mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-22 11:17:19 +00:00
68e8e04e93
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing
Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.
477 lines
14 KiB
C
477 lines
14 KiB
C
/*-
|
|
* Copyright (c) 2002-2007 Sam Leffler, Errno Consulting
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
/*
|
|
* IEEE 802.11 WEP crypto support.
|
|
*/
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/module.h>
|
|
#include <sys/endian.h>
|
|
|
|
#include <sys/socket.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_media.h>
|
|
#include <net/ethernet.h>
|
|
|
|
#include <net80211/ieee80211_var.h>
|
|
|
|
static void *wep_attach(struct ieee80211com *, struct ieee80211_key *);
|
|
static void wep_detach(struct ieee80211_key *);
|
|
static int wep_setkey(struct ieee80211_key *);
|
|
static int wep_encap(struct ieee80211_key *, struct mbuf *, uint8_t keyid);
|
|
static int wep_decap(struct ieee80211_key *, struct mbuf *, int hdrlen);
|
|
static int wep_enmic(struct ieee80211_key *, struct mbuf *, int);
|
|
static int wep_demic(struct ieee80211_key *, struct mbuf *, int);
|
|
|
|
static const struct ieee80211_cipher wep = {
|
|
.ic_name = "WEP",
|
|
.ic_cipher = IEEE80211_CIPHER_WEP,
|
|
.ic_header = IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN,
|
|
.ic_trailer = IEEE80211_WEP_CRCLEN,
|
|
.ic_miclen = 0,
|
|
.ic_attach = wep_attach,
|
|
.ic_detach = wep_detach,
|
|
.ic_setkey = wep_setkey,
|
|
.ic_encap = wep_encap,
|
|
.ic_decap = wep_decap,
|
|
.ic_enmic = wep_enmic,
|
|
.ic_demic = wep_demic,
|
|
};
|
|
|
|
static int wep_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
|
|
static int wep_decrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
|
|
|
|
struct wep_ctx {
|
|
struct ieee80211com *wc_ic; /* for diagnostics */
|
|
uint32_t wc_iv; /* initial vector for crypto */
|
|
};
|
|
|
|
/* number of references from net80211 layer */
|
|
static int nrefs = 0;
|
|
|
|
static void *
|
|
wep_attach(struct ieee80211com *ic, struct ieee80211_key *k)
|
|
{
|
|
struct wep_ctx *ctx;
|
|
|
|
MALLOC(ctx, struct wep_ctx *, sizeof(struct wep_ctx),
|
|
M_DEVBUF, M_NOWAIT | M_ZERO);
|
|
if (ctx == NULL) {
|
|
ic->ic_stats.is_crypto_nomem++;
|
|
return NULL;
|
|
}
|
|
|
|
ctx->wc_ic = ic;
|
|
get_random_bytes(&ctx->wc_iv, sizeof(ctx->wc_iv));
|
|
nrefs++; /* NB: we assume caller locking */
|
|
return ctx;
|
|
}
|
|
|
|
static void
|
|
wep_detach(struct ieee80211_key *k)
|
|
{
|
|
struct wep_ctx *ctx = k->wk_private;
|
|
|
|
FREE(ctx, M_DEVBUF);
|
|
KASSERT(nrefs > 0, ("imbalanced attach/detach"));
|
|
nrefs--; /* NB: we assume caller locking */
|
|
}
|
|
|
|
static int
|
|
wep_setkey(struct ieee80211_key *k)
|
|
{
|
|
return k->wk_keylen >= 40/NBBY;
|
|
}
|
|
|
|
/*
|
|
* Add privacy headers appropriate for the specified key.
|
|
*/
|
|
static int
|
|
wep_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid)
|
|
{
|
|
struct wep_ctx *ctx = k->wk_private;
|
|
struct ieee80211com *ic = ctx->wc_ic;
|
|
uint32_t iv;
|
|
uint8_t *ivp;
|
|
int hdrlen;
|
|
|
|
hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
|
|
|
|
/*
|
|
* Copy down 802.11 header and add the IV + KeyID.
|
|
*/
|
|
M_PREPEND(m, wep.ic_header, M_NOWAIT);
|
|
if (m == NULL)
|
|
return 0;
|
|
ivp = mtod(m, uint8_t *);
|
|
ovbcopy(ivp + wep.ic_header, ivp, hdrlen);
|
|
ivp += hdrlen;
|
|
|
|
/*
|
|
* XXX
|
|
* IV must not duplicate during the lifetime of the key.
|
|
* But no mechanism to renew keys is defined in IEEE 802.11
|
|
* for WEP. And the IV may be duplicated at other stations
|
|
* because the session key itself is shared. So we use a
|
|
* pseudo random IV for now, though it is not the right way.
|
|
*
|
|
* NB: Rather than use a strictly random IV we select a
|
|
* random one to start and then increment the value for
|
|
* each frame. This is an explicit tradeoff between
|
|
* overhead and security. Given the basic insecurity of
|
|
* WEP this seems worthwhile.
|
|
*/
|
|
|
|
/*
|
|
* Skip 'bad' IVs from Fluhrer/Mantin/Shamir:
|
|
* (B, 255, N) with 3 <= B < 16 and 0 <= N <= 255
|
|
*/
|
|
iv = ctx->wc_iv;
|
|
if ((iv & 0xff00) == 0xff00) {
|
|
int B = (iv & 0xff0000) >> 16;
|
|
if (3 <= B && B < 16)
|
|
iv += 0x0100;
|
|
}
|
|
ctx->wc_iv = iv + 1;
|
|
|
|
/*
|
|
* NB: Preserve byte order of IV for packet
|
|
* sniffers; it doesn't matter otherwise.
|
|
*/
|
|
#if _BYTE_ORDER == _BIG_ENDIAN
|
|
ivp[0] = iv >> 0;
|
|
ivp[1] = iv >> 8;
|
|
ivp[2] = iv >> 16;
|
|
#else
|
|
ivp[2] = iv >> 0;
|
|
ivp[1] = iv >> 8;
|
|
ivp[0] = iv >> 16;
|
|
#endif
|
|
ivp[3] = keyid;
|
|
|
|
/*
|
|
* Finally, do software encrypt if neeed.
|
|
*/
|
|
if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
|
|
!wep_encrypt(k, m, hdrlen))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Add MIC to the frame as needed.
|
|
*/
|
|
static int
|
|
wep_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
|
|
{
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Validate and strip privacy headers (and trailer) for a
|
|
* received frame. If necessary, decrypt the frame using
|
|
* the specified key.
|
|
*/
|
|
static int
|
|
wep_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
|
|
{
|
|
struct wep_ctx *ctx = k->wk_private;
|
|
struct ieee80211_frame *wh;
|
|
|
|
wh = mtod(m, struct ieee80211_frame *);
|
|
|
|
/*
|
|
* Check if the device handled the decrypt in hardware.
|
|
* If so we just strip the header; otherwise we need to
|
|
* handle the decrypt in software.
|
|
*/
|
|
if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
|
|
!wep_decrypt(k, m, hdrlen)) {
|
|
IEEE80211_DPRINTF(ctx->wc_ic, IEEE80211_MSG_CRYPTO,
|
|
"[%s] WEP ICV mismatch on decrypt\n",
|
|
ether_sprintf(wh->i_addr2));
|
|
ctx->wc_ic->ic_stats.is_rx_wepfail++;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy up 802.11 header and strip crypto bits.
|
|
*/
|
|
ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + wep.ic_header, hdrlen);
|
|
m_adj(m, wep.ic_header);
|
|
m_adj(m, -wep.ic_trailer);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Verify and strip MIC from the frame.
|
|
*/
|
|
static int
|
|
wep_demic(struct ieee80211_key *k, struct mbuf *skb, int force)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static const uint32_t crc32_table[256] = {
|
|
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
|
|
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
|
|
0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
|
|
0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
|
|
0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
|
|
0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
|
|
0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
|
|
0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
|
|
0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
|
|
0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
|
|
0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
|
|
0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
|
|
0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
|
|
0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
|
|
0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
|
|
0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
|
|
0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
|
|
0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
|
|
0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
|
|
0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
|
|
0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
|
|
0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
|
|
0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
|
|
0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
|
|
0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
|
|
0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
|
|
0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
|
|
0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
|
|
0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
|
|
0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
|
|
0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
|
|
0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
|
|
0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
|
|
0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
|
|
0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
|
|
0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
|
|
0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
|
|
0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
|
|
0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
|
|
0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
|
|
0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
|
|
0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
|
|
0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
|
|
0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
|
|
0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
|
|
0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
|
|
0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
|
|
0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
|
|
0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
|
|
0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
|
|
0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
|
|
0x2d02ef8dL
|
|
};
|
|
|
|
static int
|
|
wep_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
|
|
{
|
|
#define S_SWAP(a,b) do { uint8_t t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
|
|
struct wep_ctx *ctx = key->wk_private;
|
|
struct mbuf *m = m0;
|
|
uint8_t rc4key[IEEE80211_WEP_IVLEN + IEEE80211_KEYBUF_SIZE];
|
|
uint8_t icv[IEEE80211_WEP_CRCLEN];
|
|
uint32_t i, j, k, crc;
|
|
size_t buflen, data_len;
|
|
uint8_t S[256];
|
|
uint8_t *pos;
|
|
u_int off, keylen;
|
|
|
|
ctx->wc_ic->ic_stats.is_crypto_wep++;
|
|
|
|
/* NB: this assumes the header was pulled up */
|
|
memcpy(rc4key, mtod(m, uint8_t *) + hdrlen, IEEE80211_WEP_IVLEN);
|
|
memcpy(rc4key + IEEE80211_WEP_IVLEN, key->wk_key, key->wk_keylen);
|
|
|
|
/* Setup RC4 state */
|
|
for (i = 0; i < 256; i++)
|
|
S[i] = i;
|
|
j = 0;
|
|
keylen = key->wk_keylen + IEEE80211_WEP_IVLEN;
|
|
for (i = 0; i < 256; i++) {
|
|
j = (j + S[i] + rc4key[i % keylen]) & 0xff;
|
|
S_SWAP(i, j);
|
|
}
|
|
|
|
off = hdrlen + wep.ic_header;
|
|
data_len = m->m_pkthdr.len - off;
|
|
|
|
/* Compute CRC32 over unencrypted data and apply RC4 to data */
|
|
crc = ~0;
|
|
i = j = 0;
|
|
pos = mtod(m, uint8_t *) + off;
|
|
buflen = m->m_len - off;
|
|
for (;;) {
|
|
if (buflen > data_len)
|
|
buflen = data_len;
|
|
data_len -= buflen;
|
|
for (k = 0; k < buflen; k++) {
|
|
crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
|
|
i = (i + 1) & 0xff;
|
|
j = (j + S[i]) & 0xff;
|
|
S_SWAP(i, j);
|
|
*pos++ ^= S[(S[i] + S[j]) & 0xff];
|
|
}
|
|
if (m->m_next == NULL) {
|
|
if (data_len != 0) { /* out of data */
|
|
IEEE80211_DPRINTF(ctx->wc_ic,
|
|
IEEE80211_MSG_CRYPTO,
|
|
"[%s] out of data for WEP (data_len %zu)\n",
|
|
ether_sprintf(mtod(m0,
|
|
struct ieee80211_frame *)->i_addr2),
|
|
data_len);
|
|
return 0;
|
|
}
|
|
break;
|
|
}
|
|
m = m->m_next;
|
|
pos = mtod(m, uint8_t *);
|
|
buflen = m->m_len;
|
|
}
|
|
crc = ~crc;
|
|
|
|
/* Append little-endian CRC32 and encrypt it to produce ICV */
|
|
icv[0] = crc;
|
|
icv[1] = crc >> 8;
|
|
icv[2] = crc >> 16;
|
|
icv[3] = crc >> 24;
|
|
for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) {
|
|
i = (i + 1) & 0xff;
|
|
j = (j + S[i]) & 0xff;
|
|
S_SWAP(i, j);
|
|
icv[k] ^= S[(S[i] + S[j]) & 0xff];
|
|
}
|
|
return m_append(m0, IEEE80211_WEP_CRCLEN, icv);
|
|
#undef S_SWAP
|
|
}
|
|
|
|
static int
|
|
wep_decrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
|
|
{
|
|
#define S_SWAP(a,b) do { uint8_t t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
|
|
struct wep_ctx *ctx = key->wk_private;
|
|
struct mbuf *m = m0;
|
|
uint8_t rc4key[IEEE80211_WEP_IVLEN + IEEE80211_KEYBUF_SIZE];
|
|
uint8_t icv[IEEE80211_WEP_CRCLEN];
|
|
uint32_t i, j, k, crc;
|
|
size_t buflen, data_len;
|
|
uint8_t S[256];
|
|
uint8_t *pos;
|
|
u_int off, keylen;
|
|
|
|
ctx->wc_ic->ic_stats.is_crypto_wep++;
|
|
|
|
/* NB: this assumes the header was pulled up */
|
|
memcpy(rc4key, mtod(m, uint8_t *) + hdrlen, IEEE80211_WEP_IVLEN);
|
|
memcpy(rc4key + IEEE80211_WEP_IVLEN, key->wk_key, key->wk_keylen);
|
|
|
|
/* Setup RC4 state */
|
|
for (i = 0; i < 256; i++)
|
|
S[i] = i;
|
|
j = 0;
|
|
keylen = key->wk_keylen + IEEE80211_WEP_IVLEN;
|
|
for (i = 0; i < 256; i++) {
|
|
j = (j + S[i] + rc4key[i % keylen]) & 0xff;
|
|
S_SWAP(i, j);
|
|
}
|
|
|
|
off = hdrlen + wep.ic_header;
|
|
data_len = m->m_pkthdr.len - (off + wep.ic_trailer),
|
|
|
|
/* Compute CRC32 over unencrypted data and apply RC4 to data */
|
|
crc = ~0;
|
|
i = j = 0;
|
|
pos = mtod(m, uint8_t *) + off;
|
|
buflen = m->m_len - off;
|
|
for (;;) {
|
|
if (buflen > data_len)
|
|
buflen = data_len;
|
|
data_len -= buflen;
|
|
for (k = 0; k < buflen; k++) {
|
|
i = (i + 1) & 0xff;
|
|
j = (j + S[i]) & 0xff;
|
|
S_SWAP(i, j);
|
|
*pos ^= S[(S[i] + S[j]) & 0xff];
|
|
crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
|
|
pos++;
|
|
}
|
|
m = m->m_next;
|
|
if (m == NULL) {
|
|
if (data_len != 0) { /* out of data */
|
|
IEEE80211_DPRINTF(ctx->wc_ic,
|
|
IEEE80211_MSG_CRYPTO,
|
|
"[%s] out of data for WEP (data_len %zu)\n",
|
|
ether_sprintf(mtod(m0,
|
|
struct ieee80211_frame *)->i_addr2),
|
|
data_len);
|
|
return 0;
|
|
}
|
|
break;
|
|
}
|
|
pos = mtod(m, uint8_t *);
|
|
buflen = m->m_len;
|
|
}
|
|
crc = ~crc;
|
|
|
|
/* Encrypt little-endian CRC32 and verify that it matches with
|
|
* received ICV */
|
|
icv[0] = crc;
|
|
icv[1] = crc >> 8;
|
|
icv[2] = crc >> 16;
|
|
icv[3] = crc >> 24;
|
|
for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) {
|
|
i = (i + 1) & 0xff;
|
|
j = (j + S[i]) & 0xff;
|
|
S_SWAP(i, j);
|
|
/* XXX assumes ICV is contiguous in mbuf */
|
|
if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) {
|
|
/* ICV mismatch - drop frame */
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
#undef S_SWAP
|
|
}
|
|
|
|
/*
|
|
* Module glue.
|
|
*/
|
|
IEEE80211_CRYPTO_MODULE(wep, 1);
|