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>
56 /* #define WEP_DEBUG */
58 #include "p80211hdr.h"
59 #include "p80211types.h"
60 #include "p80211msg.h"
61 #include "p80211conv.h"
62 #include "p80211netdev.h"
64 #define WEP_KEY(x) (((x) & 0xC0) >> 6)
66 static const u32 wep_crc32_table[256] = {
67 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
68 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
69 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
70 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
71 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
72 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
73 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
74 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
75 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
76 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
77 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
78 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
79 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
80 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
81 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
82 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
83 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
84 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
85 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
86 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
87 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
88 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
89 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
90 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
91 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
92 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
93 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
94 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
95 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
96 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
97 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
98 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
99 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
100 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
101 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
102 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
103 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
104 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
105 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
106 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
107 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
108 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
109 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
110 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
111 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
112 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
113 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
114 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
115 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
116 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
117 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
121 /* keylen in bytes! */
123 int wep_change_key(wlandevice_t *wlandev, int keynum, u8 *key, int keylen)
127 if (keylen >= MAX_KEYLEN)
133 if (keynum >= NUM_WEPKEYS)
137 printk(KERN_DEBUG "WEP key %d len %d = %*phC\n", keynum, keylen,
141 wlandev->wep_keylens[keynum] = keylen;
142 memcpy(wlandev->wep_keys[keynum], key, keylen);
148 4-byte IV at start of buffer, 4-byte ICV at end of buffer.
149 if successful, buf start is payload begin, length -= 8;
151 int wep_decrypt(wlandevice_t *wlandev, u8 *buf, u32 len, int key_override,
154 u32 i, j, k, crc, keylen;
155 u8 s[256], key[64], c_crc[4];
158 /* Needs to be at least 8 bytes of payload */
162 /* initialize the first bytes of the key from the IV */
166 keyidx = WEP_KEY(iv[3]);
168 if (key_override >= 0)
169 keyidx = key_override;
171 if (keyidx >= NUM_WEPKEYS)
174 keylen = wlandev->wep_keylens[keyidx];
179 /* copy the rest of the key over from the designated key */
180 memcpy(key + 3, wlandev->wep_keys[keyidx], keylen);
182 keylen += 3; /* add in IV bytes */
185 printk(KERN_DEBUG "D %d: %*ph (%d %d) %*phC\n", len, 3, key,
186 keyidx, keylen, 5, key + 3);
189 /* set up the RC4 state */
190 for (i = 0; i < 256; i++)
193 for (i = 0; i < 256; i++) {
194 j = (j + s[i] + key[i % keylen]) & 0xff;
198 /* Apply the RC4 to the data, update the CRC32 */
201 for (k = 0; k < len; k++) {
203 j = (j + s[i]) & 0xff;
205 buf[k] ^= s[(s[i] + s[j]) & 0xff];
206 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
210 /* now let's check the crc */
213 c_crc[2] = crc >> 16;
214 c_crc[3] = crc >> 24;
216 for (k = 0; k < 4; k++) {
218 j = (j + s[i]) & 0xff;
220 if ((c_crc[k] ^ s[(s[i] + s[j]) & 0xff]) != icv[k])
221 return -(4 | (k << 4)); /* ICV mismatch */
227 /* encrypts in-place. */
228 int wep_encrypt(wlandevice_t *wlandev, u8 *buf, u8 *dst, u32 len, int keynum,
231 u32 i, j, k, crc, keylen;
234 /* no point in WEPping an empty frame */
238 /* we need to have a real key.. */
239 if (keynum >= NUM_WEPKEYS)
241 keylen = wlandev->wep_keylens[keynum];
245 /* use a random IV. And skip known weak ones. */
246 get_random_bytes(iv, 3);
247 while ((iv[1] == 0xff) && (iv[0] >= 3) && (iv[0] < keylen))
248 get_random_bytes(iv, 3);
250 iv[3] = (keynum & 0x03) << 6;
256 /* copy the rest of the key over from the designated key */
257 memcpy(key + 3, wlandev->wep_keys[keynum], keylen);
259 keylen += 3; /* add in IV bytes */
262 printk(KERN_DEBUG "E %d (%d/%d %d) %*ph %*phC\n", len,
263 iv[3], keynum, keylen, 3, key, 5, key + 3);
266 /* set up the RC4 state */
267 for (i = 0; i < 256; i++)
270 for (i = 0; i < 256; i++) {
271 j = (j + s[i] + key[i % keylen]) & 0xff;
275 /* Update CRC32 then apply RC4 to the data */
278 for (k = 0; k < len; k++) {
279 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
281 j = (j + s[i]) & 0xff;
283 dst[k] = buf[k] ^ s[(s[i] + s[j]) & 0xff];
287 /* now let's encrypt the crc */
293 for (k = 0; k < 4; k++) {
295 j = (j + s[i]) & 0xff;
297 icv[k] ^= s[(s[i] + s[j]) & 0xff];