xform_ah.c revision 1.3
1/* $NetBSD: xform_ah.c,v 1.3 2003/09/12 11:21:00 itojun 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 1.3 2003/09/12 11:21:00 itojun Exp $"); 43 44#include "opt_inet.h" 45#ifdef __FreeBSD__ 46#include "opt_inet6.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 57#include <net/if.h> 58 59#include <netinet/in.h> 60#include <netinet/in_systm.h> 61#include <netinet/ip.h> 62#include <netinet/ip_ecn.h> 63#include <netinet/ip6.h> 64 65#include <net/route.h> 66#include <netipsec/ipsec.h> 67#include <netipsec/ah.h> 68#include <netipsec/ah_var.h> 69#include <netipsec/xform.h> 70 71#ifdef INET6 72#include <netinet6/ip6_var.h> 73#include <netipsec/ipsec6.h> 74#include <netinet6/ip6_ecn.h> 75#endif 76 77#include <netkey/key.h> 78#include <netkey/key_debug.h> 79#include <netipsec/ipsec_osdep.h> 80 81#include <opencrypto/cryptodev.h> 82 83/* 84 * Return header size in bytes. The old protocol did not support 85 * the replay counter; the new protocol always includes the counter. 86 */ 87#define HDRSIZE(sav) \ 88 (((sav)->flags & SADB_X_EXT_OLD) ? \ 89 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t)) 90/* 91 * Return authenticator size in bytes. The old protocol is known 92 * to use a fixed 16-byte authenticator. The new algorithm gets 93 * this size from the xform but is (currently) always 12. 94 */ 95#define AUTHSIZE(sav) \ 96 ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize) 97 98int ah_enable = 1; /* control flow of packets with AH */ 99int ah_cleartos = 1; /* clear ip_tos when doing AH calc */ 100struct ahstat ahstat; 101 102#ifdef __FreeBSD__ 103SYSCTL_DECL(_net_inet_ah); 104SYSCTL_INT(_net_inet_ah, OID_AUTO, 105 ah_enable, CTLFLAG_RW, &ah_enable, 0, ""); 106SYSCTL_INT(_net_inet_ah, OID_AUTO, 107 ah_cleartos, CTLFLAG_RW, &ah_cleartos, 0, ""); 108SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS, 109 stats, CTLFLAG_RD, &ahstat, ahstat, ""); 110 111#endif __FreeBSD__ 112 113static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 114 115static int ah_input_cb(struct cryptop*); 116static int ah_output_cb(struct cryptop*); 117 118/* 119 * NB: this is public for use by the PF_KEY support. 120 */ 121struct auth_hash * 122ah_algorithm_lookup(int alg) 123{ 124 if (alg >= AH_ALG_MAX) 125 return NULL; 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 } 146 return NULL; 147} 148 149size_t 150ah_hdrsiz(struct secasvar *sav) 151{ 152 size_t size; 153 154 if (sav != NULL) { 155 int authsize; 156 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, 157 ("ah_hdrsiz: null xform")); 158 /*XXX not right for null algorithm--does it matter??*/ 159 authsize = AUTHSIZE(sav); 160 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav); 161 } else { 162 /* default guess */ 163 size = sizeof (struct ah) + sizeof (u_int32_t) + 16; 164 } 165 return size; 166} 167 168/* 169 * NB: public for use by esp_init. 170 */ 171int 172ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria) 173{ 174 struct auth_hash *thash; 175 int keylen; 176 177 thash = ah_algorithm_lookup(sav->alg_auth); 178 if (thash == NULL) { 179 DPRINTF(("ah_init: unsupported authentication algorithm %u\n", 180 sav->alg_auth)); 181 return EINVAL; 182 } 183 /* 184 * Verify the replay state block allocation is consistent with 185 * the protocol type. We check here so we can make assumptions 186 * later during protocol processing. 187 */ 188 /* NB: replay state is setup elsewhere (sigh) */ 189 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) { 190 DPRINTF(("ah_init: replay state block inconsistency, " 191 "%s algorithm %s replay state\n", 192 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new", 193 sav->replay == NULL ? "without" : "with")); 194 return EINVAL; 195 } 196 if (sav->key_auth == NULL) { 197 DPRINTF(("ah_init: no authentication key for %s " 198 "algorithm\n", thash->name)); 199 return EINVAL; 200 } 201 keylen = _KEYLEN(sav->key_auth); 202 if (keylen != thash->keysize && thash->keysize != 0) { 203 DPRINTF(("ah_init: invalid keylength %d, algorithm " 204 "%s requires keysize %d\n", 205 keylen, thash->name, thash->keysize)); 206 return EINVAL; 207 } 208 209 sav->tdb_xform = xsp; 210 sav->tdb_authalgxform = thash; 211 212 /* Initialize crypto session. */ 213 bzero(cria, sizeof (*cria)); 214 cria->cri_alg = sav->tdb_authalgxform->type; 215 cria->cri_klen = _KEYBITS(sav->key_auth); 216 cria->cri_key = _KEYBUF(sav->key_auth); 217 218 return 0; 219} 220 221/* 222 * ah_init() is called when an SPI is being set up. 223 */ 224static int 225ah_init(struct secasvar *sav, struct xformsw *xsp) 226{ 227 struct cryptoini cria; 228 int error; 229 230 error = ah_init0(sav, xsp, &cria); 231 return error ? error : 232 crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support); 233} 234 235/* 236 * Paranoia. 237 * 238 * NB: public for use by esp_zeroize (XXX). 239 */ 240int 241ah_zeroize(struct secasvar *sav) 242{ 243 int err; 244 245 if (sav->key_auth) 246 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); 247 248 err = crypto_freesession(sav->tdb_cryptoid); 249 sav->tdb_cryptoid = 0; 250 sav->tdb_authalgxform = NULL; 251 sav->tdb_xform = NULL; 252 return err; 253} 254 255/* 256 * Massage IPv4/IPv6 headers for AH processing. 257 */ 258static int 259ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) 260{ 261 struct mbuf *m = *m0; 262 unsigned char *ptr; 263 int off, count; 264 265#ifdef INET 266 struct ip *ip; 267#endif /* INET */ 268 269#ifdef INET6 270 struct ip6_ext *ip6e; 271 struct ip6_hdr ip6; 272 int alloc, len, ad; 273#endif /* INET6 */ 274 275 switch (proto) { 276#ifdef INET 277 case AF_INET: 278 /* 279 * This is the least painful way of dealing with IPv4 header 280 * and option processing -- just make sure they're in 281 * contiguous memory. 282 */ 283 *m0 = m = m_pullup(m, skip); 284 if (m == NULL) { 285 DPRINTF(("ah_massage_headers: m_pullup failed\n")); 286 return ENOBUFS; 287 } 288 289 /* Fix the IP header */ 290 ip = mtod(m, struct ip *); 291 if (ah_cleartos) 292 ip->ip_tos = 0; 293 ip->ip_ttl = 0; 294 ip->ip_sum = 0; 295 296 /* 297 * On input, fix ip_len which has been byte-swapped 298 * at ip_input(). 299 */ 300/* On FreeBSD, ip_off and ip_len assumed in host endian. */ 301#ifdef __FreeBSD__ 302 #define TOHOST(x) (x) 303#else 304 #define TOHOST(x) (ntohs(x)) 305#endif 306 if (!out) { 307 u_int16_t inlen = ip->ip_len; 308 309 ip->ip_len = htons(TOHOST(ip->ip_len) + skip); 310 DPRINTF(("ip len: skip %d, " 311 "in %d host %d: new: raw %d host %d\n", 312 skip, 313 inlen, TOHOST(inlen), 314 ip->ip_len, ntohs(ip->ip_len))); 315 316 317 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 318 ip->ip_off = htons(TOHOST(ip->ip_off) & IP_DF); 319 else 320 ip->ip_off = 0; 321 } else { 322 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 323 ip->ip_off = htons(ntohs(ip->ip_off) & IP_DF); 324 else 325 ip->ip_off = 0; 326 } 327 328 ptr = mtod(m, unsigned char *) + sizeof(struct ip); 329 330 /* IPv4 option processing */ 331 for (off = sizeof(struct ip); off < skip;) { 332 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP || 333 off + 1 < skip) 334 ; 335 else { 336 DPRINTF(("ah_massage_headers: illegal IPv4 " 337 "option length for option %d\n", 338 ptr[off])); 339 340 m_freem(m); 341 return EINVAL; 342 } 343 344 switch (ptr[off]) { 345 case IPOPT_EOL: 346 off = skip; /* End the loop. */ 347 break; 348 349 case IPOPT_NOP: 350 off++; 351 break; 352 353 case IPOPT_SECURITY: /* 0x82 */ 354 case 0x85: /* Extended security. */ 355 case 0x86: /* Commercial security. */ 356 case 0x94: /* Router alert */ 357 case 0x95: /* RFC1770 */ 358 /* Sanity check for option length. */ 359 if (ptr[off + 1] < 2) { 360 DPRINTF(("ah_massage_headers: " 361 "illegal IPv4 option length for " 362 "option %d\n", ptr[off])); 363 364 m_freem(m); 365 return EINVAL; 366 } 367 368 off += ptr[off + 1]; 369 break; 370 371 case IPOPT_LSRR: 372 case IPOPT_SSRR: 373 /* Sanity check for option length. */ 374 if (ptr[off + 1] < 2) { 375 DPRINTF(("ah_massage_headers: " 376 "illegal IPv4 option length for " 377 "option %d\n", ptr[off])); 378 379 m_freem(m); 380 return EINVAL; 381 } 382 383 /* 384 * On output, if we have either of the 385 * source routing options, we should 386 * swap the destination address of the 387 * IP header with the last address 388 * specified in the option, as that is 389 * what the destination's IP header 390 * will look like. 391 */ 392 if (out) 393 bcopy(ptr + off + ptr[off + 1] - 394 sizeof(struct in_addr), 395 &(ip->ip_dst), sizeof(struct in_addr)); 396 397 /* Fall through */ 398 default: 399 /* Sanity check for option length. */ 400 if (ptr[off + 1] < 2) { 401 DPRINTF(("ah_massage_headers: " 402 "illegal IPv4 option length for " 403 "option %d\n", ptr[off])); 404 m_freem(m); 405 return EINVAL; 406 } 407 408 /* Zeroize all other options. */ 409 count = ptr[off + 1]; 410 bcopy(ipseczeroes, ptr, count); 411 off += count; 412 break; 413 } 414 415 /* Sanity check. */ 416 if (off > skip) { 417 DPRINTF(("ah_massage_headers(): malformed " 418 "IPv4 options header\n")); 419 420 m_freem(m); 421 return EINVAL; 422 } 423 } 424 425 break; 426#endif /* INET */ 427 428#ifdef INET6 429 case AF_INET6: /* Ugly... */ 430 /* Copy and "cook" the IPv6 header. */ 431 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6); 432 433 /* We don't do IPv6 Jumbograms. */ 434 if (ip6.ip6_plen == 0) { 435 DPRINTF(("ah_massage_headers: unsupported IPv6 jumbogram\n")); 436 m_freem(m); 437 return EMSGSIZE; 438 } 439 440 ip6.ip6_flow = 0; 441 ip6.ip6_hlim = 0; 442 ip6.ip6_vfc &= ~IPV6_VERSION_MASK; 443 ip6.ip6_vfc |= IPV6_VERSION; 444 445 /* Scoped address handling. */ 446 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) 447 ip6.ip6_src.s6_addr16[1] = 0; 448 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) 449 ip6.ip6_dst.s6_addr16[1] = 0; 450 451 /* Done with IPv6 header. */ 452 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6); 453 454 /* Let's deal with the remaining headers (if any). */ 455 if (skip - sizeof(struct ip6_hdr) > 0) { 456 if (m->m_len <= skip) { 457 ptr = (unsigned char *) malloc( 458 skip - sizeof(struct ip6_hdr), 459 M_XDATA, M_NOWAIT); 460 if (ptr == NULL) { 461 DPRINTF(("ah_massage_headers: failed " 462 "to allocate memory for IPv6 " 463 "headers\n")); 464 m_freem(m); 465 return ENOBUFS; 466 } 467 468 /* 469 * Copy all the protocol headers after 470 * the IPv6 header. 471 */ 472 m_copydata(m, sizeof(struct ip6_hdr), 473 skip - sizeof(struct ip6_hdr), ptr); 474 alloc = 1; 475 } else { 476 /* No need to allocate memory. */ 477 ptr = mtod(m, unsigned char *) + 478 sizeof(struct ip6_hdr); 479 alloc = 0; 480 } 481 } else 482 break; 483 484 off = ip6.ip6_nxt & 0xff; /* Next header type. */ 485 486 for (len = 0; len < skip - sizeof(struct ip6_hdr);) 487 switch (off) { 488 case IPPROTO_HOPOPTS: 489 case IPPROTO_DSTOPTS: 490 ip6e = (struct ip6_ext *) (ptr + len); 491 492 /* 493 * Process the mutable/immutable 494 * options -- borrows heavily from the 495 * KAME code. 496 */ 497 for (count = len + sizeof(struct ip6_ext); 498 count < len + ((ip6e->ip6e_len + 1) << 3);) { 499 if (ptr[count] == IP6OPT_PAD1) { 500 count++; 501 continue; /* Skip padding. */ 502 } 503 504 /* Sanity check. */ 505 if (count > len + 506 ((ip6e->ip6e_len + 1) << 3)) { 507 m_freem(m); 508 509 /* Free, if we allocated. */ 510 if (alloc) 511 FREE(ptr, M_XDATA); 512 return EINVAL; 513 } 514 515 ad = ptr[count + 1]; 516 517 /* If mutable option, zeroize. */ 518 if (ptr[count] & IP6OPT_MUTABLE) 519 bcopy(ipseczeroes, ptr + count, 520 ptr[count + 1]); 521 522 count += ad; 523 524 /* Sanity check. */ 525 if (count > 526 skip - sizeof(struct ip6_hdr)) { 527 m_freem(m); 528 529 /* Free, if we allocated. */ 530 if (alloc) 531 FREE(ptr, M_XDATA); 532 return EINVAL; 533 } 534 } 535 536 /* Advance. */ 537 len += ((ip6e->ip6e_len + 1) << 3); 538 off = ip6e->ip6e_nxt; 539 break; 540 541 case IPPROTO_ROUTING: 542 /* 543 * Always include routing headers in 544 * computation. 545 */ 546 ip6e = (struct ip6_ext *) (ptr + len); 547 len += ((ip6e->ip6e_len + 1) << 3); 548 off = ip6e->ip6e_nxt; 549 break; 550 551 default: 552 DPRINTF(("ah_massage_headers: unexpected " 553 "IPv6 header type %d", off)); 554 if (alloc) 555 FREE(ptr, M_XDATA); 556 m_freem(m); 557 return EINVAL; 558 } 559 560 /* Copyback and free, if we allocated. */ 561 if (alloc) { 562 m_copyback(m, sizeof(struct ip6_hdr), 563 skip - sizeof(struct ip6_hdr), ptr); 564 free(ptr, M_XDATA); 565 } 566 567 break; 568#endif /* INET6 */ 569 } 570 571 return 0; 572} 573 574/* 575 * ah_input() gets called to verify that an input packet 576 * passes authentication. 577 */ 578static int 579ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 580{ 581 struct auth_hash *ahx; 582 struct tdb_ident *tdbi; 583 struct tdb_crypto *tc; 584 struct m_tag *mtag; 585 struct newah *ah; 586 int hl, rplen, authsize; 587 588 struct cryptodesc *crda; 589 struct cryptop *crp; 590 591 IPSEC_SPLASSERT_SOFTNET("ah_input"); 592 593 IPSEC_ASSERT(sav != NULL, ("ah_input: null SA")); 594 IPSEC_ASSERT(sav->key_auth != NULL, 595 ("ah_input: null authentication key")); 596 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, 597 ("ah_input: null authentication xform")); 598 599 /* Figure out header size. */ 600 rplen = HDRSIZE(sav); 601 602 /* XXX don't pullup, just copy header */ 603 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 604 if (ah == NULL) { 605 DPRINTF(("ah_input: cannot pullup header\n")); 606 ahstat.ahs_hdrops++; /*XXX*/ 607 m_freem(m); 608 return ENOBUFS; 609 } 610 611 /* Check replay window, if applicable. */ 612 if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) { 613 ahstat.ahs_replay++; 614 DPRINTF(("ah_input: packet replay failure: %s\n", 615 ipsec_logsastr(sav))); 616 m_freem(m); 617 return ENOBUFS; 618 } 619 620 /* Verify AH header length. */ 621 hl = ah->ah_len * sizeof (u_int32_t); 622 ahx = sav->tdb_authalgxform; 623 authsize = AUTHSIZE(sav); 624 if (hl != authsize + rplen - sizeof (struct ah)) { 625 DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)" 626 " for packet in SA %s/%08lx\n", 627 hl, (u_long) (authsize + rplen - sizeof (struct ah)), 628 ipsec_address(&sav->sah->saidx.dst), 629 (u_long) ntohl(sav->spi))); 630 ahstat.ahs_badauthl++; 631 m_freem(m); 632 return EACCES; 633 } 634 ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl; 635 DPRINTF(("ah_input skip %d poff %d\n" 636 "len: hl %d authsize %d rpl %d expect %d\n", 637 skip, protoff, 638 hl, authsize, rplen, 639 authsize + rplen - sizeof(struct ah))); 640 641 /* Get crypto descriptors. */ 642 crp = crypto_getreq(1); 643 if (crp == NULL) { 644 DPRINTF(("ah_input: failed to acquire crypto descriptor\n")); 645 ahstat.ahs_crypto++; 646 m_freem(m); 647 return ENOBUFS; 648 } 649 650 crda = crp->crp_desc; 651 IPSEC_ASSERT(crda != NULL, ("ah_input: null crypto descriptor")); 652 653 crda->crd_skip = 0; 654 crda->crd_len = m->m_pkthdr.len; 655 crda->crd_inject = skip + rplen; 656 657 /* Authentication operation. */ 658 crda->crd_alg = ahx->type; 659 crda->crd_key = _KEYBUF(sav->key_auth); 660 crda->crd_klen = _KEYBITS(sav->key_auth); 661 662 /* Find out if we've already done crypto. */ 663 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 664 mtag != NULL; 665 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 666 tdbi = (struct tdb_ident *) (mtag + 1); 667 if (tdbi->proto == sav->sah->saidx.proto && 668 tdbi->spi == sav->spi && 669 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 670 sizeof (union sockaddr_union))) 671 break; 672 } 673 674 /* Allocate IPsec-specific opaque crypto info. */ 675 if (mtag == NULL) { 676 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) + 677 skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO); 678 } else { 679 /* Hash verification has already been done successfully. */ 680 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto), 681 M_XDATA, M_NOWAIT|M_ZERO); 682 } 683 if (tc == NULL) { 684 DPRINTF(("ah_input: failed to allocate tdb_crypto\n")); 685 ahstat.ahs_crypto++; 686 crypto_freereq(crp); 687 m_freem(m); 688 return ENOBUFS; 689 } 690 691 /* Only save information if crypto processing is needed. */ 692 if (mtag == NULL) { 693 int error; 694 695 /* 696 * Save the authenticator, the skipped portion of the packet, 697 * and the AH header. 698 */ 699 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1)); 700 701 { 702 u_int8_t *pppp = ((caddr_t)(tc+1))+skip+rplen; 703 DPRINTF(("ah_input: zeroing %d bytes of authent " \ 704 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", 705 authsize, 706 pppp[0], pppp[1], pppp[2], pppp[3], 707 pppp[4], pppp[5], pppp[6], pppp[7], 708 pppp[8], pppp[9], pppp[10], pppp[11])); 709 } 710 711 /* Zeroize the authenticator on the packet. */ 712 m_copyback(m, skip + rplen, authsize, ipseczeroes); 713 714 /* "Massage" the packet headers for crypto processing. */ 715 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 716 skip, ahx->type, 0); 717 if (error != 0) { 718 /* NB: mbuf is free'd by ah_massage_headers */ 719 ahstat.ahs_hdrops++; 720 free(tc, M_XDATA); 721 crypto_freereq(crp); 722 return error; 723 } 724 } 725 726 /* Crypto operation descriptor. */ 727 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 728 crp->crp_flags = CRYPTO_F_IMBUF; 729 crp->crp_buf = (caddr_t) m; 730 crp->crp_callback = ah_input_cb; 731 crp->crp_sid = sav->tdb_cryptoid; 732 crp->crp_opaque = (caddr_t) tc; 733 734 /* These are passed as-is to the callback. */ 735 tc->tc_spi = sav->spi; 736 tc->tc_dst = sav->sah->saidx.dst; 737 tc->tc_proto = sav->sah->saidx.proto; 738 tc->tc_nxt = ah->ah_nxt; 739 tc->tc_protoff = protoff; 740 tc->tc_skip = skip; 741 tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */ 742 743 DPRINTF(("ah: hash over %d bytes, skip %d: " 744 "crda len %d skip %d inject %d\n", 745 crp->crp_ilen, tc->tc_skip, 746 crda->crd_len, crda->crd_skip, crda->crd_inject)); 747 748 if (mtag == NULL) 749 return crypto_dispatch(crp); 750 else 751 return ah_input_cb(crp); 752} 753 754#ifdef INET6 755#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 756 if (saidx->dst.sa.sa_family == AF_INET6) { \ 757 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 758 } else { \ 759 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 760 } \ 761} while (0) 762#else 763#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 764 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 765#endif 766 767/* 768 * AH input callback from the crypto driver. 769 */ 770static int 771ah_input_cb(struct cryptop *crp) 772{ 773 int rplen, error, skip, protoff; 774 unsigned char calc[AH_ALEN_MAX]; 775 struct mbuf *m; 776 struct cryptodesc *crd; 777 struct auth_hash *ahx; 778 struct tdb_crypto *tc; 779 struct m_tag *mtag; 780 struct secasvar *sav; 781 struct secasindex *saidx; 782 u_int8_t nxt; 783 caddr_t ptr; 784 int s, authsize; 785 786 crd = crp->crp_desc; 787 788 tc = (struct tdb_crypto *) crp->crp_opaque; 789 IPSEC_ASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!")); 790 skip = tc->tc_skip; 791 nxt = tc->tc_nxt; 792 protoff = tc->tc_protoff; 793 mtag = (struct m_tag *) tc->tc_ptr; 794 m = (struct mbuf *) crp->crp_buf; 795 796 s = splsoftnet(); 797 798 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 799 if (sav == NULL) { 800 ahstat.ahs_notdb++; 801 DPRINTF(("ah_input_cb: SA expired while in crypto\n")); 802 error = ENOBUFS; /*XXX*/ 803 goto bad; 804 } 805 806 saidx = &sav->sah->saidx; 807 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 808 saidx->dst.sa.sa_family == AF_INET6, 809 ("ah_input_cb: unexpected protocol family %u", 810 saidx->dst.sa.sa_family)); 811 812 ahx = (struct auth_hash *) sav->tdb_authalgxform; 813 814 /* Check for crypto errors. */ 815 if (crp->crp_etype) { 816 if (sav->tdb_cryptoid != 0) 817 sav->tdb_cryptoid = crp->crp_sid; 818 819 if (crp->crp_etype == EAGAIN) 820 return crypto_dispatch(crp); 821 822 ahstat.ahs_noxform++; 823 DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype)); 824 error = crp->crp_etype; 825 goto bad; 826 } else { 827 ahstat.ahs_hist[sav->alg_auth]++; 828 crypto_freereq(crp); /* No longer needed. */ 829 crp = NULL; 830 } 831 832 /* Shouldn't happen... */ 833 if (m == NULL) { 834 ahstat.ahs_crypto++; 835 DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n")); 836 error = EINVAL; 837 goto bad; 838 } 839 840 /* Figure out header size. */ 841 rplen = HDRSIZE(sav); 842 authsize = AUTHSIZE(sav); 843 844 if (ipsec_debug) 845 bzero(calc, sizeof(calc)); 846 847 /* Copy authenticator off the packet. */ 848 m_copydata(m, skip + rplen, authsize, calc); 849 850 /* 851 * If we have an mtag, we don't need to verify the authenticator -- 852 * it has been verified by an IPsec-aware NIC. 853 */ 854 if (mtag == NULL) { 855 ptr = (caddr_t) (tc + 1); 856 857 /* Verify authenticator. */ 858 if (bcmp(ptr + skip + rplen, calc, authsize)) { 859 u_int8_t *pppp = ptr + skip+rplen; 860 DPRINTF(("ah_input: authentication hash mismatch " \ 861 "over %d bytes " \ 862 "for packet in SA %s/%08lx:\n" \ 863 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \ 864 "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", 865 authsize, 866 ipsec_address(&saidx->dst), 867 (u_long) ntohl(sav->spi), 868 calc[0], calc[1], calc[2], calc[3], 869 calc[4], calc[5], calc[6], calc[7], 870 calc[8], calc[9], calc[10], calc[11], 871 pppp[0], pppp[1], pppp[2], pppp[3], 872 pppp[4], pppp[5], pppp[6], pppp[7], 873 pppp[8], pppp[9], pppp[10], pppp[11] 874 )); 875 ahstat.ahs_badauth++; 876 error = EACCES; 877 goto bad; 878 } 879 880 /* Fix the Next Protocol field. */ 881 ((u_int8_t *) ptr)[protoff] = nxt; 882 883 /* Copyback the saved (uncooked) network headers. */ 884 m_copyback(m, 0, skip, ptr); 885 } else { 886 /* Fix the Next Protocol field. */ 887 m_copyback(m, protoff, sizeof(u_int8_t), &nxt); 888 } 889 890 free(tc, M_XDATA), tc = NULL; /* No longer needed */ 891 892 /* 893 * Header is now authenticated. 894 */ 895 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM; 896 897 /* 898 * Update replay sequence number, if appropriate. 899 */ 900 if (sav->replay) { 901 u_int32_t seq; 902 903 m_copydata(m, skip + offsetof(struct newah, ah_seq), 904 sizeof (seq), (caddr_t) &seq); 905 if (ipsec_updatereplay(ntohl(seq), sav)) { 906 ahstat.ahs_replay++; 907 error = ENOBUFS; /*XXX as above*/ 908 goto bad; 909 } 910 } 911 912 /* 913 * Remove the AH header and authenticator from the mbuf. 914 */ 915 error = m_striphdr(m, skip, rplen + authsize); 916 if (error) { 917 DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n", 918 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 919 920 ahstat.ahs_hdrops++; 921 goto bad; 922 } 923 924 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 925 926 KEY_FREESAV(&sav); 927 splx(s); 928 return error; 929bad: 930 if (sav) 931 KEY_FREESAV(&sav); 932 splx(s); 933 if (m != NULL) 934 m_freem(m); 935 if (tc != NULL) 936 free(tc, M_XDATA); 937 if (crp != NULL) 938 crypto_freereq(crp); 939 return error; 940} 941 942/* 943 * AH output routine, called by ipsec[46]_process_packet(). 944 */ 945static int 946ah_output( 947 struct mbuf *m, 948 struct ipsecrequest *isr, 949 struct mbuf **mp, 950 int skip, 951 int protoff) 952{ 953 struct secasvar *sav; 954 struct auth_hash *ahx; 955 struct cryptodesc *crda; 956 struct tdb_crypto *tc; 957 struct mbuf *mi; 958 struct cryptop *crp; 959 u_int16_t iplen; 960 int error, rplen, authsize, maxpacketsize, roff; 961 u_int8_t prot; 962 struct newah *ah; 963 964 IPSEC_SPLASSERT_SOFTNET("ah_output"); 965 966 sav = isr->sav; 967 IPSEC_ASSERT(sav != NULL, ("ah_output: null SA")); 968 ahx = sav->tdb_authalgxform; 969 IPSEC_ASSERT(ahx != NULL, ("ah_output: null authentication xform")); 970 971 ahstat.ahs_output++; 972 973 /* Figure out header size. */ 974 rplen = HDRSIZE(sav); 975 976 /* Check for maximum packet size violations. */ 977 switch (sav->sah->saidx.dst.sa.sa_family) { 978#ifdef INET 979 case AF_INET: 980 maxpacketsize = IP_MAXPACKET; 981 break; 982#endif /* INET */ 983#ifdef INET6 984 case AF_INET6: 985 maxpacketsize = IPV6_MAXPACKET; 986 break; 987#endif /* INET6 */ 988 default: 989 DPRINTF(("ah_output: unknown/unsupported protocol " 990 "family %u, SA %s/%08lx\n", 991 sav->sah->saidx.dst.sa.sa_family, 992 ipsec_address(&sav->sah->saidx.dst), 993 (u_long) ntohl(sav->spi))); 994 ahstat.ahs_nopf++; 995 error = EPFNOSUPPORT; 996 goto bad; 997 } 998 authsize = AUTHSIZE(sav); 999 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 1000 DPRINTF(("ah_output: packet in SA %s/%08lx got too big " 1001 "(len %u, max len %u)\n", 1002 ipsec_address(&sav->sah->saidx.dst), 1003 (u_long) ntohl(sav->spi), 1004 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 1005 ahstat.ahs_toobig++; 1006 error = EMSGSIZE; 1007 goto bad; 1008 } 1009 1010 /* Update the counters. */ 1011 ahstat.ahs_obytes += m->m_pkthdr.len - skip; 1012 1013 m = m_clone(m); 1014 if (m == NULL) { 1015 DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n", 1016 ipsec_address(&sav->sah->saidx.dst), 1017 (u_long) ntohl(sav->spi))); 1018 ahstat.ahs_hdrops++; 1019 error = ENOBUFS; 1020 goto bad; 1021 } 1022 1023 /* Inject AH header. */ 1024 mi = m_makespace(m, skip, rplen + authsize, &roff); 1025 if (mi == NULL) { 1026 DPRINTF(("ah_output: failed to inject %u byte AH header for SA " 1027 "%s/%08lx\n", 1028 rplen + authsize, 1029 ipsec_address(&sav->sah->saidx.dst), 1030 (u_long) ntohl(sav->spi))); 1031 ahstat.ahs_hdrops++; /*XXX differs from openbsd */ 1032 error = ENOBUFS; 1033 goto bad; 1034 } 1035 1036 /* 1037 * The AH header is guaranteed by m_makespace() to be in 1038 * contiguous memory, at roff bytes offset into the returned mbuf. 1039 */ 1040 ah = (struct newah *)(mtod(mi, caddr_t) + roff); 1041 1042 /* Initialize the AH header. */ 1043 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt); 1044 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t); 1045 ah->ah_reserve = 0; 1046 ah->ah_spi = sav->spi; 1047 1048 /* Zeroize authenticator. */ 1049 m_copyback(m, skip + rplen, authsize, ipseczeroes); 1050 1051 /* Insert packet replay counter, as requested. */ 1052 if (sav->replay) { 1053 if (sav->replay->count == ~0 && 1054 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 1055 DPRINTF(("ah_output: replay counter wrapped for SA " 1056 "%s/%08lx\n", 1057 ipsec_address(&sav->sah->saidx.dst), 1058 (u_long) ntohl(sav->spi))); 1059 ahstat.ahs_wrap++; 1060 error = EINVAL; 1061 goto bad; 1062 } 1063 sav->replay->count++; 1064 ah->ah_seq = htonl(sav->replay->count); 1065 } 1066 1067 /* Get crypto descriptors. */ 1068 crp = crypto_getreq(1); 1069 if (crp == NULL) { 1070 DPRINTF(("ah_output: failed to acquire crypto descriptors\n")); 1071 ahstat.ahs_crypto++; 1072 error = ENOBUFS; 1073 goto bad; 1074 } 1075 1076 crda = crp->crp_desc; 1077 1078 crda->crd_skip = 0; 1079 crda->crd_inject = skip + rplen; 1080 crda->crd_len = m->m_pkthdr.len; 1081 1082 /* Authentication operation. */ 1083 crda->crd_alg = ahx->type; 1084 crda->crd_key = _KEYBUF(sav->key_auth); 1085 crda->crd_klen = _KEYBITS(sav->key_auth); 1086 1087 /* Allocate IPsec-specific opaque crypto info. */ 1088 tc = (struct tdb_crypto *) malloc( 1089 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO); 1090 if (tc == NULL) { 1091 crypto_freereq(crp); 1092 DPRINTF(("ah_output: failed to allocate tdb_crypto\n")); 1093 ahstat.ahs_crypto++; 1094 error = ENOBUFS; 1095 goto bad; 1096 } 1097 1098 /* Save the skipped portion of the packet. */ 1099 m_copydata(m, 0, skip, (caddr_t) (tc + 1)); 1100 1101 /* 1102 * Fix IP header length on the header used for 1103 * authentication. We don't need to fix the original 1104 * header length as it will be fixed by our caller. 1105 */ 1106 switch (sav->sah->saidx.dst.sa.sa_family) { 1107#ifdef INET 1108 case AF_INET: 1109 bcopy(((caddr_t)(tc + 1)) + 1110 offsetof(struct ip, ip_len), 1111 (caddr_t) &iplen, sizeof(u_int16_t)); 1112 iplen = htons(ntohs(iplen) + rplen + authsize); 1113 m_copyback(m, offsetof(struct ip, ip_len), 1114 sizeof(u_int16_t), (caddr_t) &iplen); 1115 break; 1116#endif /* INET */ 1117 1118#ifdef INET6 1119 case AF_INET6: 1120 bcopy(((caddr_t)(tc + 1)) + 1121 offsetof(struct ip6_hdr, ip6_plen), 1122 (caddr_t) &iplen, sizeof(u_int16_t)); 1123 iplen = htons(ntohs(iplen) + rplen + authsize); 1124 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), 1125 sizeof(u_int16_t), (caddr_t) &iplen); 1126 break; 1127#endif /* INET6 */ 1128 } 1129 1130 /* Fix the Next Header field in saved header. */ 1131 ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH; 1132 1133 /* Update the Next Protocol field in the IP header. */ 1134 prot = IPPROTO_AH; 1135 m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot); 1136 1137 /* "Massage" the packet headers for crypto processing. */ 1138 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1139 skip, ahx->type, 1); 1140 if (error != 0) { 1141 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1142 free(tc, M_XDATA); 1143 crypto_freereq(crp); 1144 goto bad; 1145 } 1146 1147 /* Crypto operation descriptor. */ 1148 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1149 crp->crp_flags = CRYPTO_F_IMBUF; 1150 crp->crp_buf = (caddr_t) m; 1151 crp->crp_callback = ah_output_cb; 1152 crp->crp_sid = sav->tdb_cryptoid; 1153 crp->crp_opaque = (caddr_t) tc; 1154 1155 /* These are passed as-is to the callback. */ 1156 tc->tc_isr = isr; 1157 tc->tc_spi = sav->spi; 1158 tc->tc_dst = sav->sah->saidx.dst; 1159 tc->tc_proto = sav->sah->saidx.proto; 1160 tc->tc_skip = skip; 1161 tc->tc_protoff = protoff; 1162 1163 return crypto_dispatch(crp); 1164bad: 1165 if (m) 1166 m_freem(m); 1167 return (error); 1168} 1169 1170/* 1171 * AH output callback from the crypto driver. 1172 */ 1173static int 1174ah_output_cb(struct cryptop *crp) 1175{ 1176 int skip, protoff, error; 1177 struct tdb_crypto *tc; 1178 struct ipsecrequest *isr; 1179 struct secasvar *sav; 1180 struct mbuf *m; 1181 caddr_t ptr; 1182 int s, err; 1183 1184 tc = (struct tdb_crypto *) crp->crp_opaque; 1185 IPSEC_ASSERT(tc != NULL, ("ah_output_cb: null opaque data area!")); 1186 skip = tc->tc_skip; 1187 protoff = tc->tc_protoff; 1188 ptr = (caddr_t) (tc + 1); 1189 m = (struct mbuf *) crp->crp_buf; 1190 1191 s = splsoftnet(); 1192 1193 isr = tc->tc_isr; 1194 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 1195 if (sav == NULL) { 1196 ahstat.ahs_notdb++; 1197 DPRINTF(("ah_output_cb: SA expired while in crypto\n")); 1198 error = ENOBUFS; /*XXX*/ 1199 goto bad; 1200 } 1201 IPSEC_ASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n")); 1202 1203 /* Check for crypto errors. */ 1204 if (crp->crp_etype) { 1205 if (sav->tdb_cryptoid != 0) 1206 sav->tdb_cryptoid = crp->crp_sid; 1207 1208 if (crp->crp_etype == EAGAIN) { 1209 KEY_FREESAV(&sav); 1210 splx(s); 1211 return crypto_dispatch(crp); 1212 } 1213 1214 ahstat.ahs_noxform++; 1215 DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype)); 1216 error = crp->crp_etype; 1217 goto bad; 1218 } 1219 1220 /* Shouldn't happen... */ 1221 if (m == NULL) { 1222 ahstat.ahs_crypto++; 1223 DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n")); 1224 error = EINVAL; 1225 goto bad; 1226 } 1227 ahstat.ahs_hist[sav->alg_auth]++; 1228 1229 /* 1230 * Copy original headers (with the new protocol number) back 1231 * in place. 1232 */ 1233 m_copyback(m, 0, skip, ptr); 1234 1235 /* No longer needed. */ 1236 free(tc, M_XDATA); 1237 crypto_freereq(crp); 1238 1239 /* NB: m is reclaimed by ipsec_process_done. */ 1240 err = ipsec_process_done(m, isr); 1241 KEY_FREESAV(&sav); 1242 splx(s); 1243 return err; 1244bad: 1245 if (sav) 1246 KEY_FREESAV(&sav); 1247 splx(s); 1248 if (m) 1249 m_freem(m); 1250 free(tc, M_XDATA); 1251 crypto_freereq(crp); 1252 return error; 1253} 1254 1255static struct xformsw ah_xformsw = { 1256 XF_AH, XFT_AUTH, "IPsec AH", 1257 ah_init, ah_zeroize, ah_input, ah_output, 1258}; 1259 1260INITFN void 1261ah_attach(void) 1262{ 1263 xform_register(&ah_xformsw); 1264} 1265 1266#ifdef __FreeBSD__ 1267SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL); 1268#endif 1269