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sys/netipsec/xform_ah.c
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1 /* $FreeBSD$ */ 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 #include "opt_ipsec.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/mbuf.h> 46 #include <sys/socket.h> 47 #include <sys/syslog.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/mutex.h> 51 #include <sys/sysctl.h> 52 53 #include <net/if.h> 54 #include <net/vnet.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_ecn.h> 60 #include <netinet/ip6.h> 61 62 #include <netipsec/ipsec.h> 63 #include <netipsec/ah.h> 64 #include <netipsec/ah_var.h> 65 #include <netipsec/xform.h> 66 67 #ifdef INET6 68 #include <netinet6/ip6_var.h> 69 #include <netipsec/ipsec6.h> 70 #include <netinet6/ip6_ecn.h> 71 #endif 72 73 #include <netipsec/key.h> 74 #include <netipsec/key_debug.h> 75 76 #include <opencrypto/cryptodev.h> 77 78 /* 79 * Return header size in bytes. The old protocol did not support 80 * the replay counter; the new protocol always includes the counter. 81 */ 82 #define HDRSIZE(sav) \ 83 (((sav)->flags & SADB_X_EXT_OLD) ? \ 84 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t)) 85 /* 86 * Return authenticator size in bytes, based on a field in the 87 * algorithm descriptor. 88 */ 89 #define AUTHSIZE(sav) ((sav->flags & SADB_X_EXT_OLD) ? 16 : \ 90 xform_ah_authsize((sav)->tdb_authalgxform)) 91 92 VNET_DEFINE(int, ah_enable) = 1; /* control flow of packets with AH */ 93 VNET_DEFINE(int, ah_cleartos) = 1; /* clear ip_tos when doing AH calc */ 94 VNET_PCPUSTAT_DEFINE(struct ahstat, ahstat); 95 VNET_PCPUSTAT_SYSINIT(ahstat); 96 97 #ifdef VIMAGE 98 VNET_PCPUSTAT_SYSUNINIT(ahstat); 99 #endif /* VIMAGE */ 100 101 #ifdef INET 102 SYSCTL_DECL(_net_inet_ah); 103 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_enable, 104 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_enable), 0, ""); 105 SYSCTL_INT(_net_inet_ah, OID_AUTO, ah_cleartos, 106 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0, ""); 107 SYSCTL_VNET_PCPUSTAT(_net_inet_ah, IPSECCTL_STATS, stats, struct ahstat, 108 ahstat, "AH statistics (struct ahstat, netipsec/ah_var.h)"); 109 #endif 110 111 static unsigned char ipseczeroes[256]; /* larger than an ip6 extension hdr */ 112 static struct timeval md5warn, ripewarn, kpdkmd5warn, kpdksha1warn; 113 114 static int ah_input_cb(struct cryptop*); 115 static int ah_output_cb(struct cryptop*); 116 117 int 118 xform_ah_authsize(const struct auth_hash *esph) 119 { 120 int alen; 121 122 if (esph == NULL) 123 return 0; 124 125 switch (esph->type) { 126 case CRYPTO_SHA2_256_HMAC: 127 case CRYPTO_SHA2_384_HMAC: 128 case CRYPTO_SHA2_512_HMAC: 129 alen = esph->hashsize / 2; /* RFC4868 2.3 */ 130 break; 131 132 case CRYPTO_AES_128_NIST_GMAC: 133 case CRYPTO_AES_192_NIST_GMAC: 134 case CRYPTO_AES_256_NIST_GMAC: 135 alen = esph->hashsize; 136 break; 137 138 default: 139 alen = AH_HMAC_HASHLEN; 140 break; 141 } 142 143 return alen; 144 } 145 146 size_t 147 ah_hdrsiz(struct secasvar *sav) 148 { 149 size_t size; 150 151 if (sav != NULL) { 152 int authsize; 153 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, ("null xform")); 154 /*XXX not right for null algorithm--does it matter??*/ 155 authsize = AUTHSIZE(sav); 156 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav); 157 } else { 158 /* default guess */ 159 size = sizeof (struct ah) + sizeof (u_int32_t) + 16; 160 } 161 return size; 162 } 163 164 /* 165 * NB: public for use by esp_init. 166 */ 167 int 168 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria) 169 { 170 const struct auth_hash *thash; 171 int keylen; 172 173 thash = auth_algorithm_lookup(sav->alg_auth); 174 if (thash == NULL) { 175 DPRINTF(("%s: unsupported authentication algorithm %u\n", 176 __func__, sav->alg_auth)); 177 return EINVAL; 178 } 179 180 switch (sav->alg_auth) { 181 case SADB_AALG_MD5HMAC: 182 if (ratecheck(&md5warn, &ipsec_warn_interval)) 183 gone_in(13, "MD5-HMAC authenticator for IPsec"); 184 break; 185 case SADB_X_AALG_RIPEMD160HMAC: 186 if (ratecheck(&ripewarn, &ipsec_warn_interval)) 187 gone_in(13, "RIPEMD160-HMAC authenticator for IPsec"); 188 break; 189 case SADB_X_AALG_MD5: 190 if (ratecheck(&kpdkmd5warn, &ipsec_warn_interval)) 191 gone_in(13, "Keyed-MD5 authenticator for IPsec"); 192 break; 193 case SADB_X_AALG_SHA: 194 if (ratecheck(&kpdksha1warn, &ipsec_warn_interval)) 195 gone_in(13, "Keyed-SHA1 authenticator for IPsec"); 196 break; 197 } 198 199 /* 200 * Verify the replay state block allocation is consistent with 201 * the protocol type. We check here so we can make assumptions 202 * later during protocol processing. 203 */ 204 /* NB: replay state is setup elsewhere (sigh) */ 205 if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) { 206 DPRINTF(("%s: replay state block inconsistency, " 207 "%s algorithm %s replay state\n", __func__, 208 (sav->flags & SADB_X_EXT_OLD) ? "old" : "new", 209 sav->replay == NULL ? "without" : "with")); 210 return EINVAL; 211 } 212 if (sav->key_auth == NULL) { 213 DPRINTF(("%s: no authentication key for %s algorithm\n", 214 __func__, thash->name)); 215 return EINVAL; 216 } 217 keylen = _KEYLEN(sav->key_auth); 218 if (keylen != thash->keysize && thash->keysize != 0) { 219 DPRINTF(("%s: invalid keylength %d, algorithm %s requires " 220 "keysize %d\n", __func__, 221 keylen, thash->name, thash->keysize)); 222 return EINVAL; 223 } 224 225 sav->tdb_xform = xsp; 226 sav->tdb_authalgxform = thash; 227 228 /* Initialize crypto session. */ 229 bzero(cria, sizeof (*cria)); 230 cria->cri_alg = sav->tdb_authalgxform->type; 231 cria->cri_klen = _KEYBITS(sav->key_auth); 232 cria->cri_key = sav->key_auth->key_data; 233 cria->cri_mlen = AUTHSIZE(sav); 234 235 return 0; 236 } 237 238 /* 239 * ah_init() is called when an SPI is being set up. 240 */ 241 static int 242 ah_init(struct secasvar *sav, struct xformsw *xsp) 243 { 244 struct cryptoini cria; 245 int error; 246 247 error = ah_init0(sav, xsp, &cria); 248 return error ? error : 249 crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support); 250 } 251 252 /* 253 * Paranoia. 254 * 255 * NB: public for use by esp_zeroize (XXX). 256 */ 257 int 258 ah_zeroize(struct secasvar *sav) 259 { 260 int err; 261 262 if (sav->key_auth) 263 bzero(sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 264 265 err = crypto_freesession(sav->tdb_cryptoid); 266 sav->tdb_cryptoid = 0; 267 sav->tdb_authalgxform = NULL; 268 sav->tdb_xform = NULL; 269 return err; 270 } 271 272 /* 273 * Massage IPv4/IPv6 headers for AH processing. 274 */ 275 static int 276 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out) 277 { 278 struct mbuf *m = *m0; 279 unsigned char *ptr; 280 int off, count; 281 282 #ifdef INET 283 struct ip *ip; 284 #endif /* INET */ 285 286 #ifdef INET6 287 struct ip6_ext *ip6e; 288 struct ip6_hdr ip6; 289 int ad, alloc, nxt, noff; 290 #endif /* INET6 */ 291 292 switch (proto) { 293 #ifdef INET 294 case AF_INET: 295 /* 296 * This is the least painful way of dealing with IPv4 header 297 * and option processing -- just make sure they're in 298 * contiguous memory. 299 */ 300 *m0 = m = m_pullup(m, skip); 301 if (m == NULL) { 302 DPRINTF(("%s: m_pullup failed\n", __func__)); 303 return ENOBUFS; 304 } 305 306 /* Fix the IP header */ 307 ip = mtod(m, struct ip *); 308 if (V_ah_cleartos) 309 ip->ip_tos = 0; 310 ip->ip_ttl = 0; 311 ip->ip_sum = 0; 312 313 if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK) 314 ip->ip_off &= htons(IP_DF); 315 else 316 ip->ip_off = htons(0); 317 318 ptr = mtod(m, unsigned char *); 319 320 /* IPv4 option processing */ 321 for (off = sizeof(struct ip); off < skip;) { 322 if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP || 323 off + 1 < skip) 324 ; 325 else { 326 DPRINTF(("%s: illegal IPv4 option length for " 327 "option %d\n", __func__, ptr[off])); 328 329 m_freem(m); 330 return EINVAL; 331 } 332 333 switch (ptr[off]) { 334 case IPOPT_EOL: 335 off = skip; /* End the loop. */ 336 break; 337 338 case IPOPT_NOP: 339 off++; 340 break; 341 342 case IPOPT_SECURITY: /* 0x82 */ 343 case 0x85: /* Extended security. */ 344 case 0x86: /* Commercial security. */ 345 case 0x94: /* Router alert */ 346 case 0x95: /* RFC1770 */ 347 /* Sanity check for option length. */ 348 if (ptr[off + 1] < 2) { 349 DPRINTF(("%s: illegal IPv4 option " 350 "length for option %d\n", 351 __func__, ptr[off])); 352 353 m_freem(m); 354 return EINVAL; 355 } 356 357 off += ptr[off + 1]; 358 break; 359 360 case IPOPT_LSRR: 361 case IPOPT_SSRR: 362 /* Sanity check for option length. */ 363 if (ptr[off + 1] < 2) { 364 DPRINTF(("%s: illegal IPv4 option " 365 "length for option %d\n", 366 __func__, ptr[off])); 367 368 m_freem(m); 369 return EINVAL; 370 } 371 372 /* 373 * On output, if we have either of the 374 * source routing options, we should 375 * swap the destination address of the 376 * IP header with the last address 377 * specified in the option, as that is 378 * what the destination's IP header 379 * will look like. 380 */ 381 if (out) 382 bcopy(ptr + off + ptr[off + 1] - 383 sizeof(struct in_addr), 384 &(ip->ip_dst), sizeof(struct in_addr)); 385 386 /* Fall through */ 387 default: 388 /* Sanity check for option length. */ 389 if (ptr[off + 1] < 2) { 390 DPRINTF(("%s: illegal IPv4 option " 391 "length for option %d\n", 392 __func__, ptr[off])); 393 m_freem(m); 394 return EINVAL; 395 } 396 397 /* Zeroize all other options. */ 398 count = ptr[off + 1]; 399 bcopy(ipseczeroes, ptr + off, count); 400 off += count; 401 break; 402 } 403 404 /* Sanity check. */ 405 if (off > skip) { 406 DPRINTF(("%s: malformed IPv4 options header\n", 407 __func__)); 408 409 m_freem(m); 410 return EINVAL; 411 } 412 } 413 414 break; 415 #endif /* INET */ 416 417 #ifdef INET6 418 case AF_INET6: /* Ugly... */ 419 /* Copy and "cook" the IPv6 header. */ 420 m_copydata(m, 0, sizeof(ip6), (caddr_t) &ip6); 421 422 /* We don't do IPv6 Jumbograms. */ 423 if (ip6.ip6_plen == 0) { 424 DPRINTF(("%s: unsupported IPv6 jumbogram\n", __func__)); 425 m_freem(m); 426 return EMSGSIZE; 427 } 428 429 ip6.ip6_flow = 0; 430 ip6.ip6_hlim = 0; 431 ip6.ip6_vfc &= ~IPV6_VERSION_MASK; 432 ip6.ip6_vfc |= IPV6_VERSION; 433 434 /* Scoped address handling. */ 435 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src)) 436 ip6.ip6_src.s6_addr16[1] = 0; 437 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst)) 438 ip6.ip6_dst.s6_addr16[1] = 0; 439 440 /* Done with IPv6 header. */ 441 m_copyback(m, 0, sizeof(struct ip6_hdr), (caddr_t) &ip6); 442 443 /* Let's deal with the remaining headers (if any). */ 444 if (skip - sizeof(struct ip6_hdr) > 0) { 445 if (m->m_len <= skip) { 446 ptr = (unsigned char *) malloc( 447 skip - sizeof(struct ip6_hdr), 448 M_XDATA, M_NOWAIT); 449 if (ptr == NULL) { 450 DPRINTF(("%s: failed to allocate memory" 451 "for IPv6 headers\n",__func__)); 452 m_freem(m); 453 return ENOBUFS; 454 } 455 456 /* 457 * Copy all the protocol headers after 458 * the IPv6 header. 459 */ 460 m_copydata(m, sizeof(struct ip6_hdr), 461 skip - sizeof(struct ip6_hdr), ptr); 462 alloc = 1; 463 } else { 464 /* No need to allocate memory. */ 465 ptr = mtod(m, unsigned char *) + 466 sizeof(struct ip6_hdr); 467 alloc = 0; 468 } 469 } else 470 break; 471 472 nxt = ip6.ip6_nxt & 0xff; /* Next header type. */ 473 474 for (off = 0; off < skip - sizeof(struct ip6_hdr);) 475 switch (nxt) { 476 case IPPROTO_HOPOPTS: 477 case IPPROTO_DSTOPTS: 478 ip6e = (struct ip6_ext *)(ptr + off); 479 noff = off + ((ip6e->ip6e_len + 1) << 3); 480 481 /* Sanity check. */ 482 if (noff > skip - sizeof(struct ip6_hdr)) 483 goto error6; 484 485 /* 486 * Zero out mutable options. 487 */ 488 for (count = off + sizeof(struct ip6_ext); 489 count < noff;) { 490 if (ptr[count] == IP6OPT_PAD1) { 491 count++; 492 continue; /* Skip padding. */ 493 } 494 495 ad = ptr[count + 1] + 2; 496 if (count + ad > noff) 497 goto error6; 498 499 if (ptr[count] & IP6OPT_MUTABLE) 500 memset(ptr + count, 0, ad); 501 count += ad; 502 } 503 504 if (count != noff) 505 goto error6; 506 507 /* Advance. */ 508 off += ((ip6e->ip6e_len + 1) << 3); 509 nxt = ip6e->ip6e_nxt; 510 break; 511 512 case IPPROTO_ROUTING: 513 /* 514 * Always include routing headers in 515 * computation. 516 */ 517 ip6e = (struct ip6_ext *) (ptr + off); 518 off += ((ip6e->ip6e_len + 1) << 3); 519 nxt = ip6e->ip6e_nxt; 520 break; 521 522 default: 523 DPRINTF(("%s: unexpected IPv6 header type %d", 524 __func__, off)); 525 error6: 526 if (alloc) 527 free(ptr, M_XDATA); 528 m_freem(m); 529 return EINVAL; 530 } 531 532 /* Copyback and free, if we allocated. */ 533 if (alloc) { 534 m_copyback(m, sizeof(struct ip6_hdr), 535 skip - sizeof(struct ip6_hdr), ptr); 536 free(ptr, M_XDATA); 537 } 538 539 break; 540 #endif /* INET6 */ 541 } 542 543 return 0; 544 } 545 546 /* 547 * ah_input() gets called to verify that an input packet 548 * passes authentication. 549 */ 550 static int 551 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 552 { 553 IPSEC_DEBUG_DECLARE(char buf[128]); 554 const struct auth_hash *ahx; 555 struct cryptodesc *crda; 556 struct cryptop *crp; 557 struct xform_data *xd; 558 struct newah *ah; 559 uint64_t cryptoid; 560 int hl, rplen, authsize, error; 561 562 IPSEC_ASSERT(sav != NULL, ("null SA")); 563 IPSEC_ASSERT(sav->key_auth != NULL, ("null authentication key")); 564 IPSEC_ASSERT(sav->tdb_authalgxform != NULL, 565 ("null authentication xform")); 566 567 /* Figure out header size. */ 568 rplen = HDRSIZE(sav); 569 570 /* XXX don't pullup, just copy header */ 571 IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen); 572 if (ah == NULL) { 573 DPRINTF(("ah_input: cannot pullup header\n")); 574 AHSTAT_INC(ahs_hdrops); /*XXX*/ 575 error = ENOBUFS; 576 goto bad; 577 } 578 579 /* Check replay window, if applicable. */ 580 SECASVAR_LOCK(sav); 581 if (sav->replay != NULL && sav->replay->wsize != 0 && 582 ipsec_chkreplay(ntohl(ah->ah_seq), sav) == 0) { 583 SECASVAR_UNLOCK(sav); 584 AHSTAT_INC(ahs_replay); 585 DPRINTF(("%s: packet replay failure: %s\n", __func__, 586 ipsec_sa2str(sav, buf, sizeof(buf)))); 587 error = EACCES; 588 goto bad; 589 } 590 cryptoid = sav->tdb_cryptoid; 591 SECASVAR_UNLOCK(sav); 592 593 /* Verify AH header length. */ 594 hl = ah->ah_len * sizeof (u_int32_t); 595 ahx = sav->tdb_authalgxform; 596 authsize = AUTHSIZE(sav); 597 if (hl != authsize + rplen - sizeof (struct ah)) { 598 DPRINTF(("%s: bad authenticator length %u (expecting %lu)" 599 " for packet in SA %s/%08lx\n", __func__, hl, 600 (u_long) (authsize + rplen - sizeof (struct ah)), 601 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 602 (u_long) ntohl(sav->spi))); 603 AHSTAT_INC(ahs_badauthl); 604 error = EACCES; 605 goto bad; 606 } 607 if (skip + authsize + rplen > m->m_pkthdr.len) { 608 DPRINTF(("%s: bad mbuf length %u (expecting %lu)" 609 " for packet in SA %s/%08lx\n", __func__, 610 m->m_pkthdr.len, (u_long) (skip + authsize + rplen), 611 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 612 (u_long) ntohl(sav->spi))); 613 AHSTAT_INC(ahs_badauthl); 614 error = EACCES; 615 goto bad; 616 } 617 AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl); 618 619 /* Get crypto descriptors. */ 620 crp = crypto_getreq(1); 621 if (crp == NULL) { 622 DPRINTF(("%s: failed to acquire crypto descriptor\n", 623 __func__)); 624 AHSTAT_INC(ahs_crypto); 625 error = ENOBUFS; 626 goto bad; 627 } 628 629 crda = crp->crp_desc; 630 IPSEC_ASSERT(crda != NULL, ("null crypto descriptor")); 631 632 crda->crd_skip = 0; 633 crda->crd_len = m->m_pkthdr.len; 634 crda->crd_inject = skip + rplen; 635 636 /* Authentication operation. */ 637 crda->crd_alg = ahx->type; 638 crda->crd_klen = _KEYBITS(sav->key_auth); 639 crda->crd_key = sav->key_auth->key_data; 640 641 /* Allocate IPsec-specific opaque crypto info. */ 642 xd = malloc(sizeof(*xd) + skip + rplen + authsize, M_XDATA, 643 M_NOWAIT | M_ZERO); 644 if (xd == NULL) { 645 DPRINTF(("%s: failed to allocate xform_data\n", __func__)); 646 AHSTAT_INC(ahs_crypto); 647 crypto_freereq(crp); 648 error = ENOBUFS; 649 goto bad; 650 } 651 652 /* 653 * Save the authenticator, the skipped portion of the packet, 654 * and the AH header. 655 */ 656 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(xd + 1)); 657 658 /* Zeroize the authenticator on the packet. */ 659 m_copyback(m, skip + rplen, authsize, ipseczeroes); 660 661 /* Save ah_nxt, since ah pointer can become invalid after "massage" */ 662 hl = ah->ah_nxt; 663 664 /* "Massage" the packet headers for crypto processing. */ 665 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 666 skip, ahx->type, 0); 667 if (error != 0) { 668 /* NB: mbuf is free'd by ah_massage_headers */ 669 AHSTAT_INC(ahs_hdrops); 670 free(xd, M_XDATA); 671 crypto_freereq(crp); 672 key_freesav(&sav); 673 return (error); 674 } 675 676 /* Crypto operation descriptor. */ 677 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 678 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 679 crp->crp_buf = (caddr_t) m; 680 crp->crp_callback = ah_input_cb; 681 crp->crp_sid = cryptoid; 682 crp->crp_opaque = (caddr_t) xd; 683 684 /* These are passed as-is to the callback. */ 685 xd->sav = sav; 686 xd->nxt = hl; 687 xd->protoff = protoff; 688 xd->skip = skip; 689 xd->cryptoid = cryptoid; 690 xd->vnet = curvnet; 691 return (crypto_dispatch(crp)); 692 bad: 693 m_freem(m); 694 key_freesav(&sav); 695 return (error); 696 } 697 698 /* 699 * AH input callback from the crypto driver. 700 */ 701 static int 702 ah_input_cb(struct cryptop *crp) 703 { 704 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 705 unsigned char calc[AH_ALEN_MAX]; 706 const struct auth_hash *ahx; 707 struct mbuf *m; 708 struct cryptodesc *crd; 709 struct xform_data *xd; 710 struct secasvar *sav; 711 struct secasindex *saidx; 712 caddr_t ptr; 713 uint64_t cryptoid; 714 int authsize, rplen, error, skip, protoff; 715 uint8_t nxt; 716 717 crd = crp->crp_desc; 718 m = (struct mbuf *) crp->crp_buf; 719 xd = (struct xform_data *) crp->crp_opaque; 720 CURVNET_SET(xd->vnet); 721 sav = xd->sav; 722 skip = xd->skip; 723 nxt = xd->nxt; 724 protoff = xd->protoff; 725 cryptoid = xd->cryptoid; 726 saidx = &sav->sah->saidx; 727 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 728 saidx->dst.sa.sa_family == AF_INET6, 729 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 730 731 ahx = sav->tdb_authalgxform; 732 733 /* Check for crypto errors. */ 734 if (crp->crp_etype) { 735 if (crp->crp_etype == EAGAIN) { 736 /* Reset the session ID */ 737 if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0) 738 crypto_freesession(cryptoid); 739 xd->cryptoid = crp->crp_sid; 740 CURVNET_RESTORE(); 741 return (crypto_dispatch(crp)); 742 } 743 AHSTAT_INC(ahs_noxform); 744 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 745 error = crp->crp_etype; 746 goto bad; 747 } else { 748 AHSTAT_INC(ahs_hist[sav->alg_auth]); 749 crypto_freereq(crp); /* No longer needed. */ 750 crp = NULL; 751 } 752 753 /* Shouldn't happen... */ 754 if (m == NULL) { 755 AHSTAT_INC(ahs_crypto); 756 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 757 error = EINVAL; 758 goto bad; 759 } 760 761 /* Figure out header size. */ 762 rplen = HDRSIZE(sav); 763 authsize = AUTHSIZE(sav); 764 765 /* Copy authenticator off the packet. */ 766 m_copydata(m, skip + rplen, authsize, calc); 767 768 /* Verify authenticator. */ 769 ptr = (caddr_t) (xd + 1); 770 if (timingsafe_bcmp(ptr + skip + rplen, calc, authsize)) { 771 DPRINTF(("%s: authentication hash mismatch for packet " 772 "in SA %s/%08lx\n", __func__, 773 ipsec_address(&saidx->dst, buf, sizeof(buf)), 774 (u_long) ntohl(sav->spi))); 775 AHSTAT_INC(ahs_badauth); 776 error = EACCES; 777 goto bad; 778 } 779 /* Fix the Next Protocol field. */ 780 ((uint8_t *) ptr)[protoff] = nxt; 781 782 /* Copyback the saved (uncooked) network headers. */ 783 m_copyback(m, 0, skip, ptr); 784 free(xd, M_XDATA), xd = NULL; /* No longer needed */ 785 786 /* 787 * Header is now authenticated. 788 */ 789 m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM; 790 791 /* 792 * Update replay sequence number, if appropriate. 793 */ 794 if (sav->replay) { 795 u_int32_t seq; 796 797 m_copydata(m, skip + offsetof(struct newah, ah_seq), 798 sizeof (seq), (caddr_t) &seq); 799 SECASVAR_LOCK(sav); 800 if (ipsec_updatereplay(ntohl(seq), sav)) { 801 SECASVAR_UNLOCK(sav); 802 AHSTAT_INC(ahs_replay); 803 error = EACCES; 804 goto bad; 805 } 806 SECASVAR_UNLOCK(sav); 807 } 808 809 /* 810 * Remove the AH header and authenticator from the mbuf. 811 */ 812 error = m_striphdr(m, skip, rplen + authsize); 813 if (error) { 814 DPRINTF(("%s: mangled mbuf chain for SA %s/%08lx\n", __func__, 815 ipsec_address(&saidx->dst, buf, sizeof(buf)), 816 (u_long) ntohl(sav->spi))); 817 AHSTAT_INC(ahs_hdrops); 818 goto bad; 819 } 820 821 switch (saidx->dst.sa.sa_family) { 822 #ifdef INET6 823 case AF_INET6: 824 error = ipsec6_common_input_cb(m, sav, skip, protoff); 825 break; 826 #endif 827 #ifdef INET 828 case AF_INET: 829 error = ipsec4_common_input_cb(m, sav, skip, protoff); 830 break; 831 #endif 832 default: 833 panic("%s: Unexpected address family: %d saidx=%p", __func__, 834 saidx->dst.sa.sa_family, saidx); 835 } 836 CURVNET_RESTORE(); 837 return error; 838 bad: 839 CURVNET_RESTORE(); 840 if (sav) 841 key_freesav(&sav); 842 if (m != NULL) 843 m_freem(m); 844 if (xd != NULL) 845 free(xd, M_XDATA); 846 if (crp != NULL) 847 crypto_freereq(crp); 848 return error; 849 } 850 851 /* 852 * AH output routine, called by ipsec[46]_perform_request(). 853 */ 854 static int 855 ah_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav, 856 u_int idx, int skip, int protoff) 857 { 858 IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); 859 const struct auth_hash *ahx; 860 struct cryptodesc *crda; 861 struct xform_data *xd; 862 struct mbuf *mi; 863 struct cryptop *crp; 864 struct newah *ah; 865 uint64_t cryptoid; 866 uint16_t iplen; 867 int error, rplen, authsize, maxpacketsize, roff; 868 uint8_t prot; 869 870 IPSEC_ASSERT(sav != NULL, ("null SA")); 871 ahx = sav->tdb_authalgxform; 872 IPSEC_ASSERT(ahx != NULL, ("null authentication xform")); 873 874 AHSTAT_INC(ahs_output); 875 876 /* Figure out header size. */ 877 rplen = HDRSIZE(sav); 878 879 /* Check for maximum packet size violations. */ 880 switch (sav->sah->saidx.dst.sa.sa_family) { 881 #ifdef INET 882 case AF_INET: 883 maxpacketsize = IP_MAXPACKET; 884 break; 885 #endif /* INET */ 886 #ifdef INET6 887 case AF_INET6: 888 maxpacketsize = IPV6_MAXPACKET; 889 break; 890 #endif /* INET6 */ 891 default: 892 DPRINTF(("%s: unknown/unsupported protocol family %u, " 893 "SA %s/%08lx\n", __func__, 894 sav->sah->saidx.dst.sa.sa_family, 895 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 896 (u_long) ntohl(sav->spi))); 897 AHSTAT_INC(ahs_nopf); 898 error = EPFNOSUPPORT; 899 goto bad; 900 } 901 authsize = AUTHSIZE(sav); 902 if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) { 903 DPRINTF(("%s: packet in SA %s/%08lx got too big " 904 "(len %u, max len %u)\n", __func__, 905 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 906 (u_long) ntohl(sav->spi), 907 rplen + authsize + m->m_pkthdr.len, maxpacketsize)); 908 AHSTAT_INC(ahs_toobig); 909 error = EMSGSIZE; 910 goto bad; 911 } 912 913 /* Update the counters. */ 914 AHSTAT_ADD(ahs_obytes, m->m_pkthdr.len - skip); 915 916 m = m_unshare(m, M_NOWAIT); 917 if (m == NULL) { 918 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 919 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 920 (u_long) ntohl(sav->spi))); 921 AHSTAT_INC(ahs_hdrops); 922 error = ENOBUFS; 923 goto bad; 924 } 925 926 /* Inject AH header. */ 927 mi = m_makespace(m, skip, rplen + authsize, &roff); 928 if (mi == NULL) { 929 DPRINTF(("%s: failed to inject %u byte AH header for SA " 930 "%s/%08lx\n", __func__, 931 rplen + authsize, 932 ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)), 933 (u_long) ntohl(sav->spi))); 934 AHSTAT_INC(ahs_hdrops); /*XXX differs from openbsd */ 935 error = ENOBUFS; 936 goto bad; 937 } 938 939 /* 940 * The AH header is guaranteed by m_makespace() to be in 941 * contiguous memory, at roff bytes offset into the returned mbuf. 942 */ 943 ah = (struct newah *)(mtod(mi, caddr_t) + roff); 944 945 /* Initialize the AH header. */ 946 m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt); 947 ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t); 948 ah->ah_reserve = 0; 949 ah->ah_spi = sav->spi; 950 951 /* Zeroize authenticator. */ 952 m_copyback(m, skip + rplen, authsize, ipseczeroes); 953 954 /* Insert packet replay counter, as requested. */ 955 SECASVAR_LOCK(sav); 956 if (sav->replay) { 957 if (sav->replay->count == ~0 && 958 (sav->flags & SADB_X_EXT_CYCSEQ) == 0) { 959 SECASVAR_UNLOCK(sav); 960 DPRINTF(("%s: replay counter wrapped for SA %s/%08lx\n", 961 __func__, ipsec_address(&sav->sah->saidx.dst, buf, 962 sizeof(buf)), (u_long) ntohl(sav->spi))); 963 AHSTAT_INC(ahs_wrap); 964 error = EACCES; 965 goto bad; 966 } 967 #ifdef REGRESSION 968 /* Emulate replay attack when ipsec_replay is TRUE. */ 969 if (!V_ipsec_replay) 970 #endif 971 sav->replay->count++; 972 ah->ah_seq = htonl(sav->replay->count); 973 } 974 cryptoid = sav->tdb_cryptoid; 975 SECASVAR_UNLOCK(sav); 976 977 /* Get crypto descriptors. */ 978 crp = crypto_getreq(1); 979 if (crp == NULL) { 980 DPRINTF(("%s: failed to acquire crypto descriptors\n", 981 __func__)); 982 AHSTAT_INC(ahs_crypto); 983 error = ENOBUFS; 984 goto bad; 985 } 986 987 crda = crp->crp_desc; 988 crda->crd_skip = 0; 989 crda->crd_inject = skip + rplen; 990 crda->crd_len = m->m_pkthdr.len; 991 992 /* Authentication operation. */ 993 crda->crd_alg = ahx->type; 994 crda->crd_key = sav->key_auth->key_data; 995 crda->crd_klen = _KEYBITS(sav->key_auth); 996 997 /* Allocate IPsec-specific opaque crypto info. */ 998 xd = malloc(sizeof(struct xform_data) + skip, M_XDATA, 999 M_NOWAIT | M_ZERO); 1000 if (xd == NULL) { 1001 crypto_freereq(crp); 1002 DPRINTF(("%s: failed to allocate xform_data\n", __func__)); 1003 AHSTAT_INC(ahs_crypto); 1004 error = ENOBUFS; 1005 goto bad; 1006 } 1007 1008 /* Save the skipped portion of the packet. */ 1009 m_copydata(m, 0, skip, (caddr_t) (xd + 1)); 1010 1011 /* 1012 * Fix IP header length on the header used for 1013 * authentication. We don't need to fix the original 1014 * header length as it will be fixed by our caller. 1015 */ 1016 switch (sav->sah->saidx.dst.sa.sa_family) { 1017 #ifdef INET 1018 case AF_INET: 1019 bcopy(((caddr_t)(xd + 1)) + 1020 offsetof(struct ip, ip_len), 1021 (caddr_t) &iplen, sizeof(u_int16_t)); 1022 iplen = htons(ntohs(iplen) + rplen + authsize); 1023 m_copyback(m, offsetof(struct ip, ip_len), 1024 sizeof(u_int16_t), (caddr_t) &iplen); 1025 break; 1026 #endif /* INET */ 1027 1028 #ifdef INET6 1029 case AF_INET6: 1030 bcopy(((caddr_t)(xd + 1)) + 1031 offsetof(struct ip6_hdr, ip6_plen), 1032 (caddr_t) &iplen, sizeof(uint16_t)); 1033 iplen = htons(ntohs(iplen) + rplen + authsize); 1034 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen), 1035 sizeof(uint16_t), (caddr_t) &iplen); 1036 break; 1037 #endif /* INET6 */ 1038 } 1039 1040 /* Fix the Next Header field in saved header. */ 1041 ((uint8_t *) (xd + 1))[protoff] = IPPROTO_AH; 1042 1043 /* Update the Next Protocol field in the IP header. */ 1044 prot = IPPROTO_AH; 1045 m_copyback(m, protoff, sizeof(uint8_t), (caddr_t) &prot); 1046 1047 /* "Massage" the packet headers for crypto processing. */ 1048 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family, 1049 skip, ahx->type, 1); 1050 if (error != 0) { 1051 m = NULL; /* mbuf was free'd by ah_massage_headers. */ 1052 free(xd, M_XDATA); 1053 crypto_freereq(crp); 1054 goto bad; 1055 } 1056 1057 /* Crypto operation descriptor. */ 1058 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 1059 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 1060 crp->crp_buf = (caddr_t) m; 1061 crp->crp_callback = ah_output_cb; 1062 crp->crp_sid = cryptoid; 1063 crp->crp_opaque = (caddr_t) xd; 1064 1065 /* These are passed as-is to the callback. */ 1066 xd->sp = sp; 1067 xd->sav = sav; 1068 xd->skip = skip; 1069 xd->idx = idx; 1070 xd->cryptoid = cryptoid; 1071 xd->vnet = curvnet; 1072 1073 return crypto_dispatch(crp); 1074 bad: 1075 if (m) 1076 m_freem(m); 1077 key_freesav(&sav); 1078 key_freesp(&sp); 1079 return (error); 1080 } 1081 1082 /* 1083 * AH output callback from the crypto driver. 1084 */ 1085 static int 1086 ah_output_cb(struct cryptop *crp) 1087 { 1088 struct xform_data *xd; 1089 struct secpolicy *sp; 1090 struct secasvar *sav; 1091 struct mbuf *m; 1092 uint64_t cryptoid; 1093 caddr_t ptr; 1094 u_int idx; 1095 int skip, error; 1096 1097 m = (struct mbuf *) crp->crp_buf; 1098 xd = (struct xform_data *) crp->crp_opaque; 1099 CURVNET_SET(xd->vnet); 1100 sp = xd->sp; 1101 sav = xd->sav; 1102 skip = xd->skip; 1103 idx = xd->idx; 1104 cryptoid = xd->cryptoid; 1105 ptr = (caddr_t) (xd + 1); 1106 1107 /* Check for crypto errors. */ 1108 if (crp->crp_etype) { 1109 if (crp->crp_etype == EAGAIN) { 1110 /* Reset the session ID */ 1111 if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0) 1112 crypto_freesession(cryptoid); 1113 xd->cryptoid = crp->crp_sid; 1114 CURVNET_RESTORE(); 1115 return (crypto_dispatch(crp)); 1116 } 1117 AHSTAT_INC(ahs_noxform); 1118 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 1119 error = crp->crp_etype; 1120 m_freem(m); 1121 goto bad; 1122 } 1123 1124 /* Shouldn't happen... */ 1125 if (m == NULL) { 1126 AHSTAT_INC(ahs_crypto); 1127 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 1128 error = EINVAL; 1129 goto bad; 1130 } 1131 /* 1132 * Copy original headers (with the new protocol number) back 1133 * in place. 1134 */ 1135 m_copyback(m, 0, skip, ptr); 1136 1137 free(xd, M_XDATA); 1138 crypto_freereq(crp); 1139 AHSTAT_INC(ahs_hist[sav->alg_auth]); 1140 #ifdef REGRESSION 1141 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 1142 if (V_ipsec_integrity) { 1143 int alen; 1144 1145 /* 1146 * Corrupt HMAC if we want to test integrity verification of 1147 * the other side. 1148 */ 1149 alen = AUTHSIZE(sav); 1150 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); 1151 } 1152 #endif 1153 1154 /* NB: m is reclaimed by ipsec_process_done. */ 1155 error = ipsec_process_done(m, sp, sav, idx); 1156 CURVNET_RESTORE(); 1157 return (error); 1158 bad: 1159 CURVNET_RESTORE(); 1160 free(xd, M_XDATA); 1161 crypto_freereq(crp); 1162 key_freesav(&sav); 1163 key_freesp(&sp); 1164 return (error); 1165 } 1166 1167 static struct xformsw ah_xformsw = { 1168 .xf_type = XF_AH, 1169 .xf_name = "IPsec AH", 1170 .xf_init = ah_init, 1171 .xf_zeroize = ah_zeroize, 1172 .xf_input = ah_input, 1173 .xf_output = ah_output, 1174 }; 1175 1176 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, 1177 xform_attach, &ah_xformsw); 1178 SYSUNINIT(ah_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, 1179 xform_detach, &ah_xformsw);
Cache object: 609fd4dcf1bfe2287b3b40a3248976c4
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