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>
55 #include "p80211hdr.h"
56 #include "p80211types.h"
57 #include "p80211msg.h"
58 #include "p80211conv.h"
59 #include "p80211netdev.h"
61 #define WEP_KEY(x) (((x) & 0xC0) >> 6)
63 static const u32 wep_crc32_table[256] = {
64 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
65 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
66 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
67 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
68 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
69 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
70 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
71 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
72 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
73 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
74 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
75 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
76 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
77 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
78 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
79 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
80 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
81 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
82 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
83 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
84 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
85 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
86 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
87 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
88 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
89 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
90 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
91 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
92 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
93 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
94 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
95 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
96 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
97 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
98 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
99 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
100 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
101 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
102 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
103 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
104 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
105 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
106 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
107 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
108 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
109 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
110 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
111 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
112 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
113 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
114 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
118 /* keylen in bytes! */
120 int wep_change_key(struct wlandevice *wlandev, int keynum, u8 *key, int keylen)
124 if (keylen >= MAX_KEYLEN)
130 if (keynum >= NUM_WEPKEYS)
133 wlandev->wep_keylens[keynum] = keylen;
134 memcpy(wlandev->wep_keys[keynum], key, keylen);
140 * 4-byte IV at start of buffer, 4-byte ICV at end of buffer.
141 * if successful, buf start is payload begin, length -= 8;
143 int wep_decrypt(struct wlandevice *wlandev, u8 *buf, u32 len, int key_override,
146 u32 i, j, k, crc, keylen;
147 u8 s[256], key[64], c_crc[4];
150 /* Needs to be at least 8 bytes of payload */
154 /* initialize the first bytes of the key from the IV */
158 keyidx = WEP_KEY(iv[3]);
160 if (key_override >= 0)
161 keyidx = key_override;
163 if (keyidx >= NUM_WEPKEYS)
166 keylen = wlandev->wep_keylens[keyidx];
171 /* copy the rest of the key over from the designated key */
172 memcpy(key + 3, wlandev->wep_keys[keyidx], keylen);
174 keylen += 3; /* add in IV bytes */
176 /* set up the RC4 state */
177 for (i = 0; i < 256; i++)
180 for (i = 0; i < 256; i++) {
181 j = (j + s[i] + key[i % keylen]) & 0xff;
185 /* Apply the RC4 to the data, update the CRC32 */
189 for (k = 0; k < len; k++) {
191 j = (j + s[i]) & 0xff;
193 buf[k] ^= s[(s[i] + s[j]) & 0xff];
194 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
198 /* now let's check the crc */
201 c_crc[2] = crc >> 16;
202 c_crc[3] = crc >> 24;
204 for (k = 0; k < 4; k++) {
206 j = (j + s[i]) & 0xff;
208 if ((c_crc[k] ^ s[(s[i] + s[j]) & 0xff]) != icv[k])
209 return -(4 | (k << 4)); /* ICV mismatch */
215 /* encrypts in-place. */
216 int wep_encrypt(struct wlandevice *wlandev, u8 *buf,
217 u8 *dst, u32 len, int keynum, u8 *iv, u8 *icv)
219 u32 i, j, k, crc, keylen;
222 /* no point in WEPping an empty frame */
226 /* we need to have a real key.. */
227 if (keynum >= NUM_WEPKEYS)
229 keylen = wlandev->wep_keylens[keynum];
233 /* use a random IV. And skip known weak ones. */
234 get_random_bytes(iv, 3);
235 while ((iv[1] == 0xff) && (iv[0] >= 3) && (iv[0] < keylen))
236 get_random_bytes(iv, 3);
238 iv[3] = (keynum & 0x03) << 6;
244 /* copy the rest of the key over from the designated key */
245 memcpy(key + 3, wlandev->wep_keys[keynum], keylen);
247 keylen += 3; /* add in IV bytes */
249 /* set up the RC4 state */
250 for (i = 0; i < 256; i++)
253 for (i = 0; i < 256; i++) {
254 j = (j + s[i] + key[i % keylen]) & 0xff;
258 /* Update CRC32 then apply RC4 to the data */
262 for (k = 0; k < len; k++) {
263 crc = wep_crc32_table[(crc ^ buf[k]) & 0xff] ^ (crc >> 8);
265 j = (j + s[i]) & 0xff;
267 dst[k] = buf[k] ^ s[(s[i] + s[j]) & 0xff];
271 /* now let's encrypt the crc */
277 for (k = 0; k < 4; k++) {
279 j = (j + s[i]) & 0xff;
281 icv[k] ^= s[(s[i] + s[j]) & 0xff];