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path: root/drivers/net/wireless/hostap/hostap_crypt_ccmp.c
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Diffstat (limited to 'drivers/net/wireless/hostap/hostap_crypt_ccmp.c')
-rw-r--r--drivers/net/wireless/hostap/hostap_crypt_ccmp.c486
1 files changed, 486 insertions, 0 deletions
diff --git a/drivers/net/wireless/hostap/hostap_crypt_ccmp.c b/drivers/net/wireless/hostap/hostap_crypt_ccmp.c
new file mode 100644
index 000000000000..e95bcc73dbf1
--- /dev/null
+++ b/drivers/net/wireless/hostap/hostap_crypt_ccmp.c
@@ -0,0 +1,486 @@
1/*
2 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
3 *
4 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation. See README and COPYING for
9 * more details.
10 */
11
12#include <linux/config.h>
13#include <linux/version.h>
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/random.h>
18#include <linux/skbuff.h>
19#include <linux/netdevice.h>
20#include <linux/if_ether.h>
21#include <linux/if_arp.h>
22#include <linux/wireless.h>
23#include <net/iw_handler.h>
24#include <asm/string.h>
25
26#include "hostap_crypt.h"
27#include "hostap_wlan.h"
28#include "hostap_80211.h"
29
30#ifndef CONFIG_CRYPTO
31#error CONFIG_CRYPTO is required to build this module.
32#endif
33#include <linux/crypto.h>
34#include <asm/scatterlist.h>
35
36MODULE_AUTHOR("Jouni Malinen");
37MODULE_DESCRIPTION("Host AP crypt: CCMP");
38MODULE_LICENSE("GPL");
39
40
41#define AES_BLOCK_LEN 16
42#define CCMP_HDR_LEN 8
43#define CCMP_MIC_LEN 8
44#define CCMP_TK_LEN 16
45#define CCMP_PN_LEN 6
46
47
48struct hostap_ccmp_data {
49 u8 key[CCMP_TK_LEN];
50 int key_set;
51
52 u8 tx_pn[CCMP_PN_LEN];
53 u8 rx_pn[CCMP_PN_LEN];
54
55 u32 dot11RSNAStatsCCMPFormatErrors;
56 u32 dot11RSNAStatsCCMPReplays;
57 u32 dot11RSNAStatsCCMPDecryptErrors;
58
59 int key_idx;
60
61 struct crypto_tfm *tfm;
62
63 /* scratch buffers for virt_to_page() (crypto API) */
64 u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
65 tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
66 u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
67};
68
69
70void hostap_ccmp_aes_encrypt(struct crypto_tfm *tfm,
71 const u8 pt[16], u8 ct[16])
72{
73 struct scatterlist src, dst;
74
75 src.page = virt_to_page(pt);
76 src.offset = offset_in_page(pt);
77 src.length = AES_BLOCK_LEN;
78
79 dst.page = virt_to_page(ct);
80 dst.offset = offset_in_page(ct);
81 dst.length = AES_BLOCK_LEN;
82
83 crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
84}
85
86
87static void * hostap_ccmp_init(int key_idx)
88{
89 struct hostap_ccmp_data *priv;
90
91 if (!try_module_get(THIS_MODULE))
92 return NULL;
93
94 priv = (struct hostap_ccmp_data *) kmalloc(sizeof(*priv), GFP_ATOMIC);
95 if (priv == NULL) {
96 goto fail;
97 }
98 memset(priv, 0, sizeof(*priv));
99 priv->key_idx = key_idx;
100
101 priv->tfm = crypto_alloc_tfm("aes", 0);
102 if (priv->tfm == NULL) {
103 printk(KERN_DEBUG "hostap_crypt_ccmp: could not allocate "
104 "crypto API aes\n");
105 goto fail;
106 }
107
108 return priv;
109
110fail:
111 if (priv) {
112 if (priv->tfm)
113 crypto_free_tfm(priv->tfm);
114 kfree(priv);
115 }
116 module_put(THIS_MODULE);
117 return NULL;
118}
119
120
121static void hostap_ccmp_deinit(void *priv)
122{
123 struct hostap_ccmp_data *_priv = priv;
124 if (_priv && _priv->tfm)
125 crypto_free_tfm(_priv->tfm);
126 kfree(priv);
127 module_put(THIS_MODULE);
128}
129
130
131static inline void xor_block(u8 *b, u8 *a, size_t len)
132{
133 int i;
134 for (i = 0; i < len; i++)
135 b[i] ^= a[i];
136}
137
138
139static void ccmp_init_blocks(struct crypto_tfm *tfm,
140 struct hostap_ieee80211_hdr *hdr,
141 u8 *pn, size_t dlen, u8 *b0, u8 *auth,
142 u8 *s0)
143{
144 u8 *pos, qc = 0;
145 size_t aad_len;
146 u16 fc;
147 int a4_included, qc_included;
148 u8 aad[2 * AES_BLOCK_LEN];
149
150 fc = le16_to_cpu(hdr->frame_control);
151 a4_included = ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
152 (WLAN_FC_TODS | WLAN_FC_FROMDS));
153 qc_included = ((WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA) &&
154 (WLAN_FC_GET_STYPE(fc) & 0x08));
155 aad_len = 22;
156 if (a4_included)
157 aad_len += 6;
158 if (qc_included) {
159 pos = (u8 *) &hdr->addr4;
160 if (a4_included)
161 pos += 6;
162 qc = *pos & 0x0f;
163 aad_len += 2;
164 }
165
166 /* CCM Initial Block:
167 * Flag (Include authentication header, M=3 (8-octet MIC),
168 * L=1 (2-octet Dlen))
169 * Nonce: 0x00 | A2 | PN
170 * Dlen */
171 b0[0] = 0x59;
172 b0[1] = qc;
173 memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
174 memcpy(b0 + 8, pn, CCMP_PN_LEN);
175 b0[14] = (dlen >> 8) & 0xff;
176 b0[15] = dlen & 0xff;
177
178 /* AAD:
179 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
180 * A1 | A2 | A3
181 * SC with bits 4..15 (seq#) masked to zero
182 * A4 (if present)
183 * QC (if present)
184 */
185 pos = (u8 *) hdr;
186 aad[0] = 0; /* aad_len >> 8 */
187 aad[1] = aad_len & 0xff;
188 aad[2] = pos[0] & 0x8f;
189 aad[3] = pos[1] & 0xc7;
190 memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
191 pos = (u8 *) &hdr->seq_ctrl;
192 aad[22] = pos[0] & 0x0f;
193 aad[23] = 0; /* all bits masked */
194 memset(aad + 24, 0, 8);
195 if (a4_included)
196 memcpy(aad + 24, hdr->addr4, ETH_ALEN);
197 if (qc_included) {
198 aad[a4_included ? 30 : 24] = qc;
199 /* rest of QC masked */
200 }
201
202 /* Start with the first block and AAD */
203 hostap_ccmp_aes_encrypt(tfm, b0, auth);
204 xor_block(auth, aad, AES_BLOCK_LEN);
205 hostap_ccmp_aes_encrypt(tfm, auth, auth);
206 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
207 hostap_ccmp_aes_encrypt(tfm, auth, auth);
208 b0[0] &= 0x07;
209 b0[14] = b0[15] = 0;
210 hostap_ccmp_aes_encrypt(tfm, b0, s0);
211}
212
213
214static int hostap_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
215{
216 struct hostap_ccmp_data *key = priv;
217 int data_len, i, blocks, last, len;
218 u8 *pos, *mic;
219 struct hostap_ieee80211_hdr *hdr;
220 u8 *b0 = key->tx_b0;
221 u8 *b = key->tx_b;
222 u8 *e = key->tx_e;
223 u8 *s0 = key->tx_s0;
224
225 if (skb_headroom(skb) < CCMP_HDR_LEN ||
226 skb_tailroom(skb) < CCMP_MIC_LEN ||
227 skb->len < hdr_len)
228 return -1;
229
230 data_len = skb->len - hdr_len;
231 pos = skb_push(skb, CCMP_HDR_LEN);
232 memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
233 pos += hdr_len;
234 mic = skb_put(skb, CCMP_MIC_LEN);
235
236 i = CCMP_PN_LEN - 1;
237 while (i >= 0) {
238 key->tx_pn[i]++;
239 if (key->tx_pn[i] != 0)
240 break;
241 i--;
242 }
243
244 *pos++ = key->tx_pn[5];
245 *pos++ = key->tx_pn[4];
246 *pos++ = 0;
247 *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */;
248 *pos++ = key->tx_pn[3];
249 *pos++ = key->tx_pn[2];
250 *pos++ = key->tx_pn[1];
251 *pos++ = key->tx_pn[0];
252
253 hdr = (struct hostap_ieee80211_hdr *) skb->data;
254 ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
255
256 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
257 last = data_len % AES_BLOCK_LEN;
258
259 for (i = 1; i <= blocks; i++) {
260 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
261 /* Authentication */
262 xor_block(b, pos, len);
263 hostap_ccmp_aes_encrypt(key->tfm, b, b);
264 /* Encryption, with counter */
265 b0[14] = (i >> 8) & 0xff;
266 b0[15] = i & 0xff;
267 hostap_ccmp_aes_encrypt(key->tfm, b0, e);
268 xor_block(pos, e, len);
269 pos += len;
270 }
271
272 for (i = 0; i < CCMP_MIC_LEN; i++)
273 mic[i] = b[i] ^ s0[i];
274
275 return 0;
276}
277
278
279static int hostap_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
280{
281 struct hostap_ccmp_data *key = priv;
282 u8 keyidx, *pos;
283 struct hostap_ieee80211_hdr *hdr;
284 u8 *b0 = key->rx_b0;
285 u8 *b = key->rx_b;
286 u8 *a = key->rx_a;
287 u8 pn[6];
288 int i, blocks, last, len;
289 size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
290 u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
291
292 if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
293 key->dot11RSNAStatsCCMPFormatErrors++;
294 return -1;
295 }
296
297 hdr = (struct hostap_ieee80211_hdr *) skb->data;
298 pos = skb->data + hdr_len;
299 keyidx = pos[3];
300 if (!(keyidx & (1 << 5))) {
301 if (net_ratelimit()) {
302 printk(KERN_DEBUG "CCMP: received packet without ExtIV"
303 " flag from " MACSTR "\n", MAC2STR(hdr->addr2));
304 }
305 key->dot11RSNAStatsCCMPFormatErrors++;
306 return -2;
307 }
308 keyidx >>= 6;
309 if (key->key_idx != keyidx) {
310 printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
311 "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
312 return -6;
313 }
314 if (!key->key_set) {
315 if (net_ratelimit()) {
316 printk(KERN_DEBUG "CCMP: received packet from " MACSTR
317 " with keyid=%d that does not have a configured"
318 " key\n", MAC2STR(hdr->addr2), keyidx);
319 }
320 return -3;
321 }
322
323 pn[0] = pos[7];
324 pn[1] = pos[6];
325 pn[2] = pos[5];
326 pn[3] = pos[4];
327 pn[4] = pos[1];
328 pn[5] = pos[0];
329 pos += 8;
330
331 if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
332 if (net_ratelimit()) {
333 printk(KERN_DEBUG "CCMP: replay detected: STA=" MACSTR
334 " previous PN %02x%02x%02x%02x%02x%02x "
335 "received PN %02x%02x%02x%02x%02x%02x\n",
336 MAC2STR(hdr->addr2), MAC2STR(key->rx_pn),
337 MAC2STR(pn));
338 }
339 key->dot11RSNAStatsCCMPReplays++;
340 return -4;
341 }
342
343 ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
344 xor_block(mic, b, CCMP_MIC_LEN);
345
346 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
347 last = data_len % AES_BLOCK_LEN;
348
349 for (i = 1; i <= blocks; i++) {
350 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
351 /* Decrypt, with counter */
352 b0[14] = (i >> 8) & 0xff;
353 b0[15] = i & 0xff;
354 hostap_ccmp_aes_encrypt(key->tfm, b0, b);
355 xor_block(pos, b, len);
356 /* Authentication */
357 xor_block(a, pos, len);
358 hostap_ccmp_aes_encrypt(key->tfm, a, a);
359 pos += len;
360 }
361
362 if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
363 if (net_ratelimit()) {
364 printk(KERN_DEBUG "CCMP: decrypt failed: STA="
365 MACSTR "\n", MAC2STR(hdr->addr2));
366 }
367 key->dot11RSNAStatsCCMPDecryptErrors++;
368 return -5;
369 }
370
371 memcpy(key->rx_pn, pn, CCMP_PN_LEN);
372
373 /* Remove hdr and MIC */
374 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
375 skb_pull(skb, CCMP_HDR_LEN);
376 skb_trim(skb, skb->len - CCMP_MIC_LEN);
377
378 return keyidx;
379}
380
381
382static int hostap_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
383{
384 struct hostap_ccmp_data *data = priv;
385 int keyidx;
386 struct crypto_tfm *tfm = data->tfm;
387
388 keyidx = data->key_idx;
389 memset(data, 0, sizeof(*data));
390 data->key_idx = keyidx;
391 data->tfm = tfm;
392 if (len == CCMP_TK_LEN) {
393 memcpy(data->key, key, CCMP_TK_LEN);
394 data->key_set = 1;
395 if (seq) {
396 data->rx_pn[0] = seq[5];
397 data->rx_pn[1] = seq[4];
398 data->rx_pn[2] = seq[3];
399 data->rx_pn[3] = seq[2];
400 data->rx_pn[4] = seq[1];
401 data->rx_pn[5] = seq[0];
402 }
403 crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
404 } else if (len == 0) {
405 data->key_set = 0;
406 } else
407 return -1;
408
409 return 0;
410}
411
412
413static int hostap_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
414{
415 struct hostap_ccmp_data *data = priv;
416
417 if (len < CCMP_TK_LEN)
418 return -1;
419
420 if (!data->key_set)
421 return 0;
422 memcpy(key, data->key, CCMP_TK_LEN);
423
424 if (seq) {
425 seq[0] = data->tx_pn[5];
426 seq[1] = data->tx_pn[4];
427 seq[2] = data->tx_pn[3];
428 seq[3] = data->tx_pn[2];
429 seq[4] = data->tx_pn[1];
430 seq[5] = data->tx_pn[0];
431 }
432
433 return CCMP_TK_LEN;
434}
435
436
437static char * hostap_ccmp_print_stats(char *p, void *priv)
438{
439 struct hostap_ccmp_data *ccmp = priv;
440 p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
441 "tx_pn=%02x%02x%02x%02x%02x%02x "
442 "rx_pn=%02x%02x%02x%02x%02x%02x "
443 "format_errors=%d replays=%d decrypt_errors=%d\n",
444 ccmp->key_idx, ccmp->key_set,
445 MAC2STR(ccmp->tx_pn), MAC2STR(ccmp->rx_pn),
446 ccmp->dot11RSNAStatsCCMPFormatErrors,
447 ccmp->dot11RSNAStatsCCMPReplays,
448 ccmp->dot11RSNAStatsCCMPDecryptErrors);
449
450 return p;
451}
452
453
454static struct hostap_crypto_ops hostap_crypt_ccmp = {
455 .name = "CCMP",
456 .init = hostap_ccmp_init,
457 .deinit = hostap_ccmp_deinit,
458 .encrypt_mpdu = hostap_ccmp_encrypt,
459 .decrypt_mpdu = hostap_ccmp_decrypt,
460 .encrypt_msdu = NULL,
461 .decrypt_msdu = NULL,
462 .set_key = hostap_ccmp_set_key,
463 .get_key = hostap_ccmp_get_key,
464 .print_stats = hostap_ccmp_print_stats,
465 .extra_prefix_len = CCMP_HDR_LEN,
466 .extra_postfix_len = CCMP_MIC_LEN
467};
468
469
470static int __init hostap_crypto_ccmp_init(void)
471{
472 if (hostap_register_crypto_ops(&hostap_crypt_ccmp) < 0)
473 return -1;
474
475 return 0;
476}
477
478
479static void __exit hostap_crypto_ccmp_exit(void)
480{
481 hostap_unregister_crypto_ops(&hostap_crypt_ccmp);
482}
483
484
485module_init(hostap_crypto_ccmp_init);
486module_exit(hostap_crypto_ccmp_exit);
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-03 16:59:51 -0400