~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/mac80211/tkip.c

Version: ~ [ linux-5.19-rc3 ] ~ [ linux-5.18.5 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.48 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.123 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.199 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.248 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.284 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.319 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * Copyright 2002-2004, Instant802 Networks, Inc.
  4  * Copyright 2005, Devicescape Software, Inc.
  5  * Copyright (C) 2016 Intel Deutschland GmbH
  6  */
  7 #include <linux/kernel.h>
  8 #include <linux/bitops.h>
  9 #include <linux/types.h>
 10 #include <linux/netdevice.h>
 11 #include <linux/export.h>
 12 #include <asm/unaligned.h>
 13 
 14 #include <net/mac80211.h>
 15 #include "driver-ops.h"
 16 #include "key.h"
 17 #include "tkip.h"
 18 #include "wep.h"
 19 
 20 #define PHASE1_LOOP_COUNT 8
 21 
 22 /*
 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
 25  */
 26 static const u16 tkip_sbox[256] =
 27 {
 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,
 60 };
 61 
 62 static u16 tkipS(u16 val)
 63 {
 64         return tkip_sbox[val & 0xff] ^ swab16(tkip_sbox[val >> 8]);
 65 }
 66 
 67 static u8 *write_tkip_iv(u8 *pos, u16 iv16)
 68 {
 69         *pos++ = iv16 >> 8;
 70         *pos++ = ((iv16 >> 8) | 0x20) & 0x7f;
 71         *pos++ = iv16 & 0xFF;
 72         return pos;
 73 }
 74 
 75 /*
 76  * P1K := Phase1(TA, TK, TSC)
 77  * TA = transmitter address (48 bits)
 78  * TK = dot11DefaultKeyValue or dot11KeyMappingValue (128 bits)
 79  * TSC = TKIP sequence counter (48 bits, only 32 msb bits used)
 80  * P1K: 80 bits
 81  */
 82 static void tkip_mixing_phase1(const u8 *tk, struct tkip_ctx *ctx,
 83                                const u8 *ta, u32 tsc_IV32)
 84 {
 85         int i, j;
 86         u16 *p1k = ctx->p1k;
 87 
 88         p1k[0] = tsc_IV32 & 0xFFFF;
 89         p1k[1] = tsc_IV32 >> 16;
 90         p1k[2] = get_unaligned_le16(ta + 0);
 91         p1k[3] = get_unaligned_le16(ta + 2);
 92         p1k[4] = get_unaligned_le16(ta + 4);
 93 
 94         for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
 95                 j = 2 * (i & 1);
 96                 p1k[0] += tkipS(p1k[4] ^ get_unaligned_le16(tk + 0 + j));
 97                 p1k[1] += tkipS(p1k[0] ^ get_unaligned_le16(tk + 4 + j));
 98                 p1k[2] += tkipS(p1k[1] ^ get_unaligned_le16(tk + 8 + j));
 99                 p1k[3] += tkipS(p1k[2] ^ get_unaligned_le16(tk + 12 + j));
100                 p1k[4] += tkipS(p1k[3] ^ get_unaligned_le16(tk + 0 + j)) + i;
101         }
102         ctx->state = TKIP_STATE_PHASE1_DONE;
103         ctx->p1k_iv32 = tsc_IV32;
104 }
105 
106 static void tkip_mixing_phase2(const u8 *tk, struct tkip_ctx *ctx,
107                                u16 tsc_IV16, u8 *rc4key)
108 {
109         u16 ppk[6];
110         const u16 *p1k = ctx->p1k;
111         int i;
112 
113         ppk[0] = p1k[0];
114         ppk[1] = p1k[1];
115         ppk[2] = p1k[2];
116         ppk[3] = p1k[3];
117         ppk[4] = p1k[4];
118         ppk[5] = p1k[4] + tsc_IV16;
119 
120         ppk[0] += tkipS(ppk[5] ^ get_unaligned_le16(tk + 0));
121         ppk[1] += tkipS(ppk[0] ^ get_unaligned_le16(tk + 2));
122         ppk[2] += tkipS(ppk[1] ^ get_unaligned_le16(tk + 4));
123         ppk[3] += tkipS(ppk[2] ^ get_unaligned_le16(tk + 6));
124         ppk[4] += tkipS(ppk[3] ^ get_unaligned_le16(tk + 8));
125         ppk[5] += tkipS(ppk[4] ^ get_unaligned_le16(tk + 10));
126         ppk[0] += ror16(ppk[5] ^ get_unaligned_le16(tk + 12), 1);
127         ppk[1] += ror16(ppk[0] ^ get_unaligned_le16(tk + 14), 1);
128         ppk[2] += ror16(ppk[1], 1);
129         ppk[3] += ror16(ppk[2], 1);
130         ppk[4] += ror16(ppk[3], 1);
131         ppk[5] += ror16(ppk[4], 1);
132 
133         rc4key = write_tkip_iv(rc4key, tsc_IV16);
134         *rc4key++ = ((ppk[5] ^ get_unaligned_le16(tk)) >> 1) & 0xFF;
135 
136         for (i = 0; i < 6; i++)
137                 put_unaligned_le16(ppk[i], rc4key + 2 * i);
138 }
139 
140 /* Add TKIP IV and Ext. IV at @pos. @iv0, @iv1, and @iv2 are the first octets
141  * of the IV. Returns pointer to the octet following IVs (i.e., beginning of
142  * the packet payload). */
143 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key_conf *keyconf, u64 pn)
144 {
145         pos = write_tkip_iv(pos, TKIP_PN_TO_IV16(pn));
146         *pos++ = (keyconf->keyidx << 6) | (1 << 5) /* Ext IV */;
147         put_unaligned_le32(TKIP_PN_TO_IV32(pn), pos);
148         return pos + 4;
149 }
150 EXPORT_SYMBOL_GPL(ieee80211_tkip_add_iv);
151 
152 static void ieee80211_compute_tkip_p1k(struct ieee80211_key *key, u32 iv32)
153 {
154         struct ieee80211_sub_if_data *sdata = key->sdata;
155         struct tkip_ctx *ctx = &key->u.tkip.tx;
156         const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
157 
158         lockdep_assert_held(&key->u.tkip.txlock);
159 
160         /*
161          * Update the P1K when the IV32 is different from the value it
162          * had when we last computed it (or when not initialised yet).
163          * This might flip-flop back and forth if packets are processed
164          * out-of-order due to the different ACs, but then we have to
165          * just compute the P1K more often.
166          */
167         if (ctx->p1k_iv32 != iv32 || ctx->state == TKIP_STATE_NOT_INIT)
168                 tkip_mixing_phase1(tk, ctx, sdata->vif.addr, iv32);
169 }
170 
171 void ieee80211_get_tkip_p1k_iv(struct ieee80211_key_conf *keyconf,
172                                u32 iv32, u16 *p1k)
173 {
174         struct ieee80211_key *key = (struct ieee80211_key *)
175                         container_of(keyconf, struct ieee80211_key, conf);
176         struct tkip_ctx *ctx = &key->u.tkip.tx;
177 
178         spin_lock_bh(&key->u.tkip.txlock);
179         ieee80211_compute_tkip_p1k(key, iv32);
180         memcpy(p1k, ctx->p1k, sizeof(ctx->p1k));
181         spin_unlock_bh(&key->u.tkip.txlock);
182 }
183 EXPORT_SYMBOL(ieee80211_get_tkip_p1k_iv);
184 
185 void ieee80211_get_tkip_rx_p1k(struct ieee80211_key_conf *keyconf,
186                                const u8 *ta, u32 iv32, u16 *p1k)
187 {
188         const u8 *tk = &keyconf->key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
189         struct tkip_ctx ctx;
190 
191         tkip_mixing_phase1(tk, &ctx, ta, iv32);
192         memcpy(p1k, ctx.p1k, sizeof(ctx.p1k));
193 }
194 EXPORT_SYMBOL(ieee80211_get_tkip_rx_p1k);
195 
196 void ieee80211_get_tkip_p2k(struct ieee80211_key_conf *keyconf,
197                             struct sk_buff *skb, u8 *p2k)
198 {
199         struct ieee80211_key *key = (struct ieee80211_key *)
200                         container_of(keyconf, struct ieee80211_key, conf);
201         const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
202         struct tkip_ctx *ctx = &key->u.tkip.tx;
203         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
204         const u8 *data = (u8 *)hdr + ieee80211_hdrlen(hdr->frame_control);
205         u32 iv32 = get_unaligned_le32(&data[4]);
206         u16 iv16 = data[2] | (data[0] << 8);
207 
208         spin_lock(&key->u.tkip.txlock);
209         ieee80211_compute_tkip_p1k(key, iv32);
210         tkip_mixing_phase2(tk, ctx, iv16, p2k);
211         spin_unlock(&key->u.tkip.txlock);
212 }
213 EXPORT_SYMBOL(ieee80211_get_tkip_p2k);
214 
215 /*
216  * Encrypt packet payload with TKIP using @key. @pos is a pointer to the
217  * beginning of the buffer containing payload. This payload must include
218  * the IV/Ext.IV and space for (taildroom) four octets for ICV.
219  * @payload_len is the length of payload (_not_ including IV/ICV length).
220  * @ta is the transmitter addresses.
221  */
222 int ieee80211_tkip_encrypt_data(struct arc4_ctx *ctx,
223                                 struct ieee80211_key *key,
224                                 struct sk_buff *skb,
225                                 u8 *payload, size_t payload_len)
226 {
227         u8 rc4key[16];
228 
229         ieee80211_get_tkip_p2k(&key->conf, skb, rc4key);
230 
231         return ieee80211_wep_encrypt_data(ctx, rc4key, 16,
232                                           payload, payload_len);
233 }
234 
235 /* Decrypt packet payload with TKIP using @key. @pos is a pointer to the
236  * beginning of the buffer containing IEEE 802.11 header payload, i.e.,
237  * including IV, Ext. IV, real data, Michael MIC, ICV. @payload_len is the
238  * length of payload, including IV, Ext. IV, MIC, ICV.  */
239 int ieee80211_tkip_decrypt_data(struct arc4_ctx *ctx,
240                                 struct ieee80211_key *key,
241                                 u8 *payload, size_t payload_len, u8 *ta,
242                                 u8 *ra, int only_iv, int queue,
243                                 u32 *out_iv32, u16 *out_iv16)
244 {
245         u32 iv32;
246         u32 iv16;
247         u8 rc4key[16], keyid, *pos = payload;
248         int res;
249         const u8 *tk = &key->conf.key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY];
250         struct tkip_ctx_rx *rx_ctx = &key->u.tkip.rx[queue];
251 
252         if (payload_len < 12)
253                 return -1;
254 
255         iv16 = (pos[0] << 8) | pos[2];
256         keyid = pos[3];
257         iv32 = get_unaligned_le32(pos + 4);
258         pos += 8;
259 
260         if (!(keyid & (1 << 5)))
261                 return TKIP_DECRYPT_NO_EXT_IV;
262 
263         if ((keyid >> 6) != key->conf.keyidx)
264                 return TKIP_DECRYPT_INVALID_KEYIDX;
265 
266         /* Reject replays if the received TSC is smaller than or equal to the
267          * last received value in a valid message, but with an exception for
268          * the case where a new key has been set and no valid frame using that
269          * key has yet received and the local RSC was initialized to 0. This
270          * exception allows the very first frame sent by the transmitter to be
271          * accepted even if that transmitter were to use TSC 0 (IEEE 802.11
272          * described TSC to be initialized to 1 whenever a new key is taken into
273          * use).
274          */
275         if (iv32 < rx_ctx->iv32 ||
276             (iv32 == rx_ctx->iv32 &&
277              (iv16 < rx_ctx->iv16 ||
278               (iv16 == rx_ctx->iv16 &&
279                (rx_ctx->iv32 || rx_ctx->iv16 ||
280                 rx_ctx->ctx.state != TKIP_STATE_NOT_INIT)))))
281                 return TKIP_DECRYPT_REPLAY;
282 
283         if (only_iv) {
284                 res = TKIP_DECRYPT_OK;
285                 rx_ctx->ctx.state = TKIP_STATE_PHASE1_HW_UPLOADED;
286                 goto done;
287         }
288 
289         if (rx_ctx->ctx.state == TKIP_STATE_NOT_INIT ||
290             rx_ctx->iv32 != iv32) {
291                 /* IV16 wrapped around - perform TKIP phase 1 */
292                 tkip_mixing_phase1(tk, &rx_ctx->ctx, ta, iv32);
293         }
294         if (key->local->ops->update_tkip_key &&
295             key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
296             rx_ctx->ctx.state != TKIP_STATE_PHASE1_HW_UPLOADED) {
297                 struct ieee80211_sub_if_data *sdata = key->sdata;
298 
299                 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
300                         sdata = container_of(key->sdata->bss,
301                                         struct ieee80211_sub_if_data, u.ap);
302                 drv_update_tkip_key(key->local, sdata, &key->conf, key->sta,
303                                 iv32, rx_ctx->ctx.p1k);
304                 rx_ctx->ctx.state = TKIP_STATE_PHASE1_HW_UPLOADED;
305         }
306 
307         tkip_mixing_phase2(tk, &rx_ctx->ctx, iv16, rc4key);
308 
309         res = ieee80211_wep_decrypt_data(ctx, rc4key, 16, pos, payload_len - 12);
310  done:
311         if (res == TKIP_DECRYPT_OK) {
312                 /*
313                  * Record previously received IV, will be copied into the
314                  * key information after MIC verification. It is possible
315                  * that we don't catch replays of fragments but that's ok
316                  * because the Michael MIC verication will then fail.
317                  */
318                 *out_iv32 = iv32;
319                 *out_iv16 = iv16;
320         }
321 
322         return res;
323 }
324 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp