Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * lib80211 crypt: host-based TKIP encryption implementation for lib80211
4 *
5 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
6 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/err.h>
12#include <linux/fips.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/random.h>
17#include <linux/scatterlist.h>
18#include <linux/skbuff.h>
19#include <linux/netdevice.h>
20#include <linux/mm.h>
21#include <linux/if_ether.h>
22#include <linux/if_arp.h>
23#include <asm/string.h>
24
25#include <linux/wireless.h>
26#include <linux/ieee80211.h>
27#include <net/iw_handler.h>
28
29#include <crypto/arc4.h>
30#include <crypto/hash.h>
31#include <linux/crypto.h>
32#include <linux/crc32.h>
33
34#include <net/lib80211.h>
35
36MODULE_AUTHOR("Jouni Malinen");
37MODULE_DESCRIPTION("lib80211 crypt: TKIP");
38MODULE_LICENSE("GPL");
39
40#define TKIP_HDR_LEN 8
41
42struct lib80211_tkip_data {
43#define TKIP_KEY_LEN 32
44 u8 key[TKIP_KEY_LEN];
45 int key_set;
46
47 u32 tx_iv32;
48 u16 tx_iv16;
49 u16 tx_ttak[5];
50 int tx_phase1_done;
51
52 u32 rx_iv32;
53 u16 rx_iv16;
54 u16 rx_ttak[5];
55 int rx_phase1_done;
56 u32 rx_iv32_new;
57 u16 rx_iv16_new;
58
59 u32 dot11RSNAStatsTKIPReplays;
60 u32 dot11RSNAStatsTKIPICVErrors;
61 u32 dot11RSNAStatsTKIPLocalMICFailures;
62
63 int key_idx;
64
65 struct arc4_ctx rx_ctx_arc4;
66 struct arc4_ctx tx_ctx_arc4;
67 struct crypto_shash *rx_tfm_michael;
68 struct crypto_shash *tx_tfm_michael;
69
70 /* scratch buffers for virt_to_page() (crypto API) */
71 u8 rx_hdr[16], tx_hdr[16];
72
73 unsigned long flags;
74};
75
76static unsigned long lib80211_tkip_set_flags(unsigned long flags, void *priv)
77{
78 struct lib80211_tkip_data *_priv = priv;
79 unsigned long old_flags = _priv->flags;
80 _priv->flags = flags;
81 return old_flags;
82}
83
84static unsigned long lib80211_tkip_get_flags(void *priv)
85{
86 struct lib80211_tkip_data *_priv = priv;
87 return _priv->flags;
88}
89
90static void *lib80211_tkip_init(int key_idx)
91{
92 struct lib80211_tkip_data *priv;
93
94 if (fips_enabled)
95 return NULL;
96
97 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
98 if (priv == NULL)
99 goto fail;
100
101 priv->key_idx = key_idx;
102
103 priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
104 if (IS_ERR(priv->tx_tfm_michael)) {
105 priv->tx_tfm_michael = NULL;
106 goto fail;
107 }
108
109 priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
110 if (IS_ERR(priv->rx_tfm_michael)) {
111 priv->rx_tfm_michael = NULL;
112 goto fail;
113 }
114
115 return priv;
116
117 fail:
118 if (priv) {
119 crypto_free_shash(priv->tx_tfm_michael);
120 crypto_free_shash(priv->rx_tfm_michael);
121 kfree(priv);
122 }
123
124 return NULL;
125}
126
127static void lib80211_tkip_deinit(void *priv)
128{
129 struct lib80211_tkip_data *_priv = priv;
130 if (_priv) {
131 crypto_free_shash(_priv->tx_tfm_michael);
132 crypto_free_shash(_priv->rx_tfm_michael);
133 }
134 kfree_sensitive(priv);
135}
136
137static inline u16 RotR1(u16 val)
138{
139 return (val >> 1) | (val << 15);
140}
141
142static inline u8 Lo8(u16 val)
143{
144 return val & 0xff;
145}
146
147static inline u8 Hi8(u16 val)
148{
149 return val >> 8;
150}
151
152static inline u16 Lo16(u32 val)
153{
154 return val & 0xffff;
155}
156
157static inline u16 Hi16(u32 val)
158{
159 return val >> 16;
160}
161
162static inline u16 Mk16(u8 hi, u8 lo)
163{
164 return lo | (((u16) hi) << 8);
165}
166
167static inline u16 Mk16_le(__le16 * v)
168{
169 return le16_to_cpu(*v);
170}
171
172static const u16 Sbox[256] = {
173 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
174 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
175 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
176 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
177 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
178 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
179 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
180 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
181 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
182 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
183 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
184 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
185 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
186 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
187 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
188 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
189 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
190 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
191 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
192 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
193 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
194 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
195 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
196 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
197 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
198 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
199 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
200 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
201 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
202 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
203 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
204 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
205};
206
207static inline u16 _S_(u16 v)
208{
209 u16 t = Sbox[Hi8(v)];
210 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
211}
212
213#define PHASE1_LOOP_COUNT 8
214
215static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
216 u32 IV32)
217{
218 int i, j;
219
220 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
221 TTAK[0] = Lo16(IV32);
222 TTAK[1] = Hi16(IV32);
223 TTAK[2] = Mk16(TA[1], TA[0]);
224 TTAK[3] = Mk16(TA[3], TA[2]);
225 TTAK[4] = Mk16(TA[5], TA[4]);
226
227 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
228 j = 2 * (i & 1);
229 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
230 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
231 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
232 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
233 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
234 }
235}
236
237static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
238 u16 IV16)
239{
240 /* Make temporary area overlap WEP seed so that the final copy can be
241 * avoided on little endian hosts. */
242 u16 *PPK = (u16 *) & WEPSeed[4];
243
244 /* Step 1 - make copy of TTAK and bring in TSC */
245 PPK[0] = TTAK[0];
246 PPK[1] = TTAK[1];
247 PPK[2] = TTAK[2];
248 PPK[3] = TTAK[3];
249 PPK[4] = TTAK[4];
250 PPK[5] = TTAK[4] + IV16;
251
252 /* Step 2 - 96-bit bijective mixing using S-box */
253 PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0]));
254 PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
255 PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
256 PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
257 PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
258 PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
259
260 PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
261 PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14]));
262 PPK[2] += RotR1(PPK[1]);
263 PPK[3] += RotR1(PPK[2]);
264 PPK[4] += RotR1(PPK[3]);
265 PPK[5] += RotR1(PPK[4]);
266
267 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
268 * WEPSeed[0..2] is transmitted as WEP IV */
269 WEPSeed[0] = Hi8(IV16);
270 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
271 WEPSeed[2] = Lo8(IV16);
272 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1);
273
274#ifdef __BIG_ENDIAN
275 {
276 int i;
277 for (i = 0; i < 6; i++)
278 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
279 }
280#endif
281}
282
283static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
284 u8 * rc4key, int keylen, void *priv)
285{
286 struct lib80211_tkip_data *tkey = priv;
287 u8 *pos;
288 struct ieee80211_hdr *hdr;
289
290 hdr = (struct ieee80211_hdr *)skb->data;
291
292 if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
293 return -1;
294
295 if (rc4key == NULL || keylen < 16)
296 return -1;
297
298 if (!tkey->tx_phase1_done) {
299 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
300 tkey->tx_iv32);
301 tkey->tx_phase1_done = 1;
302 }
303 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
304
305 pos = skb_push(skb, TKIP_HDR_LEN);
306 memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
307 pos += hdr_len;
308
309 *pos++ = *rc4key;
310 *pos++ = *(rc4key + 1);
311 *pos++ = *(rc4key + 2);
312 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
313 *pos++ = tkey->tx_iv32 & 0xff;
314 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
315 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
316 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
317
318 tkey->tx_iv16++;
319 if (tkey->tx_iv16 == 0) {
320 tkey->tx_phase1_done = 0;
321 tkey->tx_iv32++;
322 }
323
324 return TKIP_HDR_LEN;
325}
326
327static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
328{
329 struct lib80211_tkip_data *tkey = priv;
330 int len;
331 u8 rc4key[16], *pos, *icv;
332 u32 crc;
333
334 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
335 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
336 net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
337 hdr->addr1);
338 return -1;
339 }
340
341 if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
342 return -1;
343
344 len = skb->len - hdr_len;
345 pos = skb->data + hdr_len;
346
347 if ((lib80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
348 return -1;
349
350 crc = ~crc32_le(~0, pos, len);
351 icv = skb_put(skb, 4);
352 icv[0] = crc;
353 icv[1] = crc >> 8;
354 icv[2] = crc >> 16;
355 icv[3] = crc >> 24;
356
357 arc4_setkey(&tkey->tx_ctx_arc4, rc4key, 16);
358 arc4_crypt(&tkey->tx_ctx_arc4, pos, pos, len + 4);
359
360 return 0;
361}
362
363/*
364 * deal with seq counter wrapping correctly.
365 * refer to timer_after() for jiffies wrapping handling
366 */
367static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
368 u32 iv32_o, u16 iv16_o)
369{
370 if ((s32)iv32_n - (s32)iv32_o < 0 ||
371 (iv32_n == iv32_o && iv16_n <= iv16_o))
372 return 1;
373 return 0;
374}
375
376static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
377{
378 struct lib80211_tkip_data *tkey = priv;
379 u8 rc4key[16];
380 u8 keyidx, *pos;
381 u32 iv32;
382 u16 iv16;
383 struct ieee80211_hdr *hdr;
384 u8 icv[4];
385 u32 crc;
386 int plen;
387
388 hdr = (struct ieee80211_hdr *)skb->data;
389
390 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
391 net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
392 hdr->addr2);
393 return -1;
394 }
395
396 if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
397 return -1;
398
399 pos = skb->data + hdr_len;
400 keyidx = pos[3];
401 if (!(keyidx & (1 << 5))) {
402 net_dbg_ratelimited("TKIP: received packet without ExtIV flag from %pM\n",
403 hdr->addr2);
404 return -2;
405 }
406 keyidx >>= 6;
407 if (tkey->key_idx != keyidx) {
408 net_dbg_ratelimited("TKIP: RX tkey->key_idx=%d frame keyidx=%d\n",
409 tkey->key_idx, keyidx);
410 return -6;
411 }
412 if (!tkey->key_set) {
413 net_dbg_ratelimited("TKIP: received packet from %pM with keyid=%d that does not have a configured key\n",
414 hdr->addr2, keyidx);
415 return -3;
416 }
417 iv16 = (pos[0] << 8) | pos[2];
418 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
419 pos += TKIP_HDR_LEN;
420
421 if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
422#ifdef CONFIG_LIB80211_DEBUG
423 net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
424 hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
425 iv32, iv16);
426#endif
427 tkey->dot11RSNAStatsTKIPReplays++;
428 return -4;
429 }
430
431 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
432 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
433 tkey->rx_phase1_done = 1;
434 }
435 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
436
437 plen = skb->len - hdr_len - 12;
438
439 arc4_setkey(&tkey->rx_ctx_arc4, rc4key, 16);
440 arc4_crypt(&tkey->rx_ctx_arc4, pos, pos, plen + 4);
441
442 crc = ~crc32_le(~0, pos, plen);
443 icv[0] = crc;
444 icv[1] = crc >> 8;
445 icv[2] = crc >> 16;
446 icv[3] = crc >> 24;
447 if (memcmp(icv, pos + plen, 4) != 0) {
448 if (iv32 != tkey->rx_iv32) {
449 /* Previously cached Phase1 result was already lost, so
450 * it needs to be recalculated for the next packet. */
451 tkey->rx_phase1_done = 0;
452 }
453#ifdef CONFIG_LIB80211_DEBUG
454 net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
455 hdr->addr2);
456#endif
457 tkey->dot11RSNAStatsTKIPICVErrors++;
458 return -5;
459 }
460
461 /* Update real counters only after Michael MIC verification has
462 * completed */
463 tkey->rx_iv32_new = iv32;
464 tkey->rx_iv16_new = iv16;
465
466 /* Remove IV and ICV */
467 memmove(skb->data + TKIP_HDR_LEN, skb->data, hdr_len);
468 skb_pull(skb, TKIP_HDR_LEN);
469 skb_trim(skb, skb->len - 4);
470
471 return keyidx;
472}
473
474static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
475 u8 *data, size_t data_len, u8 *mic)
476{
477 SHASH_DESC_ON_STACK(desc, tfm_michael);
478 int err;
479
480 if (tfm_michael == NULL) {
481 pr_warn("%s(): tfm_michael == NULL\n", __func__);
482 return -1;
483 }
484
485 desc->tfm = tfm_michael;
486
487 if (crypto_shash_setkey(tfm_michael, key, 8))
488 return -1;
489
490 err = crypto_shash_init(desc);
491 if (err)
492 goto out;
493 err = crypto_shash_update(desc, hdr, 16);
494 if (err)
495 goto out;
496 err = crypto_shash_update(desc, data, data_len);
497 if (err)
498 goto out;
499 err = crypto_shash_final(desc, mic);
500
501out:
502 shash_desc_zero(desc);
503 return err;
504}
505
506static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
507{
508 struct ieee80211_hdr *hdr11;
509
510 hdr11 = (struct ieee80211_hdr *)skb->data;
511
512 switch (le16_to_cpu(hdr11->frame_control) &
513 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
514 case IEEE80211_FCTL_TODS:
515 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
516 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
517 break;
518 case IEEE80211_FCTL_FROMDS:
519 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
520 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
521 break;
522 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
523 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
524 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
525 break;
526 default:
527 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
528 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
529 break;
530 }
531
532 if (ieee80211_is_data_qos(hdr11->frame_control)) {
533 hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
534 & IEEE80211_QOS_CTL_TID_MASK;
535 } else
536 hdr[12] = 0; /* priority */
537
538 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
539}
540
541static int lib80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
542 void *priv)
543{
544 struct lib80211_tkip_data *tkey = priv;
545 u8 *pos;
546
547 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
548 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
549 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
550 skb_tailroom(skb), hdr_len, skb->len);
551 return -1;
552 }
553
554 michael_mic_hdr(skb, tkey->tx_hdr);
555 pos = skb_put(skb, 8);
556 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
557 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
558 return -1;
559
560 return 0;
561}
562
563static void lib80211_michael_mic_failure(struct net_device *dev,
564 struct ieee80211_hdr *hdr,
565 int keyidx)
566{
567 union iwreq_data wrqu;
568 struct iw_michaelmicfailure ev;
569
570 /* TODO: needed parameters: count, keyid, key type, TSC */
571 memset(&ev, 0, sizeof(ev));
572 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
573 if (hdr->addr1[0] & 0x01)
574 ev.flags |= IW_MICFAILURE_GROUP;
575 else
576 ev.flags |= IW_MICFAILURE_PAIRWISE;
577 ev.src_addr.sa_family = ARPHRD_ETHER;
578 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
579 memset(&wrqu, 0, sizeof(wrqu));
580 wrqu.data.length = sizeof(ev);
581 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
582}
583
584static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
585 int hdr_len, void *priv)
586{
587 struct lib80211_tkip_data *tkey = priv;
588 u8 mic[8];
589
590 if (!tkey->key_set)
591 return -1;
592
593 michael_mic_hdr(skb, tkey->rx_hdr);
594 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
595 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
596 return -1;
597 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
598 struct ieee80211_hdr *hdr;
599 hdr = (struct ieee80211_hdr *)skb->data;
600 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
601 "MSDU from %pM keyidx=%d\n",
602 skb->dev ? skb->dev->name : "N/A", hdr->addr2,
603 keyidx);
604 if (skb->dev)
605 lib80211_michael_mic_failure(skb->dev, hdr, keyidx);
606 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
607 return -1;
608 }
609
610 /* Update TSC counters for RX now that the packet verification has
611 * completed. */
612 tkey->rx_iv32 = tkey->rx_iv32_new;
613 tkey->rx_iv16 = tkey->rx_iv16_new;
614
615 skb_trim(skb, skb->len - 8);
616
617 return 0;
618}
619
620static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
621{
622 struct lib80211_tkip_data *tkey = priv;
623 int keyidx;
624 struct crypto_shash *tfm = tkey->tx_tfm_michael;
625 struct arc4_ctx *tfm2 = &tkey->tx_ctx_arc4;
626 struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
627 struct arc4_ctx *tfm4 = &tkey->rx_ctx_arc4;
628
629 keyidx = tkey->key_idx;
630 memset(tkey, 0, sizeof(*tkey));
631 tkey->key_idx = keyidx;
632 tkey->tx_tfm_michael = tfm;
633 tkey->tx_ctx_arc4 = *tfm2;
634 tkey->rx_tfm_michael = tfm3;
635 tkey->rx_ctx_arc4 = *tfm4;
636 if (len == TKIP_KEY_LEN) {
637 memcpy(tkey->key, key, TKIP_KEY_LEN);
638 tkey->key_set = 1;
639 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
640 if (seq) {
641 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
642 (seq[3] << 8) | seq[2];
643 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
644 }
645 } else if (len == 0)
646 tkey->key_set = 0;
647 else
648 return -1;
649
650 return 0;
651}
652
653static int lib80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
654{
655 struct lib80211_tkip_data *tkey = priv;
656
657 if (len < TKIP_KEY_LEN)
658 return -1;
659
660 if (!tkey->key_set)
661 return 0;
662 memcpy(key, tkey->key, TKIP_KEY_LEN);
663
664 if (seq) {
665 /*
666 * Not clear if this should return the value as is
667 * or - as the code previously seemed to partially
668 * have been written as - subtract one from it. It
669 * was working this way for a long time so leave it.
670 */
671 seq[0] = tkey->tx_iv16;
672 seq[1] = tkey->tx_iv16 >> 8;
673 seq[2] = tkey->tx_iv32;
674 seq[3] = tkey->tx_iv32 >> 8;
675 seq[4] = tkey->tx_iv32 >> 16;
676 seq[5] = tkey->tx_iv32 >> 24;
677 }
678
679 return TKIP_KEY_LEN;
680}
681
682static void lib80211_tkip_print_stats(struct seq_file *m, void *priv)
683{
684 struct lib80211_tkip_data *tkip = priv;
685 seq_printf(m,
686 "key[%d] alg=TKIP key_set=%d "
687 "tx_pn=%02x%02x%02x%02x%02x%02x "
688 "rx_pn=%02x%02x%02x%02x%02x%02x "
689 "replays=%d icv_errors=%d local_mic_failures=%d\n",
690 tkip->key_idx, tkip->key_set,
691 (tkip->tx_iv32 >> 24) & 0xff,
692 (tkip->tx_iv32 >> 16) & 0xff,
693 (tkip->tx_iv32 >> 8) & 0xff,
694 tkip->tx_iv32 & 0xff,
695 (tkip->tx_iv16 >> 8) & 0xff,
696 tkip->tx_iv16 & 0xff,
697 (tkip->rx_iv32 >> 24) & 0xff,
698 (tkip->rx_iv32 >> 16) & 0xff,
699 (tkip->rx_iv32 >> 8) & 0xff,
700 tkip->rx_iv32 & 0xff,
701 (tkip->rx_iv16 >> 8) & 0xff,
702 tkip->rx_iv16 & 0xff,
703 tkip->dot11RSNAStatsTKIPReplays,
704 tkip->dot11RSNAStatsTKIPICVErrors,
705 tkip->dot11RSNAStatsTKIPLocalMICFailures);
706}
707
708static struct lib80211_crypto_ops lib80211_crypt_tkip = {
709 .name = "TKIP",
710 .init = lib80211_tkip_init,
711 .deinit = lib80211_tkip_deinit,
712 .encrypt_mpdu = lib80211_tkip_encrypt,
713 .decrypt_mpdu = lib80211_tkip_decrypt,
714 .encrypt_msdu = lib80211_michael_mic_add,
715 .decrypt_msdu = lib80211_michael_mic_verify,
716 .set_key = lib80211_tkip_set_key,
717 .get_key = lib80211_tkip_get_key,
718 .print_stats = lib80211_tkip_print_stats,
719 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
720 .extra_mpdu_postfix_len = 4, /* ICV */
721 .extra_msdu_postfix_len = 8, /* MIC */
722 .get_flags = lib80211_tkip_get_flags,
723 .set_flags = lib80211_tkip_set_flags,
724 .owner = THIS_MODULE,
725};
726
727static int __init lib80211_crypto_tkip_init(void)
728{
729 return lib80211_register_crypto_ops(&lib80211_crypt_tkip);
730}
731
732static void __exit lib80211_crypto_tkip_exit(void)
733{
734 lib80211_unregister_crypto_ops(&lib80211_crypt_tkip);
735}
736
737module_init(lib80211_crypto_tkip_init);
738module_exit(lib80211_crypto_tkip_exit);
1/*
2 * lib80211 crypt: host-based TKIP encryption implementation for lib80211
3 *
4 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
5 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation. See README and COPYING for
10 * more details.
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/err.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/random.h>
20#include <linux/scatterlist.h>
21#include <linux/skbuff.h>
22#include <linux/netdevice.h>
23#include <linux/mm.h>
24#include <linux/if_ether.h>
25#include <linux/if_arp.h>
26#include <asm/string.h>
27
28#include <linux/wireless.h>
29#include <linux/ieee80211.h>
30#include <net/iw_handler.h>
31
32#include <linux/crypto.h>
33#include <linux/crc32.h>
34
35#include <net/lib80211.h>
36
37MODULE_AUTHOR("Jouni Malinen");
38MODULE_DESCRIPTION("lib80211 crypt: TKIP");
39MODULE_LICENSE("GPL");
40
41#define TKIP_HDR_LEN 8
42
43struct lib80211_tkip_data {
44#define TKIP_KEY_LEN 32
45 u8 key[TKIP_KEY_LEN];
46 int key_set;
47
48 u32 tx_iv32;
49 u16 tx_iv16;
50 u16 tx_ttak[5];
51 int tx_phase1_done;
52
53 u32 rx_iv32;
54 u16 rx_iv16;
55 u16 rx_ttak[5];
56 int rx_phase1_done;
57 u32 rx_iv32_new;
58 u16 rx_iv16_new;
59
60 u32 dot11RSNAStatsTKIPReplays;
61 u32 dot11RSNAStatsTKIPICVErrors;
62 u32 dot11RSNAStatsTKIPLocalMICFailures;
63
64 int key_idx;
65
66 struct crypto_blkcipher *rx_tfm_arc4;
67 struct crypto_hash *rx_tfm_michael;
68 struct crypto_blkcipher *tx_tfm_arc4;
69 struct crypto_hash *tx_tfm_michael;
70
71 /* scratch buffers for virt_to_page() (crypto API) */
72 u8 rx_hdr[16], tx_hdr[16];
73
74 unsigned long flags;
75};
76
77static unsigned long lib80211_tkip_set_flags(unsigned long flags, void *priv)
78{
79 struct lib80211_tkip_data *_priv = priv;
80 unsigned long old_flags = _priv->flags;
81 _priv->flags = flags;
82 return old_flags;
83}
84
85static unsigned long lib80211_tkip_get_flags(void *priv)
86{
87 struct lib80211_tkip_data *_priv = priv;
88 return _priv->flags;
89}
90
91static void *lib80211_tkip_init(int key_idx)
92{
93 struct lib80211_tkip_data *priv;
94
95 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
96 if (priv == NULL)
97 goto fail;
98
99 priv->key_idx = key_idx;
100
101 priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
102 CRYPTO_ALG_ASYNC);
103 if (IS_ERR(priv->tx_tfm_arc4)) {
104 priv->tx_tfm_arc4 = NULL;
105 goto fail;
106 }
107
108 priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
109 CRYPTO_ALG_ASYNC);
110 if (IS_ERR(priv->tx_tfm_michael)) {
111 priv->tx_tfm_michael = NULL;
112 goto fail;
113 }
114
115 priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
116 CRYPTO_ALG_ASYNC);
117 if (IS_ERR(priv->rx_tfm_arc4)) {
118 priv->rx_tfm_arc4 = NULL;
119 goto fail;
120 }
121
122 priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
123 CRYPTO_ALG_ASYNC);
124 if (IS_ERR(priv->rx_tfm_michael)) {
125 priv->rx_tfm_michael = NULL;
126 goto fail;
127 }
128
129 return priv;
130
131 fail:
132 if (priv) {
133 if (priv->tx_tfm_michael)
134 crypto_free_hash(priv->tx_tfm_michael);
135 if (priv->tx_tfm_arc4)
136 crypto_free_blkcipher(priv->tx_tfm_arc4);
137 if (priv->rx_tfm_michael)
138 crypto_free_hash(priv->rx_tfm_michael);
139 if (priv->rx_tfm_arc4)
140 crypto_free_blkcipher(priv->rx_tfm_arc4);
141 kfree(priv);
142 }
143
144 return NULL;
145}
146
147static void lib80211_tkip_deinit(void *priv)
148{
149 struct lib80211_tkip_data *_priv = priv;
150 if (_priv) {
151 if (_priv->tx_tfm_michael)
152 crypto_free_hash(_priv->tx_tfm_michael);
153 if (_priv->tx_tfm_arc4)
154 crypto_free_blkcipher(_priv->tx_tfm_arc4);
155 if (_priv->rx_tfm_michael)
156 crypto_free_hash(_priv->rx_tfm_michael);
157 if (_priv->rx_tfm_arc4)
158 crypto_free_blkcipher(_priv->rx_tfm_arc4);
159 }
160 kfree(priv);
161}
162
163static inline u16 RotR1(u16 val)
164{
165 return (val >> 1) | (val << 15);
166}
167
168static inline u8 Lo8(u16 val)
169{
170 return val & 0xff;
171}
172
173static inline u8 Hi8(u16 val)
174{
175 return val >> 8;
176}
177
178static inline u16 Lo16(u32 val)
179{
180 return val & 0xffff;
181}
182
183static inline u16 Hi16(u32 val)
184{
185 return val >> 16;
186}
187
188static inline u16 Mk16(u8 hi, u8 lo)
189{
190 return lo | (((u16) hi) << 8);
191}
192
193static inline u16 Mk16_le(__le16 * v)
194{
195 return le16_to_cpu(*v);
196}
197
198static const u16 Sbox[256] = {
199 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
200 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
201 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
202 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
203 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
204 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
205 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
206 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
207 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
208 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
209 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
210 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
211 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
212 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
213 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
214 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
215 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
216 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
217 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
218 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
219 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
220 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
221 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
222 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
223 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
224 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
225 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
226 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
227 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
228 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
229 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
230 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
231};
232
233static inline u16 _S_(u16 v)
234{
235 u16 t = Sbox[Hi8(v)];
236 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
237}
238
239#define PHASE1_LOOP_COUNT 8
240
241static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
242 u32 IV32)
243{
244 int i, j;
245
246 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
247 TTAK[0] = Lo16(IV32);
248 TTAK[1] = Hi16(IV32);
249 TTAK[2] = Mk16(TA[1], TA[0]);
250 TTAK[3] = Mk16(TA[3], TA[2]);
251 TTAK[4] = Mk16(TA[5], TA[4]);
252
253 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
254 j = 2 * (i & 1);
255 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
256 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
257 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
258 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
259 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
260 }
261}
262
263static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
264 u16 IV16)
265{
266 /* Make temporary area overlap WEP seed so that the final copy can be
267 * avoided on little endian hosts. */
268 u16 *PPK = (u16 *) & WEPSeed[4];
269
270 /* Step 1 - make copy of TTAK and bring in TSC */
271 PPK[0] = TTAK[0];
272 PPK[1] = TTAK[1];
273 PPK[2] = TTAK[2];
274 PPK[3] = TTAK[3];
275 PPK[4] = TTAK[4];
276 PPK[5] = TTAK[4] + IV16;
277
278 /* Step 2 - 96-bit bijective mixing using S-box */
279 PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0]));
280 PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
281 PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
282 PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
283 PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
284 PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
285
286 PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
287 PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14]));
288 PPK[2] += RotR1(PPK[1]);
289 PPK[3] += RotR1(PPK[2]);
290 PPK[4] += RotR1(PPK[3]);
291 PPK[5] += RotR1(PPK[4]);
292
293 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
294 * WEPSeed[0..2] is transmitted as WEP IV */
295 WEPSeed[0] = Hi8(IV16);
296 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
297 WEPSeed[2] = Lo8(IV16);
298 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1);
299
300#ifdef __BIG_ENDIAN
301 {
302 int i;
303 for (i = 0; i < 6; i++)
304 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
305 }
306#endif
307}
308
309static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
310 u8 * rc4key, int keylen, void *priv)
311{
312 struct lib80211_tkip_data *tkey = priv;
313 u8 *pos;
314 struct ieee80211_hdr *hdr;
315
316 hdr = (struct ieee80211_hdr *)skb->data;
317
318 if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
319 return -1;
320
321 if (rc4key == NULL || keylen < 16)
322 return -1;
323
324 if (!tkey->tx_phase1_done) {
325 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
326 tkey->tx_iv32);
327 tkey->tx_phase1_done = 1;
328 }
329 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
330
331 pos = skb_push(skb, TKIP_HDR_LEN);
332 memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
333 pos += hdr_len;
334
335 *pos++ = *rc4key;
336 *pos++ = *(rc4key + 1);
337 *pos++ = *(rc4key + 2);
338 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
339 *pos++ = tkey->tx_iv32 & 0xff;
340 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
341 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
342 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
343
344 tkey->tx_iv16++;
345 if (tkey->tx_iv16 == 0) {
346 tkey->tx_phase1_done = 0;
347 tkey->tx_iv32++;
348 }
349
350 return TKIP_HDR_LEN;
351}
352
353static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
354{
355 struct lib80211_tkip_data *tkey = priv;
356 struct blkcipher_desc desc = { .tfm = tkey->tx_tfm_arc4 };
357 int len;
358 u8 rc4key[16], *pos, *icv;
359 u32 crc;
360 struct scatterlist sg;
361
362 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
363 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
364 net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
365 hdr->addr1);
366 return -1;
367 }
368
369 if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
370 return -1;
371
372 len = skb->len - hdr_len;
373 pos = skb->data + hdr_len;
374
375 if ((lib80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
376 return -1;
377
378 crc = ~crc32_le(~0, pos, len);
379 icv = skb_put(skb, 4);
380 icv[0] = crc;
381 icv[1] = crc >> 8;
382 icv[2] = crc >> 16;
383 icv[3] = crc >> 24;
384
385 crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
386 sg_init_one(&sg, pos, len + 4);
387 return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
388}
389
390/*
391 * deal with seq counter wrapping correctly.
392 * refer to timer_after() for jiffies wrapping handling
393 */
394static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
395 u32 iv32_o, u16 iv16_o)
396{
397 if ((s32)iv32_n - (s32)iv32_o < 0 ||
398 (iv32_n == iv32_o && iv16_n <= iv16_o))
399 return 1;
400 return 0;
401}
402
403static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
404{
405 struct lib80211_tkip_data *tkey = priv;
406 struct blkcipher_desc desc = { .tfm = tkey->rx_tfm_arc4 };
407 u8 rc4key[16];
408 u8 keyidx, *pos;
409 u32 iv32;
410 u16 iv16;
411 struct ieee80211_hdr *hdr;
412 u8 icv[4];
413 u32 crc;
414 struct scatterlist sg;
415 int plen;
416
417 hdr = (struct ieee80211_hdr *)skb->data;
418
419 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
420 net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
421 hdr->addr2);
422 return -1;
423 }
424
425 if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
426 return -1;
427
428 pos = skb->data + hdr_len;
429 keyidx = pos[3];
430 if (!(keyidx & (1 << 5))) {
431 net_dbg_ratelimited("TKIP: received packet without ExtIV flag from %pM\n",
432 hdr->addr2);
433 return -2;
434 }
435 keyidx >>= 6;
436 if (tkey->key_idx != keyidx) {
437 printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame "
438 "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
439 return -6;
440 }
441 if (!tkey->key_set) {
442 net_dbg_ratelimited("TKIP: received packet from %pM with keyid=%d that does not have a configured key\n",
443 hdr->addr2, keyidx);
444 return -3;
445 }
446 iv16 = (pos[0] << 8) | pos[2];
447 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
448 pos += TKIP_HDR_LEN;
449
450 if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
451#ifdef CONFIG_LIB80211_DEBUG
452 net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
453 hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
454 iv32, iv16);
455#endif
456 tkey->dot11RSNAStatsTKIPReplays++;
457 return -4;
458 }
459
460 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
461 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
462 tkey->rx_phase1_done = 1;
463 }
464 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
465
466 plen = skb->len - hdr_len - 12;
467
468 crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
469 sg_init_one(&sg, pos, plen + 4);
470 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) {
471 net_dbg_ratelimited("TKIP: failed to decrypt received packet from %pM\n",
472 hdr->addr2);
473 return -7;
474 }
475
476 crc = ~crc32_le(~0, pos, plen);
477 icv[0] = crc;
478 icv[1] = crc >> 8;
479 icv[2] = crc >> 16;
480 icv[3] = crc >> 24;
481 if (memcmp(icv, pos + plen, 4) != 0) {
482 if (iv32 != tkey->rx_iv32) {
483 /* Previously cached Phase1 result was already lost, so
484 * it needs to be recalculated for the next packet. */
485 tkey->rx_phase1_done = 0;
486 }
487#ifdef CONFIG_LIB80211_DEBUG
488 net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
489 hdr->addr2);
490#endif
491 tkey->dot11RSNAStatsTKIPICVErrors++;
492 return -5;
493 }
494
495 /* Update real counters only after Michael MIC verification has
496 * completed */
497 tkey->rx_iv32_new = iv32;
498 tkey->rx_iv16_new = iv16;
499
500 /* Remove IV and ICV */
501 memmove(skb->data + TKIP_HDR_LEN, skb->data, hdr_len);
502 skb_pull(skb, TKIP_HDR_LEN);
503 skb_trim(skb, skb->len - 4);
504
505 return keyidx;
506}
507
508static int michael_mic(struct crypto_hash *tfm_michael, u8 * key, u8 * hdr,
509 u8 * data, size_t data_len, u8 * mic)
510{
511 struct hash_desc desc;
512 struct scatterlist sg[2];
513
514 if (tfm_michael == NULL) {
515 pr_warn("%s(): tfm_michael == NULL\n", __func__);
516 return -1;
517 }
518 sg_init_table(sg, 2);
519 sg_set_buf(&sg[0], hdr, 16);
520 sg_set_buf(&sg[1], data, data_len);
521
522 if (crypto_hash_setkey(tfm_michael, key, 8))
523 return -1;
524
525 desc.tfm = tfm_michael;
526 desc.flags = 0;
527 return crypto_hash_digest(&desc, sg, data_len + 16, mic);
528}
529
530static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
531{
532 struct ieee80211_hdr *hdr11;
533
534 hdr11 = (struct ieee80211_hdr *)skb->data;
535
536 switch (le16_to_cpu(hdr11->frame_control) &
537 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
538 case IEEE80211_FCTL_TODS:
539 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
540 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
541 break;
542 case IEEE80211_FCTL_FROMDS:
543 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
544 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
545 break;
546 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
547 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
548 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
549 break;
550 case 0:
551 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
552 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
553 break;
554 }
555
556 if (ieee80211_is_data_qos(hdr11->frame_control)) {
557 hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
558 & IEEE80211_QOS_CTL_TID_MASK;
559 } else
560 hdr[12] = 0; /* priority */
561
562 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
563}
564
565static int lib80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
566 void *priv)
567{
568 struct lib80211_tkip_data *tkey = priv;
569 u8 *pos;
570
571 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
572 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
573 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
574 skb_tailroom(skb), hdr_len, skb->len);
575 return -1;
576 }
577
578 michael_mic_hdr(skb, tkey->tx_hdr);
579 pos = skb_put(skb, 8);
580 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
581 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
582 return -1;
583
584 return 0;
585}
586
587static void lib80211_michael_mic_failure(struct net_device *dev,
588 struct ieee80211_hdr *hdr,
589 int keyidx)
590{
591 union iwreq_data wrqu;
592 struct iw_michaelmicfailure ev;
593
594 /* TODO: needed parameters: count, keyid, key type, TSC */
595 memset(&ev, 0, sizeof(ev));
596 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
597 if (hdr->addr1[0] & 0x01)
598 ev.flags |= IW_MICFAILURE_GROUP;
599 else
600 ev.flags |= IW_MICFAILURE_PAIRWISE;
601 ev.src_addr.sa_family = ARPHRD_ETHER;
602 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
603 memset(&wrqu, 0, sizeof(wrqu));
604 wrqu.data.length = sizeof(ev);
605 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
606}
607
608static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
609 int hdr_len, void *priv)
610{
611 struct lib80211_tkip_data *tkey = priv;
612 u8 mic[8];
613
614 if (!tkey->key_set)
615 return -1;
616
617 michael_mic_hdr(skb, tkey->rx_hdr);
618 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
619 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
620 return -1;
621 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
622 struct ieee80211_hdr *hdr;
623 hdr = (struct ieee80211_hdr *)skb->data;
624 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
625 "MSDU from %pM keyidx=%d\n",
626 skb->dev ? skb->dev->name : "N/A", hdr->addr2,
627 keyidx);
628 if (skb->dev)
629 lib80211_michael_mic_failure(skb->dev, hdr, keyidx);
630 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
631 return -1;
632 }
633
634 /* Update TSC counters for RX now that the packet verification has
635 * completed. */
636 tkey->rx_iv32 = tkey->rx_iv32_new;
637 tkey->rx_iv16 = tkey->rx_iv16_new;
638
639 skb_trim(skb, skb->len - 8);
640
641 return 0;
642}
643
644static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
645{
646 struct lib80211_tkip_data *tkey = priv;
647 int keyidx;
648 struct crypto_hash *tfm = tkey->tx_tfm_michael;
649 struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4;
650 struct crypto_hash *tfm3 = tkey->rx_tfm_michael;
651 struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4;
652
653 keyidx = tkey->key_idx;
654 memset(tkey, 0, sizeof(*tkey));
655 tkey->key_idx = keyidx;
656 tkey->tx_tfm_michael = tfm;
657 tkey->tx_tfm_arc4 = tfm2;
658 tkey->rx_tfm_michael = tfm3;
659 tkey->rx_tfm_arc4 = tfm4;
660 if (len == TKIP_KEY_LEN) {
661 memcpy(tkey->key, key, TKIP_KEY_LEN);
662 tkey->key_set = 1;
663 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
664 if (seq) {
665 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
666 (seq[3] << 8) | seq[2];
667 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
668 }
669 } else if (len == 0)
670 tkey->key_set = 0;
671 else
672 return -1;
673
674 return 0;
675}
676
677static int lib80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
678{
679 struct lib80211_tkip_data *tkey = priv;
680
681 if (len < TKIP_KEY_LEN)
682 return -1;
683
684 if (!tkey->key_set)
685 return 0;
686 memcpy(key, tkey->key, TKIP_KEY_LEN);
687
688 if (seq) {
689 /* Return the sequence number of the last transmitted frame. */
690 u16 iv16 = tkey->tx_iv16;
691 u32 iv32 = tkey->tx_iv32;
692 if (iv16 == 0)
693 iv32--;
694 iv16--;
695 seq[0] = tkey->tx_iv16;
696 seq[1] = tkey->tx_iv16 >> 8;
697 seq[2] = tkey->tx_iv32;
698 seq[3] = tkey->tx_iv32 >> 8;
699 seq[4] = tkey->tx_iv32 >> 16;
700 seq[5] = tkey->tx_iv32 >> 24;
701 }
702
703 return TKIP_KEY_LEN;
704}
705
706static void lib80211_tkip_print_stats(struct seq_file *m, void *priv)
707{
708 struct lib80211_tkip_data *tkip = priv;
709 seq_printf(m,
710 "key[%d] alg=TKIP key_set=%d "
711 "tx_pn=%02x%02x%02x%02x%02x%02x "
712 "rx_pn=%02x%02x%02x%02x%02x%02x "
713 "replays=%d icv_errors=%d local_mic_failures=%d\n",
714 tkip->key_idx, tkip->key_set,
715 (tkip->tx_iv32 >> 24) & 0xff,
716 (tkip->tx_iv32 >> 16) & 0xff,
717 (tkip->tx_iv32 >> 8) & 0xff,
718 tkip->tx_iv32 & 0xff,
719 (tkip->tx_iv16 >> 8) & 0xff,
720 tkip->tx_iv16 & 0xff,
721 (tkip->rx_iv32 >> 24) & 0xff,
722 (tkip->rx_iv32 >> 16) & 0xff,
723 (tkip->rx_iv32 >> 8) & 0xff,
724 tkip->rx_iv32 & 0xff,
725 (tkip->rx_iv16 >> 8) & 0xff,
726 tkip->rx_iv16 & 0xff,
727 tkip->dot11RSNAStatsTKIPReplays,
728 tkip->dot11RSNAStatsTKIPICVErrors,
729 tkip->dot11RSNAStatsTKIPLocalMICFailures);
730}
731
732static struct lib80211_crypto_ops lib80211_crypt_tkip = {
733 .name = "TKIP",
734 .init = lib80211_tkip_init,
735 .deinit = lib80211_tkip_deinit,
736 .encrypt_mpdu = lib80211_tkip_encrypt,
737 .decrypt_mpdu = lib80211_tkip_decrypt,
738 .encrypt_msdu = lib80211_michael_mic_add,
739 .decrypt_msdu = lib80211_michael_mic_verify,
740 .set_key = lib80211_tkip_set_key,
741 .get_key = lib80211_tkip_get_key,
742 .print_stats = lib80211_tkip_print_stats,
743 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
744 .extra_mpdu_postfix_len = 4, /* ICV */
745 .extra_msdu_postfix_len = 8, /* MIC */
746 .get_flags = lib80211_tkip_get_flags,
747 .set_flags = lib80211_tkip_set_flags,
748 .owner = THIS_MODULE,
749};
750
751static int __init lib80211_crypto_tkip_init(void)
752{
753 return lib80211_register_crypto_ops(&lib80211_crypt_tkip);
754}
755
756static void __exit lib80211_crypto_tkip_exit(void)
757{
758 lib80211_unregister_crypto_ops(&lib80211_crypt_tkip);
759}
760
761module_init(lib80211_crypto_tkip_init);
762module_exit(lib80211_crypto_tkip_exit);