/* $FreeBSD$ */ /* $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 "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #endif #include #include #include #include VNET_DEFINE(int, esp_enable) = 1; VNET_PCPUSTAT_DEFINE(struct espstat, espstat); VNET_PCPUSTAT_SYSINIT(espstat); #ifdef VIMAGE VNET_PCPUSTAT_SYSUNINIT(espstat); #endif /* VIMAGE */ SYSCTL_DECL(_net_inet_esp); SYSCTL_VNET_INT(_net_inet_esp, OID_AUTO, esp_enable, CTLFLAG_RW, &VNET_NAME(esp_enable), 0, ""); SYSCTL_VNET_PCPUSTAT(_net_inet_esp, IPSECCTL_STATS, stats, struct espstat, espstat, "ESP statistics (struct espstat, netipsec/esp_var.h"); 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! */ 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_EALG_NULL: return &enc_xform_null; case SADB_X_EALG_CAMELLIACBC: return &enc_xform_camellia; } return NULL; } size_t esp_hdrsiz(struct secasvar *sav) { size_t size; if (sav != NULL) { /*XXX not right for null algorithm--does it matter??*/ IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("SA with null xform")); if (sav->flags & SADB_X_EXT_OLD) size = sizeof (struct esp); else size = sizeof (struct newesp); size += sav->tdb_encalgxform->blocksize + 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) + EALG_MAX_BLOCK_LEN + 9 + 16; } return size; } /* * esp_init() is called when an SPI is being set up. */ static int esp_init(struct secasvar *sav, struct xformsw *xsp) { struct enc_xform *txform; struct cryptoini cria, crie; int keylen; int error; txform = esp_algorithm_lookup(sav->alg_enc); if (txform == NULL) { DPRINTF(("%s: unsupported encryption algorithm %d\n", __func__, sav->alg_enc)); return EINVAL; } if (sav->key_enc == NULL) { DPRINTF(("%s: no encoding key for %s algorithm\n", __func__, txform->name)); return EINVAL; } if ((sav->flags&(SADB_X_EXT_OLD|SADB_X_EXT_IV4B)) == SADB_X_EXT_IV4B) { DPRINTF(("%s: 4-byte IV not supported with protocol\n", __func__)); return EINVAL; } keylen = _KEYLEN(sav->key_enc); if (txform->minkey > keylen || keylen > txform->maxkey) { DPRINTF(("%s: invalid key length %u, must be in the range " "[%u..%u] for algorithm %s\n", __func__, keylen, txform->minkey, txform->maxkey, txform->name)); return EINVAL; } /* * NB: The null xform needs a non-zero blocksize to keep the * crypto code happy but if we use it to set ivlen then * the ESP header will be processed incorrectly. The * compromise is to force it to zero here. */ sav->ivlen = (txform == &enc_xform_null ? 0 : txform->blocksize); sav->iv = (caddr_t) malloc(sav->ivlen, M_XDATA, M_WAITOK); key_randomfill(sav->iv, sav->ivlen); /*XXX*/ /* * 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. */ bzero(&crie, sizeof (crie)); crie.cri_alg = sav->tdb_encalgxform->type; crie.cri_klen = _KEYBITS(sav->key_enc); crie.cri_key = sav->key_enc->key_data; /* XXX Rounds ? */ if (sav->tdb_authalgxform && sav->tdb_encalgxform) { /* init both auth & enc */ crie.cri_next = &cria; error = crypto_newsession(&sav->tdb_cryptoid, &crie, V_crypto_support); } else if (sav->tdb_encalgxform) { error = crypto_newsession(&sav->tdb_cryptoid, &crie, V_crypto_support); } else if (sav->tdb_authalgxform) { error = crypto_newsession(&sav->tdb_cryptoid, &cria, V_crypto_support); } else { /* XXX cannot happen? */ DPRINTF(("%s: no encoding OR authentication xform!\n", __func__)); 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) bzero(sav->key_enc->key_data, _KEYLEN(sav->key_enc)); if (sav->iv) { free(sav->iv, M_XDATA); sav->iv = NULL; } 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, struct secasvar *sav, int skip, int protoff) { struct auth_hash *esph; 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_ASSERT(sav != NULL, ("null SA")); IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform")); /* Valid IP Packet length ? */ if ( (skip&3) || (m->m_pkthdr.len&3) ){ DPRINTF(("%s: misaligned packet, skip %u pkt len %u", __func__, skip, m->m_pkthdr.len)); ESPSTAT_INC(esps_badilen); m_freem(m); return EINVAL; } /* 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 */ if (esph != NULL) { switch (esph->type) { case CRYPTO_SHA2_256_HMAC: case CRYPTO_SHA2_384_HMAC: case CRYPTO_SHA2_512_HMAC: alen = esph->hashsize/2; break; default: alen = AH_HMAC_HASHLEN; break; } }else alen = 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(("%s: payload of %d octets not a multiple of %d octets," " SA %s/%08lx\n", __func__, plen, espx->blocksize, ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_badilen); m_freem(m); return EINVAL; } /* * Check sequence number. */ if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) { DPRINTF(("%s: packet replay check for %s\n", __func__, ipsec_logsastr(sav))); /*XXX*/ ESPSTAT_INC(esps_replay); m_freem(m); return ENOBUFS; /*XXX*/ } /* Update the counters */ ESPSTAT_ADD(esps_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 && !bcmp(&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(("%s: failed to acquire crypto descriptors\n", __func__)); ESPSTAT_INC(esps_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(("%s: failed to allocate tdb_crypto\n", __func__)); ESPSTAT_INC(esps_crypto); m_freem(m); return ENOBUFS; } tc->tc_ptr = (caddr_t) mtag; if (esph) { struct cryptodesc *crda = crp->crp_desc; IPSEC_ASSERT(crda != NULL, ("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 = sav->key_auth->key_data; crda->crd_klen = _KEYBITS(sav->key_auth); /* Copy the authenticator */ if (mtag == NULL) m_copydata(m, m->m_pkthdr.len - alen, alen, (caddr_t) (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 | CRYPTO_F_CBIFSYNC; crp->crp_buf = (caddr_t) m; crp->crp_callback = esp_input_cb; crp->crp_sid = sav->tdb_cryptoid; crp->crp_opaque = (caddr_t) 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; KEY_ADDREFSA(sav); tc->tc_sav = sav; /* Decryption descriptor */ if (espx) { IPSEC_ASSERT(crde != NULL, ("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 = sav->key_enc->key_data; crde->crd_klen = _KEYBITS(sav->key_enc); /* XXX Rounds ? */ } if (mtag == NULL) return crypto_dispatch(crp); else return esp_input_cb(crp); } /* * ESP input callback from the crypto driver. */ static int esp_input_cb(struct cryptop *crp) { u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN]; int hlen, skip, protoff, error, alen; struct mbuf *m; struct cryptodesc *crd; struct auth_hash *esph; struct enc_xform *espx; struct tdb_crypto *tc; struct m_tag *mtag; struct secasvar *sav; struct secasindex *saidx; caddr_t ptr; crd = crp->crp_desc; IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); tc = (struct tdb_crypto *) crp->crp_opaque; IPSEC_ASSERT(tc != NULL, ("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; sav = tc->tc_sav; IPSEC_ASSERT(sav != NULL, ("null SA!")); saidx = &sav->sah->saidx; IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || saidx->dst.sa.sa_family == AF_INET6, ("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) return (crypto_dispatch(crp)); ESPSTAT_INC(esps_noxform); DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); error = crp->crp_etype; goto bad; } /* Shouldn't happen... */ if (m == NULL) { ESPSTAT_INC(esps_crypto); DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); error = EINVAL; goto bad; } ESPSTAT_INC(esps_hist[sav->alg_enc]); /* If authentication was performed, check now. */ if (esph != NULL) { switch (esph->type) { case CRYPTO_SHA2_256_HMAC: case CRYPTO_SHA2_384_HMAC: case CRYPTO_SHA2_512_HMAC: alen = esph->hashsize/2; break; default: alen = AH_HMAC_HASHLEN; break; } /* * If we have a tag, it means an IPsec-aware NIC did * the verification for us. Otherwise we need to * check the authentication calculation. */ AHSTAT_INC(ahs_hist[sav->alg_auth]); if (mtag == NULL) { /* Copy the authenticator from the packet */ m_copydata(m, m->m_pkthdr.len - alen, alen, aalg); ptr = (caddr_t) (tc + 1); /* Verify authenticator */ if (bcmp(ptr, aalg, alen) != 0) { DPRINTF(("%s: " "authentication hash mismatch for packet in SA %s/%08lx\n", __func__, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_badauth); error = EACCES; goto bad; } } /* Remove trailing authenticator */ m_adj(m, -alen); } /* 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), (caddr_t) &seq); if (ipsec_updatereplay(ntohl(seq), sav)) { DPRINTF(("%s: packet replay check for %s\n", __func__, ipsec_logsastr(sav))); ESPSTAT_INC(esps_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) { ESPSTAT_INC(esps_hdrops); DPRINTF(("%s: bad mbuf chain, SA %s/%08lx\n", __func__, 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) { ESPSTAT_INC(esps_badilen); DPRINTF(("%s: invalid padding length %d for %u byte packet " "in SA %s/%08lx\n", __func__, 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) { ESPSTAT_INC(esps_badenc); DPRINTF(("%s: decryption failed for packet in " "SA %s/%08lx\n", __func__, ipsec_address(&sav->sah->saidx.dst), (u_long) ntohl(sav->spi))); 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_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); switch (saidx->dst.sa.sa_family) { #ifdef INET6 case AF_INET6: error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); break; #endif #ifdef INET case AF_INET: error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); break; #endif default: panic("%s: Unexpected address family: %d saidx=%p", __func__, saidx->dst.sa.sa_family, saidx); } KEY_FREESAV(&sav); return error; bad: if (sav) KEY_FREESAV(&sav); 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 ) { struct enc_xform *espx; struct auth_hash *esph; int hlen, rlen, padding, blks, alen, i, roff; struct mbuf *mo = (struct mbuf *) NULL; struct tdb_crypto *tc; 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; sav = isr->sav; IPSEC_ASSERT(sav != NULL, ("null SA")); esph = sav->tdb_authalgxform; espx = sav->tdb_encalgxform; IPSEC_ASSERT(espx != NULL, ("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; if (esph) switch (esph->type) { case CRYPTO_SHA2_256_HMAC: case CRYPTO_SHA2_384_HMAC: case CRYPTO_SHA2_512_HMAC: alen = esph->hashsize/2; break; default: alen = AH_HMAC_HASHLEN; break; } else alen = 0; ESPSTAT_INC(esps_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(("%s: unknown/unsupported protocol " "family %d, SA %s/%08lx\n", __func__, saidx->dst.sa.sa_family, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_nopf); error = EPFNOSUPPORT; goto bad; } if (skip + hlen + rlen + padding + alen > maxpacketsize) { DPRINTF(("%s: packet in SA %s/%08lx got too big " "(len %u, max len %u)\n", __func__, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi), skip + hlen + rlen + padding + alen, maxpacketsize)); ESPSTAT_INC(esps_toobig); error = EMSGSIZE; goto bad; } /* Update the counters. */ ESPSTAT_ADD(esps_obytes, m->m_pkthdr.len - skip); m = m_unshare(m, M_NOWAIT); if (m == NULL) { DPRINTF(("%s: cannot clone mbuf chain, SA %s/%08lx\n", __func__, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_hdrops); error = ENOBUFS; goto bad; } /* Inject ESP header. */ mo = m_makespace(m, skip, hlen, &roff); if (mo == NULL) { DPRINTF(("%s: %u byte ESP hdr inject failed for SA %s/%08lx\n", __func__, hlen, ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_hdrops); /* XXX diffs from openbsd */ error = ENOBUFS; goto bad; } /* Initialize ESP header. */ bcopy((caddr_t) &sav->spi, mtod(mo, caddr_t) + roff, sizeof(u_int32_t)); if (sav->replay) { u_int32_t replay; #ifdef REGRESSION /* Emulate replay attack when ipsec_replay is TRUE. */ if (!V_ipsec_replay) #endif sav->replay->count++; replay = htonl(sav->replay->count); bcopy((caddr_t) &replay, mtod(mo, caddr_t) + 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(("%s: m_pad failed for SA %s/%08lx\n", __func__, 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: bzero(pad, 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(("%s: failed to acquire crypto descriptors\n", __func__)); ESPSTAT_INC(esps_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 = sav->key_enc->key_data; 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(("%s: failed to allocate tdb_crypto\n", __func__)); ESPSTAT_INC(esps_crypto); error = ENOBUFS; goto bad; } /* Callback parameters */ tc->tc_isr = isr; KEY_ADDREFSA(sav); tc->tc_sav = sav; 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 | CRYPTO_F_CBIFSYNC; crp->crp_buf = (caddr_t) m; crp->crp_callback = esp_output_cb; crp->crp_opaque = (caddr_t) 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 = sav->key_auth->key_data; 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 error; tc = (struct tdb_crypto *) crp->crp_opaque; IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); m = (struct mbuf *) crp->crp_buf; isr = tc->tc_isr; IPSECREQUEST_LOCK(isr); sav = tc->tc_sav; /* With the isr lock released SA pointer can be updated. */ if (sav != isr->sav) { ESPSTAT_INC(esps_notdb); DPRINTF(("%s: SA gone during crypto (SA %s/%08lx proto %u)\n", __func__, ipsec_address(&tc->tc_dst), (u_long) ntohl(tc->tc_spi), tc->tc_proto)); error = ENOBUFS; /*XXX*/ goto bad; } /* 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) { IPSECREQUEST_UNLOCK(isr); return (crypto_dispatch(crp)); } ESPSTAT_INC(esps_noxform); DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); error = crp->crp_etype; goto bad; } /* Shouldn't happen... */ if (m == NULL) { ESPSTAT_INC(esps_crypto); DPRINTF(("%s: bogus returned buffer from crypto\n", __func__)); error = EINVAL; goto bad; } ESPSTAT_INC(esps_hist[sav->alg_enc]); if (sav->tdb_authalgxform != NULL) AHSTAT_INC(ahs_hist[sav->alg_auth]); /* Release crypto descriptors. */ free(tc, M_XDATA); crypto_freereq(crp); #ifdef REGRESSION /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ if (V_ipsec_integrity) { static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN]; struct auth_hash *esph; /* * Corrupt HMAC if we want to test integrity verification of * the other side. */ esph = sav->tdb_authalgxform; if (esph != NULL) { int alen; switch (esph->type) { case CRYPTO_SHA2_256_HMAC: case CRYPTO_SHA2_384_HMAC: case CRYPTO_SHA2_512_HMAC: alen = esph->hashsize/2; break; default: alen = AH_HMAC_HASHLEN; break; } m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); } } #endif /* NB: m is reclaimed by ipsec_process_done. */ error = ipsec_process_done(m, isr); KEY_FREESAV(&sav); IPSECREQUEST_UNLOCK(isr); return error; bad: if (sav) KEY_FREESAV(&sav); IPSECREQUEST_UNLOCK(isr); 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 }; static void esp_attach(void) { xform_register(&esp_xformsw); } SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);