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
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 <asm/string.h>
23 #include <linux/wireless.h>
25 #include "ieee80211.h"
27 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
28 #include "rtl_crypto.h"
30 #include <linux/crypto.h>
32 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
33 #include <asm/scatterlist.h>
35 #include <linux/scatterlist.h>
38 //#include <asm/scatterlist.h>
40 MODULE_AUTHOR("Jouni Malinen");
41 MODULE_DESCRIPTION("Host AP crypt: CCMP");
42 MODULE_LICENSE("GPL");
45 #ifndef IN_OPENSUSE_SLED
46 #define IN_OPENSUSE_SLED 1
50 #define AES_BLOCK_LEN 16
51 #define CCMP_HDR_LEN 8
52 #define CCMP_MIC_LEN 8
53 #define CCMP_TK_LEN 16
56 struct ieee80211_ccmp_data {
60 u8 tx_pn[CCMP_PN_LEN];
61 u8 rx_pn[CCMP_PN_LEN];
63 u32 dot11RSNAStatsCCMPFormatErrors;
64 u32 dot11RSNAStatsCCMPReplays;
65 u32 dot11RSNAStatsCCMPDecryptErrors;
69 struct crypto_tfm *tfm;
71 /* scratch buffers for virt_to_page() (crypto API) */
72 u8 tx_b0[AES_BLOCK_LEN], tx_b[AES_BLOCK_LEN],
73 tx_e[AES_BLOCK_LEN], tx_s0[AES_BLOCK_LEN];
74 u8 rx_b0[AES_BLOCK_LEN], rx_b[AES_BLOCK_LEN], rx_a[AES_BLOCK_LEN];
77 void ieee80211_ccmp_aes_encrypt(struct crypto_tfm *tfm,
78 const u8 pt[16], u8 ct[16])
80 #if((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,21))||(IN_OPENSUSE_SLED))
81 crypto_cipher_encrypt_one((void *)tfm, ct, pt);
83 struct scatterlist src, dst;
85 src.page = virt_to_page(pt);
86 src.offset = offset_in_page(pt);
87 src.length = AES_BLOCK_LEN;
89 dst.page = virt_to_page(ct);
90 dst.offset = offset_in_page(ct);
91 dst.length = AES_BLOCK_LEN;
93 crypto_cipher_encrypt(tfm, &dst, &src, AES_BLOCK_LEN);
97 static void * ieee80211_ccmp_init(int key_idx)
99 struct ieee80211_ccmp_data *priv;
101 priv = kmalloc(sizeof(*priv), GFP_ATOMIC);
104 memset(priv, 0, sizeof(*priv));
105 priv->key_idx = key_idx;
107 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
108 priv->tfm = crypto_alloc_tfm("aes", 0);
109 if (priv->tfm == NULL) {
110 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
115 priv->tfm = (void *)crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
116 if (IS_ERR(priv->tfm)) {
117 printk(KERN_DEBUG "ieee80211_crypt_ccmp: could not allocate "
128 //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
129 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
130 crypto_free_tfm(priv->tfm);
132 crypto_free_cipher((void *)priv->tfm);
141 static void ieee80211_ccmp_deinit(void *priv)
143 struct ieee80211_ccmp_data *_priv = priv;
144 if (_priv && _priv->tfm)
145 //#if(LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21))
146 #if((LINUX_VERSION_CODE < KERNEL_VERSION(2,6,21)) && (!IN_OPENSUSE_SLED))
147 crypto_free_tfm(_priv->tfm);
149 crypto_free_cipher((void *)_priv->tfm);
155 static inline void xor_block(u8 *b, u8 *a, size_t len)
158 for (i = 0; i < len; i++)
163 static void ccmp_init_blocks(struct crypto_tfm *tfm,
164 struct ieee80211_hdr *hdr,
165 u8 *pn, size_t dlen, u8 *b0, u8 *auth,
171 int a4_included, qc_included;
172 u8 aad[2 * AES_BLOCK_LEN];
174 fc = le16_to_cpu(hdr->frame_ctl);
175 a4_included = ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
176 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS));
178 qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
179 (WLAN_FC_GET_STYPE(fc) & 0x08));
181 // fixed by David :2006.9.6
182 qc_included = ((WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA) &&
183 (WLAN_FC_GET_STYPE(fc) & 0x80));
188 pos = (u8 *) &hdr->addr4;
194 /* CCM Initial Block:
195 * Flag (Include authentication header, M=3 (8-octet MIC),
196 * L=1 (2-octet Dlen))
197 * Nonce: 0x00 | A2 | PN
201 memcpy(b0 + 2, hdr->addr2, ETH_ALEN);
202 memcpy(b0 + 8, pn, CCMP_PN_LEN);
203 b0[14] = (dlen >> 8) & 0xff;
204 b0[15] = dlen & 0xff;
207 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
209 * SC with bits 4..15 (seq#) masked to zero
214 aad[0] = 0; /* aad_len >> 8 */
215 aad[1] = aad_len & 0xff;
216 aad[2] = pos[0] & 0x8f;
217 aad[3] = pos[1] & 0xc7;
218 memcpy(aad + 4, hdr->addr1, 3 * ETH_ALEN);
219 pos = (u8 *) &hdr->seq_ctl;
220 aad[22] = pos[0] & 0x0f;
221 aad[23] = 0; /* all bits masked */
222 memset(aad + 24, 0, 8);
224 memcpy(aad + 24, hdr->addr4, ETH_ALEN);
226 aad[a4_included ? 30 : 24] = qc;
227 /* rest of QC masked */
230 /* Start with the first block and AAD */
231 ieee80211_ccmp_aes_encrypt(tfm, b0, auth);
232 xor_block(auth, aad, AES_BLOCK_LEN);
233 ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
234 xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
235 ieee80211_ccmp_aes_encrypt(tfm, auth, auth);
238 ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
242 static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
244 struct ieee80211_ccmp_data *key = priv;
247 struct ieee80211_hdr *hdr;
249 int blocks, last, len;
256 if (skb_headroom(skb) < CCMP_HDR_LEN ||
257 skb_tailroom(skb) < CCMP_MIC_LEN ||
261 data_len = skb->len - hdr_len;
262 pos = skb_push(skb, CCMP_HDR_LEN);
263 memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
265 // mic = skb_put(skb, CCMP_MIC_LEN);
270 if (key->tx_pn[i] != 0)
275 *pos++ = key->tx_pn[5];
276 *pos++ = key->tx_pn[4];
278 *pos++ = (key->key_idx << 6) | (1 << 5) /* Ext IV included */;
279 *pos++ = key->tx_pn[3];
280 *pos++ = key->tx_pn[2];
281 *pos++ = key->tx_pn[1];
282 *pos++ = key->tx_pn[0];
284 hdr = (struct ieee80211_hdr *) skb->data;
286 //mic is moved to here by john
287 mic = skb_put(skb, CCMP_MIC_LEN);
289 ccmp_init_blocks(key->tfm, hdr, key->tx_pn, data_len, b0, b, s0);
291 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
292 last = data_len % AES_BLOCK_LEN;
294 for (i = 1; i <= blocks; i++) {
295 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
297 xor_block(b, pos, len);
298 ieee80211_ccmp_aes_encrypt(key->tfm, b, b);
299 /* Encryption, with counter */
300 b0[14] = (i >> 8) & 0xff;
302 ieee80211_ccmp_aes_encrypt(key->tfm, b0, e);
303 xor_block(pos, e, len);
307 for (i = 0; i < CCMP_MIC_LEN; i++)
308 mic[i] = b[i] ^ s0[i];
314 static int ieee80211_ccmp_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
316 struct ieee80211_ccmp_data *key = priv;
318 struct ieee80211_hdr *hdr;
321 size_t data_len = skb->len - hdr_len - CCMP_HDR_LEN - CCMP_MIC_LEN;
322 u8 *mic = skb->data + skb->len - CCMP_MIC_LEN;
326 int i, blocks, last, len;
328 if (skb->len < hdr_len + CCMP_HDR_LEN + CCMP_MIC_LEN) {
329 key->dot11RSNAStatsCCMPFormatErrors++;
333 hdr = (struct ieee80211_hdr *) skb->data;
334 pos = skb->data + hdr_len;
336 if (!(keyidx & (1 << 5))) {
337 if (net_ratelimit()) {
338 printk(KERN_DEBUG "CCMP: received packet without ExtIV"
339 " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
341 key->dot11RSNAStatsCCMPFormatErrors++;
345 if (key->key_idx != keyidx) {
346 printk(KERN_DEBUG "CCMP: RX tkey->key_idx=%d frame "
347 "keyidx=%d priv=%p\n", key->key_idx, keyidx, priv);
351 if (net_ratelimit()) {
352 printk(KERN_DEBUG "CCMP: received packet from " MAC_FMT
353 " with keyid=%d that does not have a configured"
354 " key\n", MAC_ARG(hdr->addr2), keyidx);
367 if (memcmp(pn, key->rx_pn, CCMP_PN_LEN) <= 0) {
368 if (net_ratelimit()) {
369 printk(KERN_DEBUG "CCMP: replay detected: STA=" MAC_FMT
370 " previous PN %02x%02x%02x%02x%02x%02x "
371 "received PN %02x%02x%02x%02x%02x%02x\n",
372 MAC_ARG(hdr->addr2), MAC_ARG(key->rx_pn),
375 key->dot11RSNAStatsCCMPReplays++;
380 ccmp_init_blocks(key->tfm, hdr, pn, data_len, b0, a, b);
381 xor_block(mic, b, CCMP_MIC_LEN);
383 blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN;
384 last = data_len % AES_BLOCK_LEN;
386 for (i = 1; i <= blocks; i++) {
387 len = (i == blocks && last) ? last : AES_BLOCK_LEN;
388 /* Decrypt, with counter */
389 b0[14] = (i >> 8) & 0xff;
391 ieee80211_ccmp_aes_encrypt(key->tfm, b0, b);
392 xor_block(pos, b, len);
394 xor_block(a, pos, len);
395 ieee80211_ccmp_aes_encrypt(key->tfm, a, a);
399 if (memcmp(mic, a, CCMP_MIC_LEN) != 0) {
400 if (net_ratelimit()) {
401 printk(KERN_DEBUG "CCMP: decrypt failed: STA="
402 MAC_FMT "\n", MAC_ARG(hdr->addr2));
404 key->dot11RSNAStatsCCMPDecryptErrors++;
408 memcpy(key->rx_pn, pn, CCMP_PN_LEN);
411 /* Remove hdr and MIC */
412 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdr_len);
413 skb_pull(skb, CCMP_HDR_LEN);
414 skb_trim(skb, skb->len - CCMP_MIC_LEN);
420 static int ieee80211_ccmp_set_key(void *key, int len, u8 *seq, void *priv)
422 struct ieee80211_ccmp_data *data = priv;
424 struct crypto_tfm *tfm = data->tfm;
426 keyidx = data->key_idx;
427 memset(data, 0, sizeof(*data));
428 data->key_idx = keyidx;
430 if (len == CCMP_TK_LEN) {
431 memcpy(data->key, key, CCMP_TK_LEN);
434 data->rx_pn[0] = seq[5];
435 data->rx_pn[1] = seq[4];
436 data->rx_pn[2] = seq[3];
437 data->rx_pn[3] = seq[2];
438 data->rx_pn[4] = seq[1];
439 data->rx_pn[5] = seq[0];
441 crypto_cipher_setkey((void *)data->tfm, data->key, CCMP_TK_LEN);
451 static int ieee80211_ccmp_get_key(void *key, int len, u8 *seq, void *priv)
453 struct ieee80211_ccmp_data *data = priv;
455 if (len < CCMP_TK_LEN)
460 memcpy(key, data->key, CCMP_TK_LEN);
463 seq[0] = data->tx_pn[5];
464 seq[1] = data->tx_pn[4];
465 seq[2] = data->tx_pn[3];
466 seq[3] = data->tx_pn[2];
467 seq[4] = data->tx_pn[1];
468 seq[5] = data->tx_pn[0];
475 static char * ieee80211_ccmp_print_stats(char *p, void *priv)
477 struct ieee80211_ccmp_data *ccmp = priv;
478 p += sprintf(p, "key[%d] alg=CCMP key_set=%d "
479 "tx_pn=%02x%02x%02x%02x%02x%02x "
480 "rx_pn=%02x%02x%02x%02x%02x%02x "
481 "format_errors=%d replays=%d decrypt_errors=%d\n",
482 ccmp->key_idx, ccmp->key_set,
483 MAC_ARG(ccmp->tx_pn), MAC_ARG(ccmp->rx_pn),
484 ccmp->dot11RSNAStatsCCMPFormatErrors,
485 ccmp->dot11RSNAStatsCCMPReplays,
486 ccmp->dot11RSNAStatsCCMPDecryptErrors);
491 void ieee80211_ccmp_null(void)
493 // printk("============>%s()\n", __func__);
496 static struct ieee80211_crypto_ops ieee80211_crypt_ccmp = {
498 .init = ieee80211_ccmp_init,
499 .deinit = ieee80211_ccmp_deinit,
500 .encrypt_mpdu = ieee80211_ccmp_encrypt,
501 .decrypt_mpdu = ieee80211_ccmp_decrypt,
502 .encrypt_msdu = NULL,
503 .decrypt_msdu = NULL,
504 .set_key = ieee80211_ccmp_set_key,
505 .get_key = ieee80211_ccmp_get_key,
506 .print_stats = ieee80211_ccmp_print_stats,
507 .extra_prefix_len = CCMP_HDR_LEN,
508 .extra_postfix_len = CCMP_MIC_LEN,
509 .owner = THIS_MODULE,
513 int ieee80211_crypto_ccmp_init(void)
515 return ieee80211_register_crypto_ops(&ieee80211_crypt_ccmp);
519 void ieee80211_crypto_ccmp_exit(void)
521 ieee80211_unregister_crypto_ops(&ieee80211_crypt_ccmp);
525 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
526 EXPORT_SYMBOL(ieee80211_ccmp_null);
528 EXPORT_SYMBOL_NOVERS(ieee80211_ccmp_null);
532 //module_init(ieee80211_crypto_ccmp_init);
533 //module_exit(ieee80211_crypto_ccmp_exit);