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NetBSD/sys/netinet6/esp_core.c

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/* $NetBSD: esp_core.c,v 1.46 2010/08/14 18:28:59 jym Exp $ */
/* $KAME: esp_core.c,v 1.53 2001/11/27 09:47:30 sakane Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: esp_core.c,v 1.46 2010/08/14 18:28:59 jym Exp $");
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet6/ipsec.h>
#include <netinet6/ah.h>
#include <netinet6/esp.h>
#include <netinet6/esp_rijndael.h>
#include <netinet6/esp_aesctr.h>
#include <net/pfkeyv2.h>
#include <netkey/key.h>
#include <crypto/des/des.h>
#include <crypto/blowfish/blowfish.h>
#include <crypto/cast128/cast128.h>
#include <net/net_osdep.h>
static int esp_null_mature(struct secasvar *);
static int esp_null_decrypt(struct mbuf *, size_t,
struct secasvar *, const struct esp_algorithm *, int);
static int esp_null_encrypt(struct mbuf *, size_t, size_t,
struct secasvar *, const struct esp_algorithm *, int);
static int esp_descbc_mature(struct secasvar *);
static int esp_descbc_ivlen(const struct esp_algorithm *,
struct secasvar *);
static int esp_des_schedule(const struct esp_algorithm *,
struct secasvar *);
static size_t esp_des_schedlen(const struct esp_algorithm *);
static int esp_des_blockdecrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_des_blockencrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_cbc_mature(struct secasvar *);
static int esp_blowfish_schedule(const struct esp_algorithm *,
struct secasvar *);
static size_t esp_blowfish_schedlen(const struct esp_algorithm *);
static int esp_blowfish_blockdecrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_blowfish_blockencrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_cast128_schedule(const struct esp_algorithm *,
struct secasvar *);
static size_t esp_cast128_schedlen(const struct esp_algorithm *);
static int esp_cast128_blockdecrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_cast128_blockencrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_3des_schedule(const struct esp_algorithm *,
struct secasvar *);
static size_t esp_3des_schedlen(const struct esp_algorithm *);
static int esp_3des_blockdecrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_3des_blockencrypt(const struct esp_algorithm *,
struct secasvar *, u_int8_t *, u_int8_t *);
static int esp_common_ivlen(const struct esp_algorithm *,
struct secasvar *);
static int esp_cbc_decrypt(struct mbuf *, size_t,
struct secasvar *, const struct esp_algorithm *, int);
static int esp_cbc_encrypt(struct mbuf *, size_t, size_t,
struct secasvar *, const struct esp_algorithm *, int);
#define MAXIVLEN 16
static const struct esp_algorithm esp_algorithms[] = {
{ 8, -1, esp_descbc_mature, 64, 64, esp_des_schedlen,
"des-cbc",
esp_descbc_ivlen, esp_cbc_decrypt,
esp_cbc_encrypt, esp_des_schedule,
esp_des_blockdecrypt, esp_des_blockencrypt, },
{ 8, 8, esp_cbc_mature, 192, 192, esp_3des_schedlen,
"3des-cbc",
esp_common_ivlen, esp_cbc_decrypt,
esp_cbc_encrypt, esp_3des_schedule,
esp_3des_blockdecrypt, esp_3des_blockencrypt, },
{ 1, 0, esp_null_mature, 0, 2048, NULL,
"null",
esp_common_ivlen, esp_null_decrypt,
esp_null_encrypt, NULL,
NULL, NULL },
{ 8, 8, esp_cbc_mature, 40, 448, esp_blowfish_schedlen, "blowfish-cbc",
esp_common_ivlen, esp_cbc_decrypt,
esp_cbc_encrypt, esp_blowfish_schedule,
esp_blowfish_blockdecrypt, esp_blowfish_blockencrypt, },
{ 8, 8, esp_cbc_mature, 40, 128, esp_cast128_schedlen,
"cast128-cbc",
esp_common_ivlen, esp_cbc_decrypt,
esp_cbc_encrypt, esp_cast128_schedule,
esp_cast128_blockdecrypt, esp_cast128_blockencrypt, },
{ 16, 16, esp_cbc_mature, 128, 256, esp_rijndael_schedlen,
"rijndael-cbc",
esp_common_ivlen, esp_cbc_decrypt,
esp_cbc_encrypt, esp_rijndael_schedule,
esp_rijndael_blockdecrypt, esp_rijndael_blockencrypt },
{ 16, 8, esp_aesctr_mature, 160, 288, esp_aesctr_schedlen,
"aes-ctr",
esp_common_ivlen, esp_aesctr_decrypt,
esp_aesctr_encrypt, esp_aesctr_schedule,
NULL, NULL },
};
const struct esp_algorithm *
esp_algorithm_lookup(int idx)
{
switch (idx) {
case SADB_EALG_DESCBC:
return &esp_algorithms[0];
case SADB_EALG_3DESCBC:
return &esp_algorithms[1];
case SADB_EALG_NULL:
return &esp_algorithms[2];
case SADB_X_EALG_BLOWFISHCBC:
return &esp_algorithms[3];
case SADB_X_EALG_CAST128CBC:
return &esp_algorithms[4];
case SADB_X_EALG_RIJNDAELCBC:
return &esp_algorithms[5];
case SADB_X_EALG_AESCTR:
return &esp_algorithms[6];
default:
return NULL;
}
}
int
esp_max_padbound(void)
{
int idx;
static int padbound = 0;
if (padbound)
return padbound;
for (idx = 0; idx < sizeof(esp_algorithms)/sizeof(esp_algorithms[0]);
idx++) {
if (esp_algorithms[idx].padbound > padbound)
padbound = esp_algorithms[idx].padbound;
}
return padbound;
}
int
esp_max_ivlen(void)
{
int idx;
static int ivlen = 0;
if (ivlen)
return ivlen;
for (idx = 0; idx < sizeof(esp_algorithms)/sizeof(esp_algorithms[0]);
idx++) {
if (esp_algorithms[idx].ivlenval > ivlen)
ivlen = esp_algorithms[idx].ivlenval;
}
return ivlen;
}
int
esp_schedule(const struct esp_algorithm *algo, struct secasvar *sav)
{
int error;
/* check for key length */
if (_KEYBITS(sav->key_enc) < algo->keymin ||
_KEYBITS(sav->key_enc) > algo->keymax) {
ipseclog((LOG_ERR,
"esp_schedule %s: unsupported key length %d: "
"needs %d to %d bits\n", algo->name, _KEYBITS(sav->key_enc),
algo->keymin, algo->keymax));
return EINVAL;
}
/* already allocated */
if (sav->sched && sav->schedlen != 0)
return 0;
/* no schedule necessary */
if (!algo->schedule || !algo->schedlen)
return 0;
sav->schedlen = (*algo->schedlen)(algo);
sav->sched = malloc(sav->schedlen, M_SECA, M_DONTWAIT);
if (!sav->sched) {
sav->schedlen = 0;
return ENOBUFS;
}
error = (*algo->schedule)(algo, sav);
if (error) {
ipseclog((LOG_ERR, "esp_schedule %s: error %d\n",
algo->name, error));
memset(sav->sched, 0, sav->schedlen);
free(sav->sched, M_SECA);
sav->sched = NULL;
sav->schedlen = 0;
}
return error;
}
static int
esp_null_mature(struct secasvar *sav)
{
/* anything is okay */
return 0;
}
static int
esp_null_decrypt(
struct mbuf *m,
size_t off, /* offset to ESP header */
struct secasvar *sav,
const struct esp_algorithm *algo,
int ivlen
)
{
return 0; /* do nothing */
}
static int
esp_null_encrypt(
struct mbuf *m,
size_t off, /* offset to ESP header */
size_t plen, /* payload length (to be encrypted) */
struct secasvar *sav,
const struct esp_algorithm *algo,
int ivlen
)
{
return 0; /* do nothing */
}
static int
esp_descbc_mature(struct secasvar *sav)
{
const struct esp_algorithm *algo;
if (!(sav->flags & SADB_X_EXT_OLD) && (sav->flags & SADB_X_EXT_IV4B)) {
ipseclog((LOG_ERR, "esp_cbc_mature: "
"algorithm incompatible with 4 octets IV length\n"));
return 1;
}
if (!sav->key_enc) {
ipseclog((LOG_ERR, "esp_descbc_mature: no key is given.\n"));
return 1;
}
algo = esp_algorithm_lookup(sav->alg_enc);
if (!algo) {
ipseclog((LOG_ERR,
"esp_descbc_mature: unsupported algorithm.\n"));
return 1;
}
if (_KEYBITS(sav->key_enc) < algo->keymin ||
_KEYBITS(sav->key_enc) > algo->keymax) {
ipseclog((LOG_ERR,
"esp_descbc_mature: invalid key length %d.\n",
_KEYBITS(sav->key_enc)));
return 1;
}
/* weak key check */
if (des_is_weak_key((des_cblock *)_KEYBUF(sav->key_enc))) {
ipseclog((LOG_ERR,
"esp_descbc_mature: weak key was passed.\n"));
return 1;
}
return 0;
}
static int
esp_descbc_ivlen(const struct esp_algorithm *algo,
struct secasvar *sav)
{
if (!sav)
return 8;
if ((sav->flags & SADB_X_EXT_OLD) && (sav->flags & SADB_X_EXT_IV4B))
return 4;
if (!(sav->flags & SADB_X_EXT_OLD) && (sav->flags & SADB_X_EXT_DERIV))
return 4;
return 8;
}
static size_t
esp_des_schedlen(const struct esp_algorithm *algo)
{
return sizeof(des_key_schedule);
}
static int
esp_des_schedule(const struct esp_algorithm *algo,
struct secasvar *sav)
{
if (des_key_sched((des_cblock *)_KEYBUF(sav->key_enc),
*(des_key_schedule *)sav->sched))
return EINVAL;
else
return 0;
}
static int
esp_des_blockdecrypt( const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
/* assumption: d has a good alignment */
memcpy(d, s, sizeof(DES_LONG) * 2);
des_ecb_encrypt((des_cblock *)d, (des_cblock *)d,
*(des_key_schedule *)sav->sched, DES_DECRYPT);
return 0;
}
static int
esp_des_blockencrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
/* assumption: d has a good alignment */
memcpy(d, s, sizeof(DES_LONG) * 2);
des_ecb_encrypt((des_cblock *)d, (des_cblock *)d,
*(des_key_schedule *)sav->sched, DES_ENCRYPT);
return 0;
}
static int
esp_cbc_mature(struct secasvar *sav)
{
int keylen;
const struct esp_algorithm *algo;
if (sav->flags & SADB_X_EXT_OLD) {
ipseclog((LOG_ERR,
"esp_cbc_mature: algorithm incompatible with esp-old\n"));
return 1;
}
if (sav->flags & SADB_X_EXT_DERIV) {
ipseclog((LOG_ERR,
"esp_cbc_mature: algorithm incompatible with derived\n"));
return 1;
}
if (!sav->key_enc) {
ipseclog((LOG_ERR, "esp_cbc_mature: no key is given.\n"));
return 1;
}
algo = esp_algorithm_lookup(sav->alg_enc);
if (algo == NULL) {
ipseclog((LOG_ERR,
"esp_cbc_mature: unsupported encryption algorithm %d\n",
sav->alg_enc));
return 1;
}
keylen = sav->key_enc->sadb_key_bits;
if (keylen < algo->keymin || algo->keymax < keylen) {
ipseclog((LOG_ERR,
"esp_cbc_mature %s: invalid key length %d.\n",
algo->name, sav->key_enc->sadb_key_bits));
return 1;
}
switch (sav->alg_enc) {
case SADB_EALG_3DESCBC:
/* weak key check */
if (des_is_weak_key((des_cblock *)_KEYBUF(sav->key_enc)) ||
des_is_weak_key((des_cblock *)(_KEYBUF(sav->key_enc) + 8)) ||
des_is_weak_key((des_cblock *)(_KEYBUF(sav->key_enc) + 16))) {
ipseclog((LOG_ERR,
"esp_cbc_mature %s: weak key was passed.\n",
algo->name));
return 1;
}
break;
case SADB_X_EALG_BLOWFISHCBC:
case SADB_X_EALG_CAST128CBC:
break;
case SADB_X_EALG_RIJNDAELCBC:
/* allows specific key sizes only */
if (!(keylen == 128 || keylen == 192 || keylen == 256)) {
ipseclog((LOG_ERR,
"esp_cbc_mature %s: invalid key length %d.\n",
algo->name, keylen));
return 1;
}
break;
}
return 0;
}
static size_t
esp_blowfish_schedlen(const struct esp_algorithm *algo)
{
return sizeof(BF_KEY);
}
static int
esp_blowfish_schedule(const struct esp_algorithm *algo,
struct secasvar *sav)
{
BF_set_key((BF_KEY *)sav->sched, _KEYLEN(sav->key_enc),
_KEYBUF(sav->key_enc));
return 0;
}
static int
esp_blowfish_blockdecrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
BF_ecb_encrypt(s, d, (BF_KEY *)sav->sched, 0);
return 0;
}
static int
esp_blowfish_blockencrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
BF_ecb_encrypt(s, d, (BF_KEY *)sav->sched, 1);
return 0;
}
static size_t
esp_cast128_schedlen(const struct esp_algorithm *algo)
{
return sizeof(cast128_key);
}
static int
esp_cast128_schedule(const struct esp_algorithm *algo,
struct secasvar *sav)
{
cast128_setkey((cast128_key *)sav->sched, _KEYBUF(sav->key_enc),
_KEYLEN(sav->key_enc));
return 0;
}
static int
esp_cast128_blockdecrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
cast128_decrypt((cast128_key *)sav->sched, s, d);
return 0;
}
static int
esp_cast128_blockencrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
cast128_encrypt((cast128_key *)sav->sched, s, d);
return 0;
}
static size_t
esp_3des_schedlen(const struct esp_algorithm *algo)
{
return sizeof(des_key_schedule) * 3;
}
static int
esp_3des_schedule(const struct esp_algorithm *algo,
struct secasvar *sav)
{
int error;
des_key_schedule *p;
int i;
u_int8_t *k;
p = (des_key_schedule *)sav->sched;
k = _KEYBUF(sav->key_enc);
for (i = 0; i < 3; i++) {
error = des_key_sched((des_cblock *)(k + 8 * i), p[i]);
if (error)
return EINVAL;
}
return 0;
}
static int
esp_3des_blockdecrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
des_key_schedule *p;
/* assumption: d has a good alignment */
p = (des_key_schedule *)sav->sched;
memcpy(d, s, sizeof(DES_LONG) * 2);
des_ecb3_encrypt((des_cblock *)d, (des_cblock *)d,
p[0], p[1], p[2], DES_DECRYPT);
return 0;
}
static int
esp_3des_blockencrypt(const struct esp_algorithm *algo,
struct secasvar *sav, u_int8_t *s, u_int8_t *d)
{
des_key_schedule *p;
/* assumption: d has a good alignment */
p = (des_key_schedule *)sav->sched;
memcpy(d, s, sizeof(DES_LONG) * 2);
des_ecb3_encrypt((des_cblock *)d, (des_cblock *)d,
p[0], p[1], p[2], DES_ENCRYPT);
return 0;
}
static int
esp_common_ivlen(const struct esp_algorithm *algo,
struct secasvar *sav)
{
if (!algo)
panic("esp_common_ivlen: unknown algorithm");
return algo->ivlenval;
}
static int
esp_cbc_decrypt(struct mbuf *m, size_t off, struct secasvar *sav,
const struct esp_algorithm *algo, int ivlen)
{
struct mbuf *s;
struct mbuf *d, *d0, *dp;
int soff, doff; /* offset from the head of chain, to head of this mbuf */
int sn, dn; /* offset from the head of the mbuf, to meat */
size_t ivoff, bodyoff;
u_int8_t iv[MAXIVLEN], *ivp;
u_int8_t sbuf[MAXIVLEN], *sp;
u_int8_t *p, *q;
struct mbuf *scut;
int scutoff;
int i;
int blocklen;
if (ivlen != sav->ivlen || ivlen > sizeof(iv)) {
ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
"unsupported ivlen %d\n", algo->name, ivlen));
m_freem(m);
return EINVAL;
}
/* assumes blocklen == padbound */
blocklen = algo->padbound;
#ifdef DIAGNOSTIC
if (blocklen > sizeof(iv)) {
ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
"unsupported blocklen %d\n", algo->name, blocklen));
m_freem(m);
return EINVAL;
}
#endif
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1827 */
ivoff = off + sizeof(struct esp);
bodyoff = off + sizeof(struct esp) + ivlen;
} else {
/* RFC 2406 */
if (sav->flags & SADB_X_EXT_DERIV) {
/*
* draft-ietf-ipsec-ciph-des-derived-00.txt
* uses sequence number field as IV field.
*/
ivoff = off + sizeof(struct esp);
bodyoff = off + sizeof(struct esp) + sizeof(u_int32_t);
ivlen = sizeof(u_int32_t);
} else {
ivoff = off + sizeof(struct newesp);
bodyoff = off + sizeof(struct newesp) + ivlen;
}
}
/* grab iv */
m_copydata(m, ivoff, ivlen, (void *)iv);
/* extend iv */
if (ivlen == blocklen)
;
else if (ivlen == 4 && blocklen == 8) {
memcpy(&iv[4], &iv[0], 4);
iv[4] ^= 0xff;
iv[5] ^= 0xff;
iv[6] ^= 0xff;
iv[7] ^= 0xff;
} else {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
"unsupported ivlen/blocklen: %d %d\n",
algo->name, ivlen, blocklen));
m_freem(m);
return EINVAL;
}
if (m->m_pkthdr.len < bodyoff) {
ipseclog((LOG_ERR, "esp_cbc_decrypt %s: bad len %d/%lu\n",
algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
m_freem(m);
return EINVAL;
}
if ((m->m_pkthdr.len - bodyoff) % blocklen) {
ipseclog((LOG_ERR, "esp_cbc_decrypt %s: "
"payload length must be multiple of %d\n",
algo->name, blocklen));
m_freem(m);
return EINVAL;
}
s = m;
d = d0 = dp = NULL;
soff = doff = sn = dn = 0;
ivp = sp = NULL;
/* skip bodyoff */
while (soff < bodyoff) {
if (soff + s->m_len > bodyoff) {
sn = bodyoff - soff;
break;
}
soff += s->m_len;
s = s->m_next;
}
scut = s;
scutoff = sn;
/* skip over empty mbuf */
while (s && s->m_len == 0)
s = s->m_next;
while (soff < m->m_pkthdr.len) {
/* source */
if (sn + blocklen <= s->m_len) {
/* body is continuous */
sp = mtod(s, u_int8_t *) + sn;
} else {
/* body is non-continuous */
m_copydata(s, sn, blocklen, (void *)sbuf);
sp = sbuf;
}
/* destination */
if (!d || dn + blocklen > d->m_len) {
if (d)
dp = d;
MGET(d, M_DONTWAIT, MT_DATA);
i = m->m_pkthdr.len - (soff + sn);
if (d && i > MLEN) {
MCLGET(d, M_DONTWAIT);
if ((d->m_flags & M_EXT) == 0) {
m_free(d);
d = NULL;
}
}
if (!d) {
m_freem(m);
if (d0)
m_freem(d0);
return ENOBUFS;
}
if (!d0)
d0 = d;
if (dp)
dp->m_next = d;
d->m_len = 0;
d->m_len = (M_TRAILINGSPACE(d) / blocklen) * blocklen;
if (d->m_len > i)
d->m_len = i;
dn = 0;
}
/* decrypt */
(*algo->blockdecrypt)(algo, sav, sp, mtod(d, u_int8_t *) + dn);
/* xor */
p = ivp ? ivp : iv;
q = mtod(d, u_int8_t *) + dn;
for (i = 0; i < blocklen; i++)
q[i] ^= p[i];
/* next iv */
if (sp == sbuf) {
memcpy(iv, sbuf, blocklen);
ivp = NULL;
} else
ivp = sp;
sn += blocklen;
dn += blocklen;
/* find the next source block */
while (s && sn >= s->m_len) {
sn -= s->m_len;
soff += s->m_len;
s = s->m_next;
}
/* skip over empty mbuf */
while (s && s->m_len == 0)
s = s->m_next;
}
m_freem(scut->m_next);
scut->m_len = scutoff;
scut->m_next = d0;
/* just in case */
memset(iv, 0, sizeof(iv));
memset(sbuf, 0, sizeof(sbuf));
return 0;
}
static int
esp_cbc_encrypt(
struct mbuf *m,
size_t off,
size_t plen,
struct secasvar *sav,
const struct esp_algorithm *algo,
int ivlen
)
{
struct mbuf *s;
struct mbuf *d, *d0, *dp;
int soff, doff; /* offset from the head of chain, to head of this mbuf */
int sn, dn; /* offset from the head of the mbuf, to meat */
size_t ivoff, bodyoff;
u_int8_t iv[MAXIVLEN], *ivp;
u_int8_t sbuf[MAXIVLEN], *sp;
u_int8_t *p, *q;
struct mbuf *scut;
int scutoff;
int i;
int blocklen;
int derived;
if (ivlen != sav->ivlen || ivlen > sizeof(iv)) {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
"unsupported ivlen %d\n", algo->name, ivlen));
m_freem(m);
return EINVAL;
}
/* assumes blocklen == padbound */
blocklen = algo->padbound;
#ifdef DIAGNOSTIC
if (blocklen > sizeof(iv)) {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
"unsupported blocklen %d\n", algo->name, blocklen));
m_freem(m);
return EINVAL;
}
#endif
if (sav->flags & SADB_X_EXT_OLD) {
/* RFC 1827 */
ivoff = off + sizeof(struct esp);
bodyoff = off + sizeof(struct esp) + ivlen;
derived = 0;
} else {
/* RFC 2406 */
if (sav->flags & SADB_X_EXT_DERIV) {
/*
* draft-ietf-ipsec-ciph-des-derived-00.txt
* uses sequence number field as IV field.
*/
ivoff = off + sizeof(struct esp);
bodyoff = off + sizeof(struct esp) + sizeof(u_int32_t);
ivlen = sizeof(u_int32_t);
derived = 1;
} else {
ivoff = off + sizeof(struct newesp);
bodyoff = off + sizeof(struct newesp) + ivlen;
derived = 0;
}
}
/* put iv into the packet. if we are in derived mode, use seqno. */
if (derived)
m_copydata(m, ivoff, ivlen, (void *)iv);
else {
memcpy(iv, sav->iv, ivlen);
/* maybe it is better to overwrite dest, not source */
m_copyback(m, ivoff, ivlen, (void *)iv);
}
/* extend iv */
if (ivlen == blocklen)
;
else if (ivlen == 4 && blocklen == 8) {
memcpy(&iv[4], &iv[0], 4);
iv[4] ^= 0xff;
iv[5] ^= 0xff;
iv[6] ^= 0xff;
iv[7] ^= 0xff;
} else {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
"unsupported ivlen/blocklen: %d %d\n",
algo->name, ivlen, blocklen));
m_freem(m);
return EINVAL;
}
if (m->m_pkthdr.len < bodyoff) {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: bad len %d/%lu\n",
algo->name, m->m_pkthdr.len, (unsigned long)bodyoff));
m_freem(m);
return EINVAL;
}
if ((m->m_pkthdr.len - bodyoff) % blocklen) {
ipseclog((LOG_ERR, "esp_cbc_encrypt %s: "
"payload length must be multiple of %lu\n",
algo->name, (unsigned long)algo->padbound));
m_freem(m);
return EINVAL;
}
s = m;
d = d0 = dp = NULL;
soff = doff = sn = dn = 0;
ivp = sp = NULL;
/* skip bodyoff */
while (soff < bodyoff) {
if (soff + s->m_len > bodyoff) {
sn = bodyoff - soff;
break;
}
soff += s->m_len;
s = s->m_next;
}
scut = s;
scutoff = sn;
/* skip over empty mbuf */
while (s && s->m_len == 0)
s = s->m_next;
while (soff < m->m_pkthdr.len) {
/* source */
if (sn + blocklen <= s->m_len) {
/* body is continuous */
sp = mtod(s, u_int8_t *) + sn;
} else {
/* body is non-continuous */
m_copydata(s, sn, blocklen, (void *)sbuf);
sp = sbuf;
}
/* destination */
if (!d || dn + blocklen > d->m_len) {
if (d)
dp = d;
MGET(d, M_DONTWAIT, MT_DATA);
i = m->m_pkthdr.len - (soff + sn);
if (d && i > MLEN) {
MCLGET(d, M_DONTWAIT);
if ((d->m_flags & M_EXT) == 0) {
m_free(d);
d = NULL;
}
}
if (!d) {
m_freem(m);
if (d0)
m_freem(d0);
return ENOBUFS;
}
if (!d0)
d0 = d;
if (dp)
dp->m_next = d;
d->m_len = 0;
d->m_len = (M_TRAILINGSPACE(d) / blocklen) * blocklen;
if (d->m_len > i)
d->m_len = i;
dn = 0;
}
/* xor */
p = ivp ? ivp : iv;
q = sp;
for (i = 0; i < blocklen; i++)
q[i] ^= p[i];
/* encrypt */
(*algo->blockencrypt)(algo, sav, sp, mtod(d, u_int8_t *) + dn);
/* next iv */
ivp = mtod(d, u_int8_t *) + dn;
sn += blocklen;
dn += blocklen;
/* find the next source block */
while (s && sn >= s->m_len) {
sn -= s->m_len;
soff += s->m_len;
s = s->m_next;
}
/* skip over empty mbuf */
while (s && s->m_len == 0)
s = s->m_next;
}
m_freem(scut->m_next);
scut->m_len = scutoff;
scut->m_next = d0;
/* just in case */
memset(iv, 0, sizeof(iv));
memset(sbuf, 0, sizeof(sbuf));
key_sa_stir_iv(sav);
return 0;
}
/*------------------------------------------------------------*/
/* does not free m0 on error
*
* skip - offset to ESP header
* length - payloadd length
*/
int
esp_auth(struct mbuf *m0, size_t skip, size_t length,
struct secasvar *sav, u_char *sum)
{
struct mbuf *m;
size_t off;
struct ah_algorithm_state s;
u_char sumbuf[AH_MAXSUMSIZE];
const struct ah_algorithm *algo;
size_t siz;
int error;
/* sanity checks */
if (m0->m_pkthdr.len < skip) {
ipseclog((LOG_DEBUG, "esp_auth: mbuf length < skip\n"));
return EINVAL;
}
if (m0->m_pkthdr.len < skip + length) {
ipseclog((LOG_DEBUG,
"esp_auth: mbuf length < skip + length\n"));
return EINVAL;
}
/*
* length of esp part (excluding authentication data) must be 4n,
* since nexthdr must be at offset 4n+3.
*/
if (length % 4) {
ipseclog((LOG_ERR, "esp_auth: length is not multiple of 4\n"));
return EINVAL;
}
if (!sav) {
ipseclog((LOG_DEBUG, "esp_auth: NULL SA passed\n"));
return EINVAL;
}
algo = ah_algorithm_lookup(sav->alg_auth);
if (!algo) {
ipseclog((LOG_ERR,
"esp_auth: bad ESP auth algorithm passed: %d\n",
sav->alg_auth));
return EINVAL;
}
m = m0;
off = 0;
siz = (((*algo->sumsiz)(sav) + 3) & ~(4 - 1));
if (sizeof(sumbuf) < siz) {
ipseclog((LOG_DEBUG,
"esp_auth: AH_MAXSUMSIZE is too small: siz=%lu\n",
(u_long)siz));
return EINVAL;
}
/* skip the header */
while (skip) {
if (!m)
panic("mbuf chain?");
if (m->m_len <= skip) {
skip -= m->m_len;
m = m->m_next;
off = 0;
} else {
off = skip;
skip = 0;
}
}
error = (*algo->init)(&s, sav);
if (error)
return error;
while (0 < length) {
if (!m)
panic("mbuf chain?");
if (m->m_len - off < length) {
(*algo->update)(&s, mtod(m, u_char *) + off,
m->m_len - off);
length -= m->m_len - off;
m = m->m_next;
off = 0;
} else {
(*algo->update)(&s, mtod(m, u_char *) + off, length);
break;
}
}
(*algo->result)(&s, sumbuf, sizeof(sumbuf));
memcpy(sum, sumbuf, siz); /* XXX */
return 0;
}
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