1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Host AP crypt: host-based TKIP encryption implementation for Host AP driver
4  *
5  * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
6  */
7 
8 #include <linux/fips.h>
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/slab.h>
12 #include <linux/random.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/if_ether.h>
16 #include <linux/if_arp.h>
17 #include <linux/string.h>
18 
19 #include "ieee80211.h"
20 
21 #include <crypto/arc4.h>
22 #include <crypto/hash.h>
23 #include <linux/crc32.h>
24 
25 MODULE_AUTHOR("Jouni Malinen");
26 MODULE_DESCRIPTION("Host AP crypt: TKIP");
27 MODULE_LICENSE("GPL");
28 
29 struct ieee80211_tkip_data {
30 #define TKIP_KEY_LEN 32
31 	u8 key[TKIP_KEY_LEN];
32 	int key_set;
33 
34 	u32 tx_iv32;
35 	u16 tx_iv16;
36 	u16 tx_ttak[5];
37 	int tx_phase1_done;
38 
39 	u32 rx_iv32;
40 	u16 rx_iv16;
41 	u16 rx_ttak[5];
42 	int rx_phase1_done;
43 	u32 rx_iv32_new;
44 	u16 rx_iv16_new;
45 
46 	u32 dot11RSNAStatsTKIPReplays;
47 	u32 dot11RSNAStatsTKIPICVErrors;
48 	u32 dot11RSNAStatsTKIPLocalMICFailures;
49 
50 	int key_idx;
51 
52 	struct arc4_ctx rx_ctx_arc4;
53 	struct arc4_ctx tx_ctx_arc4;
54 	struct crypto_shash *rx_tfm_michael;
55 	struct crypto_shash *tx_tfm_michael;
56 
57 	/* scratch buffers for virt_to_page() (crypto API) */
58 	u8 rx_hdr[16], tx_hdr[16];
59 };
60 
ieee80211_tkip_init(int key_idx)61 static void *ieee80211_tkip_init(int key_idx)
62 {
63 	struct ieee80211_tkip_data *priv;
64 
65 	if (fips_enabled)
66 		return NULL;
67 
68 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
69 	if (!priv)
70 		goto fail;
71 	priv->key_idx = key_idx;
72 
73 	priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
74 	if (IS_ERR(priv->tx_tfm_michael)) {
75 		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
76 				"crypto API michael_mic\n");
77 		priv->tx_tfm_michael = NULL;
78 		goto fail;
79 	}
80 
81 	priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
82 	if (IS_ERR(priv->rx_tfm_michael)) {
83 		printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
84 				"crypto API michael_mic\n");
85 		priv->rx_tfm_michael = NULL;
86 		goto fail;
87 	}
88 
89 	return priv;
90 
91 fail:
92 	if (priv) {
93 		crypto_free_shash(priv->tx_tfm_michael);
94 		crypto_free_shash(priv->rx_tfm_michael);
95 		kfree(priv);
96 	}
97 
98 	return NULL;
99 }
100 
101 
ieee80211_tkip_deinit(void * priv)102 static void ieee80211_tkip_deinit(void *priv)
103 {
104 	struct ieee80211_tkip_data *_priv = priv;
105 
106 	if (_priv) {
107 		crypto_free_shash(_priv->tx_tfm_michael);
108 		crypto_free_shash(_priv->rx_tfm_michael);
109 	}
110 	kfree_sensitive(priv);
111 }
112 
113 
RotR1(u16 val)114 static inline u16 RotR1(u16 val)
115 {
116 	return (val >> 1) | (val << 15);
117 }
118 
119 
Lo8(u16 val)120 static inline u8 Lo8(u16 val)
121 {
122 	return val & 0xff;
123 }
124 
125 
Hi8(u16 val)126 static inline u8 Hi8(u16 val)
127 {
128 	return val >> 8;
129 }
130 
131 
Lo16(u32 val)132 static inline u16 Lo16(u32 val)
133 {
134 	return val & 0xffff;
135 }
136 
137 
Hi16(u32 val)138 static inline u16 Hi16(u32 val)
139 {
140 	return val >> 16;
141 }
142 
143 
Mk16(u8 hi,u8 lo)144 static inline u16 Mk16(u8 hi, u8 lo)
145 {
146 	return lo | (((u16)hi) << 8);
147 }
148 
149 static const u16 Sbox[256] = {
150 	0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
151 	0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
152 	0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
153 	0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
154 	0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
155 	0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
156 	0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
157 	0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
158 	0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
159 	0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
160 	0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
161 	0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
162 	0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
163 	0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
164 	0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
165 	0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
166 	0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
167 	0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
168 	0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
169 	0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
170 	0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
171 	0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
172 	0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
173 	0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
174 	0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
175 	0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
176 	0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
177 	0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
178 	0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
179 	0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
180 	0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
181 	0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
182 };
183 
184 
_S_(u16 v)185 static inline u16 _S_(u16 v)
186 {
187 	u16 t = Sbox[Hi8(v)];
188 	return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
189 }
190 
191 
192 #define PHASE1_LOOP_COUNT 8
193 
194 
tkip_mixing_phase1(u16 * TTAK,const u8 * TK,const u8 * TA,u32 IV32)195 static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
196 {
197 	int i, j;
198 
199 	/* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
200 	TTAK[0] = Lo16(IV32);
201 	TTAK[1] = Hi16(IV32);
202 	TTAK[2] = Mk16(TA[1], TA[0]);
203 	TTAK[3] = Mk16(TA[3], TA[2]);
204 	TTAK[4] = Mk16(TA[5], TA[4]);
205 
206 	for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
207 		j = 2 * (i & 1);
208 		TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
209 		TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
210 		TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
211 		TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
212 		TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
213 	}
214 }
215 
216 
tkip_mixing_phase2(u8 * WEPSeed,const u8 * TK,const u16 * TTAK,u16 IV16)217 static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
218 			       u16 IV16)
219 {
220 	/*
221 	 * Make temporary area overlap WEP seed so that the final copy can be
222 	 * avoided on little endian hosts.
223 	 */
224 	u16 *PPK = (u16 *)&WEPSeed[4];
225 
226 	/* Step 1 - make copy of TTAK and bring in TSC */
227 	PPK[0] = TTAK[0];
228 	PPK[1] = TTAK[1];
229 	PPK[2] = TTAK[2];
230 	PPK[3] = TTAK[3];
231 	PPK[4] = TTAK[4];
232 	PPK[5] = TTAK[4] + IV16;
233 
234 	/* Step 2 - 96-bit bijective mixing using S-box */
235 	PPK[0] += _S_(PPK[5] ^ le16_to_cpu(*(__le16 *)(&TK[0])));
236 	PPK[1] += _S_(PPK[0] ^ le16_to_cpu(*(__le16 *)(&TK[2])));
237 	PPK[2] += _S_(PPK[1] ^ le16_to_cpu(*(__le16 *)(&TK[4])));
238 	PPK[3] += _S_(PPK[2] ^ le16_to_cpu(*(__le16 *)(&TK[6])));
239 	PPK[4] += _S_(PPK[3] ^ le16_to_cpu(*(__le16 *)(&TK[8])));
240 	PPK[5] += _S_(PPK[4] ^ le16_to_cpu(*(__le16 *)(&TK[10])));
241 
242 	PPK[0] += RotR1(PPK[5] ^ le16_to_cpu(*(__le16 *)(&TK[12])));
243 	PPK[1] += RotR1(PPK[0] ^ le16_to_cpu(*(__le16 *)(&TK[14])));
244 	PPK[2] += RotR1(PPK[1]);
245 	PPK[3] += RotR1(PPK[2]);
246 	PPK[4] += RotR1(PPK[3]);
247 	PPK[5] += RotR1(PPK[4]);
248 
249 	/*
250 	 * Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
251 	 * WEPSeed[0..2] is transmitted as WEP IV
252 	 */
253 	WEPSeed[0] = Hi8(IV16);
254 	WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
255 	WEPSeed[2] = Lo8(IV16);
256 	WEPSeed[3] = Lo8((PPK[5] ^ le16_to_cpu(*(__le16 *)(&TK[0]))) >> 1);
257 
258 #ifdef __BIG_ENDIAN
259 	{
260 		int i;
261 
262 		for (i = 0; i < 6; i++)
263 			PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
264 	}
265 #endif
266 }
267 
268 
ieee80211_tkip_encrypt(struct sk_buff * skb,int hdr_len,void * priv)269 static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
270 {
271 	struct ieee80211_tkip_data *tkey = priv;
272 	int len;
273 	u8 *pos;
274 	struct rtl_80211_hdr_4addr *hdr;
275 	struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
276 	u8 rc4key[16],  *icv;
277 	u32 crc;
278 
279 	if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 ||
280 	    skb->len < hdr_len)
281 		return -1;
282 
283 	hdr = (struct rtl_80211_hdr_4addr *)skb->data;
284 
285 	if (!tcb_desc->bHwSec) {
286 		if (!tkey->tx_phase1_done) {
287 			tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
288 					   tkey->tx_iv32);
289 			tkey->tx_phase1_done = 1;
290 		}
291 		tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
292 	} else
293 		tkey->tx_phase1_done = 1;
294 
295 
296 	len = skb->len - hdr_len;
297 	pos = skb_push(skb, 8);
298 	memmove(pos, pos + 8, hdr_len);
299 	pos += hdr_len;
300 
301 	if (tcb_desc->bHwSec) {
302 		*pos++ = Hi8(tkey->tx_iv16);
303 		*pos++ = (Hi8(tkey->tx_iv16) | 0x20) & 0x7F;
304 		*pos++ = Lo8(tkey->tx_iv16);
305 	} else {
306 		*pos++ = rc4key[0];
307 		*pos++ = rc4key[1];
308 		*pos++ = rc4key[2];
309 	}
310 
311 	*pos++ = (tkey->key_idx << 6) | BIT(5) /* Ext IV included */;
312 	*pos++ = tkey->tx_iv32 & 0xff;
313 	*pos++ = (tkey->tx_iv32 >> 8) & 0xff;
314 	*pos++ = (tkey->tx_iv32 >> 16) & 0xff;
315 	*pos++ = (tkey->tx_iv32 >> 24) & 0xff;
316 
317 	if (!tcb_desc->bHwSec) {
318 		icv = skb_put(skb, 4);
319 		crc = ~crc32_le(~0, pos, len);
320 		icv[0] = crc;
321 		icv[1] = crc >> 8;
322 		icv[2] = crc >> 16;
323 		icv[3] = crc >> 24;
324 
325 		arc4_setkey(&tkey->tx_ctx_arc4, rc4key, 16);
326 		arc4_crypt(&tkey->tx_ctx_arc4, pos, pos, len + 4);
327 	}
328 
329 	tkey->tx_iv16++;
330 	if (tkey->tx_iv16 == 0) {
331 		tkey->tx_phase1_done = 0;
332 		tkey->tx_iv32++;
333 	}
334 
335 	return 0;
336 }
337 
ieee80211_tkip_decrypt(struct sk_buff * skb,int hdr_len,void * priv)338 static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
339 {
340 	struct ieee80211_tkip_data *tkey = priv;
341 	u8 keyidx, *pos;
342 	u32 iv32;
343 	u16 iv16;
344 	struct rtl_80211_hdr_4addr *hdr;
345 	struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb + MAX_DEV_ADDR_SIZE);
346 	u8 rc4key[16];
347 	u8 icv[4];
348 	u32 crc;
349 	int plen;
350 
351 	if (skb->len < hdr_len + 8 + 4)
352 		return -1;
353 
354 	hdr = (struct rtl_80211_hdr_4addr *)skb->data;
355 	pos = skb->data + hdr_len;
356 	keyidx = pos[3];
357 	if (!(keyidx & BIT(5))) {
358 		if (net_ratelimit()) {
359 			netdev_dbg(skb->dev, "TKIP: received packet without ExtIV"
360 			       " flag from %pM\n", hdr->addr2);
361 		}
362 		return -2;
363 	}
364 	keyidx >>= 6;
365 	if (tkey->key_idx != keyidx) {
366 		netdev_dbg(skb->dev, "TKIP: RX tkey->key_idx=%d frame "
367 		       "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
368 		return -6;
369 	}
370 	if (!tkey->key_set) {
371 		if (net_ratelimit()) {
372 			netdev_dbg(skb->dev, "TKIP: received packet from %pM"
373 			       " with keyid=%d that does not have a configured"
374 			       " key\n", hdr->addr2, keyidx);
375 		}
376 		return -3;
377 	}
378 	iv16 = (pos[0] << 8) | pos[2];
379 	iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
380 	pos += 8;
381 
382 	if (!tcb_desc->bHwSec) {
383 		if (iv32 < tkey->rx_iv32 ||
384 		(iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) {
385 			if (net_ratelimit()) {
386 				netdev_dbg(skb->dev, "TKIP: replay detected: STA=%pM"
387 				" previous TSC %08x%04x received TSC "
388 				"%08x%04x\n", hdr->addr2,
389 				tkey->rx_iv32, tkey->rx_iv16, iv32, iv16);
390 			}
391 			tkey->dot11RSNAStatsTKIPReplays++;
392 			return -4;
393 		}
394 
395 		if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
396 			tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
397 			tkey->rx_phase1_done = 1;
398 		}
399 		tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
400 
401 		plen = skb->len - hdr_len - 12;
402 
403 		arc4_setkey(&tkey->rx_ctx_arc4, rc4key, 16);
404 		arc4_crypt(&tkey->rx_ctx_arc4, pos, pos, plen + 4);
405 
406 		crc = ~crc32_le(~0, pos, plen);
407 		icv[0] = crc;
408 		icv[1] = crc >> 8;
409 		icv[2] = crc >> 16;
410 		icv[3] = crc >> 24;
411 
412 		if (memcmp(icv, pos + plen, 4) != 0) {
413 			if (iv32 != tkey->rx_iv32) {
414 				/*
415 				 * Previously cached Phase1 result was already
416 				 * lost, so it needs to be recalculated for the
417 				 * next packet.
418 				 */
419 				tkey->rx_phase1_done = 0;
420 			}
421 			if (net_ratelimit()) {
422 				netdev_dbg(skb->dev, "TKIP: ICV error detected: STA="
423 				"%pM\n", hdr->addr2);
424 			}
425 			tkey->dot11RSNAStatsTKIPICVErrors++;
426 			return -5;
427 		}
428 
429 	}
430 
431 	/*
432 	 * Update real counters only after Michael MIC verification has
433 	 * completed.
434 	 */
435 	tkey->rx_iv32_new = iv32;
436 	tkey->rx_iv16_new = iv16;
437 
438 	/* Remove IV and ICV */
439 	memmove(skb->data + 8, skb->data, hdr_len);
440 	skb_pull(skb, 8);
441 	skb_trim(skb, skb->len - 4);
442 
443 	return keyidx;
444 }
445 
michael_mic(struct crypto_shash * tfm_michael,u8 * key,u8 * hdr,u8 * data,size_t data_len,u8 * mic)446 static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
447 		       u8 *data, size_t data_len, u8 *mic)
448 {
449 	SHASH_DESC_ON_STACK(desc, tfm_michael);
450 	int err;
451 
452 	desc->tfm = tfm_michael;
453 
454 	if (crypto_shash_setkey(tfm_michael, key, 8))
455 		return -1;
456 
457 	err = crypto_shash_init(desc);
458 	if (err)
459 		goto out;
460 	err = crypto_shash_update(desc, hdr, 16);
461 	if (err)
462 		goto out;
463 	err = crypto_shash_update(desc, data, data_len);
464 	if (err)
465 		goto out;
466 	err = crypto_shash_final(desc, mic);
467 
468 out:
469 	shash_desc_zero(desc);
470 	return err;
471 }
472 
michael_mic_hdr(struct sk_buff * skb,u8 * hdr)473 static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr)
474 {
475 	struct rtl_80211_hdr_4addr *hdr11;
476 
477 	hdr11 = (struct rtl_80211_hdr_4addr *)skb->data;
478 	switch (le16_to_cpu(hdr11->frame_ctl) &
479 		(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
480 	case IEEE80211_FCTL_TODS:
481 		memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
482 		memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
483 		break;
484 	case IEEE80211_FCTL_FROMDS:
485 		memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
486 		memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
487 		break;
488 	case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
489 		memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
490 		memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
491 		break;
492 	default:
493 		memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
494 		memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
495 		break;
496 	}
497 
498 	hdr[12] = 0; /* priority */
499 
500 	hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
501 }
502 
503 
ieee80211_michael_mic_add(struct sk_buff * skb,int hdr_len,void * priv)504 static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv)
505 {
506 	struct ieee80211_tkip_data *tkey = priv;
507 	u8 *pos;
508 	struct rtl_80211_hdr_4addr *hdr;
509 
510 	hdr = (struct rtl_80211_hdr_4addr *)skb->data;
511 
512 	if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
513 		netdev_dbg(skb->dev, "Invalid packet for Michael MIC add "
514 		       "(tailroom=%d hdr_len=%d skb->len=%d)\n",
515 		       skb_tailroom(skb), hdr_len, skb->len);
516 		return -1;
517 	}
518 
519 	michael_mic_hdr(skb, tkey->tx_hdr);
520 
521 	// { david, 2006.9.1
522 	// fix the wpa process with wmm enabled.
523 	if (IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl)))
524 		tkey->tx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
525 	// }
526 	pos = skb_put(skb, 8);
527 
528 	if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
529 				skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
530 		return -1;
531 
532 	return 0;
533 }
534 
ieee80211_michael_mic_failure(struct net_device * dev,struct rtl_80211_hdr_4addr * hdr,int keyidx)535 static void ieee80211_michael_mic_failure(struct net_device *dev,
536 				       struct rtl_80211_hdr_4addr *hdr,
537 				       int keyidx)
538 {
539 	union iwreq_data wrqu;
540 	struct iw_michaelmicfailure ev;
541 
542 	/* TODO: needed parameters: count, keyid, key type, TSC */
543 	memset(&ev, 0, sizeof(ev));
544 	ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
545 	if (hdr->addr1[0] & 0x01)
546 		ev.flags |= IW_MICFAILURE_GROUP;
547 	else
548 		ev.flags |= IW_MICFAILURE_PAIRWISE;
549 	ev.src_addr.sa_family = ARPHRD_ETHER;
550 	memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
551 	memset(&wrqu, 0, sizeof(wrqu));
552 	wrqu.data.length = sizeof(ev);
553 	wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
554 }
555 
ieee80211_michael_mic_verify(struct sk_buff * skb,int keyidx,int hdr_len,void * priv)556 static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
557 					int hdr_len, void *priv)
558 {
559 	struct ieee80211_tkip_data *tkey = priv;
560 	u8 mic[8];
561 	struct rtl_80211_hdr_4addr *hdr;
562 
563 	hdr = (struct rtl_80211_hdr_4addr *)skb->data;
564 
565 	if (!tkey->key_set)
566 		return -1;
567 
568 	michael_mic_hdr(skb, tkey->rx_hdr);
569 	// { david, 2006.9.1
570 	// fix the wpa process with wmm enabled.
571 	if (IEEE80211_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl)))
572 		tkey->rx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
573 	// }
574 
575 	if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
576 			skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
577 		return -1;
578 	if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
579 		struct rtl_80211_hdr_4addr *hdr;
580 		hdr = (struct rtl_80211_hdr_4addr *)skb->data;
581 
582 		netdev_dbg(skb->dev, "Michael MIC verification failed for "
583 		       "MSDU from %pM keyidx=%d\n",
584 		       hdr->addr2, keyidx);
585 		if (skb->dev)
586 			ieee80211_michael_mic_failure(skb->dev, hdr, keyidx);
587 		tkey->dot11RSNAStatsTKIPLocalMICFailures++;
588 		return -1;
589 	}
590 
591 	/*
592 	 * Update TSC counters for RX now that the packet verification has
593 	 * completed.
594 	 */
595 	tkey->rx_iv32 = tkey->rx_iv32_new;
596 	tkey->rx_iv16 = tkey->rx_iv16_new;
597 
598 	skb_trim(skb, skb->len - 8);
599 
600 	return 0;
601 }
602 
603 
ieee80211_tkip_set_key(void * key,int len,u8 * seq,void * priv)604 static int ieee80211_tkip_set_key(void *key, int len, u8 *seq, void *priv)
605 {
606 	struct ieee80211_tkip_data *tkey = priv;
607 	int keyidx;
608 	struct crypto_shash *tfm = tkey->tx_tfm_michael;
609 	struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
610 
611 	keyidx = tkey->key_idx;
612 	memset(tkey, 0, sizeof(*tkey));
613 	tkey->key_idx = keyidx;
614 	tkey->tx_tfm_michael = tfm;
615 	tkey->rx_tfm_michael = tfm3;
616 
617 	if (len == TKIP_KEY_LEN) {
618 		memcpy(tkey->key, key, TKIP_KEY_LEN);
619 		tkey->key_set = 1;
620 		tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
621 		if (seq) {
622 			tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
623 				(seq[3] << 8) | seq[2];
624 			tkey->rx_iv16 = (seq[1] << 8) | seq[0];
625 		}
626 	} else if (len == 0)
627 		tkey->key_set = 0;
628 	else
629 		return -1;
630 
631 	return 0;
632 }
633 
634 
ieee80211_tkip_get_key(void * key,int len,u8 * seq,void * priv)635 static int ieee80211_tkip_get_key(void *key, int len, u8 *seq, void *priv)
636 {
637 	struct ieee80211_tkip_data *tkey = priv;
638 
639 	if (len < TKIP_KEY_LEN)
640 		return 0;
641 
642 	if (!tkey->key_set)
643 		return 0;
644 	memcpy(key, tkey->key, TKIP_KEY_LEN);
645 
646 	if (seq) {
647 		/* Return the sequence number of the last transmitted frame. */
648 		u16 iv16 = tkey->tx_iv16;
649 		u32 iv32 = tkey->tx_iv32;
650 
651 		if (iv16 == 0)
652 			iv32--;
653 		iv16--;
654 		seq[0] = tkey->tx_iv16;
655 		seq[1] = tkey->tx_iv16 >> 8;
656 		seq[2] = tkey->tx_iv32;
657 		seq[3] = tkey->tx_iv32 >> 8;
658 		seq[4] = tkey->tx_iv32 >> 16;
659 		seq[5] = tkey->tx_iv32 >> 24;
660 	}
661 
662 	return TKIP_KEY_LEN;
663 }
664 
665 
ieee80211_tkip_print_stats(char * p,void * priv)666 static char *ieee80211_tkip_print_stats(char *p, void *priv)
667 {
668 	struct ieee80211_tkip_data *tkip = priv;
669 
670 	p += sprintf(p, "key[%d] alg=TKIP key_set=%d "
671 		     "tx_pn=%02x%02x%02x%02x%02x%02x "
672 		     "rx_pn=%02x%02x%02x%02x%02x%02x "
673 		     "replays=%d icv_errors=%d local_mic_failures=%d\n",
674 		     tkip->key_idx, tkip->key_set,
675 		     (tkip->tx_iv32 >> 24) & 0xff,
676 		     (tkip->tx_iv32 >> 16) & 0xff,
677 		     (tkip->tx_iv32 >> 8) & 0xff,
678 		     tkip->tx_iv32 & 0xff,
679 		     (tkip->tx_iv16 >> 8) & 0xff,
680 		     tkip->tx_iv16 & 0xff,
681 		     (tkip->rx_iv32 >> 24) & 0xff,
682 		     (tkip->rx_iv32 >> 16) & 0xff,
683 		     (tkip->rx_iv32 >> 8) & 0xff,
684 		     tkip->rx_iv32 & 0xff,
685 		     (tkip->rx_iv16 >> 8) & 0xff,
686 		     tkip->rx_iv16 & 0xff,
687 		     tkip->dot11RSNAStatsTKIPReplays,
688 		     tkip->dot11RSNAStatsTKIPICVErrors,
689 		     tkip->dot11RSNAStatsTKIPLocalMICFailures);
690 	return p;
691 }
692 
693 
694 static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
695 	.name			= "TKIP",
696 	.init			= ieee80211_tkip_init,
697 	.deinit			= ieee80211_tkip_deinit,
698 	.encrypt_mpdu		= ieee80211_tkip_encrypt,
699 	.decrypt_mpdu		= ieee80211_tkip_decrypt,
700 	.encrypt_msdu		= ieee80211_michael_mic_add,
701 	.decrypt_msdu		= ieee80211_michael_mic_verify,
702 	.set_key		= ieee80211_tkip_set_key,
703 	.get_key		= ieee80211_tkip_get_key,
704 	.print_stats		= ieee80211_tkip_print_stats,
705 	.extra_prefix_len	= 4 + 4, /* IV + ExtIV */
706 	.extra_postfix_len	= 8 + 4, /* MIC + ICV */
707 	.owner			= THIS_MODULE,
708 };
709 
ieee80211_crypto_tkip_init(void)710 int __init ieee80211_crypto_tkip_init(void)
711 {
712 	return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip);
713 }
714 
ieee80211_crypto_tkip_exit(void)715 void ieee80211_crypto_tkip_exit(void)
716 {
717 	ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip);
718 }
719 
ieee80211_tkip_null(void)720 void ieee80211_tkip_null(void)
721 {
722 //    printk("============>%s()\n", __func__);
723 	return;
724 }
725