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sys/netipsec/xform_esp.c
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1 /* $FreeBSD: releng/8.4/sys/netipsec/xform_esp.c 221525 2011-05-06 13:24:10Z fabient $ */ 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 static VNET_DEFINE(int, esp_max_ivlen); /* max iv length over all algorithms */ 89 #define V_esp_max_ivlen VNET(esp_max_ivlen) 90 91 static int esp_input_cb(struct cryptop *op); 92 static int esp_output_cb(struct cryptop *crp); 93 94 /* 95 * NB: this is public for use by the PF_KEY support. 96 * NB: if you add support here; be sure to add code to esp_attach below! 97 */ 98 struct enc_xform * 99 esp_algorithm_lookup(int alg) 100 { 101 if (alg >= ESP_ALG_MAX) 102 return NULL; 103 switch (alg) { 104 case SADB_EALG_DESCBC: 105 return &enc_xform_des; 106 case SADB_EALG_3DESCBC: 107 return &enc_xform_3des; 108 case SADB_X_EALG_AES: 109 return &enc_xform_rijndael128; 110 case SADB_X_EALG_BLOWFISHCBC: 111 return &enc_xform_blf; 112 case SADB_X_EALG_CAST128CBC: 113 return &enc_xform_cast5; 114 case SADB_X_EALG_SKIPJACK: 115 return &enc_xform_skipjack; 116 case SADB_EALG_NULL: 117 return &enc_xform_null; 118 case SADB_X_EALG_CAMELLIACBC: 119 return &enc_xform_camellia; 120 } 121 return NULL; 122 } 123 124 size_t 125 esp_hdrsiz(struct secasvar *sav) 126 { 127 size_t size; 128 129 if (sav != NULL) { 130 /*XXX not right for null algorithm--does it matter??*/ 131 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, 132 ("SA with null xform")); 133 if (sav->flags & SADB_X_EXT_OLD) 134 size = sizeof (struct esp); 135 else 136 size = sizeof (struct newesp); 137 size += sav->tdb_encalgxform->blocksize + 9; 138 /*XXX need alg check???*/ 139 if (sav->tdb_authalgxform != NULL && sav->replay) 140 size += ah_hdrsiz(sav); 141 } else { 142 /* 143 * base header size 144 * + max iv length for CBC mode 145 * + max pad length 146 * + sizeof (pad length field) 147 * + sizeof (next header field) 148 * + max icv supported. 149 */ 150 size = sizeof (struct newesp) + V_esp_max_ivlen + 9 + 16; 151 } 152 return size; 153 } 154 155 /* 156 * esp_init() is called when an SPI is being set up. 157 */ 158 static int 159 esp_init(struct secasvar *sav, struct xformsw *xsp) 160 { 161 struct enc_xform *txform; 162 struct cryptoini cria, crie; 163 int keylen; 164 int error; 165 166 txform = esp_algorithm_lookup(sav->alg_enc); 167 if (txform == NULL) { 168 DPRINTF(("%s: unsupported encryption algorithm %d\n", 169 __func__, sav->alg_enc)); 170 return EINVAL; 171 } 172 if (sav->key_enc == NULL) { 173 DPRINTF(("%s: no encoding key for %s algorithm\n", 174 __func__, txform->name)); 175 return EINVAL; 176 } 177 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { 178 DPRINTF(("%s: 4-byte IV not supported with protocol\n", 179 __func__)); 180 return EINVAL; 181 } 182 keylen = _KEYLEN(sav->key_enc); 183 if (txform->minkey > keylen || keylen > txform->maxkey) { 184 DPRINTF(("%s: invalid key length %u, must be in the range " 185 "[%u..%u] for algorithm %s\n", __func__, 186 keylen, txform->minkey, txform->maxkey, 187 txform->name)); 188 return EINVAL; 189 } 190 191 /* 192 * NB: The null xform needs a non-zero blocksize to keep the 193 * crypto code happy but if we use it to set ivlen then 194 * the ESP header will be processed incorrectly. The 195 * compromise is to force it to zero here. 196 */ 197 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize); 198 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK); 199 if (sav->iv == NULL) { 200 DPRINTF(("%s: no memory for IV\n", __func__)); 201 return EINVAL; 202 } 203 key_randomfill(sav->iv, sav->ivlen); /*XXX*/ 204 205 /* 206 * Setup AH-related state. 207 */ 208 if (sav->alg_auth != 0) { 209 error = ah_init0(sav, xsp, &cria); 210 if (error) 211 return error; 212 } 213 214 /* NB: override anything set in ah_init0 */ 215 sav->tdb_xform = xsp; 216 sav->tdb_encalgxform = txform; 217 218 /* Initialize crypto session. */ 219 bzero(&crie, sizeof (crie)); 220 crie.cri_alg = sav->tdb_encalgxform->type; 221 crie.cri_klen = _KEYBITS(sav->key_enc); 222 crie.cri_key = sav->key_enc->key_data; 223 /* XXX Rounds ? */ 224 225 if (sav->tdb_authalgxform && sav->tdb_encalgxform) { 226 /* init both auth & enc */ 227 crie.cri_next = &cria; 228 error = crypto_newsession(&sav->tdb_cryptoid, 229 &crie, V_crypto_support); 230 } else if (sav->tdb_encalgxform) { 231 error = crypto_newsession(&sav->tdb_cryptoid, 232 &crie, V_crypto_support); 233 } else if (sav->tdb_authalgxform) { 234 error = crypto_newsession(&sav->tdb_cryptoid, 235 &cria, V_crypto_support); 236 } else { 237 /* XXX cannot happen? */ 238 DPRINTF(("%s: no encoding OR authentication xform!\n", 239 __func__)); 240 error = EINVAL; 241 } 242 return error; 243 } 244 245 /* 246 * Paranoia. 247 */ 248 static int 249 esp_zeroize(struct secasvar *sav) 250 { 251 /* NB: ah_zerorize free's the crypto session state */ 252 int error = ah_zeroize(sav); 253 254 if (sav->key_enc) 255 bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc)); 256 if (sav->iv) { 257 free(sav->iv, M_XDATA); 258 sav->iv = NULL; 259 } 260 sav->tdb_encalgxform = NULL; 261 sav->tdb_xform = NULL; 262 return error; 263 } 264 265 /* 266 * ESP input processing, called (eventually) through the protocol switch. 267 */ 268 static int 269 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 270 { 271 struct auth_hash *esph; 272 struct enc_xform *espx; 273 struct tdb_ident *tdbi; 274 struct tdb_crypto *tc; 275 int plen, alen, hlen; 276 struct m_tag *mtag; 277 struct newesp *esp; 278 279 struct cryptodesc *crde; 280 struct cryptop *crp; 281 282 IPSEC_ASSERT(sav != NULL, ("null SA")); 283 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform")); 284 IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0, 285 ("misaligned packet, skip %u pkt len %u", 286 skip, m->m_pkthdr.len)); 287 288 /* XXX don't pullup, just copy header */ 289 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); 290 291 esph = sav->tdb_authalgxform; 292 espx = sav->tdb_encalgxform; 293 294 /* Determine the ESP header length */ 295 if (sav->flags & SADB_X_EXT_OLD) 296 hlen = sizeof (struct esp) + sav->ivlen; 297 else 298 hlen = sizeof (struct newesp) + sav->ivlen; 299 /* Authenticator hash size */ 300 if (esph != NULL) { 301 switch (esph->type) { 302 case CRYPTO_SHA2_256_HMAC: 303 case CRYPTO_SHA2_384_HMAC: 304 case CRYPTO_SHA2_512_HMAC: 305 alen = esph->hashsize/2; 306 break; 307 default: 308 alen = AH_HMAC_HASHLEN; 309 break; 310 } 311 }else 312 alen = 0; 313 314 /* 315 * Verify payload length is multiple of encryption algorithm 316 * block size. 317 * 318 * NB: This works for the null algorithm because the blocksize 319 * is 4 and all packets must be 4-byte aligned regardless 320 * of the algorithm. 321 */ 322 plen = m->m_pkthdr.len - (skip + hlen + alen); 323 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { 324 DPRINTF(("%s: payload of %d octets not a multiple of %d octets," 325 " SA %s/%08lx\n", __func__, 326 plen, espx->blocksize, 327 ipsec_address(&sav->sah->saidx.dst), 328 (u_long) ntohl(sav->spi))); 329 V_espstat.esps_badilen++; 330 m_freem(m); 331 return EINVAL; 332 } 333 334 /* 335 * Check sequence number. 336 */ 337 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { 338 DPRINTF(("%s: packet replay check for %s\n", __func__, 339 ipsec_logsastr(sav))); /*XXX*/ 340 V_espstat.esps_replay++; 341 m_freem(m); 342 return ENOBUFS; /*XXX*/ 343 } 344 345 /* Update the counters */ 346 V_espstat.esps_ibytes += m->m_pkthdr.len - (skip + hlen + alen); 347 348 /* Find out if we've already done crypto */ 349 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 350 mtag != NULL; 351 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 352 tdbi = (struct tdb_ident *) (mtag + 1); 353 if (tdbi->proto == sav->sah->saidx.proto && 354 tdbi->spi == sav->spi && 355 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 356 sizeof(union sockaddr_union))) 357 break; 358 } 359 360 /* Get crypto descriptors */ 361 crp = crypto_getreq(esph && espx ? 2 : 1); 362 if (crp == NULL) { 363 DPRINTF(("%s: failed to acquire crypto descriptors\n", 364 __func__)); 365 V_espstat.esps_crypto++; 366 m_freem(m); 367 return ENOBUFS; 368 } 369 370 /* Get IPsec-specific opaque pointer */ 371 if (esph == NULL || mtag != NULL) 372 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 373 M_XDATA, M_NOWAIT|M_ZERO); 374 else 375 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, 376 M_XDATA, M_NOWAIT|M_ZERO); 377 if (tc == NULL) { 378 crypto_freereq(crp); 379 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 380 V_espstat.esps_crypto++; 381 m_freem(m); 382 return ENOBUFS; 383 } 384 385 tc->tc_ptr = (caddr_t) mtag; 386 387 if (esph) { 388 struct cryptodesc *crda = crp->crp_desc; 389 390 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor")); 391 392 /* Authentication descriptor */ 393 crda->crd_skip = skip; 394 crda->crd_len = m->m_pkthdr.len - (skip + alen); 395 crda->crd_inject = m->m_pkthdr.len - alen; 396 397 crda->crd_alg = esph->type; 398 crda->crd_key = sav->key_auth->key_data; 399 crda->crd_klen = _KEYBITS(sav->key_auth); 400 401 /* Copy the authenticator */ 402 if (mtag == NULL) 403 m_copydata(m, m->m_pkthdr.len - alen, alen, 404 (caddr_t) (tc + 1)); 405 406 /* Chain authentication request */ 407 crde = crda->crd_next; 408 } else { 409 crde = crp->crp_desc; 410 } 411 412 /* Crypto operation descriptor */ 413 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 414 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 415 crp->crp_buf = (caddr_t) m; 416 crp->crp_callback = esp_input_cb; 417 crp->crp_sid = sav->tdb_cryptoid; 418 crp->crp_opaque = (caddr_t) tc; 419 420 /* These are passed as-is to the callback */ 421 tc->tc_spi = sav->spi; 422 tc->tc_dst = sav->sah->saidx.dst; 423 tc->tc_proto = sav->sah->saidx.proto; 424 tc->tc_protoff = protoff; 425 tc->tc_skip = skip; 426 KEY_ADDREFSA(sav); 427 tc->tc_sav = sav; 428 429 /* Decryption descriptor */ 430 if (espx) { 431 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor")); 432 crde->crd_skip = skip + hlen; 433 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 434 crde->crd_inject = skip + hlen - sav->ivlen; 435 436 crde->crd_alg = espx->type; 437 crde->crd_key = sav->key_enc->key_data; 438 crde->crd_klen = _KEYBITS(sav->key_enc); 439 /* XXX Rounds ? */ 440 } 441 442 if (mtag == NULL) 443 return crypto_dispatch(crp); 444 else 445 return esp_input_cb(crp); 446 } 447 448 #ifdef INET6 449 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 450 if (saidx->dst.sa.sa_family == AF_INET6) { \ 451 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 452 } else { \ 453 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 454 } \ 455 } while (0) 456 #else 457 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 458 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 459 #endif 460 461 /* 462 * ESP input callback from the crypto driver. 463 */ 464 static int 465 esp_input_cb(struct cryptop *crp) 466 { 467 u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN]; 468 int hlen, skip, protoff, error, alen; 469 struct mbuf *m; 470 struct cryptodesc *crd; 471 struct auth_hash *esph; 472 struct enc_xform *espx; 473 struct tdb_crypto *tc; 474 struct m_tag *mtag; 475 struct secasvar *sav; 476 struct secasindex *saidx; 477 caddr_t ptr; 478 479 crd = crp->crp_desc; 480 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); 481 482 tc = (struct tdb_crypto *) crp->crp_opaque; 483 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 484 skip = tc->tc_skip; 485 protoff = tc->tc_protoff; 486 mtag = (struct m_tag *) tc->tc_ptr; 487 m = (struct mbuf *) crp->crp_buf; 488 489 sav = tc->tc_sav; 490 IPSEC_ASSERT(sav != NULL, ("null SA!")); 491 492 saidx = &sav->sah->saidx; 493 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 494 saidx->dst.sa.sa_family == AF_INET6, 495 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 496 497 esph = sav->tdb_authalgxform; 498 espx = sav->tdb_encalgxform; 499 500 /* Check for crypto errors */ 501 if (crp->crp_etype) { 502 /* Reset the session ID */ 503 if (sav->tdb_cryptoid != 0) 504 sav->tdb_cryptoid = crp->crp_sid; 505 506 if (crp->crp_etype == EAGAIN) { 507 error = crypto_dispatch(crp); 508 return error; 509 } 510 511 V_espstat.esps_noxform++; 512 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 513 error = crp->crp_etype; 514 goto bad; 515 } 516 517 /* Shouldn't happen... */ 518 if (m == NULL) { 519 V_espstat.esps_crypto++; 520 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 521 error = EINVAL; 522 goto bad; 523 } 524 V_espstat.esps_hist[sav->alg_enc]++; 525 526 /* If authentication was performed, check now. */ 527 if (esph != NULL) { 528 switch (esph->type) { 529 case CRYPTO_SHA2_256_HMAC: 530 case CRYPTO_SHA2_384_HMAC: 531 case CRYPTO_SHA2_512_HMAC: 532 alen = esph->hashsize/2; 533 break; 534 default: 535 alen = AH_HMAC_HASHLEN; 536 break; 537 } 538 /* 539 * If we have a tag, it means an IPsec-aware NIC did 540 * the verification for us. Otherwise we need to 541 * check the authentication calculation. 542 */ 543 V_ahstat.ahs_hist[sav->alg_auth]++; 544 if (mtag == NULL) { 545 /* Copy the authenticator from the packet */ 546 m_copydata(m, m->m_pkthdr.len - alen, 547 alen, aalg); 548 549 ptr = (caddr_t) (tc + 1); 550 551 /* Verify authenticator */ 552 if (bcmp(ptr, aalg, alen) != 0) { 553 DPRINTF(("%s: " 554 "authentication hash mismatch for packet in SA %s/%08lx\n", 555 __func__, 556 ipsec_address(&saidx->dst), 557 (u_long) ntohl(sav->spi))); 558 V_espstat.esps_badauth++; 559 error = EACCES; 560 goto bad; 561 } 562 } 563 564 /* Remove trailing authenticator */ 565 m_adj(m, -alen); 566 } 567 568 /* Release the crypto descriptors */ 569 free(tc, M_XDATA), tc = NULL; 570 crypto_freereq(crp), crp = NULL; 571 572 /* 573 * Packet is now decrypted. 574 */ 575 m->m_flags |= M_DECRYPTED; 576 577 /* 578 * Update replay sequence number, if appropriate. 579 */ 580 if (sav->replay) { 581 u_int32_t seq; 582 583 m_copydata(m, skip + offsetof(struct newesp, esp_seq), 584 sizeof (seq), (caddr_t) &seq); 585 if (ipsec_updatereplay(ntohl(seq), sav)) { 586 DPRINTF(("%s: packet replay check for %s\n", __func__, 587 ipsec_logsastr(sav))); 588 V_espstat.esps_replay++; 589 error = ENOBUFS; 590 goto bad; 591 } 592 } 593 594 /* Determine the ESP header length */ 595 if (sav->flags & SADB_X_EXT_OLD) 596 hlen = sizeof (struct esp) + sav->ivlen; 597 else 598 hlen = sizeof (struct newesp) + sav->ivlen; 599 600 /* Remove the ESP header and IV from the mbuf. */ 601 error = m_striphdr(m, skip, hlen); 602 if (error) { 603 V_espstat.esps_hdrops++; 604 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__, 605 ipsec_address(&sav->sah->saidx.dst), 606 (u_long) ntohl(sav->spi))); 607 goto bad; 608 } 609 610 /* Save the last three bytes of decrypted data */ 611 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); 612 613 /* Verify pad length */ 614 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { 615 V_espstat.esps_badilen++; 616 DPRINTF(("%s: invalid padding length %d for %u byte packet " 617 "in SA %s/%08lx\n", __func__, 618 lastthree[1], m->m_pkthdr.len - skip, 619 ipsec_address(&sav->sah->saidx.dst), 620 (u_long) ntohl(sav->spi))); 621 error = EINVAL; 622 goto bad; 623 } 624 625 /* Verify correct decryption by checking the last padding bytes */ 626 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { 627 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { 628 V_espstat.esps_badenc++; 629 DPRINTF(("%s: decryption failed for packet in " 630 "SA %s/%08lx\n", __func__, 631 ipsec_address(&sav->sah->saidx.dst), 632 (u_long) ntohl(sav->spi))); 633 error = EINVAL; 634 goto bad; 635 } 636 } 637 638 /* Trim the mbuf chain to remove trailing authenticator and padding */ 639 m_adj(m, -(lastthree[1] + 2)); 640 641 /* Restore the Next Protocol field */ 642 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); 643 644 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 645 646 KEY_FREESAV(&sav); 647 return error; 648 bad: 649 if (sav) 650 KEY_FREESAV(&sav); 651 if (m != NULL) 652 m_freem(m); 653 if (tc != NULL) 654 free(tc, M_XDATA); 655 if (crp != NULL) 656 crypto_freereq(crp); 657 return error; 658 } 659 660 /* 661 * ESP output routine, called by ipsec[46]_process_packet(). 662 */ 663 static int 664 esp_output( 665 struct mbuf *m, 666 struct ipsecrequest *isr, 667 struct mbuf **mp, 668 int skip, 669 int protoff 670 ) 671 { 672 struct enc_xform *espx; 673 struct auth_hash *esph; 674 int hlen, rlen, plen, padding, blks, alen, i, roff; 675 struct mbuf *mo = (struct mbuf *) NULL; 676 struct tdb_crypto *tc; 677 struct secasvar *sav; 678 struct secasindex *saidx; 679 unsigned char *pad; 680 u_int8_t prot; 681 int error, maxpacketsize; 682 683 struct cryptodesc *crde = NULL, *crda = NULL; 684 struct cryptop *crp; 685 686 sav = isr->sav; 687 IPSEC_ASSERT(sav != NULL, ("null SA")); 688 esph = sav->tdb_authalgxform; 689 espx = sav->tdb_encalgxform; 690 IPSEC_ASSERT(espx != NULL, ("null encoding xform")); 691 692 if (sav->flags & SADB_X_EXT_OLD) 693 hlen = sizeof (struct esp) + sav->ivlen; 694 else 695 hlen = sizeof (struct newesp) + sav->ivlen; 696 697 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */ 698 /* 699 * NB: The null encoding transform has a blocksize of 4 700 * so that headers are properly aligned. 701 */ 702 blks = espx->blocksize; /* IV blocksize */ 703 704 /* XXX clamp padding length a la KAME??? */ 705 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; 706 plen = rlen + padding; /* Padded payload length. */ 707 708 if (esph) 709 switch (esph->type) { 710 case CRYPTO_SHA2_256_HMAC: 711 case CRYPTO_SHA2_384_HMAC: 712 case CRYPTO_SHA2_512_HMAC: 713 alen = esph->hashsize/2; 714 break; 715 default: 716 alen = AH_HMAC_HASHLEN; 717 break; 718 } 719 else 720 alen = 0; 721 722 V_espstat.esps_output++; 723 724 saidx = &sav->sah->saidx; 725 /* Check for maximum packet size violations. */ 726 switch (saidx->dst.sa.sa_family) { 727 #ifdef INET 728 case AF_INET: 729 maxpacketsize = IP_MAXPACKET; 730 break; 731 #endif /* INET */ 732 #ifdef INET6 733 case AF_INET6: 734 maxpacketsize = IPV6_MAXPACKET; 735 break; 736 #endif /* INET6 */ 737 default: 738 DPRINTF(("%s: unknown/unsupported protocol " 739 "family %d, SA %s/%08lx\n", __func__, 740 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), 741 (u_long) ntohl(sav->spi))); 742 V_espstat.esps_nopf++; 743 error = EPFNOSUPPORT; 744 goto bad; 745 } 746 if (skip + hlen + rlen + padding + alen > maxpacketsize) { 747 DPRINTF(("%s: packet in SA %s/%08lx got too big " 748 "(len %u, max len %u)\n", __func__, 749 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), 750 skip + hlen + rlen + padding + alen, maxpacketsize)); 751 V_espstat.esps_toobig++; 752 error = EMSGSIZE; 753 goto bad; 754 } 755 756 /* Update the counters. */ 757 V_espstat.esps_obytes += m->m_pkthdr.len - skip; 758 759 m = m_unshare(m, M_NOWAIT); 760 if (m == NULL) { 761 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 762 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 763 V_espstat.esps_hdrops++; 764 error = ENOBUFS; 765 goto bad; 766 } 767 768 /* Inject ESP header. */ 769 mo = m_makespace(m, skip, hlen, &roff); 770 if (mo == NULL) { 771 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n", 772 __func__, hlen, ipsec_address(&saidx->dst), 773 (u_long) ntohl(sav->spi))); 774 V_espstat.esps_hdrops++; /* XXX diffs from openbsd */ 775 error = ENOBUFS; 776 goto bad; 777 } 778 779 /* Initialize ESP header. */ 780 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); 781 if (sav->replay) { 782 u_int32_t replay; 783 784 #ifdef REGRESSION 785 /* Emulate replay attack when ipsec_replay is TRUE. */ 786 if (!V_ipsec_replay) 787 #endif 788 sav->replay->count++; 789 replay = htonl(sav->replay->count); 790 bcopy((caddr_t) &replay, 791 mtod(mo, caddr_t) + roff + sizeof(u_int32_t), 792 sizeof(u_int32_t)); 793 } 794 795 /* 796 * Add padding -- better to do it ourselves than use the crypto engine, 797 * although if/when we support compression, we'd have to do that. 798 */ 799 pad = (u_char *) m_pad(m, padding + alen); 800 if (pad == NULL) { 801 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__, 802 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 803 m = NULL; /* NB: free'd by m_pad */ 804 error = ENOBUFS; 805 goto bad; 806 } 807 808 /* 809 * Add padding: random, zero, or self-describing. 810 * XXX catch unexpected setting 811 */ 812 switch (sav->flags & SADB_X_EXT_PMASK) { 813 case SADB_X_EXT_PRAND: 814 (void) read_random(pad, padding - 2); 815 break; 816 case SADB_X_EXT_PZERO: 817 bzero(pad, padding - 2); 818 break; 819 case SADB_X_EXT_PSEQ: 820 for (i = 0; i < padding - 2; i++) 821 pad[i] = i+1; 822 break; 823 } 824 825 /* Fix padding length and Next Protocol in padding itself. */ 826 pad[padding - 2] = padding - 2; 827 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); 828 829 /* Fix Next Protocol in IPv4/IPv6 header. */ 830 prot = IPPROTO_ESP; 831 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); 832 833 /* Get crypto descriptors. */ 834 crp = crypto_getreq(esph && espx ? 2 : 1); 835 if (crp == NULL) { 836 DPRINTF(("%s: failed to acquire crypto descriptors\n", 837 __func__)); 838 V_espstat.esps_crypto++; 839 error = ENOBUFS; 840 goto bad; 841 } 842 843 if (espx) { 844 crde = crp->crp_desc; 845 crda = crde->crd_next; 846 847 /* Encryption descriptor. */ 848 crde->crd_skip = skip + hlen; 849 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 850 crde->crd_flags = CRD_F_ENCRYPT; 851 crde->crd_inject = skip + hlen - sav->ivlen; 852 853 /* Encryption operation. */ 854 crde->crd_alg = espx->type; 855 crde->crd_key = sav->key_enc->key_data; 856 crde->crd_klen = _KEYBITS(sav->key_enc); 857 /* XXX Rounds ? */ 858 } else 859 crda = crp->crp_desc; 860 861 /* IPsec-specific opaque crypto info. */ 862 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 863 M_XDATA, M_NOWAIT|M_ZERO); 864 if (tc == NULL) { 865 crypto_freereq(crp); 866 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 867 V_espstat.esps_crypto++; 868 error = ENOBUFS; 869 goto bad; 870 } 871 872 /* Callback parameters */ 873 tc->tc_isr = isr; 874 KEY_ADDREFSA(sav); 875 tc->tc_sav = sav; 876 tc->tc_spi = sav->spi; 877 tc->tc_dst = saidx->dst; 878 tc->tc_proto = saidx->proto; 879 880 /* Crypto operation descriptor. */ 881 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 882 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 883 crp->crp_buf = (caddr_t) m; 884 crp->crp_callback = esp_output_cb; 885 crp->crp_opaque = (caddr_t) tc; 886 crp->crp_sid = sav->tdb_cryptoid; 887 888 if (esph) { 889 /* Authentication descriptor. */ 890 crda->crd_skip = skip; 891 crda->crd_len = m->m_pkthdr.len - (skip + alen); 892 crda->crd_inject = m->m_pkthdr.len - alen; 893 894 /* Authentication operation. */ 895 crda->crd_alg = esph->type; 896 crda->crd_key = sav->key_auth->key_data; 897 crda->crd_klen = _KEYBITS(sav->key_auth); 898 } 899 900 return crypto_dispatch(crp); 901 bad: 902 if (m) 903 m_freem(m); 904 return (error); 905 } 906 907 /* 908 * ESP output callback from the crypto driver. 909 */ 910 static int 911 esp_output_cb(struct cryptop *crp) 912 { 913 struct tdb_crypto *tc; 914 struct ipsecrequest *isr; 915 struct secasvar *sav; 916 struct mbuf *m; 917 int err, error; 918 919 tc = (struct tdb_crypto *) crp->crp_opaque; 920 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 921 m = (struct mbuf *) crp->crp_buf; 922 923 isr = tc->tc_isr; 924 IPSECREQUEST_LOCK(isr); 925 sav = tc->tc_sav; 926 /* With the isr lock released SA pointer can be updated. */ 927 if (sav != isr->sav) { 928 V_espstat.esps_notdb++; 929 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 930 __func__, ipsec_address(&tc->tc_dst), 931 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 932 error = ENOBUFS; /*XXX*/ 933 goto bad; 934 } 935 936 /* Check for crypto errors. */ 937 if (crp->crp_etype) { 938 /* Reset session ID. */ 939 if (sav->tdb_cryptoid != 0) 940 sav->tdb_cryptoid = crp->crp_sid; 941 942 if (crp->crp_etype == EAGAIN) { 943 IPSECREQUEST_UNLOCK(isr); 944 error = crypto_dispatch(crp); 945 return error; 946 } 947 948 V_espstat.esps_noxform++; 949 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 950 error = crp->crp_etype; 951 goto bad; 952 } 953 954 /* Shouldn't happen... */ 955 if (m == NULL) { 956 V_espstat.esps_crypto++; 957 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 958 error = EINVAL; 959 goto bad; 960 } 961 V_espstat.esps_hist[sav->alg_enc]++; 962 if (sav->tdb_authalgxform != NULL) 963 V_ahstat.ahs_hist[sav->alg_auth]++; 964 965 /* Release crypto descriptors. */ 966 free(tc, M_XDATA); 967 crypto_freereq(crp); 968 969 #ifdef REGRESSION 970 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 971 if (V_ipsec_integrity) { 972 static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN]; 973 struct auth_hash *esph; 974 975 /* 976 * Corrupt HMAC if we want to test integrity verification of 977 * the other side. 978 */ 979 esph = sav->tdb_authalgxform; 980 if (esph != NULL) { 981 int alen; 982 983 switch (esph->type) { 984 case CRYPTO_SHA2_256_HMAC: 985 case CRYPTO_SHA2_384_HMAC: 986 case CRYPTO_SHA2_512_HMAC: 987 alen = esph->hashsize/2; 988 break; 989 default: 990 alen = AH_HMAC_HASHLEN; 991 break; 992 } 993 m_copyback(m, m->m_pkthdr.len - alen, 994 alen, ipseczeroes); 995 } 996 } 997 #endif 998 999 /* NB: m is reclaimed by ipsec_process_done. */ 1000 err = ipsec_process_done(m, isr); 1001 KEY_FREESAV(&sav); 1002 IPSECREQUEST_UNLOCK(isr); 1003 return err; 1004 bad: 1005 if (sav) 1006 KEY_FREESAV(&sav); 1007 IPSECREQUEST_UNLOCK(isr); 1008 if (m) 1009 m_freem(m); 1010 free(tc, M_XDATA); 1011 crypto_freereq(crp); 1012 return error; 1013 } 1014 1015 static struct xformsw esp_xformsw = { 1016 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", 1017 esp_init, esp_zeroize, esp_input, 1018 esp_output 1019 }; 1020 1021 static void 1022 esp_attach(void) 1023 { 1024 #define MAXIV(xform) \ 1025 if (xform.blocksize > V_esp_max_ivlen) \ 1026 V_esp_max_ivlen = xform.blocksize \ 1027 1028 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ 1029 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ 1030 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ 1031 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ 1032 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ 1033 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ 1034 MAXIV(enc_xform_null); /* SADB_EALG_NULL */ 1035 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */ 1036 1037 xform_register(&esp_xformsw); 1038 #undef MAXIV 1039 } 1040 SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
Cache object: 6ad7c65d26c6289d19a51de707d71d2f
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