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sys/netipsec/xform_esp.c
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1 /* $FreeBSD: releng/8.0/sys/netipsec/xform_esp.c 196019 2009-08-01 19:26:27Z rwatson $ */ 2 /* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 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. 18 * 19 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 20 * Angelos D. Keromytis and Niels Provos. 21 * Copyright (c) 2001 Angelos D. Keromytis. 22 * 23 * Permission to use, copy, and modify this software with or without fee 24 * is hereby granted, provided that this entire notice is included in 25 * all copies of any software which is or includes a copy or 26 * modification of this software. 27 * You may use this code under the GNU public license if you so wish. Please 28 * contribute changes back to the authors under this freer than GPL license 29 * so that we may further the use of strong encryption without limitations to 30 * all. 31 * 32 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 33 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 34 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 35 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 36 * PURPOSE. 37 */ 38 #include "opt_inet.h" 39 #include "opt_inet6.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/mbuf.h> 44 #include <sys/socket.h> 45 #include <sys/syslog.h> 46 #include <sys/kernel.h> 47 #include <sys/random.h> 48 #include <sys/sysctl.h> 49 50 #include <net/if.h> 51 #include <net/vnet.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_ecn.h> 57 #include <netinet/ip6.h> 58 59 #include <net/route.h> 60 #include <netipsec/ipsec.h> 61 #include <netipsec/ah.h> 62 #include <netipsec/ah_var.h> 63 #include <netipsec/esp.h> 64 #include <netipsec/esp_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 #include <opencrypto/xform.h> 78 79 VNET_DEFINE(int, esp_enable) = 1; 80 VNET_DEFINE(struct espstat, espstat); 81 82 SYSCTL_DECL(_net_inet_esp); 83 SYSCTL_VNET_INT(_net_inet_esp, OID_AUTO, 84 esp_enable, CTLFLAG_RW, &VNET_NAME(esp_enable), 0, ""); 85 SYSCTL_VNET_STRUCT(_net_inet_esp, IPSECCTL_STATS, 86 stats, CTLFLAG_RD, &VNET_NAME(espstat), espstat, ""); 87 88 /* max iv length over all algorithms */ 89 static VNET_DEFINE(int, esp_max_ivlen) = 0; 90 #define V_esp_max_ivlen VNET(esp_max_ivlen) 91 92 static int esp_input_cb(struct cryptop *op); 93 static int esp_output_cb(struct cryptop *crp); 94 95 /* 96 * NB: this is public for use by the PF_KEY support. 97 * NB: if you add support here; be sure to add code to esp_attach below! 98 */ 99 struct enc_xform * 100 esp_algorithm_lookup(int alg) 101 { 102 if (alg >= ESP_ALG_MAX) 103 return NULL; 104 switch (alg) { 105 case SADB_EALG_DESCBC: 106 return &enc_xform_des; 107 case SADB_EALG_3DESCBC: 108 return &enc_xform_3des; 109 case SADB_X_EALG_AES: 110 return &enc_xform_rijndael128; 111 case SADB_X_EALG_BLOWFISHCBC: 112 return &enc_xform_blf; 113 case SADB_X_EALG_CAST128CBC: 114 return &enc_xform_cast5; 115 case SADB_X_EALG_SKIPJACK: 116 return &enc_xform_skipjack; 117 case SADB_EALG_NULL: 118 return &enc_xform_null; 119 case SADB_X_EALG_CAMELLIACBC: 120 return &enc_xform_camellia; 121 } 122 return NULL; 123 } 124 125 size_t 126 esp_hdrsiz(struct secasvar *sav) 127 { 128 size_t size; 129 130 if (sav != NULL) { 131 /*XXX not right for null algorithm--does it matter??*/ 132 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, 133 ("SA with null xform")); 134 if (sav->flags & SADB_X_EXT_OLD) 135 size = sizeof (struct esp); 136 else 137 size = sizeof (struct newesp); 138 size += sav->tdb_encalgxform->blocksize + 9; 139 /*XXX need alg check???*/ 140 if (sav->tdb_authalgxform != NULL && sav->replay) 141 size += ah_hdrsiz(sav); 142 } else { 143 /* 144 * base header size 145 * + max iv length for CBC mode 146 * + max pad length 147 * + sizeof (pad length field) 148 * + sizeof (next header field) 149 * + max icv supported. 150 */ 151 size = sizeof (struct newesp) + V_esp_max_ivlen + 9 + 16; 152 } 153 return size; 154 } 155 156 /* 157 * esp_init() is called when an SPI is being set up. 158 */ 159 static int 160 esp_init(struct secasvar *sav, struct xformsw *xsp) 161 { 162 struct enc_xform *txform; 163 struct cryptoini cria, crie; 164 int keylen; 165 int error; 166 167 txform = esp_algorithm_lookup(sav->alg_enc); 168 if (txform == NULL) { 169 DPRINTF(("%s: unsupported encryption algorithm %d\n", 170 __func__, sav->alg_enc)); 171 return EINVAL; 172 } 173 if (sav->key_enc == NULL) { 174 DPRINTF(("%s: no encoding key for %s algorithm\n", 175 __func__, txform->name)); 176 return EINVAL; 177 } 178 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { 179 DPRINTF(("%s: 4-byte IV not supported with protocol\n", 180 __func__)); 181 return EINVAL; 182 } 183 keylen = _KEYLEN(sav->key_enc); 184 if (txform->minkey > keylen || keylen > txform->maxkey) { 185 DPRINTF(("%s: invalid key length %u, must be in the range " 186 "[%u..%u] for algorithm %s\n", __func__, 187 keylen, txform->minkey, txform->maxkey, 188 txform->name)); 189 return EINVAL; 190 } 191 192 /* 193 * NB: The null xform needs a non-zero blocksize to keep the 194 * crypto code happy but if we use it to set ivlen then 195 * the ESP header will be processed incorrectly. The 196 * compromise is to force it to zero here. 197 */ 198 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize); 199 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK); 200 if (sav->iv == NULL) { 201 DPRINTF(("%s: no memory for IV\n", __func__)); 202 return EINVAL; 203 } 204 key_randomfill(sav->iv, sav->ivlen); /*XXX*/ 205 206 /* 207 * Setup AH-related state. 208 */ 209 if (sav->alg_auth != 0) { 210 error = ah_init0(sav, xsp, &cria); 211 if (error) 212 return error; 213 } 214 215 /* NB: override anything set in ah_init0 */ 216 sav->tdb_xform = xsp; 217 sav->tdb_encalgxform = txform; 218 219 /* Initialize crypto session. */ 220 bzero(&crie, sizeof (crie)); 221 crie.cri_alg = sav->tdb_encalgxform->type; 222 crie.cri_klen = _KEYBITS(sav->key_enc); 223 crie.cri_key = sav->key_enc->key_data; 224 /* XXX Rounds ? */ 225 226 if (sav->tdb_authalgxform && sav->tdb_encalgxform) { 227 /* init both auth & enc */ 228 crie.cri_next = &cria; 229 error = crypto_newsession(&sav->tdb_cryptoid, 230 &crie, V_crypto_support); 231 } else if (sav->tdb_encalgxform) { 232 error = crypto_newsession(&sav->tdb_cryptoid, 233 &crie, V_crypto_support); 234 } else if (sav->tdb_authalgxform) { 235 error = crypto_newsession(&sav->tdb_cryptoid, 236 &cria, V_crypto_support); 237 } else { 238 /* XXX cannot happen? */ 239 DPRINTF(("%s: no encoding OR authentication xform!\n", 240 __func__)); 241 error = EINVAL; 242 } 243 return error; 244 } 245 246 /* 247 * Paranoia. 248 */ 249 static int 250 esp_zeroize(struct secasvar *sav) 251 { 252 /* NB: ah_zerorize free's the crypto session state */ 253 int error = ah_zeroize(sav); 254 255 if (sav->key_enc) 256 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc)); 257 if (sav->iv) { 258 free(sav->iv, M_XDATA); 259 sav->iv = NULL; 260 } 261 sav->tdb_encalgxform = NULL; 262 sav->tdb_xform = NULL; 263 return error; 264 } 265 266 /* 267 * ESP input processing, called (eventually) through the protocol switch. 268 */ 269 static int 270 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 271 { 272 struct auth_hash *esph; 273 struct enc_xform *espx; 274 struct tdb_ident *tdbi; 275 struct tdb_crypto *tc; 276 int plen, alen, hlen; 277 struct m_tag *mtag; 278 struct newesp *esp; 279 280 struct cryptodesc *crde; 281 struct cryptop *crp; 282 283 IPSEC_ASSERT(sav != NULL, ("null SA")); 284 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform")); 285 IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0, 286 ("misaligned packet, skip %u pkt len %u", 287 skip, m->m_pkthdr.len)); 288 289 /* XXX don't pullup, just copy header */ 290 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); 291 292 esph = sav->tdb_authalgxform; 293 espx = sav->tdb_encalgxform; 294 295 /* Determine the ESP header length */ 296 if (sav->flags & SADB_X_EXT_OLD) 297 hlen = sizeof (struct esp) + sav->ivlen; 298 else 299 hlen = sizeof (struct newesp) + sav->ivlen; 300 /* Authenticator hash size */ 301 alen = esph ? AH_HMAC_HASHLEN : 0; 302 303 /* 304 * Verify payload length is multiple of encryption algorithm 305 * block size. 306 * 307 * NB: This works for the null algorithm because the blocksize 308 * is 4 and all packets must be 4-byte aligned regardless 309 * of the algorithm. 310 */ 311 plen = m->m_pkthdr.len - (skip + hlen + alen); 312 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { 313 DPRINTF(("%s: payload of %d octets not a multiple of %d octets," 314 " SA %s/%08lx\n", __func__, 315 plen, espx->blocksize, 316 ipsec_address(&sav->sah->saidx.dst), 317 (u_long) ntohl(sav->spi))); 318 V_espstat.esps_badilen++; 319 m_freem(m); 320 return EINVAL; 321 } 322 323 /* 324 * Check sequence number. 325 */ 326 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { 327 DPRINTF(("%s: packet replay check for %s\n", __func__, 328 ipsec_logsastr(sav))); /*XXX*/ 329 V_espstat.esps_replay++; 330 m_freem(m); 331 return ENOBUFS; /*XXX*/ 332 } 333 334 /* Update the counters */ 335 V_espstat.esps_ibytes += m->m_pkthdr.len - (skip + hlen + alen); 336 337 /* Find out if we've already done crypto */ 338 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 339 mtag != NULL; 340 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 341 tdbi = (struct tdb_ident *) (mtag + 1); 342 if (tdbi->proto == sav->sah->saidx.proto && 343 tdbi->spi == sav->spi && 344 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 345 sizeof(union sockaddr_union))) 346 break; 347 } 348 349 /* Get crypto descriptors */ 350 crp = crypto_getreq(esph && espx ? 2 : 1); 351 if (crp == NULL) { 352 DPRINTF(("%s: failed to acquire crypto descriptors\n", 353 __func__)); 354 V_espstat.esps_crypto++; 355 m_freem(m); 356 return ENOBUFS; 357 } 358 359 /* Get IPsec-specific opaque pointer */ 360 if (esph == NULL || mtag != NULL) 361 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 362 M_XDATA, M_NOWAIT|M_ZERO); 363 else 364 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, 365 M_XDATA, M_NOWAIT|M_ZERO); 366 if (tc == NULL) { 367 crypto_freereq(crp); 368 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 369 V_espstat.esps_crypto++; 370 m_freem(m); 371 return ENOBUFS; 372 } 373 374 tc->tc_ptr = (caddr_t) mtag; 375 376 if (esph) { 377 struct cryptodesc *crda = crp->crp_desc; 378 379 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor")); 380 381 /* Authentication descriptor */ 382 crda->crd_skip = skip; 383 crda->crd_len = m->m_pkthdr.len - (skip + alen); 384 crda->crd_inject = m->m_pkthdr.len - alen; 385 386 crda->crd_alg = esph->type; 387 crda->crd_key = sav->key_auth->key_data; 388 crda->crd_klen = _KEYBITS(sav->key_auth); 389 390 /* Copy the authenticator */ 391 if (mtag == NULL) 392 m_copydata(m, m->m_pkthdr.len - alen, alen, 393 (caddr_t) (tc + 1)); 394 395 /* Chain authentication request */ 396 crde = crda->crd_next; 397 } else { 398 crde = crp->crp_desc; 399 } 400 401 /* Crypto operation descriptor */ 402 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 403 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 404 crp->crp_buf = (caddr_t) m; 405 crp->crp_callback = esp_input_cb; 406 crp->crp_sid = sav->tdb_cryptoid; 407 crp->crp_opaque = (caddr_t) tc; 408 409 /* These are passed as-is to the callback */ 410 tc->tc_spi = sav->spi; 411 tc->tc_dst = sav->sah->saidx.dst; 412 tc->tc_proto = sav->sah->saidx.proto; 413 tc->tc_protoff = protoff; 414 tc->tc_skip = skip; 415 416 /* Decryption descriptor */ 417 if (espx) { 418 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor")); 419 crde->crd_skip = skip + hlen; 420 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 421 crde->crd_inject = skip + hlen - sav->ivlen; 422 423 crde->crd_alg = espx->type; 424 crde->crd_key = sav->key_enc->key_data; 425 crde->crd_klen = _KEYBITS(sav->key_enc); 426 /* XXX Rounds ? */ 427 } 428 429 if (mtag == NULL) 430 return crypto_dispatch(crp); 431 else 432 return esp_input_cb(crp); 433 } 434 435 #ifdef INET6 436 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 437 if (saidx->dst.sa.sa_family == AF_INET6) { \ 438 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 439 } else { \ 440 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 441 } \ 442 } while (0) 443 #else 444 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 445 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 446 #endif 447 448 /* 449 * ESP input callback from the crypto driver. 450 */ 451 static int 452 esp_input_cb(struct cryptop *crp) 453 { 454 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN]; 455 int hlen, skip, protoff, error; 456 struct mbuf *m; 457 struct cryptodesc *crd; 458 struct auth_hash *esph; 459 struct enc_xform *espx; 460 struct tdb_crypto *tc; 461 struct m_tag *mtag; 462 struct secasvar *sav; 463 struct secasindex *saidx; 464 caddr_t ptr; 465 466 crd = crp->crp_desc; 467 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); 468 469 tc = (struct tdb_crypto *) crp->crp_opaque; 470 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 471 skip = tc->tc_skip; 472 protoff = tc->tc_protoff; 473 mtag = (struct m_tag *) tc->tc_ptr; 474 m = (struct mbuf *) crp->crp_buf; 475 476 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 477 if (sav == NULL) { 478 V_espstat.esps_notdb++; 479 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 480 __func__, ipsec_address(&tc->tc_dst), 481 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 482 error = ENOBUFS; /*XXX*/ 483 goto bad; 484 } 485 486 saidx = &sav->sah->saidx; 487 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 488 saidx->dst.sa.sa_family == AF_INET6, 489 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 490 491 esph = sav->tdb_authalgxform; 492 espx = sav->tdb_encalgxform; 493 494 /* Check for crypto errors */ 495 if (crp->crp_etype) { 496 /* Reset the session ID */ 497 if (sav->tdb_cryptoid != 0) 498 sav->tdb_cryptoid = crp->crp_sid; 499 500 if (crp->crp_etype == EAGAIN) { 501 KEY_FREESAV(&sav); 502 error = crypto_dispatch(crp); 503 return error; 504 } 505 506 V_espstat.esps_noxform++; 507 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 508 error = crp->crp_etype; 509 goto bad; 510 } 511 512 /* Shouldn't happen... */ 513 if (m == NULL) { 514 V_espstat.esps_crypto++; 515 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 516 error = EINVAL; 517 goto bad; 518 } 519 V_espstat.esps_hist[sav->alg_enc]++; 520 521 /* If authentication was performed, check now. */ 522 if (esph != NULL) { 523 /* 524 * If we have a tag, it means an IPsec-aware NIC did 525 * the verification for us. Otherwise we need to 526 * check the authentication calculation. 527 */ 528 V_ahstat.ahs_hist[sav->alg_auth]++; 529 if (mtag == NULL) { 530 /* Copy the authenticator from the packet */ 531 m_copydata(m, m->m_pkthdr.len - AH_HMAC_HASHLEN, 532 AH_HMAC_HASHLEN, aalg); 533 534 ptr = (caddr_t) (tc + 1); 535 536 /* Verify authenticator */ 537 if (bcmp(ptr, aalg, AH_HMAC_HASHLEN) != 0) { 538 DPRINTF(("%s: " 539 "authentication hash mismatch for packet in SA %s/%08lx\n", 540 __func__, 541 ipsec_address(&saidx->dst), 542 (u_long) ntohl(sav->spi))); 543 V_espstat.esps_badauth++; 544 error = EACCES; 545 goto bad; 546 } 547 } 548 549 /* Remove trailing authenticator */ 550 m_adj(m, -AH_HMAC_HASHLEN); 551 } 552 553 /* Release the crypto descriptors */ 554 free(tc, M_XDATA), tc = NULL; 555 crypto_freereq(crp), crp = NULL; 556 557 /* 558 * Packet is now decrypted. 559 */ 560 m->m_flags |= M_DECRYPTED; 561 562 /* 563 * Update replay sequence number, if appropriate. 564 */ 565 if (sav->replay) { 566 u_int32_t seq; 567 568 m_copydata(m, skip + offsetof(struct newesp, esp_seq), 569 sizeof (seq), (caddr_t) &seq); 570 if (ipsec_updatereplay(ntohl(seq), sav)) { 571 DPRINTF(("%s: packet replay check for %s\n", __func__, 572 ipsec_logsastr(sav))); 573 V_espstat.esps_replay++; 574 error = ENOBUFS; 575 goto bad; 576 } 577 } 578 579 /* Determine the ESP header length */ 580 if (sav->flags & SADB_X_EXT_OLD) 581 hlen = sizeof (struct esp) + sav->ivlen; 582 else 583 hlen = sizeof (struct newesp) + sav->ivlen; 584 585 /* Remove the ESP header and IV from the mbuf. */ 586 error = m_striphdr(m, skip, hlen); 587 if (error) { 588 V_espstat.esps_hdrops++; 589 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__, 590 ipsec_address(&sav->sah->saidx.dst), 591 (u_long) ntohl(sav->spi))); 592 goto bad; 593 } 594 595 /* Save the last three bytes of decrypted data */ 596 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); 597 598 /* Verify pad length */ 599 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { 600 V_espstat.esps_badilen++; 601 DPRINTF(("%s: invalid padding length %d for %u byte packet " 602 "in SA %s/%08lx\n", __func__, 603 lastthree[1], m->m_pkthdr.len - skip, 604 ipsec_address(&sav->sah->saidx.dst), 605 (u_long) ntohl(sav->spi))); 606 error = EINVAL; 607 goto bad; 608 } 609 610 /* Verify correct decryption by checking the last padding bytes */ 611 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { 612 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { 613 V_espstat.esps_badenc++; 614 DPRINTF(("%s: decryption failed for packet in " 615 "SA %s/%08lx\n", __func__, 616 ipsec_address(&sav->sah->saidx.dst), 617 (u_long) ntohl(sav->spi))); 618 error = EINVAL; 619 goto bad; 620 } 621 } 622 623 /* Trim the mbuf chain to remove trailing authenticator and padding */ 624 m_adj(m, -(lastthree[1] + 2)); 625 626 /* Restore the Next Protocol field */ 627 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); 628 629 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 630 631 KEY_FREESAV(&sav); 632 return error; 633 bad: 634 if (sav) 635 KEY_FREESAV(&sav); 636 if (m != NULL) 637 m_freem(m); 638 if (tc != NULL) 639 free(tc, M_XDATA); 640 if (crp != NULL) 641 crypto_freereq(crp); 642 return error; 643 } 644 645 /* 646 * ESP output routine, called by ipsec[46]_process_packet(). 647 */ 648 static int 649 esp_output( 650 struct mbuf *m, 651 struct ipsecrequest *isr, 652 struct mbuf **mp, 653 int skip, 654 int protoff 655 ) 656 { 657 struct enc_xform *espx; 658 struct auth_hash *esph; 659 int hlen, rlen, plen, padding, blks, alen, i, roff; 660 struct mbuf *mo = (struct mbuf *) NULL; 661 struct tdb_crypto *tc; 662 struct secasvar *sav; 663 struct secasindex *saidx; 664 unsigned char *pad; 665 u_int8_t prot; 666 int error, maxpacketsize; 667 668 struct cryptodesc *crde = NULL, *crda = NULL; 669 struct cryptop *crp; 670 671 sav = isr->sav; 672 IPSEC_ASSERT(sav != NULL, ("null SA")); 673 esph = sav->tdb_authalgxform; 674 espx = sav->tdb_encalgxform; 675 IPSEC_ASSERT(espx != NULL, ("null encoding xform")); 676 677 if (sav->flags & SADB_X_EXT_OLD) 678 hlen = sizeof (struct esp) + sav->ivlen; 679 else 680 hlen = sizeof (struct newesp) + sav->ivlen; 681 682 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */ 683 /* 684 * NB: The null encoding transform has a blocksize of 4 685 * so that headers are properly aligned. 686 */ 687 blks = espx->blocksize; /* IV blocksize */ 688 689 /* XXX clamp padding length a la KAME??? */ 690 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; 691 plen = rlen + padding; /* Padded payload length. */ 692 693 if (esph) 694 alen = AH_HMAC_HASHLEN; 695 else 696 alen = 0; 697 698 V_espstat.esps_output++; 699 700 saidx = &sav->sah->saidx; 701 /* Check for maximum packet size violations. */ 702 switch (saidx->dst.sa.sa_family) { 703 #ifdef INET 704 case AF_INET: 705 maxpacketsize = IP_MAXPACKET; 706 break; 707 #endif /* INET */ 708 #ifdef INET6 709 case AF_INET6: 710 maxpacketsize = IPV6_MAXPACKET; 711 break; 712 #endif /* INET6 */ 713 default: 714 DPRINTF(("%s: unknown/unsupported protocol " 715 "family %d, SA %s/%08lx\n", __func__, 716 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), 717 (u_long) ntohl(sav->spi))); 718 V_espstat.esps_nopf++; 719 error = EPFNOSUPPORT; 720 goto bad; 721 } 722 if (skip + hlen + rlen + padding + alen > maxpacketsize) { 723 DPRINTF(("%s: packet in SA %s/%08lx got too big " 724 "(len %u, max len %u)\n", __func__, 725 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), 726 skip + hlen + rlen + padding + alen, maxpacketsize)); 727 V_espstat.esps_toobig++; 728 error = EMSGSIZE; 729 goto bad; 730 } 731 732 /* Update the counters. */ 733 V_espstat.esps_obytes += m->m_pkthdr.len - skip; 734 735 m = m_unshare(m, M_NOWAIT); 736 if (m == NULL) { 737 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 738 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 739 V_espstat.esps_hdrops++; 740 error = ENOBUFS; 741 goto bad; 742 } 743 744 /* Inject ESP header. */ 745 mo = m_makespace(m, skip, hlen, &roff); 746 if (mo == NULL) { 747 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n", 748 __func__, hlen, ipsec_address(&saidx->dst), 749 (u_long) ntohl(sav->spi))); 750 V_espstat.esps_hdrops++; /* XXX diffs from openbsd */ 751 error = ENOBUFS; 752 goto bad; 753 } 754 755 /* Initialize ESP header. */ 756 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); 757 if (sav->replay) { 758 u_int32_t replay; 759 760 #ifdef REGRESSION 761 /* Emulate replay attack when ipsec_replay is TRUE. */ 762 if (!V_ipsec_replay) 763 #endif 764 sav->replay->count++; 765 replay = htonl(sav->replay->count); 766 bcopy((caddr_t) &replay, 767 mtod(mo, caddr_t) + roff + sizeof(u_int32_t), 768 sizeof(u_int32_t)); 769 } 770 771 /* 772 * Add padding -- better to do it ourselves than use the crypto engine, 773 * although if/when we support compression, we'd have to do that. 774 */ 775 pad = (u_char *) m_pad(m, padding + alen); 776 if (pad == NULL) { 777 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__, 778 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 779 m = NULL; /* NB: free'd by m_pad */ 780 error = ENOBUFS; 781 goto bad; 782 } 783 784 /* 785 * Add padding: random, zero, or self-describing. 786 * XXX catch unexpected setting 787 */ 788 switch (sav->flags & SADB_X_EXT_PMASK) { 789 case SADB_X_EXT_PRAND: 790 (void) read_random(pad, padding - 2); 791 break; 792 case SADB_X_EXT_PZERO: 793 bzero(pad, padding - 2); 794 break; 795 case SADB_X_EXT_PSEQ: 796 for (i = 0; i < padding - 2; i++) 797 pad[i] = i+1; 798 break; 799 } 800 801 /* Fix padding length and Next Protocol in padding itself. */ 802 pad[padding - 2] = padding - 2; 803 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); 804 805 /* Fix Next Protocol in IPv4/IPv6 header. */ 806 prot = IPPROTO_ESP; 807 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); 808 809 /* Get crypto descriptors. */ 810 crp = crypto_getreq(esph && espx ? 2 : 1); 811 if (crp == NULL) { 812 DPRINTF(("%s: failed to acquire crypto descriptors\n", 813 __func__)); 814 V_espstat.esps_crypto++; 815 error = ENOBUFS; 816 goto bad; 817 } 818 819 if (espx) { 820 crde = crp->crp_desc; 821 crda = crde->crd_next; 822 823 /* Encryption descriptor. */ 824 crde->crd_skip = skip + hlen; 825 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 826 crde->crd_flags = CRD_F_ENCRYPT; 827 crde->crd_inject = skip + hlen - sav->ivlen; 828 829 /* Encryption operation. */ 830 crde->crd_alg = espx->type; 831 crde->crd_key = sav->key_enc->key_data; 832 crde->crd_klen = _KEYBITS(sav->key_enc); 833 /* XXX Rounds ? */ 834 } else 835 crda = crp->crp_desc; 836 837 /* IPsec-specific opaque crypto info. */ 838 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 839 M_XDATA, M_NOWAIT|M_ZERO); 840 if (tc == NULL) { 841 crypto_freereq(crp); 842 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 843 V_espstat.esps_crypto++; 844 error = ENOBUFS; 845 goto bad; 846 } 847 848 /* Callback parameters */ 849 tc->tc_isr = isr; 850 tc->tc_spi = sav->spi; 851 tc->tc_dst = saidx->dst; 852 tc->tc_proto = saidx->proto; 853 854 /* Crypto operation descriptor. */ 855 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 856 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 857 crp->crp_buf = (caddr_t) m; 858 crp->crp_callback = esp_output_cb; 859 crp->crp_opaque = (caddr_t) tc; 860 crp->crp_sid = sav->tdb_cryptoid; 861 862 if (esph) { 863 /* Authentication descriptor. */ 864 crda->crd_skip = skip; 865 crda->crd_len = m->m_pkthdr.len - (skip + alen); 866 crda->crd_inject = m->m_pkthdr.len - alen; 867 868 /* Authentication operation. */ 869 crda->crd_alg = esph->type; 870 crda->crd_key = sav->key_auth->key_data; 871 crda->crd_klen = _KEYBITS(sav->key_auth); 872 } 873 874 return crypto_dispatch(crp); 875 bad: 876 if (m) 877 m_freem(m); 878 return (error); 879 } 880 881 /* 882 * ESP output callback from the crypto driver. 883 */ 884 static int 885 esp_output_cb(struct cryptop *crp) 886 { 887 struct tdb_crypto *tc; 888 struct ipsecrequest *isr; 889 struct secasvar *sav; 890 struct mbuf *m; 891 int err, error; 892 893 tc = (struct tdb_crypto *) crp->crp_opaque; 894 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 895 m = (struct mbuf *) crp->crp_buf; 896 897 isr = tc->tc_isr; 898 IPSECREQUEST_LOCK(isr); 899 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 900 if (sav == NULL) { 901 V_espstat.esps_notdb++; 902 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 903 __func__, ipsec_address(&tc->tc_dst), 904 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 905 error = ENOBUFS; /*XXX*/ 906 goto bad; 907 } 908 IPSEC_ASSERT(isr->sav == sav, 909 ("SA changed was %p now %p\n", isr->sav, sav)); 910 911 /* Check for crypto errors. */ 912 if (crp->crp_etype) { 913 /* Reset session ID. */ 914 if (sav->tdb_cryptoid != 0) 915 sav->tdb_cryptoid = crp->crp_sid; 916 917 if (crp->crp_etype == EAGAIN) { 918 KEY_FREESAV(&sav); 919 IPSECREQUEST_UNLOCK(isr); 920 error = crypto_dispatch(crp); 921 return error; 922 } 923 924 V_espstat.esps_noxform++; 925 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 926 error = crp->crp_etype; 927 goto bad; 928 } 929 930 /* Shouldn't happen... */ 931 if (m == NULL) { 932 V_espstat.esps_crypto++; 933 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 934 error = EINVAL; 935 goto bad; 936 } 937 V_espstat.esps_hist[sav->alg_enc]++; 938 if (sav->tdb_authalgxform != NULL) 939 V_ahstat.ahs_hist[sav->alg_auth]++; 940 941 /* Release crypto descriptors. */ 942 free(tc, M_XDATA); 943 crypto_freereq(crp); 944 945 #ifdef REGRESSION 946 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 947 if (V_ipsec_integrity) { 948 static unsigned char ipseczeroes[AH_HMAC_HASHLEN]; 949 struct auth_hash *esph; 950 951 /* 952 * Corrupt HMAC if we want to test integrity verification of 953 * the other side. 954 */ 955 esph = sav->tdb_authalgxform; 956 if (esph != NULL) { 957 m_copyback(m, m->m_pkthdr.len - AH_HMAC_HASHLEN, 958 AH_HMAC_HASHLEN, ipseczeroes); 959 } 960 } 961 #endif 962 963 /* NB: m is reclaimed by ipsec_process_done. */ 964 err = ipsec_process_done(m, isr); 965 KEY_FREESAV(&sav); 966 IPSECREQUEST_UNLOCK(isr); 967 return err; 968 bad: 969 if (sav) 970 KEY_FREESAV(&sav); 971 IPSECREQUEST_UNLOCK(isr); 972 if (m) 973 m_freem(m); 974 free(tc, M_XDATA); 975 crypto_freereq(crp); 976 return error; 977 } 978 979 static struct xformsw esp_xformsw = { 980 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", 981 esp_init, esp_zeroize, esp_input, 982 esp_output 983 }; 984 985 static void 986 esp_attach(void) 987 { 988 #define MAXIV(xform) \ 989 if (xform.blocksize > V_esp_max_ivlen) \ 990 V_esp_max_ivlen = xform.blocksize \ 991 992 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ 993 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ 994 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ 995 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ 996 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ 997 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ 998 MAXIV(enc_xform_null); /* SADB_EALG_NULL */ 999 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */ 1000 1001 xform_register(&esp_xformsw); 1002 #undef MAXIV 1003 } 1004 SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
Cache object: 2f97be16a3d4fbb25e4642e2047d706b
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