1 /* src/p80211/p80211wep.c
3 * WEP encode/decode for P80211.
5 * Copyright (C) 2002 AbsoluteValue Systems, Inc. All Rights Reserved.
6 * --------------------------------------------------------------------
10 * The contents of this file are subject to the Mozilla Public
11 * License Version 1.1 (the "License"); you may not use this file
12 * except in compliance with the License. You may obtain a copy of
13 * the License at http://www.mozilla.org/MPL/
15 * Software distributed under the License is distributed on an "AS
16 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17 * implied. See the License for the specific language governing
18 * rights and limitations under the License.
20 * Alternatively, the contents of this file may be used under the
21 * terms of the GNU Public License version 2 (the "GPL"), in which
22 * case the provisions of the GPL are applicable instead of the
23 * above. If you wish to allow the use of your version of this file
24 * only under the terms of the GPL and not to allow others to use
25 * your version of this file under the MPL, indicate your decision
26 * by deleting the provisions above and replace them with the notice
27 * and other provisions required by the GPL. If you do not delete
28 * the provisions above, a recipient may use your version of this
29 * file under either the MPL or the GPL.
31 * --------------------------------------------------------------------
33 * Inquiries regarding the linux-wlan Open Source project can be
36 * AbsoluteValue Systems Inc.
38 * http://www.linux-wlan.com
40 * --------------------------------------------------------------------
42 * Portions of the development of this software were funded by
43 * Intersil Corporation as part of PRISM(R) chipset product development.
45 * --------------------------------------------------------------------
48 /*================================================================*/
51 #include <linux/netdevice.h>
52 #include <linux/wireless.h>
53 #include <linux/random.h>
54 #include <linux/kernel.h>
57 #include "p80211hdr.h"
58 #include "p80211types.h"
59 #include "p80211msg.h"
60 #include "p80211conv.h"
61 #include "p80211netdev.h"
63 #define WEP_KEY(x) (((x) & 0xC0) >> 6)
65 static const u32 wep_crc32_table[256] = {
66 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
67 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
68 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
69 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
70 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
71 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
72 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
73 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
74 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
75 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
76 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
77 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
78 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
79 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
80 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
81 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
82 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
83 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
84 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
85 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
86 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
87 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
88 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
89 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
90 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
91 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
92 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
93 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
94 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
95 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
96 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
97 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
98 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
99 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
100 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
101 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
102 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
103 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
104 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
105 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
106 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
107 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
108 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
109 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
110 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
111 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
112 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
113 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
114 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
115 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
116 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
120 /* keylen in bytes! */
122 int wep_change_key(wlandevice_t *wlandev, int keynum, u8 *key, int keylen)
126 if (keylen >= MAX_KEYLEN)
132 if (keynum >= NUM_WEPKEYS)
136 wlandev->wep_keylens[keynum] = keylen;
137 memcpy(wlandev->wep_keys[keynum], key, keylen);
143 4-byte IV at start of buffer, 4-byte ICV at end of buffer.
144 if successful, buf start is payload begin, length -= 8;
146 int wep_decrypt(wlandevice_t *wlandev, u8 *buf, u32 len, int key_override,
149 u32 i, j, k, crc, keylen;
150 u8 s[256], key[64], c_crc[4];
153 /* Needs to be at least 8 bytes of payload */
157 /* initialize the first bytes of the key from the IV */
161 keyidx = WEP_KEY(iv[3]);
163 if (key_override >= 0)
164 keyidx = key_override;
166 if (keyidx >= NUM_WEPKEYS)
169 keylen = wlandev->wep_keylens[keyidx];
174 /* copy the rest of the key over from the designated key */
175 memcpy(key + 3, wlandev->wep_keys[keyidx], keylen);
177 keylen += 3; /* add in IV bytes */
180 /* set up the RC4 state */
181 for (i = 0; i < 256; i++)
184 for (i = 0; i < 256; i++) {
185 j = (j + s[i] + key[i % keylen]) & 0xff;
189 /* Apply the RC4 to the data, update the CRC32 */
192 for (k = 0; k < len; k++) {
194 j = (j + s[i]) & 0xff;
196 buf[k] ^= s[(s[i] + s[j]) & 0xff];
197 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
201 /* now let's check the crc */
204 c_crc[2] = crc >> 16;
205 c_crc[3] = crc >> 24;
207 for (k = 0; k < 4; k++) {
209 j = (j + s[i]) & 0xff;
211 if ((c_crc[k] ^ s[(s[i] + s[j]) & 0xff]) != icv[k])
212 return -(4 | (k << 4)); /* ICV mismatch */
218 /* encrypts in-place. */
219 int wep_encrypt(wlandevice_t *wlandev, u8 *buf, u8 *dst, u32 len, int keynum,
222 u32 i, j, k, crc, keylen;
225 /* no point in WEPping an empty frame */
229 /* we need to have a real key.. */
230 if (keynum >= NUM_WEPKEYS)
232 keylen = wlandev->wep_keylens[keynum];
236 /* use a random IV. And skip known weak ones. */
237 get_random_bytes(iv, 3);
238 while ((iv[1] == 0xff) && (iv[0] >= 3) && (iv[0] < keylen))
239 get_random_bytes(iv, 3);
241 iv[3] = (keynum & 0x03) << 6;
247 /* copy the rest of the key over from the designated key */
248 memcpy(key + 3, wlandev->wep_keys[keynum], keylen);
250 keylen += 3; /* add in IV bytes */
252 /* set up the RC4 state */
253 for (i = 0; i < 256; i++)
256 for (i = 0; i < 256; i++) {
257 j = (j + s[i] + key[i % keylen]) & 0xff;
261 /* Update CRC32 then apply RC4 to the data */
264 for (k = 0; k < len; k++) {
265 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
267 j = (j + s[i]) & 0xff;
269 dst[k] = buf[k] ^ s[(s[i] + s[j]) & 0xff];
273 /* now let's encrypt the crc */
279 for (k = 0; k < 4; k++) {
281 j = (j + s[i]) & 0xff;
283 icv[k] ^= s[(s[i] + s[j]) & 0xff];