/* $NetBSD: xform_esp.c,v 1.37 2011/05/23 15:17:25 drochner Exp $ */ /* $FreeBSD: src/sys/netipsec/xform_esp.c,v 1.2.2.1 2003/01/24 05:11:36 sam Exp $ */ /* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */ /* * The authors of this code are John Ioannidis (ji@tla.org), * Angelos D. Keromytis (kermit@csd.uch.gr) and * Niels Provos (provos@physnet.uni-hamburg.de). * * The original version of this code was written by John Ioannidis * for BSD/OS in Athens, Greece, in November 1995. * * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, * by Angelos D. Keromytis. * * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis * and Niels Provos. * * Additional features in 1999 by Angelos D. Keromytis. * * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, * Angelos D. Keromytis and Niels Provos. * Copyright (c) 2001 Angelos D. Keromytis. * * Permission to use, copy, and modify this software with or without fee * is hereby granted, provided that this entire notice is included in * all copies of any software which is or includes a copy or * modification of this software. * You may use this code under the GNU public license if you so wish. Please * contribute changes back to the authors under this freer than GPL license * so that we may further the use of strong encryption without limitations to * all. * * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR * PURPOSE. */ #include __KERNEL_RCSID(0, "$NetBSD: xform_esp.c,v 1.37 2011/05/23 15:17:25 drochner Exp $"); #include "opt_inet.h" #ifdef __FreeBSD__ #include "opt_inet6.h" #endif #include #include #include #include #include #include /*#include */ #include #include /* for softnet_lock */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include # ifdef __FreeBSD__ # include # endif #endif #include #include #include #include #include percpu_t *espstat_percpu; int esp_enable = 1; #ifdef __FreeBSD__ SYSCTL_DECL(_net_inet_esp); SYSCTL_INT(_net_inet_esp, OID_AUTO, esp_enable, CTLFLAG_RW, &esp_enable, 0, ""); SYSCTL_STRUCT(_net_inet_esp, IPSECCTL_STATS, stats, CTLFLAG_RD, &espstat, espstat, ""); #endif /* __FreeBSD__ */ static int esp_max_ivlen; /* max iv length over all algorithms */ static int esp_input_cb(struct cryptop *op); static int esp_output_cb(struct cryptop *crp); /* * NB: this is public for use by the PF_KEY support. * NB: if you add support here; be sure to add code to esp_attach below! */ const struct enc_xform * esp_algorithm_lookup(int alg) { if (alg >= ESP_ALG_MAX) return NULL; switch (alg) { case SADB_EALG_DESCBC: return &enc_xform_des; case SADB_EALG_3DESCBC: return &enc_xform_3des; case SADB_X_EALG_AES: return &enc_xform_rijndael128; case SADB_X_EALG_BLOWFISHCBC: return &enc_xform_blf; case SADB_X_EALG_CAST128CBC: return &enc_xform_cast5; case SADB_X_EALG_SKIPJACK: return &enc_xform_skipjack; case SADB_X_EALG_CAMELLIACBC: return &enc_xform_camellia; case SADB_X_EALG_AESCTR: return &enc_xform_aes_ctr; case SADB_EALG_NULL: return &enc_xform_null; } return NULL; } size_t esp_hdrsiz(const struct secasvar *sav) { size_t size; if (sav != NULL) { /*XXX not right for null algorithm--does it matter??*/ IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("esp_hdrsiz: SA with null xform")); if (sav->flags & SADB_X_EXT_OLD) size = sizeof (struct esp); else size = sizeof (struct newesp); size += sav->tdb_encalgxform->ivsize + 9; /*XXX need alg check???*/ if (sav->tdb_authalgxform != NULL && sav->replay) size += ah_hdrsiz(sav); } else { /* * base header size * + max iv length for CBC mode * + max pad length * + sizeof (pad length field) * + sizeof (next header field) * + max icv supported. */ size = sizeof (struct newesp) + esp_max_ivlen + 9 + 16; } return size; } /* * esp_init() is called when an SPI is being set up. */ static int esp_init(struct secasvar *sav, const struct xformsw *xsp) { const struct enc_xform *txform; struct cryptoini cria, crie; int keylen; int error; txform = esp_algorithm_lookup(sav->alg_enc); if (txform == NULL) { DPRINTF(("esp_init: unsupported encryption algorithm %d\n", sav->alg_enc)); return EINVAL; } if (sav->key_enc == NULL) { DPRINTF(("esp_init: no encoding key for %s algorithm\n", txform->name)); return EINVAL; } if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { DPRINTF(("esp_init: 4-byte IV not supported with protocol\n")); return EINVAL; } keylen = _KEYLEN(sav->key_enc); if (txform->minkey > keylen || keylen > txform->maxkey) { DPRINTF(("esp_init: invalid key length %u, must be in " "the range [%u..%u] for algorithm %s\n", keylen, txform->minkey, txform->maxkey, txform->name)); return EINVAL; } sav->ivlen = txform->ivsize; /* * Setup AH-related state. */ if (sav->alg_auth != 0) { error = ah_init0(sav, xsp, &cria); if (error) return error; } /* NB: override anything set in ah_init0 */ sav->tdb_xform = xsp; sav->tdb_encalgxform = txform; /* Initialize crypto session. */ memset(&crie, 0, sizeof (crie)); crie.cri_alg = sav->tdb_encalgxform->type; crie.cri_klen = _KEYBITS(sav->key_enc); crie.cri_key = _KEYBUF(sav->key_enc); /* XXX Rounds ? */ if (sav->tdb_authalgxform && sav->tdb_encalgxform) { /* init both auth & enc */ crie.cri_next = &cria; error = crypto_newsession(&sav->tdb_cryptoid, &crie, crypto_support); } else if (sav->tdb_encalgxform) { error = crypto_newsession(&sav->tdb_cryptoid, &crie, crypto_support); } else if (sav->tdb_authalgxform) { error = crypto_newsession(&sav->tdb_cryptoid, &cria, crypto_support); } else { /* XXX cannot happen? */ DPRINTF(("esp_init: no encoding OR authentication xform!\n")); error = EINVAL; } return error; } /* * Paranoia. */ static int esp_zeroize(struct secasvar *sav) { /* NB: ah_zerorize free's the crypto session state */ int error = ah_zeroize(sav); if (sav->key_enc) memset(_KEYBUF(sav->key_enc), 0, _KEYLEN(sav->key_enc)); sav->tdb_encalgxform = NULL; sav->tdb_xform = NULL; return error; } /* * ESP input processing, called (eventually) through the protocol switch. */ static int esp_input(struct mbuf *m, const struct secasvar *sav, int skip, int protoff) { const struct auth_hash *esph; const struct enc_xform *espx; struct tdb_ident *tdbi; struct tdb_crypto *tc; int plen, alen, hlen; struct m_tag *mtag; struct newesp *esp; struct cryptodesc *crde; struct cryptop *crp; IPSEC_SPLASSERT_SOFTNET("esp_input"); IPSEC_ASSERT(sav != NULL, ("esp_input: null SA")); IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("esp_input: null encoding xform")); IPSEC_ASSERT((skip&3) == 0 && (m->m_pkthdr.len&3) == 0, ("esp_input: misaligned packet, skip %u pkt len %u", skip, m->m_pkthdr.len)); /* XXX don't pullup, just copy header */ IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof (struct newesp)); esph = sav->tdb_authalgxform; espx = sav->tdb_encalgxform; /* Determine the ESP header length */ if (sav->flags & SADB_X_EXT_OLD) hlen = sizeof (struct esp) + sav->ivlen; else hlen = sizeof (struct newesp) + sav->ivlen; /* Authenticator hash size */ alen = esph ? esph->authsize : 0; /* * Verify payload length is multiple of encryption algorithm * block size. * * NB: This works for the null algorithm because the blocksize * is 4 and all packets must be 4-byte aligned regardless * of the algorithm. */ plen = m->m_pkthdr.len - (skip + hlen + alen); if ((plen & (espx->blocksize - 1)) || (plen <= 0)) { DPRINTF(("esp_input: " "payload of %d octets not a multiple of %d octets," " SA %s/%08lx\n", plen, espx->blocksize, ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); ESP_STATINC(ESP_STAT_BADILEN); m_freem(m); return EINVAL; } /* * Check sequence number. */ if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { DPRINTF(("esp_input: packet replay check for %s\n", ipsec_logsastr(sav))); /*XXX*/ ESP_STATINC(ESP_STAT_REPLAY); m_freem(m); return ENOBUFS; /*XXX*/ } /* Update the counters */ ESP_STATADD(ESP_STAT_IBYTES, m->m_pkthdr.len - skip - hlen - alen); /* Find out if we've already done crypto */ for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL); mtag != NULL; mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) { tdbi = (struct tdb_ident *) (mtag + 1); if (tdbi->proto == sav->sah->saidx.proto && tdbi->spi == sav->spi && !memcmp(&tdbi->dst, &sav->sah->saidx.dst, sizeof(union sockaddr_union))) break; } /* Get crypto descriptors */ crp = crypto_getreq(esph && espx ? 2 : 1); if (crp == NULL) { DPRINTF(("esp_input: failed to acquire crypto descriptors\n")); ESP_STATINC(ESP_STAT_CRYPTO); m_freem(m); return ENOBUFS; } /* Get IPsec-specific opaque pointer */ if (esph == NULL || mtag != NULL) tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), M_XDATA, M_NOWAIT|M_ZERO); else tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto) + alen, M_XDATA, M_NOWAIT|M_ZERO); if (tc == NULL) { crypto_freereq(crp); DPRINTF(("esp_input: failed to allocate tdb_crypto\n")); ESP_STATINC(ESP_STAT_CRYPTO); m_freem(m); return ENOBUFS; } tc->tc_ptr = mtag; if (esph) { struct cryptodesc *crda = crp->crp_desc; IPSEC_ASSERT(crda != NULL, ("esp_input: null ah crypto descriptor")); /* Authentication descriptor */ crda->crd_skip = skip; crda->crd_len = m->m_pkthdr.len - (skip + alen); crda->crd_inject = m->m_pkthdr.len - alen; crda->crd_alg = esph->type; crda->crd_key = _KEYBUF(sav->key_auth); crda->crd_klen = _KEYBITS(sav->key_auth); /* Copy the authenticator */ if (mtag == NULL) m_copydata(m, m->m_pkthdr.len - alen, alen, (tc + 1)); /* Chain authentication request */ crde = crda->crd_next; } else { crde = crp->crp_desc; } /* Crypto operation descriptor */ crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ crp->crp_flags = CRYPTO_F_IMBUF; crp->crp_buf = m; crp->crp_callback = esp_input_cb; crp->crp_sid = sav->tdb_cryptoid; crp->crp_opaque = tc; /* These are passed as-is to the callback */ tc->tc_spi = sav->spi; tc->tc_dst = sav->sah->saidx.dst; tc->tc_proto = sav->sah->saidx.proto; tc->tc_protoff = protoff; tc->tc_skip = skip; /* Decryption descriptor */ if (espx) { IPSEC_ASSERT(crde != NULL, ("esp_input: null esp crypto descriptor")); crde->crd_skip = skip + hlen; crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); crde->crd_inject = skip + hlen - sav->ivlen; crde->crd_alg = espx->type; crde->crd_key = _KEYBUF(sav->key_enc); crde->crd_klen = _KEYBITS(sav->key_enc); /* XXX Rounds ? */ } if (mtag == NULL) return crypto_dispatch(crp); else return esp_input_cb(crp); } #ifdef INET6 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ if (saidx->dst.sa.sa_family == AF_INET6) { \ error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ } else { \ error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ } \ } while (0) #else #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) #endif /* * ESP input callback from the crypto driver. */ static int esp_input_cb(struct cryptop *crp) { u_int8_t lastthree[3], aalg[AH_ALEN_MAX]; int s, hlen, skip, protoff, error; struct mbuf *m; struct cryptodesc *crd; const struct auth_hash *esph; const struct enc_xform *espx; struct tdb_crypto *tc; struct m_tag *mtag; struct secasvar *sav; struct secasindex *saidx; void *ptr; u_int16_t dport = 0; u_int16_t sport = 0; #ifdef IPSEC_NAT_T struct m_tag * tag = NULL; #endif crd = crp->crp_desc; IPSEC_ASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!")); tc = (struct tdb_crypto *) crp->crp_opaque; IPSEC_ASSERT(tc != NULL, ("esp_input_cb: null opaque crypto data area!")); skip = tc->tc_skip; protoff = tc->tc_protoff; mtag = (struct m_tag *) tc->tc_ptr; m = (struct mbuf *) crp->crp_buf; #ifdef IPSEC_NAT_T /* find the source port for NAT-T */ if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) { sport = ((u_int16_t *)(tag + 1))[0]; dport = ((u_int16_t *)(tag + 1))[1]; } #endif s = splsoftnet(); mutex_enter(softnet_lock); sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport); if (sav == NULL) { ESP_STATINC(ESP_STAT_NOTDB); DPRINTF(("esp_input_cb: SA expired while in crypto " "(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst), (u_long) ntohl(tc->tc_spi), tc->tc_proto)); error = ENOBUFS; /*XXX*/ goto bad; } saidx = &sav->sah->saidx; IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || saidx->dst.sa.sa_family == AF_INET6, ("esp_input_cb: unexpected protocol family %u", saidx->dst.sa.sa_family)); esph = sav->tdb_authalgxform; espx = sav->tdb_encalgxform; /* Check for crypto errors */ if (crp->crp_etype) { /* Reset the session ID */ if (sav->tdb_cryptoid != 0) sav->tdb_cryptoid = crp->crp_sid; if (crp->crp_etype == EAGAIN) { KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); return crypto_dispatch(crp); } ESP_STATINC(ESP_STAT_NOXFORM); DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype)); error = crp->crp_etype; goto bad; } /* Shouldn't happen... */ if (m == NULL) { ESP_STATINC(ESP_STAT_CRYPTO); DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n")); error = EINVAL; goto bad; } ESP_STATINC(ESP_STAT_HIST + sav->alg_enc); /* If authentication was performed, check now. */ if (esph != NULL) { /* * If we have a tag, it means an IPsec-aware NIC did * the verification for us. Otherwise we need to * check the authentication calculation. */ AH_STATINC(AH_STAT_HIST + sav->alg_auth); if (mtag == NULL) { /* Copy the authenticator from the packet */ m_copydata(m, m->m_pkthdr.len - esph->authsize, esph->authsize, aalg); ptr = (tc + 1); /* Verify authenticator */ if (memcmp(ptr, aalg, esph->authsize) != 0) { DPRINTF(("esp_input_cb: " "authentication hash mismatch for packet in SA %s/%08lx\n", ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESP_STATINC(ESP_STAT_BADAUTH); error = EACCES; goto bad; } } /* Remove trailing authenticator */ m_adj(m, -(esph->authsize)); } /* Release the crypto descriptors */ free(tc, M_XDATA), tc = NULL; crypto_freereq(crp), crp = NULL; /* * Packet is now decrypted. */ m->m_flags |= M_DECRYPTED; /* * Update replay sequence number, if appropriate. */ if (sav->replay) { u_int32_t seq; m_copydata(m, skip + offsetof(struct newesp, esp_seq), sizeof (seq), &seq); if (ipsec_updatereplay(ntohl(seq), sav)) { DPRINTF(("%s: packet replay check for %s\n", __func__, ipsec_logsastr(sav))); ESP_STATINC(ESP_STAT_REPLAY); error = ENOBUFS; goto bad; } } /* Determine the ESP header length */ if (sav->flags & SADB_X_EXT_OLD) hlen = sizeof (struct esp) + sav->ivlen; else hlen = sizeof (struct newesp) + sav->ivlen; /* Remove the ESP header and IV from the mbuf. */ error = m_striphdr(m, skip, hlen); if (error) { ESP_STATINC(ESP_STAT_HDROPS); DPRINTF(("esp_input_cb: bad mbuf chain, SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); goto bad; } /* Save the last three bytes of decrypted data */ m_copydata(m, m->m_pkthdr.len - 3, 3, lastthree); /* Verify pad length */ if (lastthree[1] + 2 > m->m_pkthdr.len - skip) { ESP_STATINC(ESP_STAT_BADILEN); DPRINTF(("esp_input_cb: invalid padding length %d " "for %u byte packet in SA %s/%08lx\n", lastthree[1], m->m_pkthdr.len - skip, ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); error = EINVAL; goto bad; } /* Verify correct decryption by checking the last padding bytes */ if ((sav->flags & SADB_X_EXT_PMASK) != SADB_X_EXT_PRAND) { if (lastthree[1] != lastthree[0] && lastthree[1] != 0) { ESP_STATINC(ESP_STAT_BADENC); DPRINTF(("esp_input_cb: decryption failed " "for packet in SA %s/%08lx\n", ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); DPRINTF(("esp_input_cb: %x %x\n", lastthree[0], lastthree[1])); error = EINVAL; goto bad; } } /* Trim the mbuf chain to remove trailing authenticator and padding */ m_adj(m, -(lastthree[1] + 2)); /* Restore the Next Protocol field */ m = m_copyback_cow(m, protoff, sizeof (u_int8_t), lastthree + 2, M_DONTWAIT); if (m == NULL) { ESP_STATINC(ESP_STAT_CRYPTO); DPRINTF(("esp_input_cb: failed to allocate mbuf\n")); error = ENOBUFS; goto bad; } IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); return error; bad: if (sav) KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); if (m != NULL) m_freem(m); if (tc != NULL) free(tc, M_XDATA); if (crp != NULL) crypto_freereq(crp); return error; } /* * ESP output routine, called by ipsec[46]_process_packet(). */ static int esp_output( struct mbuf *m, struct ipsecrequest *isr, struct mbuf **mp, int skip, int protoff ) { const struct enc_xform *espx; const struct auth_hash *esph; int hlen, rlen, plen, padding, blks, alen, i, roff; struct mbuf *mo = (struct mbuf *) NULL; struct tdb_crypto *tc; const struct secasvar *sav; struct secasindex *saidx; unsigned char *pad; u_int8_t prot; int error, maxpacketsize; struct cryptodesc *crde = NULL, *crda = NULL; struct cryptop *crp; IPSEC_SPLASSERT_SOFTNET("esp_output"); sav = isr->sav; IPSEC_ASSERT(sav != NULL, ("esp_output: null SA")); esph = sav->tdb_authalgxform; espx = sav->tdb_encalgxform; IPSEC_ASSERT(espx != NULL, ("esp_output: null encoding xform")); if (sav->flags & SADB_X_EXT_OLD) hlen = sizeof (struct esp) + sav->ivlen; else hlen = sizeof (struct newesp) + sav->ivlen; rlen = m->m_pkthdr.len - skip; /* Raw payload length. */ /* * NB: The null encoding transform has a blocksize of 4 * so that headers are properly aligned. */ blks = espx->blocksize; /* IV blocksize */ /* XXX clamp padding length a la KAME??? */ padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; plen = rlen + padding; /* Padded payload length. */ if (esph) alen = esph->authsize; else alen = 0; ESP_STATINC(ESP_STAT_OUTPUT); saidx = &sav->sah->saidx; /* Check for maximum packet size violations. */ switch (saidx->dst.sa.sa_family) { #ifdef INET case AF_INET: maxpacketsize = IP_MAXPACKET; break; #endif /* INET */ #ifdef INET6 case AF_INET6: maxpacketsize = IPV6_MAXPACKET; break; #endif /* INET6 */ default: DPRINTF(("esp_output: unknown/unsupported protocol " "family %d, SA %s/%08lx\n", saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESP_STATINC(ESP_STAT_NOPF); error = EPFNOSUPPORT; goto bad; } if (skip + hlen + rlen + padding + alen > maxpacketsize) { DPRINTF(("esp_output: packet in SA %s/%08lx got too big " "(len %u, max len %u)\n", ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), skip + hlen + rlen + padding + alen, maxpacketsize)); ESP_STATINC(ESP_STAT_TOOBIG); error = EMSGSIZE; goto bad; } /* Update the counters. */ ESP_STATADD(ESP_STAT_OBYTES, m->m_pkthdr.len - skip); m = m_clone(m); if (m == NULL) { DPRINTF(("esp_output: cannot clone mbuf chain, SA %s/%08lx\n", ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESP_STATINC(ESP_STAT_HDROPS); error = ENOBUFS; goto bad; } /* Inject ESP header. */ mo = m_makespace(m, skip, hlen, &roff); if (mo == NULL) { DPRINTF(("esp_output: failed to inject %u byte ESP hdr for SA " "%s/%08lx\n", hlen, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESP_STATINC(ESP_STAT_HDROPS); /* XXX diffs from openbsd */ error = ENOBUFS; goto bad; } /* Initialize ESP header. */ memcpy(mtod(mo, char *) + roff, &sav->spi, sizeof(u_int32_t)); if (sav->replay) { u_int32_t replay; #ifdef IPSEC_DEBUG /* Emulate replay attack when ipsec_replay is TRUE. */ if (!ipsec_replay) #endif sav->replay->count++; replay = htonl(sav->replay->count); bcopy(&replay, mtod(mo,char *) + roff + sizeof(u_int32_t), sizeof(u_int32_t)); } /* * Add padding -- better to do it ourselves than use the crypto engine, * although if/when we support compression, we'd have to do that. */ pad = (u_char *) m_pad(m, padding + alen); if (pad == NULL) { DPRINTF(("esp_output: m_pad failed for SA %s/%08lx\n", ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); m = NULL; /* NB: free'd by m_pad */ error = ENOBUFS; goto bad; } /* * Add padding: random, zero, or self-describing. * XXX catch unexpected setting */ switch (sav->flags & SADB_X_EXT_PMASK) { case SADB_X_EXT_PRAND: (void) read_random(pad, padding - 2); break; case SADB_X_EXT_PZERO: memset(pad, 0, padding - 2); break; case SADB_X_EXT_PSEQ: for (i = 0; i < padding - 2; i++) pad[i] = i+1; break; } /* Fix padding length and Next Protocol in padding itself. */ pad[padding - 2] = padding - 2; m_copydata(m, protoff, sizeof(u_int8_t), pad + padding - 1); /* Fix Next Protocol in IPv4/IPv6 header. */ prot = IPPROTO_ESP; m_copyback(m, protoff, sizeof(u_int8_t), (u_char *) &prot); /* Get crypto descriptors. */ crp = crypto_getreq(esph && espx ? 2 : 1); if (crp == NULL) { DPRINTF(("esp_output: failed to acquire crypto descriptors\n")); ESP_STATINC(ESP_STAT_CRYPTO); error = ENOBUFS; goto bad; } if (espx) { crde = crp->crp_desc; crda = crde->crd_next; /* Encryption descriptor. */ crde->crd_skip = skip + hlen; crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen); crde->crd_flags = CRD_F_ENCRYPT; crde->crd_inject = skip + hlen - sav->ivlen; /* Encryption operation. */ crde->crd_alg = espx->type; crde->crd_key = _KEYBUF(sav->key_enc); crde->crd_klen = _KEYBITS(sav->key_enc); /* XXX Rounds ? */ } else crda = crp->crp_desc; /* IPsec-specific opaque crypto info. */ tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), M_XDATA, M_NOWAIT|M_ZERO); if (tc == NULL) { crypto_freereq(crp); DPRINTF(("esp_output: failed to allocate tdb_crypto\n")); ESP_STATINC(ESP_STAT_CRYPTO); error = ENOBUFS; goto bad; } /* Callback parameters */ tc->tc_isr = isr; tc->tc_spi = sav->spi; tc->tc_dst = saidx->dst; tc->tc_proto = saidx->proto; /* Crypto operation descriptor. */ crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ crp->crp_flags = CRYPTO_F_IMBUF; crp->crp_buf = m; crp->crp_callback = esp_output_cb; crp->crp_opaque = tc; crp->crp_sid = sav->tdb_cryptoid; if (esph) { /* Authentication descriptor. */ crda->crd_skip = skip; crda->crd_len = m->m_pkthdr.len - (skip + alen); crda->crd_inject = m->m_pkthdr.len - alen; /* Authentication operation. */ crda->crd_alg = esph->type; crda->crd_key = _KEYBUF(sav->key_auth); crda->crd_klen = _KEYBITS(sav->key_auth); } return crypto_dispatch(crp); bad: if (m) m_freem(m); return (error); } /* * ESP output callback from the crypto driver. */ static int esp_output_cb(struct cryptop *crp) { struct tdb_crypto *tc; struct ipsecrequest *isr; struct secasvar *sav; struct mbuf *m; int s, err, error; tc = (struct tdb_crypto *) crp->crp_opaque; IPSEC_ASSERT(tc != NULL, ("esp_output_cb: null opaque data area!")); m = (struct mbuf *) crp->crp_buf; s = splsoftnet(); mutex_enter(softnet_lock); isr = tc->tc_isr; sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0); if (sav == NULL) { ESP_STATINC(ESP_STAT_NOTDB); DPRINTF(("esp_output_cb: SA expired while in crypto " "(SA %s/%08lx proto %u)\n", ipsec_address(&tc->tc_dst), (u_long) ntohl(tc->tc_spi), tc->tc_proto)); error = ENOBUFS; /*XXX*/ goto bad; } IPSEC_ASSERT(isr->sav == sav, ("esp_output_cb: SA changed was %p now %p\n", isr->sav, sav)); /* Check for crypto errors. */ if (crp->crp_etype) { /* Reset session ID. */ if (sav->tdb_cryptoid != 0) sav->tdb_cryptoid = crp->crp_sid; if (crp->crp_etype == EAGAIN) { KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); return crypto_dispatch(crp); } ESP_STATINC(ESP_STAT_NOXFORM); DPRINTF(("esp_output_cb: crypto error %d\n", crp->crp_etype)); error = crp->crp_etype; goto bad; } /* Shouldn't happen... */ if (m == NULL) { ESP_STATINC(ESP_STAT_CRYPTO); DPRINTF(("esp_output_cb: bogus returned buffer from crypto\n")); error = EINVAL; goto bad; } ESP_STATINC(ESP_STAT_HIST + sav->alg_enc); if (sav->tdb_authalgxform != NULL) AH_STATINC(AH_STAT_HIST + sav->alg_auth); /* Release crypto descriptors. */ free(tc, M_XDATA); crypto_freereq(crp); #ifdef IPSEC_DEBUG /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ if (ipsec_integrity) { static unsigned char ipseczeroes[AH_ALEN_MAX]; const struct auth_hash *esph; /* * Corrupt HMAC if we want to test integrity verification of * the other side. */ esph = sav->tdb_authalgxform; if (esph != NULL) { m_copyback(m, m->m_pkthdr.len - esph->authsize, esph->authsize, ipseczeroes); } } #endif /* NB: m is reclaimed by ipsec_process_done. */ err = ipsec_process_done(m, isr); KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); return err; bad: if (sav) KEY_FREESAV(&sav); mutex_exit(softnet_lock); splx(s); if (m) m_freem(m); free(tc, M_XDATA); crypto_freereq(crp); return error; } static struct xformsw esp_xformsw = { XF_ESP, XFT_CONF|XFT_AUTH, "IPsec ESP", esp_init, esp_zeroize, esp_input, esp_output, NULL, }; INITFN void esp_attach(void) { espstat_percpu = percpu_alloc(sizeof(uint64_t) * ESP_NSTATS); #define MAXIV(xform) \ if (xform.ivsize > esp_max_ivlen) \ esp_max_ivlen = xform.ivsize \ esp_max_ivlen = 0; MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */ MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */ MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */ MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */ MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */ MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */ MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */ MAXIV(enc_xform_aes_ctr); /* SADB_X_EALG_AESCTR */ MAXIV(enc_xform_null); /* SADB_EALG_NULL */ xform_register(&esp_xformsw); #undef MAXIV } #ifdef __FreeBSD__ SYSINIT(esp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, esp_attach, NULL) #else #endif