NetBSD/sys/netipsec/xform_esp.c

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/* $NetBSD: xform_esp.c,v 1.68 2017/08/02 01:28:03 ozaki-r Exp $ */
/* $FreeBSD: src/sys/netipsec/xform_esp.c,v 1.2.2.1 2003/01/24 05:11:36 sam Exp $ */
/* $OpenBSD: ip_esp.c,v 1.69 2001/06/26 06:18:59 angelos Exp $ */
/*
* The authors of this code are John Ioannidis (ji@tla.org),
* Angelos D. Keromytis (kermit@csd.uch.gr) and
* Niels Provos (provos@physnet.uni-hamburg.de).
*
* The original version of this code was written by John Ioannidis
* for BSD/OS in Athens, Greece, in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis.
*
* Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
* and Niels Provos.
*
* Additional features in 1999 by Angelos D. Keromytis.
*
* Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
* Angelos D. Keromytis and Niels Provos.
* Copyright (c) 2001 Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software with or without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
* You may use this code under the GNU public license if you so wish. Please
* contribute changes back to the authors under this freer than GPL license
* so that we may further the use of strong encryption without limitations to
* all.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: xform_esp.c,v 1.68 2017/08/02 01:28:03 ozaki-r Exp $");
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
#include "opt_ipsec.h"
#endif
#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/sysctl.h>
#include <sys/cprng.h>
#include <sys/pool.h>
#include <sys/pserialize.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/ipsec_private.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>
#endif
#include <netipsec/key.h>
#include <netipsec/key_debug.h>
#include <opencrypto/cryptodev.h>
#include <opencrypto/xform.h>
percpu_t *espstat_percpu;
int esp_enable = 1;
#ifdef __FreeBSD__
SYSCTL_DECL(_net_inet_esp);
SYSCTL_INT(_net_inet_esp, OID_AUTO,
esp_enable, CTLFLAG_RW, &esp_enable, 0, "");
SYSCTL_STRUCT(_net_inet_esp, IPSECCTL_STATS,
stats, CTLFLAG_RD, &espstat, espstat, "");
#endif /* __FreeBSD__ */
static int esp_max_ivlen; /* max iv length over all algorithms */
static int esp_input_cb(struct cryptop *op);
static int esp_output_cb(struct cryptop *crp);
const uint8_t esp_stats[256] = { SADB_EALG_STATS_INIT };
static struct pool esp_tdb_crypto_pool;
static size_t esp_pool_item_size;
/*
* 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!
*/
2011-02-18 22:56:01 +03:00
const struct enc_xform *
esp_algorithm_lookup(int alg)
{
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;
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case SADB_X_EALG_CAMELLIACBC:
return &enc_xform_camellia;
case SADB_X_EALG_AESCTR:
return &enc_xform_aes_ctr;
case SADB_X_EALG_AESGCM16:
return &enc_xform_aes_gcm;
case SADB_X_EALG_AESGMAC:
return &enc_xform_aes_gmac;
case SADB_EALG_NULL:
return &enc_xform_null;
}
return NULL;
}
size_t
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esp_hdrsiz(const struct secasvar *sav)
{
size_t size;
if (sav != NULL) {
/*XXX not right for null algorithm--does it matter??*/
KASSERT(sav->tdb_encalgxform != NULL);
if (sav->flags & SADB_X_EXT_OLD)
size = sizeof(struct esp);
else
size = sizeof(struct newesp);
size += sav->tdb_encalgxform->ivsize + 9;
/*XXX need alg check???*/
if (sav->tdb_authalgxform != NULL && sav->replay)
size += ah_hdrsiz(sav);
} else {
/*
* base header size
* + max iv length for CBC mode
* + max pad length
* + sizeof(pad length field)
* + sizeof(next header field)
* + max icv supported.
*/
size = sizeof(struct newesp) + esp_max_ivlen + 9 +
ah_hdrsiz(NULL);
}
return size;
}
/*
* esp_init() is called when an SPI is being set up.
*/
static int
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esp_init(struct secasvar *sav, const struct xformsw *xsp)
{
2011-02-18 22:56:01 +03:00
const struct enc_xform *txform;
struct cryptoini cria, crie, *cr;
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;
}
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;
switch (sav->alg_enc) {
case SADB_X_EALG_AESGCM16:
case SADB_X_EALG_AESGMAC:
switch (keylen) {
case 20:
sav->alg_auth = SADB_X_AALG_AES128GMAC;
sav->tdb_authalgxform = &auth_hash_gmac_aes_128;
break;
case 28:
sav->alg_auth = SADB_X_AALG_AES192GMAC;
sav->tdb_authalgxform = &auth_hash_gmac_aes_192;
break;
case 36:
sav->alg_auth = SADB_X_AALG_AES256GMAC;
sav->tdb_authalgxform = &auth_hash_gmac_aes_256;
break;
default:
DPRINTF(("%s: invalid key length %u, must be either of "
"20, 28 or 36\n", __func__, keylen));
return EINVAL;
}
memset(&cria, 0, sizeof(cria));
cria.cri_alg = sav->tdb_authalgxform->type;
cria.cri_klen = _KEYBITS(sav->key_enc);
cria.cri_key = _KEYBUF(sav->key_enc);
break;
default:
break;
}
/* Initialize crypto session. */
memset(&crie, 0, sizeof(crie));
crie.cri_alg = sav->tdb_encalgxform->type;
crie.cri_klen = _KEYBITS(sav->key_enc);
crie.cri_key = _KEYBUF(sav->key_enc);
/* XXX Rounds ? */
if (sav->tdb_authalgxform && sav->tdb_encalgxform) {
/* init both auth & enc */
crie.cri_next = &cria;
cr = &crie;
} else if (sav->tdb_encalgxform) {
cr = &crie;
} else if (sav->tdb_authalgxform) {
cr = &cria;
} else {
/* XXX cannot happen? */
DPRINTF(("%s: no encoding OR authentication xform!\n",
__func__));
return EINVAL;
}
return crypto_newsession(&sav->tdb_cryptoid, cr, crypto_support);
}
/*
* 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) {
explicit_memset(_KEYBUF(sav->key_enc), 0,
_KEYLEN(sav->key_enc));
}
sav->tdb_encalgxform = NULL;
sav->tdb_xform = NULL;
return error;
}
/*
* ESP input processing, called (eventually) through the protocol switch.
*/
static int
esp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
{
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const struct auth_hash *esph;
const struct enc_xform *espx;
struct tdb_crypto *tc;
int plen, alen, hlen, error;
struct newesp *esp;
struct cryptodesc *crde;
struct cryptop *crp;
IPSEC_SPLASSERT_SOFTNET(__func__);
KASSERT(sav != NULL);
KASSERT(sav->tdb_encalgxform != NULL);
KASSERTMSG((skip&3) == 0 && (m->m_pkthdr.len&3) == 0,
"misaligned packet, skip %u pkt len %u",
skip, m->m_pkthdr.len);
/* XXX don't pullup, just copy header */
IP6_EXTHDR_GET(esp, struct newesp *, m, skip, sizeof(struct newesp));
esph = sav->tdb_authalgxform;
espx = sav->tdb_encalgxform;
/* Determine the ESP header length */
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof(struct esp) + sav->ivlen;
else
hlen = sizeof(struct newesp) + sav->ivlen;
/* Authenticator hash size */
alen = esph ? esph->authsize : 0;
/*
* Verify payload length is multiple of encryption algorithm
* block size.
*
* NB: This works for the null algorithm because the blocksize
* is 4 and all packets must be 4-byte aligned regardless
* of the algorithm.
*/
plen = m->m_pkthdr.len - (skip + hlen + alen);
if ((plen & (espx->blocksize - 1)) || (plen <= 0)) {
char buf[IPSEC_ADDRSTRLEN];
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)));
ESP_STATINC(ESP_STAT_BADILEN);
m_freem(m);
return EINVAL;
}
/*
* Check sequence number.
*/
if (esph && sav->replay && !ipsec_chkreplay(ntohl(esp->esp_seq), sav)) {
char logbuf[IPSEC_LOGSASTRLEN];
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav, logbuf, sizeof(logbuf)))); /*XXX*/
ESP_STATINC(ESP_STAT_REPLAY);
m_freem(m);
return ENOBUFS; /*XXX*/
}
/* Update the counters */
ESP_STATADD(ESP_STAT_IBYTES, m->m_pkthdr.len - skip - hlen - alen);
/* Get crypto descriptors */
crp = crypto_getreq(esph && espx ? 2 : 1);
if (crp == NULL) {
DPRINTF(("%s: failed to acquire crypto descriptors\n",
__func__));
error = ENOBUFS;
goto out;
}
/* Get IPsec-specific opaque pointer */
size_t extra __diagused = esph == NULL ? 0 : alen;
KASSERTMSG(sizeof(*tc) + extra <= esp_pool_item_size,
"sizeof(*tc) + extra=%zu > esp_pool_item_size=%zu\n",
sizeof(*tc) + extra, esp_pool_item_size);
tc = pool_get(&esp_tdb_crypto_pool, PR_NOWAIT);
if (tc == NULL) {
DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
error = ENOBUFS;
goto out1;
}
error = m_makewritable(&m, 0, m->m_pkthdr.len, M_NOWAIT);
if (error) {
DPRINTF(("%s: m_makewritable failed\n", __func__));
goto out2;
}
if (esph) {
struct cryptodesc *crda;
KASSERT(crp->crp_desc != NULL);
crda = crp->crp_desc;
/* Authentication descriptor */
crda->crd_skip = skip;
if (espx && espx->type == CRYPTO_AES_GCM_16)
crda->crd_len = hlen - sav->ivlen;
else
crda->crd_len = m->m_pkthdr.len - (skip + alen);
crda->crd_inject = m->m_pkthdr.len - alen;
crda->crd_alg = esph->type;
if (espx && (espx->type == CRYPTO_AES_GCM_16 ||
espx->type == CRYPTO_AES_GMAC)) {
crda->crd_key = _KEYBUF(sav->key_enc);
crda->crd_klen = _KEYBITS(sav->key_enc);
} else {
crda->crd_key = _KEYBUF(sav->key_auth);
crda->crd_klen = _KEYBITS(sav->key_auth);
}
/* Copy the authenticator */
m_copydata(m, m->m_pkthdr.len - alen, alen, (tc + 1));
/* Chain authentication request */
crde = crda->crd_next;
} else {
crde = crp->crp_desc;
}
/* Crypto operation descriptor */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
crp->crp_flags = CRYPTO_F_IMBUF;
crp->crp_buf = m;
crp->crp_callback = esp_input_cb;
crp->crp_sid = sav->tdb_cryptoid;
crp->crp_opaque = tc;
/* These are passed as-is to the callback */
tc->tc_spi = sav->spi;
tc->tc_dst = sav->sah->saidx.dst;
tc->tc_proto = sav->sah->saidx.proto;
tc->tc_protoff = protoff;
tc->tc_skip = skip;
tc->tc_sav = sav;
KEY_SA_REF(sav);
/* Decryption descriptor */
if (espx) {
KASSERTMSG(crde != NULL, "null esp crypto descriptor");
crde->crd_skip = skip + hlen;
if (espx->type == CRYPTO_AES_GMAC)
crde->crd_len = 0;
else
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 ? */
}
return crypto_dispatch(crp);
out2:
pool_put(&esp_tdb_crypto_pool, tc);
out1:
crypto_freereq(crp);
out:
ESP_STATINC(ESP_STAT_CRYPTO);
m_freem(m);
return error;
}
#ifdef INET6
#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) do { \
if (saidx->dst.sa.sa_family == AF_INET6) { \
error = ipsec6_common_input_cb(m, sav, skip, protoff); \
} else { \
error = ipsec4_common_input_cb(m, sav, skip, protoff); \
} \
} while (0)
#else
#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff) \
(error = ipsec4_common_input_cb(m, sav, skip, protoff))
#endif
/*
* ESP input callback from the crypto driver.
*/
static int
esp_input_cb(struct cryptop *crp)
{
char buf[IPSEC_ADDRSTRLEN];
uint8_t lastthree[3], aalg[AH_ALEN_MAX];
int hlen, skip, protoff, error;
struct mbuf *m;
2011-02-18 22:56:01 +03:00
const struct auth_hash *esph;
struct tdb_crypto *tc;
struct secasvar *sav;
struct secasindex *saidx;
void *ptr;
uint16_t dport;
uint16_t sport;
IPSEC_DECLARE_LOCK_VARIABLE;
KASSERT(crp->crp_desc != NULL);
KASSERT(crp->crp_opaque != NULL);
tc = crp->crp_opaque;
skip = tc->tc_skip;
protoff = tc->tc_protoff;
m = crp->crp_buf;
/* find the source port for NAT-T */
nat_t_ports_get(m, &dport, &sport);
IPSEC_ACQUIRE_GLOBAL_LOCKS();
sav = tc->tc_sav;
if (__predict_false(!SADB_SASTATE_USABLE_P(sav))) {
KEY_FREESAV(&sav);
sav = KEY_LOOKUP_SA(&tc->tc_dst, tc->tc_proto, tc->tc_spi,
sport, dport);
if (sav == NULL) {
ESP_STATINC(ESP_STAT_NOTDB);
DPRINTF(("%s: SA expired while in crypto "
"(SA %s/%08lx proto %u)\n", __func__,
ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
(u_long) ntohl(tc->tc_spi), tc->tc_proto));
error = ENOBUFS; /*XXX*/
goto bad;
}
}
saidx = &sav->sah->saidx;
KASSERTMSG(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;
/* 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);
IPSEC_RELEASE_GLOBAL_LOCKS();
return crypto_dispatch(crp);
}
ESP_STATINC(ESP_STAT_NOXFORM);
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
ESP_STATINC(ESP_STAT_HIST + esp_stats[sav->alg_enc]);
/* If authentication was performed, check now. */
if (esph != NULL) {
/*
* If we have a tag, it means an IPsec-aware NIC did
* the verification for us. Otherwise we need to
* check the authentication calculation.
*/
AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]);
/* Copy the authenticator from the packet */
m_copydata(m, m->m_pkthdr.len - esph->authsize,
esph->authsize, aalg);
ptr = (tc + 1);
/* Verify authenticator */
if (!consttime_memequal(ptr, aalg, esph->authsize)) {
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)));
ESP_STATINC(ESP_STAT_BADAUTH);
error = EACCES;
goto bad;
}
/* Remove trailing authenticator */
m_adj(m, -(esph->authsize));
}
/* Release the crypto descriptors */
pool_put(&esp_tdb_crypto_pool, tc);
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) {
uint32_t seq;
m_copydata(m, skip + offsetof(struct newesp, esp_seq),
sizeof(seq), &seq);
if (ipsec_updatereplay(ntohl(seq), sav)) {
char logbuf[IPSEC_LOGSASTRLEN];
DPRINTF(("%s: packet replay check for %s\n", __func__,
ipsec_logsastr(sav, logbuf, sizeof(logbuf))));
ESP_STATINC(ESP_STAT_REPLAY);
error = ENOBUFS;
goto bad;
}
}
/* Determine the ESP header length */
if (sav->flags & SADB_X_EXT_OLD)
hlen = sizeof(struct esp) + sav->ivlen;
else
hlen = sizeof(struct newesp) + sav->ivlen;
/* Remove the ESP header and IV from the mbuf. */
error = m_striphdr(m, skip, hlen);
if (error) {
ESP_STATINC(ESP_STAT_HDROPS);
DPRINTF(("%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) {
ESP_STATINC(ESP_STAT_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) {
ESP_STATINC(ESP_STAT_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)));
DPRINTF(("%s: %x %x\n", __func__, 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(uint8_t), lastthree + 2);
IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff);
KEY_FREESAV(&sav);
IPSEC_RELEASE_GLOBAL_LOCKS();
return error;
bad:
if (sav)
KEY_FREESAV(&sav);
IPSEC_RELEASE_GLOBAL_LOCKS();
if (m != NULL)
m_freem(m);
if (tc != NULL)
pool_put(&esp_tdb_crypto_pool, tc);
if (crp != NULL)
crypto_freereq(crp);
return error;
}
/*
* ESP output routine, called by ipsec[46]_process_packet().
*/
static int
esp_output(
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struct mbuf *m,
struct ipsecrequest *isr,
struct secasvar *sav,
struct mbuf **mp,
2006-10-14 00:53:59 +04:00
int skip,
int protoff
)
{
char buf[IPSEC_ADDRSTRLEN];
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const struct enc_xform *espx;
const struct auth_hash *esph;
int hlen, rlen, padding, blks, alen, i, roff;
2011-08-31 22:31:02 +04:00
struct mbuf *mo = NULL;
struct tdb_crypto *tc;
struct secasindex *saidx;
unsigned char *pad;
uint8_t prot;
int error, maxpacketsize;
struct cryptodesc *crde = NULL, *crda = NULL;
struct cryptop *crp;
IPSEC_SPLASSERT_SOFTNET(__func__);
esph = sav->tdb_authalgxform;
KASSERT(sav->tdb_encalgxform != NULL);
espx = sav->tdb_encalgxform;
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)
alen = esph->authsize;
else
alen = 0;
ESP_STATINC(ESP_STAT_OUTPUT);
saidx = &sav->sah->saidx;
/* Check for maximum packet size violations. */
switch (saidx->dst.sa.sa_family) {
#ifdef INET
case AF_INET:
maxpacketsize = IP_MAXPACKET;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
maxpacketsize = IPV6_MAXPACKET;
break;
#endif /* INET6 */
default:
DPRINTF(("%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)));
ESP_STATINC(ESP_STAT_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, buf, sizeof(buf)),
(u_long) ntohl(sav->spi),
skip + hlen + rlen + padding + alen, maxpacketsize));
ESP_STATINC(ESP_STAT_TOOBIG);
error = EMSGSIZE;
goto bad;
}
/* Update the counters. */
2011-02-14 19:34:43 +03:00
ESP_STATADD(ESP_STAT_OBYTES, m->m_pkthdr.len - skip);
m = m_clone(m);
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)));
ESP_STATINC(ESP_STAT_HDROPS);
error = ENOBUFS;
goto bad;
}
/* Inject ESP header. */
mo = m_makespace(m, skip, hlen, &roff);
if (mo == NULL) {
DPRINTF(("%s: failed to inject %u byte ESP hdr for SA "
"%s/%08lx\n", __func__, hlen,
ipsec_address(&saidx->dst, buf, sizeof(buf)),
(u_long) ntohl(sav->spi)));
ESP_STATINC(ESP_STAT_HDROPS); /* XXX diffs from openbsd */
error = ENOBUFS;
goto bad;
}
/* Initialize ESP header. */
memcpy(mtod(mo, char *) + roff, &sav->spi, sizeof(uint32_t));
if (sav->replay) {
uint32_t replay;
#ifdef IPSEC_DEBUG
/* Emulate replay attack when ipsec_replay is TRUE. */
if (!ipsec_replay)
#endif
sav->replay->count++;
replay = htonl(sav->replay->count);
memcpy(mtod(mo,char *) + roff + sizeof(uint32_t), &replay,
sizeof(uint32_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 = 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) cprng_fast(pad, padding - 2);
break;
case SADB_X_EXT_PZERO:
2009-03-18 19:00:08 +03:00
memset(pad, 0, padding - 2);
break;
case SADB_X_EXT_PSEQ:
for (i = 0; i < padding - 2; i++)
pad[i] = i+1;
break;
}
/* Fix padding length and Next Protocol in padding itself. */
pad[padding - 2] = padding - 2;
m_copydata(m, protoff, sizeof(uint8_t), pad + padding - 1);
/* Fix Next Protocol in IPv4/IPv6 header. */
prot = IPPROTO_ESP;
m_copyback(m, protoff, sizeof(uint8_t), &prot);
/* Get crypto descriptors. */
crp = crypto_getreq(esph && espx ? 2 : 1);
if (crp == NULL) {
DPRINTF(("%s: failed to acquire crypto descriptors\n",
__func__));
ESP_STATINC(ESP_STAT_CRYPTO);
error = ENOBUFS;
goto bad;
}
if (espx) {
crde = crp->crp_desc;
crda = crde->crd_next;
/* Encryption descriptor. */
crde->crd_skip = skip + hlen;
if (espx->type == CRYPTO_AES_GMAC)
crde->crd_len = 0;
else
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 = pool_get(&esp_tdb_crypto_pool, PR_NOWAIT);
if (tc == NULL) {
crypto_freereq(crp);
DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__));
ESP_STATINC(ESP_STAT_CRYPTO);
error = ENOBUFS;
goto bad;
}
{
int s = pserialize_read_enter();
if (__predict_false(isr->sp->state == IPSEC_SPSTATE_DEAD)) {
pserialize_read_exit(s);
pool_put(&esp_tdb_crypto_pool, tc);
crypto_freereq(crp);
ESP_STATINC(ESP_STAT_NOTDB);
error = ENOENT;
goto bad;
}
KEY_SP_REF(isr->sp);
pserialize_read_exit(s);
}
/* Callback parameters */
tc->tc_isr = isr;
tc->tc_spi = sav->spi;
tc->tc_dst = saidx->dst;
tc->tc_proto = saidx->proto;
tc->tc_sav = sav;
KEY_SA_REF(sav);
/* Crypto operation descriptor. */
crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
crp->crp_flags = CRYPTO_F_IMBUF;
crp->crp_buf = m;
crp->crp_callback = esp_output_cb;
crp->crp_opaque = tc;
crp->crp_sid = sav->tdb_cryptoid;
if (esph) {
/* Authentication descriptor. */
crda->crd_skip = skip;
if (espx && espx->type == CRYPTO_AES_GCM_16)
crda->crd_len = hlen - sav->ivlen;
else
crda->crd_len = m->m_pkthdr.len - (skip + alen);
crda->crd_inject = m->m_pkthdr.len - alen;
/* Authentication operation. */
crda->crd_alg = esph->type;
if (espx && (espx->type == CRYPTO_AES_GCM_16 ||
espx->type == CRYPTO_AES_GMAC)) {
crda->crd_key = _KEYBUF(sav->key_enc);
crda->crd_klen = _KEYBITS(sav->key_enc);
} else {
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 err, error;
IPSEC_DECLARE_LOCK_VARIABLE;
KASSERT(crp->crp_opaque != NULL);
tc = crp->crp_opaque;
m = crp->crp_buf;
IPSEC_ACQUIRE_GLOBAL_LOCKS();
isr = tc->tc_isr;
sav = tc->tc_sav;
if (__predict_false(isr->sp->state == IPSEC_SPSTATE_DEAD)) {
ESP_STATINC(ESP_STAT_NOTDB);
IPSECLOG(LOG_DEBUG,
"SP is being destroyed while in crypto (id=%u)\n",
isr->sp->id);
error = ENOENT;
goto bad;
}
if (__predict_false(!SADB_SASTATE_USABLE_P(sav))) {
KEY_FREESAV(&sav);
sav = KEY_LOOKUP_SA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
if (sav == NULL) {
char buf[IPSEC_ADDRSTRLEN];
ESP_STATINC(ESP_STAT_NOTDB);
DPRINTF(("%s: SA expired while in crypto (SA %s/%08lx "
"proto %u)\n", __func__,
ipsec_address(&tc->tc_dst, buf, sizeof(buf)),
(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) {
IPSEC_RELEASE_GLOBAL_LOCKS();
return crypto_dispatch(crp);
}
ESP_STATINC(ESP_STAT_NOXFORM);
DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
error = crp->crp_etype;
goto bad;
}
ESP_STATINC(ESP_STAT_HIST + esp_stats[sav->alg_enc]);
if (sav->tdb_authalgxform != NULL)
AH_STATINC(AH_STAT_HIST + ah_stats[sav->alg_auth]);
/* Release crypto descriptors. */
pool_put(&esp_tdb_crypto_pool, tc);
crypto_freereq(crp);
#ifdef IPSEC_DEBUG
/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
if (ipsec_integrity) {
static unsigned char ipseczeroes[AH_ALEN_MAX];
const struct auth_hash *esph;
/*
* Corrupt HMAC if we want to test integrity verification of
* the other side.
*/
esph = sav->tdb_authalgxform;
if (esph != NULL) {
m_copyback(m, m->m_pkthdr.len - esph->authsize,
esph->authsize, ipseczeroes);
}
}
#endif
/* NB: m is reclaimed by ipsec_process_done. */
err = ipsec_process_done(m, isr, sav);
KEY_FREESAV(&sav);
KEY_SP_UNREF(&isr->sp);
IPSEC_RELEASE_GLOBAL_LOCKS();
return err;
bad:
if (sav)
KEY_FREESAV(&sav);
KEY_SP_UNREF(&isr->sp);
IPSEC_RELEASE_GLOBAL_LOCKS();
if (m)
m_freem(m);
pool_put(&esp_tdb_crypto_pool, tc);
crypto_freereq(crp);
return error;
}
static struct xformsw esp_xformsw = {
.xf_type = XF_ESP,
.xf_flags = XFT_CONF|XFT_AUTH,
.xf_name = "IPsec ESP",
.xf_init = esp_init,
.xf_zeroize = esp_zeroize,
.xf_input = esp_input,
.xf_output = esp_output,
.xf_next = NULL,
};
void
esp_attach(void)
{
espstat_percpu = percpu_alloc(sizeof(uint64_t) * ESP_NSTATS);
extern int ah_max_authsize;
KASSERT(ah_max_authsize != 0);
esp_pool_item_size = sizeof(struct tdb_crypto) + ah_max_authsize;
pool_init(&esp_tdb_crypto_pool, esp_pool_item_size,
0, 0, 0, "esp_tdb_crypto", NULL, IPL_SOFTNET);
#define MAXIV(xform) \
if (xform.ivsize > esp_max_ivlen) \
esp_max_ivlen = xform.ivsize \
esp_max_ivlen = 0;
MAXIV(enc_xform_des); /* SADB_EALG_DESCBC */
MAXIV(enc_xform_3des); /* SADB_EALG_3DESCBC */
MAXIV(enc_xform_rijndael128); /* SADB_X_EALG_AES */
MAXIV(enc_xform_blf); /* SADB_X_EALG_BLOWFISHCBC */
MAXIV(enc_xform_cast5); /* SADB_X_EALG_CAST128CBC */
MAXIV(enc_xform_skipjack); /* SADB_X_EALG_SKIPJACK */
2011-05-05 21:48:29 +04:00
MAXIV(enc_xform_camellia); /* SADB_X_EALG_CAMELLIACBC */
MAXIV(enc_xform_aes_ctr); /* SADB_X_EALG_AESCTR */
MAXIV(enc_xform_null); /* SADB_EALG_NULL */
xform_register(&esp_xformsw);
#undef MAXIV
}