blob: f4971cd45c64f53eaa248680ca965a471abb7564 [file] [log] [blame]
Jiri Bencf0706e82007-05-05 11:45:53 -07001/*
2 * Copyright 2002-2004, Instant802 Networks, Inc.
Jouni Malinen765cb462009-01-08 13:32:01 +02003 * Copyright 2008, Jouni Malinen <j@w1.fi>
Jiri Bencf0706e82007-05-05 11:45:53 -07004 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/netdevice.h>
11#include <linux/types.h>
12#include <linux/slab.h>
13#include <linux/skbuff.h>
14#include <linux/compiler.h>
Harvey Harrisonf14df802008-07-02 11:05:35 -070015#include <linux/ieee80211.h>
16#include <asm/unaligned.h>
Jiri Bencf0706e82007-05-05 11:45:53 -070017#include <net/mac80211.h>
Johannes Bergeb063c12007-08-28 17:01:53 -040018
Jiri Bencf0706e82007-05-05 11:45:53 -070019#include "ieee80211_i.h"
20#include "michael.h"
21#include "tkip.h"
22#include "aes_ccm.h"
Jouni Malinen765cb462009-01-08 13:32:01 +020023#include "aes_cmac.h"
Jiri Bencf0706e82007-05-05 11:45:53 -070024#include "wpa.h"
25
Johannes Berg9ae54c82008-01-31 19:48:20 +010026ieee80211_tx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +010027ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
Jiri Bencf0706e82007-05-05 11:45:53 -070028{
Harvey Harrison8e8862b2008-07-02 11:05:35 -070029 u8 *data, *key, *mic, key_offset;
Jiri Bencf0706e82007-05-05 11:45:53 -070030 size_t data_len;
Harvey Harrison8e8862b2008-07-02 11:05:35 -070031 unsigned int hdrlen;
32 struct ieee80211_hdr *hdr;
Jiri Bencf0706e82007-05-05 11:45:53 -070033 struct sk_buff *skb = tx->skb;
Johannes Berg813d7662010-01-17 01:47:58 +010034 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
Jiri Bencf0706e82007-05-05 11:45:53 -070035 int authenticator;
Johannes Berg23c07522008-05-29 10:38:53 +020036 int tail;
Jiri Bencf0706e82007-05-05 11:45:53 -070037
Harvey Harrisonc34498b2008-07-02 16:30:52 -070038 hdr = (struct ieee80211_hdr *)skb->data;
Johannes Berg8f20fc22007-08-28 17:01:54 -040039 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
Harvey Harrisonc34498b2008-07-02 16:30:52 -070040 !ieee80211_is_data_present(hdr->frame_control))
Johannes Berg9ae54c82008-01-31 19:48:20 +010041 return TX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -070042
Harvey Harrison8e8862b2008-07-02 11:05:35 -070043 hdrlen = ieee80211_hdrlen(hdr->frame_control);
44 if (skb->len < hdrlen)
Johannes Berg9ae54c82008-01-31 19:48:20 +010045 return TX_DROP;
Jiri Bencf0706e82007-05-05 11:45:53 -070046
Harvey Harrison8e8862b2008-07-02 11:05:35 -070047 data = skb->data + hdrlen;
48 data_len = skb->len - hdrlen;
49
Johannes Berg813d7662010-01-17 01:47:58 +010050 if (info->control.hw_key &&
Johannes Berg5cf121c2008-02-25 16:27:43 +010051 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
Johannes Berg813d7662010-01-17 01:47:58 +010052 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
53 /* hwaccel - with no need for SW-generated MMIC */
Johannes Berg9ae54c82008-01-31 19:48:20 +010054 return TX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -070055 }
56
Johannes Berg23c07522008-05-29 10:38:53 +020057 tail = MICHAEL_MIC_LEN;
Johannes Berg813d7662010-01-17 01:47:58 +010058 if (!info->control.hw_key)
Johannes Berg23c07522008-05-29 10:38:53 +020059 tail += TKIP_ICV_LEN;
60
61 if (WARN_ON(skb_tailroom(skb) < tail ||
62 skb_headroom(skb) < TKIP_IV_LEN))
63 return TX_DROP;
Jiri Bencf0706e82007-05-05 11:45:53 -070064
65#if 0
66 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
67#else
68 authenticator = 1;
69#endif
Luis R. Rodriguezffd78912008-06-21 10:02:46 -040070 key_offset = authenticator ?
71 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
72 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
73 key = &tx->key->conf.key[key_offset];
Jiri Bencf0706e82007-05-05 11:45:53 -070074 mic = skb_put(skb, MICHAEL_MIC_LEN);
Harvey Harrison8e8862b2008-07-02 11:05:35 -070075 michael_mic(key, hdr, data, data_len, mic);
Jiri Bencf0706e82007-05-05 11:45:53 -070076
Johannes Berg9ae54c82008-01-31 19:48:20 +010077 return TX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -070078}
79
80
Johannes Berg9ae54c82008-01-31 19:48:20 +010081ieee80211_rx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +010082ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
Jiri Bencf0706e82007-05-05 11:45:53 -070083{
Harvey Harrison8e8862b2008-07-02 11:05:35 -070084 u8 *data, *key = NULL, key_offset;
Jiri Bencf0706e82007-05-05 11:45:53 -070085 size_t data_len;
Harvey Harrison8e8862b2008-07-02 11:05:35 -070086 unsigned int hdrlen;
Jiri Bencf0706e82007-05-05 11:45:53 -070087 u8 mic[MICHAEL_MIC_LEN];
88 struct sk_buff *skb = rx->skb;
Johannes Bergeb9fb5b82009-11-16 13:58:20 +010089 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
90 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
Jiri Bencf0706e82007-05-05 11:45:53 -070091 int authenticator = 1, wpa_test = 0;
92
Johannes Bergc6a1fa12008-10-07 12:04:32 +020093 /* No way to verify the MIC if the hardware stripped it */
Johannes Bergeb9fb5b82009-11-16 13:58:20 +010094 if (status->flag & RX_FLAG_MMIC_STRIPPED)
Johannes Berg9ae54c82008-01-31 19:48:20 +010095 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -070096
Johannes Berg8f20fc22007-08-28 17:01:54 -040097 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
Harvey Harrisonc34498b2008-07-02 16:30:52 -070098 !ieee80211_has_protected(hdr->frame_control) ||
99 !ieee80211_is_data_present(hdr->frame_control))
Johannes Berg9ae54c82008-01-31 19:48:20 +0100100 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700101
Harvey Harrison8e8862b2008-07-02 11:05:35 -0700102 hdrlen = ieee80211_hdrlen(hdr->frame_control);
103 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
Johannes Berge4c26ad2008-01-31 19:48:21 +0100104 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700105
Harvey Harrison8e8862b2008-07-02 11:05:35 -0700106 data = skb->data + hdrlen;
107 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
Jiri Bencf0706e82007-05-05 11:45:53 -0700108
109#if 0
110 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
111#else
112 authenticator = 1;
113#endif
Luis R. Rodriguezffd78912008-06-21 10:02:46 -0400114 key_offset = authenticator ?
115 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
116 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
117 key = &rx->key->conf.key[key_offset];
Harvey Harrison8e8862b2008-07-02 11:05:35 -0700118 michael_mic(key, hdr, data, data_len, mic);
Jiri Bencf0706e82007-05-05 11:45:53 -0700119 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
Johannes Berg5cf121c2008-02-25 16:27:43 +0100120 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
Johannes Berge4c26ad2008-01-31 19:48:21 +0100121 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700122
Jasper Bryant-Greenef698d852008-08-03 12:04:37 +1200123 mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx,
Johannes Berge6d6e342009-07-01 21:26:47 +0200124 (void *) skb->data, NULL,
125 GFP_ATOMIC);
Johannes Berge4c26ad2008-01-31 19:48:21 +0100126 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700127 }
128
Jiri Bencf0706e82007-05-05 11:45:53 -0700129 /* remove Michael MIC from payload */
130 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
131
Johannes Berg50741ae2007-09-26 15:19:45 +0200132 /* update IV in key information to be able to detect replays */
Harvey Harrisonb0f76b32008-05-14 16:26:19 -0700133 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
134 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
Johannes Berg50741ae2007-09-26 15:19:45 +0200135
Johannes Berg9ae54c82008-01-31 19:48:20 +0100136 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700137}
138
139
Johannes Berge039fa42008-05-15 12:55:29 +0200140static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
Jiri Bencf0706e82007-05-05 11:45:53 -0700141{
142 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
143 struct ieee80211_key *key = tx->key;
Johannes Berge039fa42008-05-15 12:55:29 +0200144 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
Harvey Harrisond5184ca2008-06-11 14:21:58 -0700145 unsigned int hdrlen;
146 int len, tail;
Jiri Bencf0706e82007-05-05 11:45:53 -0700147 u8 *pos;
148
Johannes Berg813d7662010-01-17 01:47:58 +0100149 if (info->control.hw_key &&
150 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
151 /* hwaccel - with no need for software-generated IV */
Johannes Berg23c07522008-05-29 10:38:53 +0200152 return 0;
Johannes Berge039fa42008-05-15 12:55:29 +0200153 }
154
Harvey Harrisond5184ca2008-06-11 14:21:58 -0700155 hdrlen = ieee80211_hdrlen(hdr->frame_control);
Jiri Bencf0706e82007-05-05 11:45:53 -0700156 len = skb->len - hdrlen;
157
Johannes Berg813d7662010-01-17 01:47:58 +0100158 if (info->control.hw_key)
Johannes Berg23c07522008-05-29 10:38:53 +0200159 tail = 0;
Johannes Berg11a843b2007-08-28 17:01:55 -0400160 else
Johannes Berg23c07522008-05-29 10:38:53 +0200161 tail = TKIP_ICV_LEN;
Johannes Berg8f20fc22007-08-28 17:01:54 -0400162
Johannes Berg23c07522008-05-29 10:38:53 +0200163 if (WARN_ON(skb_tailroom(skb) < tail ||
164 skb_headroom(skb) < TKIP_IV_LEN))
165 return -1;
Jiri Bencf0706e82007-05-05 11:45:53 -0700166
167 pos = skb_push(skb, TKIP_IV_LEN);
168 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
169 pos += hdrlen;
170
171 /* Increase IV for the frame */
Harvey Harrisonb0f76b32008-05-14 16:26:19 -0700172 key->u.tkip.tx.iv16++;
173 if (key->u.tkip.tx.iv16 == 0)
174 key->u.tkip.tx.iv32++;
Jiri Bencf0706e82007-05-05 11:45:53 -0700175
Johannes Berg813d7662010-01-17 01:47:58 +0100176 pos = ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
Jiri Bencf0706e82007-05-05 11:45:53 -0700177
Johannes Berg813d7662010-01-17 01:47:58 +0100178 /* hwaccel - with software IV */
179 if (info->control.hw_key)
Jiri Bencf0706e82007-05-05 11:45:53 -0700180 return 0;
Jiri Bencf0706e82007-05-05 11:45:53 -0700181
182 /* Add room for ICV */
183 skb_put(skb, TKIP_ICV_LEN);
184
185 hdr = (struct ieee80211_hdr *) skb->data;
186 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
187 key, pos, len, hdr->addr2);
188 return 0;
189}
190
191
Johannes Berg9ae54c82008-01-31 19:48:20 +0100192ieee80211_tx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +0100193ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700194{
Jiri Bencf0706e82007-05-05 11:45:53 -0700195 struct sk_buff *skb = tx->skb;
Jiri Bencf0706e82007-05-05 11:45:53 -0700196
Johannes Berg5cf121c2008-02-25 16:27:43 +0100197 ieee80211_tx_set_protected(tx);
Jiri Bencf0706e82007-05-05 11:45:53 -0700198
Johannes Berg2de8e0d2009-03-23 17:28:35 +0100199 do {
200 if (tkip_encrypt_skb(tx, skb) < 0)
201 return TX_DROP;
202 } while ((skb = skb->next));
Jiri Bencf0706e82007-05-05 11:45:53 -0700203
Johannes Berg9ae54c82008-01-31 19:48:20 +0100204 return TX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700205}
206
207
Johannes Berg9ae54c82008-01-31 19:48:20 +0100208ieee80211_rx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +0100209ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700210{
211 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
Jiri Bencf0706e82007-05-05 11:45:53 -0700212 int hdrlen, res, hwaccel = 0, wpa_test = 0;
213 struct ieee80211_key *key = rx->key;
214 struct sk_buff *skb = rx->skb;
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100215 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
Jiri Bencf0706e82007-05-05 11:45:53 -0700216
Harvey Harrisond5184ca2008-06-11 14:21:58 -0700217 hdrlen = ieee80211_hdrlen(hdr->frame_control);
Jiri Bencf0706e82007-05-05 11:45:53 -0700218
Harvey Harrisonc34498b2008-07-02 16:30:52 -0700219 if (!ieee80211_is_data(hdr->frame_control))
Johannes Berg9ae54c82008-01-31 19:48:20 +0100220 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700221
222 if (!rx->sta || skb->len - hdrlen < 12)
Johannes Berge4c26ad2008-01-31 19:48:21 +0100223 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700224
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100225 if (status->flag & RX_FLAG_DECRYPTED) {
226 if (status->flag & RX_FLAG_IV_STRIPPED) {
Johannes Berg7848ba72007-09-14 11:10:25 -0400227 /*
228 * Hardware took care of all processing, including
229 * replay protection, and stripped the ICV/IV so
230 * we cannot do any checks here.
231 */
Johannes Berg9ae54c82008-01-31 19:48:20 +0100232 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700233 }
234
235 /* let TKIP code verify IV, but skip decryption */
236 hwaccel = 1;
237 }
238
239 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
240 key, skb->data + hdrlen,
Johannes Berg17741cd2008-09-11 00:02:02 +0200241 skb->len - hdrlen, rx->sta->sta.addr,
Emmanuel Grumbach9ae4fda2008-03-20 15:06:42 +0200242 hdr->addr1, hwaccel, rx->queue,
Johannes Berg5cf121c2008-02-25 16:27:43 +0100243 &rx->tkip_iv32,
244 &rx->tkip_iv16);
Johannes Bergf4ea83d2008-06-30 15:10:46 +0200245 if (res != TKIP_DECRYPT_OK || wpa_test)
Johannes Berge4c26ad2008-01-31 19:48:21 +0100246 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700247
248 /* Trim ICV */
249 skb_trim(skb, skb->len - TKIP_ICV_LEN);
250
251 /* Remove IV */
252 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
253 skb_pull(skb, TKIP_IV_LEN);
254
Johannes Berg9ae54c82008-01-31 19:48:20 +0100255 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700256}
257
258
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700259static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
Jiri Bencf0706e82007-05-05 11:45:53 -0700260 int encrypted)
261{
Harvey Harrisonf14df802008-07-02 11:05:35 -0700262 __le16 mask_fc;
Jouni Malinenfb733332009-01-08 13:32:00 +0200263 int a4_included, mgmt;
Harvey Harrisonf14df802008-07-02 11:05:35 -0700264 u8 qos_tid;
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700265 u8 *b_0, *aad;
Harvey Harrisonf14df802008-07-02 11:05:35 -0700266 u16 data_len, len_a;
267 unsigned int hdrlen;
268 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
Jiri Bencf0706e82007-05-05 11:45:53 -0700269
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700270 b_0 = scratch + 3 * AES_BLOCK_LEN;
271 aad = scratch + 4 * AES_BLOCK_LEN;
272
Harvey Harrisonf14df802008-07-02 11:05:35 -0700273 /*
Jouni Malinenfb733332009-01-08 13:32:00 +0200274 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
Harvey Harrisonf14df802008-07-02 11:05:35 -0700275 * Retry, PwrMgt, MoreData; set Protected
276 */
Jouni Malinenfb733332009-01-08 13:32:00 +0200277 mgmt = ieee80211_is_mgmt(hdr->frame_control);
Harvey Harrisonf14df802008-07-02 11:05:35 -0700278 mask_fc = hdr->frame_control;
Jouni Malinenfb733332009-01-08 13:32:00 +0200279 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
Harvey Harrisonf14df802008-07-02 11:05:35 -0700280 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
Jouni Malinenfb733332009-01-08 13:32:00 +0200281 if (!mgmt)
282 mask_fc &= ~cpu_to_le16(0x0070);
Harvey Harrisonf14df802008-07-02 11:05:35 -0700283 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
Jiri Bencf0706e82007-05-05 11:45:53 -0700284
Harvey Harrisonf14df802008-07-02 11:05:35 -0700285 hdrlen = ieee80211_hdrlen(hdr->frame_control);
286 len_a = hdrlen - 2;
287 a4_included = ieee80211_has_a4(hdr->frame_control);
288
289 if (ieee80211_is_data_qos(hdr->frame_control))
290 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
291 else
292 qos_tid = 0;
293
294 data_len = skb->len - hdrlen - CCMP_HDR_LEN;
295 if (encrypted)
296 data_len -= CCMP_MIC_LEN;
297
Jiri Bencf0706e82007-05-05 11:45:53 -0700298 /* First block, b_0 */
Jiri Bencf0706e82007-05-05 11:45:53 -0700299 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
Jouni Malinenfb733332009-01-08 13:32:00 +0200300 /* Nonce: Nonce Flags | A2 | PN
301 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
302 */
303 b_0[1] = qos_tid | (mgmt << 4);
Harvey Harrison73e1f7c2008-07-02 11:05:34 -0700304 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
Jiri Bencf0706e82007-05-05 11:45:53 -0700305 memcpy(&b_0[8], pn, CCMP_PN_LEN);
306 /* l(m) */
Harvey Harrisonf14df802008-07-02 11:05:35 -0700307 put_unaligned_be16(data_len, &b_0[14]);
Jiri Bencf0706e82007-05-05 11:45:53 -0700308
309 /* AAD (extra authenticate-only data) / masked 802.11 header
310 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
Harvey Harrisonf14df802008-07-02 11:05:35 -0700311 put_unaligned_be16(len_a, &aad[0]);
312 put_unaligned(mask_fc, (__le16 *)&aad[2]);
Harvey Harrison73e1f7c2008-07-02 11:05:34 -0700313 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
Jiri Bencf0706e82007-05-05 11:45:53 -0700314
315 /* Mask Seq#, leave Frag# */
316 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
317 aad[23] = 0;
Harvey Harrisonf14df802008-07-02 11:05:35 -0700318
Jiri Bencf0706e82007-05-05 11:45:53 -0700319 if (a4_included) {
Harvey Harrison73e1f7c2008-07-02 11:05:34 -0700320 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
Harvey Harrisonf14df802008-07-02 11:05:35 -0700321 aad[30] = qos_tid;
Jiri Bencf0706e82007-05-05 11:45:53 -0700322 aad[31] = 0;
Harvey Harrisonf14df802008-07-02 11:05:35 -0700323 } else {
Harvey Harrison73e1f7c2008-07-02 11:05:34 -0700324 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
Harvey Harrisonf14df802008-07-02 11:05:35 -0700325 aad[24] = qos_tid;
Jiri Bencf0706e82007-05-05 11:45:53 -0700326 }
327}
328
329
330static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
331{
332 hdr[0] = pn[5];
333 hdr[1] = pn[4];
334 hdr[2] = 0;
335 hdr[3] = 0x20 | (key_id << 6);
336 hdr[4] = pn[3];
337 hdr[5] = pn[2];
338 hdr[6] = pn[1];
339 hdr[7] = pn[0];
340}
341
342
Johannes Bergc6a1fa12008-10-07 12:04:32 +0200343static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
Jiri Bencf0706e82007-05-05 11:45:53 -0700344{
345 pn[0] = hdr[7];
346 pn[1] = hdr[6];
347 pn[2] = hdr[5];
348 pn[3] = hdr[4];
349 pn[4] = hdr[1];
350 pn[5] = hdr[0];
Jiri Bencf0706e82007-05-05 11:45:53 -0700351}
352
353
Johannes Berge039fa42008-05-15 12:55:29 +0200354static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
Jiri Bencf0706e82007-05-05 11:45:53 -0700355{
356 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
357 struct ieee80211_key *key = tx->key;
Johannes Berge039fa42008-05-15 12:55:29 +0200358 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
Johannes Berg23c07522008-05-29 10:38:53 +0200359 int hdrlen, len, tail;
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700360 u8 *pos, *pn;
Jiri Bencf0706e82007-05-05 11:45:53 -0700361 int i;
Jouni Malinen1f7d77a2009-01-08 13:32:10 +0200362
Johannes Berg813d7662010-01-17 01:47:58 +0100363 if (info->control.hw_key &&
364 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
365 /*
366 * hwaccel has no need for preallocated room for CCMP
367 * header or MIC fields
368 */
Johannes Berg23c07522008-05-29 10:38:53 +0200369 return 0;
Johannes Berge039fa42008-05-15 12:55:29 +0200370 }
371
Harvey Harrisond5184ca2008-06-11 14:21:58 -0700372 hdrlen = ieee80211_hdrlen(hdr->frame_control);
Jiri Bencf0706e82007-05-05 11:45:53 -0700373 len = skb->len - hdrlen;
374
Johannes Berg813d7662010-01-17 01:47:58 +0100375 if (info->control.hw_key)
Johannes Berg23c07522008-05-29 10:38:53 +0200376 tail = 0;
Johannes Berg11a843b2007-08-28 17:01:55 -0400377 else
Johannes Berg23c07522008-05-29 10:38:53 +0200378 tail = CCMP_MIC_LEN;
Jiri Bencf0706e82007-05-05 11:45:53 -0700379
Johannes Berg23c07522008-05-29 10:38:53 +0200380 if (WARN_ON(skb_tailroom(skb) < tail ||
381 skb_headroom(skb) < CCMP_HDR_LEN))
382 return -1;
Jiri Bencf0706e82007-05-05 11:45:53 -0700383
384 pos = skb_push(skb, CCMP_HDR_LEN);
385 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
386 hdr = (struct ieee80211_hdr *) pos;
387 pos += hdrlen;
388
389 /* PN = PN + 1 */
390 pn = key->u.ccmp.tx_pn;
391
392 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
393 pn[i]++;
394 if (pn[i])
395 break;
396 }
397
Johannes Berg8f20fc22007-08-28 17:01:54 -0400398 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
Jiri Bencf0706e82007-05-05 11:45:53 -0700399
Johannes Berg813d7662010-01-17 01:47:58 +0100400 /* hwaccel - with software CCMP header */
401 if (info->control.hw_key)
Jiri Bencf0706e82007-05-05 11:45:53 -0700402 return 0;
Jiri Bencf0706e82007-05-05 11:45:53 -0700403
404 pos += CCMP_HDR_LEN;
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700405 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0);
406 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len,
Jiri Bencf0706e82007-05-05 11:45:53 -0700407 pos, skb_put(skb, CCMP_MIC_LEN));
408
409 return 0;
410}
411
412
Johannes Berg9ae54c82008-01-31 19:48:20 +0100413ieee80211_tx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +0100414ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700415{
Jiri Bencf0706e82007-05-05 11:45:53 -0700416 struct sk_buff *skb = tx->skb;
Jiri Bencf0706e82007-05-05 11:45:53 -0700417
Johannes Berg5cf121c2008-02-25 16:27:43 +0100418 ieee80211_tx_set_protected(tx);
Jiri Bencf0706e82007-05-05 11:45:53 -0700419
Johannes Berg2de8e0d2009-03-23 17:28:35 +0100420 do {
421 if (ccmp_encrypt_skb(tx, skb) < 0)
422 return TX_DROP;
423 } while ((skb = skb->next));
Jiri Bencf0706e82007-05-05 11:45:53 -0700424
Johannes Berg9ae54c82008-01-31 19:48:20 +0100425 return TX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700426}
427
428
Johannes Berg9ae54c82008-01-31 19:48:20 +0100429ieee80211_rx_result
Johannes Berg5cf121c2008-02-25 16:27:43 +0100430ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700431{
Harvey Harrisonc34498b2008-07-02 16:30:52 -0700432 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
Jiri Bencf0706e82007-05-05 11:45:53 -0700433 int hdrlen;
434 struct ieee80211_key *key = rx->key;
435 struct sk_buff *skb = rx->skb;
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100436 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
Jiri Bencf0706e82007-05-05 11:45:53 -0700437 u8 pn[CCMP_PN_LEN];
438 int data_len;
439
Harvey Harrisond5184ca2008-06-11 14:21:58 -0700440 hdrlen = ieee80211_hdrlen(hdr->frame_control);
Jiri Bencf0706e82007-05-05 11:45:53 -0700441
Jouni Malinenfb733332009-01-08 13:32:00 +0200442 if (!ieee80211_is_data(hdr->frame_control) &&
443 !ieee80211_is_robust_mgmt_frame(hdr))
Johannes Berg9ae54c82008-01-31 19:48:20 +0100444 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700445
446 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
447 if (!rx->sta || data_len < 0)
Johannes Berge4c26ad2008-01-31 19:48:21 +0100448 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700449
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100450 if ((status->flag & RX_FLAG_DECRYPTED) &&
451 (status->flag & RX_FLAG_IV_STRIPPED))
Johannes Berg9ae54c82008-01-31 19:48:20 +0100452 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700453
Johannes Bergc6a1fa12008-10-07 12:04:32 +0200454 ccmp_hdr2pn(pn, skb->data + hdrlen);
Jiri Bencf0706e82007-05-05 11:45:53 -0700455
Johannes Berg5cf121c2008-02-25 16:27:43 +0100456 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
Jiri Bencf0706e82007-05-05 11:45:53 -0700457 key->u.ccmp.replays++;
Johannes Berge4c26ad2008-01-31 19:48:21 +0100458 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700459 }
460
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100461 if (!(status->flag & RX_FLAG_DECRYPTED)) {
Johannes Berg7848ba72007-09-14 11:10:25 -0400462 /* hardware didn't decrypt/verify MIC */
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700463 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1);
Jiri Bencf0706e82007-05-05 11:45:53 -0700464
465 if (ieee80211_aes_ccm_decrypt(
Harvey Harrisonfeccb462008-07-02 16:30:52 -0700466 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf,
Jiri Bencf0706e82007-05-05 11:45:53 -0700467 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
468 skb->data + skb->len - CCMP_MIC_LEN,
Johannes Bergc6a1fa12008-10-07 12:04:32 +0200469 skb->data + hdrlen + CCMP_HDR_LEN))
Johannes Berge4c26ad2008-01-31 19:48:21 +0100470 return RX_DROP_UNUSABLE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700471 }
472
Johannes Berg5cf121c2008-02-25 16:27:43 +0100473 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
Jiri Bencf0706e82007-05-05 11:45:53 -0700474
475 /* Remove CCMP header and MIC */
476 skb_trim(skb, skb->len - CCMP_MIC_LEN);
477 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
478 skb_pull(skb, CCMP_HDR_LEN);
479
Johannes Berg9ae54c82008-01-31 19:48:20 +0100480 return RX_CONTINUE;
Jiri Bencf0706e82007-05-05 11:45:53 -0700481}
Jouni Malinen765cb462009-01-08 13:32:01 +0200482
483
484static void bip_aad(struct sk_buff *skb, u8 *aad)
485{
486 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
487
488 /* FC type/subtype */
489 aad[0] = skb->data[0];
490 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
491 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6));
492 /* A1 || A2 || A3 */
493 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN);
494}
495
496
497static inline void bip_ipn_swap(u8 *d, const u8 *s)
498{
499 *d++ = s[5];
500 *d++ = s[4];
501 *d++ = s[3];
502 *d++ = s[2];
503 *d++ = s[1];
504 *d = s[0];
505}
506
507
508ieee80211_tx_result
509ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
510{
511 struct sk_buff *skb = tx->skb;
512 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
513 struct ieee80211_key *key = tx->key;
514 struct ieee80211_mmie *mmie;
515 u8 *pn, aad[20];
516 int i;
517
Johannes Berg813d7662010-01-17 01:47:58 +0100518 if (info->control.hw_key)
Jouni Malinen765cb462009-01-08 13:32:01 +0200519 return 0;
Jouni Malinen765cb462009-01-08 13:32:01 +0200520
521 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
522 return TX_DROP;
523
524 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
525 mmie->element_id = WLAN_EID_MMIE;
526 mmie->length = sizeof(*mmie) - 2;
527 mmie->key_id = cpu_to_le16(key->conf.keyidx);
528
529 /* PN = PN + 1 */
530 pn = key->u.aes_cmac.tx_pn;
531
532 for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) {
533 pn[i]++;
534 if (pn[i])
535 break;
536 }
537 bip_ipn_swap(mmie->sequence_number, pn);
538
539 bip_aad(skb, aad);
540
541 /*
542 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
543 */
544 ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf,
545 aad, skb->data + 24, skb->len - 24, mmie->mic);
546
547 return TX_CONTINUE;
548}
549
550
551ieee80211_rx_result
552ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
553{
554 struct sk_buff *skb = rx->skb;
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100555 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
Jouni Malinen765cb462009-01-08 13:32:01 +0200556 struct ieee80211_key *key = rx->key;
557 struct ieee80211_mmie *mmie;
558 u8 aad[20], mic[8], ipn[6];
559 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
560
561 if (!ieee80211_is_mgmt(hdr->frame_control))
562 return RX_CONTINUE;
563
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100564 if ((status->flag & RX_FLAG_DECRYPTED) &&
565 (status->flag & RX_FLAG_IV_STRIPPED))
Jouni Malinen765cb462009-01-08 13:32:01 +0200566 return RX_CONTINUE;
567
568 if (skb->len < 24 + sizeof(*mmie))
569 return RX_DROP_UNUSABLE;
570
571 mmie = (struct ieee80211_mmie *)
572 (skb->data + skb->len - sizeof(*mmie));
573 if (mmie->element_id != WLAN_EID_MMIE ||
574 mmie->length != sizeof(*mmie) - 2)
575 return RX_DROP_UNUSABLE; /* Invalid MMIE */
576
577 bip_ipn_swap(ipn, mmie->sequence_number);
578
579 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
580 key->u.aes_cmac.replays++;
581 return RX_DROP_UNUSABLE;
582 }
583
Johannes Bergeb9fb5b82009-11-16 13:58:20 +0100584 if (!(status->flag & RX_FLAG_DECRYPTED)) {
Jouni Malinen765cb462009-01-08 13:32:01 +0200585 /* hardware didn't decrypt/verify MIC */
586 bip_aad(skb, aad);
587 ieee80211_aes_cmac(key->u.aes_cmac.tfm,
588 key->u.aes_cmac.rx_crypto_buf, aad,
589 skb->data + 24, skb->len - 24, mic);
590 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
591 key->u.aes_cmac.icverrors++;
592 return RX_DROP_UNUSABLE;
593 }
594 }
595
596 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
597
598 /* Remove MMIE */
599 skb_trim(skb, skb->len - sizeof(*mmie));
600
601 return RX_CONTINUE;
602}