/* $FreeBSD$ */ /* $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 #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_INT(_net_inet_esp, OID_AUTO, esp_enable, CTLFLAG_VNET | 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); 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) { const struct enc_xform *txform; struct cryptoini cria, crie; int keylen; int error; txform = enc_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; } /* subtract off the salt, RFC4106, 8.1 and RFC3686, 5.1 */ keylen = _KEYLEN(sav->key_enc) - SAV_ISCTRORGCM(sav) * 4; 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; } if (SAV_ISCTRORGCM(sav)) sav->ivlen = 8; /* RFC4106 3.1 and RFC3686 3.1 */ else 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; /* * Whenever AES-GCM is used for encryption, one * of the AES authentication algorithms is chosen * as well, based on the key size. */ if (sav->alg_enc == SADB_X_EALG_AESGCM16) { switch (keylen) { case AES_128_GMAC_KEY_LEN: sav->alg_auth = SADB_X_AALG_AES128GMAC; sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_128; break; case AES_192_GMAC_KEY_LEN: sav->alg_auth = SADB_X_AALG_AES192GMAC; sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_192; break; case AES_256_GMAC_KEY_LEN: sav->alg_auth = SADB_X_AALG_AES256GMAC; sav->tdb_authalgxform = &auth_hash_nist_gmac_aes_256; break; default: DPRINTF(("%s: invalid key length %u" "for algorithm %s\n", __func__, keylen, txform->name)); return EINVAL; } bzero(&cria, sizeof(cria)); cria.cri_alg = sav->tdb_authalgxform->type; cria.cri_key = sav->key_enc->key_data; cria.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISGCM(sav) * 32; } /* Initialize crypto session. */ bzero(&crie, sizeof(crie)); crie.cri_alg = sav->tdb_encalgxform->type; crie.cri_key = sav->key_enc->key_data; crie.cri_klen = _KEYBITS(sav->key_enc) - SAV_ISCTRORGCM(sav) * 32; 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)); 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) { IPSEC_DEBUG_DECLARE(char buf[128]); const struct auth_hash *esph; const struct enc_xform *espx; struct xform_data *xd; struct cryptodesc *crde; struct cryptop *crp; struct newesp *esp; uint8_t *ivp; crypto_session_t cryptoid; int alen, error, hlen, plen; IPSEC_ASSERT(sav != NULL, ("null SA")); IPSEC_ASSERT(sav->tdb_encalgxform != NULL, ("null encoding xform")); error = EINVAL; /* 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); goto bad; } /* 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 and auth length */ if (sav->flags & SADB_X_EXT_OLD) hlen = sizeof (struct esp) + sav->ivlen; else hlen = sizeof (struct newesp) + sav->ivlen; alen = xform_ah_authsize(esph); /* * 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, buf, sizeof(buf)), (u_long)ntohl(sav->spi))); ESPSTAT_INC(esps_badilen); goto bad; } /* * Check sequence number. */ SECASVAR_LOCK(sav); if (esph != NULL && sav->replay != NULL && sav->replay->wsize != 0) { if (ipsec_chkreplay(ntohl(esp->esp_seq), sav) == 0) { SECASVAR_UNLOCK(sav); DPRINTF(("%s: packet replay check for %s\n", __func__, ipsec_sa2str(sav, buf, sizeof(buf)))); ESPSTAT_INC(esps_replay); error = EACCES; goto bad; } } cryptoid = sav->tdb_cryptoid; SECASVAR_UNLOCK(sav); /* Update the counters */ ESPSTAT_ADD(esps_ibytes, m->m_pkthdr.len - (skip + hlen + alen)); /* 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; } /* Get IPsec-specific opaque pointer */ xd = malloc(sizeof(*xd) + alen, M_XDATA, M_NOWAIT | M_ZERO); if (xd == NULL) { DPRINTF(("%s: failed to allocate xform_data\n", __func__)); ESPSTAT_INC(esps_crypto); crypto_freereq(crp); error = ENOBUFS; goto bad; } if (esph != NULL) { struct cryptodesc *crda = crp->crp_desc; IPSEC_ASSERT(crda != NULL, ("null ah crypto descriptor")); /* Authentication descriptor */ crda->crd_skip = skip; if (SAV_ISGCM(sav)) crda->crd_len = 8; /* RFC4106 5, SPI + SN */ else crda->crd_len = m->m_pkthdr.len - (skip + alen); crda->crd_inject = m->m_pkthdr.len - alen; crda->crd_alg = esph->type; /* Copy the authenticator */ m_copydata(m, m->m_pkthdr.len - alen, alen, (caddr_t) (xd + 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; if (V_async_crypto) crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER; crp->crp_buf = (caddr_t) m; crp->crp_callback = esp_input_cb; crp->crp_sid = cryptoid; crp->crp_opaque = (caddr_t) xd; /* These are passed as-is to the callback */ xd->sav = sav; xd->protoff = protoff; xd->skip = skip; xd->cryptoid = cryptoid; xd->vnet = curvnet; /* Decryption descriptor */ 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; if (SAV_ISCTRORGCM(sav)) { ivp = &crde->crd_iv[0]; /* GCM IV Format: RFC4106 4 */ /* CTR IV Format: RFC3686 4 */ /* Salt is last four bytes of key, RFC4106 8.1 */ /* Nonce is last four bytes of key, RFC3686 5.1 */ memcpy(ivp, sav->key_enc->key_data + _KEYLEN(sav->key_enc) - 4, 4); if (SAV_ISCTR(sav)) { /* Initial block counter is 1, RFC3686 4 */ be32enc(&ivp[sav->ivlen + 4], 1); } m_copydata(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]); crde->crd_flags |= CRD_F_IV_EXPLICIT; } crde->crd_alg = espx->type; return (crypto_dispatch(crp)); bad: m_freem(m); key_freesav(&sav); return (error); } /* * ESP input callback from the crypto driver. */ static int esp_input_cb(struct cryptop *crp) { IPSEC_DEBUG_DECLARE(char buf[128]); u_int8_t lastthree[3], aalg[AH_HMAC_MAXHASHLEN]; const struct auth_hash *esph; struct mbuf *m; struct cryptodesc *crd; struct xform_data *xd; struct secasvar *sav; struct secasindex *saidx; caddr_t ptr; crypto_session_t cryptoid; int hlen, skip, protoff, error, alen; crd = crp->crp_desc; IPSEC_ASSERT(crd != NULL, ("null crypto descriptor!")); m = (struct mbuf *) crp->crp_buf; xd = (struct xform_data *) crp->crp_opaque; CURVNET_SET(xd->vnet); sav = xd->sav; skip = xd->skip; protoff = xd->protoff; cryptoid = xd->cryptoid; saidx = &sav->sah->saidx; esph = sav->tdb_authalgxform; /* Check for crypto errors */ if (crp->crp_etype) { if (crp->crp_etype == EAGAIN) { /* Reset the session ID */ if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0) crypto_freesession(cryptoid); xd->cryptoid = crp->crp_sid; CURVNET_RESTORE(); 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) { alen = xform_ah_authsize(esph); AHSTAT_INC(ahs_hist[sav->alg_auth]); /* Copy the authenticator from the packet */ m_copydata(m, m->m_pkthdr.len - alen, alen, aalg); ptr = (caddr_t) (xd + 1); /* Verify authenticator */ if (timingsafe_bcmp(ptr, aalg, alen) != 0) { DPRINTF(("%s: authentication hash mismatch for " "packet in SA %s/%08lx\n", __func__, ipsec_address(&saidx->dst, buf, sizeof(buf)), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_badauth); error = EACCES; goto bad; } m->m_flags |= M_AUTHIPDGM; /* Remove trailing authenticator */ m_adj(m, -alen); } /* Release the crypto descriptors */ free(xd, M_XDATA), xd = 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); SECASVAR_LOCK(sav); if (ipsec_updatereplay(ntohl(seq), sav)) { SECASVAR_UNLOCK(sav); DPRINTF(("%s: packet replay check for %s\n", __func__, ipsec_sa2str(sav, buf, sizeof(buf)))); ESPSTAT_INC(esps_replay); error = EACCES; goto bad; } SECASVAR_UNLOCK(sav); } /* 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, buf, sizeof(buf)), (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, buf, sizeof(buf)), (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, buf, sizeof(buf)), (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); break; #endif #ifdef INET case AF_INET: error = ipsec4_common_input_cb(m, sav, skip, protoff); break; #endif default: panic("%s: Unexpected address family: %d saidx=%p", __func__, saidx->dst.sa.sa_family, saidx); } CURVNET_RESTORE(); return error; bad: CURVNET_RESTORE(); if (sav != NULL) key_freesav(&sav); if (m != NULL) m_freem(m); if (xd != NULL) free(xd, M_XDATA); if (crp != NULL) crypto_freereq(crp); return error; } /* * ESP output routine, called by ipsec[46]_perform_request(). */ static int esp_output(struct mbuf *m, struct secpolicy *sp, struct secasvar *sav, u_int idx, int skip, int protoff) { IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]); struct cryptodesc *crde = NULL, *crda = NULL; struct cryptop *crp; const struct auth_hash *esph; const struct enc_xform *espx; struct mbuf *mo = NULL; struct xform_data *xd; struct secasindex *saidx; unsigned char *pad; uint8_t *ivp; uint64_t cntr; crypto_session_t cryptoid; int hlen, rlen, padding, blks, alen, i, roff; int error, maxpacketsize; uint8_t prot; 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. */ /* * RFC4303 2.4 Requires 4 byte alignment. */ blks = MAX(4, espx->blocksize); /* Cipher blocksize */ /* XXX clamp padding length a la KAME??? */ padding = ((blks - ((rlen + 2) % blks)) % blks) + 2; alen = xform_ah_authsize(esph); 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, buf, sizeof(buf)), (u_long) ntohl(sav->spi))); ESPSTAT_INC(esps_nopf); error = EPFNOSUPPORT; goto bad; } /* DPRINTF(("%s: skip %d hlen %d rlen %d padding %d alen %d blksd %d\n", __func__, skip, hlen, rlen, padding, alen, blks)); */ 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, buf, sizeof(buf)), (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, buf, sizeof(buf)), (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, buf, sizeof(buf)), (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(uint32_t)); SECASVAR_LOCK(sav); if (sav->replay) { uint32_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(uint32_t), sizeof(uint32_t)); } cryptoid = sav->tdb_cryptoid; if (SAV_ISCTRORGCM(sav)) cntr = sav->cntr++; SECASVAR_UNLOCK(sav); /* * 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, buf, sizeof(buf)), (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 != NULL ? 2 : 1); if (crp == NULL) { DPRINTF(("%s: failed to acquire crypto descriptors\n", __func__)); ESPSTAT_INC(esps_crypto); error = ENOBUFS; goto bad; } /* IPsec-specific opaque crypto info. */ xd = malloc(sizeof(struct xform_data), M_XDATA, M_NOWAIT | M_ZERO); if (xd == NULL) { crypto_freereq(crp); DPRINTF(("%s: failed to allocate xform_data\n", __func__)); ESPSTAT_INC(esps_crypto); error = ENOBUFS; goto bad; } 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; if (SAV_ISCTRORGCM(sav)) { ivp = &crde->crd_iv[0]; /* GCM IV Format: RFC4106 4 */ /* CTR IV Format: RFC3686 4 */ /* Salt is last four bytes of key, RFC4106 8.1 */ /* Nonce is last four bytes of key, RFC3686 5.1 */ memcpy(ivp, sav->key_enc->key_data + _KEYLEN(sav->key_enc) - 4, 4); be64enc(&ivp[4], cntr); if (SAV_ISCTR(sav)) { /* Initial block counter is 1, RFC3686 4 */ /* XXXAE: should we use this only for first packet? */ be32enc(&ivp[sav->ivlen + 4], 1); } m_copyback(m, skip + hlen - sav->ivlen, sav->ivlen, &ivp[4]); crde->crd_flags |= CRD_F_IV_EXPLICIT|CRD_F_IV_PRESENT; } /* Callback parameters */ xd->sp = sp; xd->sav = sav; xd->idx = idx; xd->cryptoid = cryptoid; xd->vnet = curvnet; /* Crypto operation descriptor. */ crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */ crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; if (V_async_crypto) crp->crp_flags |= CRYPTO_F_ASYNC | CRYPTO_F_ASYNC_KEEPORDER; crp->crp_buf = (caddr_t) m; crp->crp_callback = esp_output_cb; crp->crp_opaque = (caddr_t) xd; crp->crp_sid = cryptoid; if (esph) { /* Authentication descriptor. */ crda->crd_alg = esph->type; crda->crd_skip = skip; if (SAV_ISGCM(sav)) crda->crd_len = 8; /* RFC4106 5, SPI + SN */ else crda->crd_len = m->m_pkthdr.len - (skip + alen); crda->crd_inject = m->m_pkthdr.len - alen; } return crypto_dispatch(crp); bad: if (m) m_freem(m); key_freesav(&sav); key_freesp(&sp); return (error); } /* * ESP output callback from the crypto driver. */ static int esp_output_cb(struct cryptop *crp) { struct xform_data *xd; struct secpolicy *sp; struct secasvar *sav; struct mbuf *m; crypto_session_t cryptoid; u_int idx; int error; xd = (struct xform_data *) crp->crp_opaque; CURVNET_SET(xd->vnet); m = (struct mbuf *) crp->crp_buf; sp = xd->sp; sav = xd->sav; idx = xd->idx; cryptoid = xd->cryptoid; /* Check for crypto errors. */ if (crp->crp_etype) { if (crp->crp_etype == EAGAIN) { /* Reset the session ID */ if (ipsec_updateid(sav, &crp->crp_sid, &cryptoid) != 0) crypto_freesession(cryptoid); xd->cryptoid = crp->crp_sid; CURVNET_RESTORE(); return (crypto_dispatch(crp)); } ESPSTAT_INC(esps_noxform); DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); error = crp->crp_etype; m_freem(m); 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; } free(xd, M_XDATA); crypto_freereq(crp); ESPSTAT_INC(esps_hist[sav->alg_enc]); if (sav->tdb_authalgxform != NULL) AHSTAT_INC(ahs_hist[sav->alg_auth]); #ifdef REGRESSION /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */ if (V_ipsec_integrity) { static unsigned char ipseczeroes[AH_HMAC_MAXHASHLEN]; 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) { int alen; alen = xform_ah_authsize(esph); m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes); } } #endif /* NB: m is reclaimed by ipsec_process_done. */ error = ipsec_process_done(m, sp, sav, idx); CURVNET_RESTORE(); return (error); bad: CURVNET_RESTORE(); free(xd, M_XDATA); crypto_freereq(crp); key_freesav(&sav); key_freesp(&sp); return (error); } static struct xformsw esp_xformsw = { .xf_type = XF_ESP, .xf_name = "IPsec ESP", .xf_init = esp_init, .xf_zeroize = esp_zeroize, .xf_input = esp_input, .xf_output = esp_output, }; SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, xform_attach, &esp_xformsw); SYSUNINIT(esp_xform_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, xform_detach, &esp_xformsw);