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f0706e82 JB |
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; | |
8f20fc24 | 185 | *pos++ = (key->conf.keyidx << 6) | (1 << 5) /* Ext IV */; |
f0706e82 JB |
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 | { | |
8f20fc24 | 197 | tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], |
f0706e82 JB |
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 */ | |
8f20fc24 | 207 | tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], |
f0706e82 JB |
208 | key->u.tkip.iv32, key->u.tkip.p1k); |
209 | key->u.tkip.tx_initialized = 1; | |
210 | } | |
211 | ||
8f20fc24 JB |
212 | tkip_mixing_phase2(key->u.tkip.p1k, |
213 | &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], | |
f0706e82 JB |
214 | key->u.tkip.iv16, rc4key); |
215 | } | |
216 | ||
5d2cdcd4 EG |
217 | void 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 | } | |
268 | EXPORT_SYMBOL(ieee80211_get_tkip_key); | |
269 | ||
f0706e82 JB |
270 | /* 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. */ | |
275 | void 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. */ | |
291 | int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm, | |
292 | struct ieee80211_key *key, | |
293 | u8 *payload, size_t payload_len, u8 *ta, | |
50741ae0 JB |
294 | int only_iv, int queue, |
295 | u32 *out_iv32, u16 *out_iv16) | |
f0706e82 JB |
296 | { |
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 | ||
8f20fc24 | 324 | if ((keyid >> 6) != key->conf.keyidx) |
f0706e82 JB |
325 | 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 | |
0795af57 | 332 | DECLARE_MAC_BUF(mac); |
f0706e82 | 333 | printk(KERN_DEBUG "TKIP replay detected for RX frame from " |
0795af57 JP |
334 | "%s (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n", |
335 | print_mac(mac, ta), | |
f0706e82 JB |
336 | 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 */ | |
8f20fc24 | 352 | tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], |
f0706e82 JB |
353 | iv32, key->u.tkip.p1k_rx[queue]); |
354 | #ifdef CONFIG_TKIP_DEBUG | |
355 | { | |
356 | int i; | |
0795af57 JP |
357 | DECLARE_MAC_BUF(mac); |
358 | printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=%s" | |
359 | " TK=", print_mac(mac, ta)); | |
f0706e82 JB |
360 | for (i = 0; i < 16; i++) |
361 | printk("%02x ", | |
8f20fc24 JB |
362 | key->conf.key[ |
363 | ALG_TKIP_TEMP_ENCR_KEY + i]); | |
f0706e82 JB |
364 | 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 */ | |
371 | } | |
372 | ||
373 | tkip_mixing_phase2(key->u.tkip.p1k_rx[queue], | |
8f20fc24 | 374 | &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], |
f0706e82 JB |
375 | iv16, rc4key); |
376 | #ifdef CONFIG_TKIP_DEBUG | |
377 | { | |
378 | int i; | |
379 | printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key="); | |
380 | for (i = 0; i < 16; i++) | |
381 | printk("%02x ", rc4key[i]); | |
382 | printk("\n"); | |
383 | } | |
384 | #endif /* CONFIG_TKIP_DEBUG */ | |
385 | ||
386 | res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12); | |
387 | done: | |
388 | if (res == TKIP_DECRYPT_OK) { | |
50741ae0 JB |
389 | /* |
390 | * Record previously received IV, will be copied into the | |
391 | * key information after MIC verification. It is possible | |
392 | * that we don't catch replays of fragments but that's ok | |
393 | * because the Michael MIC verication will then fail. | |
394 | */ | |
395 | *out_iv32 = iv32; | |
396 | *out_iv16 = iv16; | |
f0706e82 JB |
397 | } |
398 | ||
399 | return res; | |
400 | } | |
401 | ||
402 |