sys/netproto/ipsec/xform_ah.c

   1 /*      $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.2 2003/02/26 00:14:05 sam Exp $   */
   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         SPLASSERT(net, "ah_input");
 567
 568         KASSERT(sav != NULL, ("ah_input: null SA"));
 569         KASSERT(sav->key_auth != NULL,
 570                 ("ah_input: null authentication key"));
 571         KASSERT(sav->tdb_authalgxform != NULL,
 572                 ("ah_input: null authentication xform"));
 573
 574         /* Figure out header size. */
 575         rplen = HDRSIZE(sav);
 576
 577         /* XXX don't pullup, just copy header */
 578         IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
 579         if (ah == NULL) {
 580                 DPRINTF(("ah_input: cannot pullup header\n"));
 581                 ahstat.ahs_hdrops++;            /*XXX*/
 582                 m_freem(m);
 583                 return ENOBUFS;
 584         }
 585
 586         /* Check replay window, if applicable. */
 587         if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
 588                 ahstat.ahs_replay++;
 589                 DPRINTF(("ah_input: packet replay failure: %s\n",
 590                           ipsec_logsastr(sav)));
 591                 m_freem(m);
 592                 return ENOBUFS;
 593         }
 594
 595         /* Verify AH header length. */
 596         hl = ah->ah_len * sizeof (u_int32_t);
 597         ahx = sav->tdb_authalgxform;
 598         authsize = AUTHSIZE(sav);
 599         if (hl != authsize + rplen - sizeof (struct ah)) {
 600                 DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)"
 601                         " for packet in SA %s/%08lx\n",
 602                         hl, (u_long) (authsize + rplen - sizeof (struct ah)),
 603                         ipsec_address(&sav->sah->saidx.dst),
 604                         (u_long) ntohl(sav->spi)));
 605                 ahstat.ahs_badauthl++;
 606                 m_freem(m);
 607                 return EACCES;
 608         }
 609         ahstat.ahs_ibytes += m->m_pkthdr.len - skip - hl;
 610
 611         /* Get crypto descriptors. */
 612         crp = crypto_getreq(1);
 613         if (crp == NULL) {
 614                 DPRINTF(("ah_input: failed to acquire crypto descriptor\n"));
 615                 ahstat.ahs_crypto++;
 616                 m_freem(m);
 617                 return ENOBUFS;
 618         }
 619
 620         crda = crp->crp_desc;
 621         KASSERT(crda != NULL, ("ah_input: null crypto descriptor"));
 622
 623         crda->crd_skip = 0;
 624         crda->crd_len = m->m_pkthdr.len;
 625         crda->crd_inject = skip + rplen;
 626
 627         /* Authentication operation. */
 628         crda->crd_alg = ahx->type;
 629         crda->crd_key = _KEYBUF(sav->key_auth);
 630         crda->crd_klen = _KEYBITS(sav->key_auth);
 631
 632         /* Find out if we've already done crypto. */
 633         for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
 634              mtag != NULL;
 635              mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
 636                 tdbi = (struct tdb_ident *) (mtag + 1);
 637                 if (tdbi->proto == sav->sah->saidx.proto &&
 638                     tdbi->spi == sav->spi &&
 639                     !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
 640                           sizeof (union sockaddr_union)))
 641                         break;
 642         }
 643
 644         /* Allocate IPsec-specific opaque crypto info. */
 645         if (mtag == NULL) {
 646                 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
 647                         skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
 648         } else {
 649                 /* Hash verification has already been done successfully. */
 650                 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
 651                                                     M_XDATA, M_NOWAIT|M_ZERO);
 652         }
 653         if (tc == NULL) {
 654                 DPRINTF(("ah_input: failed to allocate tdb_crypto\n"));
 655                 ahstat.ahs_crypto++;
 656                 crypto_freereq(crp);
 657                 m_freem(m);
 658                 return ENOBUFS;
 659         }
 660
 661         /* Only save information if crypto processing is needed. */
 662         if (mtag == NULL) {
 663                 int error;
 664
 665                 /*
 666                  * Save the authenticator, the skipped portion of the packet,
 667                  * and the AH header.
 668                  */
 669                 m_copydata(m, 0, skip + rplen + authsize, (caddr_t)(tc+1));
 670
 671                 /* Zeroize the authenticator on the packet. */
 672                 m_copyback(m, skip + rplen, authsize, ipseczeroes);
 673
 674                 /* "Massage" the packet headers for crypto processing. */
 675                 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
 676                     skip, ahx->type, 0);
 677                 if (error != 0) {
 678                         /* NB: mbuf is free'd by ah_massage_headers */
 679                         ahstat.ahs_hdrops++;
 680                         free(tc, M_XDATA);
 681                         crypto_freereq(crp);
 682                         return error;
 683                 }
 684         }
 685
 686         /* Crypto operation descriptor. */
 687         crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
 688         crp->crp_flags = CRYPTO_F_IMBUF;
 689         crp->crp_buf = (caddr_t) m;
 690         crp->crp_callback = ah_input_cb;
 691         crp->crp_sid = sav->tdb_cryptoid;
 692         crp->crp_opaque = (caddr_t) tc;
 693
 694         /* These are passed as-is to the callback. */
 695         tc->tc_spi = sav->spi;
 696         tc->tc_dst = sav->sah->saidx.dst;
 697         tc->tc_proto = sav->sah->saidx.proto;
 698         tc->tc_nxt = ah->ah_nxt;
 699         tc->tc_protoff = protoff;
 700         tc->tc_skip = skip;
 701         tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
 702
 703         if (mtag == NULL)
 704                 return crypto_dispatch(crp);
 705         else
 706                 return ah_input_cb(crp);
 707 }
 708
 709 #ifdef INET6
 710 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {              \
 711         if (saidx->dst.sa.sa_family == AF_INET6) {                           \
 712                 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
 713         } else {                                                             \
 714                 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
 715         }                                                                    \
 716 } while (0)
 717 #else
 718 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)                   \
 719         (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
 720 #endif
 721
 722 /*
 723  * AH input callback from the crypto driver.
 724  */
 725 static int
 726 ah_input_cb(struct cryptop *crp)
 727 {
 728         int rplen, error, skip, protoff;
 729         unsigned char calc[AH_ALEN_MAX];
 730         struct mbuf *m;
 731         struct cryptodesc *crd;
 732         struct auth_hash *ahx;
 733         struct tdb_crypto *tc;
 734         struct m_tag *mtag;
 735         struct secasvar *sav;
 736         struct secasindex *saidx;
 737         u_int8_t nxt;
 738         caddr_t ptr;
 739         int s, authsize;
 740
 741         crd = crp->crp_desc;
 742
 743         tc = (struct tdb_crypto *) crp->crp_opaque;
 744         KASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!"));
 745         skip = tc->tc_skip;
 746         nxt = tc->tc_nxt;
 747         protoff = tc->tc_protoff;
 748         mtag = (struct m_tag *) tc->tc_ptr;
 749         m = (struct mbuf *) crp->crp_buf;
 750
 751         s = splnet();
 752
 753         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
 754         if (sav == NULL) {
 755                 ahstat.ahs_notdb++;
 756                 DPRINTF(("ah_input_cb: SA expired while in crypto\n"));
 757                 error = ENOBUFS;                /*XXX*/
 758                 goto bad;
 759         }
 760
 761         saidx = &sav->sah->saidx;
 762         KASSERT(saidx->dst.sa.sa_family == AF_INET ||
 763                 saidx->dst.sa.sa_family == AF_INET6,
 764                 ("ah_input_cb: unexpected protocol family %u",
 765                  saidx->dst.sa.sa_family));
 766
 767         ahx = (struct auth_hash *) sav->tdb_authalgxform;
 768
 769         /* Check for crypto errors. */
 770         if (crp->crp_etype) {
 771                 if (sav->tdb_cryptoid != 0)
 772                         sav->tdb_cryptoid = crp->crp_sid;
 773
 774                 if (crp->crp_etype == EAGAIN)
 775                         return crypto_dispatch(crp);
 776
 777                 ahstat.ahs_noxform++;
 778                 DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype));
 779                 error = crp->crp_etype;
 780                 goto bad;
 781         } else {
 782                 ahstat.ahs_hist[sav->alg_auth]++;
 783                 crypto_freereq(crp);            /* No longer needed. */
 784                 crp = NULL;
 785         }
 786
 787         /* Shouldn't happen... */
 788         if (m == NULL) {
 789                 ahstat.ahs_crypto++;
 790                 DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n"));
 791                 error = EINVAL;
 792                 goto bad;
 793         }
 794
 795         /* Figure out header size. */
 796         rplen = HDRSIZE(sav);
 797         authsize = AUTHSIZE(sav);
 798
 799         /* Copy authenticator off the packet. */
 800         m_copydata(m, skip + rplen, authsize, calc);
 801
 802         /*
 803          * If we have an mtag, we don't need to verify the authenticator --
 804          * it has been verified by an IPsec-aware NIC.
 805          */
 806         if (mtag == NULL) {
 807                 ptr = (caddr_t) (tc + 1);
 808
 809                 /* Verify authenticator. */
 810                 if (bcmp(ptr + skip + rplen, calc, authsize)) {
 811                         DPRINTF(("ah_input: authentication hash mismatch "
 812                             "for packet in SA %s/%08lx\n",
 813                             ipsec_address(&saidx->dst),
 814                             (u_long) ntohl(sav->spi)));
 815                         ahstat.ahs_badauth++;
 816                         error = EACCES;
 817                         goto bad;
 818                 }
 819
 820                 /* Fix the Next Protocol field. */
 821                 ((u_int8_t *) ptr)[protoff] = nxt;
 822
 823                 /* Copyback the saved (uncooked) network headers. */
 824                 m_copyback(m, 0, skip, ptr);
 825         } else {
 826                 /* Fix the Next Protocol field. */
 827                 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
 828         }
 829
 830         free(tc, M_XDATA), tc = NULL;                   /* No longer needed */
 831
 832         /*
 833          * Header is now authenticated.
 834          */
 835         m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
 836
 837         /*
 838          * Update replay sequence number, if appropriate.
 839          */
 840         if (sav->replay) {
 841                 u_int32_t seq;
 842
 843                 m_copydata(m, skip + offsetof(struct newah, ah_seq),
 844                            sizeof (seq), (caddr_t) &seq);
 845                 if (ipsec_updatereplay(ntohl(seq), sav)) {
 846                         ahstat.ahs_replay++;
 847                         error = ENOBUFS;                        /*XXX as above*/
 848                         goto bad;
 849                 }
 850         }
 851
 852         /*
 853          * Remove the AH header and authenticator from the mbuf.
 854          */
 855         error = m_striphdr(m, skip, rplen + authsize);
 856         if (error) {
 857                 DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n",
 858                     ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
 859
 860                 ahstat.ahs_hdrops++;
 861                 goto bad;
 862         }
 863
 864         IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
 865
 866         KEY_FREESAV(&sav);
 867         splx(s);
 868         return error;
 869 bad:
 870         if (sav)
 871                 KEY_FREESAV(&sav);
 872         splx(s);
 873         if (m != NULL)
 874                 m_freem(m);
 875         if (tc != NULL)
 876                 free(tc, M_XDATA);
 877         if (crp != NULL)
 878                 crypto_freereq(crp);
 879         return error;
 880 }
 881
 882 /*
 883  * AH output routine, called by ipsec[46]_process_packet().
 884  */
 885 static int
 886 ah_output(
 887         struct mbuf *m,
 888         struct ipsecrequest *isr,
 889         struct mbuf **mp,
 890         int skip,
 891         int protoff)
 892 {
 893         struct secasvar *sav;
 894         struct auth_hash *ahx;
 895         struct cryptodesc *crda;
 896         struct tdb_crypto *tc;
 897         struct mbuf *mi;
 898         struct cryptop *crp;
 899         u_int16_t iplen;
 900         int error, rplen, authsize, maxpacketsize, roff;
 901         u_int8_t prot;
 902         struct newah *ah;
 903
 904         SPLASSERT(net, "ah_output");
 905
 906         sav = isr->sav;
 907         KASSERT(sav != NULL, ("ah_output: null SA"));
 908         ahx = sav->tdb_authalgxform;
 909         KASSERT(ahx != NULL, ("ah_output: null authentication xform"));
 910
 911         ahstat.ahs_output++;
 912
 913         /* Figure out header size. */
 914         rplen = HDRSIZE(sav);
 915
 916         /* Check for maximum packet size violations. */
 917         switch (sav->sah->saidx.dst.sa.sa_family) {
 918 #ifdef INET
 919         case AF_INET:
 920                 maxpacketsize = IP_MAXPACKET;
 921                 break;
 922 #endif /* INET */
 923 #ifdef INET6
 924         case AF_INET6:
 925                 maxpacketsize = IPV6_MAXPACKET;
 926                 break;
 927 #endif /* INET6 */
 928         default:
 929                 DPRINTF(("ah_output: unknown/unsupported protocol "
 930                     "family %u, SA %s/%08lx\n",
 931                     sav->sah->saidx.dst.sa.sa_family,
 932                     ipsec_address(&sav->sah->saidx.dst),
 933                     (u_long) ntohl(sav->spi)));
 934                 ahstat.ahs_nopf++;
 935                 error = EPFNOSUPPORT;
 936                 goto bad;
 937         }
 938         authsize = AUTHSIZE(sav);
 939         if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
 940                 DPRINTF(("ah_output: packet in SA %s/%08lx got too big "
 941                     "(len %u, max len %u)\n",
 942                     ipsec_address(&sav->sah->saidx.dst),
 943                     (u_long) ntohl(sav->spi),
 944                     rplen + authsize + m->m_pkthdr.len, maxpacketsize));
 945                 ahstat.ahs_toobig++;
 946                 error = EMSGSIZE;
 947                 goto bad;
 948         }
 949
 950         /* Update the counters. */
 951         ahstat.ahs_obytes += m->m_pkthdr.len - skip;
 952
 953         m = m_clone(m);
 954         if (m == NULL) {
 955                 DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n",
 956                     ipsec_address(&sav->sah->saidx.dst),
 957                     (u_long) ntohl(sav->spi)));
 958                 ahstat.ahs_hdrops++;
 959                 error = ENOBUFS;
 960                 goto bad;
 961         }
 962
 963         /* Inject AH header. */
 964         mi = m_makespace(m, skip, rplen + authsize, &roff);
 965         if (mi == NULL) {
 966                 DPRINTF(("ah_output: failed to inject %u byte AH header for SA "
 967                     "%s/%08lx\n",
 968                     rplen + authsize,
 969                     ipsec_address(&sav->sah->saidx.dst),
 970                     (u_long) ntohl(sav->spi)));
 971                 ahstat.ahs_hdrops++;            /*XXX differs from openbsd */
 972                 error = ENOBUFS;
 973                 goto bad;
 974         }
 975
 976         /*
 977          * The AH header is guaranteed by m_makespace() to be in
 978          * contiguous memory, at roff bytes offset into the returned mbuf.
 979          */
 980         ah = (struct newah *)(mtod(mi, caddr_t) + roff);
 981
 982         /* Initialize the AH header. */
 983         m_copydata(m, protoff, sizeof(u_int8_t), (caddr_t) &ah->ah_nxt);
 984         ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
 985         ah->ah_reserve = 0;
 986         ah->ah_spi = sav->spi;
 987
 988         /* Zeroize authenticator. */
 989         m_copyback(m, skip + rplen, authsize, ipseczeroes);
 990
 991         /* Insert packet replay counter, as requested.  */
 992         if (sav->replay) {
 993                 if (sav->replay->count == ~0 &&
 994                     (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
 995                         DPRINTF(("ah_output: replay counter wrapped for SA "
 996                                 "%s/%08lx\n",
 997                                 ipsec_address(&sav->sah->saidx.dst),
 998                                 (u_long) ntohl(sav->spi)));
 999                         ahstat.ahs_wrap++;
1000                         error = EINVAL;
1001                         goto bad;
1002                 }
1003                 sav->replay->count++;
1004                 ah->ah_seq = htonl(sav->replay->count);
1005         }
1006
1007         /* Get crypto descriptors. */
1008         crp = crypto_getreq(1);
1009         if (crp == NULL) {
1010                 DPRINTF(("ah_output: failed to acquire crypto descriptors\n"));
1011                 ahstat.ahs_crypto++;
1012                 error = ENOBUFS;
1013                 goto bad;
1014         }
1015
1016         crda = crp->crp_desc;
1017
1018         crda->crd_skip = 0;
1019         crda->crd_inject = skip + rplen;
1020         crda->crd_len = m->m_pkthdr.len;
1021
1022         /* Authentication operation. */
1023         crda->crd_alg = ahx->type;
1024         crda->crd_key = _KEYBUF(sav->key_auth);
1025         crda->crd_klen = _KEYBITS(sav->key_auth);
1026
1027         /* Allocate IPsec-specific opaque crypto info. */
1028         tc = (struct tdb_crypto *) malloc(
1029                 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1030         if (tc == NULL) {
1031                 crypto_freereq(crp);
1032                 DPRINTF(("ah_output: failed to allocate tdb_crypto\n"));
1033                 ahstat.ahs_crypto++;
1034                 error = ENOBUFS;
1035                 goto bad;
1036         }
1037
1038         /* Save the skipped portion of the packet. */
1039         m_copydata(m, 0, skip, (caddr_t) (tc + 1));
1040
1041         /*
1042          * Fix IP header length on the header used for
1043          * authentication. We don't need to fix the original
1044          * header length as it will be fixed by our caller.
1045          */
1046         switch (sav->sah->saidx.dst.sa.sa_family) {
1047 #ifdef INET
1048         case AF_INET:
1049                 bcopy(((caddr_t)(tc + 1)) +
1050                     offsetof(struct ip, ip_len),
1051                     (caddr_t) &iplen, sizeof(u_int16_t));
1052                 iplen = htons(ntohs(iplen) + rplen + authsize);
1053                 m_copyback(m, offsetof(struct ip, ip_len),
1054                     sizeof(u_int16_t), (caddr_t) &iplen);
1055                 break;
1056 #endif /* INET */
1057
1058 #ifdef INET6
1059         case AF_INET6:
1060                 bcopy(((caddr_t)(tc + 1)) +
1061                     offsetof(struct ip6_hdr, ip6_plen),
1062                     (caddr_t) &iplen, sizeof(u_int16_t));
1063                 iplen = htons(ntohs(iplen) + rplen + authsize);
1064                 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1065                     sizeof(u_int16_t), (caddr_t) &iplen);
1066                 break;
1067 #endif /* INET6 */
1068         }
1069
1070         /* Fix the Next Header field in saved header. */
1071         ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1072
1073         /* Update the Next Protocol field in the IP header. */
1074         prot = IPPROTO_AH;
1075         m_copyback(m, protoff, sizeof(u_int8_t), (caddr_t) &prot);
1076
1077         /* "Massage" the packet headers for crypto processing. */
1078         error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1079                         skip, ahx->type, 1);
1080         if (error != 0) {
1081                 m = NULL;       /* mbuf was free'd by ah_massage_headers. */
1082                 free(tc, M_XDATA);
1083                 crypto_freereq(crp);
1084                 goto bad;
1085         }
1086
1087         /* Crypto operation descriptor. */
1088         crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1089         crp->crp_flags = CRYPTO_F_IMBUF;
1090         crp->crp_buf = (caddr_t) m;
1091         crp->crp_callback = ah_output_cb;
1092         crp->crp_sid = sav->tdb_cryptoid;
1093         crp->crp_opaque = (caddr_t) tc;
1094
1095         /* These are passed as-is to the callback. */
1096         tc->tc_isr = isr;
1097         tc->tc_spi = sav->spi;
1098         tc->tc_dst = sav->sah->saidx.dst;
1099         tc->tc_proto = sav->sah->saidx.proto;
1100         tc->tc_skip = skip;
1101         tc->tc_protoff = protoff;
1102
1103         return crypto_dispatch(crp);
1104 bad:
1105         if (m)
1106                 m_freem(m);
1107         return (error);
1108 }
1109
1110 /*
1111  * AH output callback from the crypto driver.
1112  */
1113 static int
1114 ah_output_cb(struct cryptop *crp)
1115 {
1116         int skip, protoff, error;
1117         struct tdb_crypto *tc;
1118         struct ipsecrequest *isr;
1119         struct secasvar *sav;
1120         struct mbuf *m;
1121         caddr_t ptr;
1122         int s, err;
1123
1124         tc = (struct tdb_crypto *) crp->crp_opaque;
1125         KASSERT(tc != NULL, ("ah_output_cb: null opaque data area!"));
1126         skip = tc->tc_skip;
1127         protoff = tc->tc_protoff;
1128         ptr = (caddr_t) (tc + 1);
1129         m = (struct mbuf *) crp->crp_buf;
1130
1131         s = splnet();
1132
1133         isr = tc->tc_isr;
1134         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi);
1135         if (sav == NULL) {
1136                 ahstat.ahs_notdb++;
1137                 DPRINTF(("ah_output_cb: SA expired while in crypto\n"));
1138                 error = ENOBUFS;                /*XXX*/
1139                 goto bad;
1140         }
1141         KASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n"));
1142
1143         /* Check for crypto errors. */
1144         if (crp->crp_etype) {
1145                 if (sav->tdb_cryptoid != 0)
1146                         sav->tdb_cryptoid = crp->crp_sid;
1147
1148                 if (crp->crp_etype == EAGAIN) {
1149                         KEY_FREESAV(&sav);
1150                         splx(s);
1151                         return crypto_dispatch(crp);
1152                 }
1153
1154                 ahstat.ahs_noxform++;
1155                 DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype));
1156                 error = crp->crp_etype;
1157                 goto bad;
1158         }
1159
1160         /* Shouldn't happen... */
1161         if (m == NULL) {
1162                 ahstat.ahs_crypto++;
1163                 DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n"));
1164                 error = EINVAL;
1165                 goto bad;
1166         }
1167         ahstat.ahs_hist[sav->alg_auth]++;
1168
1169         /*
1170          * Copy original headers (with the new protocol number) back
1171          * in place.
1172          */
1173         m_copyback(m, 0, skip, ptr);
1174
1175         /* No longer needed. */
1176         free(tc, M_XDATA);
1177         crypto_freereq(crp);
1178
1179         /* NB: m is reclaimed by ipsec_process_done. */
1180         err = ipsec_process_done(m, isr);
1181         KEY_FREESAV(&sav);
1182         splx(s);
1183         return err;
1184 bad:
1185         if (sav)
1186                 KEY_FREESAV(&sav);
1187         splx(s);
1188         if (m)
1189                 m_freem(m);
1190         free(tc, M_XDATA);
1191         crypto_freereq(crp);
1192         return error;
1193 }
1194
1195 static struct xformsw ah_xformsw = {
1196         XF_AH,          XFT_AUTH,       "IPsec AH",
1197         ah_init,        ah_zeroize,     ah_input,       ah_output,
1198 };
1199
1200 static void
1201 ah_attach(void)
1202 {
1203         xform_register(&ah_xformsw);
1204 }
1205 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);