *sav; 1124 struct mbuf *m; 1125 caddr_t ptr; 1126 int s, err; 1127 1128 tc = (struct tdb_crypto *) crp->crp_opaque; 1129 KASSERT(tc != NULL, ("ah_output_cb: null opaque data area!")); 1130 skip = tc->tc_skip; 1131 protoff = tc->tc_protoff; 1132 ptr = (caddr_t) (tc + 1); 1133 m = (struct mbuf *) crp->crp_buf; 1134 1135 s = splnet(); 1136 1137 isr = tc->tc_isr; 1138 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 1139 if (sav == NULL) { 1140 ahstat.ahs_notdb++; 1141 DPRINTF(("ah_output_cb: SA expired while in crypto\n")); 1142 error = ENOBUFS; /*XXX*/ 1143 goto bad; 1144 } 1145 KASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n")); 1146 1147 /* Check for crypto errors. */ 1148 if (crp->crp_etype) { 1149 if (sav->tdb_cryptoid != 0) 1150 sav->tdb_cryptoid = crp->crp_sid; 1151 1152 if (crp->crp_etype == EAGAIN) { 1153 KEY_FREESAV(&sav); 1154 splx(s); 1155 return crypto_dispatch(crp); 1156 } 1157 1158 ahstat.ahs_noxform++; 1159 DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype)); 1160 error = crp->crp_etype; 1161 goto bad; 1162 } 1163 1164 /* Shouldn't happen... */ 1165 if (m == NULL) { 1166 ahstat.ahs_crypto++; 1167 DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n")); 1168 error = EINVAL; 1169 goto bad; 1170 } 1171 ahstat.ahs_hist[sav->alg_auth]++; 1172 1173 /* 1174 * Copy original headers (with the new protocol number) back 1175 * in place. 1176 */ 1177 m_copyback(m, 0, skip, ptr); 1178 1179 /* No longer needed. */ 1180 free(tc, M_XDATA); 1181 crypto_freereq(crp); 1182 1183 /* NB: m is reclaimed by ipsec_process_done. */ 1184 err = ipsec_process_done(m, isr); 1185 KEY_FREESAV(&sav); 1186 splx(s); 1187 return err; 1188 bad: 1189 if (sav) 1190 KEY_FREESAV(&sav); 1191 splx(s); 1192 if (m) 1193 m_freem(m); 1194 free(tc, M_XDATA); 1195 crypto_freereq(crp); 1196 return error; 1197 } 1198 1199 static struct xformsw ah_xformsw = { 1200 XF_AH, XFT_AUTH, "IPsec AH", 1201 ah_init, ah_zeroize, ah_input, ah_output, 1202 }; 1203 1204 static void 1205 ah_attach(void) 1206 { 1207 xform_register(&ah_xformsw); 1208 } 1209 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
Cache object: fd3ee18b5469ce5cabe94e8b91da20c5
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