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sys/netipsec/xform_esp.c
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1 /* $FreeBSD$ */ 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 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/esp.h> 63 #include <netipsec/esp_var.h> 64 #include <netipsec/xform.h> 65 66 #ifdef INET6 67 #include <netinet6/ip6_var.h> 68 #include <netipsec/ipsec6.h> 69 #include <netinet6/ip6_ecn.h> 70 #endif 71 72 #include <netipsec/key.h> 73 #include <netipsec/key_debug.h> 74 75 #include <opencrypto/cryptodev.h> 76 #include <opencrypto/xform.h> 77 78 int esp_enable = 1; 79 struct espstat espstat; 80 81 SYSCTL_DECL(_net_inet_esp); 82 SYSCTL_INT(_net_inet_esp, OID_AUTO, 83 esp_enable, CTLFLAG_RW, &esp_enable, 0, ""); 84 SYSCTL_STRUCT(_net_inet_esp, IPSECCTL_STATS, 85 stats, CTLFLAG_RD, &espstat, espstat, ""); 86 87 static int esp_max_ivlen; /* max iv length over all algorithms */ 88 89 static int esp_input_cb(struct cryptop *op); 90 static int esp_output_cb(struct cryptop *crp); 91 92 /* 93 * NB: this is public for use by the PF_KEY support. 94 * NB: if you add support here; be sure to add code to esp_attach below! 95 */ 96 struct enc_xform * 97 esp_algorithm_lookup(int alg) 98 { 99 if (alg >= ESP_ALG_MAX) 100 return NULL; 101 switch (alg) { 102 case SADB_EALG_DESCBC: 103 return &enc_xform_des; 104 case SADB_EALG_3DESCBC: 105 return &enc_xform_3des; 106 case SADB_X_EALG_AES: 107 return &enc_xform_rijndael128; 108 case SADB_X_EALG_BLOWFISHCBC: 109 return &enc_xform_blf; 110 case SADB_X_EALG_CAST128CBC: 111 return &enc_xform_cast5; 112 case SADB_X_EALG_SKIPJACK: 113 return &enc_xform_skipjack; 114 case SADB_EALG_NULL: 115 return &enc_xform_null; 116 } 117 return NULL; 118 } 119 120 size_t 121 esp_hdrsiz(struct secasvar *sav) 122 { 123 size_t size; 124 125 if (sav != NULL) { 126 /*XXX not right for null algorithm--does it matter??*/ 127 KASSERT(sav->tdb_encalgxform != NULL, 128 ("esp_hdrsiz: SA with null xform")); 129 if (sav->flags & SADB_X_EXT_OLD) 130 size = sizeof (struct esp); 131 else 132 size = sizeof (struct newesp); 133 size += sav->tdb_encalgxform->blocksize + 9; 134 /*XXX need alg check???*/ 135 if (sav->tdb_authalgxform != NULL && sav->replay) 136 size += ah_hdrsiz(sav); 137 } else { 138 /* 139 * base header size 140 * + max iv length for CBC mode 141 * + max pad length 142 * + sizeof (pad length field) 143 * + sizeof (next header field) 144 * + max icv supported. 145 */ 146 size = sizeof (struct newesp) + esp_max_ivlen + 9 + 16; 147 } 148 return size; 149 } 150 151 /* 152 * esp_init() is called when an SPI is being set up. 153 */ 154 static int 155 esp_init(struct secasvar *sav, struct xformsw *xsp) 156 { 157 struct enc_xform *txform; 158 struct cryptoini cria, crie; 159 int keylen; 160 int error; 161 162 txform = esp_algorithm_lookup(sav->alg_enc); 163 if (txform == NULL) { 164 DPRINTF(("esp_init: unsupported encryption algorithm %d\n", 165 sav->alg_enc)); 166 return EINVAL; 167 } 168 if (sav->key_enc == NULL) { 169 DPRINTF(("esp_init: no encoding key for %s algorithm\n", 170 txform->name)); 171 return EINVAL; 172 } 173 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { 174 DPRINTF(("esp_init: 4-byte IV not supported with protocol\n")); 175 return EINVAL; 176 } 177 keylen = _KEYLEN(sav->key_enc); 178 if (txform->minkey > keylen || keylen > txform->maxkey) { 179 DPRINTF(("esp_init: invalid key length %u, must be in " 180 "the range [%u..%u] for algorithm %s\n", 181 keylen, txform->minkey, txform->maxkey, 182 txform->name)); 183 return EINVAL; 184 } 185 186 /* 187 * NB: The null xform needs a non-zero blocksize to keep the 188 * crypto code happy but if we use it to set ivlen then 189 * the ESP header will be processed incorrectly. The 190 * compromise is to force it to zero here. 191 */ 192 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize); 193 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK); 194 if (sav->iv == NULL) { 195 DPRINTF(("esp_init: no memory for IV\n")); 196 return EINVAL; 197 } 198 key_randomfill(sav->iv, sav->ivlen); /*XXX*/ 199 200 /* 201 * Setup AH-related state. 202 */ 203 if (sav->alg_auth != 0) { 204 error = ah_init0(sav, xsp, &cria); 205 if (error) 206 return error; 207 } 208 209 /* NB: override anything set in ah_init0 */ 210 sav->tdb_xform = xsp; 211 sav->tdb_encalgxform = txform; 212 213 /* Initialize crypto session. */ 214 bzero(&crie, sizeof (crie)); 215 crie.cri_alg = sav->tdb_encalgxform->type; 216 crie.cri_klen = _KEYBITS(sav->key_enc); 217 crie.cri_key = _KEYBUF(sav->key_enc); 218 /* XXX Rounds ? */ 219 220 if (sav->tdb_authalgxform && sav->tdb_encalgxform) { 221 /* init both auth & enc */ 222 crie.cri_next = &cria; 223 error = crypto_newsession(&sav->tdb_cryptoid, 224 &crie, crypto_support); 225 } else if (sav->tdb_encalgxform) { 226 error = crypto_newsession(&sav->tdb_cryptoid, 227 &crie, crypto_support); 228 } else if (sav->tdb_authalgxform) { 229 error = crypto_newsession(&sav->tdb_cryptoid, 230 &cria, crypto_support); 231 } else { 232 /* XXX cannot happen? */ 233 DPRINTF(("esp_init: no encoding OR authentication xform!\n")); 234 error = EINVAL; 235 } 236 return error; 237 } 238 239 /* 240 * Paranoia. 241 */ 242 static int 243 esp_zeroize(struct secasvar *sav) 244 { 245 /* NB: ah_zerorize free's the crypto session state */ 246 int error = ah_zeroize(sav); 247 248 if (sav->key_enc) 249 bzero(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc)); 250 /* NB: sav->iv is freed elsewhere, even though we malloc it! */ 251 sav->tdb_encalgxform = NULL; 252 sav->tdb_xform = NULL; 253 return error; 254 } 255 256 /* 257 * ESP input processing, called (eventually) through the protocol switch. 258 */ 259 static int 260 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 261 { 262 struct auth_hash *esph; 263 struct enc_xform *espx; 264 struct tdb_ident *tdbi; 265 struct tdb_crypto *tc; 266 int plen, alen, hlen; 267 struct m_tag *mtag; 268 struct newesp *esp; 269 270 struct cryptodesc *crde; 271 struct cryptop *crp; 272 273 SPLASSERT(net, "esp_input"); 274 275 KASSERT(sav != NULL, ("esp_input: null SA")); 276 KASSERT(sav->tdb_encalgxform != NULL, 277 ("esp_input: null encoding xform")); 278 KASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0, 279 ("esp_input: misaligned packet, skip %u pkt len %u", 280 skip, m->m_pkthdr.len)); 281 282 /* XXX don't pullup, just copy header */ 283 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); 284 285 esph = sav->tdb_authalgxform; 286 espx = sav->tdb_encalgxform; 287 288 /* Determine the ESP header length */ 289 if (sav->flags & SADB_X_EXT_OLD) 290 hlen = sizeof (struct esp) + sav->ivlen; 291 else 292 hlen = sizeof (struct newesp) + sav->ivlen; 293 /* Authenticator hash size */ 294 alen = esph ? AH_HMAC_HASHLEN : 0; 295 296 /* 297 * Verify payload length is multiple of encryption algorithm 298 * block size. 299 * 300 * NB: This works for the null algorithm because the blocksize 301 * is 4 and all packets must be 4-byte aligned regardless 302 * of the algorithm. 303 */ 304 plen = m->m_pkthdr.len - (skip + hlen + alen); 305 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { 306 DPRINTF(("esp_input: " 307 "payload of %d octets not a multiple of %d octets," 308 " SA %s/%08lx\n", 309 plen, espx->blocksize, 310 ipsec_address(&sav->sah->saidx.dst), 311 (u_long) ntohl(sav->spi))); 312 espstat.esps_badilen++; 313 m_freem(m); 314 return EINVAL; 315 } 316 317 /* 318 * Check sequence number. 319 */ 320 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { 321 DPRINTF(("esp_input: packet replay check for %s\n", 322 ipsec_logsastr(sav))); /*XXX*/ 323 espstat.esps_replay++; 324 m_freem(m); 325 return ENOBUFS; /*XXX*/ 326 } 327 328 /* Update the counters */ 329 espstat.esps_ibytes += m->m_pkthdr.len - skip - hlen - alen; 330 331 /* Find out if we've already done crypto */ 332 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 333 mtag != NULL; 334 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 335 tdbi = (struct tdb_ident *) (mtag + 1); 336 if (tdbi->proto == sav->sah->saidx.proto && 337 tdbi->spi == sav->spi && 338 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 339 sizeof(union sockaddr_union))) 340 break; 341 } 342 343 /* Get crypto descriptors */ 344 crp = crypto_getreq(esph && espx ? 2 : 1); 345 if (crp == NULL) { 346 DPRINTF(("esp_input: failed to acquire crypto descriptors\n")); 347 espstat.esps_crypto++; 348 m_freem(m); 349 return ENOBUFS; 350 } 351 352 /* Get IPsec-specific opaque pointer */ 353 if (esph == NULL || mtag != NULL) 354 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 355 M_XDATA, M_NOWAIT|M_ZERO); 356 else 357 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, 358 M_XDATA, M_NOWAIT|M_ZERO); 359 if (tc == NULL) { 360 crypto_freereq(crp); 361 DPRINTF(("esp_input: failed to allocate tdb_crypto\n")); 362 espstat.esps_crypto++; 363 m_freem(m); 364 return ENOBUFS; 365 } 366 367 tc->tc_ptr = (caddr_t) mtag; 368 369 if (esph) { 370 struct cryptodesc *crda = crp->crp_desc; 371 372 KASSERT(crda != NULL, ("esp_input: null ah crypto descriptor")); 373 374 /* Authentication descriptor */ 375 crda->crd_skip = skip; 376 crda->crd_len = m->m_pkthdr.len - (skip + alen); 377 crda->crd_inject = m->m_pkthdr.len - alen; 378 379 crda->crd_alg = esph->type; 380 crda->crd_key = _KEYBUF(sav->key_auth); 381 crda->crd_klen = _KEYBITS(sav->key_auth); 382 383 /* Copy the authenticator */ 384 if (mtag == NULL) 385 m_copydata(m, m->m_pkthdr.len - alen, alen, 386 (caddr_t) (tc + 1)); 387 388 /* Chain authentication request */ 389 crde = crda->crd_next; 390 } else { 391 crde = crp->crp_desc; 392 } 393 394 /* Crypto operation descriptor */ 395 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 396 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 397 crp->crp_buf = (caddr_t) m; 398 crp->crp_callback = esp_input_cb; 399 crp->crp_sid = sav->tdb_cryptoid; 400 crp->crp_opaque = (caddr_t) tc; 401 402 /* These are passed as-is to the callback */ 403 tc->tc_spi = sav->spi; 404 tc->tc_dst = sav->sah->saidx.dst; 405 tc->tc_proto = sav->sah->saidx.proto; 406 tc->tc_protoff = protoff; 407 tc->tc_skip = skip; 408 409 /* Decryption descriptor */ 410 if (espx) { 411 KASSERT(crde != NULL, ("esp_input: null esp crypto descriptor")); 412 crde->crd_skip = skip + hlen; 413 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 414 crde->crd_inject = skip + hlen - sav->ivlen; 415 416 crde->crd_alg = espx->type; 417 crde->crd_key = _KEYBUF(sav->key_enc); 418 crde->crd_klen = _KEYBITS(sav->key_enc); 419 /* XXX Rounds ? */ 420 } 421 422 if (mtag == NULL) 423 return crypto_dispatch(crp); 424 else 425 return esp_input_cb(crp); 426 } 427 428 #ifdef INET6 429 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 430 if (saidx->dst.sa.sa_family == AF_INET6) { \ 431 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 432 } else { \ 433 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 434 } \ 435 } while (0) 436 #else 437 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 438 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 439 #endif 440 441 /* 442 * ESP input callback from the crypto driver. 443 */ 444 static int 445 esp_input_cb(struct cryptop *crp) 446 { 447 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN]; 448 int s, hlen, skip, protoff, error; 449 struct mbuf *m; 450 struct cryptodesc *crd; 451 struct auth_hash *esph; 452 struct enc_xform *espx; 453 struct tdb_crypto *tc; 454 struct m_tag *mtag; 455 struct secasvar *sav; 456 struct secasindex *saidx; 457 caddr_t ptr; 458 459 crd = crp->crp_desc; 460 KASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!")); 461 462 tc = (struct tdb_crypto *) crp->crp_opaque; 463 KASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!")); 464 skip = tc->tc_skip; 465 protoff = tc->tc_protoff; 466 mtag = (struct m_tag *) tc->tc_ptr; 467 m = (struct mbuf *) crp->crp_buf; 468 469 s = splnet(); 470 471 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 472 if (sav == NULL) { 473 espstat.esps_notdb++; 474 DPRINTF(("esp_input_cb: SA expired while in crypto " 475 "(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst), 476 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 477 error = ENOBUFS; /*XXX*/ 478 goto bad; 479 } 480 481 saidx = &sav->sah->saidx; 482 KASSERT(saidx->dst.sa.sa_family == AF_INET || 483 saidx->dst.sa.sa_family == AF_INET6, 484 ("ah_input_cb: unexpected protocol family %u", 485 saidx->dst.sa.sa_family)); 486 487 esph = sav->tdb_authalgxform; 488 espx = sav->tdb_encalgxform; 489 490 /* Check for crypto errors */ 491 if (crp->crp_etype) { 492 /* Reset the session ID */ 493 if (sav->tdb_cryptoid != 0) 494 sav->tdb_cryptoid = crp->crp_sid; 495 496 if (crp->crp_etype == EAGAIN) { 497 KEY_FREESAV(&sav); 498 splx(s); 499 return crypto_dispatch(crp); 500 } 501 502 espstat.esps_noxform++; 503 DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype)); 504 error = crp->crp_etype; 505 goto bad; 506 } 507 508 /* Shouldn't happen... */ 509 if (m == NULL) { 510 espstat.esps_crypto++; 511 DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n")); 512 error = EINVAL; 513 goto bad; 514 } 515 espstat.esps_hist[sav->alg_enc]++; 516 517 /* If authentication was performed, check now. */ 518 if (esph != NULL) { 519 /* 520 * If we have a tag, it means an IPsec-aware NIC did 521 * the verification for us. Otherwise we need to 522 * check the authentication calculation. 523 */ 524 ahstat.ahs_hist[sav->alg_auth]++; 525 if (mtag == NULL) { 526 /* Copy the authenticator from the packet */ 527 m_copydata(m, m->m_pkthdr.len - esph->authsize, 528 esph->authsize, aalg); 529 530 ptr = (caddr_t) (tc + 1); 531 532 /* Verify authenticator */ 533 if (bcmp(ptr, aalg, esph->authsize) != 0) { 534 DPRINTF(("esp_input_cb: " 535 "authentication hash mismatch for packet in SA %s/%08lx\n", 536 ipsec_address(&saidx->dst), 537 (u_long) ntohl(sav->spi))); 538 espstat.esps_badauth++; 539 error = EACCES; 540 goto bad; 541 } 542 } 543 544 /* Remove trailing authenticator */ 545 m_adj(m, -(esph->authsize)); 546 } 547 548 /* Release the crypto descriptors */ 549 free(tc, M_XDATA), tc = NULL; 550 crypto_freereq(crp), crp = NULL; 551 552 /* 553 * Packet is now decrypted. 554 */ 555 m->m_flags |= M_DECRYPTED; 556 557 /* 558 * Update replay sequence number, if appropriate. 559 */ 560 if (sav->replay) { 561 u_int32_t seq; 562 563 m_copydata(m, skip + offsetof(struct newesp, esp_seq), 564 sizeof (seq), (caddr_t) &seq); 565 if (ipsec_updatereplay(ntohl(seq), sav)) { 566 DPRINTF(("%s: packet replay check for %s\n", __func__, 567 ipsec_logsastr(sav))); 568 espstat.esps_replay++; 569 error = ENOBUFS; 570 goto bad; 571 } 572 } 573 574 /* Determine the ESP header length */ 575 if (sav->flags & SADB_X_EXT_OLD) 576 hlen = sizeof (struct esp) + sav->ivlen; 577 else 578 hlen = sizeof (struct newesp) + sav->ivlen; 579 580 /* Remove the ESP header and IV from the mbuf. */ 581 error = m_striphdr(m, skip, hlen); 582 if (error) { 583 espstat.esps_hdrops++; 584 DPRINTF(("esp_input_cb: bad mbuf chain, SA %s/%08lx\n", 585 ipsec_address(&sav->sah->saidx.dst), 586 (u_long) ntohl(sav->spi))); 587 goto bad; 588 } 589 590 /* Save the last three bytes of decrypted data */ 591 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); 592 593 /* Verify pad length */ 594 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { 595 espstat.esps_badilen++; 596 DPRINTF(("esp_input_cb: invalid padding length %d " 597 "for %u byte packet in SA %s/%08lx\n", 598 lastthree[1], m->m_pkthdr.len - skip, 599 ipsec_address(&sav->sah->saidx.dst), 600 (u_long) ntohl(sav->spi))); 601 error = EINVAL; 602 goto bad; 603 } 604 605 /* Verify correct decryption by checking the last padding bytes */ 606 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { 607 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { 608 espstat.esps_badenc++; 609 DPRINTF(("esp_input_cb: decryption failed " 610 "for packet in SA %s/%08lx\n", 611 ipsec_address(&sav->sah->saidx.dst), 612 (u_long) ntohl(sav->spi))); 613 DPRINTF(("esp_input_cb: %x %x\n", lastthree[0], lastthree[1])); 614 error = EINVAL; 615 goto bad; 616 } 617 } 618 619 /* Trim the mbuf chain to remove trailing authenticator and padding */ 620 m_adj(m, -(lastthree[1] + 2)); 621 622 /* Restore the Next Protocol field */ 623 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); 624 625 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 626 627 KEY_FREESAV(&sav); 628 splx(s); 629 return error; 630 bad: 631 if (sav) 632 KEY_FREESAV(&sav); 633 splx(s); 634 if (m != NULL) 635 m_freem(m); 636 if (tc != NULL) 637 free(tc, M_XDATA); 638 if (crp != NULL) 639 crypto_freereq(crp); 640 return error; 641 } 642 643 /* 644 * ESP output routine, called by ipsec[46]_process_packet(). 645 */ 646 static int 647 esp_output( 648 struct mbuf *m, 649 struct ipsecrequest *isr, 650 struct mbuf **mp, 651 int skip, 652 int protoff 653 ) 654 { 655 struct enc_xform *espx; 656 struct auth_hash *esph; 657 int hlen, rlen, plen, padding, blks, alen, i, roff; 658 struct mbuf *mo = (struct mbuf *) NULL; 659 struct tdb_crypto *tc; 660 struct secasvar *sav; 661 struct secasindex *saidx; 662 unsigned char *pad; 663 u_int8_t prot; 664 int error, maxpacketsize; 665 666 struct cryptodesc *crde = NULL, *crda = NULL; 667 struct cryptop *crp; 668 669 SPLASSERT(net, "esp_output"); 670 671 sav = isr->sav; 672 KASSERT(sav != NULL, ("esp_output: null SA")); 673 esph = sav->tdb_authalgxform; 674 espx = sav->tdb_encalgxform; 675 KASSERT(espx != NULL, ("esp_output: 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 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(("esp_output: unknown/unsupported protocol " 715 "family %d, SA %s/%08lx\n", 716 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), 717 (u_long) ntohl(sav->spi))); 718 espstat.esps_nopf++; 719 error = EPFNOSUPPORT; 720 goto bad; 721 } 722 if (skip + hlen + rlen + padding + alen > maxpacketsize) { 723 DPRINTF(("esp_output: packet in SA %s/%08lx got too big " 724 "(len %u, max len %u)\n", 725 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), 726 skip + hlen + rlen + padding + alen, maxpacketsize)); 727 espstat.esps_toobig++; 728 error = EMSGSIZE; 729 goto bad; 730 } 731 732 /* Update the counters. */ 733 espstat.esps_obytes += m->m_pkthdr.len - skip; 734 735 m = m_clone(m); 736 if (m == NULL) { 737 DPRINTF(("esp_output: cannot clone mbuf chain, SA %s/%08lx\n", 738 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 739 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(("esp_output: failed to inject %u byte ESP hdr for SA " 748 "%s/%08lx\n", 749 hlen, ipsec_address(&saidx->dst), 750 (u_long) ntohl(sav->spi))); 751 espstat.esps_hdrops++; /* XXX diffs from openbsd */ 752 error = ENOBUFS; 753 goto bad; 754 } 755 756 /* Initialize ESP header. */ 757 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); 758 if (sav->replay) { 759 u_int32_t replay = htonl(++(sav->replay->count)); 760 bcopy((caddr_t) &replay, 761 mtod(mo, caddr_t) + roff + sizeof(u_int32_t), 762 sizeof(u_int32_t)); 763 } 764 765 /* 766 * Add padding -- better to do it ourselves than use the crypto engine, 767 * although if/when we support compression, we'd have to do that. 768 */ 769 pad = (u_char *) m_pad(m, padding + alen); 770 if (pad == NULL) { 771 DPRINTF(("esp_output: m_pad failed for SA %s/%08lx\n", 772 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 773 m = NULL; /* NB: free'd by m_pad */ 774 error = ENOBUFS; 775 goto bad; 776 } 777 778 /* 779 * Add padding: random, zero, or self-describing. 780 * XXX catch unexpected setting 781 */ 782 switch (sav->flags & SADB_X_EXT_PMASK) { 783 case SADB_X_EXT_PRAND: 784 (void) read_random(pad, padding - 2); 785 break; 786 case SADB_X_EXT_PZERO: 787 bzero(pad, padding - 2); 788 break; 789 case SADB_X_EXT_PSEQ: 790 for (i = 0; i < padding - 2; i++) 791 pad[i] = i+1; 792 break; 793 } 794 795 /* Fix padding length and Next Protocol in padding itself. */ 796 pad[padding - 2] = padding - 2; 797 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); 798 799 /* Fix Next Protocol in IPv4/IPv6 header. */ 800 prot = IPPROTO_ESP; 801 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); 802 803 /* Get crypto descriptors. */ 804 crp = crypto_getreq(esph && espx ? 2 : 1); 805 if (crp == NULL) { 806 DPRINTF(("esp_output: failed to acquire crypto descriptors\n")); 807 espstat.esps_crypto++; 808 error = ENOBUFS; 809 goto bad; 810 } 811 812 if (espx) { 813 crde = crp->crp_desc; 814 crda = crde->crd_next; 815 816 /* Encryption descriptor. */ 817 crde->crd_skip = skip + hlen; 818 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 819 crde->crd_flags = CRD_F_ENCRYPT; 820 crde->crd_inject = skip + hlen - sav->ivlen; 821 822 /* Encryption operation. */ 823 crde->crd_alg = espx->type; 824 crde->crd_key = _KEYBUF(sav->key_enc); 825 crde->crd_klen = _KEYBITS(sav->key_enc); 826 /* XXX Rounds ? */ 827 } else 828 crda = crp->crp_desc; 829 830 /* IPsec-specific opaque crypto info. */ 831 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 832 M_XDATA, M_NOWAIT|M_ZERO); 833 if (tc == NULL) { 834 crypto_freereq(crp); 835 DPRINTF(("esp_output: failed to allocate tdb_crypto\n")); 836 espstat.esps_crypto++; 837 error = ENOBUFS; 838 goto bad; 839 } 840 841 /* Callback parameters */ 842 tc->tc_isr = isr; 843 tc->tc_spi = sav->spi; 844 tc->tc_dst = saidx->dst; 845 tc->tc_proto = saidx->proto; 846 847 /* Crypto operation descriptor. */ 848 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 849 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 850 crp->crp_buf = (caddr_t) m; 851 crp->crp_callback = esp_output_cb; 852 crp->crp_opaque = (caddr_t) tc; 853 crp->crp_sid = sav->tdb_cryptoid; 854 855 if (esph) { 856 /* Authentication descriptor. */ 857 crda->crd_skip = skip; 858 crda->crd_len = m->m_pkthdr.len - (skip + alen); 859 crda->crd_inject = m->m_pkthdr.len - alen; 860 861 /* Authentication operation. */ 862 crda->crd_alg = esph->type; 863 crda->crd_key = _KEYBUF(sav->key_auth); 864 crda->crd_klen = _KEYBITS(sav->key_auth); 865 } 866 867 return crypto_dispatch(crp); 868 bad: 869 if (m) 870 m_freem(m); 871 return (error); 872 } 873 874 /* 875 * ESP output callback from the crypto driver. 876 */ 877 static int 878 esp_output_cb(struct cryptop *crp) 879 { 880 struct tdb_crypto *tc; 881 struct ipsecrequest *isr; 882 struct secasvar *sav; 883 struct mbuf *m; 884 int s, err, error; 885 886 tc = (struct tdb_crypto *) crp->crp_opaque; 887 KASSERT(tc != NULL, ("esp_output_cb: null opaque data area!")); 888 m = (struct mbuf *) crp->crp_buf; 889 890 s = splnet(); 891 892 isr = tc->tc_isr; 893 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 894 if (sav == NULL) { 895 espstat.esps_notdb++; 896 DPRINTF(("esp_output_cb: SA expired while in crypto " 897 "(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst), 898 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 899 error = ENOBUFS; /*XXX*/ 900 goto bad; 901 } 902 KASSERT(isr->sav == sav, 903 ("esp_output_cb: SA changed was %p now %p\n", isr->sav, sav)); 904 905 /* Check for crypto errors. */ 906 if (crp->crp_etype) { 907 /* Reset session ID. */ 908 if (sav->tdb_cryptoid != 0) 909 sav->tdb_cryptoid = crp->crp_sid; 910 911 if (crp->crp_etype == EAGAIN) { 912 KEY_FREESAV(&sav); 913 splx(s); 914 return crypto_dispatch(crp); 915 } 916 917 espstat.esps_noxform++; 918 DPRINTF(("esp_output_cb: crypto error %d\n", crp->crp_etype)); 919 error = crp->crp_etype; 920 goto bad; 921 } 922 923 /* Shouldn't happen... */ 924 if (m == NULL) { 925 espstat.esps_crypto++; 926 DPRINTF(("esp_output_cb: bogus returned buffer from crypto\n")); 927 error = EINVAL; 928 goto bad; 929 } 930 espstat.esps_hist[sav->alg_enc]++; 931 if (sav->tdb_authalgxform != NULL) 932 ahstat.ahs_hist[sav->alg_auth]++; 933 934 /* Release crypto descriptors. */ 935 free(tc, M_XDATA); 936 crypto_freereq(crp); 937 938 /* NB: m is reclaimed by ipsec_process_done. */ 939 err = ipsec_process_done(m, isr); 940 KEY_FREESAV(&sav); 941 splx(s); 942 return err; 943 bad: 944 if (sav) 945 KEY_FREESAV(&sav); 946 splx(s); 947 if (m) 948 m_freem(m); 949 free(tc, M_XDATA); 950 crypto_freereq(crp); 951 return error; 952 } 953 954 static struct xformsw esp_xformsw = { 955 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", 956 esp_init, esp_zeroize, esp_input, 957 esp_output 958 }; 959 960 static void 961 esp_attach(void) 962 { 963 #define MAXIV(xform) \ 964 if (xform.blocksize > esp_max_ivlen) \ 965 esp_max_ivlen = xform.blocksize \ 966 967 esp_max_ivlen = 0; 968 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ 969 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ 970 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ 971 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ 972 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ 973 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ 974 MAXIV(enc_xform_null); /* SADB_EALG_NULL */ 975 976 xform_register(&esp_xformsw); 977 #undef MAXIV 978 } 979 SYSINIT(esp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, esp_attach, NULL)
Cache object: 43a99d7ed56eb3a62c46db60828c7ae5
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