blob: dddbfd60f35148e790a46d80db2ae70821f7850e [file] [log] [blame]
Jiri Bencf0706e82007-05-05 11:45:53 -07001/*
2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
4 *
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.
8 */
9
10#include <linux/kernel.h>
11#include <linux/types.h>
12#include <linux/netdevice.h>
13
14#include <net/mac80211.h>
Johannes Berg2c8dccc2008-04-08 15:14:40 -040015#include "key.h"
Jiri Bencf0706e82007-05-05 11:45:53 -070016#include "tkip.h"
17#include "wep.h"
18
19
20/* TKIP key mixing functions */
21
22
23#define PHASE1_LOOP_COUNT 8
24
25
26/* 2-byte by 2-byte subset of the full AES S-box table; second part of this
27 * table is identical to first part but byte-swapped */
28static const u16 tkip_sbox[256] =
29{
30 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
31 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
32 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
33 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
34 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
35 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
36 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
37 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
38 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
39 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
40 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
41 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
42 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
43 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
44 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
45 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
46 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
47 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
48 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
49 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
50 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
51 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
52 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
53 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
54 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
55 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
56 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
57 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
58 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
59 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
60 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
61 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
62};
63
64
65static inline u16 Mk16(u8 x, u8 y)
66{
67 return ((u16) x << 8) | (u16) y;
68}
69
70
71static inline u8 Hi8(u16 v)
72{
73 return v >> 8;
74}
75
76
77static inline u8 Lo8(u16 v)
78{
79 return v & 0xff;
80}
81
82
83static inline u16 Hi16(u32 v)
84{
85 return v >> 16;
86}
87
88
89static inline u16 Lo16(u32 v)
90{
91 return v & 0xffff;
92}
93
94
95static inline u16 RotR1(u16 v)
96{
97 return (v >> 1) | ((v & 0x0001) << 15);
98}
99
100
101static inline u16 tkip_S(u16 val)
102{
103 u16 a = tkip_sbox[Hi8(val)];
104
105 return tkip_sbox[Lo8(val)] ^ Hi8(a) ^ (Lo8(a) << 8);
106}
107
108
109
110/* P1K := Phase1(TA, TK, TSC)
111 * TA = transmitter address (48 bits)
112 * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits)
113 * TSC = TKIP sequence counter (48 bits, only 32 msb bits used)
114 * P1K: 80 bits
115 */
116static void tkip_mixing_phase1(const u8 *ta, const u8 *tk, u32 tsc_IV32,
117 u16 *p1k)
118{
119 int i, j;
120
121 p1k[0] = Lo16(tsc_IV32);
122 p1k[1] = Hi16(tsc_IV32);
123 p1k[2] = Mk16(ta[1], ta[0]);
124 p1k[3] = Mk16(ta[3], ta[2]);
125 p1k[4] = Mk16(ta[5], ta[4]);
126
127 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
128 j = 2 * (i & 1);
129 p1k[0] += tkip_S(p1k[4] ^ Mk16(tk[ 1 + j], tk[ 0 + j]));
130 p1k[1] += tkip_S(p1k[0] ^ Mk16(tk[ 5 + j], tk[ 4 + j]));
131 p1k[2] += tkip_S(p1k[1] ^ Mk16(tk[ 9 + j], tk[ 8 + j]));
132 p1k[3] += tkip_S(p1k[2] ^ Mk16(tk[13 + j], tk[12 + j]));
133 p1k[4] += tkip_S(p1k[3] ^ Mk16(tk[ 1 + j], tk[ 0 + j])) + i;
134 }
135}
136
137
138static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16,
139 u8 *rc4key)
140{
141 u16 ppk[6];
142 int i;
143
144 ppk[0] = p1k[0];
145 ppk[1] = p1k[1];
146 ppk[2] = p1k[2];
147 ppk[3] = p1k[3];
148 ppk[4] = p1k[4];
149 ppk[5] = p1k[4] + tsc_IV16;
150
151 ppk[0] += tkip_S(ppk[5] ^ Mk16(tk[ 1], tk[ 0]));
152 ppk[1] += tkip_S(ppk[0] ^ Mk16(tk[ 3], tk[ 2]));
153 ppk[2] += tkip_S(ppk[1] ^ Mk16(tk[ 5], tk[ 4]));
154 ppk[3] += tkip_S(ppk[2] ^ Mk16(tk[ 7], tk[ 6]));
155 ppk[4] += tkip_S(ppk[3] ^ Mk16(tk[ 9], tk[ 8]));
156 ppk[5] += tkip_S(ppk[4] ^ Mk16(tk[11], tk[10]));
157 ppk[0] += RotR1(ppk[5] ^ Mk16(tk[13], tk[12]));
158 ppk[1] += RotR1(ppk[0] ^ Mk16(tk[15], tk[14]));
159 ppk[2] += RotR1(ppk[1]);
160 ppk[3] += RotR1(ppk[2]);
161 ppk[4] += RotR1(ppk[3]);
162 ppk[5] += RotR1(ppk[4]);
163
164 rc4key[0] = Hi8(tsc_IV16);
165 rc4key[1] = (Hi8(tsc_IV16) | 0x20) & 0x7f;
166 rc4key[2] = Lo8(tsc_IV16);
167 rc4key[3] = Lo8((ppk[5] ^ Mk16(tk[1], tk[0])) >> 1);
168
169 for (i = 0; i < 6; i++) {
170 rc4key[4 + 2 * i] = Lo8(ppk[i]);
171 rc4key[5 + 2 * i] = Hi8(ppk[i]);
172 }
173}
174
175
176/* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets
177 * of the IV. Returns pointer to the octet following IVs (i.e., beginning of
178 * the packet payload). */
179u8 * ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key,
180 u8 iv0, u8 iv1, u8 iv2)
181{
182 *pos++ = iv0;
183 *pos++ = iv1;
184 *pos++ = iv2;
Johannes Berg8f20fc22007-08-28 17:01:54 -0400185 *pos++ = (key->conf.keyidx << 6) | (1 << 5) /* Ext IV */;
Jiri Bencf0706e82007-05-05 11:45:53 -0700186 *pos++ = key->u.tkip.iv32 & 0xff;
187 *pos++ = (key->u.tkip.iv32 >> 8) & 0xff;
188 *pos++ = (key->u.tkip.iv32 >> 16) & 0xff;
189 *pos++ = (key->u.tkip.iv32 >> 24) & 0xff;
190 return pos;
191}
192
193
194void ieee80211_tkip_gen_phase1key(struct ieee80211_key *key, u8 *ta,
195 u16 *phase1key)
196{
Johannes Berg8f20fc22007-08-28 17:01:54 -0400197 tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
Jiri Bencf0706e82007-05-05 11:45:53 -0700198 key->u.tkip.iv32, phase1key);
199}
200
201void ieee80211_tkip_gen_rc4key(struct ieee80211_key *key, u8 *ta,
202 u8 *rc4key)
203{
204 /* Calculate per-packet key */
205 if (key->u.tkip.iv16 == 0 || !key->u.tkip.tx_initialized) {
206 /* IV16 wrapped around - perform TKIP phase 1 */
Johannes Berg8f20fc22007-08-28 17:01:54 -0400207 tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
Jiri Bencf0706e82007-05-05 11:45:53 -0700208 key->u.tkip.iv32, key->u.tkip.p1k);
209 key->u.tkip.tx_initialized = 1;
210 }
211
Johannes Berg8f20fc22007-08-28 17:01:54 -0400212 tkip_mixing_phase2(key->u.tkip.p1k,
213 &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
Jiri Bencf0706e82007-05-05 11:45:53 -0700214 key->u.tkip.iv16, rc4key);
215}
216
Emmanuel Grumbach5d2cdcd2008-03-20 15:06:41 +0200217void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
218 struct sk_buff *skb, enum ieee80211_tkip_key_type type,
219 u8 *outkey)
220{
221 struct ieee80211_key *key = (struct ieee80211_key *)
222 container_of(keyconf, struct ieee80211_key, conf);
223 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
224 u8 *data = (u8 *) hdr;
225 u16 fc = le16_to_cpu(hdr->frame_control);
226 int hdr_len = ieee80211_get_hdrlen(fc);
227 u8 *ta = hdr->addr2;
228 u16 iv16;
229 u32 iv32;
230
231 iv16 = data[hdr_len] << 8;
232 iv16 += data[hdr_len + 2];
233 iv32 = data[hdr_len + 4] +
234 (data[hdr_len + 5] >> 8) +
235 (data[hdr_len + 6] >> 16) +
236 (data[hdr_len + 7] >> 24);
237
238#ifdef CONFIG_TKIP_DEBUG
239 printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n",
240 iv16, iv32);
241
242 if (iv32 != key->u.tkip.iv32) {
243 printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n",
244 iv32, key->u.tkip.iv32);
245 printk(KERN_DEBUG "Wrap around of iv16 in the middle of a "
246 "fragmented packet\n");
247 }
248#endif /* CONFIG_TKIP_DEBUG */
249
250 /* Update the p1k only when the iv16 in the packet wraps around, this
251 * might occur after the wrap around of iv16 in the key in case of
252 * fragmented packets. */
253 if (iv16 == 0 || !key->u.tkip.tx_initialized) {
254 /* IV16 wrapped around - perform TKIP phase 1 */
255 tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
256 iv32, key->u.tkip.p1k);
257 key->u.tkip.tx_initialized = 1;
258 }
259
260 if (type == IEEE80211_TKIP_P1_KEY) {
261 memcpy(outkey, key->u.tkip.p1k, sizeof(u16) * 5);
262 return;
263 }
264
265 tkip_mixing_phase2(key->u.tkip.p1k,
266 &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], iv16, outkey);
267}
268EXPORT_SYMBOL(ieee80211_get_tkip_key);
269
Jiri Bencf0706e82007-05-05 11:45:53 -0700270/* Encrypt packet payload with TKIP using @key. @pos is a pointer to the
271 * beginning of the buffer containing payload. This payload must include
272 * headroom of eight octets for IV and Ext. IV and taildroom of four octets
273 * for ICV. @payload_len is the length of payload (_not_ including extra
274 * headroom and tailroom). @ta is the transmitter addresses. */
275void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
276 struct ieee80211_key *key,
277 u8 *pos, size_t payload_len, u8 *ta)
278{
279 u8 rc4key[16];
280
281 ieee80211_tkip_gen_rc4key(key, ta, rc4key);
282 pos = ieee80211_tkip_add_iv(pos, key, rc4key[0], rc4key[1], rc4key[2]);
283 ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
284}
285
286
287/* Decrypt packet payload with TKIP using @key. @pos is a pointer to the
288 * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
289 * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
290 * length of payload, including IV, Ext. IV, MIC, ICV. */
291int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm,
292 struct ieee80211_key *key,
293 u8 *payload, size_t payload_len, u8 *ta,
Emmanuel Grumbach9ae4fda2008-03-20 15:06:42 +0200294 u8 *ra, int only_iv, int queue,
Johannes Berg50741ae2007-09-26 15:19:45 +0200295 u32 *out_iv32, u16 *out_iv16)
Jiri Bencf0706e82007-05-05 11:45:53 -0700296{
297 u32 iv32;
298 u32 iv16;
299 u8 rc4key[16], keyid, *pos = payload;
300 int res;
301
302 if (payload_len < 12)
303 return -1;
304
305 iv16 = (pos[0] << 8) | pos[2];
306 keyid = pos[3];
307 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
308 pos += 8;
309#ifdef CONFIG_TKIP_DEBUG
310 {
311 int i;
312 printk(KERN_DEBUG "TKIP decrypt: data(len=%zd)", payload_len);
313 for (i = 0; i < payload_len; i++)
314 printk(" %02x", payload[i]);
315 printk("\n");
316 printk(KERN_DEBUG "TKIP decrypt: iv16=%04x iv32=%08x\n",
317 iv16, iv32);
318 }
319#endif /* CONFIG_TKIP_DEBUG */
320
321 if (!(keyid & (1 << 5)))
322 return TKIP_DECRYPT_NO_EXT_IV;
323
Johannes Berg8f20fc22007-08-28 17:01:54 -0400324 if ((keyid >> 6) != key->conf.keyidx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700325 return TKIP_DECRYPT_INVALID_KEYIDX;
326
327 if (key->u.tkip.rx_initialized[queue] &&
328 (iv32 < key->u.tkip.iv32_rx[queue] ||
329 (iv32 == key->u.tkip.iv32_rx[queue] &&
330 iv16 <= key->u.tkip.iv16_rx[queue]))) {
331#ifdef CONFIG_TKIP_DEBUG
Joe Perches0795af52007-10-03 17:59:30 -0700332 DECLARE_MAC_BUF(mac);
Jiri Bencf0706e82007-05-05 11:45:53 -0700333 printk(KERN_DEBUG "TKIP replay detected for RX frame from "
Joe Perches0795af52007-10-03 17:59:30 -0700334 "%s (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n",
335 print_mac(mac, ta),
Jiri Bencf0706e82007-05-05 11:45:53 -0700336 iv32, iv16, key->u.tkip.iv32_rx[queue],
337 key->u.tkip.iv16_rx[queue]);
338#endif /* CONFIG_TKIP_DEBUG */
339 return TKIP_DECRYPT_REPLAY;
340 }
341
342 if (only_iv) {
343 res = TKIP_DECRYPT_OK;
344 key->u.tkip.rx_initialized[queue] = 1;
345 goto done;
346 }
347
348 if (!key->u.tkip.rx_initialized[queue] ||
349 key->u.tkip.iv32_rx[queue] != iv32) {
350 key->u.tkip.rx_initialized[queue] = 1;
351 /* IV16 wrapped around - perform TKIP phase 1 */
Johannes Berg8f20fc22007-08-28 17:01:54 -0400352 tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
Jiri Bencf0706e82007-05-05 11:45:53 -0700353 iv32, key->u.tkip.p1k_rx[queue]);
354#ifdef CONFIG_TKIP_DEBUG
355 {
356 int i;
Joe Perches0795af52007-10-03 17:59:30 -0700357 DECLARE_MAC_BUF(mac);
358 printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=%s"
359 " TK=", print_mac(mac, ta));
Jiri Bencf0706e82007-05-05 11:45:53 -0700360 for (i = 0; i < 16; i++)
361 printk("%02x ",
Johannes Berg8f20fc22007-08-28 17:01:54 -0400362 key->conf.key[
363 ALG_TKIP_TEMP_ENCR_KEY + i]);
Jiri Bencf0706e82007-05-05 11:45:53 -0700364 printk("\n");
365 printk(KERN_DEBUG "TKIP decrypt: P1K=");
366 for (i = 0; i < 5; i++)
367 printk("%04x ", key->u.tkip.p1k_rx[queue][i]);
368 printk("\n");
369 }
370#endif /* CONFIG_TKIP_DEBUG */
Emmanuel Grumbach9ae4fda2008-03-20 15:06:42 +0200371 if (key->local->ops->update_tkip_key &&
372 key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
373 u8 bcast[ETH_ALEN] =
374 {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
375 u8 *sta_addr = key->sta->addr;
376
377 if (is_multicast_ether_addr(ra))
378 sta_addr = bcast;
379
380 key->local->ops->update_tkip_key(
381 local_to_hw(key->local), &key->conf,
382 sta_addr, iv32, key->u.tkip.p1k_rx[queue]);
383 }
Jiri Bencf0706e82007-05-05 11:45:53 -0700384 }
385
386 tkip_mixing_phase2(key->u.tkip.p1k_rx[queue],
Johannes Berg8f20fc22007-08-28 17:01:54 -0400387 &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
Jiri Bencf0706e82007-05-05 11:45:53 -0700388 iv16, rc4key);
389#ifdef CONFIG_TKIP_DEBUG
390 {
391 int i;
392 printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key=");
393 for (i = 0; i < 16; i++)
394 printk("%02x ", rc4key[i]);
395 printk("\n");
396 }
397#endif /* CONFIG_TKIP_DEBUG */
398
399 res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12);
400 done:
401 if (res == TKIP_DECRYPT_OK) {
Johannes Berg50741ae2007-09-26 15:19:45 +0200402 /*
403 * Record previously received IV, will be copied into the
404 * key information after MIC verification. It is possible
405 * that we don't catch replays of fragments but that's ok
406 * because the Michael MIC verication will then fail.
407 */
408 *out_iv32 = iv32;
409 *out_iv16 = iv16;
Jiri Bencf0706e82007-05-05 11:45:53 -0700410 }
411
412 return res;
413}
414
415