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sys/netipsec/xform_esp.c
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1 /* $FreeBSD: releng/5.2/sys/netipsec/xform_esp.c 120585 2003-09-29 22:57:43Z sam $ */ 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 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, 128 ("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(("%s: unsupported encryption algorithm %d\n", 165 __func__, sav->alg_enc)); 166 return EINVAL; 167 } 168 if (sav->key_enc == NULL) { 169 DPRINTF(("%s: no encoding key for %s algorithm\n", 170 __func__, txform->name)); 171 return EINVAL; 172 } 173 if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { 174 DPRINTF(("%s: 4-byte IV not supported with protocol\n", 175 __func__)); 176 return EINVAL; 177 } 178 keylen = _KEYLEN(sav->key_enc); 179 if (txform->minkey > keylen || keylen > txform->maxkey) { 180 DPRINTF(("%s: invalid key length %u, must be in the range " 181 "[%u..%u] for algorithm %s\n", __func__, 182 keylen, txform->minkey, txform->maxkey, 183 txform->name)); 184 return EINVAL; 185 } 186 187 /* 188 * NB: The null xform needs a non-zero blocksize to keep the 189 * crypto code happy but if we use it to set ivlen then 190 * the ESP header will be processed incorrectly. The 191 * compromise is to force it to zero here. 192 */ 193 sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize); 194 sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK); 195 if (sav->iv == NULL) { 196 DPRINTF(("%s: no memory for IV\n", __func__)); 197 return EINVAL; 198 } 199 key_randomfill(sav->iv, sav->ivlen); /*XXX*/ 200 201 /* 202 * Setup AH-related state. 203 */ 204 if (sav->alg_auth != 0) { 205 error = ah_init0(sav, xsp, &cria); 206 if (error) 207 return error; 208 } 209 210 /* NB: override anything set in ah_init0 */ 211 sav->tdb_xform = xsp; 212 sav->tdb_encalgxform = txform; 213 214 /* Initialize crypto session. */ 215 bzero(&crie, sizeof (crie)); 216 crie.cri_alg = sav->tdb_encalgxform->type; 217 crie.cri_klen = _KEYBITS(sav->key_enc); 218 crie.cri_key = _KEYBUF(sav->key_enc); 219 /* XXX Rounds ? */ 220 221 if (sav->tdb_authalgxform && sav->tdb_encalgxform) { 222 /* init both auth & enc */ 223 crie.cri_next = &cria; 224 error = crypto_newsession(&sav->tdb_cryptoid, 225 &crie, crypto_support); 226 } else if (sav->tdb_encalgxform) { 227 error = crypto_newsession(&sav->tdb_cryptoid, 228 &crie, crypto_support); 229 } else if (sav->tdb_authalgxform) { 230 error = crypto_newsession(&sav->tdb_cryptoid, 231 &cria, crypto_support); 232 } else { 233 /* XXX cannot happen? */ 234 DPRINTF(("%s: no encoding OR authentication xform!\n", 235 __func__)); 236 error = EINVAL; 237 } 238 return error; 239 } 240 241 /* 242 * Paranoia. 243 */ 244 static int 245 esp_zeroize(struct secasvar *sav) 246 { 247 /* NB: ah_zerorize free's the crypto session state */ 248 int error = ah_zeroize(sav); 249 250 if (sav->key_enc) 251 bzero(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc)); 252 if (sav->iv) { 253 free(sav->iv, M_XDATA); 254 sav->iv = NULL; 255 } 256 sav->tdb_encalgxform = NULL; 257 sav->tdb_xform = NULL; 258 return error; 259 } 260 261 /* 262 * ESP input processing, called (eventually) through the protocol switch. 263 */ 264 static int 265 esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 266 { 267 struct auth_hash *esph; 268 struct enc_xform *espx; 269 struct tdb_ident *tdbi; 270 struct tdb_crypto *tc; 271 int plen, alen, hlen; 272 struct m_tag *mtag; 273 struct newesp *esp; 274 275 struct cryptodesc *crde; 276 struct cryptop *crp; 277 278 IPSEC_SPLASSERT_SOFTNET(__func__); 279 280 IPSEC_ASSERT(sav != NULL, ("null SA")); 281 IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform")); 282 IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0, 283 ("misaligned packet, skip %u pkt len %u", 284 skip, m->m_pkthdr.len)); 285 286 /* XXX don't pullup, just copy header */ 287 IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); 288 289 esph = sav->tdb_authalgxform; 290 espx = sav->tdb_encalgxform; 291 292 /* Determine the ESP header length */ 293 if (sav->flags & SADB_X_EXT_OLD) 294 hlen = sizeof (struct esp) + sav->ivlen; 295 else 296 hlen = sizeof (struct newesp) + sav->ivlen; 297 /* Authenticator hash size */ 298 alen = esph ? AH_HMAC_HASHLEN : 0; 299 300 /* 301 * Verify payload length is multiple of encryption algorithm 302 * block size. 303 * 304 * NB: This works for the null algorithm because the blocksize 305 * is 4 and all packets must be 4-byte aligned regardless 306 * of the algorithm. 307 */ 308 plen = m->m_pkthdr.len - (skip + hlen + alen); 309 if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { 310 DPRINTF(("%s: payload of %d octets not a multiple of %d octets," 311 " SA %s/%08lx\n", __func__, 312 plen, espx->blocksize, 313 ipsec_address(&sav->sah->saidx.dst), 314 (u_long) ntohl(sav->spi))); 315 espstat.esps_badilen++; 316 m_freem(m); 317 return EINVAL; 318 } 319 320 /* 321 * Check sequence number. 322 */ 323 if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { 324 DPRINTF(("%s: packet replay check for %s\n", __func__, 325 ipsec_logsastr(sav))); /*XXX*/ 326 espstat.esps_replay++; 327 m_freem(m); 328 return ENOBUFS; /*XXX*/ 329 } 330 331 /* Update the counters */ 332 espstat.esps_ibytes += m->m_pkthdr.len - skip - hlen - alen; 333 334 /* Find out if we've already done crypto */ 335 for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); 336 mtag != NULL; 337 mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { 338 tdbi = (struct tdb_ident *) (mtag + 1); 339 if (tdbi->proto == sav->sah->saidx.proto && 340 tdbi->spi == sav->spi && 341 !bcmp(&tdbi->dst, &sav->sah->saidx.dst, 342 sizeof(union sockaddr_union))) 343 break; 344 } 345 346 /* Get crypto descriptors */ 347 crp = crypto_getreq(esph && espx ? 2 : 1); 348 if (crp == NULL) { 349 DPRINTF(("%s: failed to acquire crypto descriptors\n", 350 __func__)); 351 espstat.esps_crypto++; 352 m_freem(m); 353 return ENOBUFS; 354 } 355 356 /* Get IPsec-specific opaque pointer */ 357 if (esph == NULL || mtag != NULL) 358 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 359 M_XDATA, M_NOWAIT|M_ZERO); 360 else 361 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, 362 M_XDATA, M_NOWAIT|M_ZERO); 363 if (tc == NULL) { 364 crypto_freereq(crp); 365 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 366 espstat.esps_crypto++; 367 m_freem(m); 368 return ENOBUFS; 369 } 370 371 tc->tc_ptr = (caddr_t) mtag; 372 373 if (esph) { 374 struct cryptodesc *crda = crp->crp_desc; 375 376 IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor")); 377 378 /* Authentication descriptor */ 379 crda->crd_skip = skip; 380 crda->crd_len = m->m_pkthdr.len - (skip + alen); 381 crda->crd_inject = m->m_pkthdr.len - alen; 382 383 crda->crd_alg = esph->type; 384 crda->crd_key = _KEYBUF(sav->key_auth); 385 crda->crd_klen = _KEYBITS(sav->key_auth); 386 387 /* Copy the authenticator */ 388 if (mtag == NULL) 389 m_copydata(m, m->m_pkthdr.len - alen, alen, 390 (caddr_t) (tc + 1)); 391 392 /* Chain authentication request */ 393 crde = crda->crd_next; 394 } else { 395 crde = crp->crp_desc; 396 } 397 398 /* Crypto operation descriptor */ 399 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 400 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 401 crp->crp_buf = (caddr_t) m; 402 crp->crp_callback = esp_input_cb; 403 crp->crp_sid = sav->tdb_cryptoid; 404 crp->crp_opaque = (caddr_t) tc; 405 406 /* These are passed as-is to the callback */ 407 tc->tc_spi = sav->spi; 408 tc->tc_dst = sav->sah->saidx.dst; 409 tc->tc_proto = sav->sah->saidx.proto; 410 tc->tc_protoff = protoff; 411 tc->tc_skip = skip; 412 413 /* Decryption descriptor */ 414 if (espx) { 415 IPSEC_ASSERT(crde != NULL, ("null esp crypto descriptor")); 416 crde->crd_skip = skip + hlen; 417 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 418 crde->crd_inject = skip + hlen - sav->ivlen; 419 420 crde->crd_alg = espx->type; 421 crde->crd_key = _KEYBUF(sav->key_enc); 422 crde->crd_klen = _KEYBITS(sav->key_enc); 423 /* XXX Rounds ? */ 424 } 425 426 if (mtag == NULL) 427 return crypto_dispatch(crp); 428 else 429 return esp_input_cb(crp); 430 } 431 432 #ifdef INET6 433 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 434 if (saidx->dst.sa.sa_family == AF_INET6) { \ 435 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 436 } else { \ 437 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 438 } \ 439 } while (0) 440 #else 441 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 442 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 443 #endif 444 445 /* 446 * ESP input callback from the crypto driver. 447 */ 448 static int 449 esp_input_cb(struct cryptop *crp) 450 { 451 u_int8_t lastthree[3], aalg[AH_HMAC_HASHLEN]; 452 int hlen, skip, protoff, error; 453 struct mbuf *m; 454 struct cryptodesc *crd; 455 struct auth_hash *esph; 456 struct enc_xform *espx; 457 struct tdb_crypto *tc; 458 struct m_tag *mtag; 459 struct secasvar *sav; 460 struct secasindex *saidx; 461 caddr_t ptr; 462 463 crd = crp->crp_desc; 464 IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); 465 466 tc = (struct tdb_crypto *) crp->crp_opaque; 467 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 468 skip = tc->tc_skip; 469 protoff = tc->tc_protoff; 470 mtag = (struct m_tag *) tc->tc_ptr; 471 m = (struct mbuf *) crp->crp_buf; 472 473 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 474 if (sav == NULL) { 475 espstat.esps_notdb++; 476 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 477 __func__, ipsec_address(&tc->tc_dst), 478 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 479 error = ENOBUFS; /*XXX*/ 480 goto bad; 481 } 482 483 saidx = &sav->sah->saidx; 484 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 485 saidx->dst.sa.sa_family == AF_INET6, 486 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 487 488 esph = sav->tdb_authalgxform; 489 espx = sav->tdb_encalgxform; 490 491 /* Check for crypto errors */ 492 if (crp->crp_etype) { 493 /* Reset the session ID */ 494 if (sav->tdb_cryptoid != 0) 495 sav->tdb_cryptoid = crp->crp_sid; 496 497 if (crp->crp_etype == EAGAIN) { 498 KEY_FREESAV(&sav); 499 return crypto_dispatch(crp); 500 } 501 502 espstat.esps_noxform++; 503 DPRINTF(("%s: crypto error %d\n", __func__, 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(("%s: bogus returned buffer from crypto\n", __func__)); 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(("%s: " 535 "authentication hash mismatch for packet in SA %s/%08lx\n", 536 __func__, 537 ipsec_address(&saidx->dst), 538 (u_long) ntohl(sav->spi))); 539 espstat.esps_badauth++; 540 error = EACCES; 541 goto bad; 542 } 543 } 544 545 /* Remove trailing authenticator */ 546 m_adj(m, -(esph->authsize)); 547 } 548 549 /* Release the crypto descriptors */ 550 free(tc, M_XDATA), tc = NULL; 551 crypto_freereq(crp), crp = NULL; 552 553 /* 554 * Packet is now decrypted. 555 */ 556 m->m_flags |= M_DECRYPTED; 557 558 /* Determine the ESP header length */ 559 if (sav->flags & SADB_X_EXT_OLD) 560 hlen = sizeof (struct esp) + sav->ivlen; 561 else 562 hlen = sizeof (struct newesp) + sav->ivlen; 563 564 /* Remove the ESP header and IV from the mbuf. */ 565 error = m_striphdr(m, skip, hlen); 566 if (error) { 567 espstat.esps_hdrops++; 568 DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__, 569 ipsec_address(&sav->sah->saidx.dst), 570 (u_long) ntohl(sav->spi))); 571 goto bad; 572 } 573 574 /* Save the last three bytes of decrypted data */ 575 m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); 576 577 /* Verify pad length */ 578 if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { 579 espstat.esps_badilen++; 580 DPRINTF(("%s: invalid padding length %d for %u byte packet " 581 "in SA %s/%08lx\n", __func__, 582 lastthree[1], m->m_pkthdr.len - skip, 583 ipsec_address(&sav->sah->saidx.dst), 584 (u_long) ntohl(sav->spi))); 585 error = EINVAL; 586 goto bad; 587 } 588 589 /* Verify correct decryption by checking the last padding bytes */ 590 if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { 591 if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { 592 espstat.esps_badenc++; 593 DPRINTF(("%s: decryption failed for packet in " 594 "SA %s/%08lx\n", __func__, 595 ipsec_address(&sav->sah->saidx.dst), 596 (u_long) ntohl(sav->spi))); 597 error = EINVAL; 598 goto bad; 599 } 600 } 601 602 /* Trim the mbuf chain to remove trailing authenticator and padding */ 603 m_adj(m, -(lastthree[1] + 2)); 604 605 /* Restore the Next Protocol field */ 606 m_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); 607 608 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); 609 610 KEY_FREESAV(&sav); 611 return error; 612 bad: 613 if (sav) 614 KEY_FREESAV(&sav); 615 if (m != NULL) 616 m_freem(m); 617 if (tc != NULL) 618 free(tc, M_XDATA); 619 if (crp != NULL) 620 crypto_freereq(crp); 621 return error; 622 } 623 624 /* 625 * ESP output routine, called by ipsec[46]_process_packet(). 626 */ 627 static int 628 esp_output( 629 struct mbuf *m, 630 struct ipsecrequest *isr, 631 struct mbuf **mp, 632 int skip, 633 int protoff 634 ) 635 { 636 struct enc_xform *espx; 637 struct auth_hash *esph; 638 int hlen, rlen, plen, padding, blks, alen, i, roff; 639 struct mbuf *mo = (struct mbuf *) NULL; 640 struct tdb_crypto *tc; 641 struct secasvar *sav; 642 struct secasindex *saidx; 643 unsigned char *pad; 644 u_int8_t prot; 645 int error, maxpacketsize; 646 647 struct cryptodesc *crde = NULL, *crda = NULL; 648 struct cryptop *crp; 649 650 IPSEC_SPLASSERT_SOFTNET(__func__); 651 652 sav = isr->sav; 653 IPSEC_ASSERT(sav != NULL, ("null SA")); 654 esph = sav->tdb_authalgxform; 655 espx = sav->tdb_encalgxform; 656 IPSEC_ASSERT(espx != NULL, ("null encoding xform")); 657 658 if (sav->flags & SADB_X_EXT_OLD) 659 hlen = sizeof (struct esp) + sav->ivlen; 660 else 661 hlen = sizeof (struct newesp) + sav->ivlen; 662 663 rlen = m->m_pkthdr.len - skip; /* Raw payload length. */ 664 /* 665 * NB: The null encoding transform has a blocksize of 4 666 * so that headers are properly aligned. 667 */ 668 blks = espx->blocksize; /* IV blocksize */ 669 670 /* XXX clamp padding length a la KAME??? */ 671 padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; 672 plen = rlen + padding; /* Padded payload length. */ 673 674 if (esph) 675 alen = AH_HMAC_HASHLEN; 676 else 677 alen = 0; 678 679 espstat.esps_output++; 680 681 saidx = &sav->sah->saidx; 682 /* Check for maximum packet size violations. */ 683 switch (saidx->dst.sa.sa_family) { 684 #ifdef INET 685 case AF_INET: 686 maxpacketsize = IP_MAXPACKET; 687 break; 688 #endif /* INET */ 689 #ifdef INET6 690 case AF_INET6: 691 maxpacketsize = IPV6_MAXPACKET; 692 break; 693 #endif /* INET6 */ 694 default: 695 DPRINTF(("%s: unknown/unsupported protocol " 696 "family %d, SA %s/%08lx\n", __func__, 697 saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), 698 (u_long) ntohl(sav->spi))); 699 espstat.esps_nopf++; 700 error = EPFNOSUPPORT; 701 goto bad; 702 } 703 if (skip + hlen + rlen + padding + alen > maxpacketsize) { 704 DPRINTF(("%s: packet in SA %s/%08lx got too big " 705 "(len %u, max len %u)\n", __func__, 706 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), 707 skip + hlen + rlen + padding + alen, maxpacketsize)); 708 espstat.esps_toobig++; 709 error = EMSGSIZE; 710 goto bad; 711 } 712 713 /* Update the counters. */ 714 espstat.esps_obytes += m->m_pkthdr.len - skip; 715 716 m = m_clone(m); 717 if (m == NULL) { 718 DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, 719 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 720 espstat.esps_hdrops++; 721 error = ENOBUFS; 722 goto bad; 723 } 724 725 /* Inject ESP header. */ 726 mo = m_makespace(m, skip, hlen, &roff); 727 if (mo == NULL) { 728 DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n", 729 __func__, hlen, ipsec_address(&saidx->dst), 730 (u_long) ntohl(sav->spi))); 731 espstat.esps_hdrops++; /* XXX diffs from openbsd */ 732 error = ENOBUFS; 733 goto bad; 734 } 735 736 /* Initialize ESP header. */ 737 bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); 738 if (sav->replay) { 739 u_int32_t replay = htonl(++(sav->replay->count)); 740 bcopy((caddr_t) &replay, 741 mtod(mo, caddr_t) + roff + sizeof(u_int32_t), 742 sizeof(u_int32_t)); 743 } 744 745 /* 746 * Add padding -- better to do it ourselves than use the crypto engine, 747 * although if/when we support compression, we'd have to do that. 748 */ 749 pad = (u_char *) m_pad(m, padding + alen); 750 if (pad == NULL) { 751 DPRINTF(("%s: m_pad failed for SA %s/%08lx\n", __func__, 752 ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); 753 m = NULL; /* NB: free'd by m_pad */ 754 error = ENOBUFS; 755 goto bad; 756 } 757 758 /* 759 * Add padding: random, zero, or self-describing. 760 * XXX catch unexpected setting 761 */ 762 switch (sav->flags & SADB_X_EXT_PMASK) { 763 case SADB_X_EXT_PRAND: 764 (void) read_random(pad, padding - 2); 765 break; 766 case SADB_X_EXT_PZERO: 767 bzero(pad, padding - 2); 768 break; 769 case SADB_X_EXT_PSEQ: 770 for (i = 0; i < padding - 2; i++) 771 pad[i] = i+1; 772 break; 773 } 774 775 /* Fix padding length and Next Protocol in padding itself. */ 776 pad[padding - 2] = padding - 2; 777 m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); 778 779 /* Fix Next Protocol in IPv4/IPv6 header. */ 780 prot = IPPROTO_ESP; 781 m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); 782 783 /* Get crypto descriptors. */ 784 crp = crypto_getreq(esph && espx ? 2 : 1); 785 if (crp == NULL) { 786 DPRINTF(("%s: failed to acquire crypto descriptors\n", 787 __func__)); 788 espstat.esps_crypto++; 789 error = ENOBUFS; 790 goto bad; 791 } 792 793 if (espx) { 794 crde = crp->crp_desc; 795 crda = crde->crd_next; 796 797 /* Encryption descriptor. */ 798 crde->crd_skip = skip + hlen; 799 crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); 800 crde->crd_flags = CRD_F_ENCRYPT; 801 crde->crd_inject = skip + hlen - sav->ivlen; 802 803 /* Encryption operation. */ 804 crde->crd_alg = espx->type; 805 crde->crd_key = _KEYBUF(sav->key_enc); 806 crde->crd_klen = _KEYBITS(sav->key_enc); 807 /* XXX Rounds ? */ 808 } else 809 crda = crp->crp_desc; 810 811 /* IPsec-specific opaque crypto info. */ 812 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 813 M_XDATA, M_NOWAIT|M_ZERO); 814 if (tc == NULL) { 815 crypto_freereq(crp); 816 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 817 espstat.esps_crypto++; 818 error = ENOBUFS; 819 goto bad; 820 } 821 822 /* Callback parameters */ 823 tc->tc_isr = isr; 824 tc->tc_spi = sav->spi; 825 tc->tc_dst = saidx->dst; 826 tc->tc_proto = saidx->proto; 827 828 /* Crypto operation descriptor. */ 829 crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ 830 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 831 crp->crp_buf = (caddr_t) m; 832 crp->crp_callback = esp_output_cb; 833 crp->crp_opaque = (caddr_t) tc; 834 crp->crp_sid = sav->tdb_cryptoid; 835 836 if (esph) { 837 /* Authentication descriptor. */ 838 crda->crd_skip = skip; 839 crda->crd_len = m->m_pkthdr.len - (skip + alen); 840 crda->crd_inject = m->m_pkthdr.len - alen; 841 842 /* Authentication operation. */ 843 crda->crd_alg = esph->type; 844 crda->crd_key = _KEYBUF(sav->key_auth); 845 crda->crd_klen = _KEYBITS(sav->key_auth); 846 } 847 848 return crypto_dispatch(crp); 849 bad: 850 if (m) 851 m_freem(m); 852 return (error); 853 } 854 855 /* 856 * ESP output callback from the crypto driver. 857 */ 858 static int 859 esp_output_cb(struct cryptop *crp) 860 { 861 struct tdb_crypto *tc; 862 struct ipsecrequest *isr; 863 struct secasvar *sav; 864 struct mbuf *m; 865 int err, error; 866 867 tc = (struct tdb_crypto *) crp->crp_opaque; 868 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 869 m = (struct mbuf *) crp->crp_buf; 870 871 isr = tc->tc_isr; 872 IPSECREQUEST_LOCK(isr); 873 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 874 if (sav == NULL) { 875 espstat.esps_notdb++; 876 DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", 877 __func__, ipsec_address(&tc->tc_dst), 878 (u_long) ntohl(tc->tc_spi), tc->tc_proto)); 879 error = ENOBUFS; /*XXX*/ 880 goto bad; 881 } 882 IPSEC_ASSERT(isr->sav == sav, 883 ("SA changed was %p now %p\n", isr->sav, sav)); 884 885 /* Check for crypto errors. */ 886 if (crp->crp_etype) { 887 /* Reset session ID. */ 888 if (sav->tdb_cryptoid != 0) 889 sav->tdb_cryptoid = crp->crp_sid; 890 891 if (crp->crp_etype == EAGAIN) { 892 KEY_FREESAV(&sav); 893 IPSECREQUEST_UNLOCK(isr); 894 return crypto_dispatch(crp); 895 } 896 897 espstat.esps_noxform++; 898 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 899 error = crp->crp_etype; 900 goto bad; 901 } 902 903 /* Shouldn't happen... */ 904 if (m == NULL) { 905 espstat.esps_crypto++; 906 DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); 907 error = EINVAL; 908 goto bad; 909 } 910 espstat.esps_hist[sav->alg_enc]++; 911 if (sav->tdb_authalgxform != NULL) 912 ahstat.ahs_hist[sav->alg_auth]++; 913 914 /* Release crypto descriptors. */ 915 free(tc, M_XDATA); 916 crypto_freereq(crp); 917 918 /* NB: m is reclaimed by ipsec_process_done. */ 919 err = ipsec_process_done(m, isr); 920 KEY_FREESAV(&sav); 921 IPSECREQUEST_UNLOCK(isr); 922 923 return err; 924 bad: 925 if (sav) 926 KEY_FREESAV(&sav); 927 IPSECREQUEST_UNLOCK(isr); 928 if (m) 929 m_freem(m); 930 free(tc, M_XDATA); 931 crypto_freereq(crp); 932 return error; 933 } 934 935 static struct xformsw esp_xformsw = { 936 XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", 937 esp_init, esp_zeroize, esp_input, 938 esp_output 939 }; 940 941 static void 942 esp_attach(void) 943 { 944 #define MAXIV(xform) \ 945 if (xform.blocksize > esp_max_ivlen) \ 946 esp_max_ivlen = xform.blocksize \ 947 948 esp_max_ivlen = 0; 949 MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ 950 MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ 951 MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ 952 MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ 953 MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ 954 MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ 955 MAXIV(enc_xform_null); /* SADB_EALG_NULL */ 956 957 xform_register(&esp_xformsw); 958 #undef MAXIV 959 } 960 SYSINIT(esp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, esp_attach, NULL)
Cache object: 9a4273bc0ae2c54c975300787e05a01e
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