freebsd-dev/sys/dev/awi/awi_wep.c
2003-06-28 06:17:26 +00:00

533 lines
12 KiB
C

/* $NetBSD: awi_wep.c,v 1.4 2000/08/14 11:28:03 onoe Exp $ */
/* $FreeBSD$ */
/*
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Atsushi Onoe.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* WEP support framework for the awi driver.
*
* No actual encryption capability is provided here, but any can be added
* to awi_wep_algo table below.
*
* Note that IEEE802.11 specification states WEP uses RC4 with 40bit key,
* which is a proprietary encryption algorithm available under license
* from RSA Data Security Inc. Using another algorithm, includes null
* encryption provided here, the awi driver cannot be able to communicate
* with other stations.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/sockio.h>
#if defined(__FreeBSD__) && __FreeBSD_version >= 400000
#include <sys/bus.h>
#else
#include <sys/device.h>
#endif
#include <net/if.h>
#include <net/if_dl.h>
#ifdef __FreeBSD__
#include <net/ethernet.h>
#include <net/if_arp.h>
#else
#include <net/if_ether.h>
#endif
#include <net/if_media.h>
#include <net80211/ieee80211.h>
#include <machine/cpu.h>
#include <machine/bus.h>
#ifdef __NetBSD__
#include <dev/ic/am79c930reg.h>
#include <dev/ic/am79c930var.h>
#include <dev/ic/awireg.h>
#include <dev/ic/awivar.h>
#include <crypto/arc4/arc4.h>
#endif
#ifdef __FreeBSD__
#include <dev/awi/am79c930reg.h>
#include <dev/awi/am79c930var.h>
#include <dev/awi/awireg.h>
#include <dev/awi/awivar.h>
#include <crypto/rc4/rc4.h>
static __inline int
arc4_ctxlen(void)
{
return sizeof(struct rc4_state);
}
static __inline void
arc4_setkey(void *ctx, u_int8_t *key, int keylen)
{
rc4_init(ctx, key, keylen);
}
static __inline void
arc4_encrypt(void *ctx, u_int8_t *dst, u_int8_t *src, int len)
{
rc4_crypt(ctx, src, dst, len);
}
#endif
static void awi_crc_init(void);
static u_int32_t awi_crc_update(u_int32_t crc, u_int8_t *buf, int len);
static int awi_null_ctxlen(void);
static void awi_null_setkey(void *ctx, u_int8_t *key, int keylen);
static void awi_null_copy(void *ctx, u_int8_t *dst, u_int8_t *src, int len);
/* XXX: the order should be known to wiconfig/user */
static struct awi_wep_algo awi_wep_algo[] = {
/* 0: no wep */
{ "no" }, /* dummy for no wep */
/* 1: normal wep (arc4) */
{ "arc4", arc4_ctxlen, arc4_setkey,
arc4_encrypt, arc4_encrypt },
/* 2: debug wep (null) */
{ "null", awi_null_ctxlen, awi_null_setkey,
awi_null_copy, awi_null_copy },
/* dummy for wep without encryption */
};
int
awi_wep_setnwkey(sc, nwkey)
struct awi_softc *sc;
struct ieee80211_nwkey *nwkey;
{
int i, len, error;
u_int8_t keybuf[AWI_MAX_KEYLEN];
if (nwkey->i_defkid <= 0 ||
nwkey->i_defkid > IEEE80211_WEP_NKID)
return EINVAL;
error = 0;
for (i = 0; i < IEEE80211_WEP_NKID; i++) {
if (nwkey->i_key[i].i_keydat == NULL)
continue;
len = nwkey->i_key[i].i_keylen;
if (len > sizeof(keybuf)) {
error = EINVAL;
break;
}
error = copyin(nwkey->i_key[i].i_keydat, keybuf, len);
if (error)
break;
error = awi_wep_setkey(sc, i, keybuf, len);
if (error)
break;
}
if (error == 0) {
sc->sc_wep_defkid = nwkey->i_defkid - 1;
error = awi_wep_setalgo(sc, nwkey->i_wepon);
if (error == 0 && sc->sc_enabled) {
awi_stop(sc);
error = awi_init(sc);
}
}
return error;
}
int
awi_wep_getnwkey(sc, nwkey)
struct awi_softc *sc;
struct ieee80211_nwkey *nwkey;
{
int i, len, error, suerr;
u_int8_t keybuf[AWI_MAX_KEYLEN];
nwkey->i_wepon = awi_wep_getalgo(sc);
nwkey->i_defkid = sc->sc_wep_defkid + 1;
/* do not show any keys to non-root user */
#ifdef __FreeBSD__
#if __FreeBSD_version < 500028
suerr = suser(curproc);
#else
suerr = suser(curthread);
#endif
#else
suerr = suser(curproc->p_ucred, &curproc->p_acflag);
#endif
error = 0;
for (i = 0; i < IEEE80211_WEP_NKID; i++) {
if (nwkey->i_key[i].i_keydat == NULL)
continue;
if (suerr) {
error = suerr;
break;
}
len = sizeof(keybuf);
error = awi_wep_getkey(sc, i, keybuf, &len);
if (error)
break;
if (nwkey->i_key[i].i_keylen < len) {
error = ENOSPC;
break;
}
nwkey->i_key[i].i_keylen = len;
error = copyout(keybuf, nwkey->i_key[i].i_keydat, len);
if (error)
break;
}
return error;
}
int
awi_wep_getalgo(sc)
struct awi_softc *sc;
{
if (sc->sc_wep_algo == NULL)
return 0;
return sc->sc_wep_algo - awi_wep_algo;
}
int
awi_wep_setalgo(sc, algo)
struct awi_softc *sc;
int algo;
{
struct awi_wep_algo *awa;
int ctxlen;
awi_crc_init(); /* XXX: not belongs here */
if (algo < 0 || algo > sizeof(awi_wep_algo)/sizeof(awi_wep_algo[0]))
return EINVAL;
awa = &awi_wep_algo[algo];
if (awa->awa_name == NULL)
return EINVAL;
if (awa->awa_ctxlen == NULL) {
awa = NULL;
ctxlen = 0;
} else
ctxlen = awa->awa_ctxlen();
if (sc->sc_wep_ctx != NULL) {
free(sc->sc_wep_ctx, M_DEVBUF);
sc->sc_wep_ctx = NULL;
}
if (ctxlen) {
sc->sc_wep_ctx = malloc(ctxlen, M_DEVBUF, M_NOWAIT);
if (sc->sc_wep_ctx == NULL)
return ENOMEM;
}
sc->sc_wep_algo = awa;
return 0;
}
int
awi_wep_setkey(sc, kid, key, keylen)
struct awi_softc *sc;
int kid;
unsigned char *key;
int keylen;
{
if (kid < 0 || kid >= IEEE80211_WEP_NKID)
return EINVAL;
if (keylen < 0 || keylen + IEEE80211_WEP_IVLEN > AWI_MAX_KEYLEN)
return EINVAL;
sc->sc_wep_keylen[kid] = keylen;
if (keylen > 0)
memcpy(sc->sc_wep_key[kid] + IEEE80211_WEP_IVLEN, key, keylen);
return 0;
}
int
awi_wep_getkey(sc, kid, key, keylen)
struct awi_softc *sc;
int kid;
unsigned char *key;
int *keylen;
{
if (kid < 0 || kid >= IEEE80211_WEP_NKID)
return EINVAL;
if (*keylen < sc->sc_wep_keylen[kid])
return ENOSPC;
*keylen = sc->sc_wep_keylen[kid];
if (*keylen > 0)
memcpy(key, sc->sc_wep_key[kid] + IEEE80211_WEP_IVLEN, *keylen);
return 0;
}
struct mbuf *
awi_wep_encrypt(sc, m0, txflag)
struct awi_softc *sc;
struct mbuf *m0;
int txflag;
{
struct mbuf *m, *n, *n0;
struct ieee80211_frame *wh;
struct awi_wep_algo *awa;
int left, len, moff, noff, keylen, kid;
u_int32_t iv, crc;
u_int8_t *key, *ivp;
void *ctx;
u_int8_t crcbuf[IEEE80211_WEP_CRCLEN];
n0 = NULL;
awa = sc->sc_wep_algo;
if (awa == NULL)
goto fail;
ctx = sc->sc_wep_ctx;
m = m0;
left = m->m_pkthdr.len;
MGET(n, M_DONTWAIT, m->m_type);
n0 = n;
if (n == NULL)
goto fail;
M_MOVE_PKTHDR(n, m);
len = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN + IEEE80211_WEP_CRCLEN;
if (txflag) {
n->m_pkthdr.len += len;
} else {
n->m_pkthdr.len -= len;
left -= len;
}
n->m_len = MHLEN;
if (n->m_pkthdr.len >= MINCLSIZE) {
MCLGET(n, M_DONTWAIT);
if (n->m_flags & M_EXT)
n->m_len = n->m_ext.ext_size;
}
len = sizeof(struct ieee80211_frame);
memcpy(mtod(n, caddr_t), mtod(m, caddr_t), len);
left -= len;
moff = len;
noff = len;
if (txflag) {
kid = sc->sc_wep_defkid;
wh = mtod(n, struct ieee80211_frame *);
wh->i_fc[1] |= IEEE80211_FC1_WEP;
iv = random();
/*
* store IV, byte order is not the matter since it's random.
* assuming IEEE80211_WEP_IVLEN is 3
*/
ivp = mtod(n, u_int8_t *) + noff;
ivp[0] = (iv >> 16) & 0xff;
ivp[1] = (iv >> 8) & 0xff;
ivp[2] = iv & 0xff;
ivp[IEEE80211_WEP_IVLEN] = kid << 6; /* pad and keyid */
noff += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
} else {
ivp = mtod(m, u_int8_t *) + moff;
kid = ivp[IEEE80211_WEP_IVLEN] >> 6;
moff += IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN;
}
key = sc->sc_wep_key[kid];
keylen = sc->sc_wep_keylen[kid];
/* assuming IEEE80211_WEP_IVLEN is 3 */
key[0] = ivp[0];
key[1] = ivp[1];
key[2] = ivp[2];
awa->awa_setkey(ctx, key, IEEE80211_WEP_IVLEN + keylen);
/* encrypt with calculating CRC */
crc = ~0;
while (left > 0) {
len = m->m_len - moff;
if (len == 0) {
m = m->m_next;
moff = 0;
continue;
}
if (len > n->m_len - noff) {
len = n->m_len - noff;
if (len == 0) {
MGET(n->m_next, M_DONTWAIT, n->m_type);
if (n->m_next == NULL)
goto fail;
n = n->m_next;
n->m_len = MLEN;
if (left >= MINCLSIZE) {
MCLGET(n, M_DONTWAIT);
if (n->m_flags & M_EXT)
n->m_len = n->m_ext.ext_size;
}
noff = 0;
continue;
}
}
if (len > left)
len = left;
if (txflag) {
awa->awa_encrypt(ctx, mtod(n, caddr_t) + noff,
mtod(m, caddr_t) + moff, len);
crc = awi_crc_update(crc, mtod(m, caddr_t) + moff, len);
} else {
awa->awa_decrypt(ctx, mtod(n, caddr_t) + noff,
mtod(m, caddr_t) + moff, len);
crc = awi_crc_update(crc, mtod(n, caddr_t) + noff, len);
}
left -= len;
moff += len;
noff += len;
}
crc = ~crc;
if (txflag) {
LE_WRITE_4(crcbuf, crc);
if (n->m_len >= noff + sizeof(crcbuf))
n->m_len = noff + sizeof(crcbuf);
else {
n->m_len = noff;
MGET(n->m_next, M_DONTWAIT, n->m_type);
if (n->m_next == NULL)
goto fail;
n = n->m_next;
n->m_len = sizeof(crcbuf);
noff = 0;
}
awa->awa_encrypt(ctx, mtod(n, caddr_t) + noff, crcbuf,
sizeof(crcbuf));
} else {
n->m_len = noff;
for (noff = 0; noff < sizeof(crcbuf); noff += len) {
len = sizeof(crcbuf) - noff;
if (len > m->m_len - moff)
len = m->m_len - moff;
if (len > 0)
awa->awa_decrypt(ctx, crcbuf + noff,
mtod(m, caddr_t) + moff, len);
m = m->m_next;
moff = 0;
}
if (crc != LE_READ_4(crcbuf))
goto fail;
}
m_freem(m0);
return n0;
fail:
m_freem(m0);
m_freem(n0);
return NULL;
}
/*
* CRC 32 -- routine from RFC 2083
*/
/* Table of CRCs of all 8-bit messages */
static u_int32_t awi_crc_table[256];
static int awi_crc_table_computed = 0;
/* Make the table for a fast CRC. */
static void
awi_crc_init()
{
u_int32_t c;
int n, k;
if (awi_crc_table_computed)
return;
for (n = 0; n < 256; n++) {
c = (u_int32_t)n;
for (k = 0; k < 8; k++) {
if (c & 1)
c = 0xedb88320UL ^ (c >> 1);
else
c = c >> 1;
}
awi_crc_table[n] = c;
}
awi_crc_table_computed = 1;
}
/*
* Update a running CRC with the bytes buf[0..len-1]--the CRC
* should be initialized to all 1's, and the transmitted value
* is the 1's complement of the final running CRC
*/
static u_int32_t
awi_crc_update(crc, buf, len)
u_int32_t crc;
u_int8_t *buf;
int len;
{
u_int8_t *endbuf;
for (endbuf = buf + len; buf < endbuf; buf++)
crc = awi_crc_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
return crc;
}
/*
* Null -- do nothing but copy.
*/
static int
awi_null_ctxlen()
{
return 0;
}
static void
awi_null_setkey(ctx, key, keylen)
void *ctx;
u_char *key;
int keylen;
{
}
static void
awi_null_copy(ctx, dst, src, len)
void *ctx;
u_char *dst;
u_char *src;
int len;
{
memcpy(dst, src, len);
}