2 * Wired Equivalent Privacy (WEP)
3 * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
9 #include "utils/includes.h"
11 #include "utils/common.h"
12 #include "common/ieee802_11_defs.h"
16 void wep_crypt(u8 *key, u8 *buf, size_t plen)
20 #define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
24 for (i = 0; i < 256; i++)
27 for (i = 0; i < 256; i++) {
28 j = (j + S[i] + key[i & 0x0f]) & 0xff;
32 /* Apply RC4 to data */
35 for (k = 0; k < plen; k++) {
37 j = (j + S[i]) & 0xff;
39 *pos ^= S[(S[i] + S[j]) & 0xff];
45 static int try_wep(const u8 *key, size_t key_len, const u8 *data,
46 size_t data_len, u8 *plain)
52 for (i = 0, j = 0; i < sizeof(k); i++) {
59 os_memcpy(plain, data, data_len);
60 wep_crypt(k, plain, data_len);
61 icv = crc32(plain, data_len - 4);
62 rx_icv = WPA_GET_LE32(plain + data_len - 4);
70 u8 * wep_decrypt(struct wlantest *wt, const struct ieee80211_hdr *hdr,
71 const u8 *data, size_t data_len, size_t *decrypted_len)
74 struct wlantest_wep *w;
78 if (dl_list_empty(&wt->wep))
83 plain = os_malloc(data_len - 4);
87 dl_list_for_each(w, &wt->wep, struct wlantest_wep, list) {
88 os_memcpy(key, data, 3);
89 os_memcpy(key + 3, w->key, w->key_len);
90 if (try_wep(key, 3 + w->key_len, data + 4, data_len - 4, plain)
101 *decrypted_len = data_len - 4 - 4;