2 * Wired Equivalent Privacy (WEP)
3 * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
15 #include "utils/includes.h"
17 #include "utils/common.h"
18 #include "common/ieee802_11_defs.h"
22 void wep_crypt(u8 *key, u8 *buf, size_t plen)
26 #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
30 for (i = 0; i < 256; i++)
33 for (i = 0; i < 256; i++) {
34 j = (j + S[i] + key[i & 0x0f]) & 0xff;
38 /* Apply RC4 to data */
41 for (k = 0; k < plen; k++) {
43 j = (j + S[i]) & 0xff;
45 *pos ^= S[(S[i] + S[j]) & 0xff];
51 static int try_wep(const u8 *key, size_t key_len, const u8 *data,
52 size_t data_len, u8 *plain)
58 for (i = 0, j = 0; i < sizeof(k); i++) {
65 os_memcpy(plain, data, data_len);
66 wep_crypt(k, plain, data_len);
67 icv = crc32(plain, data_len - 4);
68 rx_icv = WPA_GET_LE32(plain + data_len - 4);
76 u8 * wep_decrypt(struct wlantest *wt, const struct ieee80211_hdr *hdr,
77 const u8 *data, size_t data_len, size_t *decrypted_len)
80 struct wlantest_wep *w;
84 if (dl_list_empty(&wt->wep))
89 plain = os_malloc(data_len - 4);
93 dl_list_for_each(w, &wt->wep, struct wlantest_wep, list) {
94 os_memcpy(key, data, 3);
95 os_memcpy(key + 3, w->key, w->key_len);
96 if (try_wep(key, 3 + w->key_len, data + 4, data_len - 4, plain)
107 *decrypted_len = data_len - 4 - 4;