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NetBSD/sys/netinet6/ah_core.c

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/* $NetBSD: ah_core.c,v 1.16 2000/02/06 12:49:40 itojun 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.
*/
/*
* RFC1826/2402 authentication header.
*/
#include "opt_inet.h"
#include "opt_ipsec.h"
/* Some of operating systems have standard crypto checksum library */
#ifdef __NetBSD__
#define HAVE_MD5
#define HAVE_SHA1
#endif
#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/socketvar.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 <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_var.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#endif
#include <netinet6/ipsec.h>
#include <netinet6/ah.h>
#ifdef IPSEC_ESP
#include <netinet6/esp.h>
#endif
#include <net/pfkeyv2.h>
#include <netkey/keydb.h>
#ifdef HAVE_MD5
#include <sys/md5.h>
#else
#include <crypto/md5.h>
#endif
#ifdef HAVE_SHA1
#include <sys/sha1.h>
#define SHA1_RESULTLEN 20
#else
#include <crypto/sha1.h>
#endif
#include <net/net_osdep.h>
#define HMACSIZE 16
#ifdef INET6
#define ZEROBUFLEN 256
static char zerobuf[ZEROBUFLEN];
#endif
static int ah_sumsiz_1216 __P((struct secasvar *));
static int ah_sumsiz_zero __P((struct secasvar *));
static int ah_none_mature __P((struct secasvar *));
static void ah_none_init __P((struct ah_algorithm_state *,
struct secasvar *));
static void ah_none_loop __P((struct ah_algorithm_state *, caddr_t, size_t));
static void ah_none_result __P((struct ah_algorithm_state *, caddr_t));
static int ah_keyed_md5_mature __P((struct secasvar *));
static void ah_keyed_md5_init __P((struct ah_algorithm_state *,
struct secasvar *));
static void ah_keyed_md5_loop __P((struct ah_algorithm_state *, caddr_t,
size_t));
static void ah_keyed_md5_result __P((struct ah_algorithm_state *, caddr_t));
static int ah_keyed_sha1_mature __P((struct secasvar *));
static void ah_keyed_sha1_init __P((struct ah_algorithm_state *,
struct secasvar *));
static void ah_keyed_sha1_loop __P((struct ah_algorithm_state *, caddr_t,
size_t));
static void ah_keyed_sha1_result __P((struct ah_algorithm_state *, caddr_t));
static int ah_hmac_md5_mature __P((struct secasvar *));
static void ah_hmac_md5_init __P((struct ah_algorithm_state *,
struct secasvar *));
static void ah_hmac_md5_loop __P((struct ah_algorithm_state *, caddr_t,
size_t));
static void ah_hmac_md5_result __P((struct ah_algorithm_state *, caddr_t));
static int ah_hmac_sha1_mature __P((struct secasvar *));
static void ah_hmac_sha1_init __P((struct ah_algorithm_state *,
struct secasvar *));
static void ah_hmac_sha1_loop __P((struct ah_algorithm_state *, caddr_t,
size_t));
static void ah_hmac_sha1_result __P((struct ah_algorithm_state *, caddr_t));
/* checksum algorithms */
/* NOTE: The order depends on SADB_AALG_x in net/pfkeyv2.h.h */
struct ah_algorithm ah_algorithms[] = {
{ 0, 0, 0, 0, 0, 0, },
{ ah_sumsiz_1216, ah_hmac_md5_mature, 128, 128,
ah_hmac_md5_init, ah_hmac_md5_loop, ah_hmac_md5_result, },
{ ah_sumsiz_1216, ah_hmac_sha1_mature, 160, 160,
ah_hmac_sha1_init, ah_hmac_sha1_loop, ah_hmac_sha1_result, },
{ ah_sumsiz_1216, ah_keyed_md5_mature, 128, 128,
ah_keyed_md5_init, ah_keyed_md5_loop, ah_keyed_md5_result, },
{ ah_sumsiz_1216, ah_keyed_sha1_mature, 160, 160,
ah_keyed_sha1_init, ah_keyed_sha1_loop, ah_keyed_sha1_result, },
{ ah_sumsiz_zero, ah_none_mature, 0, 2048,
ah_none_init, ah_none_loop, ah_none_result, },
};
static int
ah_sumsiz_1216(sav)
struct secasvar *sav;
{
if (!sav)
return -1;
if (sav->flags & SADB_X_EXT_OLD)
return 16;
else
return 12;
}
static int
ah_sumsiz_zero(sav)
struct secasvar *sav;
{
if (!sav)
return -1;
return 0;
}
static int
ah_none_mature(sav)
struct secasvar *sav;
{
if (sav->sah->saidx.proto == IPPROTO_AH) {
ipseclog((LOG_ERR,
"ah_none_mature: protocol and algorithm mismatch.\n"));
return 1;
}
return 0;
}
static void
ah_none_init(state, sav)
struct ah_algorithm_state *state;
struct secasvar *sav;
{
state->foo = NULL;
}
static void
ah_none_loop(state, addr, len)
struct ah_algorithm_state *state;
caddr_t addr;
size_t len;
{
}
static void
ah_none_result(state, addr)
struct ah_algorithm_state *state;
caddr_t addr;
{
}
static int
ah_keyed_md5_mature(sav)
struct secasvar *sav;
{
/* anything is okay */
return 0;
}
static void
ah_keyed_md5_init(state, sav)
struct ah_algorithm_state *state;
struct secasvar *sav;
{
if (!state)
panic("ah_keyed_md5_init: what?");
state->sav = sav;
state->foo = (void *)malloc(sizeof(MD5_CTX), M_TEMP, M_NOWAIT);
if (state->foo == NULL)
panic("ah_keyed_md5_init: what?");
MD5Init((MD5_CTX *)state->foo);
if (state->sav) {
MD5Update((MD5_CTX *)state->foo,
(u_int8_t *)_KEYBUF(state->sav->key_auth),
(u_int)_KEYLEN(state->sav->key_auth));
{
/*
* Pad after the key.
* We cannot simply use md5_pad() since the function
* won't update the total length.
*/
size_t padlen;
size_t keybitlen;
u_int8_t buf[32];
if (_KEYLEN(state->sav->key_auth) < 56)
padlen = 64 - 8 - _KEYLEN(state->sav->key_auth);
else
padlen = 64 + 64 - 8 - _KEYLEN(state->sav->key_auth);
keybitlen = _KEYLEN(state->sav->key_auth);
keybitlen *= 8;
buf[0] = 0x80;
MD5Update((MD5_CTX *)state->foo, &buf[0], 1);
padlen--;
bzero(buf, sizeof(buf));
while (sizeof(buf) < padlen) {
MD5Update((MD5_CTX *)state->foo, &buf[0], sizeof(buf));
padlen -= sizeof(buf);
}
if (padlen) {
MD5Update((MD5_CTX *)state->foo, &buf[0], padlen);
}
buf[0] = (keybitlen >> 0) & 0xff;
buf[1] = (keybitlen >> 8) & 0xff;
buf[2] = (keybitlen >> 16) & 0xff;
buf[3] = (keybitlen >> 24) & 0xff;
MD5Update((MD5_CTX *)state->foo, buf, 8);
}
}
}
static void
ah_keyed_md5_loop(state, addr, len)
struct ah_algorithm_state *state;
caddr_t addr;
size_t len;
{
if (!state)
panic("ah_keyed_md5_loop: what?");
MD5Update((MD5_CTX *)state->foo, addr, len);
}
static void
ah_keyed_md5_result(state, addr)
struct ah_algorithm_state *state;
caddr_t addr;
{
u_char digest[16];
if (!state)
panic("ah_keyed_md5_result: what?");
if (state->sav) {
MD5Update((MD5_CTX *)state->foo,
(u_int8_t *)_KEYBUF(state->sav->key_auth),
(u_int)_KEYLEN(state->sav->key_auth));
}
MD5Final(&digest[0], (MD5_CTX *)state->foo);
free(state->foo, M_TEMP);
bcopy(&digest[0], (void *)addr, sizeof(digest));
}
static int
ah_keyed_sha1_mature(sav)
struct secasvar *sav;
{
struct ah_algorithm *algo;
if (!sav->key_auth) {
ipseclog((LOG_ERR, "ah_keyed_sha1_mature: no key is given.\n"));
return 1;
}
algo = &ah_algorithms[sav->alg_auth];
if (sav->key_auth->sadb_key_bits < algo->keymin
|| algo->keymax < sav->key_auth->sadb_key_bits) {
ipseclog((LOG_ERR,
"ah_keyed_sha1_mature: invalid key length %d.\n",
sav->key_auth->sadb_key_bits));
return 1;
}
return 0;
}
static void
ah_keyed_sha1_init(state, sav)
struct ah_algorithm_state *state;
struct secasvar *sav;
{
SHA1_CTX *ctxt;
if (!state)
panic("ah_keyed_sha1_init: what?");
state->sav = sav;
state->foo = (void *)malloc(sizeof(SHA1_CTX), M_TEMP, M_NOWAIT);
if (!state->foo)
panic("ah_keyed_sha1_init: what?");
ctxt = (SHA1_CTX *)state->foo;
SHA1Init(ctxt);
if (state->sav) {
SHA1Update(ctxt, (u_int8_t *)_KEYBUF(state->sav->key_auth),
(u_int)_KEYLEN(state->sav->key_auth));
{
/*
* Pad after the key.
*/
size_t padlen;
size_t keybitlen;
u_int8_t buf[32];
if (_KEYLEN(state->sav->key_auth) < 56)
padlen = 64 - 8 - _KEYLEN(state->sav->key_auth);
else
padlen = 64 + 64 - 8 - _KEYLEN(state->sav->key_auth);
keybitlen = _KEYLEN(state->sav->key_auth);
keybitlen *= 8;
buf[0] = 0x80;
SHA1Update(ctxt, &buf[0], 1);
padlen--;
bzero(buf, sizeof(buf));
while (sizeof(buf) < padlen) {
SHA1Update(ctxt, &buf[0], sizeof(buf));
padlen -= sizeof(buf);
}
if (padlen) {
SHA1Update(ctxt, &buf[0], padlen);
}
buf[0] = (keybitlen >> 0) & 0xff;
buf[1] = (keybitlen >> 8) & 0xff;
buf[2] = (keybitlen >> 16) & 0xff;
buf[3] = (keybitlen >> 24) & 0xff;
SHA1Update(ctxt, buf, 8);
}
}
}
static void
ah_keyed_sha1_loop(state, addr, len)
struct ah_algorithm_state *state;
caddr_t addr;
size_t len;
{
SHA1_CTX *ctxt;
if (!state || !state->foo)
panic("ah_keyed_sha1_loop: what?");
ctxt = (SHA1_CTX *)state->foo;
SHA1Update(ctxt, (caddr_t)addr, (size_t)len);
}
static void
ah_keyed_sha1_result(state, addr)
struct ah_algorithm_state *state;
caddr_t addr;
{
u_char digest[SHA1_RESULTLEN]; /* SHA-1 generates 160 bits */
SHA1_CTX *ctxt;
if (!state || !state->foo)
panic("ah_keyed_sha1_result: what?");
ctxt = (SHA1_CTX *)state->foo;
if (state->sav) {
SHA1Update(ctxt, (u_int8_t *)_KEYBUF(state->sav->key_auth),
(u_int)_KEYLEN(state->sav->key_auth));
}
SHA1Final((caddr_t)&digest[0], ctxt);
bcopy(&digest[0], (void *)addr, HMACSIZE);
free(state->foo, M_TEMP);
}
static int
ah_hmac_md5_mature(sav)
struct secasvar *sav;
{
struct ah_algorithm *algo;
if (!sav->key_auth) {
ipseclog((LOG_ERR, "ah_hmac_md5_mature: no key is given.\n"));
return 1;
}
algo = &ah_algorithms[sav->alg_auth];
if (sav->key_auth->sadb_key_bits < algo->keymin
|| algo->keymax < sav->key_auth->sadb_key_bits) {
ipseclog((LOG_ERR,
"ah_hmac_md5_mature: invalid key length %d.\n",
sav->key_auth->sadb_key_bits));
return 1;
}
return 0;
}
static void
ah_hmac_md5_init(state, sav)
struct ah_algorithm_state *state;
struct secasvar *sav;
{
u_char *ipad;
u_char *opad;
u_char tk[16];
u_char *key;
size_t keylen;
size_t i;
MD5_CTX *ctxt;
if (!state)
panic("ah_hmac_md5_init: what?");
state->sav = sav;
state->foo = (void *)malloc(64 + 64 + sizeof(MD5_CTX), M_TEMP, M_NOWAIT);
if (!state->foo)
panic("ah_hmac_md5_init: what?");
ipad = (u_char *)state->foo;
opad = (u_char *)(ipad + 64);
ctxt = (MD5_CTX *)(opad + 64);
/* compress the key if necessery */
if (64 < _KEYLEN(state->sav->key_auth)) {
MD5Init(ctxt);
MD5Update(ctxt, _KEYBUF(state->sav->key_auth),
_KEYLEN(state->sav->key_auth));
MD5Final(&tk[0], ctxt);
key = &tk[0];
keylen = 16;
} else {
key = _KEYBUF(state->sav->key_auth);
keylen = _KEYLEN(state->sav->key_auth);
}
bzero(ipad, 64);
bzero(opad, 64);
bcopy(key, ipad, keylen);
bcopy(key, opad, keylen);
for (i = 0; i < 64; i++) {
ipad[i] ^= 0x36;
opad[i] ^= 0x5c;
}
MD5Init(ctxt);
MD5Update(ctxt, ipad, 64);
}
static void
ah_hmac_md5_loop(state, addr, len)
struct ah_algorithm_state *state;
caddr_t addr;
size_t len;
{
MD5_CTX *ctxt;
if (!state || !state->foo)
panic("ah_hmac_md5_loop: what?");
ctxt = (MD5_CTX *)(((caddr_t)state->foo) + 128);
MD5Update(ctxt, addr, len);
}
static void
ah_hmac_md5_result(state, addr)
struct ah_algorithm_state *state;
caddr_t addr;
{
u_char digest[16];
u_char *ipad;
u_char *opad;
MD5_CTX *ctxt;
if (!state || !state->foo)
panic("ah_hmac_md5_result: what?");
ipad = (u_char *)state->foo;
opad = (u_char *)(ipad + 64);
ctxt = (MD5_CTX *)(opad + 64);
MD5Final(&digest[0], ctxt);
MD5Init(ctxt);
MD5Update(ctxt, opad, 64);
MD5Update(ctxt, &digest[0], sizeof(digest));
MD5Final(&digest[0], ctxt);
bcopy(&digest[0], (void *)addr, HMACSIZE);
free(state->foo, M_TEMP);
}
static int
ah_hmac_sha1_mature(sav)
struct secasvar *sav;
{
struct ah_algorithm *algo;
if (!sav->key_auth) {
ipseclog((LOG_ERR, "ah_hmac_sha1_mature: no key is given.\n"));
return 1;
}
algo = &ah_algorithms[sav->alg_auth];
if (sav->key_auth->sadb_key_bits < algo->keymin
|| algo->keymax < sav->key_auth->sadb_key_bits) {
ipseclog((LOG_ERR,
"ah_hmac_sha1_mature: invalid key length %d.\n",
sav->key_auth->sadb_key_bits));
return 1;
}
return 0;
}
static void
ah_hmac_sha1_init(state, sav)
struct ah_algorithm_state *state;
struct secasvar *sav;
{
u_char *ipad;
u_char *opad;
SHA1_CTX *ctxt;
u_char tk[SHA1_RESULTLEN]; /* SHA-1 generates 160 bits */
u_char *key;
size_t keylen;
size_t i;
if (!state)
panic("ah_hmac_sha1_init: what?");
state->sav = sav;
state->foo = (void *)malloc(64 + 64 + sizeof(SHA1_CTX),
M_TEMP, M_NOWAIT);
if (!state->foo)
panic("ah_hmac_sha1_init: what?");
ipad = (u_char *)state->foo;
opad = (u_char *)(ipad + 64);
ctxt = (SHA1_CTX *)(opad + 64);
/* compress the key if necessery */
if (64 < _KEYLEN(state->sav->key_auth)) {
SHA1Init(ctxt);
SHA1Update(ctxt, _KEYBUF(state->sav->key_auth),
_KEYLEN(state->sav->key_auth));
SHA1Final(&tk[0], ctxt);
key = &tk[0];
keylen = SHA1_RESULTLEN;
} else {
key = _KEYBUF(state->sav->key_auth);
keylen = _KEYLEN(state->sav->key_auth);
}
bzero(ipad, 64);
bzero(opad, 64);
bcopy(key, ipad, keylen);
bcopy(key, opad, keylen);
for (i = 0; i < 64; i++) {
ipad[i] ^= 0x36;
opad[i] ^= 0x5c;
}
SHA1Init(ctxt);
SHA1Update(ctxt, ipad, 64);
}
static void
ah_hmac_sha1_loop(state, addr, len)
struct ah_algorithm_state *state;
caddr_t addr;
size_t len;
{
SHA1_CTX *ctxt;
if (!state || !state->foo)
panic("ah_hmac_sha1_loop: what?");
ctxt = (SHA1_CTX *)(((u_char *)state->foo) + 128);
SHA1Update(ctxt, (caddr_t)addr, (size_t)len);
}
static void
ah_hmac_sha1_result(state, addr)
struct ah_algorithm_state *state;
caddr_t addr;
{
u_char digest[SHA1_RESULTLEN]; /* SHA-1 generates 160 bits */
u_char *ipad;
u_char *opad;
SHA1_CTX *ctxt;
if (!state || !state->foo)
panic("ah_hmac_sha1_result: what?");
ipad = (u_char *)state->foo;
opad = (u_char *)(ipad + 64);
ctxt = (SHA1_CTX *)(opad + 64);
SHA1Final((caddr_t)&digest[0], ctxt);
SHA1Init(ctxt);
SHA1Update(ctxt, opad, 64);
SHA1Update(ctxt, (caddr_t)&digest[0], sizeof(digest));
SHA1Final((caddr_t)&digest[0], ctxt);
bcopy(&digest[0], (void *)addr, HMACSIZE);
free(state->foo, M_TEMP);
}
/*------------------------------------------------------------*/
/*
* go generate the checksum.
*/
int
ah4_calccksum(m0, ahdat, algo, sav)
struct mbuf *m0;
caddr_t ahdat;
struct ah_algorithm *algo;
struct secasvar *sav;
{
struct mbuf *m;
int hdrtype;
u_char *p;
size_t advancewidth;
struct ah_algorithm_state algos;
int tlen;
u_char sumbuf[AH_MAXSUMSIZE];
int error = 0;
hdrtype = -1; /*dummy, it is called IPPROTO_IP*/
m = m0;
p = mtod(m, u_char *);
(algo->init)(&algos, sav);
advancewidth = 0; /*safety*/
again:
/* gory. */
switch (hdrtype) {
case -1: /*first one*/
{
/*
* copy ip hdr, modify to fit the AH checksum rule,
* then take a checksum.
* XXX need to care about source routing... jesus.
*/
struct ip iphdr;
size_t hlen;
bcopy((caddr_t)p, (caddr_t)&iphdr, sizeof(struct ip));
#ifdef _IP_VHL
hlen = IP_VHL_HL(iphdr.ip_vhl) << 2;
#else
hlen = iphdr.ip_hl << 2;
#endif
iphdr.ip_ttl = 0;
iphdr.ip_sum = htons(0);
if (ip4_ah_cleartos) iphdr.ip_tos = 0;
iphdr.ip_off = htons(ntohs(iphdr.ip_off) & ip4_ah_offsetmask);
(algo->update)(&algos, (caddr_t)&iphdr, sizeof(struct ip));
if (hlen != sizeof(struct ip)) {
u_char *p;
int i, j;
int l, skip;
u_char dummy[4];
/*
* IP options processing.
* See RFC2402 appendix A.
*/
bzero(dummy, sizeof(dummy));
p = mtod(m, u_char *);
i = sizeof(struct ip);
while (i < hlen) {
skip = 1;
switch (p[i + IPOPT_OPTVAL]) {
case IPOPT_EOL:
case IPOPT_NOP:
l = 1;
skip = 0;
break;
case IPOPT_SECURITY: /* 0x82 */
case 0x85: /* Extended security */
case 0x86: /* Commercial security */
case 0x94: /* Router alert */
case 0x95: /* RFC1770 */
l = p[i + IPOPT_OLEN];
skip = 0;
break;
default:
l = p[i + IPOPT_OLEN];
skip = 1;
break;
}
if (l <= 0 || hlen - i < l) {
ipseclog((LOG_ERR,
"ah4_calccksum: invalid IP option "
"(type=%02x len=%02x)\n",
p[i + IPOPT_OPTVAL],
p[i + IPOPT_OLEN]));
break;
}
if (skip) {
for (j = 0; j < l / sizeof(dummy); j++)
(algo->update)(&algos, dummy, sizeof(dummy));
(algo->update)(&algos, dummy, l % sizeof(dummy));
} else
(algo->update)(&algos, p + i, l);
if (p[i + IPOPT_OPTVAL] == IPOPT_EOL)
break;
i += l;
}
}
hdrtype = (iphdr.ip_p) & 0xff;
advancewidth = hlen;
break;
}
case IPPROTO_AH:
{
u_char dummy[4];
int siz;
int hdrsiz;
hdrsiz = (sav->flags & SADB_X_EXT_OLD) ?
sizeof(struct ah) : sizeof(struct newah);
(algo->update)(&algos, p, hdrsiz);
/* key data region. */
siz = (*algo->sumsiz)(sav);
bzero(&dummy[0], sizeof(dummy));
while (sizeof(dummy) <= siz) {
(algo->update)(&algos, dummy, sizeof(dummy));
siz -= sizeof(dummy);
}
/* can't happen, but just in case */
if (siz)
(algo->update)(&algos, dummy, siz);
/* padding region, just in case */
siz = (((struct ah *)p)->ah_len << 2) - (*algo->sumsiz)(sav);
if ((sav->flags & SADB_X_EXT_OLD) == 0)
siz -= 4; /* sequence number field */
if (0 < siz) {
/* RFC 1826 */
(algo->update)(&algos, p + hdrsiz + (*algo->sumsiz)(sav),
siz);
}
hdrtype = ((struct ah *)p)->ah_nxt;
advancewidth = hdrsiz;
advancewidth += ((struct ah *)p)->ah_len << 2;
if ((sav->flags & SADB_X_EXT_OLD) == 0)
advancewidth -= 4; /* sequence number field */
break;
}
default:
ipseclog((LOG_DEBUG, "ah4_calccksum: unexpected hdrtype=%x; "
"treating rest as payload\n", hdrtype));
/*fall through*/
case IPPROTO_ICMP:
case IPPROTO_IGMP:
case IPPROTO_IPIP:
#ifdef INET6
case IPPROTO_IPV6:
case IPPROTO_ICMPV6:
#endif
case IPPROTO_UDP:
case IPPROTO_TCP:
case IPPROTO_ESP:
case IPPROTO_IPCOMP:
while (m) {
tlen = m->m_len - (p - mtod(m, u_char *));
(algo->update)(&algos, p, tlen);
m = m->m_next;
p = m ? mtod(m, u_char *) : NULL;
}
advancewidth = 0; /*loop finished*/
break;
}
if (advancewidth) {
/* is it safe? */
while (m && advancewidth) {
tlen = m->m_len - (p - mtod(m, u_char *));
if (advancewidth < tlen) {
p += advancewidth;
advancewidth = 0;
} else {
advancewidth -= tlen;
m = m->m_next;
if (m)
p = mtod(m, u_char *);
else {
ipseclog((LOG_DEBUG,
"hit the end-of-mbuf...\n"));
p = NULL;
}
}
}
if (m)
goto again;
}
/* for HMAC algorithms... */
(algo->result)(&algos, &sumbuf[0]);
bcopy(&sumbuf[0], ahdat, (*algo->sumsiz)(sav));
return error;
}
#ifdef INET6
/*
* go generate the checksum. This function won't modify the mbuf chain
* except AH itself.
*/
int
ah6_calccksum(m0, ahdat, algo, sav)
struct mbuf *m0;
caddr_t ahdat;
struct ah_algorithm *algo;
struct secasvar *sav;
{
struct mbuf *m;
int hdrtype;
u_char *p;
size_t advancewidth;
struct ah_algorithm_state algos;
int tlen;
int error = 0;
u_char sumbuf[AH_MAXSUMSIZE];
int nest;
hdrtype = -1; /*dummy, it is called IPPROTO_IPV6 */
m = m0;
p = mtod(m, u_char *);
(algo->init)(&algos, sav);
advancewidth = 0; /*safety*/
nest = 0;
again:
if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
ip6stat.ip6s_toomanyhdr++;
error = EINVAL; /*XXX*/
goto bad;
}
/* gory. */
switch (hdrtype) {
case -1: /*first one*/
{
struct ip6_hdr ip6copy;
bcopy(p, &ip6copy, sizeof(struct ip6_hdr));
/* RFC2402 */
ip6copy.ip6_flow = 0;
ip6copy.ip6_vfc &= ~IPV6_VERSION_MASK;
ip6copy.ip6_vfc |= IPV6_VERSION;
ip6copy.ip6_hlim = 0;
if (IN6_IS_ADDR_LINKLOCAL(&ip6copy.ip6_src))
ip6copy.ip6_src.s6_addr16[1] = 0x0000;
if (IN6_IS_ADDR_LINKLOCAL(&ip6copy.ip6_dst))
ip6copy.ip6_dst.s6_addr16[1] = 0x0000;
(algo->update)(&algos, (caddr_t)&ip6copy,
sizeof(struct ip6_hdr));
hdrtype = (((struct ip6_hdr *)p)->ip6_nxt) & 0xff;
advancewidth = sizeof(struct ip6_hdr);
break;
}
case IPPROTO_AH:
{
u_char dummy[4];
int siz;
int hdrsiz;
hdrsiz = (sav->flags & SADB_X_EXT_OLD) ?
sizeof(struct ah) : sizeof(struct newah);
(algo->update)(&algos, p, hdrsiz);
/* key data region. */
siz = (*algo->sumsiz)(sav);
bzero(&dummy[0], 4);
while (4 <= siz) {
(algo->update)(&algos, dummy, 4);
siz -= 4;
}
/* can't happen, but just in case */
if (siz)
(algo->update)(&algos, dummy, siz);
/* padding region, just in case */
siz = (((struct ah *)p)->ah_len << 2) - (*algo->sumsiz)(sav);
if ((sav->flags & SADB_X_EXT_OLD) == 0)
siz -= 4; /* sequence number field */
if (0 < siz) {
(algo->update)(&algos, p + hdrsiz + (*algo->sumsiz)(sav),
siz);
}
hdrtype = ((struct ah *)p)->ah_nxt;
advancewidth = hdrsiz;
advancewidth += ((struct ah *)p)->ah_len << 2;
if ((sav->flags & SADB_X_EXT_OLD) == 0)
advancewidth -= 4; /* sequence number field */
break;
}
case IPPROTO_HOPOPTS:
case IPPROTO_DSTOPTS:
{
int hdrlen, optlen;
u_int8_t *optp, *lastp = p, *optend, opt;
tlen = m->m_len - (p - mtod(m, u_char *));
/* We assume all the options is contained in a single mbuf */
if (tlen < sizeof(struct ip6_ext)) {
error = EINVAL;
goto bad;
}
hdrlen = (((struct ip6_ext *)p)->ip6e_len + 1) << 3;
hdrtype = (int)((struct ip6_ext *)p)->ip6e_nxt;
if (tlen < hdrlen) {
error = EINVAL;
goto bad;
}
optend = p + hdrlen;
/*
* ICV calculation for the options header including all
* options. This part is a little tricky since there are
* two type of options; mutable and immutable. Our approach
* is to calculate ICV for a consecutive immutable options
* at once. Here is an example. In the following figure,
* suppose that we've calculated ICV from the top of the
* header to MutableOpt1, which is a mutable option.
* lastp points to the end of MutableOpt1. Some immutable
* options follows MutableOpt1, and we encounter a new
* mutable option; MutableOpt2. optp points to the head
* of MutableOpt2. In this situation, uncalculated immutable
* field is the field from lastp to optp+2 (note that the
* type and the length fields are considered as immutable
* even in a mutable option). So we first calculate ICV
* for the field as immutable, then calculate from optp+2
* to the end of MutableOpt2, whose length is optlen-2,
* where optlen is the length of MutableOpt2. Finally,
* lastp is updated to point to the end of MutableOpt2
* for further calculation. The updated point is shown as
* lastp' in the figure.
* <------ optlen ----->
* -----------+-------------------+---+---+-----------+
* MutableOpt1|ImmutableOptions...|typ|len|MutableOpt2|
* -----------+-------------------+---+---+-----------+
* ^ ^ ^
* lastp optp optp+2
* <---- optp + 2 - lastp -----><-optlen-2->
* ^
* lastp'
*/
for (optp = p + 2; optp < optend; optp += optlen) {
opt = optp[0];
if (opt == IP6OPT_PAD1) {
optlen = 1;
} else {
if (optp + 2 > optend) {
error = EINVAL; /* malformed option */
goto bad;
}
optlen = optp[1] + 2;
if (opt & IP6OPT_MUTABLE) {
/*
* ICV calc. for the (consecutive)
* immutable field followd by the
* option.
*/
(algo->update)(&algos, lastp,
optp + 2 - lastp);
if (optlen - 2 > ZEROBUFLEN) {
error = EINVAL; /* XXX */
goto bad;
}
/*
* ICV calc. for the mutable
* option using an all-0 buffer.
*/
(algo->update)(&algos, zerobuf,
optlen - 2);
lastp = optp + optlen;
}
}
}
/*
* Wrap up the calulation; compute ICV for the consecutive
* immutable options at the end of the header(if any).
*/
(algo->update)(&algos, lastp, p + hdrlen - lastp);
advancewidth = hdrlen;
break;
}
case IPPROTO_ROUTING:
{
/*
* For an input packet, we can just calculate `as is'.
* For an output packet, we assume ip6_output have already
* made packet how it will be received at the final destination.
* So we'll only check if the header is malformed.
*/
int hdrlen;
tlen = m->m_len - (p - mtod(m, u_char *));
/* We assume all the options is contained in a single mbuf */
if (tlen < sizeof(struct ip6_ext)) {
error = EINVAL;
goto bad;
}
hdrlen = (((struct ip6_ext *)p)->ip6e_len + 1) << 3;
hdrtype = (int)((struct ip6_ext *)p)->ip6e_nxt;
if (tlen < hdrlen) {
error = EINVAL;
goto bad;
}
advancewidth = hdrlen;
(algo->update)(&algos, p, hdrlen);
break;
}
default:
ipseclog((LOG_DEBUG, "ah6_calccksum: unexpected hdrtype=%x; "
"treating rest as payload\n", hdrtype));
/*fall through*/
case IPPROTO_ICMP:
case IPPROTO_IGMP:
case IPPROTO_IPIP:
case IPPROTO_IPV6:
case IPPROTO_ICMPV6:
case IPPROTO_UDP:
case IPPROTO_TCP:
case IPPROTO_ESP:
case IPPROTO_IPCOMP:
while (m) {
tlen = m->m_len - (p - mtod(m, u_char *));
(algo->update)(&algos, p, tlen);
m = m->m_next;
p = m ? mtod(m, u_char *) : NULL;
}
advancewidth = 0; /*loop finished*/
break;
}
if (advancewidth) {
/* is it safe? */
while (m && advancewidth) {
tlen = m->m_len - (p - mtod(m, u_char *));
if (advancewidth < tlen) {
p += advancewidth;
advancewidth = 0;
} else {
advancewidth -= tlen;
m = m->m_next;
if (m)
p = mtod(m, u_char *);
else {
ipseclog((LOG_DEBUG,
"hit the end-of-mbuf...\n"));
p = NULL;
}
}
}
if (m)
goto again;
}
/* for HMAC algorithms... */
(algo->result)(&algos, &sumbuf[0]);
bcopy(&sumbuf[0], ahdat, (*algo->sumsiz)(sav));
return(0);
bad:
return(error);
}
#endif
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