[PATCH] core-dumping unreadable binaries via PT_INTERP
[linux-2.6/verdex.git] / net / ieee80211 / ieee80211_crypt_ccmp.c
blob35aa3426c3fa2f34d176fb980dafd54e4c363891
1 /*
2 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
4 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
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.
12 #include <linux/err.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/random.h>
17 #include <linux/skbuff.h>
18 #include <linux/netdevice.h>
19 #include <linux/if_ether.h>
20 #include <linux/if_arp.h>
21 #include <asm/string.h>
22 #include <linux/wireless.h>
24 #include <net/ieee80211.h>
26 #include <linux/crypto.h>
27 #include <asm/scatterlist.h>
29 MODULE_AUTHOR("Jouni Malinen");
30 MODULE_DESCRIPTION("Host AP crypt: CCMP");
31 MODULE_LICENSE("GPL");
33 #define AES_BLOCK_LEN 16
34 #define CCMP_HDR_LEN 8
35 #define CCMP_MIC_LEN 8
36 #define CCMP_TK_LEN 16
37 #define CCMP_PN_LEN 6
39 struct ieee80211_ccmp_data {
40 u8 key[CCMP_TK_LEN];
41 int key_set;
43 u8 tx_pn[CCMP_PN_LEN];
44 u8 rx_pn[CCMP_PN_LEN];
46 u32 dot11RSNAStatsCCMPFormatErrors;
47 u32 dot11RSNAStatsCCMPReplays;
48 u32 dot11RSNAStatsCCMPDecryptErrors;
50 int key_idx;
52 struct crypto_cipher *tfm;
54 /* scratch buffers for virt_to_page() (crypto API) */
55 u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
56 tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
57 u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
60 static inline void ieee80211_ccmp_aes_encrypt(struct crypto_cipher *tfm,
61 const u8 pt[16], u8 ct[16])
63 crypto_cipher_encrypt_one(tfm, ct, pt);
66 static void *ieee80211_ccmp_init(int key_idx)
68 struct ieee80211_ccmp_data *priv;
70 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
71 if (priv == NULL)
72 goto fail;
73 priv->key_idx = key_idx;
75 priv->tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
76 if (IS_ERR(priv->tfm)) {
77 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
78 "crypto API aes\n");
79 priv->tfm = NULL;
80 goto fail;
83 return priv;
85 fail:
86 if (priv) {
87 if (priv->tfm)
88 crypto_free_cipher(priv->tfm);
89 kfree(priv);
92 return NULL;
95 static void ieee80211_ccmp_deinit(void *priv)
97 struct ieee80211_ccmp_data *_priv = priv;
98 if (_priv && _priv->tfm)
99 crypto_free_cipher(_priv->tfm);
100 kfree(priv);
103 static inline void xor_block(u8 * b, u8 * a, size_t len)
105 int i;
106 for (i = 0; i < len; i++)
107 b[i] ^= a[i];
110 static void ccmp_init_blocks(struct crypto_cipher *tfm,
111 struct ieee80211_hdr_4addr *hdr,
112 u8 * pn, size_t dlen, u8 * b0, u8 * auth, u8 * s0)
114 u8 *pos, qc = 0;
115 size_t aad_len;
116 u16 fc;
117 int a4_included, qc_included;
118 u8 aad[2 * AES_BLOCK_LEN];
120 fc = le16_to_cpu(hdr->frame_ctl);
121 a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
122 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
123 qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
124 (WLAN_FC_GET_STYPE(fc) & IEEE80211_STYPE_QOS_DATA));
125 aad_len = 22;
126 if (a4_included)
127 aad_len += 6;
128 if (qc_included) {
129 pos = (u8 *) & hdr->addr4;
130 if (a4_included)
131 pos += 6;
132 qc = *pos & 0x0f;
133 aad_len += 2;
136 /* CCM Initial Block:
137 * Flag (Include authentication header, M=3 (8-octet MIC),
138 * L=1 (2-octet Dlen))
139 * Nonce: 0x00 | A2 | PN
140 * Dlen */
141 b0[0] = 0x59;
142 b0[1] = qc;
143 memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
144 memcpy(b0 + 8, pn, CCMP_PN_LEN);
145 b0[14] = (dlen >> 8) & 0xff;
146 b0[15] = dlen & 0xff;
148 /* AAD:
149 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
150 * A1 | A2 | A3
151 * SC with bits 4..15 (seq#) masked to zero
152 * A4 (if present)
153 * QC (if present)
155 pos = (u8 *) hdr;
156 aad[0] = 0; /* aad_len >> 8 */
157 aad[1] = aad_len & 0xff;
158 aad[2] = pos[0] & 0x8f;
159 aad[3] = pos[1] & 0xc7;
160 memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
161 pos = (u8 *) & hdr->seq_ctl;
162 aad[22] = pos[0] & 0x0f;
163 aad[23] = 0; /* all bits masked */
164 memset(aad + 24, 0, 8);
165 if (a4_included)
166 memcpy(aad + 24, hdr->addr4, ETH_ALEN);
167 if (qc_included) {
168 aad[a4_included ? 30 : 24] = qc;
169 /* rest of QC masked */
172 /* Start with the first block and AAD */
173 ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
174 xor_block(auth, aad, AES_BLOCK_LEN);
175 ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
176 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
177 ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
178 b0[0] &= 0x07;
179 b0[14] = b0[15] = 0;
180 ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
183 static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
184 u8 *aeskey, int keylen, void *priv)
186 struct ieee80211_ccmp_data *key = priv;
187 int i;
188 u8 *pos;
190 if (skb_headroom(skb) < CCMP_HDR_LEN || skb->len < hdr_len)
191 return -1;
193 if (aeskey != NULL && keylen >= CCMP_TK_LEN)
194 memcpy(aeskey, key->key, CCMP_TK_LEN);
196 pos = skb_push(skb, CCMP_HDR_LEN);
197 memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
198 pos += hdr_len;
200 i = CCMP_PN_LEN - 1;
201 while (i >= 0) {
202 key->tx_pn[i]++;
203 if (key->tx_pn[i] != 0)
204 break;
205 i--;
208 *pos++ = key->tx_pn[5];
209 *pos++ = key->tx_pn[4];
210 *pos++ = 0;
211 *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
212 *pos++ = key->tx_pn[3];
213 *pos++ = key->tx_pn[2];
214 *pos++ = key->tx_pn[1];
215 *pos++ = key->tx_pn[0];
217 return CCMP_HDR_LEN;
220 static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
222 struct ieee80211_ccmp_data *key = priv;
223 int data_len, i, blocks, last, len;
224 u8 *pos, *mic;
225 struct ieee80211_hdr_4addr *hdr;
226 u8 *b0 = key->tx_b0;
227 u8 *b = key->tx_b;
228 u8 *e = key->tx_e;
229 u8 *s0 = key->tx_s0;
231 if (skb_tailroom(skb) < CCMP_MIC_LEN || skb->len < hdr_len)
232 return -1;
234 data_len = skb->len - hdr_len;
235 len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
236 if (len < 0)
237 return -1;
239 pos = skb->data + hdr_len + CCMP_HDR_LEN;
240 mic = skb_put(skb, CCMP_MIC_LEN);
241 hdr = (struct ieee80211_hdr_4addr *)skb->data;
242 ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
244 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
245 last = data_len % AES_BLOCK_LEN;
247 for (i = 1; i <= blocks; i++) {
248 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
249 /* Authentication */
250 xor_block(b, pos, len);
251 ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
252 /* Encryption, with counter */
253 b0[14] = (i >> 8) & 0xff;
254 b0[15] = i & 0xff;
255 ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
256 xor_block(pos, e, len);
257 pos += len;
260 for (i = 0; i < CCMP_MIC_LEN; i++)
261 mic[i] = b[i] ^ s0[i];
263 return 0;
267 * deal with seq counter wrapping correctly.
268 * refer to timer_after() for jiffies wrapping handling
270 static inline int ccmp_replay_check(u8 *pn_n, u8 *pn_o)
272 u32 iv32_n, iv16_n;
273 u32 iv32_o, iv16_o;
275 iv32_n = (pn_n[0] << 24) | (pn_n[1] << 16) | (pn_n[2] << 8) | pn_n[3];
276 iv16_n = (pn_n[4] << 8) | pn_n[5];
278 iv32_o = (pn_o[0] << 24) | (pn_o[1] << 16) | (pn_o[2] << 8) | pn_o[3];
279 iv16_o = (pn_o[4] << 8) | pn_o[5];
281 if ((s32)iv32_n - (s32)iv32_o < 0 ||
282 (iv32_n == iv32_o && iv16_n <= iv16_o))
283 return 1;
284 return 0;
287 static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
289 struct ieee80211_ccmp_data *key = priv;
290 u8 keyidx, *pos;
291 struct ieee80211_hdr_4addr *hdr;
292 u8 *b0 = key->rx_b0;
293 u8 *b = key->rx_b;
294 u8 *a = key->rx_a;
295 u8 pn[6];
296 int i, blocks, last, len;
297 size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
298 u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
300 if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
301 key->dot11RSNAStatsCCMPFormatErrors++;
302 return -1;
305 hdr = (struct ieee80211_hdr_4addr *)skb->data;
306 pos = skb->data + hdr_len;
307 keyidx = pos[3];
308 if (!(keyidx & (1 << 5))) {
309 if (net_ratelimit()) {
310 printk(KERN_DEBUG "CCMP: received packet without ExtIV"
311 " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
313 key->dot11RSNAStatsCCMPFormatErrors++;
314 return -2;
316 keyidx >>= 6;
317 if (key->key_idx != keyidx) {
318 printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
319 "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
320 return -6;
322 if (!key->key_set) {
323 if (net_ratelimit()) {
324 printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
325 " with keyid=%d that does not have a configured"
326 " key\n", MAC_ARG(hdr->addr2), keyidx);
328 return -3;
331 pn[0] = pos[7];
332 pn[1] = pos[6];
333 pn[2] = pos[5];
334 pn[3] = pos[4];
335 pn[4] = pos[1];
336 pn[5] = pos[0];
337 pos += 8;
339 if (ccmp_replay_check(pn, key->rx_pn)) {
340 if (net_ratelimit()) {
341 printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
342 " previous PN %02x%02x%02x%02x%02x%02x "
343 "received PN %02x%02x%02x%02x%02x%02x\n",
344 MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
345 MAC_ARG(pn));
347 key->dot11RSNAStatsCCMPReplays++;
348 return -4;
351 ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
352 xor_block(mic, b, CCMP_MIC_LEN);
354 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
355 last = data_len % AES_BLOCK_LEN;
357 for (i = 1; i <= blocks; i++) {
358 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
359 /* Decrypt, with counter */
360 b0[14] = (i >> 8) & 0xff;
361 b0[15] = i & 0xff;
362 ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
363 xor_block(pos, b, len);
364 /* Authentication */
365 xor_block(a, pos, len);
366 ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
367 pos += len;
370 if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
371 if (net_ratelimit()) {
372 printk(KERN_DEBUG "CCMP: decrypt failed: STA="
373 MAC_FMT "\n", MAC_ARG(hdr->addr2));
375 key->dot11RSNAStatsCCMPDecryptErrors++;
376 return -5;
379 memcpy(key->rx_pn, pn, CCMP_PN_LEN);
381 /* Remove hdr and MIC */
382 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
383 skb_pull(skb, CCMP_HDR_LEN);
384 skb_trim(skb, skb->len - CCMP_MIC_LEN);
386 return keyidx;
389 static int ieee80211_ccmp_set_key(void *key, int len, u8 * seq, void *priv)
391 struct ieee80211_ccmp_data *data = priv;
392 int keyidx;
393 struct crypto_cipher *tfm = data->tfm;
395 keyidx = data->key_idx;
396 memset(data, 0, sizeof(*data));
397 data->key_idx = keyidx;
398 data->tfm = tfm;
399 if (len == CCMP_TK_LEN) {
400 memcpy(data->key, key, CCMP_TK_LEN);
401 data->key_set = 1;
402 if (seq) {
403 data->rx_pn[0] = seq[5];
404 data->rx_pn[1] = seq[4];
405 data->rx_pn[2] = seq[3];
406 data->rx_pn[3] = seq[2];
407 data->rx_pn[4] = seq[1];
408 data->rx_pn[5] = seq[0];
410 crypto_cipher_setkey(data->tfm, data->key, CCMP_TK_LEN);
411 } else if (len == 0)
412 data->key_set = 0;
413 else
414 return -1;
416 return 0;
419 static int ieee80211_ccmp_get_key(void *key, int len, u8 * seq, void *priv)
421 struct ieee80211_ccmp_data *data = priv;
423 if (len < CCMP_TK_LEN)
424 return -1;
426 if (!data->key_set)
427 return 0;
428 memcpy(key, data->key, CCMP_TK_LEN);
430 if (seq) {
431 seq[0] = data->tx_pn[5];
432 seq[1] = data->tx_pn[4];
433 seq[2] = data->tx_pn[3];
434 seq[3] = data->tx_pn[2];
435 seq[4] = data->tx_pn[1];
436 seq[5] = data->tx_pn[0];
439 return CCMP_TK_LEN;
442 static char *ieee80211_ccmp_print_stats(char *p, void *priv)
444 struct ieee80211_ccmp_data *ccmp = priv;
445 p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
446 "tx_pn=%02x%02x%02x%02x%02x%02x "
447 "rx_pn=%02x%02x%02x%02x%02x%02x "
448 "format_errors=%d replays=%d decrypt_errors=%d\n",
449 ccmp->key_idx, ccmp->key_set,
450 MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
451 ccmp->dot11RSNAStatsCCMPFormatErrors,
452 ccmp->dot11RSNAStatsCCMPReplays,
453 ccmp->dot11RSNAStatsCCMPDecryptErrors);
455 return p;
458 static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
459 .name = "CCMP",
460 .init = ieee80211_ccmp_init,
461 .deinit = ieee80211_ccmp_deinit,
462 .build_iv = ieee80211_ccmp_hdr,
463 .encrypt_mpdu = ieee80211_ccmp_encrypt,
464 .decrypt_mpdu = ieee80211_ccmp_decrypt,
465 .encrypt_msdu = NULL,
466 .decrypt_msdu = NULL,
467 .set_key = ieee80211_ccmp_set_key,
468 .get_key = ieee80211_ccmp_get_key,
469 .print_stats = ieee80211_ccmp_print_stats,
470 .extra_mpdu_prefix_len = CCMP_HDR_LEN,
471 .extra_mpdu_postfix_len = CCMP_MIC_LEN,
472 .owner = THIS_MODULE,
475 static int __init ieee80211_crypto_ccmp_init(void)
477 return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
480 static void __exit ieee80211_crypto_ccmp_exit(void)
482 ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
485 module_init(ieee80211_crypto_ccmp_init);
486 module_exit(ieee80211_crypto_ccmp_exit);