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/* $FreeBSD: release/9.1.0/sys/netipsec/xform_esp.c 221129 2011-04-27 19:28:42Z bz $ */
/* $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 <net/vnet.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>
VNET_DEFINE(int, esp_enable) = 1;
VNET_DEFINE(struct espstat, espstat);
SYSCTL_DECL(_net_inet_esp);
SYSCTL_VNET_INT(_net_inet_esp, OID_AUTO,
esp_enable, CTLFLAG_RW, &VNET_NAME(esp_enable), 0, "");
SYSCTL_VNET_STRUCT(_net_inet_esp, IPSECCTL_STATS,
stats, CTLFLAG_RD, &VNET_NAME(espstat), espstat, "");
static VNET_DEFINE(int, esp_max_ivlen); /* max iv length over all algorithms */
#define V_esp_max_ivlen VNET(esp_max_ivlen)
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) + V_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(("%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);
if (sav->iv == NULL) {
DPRINTF(("%s: no memory for IV\n", __func__));
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 = 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));
V_espstat.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)));
V_espstat.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*/
V_espstat.esps_replay++;
m_freem(m);
return ENOBUFS; /*XXX*/
}
/* Update the counters */
V_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(("%s: failed to acquire crypto descriptors\n",
__func__));
V_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(("%s: failed to allocate tdb_crypto\n", __func__));
V_espstat.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) {
error = crypto_dispatch(crp);
return error;
}
V_espstat.esps_noxform++;
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
V_espstat.esps_crypto++;
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
error = EINVAL;
goto bad;
}
V_espstat.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.
*/
V_ahstat.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)));
V_espstat.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)));
V_espstat.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) {
V_espstat.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) {
V_espstat.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) {
V_espstat.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, 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;
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;
plen = rlen + padding; /* Padded payload length. */
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;
V_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(("%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)));
V_espstat.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));
V_espstat.esps_toobig++;
error = EMSGSIZE;
goto bad;
}
/* Update the counters. */
V_espstat.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)));
V_espstat.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)));
V_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;
#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__));
V_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 = 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__));
V_espstat.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 err, 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) {
V_espstat.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);
error = crypto_dispatch(crp);
return error;
}
V_espstat.esps_noxform++;
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
/* Shouldn't happen... */
if (m == NULL) {
V_espstat.esps_crypto++;
DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
error = EINVAL;
goto bad;
}
V_espstat.esps_hist[sav->alg_enc]++;
if (sav->tdb_authalgxform != NULL)
V_ahstat.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. */
err = ipsec_process_done(m, isr);
KEY_FREESAV(&sav);
IPSECREQUEST_UNLOCK(isr);
return err;
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)
{
#define MAXIV(xform) \
if (xform.blocksize > V_esp_max_ivlen) \
V_esp_max_ivlen = xform.blocksize \
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 */
MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */
xform_register(&esp_xformsw);
#undef MAXIV
}
SYSINIT(esp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, esp_attach, NULL);