diff options
Diffstat (limited to 'sys/netipsec/xform_esp.c')
| -rw-r--r-- | sys/netipsec/xform_esp.c | 966 |
1 files changed, 966 insertions, 0 deletions
diff --git a/sys/netipsec/xform_esp.c b/sys/netipsec/xform_esp.c new file mode 100644 index 0000000..f91d3cf --- /dev/null +++ b/sys/netipsec/xform_esp.c @@ -0,0 +1,966 @@ +/* $FreeBSD$ */ +/* $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 <sys/param.h> +#include <sys/systm.h> +#include <sys/mbuf.h> +#include <sys/socket.h> +#include <sys/syslog.h> +#include <sys/kernel.h> +#include <sys/random.h> +#include <sys/sysctl.h> + +#include <net/if.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <netinet/ip_ecn.h> +#include <netinet/ip6.h> + +#include <net/route.h> +#include <netipsec/ipsec.h> +#include <netipsec/ah.h> +#include <netipsec/ah_var.h> +#include <netipsec/esp.h> +#include <netipsec/esp_var.h> +#include <netipsec/xform.h> + +#ifdef INET6 +#include <netinet6/ip6_var.h> +#include <netipsec/ipsec6.h> +#include <netinet6/ip6_ecn.h> +#endif + +#include <netipsec/key.h> +#include <netipsec/key_debug.h> + +#include <opencrypto/cryptodev.h> +#include <opencrypto/xform.h> + +int esp_enable = 1; +struct espstat espstat; + +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, ""); + +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! + */ +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; + } + return NULL; +} + +size_t +esp_hdrsiz(struct secasvar *sav) +{ + size_t size; + + if (sav != NULL) { + /*XXX not right for null algorithm--does it matter??*/ + KASSERT(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->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) + 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, 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(("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; + } + + /* + * 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); + if (sav->iv == NULL) { + DPRINTF(("esp_init: no memory for IV\n")); + return EINVAL; + } + 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 = _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) + bzero(_KEYBUF(sav->key_enc), _KEYLEN(sav->key_enc)); + /* NB: sav->iv is freed elsewhere, even though we malloc it! */ + 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; + +#if 0 + SPLASSERT(net, "esp_input"); +#endif + + KASSERT(sav != NULL, ("esp_input: null SA")); + KASSERT(sav->tdb_encalgxform != NULL, + ("esp_input: null encoding xform")); + KASSERT((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 ? AH_HMAC_HASHLEN : 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))); + espstat.esps_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*/ + espstat.esps_replay++; + m_freem(m); + return ENOBUFS; /*XXX*/ + } + + /* Update the counters */ + espstat.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(("esp_input: failed to acquire crypto descriptors\n")); + espstat.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(("esp_input: failed to allocate tdb_crypto\n")); + espstat.esps_crypto++; + m_freem(m); + return ENOBUFS; + } + + tc->tc_ptr = (caddr_t) mtag; + + if (esph) { + struct cryptodesc *crda = crp->crp_desc; + + KASSERT(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, + (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_NODELAY; + 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; + + /* Decryption descriptor */ + if (espx) { + KASSERT(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_HMAC_HASHLEN]; + int s, hlen, skip, protoff, error; + 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; + KASSERT(crd != NULL, ("esp_input_cb: null crypto descriptor!")); + + tc = (struct tdb_crypto *) crp->crp_opaque; + KASSERT(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; + + s = splnet(); + + sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); + if (sav == NULL) { + espstat.esps_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; + KASSERT(saidx->dst.sa.sa_family == AF_INET || + saidx->dst.sa.sa_family == AF_INET6, + ("ah_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); + splx(s); + return crypto_dispatch(crp); + } + + espstat.esps_noxform++; + DPRINTF(("esp_input_cb: crypto error %d\n", crp->crp_etype)); + error = crp->crp_etype; + goto bad; + } + + /* Shouldn't happen... */ + if (m == NULL) { + espstat.esps_crypto++; + DPRINTF(("esp_input_cb: bogus returned buffer from crypto\n")); + error = EINVAL; + goto bad; + } + espstat.esps_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. + */ + ahstat.ahs_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 = (caddr_t) (tc + 1); + + /* Verify authenticator */ + if (bcmp(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))); + espstat.esps_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; + + /* 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.esps_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) { + espstat.esps_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) { + espstat.esps_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_copyback(m, protoff, sizeof (u_int8_t), lastthree + 2); + + IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag); + + KEY_FREESAV(&sav); + splx(s); + return error; +bad: + if (sav) + KEY_FREESAV(&sav); + 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 +) +{ + struct enc_xform *espx; + struct auth_hash *esph; + int hlen, rlen, plen, 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; + +#if 0 + SPLASSERT(net, "esp_output"); +#endif + + sav = isr->sav; + KASSERT(sav != NULL, ("esp_output: null SA")); + esph = sav->tdb_authalgxform; + espx = sav->tdb_encalgxform; + KASSERT(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 = AH_HMAC_HASHLEN; + else + alen = 0; + + espstat.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(("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))); + espstat.esps_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)); + espstat.esps_toobig++; + error = EMSGSIZE; + goto bad; + } + + /* Update the counters. */ + espstat.esps_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))); + espstat.esps_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))); + espstat.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 = 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(("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: + 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(("esp_output: failed to acquire crypto descriptors\n")); + espstat.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 = _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")); + espstat.esps_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 = (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 = _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; + KASSERT(tc != NULL, ("esp_output_cb: null opaque data area!")); + m = (struct mbuf *) crp->crp_buf; + + s = splnet(); + + isr = tc->tc_isr; + sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); + if (sav == NULL) { + espstat.esps_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; + } + KASSERT(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); + splx(s); + return crypto_dispatch(crp); + } + + espstat.esps_noxform++; + DPRINTF(("esp_output_cb: crypto error %d\n", crp->crp_etype)); + error = crp->crp_etype; + goto bad; + } + + /* Shouldn't happen... */ + if (m == NULL) { + espstat.esps_crypto++; + DPRINTF(("esp_output_cb: bogus returned buffer from crypto\n")); + error = EINVAL; + goto bad; + } + espstat.esps_hist[sav->alg_enc]++; + if (sav->tdb_authalgxform != NULL) + ahstat.ahs_hist[sav->alg_auth]++; + + /* Release crypto descriptors. */ + free(tc, M_XDATA); + crypto_freereq(crp); + + /* NB: m is reclaimed by ipsec_process_done. */ + err = ipsec_process_done(m, isr); + KEY_FREESAV(&sav); + splx(s); + return err; +bad: + if (sav) + KEY_FREESAV(&sav); + 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 +}; + +static void +esp_attach(void) +{ +#define MAXIV(xform) \ + if (xform.blocksize > esp_max_ivlen) \ + esp_max_ivlen = xform.blocksize \ + + 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_null); /* SADB_EALG_NULL */ + + xform_register(&esp_xformsw); +#undef MAXIV +} +SYSINIT(esp_xform_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, esp_attach, NULL) |
