blob: b3622823bad23b9a34a58b09fea1dd3e067bbcf2 [file] [log] [blame]
Jiri Bencf0706e82007-05-05 11:45:53 -07001/*
2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
Eliad Pellerf8079d42016-02-14 13:56:35 +02004 * Copyright (C) 2016 Intel Deutschland GmbH
Jiri Bencf0706e82007-05-05 11:45:53 -07005 *
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.
9 */
Jiri Bencf0706e82007-05-05 11:45:53 -070010#include <linux/kernel.h>
Harvey Harrison8c046c82008-05-02 13:47:45 -070011#include <linux/bitops.h>
Jiri Bencf0706e82007-05-05 11:45:53 -070012#include <linux/types.h>
13#include <linux/netdevice.h>
Paul Gortmakerbc3b2d72011-07-15 11:47:34 -040014#include <linux/export.h>
Harvey Harrison8c046c82008-05-02 13:47:45 -070015#include <asm/unaligned.h>
Jiri Bencf0706e82007-05-05 11:45:53 -070016
17#include <net/mac80211.h>
Johannes Berg24487982009-04-23 18:52:52 +020018#include "driver-ops.h"
Johannes Berg2c8dccc2008-04-08 15:14:40 -040019#include "key.h"
Jiri Bencf0706e82007-05-05 11:45:53 -070020#include "tkip.h"
21#include "wep.h"
22
Jiri Bencf0706e82007-05-05 11:45:53 -070023#define PHASE1_LOOP_COUNT 8
24
Harvey Harrison8c046c82008-05-02 13:47:45 -070025/*
26 * 2-byte by 2-byte subset of the full AES S-box table; second part of this
27 * table is identical to first part but byte-swapped
28 */
Jiri Bencf0706e82007-05-05 11:45:53 -070029static const u16 tkip_sbox[256] =
30{
31 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
32 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
33 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
34 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
35 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
36 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
37 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
38 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
39 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
40 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
41 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
42 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
43 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
44 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
45 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
46 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
47 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
48 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
49 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
50 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
51 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
52 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
53 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
54 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
55 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
56 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
57 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
58 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
59 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
60 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
61 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
62 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
63};
64
Harvey Harrison8c046c82008-05-02 13:47:45 -070065static u16 tkipS(u16 val)
Jiri Bencf0706e82007-05-05 11:45:53 -070066{
Harvey Harrison8c046c82008-05-02 13:47:45 -070067 return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]);
Jiri Bencf0706e82007-05-05 11:45:53 -070068}
69
Harvey Harrisonc8012422008-06-11 14:22:00 -070070static u8 *write_tkip_iv(u8 *pos, u16 iv16)
71{
72 *pos++ = iv16 >> 8;
73 *pos++ = ((iv16 >> 8) | 0x20) & 0x7f;
74 *pos++ = iv16 & 0xFF;
75 return pos;
76}
77
Harvey Harrison8c046c82008-05-02 13:47:45 -070078/*
79 * P1K := Phase1(TA, TK, TSC)
Jiri Bencf0706e82007-05-05 11:45:53 -070080 * TA = transmitter address (48 bits)
81 * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits)
82 * TSC = TKIP sequence counter (48 bits, only 32 msb bits used)
83 * P1K: 80 bits
84 */
Harvey Harrison7c705372008-06-11 14:22:00 -070085static void tkip_mixing_phase1(const u8 *tk, struct tkip_ctx *ctx,
86 const u8 *ta, u32 tsc_IV32)
Jiri Bencf0706e82007-05-05 11:45:53 -070087{
88 int i, j;
Harvey Harrison82a57442008-05-14 16:26:19 -070089 u16 *p1k = ctx->p1k;
Jiri Bencf0706e82007-05-05 11:45:53 -070090
Harvey Harrison8c046c82008-05-02 13:47:45 -070091 p1k[0] = tsc_IV32 & 0xFFFF;
92 p1k[1] = tsc_IV32 >> 16;
93 p1k[2] = get_unaligned_le16(ta + 0);
94 p1k[3] = get_unaligned_le16(ta + 2);
95 p1k[4] = get_unaligned_le16(ta + 4);
Jiri Bencf0706e82007-05-05 11:45:53 -070096
97 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
98 j = 2 * (i & 1);
Harvey Harrison8c046c82008-05-02 13:47:45 -070099 p1k[0] += tkipS(p1k[4] ^ get_unaligned_le16(tk + 0 + j));
100 p1k[1] += tkipS(p1k[0] ^ get_unaligned_le16(tk + 4 + j));
101 p1k[2] += tkipS(p1k[1] ^ get_unaligned_le16(tk + 8 + j));
102 p1k[3] += tkipS(p1k[2] ^ get_unaligned_le16(tk + 12 + j));
103 p1k[4] += tkipS(p1k[3] ^ get_unaligned_le16(tk + 0 + j)) + i;
Jiri Bencf0706e82007-05-05 11:45:53 -0700104 }
gregor kowskica998612009-12-09 23:25:05 +0100105 ctx->state = TKIP_STATE_PHASE1_DONE;
Johannes Berg523b02e2011-07-07 22:28:01 +0200106 ctx->p1k_iv32 = tsc_IV32;
Jiri Bencf0706e82007-05-05 11:45:53 -0700107}
108
Harvey Harrison7c705372008-06-11 14:22:00 -0700109static void tkip_mixing_phase2(const u8 *tk, struct tkip_ctx *ctx,
Harvey Harrison3c838092008-05-14 16:26:20 -0700110 u16 tsc_IV16, u8 *rc4key)
Jiri Bencf0706e82007-05-05 11:45:53 -0700111{
112 u16 ppk[6];
Harvey Harrison3c838092008-05-14 16:26:20 -0700113 const u16 *p1k = ctx->p1k;
Jiri Bencf0706e82007-05-05 11:45:53 -0700114 int i;
115
116 ppk[0] = p1k[0];
117 ppk[1] = p1k[1];
118 ppk[2] = p1k[2];
119 ppk[3] = p1k[3];
120 ppk[4] = p1k[4];
121 ppk[5] = p1k[4] + tsc_IV16;
122
Harvey Harrison8c046c82008-05-02 13:47:45 -0700123 ppk[0] += tkipS(ppk[5] ^ get_unaligned_le16(tk + 0));
124 ppk[1] += tkipS(ppk[0] ^ get_unaligned_le16(tk + 2));
125 ppk[2] += tkipS(ppk[1] ^ get_unaligned_le16(tk + 4));
126 ppk[3] += tkipS(ppk[2] ^ get_unaligned_le16(tk + 6));
127 ppk[4] += tkipS(ppk[3] ^ get_unaligned_le16(tk + 8));
128 ppk[5] += tkipS(ppk[4] ^ get_unaligned_le16(tk + 10));
129 ppk[0] += ror16(ppk[5] ^ get_unaligned_le16(tk + 12), 1);
130 ppk[1] += ror16(ppk[0] ^ get_unaligned_le16(tk + 14), 1);
131 ppk[2] += ror16(ppk[1], 1);
132 ppk[3] += ror16(ppk[2], 1);
133 ppk[4] += ror16(ppk[3], 1);
134 ppk[5] += ror16(ppk[4], 1);
Jiri Bencf0706e82007-05-05 11:45:53 -0700135
Harvey Harrisonc8012422008-06-11 14:22:00 -0700136 rc4key = write_tkip_iv(rc4key, tsc_IV16);
137 *rc4key++ = ((ppk[5] ^ get_unaligned_le16(tk)) >> 1) & 0xFF;
Jiri Bencf0706e82007-05-05 11:45:53 -0700138
Harvey Harrison8c046c82008-05-02 13:47:45 -0700139 for (i = 0; i < 6; i++)
140 put_unaligned_le16(ppk[i], rc4key + 2 * i);
Jiri Bencf0706e82007-05-05 11:45:53 -0700141}
142
Jiri Bencf0706e82007-05-05 11:45:53 -0700143/* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets
144 * of the IV. Returns pointer to the octet following IVs (i.e., beginning of
145 * the packet payload). */
Eliad Pellerf8079d42016-02-14 13:56:35 +0200146u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key_conf *keyconf, u64 pn)
Jiri Bencf0706e82007-05-05 11:45:53 -0700147{
Eliad Pellerf8079d42016-02-14 13:56:35 +0200148 pos = write_tkip_iv(pos, TKIP_PN_TO_IV16(pn));
149 *pos++ = (keyconf->keyidx << 6) | (1 << 5) /* Ext IV */;
150 put_unaligned_le32(TKIP_PN_TO_IV32(pn), pos);
Harvey Harrison8c046c82008-05-02 13:47:45 -0700151 return pos + 4;
Jiri Bencf0706e82007-05-05 11:45:53 -0700152}
Eliad Pellerf8079d42016-02-14 13:56:35 +0200153EXPORT_SYMBOL_GPL(ieee80211_tkip_add_iv);
Jiri Bencf0706e82007-05-05 11:45:53 -0700154
Johannes Berg523b02e2011-07-07 22:28:01 +0200155static void ieee80211_compute_tkip_p1k(struct ieee80211_key *key, u32 iv32)
156{
157 struct ieee80211_sub_if_data *sdata = key->sdata;
158 struct tkip_ctx *ctx = &key->u.tkip.tx;
159 const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
160
161 lockdep_assert_held(&key->u.tkip.txlock);
162
163 /*
164 * Update the P1K when the IV32 is different from the value it
165 * had when we last computed it (or when not initialised yet).
166 * This might flip-flop back and forth if packets are processed
167 * out-of-order due to the different ACs, but then we have to
168 * just compute the P1K more often.
169 */
170 if (ctx->p1k_iv32 != iv32 || ctx->state == TKIP_STATE_NOT_INIT)
171 tkip_mixing_phase1(tk, ctx, sdata->vif.addr, iv32);
172}
173
Johannes Berg42d98792011-07-07 18:58:01 +0200174void ieee80211_get_tkip_p1k_iv(struct ieee80211_key_conf *keyconf,
175 u32 iv32, u16 *p1k)
Emmanuel Grumbach5d2cdcd2008-03-20 15:06:41 +0200176{
177 struct ieee80211_key *key = (struct ieee80211_key *)
178 container_of(keyconf, struct ieee80211_key, conf);
Johannes Berg523b02e2011-07-07 22:28:01 +0200179 struct tkip_ctx *ctx = &key->u.tkip.tx;
Emmanuel Grumbach5d2cdcd2008-03-20 15:06:41 +0200180
Johannes Berg03395002013-02-13 18:03:00 +0100181 spin_lock_bh(&key->u.tkip.txlock);
Johannes Berg523b02e2011-07-07 22:28:01 +0200182 ieee80211_compute_tkip_p1k(key, iv32);
183 memcpy(p1k, ctx->p1k, sizeof(ctx->p1k));
Johannes Berg03395002013-02-13 18:03:00 +0100184 spin_unlock_bh(&key->u.tkip.txlock);
Emmanuel Grumbach5d2cdcd2008-03-20 15:06:41 +0200185}
Johannes Berg42d98792011-07-07 18:58:01 +0200186EXPORT_SYMBOL(ieee80211_get_tkip_p1k_iv);
Johannes Berg523b02e2011-07-07 22:28:01 +0200187
Johannes Berg8bca5d82011-07-13 19:50:34 +0200188void ieee80211_get_tkip_rx_p1k(struct ieee80211_key_conf *keyconf,
Weilong Chenf359d3f2013-12-18 15:44:16 +0800189 const u8 *ta, u32 iv32, u16 *p1k)
Johannes Berg8bca5d82011-07-13 19:50:34 +0200190{
191 const u8 *tk = &keyconf->key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
192 struct tkip_ctx ctx;
193
194 tkip_mixing_phase1(tk, &ctx, ta, iv32);
195 memcpy(p1k, ctx.p1k, sizeof(ctx.p1k));
196}
197EXPORT_SYMBOL(ieee80211_get_tkip_rx_p1k);
198
Johannes Berg523b02e2011-07-07 22:28:01 +0200199void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
200 struct sk_buff *skb, u8 *p2k)
201{
202 struct ieee80211_key *key = (struct ieee80211_key *)
203 container_of(keyconf, struct ieee80211_key, conf);
204 const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
205 struct tkip_ctx *ctx = &key->u.tkip.tx;
206 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
207 const u8 *data = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control);
208 u32 iv32 = get_unaligned_le32(&data[4]);
209 u16 iv16 = data[2] | (data[0] << 8);
Johannes Berg523b02e2011-07-07 22:28:01 +0200210
Johannes Berg655914a2013-05-06 15:54:58 +0200211 spin_lock(&key->u.tkip.txlock);
Johannes Berg523b02e2011-07-07 22:28:01 +0200212 ieee80211_compute_tkip_p1k(key, iv32);
213 tkip_mixing_phase2(tk, ctx, iv16, p2k);
Johannes Berg655914a2013-05-06 15:54:58 +0200214 spin_unlock(&key->u.tkip.txlock);
Johannes Berg523b02e2011-07-07 22:28:01 +0200215}
216EXPORT_SYMBOL(ieee80211_get_tkip_p2k);
Emmanuel Grumbach5d2cdcd2008-03-20 15:06:41 +0200217
Johannes Berg813d7662010-01-17 01:47:58 +0100218/*
219 * Encrypt packet payload with TKIP using @key. @pos is a pointer to the
Jiri Bencf0706e82007-05-05 11:45:53 -0700220 * beginning of the buffer containing payload. This payload must include
Johannes Berg813d7662010-01-17 01:47:58 +0100221 * the IV/Ext.IV and space for (taildroom) four octets for ICV.
222 * @payload_len is the length of payload (_not_ including IV/ICV length).
223 * @ta is the transmitter addresses.
224 */
Felix Fietkau5f9f1812011-03-25 21:39:19 +0100225int ieee80211_tkip_encrypt_data(struct crypto_cipher *tfm,
John W. Linville34731872010-07-07 15:07:49 -0400226 struct ieee80211_key *key,
Johannes Berg523b02e2011-07-07 22:28:01 +0200227 struct sk_buff *skb,
228 u8 *payload, size_t payload_len)
Jiri Bencf0706e82007-05-05 11:45:53 -0700229{
230 u8 rc4key[16];
231
Johannes Berg523b02e2011-07-07 22:28:01 +0200232 ieee80211_get_tkip_p2k(&key->conf, skb, rc4key);
Harvey Harrison7c705372008-06-11 14:22:00 -0700233
Johannes Berg523b02e2011-07-07 22:28:01 +0200234 return ieee80211_wep_encrypt_data(tfm, rc4key, 16,
235 payload, payload_len);
Jiri Bencf0706e82007-05-05 11:45:53 -0700236}
237
Jiri Bencf0706e82007-05-05 11:45:53 -0700238/* Decrypt packet payload with TKIP using @key. @pos is a pointer to the
239 * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
240 * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
241 * length of payload, including IV, Ext. IV, MIC, ICV. */
Felix Fietkau5f9f1812011-03-25 21:39:19 +0100242int ieee80211_tkip_decrypt_data(struct crypto_cipher *tfm,
Jiri Bencf0706e82007-05-05 11:45:53 -0700243 struct ieee80211_key *key,
244 u8 *payload, size_t payload_len, u8 *ta,
Emmanuel Grumbach9ae4fda2008-03-20 15:06:42 +0200245 u8 *ra, int only_iv, int queue,
Johannes Berg50741ae2007-09-26 15:19:45 +0200246 u32 *out_iv32, u16 *out_iv16)
Jiri Bencf0706e82007-05-05 11:45:53 -0700247{
248 u32 iv32;
249 u32 iv16;
250 u8 rc4key[16], keyid, *pos = payload;
251 int res;
Luis R. Rodriguezffd78912008-06-21 10:02:46 -0400252 const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
Eliad Pellerf8079d42016-02-14 13:56:35 +0200253 struct tkip_ctx_rx *rx_ctx = &key->u.tkip.rx[queue];
Jiri Bencf0706e82007-05-05 11:45:53 -0700254
255 if (payload_len < 12)
256 return -1;
257
258 iv16 = (pos[0] << 8) | pos[2];
259 keyid = pos[3];
Harvey Harrison8c046c82008-05-02 13:47:45 -0700260 iv32 = get_unaligned_le32(pos + 4);
Jiri Bencf0706e82007-05-05 11:45:53 -0700261 pos += 8;
Jiri Bencf0706e82007-05-05 11:45:53 -0700262
263 if (!(keyid & (1 << 5)))
264 return TKIP_DECRYPT_NO_EXT_IV;
265
Johannes Berg8f20fc22007-08-28 17:01:54 -0400266 if ((keyid >> 6) != key->conf.keyidx)
Jiri Bencf0706e82007-05-05 11:45:53 -0700267 return TKIP_DECRYPT_INVALID_KEYIDX;
268
Eliad Pellerf8079d42016-02-14 13:56:35 +0200269 if (rx_ctx->ctx.state != TKIP_STATE_NOT_INIT &&
270 (iv32 < rx_ctx->iv32 ||
271 (iv32 == rx_ctx->iv32 && iv16 <= rx_ctx->iv16)))
Jiri Bencf0706e82007-05-05 11:45:53 -0700272 return TKIP_DECRYPT_REPLAY;
Jiri Bencf0706e82007-05-05 11:45:53 -0700273
274 if (only_iv) {
275 res = TKIP_DECRYPT_OK;
Eliad Pellerf8079d42016-02-14 13:56:35 +0200276 rx_ctx->ctx.state = TKIP_STATE_PHASE1_HW_UPLOADED;
Jiri Bencf0706e82007-05-05 11:45:53 -0700277 goto done;
278 }
279
Eliad Pellerf8079d42016-02-14 13:56:35 +0200280 if (rx_ctx->ctx.state == TKIP_STATE_NOT_INIT ||
281 rx_ctx->iv32 != iv32) {
Jiri Bencf0706e82007-05-05 11:45:53 -0700282 /* IV16 wrapped around - perform TKIP phase 1 */
Eliad Pellerf8079d42016-02-14 13:56:35 +0200283 tkip_mixing_phase1(tk, &rx_ctx->ctx, ta, iv32);
gregor kowskica998612009-12-09 23:25:05 +0100284 }
285 if (key->local->ops->update_tkip_key &&
286 key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
Eliad Pellerf8079d42016-02-14 13:56:35 +0200287 rx_ctx->ctx.state != TKIP_STATE_PHASE1_HW_UPLOADED) {
Johannes Bergb3fbdcf2010-01-21 11:40:47 +0100288 struct ieee80211_sub_if_data *sdata = key->sdata;
Emmanuel Grumbach9ae4fda2008-03-20 15:06:42 +0200289
Johannes Bergb3fbdcf2010-01-21 11:40:47 +0100290 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
291 sdata = container_of(key->sdata->bss,
292 struct ieee80211_sub_if_data, u.ap);
293 drv_update_tkip_key(key->local, sdata, &key->conf, key->sta,
Eliad Pellerf8079d42016-02-14 13:56:35 +0200294 iv32, rx_ctx->ctx.p1k);
295 rx_ctx->ctx.state = TKIP_STATE_PHASE1_HW_UPLOADED;
Jiri Bencf0706e82007-05-05 11:45:53 -0700296 }
297
Eliad Pellerf8079d42016-02-14 13:56:35 +0200298 tkip_mixing_phase2(tk, &rx_ctx->ctx, iv16, rc4key);
Jiri Bencf0706e82007-05-05 11:45:53 -0700299
300 res = ieee80211_wep_decrypt_data(tfm, rc4key, 16, pos, payload_len - 12);
301 done:
302 if (res == TKIP_DECRYPT_OK) {
Johannes Berg50741ae2007-09-26 15:19:45 +0200303 /*
304 * Record previously received IV, will be copied into the
305 * key information after MIC verification. It is possible
306 * that we don't catch replays of fragments but that's ok
307 * because the Michael MIC verication will then fail.
308 */
309 *out_iv32 = iv32;
310 *out_iv16 = iv16;
Jiri Bencf0706e82007-05-05 11:45:53 -0700311 }
312
313 return res;
314}