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sys/netipsec/xform_esp.c
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1 /* $FreeBSD: releng/9.2/sys/netipsec/xform_esp.c 252693 2013-07-04 08:59:34Z ae $ */ 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")); 284 285 /* Valid IP Packet length ? */ 286 if ( (skip&3) || (m->m_pkthdr.len&3) ){ 287 DPRINTF(("%s: misaligned packet, skip %u pkt len %u", 288 __func__, skip, m->m_pkthdr.len)); 289 ESPSTAT_INC(esps_badilen); 290 m_freem(m); 291 return EINVAL; 292 } 293 294 /* XXX don't pullup, just copy header */ 295 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); 296 297 esph = sav->tdb_authalgxform; 298 espx = sav->tdb_encalgxform; 299 300 /* Determine the ESP header length */ 301 if (sav->flags & SADB_X_EXT_OLD) 302 hlen = sizeof (struct esp) + sav->ivlen; 303 else 304 hlen = sizeof (struct newesp) + sav->ivlen; 305 /* Authenticator hash size */ 306 if (esph != NULL) { 307 switch (esph->type) { 308 case CRYPTO_SHA2_256_HMAC: 309 case CRYPTO_SHA2_384_HMAC: 310 case CRYPTO_SHA2_512_HMAC: 311 alen = esph->hashsize/2; 312 break; 313 default: 314 alen = AH_HMAC_HASHLEN; 315 break; 316 } 317 }else 318 alen = 0; 319 320 /* 321 * Verify payload length is multiple of encryption algorithm 322 * block size. 323 * 324 * NB: This works for the null algorithm because the blocksize 325 * is 4 and all packets must be 4-byte aligned regardless 326 * of the algorithm. 327 */ 328 plen = m->m_pkthdr.len - (skip + hlen + alen); 329 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { 330 DPRINTF(("%s: payload of %d octets not a multiple of %d octets," 331 " SA %s/%08lx\n", __func__, 332 plen, espx->blocksize, 333 ipsec_address(&sav->sah->saidx.dst), 334 (u_long) ntohl(sav->spi))); 335 ESPSTAT_INC(esps_badilen); 336 m_freem(m); 337 return EINVAL; 338 } 339 340 /* 341 * Check sequence number. 342 */ 343 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { 344 DPRINTF(("%s: packet replay check for %s\n", __func__, 345 ipsec_logsastr(sav))); /*XXX*/ 346 ESPSTAT_INC(esps_replay); 347 m_freem(m); 348 return ENOBUFS; /*XXX*/ 349 } 350 351 /* Update the counters */ 352 ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen)); 353 354 /* Find out if we've already done crypto */ 355 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 356 mtag != NULL; 357 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 358 tdbi = (struct tdb_ident *) (mtag + 1); 359 if (tdbi->proto == sav->sah->saidx.proto && 360 tdbi->spi == sav->spi && 361 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 362 sizeof(union sockaddr_union))) 363 break; 364 } 365 366 /* Get crypto descriptors */ 367 crp = crypto_getreq(esph && espx ? 2 : 1); 368 if (crp == NULL) { 369 DPRINTF(("%s: failed to acquire crypto descriptors\n", 370 __func__)); 371 ESPSTAT_INC(esps_crypto); 372 m_freem(m); 373 return ENOBUFS; 374 } 375 376 /* Get IPsec-specific opaque pointer */ 377 if (esph == NULL || mtag != NULL) 378 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 379 M_XDATA, M_NOWAIT|M_ZERO); 380 else 381 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, 382 M_XDATA, M_NOWAIT|M_ZERO); 383 if (tc == NULL) { 384 crypto_freereq(crp); 385 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 386 ESPSTAT_INC(esps_crypto); 387 m_freem(m); 388 return ENOBUFS; 389 } 390 391 tc->tc_ptr = (caddr_t) mtag; 392 393 if (esph) { 394 struct cryptodesc *crda = crp->crp_desc; 395 396 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor")); 397 398 /* Authentication descriptor */ 399 crda->crd_skip = skip; 400 crda->crd_len = m->m_pkthdr.len - (skip + alen); 401 crda->crd_inject = m->m_pkthdr.len - alen; 402 403 crda->crd_alg = esph->type; 404 crda->crd_key = sav->key_auth->key_data; 405 crda->crd_klen = _KEYBITS(sav->key_auth); 406 407 /* Copy the authenticator */ 408 if (mtag == NULL) 409 m_copydata(m, m->m_pkthdr.len - alen, alen, 410 (caddr_t) (tc + 1)); 411 412 /* Chain authentication request */ 413 crde = crda->crd_next; 414 } else { 415 crde = crp->crp_desc; 416 } 417 418 /* Crypto operation descriptor */ 419 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 420 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 421 crp->crp_buf = (caddr_t) m; 422 crp->crp_callback = esp_input_cb; 423 crp->crp_sid = sav->tdb_cryptoid; 424 crp->crp_opaque = (caddr_t) tc; 425 426 /* These are passed as-is to the callback */ 427 tc->tc_spi = sav->spi; 428 tc->tc_dst = sav->sah->saidx.dst; 429 tc->tc_proto = sav->sah->saidx.proto; 430 tc->tc_protoff = protoff; 431 tc->tc_skip = skip; 432 KEY_ADDREFSA(sav); 433 tc->tc_sav = sav; 434 435 /* Decryption descriptor */ 436 if (espx) { 437 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor")); 438 crde->crd_skip = skip + hlen; 439 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 440 crde->crd_inject = skip + hlen - sav->ivlen; 441 442 crde->crd_alg = espx->type; 443 crde->crd_key = sav->key_enc->key_data; 444 crde->crd_klen = _KEYBITS(sav->key_enc); 445 /* XXX Rounds ? */ 446 } 447 448 if (mtag == NULL) 449 return crypto_dispatch(crp); 450 else 451 return esp_input_cb(crp); 452 } 453 454 /* 455 * ESP input callback from the crypto driver. 456 */ 457 static int 458 esp_input_cb(struct cryptop *crp) 459 { 460 u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN]; 461 int hlen, skip, protoff, error, alen; 462 struct mbuf *m; 463 struct cryptodesc *crd; 464 struct auth_hash *esph; 465 struct enc_xform *espx; 466 struct tdb_crypto *tc; 467 struct m_tag *mtag; 468 struct secasvar *sav; 469 struct secasindex *saidx; 470 caddr_t ptr; 471 472 crd = crp->crp_desc; 473 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); 474 475 tc = (struct tdb_crypto *) crp->crp_opaque; 476 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 477 skip = tc->tc_skip; 478 protoff = tc->tc_protoff; 479 mtag = (struct m_tag *) tc->tc_ptr; 480 m = (struct mbuf *) crp->crp_buf; 481 482 sav = tc->tc_sav; 483 IPSEC_ASSERT(sav != NULL, ("null SA!")); 484 485 saidx = &sav->sah->saidx; 486 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 487 saidx->dst.sa.sa_family == AF_INET6, 488 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 489 490 esph = sav->tdb_authalgxform; 491 espx = sav->tdb_encalgxform; 492 493 /* Check for crypto errors */ 494 if (crp->crp_etype) { 495 /* Reset the session ID */ 496 if (sav->tdb_cryptoid != 0) 497 sav->tdb_cryptoid = crp->crp_sid; 498 499 if (crp->crp_etype == EAGAIN) { 500 error = crypto_dispatch(crp); 501 return error; 502 } 503 504 ESPSTAT_INC(esps_noxform); 505 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 506 error = crp->crp_etype; 507 goto bad; 508 } 509 510 /* Shouldn't happen... */ 511 if (m == NULL) { 512 ESPSTAT_INC(esps_crypto); 513 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 514 error = EINVAL; 515 goto bad; 516 } 517 ESPSTAT_INC(esps_hist[sav->alg_enc]); 518 519 /* If authentication was performed, check now. */ 520 if (esph != NULL) { 521 switch (esph->type) { 522 case CRYPTO_SHA2_256_HMAC: 523 case CRYPTO_SHA2_384_HMAC: 524 case CRYPTO_SHA2_512_HMAC: 525 alen = esph->hashsize/2; 526 break; 527 default: 528 alen = AH_HMAC_HASHLEN; 529 break; 530 } 531 /* 532 * If we have a tag, it means an IPsec-aware NIC did 533 * the verification for us. Otherwise we need to 534 * check the authentication calculation. 535 */ 536 AHSTAT_INC(ahs_hist[sav->alg_auth]); 537 if (mtag == NULL) { 538 /* Copy the authenticator from the packet */ 539 m_copydata(m, m->m_pkthdr.len - alen, 540 alen, aalg); 541 542 ptr = (caddr_t) (tc + 1); 543 544 /* Verify authenticator */ 545 if (bcmp(ptr, aalg, alen) != 0) { 546 DPRINTF(("%s: " 547 "authentication hash mismatch for packet in SA %s/%08lx\n", 548 __func__, 549 ipsec_address(&saidx->dst), 550 (u_long) ntohl(sav->spi))); 551 ESPSTAT_INC(esps_badauth); 552 error = EACCES; 553 goto bad; 554 } 555 } 556 557 /* Remove trailing authenticator */ 558 m_adj(m, -alen); 559 } 560 561 /* Release the crypto descriptors */ 562 free(tc, M_XDATA), tc = NULL; 563 crypto_freereq(crp), crp = NULL; 564 565 /* 566 * Packet is now decrypted. 567 */ 568 m->m_flags |= M_DECRYPTED; 569 570 /* 571 * Update replay sequence number, if appropriate. 572 */ 573 if (sav->replay) { 574 u_int32_t seq; 575 576 m_copydata(m, skip + offsetof(struct newesp, esp_seq), 577 sizeof (seq), (caddr_t) &seq); 578 if (ipsec_updatereplay(ntohl(seq), sav)) { 579 DPRINTF(("%s: packet replay check for %s\n", __func__, 580 ipsec_logsastr(sav))); 581 ESPSTAT_INC(esps_replay); 582 error = ENOBUFS; 583 goto bad; 584 } 585 } 586 587 /* Determine the ESP header length */ 588 if (sav->flags & SADB_X_EXT_OLD) 589 hlen = sizeof (struct esp) + sav->ivlen; 590 else 591 hlen = sizeof (struct newesp) + sav->ivlen; 592 593 /* Remove the ESP header and IV from the mbuf. */ 594 error = m_striphdr(m, skip, hlen); 595 if (error) { 596 ESPSTAT_INC(esps_hdrops); 597 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__, 598 ipsec_address(&sav->sah->saidx.dst), 599 (u_long) ntohl(sav->spi))); 600 goto bad; 601 } 602 603 /* Save the last three bytes of decrypted data */ 604 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); 605 606 /* Verify pad length */ 607 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { 608 ESPSTAT_INC(esps_badilen); 609 DPRINTF(("%s: invalid padding length %d for %u byte packet " 610 "in SA %s/%08lx\n", __func__, 611 lastthree[1], m->m_pkthdr.len - skip, 612 ipsec_address(&sav->sah->saidx.dst), 613 (u_long) ntohl(sav->spi))); 614 error = EINVAL; 615 goto bad; 616 } 617 618 /* Verify correct decryption by checking the last padding bytes */ 619 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { 620 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { 621 ESPSTAT_INC(esps_badenc); 622 DPRINTF(("%s: decryption failed for packet in " 623 "SA %s/%08lx\n", __func__, 624 ipsec_address(&sav->sah->saidx.dst), 625 (u_long) ntohl(sav->spi))); 626 error = EINVAL; 627 goto bad; 628 } 629 } 630 631 /* Trim the mbuf chain to remove trailing authenticator and padding */ 632 m_adj(m, -(lastthree[1] + 2)); 633 634 /* Restore the Next Protocol field */ 635 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); 636 637 switch (saidx->dst.sa.sa_family) { 638 #ifdef INET6 639 case AF_INET6: 640 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); 641 break; 642 #endif 643 #ifdef INET 644 case AF_INET: 645 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); 646 break; 647 #endif 648 default: 649 panic("%s: Unexpected address family: %d saidx=%p", __func__, 650 saidx->dst.sa.sa_family, saidx); 651 } 652 653 KEY_FREESAV(&sav); 654 return error; 655 bad: 656 if (sav) 657 KEY_FREESAV(&sav); 658 if (m != NULL) 659 m_freem(m); 660 if (tc != NULL) 661 free(tc, M_XDATA); 662 if (crp != NULL) 663 crypto_freereq(crp); 664 return error; 665 } 666 667 /* 668 * ESP output routine, called by ipsec[46]_process_packet(). 669 */ 670 static int 671 esp_output( 672 struct mbuf *m, 673 struct ipsecrequest *isr, 674 struct mbuf **mp, 675 int skip, 676 int protoff 677 ) 678 { 679 struct enc_xform *espx; 680 struct auth_hash *esph; 681 int hlen, rlen, plen, padding, blks, alen, i, roff; 682 struct mbuf *mo = (struct mbuf *) NULL; 683 struct tdb_crypto *tc; 684 struct secasvar *sav; 685 struct secasindex *saidx; 686 unsigned char *pad; 687 u_int8_t prot; 688 int error, maxpacketsize; 689 690 struct cryptodesc *crde = NULL, *crda = NULL; 691 struct cryptop *crp; 692 693 sav = isr->sav; 694 IPSEC_ASSERT(sav != NULL, ("null SA")); 695 esph = sav->tdb_authalgxform; 696 espx = sav->tdb_encalgxform; 697 IPSEC_ASSERT(espx != NULL, ("null encoding xform")); 698 699 if (sav->flags & SADB_X_EXT_OLD) 700 hlen = sizeof (struct esp) + sav->ivlen; 701 else 702 hlen = sizeof (struct newesp) + sav->ivlen; 703 704 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */ 705 /* 706 * NB: The null encoding transform has a blocksize of 4 707 * so that headers are properly aligned. 708 */ 709 blks = espx->blocksize; /* IV blocksize */ 710 711 /* XXX clamp padding length a la KAME??? */ 712 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; 713 plen = rlen + padding; /* Padded payload length. */ 714 715 if (esph) 716 switch (esph->type) { 717 case CRYPTO_SHA2_256_HMAC: 718 case CRYPTO_SHA2_384_HMAC: 719 case CRYPTO_SHA2_512_HMAC: 720 alen = esph->hashsize/2; 721 break; 722 default: 723 alen = AH_HMAC_HASHLEN; 724 break; 725 } 726 else 727 alen = 0; 728 729 ESPSTAT_INC(esps_output); 730 731 saidx = &sav->sah->saidx; 732 /* Check for maximum packet size violations. */ 733 switch (saidx->dst.sa.sa_family) { 734 #ifdef INET 735 case AF_INET: 736 maxpacketsize = IP_MAXPACKET; 737 break; 738 #endif /* INET */ 739 #ifdef INET6 740 case AF_INET6: 741 maxpacketsize = IPV6_MAXPACKET; 742 break; 743 #endif /* INET6 */ 744 default: 745 DPRINTF(("%s: unknown/unsupported protocol " 746 "family %d, SA %s/%08lx\n", __func__, 747 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), 748 (u_long) ntohl(sav->spi))); 749 ESPSTAT_INC(esps_nopf); 750 error = EPFNOSUPPORT; 751 goto bad; 752 } 753 if (skip + hlen + rlen + padding + alen > maxpacketsize) { 754 DPRINTF(("%s: packet in SA %s/%08lx got too big " 755 "(len %u, max len %u)\n", __func__, 756 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), 757 skip + hlen + rlen + padding + alen, maxpacketsize)); 758 ESPSTAT_INC(esps_toobig); 759 error = EMSGSIZE; 760 goto bad; 761 } 762 763 /* Update the counters. */ 764 ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip); 765 766 m = m_unshare(m, M_NOWAIT); 767 if (m == NULL) { 768 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 769 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 770 ESPSTAT_INC(esps_hdrops); 771 error = ENOBUFS; 772 goto bad; 773 } 774 775 /* Inject ESP header. */ 776 mo = m_makespace(m, skip, hlen, &roff); 777 if (mo == NULL) { 778 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n", 779 __func__, hlen, ipsec_address(&saidx->dst), 780 (u_long) ntohl(sav->spi))); 781 ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */ 782 error = ENOBUFS; 783 goto bad; 784 } 785 786 /* Initialize ESP header. */ 787 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); 788 if (sav->replay) { 789 u_int32_t replay; 790 791 #ifdef REGRESSION 792 /* Emulate replay attack when ipsec_replay is TRUE. */ 793 if (!V_ipsec_replay) 794 #endif 795 sav->replay->count++; 796 replay = htonl(sav->replay->count); 797 bcopy((caddr_t) &replay, 798 mtod(mo, caddr_t) + roff + sizeof(u_int32_t), 799 sizeof(u_int32_t)); 800 } 801 802 /* 803 * Add padding -- better to do it ourselves than use the crypto engine, 804 * although if/when we support compression, we'd have to do that. 805 */ 806 pad = (u_char *) m_pad(m, padding + alen); 807 if (pad == NULL) { 808 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__, 809 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 810 m = NULL; /* NB: free'd by m_pad */ 811 error = ENOBUFS; 812 goto bad; 813 } 814 815 /* 816 * Add padding: random, zero, or self-describing. 817 * XXX catch unexpected setting 818 */ 819 switch (sav->flags & SADB_X_EXT_PMASK) { 820 case SADB_X_EXT_PRAND: 821 (void) read_random(pad, padding - 2); 822 break; 823 case SADB_X_EXT_PZERO: 824 bzero(pad, padding - 2); 825 break; 826 case SADB_X_EXT_PSEQ: 827 for (i = 0; i < padding - 2; i++) 828 pad[i] = i+1; 829 break; 830 } 831 832 /* Fix padding length and Next Protocol in padding itself. */ 833 pad[padding - 2] = padding - 2; 834 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); 835 836 /* Fix Next Protocol in IPv4/IPv6 header. */ 837 prot = IPPROTO_ESP; 838 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); 839 840 /* Get crypto descriptors. */ 841 crp = crypto_getreq(esph && espx ? 2 : 1); 842 if (crp == NULL) { 843 DPRINTF(("%s: failed to acquire crypto descriptors\n", 844 __func__)); 845 ESPSTAT_INC(esps_crypto); 846 error = ENOBUFS; 847 goto bad; 848 } 849 850 if (espx) { 851 crde = crp->crp_desc; 852 crda = crde->crd_next; 853 854 /* Encryption descriptor. */ 855 crde->crd_skip = skip + hlen; 856 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 857 crde->crd_flags = CRD_F_ENCRYPT; 858 crde->crd_inject = skip + hlen - sav->ivlen; 859 860 /* Encryption operation. */ 861 crde->crd_alg = espx->type; 862 crde->crd_key = sav->key_enc->key_data; 863 crde->crd_klen = _KEYBITS(sav->key_enc); 864 /* XXX Rounds ? */ 865 } else 866 crda = crp->crp_desc; 867 868 /* IPsec-specific opaque crypto info. */ 869 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 870 M_XDATA, M_NOWAIT|M_ZERO); 871 if (tc == NULL) { 872 crypto_freereq(crp); 873 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 874 ESPSTAT_INC(esps_crypto); 875 error = ENOBUFS; 876 goto bad; 877 } 878 879 /* Callback parameters */ 880 tc->tc_isr = isr; 881 KEY_ADDREFSA(sav); 882 tc->tc_sav = sav; 883 tc->tc_spi = sav->spi; 884 tc->tc_dst = saidx->dst; 885 tc->tc_proto = saidx->proto; 886 887 /* Crypto operation descriptor. */ 888 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 889 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 890 crp->crp_buf = (caddr_t) m; 891 crp->crp_callback = esp_output_cb; 892 crp->crp_opaque = (caddr_t) tc; 893 crp->crp_sid = sav->tdb_cryptoid; 894 895 if (esph) { 896 /* Authentication descriptor. */ 897 crda->crd_skip = skip; 898 crda->crd_len = m->m_pkthdr.len - (skip + alen); 899 crda->crd_inject = m->m_pkthdr.len - alen; 900 901 /* Authentication operation. */ 902 crda->crd_alg = esph->type; 903 crda->crd_key = sav->key_auth->key_data; 904 crda->crd_klen = _KEYBITS(sav->key_auth); 905 } 906 907 return crypto_dispatch(crp); 908 bad: 909 if (m) 910 m_freem(m); 911 return (error); 912 } 913 914 /* 915 * ESP output callback from the crypto driver. 916 */ 917 static int 918 esp_output_cb(struct cryptop *crp) 919 { 920 struct tdb_crypto *tc; 921 struct ipsecrequest *isr; 922 struct secasvar *sav; 923 struct mbuf *m; 924 int err, error; 925 926 tc = (struct tdb_crypto *) crp->crp_opaque; 927 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 928 m = (struct mbuf *) crp->crp_buf; 929 930 isr = tc->tc_isr; 931 IPSECREQUEST_LOCK(isr); 932 sav = tc->tc_sav; 933 /* With the isr lock released SA pointer can be updated. */ 934 if (sav != isr->sav) { 935 ESPSTAT_INC(esps_notdb); 936 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 937 __func__, ipsec_address(&tc->tc_dst), 938 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 939 error = ENOBUFS; /*XXX*/ 940 goto bad; 941 } 942 943 /* Check for crypto errors. */ 944 if (crp->crp_etype) { 945 /* Reset session ID. */ 946 if (sav->tdb_cryptoid != 0) 947 sav->tdb_cryptoid = crp->crp_sid; 948 949 if (crp->crp_etype == EAGAIN) { 950 IPSECREQUEST_UNLOCK(isr); 951 error = crypto_dispatch(crp); 952 return error; 953 } 954 955 ESPSTAT_INC(esps_noxform); 956 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 957 error = crp->crp_etype; 958 goto bad; 959 } 960 961 /* Shouldn't happen... */ 962 if (m == NULL) { 963 ESPSTAT_INC(esps_crypto); 964 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 965 error = EINVAL; 966 goto bad; 967 } 968 ESPSTAT_INC(esps_hist[sav->alg_enc]); 969 if (sav->tdb_authalgxform != NULL) 970 AHSTAT_INC(ahs_hist[sav->alg_auth]); 971 972 /* Release crypto descriptors. */ 973 free(tc, M_XDATA); 974 crypto_freereq(crp); 975 976 #ifdef REGRESSION 977 /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ 978 if (V_ipsec_integrity) { 979 static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN]; 980 struct auth_hash *esph; 981 982 /* 983 * Corrupt HMAC if we want to test integrity verification of 984 * the other side. 985 */ 986 esph = sav->tdb_authalgxform; 987 if (esph != NULL) { 988 int alen; 989 990 switch (esph->type) { 991 case CRYPTO_SHA2_256_HMAC: 992 case CRYPTO_SHA2_384_HMAC: 993 case CRYPTO_SHA2_512_HMAC: 994 alen = esph->hashsize/2; 995 break; 996 default: 997 alen = AH_HMAC_HASHLEN; 998 break; 999 } 1000 m_copyback(m, m->m_pkthdr.len - alen, 1001 alen, ipseczeroes); 1002 } 1003 } 1004 #endif 1005 1006 /* NB: m is reclaimed by ipsec_process_done. */ 1007 err = ipsec_process_done(m, isr); 1008 KEY_FREESAV(&sav); 1009 IPSECREQUEST_UNLOCK(isr); 1010 return err; 1011 bad: 1012 if (sav) 1013 KEY_FREESAV(&sav); 1014 IPSECREQUEST_UNLOCK(isr); 1015 if (m) 1016 m_freem(m); 1017 free(tc, M_XDATA); 1018 crypto_freereq(crp); 1019 return error; 1020 } 1021 1022 static struct xformsw esp_xformsw = { 1023 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", 1024 esp_init, esp_zeroize, esp_input, 1025 esp_output 1026 }; 1027 1028 static void 1029 esp_attach(void) 1030 { 1031 #define MAXIV(xform) \ 1032 if (xform.blocksize > V_esp_max_ivlen) \ 1033 V_esp_max_ivlen = xform.blocksize \ 1034 1035 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ 1036 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ 1037 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ 1038 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ 1039 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ 1040 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ 1041 MAXIV(enc_xform_null); /* SADB_EALG_NULL */ 1042 MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */ 1043 1044 xform_register(&esp_xformsw); 1045 #undef MAXIV 1046 } 1047 SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);
Cache object: 192c29186e9d7f14c1725ce2974e1e6c
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