diff options
author | Jiri Benc <jbenc@suse.cz> | 2007-05-05 14:45:53 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-05-05 14:45:53 -0400 |
commit | f0706e828e96d0fa4e80c0d25aa98523f6d589a0 (patch) | |
tree | a03c7f94939d74c1e1b82fcd9a215871590d8b35 /net/mac80211/tkip.c | |
parent | a9de8ce0943e03b425be18561f51159fcceb873d (diff) |
[MAC80211]: Add mac80211 wireless stack.
Add mac80211, the IEEE 802.11 software MAC layer.
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/tkip.c')
-rw-r--r-- | net/mac80211/tkip.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c new file mode 100644 index 000000000000..41621720e560 --- /dev/null +++ b/net/mac80211/tkip.c | |||
@@ -0,0 +1,341 @@ | |||
1 | /* | ||
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> | ||
15 | #include "ieee80211_key.h" | ||
16 | #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 */ | ||
28 | static 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 | |||
65 | static inline u16 Mk16(u8 x, u8 y) | ||
66 | { | ||
67 | return ((u16) x << 8) | (u16) y; | ||
68 | } | ||
69 | |||
70 | |||
71 | static inline u8 Hi8(u16 v) | ||
72 | { | ||
73 | return v >> 8; | ||
74 | } | ||
75 | |||
76 | |||
77 | static inline u8 Lo8(u16 v) | ||
78 | { | ||
79 | return v & 0xff; | ||
80 | } | ||
81 | |||
82 | |||
83 | static inline u16 Hi16(u32 v) | ||
84 | { | ||
85 | return v >> 16; | ||
86 | } | ||
87 | |||
88 | |||
89 | static inline u16 Lo16(u32 v) | ||
90 | { | ||
91 | return v & 0xffff; | ||
92 | } | ||
93 | |||
94 | |||
95 | static inline u16 RotR1(u16 v) | ||
96 | { | ||
97 | return (v >> 1) | ((v & 0x0001) << 15); | ||
98 | } | ||
99 | |||
100 | |||
101 | static 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 | */ | ||
116 | static 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 | |||
138 | static 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). */ | ||
179 | u8 * 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; | ||
185 | *pos++ = (key->keyidx << 6) | (1 << 5) /* Ext IV */; | ||
186 | *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 | |||
194 | void ieee80211_tkip_gen_phase1key(struct ieee80211_key *key, u8 *ta, | ||
195 | u16 *phase1key) | ||
196 | { | ||
197 | tkip_mixing_phase1(ta, &key->key[ALG_TKIP_TEMP_ENCR_KEY], | ||
198 | key->u.tkip.iv32, phase1key); | ||
199 | } | ||
200 | |||
201 | void 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 */ | ||
207 | tkip_mixing_phase1(ta, &key->key[ALG_TKIP_TEMP_ENCR_KEY], | ||
208 | key->u.tkip.iv32, key->u.tkip.p1k); | ||
209 | key->u.tkip.tx_initialized = 1; | ||
210 | } | ||
211 | |||
212 | tkip_mixing_phase2(key->u.tkip.p1k, &key->key[ALG_TKIP_TEMP_ENCR_KEY], | ||
213 | key->u.tkip.iv16, rc4key); | ||
214 | } | ||
215 | |||
216 | /* Encrypt packet payload with TKIP using @key. @pos is a pointer to the | ||
217 | * beginning of the buffer containing payload. This payload must include | ||
218 | * headroom of eight octets for IV and Ext. IV and taildroom of four octets | ||
219 | * for ICV. @payload_len is the length of payload (_not_ including extra | ||
220 | * headroom and tailroom). @ta is the transmitter addresses. */ | ||
221 | void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm, | ||
222 | struct ieee80211_key *key, | ||
223 | u8 *pos, size_t payload_len, u8 *ta) | ||
224 | { | ||
225 | u8 rc4key[16]; | ||
226 | |||
227 | ieee80211_tkip_gen_rc4key(key, ta, rc4key); | ||
228 | pos = ieee80211_tkip_add_iv(pos, key, rc4key[0], rc4key[1], rc4key[2]); | ||
229 | ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len); | ||
230 | } | ||
231 | |||
232 | |||
233 | /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the | ||
234 | * beginning of the buffer containing IEEE 802.11 header payload, i.e., | ||
235 | * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the | ||
236 | * length of payload, including IV, Ext. IV, MIC, ICV. */ | ||
237 | int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, | ||
238 | struct ieee80211_key *key, | ||
239 | u8 *payload, size_t payload_len, u8 *ta, | ||
240 | int only_iv, int queue) | ||
241 | { | ||
242 | u32 iv32; | ||
243 | u32 iv16; | ||
244 | u8 rc4key[16], keyid, *pos = payload; | ||
245 | int res; | ||
246 | |||
247 | if (payload_len < 12) | ||
248 | return -1; | ||
249 | |||
250 | iv16 = (pos[0] << 8) | pos[2]; | ||
251 | keyid = pos[3]; | ||
252 | iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); | ||
253 | pos += 8; | ||
254 | #ifdef CONFIG_TKIP_DEBUG | ||
255 | { | ||
256 | int i; | ||
257 | printk(KERN_DEBUG "TKIP decrypt: data(len=%zd)", payload_len); | ||
258 | for (i = 0; i < payload_len; i++) | ||
259 | printk(" %02x", payload[i]); | ||
260 | printk("\n"); | ||
261 | printk(KERN_DEBUG "TKIP decrypt: iv16=%04x iv32=%08x\n", | ||
262 | iv16, iv32); | ||
263 | } | ||
264 | #endif /* CONFIG_TKIP_DEBUG */ | ||
265 | |||
266 | if (!(keyid & (1 << 5))) | ||
267 | return TKIP_DECRYPT_NO_EXT_IV; | ||
268 | |||
269 | if ((keyid >> 6) != key->keyidx) | ||
270 | return TKIP_DECRYPT_INVALID_KEYIDX; | ||
271 | |||
272 | if (key->u.tkip.rx_initialized[queue] && | ||
273 | (iv32 < key->u.tkip.iv32_rx[queue] || | ||
274 | (iv32 == key->u.tkip.iv32_rx[queue] && | ||
275 | iv16 <= key->u.tkip.iv16_rx[queue]))) { | ||
276 | #ifdef CONFIG_TKIP_DEBUG | ||
277 | printk(KERN_DEBUG "TKIP replay detected for RX frame from " | ||
278 | MAC_FMT " (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n", | ||
279 | MAC_ARG(ta), | ||
280 | iv32, iv16, key->u.tkip.iv32_rx[queue], | ||
281 | key->u.tkip.iv16_rx[queue]); | ||
282 | #endif /* CONFIG_TKIP_DEBUG */ | ||
283 | return TKIP_DECRYPT_REPLAY; | ||
284 | } | ||
285 | |||
286 | if (only_iv) { | ||
287 | res = TKIP_DECRYPT_OK; | ||
288 | key->u.tkip.rx_initialized[queue] = 1; | ||
289 | goto done; | ||
290 | } | ||
291 | |||
292 | if (!key->u.tkip.rx_initialized[queue] || | ||
293 | key->u.tkip.iv32_rx[queue] != iv32) { | ||
294 | key->u.tkip.rx_initialized[queue] = 1; | ||
295 | /* IV16 wrapped around - perform TKIP phase 1 */ | ||
296 | tkip_mixing_phase1(ta, &key->key[ALG_TKIP_TEMP_ENCR_KEY], | ||
297 | iv32, key->u.tkip.p1k_rx[queue]); | ||
298 | #ifdef CONFIG_TKIP_DEBUG | ||
299 | { | ||
300 | int i; | ||
301 | printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=" MAC_FMT | ||
302 | " TK=", MAC_ARG(ta)); | ||
303 | for (i = 0; i < 16; i++) | ||
304 | printk("%02x ", | ||
305 | key->key[ALG_TKIP_TEMP_ENCR_KEY + i]); | ||
306 | printk("\n"); | ||
307 | printk(KERN_DEBUG "TKIP decrypt: P1K="); | ||
308 | for (i = 0; i < 5; i++) | ||
309 | printk("%04x ", key->u.tkip.p1k_rx[queue][i]); | ||
310 | printk("\n"); | ||
311 | } | ||
312 | #endif /* CONFIG_TKIP_DEBUG */ | ||
313 | } | ||
314 | |||
315 | tkip_mixing_phase2(key->u.tkip.p1k_rx[queue], | ||
316 | &key->key[ALG_TKIP_TEMP_ENCR_KEY], | ||
317 | iv16, rc4key); | ||
318 | #ifdef CONFIG_TKIP_DEBUG | ||
319 | { | ||
320 | int i; | ||
321 | printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key="); | ||
322 | for (i = 0; i < 16; i++) | ||
323 | printk("%02x ", rc4key[i]); | ||
324 | printk("\n"); | ||
325 | } | ||
326 | #endif /* CONFIG_TKIP_DEBUG */ | ||
327 | |||
328 | res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12); | ||
329 | done: | ||
330 | if (res == TKIP_DECRYPT_OK) { | ||
331 | /* FIX: these should be updated only after Michael MIC has been | ||
332 | * verified */ | ||
333 | /* Record previously received IV */ | ||
334 | key->u.tkip.iv32_rx[queue] = iv32; | ||
335 | key->u.tkip.iv16_rx[queue] = iv16; | ||
336 | } | ||
337 | |||
338 | return res; | ||
339 | } | ||
340 | |||
341 | |||