2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
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.
9 #include <linux/kernel.h>
10 #include <linux/bitops.h>
11 #include <linux/types.h>
12 #include <linux/netdevice.h>
13 #include <asm/unaligned.h>
15 #include <net/mac80211.h>
20 #define PHASE1_LOOP_COUNT 8
23 * 2-byte by 2-byte subset of the full AES S-box table; second part of this
24 * table is identical to first part but byte-swapped
26 static const u16 tkip_sbox[256] =
28 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
29 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
30 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
31 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
32 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
33 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
34 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
35 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
36 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
37 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
38 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
39 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
40 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
41 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
42 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
43 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
44 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
45 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
46 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
47 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
48 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
49 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
50 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
51 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
52 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
53 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
54 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
55 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
56 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
57 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
58 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
59 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
62 static u16 tkipS(u16 val)
64 return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]);
68 * P1K := Phase1(TA, TK, TSC)
69 * TA = transmitter address (48 bits)
70 * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits)
71 * TSC = TKIP sequence counter (48 bits, only 32 msb bits used)
74 static void tkip_mixing_phase1(struct ieee80211_key *key, const u8 *ta,
75 struct tkip_ctx *ctx, u32 tsc_IV32)
78 const u8 *tk = &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY];
81 p1k[0] = tsc_IV32 & 0xFFFF;
82 p1k[1] = tsc_IV32 >> 16;
83 p1k[2] = get_unaligned_le16(ta + 0);
84 p1k[3] = get_unaligned_le16(ta + 2);
85 p1k[4] = get_unaligned_le16(ta + 4);
87 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
89 p1k[0] += tkipS(p1k[4] ^ get_unaligned_le16(tk + 0 + j));
90 p1k[1] += tkipS(p1k[0] ^ get_unaligned_le16(tk + 4 + j));
91 p1k[2] += tkipS(p1k[1] ^ get_unaligned_le16(tk + 8 + j));
92 p1k[3] += tkipS(p1k[2] ^ get_unaligned_le16(tk + 12 + j));
93 p1k[4] += tkipS(p1k[3] ^ get_unaligned_le16(tk + 0 + j)) + i;
98 static void tkip_mixing_phase2(struct ieee80211_key *key, struct tkip_ctx *ctx,
99 u16 tsc_IV16, u8 *rc4key)
102 const u16 *p1k = ctx->p1k;
103 const u8 *tk = &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY];
111 ppk[5] = p1k[4] + tsc_IV16;
113 ppk[0] += tkipS(ppk[5] ^ get_unaligned_le16(tk + 0));
114 ppk[1] += tkipS(ppk[0] ^ get_unaligned_le16(tk + 2));
115 ppk[2] += tkipS(ppk[1] ^ get_unaligned_le16(tk + 4));
116 ppk[3] += tkipS(ppk[2] ^ get_unaligned_le16(tk + 6));
117 ppk[4] += tkipS(ppk[3] ^ get_unaligned_le16(tk + 8));
118 ppk[5] += tkipS(ppk[4] ^ get_unaligned_le16(tk + 10));
119 ppk[0] += ror16(ppk[5] ^ get_unaligned_le16(tk + 12), 1);
120 ppk[1] += ror16(ppk[0] ^ get_unaligned_le16(tk + 14), 1);
121 ppk[2] += ror16(ppk[1], 1);
122 ppk[3] += ror16(ppk[2], 1);
123 ppk[4] += ror16(ppk[3], 1);
124 ppk[5] += ror16(ppk[4], 1);
126 rc4key[0] = tsc_IV16 >> 8;
127 rc4key[1] = ((tsc_IV16 >> 8) | 0x20) & 0x7f;
128 rc4key[2] = tsc_IV16 & 0xFF;
129 rc4key[3] = ((ppk[5] ^ get_unaligned_le16(tk)) >> 1) & 0xFF;
132 for (i = 0; i < 6; i++)
133 put_unaligned_le16(ppk[i], rc4key + 2 * i);
136 /* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets
137 * of the IV. Returns pointer to the octet following IVs (i.e., beginning of
138 * the packet payload). */
139 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key,
140 u8 iv0, u8 iv1, u8 iv2)
145 *pos++ = (key->conf.keyidx << 6) | (1 << 5) /* Ext IV */;
146 put_unaligned_le32(key->u.tkip.tx.iv32, pos);
150 static void ieee80211_tkip_gen_rc4key(struct ieee80211_key *key, u8 *ta,
153 /* Calculate per-packet key */
154 if (key->u.tkip.tx.iv16 == 0 || !key->u.tkip.tx.initialized)
155 tkip_mixing_phase1(key, ta, &key->u.tkip.tx, key->u.tkip.tx.iv32);
157 tkip_mixing_phase2(key, &key->u.tkip.tx, key->u.tkip.tx.iv16, rc4key);
160 void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
161 struct sk_buff *skb, enum ieee80211_tkip_key_type type,
164 struct ieee80211_key *key = (struct ieee80211_key *)
165 container_of(keyconf, struct ieee80211_key, conf);
166 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
167 u8 *data = (u8 *) hdr;
168 u16 fc = le16_to_cpu(hdr->frame_control);
169 int hdr_len = ieee80211_get_hdrlen(fc);
174 iv16 = data[hdr_len + 2] | (data[hdr_len] << 8);
175 iv32 = get_unaligned_le32(data + hdr_len + 4);
177 #ifdef CONFIG_TKIP_DEBUG
178 printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n",
181 if (iv32 != key->u.tkip.tx.iv32) {
182 printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n",
183 iv32, key->u.tkip.tx.iv32);
184 printk(KERN_DEBUG "Wrap around of iv16 in the middle of a "
185 "fragmented packet\n");
187 #endif /* CONFIG_TKIP_DEBUG */
189 /* Update the p1k only when the iv16 in the packet wraps around, this
190 * might occur after the wrap around of iv16 in the key in case of
191 * fragmented packets. */
192 if (iv16 == 0 || !key->u.tkip.tx.initialized)
193 tkip_mixing_phase1(key, ta, &key->u.tkip.tx, iv32);
195 if (type == IEEE80211_TKIP_P1_KEY) {
196 memcpy(outkey, key->u.tkip.tx.p1k, sizeof(u16) * 5);
200 tkip_mixing_phase2(key, &key->u.tkip.tx, iv16, outkey);
202 EXPORT_SYMBOL(ieee80211_get_tkip_key);
204 /* Encrypt packet payload with TKIP using @key. @pos is a pointer to the
205 * beginning of the buffer containing payload. This payload must include
206 * headroom of eight octets for IV and Ext. IV and taildroom of four octets
207 * for ICV. @payload_len is the length of payload (_not_ including extra
208 * headroom and tailroom). @ta is the transmitter addresses. */
209 void ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
210 struct ieee80211_key *key,
211 u8 *pos, size_t payload_len, u8 *ta)
215 ieee80211_tkip_gen_rc4key(key, ta, rc4key);
216 pos = ieee80211_tkip_add_iv(pos, key, rc4key[0], rc4key[1], rc4key[2]);
217 ieee80211_wep_encrypt_data(tfm, rc4key, 16, pos, payload_len);
220 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the
221 * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
222 * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
223 * length of payload, including IV, Ext. IV, MIC, ICV. */
224 int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm,
225 struct ieee80211_key *key,
226 u8 *payload, size_t payload_len, u8 *ta,
227 u8 *ra, int only_iv, int queue,
228 u32 *out_iv32, u16 *out_iv16)
232 u8 rc4key[16], keyid, *pos = payload;
235 if (payload_len < 12)
238 iv16 = (pos[0] << 8) | pos[2];
240 iv32 = get_unaligned_le32(pos + 4);
242 #ifdef CONFIG_TKIP_DEBUG
245 printk(KERN_DEBUG "TKIP decrypt: data(len=%zd)", payload_len);
246 for (i = 0; i < payload_len; i++)
247 printk(" %02x", payload[i]);
249 printk(KERN_DEBUG "TKIP decrypt: iv16=%04x iv32=%08x\n",
252 #endif /* CONFIG_TKIP_DEBUG */
254 if (!(keyid & (1 << 5)))
255 return TKIP_DECRYPT_NO_EXT_IV;
257 if ((keyid >> 6) != key->conf.keyidx)
258 return TKIP_DECRYPT_INVALID_KEYIDX;
260 if (key->u.tkip.rx[queue].initialized &&
261 (iv32 < key->u.tkip.rx[queue].iv32 ||
262 (iv32 == key->u.tkip.rx[queue].iv32 &&
263 iv16 <= key->u.tkip.rx[queue].iv16))) {
264 #ifdef CONFIG_TKIP_DEBUG
265 DECLARE_MAC_BUF(mac);
266 printk(KERN_DEBUG "TKIP replay detected for RX frame from "
267 "%s (RX IV (%04x,%02x) <= prev. IV (%04x,%02x)\n",
269 iv32, iv16, key->u.tkip.rx[queue].iv32,
270 key->u.tkip.rx[queue].iv16);
271 #endif /* CONFIG_TKIP_DEBUG */
272 return TKIP_DECRYPT_REPLAY;
276 res = TKIP_DECRYPT_OK;
277 key->u.tkip.rx[queue].initialized = 1;
281 if (!key->u.tkip.rx[queue].initialized ||
282 key->u.tkip.rx[queue].iv32 != iv32) {
283 /* IV16 wrapped around - perform TKIP phase 1 */
284 tkip_mixing_phase1(key, ta, &key->u.tkip.rx[queue], iv32);
285 #ifdef CONFIG_TKIP_DEBUG
288 DECLARE_MAC_BUF(mac);
289 printk(KERN_DEBUG "TKIP decrypt: Phase1 TA=%s"
290 " TK=", print_mac(mac, ta));
291 for (i = 0; i < 16; i++)
294 ALG_TKIP_TEMP_ENCR_KEY + i]);
296 printk(KERN_DEBUG "TKIP decrypt: P1K=");
297 for (i = 0; i < 5; i++)
298 printk("%04x ", key->u.tkip.rx[queue].p1k[i]);
301 #endif /* CONFIG_TKIP_DEBUG */
302 if (key->local->ops->update_tkip_key &&
303 key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
305 {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
306 u8 *sta_addr = key->sta->addr;
308 if (is_multicast_ether_addr(ra))
311 key->local->ops->update_tkip_key(
312 local_to_hw(key->local), &key->conf,
313 sta_addr, iv32, key->u.tkip.rx[queue].p1k);
317 tkip_mixing_phase2(key, &key->u.tkip.rx[queue], iv16, rc4key);
318 #ifdef CONFIG_TKIP_DEBUG
321 printk(KERN_DEBUG "TKIP decrypt: Phase2 rc4key=");
322 for (i = 0; i < 16; i++)
323 printk("%02x ", rc4key[i]);
326 #endif /* CONFIG_TKIP_DEBUG */
328 res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12);
330 if (res == TKIP_DECRYPT_OK) {
332 * Record previously received IV, will be copied into the
333 * key information after MIC verification. It is possible
334 * that we don't catch replays of fragments but that's ok
335 * because the Michael MIC verication will then fail.